• Proceedings of the Korean Information Science Society Conference
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• 2007.10a
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• pp.27-31
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• 2007

최근 모바일 환경에서 우수한 특성으로 인해 플래시 메모리가 하드디스크를 대체할 만한 차세대 저장 장치로서 주목을 받고 있다. 하지만 이러한 플래시 메모리는 읽기 속도에 비해 쓰기 속도가 느리고 접근 비용의 비중이 미미한 특징 때문에 하드디스크 기반에서의 디스크 접근 횟수를 이용한 비용 예측 방법을 그대로 적용할 수 없다. 그러므로 플래시 메모리 기반의 효율적인 인덱스 설계나 질의 처리, 최적화를 위해서는 플래시 메모리에 적합한 비용 예측 방법이 필요하다. 본 논문의 목적은 플래시 메모리를 위한 파일 시스템인 플래시 전환 계층(flash Translation Layer)을 기반으로 비용 예측 모델을 제시하는 것이다. 플래시 메모리의 저장 공간에서 데이터를 읽는 비용은 플래시 메모리의 하드웨어 특성으로부터 쉽게 유추될 수 있지만, 쓰기 비용의 경우 플래시 메모리에 대한 쓰기 작업이 초래하는 가비지 컬렉션(Garbage Collection) 때문에 예측하기가 힘들다. 본 논문은 해당 파일 시스템으로부터 전체 플래시 메모리 공간 대비 유효 데이터의 사용률을 얻어낸 후 그 정보를 이용하여 가비지 컬렉션을 포함한 쓰기 비용을 예측하는 모델을 제안한다. 이러한 예측 모델을 사용하면 인덱스를 구성하거나 질의 처리 및 최적화 알고리즘을 구성하는데 있어 플래시 메모리의 특성을 반영한 비용 효율적인 설계를 수행할 수 있다.

• Journal of The Korean Society of Agricultural Engineers
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• v.50 no.6
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• pp.15-24
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• 2008

In general, ground pollution can be classified with soil pollution and underground water pollution. And ground pollution contaminates the land with garbage dumps and other harmful waste products as heavy metals that can also eventually enter our water supply. This study was conducted to define a characteristics of the electrical resistivity and the permittivity of weathered soil that was contaminated with heavy metals as Mercury and Arsenic. It is not easy whether contamination of soil as subsurface contamination is decided or not and at an early stage especially do that. Therefore the electrical resistivity and the permittivity were used to make up for this defects. These methods are more economical and more effective than the existing methods. And variation of the electrical resistivity and the permittivity values were found against the change of concentration of Mercury and Arsenic aqueous solutions and measuring frequency. These analyzed results indicate that the electrical resistivity and the permittivity tend to decrease against increasing measuring frequency. The electrical resistivity and the permittivity are also found to show the function of frequency.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.10 no.2
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• pp.26-33
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• 2007

This study was to investigate the reaction analysis of citizen on fence removal for securing green space. The results are as following; The majority of users went to green space more than one time per week to take a walk, rest and stayed there less than an hour. The places, where the fence removal was required mostly, were public institutions, parks and schools. The physical factor was the highest influence on whether the fence removal project could be expanded or not. With a slight difference from the physical factor, the environmental and emotional factor followed after. The social factor was also significant at 1 % level. In the physical aspect, the increase of garbage littering was the most negative part after fence removal.When the citizens were asked if they would participate in the fence removal project, the environmental and emotional factor and the social factor were the most influential ones on work places while the environmental and emotional factor influenced only on private houses.

• KIEAE Journal
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• v.4 no.2
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• pp.49-56
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• 2004

This study intends to propose the fundamentals of 'Ecovillage' design by researching into the cycle system of material of 'Crystalwaters' which is having been in charge of a leading role of GEN since 1996 (GEN was formed in 1996) as Ecovillage in Australia. First, to secure the water resources, we can store up rain and the water of valley, and dam. Second, we are able to use the natural filter apparatus, do tree-planting of roof to gain better quality of water. Third, it is to save the energy as supplying water. For it, we make the best of a gravity that is one of the cycle principle of water. Forth, to build a Dam can make a site of scenic beauty, do the role of recreation place and provide against emergencies (a fire, drought) as well as make a mild climate. Fifth, it can reduce the environment load because of sewage and garbage as making it compost. This is possible by treating biologically using composting apparatus of the dry or wet process. Sixth, it is to reduce the environmental pollution as to discharge seperating a recycable waste, an organic matter being able to make it compost. Finally, first of all, environmentally friendly inhabitant consciousness from lifestyle and production style plays an importent part for water cycle and the ecological cycle of waste and sewage.

• Journal of the Korean Society of Combustion
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• v.20 no.4
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• pp.26-33
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• 2015

American NREL (National Renewable Energy Laboratory) reported that BD20 could reduce PM, CO, SOx and cancerogenic matters by 13.6%, 9.3%, 17.6% and 13% respectively, compared to diesel fuel. BD20 has been being tested on garbage trucks and official vehicles at Seoul City, which is positive on air environment, but negative on combustion by higher viscosity in winter season. This study investigated the combustion characteristics by employing multi cavity piston for improving the deterioration of combustibility caused by the higher viscosity of the biodiesel fuel such as BD20 with the combustion flames taken by a high speed camera and the cylinder pressure diagram. A 4-cycle single cylinder diesel engine was remodeled to a visible 2-cycle engine for taking the flame photographs, which has a common-rail injection system. The test was done at laboratory temperature of about $4{\sim}5^{\circ}C$.

• ETRI Journal
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• v.35 no.2
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• pp.259-269
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• 2013

Android has become the most popular platform for mobile devices. However, Android still has critical performance issues, such as "application not responding" errors and hiccups resulting from garbage collection. Many phone vendors have tried to resolve the problems by characterizing and improving the performance. However, there are few insightful performance analysis tools for the Android-based systems. This paper presents AndroScope, which is a performance analysis tool for both the Android platform (Dalvik virtual machine, core libraries, Android libraries, and even Linux kernels) and its applications. To the best of our knowledge, this is the first tool to collect and analyze performance data from all the software layers of the Android-based systems. AndroScope offers a trace mechanism to collect such deep and wide performance data as hardware performance counters, time, and memory usage. In addition, the tool includes TraceBridge, which is a middleware for the fast handling of mass logs. Moreover, AndroScope offers an integrated graphical user interface with the Android software development kit to display a great volume of the detailed performance data.

• IEMEK Journal of Embedded Systems and Applications
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• v.13 no.3
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• pp.151-160
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• 2018

NAND flash memories have the advantages of fast access speed, high density and low power consumption, thus they have increasing demand in embedded system and mobile environment. Despite the low power and fast speed gains of NAND flash memory, DRAM disk buffers were used because of the performance load and limited durability of NAND flash cell. However, DRAM disk buffers are not suitable for limited energy environments due to their high static energy consumption. In this paper, we propose WAP-LRU (Write pattern Analysis based Placement by LRU) hybrid disk buffer management policy. Our policy designates the buffer location in the hybrid memory by analyzing write pattern of the workloads to check the continuity of the page operations. In our simulation, WAP-LRU increased the lifetime of NAND flash memory by reducing the number of garbage collections by 63.1% on average. In addition, energy consumption is reduced by an average of 53.4% compared to DRAM disk buffers.

• The Research Journal of the Costume Culture
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• v.7 no.1
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• pp.1-12
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• 1999

Analysis of Customer Characteristics on Environment-Friendly Clothing Products The purpose of this study is to analyze the characteristics of the environment-friendly customers in Korean fashion market. The study is analyzed through questionary paper to the domestic female group of more than or equal to age of twenty living in Seoul. The collected questionary paper is analyzed with SPSS/PC/sub +/ program and the method of statistical analysis used for this study is frequency analysis, factor analysis, cluster analysis, t-test, and crosstab analysis. The result of analysis of the characteristics of the environment -friendly customers involves the following: Firstly, there were no significant difference in the demographic characteristics between the environment-friendly customer group and non-environment-friendly customers group. Secondly, environment-friendly customers had more environmental programs, had seen and heard more environmental program through current news from TV, newspapers, and magazines, and had more interest in recycling or separated collecting of garbage, and been doing better recycling or separated collecting. These serial processes of research, have the meaning in confirming that segmented market for environment-friendly customers exists in the domestic fashion market, and these will not only set up the basis of research on the market of environment-friendly fashion product but also be able to contribute to propose future direction of research.

• Korean Journal of Community Nutrition
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• v.9 no.5
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• pp.629-635
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• 2004

The purpose of this study was to investigate school dietitians' use of processed and packaged foods in Incheon. This study was carried out through a questionnaire and the subjects were 203 school dietitians in Incheon. The results are summarized as follows. Dairy product was the processed and packaged food used most frequently by the subjects for school lunch. Most subjects used processed and packaged foods for school lunch once or twice per week. The first criteria for their choosing processed and packaged foods was manufacturing company. Also major reason for their using processed and packaged foods for school lunch was saving cooking time, easy purchase, hygienical packing and less garbage. The most common information source on processed and packaged foods for school lunch was promotion of food company. The subjects checked labelling of processed and packaged foods in order of open-date, manufacturer, origin of product, nutrition facts, ingredients and food additives. Some results were significantly different among the subjects by employment school, type of meal management and cost per meal. For children and adolescents' nutrition and well-being through school lunch, it is necessary to prepare a database of the processed and packaged foods and education program concerning nutrition labelling and food safety.

• Proceedings of the KIEE Conference
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• 2000.07c
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• pp.1614-1616
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• 2000

The purpose of this study is to manufacture and test a thermoelectric generator which converts unused energy from close-at-hand sources, such as garbage incineration heat and industrial exhaust, to electricity. A manufacturing process and the properties of a thermoelectric generator are discussed before simulating the thermal stress and thermal properties of a thermoelectric module located between an aluminum tube and alumina plate. We can design the thermoelectric modules having the good properties of thermoelectric generation. Resistivity of thermoelectric module for thermoelectric generation consisting of 62 cells was $0.15{\sim}0.4{\Omega}$. The maximum power of thermoelectric generator using thermoelectric generating modules can be defined as temperature function, and in this case it can be analogized the linear relation between current and voltage characteristics as function of temperature. The thermoelectric generator using 128 generating modules was assembled with 4 parallel connected modules sets composed with 32 directly connected modules.