• 한국위성정보통신학회논문지
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• 제8권1호
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• pp.66-70
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• 2013

본 논문에서는 협력하고자하는 소출력 기기들이 협력 스펙트럼 센싱 할 경우 협력 노드들이 같은 FA(False Alarm)가지고 있다 가정하며, 이때 최적의 임계값을 셋팅하고 서로 정보를 공유하는 시스템 모델을 제안하고 성능을 분석한다. 협력하고자하는 모든 노드의 False alarm이 같아도 각 채널에 따라 임계값이 달라지게 된다. 임계값이 낮아지면 검출확률이 낮아지게 되고, 반대로 임계값이 높을 때 검출확률은 높아지는 특성을 가지기 때문에, 따라서 가장 높음 임계값을 선택하여 세팅하고 공유하게 된다. 이는 협력스펙트럼 센싱시 가장 높은 임계값을 공유함으로써 고정되어 있는 임계값을 보다 높은 검출성능을 보일 수 있다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제6권4호
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• pp.1041-1062
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• 2012

In this paper, we propose a hybrid cooperative scheme to improve the secrecy rate for a cooperative network in presence of multiple relays. Each relay node transmits the mixed signal consisting of weighted source signal and intentional noise. The problem of power allocation, the joint design of beamforming and jamming weights are investigated, and an iterative scheme is proposed. It is demonstrated by the numerical results that the proposed hybrid scheme further improves secrecy rate, as compared to traditional cooperative schemes.

• 한국수학사학회지
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• 제33권3호
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• pp.167-177
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• 2020

Cooperative behavior may seem contrary to the notion of natural selection and adaptation, but is widely observed in nature, from the genetic level to the organism. The origin and persistence of cooperative behavior has long been a mystery to scientists studying evolution and ecology. One of the important research topics in the field of evolutionary ecology and behavioral ecology is to find out why cooperation is maintained over time. In this paper we take a historical overview of mathematical models representing cooperative relationships from the perspective of mathematical biology, which studies population dynamics between interacting biological groups, and analyze the mathematical characteristics and meanings of these cooperative models.

• 한국수학교육학회지시리즈A:수학교육
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• 제43권1호
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• pp.51-74
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• 2004

During cooperative learning in small group, we investigate what characteristics children in elementary school show at several fields of mathematics and through communicating activity etc., what influence the cooperative learning does on children's attitude, thinking, problem solving, recognition. To know them, we observe the process of children's communication and evaluate children's attitude, thinking, problem solving, recognition with checklist at each lesson. Through this research, we conclude that the figure part is the most effective when we teach with cooperative learning type, and the cooperative learning evoke the vivid communication, and make progress in affirmative attitude, thinking etc. Also, in this thesis we suggest the points which teacher should consider when he/she use cooperative learning in small-group.

• 한국초등과학교육학회지:초등과학교육
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• 제19권1호
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• pp.29-39
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• 2000

The purpose of this study was to investigate the effect of cooperative skill training on elementary school students' science achievement and self-esteem. Three different groups were used in this study. For the two treatment groups, cooperative loaming strategies were used and the one control group, traditional instruction was used. One of the treatment group was trained cooperative skills before the instruction. A total of 120 children sampled from 5th graders of a elementary school. All groups were taught about the change of the weather and structure of the plants. After the instruction a researcher made science achievement test and questionnaire of self-esteem were administered. The data analysis consisted of a 3(instructional strategies)×3(learning ability level) ANCOVA on the score of the achievement and self-esteem. The ANCOVA results revealed that there were significant main effect in the scores of achievement and also significant interaction effect between the instructional strategies and learning ability. The performance of high-level students in two treatment groups was higher than that of students in the control group, but the performance of high-level students with cooperative skill training was not higher than that of students without cooperative skill training. However, the performance of medium and low-level students with cooperative skill training was higher than that of students without cooperative skill training. The significant main effect was also found in the self-esteem but there were no significant interactions between the instructional strategies and learning ability. The academic self and social self of students with cooperative skill training was higher than that of students without cooperative skill training.

• 농촌지도와개발
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• 제2권1호
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• pp.81-86
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• 1995

The objectives of this study is to explore the cooperative directions of extension services between Rural Development Administration and National Agricultural Cooperative Federation. Both organizations should share their extension roles and functions in order to increase the effectiveness and adaptability of their services, and activity. It is desirable that the R.D.A. takes responsibility for technological of the services and the N.A.C.F. takes responsibility for management aspects.

• 한국수학교육학회지시리즈A:수학교육
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• 제51권1호
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• pp.63-76
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• 2012

The purpose of this study is to investigate the effect of cooperative learning in mathematics in university level. We share reflections from 54 and 57 students in linear algebra courses which were conducted by cooperative learning. We examine how students increase self-confidence and reduce the anxiety in learning, and also develop the social skills in communication.

• 한국수학교육학회지시리즈A:수학교육
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• 제42권3호
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• pp.327-335
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• 2003

This study analyzes the effectiveness of cooperative learning in the instruction of the underachieved students. The result of this study showed that students who participated in the cooperative teaming tended to exert positive effects on the cognitive and affective(interest, self-confidence, motivation) domains. In the cooperative teaming, the underachieved students were encouraged in mathematics teaming and improved the efficiency of loaming in mathematics.

• 로봇학회논문지
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• 제10권3호
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• pp.133-138
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• 2015

This paper presents a modified task structure of coupled-constraints consensus based bundle algorithm especially to resolve the cooperative transportation problem. The cooperative transportation mission has various types of constraints. A modified framework to generate activities and subtasks to solve time and task constraints of the transportation mission by using coupled-constraints consensus based bundle algorithm is suggested. In this paper modifications on task structure, reward function and arrival time calculation are suggested to handle the constraints of cooperative transportation mission.

• 대한조선학회논문집
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• 제40권1호
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• pp.47-54
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• 2003

The majority of small/medium sized shipbuilders in Korea is poor in capital and then, should be restructured as an efficient production system with low investment. Due to considering this situation, the cooperative work system is proposed, in this study, as more effective production system for small/medium sized shipbuilder The cooperative work system Is the production system that many small/medium sized shipbuilders in a group jointly share the common facilities except minimum equipments and have managerial cooperation such as joint purchase of raw materials. The efficiency of cooperative work system is proved from economic and technical point of view with the case study of FRP shipbuilders of Sapjin industrial complex located at Mokpo area.