• 대한기계학회논문집B
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• 제32권4호
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• pp.255-265
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• 2008

This paper presents the optimization process of evaporator for a vapor compression cooling system for high heat flux CPU. The CPU thermal capacity was given by 300W. Evaporating temperature and mass flow rate were $18^{\circ}C$ and 0.00182kg/s respectively. R134a was used as a working fluid. Channel width(CW) and height(CH) were selected as design factors. And thermal resistance, surface temperature of CPU, degree of superheat, and pressure drop were taken as objective responses. Fractional factorial DOE was used in screening phase and RSM(Response Surface Method) was used in optimization phase. As a result, CW of 2.5mm, CH of 2.5mm, and CL of 484mm were taken as an optimum geometry. Surface temperature of CPU and thermal resistance were $33^{\circ}C\;and\;0.0502^{\circ}C/W$ respectively. Thermal resistance of evaporator designed in this study was significantly lower than that of other cooling systems such as water cooling system and thermosyphon system. It was found that the evaporator considered in this work can be a excellent candidate for a high heat flux CPU cooling system.

• 유통과학연구
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• 제17권8호
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• pp.67-76
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• 2019

Purpose - This research examined whether entrepreneurial proclivity of retail employees affects job engagement and satisfaction, which are job-related positive aspects; and whether job engagement affects job satisfaction. Research design, data, and methodology - To accomplish this purpose, data were collected for 224 retail employees working in the distribution industry in the Republic of Korea. Reliability, validity, and hypotheses were tested through structural equation modeling, and mediating effects of job engagement between entrepreneurial proclivity and job satisfaction were verified through the bootstrap method by using the process model. Results - The results show that innovativeness and progressiveness in entrepreneurial proclivity positively affected job engagement and job satisfaction, but risk-taking did not affect either job engagement or job satisfaction. Also, this research confirmed that job engagement positively affects job satisfaction. Conclusions - This study contributes to the retail literature by applying the concept of entrepreneurial proclivity in the retail employee context. This study puts forward empirical evidence that identifies the effect of entrepreneurial proclivity as a job resource that influences job engagement and job satisfaction in the JD-R model. Thus, this study surmounts the limitation of prior studies by examining entrepreneurial proclivity from the aspect of retail employees.

• Architectural research
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• 제8권2호
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• pp.1-10
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• 2006

This research has acquired preliminary information about the existing conditions and understanding of members regarding time management for members in the architectural field. The goal of this research is to construct a basis for the time management education framework in architectural field in the future. This research mainly focuses on following questions based on limited objectives: Do groups of academics and professionals have understanding and knowledge of time management? Can the level of an individual's scheduling techniques be correlated to the patterns of knowledge and understanding of time management principles and practices? Can the time management practice status in individual's working environment be correlated to the patterns of knowledge and understanding of time management principles and practices? Can an individual's self-confidence level be correlated to the patterns of knowledge and understanding of time management principles and practices? Data have been collected through comprehensive questionnaires given to academics and professionals in United States. By means of statistical analysis, the hidden patterns, deficiencies and relationships in attitudes about time management have been revealed. The statistical analysis has produced conclusions that, among several subdivisions, self-discipline and planning have strong relationships and confidence, personal organization, control, and information gathering subdivisions have certain relationships with objectives of time management education in this research.

• 간호행정학회지
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• 제14권1호
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• pp.13-25
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• 2008

Purpose: The study aimed at providing better understanding of the way of carrying out nursing practice tailored to meet patient's individuality, and types of customized care in home care settings. Method: This study was conducted with qualitative design, using a grounded theory method. The directors of the home care department at three general hospitals nominated 12 staff nurses who had the experience of customized care. The data were collected using interview and field observation, and analyzed line-by-line with steps of coding. Result: The core category of customized care was 'caring in a precise manner suited to patient's individuality'. The central phenomenon was 'desire to do more for patient'. The action and interactions were: (a) knowing a patient all the more, (b) making a special relationship to a patient, (c) designing care alternatives reflecting individuality, and (d) performing the care alternatives reflecting individuality. Three types of customized care were the following: (a) completion of customized care, (b) an attempt to customized care, and (c) abandonment of working for customized care. Conclusions: The knowledge of customized care would be based on development of nursing practice program focusing on patient' individuality, and instrument development necessary for further research on care customization.

• 한국정밀공학회지
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• 제23권7호
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• pp.84-92
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• 2006

This paper deals with determination of motions of a humanoid robot using genetic algorithm. A humanoid robot has some problems of the structural instability basically. So, we have to consider the stable walking gait in gait planning. Besides, it is important to make the smoothly optimal gait for saving the electric power. A mobile robot has battery to move autonomously. But a humanoid robot needs more electric power in order to drive many joints. So, if movements of walking joint don't maintain optimally, it is hard to sustain the battery power during the working period. Also, if a gait trajectory doesn't have optimal state, the expected lift span of joints tends to be decreased. Also, if a gait trajectory doesn't have optimal state, the expected lift span of joints tends to be decreased. To solve these problems, the genetic algorithm is employed to guarantee the optimal gait trajectory. The fitness functions in a genetic algorithm are introduced to find out optimal trajectory, which enables the robot to have the less reduced jerk of joints and get smooth movement. With these all process accomplished by PC-based program, the optimal solution could be obtained from the simulation. In addition, we discuss the design consideration fur the joint motion and distributed computation of tile humanoid, ISHURO, and suggest its result such as structure of the network and a disturbance observer.

• 한국산학기술학회논문지
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• 제10권11호
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• pp.3163-3169
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• 2009

치열한 항만간의 경쟁에서 우위를 확보하고 항만의 주요고객인 화주와 선사들의 요구사항을 만족시키기 위해서는 물류서비스를 개선해야한다. 하지만 물류서비스 불만의 대부분은 터미널 내부의 문제이기 보다는 화주의 잦은 운송변경 및 선사로부터 제공되는 하역정보나 운송사로부터 반입되는 화물정보의 부정확성에 기인하고 있다. 따라서 본 연구에서는 이러한 문제들을 해결하기 위해 장치장의 업무흐름을 프로세스 중심으로 재설계하고 장치장관리 프로토타입 시스템을 구현하였다. 또한 장치 할당 계획 수립에 선복예약목록 정보가 불충분한 화물정보를 보완하여 장치장 관리에서 협업적 공급망을 구성하는데 이용될 수 있음을 확인 하였다.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2007년도 정기 학술대회 논문집
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• pp.68-73
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• 2007

Civil engineering construction work has always been accompanied by a high proportion of tasks that are either dangerous or unpleasant or both. Enhancing the general working environment and boosting safety levels are critical issues for the industry. In addition to that, the industry has been slow to utilize automation & robot technology, and there is substantial scope for the use of technology th boost efficiency, cut costs and improve quality levels in construction. In a bid to address this issue, Ministry of Construction & Transportation launched a five-year project in 2003 entitled Development of Intelligent Excavating System. The aim of the project is to use telecommunications and robotics technology to minimize inefficiencies and eliminate the dangerous and unpleasant aspects of tile construction process through the development of specific applications such as IT-equipped construction machinery and advanced construction management systems. In this paper, the project introduces on the research and development content related to multi-disciplinary, a intuitive operator control unit(Robot Technology) included.

• 설비공학논문집
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• 제11권3호
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• pp.359-368
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• 1999

The outdoor and indoor air quality surrounding highway have been measured, and the study on the design of the booth shape and the air-conditioning system also has been carried out. For the first step of the work, the air quality at the Seoul tollgate on the Kyeong-bu highway was monitored over a year. The measured indoor air quality shows seasonal average concentration 85.6-92.1ppb of >;$NO_2$and the $SO_2$and CO lower than the EAQS(Environmental Air Quality Standards). The measured TSP concentration was much higher than the EAQS. In conclusion, there is necessity to improve the working environment of the tollbooths on highways, and the current air-conditions need to be modify for the purpose. In the process of modifying the air-conditioning system, particulate pollutants needs to be considered processing and the priority needs to be put on the booths for big vehicles.

• 태양에너지
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• 제20권3호
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• pp.11-19
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• 2000

In this study, the basic data which were required for development of LHSS(latent heat storage system) were experimentally obtained. Experiments were carried out under the following conditions. The initial temperatures of P.C.M. which were used by parameter is $5^{\circ}C,\;9^{\circ}C$ and $14^{\circ}C$. The conditions of working fluid are $-6^{\circ}C,\;-4^{\circ}C$, and $65{\ell}$/min.. The pure water of which the freezing point is $0^{\circ}C$ was filled in the system, and the Ethylene glycol(brine) was circulated through the 10 vertical tubes as a secondary fluid in order to cool the P.C.M. down. The inlet temperature of the secondary fluid and the initial temperature of the water were varied to investigate the effects of the important design parameters. The phenomenons of temperature conversion of P.C.M. were appeared for the conductive heat transfer and free convective heat transfer by buoyancy force in this storage unit system. In order to find the effective water circulation path, we obtained P.CM. temperature distributions of 5 parts in the storage tank during freezing process.

• Steel and Composite Structures
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• 제20권3호
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• pp.599-621
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• 2016

In order to study the working mechanism of rectangular steel-concrete composite columns subjected to compression-bending load and further determine the seismic performance index, a bottom strengthened rectangular steel reinforced concrete (SRC) column with concealed steel plates and a bottom strengthened rectangular concrete filled steel tube (CFST) columns were proposed. Six column models with different configurations were tested under horizontal low cyclic loading. Based on the experiments, the load-bearing capacity, stiffness and degradation process, ductility, hysteretic energy dissipation capacity, and failure characteristics of the models were analyzed. The load-bearing capacity calculation formulas for a normal section and an oblique section of bottom strengthened rectangular steel-concrete composite columns were pesented and a finite element (FE) numerical simulation of the classical specimens was performed. The study shows that the load-bearing capacity, ductility, and seismic energy dissipation capacity of the bottom strengthened rectangular steel-concrete composite columns are significantly improved compared to the conventional rectangular steel-concrete composite columns and the results obtained from the calculation and the FE numerical simulation are in good agreement with those from the experiments. The rectangular steel-concrete composite column with bottom strengthened shows better seismic behavior and higher energy dissipation capacity under suitable constructional requirements and it can be applied to the structure design of high-rise buildings.