• The KIPS Transactions:PartC
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• v.10C no.3
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• pp.355-366
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• 2003

Today's market share of mobile internet service is growing rapidly in internet due to the rapid advances in wireless mobile networks. To guarantee for QoS of Mobile Nodes in wireless mobile networks, we propose the Proxy MRSVP (PMRSVP) which is efficient resource reservation protocol. The PMRSVP using a modified regional registration restrains excessive message generation from existing protocols that propose an alternative plan of existing best effort service in wireless mobile networks. We show that signaling message generation quantities and resource registration costs of the PMRSVP are lower than MRSVP and Hierarchical MRSVP (HMRSVP) because as Mobile Agent (MA) plays a proxy role instead of Corresponding Host (CH). We evaluate resource reservation cost with registration cost of intradomain and interdomain of the proposed method in the paper by comparing to that of the MRSVP and HMRSVP.

• Proceedings of the Korea Contents Association Conference
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• 2006.11a
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• pp.478-482
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• 2006

This paper implemented speech-library and the Web Services that conversion the Web page for the speech recognition. The system is consisted of Web services consumer and Web services providers. The Web services consumer has libraries that Speech-library and proxy-library. The Speech -library has functions as follows from the user's speech extracted speech-data and searching the URL in link-table that is mapped with user's speech. The proxy-library calls two web services and is received the returning result. The Web services provider consisted of Parsing Web Services and Speech-Recognition Web Services. Parsing Web Services adds ActiveX control and reconstructs web page using the speech recognition. The speech recognizer is the web service providers that implemented in the previous study. As the result of experiment, we show that reconstructs web page and creates link-Table. Also searching the URL in link-table that is mapped with user's speech. Also confirmed returning the web page to user by searching URL in link-table that is mapped with the result of speech recognition web services.

• Journal of KIISE:Information Networking
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• v.28 no.3
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• pp.369-376
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• 2001

The firewall systems can be installed between the intemal network and the extemal network. The firewall systems has the least privilege, so its does not provide transparency to user. This problem of transparency can be solved by using the proxy. In this thesis, I have designed and verified the FTP-PSM(FTP-Proxy Security Mode]) which provides transparency for the firewall systems and has a strong security function. FTP-PSM doesn't finish its work after implementing a command. Instead, its does several security functions such as user authentication, MAC(MandatOlY Access Controll, DAC(Discretionary Access Controll and authentication of user group. Those data must not be lost under any circumstances in order to implement the above security functions. So, the security against such problems as falling into deadlock or unlimited loop during the implementation must be verified. Therefore, FTP-PSM suggested in thesis was verified its security through PHPlace Invariant) based on CPNlCo]oured Petri Net).

• The Journal of Korean Association of Computer Education
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• v.13 no.1
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• pp.53-64
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• 2010

In this paper, we tried to enable a mobile device as a resource to access to mobile grid networks. By advanced Internet techniques, the use of mobile devices has been rapidly increased. Some researches in mobile grid computing tried to combine grid computing with mobile devices. However, according to intrinsic properties of mobile environments, mobile devices have many considerations, such as mobility management, disconnected operation, device heterogeneity, service discovery, resource sharing, security, and so on. To solve these problems, there are two trends for mobile grid computing: a proxy-based mobile grid architecture and an agent-based mobile grid architecture. We focus on a proxy-based mobile grid architecture with IP-paging, which can easily manage idle mobile devices and grid resource status information. Also, we use SIP(Session Initiation Protocol)to support mobility management, mobile grid services. We manage variation of mobile device state and power by paging cache. Finally, using the candidate set and the reservation set of resources, we perform task migration. The performance evaluation by simulation, shows improvement of efficiency and stability during execution.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.5C
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• pp.737-749
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• 2004

Kerberos authenticates clients using symmetric-key cryptography, and supposed to Oust other systems of the realm in distributed network environment. But, authentication and authorization are essential elements for the security. In this paper, we design an efficient and secure authentication/authorization mechanism by introducing the public/private-key and installing the proxy privilege server to Kerberos. In the proposed mechanism, to make a system more secure, the value of the session key is changed everytime using MAC(message authentication code) algorithm with the long-term key for user-authentication and a random number exchanged through the public key. Also, we reduce the number of keys by simplifying authentication steps. Proxy privilege server certifies privilege request of client and issues a privilege attribute certificate. Application server executes privilege request of client which is included a privilege attribute certificate. Also, a privilege attribute certificate is used in delegation. We design an efficient and secure authentication/authorization algorithm with Kerberos.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.14 no.1
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• pp.219-236
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• 2014

In this paper, we propose a novel Proxy Mobile IPv6 network bandwidth-efficient handoff scheme. MN are classified into slow and fast one. At first MN should be registered in the microcell for bandwidth efficient handoff scheme. microcell is overlapped to handle the overflow session request which is nested. Overflow session request in macrocell requests to go back from the boundary of the microcell to new microcell. If idle session traffic is in a cell, it is requested by the target microcell. Analysis model was developed, an existing session of the session blocking probability and forcing termination probability of the session request have improved considerably. If the total traffic load of the system is not very large, the proposed scheme has the best bandwidth efficiency and provides better quality of service (QoS) to MN without costs of a lot of processing on the system.

• The KIPS Transactions:PartA
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• v.8A no.3
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• pp.235-244
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• 2001

Development of network and computer technology results in many studies to use physically distributed computers as a single resource. Generally, these studies have focused on developing environments based on message passing. These environments are mainly used to solve problems for scientific computation and process in parallel suing inside parallelism of the given problems. Therefore, these environments provide high parallelism generally, while it is difficult to program and use as well as it is required to have user accounts in the distributed computers. If a given problem is divided into completely independent subproblems, more efficient environment can be provided. We can find these problems in bio-informatics, 3D animatin, graphics, and etc., so the development of new environment for these problems can be considered to be very important. Therefore, we suggest new environment called InterCom based on a proxy computing, which can solve these problems efficiently, and explain the implementation of this environment. This environment consists of agent, server, and client. Merits of this environment are easy programing, no need of user accounts in the distributed computers, and easiness by compiling distributed code automatically.

• Journal of the Korean Institute of Intelligent Systems
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• v.19 no.1
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• pp.40-47
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• 2009

Recently, dynamic proxy caching has been proposed on the distributed environment so that media objects by user's requests can be served directly from the proxy without contacting the server. However, it makes caching challenging due to multimedia large sizes, low latency and continuous streaming demands of media objects. To solve the problems caused by streaming demands of media objects, this paper has been proposed the grouping scheme with fuzzy filtering based on partition and mapping. For partition and mapping, this paper divides media block segments into fixed partition reference block(R$_f$P) and variable partition reference block(R$_v$P). For semantic relationship, it makes fuzzy relationship to performs according to the fixed partition temporal synchronization(T$_f$) and variable partition temporal synchronization(T$_v$). Simulation results show that the proposed scheme makes streaming service efficiently with a high average request response time rate and cache hit rate and with a low delayed startup ratio compared with other schemes.

• The KIPS Transactions:PartC
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• v.9C no.2
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• pp.181-188
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• 2002

There are recently a lot of inconvenience because every client should be set to the proxy server on the browser in order to control the access by means of the client authentication in the proxy server. The client authentication technology using the transparency cache in this paper will be transparently used for every user in the internet which option of the authentication function is simply set in the cache server. In addition, the administrator will get the benefit since he can control the traffic of each client and strengthen the security. And also, this system is expected to use in the eCRM deeply rotated to the tendency of the client in the field of the e-commerce like shopping mall in the internet since the administrator can monitor the pattern of the client using the internet. This technique can be applied to the company affiliated research center, the EC website, and the military where it is essential for the tight security even though there are no additional security devices.

• Journal of Internet Computing and Services
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• v.10 no.2
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• pp.15-28
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• 2009

This paper proposes HWbF(Hit and WLC based Firewall) design which consists of an PFS(Packet Filter Station) and APS(Application Proxy Station). PFS is designed to reduce bottleneck and to prevent the transmission delay of them by distributing packets with PLB(Packet Load Balancing) module, and APS is designed to manage a proxy cash server by using PCSLB(Proxy Cash Server Load Balancing) module and to detect a DoS attack with packet traffic quantity. Therefore, the proposed HWbF in this paper prevents packet transmission delay that was a drawback in an existing Firewall, diminishes bottleneck, and then increases the processing speed of the packet. Also, as HWbF reduce the 50% and 25% of the respective DoS attack error detection rate(TCP) about average value and the fixed critical value to 38% and 17%. with the proposed expression by manipulating the critical value according to the packet traffic quantity, it not only improve the detection of DoS attack traffic but also diminishes the overload of a proxy cash server.