• The Korean Journal of Financial Management
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• v.21 no.1
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• pp.59-86
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• 2004

This study analyzed the effects of M&A announcement before and after the 1998 amendments of 'Securities and Exchange Act' through the event study. The M&A firms turned out to gain the abnormal returns during the entire periods. The cumulative average abnormal returns of M&A firms was 1.38%(market adjusted model) or 5.37%(industry-adjusted model) higher after the 1998 amendments than before. The differences of performance of M&A were significant also in case of the related M&A, vertical or horizontal M&A, M&A in booms. In regression analysis, the 1998 amendments of Act was the significant factor to explain the cumulative abnormal returns.

• International Journal of Highway Engineering
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• v.4 no.3 s.13
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• pp.1-13
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• 2002

Design methods for new flexible pavements and overlays are in the transition from empirical to mechanistic approach, and many state highway agencies trend to move toward the adoption and use of mechanistic-empirical (M-E) design in new constructions and rehabilitations of flexible pavements. Hence, the Michigan Department of Transportation (MDOT) decided to develop a M-E flexible pavement design procedure, in which major pavement distresses such as fatigue cracking and rutting are employed as indicators of the serviceability of a flexible pavement. The main concept of the developed design procedure is that a designed pavement that is supposed to carry a certain number of traffic must satisfy designated thresholds of rut depths and fatigue lives during a service period. For the M-E design procedure, transfer functions were developed to predict rut-depths and fatigue lives. These functions related the pavement responses to pavement performance. For validation, three current new flexible pavement design cases were obtained from the MDOT. In these cases, asphalt concrete (AC) layer thicknesses determined by the suggested M-E procedure compare favorably with those determined by the current MDOT design practice that is based on AASHTO design guide. This finding implies that the suggested Michigan M-E flexible pavement design procedure can provide a good opportunity to improve the current design practice.

• The Journal of the Korea Contents Association
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• v.6 no.7
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• pp.99-110
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• 2006

Since learner-centered, participatory, real-situation education is stressed today, we need a new creative method for teaching computers to elementary school students. Nevertheless, there is scant research in this area. Therefore, in my study, I have analyzed the state of the methods of teaching computer literacy in the elementary schools. My aim is to develop a method of computer teaching in the real situation of elementary schools which will greatly improve the learning process. Creative teaching method gives students the initiation. And lead for then to join the activities for using the student's reciprocity. It is the students centered method. As a result of this study offering the educational teaching method of the creative teaching method for the improvement of computer literacy and learning attitude in the school society which has no knowledge brings the practical effects of computer attainments. Some limitation of the subject and theme of this investigation. Then requires the continual study for the of development creative teaching method with the extension experimental groups and educational subjects.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.15 no.3
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• pp.481-490
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• 2002

The purpose of this paper is to evaluate the efficiency of various solution techniques and propose new efficient solution techniques for space trusses. Solution techniques used in this study are three load control methods (Newton-Raphson Method, modified Newton-Raphson Method, Secant-Newton Method), two load-displacement control methods(Arc-length Method, Work Increment Control Method) and three combined load-displacement control methods(Combined Arc-length Method I , Combined Arc-length MethodⅡ, Combined Work Increment Control Method). To evaluate the efficiency of these solution techniques, we must examine accuracy of their solutions, convergences and computing times of numerical examples. The combined load-displacement control methods are the most efficient in the geometric nonlinear solution techniques and in tracing post-buckling behavior of space truss. The combined work increment control method is the most efficient in tracing the buckling load of spate trusses with high degrees of freedom.

• Journal of Digital Convergence
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• v.19 no.9
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• pp.411-421
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• 2021

This study was conducted to compare the effects of student-generated questions (SGQ) and online quiz-based learning (OQL) applied to a physiology and a pharmacology course with 173 nursing students in total. The levels of learning motivation of all participants at 15th week decreased significantly compared with 8th week. There were no statistical difference on learning motivation, communication, and critical thinking between SGQ and OQL, and regardless of the order SGQ and OQL were applied. However, the level of learning satisfaction in students taking pharmacology course was significantly higher in OQL than SGQ (t=2.184, p=.003). We suggest that either SGQ or OQL or both SGQ and OQL be used throughout a semester in biological nursing science subjects without changing teaching strategy during a semester.

• Journal of the Korea institute for structural maintenance and inspection
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• v.27 no.2
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• pp.42-49
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• 2023

When designing fixed jacket structures, overseas design standards are applied due to the absence of domestic design methods. Although the US API standards are mainly applied, API RP 2A suggests two design methods: the allowable stress design method (WSD) and the load resistance coefficient method (LRFD), and is applied according to the designer's judgment. In this study, the stress ratio of the two design methods was reviewed and compared using SACS, an analysis program dedicated to marine structures, for fixed marine structures actually installed on the domestic coast. As a result of the review, it was found that the LRFD design method showed a greater stress ratio for extreme load analysis and transportation analysis, and the WSD design method showed a greater stress ratio for loading and lifting. Therefore, when applying the design method, it is considered appropriate to select the final design method considering safety and economic feasibility after conducting an applicability review for the two design methods.

• Journal of the korean academy of Pediatric Dentistry
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• v.31 no.2
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• pp.236-246
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• 2004

Artificial carious lesions in various depths were observed with visual examination using light transillumination, bite-wing radiography, laser fluorescence, and dye-enhanced laser fluorescence to determine the reproducibility, correlation of each diagnostic method, diagnostic sensitivity and diagnostic specificity. And optical densities according to demineralized times were measured whether laser fluorescence could be used as a quantitative diagnostic method. The following results were obtained whether laser fluorescence could be used for diagnosis of initial proximal caries. 1. Tau-c values of visual examination was 0.08 which showed lowest reproducibility and those of bite-wing radiography, laser fluorescence, dye-enhanced laser fluorescence were 0.60, 0.48, and 0.64, respectively which showed relatively high reproducibility. 2. The correlation between demineralization time and each examination was the highest in dye-enhanced laser fluorescence$({\gamma}=0.51)$ followed by laser fluorescence$({\gamma}=0.43)$, bite-wing radiograph$({\gamma}=0.35)$, and visual examination$({\gamma}=0.33)$. Dye-enhanced laser fluorescence and laser fluorescence showed significant correlation with demineralization time. 3. The sensitivity of laser fluorescence and dye-enhanced laser fluorescence for diagnosing approximal caries based on bite-wing radiography were 67%, 100% and those of specificity were 57%, 11% which showed diagnostic specificity was relatively lower than sensitivity. 4. The difference in optical density(DFR) between sound teeth and carious lesions according to lesion depth was high with dye-enhanced laser fluorescence compared with laser fluorescence. DFR measured with laser fluorescence according to changes in lesion depth was statistically significant but was not statistically significant with dye-enhanced laser fluorescence. Based on these results, laser fluorescence and dye-enhanced laser fluorescence have comparable diagnostic power as bite-wing radiography in early diagnosis of proximal caries.

• Proceedings of the Korean Society for Environmental Edudation Conference
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• 2002.01b
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• pp.1-168
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• 2002

이 연구는 지난 20여 년 동안 우리나라 환경교육의 활성화를 위하여 많은 연구자, 학교 교사, 환경단체 지도자가 제안해 온 과업을 다루고있다. 그것은 학교 안팎에 걸쳐 요람에서 무덤까지 환경교육이 체계적이고 지속적으로 이루어질 수 있도록 법적, 제도적 기반을 마련하는 것이다. 법제적 뒷받침이 환경교육의 활성화를 위한 충분조건은 되지 못하더라도 필요조건으로서 매우 중요한 의미를 갖고 있다는 점은 분명하다. 이 연구를 수행한 사단법인 한국환경교육학회는 국회환경포럼과 함께 환경교육진흥법(가칭) 시안의 개발과, 나아가 실질적인 입법화를 위해 노력하였다. 이를 위하여 먼저 우리나라에 이미 존재하는 도서벽지 교육진흥법, 특수교육진흥법, 산업교육진흥법, 영재교육진흥법, 과학교육진흥법, 유아교육진흥법, 이상 여섯 개의 교육진흥법을 분석하여 환경교육진흥법 시안 개발을 위한 시사점을 얻고자 하였다. 다음으로 외국의 환경교육 관련법에 대한 사례 연구를 진행하였다. 특히 미국의 경우 1970년 처음 환경교육법이 제정된 이후 몇 차례의 개정과 재승인 과정을 거쳐왔다. 미국에서는 1990년에 제정된 국가환경교육법의 재승인에 관한 공청회가 지난 2000년 여름 동안 개최되어 환경교육법의 필요성, 효과, 고려할 조항 등 본 연구에 중요한 참고 자료를 얻을 수 있었다. 본 학회의 다른 연구진에 의해 2001년 10월에 완료된 제2차 환경교육 중 ·장기 강화방안 연구의 결과물도 환경교육 활성화를 위한 시안에 담아야 할 내용과 방향을 결정하는데 실질적인 도움을 주었으며, 이를 토대로 연구진과 국회환경포럼의 환경교육활성화위원회의 위원이 윤독과 수정을 거쳐 시안의 타당성과 완성도를 높이고자 하였다. 작성된 시안에 대해서는 먼저 국내의 환경 또는 환경교육 관련 전문가에게 설문지를 보내어 의견 수렴을 하였으며, 이 과정에서 시안에 포함된 대부분의 항목에 대해 높은 찬성률을 보인 것으로 나타났다. 그밖에 설문지로부터 수정 ·보완 요청 사항을 정리하여 최종 시안을 작성하는데 반영하였다. 끝으로 10월 26일 국회 의원회관에서 개최된 공청회를 통하여 다양한 집단의 의견을 수렴하였으며, 공청회 동안 제시된 의견들을 반영하여 최종 시안을 작성하였다. 이러한 과정을 거쳐 작성된 환경교육진흥법 최종 시안은, 제1조 목적에서 제11조 환경교육연구의 진흥에 이르기까지 총11조로 구성되었으며, 환경교육사 자격증제 및 환경교육 프로그램 인증제 등 획기적인 전기를 마련할 수 있는 방안들이 다수 포함되어 있다. 특히 환경교육진흥법의 주무 부처를 환경부로 제안한 것은 기존의 교육 관련 진흥법들이 교육인적자원부를 주무로 하고 있는 것에 비해 매우 특기할 만 하다. 그 이유는 본문에서 밝힌 바와 같이 환경교육이 갖고 있는 특수성 때문이다. 환경교육진흥법의 주무 부처를 환경부와 교육인적자원부 중 어디로 하는 것이 바람직한가에 대해서는 연구진 내부는 물론 공청회에 참가한 사람들 사이에도 이견이 있었음을 밝혀 둔다. 끝으로, 이 연구에서 마련된 시안과 연구 결과가 최종적으로 속히 법제화가 되고, 우리나라 환경교육 진흥에 기여하게 되기를 바란다.

• Journal of Korean Society of Steel Construction
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• v.23 no.5
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• pp.535-546
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• 2011

In this paper, semi-rigid elasto-plastic post-buckling analysis of a space frame was performed using various explicit arc-length methods. Various explicit arc-length methodsand a large-deformation and small-strain elasto-plastic 3D space frame element with semi-rigid connections and plastic hinges were developed. This element can be appliedto both explicit and implicit numerical algorithms. In this study, the Dynamic Relaxation method was adopted in the predictor and corrector processesto formulate an explicit arc-length algorithm. The developed "explicit-predictor" or "explicit-corrector" were used in the elasto-plastic post-buckling analysis. The Eulerian equations for a beam-column with finite rotation, which considers the bowing effects, were adopted for the elastic system and extended to theinelastic system with a plastic hinge concept. The derived tangent stiffness matrix was asymmetrical due to the finite rotation. The joint connection elements were introduced for semi-rigidity using a static condensation technique. Semi-rigid elasto-plastic post-buckling analyses were carried out to demonstrate the potential of the developed explicit arc-length method and advanced space frame element in terms of accuracy and efficiency.

• The Korean Society of Law and Medicine
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• v.17 no.1
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• pp.3-43
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• 2016

The North Korean medical laws are consisted of 'People's Health Act' and 'Medical Act' in the peak of the North Korean constitutional law. Before the legislation of 'People's Health Act', a number of medical laws and regulations existed. But, at present, there is no information about its amendment and effectiveness. 'People's Health Act' legislated in 1980 declared fundamental principles and policies of the North Korean health care system. 'Medical Act' legislated in 1997 is the basic law among the North Korean medical laws. It presented the goals and fundamental principles of the North Korean health care, and then regulated the basics about 'Tests and Diagnosis', 'Medical Treatment', and 'Medical Appraisal'. 'Medical Act' of North Korea was established later than South Korea, and its provisions is smaller in number. And there are lots of abstract and declaratory provisions compare with South Korean 'Medical Act'. Especially there is no provision about the kind and requirements of medical personnel and medical institutions, so it is hard to grasp the North Korean health care system at once. Regarding the medical treatment, there are many similar contents between the North and South Korean 'Medical Act'. But, the provisions, such as regarding mixing the new medicine and the korean traditional medicine, encouraging natural therapies in medical treatment, and informing the patient's protector of bad diagnostic result if there is concern to have a bad influence on patient, are different from the South Korean 'Medical Act'.