• 한국산업융합학회 논문집
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• 제4권3호
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• pp.329-337
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• 2001

This simulator is developed for the analysis of a MOSFET based on Thermally Coupled Energy Transport Model(TCETM). The simulator has the ability to calculate not only stationary characteristics but also non - stationary characteristics of a MOSFET. It solves basic semiconductor devices equations including Possion equation, current continuity equations for electrons and holes, energy balance equation for electrons and heat flow equation, using finite difference method. The conventional semiconductor device simulation technique, based on the Drift-Diffusion Model (DDM), neglects the thermal and other energy-related properties of a miniaturized device. I, therefore, developed a simulator based on the Thermally Coupled Energy Transport Model (TCETM) which treats not only steady-state but also transient phenomena of such a small-size MOSFET. In particular, the present paper investigates the breakdown characteristics in transient conditions. As a result, we found that the breakdown voltage has been largely underestimated by the DDM in transient conditions.

• 방사선산업학회지
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• 제4권4호
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• pp.391-395
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• 2010

The characteristics for pollutant transport in tidal influenced area was investigated using tidal wave hydraulic scale model. Hydraulic scale model was composed of the tidal generator, attenuation area and channel. Also, wave height, current meter and conductivity meter were used with the measured instruments in hydraulic scale model. NaCl with a tracer was used to evaluate the advection phenomena under the different velocity profiles. The arrival time of the maximum concentration in the condition of the relatively fast velocity was measured about 30 seconds faster than ones in the conditions of low velocity. The measured concentrations of the tracer were shown in the detection points of the flow direction consecutively.

• 한국산업융합학회 논문집
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• 제26권4_2호
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• pp.715-724
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• 2023

Solar energy forecasting is essential for (1) power system planning, management, and operation, requiring accurate predictions. It is crucial for (2) ensuring a continuous and sustainable power supply to customers and (3) optimizing the operation and control of renewable energy systems and the electricity market. Recently, research has been focusing on developing solar energy forecasting models that can provide daily plans for power usage and production and be verified in the electricity market. In these prediction models, various data, including solar energy generation and climate data, are chosen to be utilized in the forecasting process. The most commonly used climate data (such as temperature, relative humidity, precipitation, solar radiation, and wind speed) significantly influence the fluctuations in solar energy generation based on weather conditions. Therefore, this paper proposes a hybrid forecasting model by combining the strengths of the Prophet model and the GRU model, which exhibits excellent predictive performance. The forecasting periods for solar energy generation are tested in short-term (2 days, 7 days) and medium-term (15 days, 30 days) scenarios. The experimental results demonstrate that the proposed approach outperforms the conventional Prophet model by more than twice in terms of Root Mean Square Error (RMSE) and surpasses the modified GRU model by more than 1.5 times, showcasing superior performance.

• Journal of Nutrition and Health
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• 제39권5호
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• pp.494-504
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• 2006

This study compared eating habits, food preferences, and the nutrient intakes of university students and their parents. The subjects were 186 students (68 males and 118 females) and 143 parents (62 fathers and 81 mothers) in 2 middle-sized cities and 3 metropolises. Eating habits and food preferences were investigated by questionnaire, and nutrient intake by a self recoding for 24-hour. The university students ate out, and ate breads, fast foods, instant foods, and canned or frozen products more frequently than their parents. They had higher preferences for meats, but lower preferences for fish, beans and bean products, vegetables, and sea weeds than their parents. Students took in more energy, total fat, total cholesterol, and SFA (saturated fatty acids) than their parents. The energy ratio of carbohydrate to the total energy intake was lower in the students than in their parents, while the energy ratio of fat to the total energy intake was higher in the students than in their parents. The intake of fats by the students amounted to more than 25% of the total energy intake. In conclusion, the university students had developed a more Western eating pattern and food preference, and were exposed to more risk factors to health than their parents, They should therefore, learn how to manage their meals more carefully in order to reduce risk factors to health.

• 한국산학기술학회논문지
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• 제14권3호
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• pp.1081-1089
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• 2013

본 연구는 국내 녹색산업의 경쟁력 강화를 위한 클러스터 형성방안을 제시하고자, 녹색산업의 지역경쟁력과 영향요인을 분석했다. 첫째, 신재생에너지산업은 경기, 경남, 충북, 충남, 울산, 전남에서, 탄소저감산업은 울산, 경기, 경북, 충남, 서울, 충북, 인천에서 각각 경쟁력이 있는 것으로 나타났다. 둘째, 신재생에너지산업은 기업, 노동, 연구개발 등의 요소조건 부문이, 탄소저감산업은 성과, 정책 제도, 시장점유, 산업특화 등의 구조 및 경쟁 부문이 가장 중요한 요인으로 분석되었다. 셋째, 녹색산업은 기존의 산업기반이 양호한 지역에서 상대적으로 경쟁력이 있는 것으로 나타났다. 따라서 국내 녹색산업의 경쟁력 강화를 위해서는 기존 산업기반의 녹색화와 더불어 선택과 집중의 전략이 요구된다.

• 방사선산업학회지
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• 제5권4호
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• pp.317-323
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• 2011

Radioisotopes have been widely used throughout industry to optimize processes, solve problems and improve product quality. A gamma scanning technique using radiation via sealed source (Co-60) was carried out in order to investigate vertical density profile of catalyst regenerator of RFCCU. Also through the radiotracer experiments, the flow characteristics of catalyst was measured. The catalyst samples were irradiated with neutron in HANARO reactor to produce lanthanum-140 to be used as radiotracer for tracing the catalyst itself in catalyst regenerator of RFCCU. The radiotracer was monitored around the catalyst regenerator using collimated NaI scintillation detectors. The results of the experiments were used to diagnose the performance of the RFCCU.

• Ocean and Polar Research
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• 제38권1호
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• pp.59-70
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• 2016

Establishing the strategic plans to foster the oceans and fisheries (O&F) industry as an engine for national sustainable economic growth has become an important task for developing countries as well as developed countries. The first step to do so is to identify O&F industry and analyze its economic effects. Therefore, the prime purposes of the paper are two-fold. The first is to identify O&F industry and estimate its market size using 2012 Input-Output (I-O) table published by the Bank of Korea. The second purpose is to obtain some quantitative information on production-inducing effect, value-added creation effect, and employment-inducing effect of the O&F industry. To this end, we apply an IO analysis using exogenous specification of the O&F industry. The results show that the O&F industry covers 4.1% and 3.0% of national output and gross domestic product, respectively. Moreover, we found that 1.0 won of production or investment in the O&F industry induces 1.7363 won of production and 0.4759 won of value-added in the national economy. One billion won of production or investment in the O&F industry touches off 7.5569 persons of employment. This information can be utilized in the O&F industry-related policy-making.

• 한국태양에너지학회 논문집
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• 제30권6호
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• pp.34-43
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• 2010

Recently environmental regulations like the Kyoto Protocol, adopted in 1997, required the reduction of the greenhouse gas of 5.2% up to 1990 regulations. and 13th General Assembly in 2007, held in Bali of India, have agreed to duty reduction even in developing countries in 2013. Because of the lack of information about real process in small or middle size industries, most recent research omitted to calculate green house gas emissions from the industrial process. Bottom-up methodology will be applied for calculation of green house gasemission from industry sector to solve these problems in this research. Total amount from industry sector of Shicheung-City in 2007 was about 1,797,305 tons of greenhouse gas $CO_2$ and 3,049,403 tons of the greenhouse gas $CO_2$ calculated from industry sector of Ansan-City in 2007.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2011년도 춘계 학술논문 발표대회 1부
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• pp.193-195
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• 2011

Nowadays, climatic environment change has become a major issue in the world. This causes major emissions of carbon dioxide industries steel industry, thermal power industry, cement industry is essential in the reduction of carbon dioxide, which is based on total carbon dioxide emissions account for most of the construction industry in an effort to minimize the environmental load is needed. accordingly, through case studies, It can be induce the selection to minimize environmental load by comparing the output of quantitative energy consumption and carbon dioxide emissions per constructional methods. As a result of this study, RC Structure was less environmental load than SC structure.

• Journal of Community Nutrition
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• 제2권2호
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• pp.135-140
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• 2000

The objectives of this study were to determine whether older Americans would provide valid energy intake information using a 24-hr recall method and to determine which characteristics were predictive of under-report of energy intake. We conducted 24-hour recalls on 83 male and 105 female community-dwelling older adults(66-87y) in the USA to assess energy(EI) and nutrient intakes. Basal metabolic rate(BMR) was calculated from age-and gender-specific equations of Schofield. Under-reporting was defined a priori as EI : BMR<0.9. Subjects volunteered demographic information, underwent depression and cognition exams, and completed a Level II Nutrition Risk Screen. Differences between under- and adequate-reporters were assessed using t-tests for characteristics and macro-nutrient profile. Stepwise regression analyses were used to predict under-reporting status. Under-reporting of EI occurred in 34% of the sample. Neither geriatric depression scale(GDS) score, nor self-reported weight loss were related to under-reporting. On average, under-reporters had higher body mass indices. The most significant variables for the main effect to predict the ratio of energy intake to estimated basal metabolic rate(EI : BMRest) were BMI and age. Using a standard cut-off of 76% of the recommended dietary allowances for Americans, under-reporters were consistently more likely to be classified as having inadequate nutrient, as well as energy, intakes. (J Community 2(2) 135∼140, 2000)