• Journal of Korean Society of Transportation
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• v.25 no.6
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• pp.7-18
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• 2007

There are few studies on air pollution due to vehicle emissions in spite of the importance of this field. Therefore, this study describes trends and suggests implications through analysis relating to existing emissions research. This study has been divided into three areas. The first part is about estimating vehicle emissions. In this part, the authors analyze limits in ways of calculating emissions in the existing macroscopic view and then suggest the development of a model for calculating emissions considering velocity and acceleration. These variables are a function of traffic and individual driving behavior in the microscopic view. The second part is about management techniques for reducing vehicle emissions. The traffic management techniques for reducing vehicle emissions should conform to regional characteristics. The final part is about traffic operation for reducing vehicle emissions. The authors suggest the development of a micro-simulator and then the development of strategies for traffic operation. It is necessary to design better models estimating emissions and then, using real time data, to make a monitoring system simulating emission rates. This study serves as a literature review to make a foundation for further research about emissions research for transportation engineering.

• Journal of Labour Economics
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• v.29 no.2
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• pp.117-143
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• 2006

This paper illuminates the patterns of growth and declines in sizes of union membership in metal, chemical, financial, and auto transport sectors in three distinct periods during the last four decades from 1963 to 2003. This paper also calculates union densities in auto assembly, auto supply, and shipbuilding industries of the metal sector, cement, petroleum refining, and pharmaceutical industries of the chemical sector, private banking industry of the financial sector, and city bus industry of the auto transport sector. Such diversities in both sizes of union membership and union densities among sectors and industries turned out to be associated with attitudes and choices of employers and unions in interaction with sector- and industry-specific economic (growth stage and path), institutional (degrees of government intervention), and social (demographic features of employees and prevailing sizes of firms) environment. Such finding shows that theoretical reasonings on sizes of union membership and union densities across sectors and industries in advanced nations are also relevantly useful to analyze the Korean case.

• Journal of The Korean Association For Science Education
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• v.22 no.2
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• pp.215-229
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• 2002

This study is to analyze the contents related to 'state of water', 'state change of water', and 'conditions of state change' in K-12 science textbooks. For this, we analyzed textbooks based on the 5th kindergarten curriculum, the 6th elementary school science curriculum and the 6th middle school science curriculum. Findings show that some of the contents are designed well by topical sequencing or by spiral sequencing. But others have some problems based on topical sequencing and spiral sequencing. Generally, the contents are represented in the order of Perception of phenomena with senses level, Macroscopic understanding level, Understanding of scientific term level, Microscopic understanding level by grade. But the state change contents related to solidification and melting, and conditions of state change contents related to heat, temperature, wind, and humidity are not represented in the level of Microscopic understanding. The contents of state change and conditions related to heat and wind are not represented in the level of scientific term also.

• The Journal of Korean Society for School & Community Health Education
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• v.10 no.1
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• pp.61-86
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• 2009

본 연구는 영문으로 발표된 문헌고찰을 통해 한국의 청소년 자살행동의 예측요인을 종합적으로 이해하고 이과 관련된 정책과 중재프로그램의 동향을 파악하는데 그 목적을 두었다. 이 연구의 목적은 나아가 한국 청소년 자살을 감소시키고 억제하는데 필요한 효과적인 중재방안의 개발에 근거자료로 활용될 수 있다. 본 연구는 주제어 검색을 통해 4대 사회과학 검색엔진을 활용하여 문헌검색을 하였고 Citation Pearl Growing 기법을 적용하여 영문으로 발표된 학술지 게재 논문을 선별하였는데 추가적으로 국회도서관 전자 데이터베이스를 이용하여 최근 청소년 자살에 관한 대표적인 2개의 보고서를 찾아 고찰하였다. 본 문헌고찰은 청소년 자살예방 중재 프로그램 뿐만 아니라 청소년 자살행동에 영향을 주는 요인을 거시적, 미시적 차원으로 논하였다. 청소년 자살행동에 기여하는 거시적 또는 사회적 요인은 국가 경제수준, 대학입시에 대한 학업성취도 스트레스, 그리고 매체 및 인터넷 문화였다. 개인적 또는 미시적 위험요인은 6개의 영역으로 나누어 설명되었다. 일반적 특성, 가족 특성, 학교 환경, 약물 사용, 정신적 장애, 성적 정체성이었다 이 6개 영역의 위험요인들이 서로 조합되면서 청소년에게 자살 의도나 시도가 일어나도록 하는 경향이 높았으며 이중 청소년 자살 예방에 우선적인 3대 요소는 자아정체성 확립, 정신건강 중재서비스의 제공, 거시적 예방 정책의 구조화로 분석되었다. 종합적으로 학교는 정규학교교육과정과 학생 검사를 통해서 일반적인 정신건강교육을 실시하고 위험학생을 선별 하는데 핵심적인 장이다. 따라서 학교를 경유한 위험학생 선별사업과 이에 따른 교육 및 중재 프로그램의 지원이 활성화되는 것이 필요하다.

• Journal of Korean Society of Transportation
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• v.20 no.5
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• pp.99-111
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• 2002

전산기술의 발달에 힘입어 근래에 모의실험을 이용한 연속교통류의 미시적 분석이 활발히 수행되고 있고 다양한 모의실험 전산모형이 소개되고 있다. 미시적 연속교통류 전산모의실험은 차량추종모형과 차로변경모형을 적용하여 다양한 운전자들의 차량운행행태를 모사하여 분석하는 실험이다. 전산모형은 난수를 토대로 차량의 자유속도와 초기 발생 차로를 배정하기 때문에 낮은 자유속도를 할당받은 차량이 높은 속도의 차로(예:1차로)로 발생되는 경우가 발생한다. 많은 모의실험모형이 사용하고 있는 차로변경의 가정이 "운전자는 자신이 원하는 속도(자유속도)를 유지한다"는 것이며 그러한 가정만의 적용으로 인해 현실적이지 않은 차로 이용률이 결과되고, 따라서 전산모형을 통한 교통류 흐름분석에 문제를 제공하고 있다. 본 논문에서는 미국 도로국에서 20여년 동안 개발되고 수정되어왔으며 현재 실용적으로 가장 많이 사용되고 있는 Freeway Simulation(FRESIM) 전산모형이 내재한 차로변경모형을 토대로 고속도로 기본구간에서의 선택적 차로변경모형을 제시한다. 제시된 모형에서는 (1)저속의 선행차량이 고속의 후행차량에게 차로를 양보하는 가정이 새롭게 추가되고 (2)FRESIM모형에서 사용하는 상수값을 국내 현장조사를 통하여 도출된 분포식을 통한 값으로 대체하였다. 수집된 자료분석결과 연속 교통류에서의 15% 차두시간은 1.34초이며 차로변경시간은 평균 2.22초인 F분포를 따르고, 자유속도는 정규분포를 따르는 것으로 결과되었다. 모의실험결과 무작위난수를 토대로 배정된 차로로 생성된 차량들이 새롭게 제시된 차로변경모형의 적용으로 현장 차로이용률을 95% 신뢰수준에서 모사하는 것으로 분석되었다.

• Journal of Korean Society of Transportation
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• v.29 no.5
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• pp.107-120
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• 2011

Traffic signal is one of the major factors that affect the amount of vehicle emissions on urban highway. The amount of vehicle emissions in urban area is highly affected by the vehicle's cruising speeds heavily influenced by the traffic signal lighting conditions. It was attempted in this study to trace the changing patterns of the vehicle emissions by collecting the emission data from a set of simulation studies and by categorizing vehicle cruising conditions into four different groups: idling, acceleration, deceleration, and running at a constant speed. Authors propose a simple emission model prepared based on Kinematic theory. The validation test results showed that the amount of the emission estimated by the proposed model was relatively satisfactory compared to the one of the existing model employing the average speed data only as the determinant.

• Korean Journal of Social Welfare
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• v.56 no.4
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• pp.79-101
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• 2004

This paper examines the characteristics and determinants of welfare attitudes in Korea. Based on Survey data, this study focuses mainly on how social-economic position variables, welfare status and welfare compliances influence attitudes towards welfare. Welfare attitudes can be classified by five areas as follows: legitimacy of welfare functions, affordability of welfare costs, need-based welfare principles, responsibility of welfare provision and adequacy of welfare spending. There are the major findings. First, attitudes towards welfare is identified state-friendly or pro-welfare attitudes. Second, among the social-economic position variables, welfare status and welfare norms variables, welfare compliance has statistically the most significant effects on welfare attitudes. Third, the level of pro-welfare attitudes is largely determined by welfare norms and images espoused by individuals. These findings suggest that we can not apply cleavages thesis which are developed by studies on the support for welfare state.

• Korean Security Journal
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• no.16
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• pp.283-304
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• 2008

The development of IT technology help citizens demand information and public services through internet that they want, and the changes also help the government converge public opinions and become important measures for citizens to participate in deciding governmental policies. So, this thesis makes an overture of a possibility for utilizing PCRM, a way for citizens to participate in Police Administration, by utilizing IT technologies in which everybody can participate without difficulty. The utilization ways are, on a large scale, classified with a macroscopic aspect and microscopic aspect. One of the macroscopic aspects is, first, the consideration of access to services and convenience in utilization. Second, services should have a both-sidedproperty. Ultimately, citizens'participation should have a positive mutual participation level. One of the microscopic aspects is, first, that the police organizations have to establish a strategy to analyze and fractionate customers. Second, the police organizations have to make an effort to develop policy services and P.R strategies. Third, police organizations have to make an effort to manage customers. Fourth, police organizations have to execute customer management in general. So, all of the police organizations have to maintain unity, to some extent, about citizen participation plazas. In addition, at the same time, consciousness aspects have to be accompanied for the reasonable utilization of PCRM. Citizens have to cultivate citizen consciousness, ownership consciousness for society, and positive participation consciousness to solve social problems.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.6D
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• pp.779-784
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• 2011

Freeway FFS (Free-Flow Speed) under the state of LOS (Level of Service) A has been regarded as a homogeneous state to all levels of traffic volume. The features of low-density FFS is served as the basic data for a decision on limited maximal speed, accident analysis, simulation modeling etc. A few researches for the macroscopic characteristics of design and operation speed have been reported, and any study for the microscopic features of freeway free-flow speed under the state of low density has not been done. Therefore, the characteristics of low-density FFS according to the level of traffic volume (1-3 veh/30 sec) and daily hour periods (0-5, 6-8, 9-11, 12-19, 20-23) is microscopically analyzed in this study with huge volume and speed data. It was found that speed distributions are changed and show different behaviors under the conditions of traffic volume levels and daily time periods. V85s (85th percentile speed) at early morning and night periods decrease when levels of traffic volume increase, whereas V85s at day time do not show considerable differences. Especially, FFSs of levels of traffic volume at early morning and night periods, despite low density, is analyzed as heterogeneity, but homogeneity at day time.

• Journal of The Korean Association of Information Education
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• v.5 no.2
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• pp.240-257
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• 2001

Although many attempts have been made to use the Internet for educational purposes, not many attempts have achieved their goals. Such failure is mainly due to the lack of understanding on the way to use the Internet. The goal of this research is to investigate the potentiality of the Project-Based Learning approach using the Internet(NetPBL) and the ways to utilize the NetPBL. The NetPBL can be utilized through various activities such as keypals, mentoring, use of resources, cooperative learning, publishing, survey and data analysis, cooperative problem solving, simulation, and social action. Such diversity of the NetPBL can create a problem-based, context-based and learner-centered environment, which takes various types of the Internet use. In spite of such potentiality, little is known on how to implement the NetPBL. On this point, this research attempts to synthesize instructional strategies to implement the NetPBL at the macro and the micro level. At the macro level, instructional process is divided into four steps such as plan, preparation, implementation and closure, and some instructional suggestions are made for each step. At the micro level, detailed instructional strategies are suggested for the facilitation of self-directed learning and cooperative learning.