• Advances in Energy Research
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• 제5권2호
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• pp.179-205
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• 2017

This research presents an in-depth analysis of location planning of the solar-hydrogen power plants for electricity production in different cities situated in Kerman province of Iran. Ten cities were analyzed in order to select the most suitable location for the construction of a solar-hydrogen power plant utilizing photovoltaic panels. Data envelopment analysis (DEA) methodology was applied to prioritize cities for installing the solar-hydrogen power plant so that one candidate location was selected for each city. Different criteria including population, distance to main road, flood risk, wind speed, sunshine hours, air temperature, humidity, horizontal solar irradiation, dust, and land costare used for the analysis. From the analysis, it is found that among the candidates' cities, the site of Lalezar is ranked as the first priority for the solar-hydrogen system development. A measure of validity is obtained when results of the DEA method are compared with the results of the technique for ordering preference by similarity to ideal solution (TOPSIS). Applying TOPSIS model, it was found that city of Lalezar ranked first, and Rafsanjan gained last priority for installing the solar-hydrogen power plants. Cities of Baft, Sirjan, Kerman, Shahrbabak, Kahnouj, Shahdad, Bam, and Jiroft ranked second to ninth, respectively. The validity of the DEA model is compared with the results of TOPSIS and it is demonstrated that the two methods produced similar results. The solar-hydrogen power plant is considered for installation in the city of Lalezar. It is demonstrated that installation of the proposed solar-hydrogen system in Lalezar can lead to yearly yield of 129 ton-H2 which covers 4.3% of total annual energy demands of the city.

• KIEAE Journal
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• 제15권2호
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• pp.27-35
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• 2015

Purpose: Healthcare is on the whole a personal and critical service that consumer's use, whereas hospitalization is as a rule painful, because nature nurtures and Sun Light Luminosity for healthcare settings is considered healing. The performance and design of climate responsive buildings such as AKU requires a detailed study of attributes of climate both at micro as well as macro level. The therapeutic value of contact with nature through window view, greenery and landscape is calculated there. Method: A two prong strategy is been devised for this article, at micro level three typical morphologies are analysed by creating same environment of neighboring building on sun shading chart, radiation and temperature range. Since the analysis of local climate helps to determine the design strategies for hospital Healing Environment which is suitable for Karachi climate; in order to track the macro climatic behaviour, a considerable analysis of psychometrics chart for AKU Karachi are designed on Climate Consultant (CC) and analysed by Machine Learning. Climate Consultant proposes different design strategies suitable for Karachi. And on the other hand time wise illumination sources for clinical area which are then measured on psychrometric chart- according to singular space: multi patient admission, secondly: acute ambulatory ward, and tertiary: multi windowed space according to the mushrabiyah and sky light pattern. Result: Our findings support the hypothesis that windowed wall is 75-80% more healing wall; an accelerated evidence was found for healing at macro level if the form of the hospital is designed according to the climatologically preferences, whereas at micro level: the light resource becomes the staff attentiveness determinant. In Conclusion evidence was provided that the actual form of luminosity results consequently in satisfaction while light entering from several set of windows and other sources might be valued if design according to the healing environment. The data added on the sun shading chart to calculate rays entraining into space in patient room equal to 124416.21 Watts/ meter $m^2$ is calculated as precise healing rate-and is confirmed by questionnaire from patients belonging from each clinical stage having different illnesses.

• 대한기계학회논문집B
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• 제35권4호
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• pp.425-429
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• 2011

원자로의 노심 손상에 따른 노심 용융물의 노외 유출시 코어캐처라고 불리는 설비를 통해 용융물을 억제하고 냉각시키게 된다. 이 때 노외 노심용융물의 거동은 희생물질과의 반응을 포함한 복잡한 물리적, 화학적 현상에 의해 결정된다. 이 연구는 기존의 용융물 거동 실험결과에 대해 용융물의 유동과 열전달의 세부적인 특성을 상용코드를 이용해 해석하여 검증함으로써 코어캐처의 설계에 활용할 수 있도록 하기 위한 것이다. 단순화된 채널에서 시간에 따른 용융물과 공기의 이상유동과 복사열전달을 VOF 모델과 구분종좌법을 적용하여 비정상상태에서 해석한 결과, 열전달에 따른 용융물 내부의 온도 변화 및 이에 따른 점성 변화 등을 예측할 수 있음을 확인하였다. 이러한 접근방식을 기초로 향후 용융물의 조성, 유량 및 용도 등의 조건에 따른 용융물의 거동에 대한 자세한 평가가 필요하다.

• 대기
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• 제23권4호
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• pp.453-470
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• 2013

As a part of the KIAPS Observation Processing System (KOPS), we have developed the modules of satellite radiance data pre-processing and quality control, which include observation operators to interpolate model state variables into radiances in observation space. AMSU-A (Advanced Microwave Sounding Unit-A) level-1d radiance data have been extracted using the BUFR (Binary Universal Form for the Representation of meteorological data) decoder and a first guess has been calculated with RTTOV (Radiative Transfer for TIROS Operational Vertical Sounder) version 10.2. For initial quality checks, the pixels contaminated by large amounts of cloud liquid water, heavy precipitation, and sea ice have been removed. Channels for assimilation, rejection, or monitoring have been respectively selected for different surface types since the errors from the skin temperature are caused by inaccurate surface emissivity. Correcting the bias caused by errors in the instruments and radiative transfer model is crucial in radiance data pre-processing. We have developed bias correction modules in two steps based on 30-day innovation statistics (observed radiance minus background; O-B). The scan bias correction has been calculated individually for each channel, satellite, and scan position. Then a multiple linear regression of the scan-bias-corrected innovations with several predictors has been employed to correct the airmass bias.

• 한국해양학회지
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• 제28권4호
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• pp.292-304
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• 1993

세밀한 격자망과 정교한 개방경계 조건을 적용하고 실측 수온 염분치를 직접표층 에 적용하여 동해순환을 수치 모델화 하였다. 동해의 특징적인 현상들이 성공적으로 재현되었으며 특히 북한 한류와 동한난류가 더욱 뚜렷하여 졌다. 특기할 만한 사실로 는 울릉난수괴와 중층 저염분수가 재현되었다는 것이다. 전자는 동한난류의 바깥쪽에 서 국지적으로 생성된 시계방향의 재순환류와 연관되어 있고 후자는 동해 북, 북서 연 안역에서 침강으로 형성되어 강한 중층해류에 의해 연안을 따라 남족으로 이동된다. 모델에서는 또한 일본 연안류가 강한 계절변화를 보여서 겨울에는 순압, 여름에는 경 압구조를 나타냄을 보였으며 이 때 여름에 나타나는 강한 중층 반류가 흥미롭다. 모델 에서는 또한 동해 순환의 거시적 특징을 지워 주는데 북쪽의 반시계 방향 순환역과 남 쪽의 시계방향 순환역이 그것이다. 이들은 동해에서 국지적인 순환역학의 중요성을 시 사한다. 그러나 본 모델에서는 동한난류의 이안점이 실제보다 북쪽에 치우쳐서 나타나 는 것을 완전히 해결하지는 못하였다.

• 소성∙가공
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• 제6권3호
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• pp.239-249
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• 1997

The behaviour of alloys in the semi-solid state strongly depends on the imposed stress state and on the morphology of the phase which can vary from dendritic to globular. To optimal net shape forging of semi-solid materials, it is important to investigate for filling phenomena in forging process of arbitrarily shaped dies. To produce a automotive part which has good mechanical property, the filling pattern according to die velocity and solid fraction distribution has to be estimated for arbitrarily shaped dies. Therefore, the estimation of filling characteristic in the forging simulation with arbitrarily shaped dies of semi-solid materials are calculated by finite element method with proposed algorithm. The proposed theoretical model and a various boundary conditions for arbitrarily shaped dies is investigated with the coupling calculation between the liquid phase flow and the solid phase deformation. The simulation process with arbitrarily shaped dies is performed to the isothermal conditions of two dimensional problems. To analysis of forging process by using semi-solid materials, a new stress-strain relationship is described, and forging analysis is performed by viscoelastic model for the solid phase and the Darcy's law for the liquid flow. The calculated results for forging force and filling limitations will be compared to experimental data. The filling simulation of simple products performed with the uniform billet temperature(584$^{\circ}C$) from the induction heating by the commercial package MAGMAsoft. The initial step of computation is the touching of semi-solid material with the end of die gate and the initial concept of proposed system just fit with the capability of MAGMAsoft.

• Ocean and Polar Research
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• 제27권2호
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• pp.115-123
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• 2005

Recently, it has been observed in the East Sea that temperature increases below the thermocline, and dissolved oxygen increase in the intermediate layer but decrease below it. The layer of minimum dissolved oxygen deepens and the bottom homogeneous layer in oxygen becomes thinner. It emerges very probably that these changes are induced by the mode change of deep water formation associated with global warming. To further support this hypothesis, a one-dimensional model experiment is performed. First, a thermal profile is obtained by injecting a cold and high oxygen deep water into the bottom layer, say the bottom mode. Then, two thermal profiles are obtained from the bottom mode profile by assuming that either all the deep water introduce into the intermediate layer has been initiated, say the intermediate mode, or that only a part of the deep water has been initiated into the intermediate layer, say the intermediate-bottom mode. The results, from the intermediate-bottom mode experiment are closest to the observed results. They show quite well the tendency for oxygen to increase in the intermediate layer and the simultaneous thinning of the bottom homogeneous layer in oxygen. Therefore, it can be said that the recently observed slow variation of the thermal structure might be associated with changes in the deep water formation from the bottom mode to the intermediate-bottom mode.

• 응용통계연구
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• 제30권5호
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• pp.633-645
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• 2017

본 연구는 컨테이너선의 연료 소비 패턴의 발견을 위해 운항데이터 분석의 통계적 절차를 제안한다. 우리는 현 시점의 연료 소비를 발견하기 위해 연료 소비에 영향을 미치는 변수들을 파악하는 동시에 예측 모델을 개발 및 적용하는 것을 목적으로 한다. 선박의 데이터는 크게 운항데이터와 기기데이터로 분류할 수 있으며, 운항데이터는 항로, 항해 정보, 대수속도, 대지속도, 바람과 같은 외력에 대한 정보 등이 있고, 기기데이터는 엔진출력, RPM, 연료 소모량, 기기들의 온도 및 압력 등이 있다. 본 연구에서, 우리는 선박에 미치는 외력의 영향을 Beaufort Scale (BFS)을 기준으로 구분한 후에 PLS 회귀분석을 통한 예측 모델을 개발하였다.

• 한국자동차공학회논문집
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• 제17권1호
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• pp.137-145
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• 2009

The steady-state kinetics of the selective catalytic reduction (SCR) of $NO_X$ with $NH_3$ has been investigated over a commercial ${V_2}{O_5}/TiO_2$ catalyst. In order to account for the influence of transport effects the kinetics are coupled with a fully transient two-phase 1D+1D monolith channel model. The Langmuir-Hinshelwood (L-H) mechanism is adopted to describe the steady-state kinetic behavior of the ${V_2}{O_5}/TiO_2$ catalyst. The reaction rate expressions are based on previously reported papers and are modified to fit the experimental data. The steady-state chemical reaction scheme used in the present mathematical model has been validated extensively with experimental data of selective $NO_X$ reduction efficiency for a wide range of inlet conditions such as space velocity, oxygen concentrations, water concentration, and $NO_2/NO$ ratio. The parametric investigations are performed to examine how the $NH_3$ slip from a SCR $DeNO_X$ catalyst and the conversion of $NO_X$ are affected by the reaction temperature, $NH_3/NO_X$ feed ratio, and space velocity for feed gas compositions with $NO_2/NO_X$ ratios of 0 and 0.5.

• 한국태양에너지학회 논문집
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• 제40권1호
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• pp.25-33
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• 2020

It has been reported about the energy saving performance of UFAD(under floor air distribution) system and NPC(night purge cooling) system respectively which are applied for commercial buildings. However, when two systems are used at the same time, the effect of heat transfer from floor plenum to slab may vary depending on the operating conditions of NPC. In this study, cooling energy demands were analyzed for building models with UFAD and NPC by using TRNSYS 17 program. UFAD was applied as a cooling system of the base building model, and the cooling energy demands were compared for 64 cases in which the operating time, supply airflow rate, and outdoor air temperature(T_o) of NPC. As a result, it was confirmed that the cooling energy demands were reduced to 30 ~ 80% level compared to UFAD alone, and in particular, the energy demand was reduced in proportion to the supply airflow rate or the operating time while T_o was 16 ~ 20℃. However, when T_o was 22℃, the increase in the supply airflow rate or the operating time results in a disadvantage in terms of cooling energy demands. In addition, the cooling energy demands for UFAD+NPC model were analyzed by applying weather data from three regions with different average outdoor air temperatures. As a result, the cooling energy demand of operating NPC only when T_o was below 20℃ was reduced by 27% compared to that of operating NPC continuously for 8 hours.