• 한국정보처리학회논문지
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• 제7권10호
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• pp.3075-3085
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• 2000

소프트웨어 개발과 운영이 분산화, 대형화됨에 따라 정확하고 완전한 요구사항의 추출과 명세는 시스템의 가장 중요한 요소가 되고 있다. 또한 인터넷을 통한 공동작업 환경에서 계속적인 시스템 변경요청은 더욱 효율적인 요구사항 관리를 필요로 한다. 본 논문에서는 이러한 공동작업 환경에서 자연어 기반 요구사항 명세와 관리의 효율성을 향상시키기 위한 요구사항 명세구조와 기법 등을 정의하고, 요구공학 활동과 주기를 바탕으로 하는 요구공학 프로세서와 환경을 제안한다. 그래서 CSCW(Computer Supported Cooperative Work) 환경에서 요구사항을 정확하게 추출하고 효율적으로 관리하며 분석단계로 자연스러운 전이가 가능하도록 한다.

• 농촌지도와개발
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• 제3권2호
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• pp.197-209
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• 1996

Bangladesh that is known as the poorest country of the world has the large land of fertile soil and very good environment to live, even though we think she may be very bad to live. People being habituated to that good environment, the population explosion made the people to be starven, but the treatment has been simple support without deep analysis of the root of poverty. As the result it is general that the poverty is severer and severer in spite of continuous support. For the last century Korea changed from the country of poverty and despair to that of development and hope, to be model mid vision of under development countries including Bangladesh. At this point it is necessary to look back the way of development to help them to solve their poverty problem. That is the goal of this project, and this thesis is the result of it. It is evaluated for the 1st 5 years work of the project to apply the result to the next 5 years plan. This project had been proceeded from 1. Jul. 1990 to 30. Jun. 1995 at Chilmari area of Bangladesh, with teaching and training to wake up the mentality of the people, demonstration farming and cooperative association. It was proceeded as the Agriculture project of KDAB(Korean Development Association in Bangladesh, an NGO registered to Bangladesh) supported by Good Neighbors, KOICA and many churches and individuals. Especially the teaching and training work was proceeded as the branch of the Canaan Farmer`s School of Korea with instruction and support. After the basic survey for project, the confirmation of working place and the preparation of training facility, 10 times of long term training(3 months worse, boarding) was completed, with many times of short term training, informal training, demonstration farm, various demonstrating works. The results of the work are understanding of the not of problem by participatory observation, making plan to solve it, getting the trust from the people and beginning the practical work with the trainees for development of economy and living situation. The biggest problem of Bangladesh is being understood losing the desire to solve the poverty problem and the self-confidence to be able to do it. It is the conclusion that after solving the problem of thought and mentality, the education, technology and money can be effective for development. So the 1st 5 year project is evaluated as the basic work to analyse the root of problem, to chance mentality of people and to search income source. The next goal is to promote practical living level of people. For that it is necessary to develope die mentality of people including responsibility and self-confidence by teaching and training, to educate cooperative association and technology for economical development, to proceed integrated rural development work with economical development, educational improvement and reformation of environment. It is very important result that they decided to grow poultry for main economical source of Chilmari area, to do economical development work by joint operation of poultry through cooperative association.

• Journal of Communications and Networks
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• 제16권1호
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• pp.10-17
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• 2014

This work investigates two important performance metrics of underlay cooperative cognitive radio (CR) networks: Interference cumulative distribution function of licensed users and outage probability of unlicensed users. These metrics are thoroughly analyzed in realistic operating conditions such as imperfect fading channel information and strict transmit power constraint, which satisfies interference power constraint and maximum transmit power constraint, over Nakagami-m fading channels. Novel closed-form expressions are derived and subsequently validated extensively through comparisons with respective results from computer simulations. The proposed expressions are rather long but straightforward to handle both analytically and numerically since they are expressed in terms of well known built-in functions. In addition, the offered results provide the following technical insights: i) Channel information imperfection degrades considerably the performance of both unlicensed network in terms of OP and licensed network in terms of interference levels; ii) underlay cooperative CR networks experience the outage saturation phenomenon; iii) the probability that the interference power constraint is satisfied is relatively low and depends significantly on the corresponding fading severity conditions as well as the channel estimation quality; iv) there exists a critical performance trade-off between unlicensed and licensed networks.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제10권9호
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• pp.4326-4341
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• 2016

In this paper, an adjustable multiple relay selection (MRS) scheme for cooperative communication with amplify-and-forward (AF) relay under frequency selective channels is proposed. In the proposed scheme, the relays are ordered firstly by the steady-state mean square error (MSE), then the relays are sequentially selected out from N relays and the number of cooperating relays is adjusted dynamically according to the steady-state mean square joint error (MSJE). The aim of this work is to dynamically estimate the optimum number N_o of cooperating relays. Optimum means the minimum number of cooperating relays, N_o, achieving the minimum level of steady-state MSJE. Numerical results verify the analyses and show that the scheme can adaptively adjust the number of cooperating relays, and outperform conventional relay selection schemes. Hence, the proposed scheme provides better tradeoff between BER performance and spectral efficiency and to save more energy in cooperative wireless networks.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제12권10호
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• pp.4873-4888
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• 2018

A joint blind parameter estimation algorithm based on minimum channel stability function aimed at the non-cooperative high-order modulated paired carrier multiple access (PCMA) signals is proposed. The method, which uses hierarchical search to estimate time delay, amplitude and frequency offset and the estimation of phase offset, including finite ambiguity, is presented simultaneously based on the derivation of the channel stability function. In this work, the structure of hierarchical iterative processing is used to enhance the performance of the algorithm, and the improved algorithm is used to reduce complexity. Compared with existing data-aided algorithms, this algorithm does not require a priori information. Therefore, it has significant advantage in solving the problem of blind parameter estimation of non-cooperative high-order modulated PCMA signals. Simulation results show the performance of the proposed algorithm is similar to the modified Cramer-Rao bound (MCRB) when the signal-to-noise ratio is larger than 16 dB. The simulation results also verify the practicality of the proposed algorithm.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제11권2호
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• pp.611-627
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• 2017

For enhancing the coverage of wireless networks and increasing the spectrum efficiency, small cell networks (SCNs) are considered to be one of the most prospective schemes. Most of the existing literature on resource allocation among non-cooperative small cell base stations (SBSs) has widely drawn close attention and there are only a small number of the cooperative ideas in SCNs. Based on the motivation, we further investigate the cooperative approach, which is formulated as a coalition formation game with power control algorithm (CFG-PC). First, we formulate the downlink sub-channel resource allocation problem in an SCN as a coalition formation game. Pareto order and utilitarian order are applied to form coalitions respectively. Second, to achieve more availability and efficiency power assignment, we expand and solve the power control using particle swarm optimization (PSO). Finally, with our proposed algorithm, each SBS can cooperatively work and eventually converge to a stable SBS partition. As far as the transmit rate of per SBS and the system rate are concerned respectively, simulation results indicate that our proposed CFG-PC has a significant advantage, relative to a classical coalition formation algorithm and the non-cooperative case.

• 한국문헌정보학회지
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• 제29권
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• pp.257-279
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• 1995

Cooperative program planning and teaching is a strategy for developing and implementing resource based learning. This approach combines the classroom teacher's subject expertise and knowledge of the students with the teacher­librarian's specialized knowledge of the availability and use of learning materials. And the purpose of cooperative program planning is to develop learning experiences or units of study that effectively integrate the student's resource center activities with other learning experiences. There are also some conditions that are conducive to effective planning sessions. First, the teacher-librarian must be prepared to initiate planning with teachers, rather than waiting for teachers to come to them. Second, the teacher-librarian must be prepared to present suggestions in such a way that the teacher can respond. The purpose of this study is (1) to investigate the planning process of cooperative program planning and teaching in the previous studies and (2) to find general problems when the cooperative program planning and teaching apply in actual situation. For these purposes, I chose a school library and a teacher-librarian in Seoul to observe how this cooperative program planning and teaching carry out in the school library. Main findings are summarized as follows: (1) A teacher who teaches alone for one grade is more proper to carry out the cooperative program planning and teaching. Young teachers are usually more active to change their teaching methods. (2) The cooperative program planning and teaching is a program what needs a lot of materials. When there is no right reference book in a school library, it would be good to access DB through PC telecommunication. It is also possile to contact lirarians who work in large public libraries or university libraries. (3) The cooerative program planning and teaching needs cooperative working between a teacher-librarian and a teacher. Thus a teacher-librarian should be in his school in the day time like the other teachers for the program's planning process. ( 4) There has to be a guide to change into resource based learning in teaching method. Thus the Korean Library Association or Korean Library and Information Science Society should offer a seminar or a workshop about cooperative program planning and teaching for the teacher-librarians. (5) It needs a system that a teacher-librarian can know about student's assignments so that he can prepare reference books for them. (6) The school library can be able to offer excellent service like cooperative program planning and teaching to the teachers and students according to a teacher-librarian's enthusiasm.

• 한국과학교육학회지
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• 제20권4호
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• pp.611-623
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• 2000

과학교육에 있어서 전통적 수업은 다양한 학생들의 육성과 요구를 수용하지 못하여 학생들의 과학에 대한 흥미를 저하시켰다. 평균적인 다수의 학생들을 대상으로 한 수업에서 결국 많은 학생들이 수업에 흥미를 잃게 되고 학생들은 타율적인 대상으로만 머물러 자신의 능력을 발휘할 기회를 얻지 못하고 있다. 이러한 문제를 극복하고 학생들의 활동을 격려하며 구성원들의 합의를 통한 문제해결을 이끌어내기 위한 수업 방식으로서 협동학습이 제안되었다. 본 연구에서는 생물교과에 협동학습을 적용하여 그 효과를 분석하고 소집단 학습과 협동학습의 차이를 알아보았다. 중학교 2학년 "동물의 구조와 기능" 단원에서 협동학습, 소집단 학습, 전통적학습을 실시하여 학생들의 과학 학업 성취도와 과학학습 태도에 대한 효과를 분석하였다. 연구대상은 서울시 소재 남녀공학 중학교 2학년 188명이며 10주간 10차시 수업처치를 하였고 사전-사후 통제집단 설계를 사용하였다. 연구 결과는 SPSS 통계 프로그램을 이용하여 공변량분석으로 분석하였다. 연구 결과 협동학습은 소집단 학습이나 전통적 수업에 비해 학생들의 학업 성취도와 과학학습 태도에서 유의미한 효과가 있는 것으로 나타났다 (p<.05). 그리고 협동학습은 학업 성취도 면에서 성취수준이 상위인 학생들에게 효과가 없었고 중위와 하위의 학생들에게는 유의미한 효과가 있었다 (p<.05). 또한 협동학습은 남학생과 여학생 모두에게 효과적이었다(p<.05). 협동학습은 과학학습 태도의 세 영역인 감정적 영역, 행동 의도적 영역, 인지적 영역에서 모두 유의미한 효과를 보였다(p<.01).

• 한국지구과학회:학술대회논문집
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• 한국지구과학회 2005년도 춘계학술발표회 논문집
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• pp.193-200
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• 2005

본 연구는 김제시 1개 중학교 2학년 여학생 5개반을 연구 대상으로 협동학습 실시 전 과학 선호도에 대한 사전 검사를 실시하였다. 약 10주간의 실험 처치를 한 후 사전 검사와 동일한 검사지로 사후 검사를 실시한 결과 여중생들의 과학적 선호도에 긍정적인 효과가 나타났다. 과학 수업에 대한 인식과 과학 수업에 대한 참여도가 협동학습 전과 달리 긍정적인 변화를 보였다. 그러나 과학자들에 대한 인식이나 과학적으로 사고하거나 행동하는 습관을 나타내는 과학적 태도는 유의미한 차이가 없었다. 이는 10주 동안의 기간은 협동학습 전략을 효과적으로 시행하는데 충분하지 못한 것으로 생각된다. 협동학습에 대한 학생들의 의견 조사서에서 중위 수준 학생들은 상-하위 수준 학생들과 달리 협동학습에 대해 강한 긍정을 나타냈다. 협동학습을 통해 상위 수준 학생들에게 배우고, 하위 수준 학생들에게 나누는 모둠 활동에서 자신감을 얻고 흥미를 느낀 것으로 본다.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
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• pp.861-864
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• 2009

The authors have developed the display system which can be viewed from any direction. In this paper, we propose an omni-directional 3D display system for cooperative activity on a round table.