In this paper, the effect of dividing into several small coil groups having different current and frequency on heating characteristics is investigated using FEM (finite element method). The heating characteristics of graphite of each coil is examined, and a useful information for controlling current and frequency, which realize the nearly uniform heating, is obtained.
en-copyright= kn-copyright= en-aut-name=MiyagiDaisuke en-aut-sei=Miyagi en-aut-mei=Daisuke kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=SaitohAisya en-aut-sei=Saitoh en-aut-mei=Aisya kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=TakahashiNorio en-aut-sei=Takahashi en-aut-mei=Norio kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=UchidaNaoki en-aut-sei=Uchida en-aut-mei=Naoki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= en-aut-name=OzakiKazuhiro en-aut-sei=Ozaki en-aut-mei=Kazuhiro kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=5 ORCID= affil-num=1 en-affil= kn-affil=Okayama University affil-num=2 en-affil= kn-affil=Okayama University affil-num=3 en-affil= kn-affil=Okayama University affil-num=4 en-affil= kn-affil=Mitsui Engineering & Shipbuilding Company Limited affil-num=5 en-affil= kn-affil=Mitsui Engineering & Shipbuilding Company Limited en-keyword=coils kn-keyword=coils en-keyword=electric current control kn-keyword=electric current control en-keyword=finite element analysis kn-keyword=finite element analysis en-keyword=frequency control kn-keyword=frequency control en-keyword=graphite kn-keyword=graphite en-keyword=induction heating kn-keyword=induction heating en-keyword=semiconductor device manufacture kn-keyword=semiconductor device manufacture END start-ver=1.4 cd-journal=joma no-vol= cd-vols= no-issue= article-no= start-page= end-page= dt-received= dt-revised= dt-accepted= dt-pub-year=1999 dt-pub=19990518 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=An open magnetic path type of single sheet tester for measurement of magnetostriction of electrical steel sheet en-subtitle= kn-subtitle= en-abstract= kn-abstract= en-copyright= kn-copyright= en-aut-name=NakaseTomoya en-aut-sei=Nakase en-aut-mei=Tomoya kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=NakanoMasanori en-aut-sei=Nakano en-aut-mei=Masanori kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=FujiwaraKoji en-aut-sei=Fujiwara en-aut-mei=Koji kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=TakahashiNorio en-aut-sei=Takahashi en-aut-mei=Norio kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= affil-num=1 en-affil= kn-affil=Okayama University affil-num=2 en-affil= kn-affil=Okayama University affil-num=3 en-affil= kn-affil=Okayama University affil-num=4 en-affil= kn-affil=Okayama University END start-ver=1.4 cd-journal=joma no-vol=34 cd-vols= no-issue=4 article-no= start-page= end-page= dt-received= dt-revised= dt-accepted= dt-pub-year=1998 dt-pub=19987 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Measuring system for magnetostriction of silicon steel sheet under AC excitation using optical methods en-subtitle= kn-subtitle= en-abstract= kn-abstract=A measuring system for magnetostriction of silicon steel sheet using optical methods and a single sheet tester has been developed to establish a standard test method for IEC and JIS. Various factors affecting measurement accuracy and reproducibility of the developed system are examined. Two optical instruments, such as a laser Doppler vibrometer and a heterodyne displacement meter, are compared. 3-D characteristics of magnetostriction under ac excitation in the rolling direction are measured up to 2.0 T
en-copyright= kn-copyright= en-aut-name=NakaseTomoya en-aut-sei=Nakase en-aut-mei=Tomoya kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=NakanoMasanori en-aut-sei=Nakano en-aut-mei=Masanori kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=FujiwaraKoji en-aut-sei=Fujiwara en-aut-mei=Koji kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=TakahashiNorio en-aut-sei=Takahashi en-aut-mei=Norio kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= affil-num=1 en-affil= kn-affil=Okayama University affil-num=2 en-affil= kn-affil=Okayama University affil-num=3 en-affil= kn-affil=Okayama University affil-num=4 en-affil= kn-affil=Okayama University en-keyword=Doppler measurement kn-keyword=Doppler measurement en-keyword=ferromagnetic materials kn-keyword=ferromagnetic materials en-keyword=iron alloys kn-keyword=iron alloys en-keyword=magnetic variables measurement kn-keyword=magnetic variables measurement en-keyword=magnetostriction kn-keyword=magnetostriction en-keyword=measurement by laser beam kn-keyword=measurement by laser beam en-keyword=silicon alloys kn-keyword=silicon alloys END start-ver=1.4 cd-journal=joma no-vol=35 cd-vols= no-issue=5 article-no= start-page=3965 end-page=3967 dt-received= dt-revised= dt-accepted= dt-pub-year=1999 dt-pub=19990305 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Improvements of single sheet testers for measurement of 2-D magnetic properties up to high flux density en-subtitle= kn-subtitle= en-abstract= kn-abstract=Due to structural limitation, the currently proposed apparatus based on a single sheet tester (SST) cannot measure magnetic properties along arbitrary directions (so-called 2-D magnetic properties) of silicon steel at high flux densities. In this paper, significant improvements are carried out on magnetizing windings and auxiliary yokes of a double excitation type of SST. Furthermore, crosswise overlapped H-coils are introduced so that even an ordinary single-excitation type of SST can be applicable to the measurements of 2-D properties. It is demonstrated that 2-D magnetization property up to 1.9 T can be measured by using the newly developed SST's
en-copyright= kn-copyright= en-aut-name=NakanoMasanori en-aut-sei=Nakano en-aut-mei=Masanori kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=NishimotoHidehiko en-aut-sei=Nishimoto en-aut-mei=Hidehiko kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=FujiwaraKoji en-aut-sei=Fujiwara en-aut-mei=Koji kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=TakahashiNorio en-aut-sei=Takahashi en-aut-mei=Norio kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= affil-num=1 en-affil= kn-affil=Okayama University affil-num=2 en-affil= kn-affil=Okayama University affil-num=3 en-affil= kn-affil=Okayama University affil-num=4 en-affil= kn-affil=Okayama University en-keyword=Crosswise overlapped H-coils kn-keyword=Crosswise overlapped H-coils en-keyword=magnetic anisotropy kn-keyword=magnetic anisotropy en-keyword=permeability tensor kn-keyword=permeability tensor en-keyword=silicon steel kn-keyword=silicon steel en-keyword=single sheet tester kn-keyword=single sheet tester en-keyword=2-D magnetic properties kn-keyword=2-D magnetic properties END start-ver=1.4 cd-journal=joma no-vol= cd-vols= no-issue= article-no= start-page=3956 end-page=3958 dt-received= dt-revised= dt-accepted= dt-pub-year=1999 dt-pub=19990305 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Single sheet tester having open magnetic path for measurement of magnetostriction of electrical steel sheet en-subtitle= kn-subtitle= en-abstract= kn-abstract=A single sheet tester having closed magnetic path (a closed type of SST) has a problem that measurement accuracy of magnetostriction is considerably affected by electromagnetic force between specimen and yoke. Therefore, an open type has been developed. In order to get uniform flux distribution in a sufficiently large region, a compensating magnetizing winding is installed, and a method of waveform control is investigated, in which applied voltages to main and compensating windings are adjusted individually. The effectiveness of the newly developed open type is demonstrated by measuring magnetostrictions of thin amorphous sheet as well as highly grain-oriented silicon steel sheet
en-copyright= kn-copyright= en-aut-name=NakaseTomoya en-aut-sei=Nakase en-aut-mei=Tomoya kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=NakanoMasanori en-aut-sei=Nakano en-aut-mei=Masanori kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=FujiwaraKoji en-aut-sei=Fujiwara en-aut-mei=Koji kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=TakahashiNorio en-aut-sei=Takahashi en-aut-mei=Norio kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= affil-num=1 en-affil= kn-affil=Okayama University affil-num=2 en-affil= kn-affil=Okayama University affil-num=3 en-affil= kn-affil=Okayama University affil-num=4 en-affil= kn-affil=Okayama University en-keyword=amorphous magnetic materials kn-keyword=amorphous magnetic materials en-keyword=ferromagnetic materials kn-keyword=ferromagnetic materials en-keyword=iron alloys kn-keyword=iron alloys en-keyword=magnetic flux kn-keyword=magnetic flux en-keyword=magnetic variables measurement kn-keyword=magnetic variables measurement en-keyword=magnetostriction kn-keyword=magnetostriction en-keyword=silicon alloys kn-keyword=silicon alloys en-keyword=steel kn-keyword=steel END start-ver=1.4 cd-journal=joma no-vol=35 cd-vols= no-issue=3 article-no= start-page=1893 end-page=1896 dt-received= dt-revised= dt-accepted= dt-pub-year=1999 dt-pub=19995 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Effect of minor loop on magnetic characteristics of permanent magnet type of MRI en-subtitle= kn-subtitle= en-abstract= kn-abstract=A modeling technique of the minor loop using typical hysteresis loops is shown. The effect of the minor loop and eddy current in the pole piece of a permanent magnet type of MRI on the residual flux density of the probe coil is examined. It is illustrated that the change ΔB of residual flux density occurs due to the minor loop of the pole piece. It is also pointed out that the choice of time interval Δt is important in a nonlinear analysis considering the minor loop
en-copyright= kn-copyright= en-aut-name=TakahashiNorio en-aut-sei=Takahashi en-aut-mei=Norio kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=KayanoTakeshi en-aut-sei=Kayano en-aut-mei=Takeshi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=MiyataKoji en-aut-sei=Miyata en-aut-mei=Koji kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=OhashiKen en-aut-sei=Ohashi en-aut-mei=Ken kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= affil-num=1 en-affil= kn-affil=Okayama University affil-num=2 en-affil= kn-affil=Okayama University affil-num=3 en-affil= kn-affil=Shin-Etsu Chemical Corporation Limited affil-num=4 en-affil= kn-affil=Shin-Etsu Chemical Coporation Limited en-keyword=biomedical MRI kn-keyword=biomedical MRI en-keyword=eddy currents kn-keyword=eddy currents en-keyword=finite element analysis kn-keyword=finite element analysis en-keyword=magnetic flux kn-keyword=magnetic flux en-keyword=magnetic hysteresis kn-keyword=magnetic hysteresis en-keyword=permanent magnets kn-keyword=permanent magnets END start-ver=1.4 cd-journal=joma no-vol=39 cd-vols= no-issue=3 article-no= start-page=1337 end-page=1340 dt-received= dt-revised= dt-accepted= dt-pub-year=2003 dt-pub=20035 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Analysis of the magnetic property of a permanent-magnet-type MRI - Behavior of residual magnetization en-subtitle= kn-subtitle= en-abstract= kn-abstract=The minor loops of B and H of steel due to pulse excitation and eddy currents induced in steel affect the magnetic characteristics of a permanent-magnet-type MRI. In this paper, the magnetic properties of a permanent magnet assembly is examined by using the finite-element method taking into account minor loop. The distribution of residual magnetization in the yoke is illustrated, and the effect of residual magnetization on the behavior of residual flux density is examined. It is shown that the behavior of B and H in minor loops is affected by the eddy currents in the yoke and pole piece.
en-copyright= kn-copyright= en-aut-name=TakahashiNorio en-aut-sei=Takahashi en-aut-mei=Norio kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=SuenagaRyousuke en-aut-sei=Suenaga en-aut-mei=Ryousuke kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=MiyataKoji en-aut-sei=Miyata en-aut-mei=Koji kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=OhashiKen en-aut-sei=Ohashi en-aut-mei=Ken kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= affil-num=1 en-affil= kn-affil=Okayama University affil-num=2 en-affil= kn-affil=Okayama University affil-num=3 en-affil= kn-affil=Shin-Etsu Chemical Corporation Limited affil-num=4 en-affil= kn-affil=Shin-Etsu Chemical Coporation Limited en-keyword=biomedical MRI kn-keyword=biomedical MRI en-keyword=eddy currents kn-keyword=eddy currents en-keyword=finite element analysis kn-keyword=finite element analysis en-keyword=magnetic hysteresis kn-keyword=magnetic hysteresis en-keyword=magnetisation kn-keyword=magnetisation en-keyword=permanent magnets kn-keyword=permanent magnets en-keyword=steel kn-keyword=steel END start-ver=1.4 cd-journal=joma no-vol=31 cd-vols= no-issue=3 article-no= start-page=1364 end-page=1367 dt-received= dt-revised= dt-accepted= dt-pub-year=1995 dt-pub=19955 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=On the continuity of the magnetizing current density in 3-D magnetic field analysis with edge element en-subtitle= kn-subtitle= en-abstract= kn-abstract=The effects of the continuity of the magnetizing current density on the convergence of the incomplete Cholesky conjugate gradient method and the accuracy of the calculated flux densities are investigated by imposing different continuity conditions for both nodal and edge elements. It is shown that the continuity condition should be imposed precisely in the case of edge elements
en-copyright= kn-copyright= en-aut-name=FujiwaraKoji en-aut-sei=Fujiwara en-aut-mei=Koji kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=NakataTakayoshi en-aut-sei=Nakata en-aut-mei=Takayoshi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=TakahashiNorio en-aut-sei=Takahashi en-aut-mei=Norio kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=OhashiHiromitsu en-aut-sei=Ohashi en-aut-mei=Hiromitsu kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= affil-num=1 en-affil= kn-affil=Okayama University affil-num=2 en-affil= kn-affil=Okayama University affil-num=3 en-affil= kn-affil=Okayama University affil-num=4 en-affil= kn-affil=Okayama University en-keyword=conjugate gradient methods kn-keyword=conjugate gradient methods en-keyword=current density kn-keyword=current density en-keyword=finite element analysis kn-keyword=finite element analysis en-keyword=magnetic fields kn-keyword=magnetic fields en-keyword=magnetic kn-keyword=magnetic en-keyword=flux kn-keyword=flux END start-ver=1.4 cd-journal=joma no-vol= cd-vols= no-issue= article-no= start-page= end-page= dt-received= dt-revised= dt-accepted= dt-pub-year=2006 dt-pub=20065 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Effects of residual magnetism due to minor loop on magnetic property of permanent magnet type of MRI en-subtitle= kn-subtitle= en-abstract= kn-abstract=Summary form only given. The flux distribution of a permanent magnet type of MRI shown in Fig.1 is affected by the hysteresis (minor loop) and eddy currents in the pole piece and yoke due to the pulse current (Fig.2) of the gradient coil. In this paper, the effects of the hysteresis and the eddy current in the yoke on the residual flux density of the probe coil are investigated. It can be assumed that the eddy current does not flow in the pole piece because it is divided into pieces. The eddy current flows in the yoke. Fig.3 shows the change of residual flux density /spl Delta/B/sub z/ at the point S(0,0) in Fig.1. /spl Delta/B/sub z/ is given by /spl Delta/B/sub z/=B/sub z1/-B/sub z0/ (1), where B/sub z0/ is the flux density at the instant t=0(I=0A). B/sub z1/ is the flux density at the instant t=i(I=0A). The instant of 1,2,3,... in Fig.2 corresponds to 1,2,3,... in Fig.3. Fig.3 shows that the hysteresis in the pole piece and yoke should be taken into account. The effect of eddy current in the yoke on the residual flux density /spl Delta/B/sub z/ is not negligible. These results suggests that the reduction of the amplitudes of minor loop and eddy current is important in order to improve the operating characteristics of the permanent magnet type of MRI.
en-copyright= kn-copyright= en-aut-name=TakahashiNorio en-aut-sei=Takahashi en-aut-mei=Norio kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=SuenagaRyousuke en-aut-sei=Suenaga en-aut-mei=Ryousuke kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=MiyataKoji en-aut-sei=Miyata en-aut-mei=Koji kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=OhashiKen en-aut-sei=Ohashi en-aut-mei=Ken kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= affil-num=1 en-affil= kn-affil=Okayama University affil-num=2 en-affil= kn-affil=Okayama University affil-num=3 en-affil= kn-affil=Shin-Etsu Chemical Corporation Limited affil-num=4 en-affil= kn-affil=Shin-Etsu Chemical Coporation Limited en-keyword=eddy currents kn-keyword=eddy currents en-keyword=magnetic flux kn-keyword=magnetic flux en-keyword=magnetic hysteresis kn-keyword=magnetic hysteresis en-keyword=magnetic resonance imaging kn-keyword=magnetic resonance imaging en-keyword=permanent magnets kn-keyword=permanent magnets END start-ver=1.4 cd-journal=joma no-vol=24 cd-vols= no-issue=1 article-no= start-page=94 end-page=97 dt-received= dt-revised= dt-accepted= dt-pub-year=1988 dt-pub=19881 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Improvements of the T-Ω method for 3-D eddy current analysis en-subtitle= kn-subtitle= en-abstract= kn-abstract=An improved T-Ω method that can analyze magnetic fields produced not only by eddy currents but also by magnetizing currents is proposed. The method is applied to the analysis of 3-D eddy-current models with holes. The usefulness of the method is investigated by comparing calculated results with measured results and with results obtained by the A-Φ method. The T-Ω method has the advantage that the CPU time can be considerably reduced when most of the analyzed region is current-free and the eddy current flows two-dimensionally. The method is especially effective when the shape of the winding is simple and the distribution of magnetizing current is known beforehand. It is not effective when most of the analyzed region is current-carrying
en-copyright= kn-copyright= en-aut-name=NakataTakayoshi en-aut-sei=Nakata en-aut-mei=Takayoshi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=TakahashiNorio en-aut-sei=Takahashi en-aut-mei=Norio kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=fujiwaraK. en-aut-sei=fujiwara en-aut-mei=K. kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=OkadaY. en-aut-sei=Okada en-aut-mei=Y. kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= affil-num=1 en-affil= kn-affil=Okayama University affil-num=2 en-affil= kn-affil=Okayama University affil-num=3 en-affil= kn-affil=Okayama University affil-num=4 en-affil= kn-affil=Okayama University en-keyword=eddy currents kn-keyword=eddy currents END start-ver=1.4 cd-journal=joma no-vol=36 cd-vols= no-issue=4 article-no= start-page=1784 end-page=1787 dt-received= dt-revised= dt-accepted= dt-pub-year=2000 dt-pub=20007 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Thin film write head field analysis using a benchmark problem en-subtitle= kn-subtitle= en-abstract= kn-abstract=A benchmark problem has been proposed by the Storage Research Consortium (SRC) in Japan, for evaluating the applicability of computer codes to 3-D nonlinear eddy current analysis of thin film magnetic recording write head. Various codes using the finite element method are compared in terms of the write head field and the computational efficiency. The difficulty in 3-D mesh generation of thin film head is also discussed. The write head fields calculated by various codes using different meshes show fairly good agreement. The calculated write head fields are verified by measurement using a stroboscopic electron beam tomography. It is found that the calculation time strongly depends on unknown variables
en-copyright= kn-copyright= en-aut-name=FujiwaraKoji en-aut-sei=Fujiwara en-aut-mei=Koji kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=IkedaFumiaki en-aut-sei=Ikeda en-aut-mei=Fumiaki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=KameariAkihisa en-aut-sei=Kameari en-aut-mei=Akihisa kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=KanaiYasushi en-aut-sei=Kanai en-aut-mei=Yasushi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= en-aut-name=NakamuraKimio en-aut-sei=Nakamura en-aut-mei=Kimio kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=5 ORCID= en-aut-name=TakahashiNorio en-aut-sei=Takahashi en-aut-mei=Norio kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=6 ORCID= en-aut-name=TaniKoji en-aut-sei=Tani en-aut-mei=Koji kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=7 ORCID= en-aut-name=YamadaTakashi en-aut-sei=Yamada en-aut-mei=Takashi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=8 ORCID= affil-num=1 en-affil= kn-affil=Okayama University affil-num=2 en-affil= kn-affil=PHOTON Company Limited, Kyoto affil-num=3 en-affil= kn-affil=Science Solutions International Laboratory, Incorporated affil-num=4 en-affil= kn-affil=Niigata Institute of Technology affil-num=5 en-affil= kn-affil=Central Research Laboratory, Hitachi, Limited affil-num=6 en-affil= kn-affil=Okayama University affil-num=7 en-affil= kn-affil=Japan Research Institute, Limited affil-num=8 en-affil= kn-affil=Japan Research Institute, Limited en-keyword=eddy currents kn-keyword=eddy currents en-keyword=magnetic heads kn-keyword=magnetic heads en-keyword=magnetic recording kn-keyword=magnetic recording en-keyword=magnetic thin film devices kn-keyword=magnetic thin film devices en-keyword=mesh kn-keyword=mesh en-keyword=generation kn-keyword=generation en-keyword=tomography kn-keyword=tomography END start-ver=1.4 cd-journal=joma no-vol= cd-vols= no-issue= article-no= start-page= end-page= dt-received= dt-revised= dt-accepted= dt-pub-year=1997 dt-pub=19975 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Some useful techniques in analysis and design of electric machines en-subtitle= kn-subtitle= en-abstract= kn-abstract=Some new techniques in the analysis and design of electric machines are discussed, namely: the time-periodic analysis of the magnetic field in nonoriented materials, taking into account hysteresis characteristics; 3-D transient analysis of capacitor-discharge impulse magnetizers; and a 3-D optimization method of electric machines considering nonlinearity and eddy currents. The usefulness of these techniques is shown by applying them to actual machines and comparisons with measurement results
en-copyright= kn-copyright= en-aut-name=TakahashiNorio en-aut-sei=Takahashi en-aut-mei=Norio kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= affil-num=1 en-affil= kn-affil=Okayama University en-keyword=eddy currents kn-keyword=eddy currents en-keyword=electric machines kn-keyword=electric machines en-keyword=machine theory kn-keyword=machine theory en-keyword=magnetic fields kn-keyword=magnetic fields en-keyword=optimisation kn-keyword=optimisation en-keyword=transient analysis kn-keyword=transient analysis END start-ver=1.4 cd-journal=joma no-vol= cd-vols= no-issue= article-no= start-page=294 end-page=294 dt-received= dt-revised= dt-accepted= dt-pub-year=1992 dt-pub=19924 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Study on cause of quench at joint between multifilamentary superconducting cable and copper plate using 3-D FEM en-subtitle= kn-subtitle= en-abstract= kn-abstract= en-copyright= kn-copyright= en-aut-name=TakahashiNorio en-aut-sei=Takahashi en-aut-mei=Norio kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=NakataTakayoshi en-aut-sei=Nakata en-aut-mei=Takayoshi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=FujiiY. en-aut-sei=Fujii en-aut-mei=Y. kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=FunabikiK. en-aut-sei=Funabiki en-aut-mei=K. kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= en-aut-name=TakeoM. en-aut-sei=Takeo en-aut-mei=M. kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=5 ORCID= affil-num=1 en-affil= kn-affil=Okayama University affil-num=2 en-affil= kn-affil=Okayama University affil-num=3 en-affil= kn-affil=Okayama University affil-num=4 en-affil= kn-affil=Kyushu university affil-num=5 en-affil= kn-affil=Kyushu university END start-ver=1.4 cd-journal=joma no-vol=41 cd-vols= no-issue=5 article-no= start-page=1788 end-page=1791 dt-received= dt-revised= dt-accepted= dt-pub-year=2005 dt-pub=20055 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Magnetic shield design of perpendicular magnetic recording head by using topology optimization technique en-subtitle= kn-subtitle= en-abstract= kn-abstract=It is necessary to develop a recording head having large recording field and small stray field to adjacent tracks and adjacent bits in perpendicular magnetic recording system. In this paper, in order to decrease the leakage flux in the adjacent bit, the approach of magnetic shield design of perpendicular magnetic recording head for 200 Gb/in/sup 2/ is performed by using the topology optimization technique.
en-copyright= kn-copyright= en-aut-name=OkamotoYoshifumi en-aut-sei=Okamoto en-aut-mei=Yoshifumi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=OhtakeMasaya en-aut-sei=Ohtake en-aut-mei=Masaya kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=TakahashiNorio en-aut-sei=Takahashi en-aut-mei=Norio kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= affil-num=1 en-affil= kn-affil=Okayama University affil-num=2 en-affil= kn-affil=Okayama University affil-num=3 en-affil= kn-affil=Okayama University en-keyword=Perpendicular magnetic recording head kn-keyword=Perpendicular magnetic recording head en-keyword=sensitivity analysis kn-keyword=sensitivity analysis en-keyword=shield design kn-keyword=shield design en-keyword=topology optimization kn-keyword=topology optimization END start-ver=1.4 cd-journal=joma no-vol=32 cd-vols= no-issue=3 article-no= start-page=1210 end-page=1213 dt-received= dt-revised= dt-accepted= dt-pub-year=1996 dt-pub=19965 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Investigation of simulated annealing method and its application to optimal design of die mold for orientation of magnetic powder en-subtitle= kn-subtitle= en-abstract= kn-abstract=Factors affecting the convergence characteristics and results obtained by the optimal design method using the finite element method and simulated annealing are investigated systematically, and the optimal parameters for simulated annealing method are obtained. The optimal shape of the die mold for orientation of the magnetic powder (nonlinear magnetostatic problem) is obtained using finite elements and simulated annealing. The experimental verification is also carried out
en-copyright= kn-copyright= en-aut-name=TakahashiNorio en-aut-sei=Takahashi en-aut-mei=Norio kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=EbiharaKenji en-aut-sei=Ebihara en-aut-mei=Kenji kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=YoshidaKoji en-aut-sei=Yoshida en-aut-mei=Koji kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=NakataTakayoshi en-aut-sei=Nakata en-aut-mei=Takayoshi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= en-aut-name=OhashiKen en-aut-sei=Ohashi en-aut-mei=Ken kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=5 ORCID= en-aut-name=MiyataKoji en-aut-sei=Miyata en-aut-mei=Koji kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=6 ORCID= affil-num=1 en-affil= kn-affil=Okayama University affil-num=2 en-affil= kn-affil=Okayama University affil-num=3 en-affil= kn-affil=Okayama University affil-num=4 en-affil= kn-affil=Okayama University affil-num=5 en-affil= kn-affil=Shin-Etsu Chemical Corporation Limited affil-num=6 en-affil= kn-affil=Shin-Etsu Chemical Corporation Limited en-keyword=convergence of numerical methods kn-keyword=convergence of numerical methods en-keyword=electrical engineering kn-keyword=electrical engineering en-keyword=electrical engineering computing kn-keyword=electrical engineering computing en-keyword=electromagnets kn-keyword=electromagnets en-keyword=finite element analysis kn-keyword=finite element analysis en-keyword=magnetic particles kn-keyword=magnetic particles en-keyword=magnetostatics kn-keyword=magnetostatics en-keyword=simulated annealing kn-keyword=simulated annealing END start-ver=1.4 cd-journal=joma no-vol=40 cd-vols= no-issue=2 article-no= start-page=908 end-page=911 dt-received= dt-revised= dt-accepted= dt-pub-year=2004 dt-pub=20043 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=3-D finite element analysis of current distribution in HTS power cable taking account of E-J power law characteristic en-subtitle= kn-subtitle= en-abstract= kn-abstract=A method for analyzing the current distribution in high-T/sub c/ superconducting (HTS) power cable is examined by the aid of the novel use of anisotropic conductivity and three-dimensional finite element method in consideration of the E-J power law characteristic. The detailed current distribution in the cable is illustrated and the shielding effect of HTS shield is also examined.
en-copyright= kn-copyright= en-aut-name=MiyagiDaisuke en-aut-sei=Miyagi en-aut-mei=Daisuke kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=WakatsukiTomohiro en-aut-sei=Wakatsuki en-aut-mei=Tomohiro kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=TakahashiNorio en-aut-sei=Takahashi en-aut-mei=Norio kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=ToriiShinji en-aut-sei=Torii en-aut-mei=Shinji kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= en-aut-name=UedaKiyotaka en-aut-sei=Ueda en-aut-mei=Kiyotaka kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=5 ORCID= affil-num=1 en-affil= kn-affil=Okayama University affil-num=2 en-affil= kn-affil=Okayama University affil-num=3 en-affil= kn-affil=Okayama University affil-num=4 en-affil= kn-affil=Central Research Institute of Electric Power Industry affil-num=5 en-affil= kn-affil=Superconductive Generation Equipment and Materials en-keyword=current distribution kn-keyword=current distribution en-keyword=finite element analysis kn-keyword=finite element analysis en-keyword=high-temperature superconductors kn-keyword=high-temperature superconductors en-keyword=power cables kn-keyword=power cables en-keyword=superconducting cables kn-keyword=superconducting cables END start-ver=1.4 cd-journal=joma no-vol=31 cd-vols= no-issue=3 article-no= start-page=1416 end-page=1419 dt-received= dt-revised= dt-accepted= dt-pub-year=1995 dt-pub=19955 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Practical analysis of 3-D dynamic nonlinear magnetic field using time-periodic finite element method en-subtitle= kn-subtitle= en-abstract= kn-abstract=A practical 3-D finite element method using edge elements for analyzing stationary nonlinear magnetic fields with eddy currents in electric apparatus, in which the flux interlinking the voltage winding is given, has been proposed. The method is applied to the analysis of magnetic fields in the Epstein frame
en-copyright= kn-copyright= en-aut-name=NakataTakayoshi en-aut-sei=Nakata en-aut-mei=Takayoshi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=TakahashiNorio en-aut-sei=Takahashi en-aut-mei=Norio kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=FujiwaraKoji en-aut-sei=Fujiwara en-aut-mei=Koji kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=MuramatsuKazuhiro en-aut-sei=Muramatsu en-aut-mei=Kazuhiro kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= en-aut-name=OhashiHiromitsu en-aut-sei=Ohashi en-aut-mei=Hiromitsu kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=5 ORCID= en-aut-name=ZhuHui Ling en-aut-sei=Zhu en-aut-mei=Hui Ling kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=6 ORCID= affil-num=1 en-affil= kn-affil=Okayama University affil-num=2 en-affil= kn-affil=Okayama University affil-num=3 en-affil= kn-affil=Okayama University affil-num=4 en-affil= kn-affil=Okayama University affil-num=5 en-affil= kn-affil=Okayama University affil-num=6 en-affil= kn-affil=Okayama University en-keyword=eddy currents kn-keyword=eddy currents en-keyword=electric machine analysis computing kn-keyword=electric machine analysis computing en-keyword=finite element analysis kn-keyword=finite element analysis en-keyword=machine theory kn-keyword=machine theory en-keyword=machine windings kn-keyword=machine windings en-keyword=magnetic fields kn-keyword=magnetic fields END start-ver=1.4 cd-journal=joma no-vol=31 cd-vols= no-issue=3 article-no= start-page= end-page= dt-received= dt-revised= dt-accepted= dt-pub-year=1995 dt-pub=199505 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Practical analysis of 3-D dynamic nonlinear magnetic field using time-periodic finite element method en-subtitle= kn-subtitle= en-abstract= kn-abstract=A practical 3-D finite element method using edge elements for analyzing stationary nonlinear magnetic fields with eddy currents in electric apparatus, in which the flux interlinking the voltage winding is given, has been proposed. The method is applied to the analysis of magnetic fields in the Epstein frame
en-copyright= kn-copyright= en-aut-name=NakataTakayoshi en-aut-sei=Nakata en-aut-mei=Takayoshi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=TakahashiNorio en-aut-sei=Takahashi en-aut-mei=Norio kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=FujiwaraKoji en-aut-sei=Fujiwara en-aut-mei=Koji kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=MuramatsuKazuhiro en-aut-sei=Muramatsu en-aut-mei=Kazuhiro kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= en-aut-name=OhashiHiromitsu en-aut-sei=Ohashi en-aut-mei=Hiromitsu kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=5 ORCID= en-aut-name=ZhuHui Ling en-aut-sei=Zhu en-aut-mei=Hui Ling kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=6 ORCID= affil-num=1 en-affil= kn-affil=Okayama University affil-num=2 en-affil= kn-affil=Okayama University affil-num=3 en-affil= kn-affil=Okayama University affil-num=4 en-affil= kn-affil=Okayama University affil-num=5 en-affil= kn-affil=Okayama University affil-num=6 en-affil= kn-affil=Okayama University en-keyword=eddy currents kn-keyword=eddy currents en-keyword=electric machine analysis computing kn-keyword=electric machine analysis computing en-keyword=finite element analysis kn-keyword=finite element analysis en-keyword=machine theory kn-keyword=machine theory en-keyword=machine windings kn-keyword=machine windings en-keyword=magnetic fields kn-keyword=magnetic fields END start-ver=1.4 cd-journal=joma no-vol=35 cd-vols= no-issue=3 article-no= start-page=1670 end-page=1673 dt-received= dt-revised= dt-accepted= dt-pub-year=1999 dt-pub=19995 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Magneto-thermal-fluid analysis taking account of natural convection using semi-Lagrange coordinate system en-subtitle= kn-subtitle= en-abstract= kn-abstract=A method for magneto-thermal-fluid analysis, taking account of natural convection using a semi-Lagrange coordinate system, is developed. The developed method is applied to a simple induction heating model in which the steel plate is heated due to an eddy current. It is shown that the result, considering the convection in air, is different from the result neglecting it
en-copyright= kn-copyright= en-aut-name=MuramatsuKazuhiro en-aut-sei=Muramatsu en-aut-mei=Kazuhiro kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=TakahashiNorio en-aut-sei=Takahashi en-aut-mei=Norio kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=MimuraTakayuki en-aut-sei=Mimura en-aut-mei=Takayuki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= affil-num=1 en-affil= kn-affil=Okayama University affil-num=2 en-affil= kn-affil=Okayama University affil-num=3 en-affil= kn-affil=Okayama University en-keyword=eddy currents kn-keyword=eddy currents en-keyword=electromagnetic fields kn-keyword=electromagnetic fields en-keyword=induction heating kn-keyword=induction heating en-keyword=natural convection kn-keyword=natural convection en-keyword=thermal analysis kn-keyword=thermal analysis END start-ver=1.4 cd-journal=joma no-vol=32 cd-vols= no-issue=4 article-no= start-page=2962 end-page=2965 dt-received= dt-revised= dt-accepted= dt-pub-year=1996 dt-pub=19967 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Numerical and experimental investigations of current distribution at the joint between AC superconducting cable and normal conducting plate en-subtitle= kn-subtitle= en-abstract= kn-abstract=The effect of the configuration of the joint between an ac superconducting cable and a normal conducting plate on the current distribution and the joule loss is investigated by using the 3-D finite element method. It is shown that the concentration of current can be reduced by changing the configuration of joint. The effectiveness of the analysis is verified by measuring the current distribution on the surface of a copper plate and the quenching current
en-copyright= kn-copyright= en-aut-name=TakahashiNorio en-aut-sei=Takahashi en-aut-mei=Norio kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=MuramatsuKazuhiro en-aut-sei=Muramatsu en-aut-mei=Kazuhiro kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=NakanoMasanori en-aut-sei=Nakano en-aut-mei=Masanori kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=SatoY. en-aut-sei=Sato en-aut-mei=Y. kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= en-aut-name=KondoT. en-aut-sei=Kondo en-aut-mei=T. kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=5 ORCID= affil-num=1 en-affil= kn-affil=Okayama University affil-num=2 en-affil= kn-affil=Okayama University affil-num=3 en-affil= kn-affil=Okayama University affil-num=4 en-affil= kn-affil=Okayama University affil-num=5 en-affil= kn-affil=Okayama University en-keyword=cable jointing kn-keyword=cable jointing en-keyword=current distribution kn-keyword=current distribution en-keyword=finite element analysis kn-keyword=finite element analysis en-keyword=superconducting cables kn-keyword=superconducting cables END start-ver=1.4 cd-journal=joma no-vol=28 cd-vols= no-issue=2 article-no= start-page=1619 end-page=1622 dt-received= dt-revised= dt-accepted= dt-pub-year=1992 dt-pub=19923 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Investigation of effectiveness of edge elements en-subtitle= kn-subtitle= en-abstract= kn-abstract=The effectiveness of the edge element is investigated by comparing systematically the number of unknown variables with that of the nodal element. It is shown that the edge element is superior to the nodal element from the standpoints of computer storage and CPU time. The 3-D periodic boundary condition for the edge element is also derived in order to reduce the computer storage and the CPU time
en-copyright= kn-copyright= en-aut-name=TakahashiNorio en-aut-sei=Takahashi en-aut-mei=Norio kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=NakataTakayoshi en-aut-sei=Nakata en-aut-mei=Takayoshi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=FujiwaraK. en-aut-sei=Fujiwara en-aut-mei=K. kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=ImaiT. en-aut-sei=Imai en-aut-mei=T. kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= affil-num=1 en-affil= kn-affil=Okayama University affil-num=2 en-affil= kn-affil=Okayama University affil-num=3 en-affil= kn-affil=Okayama University affil-num=4 en-affil= kn-affil=Okayama University en-keyword=boundary-elements methods kn-keyword=boundary-elements methods en-keyword=mathematics computing kn-keyword=mathematics computing END start-ver=1.4 cd-journal=joma no-vol= cd-vols= no-issue= article-no= start-page= end-page= dt-received= dt-revised= dt-accepted= dt-pub-year=1989 dt-pub=19893 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=3-D non-linear eddy current analysis using the time-periodic finite element method en-subtitle= kn-subtitle= en-abstract= kn-abstract=A three-dimensional finite element method using the A-φ formulation for analyzing time-periodic nonlinear magnetic fields with eddy currents has been developed. The CPU time of this method can be reduced to below that of the conventional step-by-step method, because the new method calculates the time-periodic phenomena directly, not through the transient phenomena. The finite element discretization of the method is described in detail. As an example of application, a loaded transformer is analyzed
en-copyright= kn-copyright= en-aut-name=NakataTakayoshi en-aut-sei=Nakata en-aut-mei=Takayoshi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=TakahashiNorio en-aut-sei=Takahashi en-aut-mei=Norio kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=FujiwaraKoji en-aut-sei=Fujiwara en-aut-mei=Koji kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=AhagonAkira en-aut-sei=Ahagon en-aut-mei=Akira kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= affil-num=1 en-affil= kn-affil=Okayama University affil-num=2 en-affil= kn-affil=Okayama University affil-num=3 en-affil= kn-affil=Okayama University affil-num=4 en-affil= kn-affil=Okayama University en-keyword=eddy currents kn-keyword=eddy currents en-keyword=electromagnetic field theory kn-keyword=electromagnetic field theory en-keyword=electromagnetic induction kn-keyword=electromagnetic induction en-keyword=finite element analysis kn-keyword=finite element analysis en-keyword=power engineering computing kn-keyword=power engineering computing END start-ver=1.4 cd-journal=joma no-vol=27 cd-vols= no-issue=5 article-no= start-page=4061 end-page=4064 dt-received= dt-revised= dt-accepted= dt-pub-year=1991 dt-pub=19919 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=3-D finite element analysis of coupling current in multifilamentary AC superconducting cable en-subtitle= kn-subtitle= en-abstract= kn-abstract=A method for analyzing the 3-D coupling current which is induced by an AC magnetic field in a multifilamentary superconducting cable is developed. In this method, such a superconducting cable, in which many twisted filaments are embedded in a matrix, is treated as macroscopic, having anisotropic conductivity. The method for treating the anisotropy of conductivity and the 3-D finite-element formulation are presented. The effectiveness of the technique is illustrated by the analysis of the 3-D coupling currents of superconducting cables.
en-copyright= kn-copyright= en-aut-name=TakahashiNorio en-aut-sei=Takahashi en-aut-mei=Norio kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=NakataTakayoshi en-aut-sei=Nakata en-aut-mei=Takayoshi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=FujiiY. en-aut-sei=Fujii en-aut-mei=Y. kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=MuramatsuKazuhiro en-aut-sei=Muramatsu en-aut-mei=Kazuhiro kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= en-aut-name=KitagawaM. en-aut-sei=Kitagawa en-aut-mei=M. kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=5 ORCID= en-aut-name=TakeharaJun en-aut-sei=Takehara en-aut-mei=Jun kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=6 ORCID= affil-num=1 en-affil= kn-affil=Okayama University affil-num=2 en-affil= kn-affil=Okayama University affil-num=3 en-affil= kn-affil=Okayama University affil-num=4 en-affil= kn-affil=ALPS Electric Company Limited, Miyagi affil-num=5 en-affil= kn-affil=Chugoku Electrir Power Corporation affil-num=6 en-affil= kn-affil=The Chugoku Electric Power Corporation, incorporated en-keyword=electric current kn-keyword=electric current en-keyword=electromagnetic induction kn-keyword=electromagnetic induction en-keyword=finite element analysis kn-keyword=finite element analysis en-keyword=superconducting cables kn-keyword=superconducting cables END start-ver=1.4 cd-journal=joma no-vol=36 cd-vols= no-issue=4 article-no= start-page=1085 end-page=1088 dt-received= dt-revised= dt-accepted= dt-pub-year=2006 dt-pub=20067 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Investigation of evolution strategy and optimization of induction heating model en-subtitle= kn-subtitle= en-abstract= kn-abstract=An optimal design method using the finite element method and the evolution strategy (ES) is investigated. The evolution strategy is applied to the optimization of induction heating model. The position of auxiliary coil, frequency and ampere-turns are optimized so that the distribution of eddy current density on the surface of steel becomes uniform. It is shown that the selection of the appropriate parameter is important in the practical application of ES
en-copyright= kn-copyright= en-aut-name=HoriiMakoto en-aut-sei=Horii en-aut-mei=Makoto kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=TakahashiNorio en-aut-sei=Takahashi en-aut-mei=Norio kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=NaritaTakashi en-aut-sei=Narita en-aut-mei=Takashi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= affil-num=1 en-affil= kn-affil=Okayama University affil-num=2 en-affil= kn-affil=Okayama University affil-num=3 en-affil= kn-affil=Shinko Electric Corporation Limited en-keyword=coils kn-keyword=coils en-keyword=eddy currents kn-keyword=eddy currents en-keyword=evolutionary computation kn-keyword=evolutionary computation en-keyword=finite element analysis kn-keyword=finite element analysis en-keyword=induction heating kn-keyword=induction heating END start-ver=1.4 cd-journal=joma no-vol= cd-vols= no-issue= article-no= start-page= end-page= dt-received= dt-revised= dt-accepted= dt-pub-year=1989 dt-pub=19893 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Optimal design method of 3-D nonlinear magnetic circuit by using magnetization integral equation method en-subtitle= kn-subtitle= en-abstract= kn-abstract=A novel method for determining the sizes of iron parts in a magnetic circuit, which preserves the requirement of prescribed flux densities, has been developed. In order to take into account the nonlinear characteristics of iron, the magnetization integral equation method is used in the analysis. The effectiveness of the method is examined by applying it to the pole shape of an electromagnet. The developed software was verified by comparing calculated results with measured ones
en-copyright= kn-copyright= en-aut-name=TakahashiNorio en-aut-sei=Takahashi en-aut-mei=Norio kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=NakataTakayoshi en-aut-sei=Nakata en-aut-mei=Takayoshi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=UchiyamaN. en-aut-sei=Uchiyama en-aut-mei=N. kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= affil-num=1 en-affil= kn-affil=Okayama University affil-num=2 en-affil= kn-affil=Okayama University affil-num=3 en-affil= kn-affil=Okayama University en-keyword=CAD kn-keyword=CAD en-keyword=electromagnets kn-keyword=electromagnets en-keyword=magnetic circuits kn-keyword=magnetic circuits en-keyword=magnetic cores kn-keyword=magnetic cores END start-ver=1.4 cd-journal=joma no-vol= cd-vols= no-issue= article-no= start-page= end-page= dt-received= dt-revised= dt-accepted= dt-pub-year=1997 dt-pub=19975 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=3-D eddy current analysis in moving conductors of permanent magnet type retarders using moving coordinate system en-subtitle= kn-subtitle= en-abstract= kn-abstract=A 3-D DC steady state eddy current analysis of a permanent magnet type retarder which rotates at high speed is carried out using a moving coordinate system. The method of DC steady state analysis using a moving coordinate system is described. The calculated results, braking torque etc., are compared with measured ones
en-copyright= kn-copyright= en-aut-name=MuramatsuKazuhiro en-aut-sei=Muramatsu en-aut-mei=Kazuhiro kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=TakahashiNorio en-aut-sei=Takahashi en-aut-mei=Norio kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=HashinoTomohiro en-aut-sei=Hashino en-aut-mei=Tomohiro kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=YamadaChuji en-aut-sei=Yamada en-aut-mei=Chuji kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= en-aut-name=KobayashiSusumu en-aut-sei=Kobayashi en-aut-mei=Susumu kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=5 ORCID= en-aut-name=KuwaharaTohru en-aut-sei=Kuwahara en-aut-mei=Tohru kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=6 ORCID= affil-num=1 en-affil= kn-affil=Okayama University affil-num=2 en-affil= kn-affil=Okayama University affil-num=3 en-affil= kn-affil=Okayama University affil-num=4 en-affil= kn-affil=Isuzu Advanced Engineering Center, Limited affil-num=5 en-affil= kn-affil=Isuzu Advanced Engineering Center, Limited affil-num=6 en-affil= kn-affil=Isuzu Motors, Limited en-keyword=braking kn-keyword=braking en-keyword=eddy currents kn-keyword=eddy currents en-keyword=machine theory kn-keyword=machine theory en-keyword=permanent magnet machines kn-keyword=permanent magnet machines en-keyword=torque kn-keyword=torque END start-ver=1.4 cd-journal=joma no-vol=25 cd-vols= no-issue=5 article-no= start-page=4150 end-page=4152 dt-received= dt-revised= dt-accepted= dt-pub-year=1989 dt-pub=19890905 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=3-D non-linear eddy current analysis using the time-periodic finite element method en-subtitle= kn-subtitle= en-abstract= kn-abstract=A three-dimensional finite element method using the A-φ formulation for analyzing time-periodic nonlinear magnetic fields with eddy currents has been developed. The CPU time of this method can be reduced to below that of the conventional step-by-step method, because the new method calculates the time-periodic phenomena directly, not through the transient phenomena. The finite element discretization of the method is described in detail. As an example of application, a loaded transformer is analyzed
en-copyright= kn-copyright= en-aut-name=NakataTakayoshi en-aut-sei=Nakata en-aut-mei=Takayoshi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=TakahashiNorio en-aut-sei=Takahashi en-aut-mei=Norio kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=FujiwaraKoji en-aut-sei=Fujiwara en-aut-mei=Koji kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=AhagonAkira en-aut-sei=Ahagon en-aut-mei=Akira kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= affil-num=1 en-affil= kn-affil=Okayama University affil-num=2 en-affil= kn-affil=Okayama University affil-num=3 en-affil= kn-affil=Okayama University affil-num=4 en-affil= kn-affil=Okayama University en-keyword=eddy currents kn-keyword=eddy currents en-keyword=electromagnetic field theory kn-keyword=electromagnetic field theory en-keyword=electromagnetic induction kn-keyword=electromagnetic induction en-keyword=finite element analysis kn-keyword=finite element analysis en-keyword=power engineering computing kn-keyword=power engineering computing END start-ver=1.4 cd-journal=joma no-vol=27 cd-vols= no-issue=6 article-no= start-page=5223 end-page=5225 dt-received= dt-revised= dt-accepted= dt-pub-year=1991 dt-pub=19911101 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Factors affecting errors due to 2-D approximate analysis of 3-D magnetic fields with eddy currents [rotating machines] en-subtitle= kn-subtitle= en-abstract= kn-abstract=The effects of the leakage flux, eddy current path, and end coil of electric machines on the flux and eddy current density analyzed by the 2-D approximation are investigated systematically by making a comparison with 3-D analysis. It is shown that, when the gap length is relatively large, the difference between the fluxes calculated by 2-D and 3-D analyses is pronounced due to the leakage flux. The flux in the pole obtained by 3-D analysis is larger than that obtained by 2-D analysis under constant current excitation, and the flux obtained by 3-D analysis is less than that obtained by 2-D analysis under constant voltage excitation. When the eddy current flows in the thin core, a larger error occurs in the 2-D analysis, because there is a great difference in eddy current paths between 2-D and 3-D models
en-copyright= kn-copyright= en-aut-name=TakahashiNorio en-aut-sei=Takahashi en-aut-mei=Norio kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=NakataTakayoshi en-aut-sei=Nakata en-aut-mei=Takayoshi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=FujiwaraK. en-aut-sei=Fujiwara en-aut-mei=K. kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=NishimuraT. en-aut-sei=Nishimura en-aut-mei=T. kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= affil-num=1 en-affil= kn-affil=Okayama University affil-num=2 en-affil= kn-affil=Okayama University affil-num=3 en-affil= kn-affil=Okayama University affil-num=4 en-affil= kn-affil=Okayama University en-keyword=eddy currents kn-keyword=eddy currents en-keyword=electric machine analysis computing kn-keyword=electric machine analysis computing en-keyword=error analysis kn-keyword=error analysis en-keyword=finite element analysis kn-keyword=finite element analysis en-keyword=induction motors kn-keyword=induction motors en-keyword=magnetic fields kn-keyword=magnetic fields END start-ver=1.4 cd-journal=joma no-vol=14 cd-vols= no-issue=2 article-no= start-page=654 end-page=657 dt-received= dt-revised= dt-accepted= dt-pub-year=2004 dt-pub=20046 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=The shielding effect of HTS power cable based on E-J power law en-subtitle= kn-subtitle= en-abstract= kn-abstract=A method for analysing the current distribution in high-T/sub c/ superconducting (HTS) power cable is examined by the aid of the novel use of anisotropic conductivity and 3-D finite element method considering E-J power law characteristic. The detailed current distribution in the cable is illustrated and the shielding effect of HTS shield layer with intervals is also examined. It is shown that AC losses in shield layer with intervals are increased when the interval between wires becomes large. en-copyright= kn-copyright= en-aut-name=MiyagiDaisuke en-aut-sei=Miyagi en-aut-mei=Daisuke kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=IwataSatoru en-aut-sei=Iwata en-aut-mei=Satoru kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=WakatsukiTomohiro en-aut-sei=Wakatsuki en-aut-mei=Tomohiro kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=TakahashiNorio en-aut-sei=Takahashi en-aut-mei=Norio kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= en-aut-name=ToriiShinji en-aut-sei=Torii en-aut-mei=Shinji kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=5 ORCID= en-aut-name=UedaKiyotaka en-aut-sei=Ueda en-aut-mei=Kiyotaka kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=6 ORCID= en-aut-name=YasudaKenji en-aut-sei=Yasuda en-aut-mei=Kenji kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=7 ORCID= affil-num=1 en-affil= kn-affil=Okayama University affil-num=2 en-affil= kn-affil=Okayama University affil-num=3 en-affil= kn-affil=Okayama University affil-num=4 en-affil= kn-affil=Okayama University affil-num=5 en-affil= kn-affil=Central Research Institute of Electric Power Industry affil-num=6 en-affil= kn-affil=Central Research Institute of Electric Power Industry affil-num=7 en-affil= kn-affil=Engineering Research Association for Superconductive Generation Equipment and Materials en-keyword=E-J power law characteristic kn-keyword=E-J power law characteristic en-keyword=HTS power cable kn-keyword=HTS power cable en-keyword=HTS shield kn-keyword=HTS shield en-keyword=3-D finite element analysis kn-keyword=3-D finite element analysis END start-ver=1.4 cd-journal=joma no-vol= cd-vols= no-issue= article-no= start-page= end-page= dt-received= dt-revised= dt-accepted= dt-pub-year=1992 dt-pub=19920803 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Accuracy of Advanced Energy Method for Calculating Electromagnetic Force en-subtitle= kn-subtitle= en-abstract= kn-abstract= en-copyright= kn-copyright= en-aut-name=TakahashiNorio en-aut-sei=Takahashi en-aut-mei=Norio kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=NakataTakayoshi en-aut-sei=Nakata en-aut-mei=Takayoshi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=FujiwaraK. en-aut-sei=Fujiwara en-aut-mei=K. kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=MoriwakeT. en-aut-sei=Moriwake en-aut-mei=T. kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= affil-num=1 en-affil= kn-affil=Okayama University affil-num=2 en-affil= kn-affil=Okayama University affil-num=3 en-affil= kn-affil=Okayama University affil-num=4 en-affil= kn-affil=Okayama University END start-ver=1.4 cd-journal=joma no-vol=36 cd-vols= no-issue=4 article-no= start-page=1089 end-page=1093 dt-received= dt-revised= dt-accepted= dt-pub-year=2000 dt-pub=20007 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Optimal design of tank shield model of transformer en-subtitle= kn-subtitle= en-abstract= kn-abstract=A tank shield model of a transformer which is proposed by the Investigation Committee of IEE of Japan is analyzed. This is a model having the constraint that the maximum eddy current density should be less than a specified value. The automatic 3D mesh generation technique for hexahedral element is investigated for the optimal design of such a model. It is shown that reasonable results that satisfy the specified constraints can be obtained using Rosenbrock's method within the acceptable CPU time. The experimental verification is also carried out
en-copyright= kn-copyright= en-aut-name=TakahashiNorio en-aut-sei=Takahashi en-aut-mei=Norio kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=KitamuraTetsuro en-aut-sei=Kitamura en-aut-mei=Tetsuro kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=HoriiMakoto en-aut-sei=Horii en-aut-mei=Makoto kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=TakeharaJun en-aut-sei=Takehara en-aut-mei=Jun kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= affil-num=1 en-affil= kn-affil=Okayama University affil-num=2 en-affil= kn-affil=Okayama University affil-num=3 en-affil= kn-affil=Okayama University affil-num=4 en-affil= kn-affil=The Chugoku Electric Power Corporation, incorporated en-keyword=eddy currents kn-keyword=eddy currents en-keyword=magnetic shielding kn-keyword=magnetic shielding en-keyword=power transformers kn-keyword=power transformers END start-ver=1.4 cd-journal=joma no-vol=30 cd-vols= no-issue=6 article-no= start-page=4563 end-page=4565 dt-received= dt-revised= dt-accepted= dt-pub-year=1994 dt-pub=19941101 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Magnetostriction measurements with a laser Doppler velocimeter en-subtitle= kn-subtitle= en-abstract= kn-abstract=A new method for measuring the magnetostriction of silicon steel sheet using a laser Doppler velocimeter has been developed. This method has the following advantages: (a) non-contact measurement, (b) better resolution (less than 4×10-8 m under the condition that the error is within 1%) than conventional methods, (c) measurement of magnetostriction in any direction of anisotropic material and (d) little operator skill required
en-copyright= kn-copyright= en-aut-name=NakataTakayoshi en-aut-sei=Nakata en-aut-mei=Takayoshi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=TakahashiNorio en-aut-sei=Takahashi en-aut-mei=Norio kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=NakanoMasanori en-aut-sei=Nakano en-aut-mei=Masanori kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=MuramatsuKazuhiro en-aut-sei=Muramatsu en-aut-mei=Kazuhiro kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= en-aut-name=MiyakeMasahide en-aut-sei=Miyake en-aut-mei=Masahide kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=5 ORCID= affil-num=1 en-affil= kn-affil=Okayama University affil-num=2 en-affil= kn-affil=Okayama University affil-num=3 en-affil= kn-affil=Okayama University affil-num=4 en-affil= kn-affil=Okayama University affil-num=5 en-affil= kn-affil=Okayama University en-keyword=ferromagnetic materials kn-keyword=ferromagnetic materials en-keyword=iron alloys kn-keyword=iron alloys en-keyword=laser velocimetry kn-keyword=laser velocimetry en-keyword=magnetostriction kn-keyword=magnetostriction en-keyword=silicon alloys kn-keyword=silicon alloys END start-ver=1.4 cd-journal=joma no-vol=40 cd-vols= no-issue=4 article-no= start-page=2613 end-page=2615 dt-received= dt-revised= dt-accepted= dt-pub-year=2004 dt-pub=20047 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Analysis of writing characteristics of CF-SPT head using 3-D read/write simulation system en-subtitle= kn-subtitle= en-abstract= kn-abstract=Recently, the increase of areal recording density is remarkable. In order to develop a high density recording device, a read/write (R/W) simulation using three dimensional (3-D) magnetic field analysis is indispensable. In this paper, the magnetic field in a cusp-field single-pole-type (CF-SPT) head with discrete track media is analyzed using a 3-D R/W simulation system, in which edge-based finite element method and 3-D medium hysteresis model based on the ensemble of the Stoner-Wohlfarth (SW) particles are combined. The effects of ampereturns and the discrete track media on the distribution of recorded magnetization are investigated. The detailed behavior of flux around the discrete track media and continuous media is illustrated.
en-copyright= kn-copyright= en-aut-name=OhtakeMasaya en-aut-sei=Ohtake en-aut-mei=Masaya kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=TakahashiNorio en-aut-sei=Takahashi en-aut-mei=Norio kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=ShinagawaKiminari en-aut-sei=Shinagawa en-aut-mei=Kiminari kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= affil-num=1 en-affil= kn-affil=Okayama University affil-num=2 en-affil= kn-affil=Okayama University affil-num=3 en-affil= kn-affil=Okayama University en-keyword=CF-SPT kn-keyword=CF-SPT en-keyword=Cusp-field single-pole-type kn-keyword=Cusp-field single-pole-type en-keyword=discrete track media kn-keyword=discrete track media en-keyword=head kn-keyword=head en-keyword=magnetic recording kn-keyword=magnetic recording en-keyword=medium hysteresis model kn-keyword=medium hysteresis model en-keyword=three-dimensional finite element method kn-keyword=three-dimensional finite element method END start-ver=1.4 cd-journal=joma no-vol=34 cd-vols= no-issue=5 article-no= start-page=441 end-page=416 dt-received= dt-revised= dt-accepted= dt-pub-year=1997 dt-pub=19971103 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Optimization of permanent magnet type of retarder using 3-D finite element method and direct search method en-subtitle= kn-subtitle= en-abstract= kn-abstract=3-D optimization method using the combined experimental design method and direct search method is developed to apply to the optimal design of a permanent magnet type of retarder. It is shown that the braking torque is increased by using the optimization method. The CPU time can be considerably reduced by utilizing the initial values obtained by the experimental design method
en-copyright= kn-copyright= en-aut-name=TakahashiNorio en-aut-sei=Takahashi en-aut-mei=Norio kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=NatsumedaMitsutoshi en-aut-sei=Natsumeda en-aut-mei=Mitsutoshi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=MuramatsuKazuhiro en-aut-sei=Muramatsu en-aut-mei=Kazuhiro kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=YamadaChuji en-aut-sei=Yamada en-aut-mei=Chuji kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= en-aut-name=OgawaMakoto en-aut-sei=Ogawa en-aut-mei=Makoto kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=5 ORCID= en-aut-name=KobayashiShin en-aut-sei=Kobayashi en-aut-mei=Shin kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=6 ORCID= en-aut-name=KuwaharaTohru en-aut-sei=Kuwahara en-aut-mei=Tohru kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=7 ORCID= affil-num=1 en-affil= kn-affil=Okayama University affil-num=2 en-affil= kn-affil=Okayama University affil-num=3 en-affil= kn-affil=Okayama University affil-num=4 en-affil= kn-affil=Isuzu Advanced Engineering Center, Limited affil-num=5 en-affil= kn-affil=Isuzu Advanced Engineering Center, Limited affil-num=6 en-affil= kn-affil=Isuzu Advanced Engineering Center, Limited affil-num=7 en-affil= kn-affil=Isuzu Motors, Limited en-keyword=eddy current braking kn-keyword=eddy current braking en-keyword=electrical engineering computing kn-keyword=electrical engineering computing en-keyword=finite element analysis kn-keyword=finite element analysis en-keyword=optimisation kn-keyword=optimisation en-keyword=permanent magnets kn-keyword=permanent magnets en-keyword=search problems kn-keyword=search problems en-keyword=torque kn-keyword=torque en-keyword=vehicles kn-keyword=vehicles END start-ver=1.4 cd-journal=joma no-vol=25 cd-vols= no-issue=5 article-no= start-page=4144 end-page=4146 dt-received= dt-revised= dt-accepted= dt-pub-year=1989 dt-pub=19899 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Optimal design method of 3-D nonlinear magnetic circuit by using magnetization integral equation method en-subtitle= kn-subtitle= en-abstract= kn-abstract=A novel method for determining the sizes of iron parts in a magnetic circuit, which preserves the requirement of prescribed flux densities, has been developed. In order to take into account the nonlinear characteristics of iron, the magnetization integral equation method is used in the analysis. The effectiveness of the method is examined by applying it to the pole shape of an electromagnet. The developed software was verified by comparing calculated results with measured ones
en-copyright= kn-copyright= en-aut-name=TakahashiNorio en-aut-sei=Takahashi en-aut-mei=Norio kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=NakataTakayoshi en-aut-sei=Nakata en-aut-mei=Takayoshi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=UchiyamaN. en-aut-sei=Uchiyama en-aut-mei=N. kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= affil-num=1 en-affil= kn-affil=Okayama University affil-num=2 en-affil= kn-affil=Okayama University affil-num=3 en-affil= kn-affil=Okayama University en-keyword=CAD kn-keyword=CAD en-keyword=electromagnets kn-keyword=electromagnets en-keyword=magnetic circuits kn-keyword=magnetic circuits en-keyword=magnetic cores kn-keyword=magnetic cores END start-ver=1.4 cd-journal=joma no-vol=39 cd-vols= no-issue=3 article-no= start-page=1527 end-page=1530 dt-received= dt-revised= dt-accepted= dt-pub-year=2003 dt-pub=20035 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Study on problems in detecting plural cracks by alternating flux leakage testing using 3D nonlinear eddy current analysis en-subtitle= kn-subtitle= en-abstract= kn-abstract=The alternating magnetic flux leakage testing is used for the detection of cracks in a steel plate. A new technique of how to detect plural cracks, which are located at a very short distance from each other, using the parallel (x-) component of the leakage flux density is proposed. The behavior of leakage flux is examined using a three-dimensional edge-based hexahedral finite-element method. The effects of dimensions of search coils and cracks on the detection accuracy are illustrated.
en-copyright= kn-copyright= en-aut-name=GotohYuji en-aut-sei=Gotoh en-aut-mei=Yuji kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=TakahashiNorio en-aut-sei=Takahashi en-aut-mei=Norio kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= affil-num=1 en-affil= kn-affil=Chugoku Polytechnic College affil-num=2 en-affil= kn-affil=Okayama University en-keyword=coils kn-keyword=coils en-keyword=crack detection kn-keyword=crack detection en-keyword=eddy current testing kn-keyword=eddy current testing en-keyword=finite element analysis kn-keyword=finite element analysis en-keyword=magnetic flux kn-keyword=magnetic flux en-keyword=magnetic leakage kn-keyword=magnetic leakage END start-ver=1.4 cd-journal=joma no-vol=36 cd-vols= no-issue=4 article-no= start-page=1578 end-page=1582 dt-received= dt-revised= dt-accepted= dt-pub-year=2000 dt-pub=20007 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Effect of continuity of potential on accuracy in magnetic field analysis using nonconforming mesh en-subtitle= kn-subtitle= en-abstract= kn-abstract=Methods of analyzing magnetic fields in rotating machines using nonconforming meshes, in which only an interpolation technique is applied, are investigated. The effect of the continuity of potentials at nonconforming surfaces on accuracy is examined, it is shown that although the flux distribution is not affected by the discontinuity of the potential, the force and torque are fairly affected by the discontinuity. Therefore, it is shown that a continuous method, or a discontinuous method using a fine mesh should be used especially in force and torque calculation. An analysis of an induction motor is also carried out using a nonconforming mesh
en-copyright= kn-copyright= en-aut-name=MuramatsuKazuhiro en-aut-sei=Muramatsu en-aut-mei=Kazuhiro kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=YokoyamaYasuhiro en-aut-sei=Yokoyama en-aut-mei=Yasuhiro kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=TakahashiNorio en-aut-sei=Takahashi en-aut-mei=Norio kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=NafalskiAndrew en-aut-sei=Nafalski en-aut-mei=Andrew kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= en-aut-name=GolOzdemir en-aut-sei=Gol en-aut-mei=Ozdemir kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=5 ORCID= affil-num=1 en-affil= kn-affil=Okayama University affil-num=2 en-affil= kn-affil=Okayama University affil-num=3 en-affil= kn-affil=Okayama University affil-num=4 en-affil= kn-affil=University of South Australia affil-num=5 en-affil= kn-affil=University of South Australia en-keyword=electromagnetic forces kn-keyword=electromagnetic forces en-keyword=induction motors kn-keyword=induction motors en-keyword=interpolation kn-keyword=interpolation en-keyword=machine theory kn-keyword=machine theory en-keyword=magnetic fields kn-keyword=magnetic fields en-keyword=magnetic flux kn-keyword=magnetic flux en-keyword=mesh generation kn-keyword=mesh generation en-keyword=torque kn-keyword=torque END start-ver=1.4 cd-journal=joma no-vol=37 cd-vols= no-issue=5 article-no= start-page=3631 end-page=3634 dt-received= dt-revised= dt-accepted= dt-pub-year=2000 dt-pub=20000605 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=3-D optimization of design variables in x-, y- and z-directions of transformer tank shield model en-subtitle= kn-subtitle= en-abstract= kn-abstract=By using the automatic 3-D mesh generation technique using hexahedral elements, which is applicable when design variables are changed in x-, y- and z-directions, a transformer tank shield model is optimized. The volume of tank shield can be considerably reduced by using the Rosenbrock's method (RBM) compared with the previous result having design variables in one direction. It is shown that the determination of initial values for RBM using the experimental design method (EDM) is indispensable for the practical application of the optimization method to obtain a desired result within an acceptable CPU time
en-copyright= kn-copyright= en-aut-name=HoriiMakoto en-aut-sei=Horii en-aut-mei=Makoto kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=TakahashiNorio en-aut-sei=Takahashi en-aut-mei=Norio kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=TakeharaJun en-aut-sei=Takehara en-aut-mei=Jun kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= affil-num=1 en-affil= kn-affil=Okayama University affil-num=2 en-affil= kn-affil=Okayama University affil-num=3 en-affil= kn-affil=The Chugoku Electric Power Corporation, Incorporated en-keyword=design of experiments kn-keyword=design of experiments en-keyword=electromagnetic shielding kn-keyword=electromagnetic shielding en-keyword=mesh generation kn-keyword=mesh generation en-keyword=modelling kn-keyword=modelling en-keyword=optimisation kn-keyword=optimisation en-keyword=transformers kn-keyword=transformers END start-ver=1.4 cd-journal=joma no-vol= cd-vols= no-issue= article-no= start-page= end-page= dt-received= dt-revised= dt-accepted= dt-pub-year=2002 dt-pub=20025 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Effect of eddy current in shielding plate and electron gun on flux distribution in CRT en-subtitle= kn-subtitle= en-abstract= kn-abstract=Summary form only given. An inner magnetic shield (IMS) is set inside a cathode ray tube (CRT) to reduce the disturbance from outside of the CRT, such as geomagnetism. The eddy current induced in the IMS due to the changing current in the deflection coil may affect the flux distribution in the CRT. The eddy current is also induced in the electron gun when coils for velocity modulation (VM) are set near the gun. Although the effect of the eddy current is important, reports about the analysis of this phenomenon are few. In this paper, the effect of the eddy current in the IMS and electron gun on flux distribution in the CRT is analyzed by using the 3-D finite element method.
en-copyright= kn-copyright= en-aut-name=TakahashiNorio en-aut-sei=Takahashi en-aut-mei=Norio kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=ShimadaKoji en-aut-sei=Shimada en-aut-mei=Koji kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=WakasonoH. en-aut-sei=Wakasono en-aut-mei=H. kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= affil-num=1 en-affil= kn-affil=Okayama University affil-num=2 en-affil= kn-affil=Matsushita Electric Industrial Corporation, Limited affil-num=3 en-affil= kn-affil=Matsushita Electric Industrial Corporation, Limited en-keyword=cathode-ray tubes kn-keyword=cathode-ray tubes en-keyword=eddy currents kn-keyword=eddy currents en-keyword=electron guns kn-keyword=electron guns en-keyword=finite element analysis kn-keyword=finite element analysis en-keyword=magnetic flux kn-keyword=magnetic flux en-keyword=magnetic shielding kn-keyword=magnetic shielding END start-ver=1.4 cd-journal=joma no-vol=29 cd-vols= no-issue=2 article-no= start-page=1898 end-page=1901 dt-received= dt-revised= dt-accepted= dt-pub-year=1992 dt-pub=19920904 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=A simple algorithm for adaptive refinement of tetrahedral meshes combined with edge elements en-subtitle= kn-subtitle= en-abstract= kn-abstract=A simple algorithm yielding unique face subdivision patterns of locally refined tetrahedral elements by the Delaunay tessellation process is presented. Due to the numerous advantages of edge elements, the algorithm is combined with the magnetostatic edge element computer code. A comparative analysis of four different error estimates used to locate elements for refinement, including a new one suitable for edge elements, is described. The performance of the proposed algorithm and the effectiveness of the error estimates are demonstrated by means of three-dimensional test problems
en-copyright= kn-copyright= en-aut-name=OlszewskiPiotr en-aut-sei=Olszewski en-aut-mei=Piotr kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=NakataTakayoshi en-aut-sei=Nakata en-aut-mei=Takayoshi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=TakahashiNorio en-aut-sei=Takahashi en-aut-mei=Norio kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=FujiwaraKoji en-aut-sei=Fujiwara en-aut-mei=Koji kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= affil-num=1 en-affil= kn-affil=Okayama University affil-num=2 en-affil= kn-affil=Okayama University affil-num=3 en-affil= kn-affil=Okayama University affil-num=4 en-affil= kn-affil=Okayama University en-keyword=error analysis kn-keyword=error analysis en-keyword=magnetostatics kn-keyword=magnetostatics en-keyword=mesh generation kn-keyword=mesh generation END start-ver=1.4 cd-journal=joma no-vol=34 cd-vols= no-issue=4 article-no= start-page=2072 end-page=2074 dt-received= dt-revised= dt-accepted= dt-pub-year=1998 dt-pub=19987 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Measuring system for magnetostriction of silicon steel sheet under AC excitation using optical methods en-subtitle= kn-subtitle= en-abstract= kn-abstract=A measuring system for magnetostriction of silicon steel sheet using optical methods and a single sheet tester has been developed to establish a standard test method for IEC and JIS. Various factors affecting measurement accuracy and reproducibility of the developed system are examined. Two optical instruments, such as a laser Doppler vibrometer and a heterodyne displacement meter, are compared. 3-D characteristics of magnetostriction under ac excitation in the rolling direction are measured up to 2.0 T
en-copyright= kn-copyright= en-aut-name=NakaseTomoya en-aut-sei=Nakase en-aut-mei=Tomoya kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=NakanoMasanori en-aut-sei=Nakano en-aut-mei=Masanori kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=FujiwaraKoji en-aut-sei=Fujiwara en-aut-mei=Koji kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=TakahashiNorio en-aut-sei=Takahashi en-aut-mei=Norio kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= affil-num=1 en-affil= kn-affil=Okayama University affil-num=2 en-affil= kn-affil=Okayama University affil-num=3 en-affil= kn-affil=Okayama University affil-num=4 en-affil= kn-affil=Okayama University en-keyword=Doppler measurement kn-keyword=Doppler measurement en-keyword=ferromagnetic materials kn-keyword=ferromagnetic materials en-keyword=iron alloys kn-keyword=iron alloys en-keyword=magnetic variables measurement kn-keyword=magnetic variables measurement en-keyword=magnetostriction kn-keyword=magnetostriction en-keyword=measurement by laser beam kn-keyword=measurement by laser beam en-keyword=silicon alloys kn-keyword=silicon alloys END start-ver=1.4 cd-journal=joma no-vol=28 cd-vols= no-issue=5 article-no= start-page=2826 end-page=2828 dt-received= dt-revised= dt-accepted= dt-pub-year=1992 dt-pub=19929 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Study on cause of quenching at the joint between multifilamentary superconducting cable and normal conducting cable using 3D FEM en-subtitle= kn-subtitle= en-abstract= kn-abstract=Investigates the cause of quenching at the joint between a multifilamentary superconducting cable and a normal conducting cable. The 3D current distribution is analyzed. It is found that the cause of quenching is the extreme concentration of current in the joint due to the pronounced skin effect at liquid helium temperature. The mechanism of the concentration of current which is affected by the twist pitch and skin depth is also clarified quantitatively by numerical analysis
en-copyright= kn-copyright= en-aut-name=TakahashiNorio en-aut-sei=Takahashi en-aut-mei=Norio kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=NakataTakayoshi en-aut-sei=Nakata en-aut-mei=Takayoshi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=FujiiY. en-aut-sei=Fujii en-aut-mei=Y. kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=FunakiK. en-aut-sei=Funaki en-aut-mei=K. kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= en-aut-name=TakeoM. en-aut-sei=Takeo en-aut-mei=M. kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=5 ORCID= affil-num=1 en-affil= kn-affil=Okayama University affil-num=2 en-affil= kn-affil=Okayama University affil-num=3 en-affil= kn-affil=Okayama University affil-num=4 en-affil= kn-affil=Kyushu University affil-num=5 en-affil= kn-affil=Kyushu University en-keyword=cable jointing kn-keyword=cable jointing en-keyword=finite element analysis kn-keyword=finite element analysis en-keyword= quenching (thermal) kn-keyword= quenching (thermal) en-keyword=skin effect kn-keyword=skin effect en-keyword=superconducting cables kn-keyword=superconducting cables END start-ver=1.4 cd-journal=joma no-vol= cd-vols= no-issue= article-no= start-page= end-page= dt-received= dt-revised= dt-accepted= dt-pub-year=1993 dt-pub=19930413 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Measurement of Magnetic characteristics in arbitrary directions of grain-oriented silicon steel en-subtitle= kn-subtitle= en-abstract= kn-abstract= en-copyright= kn-copyright= en-aut-name=NakataTakayoshi en-aut-sei=Nakata en-aut-mei=Takayoshi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=TakahashiNorio en-aut-sei=Takahashi en-aut-mei=Norio kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=FujiwaraKoji en-aut-sei=Fujiwara en-aut-mei=Koji kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=NakanoMasanori en-aut-sei=Nakano en-aut-mei=Masanori kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= affil-num=1 en-affil= kn-affil=Okayama University affil-num=2 en-affil= kn-affil=Okayama University affil-num=3 en-affil= kn-affil=Okayama University affil-num=4 en-affil= kn-affil=Okayama University END start-ver=1.4 cd-journal=joma no-vol=38 cd-vols= no-issue=2 article-no= start-page=889 end-page=892 dt-received= dt-revised= dt-accepted= dt-pub-year=2002 dt-pub=20023 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=A proposal of finite-element analysis considering two-dimensional magnetic properties en-subtitle= kn-subtitle= en-abstract= kn-abstract=A technique for analyzing the magnetic field in anisotropic material using the effective anisotropic reluctivity proposed by Enokizono is examined. It is shown that the Enokizono model can be transformed into another model having a conventional form. By expanding the examination of such a conventional form, a new finite element formulation for taking account of the two-dimensional (2-D) magnetic property is proposed. As the modeling of the 2-D magnetic property at the high flux density region is important in the practical analysis of the magnetic device, the extrapolation method of the magnetic property is examined. It is shown that the Bezier interpolation is fairly effective to stabilize the convergence characteristic of the Newton-Raphson (N-R) iteration in the nonlinear magnetic field analysis, taking account of the 2-D magnetic property
en-copyright= kn-copyright= en-aut-name=FujiwaraKoji en-aut-sei=Fujiwara en-aut-mei=Koji kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=AdachiTakayuki en-aut-sei=Adachi en-aut-mei=Takayuki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=TakahashiNorio en-aut-sei=Takahashi en-aut-mei=Norio kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= affil-num=1 en-affil= kn-affil=Okayama University affil-num=2 en-affil= kn-affil=Okayama University affil-num=3 en-affil= kn-affil=Okayama University en-keyword=Newton-Raphson method kn-keyword=Newton-Raphson method en-keyword=convergence of numerical methods kn-keyword=convergence of numerical methods en-keyword=extrapolation kn-keyword=extrapolation en-keyword=finite element kn-keyword=finite element en-keyword=analysis kn-keyword=analysis en-keyword=interpolation kn-keyword=interpolation en-keyword=magnetic anisotropy kn-keyword=magnetic anisotropy en-keyword=magnetic materials kn-keyword=magnetic materials END start-ver=1.4 cd-journal=joma no-vol=38 cd-vols= no-issue=2 article-no= start-page=1021 end-page=1024 dt-received= dt-revised= dt-accepted= dt-pub-year=2002 dt-pub=20023 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Effective optimal design of 3-D magnetic device having complicated coil using edge element and Biot-Savart method en-subtitle= kn-subtitle= en-abstract= kn-abstract=It is troublesome and time consuming to treat a coil of complicated shape with optimization methods using edge elements, because the current vector potential in the coil of changed shape (changed mesh) should be calculated at each iteration of the optimization. In this paper, an effective optimal design method using the Biot-Savart method (As method) and the evolution strategy is investigated. As it is not necessary to generate a mesh for the coil by using the As method, the mesh becomes simple and, moreover, it is not necessary to calculate the current vector potential in the changed coil at each iteration in order to give the current vector potential in the coil. The usefulness of the proposed method is illustrated by applying it to the optimal design of a deflection coil for a cathode-ray tube
en-copyright= kn-copyright= en-aut-name=OhnishiTakuma en-aut-sei=Ohnishi en-aut-mei=Takuma kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=TakahashiNorio en-aut-sei=Takahashi en-aut-mei=Norio kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= affil-num=1 en-affil= kn-affil=Okayama University affil-num=2 en-affil= kn-affil=Okayama University en-keyword=cathode-ray tubes kn-keyword=cathode-ray tubes en-keyword=coils kn-keyword=coils en-keyword=electromagnetic field theory kn-keyword=electromagnetic field theory en-keyword=electronic design automation kn-keyword=electronic design automation en-keyword=finite element analysis kn-keyword=finite element analysis en-keyword=iterative methods kn-keyword=iterative methods en-keyword=optimisation kn-keyword=optimisation END start-ver=1.4 cd-journal=joma no-vol=31 cd-vols= no-issue=3 article-no= start-page=1416 end-page=1419 dt-received= dt-revised= dt-accepted= dt-pub-year=1995 dt-pub=19955 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Practical analysis of 3-D dynamic nonlinear magnetic field using time-periodic finite element method en-subtitle= kn-subtitle= en-abstract= kn-abstract=A practical 3-D finite element method using edge elements for analyzing stationary nonlinear magnetic fields with eddy currents in electric apparatus, in which the flux interlinking the voltage winding is given, has been proposed. The method is applied to the analysis of magnetic fields in the Epstein frame
en-copyright= kn-copyright= en-aut-name=TakahashiNorio en-aut-sei=Takahashi en-aut-mei=Norio kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=FujiwaraKoji en-aut-sei=Fujiwara en-aut-mei=Koji kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=NakataTakayoshi en-aut-sei=Nakata en-aut-mei=Takayoshi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=OguraYoichi en-aut-sei=Ogura en-aut-mei=Yoichi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= affil-num=1 en-affil= kn-affil=Okayama University affil-num=2 en-affil= kn-affil=Okayama University affil-num=3 en-affil= kn-affil=Okayama University affil-num=4 en-affil= kn-affil=Okayama University en-keyword=eddy currents kn-keyword=eddy currents en-keyword=electric machine analysis computing kn-keyword=electric machine analysis computing en-keyword=finite element analysis kn-keyword=finite element analysis en-keyword=machine theory kn-keyword=machine theory en-keyword=machine windings kn-keyword=machine windings en-keyword=magnetic fields kn-keyword=magnetic fields END start-ver=1.4 cd-journal=joma no-vol=35 cd-vols= no-issue=3 article-no= start-page=1243 end-page=1246 dt-received= dt-revised= dt-accepted= dt-pub-year=1999 dt-pub=19995 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Problems in practical finite element analysis using Preisach hysteresis model en-subtitle= kn-subtitle= en-abstract= kn-abstract=An efficient method, which is called the “inverse distribution function method”, for calculating the magnetic field strength H from the flux density B through the Preisach model is developed. By using the method, H can be directly obtained without iteration from B which is calculated by the usual FEM, with the magnetic vector potential as an unknown variable. The effects of the dimension n of the inverse distribution function on the CPU time and the memory requirements are investigated through a numerical example by increasing the dimension n of the inverse distribution function. It is shown that the additional CPU time for taking account of hysteresis is negligible when n is less than about 200
en-copyright= kn-copyright= en-aut-name=TakahashiNorio en-aut-sei=Takahashi en-aut-mei=Norio kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=MiyabaraShun-ichi en-aut-sei=Miyabara en-aut-mei=Shun-ichi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=FujiwaraKoji en-aut-sei=Fujiwara en-aut-mei=Koji kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= affil-num=1 en-affil= kn-affil=Okayama University affil-num=2 en-affil= kn-affil=Okayama University affil-num=3 en-affil= kn-affil=Okayama University en-keyword=finite element analysis kn-keyword=finite element analysis en-keyword=magnetic fields kn-keyword=magnetic fields en-keyword=magnetic flux kn-keyword=magnetic flux en-keyword=magnetic hysteresis kn-keyword=magnetic hysteresis en-keyword=magnetic materials kn-keyword=magnetic materials END start-ver=1.4 cd-journal=joma no-vol=30 cd-vols= no-issue=5 article-no= start-page=3483 end-page=3486 dt-received= dt-revised= dt-accepted= dt-pub-year=1994 dt-pub=19949 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Investigation of a model to verify software for 3-D static force calculation en-subtitle= kn-subtitle= en-abstract= kn-abstract=Requirements for a model to verify software for 3-D static force calculation are examined, and a 3-D model for static force calculation is proposed. Some factors affecting the analysis and experiments are investigated in order to obtain accurate and reproducible results
en-copyright= kn-copyright= en-aut-name=TakahashiNorio en-aut-sei=Takahashi en-aut-mei=Norio kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=NakataTakayoshi en-aut-sei=Nakata en-aut-mei=Takayoshi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=MorishigeH. en-aut-sei=Morishige en-aut-mei=H. kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= affil-num=1 en-affil= kn-affil=Okayama University affil-num=2 en-affil= kn-affil=Okayama University affil-num=3 en-affil= kn-affil=Okayama University en-keyword=electrical engineering computing kn-keyword=electrical engineering computing en-keyword=electromagnetic field theory kn-keyword=electromagnetic field theory en-keyword=mesh generation kn-keyword=mesh generation en-keyword=physics computing kn-keyword=physics computing END start-ver=1.4 cd-journal=joma no-vol=41 cd-vols= no-issue=5 article-no= start-page=1964 end-page=1967 dt-received= dt-revised= dt-accepted= dt-pub-year=2005 dt-pub=20055 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Investigation of AC loss of permanent magnet of SPM motor considering hysteresis and eddy-current losses en-subtitle= kn-subtitle= en-abstract= kn-abstract=NdFeB sintered magnets are widely used in rotating electrical machines. In order to develop an efficient rotating machine, it is important to estimate ac loss of the permanent magnet of rotor precisely. In this paper, the ac losses of the permanent magnet of IEEJ model (surface permanent-magnet motor model) are examined by using the three-dimensional finite-element method taking into account the newly measured hysteresis losses of permanent magnet. The result shows that we should consider not only the eddy-current loss but also the hysteresis loss, when the frequency of ac field due to a slot ripple is of the order of several hundred hertz.
en-copyright= kn-copyright= en-aut-name=FukumaA. en-aut-sei=Fukuma en-aut-mei=A. kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=KanazawaSusumu en-aut-sei=Kanazawa en-aut-mei=Susumu kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=MiyagiDaisuke en-aut-sei=Miyagi en-aut-mei=Daisuke kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=TakahashiNorio en-aut-sei=Takahashi en-aut-mei=Norio kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= affil-num=1 en-affil= kn-affil=Okayama University affil-num=2 en-affil= kn-affil=Okayama University affil-num=3 en-affil= kn-affil=Okayama University affil-num=4 en-affil= kn-affil=Okayama University en-keyword=Eddy-current loss kn-keyword=Eddy-current loss en-keyword=NdFeB magnet kn-keyword=NdFeB magnet en-keyword=SPM motor kn-keyword=SPM motor en-keyword=hysteresis loss kn-keyword=hysteresis loss END start-ver=1.4 cd-journal=joma no-vol=35 cd-vols= no-issue=3 article-no= start-page=1670 end-page=1673 dt-received= dt-revised= dt-accepted= dt-pub-year=1999 dt-pub=19995 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Magneto-thermal-fluid analysis taking account of natural convection using semi-Lagrange coordinate system en-subtitle= kn-subtitle= en-abstract= kn-abstract=A method for magneto-thermal-fluid analysis, taking account of natural convection using a semi-Lagrange coordinate system, is developed. The developed method is applied to a simple induction heating model in which the steel plate is heated due to an eddy current. It is shown that the result, considering the convection in air, is different from the result neglecting it
en-copyright= kn-copyright= en-aut-name=MuramatsuKazuhiro en-aut-sei=Muramatsu en-aut-mei=Kazuhiro kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=TakahashiNorio en-aut-sei=Takahashi en-aut-mei=Norio kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=MimuraTakayuki en-aut-sei=Mimura en-aut-mei=Takayuki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= affil-num=1 en-affil= kn-affil=Okayama University affil-num=2 en-affil= kn-affil=Okayama University affil-num=3 en-affil= kn-affil=Okayama University en-keyword=eddy currents kn-keyword=eddy currents en-keyword=electromagnetic fields kn-keyword=electromagnetic fields en-keyword=induction heating kn-keyword=induction heating en-keyword=natural convection kn-keyword=natural convection en-keyword=thermal analysis kn-keyword=thermal analysis END start-ver=1.4 cd-journal=joma no-vol= cd-vols= no-issue= article-no= start-page=28 end-page=28 dt-received= dt-revised= dt-accepted= dt-pub-year=1992 dt-pub=19924 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Low loss transformer using rotating magnetic field en-subtitle= kn-subtitle= en-abstract= kn-abstract= en-copyright= kn-copyright= en-aut-name=NakataTakayoshi en-aut-sei=Nakata en-aut-mei=Takayoshi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=TakahashiNorio en-aut-sei=Takahashi en-aut-mei=Norio kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=FujiwaraKoji en-aut-sei=Fujiwara en-aut-mei=Koji kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=NakanoMasanori en-aut-sei=Nakano en-aut-mei=Masanori kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= en-aut-name=NagaoM. en-aut-sei=Nagao en-aut-mei=M. kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=5 ORCID= affil-num=1 en-affil= kn-affil=Okayama University affil-num=2 en-affil= kn-affil=Okayama University affil-num=3 en-affil= kn-affil=Okayama University affil-num=4 en-affil= kn-affil=Okayama University affil-num=5 en-affil= kn-affil=Okayama University END start-ver=1.4 cd-journal=joma no-vol=42 cd-vols= no-issue=4 article-no= start-page=1087 end-page=1090 dt-received= dt-revised= dt-accepted= dt-pub-year=2006 dt-pub=20064 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=3-D topology optimization of single-pole-type head by using design sensitivity analysis en-subtitle= kn-subtitle= en-abstract= kn-abstract=It is necessary to develop a write head having a large recording field and small stray field in adjacent tracks and adjacent bits in perpendicular magnetic recording systems. In this paper, a practical three-dimensional topology optimization technique combined with the edge-based finite-element method is proposed. A technique for obtaining a smooth topology is also shown. The optimization of single-pole-type head having a magnetic shield is performed by using the topology optimization technique so that the leakage flux in the adjacent bit can be reduced. A useful shape of the magnetic shield obtained by the proposed technique is illustrated.
en-copyright= kn-copyright= en-aut-name=OkamotoYoshifumi en-aut-sei=Okamoto en-aut-mei=Yoshifumi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=AkiyamaKoji en-aut-sei=Akiyama en-aut-mei=Koji kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=TakahashiNorio en-aut-sei=Takahashi en-aut-mei=Norio kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= affil-num=1 en-affil= kn-affil=Okayama University affil-num=2 en-affil= kn-affil=Okayama University affil-num=3 en-affil= kn-affil=Okayama University en-keyword=ON/OFF method kn-keyword=ON/OFF method en-keyword=sensitivity analysis kn-keyword=sensitivity analysis en-keyword=single-pole-type-head kn-keyword=single-pole-type-head en-keyword=three-dimensional (3-D) topology optimization kn-keyword=three-dimensional (3-D) topology optimization END start-ver=1.4 cd-journal=joma no-vol=35 cd-vols= no-issue=5 article-no= start-page=3965 end-page=3967 dt-received= dt-revised= dt-accepted= dt-pub-year=1999 dt-pub=19990305 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Improvements of single sheet testers for measurement of 2-D magnetic properties up to high flux density en-subtitle= kn-subtitle= en-abstract= kn-abstract=Due to structural limitation, the currently proposed apparatus based on a single sheet tester (SST) cannot measure magnetic properties along arbitrary directions (so-called 2-D magnetic properties) of silicon steel at high flux densities. In this paper, significant improvements are carried out on magnetizing windings and auxiliary yokes of a double excitation type of SST. Furthermore, crosswise overlapped H-coils are introduced so that even an ordinary single-excitation type of SST can be applicable to the measurements of 2-D properties. It is demonstrated that 2-D magnetization property up to 1.9 T can be measured by using the newly developed SST's
en-copyright= kn-copyright= en-aut-name=NakanoMasanori en-aut-sei=Nakano en-aut-mei=Masanori kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=NishimotoHidehiko en-aut-sei=Nishimoto en-aut-mei=Hidehiko kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=FujiwaraKoji en-aut-sei=Fujiwara en-aut-mei=Koji kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=TakahashiNorio en-aut-sei=Takahashi en-aut-mei=Norio kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= affil-num=1 en-affil= kn-affil=Okayama University affil-num=2 en-affil= kn-affil=Okayama University affil-num=3 en-affil= kn-affil=Okayama University affil-num=4 en-affil= kn-affil=Okayama University en-keyword=coils kn-keyword=coils en-keyword=eddy current losses kn-keyword=eddy current losses en-keyword=ferromagnetic materials kn-keyword=ferromagnetic materials en-keyword=iron alloys kn-keyword=iron alloys en-keyword=laminations kn-keyword=laminations en-keyword=magnetic circuits kn-keyword=magnetic circuits en-keyword=magnetic flux kn-keyword=magnetic flux en-keyword=magnetic variables measurement kn-keyword=magnetic variables measurement en-keyword=magnetisation kn-keyword=magnetisation en-keyword=silicon alloys kn-keyword=silicon alloys en-keyword=test equipment kn-keyword=test equipment en-keyword=windings kn-keyword=windings END start-ver=1.4 cd-journal=joma no-vol=38 cd-vols= no-issue=2 article-no= start-page=1209 end-page=1212 dt-received= dt-revised= dt-accepted= dt-pub-year=2002 dt-pub=20023 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=3-D nonlinear eddy-current analysis of alternating magnetic flux leakage testing - analysis of one crack and two cracks en-subtitle= kn-subtitle= en-abstract= kn-abstract=The alternating magnetic flux leakage testing has been applied in the nondestructive inspection process for detecting cracks on the surface of steel. This paper describes numerical analysis using three-dimensional (3-D) edge-based hexahedral finite element method for this testing. The necessity of nonlinear analysis is clarified in comparison with the linear analysis (jω method). The characteristic of leakage flux is confirmed by verification experiment. The possibility of distinguishing two cracks is examined by calculating the detailed distribution of leakage flux around cracks
en-copyright= kn-copyright= en-aut-name=GotohYuji en-aut-sei=Gotoh en-aut-mei=Yuji kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=TakahashiNorio en-aut-sei=Takahashi en-aut-mei=Norio kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= affil-num=1 en-affil= kn-affil=Chugoku Polytechnic College affil-num=2 en-affil= kn-affil=Okayama University en-keyword=crack detection kn-keyword=crack detection en-keyword=eddy current testing kn-keyword=eddy current testing en-keyword=finite element analysis kn-keyword=finite element analysis en-keyword=magnetic leakage kn-keyword=magnetic leakage END start-ver=1.4 cd-journal=joma no-vol=37 cd-vols= no-issue=5 article-no= start-page=3672 end-page=3675 dt-received= dt-revised= dt-accepted= dt-pub-year=2000 dt-pub=20000605 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Nonlinear analysis of eddy current and hysteresis losses of 3-D stray field loss model (Problem 21) en-subtitle= kn-subtitle= en-abstract= kn-abstract=The evaluation method of stray field loss of engineering oriented loss model (TEAM Workshop Problem 21) is investigated. It is shown that the nonlinear eddy current analysis is obligatory in order to investigate the eddy current loss in the steel plate, because the flux and eddy current in steel are affected by the permeability of the plate. The hysteresis loss in such a steel plate having a substantial skin effect is not negligible, even if the flux density in air is small
en-copyright= kn-copyright= en-aut-name=TakahashiNorio en-aut-sei=Takahashi en-aut-mei=Norio kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=SakuraToshiomi en-aut-sei=Sakura en-aut-mei=Toshiomi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=ChengZhiguang en-aut-sei=Cheng en-aut-mei=Zhiguang kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= affil-num=1 en-affil= kn-affil=Okayama University affil-num=2 en-affil= kn-affil=Okayama University affil-num=3 en-affil= kn-affil=Baoding Large Power Transformer Coporation en-keyword=eddy current losses kn-keyword=eddy current losses en-keyword=ferromagnetic materials kn-keyword=ferromagnetic materials en-keyword=finite element analysis kn-keyword=finite element analysis en-keyword=magnetic flux kn-keyword=magnetic flux en-keyword=magnetic hysteresis kn-keyword=magnetic hysteresis en-keyword=magnetic leakage kn-keyword=magnetic leakage en-keyword=skin effect kn-keyword=skin effect en-keyword=steel kn-keyword=steel END start-ver=1.4 cd-journal=joma no-vol=33 cd-vols= no-issue=2 article-no= start-page=1584 end-page=1587 dt-received= dt-revised= dt-accepted= dt-pub-year=1997 dt-pub=19973 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=3-D time-periodic finite element analysis of magnetic field in non-oriented materials taking into account hysteresis characteristics en-subtitle= kn-subtitle= en-abstract= kn-abstract=Problems in analyzing 3-D stationary nonlinear magnetic field in non-oriented material taking into account hysteresis characteristics and eddy current, such as finite element formulation and convergence of nonlinear iteration, are discussed
en-copyright= kn-copyright= en-aut-name=MuramatsuKazuhiro en-aut-sei=Muramatsu en-aut-mei=Kazuhiro kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=TakahashiNorio en-aut-sei=Takahashi en-aut-mei=Norio kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=NakataTakayoshi en-aut-sei=Nakata en-aut-mei=Takayoshi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=NakanoMasanori en-aut-sei=Nakano en-aut-mei=Masanori kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= en-aut-name=EjiriYasuo en-aut-sei=Ejiri en-aut-mei=Yasuo kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=5 ORCID= affil-num=1 en-affil= kn-affil=Okayama University affil-num=2 en-affil= kn-affil=Okayama University affil-num=3 en-affil= kn-affil=Okayama University affil-num=4 en-affil= kn-affil=Okayama University affil-num=5 en-affil= kn-affil=Okayama University en-keyword=eddy currents kn-keyword=eddy currents en-keyword=magnetic heads kn-keyword=magnetic heads en-keyword=magnetic recording kn-keyword=magnetic recording en-keyword=magnetic thin film devices kn-keyword=magnetic thin film devices en-keyword=mesh generation kn-keyword=mesh generation en-keyword=tomography kn-keyword=tomography END start-ver=1.4 cd-journal=joma no-vol=32 cd-vols= no-issue=3 article-no= start-page=749 end-page=752 dt-received= dt-revised= dt-accepted= dt-pub-year=1996 dt-pub=19965 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Linear AC steady-state eddy current analysis of high speed conductor using moving coordinate system en-subtitle= kn-subtitle= en-abstract= kn-abstract=A method for linear analysis of AC steady state eddy currents in a moving conductor using a moving coordinate system is investigated. It is shown that the moving coordinate system is superior to a fixed coordinate system for the analysis of a high speed conductors from the standpoint of stability of the solution. The applicable extent of the moving coordinate system is also discussed for the modelling of electric machine characteristics
en-copyright= kn-copyright= en-aut-name=MuramatsuKazuhiro en-aut-sei=Muramatsu en-aut-mei=Kazuhiro kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=NakataTakayoshi en-aut-sei=Nakata en-aut-mei=Takayoshi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=TakahashiNorio en-aut-sei=Takahashi en-aut-mei=Norio kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=FujiwaraKoji en-aut-sei=Fujiwara en-aut-mei=Koji kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= affil-num=1 en-affil= kn-affil=Okayama University affil-num=2 en-affil= kn-affil=Okayama University affil-num=3 en-affil= kn-affil=Okayama University affil-num=4 en-affil= kn-affil=Okayama University en-keyword=AC machines kn-keyword=AC machines en-keyword=eddy currents kn-keyword=eddy currents en-keyword=machine theory kn-keyword=machine theory en-keyword=machine windings kn-keyword=machine windings en-keyword=numerical stability kn-keyword=numerical stability END start-ver=1.4 cd-journal=joma no-vol=24 cd-vols= no-issue=1 article-no= start-page=178 end-page=181 dt-received= dt-revised= dt-accepted= dt-pub-year=1988 dt-pub=19880101 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Physical meaning of gradФ in eddy current analysisusing magnetic vector potential en-subtitle= kn-subtitle= en-abstract= kn-abstract=The physical meaning of the gradφ in the A-φ method is investigated in order to determine when it can be safely neglected in order to reduce computation time. The relationship between eddy current distribution and gradφ and the effects of boundary conditions on gradφ are examined for several 2-D examples. It is shown that gradφ in 2-D analysis is a constant that modifies the interlinkage flux of the conductor, which is denoted by the magnetic vector potential A
en-copyright= kn-copyright= en-aut-name=NakataN. en-aut-sei=Nakata en-aut-mei=N. kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=TakahashiNorio en-aut-sei=Takahashi en-aut-mei=Norio kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=FujiwaraK. en-aut-sei=Fujiwara en-aut-mei=K. kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= affil-num=1 en-affil= kn-affil=Okayama University affil-num=2 en-affil= kn-affil=Okayama University affil-num=3 en-affil= kn-affil=Okayama University en-keyword=eddy currents kn-keyword=eddy currents en-keyword=electric fields kn-keyword=electric fields en-keyword=electromagnetic field theory kn-keyword=electromagnetic field theory en-keyword=magnetic fields kn-keyword=magnetic fields END start-ver=1.4 cd-journal=joma no-vol=36 cd-vols= no-issue=4 article-no= start-page=1894 end-page=1897 dt-received= dt-revised= dt-accepted= dt-pub-year=2000 dt-pub=20007 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Analysis of magnetic characteristics of three-phase reactor made of grain-oriented silicon steel en-subtitle= kn-subtitle= en-abstract= kn-abstract=Flux and iron loss distributions of three-phase reactor are analyzed using the finite element method considering 2-D B-H curves and iron losses in arbitrary directions which are measured up to high flux density. It is shown that the total iron loss of reactor yoke does not change so much by the yoke dimension, although the local iron loss is increased when the width of yoke is decreased. The experimental verification of flux and iron loss distributions are also carried out
en-copyright= kn-copyright= en-aut-name=KohsakaTakashi en-aut-sei=Kohsaka en-aut-mei=Takashi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=TakahashiNorio en-aut-sei=Takahashi en-aut-mei=Norio kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=NogawaShuichi en-aut-sei=Nogawa en-aut-mei=Shuichi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=KuwataMinoru en-aut-sei=Kuwata en-aut-mei=Minoru kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= affil-num=1 en-affil= kn-affil=Okayama University affil-num=2 en-affil= kn-affil=Okayama University affil-num=3 en-affil= kn-affil=Nissin Electric Corporation, Limited affil-num=4 en-affil= kn-affil=Nissin Electric Corporation, Limited en-keyword=finite element analysis kn-keyword=finite element analysis en-keyword=iron alloys kn-keyword=iron alloys en-keyword=magnetic flux kn-keyword=magnetic flux en-keyword=magnetic leakage kn-keyword=magnetic leakage en-keyword=reactors (electric) kn-keyword=reactors (electric) en-keyword=silicon alloys kn-keyword=silicon alloys END start-ver=1.4 cd-journal=joma no-vol= cd-vols= no-issue= article-no= start-page= end-page= dt-received= dt-revised= dt-accepted= dt-pub-year=1999 dt-pub=19990901 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Improvements of single sheet testers for measurement of 2-D magnetic properties up to high flux density en-subtitle= kn-subtitle= en-abstract= kn-abstract=Due to structural limitation, the currently proposed apparatus based on a single sheet tester (SST) cannot measure magnetic properties along arbitrary directions (so-called 2-D magnetic properties) of silicon steel at high flux densities. In this paper, significant improvements are carried out on magnetizing windings and auxiliary yokes of a double excitation type of SST. Furthermore, crosswise overlapped H-coils are introduced so that even an ordinary single-excitation type of SST can be applicable to the measurements of 2-D properties. It is demonstrated that 2-D magnetization property up to 1.9 T can be measured by using the newly developed SST's
en-copyright= kn-copyright= en-aut-name=NakanoMasanori en-aut-sei=Nakano en-aut-mei=Masanori kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=NishimotoHidehiko en-aut-sei=Nishimoto en-aut-mei=Hidehiko kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=FujiwaraKoji en-aut-sei=Fujiwara en-aut-mei=Koji kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=TakahashiNorio en-aut-sei=Takahashi en-aut-mei=Norio kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= affil-num=1 en-affil= kn-affil=Okayama University affil-num=2 en-affil= kn-affil=Okayama University affil-num=3 en-affil= kn-affil=Okayama University affil-num=4 en-affil= kn-affil=Okayama University en-keyword=coils kn-keyword=coils en-keyword=eddy current losses kn-keyword=eddy current losses en-keyword=ferromagnetic materials kn-keyword=ferromagnetic materials en-keyword=iron alloys kn-keyword=iron alloys en-keyword=laminations kn-keyword=laminations en-keyword=magnetic circuits kn-keyword=magnetic circuits en-keyword=magnetic flux kn-keyword=magnetic flux en-keyword=magnetic variables measurement kn-keyword=magnetic variables measurement en-keyword=magnetisation kn-keyword=magnetisation en-keyword=silicon alloys kn-keyword=silicon alloys en-keyword=test equipment kn-keyword=test equipment en-keyword=windings kn-keyword=windings END start-ver=1.4 cd-journal=joma no-vol=38 cd-vols= no-issue=5 article-no= start-page=2352 end-page=2354 dt-received= dt-revised= dt-accepted= dt-pub-year=2002 dt-pub=20020517 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Effect of eddy current in shielding plate and electron gun on flux distribution in CRT en-subtitle= kn-subtitle= en-abstract= kn-abstract=The eddy current induced in an inner magnetic shield (IMS) and an electron gun affect the flux distribution of a cathode ray tube, causing a possible degrade of picture quality. In this paper, the effect of the distance between an IMS and a deflection coil on the eddy-current distribution is examined. The eddy current induced in the electron gun, when the coils for velocity modulation (VM) are set near the electron gun, is also analyzed. It is found that the variation of flux distribution is mainly affected by the shape of VM coil.
en-copyright= kn-copyright= en-aut-name=TakahashiNorio en-aut-sei=Takahashi en-aut-mei=Norio kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=OchiYoshiyuki en-aut-sei=Ochi en-aut-mei=Yoshiyuki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=NakanoKatsumi en-aut-sei=Nakano en-aut-mei=Katsumi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=ShimadaKoji en-aut-sei=Shimada en-aut-mei=Koji kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= en-aut-name=WakasonoHiromi en-aut-sei=Wakasono en-aut-mei=Hiromi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=5 ORCID= affil-num=1 en-affil= kn-affil=Okayama University affil-num=2 en-affil= kn-affil=Okayama University affil-num=3 en-affil= kn-affil=Okayama University affil-num=4 en-affil= kn-affil=Matsushita Electric Industrial Corporation, Limited affil-num=5 en-affil= kn-affil=Matsushita Electric Industrial Corporation, Limited en-keyword=cathode-ray tubes kn-keyword=cathode-ray tubes en-keyword=eddy currents kn-keyword=eddy currents en-keyword=electron guns kn-keyword=electron guns en-keyword=magnetic flux kn-keyword=magnetic flux en-keyword=magnetic shielding kn-keyword=magnetic shielding END start-ver=1.4 cd-journal=joma no-vol=39 cd-vols= no-issue=3 article-no= start-page=1527 end-page=1530 dt-received= dt-revised= dt-accepted= dt-pub-year=2003 dt-pub=20035 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Study on problems in detecting plural cracks by alternating flux leakage testing using 3D nonlinear eddy current analysis en-subtitle= kn-subtitle= en-abstract= kn-abstract=The alternating magnetic flux leakage testing is used for the detection of cracks in a steel plate. A new technique of how to detect plural cracks, which are located at a very short distance from each other, using the parallel (x-) component of the leakage flux density is proposed. The behavior of leakage flux is examined using a three-dimensional edge-based hexahedral finite-element method. The effects of dimensions of search coils and cracks on the detection accuracy are illustrated.
en-copyright= kn-copyright= en-aut-name=GotohYuji en-aut-sei=Gotoh en-aut-mei=Yuji kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=TakahashiNorio en-aut-sei=Takahashi en-aut-mei=Norio kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= affil-num=1 en-affil= kn-affil=Chugoku Polytechnic College affil-num=2 en-affil= kn-affil=Okayama University en-keyword=coils kn-keyword=coils en-keyword=crack detection kn-keyword=crack detection en-keyword=eddy current testing kn-keyword=eddy current testing en-keyword=finite element analysis kn-keyword=finite element analysis en-keyword=magnetic flux kn-keyword=magnetic flux en-keyword=magnetic leakage kn-keyword=magnetic leakage END start-ver=1.4 cd-journal=joma no-vol=35 cd-vols= no-issue=5 article-no= start-page=3956 end-page=3958 dt-received= dt-revised= dt-accepted= dt-pub-year=1999 dt-pub=19990305 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Single sheet tester having open magnetic path for measurement of magnetostriction of electrical steel sheet en-subtitle= kn-subtitle= en-abstract= kn-abstract=A single sheet tester having closed magnetic path (a closed type of SST) has a problem that measurement accuracy of magnetostriction is considerably affected by electromagnetic force between specimen and yoke. Therefore, an open type has been developed. In order to get uniform flux distribution in a sufficiently large region, a compensating magnetizing winding is installed, and a method of waveform control is investigated, in which applied voltages to main and compensating windings are adjusted individually. The effectiveness of the newly developed open type is demonstrated by measuring magnetostrictions of thin amorphous sheet as well as highly grain-oriented silicon steel sheet
en-copyright= kn-copyright= en-aut-name=NakaseTomoya en-aut-sei=Nakase en-aut-mei=Tomoya kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=NakanoMasanori en-aut-sei=Nakano en-aut-mei=Masanori kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=FujiwaraKoji en-aut-sei=Fujiwara en-aut-mei=Koji kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=TakahashiNorio en-aut-sei=Takahashi en-aut-mei=Norio kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= affil-num=1 en-affil= kn-affil=Okayama University affil-num=2 en-affil= kn-affil=Okayama University affil-num=3 en-affil= kn-affil=Okayama University affil-num=4 en-affil= kn-affil=Okayama University en-keyword=amorphous magnetic materials kn-keyword=amorphous magnetic materials en-keyword=ferromagnetic materials kn-keyword=ferromagnetic materials en-keyword=iron alloys kn-keyword=iron alloys en-keyword=magnetic flux kn-keyword=magnetic flux en-keyword=magnetic kn-keyword=magnetic en-keyword=variables measurement kn-keyword=variables measurement en-keyword=magnetostriction kn-keyword=magnetostriction en-keyword=silicon alloys kn-keyword=silicon alloys en-keyword=steel kn-keyword=steel END start-ver=1.4 cd-journal=joma no-vol=42 cd-vols= no-issue=2 article-no= start-page=292 end-page=294 dt-received= dt-revised= dt-accepted= dt-pub-year=2006 dt-pub=20062 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Improvement of zone control induction heating equipment for high-speed processing of semiconductor devices en-subtitle= kn-subtitle= en-abstract= kn-abstract=In order to process a semiconductor device of high quality, uniform heating is necessary, but it is not easy to heat uniformly with conventional induction heating equipment. To solve this problem, zone control induction heating equipment has been jointly developed. In this paper, we examine the effect of dividing an induction heater into several small coil groups having different current and frequency, using the finite-element method. We describe the heating characteristics of the zone control coil groups and show that nearly uniform heating is possible by controlling both current and frequency.
en-copyright= kn-copyright= en-aut-name=MiyagiDaisuke en-aut-sei=Miyagi en-aut-mei=Daisuke kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=SaitouAisya en-aut-sei=Saitou en-aut-mei=Aisya kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=TakahashiNorio en-aut-sei=Takahashi en-aut-mei=Norio kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=UchidaNaoki en-aut-sei=Uchida en-aut-mei=Naoki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= en-aut-name=OzakiKazuhiro en-aut-sei=Ozaki en-aut-mei=Kazuhiro kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=5 ORCID= affil-num=1 en-affil= kn-affil=Okayama University affil-num=2 en-affil= kn-affil=Okayama University affil-num=3 en-affil= kn-affil=Okayama University affil-num=4 en-affil= kn-affil=Mitsui Engineering & Shipbuilding Company Limited affil-num=5 en-affil= kn-affil=Mitsui Engineering & Shipbuilding Company, Limited en-keyword=Induction heating kn-keyword=Induction heating en-keyword=uniform heating kn-keyword=uniform heating en-keyword=zone control kn-keyword=zone control END start-ver=1.4 cd-journal=joma no-vol=42 cd-vols= no-issue=4 article-no= start-page=1087 end-page=1090 dt-received= dt-revised= dt-accepted= dt-pub-year=2006 dt-pub=20064 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=3-D topology optimization of single-pole-type head by using design sensitivity analysis en-subtitle= kn-subtitle= en-abstract= kn-abstract=It is necessary to develop a write head having a large recording field and small stray field in adjacent tracks and adjacent bits in perpendicular magnetic recording systems. In this paper, a practical three-dimensional topology optimization technique combined with the edge-based finite-element method is proposed. A technique for obtaining a smooth topology is also shown. The optimization of single-pole-type head having a magnetic shield is performed by using the topology optimization technique so that the leakage flux in the adjacent bit can be reduced. A useful shape of the magnetic shield obtained by the proposed technique is illustrated.
en-copyright= kn-copyright= en-aut-name=OkamotoYoshifumi en-aut-sei=Okamoto en-aut-mei=Yoshifumi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=AkiyamaKoji en-aut-sei=Akiyama en-aut-mei=Koji kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=TakahashiNorio en-aut-sei=Takahashi en-aut-mei=Norio kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= affil-num=1 en-affil= kn-affil=Okayama University affil-num=2 en-affil= kn-affil=Okayama University affil-num=3 en-affil= kn-affil=Okayama University en-keyword=ON/OFF method kn-keyword=ON/OFF method en-keyword=sensitivity analysis kn-keyword=sensitivity analysis en-keyword=single-pole-type-head kn-keyword=single-pole-type-head en-keyword=three-dimensional (3-D) topology optimization kn-keyword=three-dimensional (3-D) topology optimization END start-ver=1.4 cd-journal=joma no-vol=18 cd-vols= no-issue=1 article-no= start-page=1 end-page=31 dt-received= dt-revised= dt-accepted= dt-pub-year=1984 dt-pub=19840330 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Finite Element Analysis of Transformer Cores en-subtitle= kn-subtitle= en-abstract= kn-abstract=The quantitative analysis of localized flux distributions in transformer cores has become easy through the progress of numerical field calculations. In this paper, the effects of core constructions, joint configurations, magnetizing characteristics of materials on the flux distributions are examined using newly developed techniques such as a gap element, an approximate method for solving three-dimensional magnetic fields, the time periodicity finite element method, an efficient technique for treating hysteresis characteristics and so on. A method for the optimum design of transformer cores is also discussed. Main results obtained can be summarized as follows: (a) The building factor of the core made of higely-oriented silicon steel is larger than that of the conventional core. (b) The iron losses at joints are much affected by overlap lengths, number of laminations per stagger layer and a small irregularity of the arrangement of sheets. (c) It is clarified that examinations of the optimum construction of core and the most desirable magnetic characteristics of core material are possible using the finite element method. en-copyright= kn-copyright= en-aut-name= en-aut-sei= en-aut-mei= kn-aut-name=NakataTakayoshi kn-aut-sei=Nakata kn-aut-mei=Takayoshi aut-affil-num=1 ORCID= en-aut-name= en-aut-sei= en-aut-mei= kn-aut-name=TakahashiNorio kn-aut-sei=Takahashi kn-aut-mei=Norio aut-affil-num=2 ORCID= affil-num=1 en-affil= kn-affil=Department of Electrical Engineering affil-num=2 en-affil= kn-affil=Department of Electrical Engineering END start-ver=1.4 cd-journal=joma no-vol=14 cd-vols= no-issue=1 article-no= start-page=15 end-page=28 dt-received= dt-revised= dt-accepted= dt-pub-year=1979 dt-pub=19791201 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Iron Losses of Silicon Steel due to Rotating Fluxes (Inclined Rotating Flux and Distorted One) en-subtitle= kn-subtitle= en-abstract= kn-abstract=Characteristics of iron losses in silicon steel due to inclined rotating fluxes and distorted ones are described. Iron losses due to rotating fluxes have been measured at various conditions for grain-oriented and non-oriented silicon steels by using an improved thermistor-bridge method. Loss measurements indicate that the iron loss due to the inclined rotating flux is greater than that due to the non-inclined one. However, the iron loss due to the distorted rotating flux is not always greater than that due to the non-distorted one. en-copyright= kn-copyright= en-aut-name= en-aut-sei= en-aut-mei= kn-aut-name=IshiharaYoshiyuki kn-aut-sei=Ishihara kn-aut-mei=Yoshiyuki aut-affil-num=1 ORCID= en-aut-name= en-aut-sei= en-aut-mei= kn-aut-name=TakahashiNorio kn-aut-sei=Takahashi kn-aut-mei=Norio aut-affil-num=2 ORCID= affil-num=1 en-affil= kn-affil=Department of Electrical Engineering affil-num=2 en-affil= kn-affil=Department of Electrical Engineering END