• Geomechanics and Engineering
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• v.21 no.6
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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.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.29 no.4
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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.

• The Journal of Bigdata
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• v.4 no.2
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• pp.23-34
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• 2019

Recently, the crime that utilizes the digital platform is continuously increasing. About 140,000 cases occurred in 2015 and about 150,000 cases occurred in 2016. Therefore, it is considered that there is a limit handling those online crimes by old-fashioned investigation techniques. Investigators' manual online search and cognitive investigation methods those are broadly used today are not enough to proactively cope with rapid changing civil crimes. In addition, the characteristics of the content that is posted to unspecified users of social media makes investigations more difficult. This study suggests the site-based collection and the Open API among the content web collection methods considering the characteristics of the online media where the infringement crimes occur. Since illegal content is published and deleted quickly, and new words and alterations are generated quickly and variously, it is difficult to recognize them quickly by dictionary-based morphological analysis registered manually. In order to solve this problem, we propose a tokenizing method in the existing dictionary-based morphological analysis through WPM (Word Piece Model), which is a data preprocessing method for quick recognizing and responding to illegal contents posting online infringement crimes. In the analysis of data, the optimal precision is verified through the Vote-based ensemble method by utilizing a classification learning model based on supervised learning for the investigation of illegal contents. This study utilizes a sorting algorithm model centering on illegal multilevel business cases to proactively recognize crimes invading the public economy, and presents an empirical study to effectively deal with social data collection and content investigation.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.05b
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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.

• Journal of The Korean Association For Science Education
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• v.15 no.1
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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).

• Proceedings of the PSK Conference
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• 2003.10b
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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)

• Journal of Environmental Health Sciences
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• v.11 no.2
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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.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.04a
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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.

• Journal of The Korean Association For Science Education
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• v.8 no.2
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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.

• Korean Security Journal
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• no.59
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• pp.189-215
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• 2019

As modern society has become specialised and complex in all areas of politics, economy and society, it has reached a point where it is difficult to control crime with the general public power. Private security, which began to fluctuate after the 19th century, has expanded its scope to subsidise public power in various areas, sometimes beyond public power. Among these private security activities, the private investigate system has long been used to provide private investigate services that are safe from personal human rights protection and crimes. This study investigate the private investigation system in the United Kingdom and South Korea focusing on the missing person investigation system by using the qualitative content analysis of research methods. First, the results of the qualitative content analysis are described through methods such as literature reviews and interviews on how the British private investigation system and the missing persons search system are implemented. Next, the results of the content analysis are presented through the methods of literature reviews and questionnaires on how the implementation of the civilian survey in Korea and the search for missing people is proceeding. It is a very important field in both countries, and there is a very limited study, especially from a Korean perspective. Therefore, it is expected that this study will not only facilitate discussions for the successful legalisation of the private research system, but also provides a basic foundation for future research. The study of the private research system should be ongoing and periodic, not temporary. In addition, in order to introduce Korea's private survey system, the private investigation system should be developed by discovering the problems of the Private Investigation Law mentioned in this study and collecting opinions from citizens, academics and related institutions. The introduction of the private investigation system requires the connection of the efforts and interests of citizens, academia and related institutions.