• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.8
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• pp.1571-1579
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• 2009

This paper proposes a P2P(Peer-to-Peer) streaming protocol which allows various QoS(Qualify of Service) requirements of video streaming to be supported for various personal IPTV applications in ubiquitous Internet environments. The proposed P2P streaming protocol takes fairly short startup delay, guarantees end-to-end delay bound and bandwidth requirements, and supports reliability level of video streaming for an IPTV application. The QoS-based P2P streaming protocol can properly use not only the advantages of scalability, availability, and ubiquity of P2P streaming but also complement its disadvantages of performance and reliability so that various types of personal IPTV applications can be properly implemented in the existing broadband Internet environments.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.9 no.7
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• pp.1412-1418
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• 2005

Recently, more and more portable terminals probably have multiple interfaces to be connected to different access technologies. Each technology has its specific characteristics in terms of coverage area, bandwidth, reliability, etc. For example, the mobile node is equipped with three heterogeneous interfaces; IEEE 802.1lb MLAM link, CDMA Cellular link, and 802.16 WiMAX link These mobile nodes may be reachable through different links at the same time or use each interface alternately depending on the network environment. As like this, the portable terminal equipped multiple interfaces can have many benefits; it should be connect to Internet through other interface in case of occurring to failure for currently activate interface, and it should share a mount of traffic efficiently per interface etc. This environment is called end node Multihoming. However, current most Internet protocols are designed originally with single interface in mind. So these potocols do not provide methods for supporting simultaneous diffentiated use of multiple access technologies. In this paper, firstly we have to refer technical consideration items to use multiple interfaces based on IPv6 simultaneously. And we should propose extended registration mechanism for multiple addresses being acquired from interfaces to support reliable accessibility and vertical handover.

• Journal of Internet Computing and Services
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• v.13 no.6
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• pp.55-62
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• 2012

Grid web applications by standard Web technology are increasingly used to provide grid service to users as normal Web user interface and service. It is however difficult to integrate a grid security system such as Grid Security Infrastructure (GSI) into Web applications because the delegation way of standard Web security is not the same as the one of Grid security. This can be solved by allowing Web applications to get a Grid credential by using an online credential repository system such as MyProxy. In this paper, we investigate the problem that occurs when MyProxy, which assumes mutual trust between a user and Grid web application, is adapted for achieving security integration between Web and Grid, and we propose a new Grid proxy delegation service to delegate a Grid credential to the Web without assuming mutual trust. In the service, the X.509 proxy delegation process is added to OAuth protocol for credential exchange, and authentication can be done by an external service such as OpenID. So, users can login onto the Grid web application in a single sign-on manner, and are allowed to securely delegate and retrieve multiple credentials for one or more Virtual Organizations.

• Journal of Internet Computing and Services
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• v.3 no.2
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• pp.79-85
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• 2002

In open communication architecture, application systems consist of objects distributed in lots of computing nodes. To reduce complexity of development. and management of distributed software, to manage efficiently distributed objects and to provide realtime service, the mechanisms for object group management and communication are needed in distributed environment. In this paper we compose object groups and provide reliable group communication mechanism based on CORBA which can adopt a new service without lots of changes on existing system. Group consist of some subgroups that subgroup manager manages for improving the efficiency of group management and message ordering is kept by using sequencer, Communication method among groups uses multicast based on paint to point communication as well as IP multicast and we provide high performance by using selective retransmission of message through message history, We analyze the performance of the proposed mechanism through simulation in distributed environment.

• Journal of Internet Computing and Services
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• v.4 no.1
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• pp.39-52
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• 2003

As software is developed for many applications and software defects have caused serious problem sin those applications, the concern of software quality evaluation increases rapidly. Although there has been many efforts for establishing standards for software evaluation, such as ISO/IEC 9126, they provide only a framework for defining quality characteristics and evaluation process. They, however, do not provide practical guidances for deriving resonable weight value criteria for software evaluation. This paper presents a method to draw quantitative weight values from evaluator's subjective data in the process of software evaluation as observing the ISO/IEC 9126 standard. To eliminate the evaluators' subjectiveness and the uncertainty of weight value during evaluation, the Dempster-Shafer (D-S) theory is adopted and utilized. In this paper, the D-S theory is supplemented with an improved merge rule to reduce the bias of weight value when they are merged with other evaluator's weight value. The proposed merge rule has been tested and proved with actual evaluation data.

• Journal of Internet Computing and Services
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• v.15 no.2
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• pp.9-18
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• 2014

The sensors attached on/in a person are moved since human body frequency changes their activity, therefore in wireless body area networks, nodal mobility and non-line-of-sight condition will impact on performance of networks such as energy efficiency and reliable communication. We then proposed schemes which study on forwarding decisions against frequent change of topology and channel conditions to increase reliable connections and improve energy efficiency. In this work, we control the size of packets, forwarding rate based on ratio of input links and output links at each node. We also robust the network topology by extending the peer to peer IEEE 802.15.4-based. The adaptive topology from chain-based to grid-based can optimal our schemes. The simulation shows that these approaches are not only extending network lifetime to 48.2 percent but also increase around 6.08 percent the packet delivery ratio. The "hot spots" problem is also resolved with this approach.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.11 no.8
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• pp.1535-1543
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• 2007

Recently, there are many researches for P2P network. P2P network technologies are a good solution about making a wide spread distributed computing in the internet environment. The recent algorithms developed by several research groups for the lookup problem present a simple and general interface, a distributed hash table (DHT). In this paper, we also introduce new schemes that enhance the available rate of an object in the MagicSquare network. Replication scheme is to replicate an object with many replicas and save them to several nodes. Fragmentation scheme is to divide an object into several fragments and save them to several nodes. Replicated Fragmentation scheme is to mix replication scheme and fragmentation scheme. We will show result of simulation for our the proposed scheme.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.21 no.4
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• pp.157-169
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• 2021

Establishing an investment evaluation system for public ICT projects is ultimately to increase the success rate of public ICT projects in which government finances are invested and to revitalize the projects, thereby establishing a foundation for national economic growth and enhancing the competitiveness of the global ICT industry. This study tried to empirically verify the effect of public ICT project investment evaluation factors established according to the existing evaluation system on actual project success, and to suggest directions for future investment evaluation factors. Five evaluation factors such as public interest, economic feasibility, technology, policy and budget efficiency were derived through prior research, and the effect of these evaluation criteria on actual project success was verified through questionnaires from experts who directly participated in the actual project. In addition, it was confirmed whether the government's support system had a moderating effect between the investment evaluation factors and the project success of the ICT project. The reliability and validity of measurement tools, structural model analysis, and path analysis were empirically analyzed, and the significance of existing ICT investment evaluation factors was verified.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.15 no.6
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• pp.283-290
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• 2015

As society has evolved to the knowledge and information society, the importance of internal information of the company has increased gradually. Especially in financial institutions which must maintain the trust of customers, the disclosure of inside information is a big problem beyond the a company's business information disclosure level to break down sales-based businesses because it contains personal or financial transaction information. Recently, since massive outflow of internal information are occurring in several enterprises, many companies including financial companies have been working a lot in order to prevent the leakage of customer information. This paper describes the internal information leakage incidents occurred in the finance companies, the PC security vulnerabilities exists despite the main security system and internal information leakage prevention and suggests countermeasures against increasing cyber infringement threats.

• Journal of Internet Computing and Services
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• v.9 no.2
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• pp.51-59
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• 2008

As the innovative IT are being developed and applied in the e-business environment, firms are recognizing the fact that amount of customer information is providing care competitive edge. However, sensitive privacy information are abused and misused, and it is affecting the firms to require appropriate measures to protect privacy information and implement security techniques to safeguard carparate resources. This research analyzes the threat of privacy information exposure in the e-business environment, suggest the IPM-Trusted Privacy Policy Model in order to resolve the related problem, and examines 4 key mechanisms (CAM, SPM, RBAC Controller, OCM) focused on privacy protection. The model is analyzed and designed to enable access management and control by assigning user access rights based on privacy information policy and procedures in the e-business environment. Further, this research suggests practical use areas by applying TPM to CRM in e-business environment.