• 설비공학논문집
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• 제24권3호
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• pp.230-239
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• 2012

Ground-coupled heat pump (GCHP) systems utilize the immense renewable storage capacity of the ground as a heat source or sink to provide space heating, cooling, and domestic hot water. The main objective of the present study is to investigate the cooling and heating performance of a small scale GCHP system with horizontal ground heat exchanger (HGHE). In order to evaluate the performance, a water-to-air ground-source heat pump unit connected to a test room with a net floor area of 18.4 m2 and a volume of 64.4 m3 in the Korea Institute of Construction Technology ($37^{\circ}39'N$, $126^{\circ}48'E$) was designed and constructed. This GCHP system mainly consisted of slinky-type HGHE with a total length of 400 m, indoor heat pump, and measuring devices. The peak cooling and heating loads of the test room were 5.07 kW and 4.12 kW, respectively. The experimental results were obtained from March 15, 2011 to August 31, 2011 and the performance coefficients of the system were determined from the measured data. The overall seasonal performance factor (SPF) for cooling was 3.31 while the system delivered heating at a daily average performance coefficients of 2.82.

• 한국지열·수열에너지학회논문집
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• 제14권4호
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• pp.53-60
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• 2018

This study was conducted for analysis of a heat pump system using waste heat in an enclosed space such as a green house. The model was developed with mathematical equations in literature and Engineering Equation Solver (EES) was used to get the solution of the developed equations. The simulation results have 5% of reliability comparing the results with actual test data of heat pump system's dynamic operation. The operating performance of the system was calculated with variation of working fluid temperature in the thermal storage tank such as $25^{\circ}C$, $35^{\circ}C$, $45^{\circ}C$ and $55^{\circ}C$. As a result, the system's the highest total heating capacity shows 280 kWh and the storage tank's operating time decreased as the starting storage tank's temperature was high.

• 대한조선학회논문집
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• 제61권1호
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• pp.19-28
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• 2024

Environmental regulations are becoming more stringent in response to climate change, especially concerning marine pollution caused by ship emissions. Large ships are adjusting by integrating technologies to reduce pollutant emissions and transitioning to eco-friendly fuels such as low-sulfur oil and LNG. However, small ships face space constraints for installing LNG propulsion systems and the risk of power depletion with pure electric propulsion. Consequently, there's growing interest in researching hybrid propulsion methods that combine electricity and diesel for smaller vessels. Hybrid propulsion systems utilize diverse energy sources, requiring an effective method for evaluating their efficiency. This study proposes employing Bond graph modeling to comprehensively analyze energy dynamics within hybrid propulsion systems, facilitating better understanding and optimization of their efficiency. Modeling of the ship's energy system using Bond graphs will be able to provide a framework for integrating various energy sources and evaluating their effects.

• 천문학회보
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• 제35권1호
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• pp.36.2-36.2
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• 2010

The CQUEAN (Camera for QUasars in EArly uNiverse) is an optical CCD camera optimized for observation of high redshift objects. It is going to be attached to the cassegrain focus of 2.1m telescope at McDonald Observatory, USA. We are making a focal reducer for CQUEAN to secure a larger field of view. The focal reducer is composed of four spherical lens, and it reduces the focal length of telescope by one third. We designed the lens configuration, performed tolerance analysis, and estimated the optical performance with ZEMAX. The differences in optical performace with/without filters were also investigated. The result from ZEMAX shows that the system has ample margin of errors for median seeing of 1.2" at McDonald observatory. Even with aberration and alignment tolerance, the performance is better than the original requirement. The lenses are now being made, and the lens barrel and an adapter for assembly of the Andor CCD camera and the filter wheel is now under designing process. We expect that the manufacturing of the focal reducer system as well as its optical test will be finished by April 2010.

• 한국주거학회논문집
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• 제20권4호
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• pp.79-88
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• 2009

A planned access method on constantly-changing-community unit plan changes and develops based on the periodical situation and also plan theory. In this research, it is to present the link between the theory of complex city change and the plan factor of it, and to show how Korean residential complex plan has changed as time passed and how new concept of city plan came up and by applying new methods how can this affect our real world and the past plan. In the phase of analysis, it analyzed the flow of 'community unit plan' and its theory and investigated the factor of compositional space and built a analysis frame. The factors of community unit plan are space structure, size and shape of block, population, distribution of facilities and movement system. It chose the place that can represent the flow of community unit plan trand and that indicates the obvious development leading to Jamsil (1975), Gwa Chun (1980), Mok Dong (1983), Sang Ge (1985), Ilsan (1989), Dong tan (2001) and Eun Jung (2003) total of 7 places. And to compare a similar size of the city, it selected a small community unit. Based on the result of theoretical study and prior research, it can be said that the space composition style has change from a whole complete complex area to a linked-cross over community unit and the access of urban level was on set. Also, a pedestrian walking area was secured and the dense of building structure and pleasant environment wanting need was in balance. For facility plans, the usage of facility and functional change brought change of type, size and disposition. The walking area for pedestrian became a huge matter. Therefore, market, education, public facilities and green system collaborated to co-build a whole community unit and activated the walking environment. Also, public transportation, environment friendly city organization was built.

• 대한교통학회지
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• 제30권5호
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• pp.33-42
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• 2012

본 연구에서는 분석대상 지역의 특성을 고려한 차량 배출물질의 사회적 비용 원단위 추정 모형을 구축하였고, 이를 바탕으로 분석 대상지역의 대기질 가치를 평가하기 위한 방법론을 제시하였다. 구축 모형은 편익이전(Benefit Transfer)기법을 활용한 것으로, 각 지역의 인구밀도와 녹지율이 설명변수로 반영되었다. 본 모형을 적용한 결과, 인구가 밀집되어 있는 서울 지역과 부산 지역에 대한 차량 배출물질의 사회적 비용 원단위는 전국 평균치보다 각각 18.68배, 10.71배 높은 것으로 나타났다. 본 연구는 최근의 녹색교통 정책에 대한 타당성을 판단함에 있어서 보다 신뢰도 있는 결과 도출에 기여할 것으로 기대된다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2011년도 제41회 하계 정기 학술대회 초록집
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• pp.199-199
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• 2011

The addition of a carbanion to ${\yen}{\acute{a}}{\yen}{\hat{a}}$-unsaturated carbonyl compounds is of importance in the C-C bond formation reactions for modern pharmaceuticals and organic synthesis. Recently, heterogeneous asymmetric catalysis became more attractive area of research because of the easy recovery and separation of the catalyst from the reaction system. Most of synthetic methods for heterogeneous catalysts were grafting or immobilization of homogeneous catalyst onto the solid supports. Trans-1,2-Diaminocyclohexane(DACH) and L-proline ligands have been enormously used as chiral ligands in several catalytic transformation under homogenous conditions. Our group prepared l-proline functionalized mesoporous silica was synthesized under acidic condition using a poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) triblock copolymer template (EO20PO70EO20, Pluronic P-123, BASF). Furthermore, we successfully directly synthesized trans-1,2 diaminocyclohexane functionalized mesoporous silica by using microwave method. The direct functionalization of chiral ligand into the framework of mesoporous materials is expected to be useful for the heterogeneous asymmetric catalysis. So, we adopt the direct synthesis of chiral ligand functionalized mesoporous silica by using thermal and microwave irradiation. Then, chiral ligand functionalized mesoporous silicas were applied to enantioselective asymmetric catalytic reactions.

• 한국철도학회논문집
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• 제19권2호
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• pp.243-250
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• 2016

지속적인 경제성장에 더불어 지역 활성화 정책이 시행되면서 지역 간 통행수요가 증가하고 있으며, 이를 다양한 교통수단이 분담하고 있다. 교통 분야에서 저탄소 녹색성장이 강조되면서 친환경 교통수단인 간선열차로 통행수요의 전환을 유도하려는 노력이 이루어지고 있다. 이를 위하여 간선열차와 경쟁적 위치에 있는 대중교통수단들에 대한 승객들의 인식 파악 및 간선열차의 경쟁력 강화 방안에 대한 연구는 필수적이다. 본 연구에서는 6개의 대표적 지역 간 대중교통수단(KTX, ITX-새마을, 무궁화, 우등고속버스, 일반고속버스, 항공기)이 제공하는 서비스 특성에 대한 유사성을 다차원척도 분석을 실시하여 2차원 공간상에 개념적 거리로 표현하고 승객들의 수단 간 유사성 인식정도를 측정하였다. 연구 결과를 통하여 지역 간 대중교통 수단들에 대한 경쟁관계를 파악할 수 있었으며, 이를 통하여 간선열차가 상대적 경쟁우위를 선점하기 위한 방안을 제시하였다.

• 한국주거학회논문집
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• 제18권1호
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• pp.61-72
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• 2007

The purposes of this study were to summarize the concept of well-being and well-being apartment, to grasp the present condition of apartments which were introduced with well-being elements, and to find out the consumer preferences on well-being elements for apartment planning. Library and internet surveys were performed to summarize the concept of well-being and well-being apartment and to grasp the present condition of apartments which were introduced with well-being elements. Questionnaire survey was carried out from 2nd to 22nd of June 2005, to investigate the preferences on well-being elements for apartment planning. The respondents were 250 residents who are from thirties to fifties and living in urban area. As results, respondents think that 'living for health of body and mind' about concept of well-being and 'certificated apartments by green building rating system' or 'apartments introduced ecological factor' about concept of well-being apartment. They answered that 'yes' about 'Do you have intention to buy well-being apartment?'. The elements in aspect of complex planning having the preference were revealed that promenade for complex design, ecological garden or walking space for landscape design, outdoor exercise space for outdoor design, and security system for foundation equipment. The elements having the preference in aspect of public facilities were fitness room for sports & health facility and study room for cultural facility. The preferred elements in aspect of building and unit design were roof garden for building design, multi-functional room for unit floor plan, natural surface material for interior surface, ventilation system for indoor environment, control system for home automation, and food waste machine for home electronics.

• 한국주거학회논문집
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• 제17권3호
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• pp.9-18
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• 2006

This study analyzes relevant data based on the mid-sized rental unit. It focuses on how we can set up appropriate mid-sized rental unit plan as its supply has been accelerated over time. The questionnaires used in this study cover a series of categories including site environment, unit plan, neighborhood, economy, and management. The 342 respondents are from the 3-year old apartments at Cheongju. The key findings are as follows. 1) As the average indices including number of family, life cycle, and income under the survey are different in terms of the rental unit sizes between 20 and 30 pyeongs. 2) In general, residents present comparatively high level of satisfaction in terms of residential environments. Their evaluation on the site environment unit plan, and neighborhood is around the average. In contrast, the economic and management efficiency categories are under the average. This study suggests residential guidelines should be derived from tenant differentiation policies dealing with diverse socio-demographic characteristics and satisfaction level. 3) In terms of improvement priority, residents present, higher preference on the management system and site environment. This study advises to establish an appropriate alternative to guarantee effective tenant participation. Considering the lower satisfaction level in the green space, common facilities, and resting space, this study also urges to secure quality control for desirable planning of the mid-sized rental apartments.