• International Journal of Computer Science & Network Security
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• v.21 no.3
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• pp.212-218
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• 2021

Low-power and Lossy Networks (LLNs) have become the common network infrastructure for a wide scope of Internet of Things (IoT) applications. For efficient routing in LLNs, IETF provides a standard solution, namely the IPv6 Routing Protocol for LLNs (RPL). It enables effective interconnectivity with IP networks and flexibly can meet the different application requirements of IoT deployments. However, it still suffers from different open issues, particularly in large-scale setups. These include the node unreachability problem which leads to increasing routing losses at RPL sink nodes. It is a result of the event of memory overflow at LLNs devices due to their limited hardware capabilities. Although this can be alleviated by the establishment of multi-sink topologies, RPL still lacks the support for effective load balancing among multiple sinks. In this paper, we address the need for an efficient multi-sink load balancing solution to enhance the performance of PRL in large-scale scenarios and alleviate the node unreachability problem. We propose a new RPL objective function, Multi-Sink Load Balancing Objective Function (MSLBOF), and introduce the Memory Utilization metrics. MSLBOF enables each RPL node to perform optimal sink selection in a way that insure better memory utilization and effective load balancing. Evaluation results demonstrate the efficiency of MSLBOF in decreasing packet loss and enhancing network stability, compared to MRHOF in standard RPL.

• The Korean Journal of Applied Statistics
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• v.36 no.5
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• pp.399-413
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• 2023

Recently, monitoring and detecting anomalies in social networks have become an interesting research topic. In this study, we investigate the detection of abnormal changes in a network modeled by the DCSBM (degree corrected stochastic block model), which reflects the propensity of both individuals and communities. To this end, we propose three methods for anomaly detection in the DCSBM networks: One method for monitoring the entire network, and two methods for dividing and monitoring the network in consideration of communities. To compare these anomaly detection methods, we design and perform simulations. The simulation results show that the method for monitoring networks divided by communities has good performance.

• Journal of Navigation and Port Research
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• v.48 no.3
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• pp.181-191
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• 2024

Ports play a crucial role in the complex global supply chain. While many researchers have used social network analysis (SNA) to study active networks, there is a lack of SNA cohesion analysis specifically related to logistics and trade. Therefore, this study aims to identify time-series structural changes in all domestic import and export logistics networks, including regions, ports, and airports, by utilizing techniques such as k-core and community analysis. To carry out this analysis, we rely on data from the Korea Customs Service's Import and Export Logistics Statistical Yearbook spanning from 2004 to 2022. The findings from the k-core and community analysis indicate that the cohesion of the domestic import and export logistics network has continuously strengthened over time. Moreover, it reveals that regions, ports, and airports are becoming more cohesive and homogeneous, with Busan Port emerging as the central hub of a large community. These insights are expected to enhance our understanding of global logistics dynamics and contribute to the development of policies and sustainable import and export logistics processes.

• The Journal of the Korea Contents Association
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• v.12 no.10
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• pp.11-21
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• 2012

Hybrid network infrastructure has been deployed as the most important technology for the advanced research networking community such as Internet2, SURFnet, etc. However, further research needs to be performed in terms of feasible design and implementation of architecture for inter-domain collaborative network infrastructure, which is essential to end-to-end collaborative research based on high-end applications. In this paper, we suggest a framework for distributed and virtual network operations based on hybrid research networks and efficient cooperation between multi-domain hybrid networks, which aims to provide collaborative network environment for high-end applications. Suggested framework is designed to adopt decentralized model of multi-domain hybrid research network management. A collaborative and distributed virtual model that is characterized by cooperation among hybrid research networks that insist on maintaining their autonomy and control, can also contribute for researchers and other end-users to manage and operate their own virtual networks.

• Journal of Internet Computing and Services
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• v.10 no.3
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• pp.131-140
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• 2009

Recently, the information visualization research community has given significant attention to graph visualization, especially visualization of social networks. However, visualization of information flows in a very large social network has not been studied in depth. However, information flows are tightly related to the structure of social networks and it shows dynamic behavior of interactions between members of social networks. Thus, we can get much useful information about social networks from information flows. In this paper, we present our research result that enables users to navigate a very large social network in Google Maps' method and to take a look at information flows on the network. To this end, we devise three techniques; (i) mapping a very large social network to a 2-dimensional graph layout, (ii) exploring the graph to all directions with zooming it in/out, and (iii) building an efficient query processing framework. With these methods, we can visualize very large social networks and information flows in a limited display area with a limited computing resources.

• The Journal of Society for e-Business Studies
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• v.13 no.4
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• pp.193-207
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• 2008

The study investigates the co-authorship networks of MIS Quarterly as one of the leading journals in IS field and examines patterns of collaboration networks of the intellectuals. These issues are addressed through a systematic Social Network Analysis (SNA) of 242 articles published from 1996 to 2004 in MIS Quarterly. Results of co-authorship network analysis indicate that the whole incomplete network has a low degree of density. Thus, we analyzed three biggest sub-networks to find out who the key players of each sub-network are. Then, following the keyword classification scheme, relevant data from the articles were collected and coded to analyze three major co-authorship networks of MIS Quarterly community. Some implications are drawn from different research keywords of each sub-network.

• Journal of Family Resource Management and Policy Review
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• v.21 no.3
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• pp.23-42
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• 2017

The purpose of this study was to identify the social networks used by the rural elderly and to analyze the effects of these social networks on the need for life services. The research subjects were 1,000 people aged 65 years and over living in the rural areas of Korea. Among the total 1,000 respondents, 979 elderly who have children were included in this study. The data were analyzed using frequency analysis, descriptive statistics, and multiple regression analysis. The results of this study were as follows. First, the frequency of contact with friends/neighbors was higher than that of children, whereas the social support of children was higher than that of friends/neighbors(excluding physical support). Second, the rate of use of home services and the elderly welfare center was very low. Promotion, a minimum cost burden, convenient transportation (circulation bus operation, etc.), and the provision of visiting services are examples of ways to be using them much more. Third, the elderly who do not live with their children have a higher need for life services. As well unlike the elderly who live with their children, in the case of the elderly who do not live with their children, the necessity for life services was influenced not only by their children but also by the relationship with their friends/neighbors and by home services. This implies that comprehensive social networks are important for the elderly who do not live with their children. Therefore, it is necessary to activate the social support of the community as well as of children and friends/neighbors.

• Journal of Agricultural Extension & Community Development
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• v.5 no.1
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• pp.61-70
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• 1998

이 연구는 인구 4,000에서 6,000명 가량의 농촌 지역사회에서의 서비스 및 용역의 제공기능의 활성화 정도와 관련하여 지도자들의 특성을 파악하고자 한다. 지역사회 지도자들간의 공식적이고 수평적인 연계와 지도자들과 지역사회 외부 조직들간의 연계를 중심으로 분석이 이루어졌다. 성(性), 교육정도, 연령, 수입, 지역사회 출신 여부, 그리고 지역사회에서의 거주기간을 포함하는 농촌 지역사회 지도자들의 개인적 특성은 지역사회 서비스 및 용역의 제공기능과 관련이 없었다. 그러나, 농촌 지역사회의 서비스 및 용역의 제공기능 활성화 정도는 그 지역사회의 지도자들이 지역사회 외부의 사람들 및 조직들과 연계를 맺고 있는 정도와 관련이 있었다. 또한 이 연구에서는 농촌 지도자들의 공식적인 지역사회 개발 활동에 능동적으로 참여하는 능력이 지역사회 서비스 및 용역 제공기능의 활성화 정도와 정적으로 관련이 있음이 밝혀졌다.

• Korean Parent-Child Health Journal
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• v.12 no.1
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• pp.37-45
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• 2009

Purpose: This study was done to review Taegyo types, the practice of Taegyo, factors of Taegyo, and the effect of Taegyo programs in Korea. Method: This study reviewed the preceding research related to Taegyo through websites, articles, and books. Result: As a result of a review of Taegyo types, the practice of Taegyo, factors of Taegyo, and the effect of Taegyo programs through websites, articles, and books, it was summarized that pregnant women were independent people able to practice Taegyo from pre-pregnancy to childbirth for baby's health. If she practiced encouraging behaviors of Taegyo with her husband's physical, emotional, and economical support, she and her husband would easily transition to parenthood and form strong attachments with their baby. In addition, the rate of mother's postpartum depression was decreased. However, some pregnant women felt a psychological, social, and economical pressure to practice Taegyo. Conclusion: Activating organized and accessible to support systems and community networks, such as community health centers, nurses can help pregnant couples to increase self-care through the performance of Taegyo.

• Korean Journal of Child Studies
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• v.27 no.5
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• pp.79-93
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• 2006

Even though social intervention in child abuse has begun in Korean society, there are many problems in terms of basic principles of child welfare services. Focusing on the principle of family preservation in child welfare services, this comparative study reviewed services for abused children and their families in the USA and Sweden. Results indicated directions for effective services for abused children are comprehensive and should be provided by community resources. Comprehensive services and follow-up of reported cases should be managed by public agencies and community networks. Education curricula for professionals and inter-disciplinary collaboration should be organized. A most important task in the future is to set up firm laws and policies for effective services in Korean society.