• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• 제19권11호
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• pp.1254-1264
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• 2008

This paper suggests an extended memory polynomial model that improves accuracy in modeling memory effects of RF power amplifiers(PAs), and verifies effectiveness of the suggested method. The extended memory polynomial model includes cross-terms that are products of input terms that have different delay values to improve the limited accuracy of basic memory polynomial model that includes the diagonal terms of Volterra kernels. The complexity of the memoryless model, memory polynomial model, and the suggested model are compared. The extended memory polynomial model is represented with a matrix equation, and the Volterra kernels are extracted using least square method. In addition, the structure of digital predistorter and digital signal processing(DSP) algorithm based on the suggested model and indirect learning method are proposed to implement a digital predistortion linearization. To verify the suggested model, the predicted output of the model is compared with the measured output for a 10W GaN HEMT RF PA and 30 W LDMOS RF PA using 2.3 GHz WiBro input signal, and adjacent-channel power ratio(ACPR) performance with the proposed digital predistortion is measured. The proposed model increases model accuracy for the PAs, and improves the linearization performance by reducing ACPR.

• Journal of The Korean Association For Science Education
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• 제34권3호
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• pp.261-272
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• 2014

In this study, to disseminate the Practical On-site Cooperation Model (POCoM) for practical improvement of science teaching and learning through cooperation between researcher and teacher, an in-service program has been developed, applied and evaluated. The in-service program emphasizes the following three aspects; (1) video-recording of actual science teaching has been used as a primary resource, (2) communication between teacher and researcher and among teachers have been emphasized, (3) activities have been mainly included. The in-service program has been implemented for nine hours, and 17 science teachers have been recruited as volunteers. The result shows that, by checking the agreements between raters, we found that teachers' expertise in analyzing the science class using the Korean Teaching Observation Protocol (KTOP) has improved, and we have confirmed that teachers are able to judge whether the science class has improved or not. Through the questionnaire, various highly positive responses could be obtained from teachers. And through the observation of teachers' activities during the in-service program, teachers' questions, their difficulties in doing activities, and their comments for improving the program has also been analyzed. Finally, based on the results, a list of recommendations for a more effective in-service program have been suggested. It is expected that this list can be utilized for more effective and meaningful design and implementation of in-service course.

• Journal of Science Education
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• 제36권2호
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• pp.263-278
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• 2012

The purpose of this study was to introduce the development and application of STEAM education science camp program conducted in J university for high school students and to suggest the ideal class design method and procedures along with STEAM logics and viewpoints. The pre-service science teachers participated in the class developed teaching materials in accordance with STEAM education model and the teaching procedures and materials were modified and supplemented through the education specialist group's assessment and the actual class. The developed program was applied to the second-year students(N=45) of a science-focus school in Jeonju City and the first and second-year students(N=61) of 13 high schools in Jeonbuk province who participated in the 'STEAM experiment camp' during the summer vacation in 2012. After the class, the learners' average satisfaction level in the program content and activities was 4.02 point out of 5 point and the pre-service science teachers' average satisfaction level in the program and teaching-learning was 4.28 point. Therefore, the STEAM education program of this case study can be a model to the teachers who desire to plan the science-focus STEAM class and conduct it.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• 제13권2호
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• pp.129-137
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• 2020

Currently, The autonomous vehicle market is researching and developing four-level autonomous vehicles beyond the commercialization of three-level autonomous vehicles. Because unlike the level 3, the level 4 autonomous vehicle has to deal with an emergency directly, the most important aspect of a four-level autonomous vehicle is its stability. In this paper, we propose an Optimized Vehicle Routing System (OVRS) that determines the route with the lowest probability of an accident at the destination of the vehicle rather than an immediate response in an emergency. The OVRS analyzes road and surrounding vehicle information collected by The RSU communication to predict road hazards, and sets the route for the safer and faster road. The OVRS can improve the stability of the vehicle by executing the route guidance according to the road situation through the RSU on the road like the network routing method. As a result, the RPNN of the ASICM, one of the OVRS modules, was about 17% better than the CNN and 40% better than the LSTM. However, because the study was conducted in a virtual environment using a PC, the possibility of accident of the VPDM was not actually verified. Therefore, in the future, experiments with high accuracy on VPDM due to the collection of accident data and actual roads should be conducted in real vehicles and RSUs.

• Journal of Distribution Science
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• 제13권2호
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• pp.105-112
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• 2015

Purpose - There is a recent social trend that is focused on the revitalization of business-founding. Business-founding now has an important impact on the progress of the national economy because of youth unemployment and an increase in baby-boom generation retirees. However, the support and infrastructure required for business-founding of the disabled are very insufficient. Since most supporting policies are on youth or middle-aged business-founding, business-founding by the disabled and the socially weak is losing competitiveness. Accordingly, this study diagnosed the issues by analyzing the current status of business-founding by the disabled and suggested a fostering direction for the advance of business-founding by the disabled. An idea for the founding of various business items is required for the competitiveness of business-founding by the disabled and the establishment of a growth-model based on marketing is required so that business-founding by the disabled would advance toward commercialization with growth potential. Research design, data, and methodology - Regarding the study method, the existing study literature on the status and issues in business-founding was mainly explored. In addition, the existing literature on the status and issues in business-founding by the disabled was also studied. The support on business-founding by the disabled by policy enforced by the 'Welfare Service Agency for the Disabled'and the support of related agencies including financial support on the commercialization of business-founding by the disabled were also examined. Results - Existing studies on business-founding by the disabled are very insufficient. It is very difficult to study a viable business-founding by the disabled fostering policy without thorough learning on the difficulties of business-founding by the disabled. Therefore, this study suggested a direction for the resolution of various issues such as market, funds, item, operational matters, and service by analyzing the difficulties in business-founding by the disabled until now. Particularly, this study suggested that building a commercialization model from the aspect of marketing strategy and the effort to change the growth aspect of the disabled into competitiveness are essential. Conclusions - This study examined the aspect of developing an item-development process for the growth and founding of disabled-owned businesses and the requirement of a government support system by multiple policies. Since the number of studies on business-founding by the disabled is very small, it is expected that this study would become an important study in the field of business-founding by the disabled. The revitalization of business-founding by the disabled substantially contributes to the progress of the state of the economy and continuous interest is required from the viewpoint of equal advance in the society. Success models in business-founding by the disabled should be created continuously and active publicizing of them to the disabled business-founders by analyzing the success cases would also be required. In addition, it is believed that a market entry strategy by way of a win-win strategy and cooperative relation with big companies should be also developed in the future.

• Cartoon and Animation Studies
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• 통권47호
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• pp.273-294
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• 2017

Korea has suffered numerous casualties due to a lot of accidents caused by safety insufficiency in recent years. Therefore, safety education is more important than ever before, and 'how to educate with what contents' is an important subject. Especially, experience education is effective rather than theoretical education because of the nature of safety education. However, it is not easy to design and develop these safety education programs. There is not much opportunity to access first-aid training, which is a part of safety education, unless it is compulsory to learn through public institutions. As a result, program utilization on safety education in Korea is still insufficient to what it should be. With that taken into account, this study proposed an effective serious game with fun and immersion for medical first-aid education. To do this, we analyzed five medical games through 20 cases of first-aid applications and elicited five factors that enhance the usability of serious games. With an analysis of five medical games, we selected one game to borrow the game rules, and applied the elicited five elements in the forms of level-up structure, iterative learning, compensation outcomes, competition system, and information transfer. The proposed medical education functional games should have 1) a character that plays a role of a patient, 2) a narrative flow that shows the situation, 3) the user should judge the situation and induce first aid. 4) compensation, levels, and simple repetition should be designed, and 5) information should be shared with the others in the given community. The results of this study is believed to contribute to enhance the medical emergency education in Korea.

• The Journal of the Korea Contents Association
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• 제20권9호
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• pp.99-106
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• 2020

Though it has been known that self-efficacy is a predictor to the successful L2 learning, the majority of studies on self-efficacy cases were targeted at secondary school students. This paper aims to explore the effects of the intermediate college students' essay writing experiences on their English self-efficiency. For this purpose, pre and post course surveys were conducted on a hundred or so freshmen who took intermediate college English classes which focused on improving English reading and writing skills. Interviews with teachers were also conducted in order to find out whether the differences of their teaching styles had any meaningful impact on their students' self-efficacy. Paired t-test was run on the responses of the post-questionnaire to identify any differences in the self-efficacies of the students before and after taking the classes, and the one-way ANOVA was conducted to find out whether the different instruction types had any significant impact on the differences. The results of the both analyses confirmed the differences of self-efficacies by the two predictors at a statistically significant level. Based on the findings of this paper, various types of writing assignments and efficient procedures of teachers' feedback need to be developed further in order to design and run an effective college English course which can contribute to enhancing self-efficacy of students.

• Journal of the Korean School Mathematics Society
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• 제19권2호
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• pp.153-176
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• 2016

The purpose of this study is to suggest ways to promote student engagement by analyzing how a teacher's student engagement strategies and questioning strategies affect class participation and problem solving in a peer mentoring teaching method. As for the purpose, after recording 7th grader's classroom using a peer mentoring and transcribing classroom discourse, we analyzed student engagement strategies for class participation and questioning strategies for helping mathematical concepts and problem solving, and compared mathematics achievements in mid-term and final exams. As results, in learning environments based on comfortable atmosphere, diverse student engagement strategies and appropriate questioning strategies with effectiveness of peer mentoring encouraged students to participate in class by motivating them, helped them to develop mathematical concepts and deepen understanding of problem solving through effective social interactions, and improved student achievement in mathematics. The results can practically help to develop class design considering both student engagement strategy and questioning strategy by specifically presenting a teaching method for promoting student engagement and teacher's contributions to it.

• Journal of the Korea Academia-Industrial cooperation Society
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• 제21권10호
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• pp.461-470
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• 2020

This study analyzed the determinants of land compensation costs using the CALS (Continuous Acquisition & Life-Cycle Support) system to generate data for the construction (planning, design, building, management) process. For analysis, variables used in the related research on land costs were used, which included eight variables (Land Area, Individual Public Land Price, Appraisal & Assessment, Land Category, Use District 1, Terrain Elevation, Terrain Shape, and Road). Also, the variables were analyzed using the machine learning-based Xgboost algorithm. Individual Public Land Price was identified as the most important variable in determining land cost. We used a linear multiple regression analysis to verify the determinants of land compensation. For this verification, the dependent variable included was the Individual Public Land Price, and the independent variables were the numeric variable (Land Area) and factor variables (Land Category, Use District 1, Terrain Elevation, Terrain Shape, Road). This study found that the significant variables were Land Category, Use District 1, and Road.

• Proceedings of the Korea Information Processing Society Conference
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• 한국정보처리학회 2001년도 춘계학술발표논문집 (하)
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• pp.727-730
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• 2001

초고속 인터넷 서비스의 확대에 따라 이를 교육에 직 간접적으로 응용하기 위한 노력이 지속적으로 진행되어 왔다. 특히 웹 기반의 가상강의 저작도구를 통한 웹 코스웨어는 원거리 학습자들의 학습 욕구를 자기 주도적인 학습을 통해 가능케 했고 기존의 텍스트, 사운드를 통한 가상강의에서 동영상이 가미된 주문형 교육 서비스(EOD: Education On Demand)가 가능해졌다. 그러나 이를 이용하는 학습자는 전체적인 모듈의 이해를 통해 수업이 진행됨에 따라 학습과정에서는 질의응답을 튜터를 통해 웹 캐스팅이 이루어졌다. 따라서, 질의응답은 텍스트 형식의 E-mail, 채팅, 게시판, 방명록을 통해 이루어지므로 학습자가 요구한 질의 내용을 잘못 이해하고 튜터가 학습 과정에서의 피드백을 제공하지 못함으로써 개인 학습의 동기부여가 감소됨에 따라 흥미를 잃게 되었다. 본 논문에서는 이러한 문제점을 개선하기 위해 멀티 캐스팅 기법을 통해 교육용 서버를 이용한 학습지원도구를 분석, 설계한다. 가상강의는 기본적인 컨텐츠를 제시하고 그를 통해 수업이 진행되는 과정에서의 질의응답을 일대다(One-To-Many)의 멀티 캐스팅 서비스를 튜터가 지정한 교육용 서버를 통해 텍스트 형식이 아닌 강의자료로 쓰인 문서 파일에 직접 작성하여 전송하게 된다. 따라서 튜터는 메일링 서비스를 통해 질문사항을 자신의 폴더 서비스로 확인하고 즉시 학습자에게 피드백을 제공함으로써 튜터와 학습자들간의 커뮤니케이션이 활발히 이루어지며, 상호작용의 증가를 통해 웹 기반의 컨퍼런싱(WBC: Web Based Conferencing)을 가질 수 있게 된다.rver는 Client가 요청한 Content(services)를 전달 해 주는 컨텐트 전달 모듈(Content Deliver Module)과 서버 Phonebook 엑세스 모들(Server Phonebook Access Module)로 구성되어 있다.외 보다 높았다(I/O ratio 2.5). BTEX의 상대적 함량도 실내가 실외보다 높아 실내에도 발생원이 있음을 암시하고 있다. 자료 분석결과 유치원 실내의 벤젠은 실외로부터 유입되고 있었고, 톨루엔, 에틸벤젠, 크실렌은 실외뿐 아니라 실내에서도 발생하고 있었다. 정량한 8개 화합물 각각과 총 휘발성 유기화합물의 스피어만 상관계수는 벤젠을 제외하고는 모두 유의하였다. 이중 톨루엔과 크실렌은 총 휘발성 유기화합물과 좋은 상관성 (톨루엔 0.76, 크실렌, 0.87)을 나타내었다. 이 연구는 톨루엔과 크실렌이 총 휘발성 유기화합물의 좋은 지표를 사용될 있고, 톨루엔, 에틸벤젠, 크실렌 등 많은 휘발성 유기화합물의 발생원은 실외뿐 아니라 실내에도 있음을 나타내고 있다.>10)의 $[^{18}F]F_2$를 얻었다. 결론: $^{18}O(p,n)^{18}F$ 핵반응을 이용하여 친전자성 방사성동위원소 $[^{18}F]F_2$를 생산하였다. 표적 챔버는 알루미늄으로 제작하였으며 본 연구에서 연구된 $[^{18}F]F_2$가스는 친핵성 치환반응으로 방사성동위원소를 도입하기 어려운 다양한 방사성의 약품개발에 유용하게 이용될 수 있을 것이다.었으나 움직임 보정 후 영상을 이용하여 비교한 경우, 결합능 변화