• The Journal of the Korea institute of electronic communication sciences
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• v.2 no.2
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• pp.99-105
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• 2007

MANET(Mobile Ad-hoc network) have recently attracted a lot of attention in the research community as well as in industry. Although the previous research mainly focused on various of MANET in routing, we consider, in this paper, how to efficiently support applications such as variable geocasting basd on MANET. The goal of a geocasting protocol is deliver data packet to a group of nodes that are located within a specified geocasting region. Previous research that support geocast service in mobilie computing based on MANET have the non-optimization problem of data delivery path, overhead by frequent reconstruction of the geocast tree, and service disruption problem. In this paper, we propose the mobility pattern based geocast technique using variable service range according to the mobility of destination node and resource reservation to solve this problem. The experimental results show that our proposed mechanism has improved performance of Accessibility & Network Overhead than previous research.

• Journal of Information Processing Systems
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• v.15 no.3
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• pp.616-631
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• 2019

With the rapid increase of information on the World Wide Web, finding useful information on the internet has become a major problem. The recommendation system helps users make decisions in complex data areas where the amount of data available is large. There are many methods that have been proposed in the recommender system. Collaborative filtering is a popular method widely used in the recommendation system. However, collaborative filtering methods still have some problems, namely cold-start problem. In this paper, we propose a movie recommendation system by using social network analysis and collaborative filtering to solve this problem associated with collaborative filtering methods. We applied personal propensity of users such as age, gender, and occupation to make relationship matrix between users, and the relationship matrix is applied to cluster user by using community detection based on edge betweenness centrality. Then the recommended system will suggest movies which were previously interested by users in the group to new users. We show shown that the proposed method is a very efficient method using mean absolute error.

• Journal of Agricultural Extension & Community Development
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• v.30 no.4
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• pp.199-212
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• 2023

Recently, despite the active interest and research on biochar, there is a lack of research on the acceptance intention of farmers, who are technology adopters. Accordingly, the purpose of this study was to conduct a survey of 168 farmers and structurally analyze the factors affecting farmers' intention to accept biochar. The analysis results are as follows. First, promotion conditions and network effects have a positive influence on farmers' intention to accept biochar. Second, the mediating variable, network effect, has a complete mediating effect between performance expectations, social influence, and acceptance intention. This suggests that organizations need to be utilized to spread biochar because network effects increase the explanatory power of acceptance intention.

• Korean Journal of Childcare and Education
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• v.7 no.3
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• pp.67-100
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• 2011

This study assesses the current status of community child centers in Jeollabuk-do by analyzing data from evaluations of 225 centers in 2009. The results are as follows. First, as of 2004, there was a total of 37 Jeollabuk-do community child centers; the number has been increasing at a rate of 20~40% yearly. The number of community child centers has been increasing since government funding was implemented, especially as an authorization is not required to open a center. In order to prevent an excessive amount of childcare centers, and to ensure that new centers meet a standard of quality, it is necessary to examine replacing the current reporting system with an authorization system. Second, out the 6,144 children in the 255 centers, 1,711 children (27.8%) were not from low-income families. This may be positive in that children from various income level families are learning together. However, in order for the community child centers to operate as they were intended, it is necessary to reinforce the itemized regulations. Third, the community child centers scored relatively poorly in utilizing community and human resources. This is because although most Jeollabuk-do childcare centers are using volunteer personnel, they are not fully utilizing community resources. The governments of the cities and counties should support the community child centers by promoting their services and roles, and thereby enable the centers to develop a network of professionals in the community.

• Journal of Home Health Care Nursing
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• v.10 no.1
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• pp.5-14
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• 2003

Recently, there has been an increasing need for long-term care and comprehensive health care services in community settings. The Ministry of Health and Welfare introduced the Hospital-Based Home Nursing Care Program in 2000. Before this initiative, there was a Home Nursing Demonstration Center, affiliated with the Seoul Nurse Association, had offered home nursing services with the financial support from the local government. since 1993, the Center's nursing staff has been engaged in a general hospital in an effort to provide home nursing care services within Korea's health care system. The purpose of this study was to analyze and identify characteristics of community-based home nursing care supplied by a community-based home nursing team engaged in a general hospital. Also. visit nursing care services provided by public health centers were evaluated in terms of accessibility and supply versus demand, to enhance the accessibility of low-income patients living in Seoul to home nursing care services. Data were collected from home nursing insurance reimbursement claims submitted by the community-based home nursing care team from March 1 to October 30 in 2001 and a questionnaire survey on home-visit nursing services of 25 public health centers in Seoul. The subjects consisted of 197 patients and 12 public health centers. The result were as follows. First, medical institution's community-based home nursing care program was better in technical quality than health-center-based home-visit nursing care. In addition. the pattern of the subject patients was similar to that of hospital-based home nursing care program. Second, there was a high demand for community-based home nursing care while only a small number of home-visiting nurses served at public health centers in Seoul. As a result, many patients could not receive adequate care. Finally, we suggest that community-based home nursing care program should be introduced in the national health system to meet the at-home care needs of severely ill low-income patients. Furthermore, to better utilize home nursing and visit-nursing care resources and offer continued care for patients in community settings, an efficient referral network should be built among related institutions. This would require improvement of reimbursement system and amendment of the law related to health insurance system and community-based home nursing care services.

• 한국HCI학회:학술대회논문집
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• 2009.02a
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• pp.1087-1094
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• 2009

As online community was revitalized, the internet became the second space for people's everyday life. People enter into a connection with other on-line members and they maintain and extend their relationships. Such relationships can be analyzed and visualized with social network analysis. The method oftentimes envisions the structural elements of complex social life. The study aims at visualizing the relationships among the Cyworld users and designs an application "Blow Blow Your Pinwheel", the main purpose of this application is visualizing social relationships between ego and '1chons' which is a concept of friendship in Cyworld. Designing such an application, the study focuses on closeness of relationships which we think is composed of 1)proximity 2)similarity, 3)familiarity, and 4)reciprocity. The study used these concepts in measuring the strength of relationship between ego and other 1chons(friends). Specifically, we devised survey questionnaires which asked users to evaluate the importance of the above factors of closeness, and implemented the result in calculating the strength of the relationship between ego and other by giving weights for each factor. These measurements then were applied in visualizing the relationships in the application, we designed. Through the application, we can compare on-line relationships with off-line relationships and attempt for the new approach of Social Networks.

• Journal of Communications and Networks
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• v.3 no.4
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• pp.342-350
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• 2001

The Internet routing instability, or the rapid fluctuation of network reachability information, is an important problem currently facing the Internet engineering community. High levels of network instability can lead to packet loss, increased network latency, and delayed routing convergence. At the extreme, high levels of routing instability can lead to the loss of internal connectivity in wide-area networks. In this paper, we investigate the variation of domain degree and domain count of the inter-domain network over time by using linear regression model in order to analyze the topology variation of inter-domain network. We Also propose an efficient policy management model to reduce the instability in the inter-domain routing system. The proposed model can be used to identify whether a routing policy is adequate to reduce convergence time that is required to return to a normal state when BGP routing instability happens. Experimental analysis shows that the proposed model can be used to set up routing policy in domains for the purpose of minimizing the effects and the propagation of BGP routing instability.

• The Journal of Bigdata
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• v.4 no.1
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• pp.99-118
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• 2019

This study used network analysis and clustering techniques to analyze studies on social media participation. As a result of the main path analysis, 37 major studies were extracted and divided into two networks: community-related networks and new media-related. Network analysis and clustering result in four clusters. This study has the academic significance of using academic data to grasp research trends at a macro level and using network analysis and machine learning as a methodology.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.5
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• pp.2144-2165
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• 2016

In a vehicular ad hoc network, the communication links are unsteady due to the rapidly changing topology, high mobility and traffic density in the urban environment. Most of the existing geographical routing protocols rely on the continuous transmission of beacon messages to update the neighbors' presence, leading to network congestion. Source-based approaches have been proven to be inefficient in the inherently unstable network. To this end, we propose an opportunistic beaconless packet forwarding approach based on a modified handshake mechanism for the urban vehicular environment. The protocol acts differently between intersections and at the intersection to find the next forwarder node toward the destination. The modified handshake mechanism contains link quality, forward progress and directional greedy metrics to determine the best relay node in the network. After designing the protocol, we compared its performance with existing routing protocols. The simulation results show the superior performance of the proposed protocol in terms of packet delay and data delivery ratio in realistic wireless channel conditions.

• Journal of The Korean Society of Agricultural Engineers
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• v.58 no.5
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• pp.19-28
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• 2016

This study was to design the optimal locations of the water level monitoring to quantify the agricultural water use in irrigation area supplied from an agricultural reservoir. In most of agricultural areas without TM/TC (Tele-Monitoring and Tele-Control) or monitoring network, irrigation water have been supplied on conventional experience and agricultural reservoir have been operated based on the operating simulation results by HOMWRS (Hydrological Operation Model for Water Resources System). Therefore, this study quantified the amount of agricultural water use in an irrigation area (Musu Reservoir, Jincheon-gun) by establishing water level monitoring network and analyzed the agricultural water saving effect. According to the evaluation of the economic values for water saving effect, the saving agricultural water of 1.7 million ton was analyzed to have economic values of 0.85 million won as water for living, and 1.78 million won as water for industrial use. It is identified to secure economic feasibility of the new water monitoring network by establishing one monitoring point in the entrance, irrigation area and endpoint through the economic analysis.