• 한국전기전자재료학회논문지
• /
• 제28권11호
• /
• pp.743-747
• /
• 2015

In this paper, the power generation efficiency of the 4 [kW] fixed-concentrated type photovoltaic power generation system and that of the 4 [kW] single axis trace type photovoltaic power generation system were compared. For that purpose, the two types of photovoltaic power generation systems have been in operation for 1 year on an experimental basis. The amounts of power generated by the two types during the months of January through December and the characteristics of their operating times during the same period have been compared and analyzed. For the study, the type with higher efficiency was selected and the following conclusions have been reached. It was shown that the amount of power generated and the average operation times during the spring months of March through May are higher that those of the summer months of June through August when more sunlight is available. The reason for this phenomenon is thought to be that as the temperatures of the solar panel surface and the surrounding environment go up, the electric current decreases.

• 한국주거학회논문집
• /
• 제26권6호
• /
• pp.139-146
• /
• 2015

In this study, the plane type of main building relics of unified Silla period house site which excavated in Gyeongju city after 1990s was classified and the architectural characteristic of them was investigated. The chronology of building relics in Silla capital city site was mostly known as 8-9th century, and by standard of column arrangement, the plane types of them could be classified as grid type, front veranda-grid type, outer column type. The outstanding characteristic of plane is wide span and open front veranda. In most relics the span were over 4 meters, and inner foundations for small post and strip foundation were found between columns. The front veranda added type buildings were composited of enclosed main room and open front veranda, and column arrangement of them dose not fall into line in most case. Thus it thought that the structures of enclosed main room and open front veranda were independent. The interior space of enclosed main room were divided two rooms by partition wall in some case. In this case, one room is enclosed by wall, and the other room has open front side. This plane is considered for the pleasant life in cold winter and hot summer.

• 한국자동차공학회논문집
• /
• 제15권3호
• /
• pp.99-105
• /
• 2007

Currently, BLDC fuel pump was applied on LPi vehicle using 3rd fuel supply system as liquified phase LPG injection method had already shown better performance than others. Its cost, however, is rather expensive because of drawbacks such as complicated structure, a fault of localization of system. In this work, demonstration system for a developed turbine type fuel pump to replace BLDC system was setup and investigated. This study results that fuel mass flow rate of turbine type pump and injection performance of injector were better compared to BLDC type. Comparing flow rate of summer LPG with that of winter LPG, the flow rate decreased about 25% using winter LPG. Performance applying turbine type LPi fuel pump to engine is confirmed.

• Journal of the Korean Wood Science and Technology
• /
• 제17권1호
• /
• pp.22-54
• /
• 1989

Seasonal semi-greenhouse type solar-drying of 2.5cm-and 5.0cm-thick lumber of Quercus aliena Blume and Quercus variailis Blume was carried out to investigate the possibility of solar-drying of wood and to decide the active solar-drying period in Korea. In the active solar-drying period obtained solar-dehumidification, semi-greenhouse type solar-, air- and kiln-drying of 2.5cm -thick lumber of oaks were carried out to analyze drying-rates. -defects, and -yield in each drying-method and to calculate daily total absorbed solar-radiation the solar dryers. The energy balance equations were set up, considering all the energy requirements, to analyze the heat efficiencies of semi-greenhouse type solar and solar-dehumidification-dryer. In a seasonal drying the drying rate of semi-greenhouse type solar-dryer was highest in summer, and greater in fall, spring, and winter in order. Solar-drying time was 45% in summer to 50% in winter of the air-drying rime, and more serious drying-defects occurred in air-drying than in solar-drying. In the active solar-drying period. April, May, and June, the average drying rate in solar-dehumidification-drying was 1.0%/day and greater than 0.8%/day in semi-greenhouse type solar-drying. In solar-dehumidification-drying the time required to dry lumber to 10% moisture content was less than 60 days, and solar-dehumidification-drying showed the highest drying-yield, 65.01%, than the other drying methods. The daily total absorbed solar radiations were 8.51MJ on the roof collector and 6.22 MJ on the south wall collector. In the energy blance 69.48% of total energy input was lost by heat conduction through walls, roof. and floor 11.68% by heat leakage, 0.33% by heating the internal structures of the solar-dryer and 5.38% by air-venting. Therefore the heat efficiency of semi-greenhouse type solar-dryer 13.13%, was lower than that of solar-dehumidification-dryer, 14.04%. Solar-drying of lumber in Korea showed the possibility to reduce the air-drying-time in every season and the efficiency of solar-dehumidification drying was higher than that of semi-greenhouse type solar-drying.

• 한국지형학회지
• /
• 제20권3호
• /
• pp.41-53
• /
• 2013

이 연구는 안면도 둔두리 해식애를 대상으로 주기적인 현장조사를 통해 침식율을 산정하고, 침식형태를 분류하였다. 침식기준목을 이용한 현장 측정결과, 해식애의 연간 침식율은 지점별로 약 25~102cm/yr 정도로 추정되었다. 침식율은 봄에서 여름까지 점차 증가하다가 가을에 다소 감소하는 경향을 보였다. 특히, 6~7월 사이의 침식율이 다소 감소하는 추세를 보이다가 7~9월 사이에 급격히 증가하였다. 이러한 원인은 연구지역에 직접적인 영향을 끼친 여름 집중호우 및 태풍으로 발생한 폭풍해일에 의해 해식애의 침식이 다른 기간에 비해 급격하게 진행된 것으로 판단된다. 그 후 해식애의 침식율은 가을철이 되면서 점차 감소하다 12월에서 1월이 되면 다시 증가세를 보이는데, 이는 겨울철 해식애의 기반암이 동결 융해작용을 반복하면서 기계적풍화가 활발히 진행되었기 때문인 것으로 판단된다. 둔두리 해식애의 침식 형태별 유형은 세 가지 유형으로 구분이 된다. 첫 번째 Type A의 경우 동일한 기반암 혹은 경암층으로 이루어진 해식애에서 관찰되는 유형이다. 두 번째, Type B의 경우 동일한 기반암 혹은 경암층으로 이루어진 해식애 면에 토양을 포함한 풍화물질이 형성되어 있는 비교적 Type A에 비해 경사가 완만한 해식애에서 관찰되는 유형이다. 마지막으로, Type C의 경우 경암층과 연암층이 혼재되어있는 해식애에서 관찰되는 유형으로, 강우나 파랑에너지에 의해 연암층이 먼저 붕락 및 침식되고 노출된 경암층이 추가적으로 붕락이 이루어지는 유형이다.

• 한국자원식물학회지
• /
• 제19권2호
• /
• pp.218-222
• /
• 2006

재배시기, 시설형태 그리고 시설내 계배위치에 따른 가상환경의 차이와 이에 따른 양액계배 오이의 생장 반응을 알아보기 위하여 여름재배와 억제재배, 1-2W형 하우스와 무기둥 하우스에 양액계배를 통해 오이를 패배한 후 시설내 부위별 기온, 상대습도, 일사량과 생장해석을 통해 얻어진 생리적 형질들을 조사하여 비교한 결과는 다음과 같다. 하우스 내부의 평균기온이나 평균상대습도는 하우스 형태간 유의한 차이가 없었으나 일사량은 1-2W형 하우스가 무기둥 하우스에 비해 유의하게 높았다. 일누적일사량은 1-2W형에서는 남서쪽이 무기둥 하우스에서는 북서쪽이 대체로 높았다. 초장과 엽수는 억제재배보다 여름재배에서 높게 나타났으며 엽면적은 억제재배에서 많았다. 상대생장율은 순동화율 및 엽면적비율과 고도로 유의한 정의 상관관계를 보였으며 상대생장율에 대한 기여도는 순동화율이 엽면적비율보다 높은 것으로 나타났다. 작물생장율은 엽면적지수와 고도로 유의한 정의 상관을 보여 엽면적지수의 증대가 단위면적당 생산량의 증대에 크게 영향하는 것으로 나타났다. 전 생육기간의 일평균기온는 상대생장을 및 순동화율과 고도로 유의한 정의 상관관계가 있었다. 억제재배에서는 전 생육기간의 누적일사량과 상대생장을 및 순동화율과 유의한 정의 상관관계가 있었다.

• 대한기계학회논문집
• /
• 제17권8호
• /
• pp.2099-2109
• /
• 1993

A gas-fired 4RT absorption heat pump was designed as an air-conditioner for domestic use during the summer. The absorption heat pump is air-cooled. double-effect, $LiBr-H_{2}O$ system with parallel flow type. The performance of the absorption heat pump in the cooling mode of operation was investigated through cycle modeling and simulation to obtain the system characteristics with parameter changes. System parameters considered in this analysis were the inlet temperature of cooling air to the absorber, the working solution concentrations, the ratio of the amount of the weak solution from the absorber, and the LTD's of each heat exchange component. The optimum designs and operating conditions were determined based on the operating constraints and the coefficient of performance.

• 대한가정학회지
• /
• 제25권3호
• /
• pp.83-94
• /
• 1987

The floor plan of the folk houses in Korean-Middle area was "-" type, "ㄱ" type and "double " type. The common terms of lifespaces were Anbang(안방), Wootbang(웃방), Cunnunbang(건넌방), Taechung(대청), Maru(마루), Buoak(부엌), Chungji(정지), Sarangbang(사랑방), Bongdang(봉당). 1) Anbang was basically a master room and was a family room. The function of another presented in Anbang was a space of the dying hour, the mourning decorums, and the memorial services. 2) Wootbang, Cunnunbang was terms that coming from the space position. Such spaces were the private rooms of children. 3) Sarangbang was basically the space of a reception of guests. 4) Buoak, Chungji were cooking and working space. Primarily, Buoak was the terms meaned Bootumk(부뚜막) in Chosun dynasty. 5) Maru, Tachung were terms of presented from side of construction. Specially, it was the chief space in family in Summer. 6) Bongdang was a terms of space that mean working areas, entry hall etc.working areas, entry hall etc.

• 한국마린엔지니어링학회:학술대회논문집
• /
• 한국마린엔지니어링학회 2011년도 전기공동학술대회 논문집
• /
• pp.202-202
• /
• 2011

Thermal energy storage(TES) cooling system using cheaper electricity of off-peak time has been applied to relief a significant portion of the peak demand of electricity during the daytime in summer. Slurry ice type thermal energy storage cooling system is one kind of more efficient ice-thermal energy storage cooling system than Ice-on-Coil type or Encapsulated type TES cooling system, even though, which are more popular TES system. This study is experimented to observe flow pattern and formation of slurry ice in reversing flow to improve efficiency of heat transfer between fluid and freezing tube.

• 대한설비공학회:학술대회논문집
• /
• 대한설비공학회 2005년도 동계학술발표대회 논문집
• /
• pp.199-204
• /
• 2005

The decrease of summer peak electric load of our country is very important. The government is arranging a lot of support policies and statutes. etc. to decrease of peak electric load. And ice storage system is known as one of the alternatives. The purpose of this study is to collect basic data for operating characteristics to plan the most suitable operation of capsule-type ice storage system. The storaging tank is designed to take charge 40% of total cooling load in building, In operation condition the storage tank took charge 50%. Coefficient Of Performance of daily screw refrigerator is around 4.