• Journal of the Korea Society for Simulation
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• v.22 no.4
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• pp.149-156
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• 2013

In this research, we dealt with an optimization problem which aims to minimize total cost of resources usage and network routing in a smart node environment. Toward this, we briefly introduced technology trends in smart nodes, methods in resource optimization fields, economic effects of smart network and content delivery (or distribution) network (CDN). Moreover, based on CDN we proposed and implemented a mathematical (mixed integer) programming model to combine replica placement and requests distribution problem (RPRDP) and routing problem. Computational result of an example on RPRDP+Routing problem is also provided.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.681-682
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• 2007

본 논문에서는 지중전력설비의 안전한 운용을 위하여 무선네트워크기술을 적용한 감시시스템을 개발하기 위하여 WiMAX 기술을 적용하기로 하였다. 지중전력설비는 환경친화적 도시설비의 추구로 전체 전력설비중에서 비중이 꾸준히 늘어나는 추세이다. 노후화되어가는 전력설비는 사고의 위험성이 증대되고 있다. 하지만 노후화된 전력설비를 교체하는 비용은 천문학적이므로, 교체보다는 안전하게 유지보수하는 방법이 훨씬 경제적일 것이다. 지중전력설비는 지상설비만큼이나 광범위한 거리에 걸쳐서 시설되어 있다. 그러므로 노후한 설비를 유지보수하기 위하여 유선네트워크를 사용하는 방법보다는 경제적으로 무선네트워크를 사용하는 방법이 유리하다. 무선네트워크 기술은 종류에 따라서 여러가지 장단점을 가지고 있으며, 지중설비 감시에 최적인 기술을 채택하는 것이 중요하다. WiMAX 기술를 적용하여 지중전력설비 감시에 사용하여 기존에 설치한 유선네트워크에 영향을 주지않으면서, 신규로 추가되는 센서네트워크 시스템을 쉽게 통합 관리할 수 있는 시스템을 설계하기로 한다.

• Journal of KIISE:Information Networking
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• v.34 no.5
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• pp.405-422
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• 2007

Recently, according to the network environment, there are many researches for home network. Nowadays, in home network, the method that access control policy is managed for each home device by using ACL is popular, and EAM (Extranet access management) is applied as a solution. In addition, the research about secure OS is ongoing based on open operating system and the research of user authentication mechanisms for home network using home server is also in progress. However, these researches have some problems as follows; First, the transmission scope of expected access technology in home network is wide, so unauthenticated outside terminal can access the home network. Second, user is inconvenient because user need to set the necessary information for each device. Third, user privacy and convenience are not considered. OSGi provides a service platform for heterogeneous technologies in home network environment. Here, user access control is one of the core parts which should have no problems such as above items, but there are no concrete researches yet. Thus in this paper, we propose an access control policy management framework and access control operation based on RBAC for user access control in home network environment in which OSGi service platform is operated. First, we list the consideration which is not clearly mentioned in OSGi standard, and then we solve these above problems through new framework. In addition, we propose the effective and economical operation method which reduces the policy change frequency for user access control by using RBAC concept though limited resource of home gateway. Besides, in this paper, these proposed policies are defined separately as user-role assignment policy and permission-role assignment policy, and user decide their own policies. In conclusion, we provide the scheme to enhance the user convenience and to solve the privacy problem.

• Information Systems Review
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• v.10 no.1
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• pp.213-235
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• 2008

Recent reports about economic structure and changes show that global economy changes to rely on service rather than manufacturing. This phenomenon can be explained in two ways: the growth of service industry itself and the increasing reliance on service by other industry areas. The importance of service is indicated by the fact that the contribution of research and development, marketing, and finance to the revenue generation of companies is getting greater than that of manufacturing. This change in the economic structure calls for researchers' attention on the importance of service and the service-based economy. In the service-based economy, firms are considered value proposition providers and consumers actual value creators so that the concept of co-value creation becomes a key thesis to study. However, there are a variety of definitions of service and diversified measurements of service anchored in the supplier-oriented understanding of service yet. This lack of understanding of the service and the economic paradigm change causes a lot of problems in the areas of service productivity, service quality, and service innovation. Even though a new movement called service science started and rigorously pursues the way of enhancing the understanding of the economic change and service productivity, there is no framework that provides a unified view about the new role of service, service productivity, service quality, and thus service innovation. This study proposes a unified framework to provide a structured view about service provision and to facilitate the research on service. The framework is built on the concepts from previous studies about service marketing and service science: service life cycle and service networks including value activity network, resource integrator network, and capability network. We hope this study can be used as the basis for future studies on service science.

• Journal of the Korean Association of Geographic Information Studies
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• v.10 no.1
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• pp.102-112
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• 2007

Like other organic beings, modern cities change every day. Unlike in the past, changes of space which have been taking place in concentrated spaces during short periods of time have worsened the environment of cities creating environmental problems. In particular, the urban heat-island phenomenon, which is caused by changes in using the earth's surface, has emerged as a key social issue along with health problems and economic difficulties. The Green Network has been introduced as an urban planning approach to solve the urban heat-island phenomenon. This study suggests constructing a Green Network through analyzing the urban heat island phenomenon, land cover classification, and linkage possibility with the Green Network and wind corridors by researching Jung-Gu, and Nam-Gu in Daegu Metropolitan City. In conclusion, this study presented the construction of a broad and detailed Green Network of object areas by assigning Apsan to the southern area and mountain area as the core, two areas of Nam-Gu and six areas of Jung-Gu such as Duryu Park and, Dalsung Park as footholds and other school land and park facility areas as footholds-to-be areas. In particular, Camp Walker, which is connected with Apsan, is not only a foothold but connected to the core, is necessary to preserve after being transferred from the U.S. Army. In addition, assigning the Susung Bridge area of Jung-Gu and the Camp Walker area of Nam-Gu as the wind corridor areas is recommended.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.9 no.6
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• pp.213-230
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• 2014

Increasing unemployment rate and creation of new jobs are most important issues around the world recently. Then many developed countries, including Republic of Korea, establish and enforce a variety of start-up activation policies to increase employment rate and boom up the national economy. Establishing linkage of entrepreneurship motivation, entrepreneurship, entrepreneurial intention and firm performance, focusing on potential entrepreneurs and entrepreneur, it could provide personalized and targeted entrepreneurial policy programs to increase entrepreneurship, because entrepreneurship is the most important factor to activate startups. On this study, it established factors of entrepreneurial motivation on potential entrepreneurs and entrepreneurs, and analyzed the linkage of factors of entrepreneurial motivation, entrepreneurship, entrepreneurial intention(potential entrepreneurs) and firm performance(entrepreneurs). For analysis, this study conducted descriptive statistics, reliability analysis, factor analysis to verify validity, correlation analysis, and regression to analyze influence between factors. Potential entrepreneurs group has 202 samples, and findings show self-efficacy, social network, economic status and government policy influence on entrepreneurship positively. And self-efficacy, startup education, economic status and government policy have a positive effect on entrepreneurial intention, too. Entrepreneurs group has 212 samples, and findings show self-efficacy, social network and economic status influence on entrepreneurship. And each linkage has a positive effect, that self-efficacy - financial and non-financial performance, startup education - financial and technological performance, social network - financial performance, economic status - financial and non-financial performance, and government policy - financial and technological performance.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.24 no.6B
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• pp.1080-1087
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• 1999

High-speed network resources and large storage devices on video servers are necessary to Provide interactive VOD services to subscribers, therefore, building networks for VOD services requires a huge amount of cost. A number of studies on network hierarchy for distributed tree architecture, on optimized server allocation with a given network topology, and on program caching etc, are currently in progress. In this study, given specific network resources, a cost effective network architecture including the optimal number of tree levels and the optimal number of branches at a node are designed by modeling cost functions, and some restrictions on network design are discussed. The results of this study are expected to be applied to network architecture design for interactive VOD services

• Journal of the Korea Institute of Information and Communication Engineering
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• v.5 no.7
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• pp.1257-1262
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• 2001

In recent years there has been a lot of interest in carrying IP over WDM networks in an efficient manner. The benefits here include larger bandwidth capacities, better network scalability, and more efficient operation. W based approach, termed "lambda-labeling" is presented for direct If over WDM integration. In this paper, we study on architecture approach method consider of optical Internet evolution that based on MPLamdaS conception of IETF. Label stack conception collect electronic LSP of optical LSP. This paper is proposed method of co-operation between MPLS domain and MPLambdaS domain. Additionally, proposed architecture of Edge Optical LSR.tical LSR.

• Journal of Satellite, Information and Communications
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• v.1 no.1
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• pp.48-53
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• 2006

A K-SBAS (Korean Satellite Based Augmentation System) is proposed as one of the space infrastructure. The proposed system considers the existed elements to the utmost for the most economical SBAS construction. As reference system the current DGPS (differential global positioning system) network is investigated. Space segment is investigated based on the COMS-1 (Communications, Oceanographic, and Meteorological Satellite-1). While bus system of COMS-1 can be kept to minimum change, the communication payload of needed, crucial parts such as software, man power can be easily secured through the DGPS network operation heritage.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.11 no.7
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• pp.1354-1358
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• 2007

Nowaday, the wideband multimedia service, high speed and great capacity internet service etc. are increasing, so the network construction with the base of optical subscriber network is necessary. As efficient and economic optical subscriber networks are developed, so efficient network construction is possible. The most technology of them is WDM(Wavelength Division Multiplexing)-PON technology of ONU(Optical Network Unit) jointing method using PON(Passive Optical Network). In this paper, we have studied on a method for automatic optimization of data modulation current as optical power when the data is transmitted.