• 오토저널
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• 제10권6호
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• pp.39-47
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• 1988

A disk photo sensor system was constructed and installed on engine for the crank angle measurement. Statically measured TDC crank angle data were compared with those obtained from engine motoring. Two groups of cylinder pressure data were compared each other, one measured by pressure transducer mounted flush on the combustion chamber and the other obtained with the help of spark plug type adaptor. A simple analysis on the gas flow in the spark plug type pressure transducer displayed reasonably good agreement with those from engine motoring tests. In various firing tests, the IMERs obtained from the spark plug type pressure transducer turned out to be higher than those from the flush mounted one at low engine speed while those two were nearly the same at high engine speed. As the engine load decreased the relative difference in IMEP measurement between the two types tended to be enlarged.

• Steel and Composite Structures
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• 제4권2호
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• pp.77-94
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• 2004

Steel beam-to-column joints are often subjected to a combination of bending and axial forces. The level of axial forces in the joint may be significant, typical of pitched-roof portal frames, sway frames or frames with incomplete floors. Current specifications for steel joints do not take into account the presence of axial forces (tension and/or compression) in the joints. A single empirical limitation of 10% of the beam's plastic axial capacity is the only enforced provision in Annex J of Eurocode 3. The objective of the present paper is to describe some experimental and numerical work carried out at the University of Coimbra to try to extend the philosophy of the component method to deal with the combined action bending moment and axial force.

• 한국정보과학회논문지:정보통신
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• 제34권2호
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• pp.110-119
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• 2007

Mobile IPv6(MIPv6)는 이동 호스트(mobile node: MN)가 인터넷의 연결 지점을 변경하더라도 임의의 호스트(correspondent node: CN)와 계속 통신을 유지할 수 있도록 하는 기술이다. 기존의 MIPv6 프로토콜에서는 핸드오버 기간 동안 CN이 MN으로 전송하는 트래픽은 손실된다. 이를 방지하기 위하여 HMIPv6 및 FMIPv6와 같은 여러 메커니즘들이 제안되었다. 그렇지만, 이들 메커니즘도 역시 패킷 손실이나 패킷의 순서 어긋남으로 인한 상위 계층의 성능 저하 문제가 발생한다. 본 논문에서는 패킷 손실과 순서 어긋남 문제를 해결할 수 있는 I-FHM1IPv6 를 제안한다. I-FHMIPv6에서는 홈 에이전트(home agent: HA) 또는 CN에게 MN의 바인딩 캐쉬 엔트리가 갱신된다는 것을 알려주는 Flush 메시지를 새로 정의했다. 이 메시지를 수신한 MN은 이전의 경로를 통한 패킷 전송이 종료된다는 것을 알 수 있으며, 이를 통하여 패킷의 순서 어긋남 문제를 해결할 수 있다. 또한 제안된 알고리즘은 효율적으로 FMIPv6 와 HMIIPv6 를 통합함으로써 패킷 손실을 최소화할 수 있다. 모의실험을 통해 제안된 알고리즘의 성능을 분석하였으며, I-FHMIIPv6의 성능이 기존 FMIPv6나 HMIIPv6보다 우수함을 알 수 있었다.

• 상하수도학회지
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• 제18권3호
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• pp.320-330
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• 2004

Most of domestic city is served combined sewer system among various sewer system like as separate sanitary, combined sewer system and storm sewers. During the wet weather, sewer and rainfall have been overflowed because it is over capacity of the combined sewer system; that is called combined sewer overflows(CSOs) This research was carried out to investigate runoff characteristics of combined sewer and to evaluate the effective CSOs volume in Hong-Chun gun. During wet weather, SS load of first rainfall at H-1, H-2, and H-3 were 600kg/event, 370kg/event, and 289kg/event, respectively. 55 load of second rainfall were 216kg/event, 113kg/event, and 37.2kg/event. When the first rainfall, event mean concentrations(EMCs) at each site were 702mg/L, 816mgjL and 861.5mg/L. The second rainfall's event mean concentrations(EMCs) were 99.9gm/L, 161.9mg/L, 103.6mg/L. Rrst flush coefficient b at each site were 0.237,0.166, and 0.151. When the first rainfall, the flow containing 80% of pollutant mass of CSOs at each site were 0.55, 0.23, 0.48 in first rainfall, respectively. The case of second rainfall were 0.79, 0.83, 0.81. Most of all, characteristics of rainfall like as analysis of first-flush, CSOs volume, pollutant loadings is investigated to decide intercepted volume for control of CSOs.

• 한국환경과학회지
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• 제24권12호
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• pp.1617-1627
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• 2015

This study was carried out to investigate the characteristics of suspended solid concentration in small forest watershed, Hwacheon, Gangwondo. For five rainfall events from July 2013 to August 2013, rainfall, discharge, and suspended solid load has been measured. The results showed that the fist flush effect was observed for suspended solid in each rainfall event, sediment rating curve was obtained with $y=30.029x^{1.573}$ at rising limb and $y=12.902x^{1.8827}$ at falling limb, and EMC (event mean concentration) of suspended solid was calculated to 9.4 mg/L. EMC was compared to the values from the watershed that has various land use types and EMC from forest watershed was much lower that from the crop, paddy or low covered forest watershed.

• 대한기계학회논문집B
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• 제21권1호
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• pp.15-23
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• 1997

An experimental investigation of two-dimensional steady natural convection cooling in a vertical open top cavity with conducting side walls of finite thickness is presented. The various heat-generating discrete heaters are located on one vertical wall of the cavity. When each heater dissipates different amount of power, the purpose of the work is to obtain the optimal array condition of the heaters. The four cases of non-uniform heating conditions are considered. The temperature fields in the cavity were visualized by the interferometer and local temperatures of the vertical wall were measured by thermocouples. The heaters were arranged in two configurations: flush-mounted on a vertical wall or protruding from the wall about 4.5 mm. The vertical wall was constructed out of copper or epoxy-resin sheet. Experiments have been conducted for air with constant Prandtl number(Pr=0.7), the aspect ratio of 4.6, 7.5, 9.5, power input in the range of 0.9 W ~ 4.2 W. For the enhancement of the cooling effectiveness, the upper and lower of vertical wall would give the better position for the heaters of higher heat flux.

• 한국물환경학회지
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• 제31권4호
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• pp.418-427
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• 2015

This study was carried out to evaluate the performance of a lab-scale novel septic tank system for improving the conventional septic tank in the developing countries of water shortages. The lab-scale novel septic tank system consists of sepetic tank, aeration tank with HBC-ring, and sand filter. Optimum HRT was reguired about 1.5days to get a total COD removal efficiency of 90%, COD, BOD and SS removal efficiency was about 70%, 60%, and 85% in sepetic tank only. The structure of sepetic tank with two stages results in the high removal efficiency of organic matter. When sepetic tank, aeration tank, and sand filter were more than HRT 1.5days, 18hrs, and 12hrs, respectively, final effluent was less than 20 mg/L of BOD, 14 mg/L of SS, so that there is a high potential of its use for reusing water in flush toilet. There is no significant effect of HRT change on nutrient removal. Total nitrogen removal efficiency was about 40%, final effluent was 30~40 mg/L of TN, total phosphorus removal efficiency was about 11~25%, final effluent was 9~12 mg/L of TP. Because there is very small amounts of organic nitrogen and phosphorus in effluent, it was possible to reuse water for agricultural use.

• 대한환경공학회지
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• 제35권9호
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• pp.643-653
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• 2013

본 연구에서는 불투수성 지역에서 강우시 비점오염원 유출특성을 파악하고, 다양한 해석방법을 통하여 비점오염물질의 초기유출현상을 규명하고자 하였다. 불투수성 지역에서의 강우사상 특성은 강우강도의 영향을 많이 받는 것으로 나타났으며, 강우강도가 크면 초기유출현상이 뚜렷하게 나타나는 것으로 나타났다. 또한 선행무강우일수에 의해서 비점오염물질의 농도차가 큰 것으로 나타나, 이에 대한 대책 마련이 필요할 것으로 판단된다. 비점오염원의 초기유출에 의한 감소율(DR) 평가 결과, 강우시 불투수성 지역에서의 비점오염 유출특성은 건기시 불투수면에 집적되어 있던 비점오염물질이 초기강우에 의해 높은 농도로 유출되는 경향을 보였기 때문에 초기강우로 인한 비점오염물질에 대한 대책을 마련하는 것은 중요하고, 이와 관련하여 비점오염 처리시설에 대한 용량 산정에 대한 평가도 필요할 것으로 판단된다. 초기유출에 의한 감소율(DR) 경향 분석은 비점오염물질에 대하여 감소율(DR) 50%를 기준으로 조사지점별 강우유출시간을 분석하였는데, TSS는 15~60 min으로 나타났으며, 유기물질은 30~90 min으로 나타나는 경향을 보였지만 강우유출이 끝날 때까지도 감소율(DR)이 50% 이하인 특성도 나타났다. 이를 근거로 하여 향후 구조적 BMPs 시설 설계 시 참고자료로 활용할 수 있을 것으로 판단된다.

• 한국버섯학회지
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• 제13권1호
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• pp.11-15
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• 2015

최근 노루궁뎅이버섯(H. erinaceus)의 다양한 효능에 대한 연구결과가 발표되면서 노루궁뎅이버섯의 소비는 점진적으로 확대되고 있는 추세이다. 노루궁뎅이버섯의 안정적인 생산을 위해 발이유도방법에 따른 버섯발생양상을 조사한 결과는 다음과 같았다. 수확기간은 표면상처를 낸 처리구가 상면상처를 낸 처리구보다 빨랐으며, 수확량은 생체중에는 차이가 없었으나 2주기 수확버섯의 건물중에서는 차이가 있었다. 2주기버섯의 재발생률은 T5처리구가 가장 높았으며, 상면처리구보다 표면상처를 낸 처리구에서 재발생률이 높은 것으로 조사되어 현재 노루궁뎅이버섯 재배농가에서 느타리버섯 재배방식에 준하여 시행하고 있는 방식인 상면 균긁기 후 발이를 유도하는 방법은 개선되어야 할 것으로 판단할 수 있었다. 노루궁뎅이버섯의 형태적 특징은 T5처리구가 가장 큰 덩어리형태로 생장하여 상품가치가 높다고 판단할 수 있었다.

• 한국실내디자인학회:학술대회논문집
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• 한국실내디자인학회 2004년도 춘계학술발표대회 논문집
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• pp.123-126
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• 2004

This study aims to identify the change of bathroom design characteristics through the investigation of bathroom space in apartment model houses. The bathroom space of each private exclusive area was analyzed from the plane characteristics perspective such as quantity, location, size and shape. For this study, site survey and observation was performed to analyze the characteristics of plane and design based on twenty seven model houses of seven large-sized construction firms with Seoul area focused on. Research object was restricted to from ten Pyeong's apartment to sixty Pyeong's in order to understand various characteristics of twenty seven model houses. Since analysis variables were not diverse, the main three factors - frequency, percentage and an average - were represented in Microsoft Excel worksheet, focusing on the quantity of each case, design characteristics and pattern. 1) The quantity of bathrooms: It was turned out that the quantity of bathroom was one in ten Pyeong's apartment while it was two in thirty, forty, and fifty Pyeong's apartment. There were mostly two bathrooms available in twenty Pyeong's apartment even if only one was planned in few cases. All powder rooms and dress rooms in twenty and fifty Pyeong's apartment were designed to be separated and be accessible through bedroom. 2) The size of bathrooms: As private exclusive area increased, the size of bathroom for both family and couple increased. Couple bathrooms had the tendency to be equipped with shower booth and bathtub at the same place or have more tubs than family bathrooms because couple bathrooms were bigger than family bathrooms. 3) The location of bathrooms: Couple bathrooms were usually located beyond dress rooms or powder rooms while family bathrooms were mostly located at the entrance side. 4) The shape of bathrooms: Shower booth was assumed to be in general vogue because family bathrooms, for the most part, were comprised of a flush toilet, a washstand and a shower booth. In the case of couple bathrooms, a flush toilet, a washstand, a shower booth and a tub were generally equipped in more than twenty Pyeong's apartments while a tub was not installed in twenty Pyeong's apartments.