• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제40권4호
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• pp.173-180
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• 2014

Objectives: The purpose of this study was to investigate the neurogenic differentiation of human dental pulp stem cells (DPSCs), periodontal ligament stem cells (PDLSCs), and stem cells from apical papilla (SCAP). Materials and Methods: After induction of neurogenic differentiation using commercial differentiation medium, expression levels of neural markers, microtubule-associated protein 2 (MAP2), class III ${\beta}$-tubulin, and glial fibrillary acidic protein (GFAP) were identified using reverse transcriptase polymerase chain reaction (PCR), real-time PCR, and immunocytochemistry. Results: The induced cells showed neuron-like morphologies, similar to axons, dendrites, and perikaryons, which are composed of neurons in DPSCs, PDLSCs, and SCAP. The mRNA levels of neuronal markers tended to increase in differentiated cells. The expression of MAP2 and ${\beta}$-tubulin III also increased at the protein level in differentiation groups, even though GFAP was not detected via immunocytochemistry. Conclusion: Human dental stem cells including DPSCs, PDLSCs, and SCAP may have neurogenic differentiation capability in vitro. The presented data support the use of human dental stem cells as a possible alternative source of stem cells for therapeutic utility in the treatment of neurological diseases.

• 한국문헌정보학회지
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• 제27권
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• pp.3-73
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• 1994

It is widely known that the public library in Korea has not been developed as a social agency which makes communication process possible. The public library in Korea just plays a role of the public study room for students using their own books. There is almost no public libraries in the sense of an open collection of comprehensive materials designed for use by anyone who seeks information. This study starts from this situation. It aims at identifying the present stage of the development of public libraries in Korea through investigating librarians' consciousness in their everyday lives. For this, a case study method is used for investingating, collecting and organizing the 'discourse' of librarians in Pusan and Kyongsangnamdo area. Major suggestions include : First of all, it is most important for public library reformation to eradicate the 'conservatism' in the consciousness of librarians in their everyday lives. So, it is essential to collect their life stories in various library conditions, and make them public discourse of librarians. Secondly, the professional organization should play a role to unify the librarians. For this role, it should maintain a R&D department and strengthen PR programs. Thirdly, Researchers who study Library and Information Science in Korea should be always concerned with the real-life context in the field. The most important type of research in our third world situation is the one that is based on the present stage of the development of our own libraries and the real library situation in the field.

• 한국학교수학회논문집
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• 제22권3호
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• pp.241-256
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• 2019

본 연구는 '확률과 통계' 교과서에 제시된 과제의 맥락 유형과 과제를 수행할 때 요구되는 인지적 역량이 학생들에게 어떠한 학습기회를 제공하는지 살펴보았다. 이를 위해 2015 개정 수학과 교육과정에 따른 '확률과 통계' 검정교과서 전체 9권을 분석한 결과, 맥락 기반 과제(CF유형, RE유형)는 각 교과서마다 전체 과제 개수의 67.5%부터 78.0%로 나타났지만 실생활에 연관된 본질적인 과제(RE유형) 비율은 0.4%부터 2.0%로 나타나 교과서에 제시된 대부분의 맥락 기반 과제는 실생활 소재를 위장한 과제임을 알 수 있었다. 그리고 맥락 기반 과제의 인지적 역량은 각 교과서마다 재생산(Rp)범주에 속하는 과제 비율은 29.6%부터 50.0%로 다양하게 나타났고, 연결(Co)범주 과제 비율은 33.8%부터 54.3%, 반성(Rf)범주 과제 비율은 8.8%부터 20.0%로 나타나 과제수행 시 학생들이 반성적 인지 과정을 경험할 수 있는 학습기회는 다소 충분하지 않음을 알 수 있었다.

• 대한수학교육학회지:학교수학
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• 제16권1호
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• pp.83-110
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• 2014

본 논문은 제 1차 교육과정을 근거로 하여 개발된 중학교 수학교과서를 오늘날의 국내 외의 수학과 교육과정에서 강조하고 있는 내용을 기반으로 분석한 것이며, 이 과정에서 한국의 현행 교과서 및 미국에서 최근 사용되고 있는 수학교과서인 MiC 교과서와 비교했다. 제 1차 교육과정에 따른 중학교 수학교과서는 모든 단원에서 실생활의 다양한 상황을 토대로 문제가 구성되어 있으며, 일련의 문제들을 통하여 수학개념을 도입하는 형식으로 전개되고 있다. 또한 수학적 개념을 연결하여 제시하고 있고, 표, 그래프, 식 등의 수학적 표현을 상호 연계하여 사용하게 하는 활동이 포함되어 있으며, 문제해결 과정에서 학생들 간의 토의를 적극적으로 권장하고 있다. 이와 같은 우리나라의 제 1차 교육과정 및 수학교과서에 대한 현대적인 재조명을 바탕으로 차기 교육과정 및 교과용 도서 개발을 위한 기초적인 자료 및 시사점을 제공하고자 한다.

• 한국기계가공학회지
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• 제20권12호
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• pp.136-144
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• 2021

The purpose of this study was to develop and verify a precision transmission error measurement system for a gear pair. The transmission error measurement system of the gear pair was developed as a measurement unit, signal processing unit, and signal analysis unit. The angular displacement for calculating the transmission error of the gear pair was measured using an encoder. The signal amplification, interpolation, and transmission error calculation of the measured angular displacement were conducted using a field-programmable gate array (FPGA) and a real-time processor. A high-pass filter (HPF) was applied to the calculated transmission error from the real-time processor. The transmission error measurement test was conducted using a gearbox, including the master gear pair. The same test was repeated three times in the clockwise and counterclockwise directions, respectively, according to the load conditions (0 - 200 N·m). The results of the gear transmission error tests showed similar tendencies, thereby confirming the stability of the system. The measured transmission error was verified by comparing it with the transmission error analyzed using commercial software. The verification showed a slight difference in the transmission error between the methods. In a future study, the measurement and analysis method of the developed precision transmission error measurement system in this study may possibly be used for gear design.

• 한국학교보건학회지
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• 제6권2호
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• pp.24-55
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• 1993

School health aims to guide and manage growing students from elementary schools to high schools in order to grow healthily through the formation of healthy life habits, the self-control health management guide and the making of pleasant school health environments. Even though this school health plays an important role in guiding the students who are in the period of growing to have a perfect personality as a democratic people of our country in the school education, there are many lacks, such as they still don't know the word itself, "school health" or recognize its importance. Also it's a real condition to practice items concerned with the health under the condition of unestablished structure. 1. The results of analyzing school health real conditions. Based on treatises concerned with school health and various statistical materials which are announced by concerned people. We divided and analyzed school health into the items concerned with health education, the items with health management, and the items with school health environments, and investigated the level of the present school health and its necessity. As the items concerned with health education, we investigated the necessary range of school health education, the effect of health education on children's daily life, family's health and the interesting contents of school health. And as the items with health management, I investigated children's obesity, dental caries, eyesight, clinics, a health examination, drug abuse, spirit health, providing meals for school children, and school health manpower. And as the items conerned with school health environments, we investigated the recognition of the problem of natural environments, the management of purification district around the school, the problem of environments within the school and classroom lighting. As the results of analyzing these, I realized that the present level of school health is still in unsatisfactory situation and school health is needed necessary. 2. The establishment of school health. In order to set the school health, above all, the management system of School health should be set. I classified and systemized the contents of each item which had been promoted till now according to the function. They are classified as followings Based on classifying school health into (1) health education, (2) health management and (3) health environments, I divided school health education into the health education of health subjects, the health education of concerned subjects and the education of health life. And I divided health management into the health managements for a prevention and a cure. And I divided health environments into the environment around the school and within the school. Each system set like these is not fixed invariably and I should keep the relationship of mutual supplement between health education and health management, between health management and health environments, and between health environments management and health education. When we run these systemetic school health, students' health could be maintained and improved to more proper directions.

• 대한공업교육학회지
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• 제37권2호
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• pp.57-75
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• 2012

이 연구의 목적은 STEAM 교육에 대한 초등교사의 인식과 요구를 조사 분석하는 것이다. 이 연구를 수행하기 위하여 군집표집 방법으로 전국의 초등교사 533명을 표집하여 연구대상으로 하였고, 우편 및 이메일을 통하여 조사를 실시하였다. 연구결과는 다음과 같다. 첫째, 초등교사는 STEAM 교육의 필요성에 대하여 긍정적으로 공감하고 있었으나 STEAM 교육에 대한 인식은 보통 수준이었다. 둘째, STEAM 교육을 적용한 경험이 있는 초등교사의 비율이 매우 낮았다. STEAM 교육 적용에 대한 어려움은 STEAM 교육 자료 준비의 어려움이 가장 높았으며, STEAM 교육에 대한 이해 부족 개발된 STEAM 교육프로그램의 보급 부족, STEAM 교육 실현을 위한 교수 학습 방법 부족 순으로 나타났다. 셋째, 초등교사는 STEAM 교육의 교육방향에 대하여 현실생활과 밀접한 관련이 있는 교육, 창의적인 사고능력 및 문제해결능력 향상을 위한 교육, STEAM 교과의 흥미 있는 교육, STEAM 교과의 학업능력 향상을 위한 교육 순으로 요구하였다. 넷째, 초등교사는 STEAM 교육에 적합한 통합 방식에 관하여 현실생활과 관련한 활동 중심의 통합, 현실생활과 관련한 주제 중심의 통합, 학생의 필요와 흥미 중심의 통합, 문제 중심의 통합 순으로 요구하였다. 다섯째, 초등교사는 STEAM 교육을 통해 함양해야 할 능력에 관하여 창의적인 설계, 문제해결 능력, 학업수행능력, 대인관계 능력 순으로 요구하였다. 마지막으로 초등교사는 STEAM 교육 활성화를 위해 STEAM 교육프로그램 개발 및 보급, STEAM 교육에 대한 교사의 이해, 다양한 교수 학습자료 보급, 교사 연수, 교사 협동, 교육과정 개선 등이 이루어져야 함을 요구하였다.

• KIEAE Journal
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• 제10권6호
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• pp.145-151
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• 2010

Bearing wall system was used extensively in most multi-residential apartment buildings in Korea. However, bearing wall apartments have the lack of architectural plan flexibility, remodelling-incompatible, causing serious economic losses in terms of construction waste. Recently, many researchers have studied the use of Rahmen structure as a potential alternative. The beam-column connection in the paper for long-life apartment housing forms connection of a Rahmen structure utilizing the advantages of steel and reinforced concrete. In addition, reduction of cast-in place concrete and construction schedule is expected by using precast concrete. Reduction effect of quantity decreased construction costs and $CO_2$ emission of key construction materials. However, verifying the feasibility of new construction method entails numerous challenges. Accordingly, the purpose of this study is to analyze the construction feasibility of sleeve, coupler, and pressure welding connections for long-life apartment building structure. A 3D modeling software was used to perform the analysis, and a real scale model was created to verify the results of construction feasibility. By verifying the construction feasibility of beam-column connections, this study will contribute to the efficient application of these methods on construction sites.

• 대한인간공학회지
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• 제30권1호
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• pp.151-160
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• 2011

There have been many efforts to prevent accidents in Korea for the last 25 years. Many measures in the area of hardware sciences including electrical, mechanical, chemical engineering, etc. were applied to eliminate or at least reduce causes of accidents. However, the accidents rate has not been reduced much despite of these measures. This research aimed to find real causes of these accidents and to suggest a comprehensive model that can mainly be applied to industrial fields to find potential or existence of human errors during the pre-installation stage or after an accident. We tried to explain sequences of an operator's information process that might cause human errors on one hand, and life cycle stages of facilities involved when human errors occur on the other hand. With this comprehensive model presented in this research, one can follow up the sequence of human errors caused by operators. Further, errors made at the design stage which could be a main cause of accidents can be tracked. It is recommended that this comprehensive model should be used to prevent human errors in industrial fields since safety personnel can easily find out errors or error potentials through the life cycle stages of manmachine facilities.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 추계학술대회 논문집
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• pp.1025-1028
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• 2005

Generally, fiber-reinforced composites have the highest possibilities of impact damages with external object collisions. Also, resulting in fatigue fracture considering the continued impact load. For the reasons mentioned above, the accurate understanding of interactions between the impact of composites and the fatigue load will be essential to understand the safety level of material structures. Furthermore, the composite materials and structures, due to the geometrical effect, vary the life in connection with the impact-fatigue. Therefore, I have reached the point that a focus of this study will be to evaluate fatigue fracture characteristics by the impacts-fatigue load of fiber-reinforced composites. Thus, in this paper, I have tried to work on impacts-fatigue load causing aspects and impact characteristics through impact-fatigue test on HTV-5Hl Black 9250 material made- structure, along with to evaluate the expected lift of real structures, the FEM analysis was carried out.