• The Transactions of the Korea Information Processing Society
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• v.4 no.5
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• pp.1319-1326
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• 1997

The Internet is a very convenient neteork, but not always a So.many orvanizations often require administrative security policies when they want to connect with ther organizations thtough a pubic network.A firewall is one way of protecting an internal network from the untrusted extemal network with a mechanism for selectively permiting or blocking traffic between the intermal network and the extermal network. The firewall also provides some limited Intemet access such as Ftp.Telet, etc.Usually , through a firewall system, X applications running on the extermal network may not access an X display on the intermal network.Thus, X applications run-ning on the extemal network are not supported through the usual firewall.In this paper, we propose a method of suppoting X application programs effedtively dffectvely through the firewall, overcoming this restriction.

• Journal of Korean Society of Rural Planning
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• v.12 no.4 s.33
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• pp.53-61
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• 2006

Rural amenity resources consist of natural, cultural and social resources. Some of resources have been surveyed in other institutes and organizations and information system about these resources has been constructed. Integrating with information of existing system or database is helpful to produce useful rural amenity resources information to users. This integration of distributed information is based on semantic integration. In this paper, we used ontology for semantic integration and introduced the method of external information integration using ontology. We designed ontology table to represent ontology in database and integrated distributed information using ontology. To examine the improvement of information service efficiency and the applicability, rural amenity resources information and tourist attraction information database were constructed and integrated. Also, the information service efficiency with information integration was evaluated using recall ratio and compared to the information service efficiency without information integration.

• 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).