• 한국진공학회지
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• 제10권4호
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• pp.424-430
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• 2001

RF나 마이크로웨이브의 전기장이 작용될 때 플라즈마 방전에서의 전자에너지분포함수를 계산하기 위하여 전자 볼츠만 방정식을 수치적으로 푼다. 2차미분 방정식인 로렌츠근사를 사용하는 동차 전자 볼츠만 방정식과 적분-미분방정식인 입자균형방정식을 동시에 풀어 자체모순이 없게 방전 전기장의 크기를 결정한다. 이 수치코드를 이용하여 아르곤 방전에 대하여 전자에너지 분포함수를 RF와 마이크로파영역에 걸쳐 계산한다. 이로부터 전자에너지 분포함수와 이온화율에 대한 고주파 전기장의 주파수 변화에 따른 영향을 조사한다.

• 대한기계학회논문집A
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• 제21권11호
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• pp.1844-1851
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• 1997

Displacement fields and interface stresses are obtained by modifying the potential energy functional with a penalty function which enforces the continuity of stresses at the interface of two-materials. Based on the displacement field and the interface stresses, a new methodology to generate a continuous stress field over the entire domain including the interface of the dissimilar materials has been proposed by combining the L$^{2}$ projection method of stress-smoothing and the Loubignac's iterative method of improving the displacement field. Stress analysis was carried out on two examples which are made of highly dissimilar materials. As a result of the analysis, it is found that the proposed method provides improved continuity of the stress field over the entire domain as well as predicting accurate nodal stresses at the interface. In contrast, the conventional displacement-based finite element method provides significant stress discontinuties at the interfaces. In addition, it was found that the total strain energy evaluated from the improved continuous stress field converge to the exact value as increasing the number of iterations in the proposed method.

• 한국초전도ㆍ저온공학회논문지
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• 제15권4호
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• pp.44-47
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• 2013

We had proposed a winding method so called "Wind-and-Flip", which enables a persistent current operation of an HTS pancake coil without any electrical joint. In order to improve the magnetic field drift characteristics, a prototype HTS coil with the technique was fabricated, and tested under various temperatures. Because the coil doesn't have any electric terminals for current leads, an HTS background magnet was used to induce the persistent current in the coil by field cooling process. A conduction cooling system with a GM cryocooler was prepared to keep the operating temperatures of the prototype coil much below the 77 K. We investigated the magnetic field drift characteristics under the various operating temperatures by measuring the center magnetic field with a cryogenic Hall sensor. The persistent current mode operation at 20 ~ 50K showed a strong possibility of the winding technique for the application such as MRI or NMR.

• 응용통계연구
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• 제23권6호
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• pp.1157-1167
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• 2010

본 논문은 남한지역 풍력자원의 계량화 및 바람환경분석 등에 필요한 풍력에너지지도를 고해상도로 작성하는 방법을 제안하였다. 이를 위해 $1Km{\times}1Km$ 격자로 나누어진 남한전역(345,682 지점)의 월별풍속에 적합한 통계적 바람장모형을 설정하여 각종 풍력에너지통계를 $1Km{\times}1Km$ 격자지점 별로 계산하고, 통계값들를 지도로 구현하는 절차를 연구하였다. 바람장모형의 적합성검정에는 국내 76개 기상관측소에서 관측된 TMY (typical meteorological year) 바람자료가 사용되었으며, Kolmogrov-Smirnov 검정결과 로그정규모형이 남한지역의 월별 바람장모형에 적합하였다. 또한 로그정규모형 하에서 얻어지는 다양한 형태의 풍력에너지통계들을 소개하였으며, 국립기상연구소가 제공하는 $1Km{\times}1Km$ 격자지점(345,682 지점)의 풍속자료를 사용하여 남한(지상 80m)의 풍력에너지밀도(W/$m^2$)지도를 공간분포도 형태로 작성해 보였다.

• 설비공학논문집
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• 제17권3호
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• pp.277-284
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• 2005

The purpose of this study is to analyze the effect of sunshine on the heating energy consumption of apartment houses by a field investigation in Haeundae, Busan. In the field, heating energy consumption of every household is researched by reading a calorimeter and the duration of sunshine of every household is calculated by Sunlight V1.0. Then, the duration of sunshine and heating energy are done regression analysis by SPSS 10. According to this study the apartment houses by orientation spend more energies order of east, west, southeast, southwest, and south. When apartment houses are same orientation, there is difference of $29{\sim}58\%$ in heating energy consumption by the duration of sunshine. And the heating energy consumption in worst condition of sunshine increases $67\%$ on the best condition of sunshine.

• Bulletin of the Korean Chemical Society
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• 제31권10호
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• pp.2903-2908
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• 2010

Protein S-nitrosation is common in cells under nitrosative stress. In order to model proteins with S-nitrosocysteine (CysSNO) residues, we first developed an Amber force field for S-nitrosoethanethiol (EtSNO) and then transferred it to CysSNO. Partial atomic charges for EtSNO and CysSNO were obtained by a restrained electrostatic potential approach to be compatible with the Amber-99 force field. The force field parameters for bonds and angles in EtSNO were obtained from a generalized Amber force field (GAFF) by running the Antechamber module of the Amber software package. The GAFF parameters for the CC-SN and CS-NO dihedrals were not accurate and thus determined anew. The CC-SN and CS-NO torsional energy profiles of EtSNO were calculated quantum mechanically at the level of B3LYP/cc-pVTZ//HF/6-$31G^*$. Torsional force constants were obtained by fitting the theoretical torsional energies with those obtained from molecular mechanics energy minimization. These parameters for EtSNO reproduced, to a reasonable accuracy, the corresponding torsional energy profiles of the capped tripeptide ACE-CysSNO-NME as well as their structures obtained from quantum mechanical geometry optimization. A molecular dynamics simulation of myoglobin with a CysSNO residue produced a well-behaved trajectory demonstrating that the parameters may be used in modeling other S-nitrosated proteins.

• KIEAE Journal
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• 제13권2호
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• pp.39-46
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• 2013

Recently, the field of construction is putting a variety of effort into reducing CO2, since global warming is being accelerated due to climate changes and the increase of greenhouse gas. For reduction of CO2 in the field of construction, it is required to make plans to cut down heating energy of buildings and especially, it is urgently needed to cut down energy of residential buildings in rural area where occupies the majority of consumption of petroleum-based energy sources. Therefore, this research compared and analyzed the actual energy consumption, by evaluating energy performance of a detached house applying passive house design components for reduction of energy. As the result, energy consumption showed remarkable differences, according to the operation of a heat recovery ventilation unit which is one of passive house design components, and building energy consumption displayed remarkable differences, too, depending on the difference of airtightness performance during building energy simulation conducted in process of design. Based on these results, the importance of airtightness performance of passive house was verified. The result of the actual measurement of energy consumption demonstrated that LNG was most economical amongst several heat resources yielded, on the basis of LPG source energy consumption measured within a certain period of time, and it was followed by kerosene. LPG was analyzed to have a low economic efficiency, when used for heating.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2009년도 하계학술발표대회 논문집
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• pp.1458-1464
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• 2009

While industrial development as many buildings were builted, amount of energy consume in building also increase rapidly. At this point be tormented the energy depletions are big problem on the rise. The development of renewable energy in trying to resolve the fundamental problem that the technical level is still incomplete. Because of this, reduce energy use in buildings to lot of study. Most of the energy involved in building mechanical system for so many research is continue. Among them, be interested in building mechanical system. Building mechanical system is configured Air conditioning, sanitation, urban (environmental) equipment. In the design of equipment, installation, maintenance, applies to all devices in the field of industrial equipment and general engineering equipment field are within bounds to say that all of the equipment field. However, domestic technology level is still fly short of international standards in architecture, we spand many energy. Because of this, find the current situation and identify the problems look up ways to improve them.

• 한국지열·수열에너지학회논문집
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• 제12권4호
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• pp.15-20
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• 2016

Even though the control device of the heating system works well, insufficient water flow rates can degrade control performance and thermal comfort. The water flow rate should be adjusted appropriately to cope with the heating load of each zone. In order to solve these problems, a new balancing concept 'dynamic balancing' was proposed where a balancing valve opening can be automatically modulated according to the heating condition of the room. This study analyzed the effects of dynamic balancing upon indoor thermal environment and energy consumption in a radiant floor heating system through field measurement. Under part-load conditions, the use of a dynamic balancing is a more effective method to reduce energy consumption and to prevent a cavitation. Dynamic balancing is able to help boost the temperature of a room in the start-up period.

• 한국초전도ㆍ저온공학회논문지
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• 제19권1호
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• pp.30-35
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• 2017

The effects of the crystallographic orientation and sample thickness on the magnetic levitation forces (F) and trapped magnetic field (B) of single grain YBCO bulk superconductors were examined. Single grain YBCO samples with a (001), (110) or (100) surface were used as the test samples. The samples used for the force-distance (F-d) measurement were cooled at 77 K without a magnetic field (zero field cooling, ZFC), whereas the samples used for the B measurement were cooled under the external magnetic field of a Nd-B-Fe permanent magnet (field cooling, FC). It was found that F and B of the (001) surface were higher than those of the (110) or (100) surface, which is attributed to the higher critical current density ($J_c$) of the (001) surface. For the (001) samples with t=5-18 mm, the maximum magnetic levitation forces ($F_{max}s$) of the ZFC samples were larger than 40 N. About 80% of the applied magnetic field was trapped in the FC samples. However, the F and B decreased rapidly as t decreased below 5 mm. There exists a critical sample thickness (t=5 mm for the experimental condition of this study) for maintaining the large levitation/trapping properties, which is dependent on the material properties and magnitude of the external magnetic fields.