• 국제물리치료학회지
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• 제3권2호
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• pp.469-474
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• 2012

The purpose of this study is to analyze the correlation between the stature and the muscle performance ratings and the subjective discomfort rations at performing lower arm's pronation and supination according to change sin the height of working table for more efficient performance at designing a working table and performing a work. For the purpose, this study conducted an experiment targeting 40 people in their 20s, who were classified into 4 groups each group composing 10 people at intervals of 5cm from the standard stature of 166.5cm. The experiment measured the maximum isometric pronation and the supination muscular power, and at measuring the factors, the heights of working tables were set as 800mm, 850mm, and 900mm. From the measurement results, it was found that the stature and the maximum muscular power was correlated. That is, as the experiment groups's average stature is higher, the maximum muscular power was higher. For the correlation between the motion patterns(pronation and supination) and the maximum muscular power, it was seen that the maximum muscular power was higher at performing the pronation than the supination. In the correlation between motion patterns and the subjective discomfort ratings, it was seen that the subjective discomfort rating was higher at performing the supination than the pronation. For the correlation between height adjustment and the subjective discomfort ratings, as the height of working table was lower, the subject discomfort rating was lower. Therefore there was no difference in the maximum muscular power according to the height changes of working table, but it was found that as the working table was higher, the user felt more comfortable.

• 한국기계가공학회지
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• 제8권3호
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• pp.46-53
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• 2009

To find the working condition is one of the important factors in precision machining. In this study, we analyzed maximum working temperature by infra-red camera and surface roughness in side wall end milling using design of experiment (DOE): RSM(response surface methodology), ANOM(analysis of means) and ANOVA(analysis of variance) by table of orthogonal array. ANOM and ANOVA are well adapted to select sensitivity of design variables for maximum working temperature and surface roughness. The effective design variables and their levels should be determined using ANOM, ANOVA. RSM is presented 2nd order approximation polynomial of maximum working temperature and surface roughness is composed with design variables. Therefore, it is expected that the proposed procedure using design of experiment : table of orthogonal array, ANOM, ANOVA and RSM can be easily utilized to solve the problem of working condition.

• 방사성폐기물학회지
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• 제4권1호
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• pp.17-24
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• 2006

한국원자력연구소에서는 현재 사용후핵연료의 효율적인 관리를 위한 차세대관리 종합공정 (ACP)의 실증용 핫셀을 건설중에 있다. 본 논문에서는 핫셀 내부의 리어도어(rear door)와 만나는 부분에 설치될 작업대(working table)의 구조적 안전성을 유한요소 해석을 통해 평가하였다. 이 부분의 작업대는 물품들의 반출입을 위해 개폐식으로 설계되었기 때문에 다른 작업대에 비해 지지 부위가 적으므로 구조적 안전성 평가가 반드시 필요하다. 핫셀을 가동할 때 작업대 위에 공정 장치들을 반입하거나 핫셀 크레인을 사용해 적재하게 되므로, 안전성 평가를 위해 정적 구조 해석과 동적 구조 해석들 함께 수행하였다. 해석 결과를 통해 두 경우 모두에 대해 개폐형 작업대가 구조적으로 충분히 안전함을 확인할 수 있었다. 또한 50 cm 낙하 충돌의 경우에도 작업대의 파손이나 붕괴가 일어나지 않고 안전성이 유지되었다.

• 한국농공학회지
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• 제17권4호
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• pp.3956-3961
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• 1975

In order primarily to establish the working stages in the reclamation works and to- analyze the working characteristics of man-power, the investigations for construction_ works were conducted on Echeon Largescale Reclamation Project Area. The results are summarized as follows; 1. The working chart on reclamation by man-power is Fig.IV-1. 2. The. ratio of actual working time to total varied with the total times, being 1.0 for less than 4 hours but about 0.9-0.83 for more than 5 hours. 3. Felling operations can be classified into three stages as truck-cutting, branch- cutting, and binding-up, of which results are in Table IV-2. The larger the diameter of stands, the more times for both the cutting operations are, but the moving time is constant to be about 15 sec. 4. Stumping and clearing works have the results prepared in Table IV-3. Between the stumping time and the diameter of stands d, there show highly significant positive correlations, expressed as t=2.212d -4.792. The more the ratio of small diameters to total, the more hastily the total hourly working results of each person are increased. 5. Working results for constructing drainage facilities and ridges are in Table IV-5. The labours for placing patches of grass are required more than twice or three times as much as those are showed in the established standards, and such the different results imply more investigation to be necessary. 6. Table IV-6 sholvs the results for plowing andh arrowing, that are less amount thant the standards. Therefore, more inverestigation should be prepared.

• 산업경영시스템학회지
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• 제34권1호
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• pp.97-102
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• 2011

This study was performed to design and develop an ergonomic equipment for strawberry sorting and packing in agricultural working environments. Potential risk of work related musculo-skeletal disorders associated with farm workers performing strawberry sorting and packing was analyzed through interviews, field surveys, work measurement, and working posture evaluation. For the evaluation of working posture, we used REBA, OWAS, and RULA assessment methods to identify multi-factorial risk factors. Based on the result of comprehensive assessment, a new concept of multi-level rotating table for strawberry sorting and packing was proposed to modify awkward working postures and improve the effectiveness of the farm work. Finally, the characteristics and effectiveness of new equipment was discussed in terms of improvements in productivity, safety, and subjective ratings of farm workers. The results of analysis showed that working conditions improved significantly.

• 한국소음진동공학회논문집
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• 제18권11호
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• pp.1097-1104
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• 2008

Working condition is one of the most important factors in precision working. In this study, we optimized the vibration acceleration of working progress direction using RSM(response surface methodology) by table of orthogonal array. RSM was well adapted to make analytic model for minimizing vibration acceleration, created the objective function and saved a great deal of computational time. Therefore, it is expected that the proposed optimization procedure using RSM can be easily utilized to solve the optimization problem of working condition. The experimental results of the surface roughness and vibration acceleration showed the validity of the proposed working condition of side wall end-milling as it can be observed.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제13권7호
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• pp.3566-3582
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• 2019

In intelligent warehouse picking system, the allocation of tasks has an important influence on the efficiency of the whole system because of the large number of robots and orders. The paper proposes a method to solve the task allocation problem that multi-robot task allocation problem is transformed into transportation problem to find a collision-free task allocation scheme and then improve the capability of task processing. The task time window and the power consumption of multi-robot (driving distance) are regarded as the utility function and the maximized utility function is the objective function. Then an integer programming formulation is constructed considering the number of task assignment on an agent according to their battery consumption restriction. The problem of task allocation is solved by table working method. Finally, simulation modeling of the methods based on table working method is carried out. Results show that the method has good performance and can improve the efficiency of the task execution.

• Journal of Preventive Medicine and Public Health
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• 제26권1호
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• pp.20-36
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• 1993

Work-related low back pain is one of the major factors that cause the loss of working power especially in actively working age, therefore controlling the work-related low back pain is one of the major issues in the field of industrial safety and health. This study was performed for detecting the risk factors and proposing the efficient control program of the work-related low back pain. The subjects were male workers employed at the manufacturing industry in Pusan with longer than 6 months' working duration. The data was collected by self-reported questionnaire and interview from May 1 to October 31,1992. The contents of questionnaire were as follows:. the experience of low back pain within the recent one month, general characteristics(age, marital status, education level, religion, regular exercise), physical characteristics(height, weight), employment status(working duration, daily working hours, rest during work, satis(action fur the job), type of work and working environments(posture, forward bending, lifting and movement, satisfaction for table and chair). The result was analyzed for 608 entire respondents by case-control comparative method. The number of cases was 152 with a history of work-related low back pain, so the relative frequency of self-reported work-related low back pain was 25.0%, and the number of controls was 344 without any history of low back pain. As a result, two characteristics of the employment status(working duration, satisfaction fur the job) and all characteristics of type of work and working environments showed a statistical significance between the case and control groups(p<0.01). The Oddb ratios of these variables for Work-related low back pain were calculated. They were 7.88 for the satisfaction fur chair, 7.86 for lifting and movement,3.31 for satisfaction for table, and 2.22 fur bending forward(p<0.01). And for the multivariate logistic regression analysis confirmed that unsatisfaction for table was independent risk factor for Work-related low back pain. In summary, though this study was based upon the self-reported questionnaire and the subjective complaints, the satisfaction for chair, lifting and movement, satisfaction for table, and bending forward concerned with the type of work and working environments were considered as the main factors causing the work-related low back pain, and the work-related low back pain may be preventable by the ergonomic control of these factors.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2000년도 추계학술대회 논문집
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• pp.86-92
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• 2000

The crew operation scheduling problem is divided into duty generation and duty allocation. The railway crew roster scheduling(duty allocation) is developed monthly for each crew's office, considering the car types and crew's driving ability. However, it is very difficult to make schedules which assign monthly working hours to each crew evenly. The purpose of this thesis is to minimize the differences between each crew's total duty times and make a rostering table. To minimize the differences among monthly working hours of each crews are grouped according to car type and crew's driving ability and a rostering table which could be shared by the group members is developed. Our approach is to apply the techniques of Constraint Programming in order to solve such problems efficiently. This algorithm is suitable to solve optimization problems which involve many complicated constraints. And including the concept of cost, we suggested the model which enable to make the rostering table with a minimum personnel.

• 한국직업건강간호학회지
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• 제7권1호
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• pp.55-64
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• 1998

In order to investigate and compare the health risk factors of nurses in the operating room(OR nurse) and ward (WARD nurse), the questionnaire survey for subjective symptoms was carried out on 553 nurses(132 OR nurses and 421 WARD nurses) who were employed at seven hospital. The self-administered questionnaries were composed of low back pain, subjective fatigue symptoms, musculo-skeletal symptoms, psychological stress and reproductive function. The results were as follows : 1. In the type of working posture and working environment, there were significant difference between two groups for working posture, waist form, height of working table, satisfaction of chair, lifting & carring. 2. Job satisfaction, duration of work, height of working table, satisfaction of chair, lifting & carring were significantly associated the low back pain. 3. In the complaints of subjective fatigue symptoms, the total mean score was higher in OR nurse than WARD nurse, but there was not significant. The items that the mean score of OR nurse was significantly higher than WARD nurse were 'head feels muddled', 'apt to forget', 'feel choky'. 4. In the complaints of musculo-skeletal syrrptoms, the total mean score was higher in OR nurse than WARD nurse, but there was not significant. The item that the mean score of OR nurse was significantly higher WARD nurse was 'wrist discomfort or pain'. 5. The comparison of spontatenous abortion in married nurses who had the experience of pregnancy were significantly associated the stress risk group. 6. In all of OR and Ward nurses, the job satisfaction is associated with subjective fatigue symptoms, musculo-skeletal symptoms, and stress. In conclusion, it suggested that working posture, working environment, stress, and job satisfaction were health risk factors of nurses working in the operating room. Further prospective intervention studies should be conducted to educate right working posture, improve of working environment, decrease of stress, and increase of job satisfaction.