• The KIPS Transactions:PartC
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• v.12C no.1 s.97
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• pp.129-136
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• 2005

WebDAV extends the web communication protocol HTTP/1.1 to provide a distributed authoring and versioning across the Internet. A property management, the principal ability of WebDAV, has many advantages for managing and utilizing additional information of server resources as well as supports a role of storage. Most WebDAV Application systems currently available are using WebDAV for providing simple storage space, not for the functionality of property management. However, to develop an advanced application such as a collaborative system based on WebDAV, it is very important to design and utilize user-defined WebDAV properties. In this paper, we propose DavSUDP(WebDAV Simple User-defined Property Definition Protocol) that describes XML-based configurations representing WebDAV user-defined properties and their processing steps. DavSUDP enables WebDAV servers to effectively manage user-defined properties in developing WebDAV-based applications. To show this, we extended the Apache mod_dav module to support DavSVDP and developed the OpenSpace in the iPlace collaborative system using the extended Apache web server.

• The Transactions of the Korea Information Processing Society
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• v.5 no.6
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• pp.1441-1456
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• 1998

The concept of a hyperpresmtation, as an extension of a hypermedia, is the presentation in which time-varying multimedia presentations are dynamically linked together and a hyperlink's context can be changed over time at any time during a continuous presentation. Problems caused by integrating the hyperpresentation into an existing multimedia system which handles a sequential presentation only are, how to describe the hyperprcsentation, how to set up a hyperlink on a continuous media, and how to check the consistency of the synchronized presentations. In this paper. a new synchronization description method for the hyperpresentation and a method for setting a hyper link on a continuous media during" presentation are proposed after havin!; SHrvey of existing methods, The proposed method deals with only the DC value in a stream ut a DCT based compressed data for checking a condition of te link. Finally, the method for checking the consistency of mixed presentations before actual play of the hnlerpresentation is described. Proposed methods are implemented on MuX(Multimedia IO Server) where a sample scenario is tested.

• Journal of the Korean Institute of Intelligent Systems
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• v.17 no.1
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• pp.80-85
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• 2007

As home network system begins serving in earnest, the recent fruits of research in home service robot show that the new epoch that human and intelligent robots are living, communicating and interacting together at home, may come true in the near future. In the other hand, it is generally known that the multiagent system, performing distributed process together with other different devices in a home network system, is better than single robot or single home server for adapting themselves to home environment and completing their mission because the characteristic of home environment is 'open'. Therefore, in this paper we suggest the framework model to define agents, which is needed lot the home with a home network system, and the communication protocol architecture between agents. For this, we focus our attention on an agent comprising the set of many agent instances rather than the single intelligent or ability of a robot or home server, and also suggest the way of adaptation for agent systems to their environments and interaction with human in the manner of cooperation and negotiation among agents or agent instances in each agent.

• The KIPS Transactions:PartC
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• v.11C no.5
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• pp.703-710
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• 2004

WebDAV is a protocol to support collaboration among one or more groups in geographically distant locations through the internet. WebDAV extends the web communication protocol HTTP/1.1 to provide a standard infrastructure for .supporting asynchronous collaboration for various contents across the internet. A WebDAV client uses HTTP requests to perform a renewal and update action to the resources in WebDAY servers. So, it is desirable that the client supports the ability of authoring and version management with a good concurrency control and property management. In this paper, to enhance usability, we developed a .NET-based WebDAV client with a user interface similar to the Windows Explorer. The developed WebDAV client supports easy launching of the authoring application and appropriate lock control for the server resources. In addition, through the functionality of process monitoring, it supports automatic update of the server resources when the modification of the resources are completed by the user. The WebDAY client is a .NET-based application written in the C＃ language, running on any platform supporting a .NET framework.

• The Transactions of the Korea Information Processing Society
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• v.7 no.8
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• pp.2505-2513
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• 2000

This paper describes the design and implementation of a CORBA/SNMP gateway. The gateway is used to integrate traditional network management systems using CORBA. The integrated network management system uses World Wide Web (WWW) and CORBA. WWW provides a platform-independent and easy-to-use interface to distributed applications and CORBA is used to integrate different network management models seamlessly. To support the traditional managed objects without modification, we use a translation gateway between two different management models. The integrated network management server consists of a WWW server with enhancement for network management and translation gateways for converting management operations between different management models. This paper describes the design and implementation of a CORBA/SNMP gateway. The CORBA/SNMP gateway provides a syntactic and dynamic translation between CORBA and SNMP management models. The gateway provides a CORBA view to SNMP MIBs and allows the CORBA managers to access SNMP agents via CORBA operations. The CORBA/SNMP gateway also delivers the traps occurred in the SNMP agents to the CORBA managers that want to receive the trap information.

• Journal of the Korea Computer Graphics Society
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• v.21 no.3
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• pp.36-45
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• 2015

It is important subject of research in engineering and natural science field that creating continuing high-definition image from very large volume data. The necessity of software that helps analyze useful information in data has improved by effectively showing visual image information of high resolution data with visualization technique. In this paper, we designed multi-platform visualization system based on client-server to analyze and express earth environment data effectively constructed with observation and prediction. The visualization server comprised of cluster transfers data to clients through parallel/distributed computing, and the client is developed to be operated in various platform and visualize data. In addition, we aim user-friendly program through multi-touch, sensor and have made realistic simulation image with image-based lighting technique.

• Journal of Korea Society of Industrial Information Systems
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• v.17 no.5
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• pp.19-28
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• 2012

Recently a grid and cloud computing collaboration have become a social issue. These collaborative network system, the P2P system based on this system. Distingui shed from the client/server systems, P2P systems in order to exchange information, its purpose and functions are divided according to the morphological Category. In accordance with the purposes and functions of information and data retrieval, remote program control and integration services for the offers. Most P2P systems client/server scalability, and management takes the form, but to overcome the disadvantages in terms of applying the mixed-mode system is increasing. And recently the distributed computing aspects of the service to users in order to provide suitable to accommodate the diverse needs of various types of mobile agent technology is needed. In this paper, as required by the mobile agent access to a remote resource access control and agent for the execution and management capabilities and improve the reliability of the mobile agent system designed to suggest.

• Journal of Internet Computing and Services
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• v.5 no.3
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• pp.25-33
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• 2004

Mobile IP Low Latency Handoffs(l) allow greater support for real-time services on a Mobile IP network by minimizing the period of time when a mobile node is unable to send or receive IP packets due to the delay in the Mobile IP Registration process. However, on Mobile IP network with AAA servers that are capable of performing Authentication, Authorization, and Accounting(AAA) services, every Registration has to be traversed to the home network to achieve new session keys, that are distributed by home AAA server, for a new Mobile IP session. This communication delay is the time taken to re-authentication the mobile node and to traverse between foreign and home network even if the mobile node has been previously authorized to old foreign agent. In order to reduce these extra time overheads, we present a method that performs Low Latency Handoffs without requiring further involvement by home AAA server. The method re-uses the previously assigned session keys. To provide confidentiality and integrity of session keys in the phase of key exchange between agents, it uses a key sharing method by gateway foreign agent that performs a trusted thirty party. The proposed method allows the mobile node to perform Low Latency Handoffs with fast as well as secure operation.

• Journal of Korea Multimedia Society
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• v.9 no.2
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• pp.189-196
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• 2006

This paper proposes a priority based AOI management model as a method to effectively process message traffic for collaboration in virtual environments. Where message traffic reaches the maximum capacity of the message replay server in DVE, some of the events might be delayed to be updated at the remote clients. Because existing AOI models depend only on the occurrence time of events, they have a problem that more important events in the context might be processed later than less serious ones. Close Interactions with other participants are relatively more important than simple events which happen at a distance from the participant. This study classifies the priorities of events according to the degree of interest, and proposes a method to reduce processing delay time of events highly interested by a user. The proposed model offers a way to effectively utilize limited capacity of a server using a priority queue mechanism, which is able to handle different kinds of events. To prevent from starvation of simple events and to give fairness to the proposed algorithm, event occurrence time is also considered as well as degree of interest when processing events.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.7
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• pp.1567-1574
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• 2012

Since a migration method of the mobile agent is a factor that affects the overall performance of the entire distributed system, it is necessary to find efficient migration methods of the mobile agent within the sensor network and to collect and store data related to various components(server, sink and sensor node) of the sensor network, thereby providing consistent naming services. Accordingly, this paper presents design and implementation of MetaTable that is divided into MetaData where information on the sensor data server is stored and SubMetaData where various types of information on sink nodes and data on sensor nodes connected with the sink nodes is stored. Moreover, the paper also presented the implementation of forward migration of an active rule mobile agent applying the naming method based on RMI that used the meta_table and proposed the possibility of constructing efficient sensor network application environment. In this paper, for registration, release and retrieval methods suitable for new sensor network environment, we designed and implemented the naming agent by applying J2EE model based on RMI-IIOP(Internet Inter-ORB Protocol) technique.