• Journal of the Korean Mathematical Society
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• v.34 no.2
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• pp.469-481
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• 1997

In this paper we consider TU-cooperative games in the form of characteristic function. We notice that if one uses the necessary and sufficient condition for the core to be not empty in a dual form, it may be used for selecting the final outcome in the core. Using the linear programming approach for constructing the subcore, which is a subset of the core, we represent it in a simple form. We consider reduced games due to Davis-Mashler, Moulin and Funaki and formulate the sufficient conditions for the subcore to be S-consistent.

• Journal of the military operations research society of Korea
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• v.27 no.1
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• pp.114-127
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• 2001

To support cooperative work in various scenes by computer systems, functions of sharing personalization, observation and control are needed. Especially, in advanced cooperative work, people have various position so that sometimes one person needs to restrict behavior of another. In this paper, we describe representation of access restriction of hypermedia system, which is framework of CSCW(Computer-Supported Cooperative Works) system we developed and propose a way to go on working cooperatively with people, restricting others.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.19 no.5
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• pp.645-652
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• 2010

For free motions, vibration suppression of single flexible manipulators has been one of the hottest research topics. However, for cooperative motions of multiple flexible manipulators, a little effort has been devoted for the vibration suppression control. So, the aim of this paper is to develop a hybrid force/position control and vibration suppression control scheme for multiple cooperation flexible manipulators handling a rigid object. In order to clarify the discussion, the motions of dual-arm experimental flexible manipulator are considered. Using the developed model, we control a robotic system with hybrid position/force control scheme. Finally, Experiments are performed, and a comparison of experimental results is given to clarify the validity of our control scheme.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.4
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• pp.2647-2655
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• 2015

This study has the purpose to evaluate the effects of cooperative learning applying Jigsaw model in simulation based infection control education by comparing perception of infection control, intrinsic motive and learning satisfaction, 54 first-year health related students. It is composed of 27 students of the experimental group and 27 students of the control group. In order to evaluate the homogeneity between the two groups, it surveyed in advance perception of infection control, intrinsic motive and learning satisfaction. There was no significant difference between the two groups, The education program composed cooperative learning applying Jigsaw Model, simulation practice and debriefing to the experimental group was performed twice for 2 weeks and lecture and skill training, simulation practice and debriefing were performed to the control group. After two-week education, perception of infection control, intrinsic motive and learning satisfaction of the participants the research were surveyed. As a result of this study, the Jigsow Model indicated the perception of infection control and learning satisfaction experimental group was significantly high in statistic. Based on this research result, I suggests that utilization of cooperative learning applying the Jigsaw Model as a strategy to improve the scholatic achievement and learning satisfaction of students in the variable simulation based education.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.1927-1932
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• 2003

In a previous study, the authors have proposed the Cooperative Collision Avoidance (CCA) method which enables mobile robots to cooperatively avoid collisions, by extending the concept of the Velocity Obstacle to multiple robot systems. The method introduced an evaluation function considering an operation objective so that each robot can choose the velocity which optimizes the function. As the evaluation function could be of an arbitrary type, this method is applicable to a wide variety of tasks. However, it complicates the optimization of the function especially in real-time. In addition, construction of the evaluation function requires an operation objective of the other robot which is very hard to obtain without communication. In this paper, the CCA method is improved considering such problems for implementation. To decrease computational costs, the previous method is simplified by introducing two essential assumptions. Then, by treating the desired direction of locomotion for each robot as the operation objective, an operation objective estimator which estimates the desired direction of the other robot is introduced. The only measurement required is the other robot's relative position, since the other information can be obtained through the estimation. Hence, communicational devices that are necessary for most other cooperative methods are not required. Moreover, mobile robots employing the method can avoid collisions with uncooperative robots or moving obstacles as well as with cooperative robots. Consequently, this improved method can be applied to general dynamic environments consisting of various mobile robots.

• The Journal of Asian Finance, Economics and Business
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• v.7 no.12
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• pp.809-818
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• 2020

This study aims to analyze the factors affecting the timeliness of cooperative financial reporting. The methods of measurement and accountability of financial statements must be timely, as it is critical information for making decision. Factors related to accounting information system problems such as timeliness of financial reporting, accounting information systems, teamwork, and internal control were identified in the study as a model. The method in this research is quantitative by taking survey data. The data were processed using SPSS 25, with a model test and partial test to produce a study to analyze the factors that affect the timeliness of cooperative financial reporting. The samples consisted of 60 cooperatives from the city of Tangerang, in Indonesia. The correspondents have published financial reports for each period of the current year and were a legal entity. Furthermore, primary data were collected by a questionnaire using a Likert scale and analyzed by multiple linear regression. The results showed that the Accounting Information System, Teamwork, and Internal Control had a positive and significant effect on the Timeliness of Financial Report Submission. Therefore, the cooperative that prepares financial reports in a timely manner has applied the principles of accountability and transparency.

• Journal of the Korean Institute of Intelligent Systems
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• v.11 no.7
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• pp.591-597
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• 2001

In this paper, we propose a method of cooperative control (T-cell modeling) and selection of group behavior strategy (B-cell modeling) based on immune system in distributed autonomous robotic system (DARS). Immune system is living body's self-protection and self-maintenance system. These features can be applied to decision making of optimal swarm behavior in dynamically changing environment. For applying immune system to DARS, a robot is regarded as a B-cell, each environmental condition as an antigen, a behavior strategy as an antibody and control parameter as a T-cell respectively. The executing process of proposed method is as follows. When the environmental condition changes, a robot selects an appropriate behavior strategy. And its behavior strategy is stimulated and suppressed by other robot using communication. Finally much stimulated strategy is adopted as a swarm behavior strategy. This control school is based on clonal selection and idiotopic network hypothesis. And it is used for decision making of optimal swarm strategy. By T-cell modeling, adaptation ability of robot is enhanced in dynamic environments.

• Journal of the Korean Society of School Health
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• v.25 no.1
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• pp.122-132
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• 2012

Purpose: The purpose of this study is to determine the effectiveness of cooperative learner-centered methods of sex education. Methods: This study was carried out on 5th grade elementary school students in D-district. Nine classes were divided into 3 groups using each different teaching methods: group A (a cooperative learning), group B (a lecture) and group C (a control group for a comparison). The study period was from Oct. 17 to Dec. 2 in 2011. Both groups A and B received sex education lessons for 40 minutes for 4 weeks and were tested their sex knowledge and attitude to compare the differences. Results: The scores of sex knowledge for all three groups were increased and their sex attitude was increased as well. The points of sex knowledge between pre and post test in group A are greater than the group B's. Thus, the cooperative learning approach with Group A was more effective to improve student's sex knowledge. But the difference between the sex attitude scores was not statistically significant. Group A and B showed a positive improvement in both their sex knowledge and attitudes compared with the control group. Conclusion: This experiment shows that an active teaching methods is more effective to improve student sex knowledge than a passive approach. Thus, a cooperative learning method results in increases of both student's sex knowledge and interests in learning sex education. It needs to develop more diverse teaching methods and programs on sex education that are more systematic and tailored.

• The Mathematical Education
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• v.48 no.3
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• pp.329-352
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• 2009

The purpose of this study was to investigate the effects of small group cooperative communicative activities on the strategies for estimating measurement. To do this, two research questions were set as follow: First, are there any differences between strategies employed by students in the experimental group and the control group before and after the estimating measurement activities? Second, are there any differences between strategies employed by students in different ability levels(upper, middle, lower) of pre-estimating measurement test in the experimental group? The research results were drawn from the investigation as below: First, the strategical change of before and after the estimating measurement tasks in the experimental group was quite noticeable. Unlike the small strategical change in the control group, small group cooperative communicative learning resulted in a decrease of simple memorization and guessing strategies and an increase of refined strategies such as the standard strategy, clustering, unit load and so on. Second, mathematical communicative activities in a small group cooperative learning showed that the students in the upper level of pre-estimating measurement test used more refined strategies and the students in the lower level used simple memorization and guessing strategy more frequently. And through interaction in small group, students could have chances to recognize error of strategies and to modify and learn strategies. In conclusion, small group cooperative activities allowed students to have chances to communicate mathematically and it is a efficient way of helping students learn estimating measurement strategies.

• Journal of Information Processing Systems
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• v.13 no.3
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• pp.630-642
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• 2017

In this paper, we propose the opportunistic non-orthogonal multiple access (NOMA)-based cooperative relaying system (CRS) with channel state information (CSI) available at the source, where CSI for the source-to-destination and source-to-relay links is used for opportunistic transmission. Using the CSI, for opportunistic transmission, the source instantaneously chooses between the direct transmission and the cooperative NOMA transmission. We provide an asymptotic expression for the average achievable rate of the opportunistic NOMA-based CRS under Rayleigh fading channels. We verify the asymptotic analysis through Monte Carlo simulations, and compare the average achievable rates of the opportunistic NOMA-based CRS and the conventional one for various channel powers and power allocation coefficients used for NOMA.