• 대한임베디드공학회논문지
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• 제13권5호
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• pp.269-277
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• 2018

NAND flash memory has widely been used because of non-volatility, low power consumption and fast access time. However, it suffers from inability to provide update-in-place and the erase cycle is limited. The unit of read/write operation is a page and the unit of erase operation is a block. Moreover erase operation is slower than other operations. We proposed the Adaptive Garbage Collection (called "AGC") policy which focuses on not only reducing garbage collection process time for real-time guarantee but also wear-leveling for a flash memory lifetime. The AGC performs better than Cost-benefit policy and Greedy policy. But the AGC does not consider the operation characteristics. So we proposed the Advanced Adaptive Garbage Collection (called "A-AGC") policy which considers the page write operation count and block erase operation count. The A-AGC reduces the write operations by considering the data update frequency and update data size. Also, it reduces the erase operations by considering the file fragmentation. We implemented the A-AGC policy and measured the performance compared with the AGC policy. Simulation results show that the A-AGC policy performs better than AGC, specially for append operation.

• 한국작물학회지
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• 제23권3호
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• pp.19-30
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• 1978

Use of herbicides in Korean agriculture has increased rapidly in recent years accompanying with ever-increasing pressure of farm labor shortage. Herbicides occupied already the second place in the rank of pesticides consumption in 1977. The agricultural experiment stations have carried out over 50 trials of chemical weed control each year since 1968. These research works and registration trials contributed much to the present wide use of herbicides. The pesticide management act amended in 1977 requires reevaluation of pesticides for their efficacy every 5 year-term. However, the development of sound weed control program and recommendations has been hempered very much by the lack of qualified workers of weed control research in agricultural experiment stations and in the institute for pesticide registration trial. Critical review of the past research works on herbicide evaluation and the present status indicates strong need for 1) the characterization of the nature of local and national weed problem, 2) the improvement of ability of the staffs in charge of weed control research through appropriate training on the basics and experimental techniques, and 3) organization and activities of weed control research committee. Furthermore, the present article attempts to clarify commonly misled points in the establishment of herbicide evaluation plan, in the design and execution of field trials, and in the assessment of trial results of the past works from the viewpoint of the basic principles with some case studies for resolution of specific enigmas.

• 한국화재소방학회논문지
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• 제6권1호
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• pp.90-98
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• 1992

Over the last 100 years since the introduction of electricity, the nation has faced ever increasing demand for electricity as consequence of the rapid economic growth. The expanded consumption ratio for electricity naturally increased the possibility for electricity related accident mainly iii the form of electrically ignited fire and human injuries from electric shock. Under such circumstances, the presented study sets a focus on analysing the causes of the electrically related fire accidents happened in the nation over the last 10 years(in the 80's) to provide a scientific basis for identifying the cause of electric fires. Identification of the cause of fire ignited electrically may be approached either by studying accident related electrical properties or by investigating power instruments at the place of the accient. In the present paper, the former approach is taken especially on investigating the consequences of over current induced by short circuiting of high power instruments which is reported as the primary cause electricity related fire accidents. In order to provide reliability of the identification method, microscopic photograph's are taken for the cross sections of the electrical materials(fuse, wire, plug socket and plug) after being exposed to over current and heated by external means respectively. The results are consequently compared and analysed.

• 대한임베디드공학회논문지
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• 제11권2호
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• pp.67-78
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• 2016

The emerging Spin-Transfer Torque RAM (STT-RAM) is a promising component that can be used to improve the efficiency as a result of its high storage density and low leakage power. However, the state-of-the-art STT-RAM is not ready to replace SRAM technology due to the negative effect of its write operations. The write operations require longer latency and more power than the same operations in SRAM. Therefore, a hybrid cache with SRAM and STT-RAM technologies is proposed to obtain the benefits of STT-RAM while minimizing its negative effects by using SRAM. To efficiently use of the hybrid cache, it is important to place write intensive data onto the cache. Such data should be placed on SRAM to minimize the negative effect. Thus, we propose a technique that optimizes placement of data in main memory. It drives the proper combination of advantages and disadvantages for SRAM and STT-RAM in the hybrid cache. As a result of the proposed technique, write intensive data are loaded to SRAM and read intensive data are loaded to STT-RAM. In addition, our technique also optimizes temporal locality to minimize conflict misses. Therefore, it improves performance and energy consumption of the hybrid cache architecture in a certain range.

• 한국정밀공학회지
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• 제24권5호
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• pp.68-76
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• 2007

It is strongly requested to reduce fuel consumption because of high oil price and exhaust gases of road vehicles for environmental preservation. To solve these problems, several types of hybrid vehicles have been developed. Among them, flywheel hybrid vehicle using variable displacement pump/motor was already proposed as one of the feasible hybrid systems in place of hybrid vehicle by the conventional storage battery. The proposed flywheel hybrid vehicle is to keep constant pressure of high pressure line by the control of swash plate angle of flywheel pump/motor as pressure compensator. The efficiency of the overall system depends severely on the efficiency of hydraulic pump/motor in the energy saving hydraulic control system by simulation. According to the control methods of swash plate angle of piston pump/motor, there remain several problems to be solved. In this paper, experimental setup for energy saving is fabricated and the efficiency of energy saving is investigated by experiments with respect to various experimental conditions.

• 한국식생활문화학회지
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• 제17권5호
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• pp.543-550
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• 2002

The purpose of this study is to provide basic materials for food service consumption culture by proving the problem with food service purchase and its improvements. For this purpose, it was attempted to grasp university students' food service purchase behavior and level of satisfaction with it and to investigate the factors influencing their level of satisfaction with food service purchase. The questionnaire research was conducted for university students living in Seoul and Chungcheong provinces. 453 questionnaires obtained from them were used for final analysis. As a results, the following finding were obtained: 1. In case of university students, their level of consumer satisfaction with food service purchase was shown to be the score of 37.99(63.06/on the basis of 100 points). They showed the highest level of satisfaction with quality, followed by facility and atmosphere, service, price and the like. 2. The factor having the greatest influence on university students' level of satisfaction with food service purchase was shown to be gender(female), followed by food service place(Korean food restaurant, Chinese food restaurant, Western food restaurant, flour-based meals restaurant), consumer attitude, average monthly food service cost.

• 한국식생활문화학회지
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• 제33권2호
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• pp.149-159
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• 2018

Malaysia is regarded as one of the leaders in the global halal marketplace, which has undergone huge growth in the past few years. The aims of this study were to identify imported food consumers in Malaysia based on Food Related Lifestyle (FRL) attributes and to investigate the demographic characteristics and purchasing behaviors of each segmented groups. Using an online survey, a total of 600 responses were collected in Malaysia. Excluding invalid responses, cluster analysis segmented imported food consumers into four FRL groups: impulsive, high interest, low interest, and traditional consumers. The results of this study were as follows. First, depending on lifestyle, the groups exhibited significant differences in demographic characteristics (age, race, religion, and education level). Second, differences in purchasing behaviors (purchasing frequency, place, and information sources of imported food products) were verified. Especially, purchasing frequency of imported food was higher in the high interest consumer group compared to the other groups. Based on these results, marketing implications of the study findings are discussed.

• 가정과삶의질연구
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• 제14권3호
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• pp.1-20
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• 1996

The purposes of this study are to investigate the living environments, focused on economic and housing environments, of the elderly households in Chungbuk and to provide for the suggestions from the perspective of the well-being of the elderly. The results are as follows: for the economic environment, 70% of the elderly households receive the economic help from children, but the amount of the help is not much. Less than 20% of the households receive the pension and public assistance. Most elderly households had more assets than debt. The households tend to spend more for the necessties than for the non-necessities. The higher the income, the more the assets and the higher the consumption expenditures the higher is the life satisfaction. Therefore it is necessary to provide the elderly with opportunities to increase their income. For the housing environment, most elderly live in their own detached house with average size of 23 pyung. And there is 1.6 households per house. The condition of housing facilities is poor. The elderly prefer staying in the same place to moving, and invest little for their housing even though being able to afford to do so. The housing satisfaction, which is significantly influenced by the ownership the size the quality change in moving and the housing facilities, is correlated with the satisfaction of their condition as elderly households and their living satisfaction. Therefore, thoughtful policy is required to improve the standard of housing condition for the elderly households.

• 대한가정학회지
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• 제28권4호
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• pp.155-176
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• 1990

The purpose of this study is to investigate the influential factors to home management ability of mothers and their unmarried daughters through researching the relationship of their home management ability. It would provide the basic data for the direction of Home Economics Education. The subjects were 653, from 20 to 30 years of unmarried women and their mothers in Chonbuk province. The questionaire was used to measure their Home Management ability. The measured areas were planing, creativity, consumption management, housework, evaluation, and human relation. The question items were respectively 6 and totally 36. Spss was used for the statistic. Frequency, Percentage, Means, Standard Deviation were used for general understanding. For data analysis, F-test, Pearson Product-moment Correlation, Duncan's Multiple Range Test, Stepwise Multi-regression Analysis were used. Lastly, the research pattern was examined by Path Analysis. The results were as follows. 1. The importnat influential factors to mother's home management ability were their schooling level and their perceived socio-economic status among the general factors(age, shooling level, perceived socio-economic status) and the family atmosphere factors(monthly income, family type). 2. The important influential factors of unmarried daughter's home management ability were the monthly income of their family and the socio-economic status perceived by them, among their mother's general factors, family atmohphere factors, their own general factors(age, schooling level, perceived socio-economics status, occupation, growing place). 3. The influence of mother's home management ability on unmarried daughter's home management ability was much more remarkable than mother's general factors, family atmosphere factors and unmarried daughter's general factors.

• KIEAE Journal
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• 제8권1호
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• pp.45-52
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• 2008

Daylighting systems can improve the luminous quality of indoor environment and reduce the building's electric lighting energy consumption. For designing good daylighting, place the light where it is desired and avoid excessive contrasts, glare and high light levels. Sun scoop, light scoop and sun catcher systems have been used for alternative systems compared to other natural lighting systems. This study aims to evaluate daylighting performance of sun scoop, light scoop and sun catcher systems using scale model experiments. For the purpose, the 1/10 scale models of the systems were made as the same areas of glazing(10 percent of floor area) on the top of the center roof. Totally 15 measuring points of illuminance on the horizontal work plane were monitored from 09:30 to 12:30 on October 29, 2007. Agilent data logger and photometric sensors Li-cor were used. As the results, the topside lighting systems can improve the illumination uniformity than side lighting and top lighting. However, the appropriated shading system should be integrated to prevent the direct sunlight.