• 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.

• 한국생활과학회지
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• 제18권2호
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• pp.407-418
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• 2009

In our modern society along with high speed economic growth and improvement of living conditions and through concentration of people in cities cars became essential necessities for people living in modern society. Due to social and economic conditions and for the need of recycling of materials and as a countermeasure for waste of materials importance of car service is stressed. In this connection need for improvement of working clothes which are suitable for safety and working efficiency in a difficult working environment is essential. However most of working clothes now being sold in the market are produced without consideration of ergonomic aspects of wearers of working clothes. For this reason there is need for basic research on development of working clothes which improve safety and comfort for working of car service workers. Accordingly in this study this author carried out research on fitness, level of satisfaction and dissatisfaction, suitability for movement and level of demand for improvement in working clothes with focus on workers at car service firms and direction for its improvement was explored. This study is intended to provide basic data for development of functional pattern of working clothes for car service workers in future.

• 한국의류산업학회지
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• 제11권1호
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• pp.174-179
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• 2009

The purpose of this study is to research the actual condition of working environment, working clothes and personal protective equipments on workers at a construction site in winter. The one to one interview by questionnaire was performed with 33 males and 2 females workers of a construction site in Daegu at $1.3^{\circ}C$ air temperature, 28% R.H., 4.7m/sec air velocity. The questionnaire consisted of 21 questions including 4 personal characteristics questions, 12 working environment/performance questions and 5 working clothes/personal protective equipments questions. It was modified from the original questionnaire developed by Finnish Institute Occupational Health. We found that physical stress of workers increased and the ability of performance decreased. The workers felt the coldest at hands/fingers, feet/toes and the face part of cheek, nose and ears. They rarely wore thermal clothing for winter and answered that the thermal gloves for winter did not provided enough warmth. Even if the workers recognized the necessity of personal protective equipments for their safety, they did not wear them for efficiency of working performance. These results will be useful elementary materials for development of working clothes and personal protective equipments from the viewpoint of improving both working performance and comfort.

• 한국태양에너지학회 논문집
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• 제32권2호
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• pp.1-10
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• 2012

A photovoltaic/thermal (PVT)solar system is the solar technology that allows for simultaneous conversion of solar energy into both electricity and heat. This paper compared the performance of PVT system with a conventional PV module and solar collector and analyzed electrical and thermal efficiency of PVT system in terms of solar irradiance and inlet temperature of the working fluid. Based on the experimental data, thermal and electrical efficiencies of he glazed PVT system were57.9% and14.27% under zero reduced temperature condition which were lower by 13.6% than the solar thermal absorber plate and by 0.08% than the PV module respectively. For the unglazed PVT system it had lower thermal efficiency than the solar thermal absorber plate but higher electrical performance than the PV module due to the cooling effect by the working fluid. However, total efficiency of the glazed PVT system was72.2% which was higher than combined efficiencies of the solar collector and PV module. Besides, total efficiency of the PVT system would be much higher if calculated based on unit area.

• 한국태양에너지학회:학술대회논문집
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• 한국태양에너지학회 2011년도 추계학술발표대회 논문집
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• pp.60-67
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• 2011

A photovoltaic/thermal(PVT)solar system is the solar technology that allows for simultaneous conversion of solar energy into both electricity and heat. This paper compared the performance of PVT system with a conventional PV module and solar collector and analyzed electrical and thermal efficiency of PVT system in terms of solar irradiance and inlet temperature of the working fluid. Based on the experimental data, thermal and electrical efficiencies of the glazed PVT system were 57.9% and 14.27% under zero reduced temperature condition which were lower by 13.6% than the solar thermal absorber plate and by 0.08% than the PV module respectively. For the unglazed PVT system, it had lower thermal efficiency than the solar thermal absorber plate but higher electrical performance than the PV module due to the cooling effect by the working fluid. However, total efficiency of the glazed PVT system was 72.2% which was higher than combined efficiencies of the solar collector and PV module. Besides, total efficiency of the PVT system would be much higher if calculated based on unit area.

• 한국의류산업학회지
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• 제13권5호
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• pp.752-758
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• 2011

In this paper, experiments to develop working clothes and evaluated, including the current and material-improved working clothes in relation to physiological functionality measurement. Experiments were conducted on subjects after wearing working clothes in an climate chamber, and the thermo-physiological response, such as human body temperature, micro-climate within the clothes, blood pressure, heart rate were measured. In this manner, the physiological functionality of improved working clothes was compared with that of current working clothes and evaluated. The summary of obtained results is as follows: For physiological functionality evaluation through material-improved working clothes, P working clothes showed significantly lower rectal temperature than C working clothes. For mean skin temperature, P's skin temperature was significantly higher than C's in the second half of the experiment. P working clothes's temperature around the thighs in Micro climate was significantly lower than that of the C working clothes. Also, humidity within the clothes showed similar trends. During the exercise period, C working clothes showed higher blood pressure than P, but P showed higher heart rates than C. Also, the oxygen uptake amount was higher in C than P during the exercise period, it explains that the energy consumption amount of P working clothes was smaller than that of C working clothes. Of the subjective evaluation, for temperature sensation, workers wearing P working clothes felt cooler. For humidity, C working clothes showed more humidity. For comfort, P working clothes were better, and for sense of fatigue, workers felt less tired wearing P working clothes. From results above, we can see that physiological functionality improved in the material-improved working clothes in the working clothes for construction site workers. The improvement of working clothes through functionality improvements not only will provide personal pleasantness to constriction site workers, but will also generate efficiency and productivity improvements at construction sites. All in all, the continuous study of functionality improvements in working clothes taking into consideration the human body's physiological responses is required.

• 패션비즈니스
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• 제17권3호
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• pp.1-14
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• 2013

This study is about the evaluation of the color arrangements of working clothes that are harmonized with working environment and assist in the protection of workers in industrial sites. This study attempted color arrangement design with the intention of giving order to the colors of working environment and working clothes so as to help improve the safety of work and the management aspects including human resource management, efficiency improvement, and the practice of business ethics. The study method consisted of literature research, empirical research, and evaluation research. The literature research performed theoretical examination about colors, industrial safety, and visibility. Three actual outdoor work sites in the machine industry were chosen and pictures were taken at 20-30 m from workers. The background colors of the work environment of each work site and the colors of the working clothes that were actually worn were analyzed through color values measured with a color-difference meter(CR-400). As a result, it was found that between value and chroma which affect visibility, color arrangement based on differences in chroma could be a greater influence than color arrangement based on differences in value. The results of this study could assist the integration of color schemes among working environment colors, people and working clothes by suggesting color arrangements with improved visibility that are applicable to the working clothes of domestic machine manufacturers that are playing a pivotal role in domestic industries and by presenting appropriate guidelines.

• 한국에너지공학회:학술대회논문집
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• 한국에너지공학회 1995년도 춘계학술발표회 초록집
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• pp.78-81
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• 1995

In the present study, the spray column type of direct contact heat exchangers are studied experimentally to analyze heat transfer characteristics for solar energy utilization. These experiments are carried out in the line of solar heating system, major results are as follows ; 1) the flow and aspect of working fluid drop for maxium heat transfer 2) efficiency and volumetric heat transfer coefficient of D. C. H. X. with a heavier working fluid are higher than those of D. C. H. X. with a lighter working fluid

• 대한방사선협회지
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• 제27권2호
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• pp.49-56
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• 2001

Ⅰ. Purpose : This study has its aim at protecting the health of workforces .of a general hospital, improving their working environment, increasing the efficiency of their work, maintaing pleasant working conditions for them and preventing occupational dis

• Journal of Advanced Marine Engineering and Technology
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• 제36권8호
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• pp.1151-1157
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• 2012

OTEC기술은 신재생에너지 기술 중의 하나로 따듯한 표층수와 차가운 심층수의 온도차를 이용하여 전력을 생산하는 기술이다. 작동유체의 선정과 OTEC 사이클의 상태에 따라 에너지효율과 환경적인 측면에 많은 영향을 준다. OTEC의 작동유체로는 ammonia, R22, R407C, R410A가 있다. 본 논문에서는 OTEC 시스템의 최적화를 위해 $25^{\circ}C$에서의 증발압력를 비교하였다. 또한 밀폐사이클과 재생사이클에서의 작동유체에 따른 출력과 효율에 대하여 연구하였다.