岡山大学工学部
Acta Medica Okayama
0475-0071
21
1
1986
A Computer Program of Assembly Line Balancing Considering the Performance Rate of Each Work Station
17
30
EN
Assembly line balancing is to assign work elements to serial work stations so as to make the work content at each station as close as possible to one limiting cycle time or pitch time, i.e., an upper time limit over every station. Until now, it is usually assumed that the
performance rates of work stations are constant. But in
practice the performance abilities of workers, machines or robots are varied by their own working conditions. Then the actual station times are different from standard ones, and consequently the line balance may diminish in many cases. Therefore in this paper, we propose an improved
balancing method, in which work elements can be assigned to the work station having the upper time limit changed by its performance rate or ability. Further we develop the computer program of the proposed method and provide an illustrative problem and computational results. In an application of our method to the practical problems, it is shown that the actual efficiency of the production line becomes near that planned.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
20
1
1985
On the Adsorptive Force in the Sucking Grasp as the Contact Surface was flat.
21
33
EN
The sucking grasp, for example, the silicon or the rubber sucker has been used widely to handle the parts in various stages of the automated process. But in order to use the sucking grasp more widely, it is necessary to develop the other type of sucking unit. In this paper, we examined the distribution of the vacuum pressure in the contact surface and estimated the adsorptive force from the vacuum pressure, the area of the contact surface, the area or the number of sucking holes, and a gap or a roughness of surface under the contact condition that the flat surface of the sucking unit sucked up the flat surface of an object. The vacuum pressure in the contact surface decreased exponentially, as the distance from the edge of the sucking hole became long. And the adsorptive force was estimated from the equation Y=1.147.P.S.(S/M)(-0.6) in the case of one sucking hole. It is necessary to consider the interaction between two sucking holes which were only separated by a very close distance to estimate the adsorptive force in case of many sucking holes. The adsorptive force became weak, as the gap
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
15
2
1981
Computer Program of Line Balancing under the Multiple Workers in Each Station (LBMW)
21
28
EN
An assembly line with no paralleling of work elements and work stations is called a serial line. The cycle time of the serial line must be at least equal to the maximum work element time. To lower the cycle time beyond the limit and increase the production rate, one may permit the paralleling of work elements or work stations. So in this paper we propose the parallel assignment method for achieving a higher production rate. In this method, work elements are assigned to work stations under the multiple upper time limits which are the products of the various numbers of workers and the limiting cycle time. Further we develop the computer program of the proposed method and provide an illustrative problem and computational results.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
18
1
1984
The Apparatus to Measure the Multi-point Critical Flicker Fusion Frequency (MCFF)
33
42
EN
In this paper, we mentioned the apparatus developed to measure CFFs at the various point of the retina. Eleven CFFs measured at the central retina of both eyes (used usually} simultaneously, at the central retina of each eye separately, and at four points of the peripheral retina of each eye were analyzed together and referred to as the multi-point critical flicker fusion frequency (MCFF) . MCFF can be used to estimate the level of cortex activity, since the temporal and nasal parts of each eye are connected to different visual cortexes through the optic nerve. As the apparatus used to measure the MCFF was controlled by a micro-computer, the order of measurements and the calculation were done automatically.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
14
2
1980
The Analysis of Vocational Aptitude Changing with Age
1
12
EN
The assumption that vocational aptitude changed with age and with the kind of occupation was examined from the tendency of the fitted curve for the score of the aptitude test. 9 vocational aptitudes were measured by the general vocational aptitude test by Japan Labor Ministry. Subjects were 382 male workers (design engineers, turners, welders, can manufacturing workers, and crane operators) of from 20 to 59 years old, and 348 male and female students (junior high school, vocational school, and university) of from 15 to 19 years old. The design engineers' aptitudes advanced along the quadratic curve until 31 years old, but almost all the aptitudes of the other workers fell along the linear curve with age. The design engineers preserved various aptitudes until 52 years old, the turners 44, and the welders, the can manufacturing workers, and the crane
operators 37. The students' aptitudes were equal to those of the workers of from 15 to 25 years old. The workers preserved Spatial aptitude and Numerical aptitude until 45 years old. This could be said in all the occupations here.
Further it was made clear from the micromotion study that the influence of age was caused by therbligs
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
13
1979
Computer Program of Line Balancing, Regarding Efficiency and Number of Stations as Variables
83
93
EN
To assign work elements to the work stations in an assembly or manufacturing line, various computer programs have been developed and used. And it does that the number of stations or the cycle time is even given. But in practice it is desirable to obtain the assignment which shows the highest efficiency of line balancing under all possible combinations of the number of stations and the cycle time. Therefore we propose a computer program of the assignment method in which the efficiency of line balancing, Ebb and the number of stations, NN are regarded as variables. In this method the minimum value (EEb) of efficiency and the constant term (d) by which Ebb is reduced are given previously. And for any COmbination of Ebb (EE<Ebb<lOO) and NN (l<NN<Nm : Nm calculated from EEb), the work elements are assigned to work stations, the precedence restrictions being used. Ebb is reduced by d from the ideal value (100) until the assignment to NN is obtained. The efficiency of
the obtained assignment, Ebo is calculated. As Ebb<Ebo<Ebb+d, the calculation is continued until the assignment to NN, which shows the maximum efficiency, is obtained. In this process NN varies from Nm to 1 by 1 by 1.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
13
1979
Computer Program for Numerical Evaluation of the work
65
81
EN
We try to evaluate the manual work numerically from a point of view of the homogeneousness and the simultaneousness of both hands using the results of the micromotion study. The weighted coefficient and the balance index are used to evaluate the homogeneousness of both hands. And the simultaneous index is used to evaluate the simultaneous movement of both hands. It is necessary to make a program in order to use efficiently the method to calculate the indexes or the coefficients. Therefore the computer program of these methods is mentioned in this paper.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
10
2
1976
The Computer Programs of Layout Methods Based on Decision Making Theory
63
80
EN
We tried to look at the allocation techniques in plant layout from the point of view of decision making theory. And it was made clear that Laplace, Minimax and Hurwicz princilpe can be applied to the allocation techniques. The techniques based on these principles were called Laplace method, Minimax method and Hurwicz method. In this paper algorithms and computer programs of these methods were described in order to solve the layout problems effectively.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
5
1
1970
A Study of the Work Load in a Monotonous Task
27
30
EN
The work load given to workers by a monotonous task was investigated. Their load was obtained by measuring the flicker value and observing its fluctuation pattern. Each flicker fluctuation was classified into one of the three patterns. It was found that the mental load of the subject carrying out the task by himself tends to become lighter according as the speed increases, while the mental load of the subject doing the task with his companion does not show this tendency. On the other hand, the scores of the disposition tests were analyzed with regard to the flicker fluctuation pattern by using the discriminant function.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
10
1
1975
Computer Program of Forward Selection and Backward Elimination Procedure in Linear Discriminant Analysis and Test for
Differences Between Mean Values of Two Populations
17
37
EN
In multivariate analysis, the linear discriminant analysis and the test for differences between mean values of two populations are of wide application. It is not essential to increase the variables only in order to increase the degree of accuracy of discrimination or test without evaluating the effect of variables. Therefore the computer program of selection procedures of variables in these two methods is
mentioned in this paper.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
9
2
1974
Computer Program of Forward Selection and Backward Elimination Procedure in Multiple Regression Analysis
89
105
EN
Multiple regression analysis are often used to explain the relation between the dependent variable and the independent variables. In case of that it arises necessity that the important independent variables which are closely correlated with the dependent variable are selected from among all given ones. There are some selection procedures. But these procedures can't be used usefully without using
computer. Therefore two selection procedures that is Forward selection procedure and Backward elimination procedure in multiple regression analysis are programmed by Fortran Ⅳ.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
8
1
1973
Allocation Technique Using Relative Distance and Relative Volume Estimated by Statistical Procedure
15
24
EN
This paper deals with the allocation technique of the layout whose solution it takes as a little computation time as possible to obtain and which becomes as near to the optimal method as possible. In this method, the relative transport distance of each location and the relative transport volume of each department are calculated from the distance matrix and the volume matriX by the statistical procedures. And allocating departments to locations is determined by one to one correspondence between the arranged relative transport distances and the arranged relative transport volumes. This method was called the allocation technique by the statistical procedure ( ATSP in short ).
This method doesn't use the heuristic algorithm.
Therefore the calculation time can be reduced much in
comparison with any other methods. As the algorithm
of ATSP method is very simple, the sub-optimal layout
can be determined easily by using the desk-calculator
in cases of any layout problems.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
7
1
1972
On a Study of the Empirical Formula to Explain the Work Amount
1
9
EN
This paper deals with the empirical formula to explain the
work amount curve of a worker during a work. The empirical
formula yt = at(b) + c was used to explain this phenomenon until now. This formula has been used mainly to approximate to the monotonous trend of the work amount curve. But it was made clear that if the work amount curve showed the polynomial trend, it could not be done so. Then the authors attempt to establish the empirical formula yt = a/{exp(Σb(i)t(i))-l} + c, which was the general form of the logistic curve in order to explain not only the monotonous trend but also the polynomial trend of the work amount curve. And it was made clear from the results of the approximation that this formula was the one of the most usuful formula in order to explain the work amount curve.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
4
1
1969
On a Relation between the Flicker Value and the Vibration
35
38
EN
Insuring fast and precise human operation is one of the engineering requirements in the developing civilization.
Some man-machine system, when any operator is exposed himself to some kind of vibration, he may not perform his operation in good conditions. Then one of the interferring factors, there is a fatigue caused by vibration. In this study, subjects sit on the chair which was set on the vibration table, and were shaken vertically for some given times, then were measured whether the fatigue occured or not by flicker friction tester. Flicker patterns were analyzed according to each vibration-condition, then the authors knew that the fatigue was occured by vibration.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
4
1
1969
On a Relation between the Flicker value and the Working Condition
31
34
EN
The appropriate disposition of the worker improves the ability of the worker and the efficiency of the labor and further decreases the rate of inferior goods and the rate of accidents. In previous paper, the variation of the flicker value, the trend of the miss frequency and the relation between them under the condition which has one surveillance point and one back-ground condition are analyzed. In this paper, the surveillance point is increased to two points and the back ground condition also two in order to examine which condition influences strongly to the flicker value in the working time. It was found that the variation of the flicker value is strongly connected with the qualification, the number of the surveillance and its miss-frequency.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
6
1
1971
On the Trial Production of the Equipment Measuring Many
Subjects' Critical Flicker Fusion Frequency at the Same Time
13
19
EN
The equipment measuring the critical flicker fusion frequency (CFF) is made in order to measure many subjects' CFF at the same time. This equipment is defined the multi-flicker. The equipment measuring CFF, used until now is defined the mono-flicker. It is analysed what factors influence CFF strongly. Then it is made clear that CFF value measured by the multi-f1icker can be used to show the brain weariness as well as that of the mono-flicker, and the vigual angle and the intensity of illumination in the room influence CFF value strongly.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
3
1
1968
On a Relation between the Flicker Value and the Learning Process
17
22
EN
The measurement of the flicker value is a method to estimate the degree of the fatigue. This method is investigated by several authors. (1),(2) The control chart of the flicker value was used for one method of the labor management and found that this chart showed the learning trend. In this paper, the simulator of automobile was used to examine the relation between the variation of the flicker value and the driving environment, the learning process of the reaction and the relation between the flicker pattern and the learning process in the working hours. These were contributed to find the beginning of the stationary condition and which group was adapted to this work. Data was analyzed by statistical methods. It was found in this study that the variation of the flicker value and the learning process of the reaction were connected with each other.
No potential conflict of interest relevant to this article was reported.
岡山大学工学部
Acta Medica Okayama
0475-0071
2
1
1967
On an analysis of Bus driver's Flicker Values (1)
26
29
EN
There are a number of methods for measuring the fatigue because the measurement of this in the working hours is useful for analyzing the factors of fatigue and for the utilization of the labor management. In this paper, the fatigue of bus drivers who have experience of various
number of years in some bus company is measured by the flicker and these values are analyzed by X(2) test or sign test and its control limit is determined. These are contributed to find a daily variation and to estimate the fatigue capacity, the degree of skill and what factors have influence on points which oversteps the limit line. It was found in this study that the limit line gets lower as the year of experience increases and the flicker values decrease in the forenoon.
No potential conflict of interest relevant to this article was reported.