• 한국수소및신에너지학회논문집
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• 제22권5호
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• pp.609-615
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• 2011

A 5 kW class SOFC system for cogeneration power units was consisted of a hot box part and cold BOPs. High temperature components such as a stack, a fuel reformer, a catalytic combustor, and heat exchanges are arranged in the bot box considering their operating temperatures for the system efficiency. The hot box was made of ceramic boards for the thermal insulation. A 5 kW class SOFC stack was composed of 2 sub-modules and each module had 64 cells with $15{\times}15cm^2$ area and stainless steel interconnects. The 5 kW class SOFC system was operated with a hydrogen and a city gas. With a hydrogen, the total power of the stacks was about 7.1 kWDC and electrical efficiency was about 49.3% at 80 A. With a city gas, the total power of the stacks was about 5.7 $kW_{DC}$ and electrical efficiency was about 38.8% at 60 A. Under self-sustained operating condition, the system efficiency including a power conditioning loss and a consumed power by BOPs was about 30.2%.

• 한국산학기술학회논문지
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• 제20권1호
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• pp.329-338
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• 2019

본 연구에서는 농산물 꾸러미 속성별 소비자선호 분석을 통해 사업 활성화 방안을 제시하고자 하였다. 꾸러미의 속성을 구성함에 있어서 상품묶음 방식과 배송 방식 및 가격으로 구분하여 설정하고, 선택실험법에 의해 각 속성의 수준변화에 대한 한계지불의사금액을 추정하였다. 계량적 분석을 수행함에 있어서 보다 효율적인 모형을 선택하기 위하여 잔차항에 대한 가정이 서로 다른 조건부로짓 모형, 이분산 극한치 모형, 다항프로빗 모형, 혼합로짓 모형 등 네 모형을 추정하였으며, 그 결과 상품묶음 방식과 배송 방식 및 가격에 대한 추정계수 값이 모두 통계적으로 유의한 것으로 나타났다. 로그우도 값의 크기를 기준으로 볼 때 이분산 극한치 모형이 자료에 가장 적합하는 것으로 나타났다. 이분산 극한치 모형의 추정계수를 활용한 한계지불의사금액은 상품묶음 방식을 고정형에서 선택형으로 변경 할 경우 1회당 7,096.6원, 배송방식 중 직접배송에 대한 소비자의 한계지불의사금액은 1회당 3,497.5원, 콜드체인 배송에 대한 한계지불의사금액은 1회당 4,035.2원으로 나타났다. 이러한 분석결과는 정부의 로컬푸드 활성화를 위한 정책수립에 기초자료로 활용될 수 있을 것이다.

• 한국실내디자인학회논문집
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• 제14권3호
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• pp.114-121
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• 2005

Louis 1. Kahn was a wise architect who learned from history. He developed his own unique architecture by combining his creative sense with design principles and vocabularies that can be found in historical architecture. When restricting a space, he surrounded the space with thick walls as it had been done in historical buildings. The interior space encompassed by this method became a center-oriented and stable space. The objective of this study is to find the characteristics of Kahn's interior spaces by analyzing his projects in terms of space, form, daylight and materials. For this purpose, five works that are considered to have significance from the aspect of interior design were selected and analyzed. The characteristics realized through this study are as follows. A) Spatial features: 1) Generally speaking, each required space has been arranged symmetrically. 2) Being clearly defined as the main space, the subsidiary space, or the service space, each space also was placed very functionally. 3) The space encompassed by thick walls became a center-oriented, stable space. And in most case, it was characterized as a dark space. B) Formative features: 4) The space was defined as a basic solid such as a cylinder, a hexahedron, and an octagonal box, and was developed into a complex shape by the recessed windows. 5) Historical vocabularies such as an arch, a vault, and a dome were reinterpreted in new ways by kahn's own eyes. 6) Haying diverse shapes, the skylights enrich the space in terms of form. C) Daylight feature: 7) The vertical light entering through the skylights creates a solemn and mysterious atmosphere. 8) Given the shadows from the windows that change according to time, the interior space becomes a very vivid space. D) Material feature: 9) Harmonized with cold and smooth materials such as exposed concrete, metal, and glass, the interior space provides a modern atmosphere. 10) Warm appearing wood was used for furniture and part of walls or floors. The effective use of wood takes on a role that is quite complementary to the cold ambience of the smooth and cold materials. 11) With flexibility In building shapes, the concrete becomes the form-endowing materials.

• Journal of Veterinary Science
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• 제24권1호
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• pp.2.1-2.14
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• 2023

Background: Hypothermia is a crucial environmental factor that elevates the risk of cardiovascular disease, but the underlying effect is unclear. Objectives: This study examined the role of cold stress (CS) in cardiac injury and its underlying mechanisms. Methods: In this study, a chronic CS-induced myocardial injury model was used; mice were subjected to chronic CS (4℃) for three hours per day for three weeks. Results: CS could result in myocardial injury by inducing the levels of heat shock proteins 70 (HSP70), enhancing the generation of creatine phosphokinase-isoenzyme (CKMB) and malondialdehyde (MDA), increasing the contents of tumor necrosis factor-α (TNF-α), high mobility group box 1 (HMGB1) interleukin1b (IL-1β), IL-18, IL-6, and triggering the depletion of superoxide dismutase (SOD), catalase (CAT), and glutathione (GSH). Multiple signaling pathways were activated by cold exposure, including pyroptosis-associated NOD-like receptor 3 (NLRP3)-regulated caspase-1-dependent/Gasdermin D (GSDMD), inflammation-related toll-like receptor 4 (TLR4)/myeloid differentiation factor 88 (MyD88)-mediated nuclear factor kappa B (NF-κB), and mitogen-activated protein kinase (MAPK), as well as oxidative stressinvolved thioredoxin-1/thioredoxin-interacting protein (Txnip) signaling pathways, which play a pivotal role in myocardial injury resulting from hypothermia. Conclusions: These findings provide new insights into the increased risk of cardiovascular disease at extremely low temperatures.

• 한국포장학회지
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• 제28권3호
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• pp.223-229
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• 2022

파프리카 저장 및 유통 전 처리와 포장방법이 저장성 및 미생물 제어에 미치는 영향에 대해 알아보고자 수행되었다. 이산화염소 가스 3, 6, 12시간과 저온 플라즈마 가스 1, 3, 6시간 처리 후 골판지 박스로 포장하여 8±1℃ 챔버에서 7일간 저장 하였을 때, 이산화염소 12시간 처리와 플라즈마 6시간 처리가 대장균과 곰팡이 발현을 낮추는 것으로 나타났다. 이에 무처리 대조구와 이산화염소 12시간, 플라즈마 6시간 처리한 후 골판지 박스 포장과 MAP 처리를 하여 8±1℃ 챔버에서 20일간 저장하였다. 저장 중 생체중 감소는 MAP 처리구가 1% 미만의 수치를 보였고, 외관상 품질은 MAP 처리구가 저장 종료일까지 상품성 한계점 이상이었다. 필름 내 산소, 이산화탄소, 에틸렌 농도는 처리구간의 차이가 나타나지 않았다. 경도의 경우 이산화염소 처리구가 낮았고, 색도를 나타낸 Hunter a^* 값은 MAP 처리구에서 증가하였다. 이취는 MAP 처리구에서 측정되었지만 매우 낮았다. 파프리카 과경의 곰팡이 발생률은 이산화염소 처리 박스 포장 처리구가 가장 빠르고 높게 발생하였고, 이산화염소 처리 MAP 처리구가 가장 낮았다. 저장 종료일 과육의 총 세균수는 플라즈마 처리 박스 포장 처리구, 대장균수는 이산화염소 처리 MAP 처리구, 곰팡이는 이산화염소 처리 박스 포장 처리구가 가장 낮았다. 이상의 결과를 종합해보면, 파프리카 저장 중 미생물 억제를 위해 포장 방법과 관계없이 저장 전 플라즈마를 6시간 처리하는 것이 적합하다고 판단된다.

• 한국초전도ㆍ저온공학회논문지
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• 제3권1호
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• pp.69-73
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• 2001

For developing the cryogenic air separation unit, it requires some technology such as basic process design. equipment design and manufacturing based on the cryogenic physical properties and separation theory. In this study, we developed a process and equipment for producing high purity nitrogen which has the production capacity of 1600N㎥/h under 1 ppm $O_2$ and $H_2O$. Also we found that the number of theoretical plate(NTP) of distillation column was 44 and maximum nitrogen recovery ration of this process was 42% from the process simulation. The performance test was also carried out for the nitrogen recovery ratio and equipment efficiency. The results showed that the optimum nitrogen recovery was 41% and the maximum equipment efficiency was attained.

• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 2003년도 동계 학술대회 논문집
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• pp.329-334
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• 2003

배추의 포장상자를 예냉ㆍ저온유통에 적합한 구조로 개선하기 위하여 3-4포기용 골판지 상자를 T11형 표준 팔레트에 적재율이 96%이상 되게 제작하여 고습조건에서도 안전하게 배추를 보호할 수 있는 상자구조를 찾기 위한 수직압축강도시험과 냉각성능 및 예냉후 품질 변화에 대한 시험을 실시하였다. 가. 배추의 저온유통에 사용하는 골판지포장상자는 개공율을 5.4%로 하고, 포장상자 형태를 접음식 형태로 하는 것이 예냉속도 및 예냉균일도에서 유리하고, 저장후 수직압축강도에서는 브릿스박스에 비하여 낮게 나타났지만, 안전압축강도 이상의 압축강도를 나타내었고 제작단가도 저렴하였다. 나. 예냉 후 저장 중 품질변화는 배추 줄기의 절단력을 측정한 결과 개선된 포장상자에서 유통기한을 6-7일정도 연장시킬 수 있는 것으로 나타났다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1995년도 추계학술대회 논문집
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• pp.350-354
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• 1995

The Tension Leveller of Cold Rolling Mill In POSCO performs levelling the strip in high speed line. But minor variations in operating condition of driving machines such as motor, gear box, and support bearings, a small gap-variation of supporter and strip slip by poor roll revolutions can cause serious problems in the quality of strip. In this study, firstly, A condition monitoring standard for each sensor is made through with the detail analysis of vibration and strip slip. Secondly, An automatic monitoring and diagnosing system was developed to monitor the condition of Tension Leveller, and diagnose the cause of abnormal condition. Finally, A diagnosing algorithm for abnormal condition and man-machine interface (MMI) for easy operation are developed.

• 한국초전도저온공학회:학술대회논문집
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• 한국초전도저온공학회 2001년도 학술대회 논문집
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• pp.163-166
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• 2001

KEPCO has a plan to construct TRF (tritium removal facility) in wolsong nuclear power plant site by 2005. In advance of WTRF construction, the pilot plant was installed at KEPRI in order to show process reliability of WTRF. The main processes of this pilot plant are LPCE(liquid phase catalytic exchange) and CD (cryogenic distillation). Deuterium is separated from heavy water in LPCE process and concentrated in CD process. CD process consists of cold box, where are a distillation column and heat exchangers, vacuum system, cryogenic refrigerant supply system and instrument & control system. The experience of the pilot plant will be used in WTRF design review, operating procedure revision and fundamental education for the operators.

• 천문학회보
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• 제39권2호
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• pp.45.1-45.1
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• 2014

structure of matters of Lambda cold dark matter (CDM) cosmology on detailed numerical simulations. To accomplish our research goal, we have added the following baryonic physics on the existing cosmological hydrodynamic code, Gadget-2: 1) radiative heating and cooling, 2) reionization of the Universe and UV shielding, 3) star formation, 4) energy and metallicity feedback by supernova. In addition, we included cluster formation to distinguish clustered star formation inside the very high density gas clumps from the field star formation. Our simulations cover a cubic box of a side length 4Mpc/h with 130 million particles. The mass of each particles is $3.4{\times}104Msun$, thus the GCs can be resolved with more than hundreds particles. We discuss various properties of the GCs such as mass function, specific frequency, baryon-to-dark matter ratio, metallicity, spatial distribution, and orbit eccentricity distribution as functions of redshift. We also discuss how the formation and evolution of the GCs are affected by UV shielding.