• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 정기총회 및 추계학술대회 논문집
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• pp.2357-2364
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• 2011

Diesel locomotive operates the generator with the power from the diesel engine, and it consists of the typical serial-hybrid system which operates the train wheels by converting its generated electric energy into the torque of DC (or AC) motor. However, the technology of locomotives is only focused on trains' controlling power generation mechanism. Hence, it is a current issue that the efficiency of its engine and its generator is relatively lower than that of auto vehicles'. Particularly, since there are no proper equipment to measure the amount of fuel which is essentially necessary for the efficient use of fuel, it is not easy to confirm the instant amount of fuel use as well as the exact average fuel consumption per an hour. Due to those difficulties, it is urgent to develop the device that measures the fuel consumption. Plus, this use of the developed measuring device allows the various and useful analysis relating to the fuel consumption, and this could lead to establishing the efficient driving pattern regarding to fuel saving. This device consists of two flux (fuel level) measuring censors, MCU for calculating the measured values, the information recorder for saving measured values, and the display device for indicating the fuel amount consumed during driving.

• 전기전자학회논문지
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• 제20권2호
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• pp.163-166
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• 2016

It is important to operate the driving circuit under the optimal condition through precisely sensing the power consumption causing the temperature made mainly by the MOSFET (metal-oxide semiconductor field-effect transistor) when a BLDC (Brushless Direct Current) motor operates. In this letter, a Super-junction (SJ) power TMOSFET (trench metal-oxide semiconductor field-effect transistor) with an ultra-low specific on-resistance of $0.96m{\Omega}{\cdot}cm^2$ under the same break down voltage of 100 V is designed by using of the SILVACO TCAD 2D device simulator, Atlas, while the specific on-resistance of the traditional power MOSFET has tens of $m{\Omega}{\cdot}cm^2$, which makes the higher power consumption. The SPICE simulation for measuring the power distribution of 25 cells for a chip is carried out, in which a unit cell is a SJ Power TMOSFET with resistor arrays. In addition, the power consumption for each unit cell of SJ Power TMOSFET, considering the number, pattern and position of bonding, is computed and the power distribution for an ANSYS model is obtained, and the SJ Power TMOSFET is designed to make the power of the chip distributed uniformly to guarantee it's reliability.

• 보건교육건강증진학회지
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• 제21권1호
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• pp.1-23
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• 2004

The purpose of this study is to examine the effects of job-related characteristics on alcohol consumption among female workers. The Data was collected from a sample of 1,000 female workers by a stratified proportional quota sampling method derived from those who were working in Seoul. Drinking behavior pattern includes total amount of pure alcohol consumed during the last month (AC) measured by graduated quantity-frequency. Job-related characteristics (JRC) were measured by job-related stress, work characteristics, and organizational structure including length of working hours, number of times dining out together with workers per year, number of staff to supervise, employment status, occupational category, and proportion of female workers to male counterpart. Confounding variables include sociodemogrphic and socio-cultural attitudes toward alcohol expectancy, subjective norm of drinking, and gender-role attitude. Hierarchical multiple regression models show that the variability of AC was accounted for by some JRC including number of times dining together and employment status, with confounding variables held constant. However, the relationship between AC and JRC varied across occupational categories. Some implications were discussed in terms of health policy for female workers and further study for female drinking behavior.

• 상하수도학회지
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• 제22권1호
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• pp.23-29
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• 2008

Throughout the analysis of field data from water distribution system, valid parameters were determined that can be included in the water service and design plan. This study investigates water consumption patterns to understand the variation of water-demand structures utilizing the pattern analysis of domestic purpose water. Water use data were collected by a public water resources management firm in Korea, Kwater, for 140 houses monitored during three years. Flow meters were installed at the faucet for drinking water, the shower booth, the laundry machine, bathroom sink, toilet, and garden faucet. Data was filtered using multiple physically meaningful criteria to improve analysis credibility. Mann Kendall and Spearman's Rho tests were used to carry out the analysis. Distinct factors of water consumption patterns can be determined for both increasing and decreasing trends of water use. Throughout the data analysis, the characterization of terms was classified and analyzed by the condition of the location of water-demand. Analysis of this data provide a physical basis for the parameter configuration of a reasonable design for a domestic water demand prediction model.

• Journal of Nutrition and Health
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• 제21권5호
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• pp.333-347
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• 1988

The purpose of the present study was to investigate the relationship between nutrient status, and bone mineral state which influenced by aging process. The subjects were 196 people over 65 years old(male 72, female124). The present dietary intake was estimated by the 24-hr, recall method, and individual dietary history concerning consumption of meat, fish and dairy products was obtained by questionaires. The syndrome of senility including seniliy was evaluated according to "Cornell Medical Index". The five subjects who showed 'Good' grade in bone senility, and five subjects who showed 'Risk' and 'Danger' grade were selected and their spine and femur bone density was measured by "Dual Photon Absorptiometry". The bone density measurement showed that the subjects with 'Good' grade in bone senility had bone density above that of normal person, and their nutrient status were satisfactory, whereas the subjects with 'Risk' and 'Danger' grade in bone senility had severe osteoporotic pattern, and their nutrient status were very poor. The food consumption score showed that the subject with higher intake of meat rather than milk had good grade in bone senility (p<0.05). Therefore, past meats consumption can be considered to be a significant factor in the present bone status. The nutrient intakes appeared to be significant factors in bone status in male, whereas there was little effect of nutrients intakes in female. Therefore, the risk of osteoporosis can increase as syndrome of bone senility and nutrient intakes were worse, and its is possible to evaluate bone status and predict osteoporosis simply from informations concerning syndrome of bone senility and nutrient intakes in old population over 65.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2009년도 하계학술발표대회 논문집
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• pp.1185-1190
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• 2009

Korea is an industrial country that overspends energy and has a policy that is more focused on a supply side. When an urban developmental program is to set up, surveys are carried out only with the respect to electricity, telecommunication, gas, and heating sources. Based on the existing survey results, the problems related to the supply side are being dealt with more importantly and the quantities of those supplies are estimated only by each energy source. The aim of this study is to provide basic information on energy consumption patterns of a diverse comsumer groups including industry, transportation, commerce, public and household to plan diverse energy policies. Through this basic information, it may be possible to analyze the energy consumption pattern by each consumer group and provide data for setting up efficient energy policies by the government. The energy consumption map that are analyzed and developed by the data obtained from Busan municipal area will be deposited and used as a part of the national energy statistics.

• 한국식품영양과학회지
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• 제26권3호
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• pp.540-548
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• 1997

According to the data published in 1990s on the intake of dietary fiber(DF) of Korean, DF intake of Korean has been gradually decreasing in the last two decades. Mean daily intake of DF in 1990s is estimated to be in the rage of 17-20g per capita and over seventy five percent of the subjects examined appeared to consume DF less than 20g per day. The major food sources of Df in Korean diet include cereals, vegetables, fruits, seaweeds and seasonings. The present level of DF intake of Korean is lower than the tentatively recommended minimum intake of DF. It is predicted that, if the present trend of change on food consumption pattern is maintained, the gradual increases in the incidence of chronic degenerative diseases will be continuing. Therefore, the beneficial effects of DF on health care and disease control should be emphasized through the nutritional education and high level consumption of DF needs to be strongly recommended in the dietary guideline. In order to raise the daily consumption of DF, more whole grain cereals need to be used as a part of staple and more frequent intake of legumes and seaweeds is required as well as the development of high-fiber diet recipes and natural high-fiber products.

• 대한기계학회논문집B
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• 제25권12호
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• pp.1730-1738
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• 2001

This paper presents an overview of testing and analyzing field performance of a centrifugal chiller which has a rated capacity of 200 RT(703 kW). Field data of a chiller installed in the cleanroom research building of KIST has been collected far performance analysis. The operating data included start-up, shut-down, and quasi-static state where cooling capacity and compressor power consumption varied cyclically. It was found that the steady-state thermodynamic model could be applied to relate the cooling capacity and COP under quasi-static conditions. The results led to finding the required cooling load pattern and a possible energy saving method. This study provides a method of evaluating performance of a large capacity centrifugal chiller in which field test is necessary.

• International Journal of Automotive Technology
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• 제8권1호
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• pp.119-126
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• 2007

Because of the low temperature operation, proton exchange membrane (PEM) fuel cell has a water phase transition. Therefore, water management is an important operation issue in a PEM fuel cell because the liquid water in the fuel cell causes electrode flooding that can lower the cell performance under high current density conditions. In this study, in order to understand the reactant distributions in the cathode channels of the PEM fuel cell, an experimental technique that can measure the species concentrations of reactant gases by using gas chromatograph (GC) is applied for an operating PEM fuel cell. The oxygen distribution along the cathode flow channels of PEM fuel cell is mainly investigated with various operating conditions. Also, the relations between cathode flooding and oxygen concentrations and oxygen consumption pattern along the cathode channel configurations of the unit cell adopted for this study are discussed using GC measurement and visualization experiment of cathode flooding. It is found that the amount of oxygen consumption is very sensitive to various operating conditions of the fuel cell and was much affected by the flooding occurrence in cathode channels.

• 한국자동차공학회논문집
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• 제13권1호
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• pp.174-183
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• 2005

A train driving requires to n the fixed distance within given time, and it is desirable to consume low energy if necessary. Reducing energy consumption depends on the train operation modes by either manual or automatic operation. In this article, an operation to reduce energy consumption by changing modes of train operation by a driver without changing the train operation requirement is investigated. The powering model, braking model and consumed energy calculation model are developed, then simulated by using a Matlab software. The accuracy of the train dynamic model established by the simulations is verified by comparing with the real experimental data. Several simulations by various operations in the real track are executed, then the desirable pattern of train driving is found.