result 48614 件
| JaLCDOI | 10.18926/fest/11495 |
|---|---|
| Title Alternative | A note on the effect of quadratic term on final pattern in Turing model |
| FullText URL | 008_019_022.pdf |
| Author | Yamauchi, Ken-ichi| Kajiwara, Tsuyoshi| |
| Abstract | The effect of the quadratic term on the final pattern in Turing model is disscussed numerically. Turing models are non linear reaction diffusion equations. Linear analysis for wave length is very useful to find evolving waves. But when a quadratic term appear in the equation, an initial wave can disappears and changes drastically to a spot which is independent of linear analysis. |
| Keywords | Turing instability Reaction Diffusion equation Quadratic term |
| Publication Title | 岡山大学環境理工学部研究報告 |
| Published Date | 2003-03 |
| Volume | volume8 |
| Issue | issue1 |
| Start Page | 19 |
| End Page | 22 |
| ISSN | 1341-9099 |
| language | Japanese |
| File Version | publisher |
| NAID | 120002313586 |
| Author | So, Jun-ichi| |
|---|---|
| Published Date | 2007-03-23 |
| Publication Title | |
| Content Type | Thesis or Dissertation |
| Author | Ohtani, Yu| |
|---|---|
| Published Date | 2007-03-23 |
| Publication Title | |
| Content Type | Thesis or Dissertation |
| JaLCDOI | 10.18926/fest/11492 |
|---|---|
| Title Alternative | Development of a statistical survey analysis system using Internet |
| FullText URL | 008_009_017.pdf |
| Author | Fujino, Tomokazu| Tarumi, Tomoyuki| |
| Abstract | We constructed the online analysis system of the Okayama Activity Area Survey in place since 1979. This is one way to solve the problem in case of releasing the result of a statistical survey. In this paper, we treat the detail of the structure of the system. |
| Keywords | microdata statistical disclosure control web based system online database |
| Publication Title | 岡山大学環境理工学部研究報告 |
| Published Date | 2003-03 |
| Volume | volume8 |
| Issue | issue1 |
| Start Page | 9 |
| End Page | 17 |
| ISSN | 1341-9099 |
| language | Japanese |
| File Version | publisher |
| NAID | 120002314053 |
| Author | Fujimoto, Tsuyoshi| |
|---|---|
| Published Date | 2007-03-23 |
| Publication Title | |
| Content Type | Thesis or Dissertation |
| Author | Suemaru, Shunji| |
|---|---|
| Published Date | 2007-03-23 |
| Publication Title | |
| Content Type | Thesis or Dissertation |
| JaLCDOI | 10.18926/fest/11489 |
|---|---|
| Title Alternative | Considering variable selection criteria in correspondence analysis |
| FullText URL | 010_049_056.pdf |
| Author | Mori, Yuichi| Du, Xiao Dong| Iizuka, Masaya| |
| Abstract | Ordinary goodness of fit criteria in correspondence analysis are considered as variable selection criteria in case correspondence analysis which is one of multivariate methods without external variables can be applied. The goodness of fit criteria focused here are proportion of cumulative eigenvalues, proportion of cumulative squared-eigenvalues and proportion of cumulative off-diagonal fitness. Each criterion is applied to a couple of real data sets and evaluated with interpretation of the selection process and result (selected subset of variables). Four selection procedures such as backward elimination and forward-backward selection are also performed to compare with each other as well as with all possible selection procedure. These results illustrate that the criteria can be used as selection criteria to select a subset of variables in correspondence analysis and to assess categorical items (questions) in a survey (questionnaire). |
| Publication Title | 岡山大学環境理工学部研究報告 |
| Published Date | 2005-02-28 |
| Volume | volume10 |
| Issue | issue1 |
| Start Page | 49 |
| End Page | 56 |
| ISSN | 1341-9099 |
| language | Japanese |
| File Version | publisher |
| NAID | 120002313834 |
| Author | Koyama, Fumihiko| |
|---|---|
| Published Date | 2007-03-23 |
| Publication Title | |
| Content Type | Thesis or Dissertation |
| JaLCDOI | 10.18926/fest/11487 |
|---|---|
| FullText URL | 008_001_007.pdf |
| Author | Tsunekuni Yasuhiro| Ohga Yukio| Ishikawa, Hirofumi| |
| Abstract | In 1990s, there were rapid increases in the number of HIV epidemics and AIDS cases in Thailand, Southeast Asia. In particular the risk of HIV infection was very high among female prostitutes who played a large part in the transmission of HIV infection. We formulated a mathematical model for the transmission of HIV in prostitutes. We carried out the model simulations to analyze the incipient spread of HIV infection and the effect of AIDS prevention methods in prostitutes. The simulation of our model indicates that even if the effect of AIDS prevention methods such as the recommendation of condom use for commercial sex workers would block the transmission at rate by 70%, the elimination of the HIV epidemic is still beyond attainment. |
| Keywords | AIDS HIV prostitution Thailand transmission model |
| Publication Title | 岡山大学環境理工学部研究報告 |
| Published Date | 2003-03 |
| Volume | volume8 |
| Issue | issue1 |
| Start Page | 1 |
| End Page | 7 |
| ISSN | 1341-9099 |
| language | English |
| File Version | publisher |
| NAID | 120002314019 |
| JaLCDOI | 10.18926/fest/11486 |
|---|---|
| Title Alternative | Variable Selection Method using Apriori Algorithm on Contingency Table |
| FullText URL | 010_041_047.pdf |
| Author | Ohno, Manabu| Tarumi, Tomoyuki| |
| Abstract | We proposed a new applied method for induction of variable selection on contingency table. This method is the application of Apriori algorithm on variable selection of contigency table with iteraction. We assume that variables are dichotomous variable. We confirm that can be select variable, when minimun support is low level by using AIC on variable selection criterion. |
| Keywords | Apriori Algorithm Varable Selection Contigency Table Interaction |
| Publication Title | 岡山大学環境理工学部研究報告 |
| Published Date | 2005-02-28 |
| Volume | volume10 |
| Issue | issue1 |
| Start Page | 41 |
| End Page | 47 |
| ISSN | 1341-9099 |
| language | Japanese |
| File Version | publisher |
| NAID | 120002313938 |
| JaLCDOI | 10.18926/fest/11485 |
|---|---|
| FullText URL | 010_029_039.pdf |
| Author | Ju Xian Meng| |
| Abstract | The generalized Grothendieck-Witt ring of nonsingular Hermitian forms with positioning map is the cartesian product of the ordinary Grothendieck-Witt ring of nonsingular Hermitian forms and a map ring. We study the generalized Grothendieck-Witt ring by computing the map ring. |
| Keywords | Grothendieck Witt ring orbit GAP |
| Publication Title | 岡山大学環境理工学部研究報告 |
| Published Date | 2005-02-28 |
| Volume | volume10 |
| Issue | issue1 |
| Start Page | 29 |
| End Page | 39 |
| ISSN | 1341-9099 |
| language | English |
| File Version | publisher |
| NAID | 120002313655 |
| JaLCDOI | 10.18926/fest/11484 |
|---|---|
| FullText URL | 010_023_028.pdf |
| Author | Watanabe, Masaji| Liu Ying| Wang Ming Jun| |
| Abstract | Topographical data of Kojima Lake have been updated by applying data obtained after dredging. Together with tide level of Kojima Bay and water levels of Kurashiki River and Sasagase river, the information was incorporated in computational analysis of unsteady flows generated in the lake when the water was discharged from Kojima Lake to Kojima, Bay. A finite element method was applied to equations governing unsteady flows, and the transition of discharge was obtained. |
| Keywords | water environment finite element method numerical simulation |
| Publication Title | 岡山大学環境理工学部研究報告 |
| Published Date | 2005-02-28 |
| Volume | volume10 |
| Issue | issue1 |
| Start Page | 23 |
| End Page | 28 |
| ISSN | 1341-9099 |
| language | English |
| File Version | publisher |
| NAID | 120002313649 |
| JaLCDOI | 10.18926/fest/11483 |
|---|---|
| Title Alternative | On Persistence in Dynamical Systems (Review) |
| FullText URL | 010_013_021.pdf |
| Author | Sasaki, Toru| Kajiwara, Tsuyoshi| |
| Abstract | Some important results on persistence are reviewed. These results concern the behavior of the orbits approaching the boundary. The orbits restrict the flow on the boundary, if one of them approaches more than one invariant set. A typical example is a model for cyclic competition, where the heteroclinic cycle can be the ω-limit set. Thus the persistence can be reduced to some conditions on the boundary flow. |
| Keywords | persistence ordinary differential equation dynamical system |
| Publication Title | 岡山大学環境理工学部研究報告 |
| Published Date | 2005-02-28 |
| Volume | volume10 |
| Issue | issue1 |
| Start Page | 13 |
| End Page | 21 |
| ISSN | 1341-9099 |
| language | Japanese |
| File Version | publisher |
| NAID | 120002313932 |
| JaLCDOI | 10.18926/fest/11482 |
|---|---|
| FullText URL | 011_093_097.pdf |
| Author | Kimura, Kunio| Yamazaki, Shinichi| Cassidy Patrick E.| Fitch John W| Venumbaka Sreenu R.| |
| Abstract | Fluorine-containing poly(ether ketone)s was synthesized by the nucleophilic aromatic substitution reaction of 2,2-bis(4-hydroxyphenyl)-1,1,1,3,3,3-hexafluoropropane and 4,4'-bis(2,3,4,5,6-pentafluorobenzoyl) diphenyl ether in super-critical CO(2). Polymerizations were carried out at 80℃ for 6 hours under 5000 psi of CO(2) pressure, which was super-critical phase. Polymerization concentration was 0.5 g of polymer in 10 - 12 mL of CO(2). The polymer was not obtained in CO(2) due to the insolubility of both the potassium bisphenoxide and the polymer into CO(2). However, the polymer was formed by an addition of DMAc and NMP in CO(2), even though molecular weight was not so high. Very small amount of co-solvents which were immiscible with CO(2) was effective, and it was 1/20 - 1/25 amount of the solvent used in the conventional poly(ether ketone) synthesis. The polymerization mechanism was also discussed. |
| Keywords | super-critical carbon dioxide plastics high performance environmentally benign |
| Publication Title | 岡山大学環境理工学部研究報告 |
| Published Date | 2006-03-15 |
| Volume | volume11 |
| Issue | issue1 |
| Start Page | 93 |
| End Page | 97 |
| ISSN | 1341-9099 |
| language | English |
| File Version | publisher |
| NAID | 120002313564 |
| JaLCDOI | 10.18926/fest/11481 |
|---|---|
| FullText URL | 010_009_011.pdf |
| Author | Kajiwara, Tsuyoshi| Sasaki, Toru| |
| Abstract | An elementary proof of permanence for a simple mathematical model proposed by Nowak and Bangham. In many papers, permanence property is proved by theorems established by the general theory of dynamical system. In this paper, we present an elementary proof only using differential inequalities and the theory of linear differential equations with constant coefficients. |
| Keywords | Permanence dynamical system pathogen |
| Publication Title | 岡山大学環境理工学部研究報告 |
| Published Date | 2005-02-28 |
| Volume | volume10 |
| Issue | issue1 |
| Start Page | 9 |
| End Page | 11 |
| ISSN | 1341-9099 |
| language | English |
| File Version | publisher |
| NAID | 120002313596 |
| JaLCDOI | 10.18926/fest/11480 |
|---|---|
| Title Alternative | A Case Study on How to Teach English at University Adopting TOEIC (2) -Evaluation after three years- |
| FullText URL | 009_167_178.pdf |
| Author | Morokawa, Shigetake| Ogino, Masaru| Kanzaki, Ken-ichi| |
| Abstract | Three years ago, we wrote an essay about our new English-teaching program that adopted TOEIC. We gave out questionnaires to the students with questions ranging from what they thought of English in general to what they thought of our new program. In the essay, we discussed some of the results. Even though students' response was relatively positive in this initial survey, we wrote in our conclusion that we would like to renew and reform our classes. Receiving feedback from students periodically would help us improve their English ability. In order to see the change of students' attitude toward English and also toward our program, we conducted the same research last February. This time the results were not as favorable. For example, the number of students who thought their English ability was poor increased and those who showed a positive attitude toward our program decreased. We discussed and wrote what we learned from those results. We raised the question whether there was a gap between what we tried to teach to the students and what they wanted from us. Possible reasons were discussed on why we could not succeed in stimulating the students into studying English further. In April 2003 Okayama University started a new English curriculum, in which the classes for proficiency tests including TOEIC were opened. Similar classes have been set at many other universities. This survey will be a help to the further development of English education adopting TOEIC. |
| Keywords | TESOL TOEIC questionnaires team teaching |
| Publication Title | 岡山大学環境理工学部研究報告 |
| Published Date | 2004-02-27 |
| Volume | volume9 |
| Issue | issue1 |
| Start Page | 167 |
| End Page | 178 |
| ISSN | 1341-9099 |
| language | Japanese |
| File Version | publisher |
| NAID | 120002313460 |
| JaLCDOI | 10.18926/fest/11479 |
|---|---|
| FullText URL | 010_001_007.pdf |
| Author | Wang Xiao Dong| Ishikawa, Hirofumi| |
| Abstract | The one-way hash function plays an important role in digital signatures and message authentication from the viewpoint of security. No effective attacking method has been discovered to the algorithm of hash function standard. In this study, we tried to attack SHA-256 in encryption mode using linear and differential cryptanalysis to solve a private key. We deduced that an estimate of the private key would require huge known and chosen plaintexts in both linear and differential cryptanalysis, and that it would be difficult to decipher SHA-256 in view of the required computation. |
| Keywords | differential cryptanalysis encryption mode hash function linear cryptanalysis SHA-256 |
| Publication Title | 岡山大学環境理工学部研究報告 |
| Published Date | 2005-02-28 |
| Volume | volume10 |
| Issue | issue1 |
| Start Page | 1 |
| End Page | 7 |
| ISSN | 1341-9099 |
| language | Japanese |
| File Version | publisher |
| NAID | 120002313630 |
| JaLCDOI | 10.18926/fest/11478 |
|---|---|
| FullText URL | 009_163_166.pdf |
| Author | Nakatsu Shogo| Tsuboi, Sadao| |
| Abstract | Diels-Alder reactions of 5,5,5-trichloro-3-penten-2-one and ethyl 4,4,4-trichloro-2-butenoate with cyclopentadiene in the presence of a chiral Lewis acid gave exo-2-acetyl-endo-3-trichloromethyl-bicyclo[2.2.1]hept-5-ene and exo-2-ethoxycarbonyl-endo-3-trichloromethylbicyclo[2.2.1]hept-5-ene with 40% and 7% e.e., respectively. |
| Keywords | asymmetric reaction Diels-Alder reaction asymmetric Diels-Alder reaction chiral Lewis acid trichloromethy group |
| Publication Title | 岡山大学環境理工学部研究報告 |
| Published Date | 2004-02-27 |
| Volume | volume9 |
| Issue | issue1 |
| Start Page | 163 |
| End Page | 166 |
| ISSN | 1341-9099 |
| language | English |
| File Version | publisher |
| NAID | 120002313377 |
| JaLCDOI | 10.18926/fest/11477 |
|---|---|
| Title Alternative | Efficient Chain Extension Reaction of Poly (butylene terephthalate) by using Crystallization |
| FullText URL | 012_167_171.pdf |
| Author | Ihara, Seiji| Shiroma, Hisashi| Yamazaki, Shinichi| Kimura, Kunio| |
| Abstract | Plastics are quite important materials for not only industrial usages but also our daily life. Many plastics are difficult to reuse because they are susceptible to UV, hydrolysis and so on leading to the reduction of molecular weight. Among them, poly (butylenes terephthalate) (PBT) is a valuable materials prepared by polycondensation reaction, and PBT has the same limitation to reuse. Hence, efficient chain extension reaction for recovered PBT has been needed to improve the properties damaged by chain scission. In this study, new chain extension reaction had been examined by using crystallization as pre-treatment. Isothermal crystallization at 161℃ concentrated the chain end-groups on the surface of the crystals, and chain extension reaction at 210℃, which was lower than the melting temperature of PBT, enhanced the molecular weight significantly compared with the reaction over the melting temperature. It concluded that the pre-treatment of crystallization was favorable for the efficient chain extension reaction and this result provided the new technology for the effective reuse of the plastics. |
| Keywords | Polyester material recycle crystallization chain extension reaction |
| Publication Title | 岡山大学環境理工学部研究報告 |
| Published Date | 2007-03-15 |
| Volume | volume12 |
| Issue | issue1 |
| Start Page | 167 |
| End Page | 171 |
| ISSN | 1341-9099 |
| language | Japanese |
| File Version | publisher |
| NAID | 120002314029 |
| JaLCDOI | 10.18926/fest/11476 |
|---|---|
| Title Alternative | Evaluation of Surface State of Ceramic Particles Suspended in Aqueous Solution by Potentiometric Titration Method |
| FullText URL | 009_153_162.pdf |
| Author | Miura, Yoshinari| Nanba, Tokuro| Shinoda, Masakatsu| |
| Abstract | Surface states of ceramic particles such as SiO(2), Al(2)O(3), Si(3)N(4) and so on suspended in aqueous alkaline solutions were successfully and easily determined by a potentiometric titration method. Isoelctric point, iep and excess surface charge density were classified and evaluated for many ceramic particles from the view points of aggregation and dispersion of particles and solubility in aqueous solution. |
| Keywords | potentiometric titration method isoelctric point excess surface charge density ceramic particle suspension aqueous solution |
| Publication Title | 岡山大学環境理工学部研究報告 |
| Published Date | 2004-02-27 |
| Volume | volume9 |
| Issue | issue1 |
| Start Page | 153 |
| End Page | 162 |
| ISSN | 1341-9099 |
| language | Japanese |
| File Version | publisher |
| NAID | 120002313753 |
