• 한국주거학회논문집
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• 제25권4호
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• pp.125-133
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• 2014

The purpose of this study was to find the role of participation in common activities and satisfaction with common space in a tentative housing adjustment framework for Swedish cohousing residents, applying the housing adjustment behavior model of Morris and Winter (1978, 1996). The data used for this research were a subset of data Choi and Paulsson (2011) surveyed from 12 Swedish cohousing units. Number of 216 cases whose age was 40 and over were selected and analyzed with Pearson correlations and hierarchical linear regressions by SPSS. The regression analyses included four main concepts as endogenous variables, which were participation in common activities, satisfaction with common space, overall life satisfaction, and intention to move out. The results showed that participation in common activities raised satisfaction with common space and overall life satisfaction but reduced intention to move out. Meanwhile, satisfaction with common space diminished intention to move out but did not impact overall life satisfaction. When overall life satisfaction was added to the final regression model, the direct impacts of security reasons, participation in common activities, and satisfaction with common space on intention to move out disappeared. It may be concluded that participation in common activities and satisfaction with common space acted as intervening variables in the tentative cohousing adjustment framework. Even though this study leaves further research on specifying the framework, it may be noteworthy as a first attempt that explains the flow of main concepts. This study may broaden the possibility of empirical studies to develop an analytical path model of housing adjustment for cohousing residents.

• 한국정보처리학회논문지
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• 제4권2호
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• pp.628-638
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• 1997

VSLI회로에서 스위치 레벨 결함 모델은 stuck-at결함만 사용하는데 한계가 있다. 따라서 본 연구는 스위치 레벨 결함 모델인 트랜지스터 stuck-open과 stuck-close결함을 다룰 수 있는결함 시뮬레이터를 구현한다. 스위치 레벨 회로는 이론적으로 신호 흐름이 양방향으로 전달되지만 실제로 대부분의 신호 흐름은 약 95%정도가 단 방향을로 설정되어 평가되는 것으로 나타내고 있다. 본 연구에서는 스위치 레벨 회로를 단반향 그래프 모델 로 변환시켜 해석한다. 스위치 레벨 회로는 EDIF컴파일러에 의해 입력되고 두개의 단방향으로 재구성된 자료구조를 만든다. 스위치 레벨 회로는 신호 흐름 경로가 도입되는 지배적 경로 기법이 제시된다. 지배적 경로는 경로를 판단하여 최종 출력 상태값을 결정하는 논리 시뮬레이션을 수행한다. 스위치 레벨 결함 시뮬레이션은 노들들로 연결되는 경로 상에 임의 트랜지스터의 stuck-open,stuck-close 결함을 주입시키고, 트랜지스터 저항값을 적용한 노드세기의 계산에 의한 지배적 경로를 평가한다. 이때 최초 입력은 two pattern vector를 인가하여 정상회로의 최종 출력 상태값과 결함회로의 출력 상태값을 비교하여 결함 검색하며, 그결함 검색의 정확성 을 보인다.

• 농업과학연구
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• 제38권4호
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• pp.747-752
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• 2011

Wireless technology has enabled farmers monitor and control protected production environment more efficiently. Utilization of USN (Ubiquitous Sensor Network) devices also brought benefits due to reduced wiring and central data handling requirements. However, wireless communication loses signal under unfavorable conditions (e.g., blocked signal path, low signal intensity). In this paper, performance of commercial wireless communication devices were evaluated for application to protected crop production. Two different models of wireless communication devices were tested. Sensors used in the study were weather units installed outside and top of a greenhouse (wind velocity and direction, precipitation, temperature and humidity), inside ambient condition units (temperature, humidity, $CO_2$, and light intensity), and irrigation status units (irrigation flow and pressure, and soil water content). Performance of wireless communication was evaluated with and without crop. For a 2.4 GHz device, communication distance was decreased by about 10% when crops were present between the transmitting and receiving antennas installed on the ground, and the best performance was obtained when the antennas were installed 2 m above the crop canopy. When tested in a greenhouse, center of a greenhouse was chosen as the location of receiving antenna. The results would provide information useful for implementation of wireless environment monitoring system for protected crop production using USN devices.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2010년도 제35회 추계학술대회논문집
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• pp.833-837
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• 2010

본 연구는 최소 압력 모사로 엔진 배기가스를 배출시키기 위한 최적 이젝터 크기를 결정하기 위한 것을 목적으로 한다. 실험 챔버로 유입되는 2차 냉각 공기는 유량제어 밸브들과 진공펌프가 장착된 배출구를 통해 엔진배기가스는 분리되어 배출된다. 기존 고도시험 장치와 달리, 본 연구에 제안한 형상은 기존 이젝터의 압력 회복을 개선한 좀 더 작은 포획 면적을 가진 배기 이젝트를 사용하면 가스에 스텔링 챔버로 부터 20% 냉각 공기를 부가하여 배출시키도록 크기가 정해진다. 제안된 형상은 벨마우스 이젝터와 엔진배기 출구의 면적비가 이론적으로 약 1.2를 갖는다. 제안된 형상의 혼합 공기 모사결과에 따르면 큰 에너지는 기존 시스템 비해 좀 더 개선된 압력 회복과 감소된 전력 소모를 같음을 확인하였다.

• 한국컴퓨터정보학회논문지
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• 제12권4호
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• pp.43-52
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• 2007

공개 웹 서비스의 수효가 증가하면 동일한 기능을 제공하는 웹 서비스가 여러 개 존재하게 될 것이다. 이들은 가격, 응답 시간, 가용성 등 다양한 QoS 특성들을 가지게 되는데, 주어진 QoS 제약을 만족하며 가장 적합한 서비스를 선택하는 것은 매우 중요한 작업이다. 본 논문에서는 비즈니스 프로세스의 병행 분기와 응답시간 제약을 중점적으로 고려하여 서비스의 선택 모형을 연구하였다. 다차원 다중선택 Knapsack 모형을 기본으로, 각 프로세스 실행 경로 별로 응답시간 제약조건을 갖는 방안과 전체 서비스 타입에 대하여 하나의 응답시간 제약조건을 갖는 방안, 그리고 특정 경로에 대해서만 응답시간 제약 조건을 적용하는 방안을 제시하고, 실험을 통하여 서비스 수, 병행 분기의 수 그리고 제약 조건 값의 크기 등의 변화에 따른 각 방안의 성능을 살펴보았다. 실험에 사용된 데이터를 기준으로 볼 때, 파레토 우세를 이용하여 후보 서비스 수를 줄이는 것은 매우 효과적이며, 중소규모의 복합 웹 서비스에서는 전체 서비스 타입에 대하여 하나의 응답시간 제약을 설정한 방안이 실행시간과 탐색 해의 최적 해 근접도 면에서 효율적인 것으로 분석되었다.

• 대한전자공학회논문지SD
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• 제46권6호
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• pp.58-64
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• 2009

재구성 구조를 위한 자동화된 툴의 개발에 있어서 명령들을 재구성 구조에 맵핑하기 위한 알고리즘의 개발은 가장 중요한 부분 중의 하나이다. 본 논문에서는 리소스가 한정된 Coarse-Grained 재구성 구조에 명령들을 맵핑하기 위한 알고리즘을 개발하고 이를 위한 휴리스틱을 제시하였다. 제안된 알고리즘에서는 하드웨어 리소스 사용에 대한 명령 할당과 라우팅 경로 할당을 사이클 기반의 타이밍 모델을 통해서 동시에 고려하였다. 제안된 알고리즘은 통신에 사용되는 리소스의 사용 및 전역 메모리 접근을 리스트 스케줄링을 기반으로 최소화한다. 리스트 스케줄링에서 맵핑되어야 할 명령들은 대상 어플리케이션의 데이터 플로우의 일반적인 특성들로 우선순위가 결정되게 된다. 제안된 맵핑 알고리즘의 대한 평가를 통해서 볼 때 전역 메모리 자원의 소모 및 수행 시간면에서 상당한 성능향상을 얻을 수 있었다.

• 농업과학연구
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• 제37권2호
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• pp.223-229
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• 2010

This study is to analyze location conditions for erosion control dams to be constructed in Chungcheongnam-do, Daejeon Metropolitan City, Chungcheongbuk-do and Gyeongsangbuk-do in order to establish proper conditions for erosion control dams in the future. 199 sites where erosion control dams are expected to be built in 2010 were chosen and investigated in terms of 12 factors including basin area, basin slope, and landslide risk. The results showed that erosion control dams for Chungcheongnam-do and Daejeon Metropolitan City are mostly impermeable gravity dams mainly composed of concrete. In contrast, Chungcheongbuk-do and Gyeongsangbuk-do are increasing the number of permeable or compound erosion control dams. Basin analysis at planned erosion control dam sites showed that at least 44.5% of the total area has high landslide risk. Gyeongsangbuk-do had the largest basin area for erosion control dam sites at 157.3ha, followed by Chungcheongbuk-do at 64.4ha and Chungcheongnam-do at 54.8ha. Analysis of sand deposits in the Chungcheongnam-do erosion control dam built in 2010 confirmed an average deposit of 971.8m3. The sand deposit capacity and amount of sediment control for erosion control dams have a very low correlation with basin area or flow path slope, and this needs to be addressed in future sand deposit capacity designs.

• 한국수소및신에너지학회논문집
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• 제24권1호
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• pp.61-69
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• 2013

Polymer exchange membrane (PEM) fuel cells have multifunctional properties, and bipolar plates are one of the key components in these fuel cells. Generally, a bipolar plate has a gas flow path for hydrogen and oxygen liberated at the anode and cathode, respectively. In this study, the influence of iodine applied to a bipolar plate was investigated. Accordingly, we compared bipolar plates with and without iodine coating, and the performances of these plates were evaluated under operating conditions of $75^{\circ}C$ and 100% relative humidity. The membrane and platinum-carbon layer were affected by the iodine-coated bipolar plate. Bipolar plates coated with iodine and a membrane-electrode assembly (MEA) were investigated by electron probe microanalyzer (EPMA) and energy-dispersive x-ray spectroscopy (EDS) analysis. Polarization curves showed that the performance of a coated bipolar plate is approximately 19% higher than that of a plate without coating. Moreover, electrochemical impedance spectroscopy (EIS) analysis revealed that charge transfer resistance and membrane resistance decreased with the influence of the iodine charge transfer complex for fuel cells on the performance.

• 한국전기전자재료학회논문지
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• 제21권9호
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• pp.835-843
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• 2008

We have fabricated the source-drain electrodes for OTFTs by screen printing method and manufactured Ag pastes as conductive paste. To obtain excellent conductivity and screen-printability of Ag pastes, the dispersion characteristics of Ag pastes prepared from two types of acryl resins with different molecular structures and Ag powder treated with caprylic acid, triethanol amine and dodecane thiol as surfactant respectively were investigated. The Ag pastes containing Ag powder treated with dodecane thiol having thiol as anchor group or AA4123 with carboxyl group(COOH) of hydrophilic group as binder resin exhibited excellent dispersity. But, Ag pastes(CA-41, TA-41, DT-41) prepared from AA4123 fabricated the insulating layer since the strong interaction between surface of Ag powder and carboxyl group(COOH) of AA4123 interfered with the formation of conduction path among Ag powders. The viscosity behavior of Ag pastes exhibited shear-thinning flow in the high shear rate range and the pastes with bad dispersion characteristic demonstrated higher shear-thinning index than those with good dispersity due to the weak flocculated network structure. The output curve of OTFT device with a channel length of 107 ${\mu}m$ using screen-printed S-D electrodes from DT-30 showed good saturation behavior and no significant contact resistance. And this device exhibited a saturation mobility of $4.0{\times}10^{-3}$ $cm^2/Vs$, on/off current ratio of about $10^5$ and a threshold voltage of about 0.7 V.

• Journal of Biosystems Engineering
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• 제26권5호
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• pp.441-448
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• 2001

Hot air heater with light oil combustion is used as the most common heater for greenhouse heating in the winter season. However, exhaust gas heat discharged to atmosphere through chimney reaches up to 10~20% of total heat capacity of the oil burred. In order to recover the heat of this exhaust gas and to use for greenhouse heating, the heat pipe type exhaust heat recovery system was manufactured and tested in this experiment. The system consisted of a heat exchanger made of heat pipes, ø15.88${\times}$600mm located in the rectangular box of 675(L)${\times}$425(W)${\times}$370(H)mm, an air suction fan and air ducts. The number of heat pipe was 60, calculated considering the heat exchange amount between exhaust gas and air and heat transfer capacity of a heat pipe. The working fluid of heat pipe was acetone because acetone is known for its excellent heat transfer capacity. The system was attached to the exhaust gas path. According to the performance test it could recover 53,809 to 74,613kJ/h depending on the inlet air temperature of 12 to -12˚at air flow rate of 1.100㎥/h. The temperature of the exhaust gas left the heat exchanger dropped to 100$^{\circ}C$ from 270$^{\circ}C$ after the heat exchange between the suction air and the exhaust gas.