• Journal of Korea Multimedia Society
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• v.14 no.3
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• pp.423-432
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• 2011

In a warehouse, because there exist frequent changes of stock status and the quality of some contents are influenced by the environment such as temperature, fast and accurate management of the warehouse's environment is very important for Warehouse Management Systems (WMS). However, due to the absence of a unified standard for the communication protocol between RFID nodes, the connection between RFID nodes can be broken in case of movement of a RFID reader to a region with a different protocol. Moreover, centralized MAC schemes for RFID communications in previous studies have severe problems. For an example, if a cluster header disappears from the cluster due to the cluster header's movement or bad channel conditions, the RFID member nodes of the cluster waste lots of time and energy to re-elect a new cluster header. Therefore, in this paper, we propose a WiMedia Distributed MAC (D-MAC) scheme for RFID communications and its cooperative relay transmission scheme for WMS applications Simulation results show performance improvement at the RFID node by using the proposed cooperative relay transmission scheme.

• Journal of the Korean Home Economics Association
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• v.38 no.11
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• pp.89-104
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• 2000

The purpose of this study is to grope the direction of the environmental movement for the improvement of welfare. The deterioration of environment which was resulted from the development of material civilization due to the industrialization made people newly recognize the importance of environment. The quality of the future life depends on the solution of the environmental problems. The family-centered environmental movement as a new cultural movement in the daily life should be revitalized for the purpose of improving welfare. This study investigated the several views on the environmental problems in the neighboring disciplines of home economics. And on the basis of the results of the study, the direction of environmental movement to be developed in home economics was represented. This study represented the directions of the environmental movement as a new cultural movement in the daily life as follows: alternative life-style, that is, pro-environmental life-style-oriented direction; community-oriented direction such as cooperative association movement in daily life; the politicalization of the environmental problems, that is, the endeavor to reflect the election promise on the environment in the vote, etc. The content of the environmental movement shoed be treated of in environmental education, consumer education, family-life education, school education, and life-long education.

• Journal of Korea Society of Digital Industry and Information Management
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• v.9 no.3
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• pp.91-98
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• 2013

Node which plays the role of cache server does not exist in the wireless ad-hoc network consisting of only mobile nodes. Even if it exists, it is difficult to provide cache services due to the movement of nodes. Therefore, the cooperative cache technique is necessary in order to improve the efficiency of information access by reducing data access time and use of bandwidth in the wireless ad-hoc network. In this paper, the whole network is divided into zones which don't overlap and master node of each zone is elected. General node of each zone has ZICT and manages cache data to cooperative cache and gateway node use NZCT to manage cache information of neighbor zone. We proposed security structure which can accomplish send and receive in the only node issued id key in the elected master node in order to prepare for cache consistent attack which is vulnerability of distributed caching techniques. The performance of the proposed method in this paper could confirm the excellent performance through comparative experiments of GCC and GC techniques.

• The Journal of the Korea Contents Association
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• v.21 no.1
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• pp.139-146
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• 2021

Ahead of the commercialization of autonomous vehicles, it's application should be considered into the current transportation infrastructure. Under limited traffic circumstances, effective set of lane change rules alone could bring benefits to the autonomous driving system. In this study, a cooperative movement (local platooning) plan with limited vehicles associated as pocket driving, aiming at effective movement between vehicles in urban environment was proposed. Under congested roadway condition, the gaussian gap between vehicles was introduced to secure gap acceptance for safe lane change maneuver. Proposed lane change method showed 86.6% delay reduction along with traffic volume improvement. This result could be considered as a crucial factor in designing a next-generation roadway infrastructure with autonomous driving.

• Journal of Navigation and Port Research
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• v.33 no.6
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• pp.443-450
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• 2009

In this paper, we propose optimizing a remarshaling plan in an automated stacking yard using a cooperative coevolutionary algorithm (CCEA). Remarshaling is the preparation task of rearranging the containers in such a way that the delay are minimized at the time of loading. A plan for remarshaling can be obtained by the following steps: first determining the target slots to which the individual containers are to be moved and then determining the order of movement of those containers. Where a given problem can be decomposed into some subproblems, CCEA efficiently searches subproblems for a solution. In our CCEA, the remarshaling problem is decomposed into two subproblems: one is the subproblem of determining the target slots and the other is that of determining the movement priority. Simulation experiments show that our CCEA derives a plan which is better in the efficiency of both loading and remarshaling compared to other methods which are not based on the idea of problem decomposition.

• Journal of The Korean Association For Science Education
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• v.20 no.4
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• pp.611-623
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• 2000

The cooperative learning movement began as parts of the desegregation process in America, aiming at increasing academic achievement and social skills among diverse students. Cooperative learning may be defined as a classroom learning environment in which students work together in small heterogeneous groups. Although many studies have shown the effectiveness of cooperative learning in a variety of subjects, relatively few have focused on biology. In this study, we investigated the effects of cooperative learning on students' achievement and attitude of middle school biology students. For this purpose this study compared three sections. In one section, a cooperative learning strategy was used. Second section was taught in small groups and the third section was instructed in the traditional method. The unit 'Structures and functions of animals' was used. A total of 188 students were included in this study. These classes were treated for 10hours during 10weeks from September 1 to November 28, 1999. The pretests-posttests control group design was applyed. An analysis of covariance(ANCOVA) was used as the data analysis procedure. Significant differences were found in the achievement and the attitude of students using cooperative learning strategy(p<.05) when compared to traditional classroom structure and small group learning. Cooperative learning was more effective in the low-ability and average-ability students than the high-ability students in the science achievement. Cooperative learning is effective in both male and female students. And students in the cooperative group achieved better than those in other groups in affective, behavioral, and intention-cognitive domain of science attitude.

• The Korean Journal of Community Living Science
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• v.17 no.1
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• pp.109-122
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• 2006

As we encounter the global and localized era, the development operations on a regional level are in active promotion. This manuscript has been completed with the purpose of probing for course of action in lifelong learning movement in terms of activating and developing of local communities. For this, the comparative analysis of practiced cases in America's community school movement, Japan's movement for establishing lifelong learning village and Sweden's study circle movement have been made. For the analytical frame of the comparison, the actual results on background of promotion, themes for practice, details of practice, methods for practice of local community centered lifelong learning movement have been applied. As a result of analysis, the local community centered lifelong learning movement has been promoted to break each country's social and economic crisis and to activate the local community. The promotion of each operation has been accomplished with the support of specific organization and the participants were the citizens of the local community. Also, the details of practice are composed of operating the people-centered lifelong learning program, cooperative learning by local citizens and local community realization activity. The details of education is closely related with the life of learners. Therefore, the lifelong movement for the activation of local community hereafter should be promoted based on the coherence of local community, should be able to contain the actual life of the citizens and should be practiced as a process of forming the lifelong learning group at concerned local community through a democratic learning process.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.1
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• pp.201-209
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• 2014

This paper proposes a genetic algorithm to maximize the connectivity among the mobile nodes for the cooperative communication in ad-hoc networks. In general, as the movement of the mobile nodes in the networks increases, the amount of calculation for finding the solution would be too much increased. To obtain the optimal solution within a reasonable computation time for a high-density network, we propose a genetic algorithm to obtain the optimal solution for maximizing the connectivity. In order to make a search more efficient, we propose some efficient neighborhood generating operations of the genetic algorithm. We evaluate those performances through some experiments in terms of the maximum number of connections and the execution time of the proposed algorithm. The comparison results show that the proposed algorithm outperforms other existing algorithms.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37 no.5B
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• pp.357-364
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• 2012

In Visible Light Communication (VLC) system, with the limitation of transmission range and Field Of View (FOV), LOS (Line of Sight) link between two transceivers should be guaranteed due to the straightness of the visible-light signal. Especially for indoor applications, link recovery is an advantage method to remain the link connection because of the link failure in which caused by movement obstacle. Link recovery schemes try to keep link dynamically without re-initialing connection. This article proposes a new link recover scheme for VLC system by using cooperative communication. Our propose scheme focuses on the QoS reservation resource by GTS in IEEE 802.15.7 specification in which the requested QoS resource from client should be guarantee during the application time. With the link recovery scheme, we will try to continue the link connection as long as possible when unexpected disconnect link. The mathematical analysis and simulation results show that proposed scheme increases the overall reliability of the VLC system.

• Journal of Agricultural Extension & Community Development
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• v.18 no.4
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• pp.1011-1049
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• 2011

This study is mainly to investigate the influences of both Western's utopian socialism and cooperatives ideas on the process of China's rural cooperation from 1919(the occurrence of 5.4 movement) to 1958(the completion of People's commune). To accomplish this, first, we will discuss that how these two ideas emerged as an alternative to Western capitalism in the before/early 20th century were introduced into China and how these ideas effected on the process of the China's Communist Revolution. Then, we will review the process of China's rural cooperation during the 1950s' new socialist nation-building period since the foundation of New China(1949), the sharp debates about rural cooperation in the process of its realization, and the reasons of radically promoting rural cooperation in the late 1950s. Finally, through these debates and experiences regarding rural cooperation in rural China during 1919-1958, any implications in solving rural cooperation problems of contemporary China facing difficulties will be provided.