• 한국콘텐츠학회논문지
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• 제15권11호
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• pp.298-306
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• 2015

본 연구는 진단용 X선 검사 시 사용하고 있는 부가필터의 재질(Cu, Ni, CaWO4, Gd+Ba)을 다양화하여 그에 따른 검사실 내의 공간선량을 평가 한 후 적합한 재질을 찾아 제시하고자 하였다. 실험은 몬테칼로 기법을 바탕으로 하는 MCNPX 프로그램을 사용하여 흉부와 복부검사를 선택하여 모의실험을 진행하였다. 그 결과 각 재질별 선량은 모의피폭체가 위치한 곳을 중심으로 반경 50 cm 인 지점의 평균 산란선량은 모의피폭체 표면선량의 약 62%, 반경 100 cm인 지점은 평균 약 47% 정도 측정되었다. 결과에 따라 현재 상용화 되어 있는 Al 재질을 Cu, Ni 재질이 충분히 대체가능 할 것으로 판단된다. 다만 원자번호와 밀도의 차이로 인하여 그 두께를 Al의 약 1/10 정도로 조정을 해서 사용하면 적합할 것이다.

• 한국주거학회논문집
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• 제17권3호
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• pp.143-155
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• 2006

The purpose of the study was to examine the housing needs of the elderly who lived in rural area and suggest the planning directions of the housing for the rural elderly. The subjects were 192 elderlies who lived in the rural area in Gyeongnam and Chonbuk. They were selected by using the stratified sampling method. Also the interview method was used for collecting the data. The results were as follows: 1) Most of the rural elderly had some problems in their health. Thus, the housing for them should be planned on the basis of their health conditions. 2) The rural elderly had active interaction with their neighborhoods. Therefore, the housing for them should be planned for maintaining this active relation. 3) The rural elderly has lived in their housing for long time and wanted to live there as long as possible. This implies that the concept of 'aging in place' should be considered as one of the Important design issues in the rural housing for the elderly. 4) Even though many rural elderlies didn't know about the planned housing facilities for the elderly, they had intentions to live in there if they were provided in rural area. 5) The rural elderly preferred the monthly payment system or the life long payment system as the payment system of the planned housing facilities for the elderly. Also, they wanted that facility to be maintained by the government. 6) The detached housing type or three story townhouse type which is located in each rural village as small size would be desirable as the housing for the rural elderly. 7) The 10-30 pyung would be desirable as the size of housing unit. Also, 2-6 persons per room in case of sharing a bedroom. 8) Ondol-bang would be desirable however the size of the bedroom should be determined by considering using the bed.

• 한국주거학회논문집
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• 제21권3호
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• pp.11-21
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• 2010

The purpose of this study is to gather baseline data on perceived priority of residential choice and housing satisfaction rates among consumers with the aim of using this information for future planning. Self-administered questionnaires were provided to 196 studio-type multi-family housing dwellers in the City of Gwangju from 2009 Apri 5th to 29th. The collected data was used to conduct comparative and descriptive statistical analysis: factor analysis, t-test, one-way ANOVA, correlation analysis. The main findings obtained are as follows: Firstly, in relation to perceived priority of residential choice, dwellers identified seven factors as important. Secondly, in terms of housing satisfaction about a unit room, the respondents identified five factors as important. This study confirmed that there existed passive correlation between priority of residential choice and housing satisfaction among residents in studio-type multi-family housings in Gwangju. It is very necessary to project a studio-type multi-family housing close to transportation for easy access, avoiding commercial districts. Delicate interior and design will attract more female residents as well as fully-equipped parking lots for people who drive to their workplace. According to research on a degree of housing satisfaction, all respondents expressed dissatisfaction with "noise". Therefore, in dealing with construction plans of studio apartment units, from now on, sound proofing facilities are required to reduce the acoustic invasion of privacy, especially, for units with more than two people. In order to satisfy all the demand of residents in studio apartment units, we have to pursue systematic and succeeding research about a studio-type multi-family housing well-fitted for the actual circumstances of local area and suitable for longer stay. To sum up, more research and development will be required for high-class studio-type multiplex housing for sale in dealing with households with financial stability such as two-paycheck couples, so-called DINK, or a professional single person, in the future.

• 한국디지털건축인테리어학회논문집
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• 제13권4호
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• pp.109-117
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• 2013

The purpose of this study is to present our elderly welfare policy and welfare facilities for the elderly and to propose the future direction of policy for the elderly with comparison to that of Japan. The comparative study results of Korea and Japan are as follows: As the basis of elderly welfare, care insurance for the elderly is now fixated in the two countries. On the other hand, for quantitative expansion in Korea, the quality level has been gone down. Due to qualitative evaluation, the growth of facilities has slowed and material welfare providers was also a decline in the number of operators. Two countries in the field of community welfare in recent years has been actively promoting. It is the most important to solve the social welfare problem with local councils who know the area, which is a part of the future to focus and to support. Due to huge construction investment of facility, there is the burden of operators. This facility is appropriate for an extension of the home. However, it is in the hard economic times. Until now, the number of people in a room is at least four according to the legal standard of Korea, there are a few private rooms. On the other hand, in Japan, unit-care was phased since 2002 and private rooms have been expanded. In Japan, health center for the elderly plays an important role with special elderly nursing home among facilities for the elderly. Health center provides services that are recovering, nursing, and caring to support independence for the elderly after acute phase of treatment. As treatment and care, the aim of health center is to return the elderly to home. On the other hand, there are a few health centers for returning the elderly to home in Korea. Furthermore, in Japan, a project for preventive care has been begun. The project is needed in Korea.

• KIEAE Journal
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• 제4권3호
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• pp.203-210
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• 2004

This dissertation identifies and investigates the possible control modes of hybrid ventilation system in applying to general apartments. It evaluates range of hybrid ventilation control modes in terms of indoor air quality, thermal comfort, and energy consumption in a living room and a kitchen of the $1000m^2$ apartment. The TRNSYS simulation program was used for evaluating the following four ventilation types : A ventilation mode relying on only infiltration for supplying air, A natural ventilation mode considering with weather condition, A hybrid ventilation (natural + mechanical ventilation) mode allowing minimum ventilation with no heat exchange, and a hybrid ventilation mode with heat exchange. This study shows the following results. As temperature being controlled by heating cooling equipments, there is without significant difference in thermal performance among ventilation types. Regarding Indoor Air quality, Indoor air contamination level of the hybrid ventilation case consistently keep the lower levels. The hybrid ventilation modes consume more energy by a 49% as compared to the A ventilation mode relying on only infiltration for supplying air. It is caused by the continuous ventilation for keeping good indoor air quality; the increase of energy consumption can be attributable to the increase of the heating energy. Therefore, the heat exchange between indoor and outdoor air is required during heating season in severe weather conditions. During the cooling seasons, Introducing natural ventilation can achieve energy saving by 40 ~ 45%. Thus, it can be an effective strategies for energy saving. Based on these results, a hybrid ventilation system can be suggested as an effective ventilation strategy for archiving high level of indoor air quality, thermal comfort, and energy consumption.

• 한국초전도ㆍ저온공학회논문지
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• 제19권2호
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• pp.38-43
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• 2017

The role of current lead in high-temperature superconducting synchronous machine (HTSSM) is to function as a power supply by connecting the power supply unit at room temperature with the HTS field coils at cryogenic temperature. Such physical and electrical connection causes conduction and Joule-heating losses, which are major thermal losses of HTSSM rotors. To ensure definite stability and economic feasibility of HTS field coils, quickly and smoothly cooling down the current lead is a key design technology. Therefore, in this paper, we introduce a novel concept of a cooling anchor to enhance the cooling performance of a metal current lead. The technical concept of this technology is the simultaneously chilling and supporting the current lead. First, the structure of the current lead and cooling anchor were conceptually designed for field coils for a 1.5 MW-class HTSSM. Then, the effect of this installation on the thermal characteristics of HTS coils was investigated by 3D finite element analysis.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2008년도 추계학술대회 논문집 Vol.21
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• pp.424-424
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• 2008

Dye-sensitized Solar Cell (DSC) is a new type of solar cell by using photocatalytic properties of $TiO_2$. The electric potential distribution in DSCs has played a major role in the operation of such cells. Models based on a built-in electric field which sets the upper limit for the open circuit voltage(Voc) and/or the possibility of a Schottky barrier at the interface between the mesoporous wide band gap semiconductor and the transparent conducting substrate have been presented. $TiO_2$ thin films were deposited on the FTO substrate by Nd:YAG Pulsed Laser Deposition(PLD) at room temperature and post-deposition annealing at $500^{\circ}C$ in flowing $O_2$ atmosphere for 1 hour. The structural properties of $TiO_2$ thin films have investigated by X-ray diffraction(XRD) and atomic force microscope(AFM). Thickness of $TiO_2$ thin films were controlled deference deposition time and measurement by scanning electron microscope(SEM). Then we manufactured a DSC unit cells and I-V and efficiency were tested using solar simulator.

• 전기학회논문지
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• 제64권9호
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• pp.1330-1336
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• 2015

It is necessary to study on acoustic and vibratory response of a MEMS resonant accelerometer before applying to military applications. In this paper, we analyze why the resonant accelerometer reacts to an acoustic wave and a high frequency vibration. And we describe experimental results on acoustic and vibratory response of the accelerometer. The accelerometer consists of a proof mass and a dual ended tuning fork. It is a differential resonant accelerometer with arranging a pair of accelerometers. The mode shape was analyzed to find out the input mode frequency by using a FEM simulation. Some experiments regarding the acoustic noise was carried out by using a tweeter and a microphone in the anechoic room. Results showed that the accelerometer reacted to the acoustic wave and vibration which had the input mode frequency as we had expected. We showed experimentally not only that the susceptibility of the accelerometer to an acoustic wave was 70 dB but also that the effectiveness of applying an acoustic absorber and a metal case was 20 dB, respectively. Also, we could minimize the vibratory response property of the accelerometer by installing a IMU with a silicone rubber mount pad.

• 대한기계학회논문집A
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• 제25권3호
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• pp.510-519
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• 2001

The tensile and fracture toughness tests have been conducted to investigate the degradations of mechanical properties induced mainly by neutron irradiations in Zr-2.5Nb CANDU pressure tube materials operated in Wolsung Unit-1. the tests were performed at room, 150, 200, 250, 300 $\^{C}$ for the irradiated and unirradiated specimens in hot cell. The specimens were directly machined from the tube retaining original curvature using specially designed electric discharge machine(EDM). From the tensile tests of the irradiated specimens, it was found that tensile strength was increased and total elongation was decreased compared to those of the unirradiated ones. The active voltages in the fracture toughness tests for the irradiated showed the discontinuous abrupt increases caused by crack jumping in lower temperature. In the crack resistance curves we found the stable crack growth in the unirradiated, whereas the unstable and three crack growth stages in the irradiated specimens due to the accumulated irradiation defects. The various fracture characteristic values in the irradiated are remarkably lower than those of the unirradiated. Through the fractography, we found in the irradiated that smaller dimple and shorter fissures than the unirradiated, and that the fractured surface had three regions that were flat, transition and slant/shear area. These can explain the difference in the crack growth characteristic values of the irradiated and the unirradiated ones.

• 한국가금학회지
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• 제39권4호
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• pp.261-267
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• 2012

Different housing systems have considerable influence on performance in poultry production. Therefore, the present study was undertaken to investigate the impact of different housing systems on the performance, bone mineral density and egg yolk fatty acid composition in laying hen. Hy-line brown pullets (n=450) of 12 weeks age were randomly divided into 3 housing systems with 6 replicates of 25 birds in each room. A diet with 2,750 kcal/kg ME and 16.5% CP was assigned to all birds. The pullets provided free access to feed and water. Significantly (P<0.05) higher values for egg production, egg mass and feed conversion efficiency were found in battery cages, however egg weight, egg shell color and breaking strength was remarkably (P<0.05) higher in floor system. The albumin height and Haugh unit were significantly higher (P<0.05) in battery cages which was statistically similar to aviary housing system. The egg yolk fatty acids concentration of linoleic acid and linolenic acids were significantly higher in aviary and in floor system, respectively, however both values were lower in battery cages. Saturated and unsaturated fatty acid content (%) in egg yolk did not influence by any housing systems. Bone mineral density was significantly higher (P<0.05) in floor and aviary housing system than that of battery cage system. It was concluded that in battery cages the egg production and composition maximized, however higher bone mineral density and yolk fatty acids content can be improved in the laying hen reared on floor and aviary housing systems.