• Geomechanics and Engineering
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• 제21권6호
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• pp.537-549
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• 2020

The presence of cracks changes the water content pattern during seepage through a cracked soil as compared to that of intact soil. In addition, several different crack networks may form in one soil type. These two factors result in a variation of water contents in the soil matrix part of a cracked soil during seepage. This paper presents an investigation of the effect of crack network representation on the water content of the soil matrix part of cracked soil using numerical models. A new method for the numerical generation of crack networks incorporating connections among crack endpoints was developed as part of the investigation. Numerical analysis results indicated that the difference in the point water content was large, whereas the difference in the average water content was relatively small, indicating the uniqueness of the crack network representation on the average water content of the soil matrix part of cracked soil.

• 조명전기설비학회논문지
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• 제29권4호
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• pp.69-76
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• 2015

This paper presents the results of an investigation into the frequency-dependent electrical parameters for different types of soil as a function of moisture content. The frequency dependence of soil electrical parameters is very important in the design of grounding systems. In fact, the performance of grounding systems is greatly dependent upon various factors such as soil type, particle size, water content, temperature, frequency, and the like. The resistivity and relative permittivity for four different soils were measured and analyzed in the frequency range of 1kHz - 1MHz. Soil resistivity declined as moisture content and frequency increased. In particular, the frequency dependence of soil resistivity was significant as the moisture content was low. In contrast, the relative permittivity of soil dramatically declined at the frequency of 10kHz or below as the moisture content increased, showing the opposite pattern in terms of variation patterns, compared to resistivity.

• 한국빅데이터학회지
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• 제4권2호
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• pp.23-34
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• 2019

최근 디지털 플랫폼을 활용한 민생 위협 범죄는 '15년 약 14만여 건, '16년 약 15만여 건 등 사이버범죄 지속 증가 추이이며 전통적인 수사기법을 통한 온라인 범죄 대응에 한계가 있다고 판단되고 있다. 현행 수기 온라인 검색 및 인지 수사 방식만으로는 빠르게 변화하는 민생 위협 범죄에 능동적으로 대처 할 수 없으며, 소셜 미디어 특성상 불특정 다수에게 게시되는 콘텐츠로 이루어 졌다는 점에서 더욱 어려움을 겪고 있다. 본 연구는 민생 침해 범죄가 발생하는 온라인 미디어의 특성을 고려한 콘텐츠 웹 수집 방식 중 사이트 중심의 수집과 Open API를 통한 방식을 제시한다. 또한 불법콘텐츠의 특성상 신속히 게시되고 삭제되며 신조어, 변조어 등이 다양하고 빠르게 생성되기 때문에 수작업 등록을 통한 사전 기반 형태소 분석으로는 빠른 인지가 어려운 상황이다. 이를 해소 하고자 온라인에서 벌어지는 민생 침해 범죄를 게시하는 불법 콘텐츠를 빠르게 인지하고 대응하기 위한 데이터 전처리인 WPM(Word Piece Model)을 통하여 기존의 사전 기반의 형태소 분석에서 토크나이징 방식을 제시한다. 데이터의 분석은 불법 콘텐츠의 수사를 위한 지도학습 기반의 분류 알고리즘 모델을 활용, 투표 기반(Voting) 앙상블 메소드를 통하여 최적의 정확도를 검증하고 있다. 본 연구에서는 민생경제를 침해하는 범죄를 사전에 인지하기 위하여 불법 다단계에 대한 사례를 중심으로 분류 알고리즘 모델을 활용하고, 소셜 데이터의 수집과 콘텐츠 수사에 대하여 효과적으로 대응하기 위한 실증 연구를 제시하고 있다.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2006년도 춘계 학술발표회 논문집(II)
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• pp.197-200
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• 2006

The ingress of chloride ions plays a crucial role for service life design of reinforced concrete structures. In view of durability design of concrete structures under marine environment, one of the most essential parameters is the surface chloride content of concrete. However, on the basis of the results of in-situ investigation, this value has been determining in the numerous studies on the durability design of concrete structures. Hence, it is necessary to confirm the range of the surface chloride content in order to establish a unified durability design system of concrete. This study suggests a rational and practical way to calculate the maximum surface chloride content of submerged concrete under marine environment. This approach starts with the calculation of the amount of chloride ingredients in normal sea water. The capillary pore structure is modeled by numerical simulation model HYMOSTRUC and it is assumed to be completely saturated by the salt ingredients of sea water. In order to validate this approach, the total chloride content of the mortar and concrete slim disc specimen was measured after the immersion into the artificial sea water solution. Additionally, the theoretical, the experimental and in-situ investigation results of other researchers are compiled and analyzed. Based on this approach, it will follow to calculate the maximum surface chloride content of concrete at tidal zone, where the environment can be considered as a condition of dry-wetting cycles.

• 한국과학교육학회지
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• 제15권1호
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• pp.116-125
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• 1995

This study is to consider hypotheses with integral view on the respect of creative thinking. Subjects of this study are Korean students in the 5th grade who participated in the Field Trip Contest of the second Korean Youth Science Festival, an openended inquiry investigation. Objectives of this study are as follows: 1) to measure the inquiry level of the Field Trip Contest activity 2) to find how many hypotheses were made on different types in the inquiry investigation 3) to measure the quality level of hypotheses made in the scientific inquiry investigation 4) to find out the correlation between the 1st and 2nd hypotheses and the final activity score in the two staged scientific investigation In the consequence of it, inquiry level of the Field Trip Contest was very high with good activity topics and openended way of investigation. Hypotheses were made in the prediction, plan, and conclusion parts in the field trip activity report. They used hypothesis-as-prediction typed statements(3.41/team) more than hypothesis-as-explanation(1.28/team) and descriptive hypothesis(0.03/team) types. Content-related hypothesis(5.03/team) and process-related hypothesis(6.16/team) were usually coupled each other. Most of them had difficulties in hypothesis-from-evidence(0.31/team, 10/32 teams) in the comparison of hypothesis-from-simple conjecture(10.62/team). The quality level of content-related hypotheses(0.74point/statement) and process-related hypotheses(1.98point/statement) were very low by the hypothesis-quality scale(Quinn and George, 1975) for the content-related hypotheses and the process-related hypothesis quality scale developed in this study. There was considerable correlation between the activity score and the 1st and 2nd hypothesis in the 2 staged inquiry investigations with the 2nd and 3rd topics($0.41{\ast}$, $0.59{\ast}{\ast}$ repectively).

• 대한약학회:학술대회논문집
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• 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2-2
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• pp.113.1-113.1
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• 2003

A 35-year-old Perubian who suffered from grand mal seizures died in aircraft on his way from United States to Hongkong. When he boarded the aircraft, he was normal but later he suffered from hyperthermia, dizziness, abdominal pain, agitation and convulsion in the flight before dead. While performing the autopsy, 115 cocaine packs were found in the GI tract. To determine the concentration of cocaine and its metabolites, blood, urine, bile juice, gastric content, liver, spleen, heart, kidney, cellebrum and lung were taken and analyzed. (omitted)

• 한국환경보건학회지
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• 제11권2호
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• pp.55-63
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• 1985

The quantities of chrome, lead, iron, copper and manganese in the formula feed were determined by A.A.S. and the results were summarized as follows 1. The content of chromium in the leather and meat meals(SN-2) were 13-66 times as much as the level of permission. 2. In the meantime, lead content in the meat meal (SN-1) was about 20 times as much as permitted level. 3. The iron which is essential constituent of the formula feed was contained in the meat and leather meals and these values were 2-10 times as much as feeding regulations, on the contrary copper and manganese content in the shaving and flesh were below the feeding regulations.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2008년도 춘계 학술발표회 제20권1호
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• pp.745-748
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• 2008

On investigation about quick measurement technology of unit water at range of W/B=35% in high strength, the average error of the Di-electric constant moisture tester A has measured more than $23.0kg/m^3$ unit water content of design and the average error of the method of unit volume weigh was less than $-9.6kg/m^3$. The average error with mixing factor has influenced with a kind of sand, but had not influenced with unit water content of design. Therefore, it will be for introduce business decide require more than a study about cement, sand, superplasticizer, etc.

• 한국과학교육학회지
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• 제8권2호
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• pp.23-32
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• 1988

This study analyzed the specific science content involved in 'the 5th curriculum in the elementary school' in Korea and four Kinds of 'Science in the elementary school' books. And innovative science content is investigated for children's living in the scientific, technological, and informationized society. As results, biology is emphasized much more than other areas. Chemistry is less emphasized than other areas. The innovative science content should inchudethe S. T.S problems, the recent developments and the value or religious problems related to science. This study suggested several innovative science contents.

• 시큐리티연구
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• 제59호
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• pp.189-215
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• 2019

현대사회가 정치, 경제, 사회를 포함한 모든 분야에서 전문화되고 복잡해지면서 일반적인 공권력으로는 범죄를 통제하기 어려운 상황에 이르렀다. 19세기 이후 요동치기 시작한 민간보안 산업은 그 범위를 넓혀 공권력이 필요한 다양한 분야에서 보조적인 역할을 수행하고 있다. 이러한 민간보안 활동 중에서 민간조사시스템은 오랫동안 개인의 인권보호와 범죄로부터 안전한 민간조사 서비스를 제공하는 데 이용되어 왔다. 이 연구에서는 선행연구 분석과 질적 내용분석을 통해 실종자 조사 시스템에 초점을 맞춘 영국과 한국의 민간조사 시스템을 비교분석 할 것이다. 질적 내용 분석의 결과는 영국의 민간조사시스템과 실종자 조사시스템이 어떻게 구현되는지에 대한 문헌 검토 및 심층면담 등의 방법을 통해 기술된다. 민간조사 분야에 대한 연구는 양국에서 매우 중요한 분야이지만 한국의 시각에서 볼 때 그 연구가 매우 제한적이라고 할 수 있다. 따라서 이 연구는 민간조사 시스템의 성공적인 합법화를 위한 논의를 촉진할 뿐만 아니라 향후 연구의 기초자료가 될 것으로 기대된다. 민간조사 시스템의 연구는 앞으로도 지속적으로 이루어져야 한다. 또한 한국에 민간조사제도를 도입하기 위해서는 본 연구에서 언급한 민간조사제도와 관련된 문제점을 발견하여 민간, 학계, 관련 기관의 의견을 수렴해 민간조사시스템을 개발해야 한다. 민간조사제도의 도입은 민간, 학계 및 관련 기관의 노력을 통해 이익을 극대화시킬 것으로 사료된다.