• Journal of Preventive Medicine and Public Health
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• 제13권1호
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• pp.19-25
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• 1980

The Occupational Job Stress Indicies Questionnaire is a selfadministered instrument consisting of 48 questions which are designed to collect the perceived Job stress about individual. This questionnaire was translated into Korean and applied to the selected groups of 300 blue collar workers musical manufacture industy for the purpose of assessing the it's reliability from April 1. to July 30, 1980. The results obtained were as follows; 1. The range of reliability coefficients for all indices was. 45-.75 which was lower than .54-.87 of original. 2. The inter-item correlation matrix for all items comprising an index along with the intercorrelation of these items with the items comprising closely related indices. 3. The reliability of JOB SATISFACTION, INTRINSIC REWARDS and IMPORTANCE REWARDS revealed .14-.20 lower than that of original. On the point of view, some items should be adjusted in parallel with acutual situation of Korea through making a cultural comparative study and item factor analysis.

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2005년도 춘계학술발표대회 논문집
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• pp.249-252
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• 2005

Prediction of damage caused by low-velocity impact in laminated composite plate is an important problem faced by designers using composites. Not only the inplane stresses but also the interlaminar normal and shear stresses playa role in estimating the damage caused. The work reported here is an effort in getting better predictions of damage in composite plate using DNS approach. In the DNS model, we discretize the composite plates through separate modeling of fiber and matrix for the local microscopic analysis. Through comparison with the homogenized model. In the view of microscopic mechanics with DNS model, interlaminar stress behaviors in the inside of composite materials is investigated and compared with the results of the homogenized model which has been used in the conventional approach of impact analysis.

• 대한기계학회논문집A
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• 제24권2호
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• pp.489-495
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• 2000

Stress and strain in continuum mechanics have a mathematical form of the second order tensor. it is well-known that the usefulness of tensor components could be explained in a relation with coordin ates system transformation and Mohr's circle could be easily used to make a coordinate system transformation of tensors. However, Mohr's circle is applied mainly to plane problems and its use to three dimensional cases is limitedly employed. In this paper, we propose a matrix and dyadic representation of stress and strain tensors which could equivalently replace the graphical representation of second order tensors. The use of the proposed representation might provide a valuable means for the educational respects as well as research view point.

• 한국생산제조학회지
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• 제8권1호
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• pp.35-44
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• 1999

In a view point of earth environmental protection and social requirement, adhesively bonded structures of aluminum alloys have become to be employed for the purpose of decreasing fuel ratio by weight reduction and to improve performance in various engineering fields such as aircrafts, automobiles, rolling stocks and so on. In spite of such wide applications in adhesively bonded structures of aluminum alloys, the quantitative fracture criterion and evolution method of its bonded strength have not been established yet. The objective of this paper is to establish fracture criterion considering stress singularity at interface edges in adhesively bonded structures of aluminum alloys. Through the analyses of boundary element method and static fracture experiments with three different types of specimens in the adhesively bonded joints of aluminum alloys, its fracture criterion was proposed and discussed about strength evolution of adhesively bonded structures.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 1999년도 봄 학술발표회 논문집
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• pp.287-294
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• 1999

The tensegrity structure by prestressed cable, which may have large freedom in scale and form and therefore are received much attention from the view points of their light weight and aesthetics, is a very flexible and geometrically unstable structure because the cable material has little initial rigidity. For the stable self-equilibrated state of the usually very deformable structure, the method to find the optimal initial stress by the shape analysis is proposed in this paper. The proposed procedure is to derive the nonlinear finite element formula of cable and truss members considering geometric nonlinearity and used to modified load incremental method adding to Newton-Raphson method with the proposed condition for optimal initial stress. The result of the shape analysis for the tensegrity structure with the radius of 30m is shown the almost approximated shape to architectural shape and the changed procedure of initial stress

• 한국초전도ㆍ저온공학회논문지
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• 제15권3호
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• pp.13-19
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• 2013

Superconducting field coils using a high-temperature superconducting (HTS) wires with high current density generate high magnetic field of 2 to 5 [T] and electromagnetic force (Lorentz force) acting on the superconducting field coils also become a very strong from the point of view of a mechanical characteristics. Because mechanical stress caused by these powerful electromagnetic force is one of the factors which worsens the critical current performance and structural characteristics of HTS wire, the mechanical stress analysis should be performed when designing the superconducting field coils. In this paper, as part of structural design of superconducting field coils for 17 MW class superconducting ship propulsion motor, mechanical stress acting on the superconducting field coils was analyzed and structural safety was also determined by the coupling analysis system that is consists of commercial electromagnetic field analysis program and structural analysis program.

• Journal of Advanced Marine Engineering and Technology
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• 제30권3호
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• pp.359-368
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• 2006

The trend on marine diesel engine productions and refinements has led to a higher mean effective pressure and thermal efficiency. These resulted in increased maximum combustion pressure within the cylinder and vibratory torque in crankshaft. In view of this. the crankshaft should be able to withstand the dynamic stresses caused by load variations. Different factors including size, material and stress concentration factors should also be considered to ensure the reliability of the shafting system. As such, crankshaft must be designed and compacted within its fatigue strength. In this paper, the strength analysis of crankshaft Is carried out by: simplified method recommended by IACS(International Association Classification Societies) M53 and a detailed method with the crankshaft assumed as a continuous beam and bearing supported in its flexibility. The results of these two methods are then compared.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2006년도 춘계학술대회 논문집
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• pp.651-652
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• 2006

The choice of suitable hip implant is one of important factors in total hip replacement (THR). In clinical view points, improper adaptation of hip implant might cause abnormal stress distribution to the bone, which can shorten the lifespan of replaced hip implant. Currently, interest in custom-designed hip implants has increased as studies reveals the importance of geometric shape of patient's femur in modeling and designing custom hip implants. In this study, we have developed the custom-designed hip implant models with various sizes in hip implant, and the stress distribution in the bone was analyzed using Finite Elements methods. It was found that minimizing the gap between implant stem and femoral cavity is crucial to minimize stress concentration in the bone.

• 한국마린엔지니어링학회:학술대회논문집
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• 한국마린엔지니어링학회 2001년도 춘계학술대회 논문집
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• pp.168-172
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• 2001

The subsurface stress field beneath the roller due to the lubricant film pressure acting on the roller surface has been calculated. Main purpose of this study in view of engineering is to prove the validity of the numerical profile roller presented by Koo et al who obtained the lubricant film pressure by elastohydrodynamic lubrication analysis on the cam-roller mechanism. The stress field for the numerical profile roller was compared with the one for the existing dub-off profile roller.

• 대한치과기공학회지
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• 제23권2호
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• pp.105-119
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• 2002

This study was designed to grasp the degree of job stress affecting dental technicians and the degree of the symptoms of their job stress. With this in mind, the researcher selected a total of 170 dental technicians living in Seoul and Incheon, conducting a research in a period ranging from August 1,2001, to August 20, 2001. The researcher made use of a structured questionnaire whose reliability and feasibility are proved. The questionnaire is composed of a total of 55 questions: thirteen questions related to the subjects' general characteristics; 28 questions connected to the measurement of job stress and fourteen questions linked with the measurement of job-stress symptoms. The researcher analyzed the findings with the aid of SPSS(Statistical Package for Social Sciences). The research came to draw the following conclusions on the basis of frequency, percentage, T-test, and F-test, multiple regression. I. The analysis into the job stress of the subjects indicates that there is a significant difference in difficult questions among their work places, working hours, academic background, job satisfaction and jobs(P<.05). The job stress stands at 3.48 on the average, and the area of conflict among too much work and job performance turns out to be highly perceived. 2. The analysis into the degree of the symptoms of the job stress of the subjects shows that there is a significant difference in work place, working hours, job satisfaction and the continual maintenance of job(P<.05). The symptoms of job stress accounts for 2.65 on the average. Physical symptoms turn out to be highly perceived; The response 'My arms and legs are killing me' proves to stand for 3.03. 3. The correlation between job stress and the symptoms of job stress turns out to be significant(r=0.519, P<0.001), and there is a significant correlation between the average points of each job-stress area and the average points of the symptoms of job stress. All in all, it is necessary that dental technicians themselves should make positive efforts to control and relieve stress and that more efficient programs should be implemented with a view to dealing with stress.