• 한국실내디자인학회논문집
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• 제13호
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• pp.187-196
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• 1997

A Study on the Characteristics of the Modern Chair Design The features of the modern chair design results from the diverse life style unfolded as per the 20th century social structure and the change of the residential space, and new design has been being developed by the scientists and the artists in various fields through their cooperated work in a way. The field of the scientific or technical study and creation of arts can be developed where they can evoke the sympathy in the circumstances under which the various styles of both arts and science meet across, complement crash together, and grow up. The operation which can control in the network of such pluralistic sphere has been needed for a long period and it has been facing the needs from a time and society. The engineering furniture as the counterplan of the above has brought the value of materials into relief to the forms of human life by making the properties of matter the maximum value or changing it. It can be summarized as following characteristics in its materials and forms along as well as the 3 types (handycrafty, mechanical, and ecological expression) in process through the 20th century. 1. Characteristics in Materials elasticity of the chair as per the changes of the flexibility in the steel pipe development of systematic chair using the plasticity of the plywood, plastic, and wire lightweight due to the materials such as aluminum. 2. Formative characteristics formative simplicity for the increase of the function and the quality improvement such as sociality, productivity, environmental and aesthetic nature emphasis on the structure as per the architectural environment and tecniques pursuit of the forms as a container of the human body seeking for the formative values as the cultural symbols coping with the needs from thepluralistic social structure Furniture is not the makeup for convenience sake but most importantexpression as necessaries of our environments. It should identify itself always as per these kind of needs and also it should be able to used to keep the relation of such mutual division, otherwise the purchase of new furniture should be necessary according to every change of the existing situatiov. Our residence doesn't need the specific style but expresses only the properties of the dwellers.

• 상하수도학회지
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• 제20권3호
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• pp.347-355
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• 2006

Anyang Stream including its main branch is the biggest branch stream of Han River in Korea. The geological and geomorphological characteristics were investigated to the affected area of Anyang Stream, in which rainfall characteristic was analyzed. The water quality surveyed that the analysis of water pollution used to biotic index and biological water pollution. The rainfall pattern in this area was like to that of typical Korea, but the rate of trigger and runoff during summer season(June~August) is more higher than mean of Korea. Before 2003, a dried stream is severe status, which was due to abundant runoff, but this status are improved. After 1997, water quality of stream is recovering status such as water pollution of stream steeply decreased. Especially after 2003, this trend is more quickly improved. Although, owing to the increasing of a T-N and SS at upstream wastewater were due to bad collection of industrial factories, livestock's and mans living, the water quality worsted at upstream. Water quality in total section of main stream was severely contaminated that water-quality limit is 5 with polysaprobic by water self-purification. That of main branch was 1~3limits with ${\alpha}$- and ${\beta}$-mesosaprobic in Anyang city area, But water quality in all area about another branch of Anyang stream except Anyang city area was almost under of 3 grades. Though trying of Anyang city for recover movement(completion of 2nd Sewage Treatment Plant and Water supply pipe system) on Anyang stream, water pollution states of upper branch in Anyang stream was not better than its of 2002 because it may be difference of control area on other cities.

• 한국작물학회지
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• 제32권1호
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• pp.10-15
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• 1987

Burley 21을 공시품종으로 하여 건조실은 파이프 비닐하우스를 이용하였고, 시험 I 은 차광율을 10∼90%까지 20%씩 차이를 두어서 5 처리를 하였으며, 시험 II는 흑색차광막, 차광강과 5가지 유색비닐 등으로 차광재료를 달리하여 잎담배 건조시 차광효과와 알맞은 차광재료를 달리하여 잎담배 건조시 차광효과와 알맞은 차광재료를 밝히기 위하여 본 실험을 수행하였던 바 결과를 요약하면 다음과 같다. 1. 차광량이 않을 수록 온도가 낮고 습도는 높은 경향이었다. 2. 노변 전까지의 차광효과는 엽중탈수속도를 지연시키는데 있었다. 3. 급건엽발생은 차광량이 많을 수록 적었으나 차광 70％ 이상에서는 큰 차이가 없었다. 4. 품질 및 물리성은 50％ 이하의 차광구에서 불량하였으나, 그 이상에서는 큰 차이가 없었다. 5. 건조시 차광량의 하한선은 70％ 본다. 6. 유색비닐 중 주황색, 백색 및 자주색비닐은 흑색차광막과 충분한 대비효과를 가지고 있다. 그러나 백색비닐은 광에 의한 내구성이 가장 약하였다. 7. 가시광선의 광질 차이는 건조에 거의 영향을 미치지 않았다. 8. 흑색계통의 차광재료는 차광량은 많으나 광energy를 흡수하여 하우스 내 온도를 높이므로, 내구성이 크고 광 반재형 차광재료의 개발이 요구되었다.

• 한국산학기술학회논문지
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• 제13권1호
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• pp.399-405
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• 2012

본 논문에서는 신형식 TO단면이 사용된 양단고정 또는 양단힌지 경계조건을 가지는 원형 강재아치의 비탄성 좌굴에 관한 연구를 수행하였다. 아치의 초기변형과 잔류응력을 고려한 비탄성 유한요소해석을 실시하기 위하여 3차원 유한요소해석 프로그램 ABAQUS가 사용되었다. 기존 연구결과와 유한요소해석결과 비교로부터 새로운 좌굴강도 산정식의 필요성을 확인 할 수 있었으며, 신형식단면 아치구조물의 임계좌굴하중을 간편하게 산정할 수 있는 새로운 좌굴계수식이 세장비 및 경계조건에 따라 제안되었다. 본 연구에서 제안하고 있는 간편 설계식을 이용하여 수직등분포하중을 받는 새로운 TO단면 강재아치의 임계좌굴하중을 합리적으로 산정할 수 있으며, 비대칭하중 및 강합성 아치교량 임계좌굴하중 산정에도 응용될 수 있을 것이다.

• 자원리싸이클링
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• 제7권2호
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• pp.16-22
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• 1998

최근 선진국에서는 폐플라스틱을 고로의 대체연료로 이용하려는 기술개발이 시도되고 있다. 본 연구에서는 포항제철 주물선 고로 풍구 1본을 대상으로 시험취입을 실시한 결과, 플라스틱의 취입속도는 다음과 같이 나타낼수 있었다. ${W}_{s}=0.265\frac{{delta}PA}{U}_{g}$ 여기서 Ws, ΔP, A 그리고 Ug는 각각 플라스틱 수송속도(kg/sec), 공급용기내의 압력과 송풍압력의 차이(atm), 수송배관의 단면적($m^2$) 그리고 총 수송공기 유속(m/sec)이다. 약 96시간의 조업기간중 최대 취입비 6.4kg-plastic/t-p까지의 반연속 시험취입 조업결과, 치환율은 1.38정도였다. 플라스틱이 취입됨에 따라 노정가스중 수소의 함량은 증가하였으며, 연소대 형상변화에 따라 bellyqn 노체의 온도는 상승하였다.

• Journal of Biosystems Engineering
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• 제30권3호
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• pp.185-191
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• 2005

Importance of alternative energy has been increasing due to environmental issues and lack of fossil fuels. In addition, heating cost that occupies from 30 to $40\%$ of the total production cost in the protected cultivation sector in Korea needs to be reduced for profitability and global competition. But, study on geothermal energy to solve these problems has not been activated for Korean protected cultivation. This study was conducted to develop an optimized geothermal exchange system through fundamental test of heat transfer characteristics in soil such as thermal diffusivity, changes in soil temperature during heating and cooling operations, and restorations of soil temperature after the heater was fumed off, These issues were investigated using computer simulation for different depths. The simulated characteristics were evaluated through controlled tests. Simulated characteristics of heat transfer in the soil at different depths showed a reasonable agreement with the results of the controlled tests. All of computer simulation and controlled tests, soil temperatures changed at 10cm and 20cm distance from pipe. but don't change at more than 30cm distance. It means that distances of heat transfer of the soil ranged from 20 to 30cm a day. Based on these results, the optimum spacing between adjacent heat exchange pipes and the pitch were selected as 50 and 40cm, respectively.

• Journal of Biosystems Engineering
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• 제39권1호
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• pp.34-38
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• 2014

Purpose: In this study, the performance of cooling system with the water-water heat pump system of 100kW scale made for cooling agricultural facilities, especially for horticultural facilities, was analyzed. It was intended to suggest performance criteria and performance improvement for the effective cooling system. Methods: The measuring instruments consisted of two flow meters, a power meter and thermocouples. An ultrasonic and a magnetic flow meter measured the flow rate of the water, which was equivalent to heat transfer fluid. The power meter measured electric power in kW consumed by the heat pump system. T-type thermocouples measured the temperature of each part of the heat pump system. All of measuring instruments were connected to the recorder to store all the data. Results: When the water temperature supplied into the evaporator of the heat pump system was over $20^{\circ}C$, the cooling Coefficient Of Performance(COP) of the system was higher than 3.0. As the water temperature supplied into the evaporator, gradually, lowered, the cooling COP, also, decreased, linearly. Especially, when the water temperature supplied into the evaporator was lower than $15^{\circ}C$, the cooling COP was lower below 2.5. Conclusions: In order to maintain the cooling COP higher than 3.0, we suggest that the water temperature supplied into evaporator from the thermal storage tank should be maintained above $20^{\circ}C$. Also, stratification in the thermal storage tank should be formed well and the circulating pumps and the pipe lines should be arranged in order for the relative low-temperature water to be stored in the lower part of the thermal storage tank.

• 한국화재소방학회논문지
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• 제32권1호
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• pp.24-32
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• 2018

수리계산방식에 의한 설계는 전산프로그램을 사용하는 방식과 직접 설계자가 계산에 의하여 설계하는 방식이 있다. 전산프로그램을 사용하는 경우 필요한 조건을 입력하면 프로그램에 의해 마찰손실, 유량, 양정 등을 계산하여 주지만 기본적인 개념과 절차를 모르게 되면 계산값이 입력자마다 다를 수가 있어 절차상의 기준을 정하는 것이 필요하다. 설계자가 직접 계산하는 경우에도 동일하다. 따라서 설계면적 내에서 수리계산의 절차를 다음과 같이 제시하였다. 가지관에 설치되는 티의 등가길이는 방출구(Outlet)의 관경이 다를지라도 설치된 배관의 관경과 동일한 관경(Run)의 등가길이를 선택한다. 가지관 중간에 손실값이 큰 다른 헤드가 있더라도 말단에서부터 계산해온 압력이 더 크다면 말단헤드에서부터 계산해온 압력으로 헤드방출량을 계산한다.

• 한국지반환경공학회 논문집
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• 제5권1호
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• pp.65-73
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• 2004

파형강관의 해석은 2차원 프레임 해석이나 압축링 모델에 의존하고 있다. 이는 흙-구조물 합성구조계의 거동을 고려하지 않은 해석이다. 파형강관 구조물은 토피고와 지간에 따라 하중저항시스템이 변화한다. 따라서, 흙-구조물 합성구조계의 작용을 고려한 유한요소해석을 통해 파형강관의 거동특성을 확인하였다. 적정토피고 이상 성토하면 파형강관은 연성관의 토압분포에 따른 거동과 유사하며, 차량하중의 영향은 적정토피고 이상 성토할수록 감소하였다. 그러나, 적정토피고 이하로 성토할 경우, 연직토압이 감소하고 파형강관 측면의 수동토압도 감소하여 완전한 연성관 거동을 나타내지 못했고, 성토 높이가 적정토피고 이하로 작아질수록 차량하중이 단면력에 미치는 영향이 커져, 파형강관 구조물의 거동을 지배하였다.

• 청정기술
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• 제2권2호
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• pp.51-59
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• 1996

Billions of tons of industrial waste are generated annually in industrialized countries. Managing and legally disposing of these wastes costs tens to hundreds of billions of dollars each year, and these costs have been increasing rapidly. The escalation is likely to continue as emission standards become even more stringent around the world. In the face of these rapidly rising costs and rapidly increasing performance standards, traditional end-of-pipe approaches to waste management have become less attractive. The most economical waste management alternatives in many cases have become recycling of the waste or the redesign of chemical processes and products so that wastes are prevented or put to productive use. These strategies of recycling or reducing waste at the source have collectively come to be known as pollution prevention. The engineering challenges associated with pollution prevention are substantial. This presentation will categorize the challenges in three levels. At the most macroscopic level, the flow of materials in our industrial economy, from natural resource extraction to consumer product disposal, can be redesigned. Currently, most of our raw materials are virgin natural resources that are used once, then discarded. Studies in what has come to be called industrial ecology examine the material efficiency of large-scale industrial systems and attempt to improve that efficiency. A second level of engineering challenges is found at the scale of individual industrial facilities, where chemical processes and products can be redesigned so that waste is reduced. Finally, on a molecular level, chemical synthesis pathways, combustion reaction pathways, and other material fabrication procedures can be redesigned to reduce emissions of pollution and unwanted by-products. All of these design activities, shown in Figure 1, have the potential to prevent pollution. All involve the tools of engineering, and in particular, chemical engineering.