• Journal of KIISE:Computing Practices and Letters
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• v.6 no.5
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• pp.496-504
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• 2000

The Web gateway is key technology for inter-operating WWW and databases. The previous KRISTAL-II information retrieval system, developed by KORDIC(Korea Research & Development Information Center), used a simple CGI structure web gateway. While the simple CGI structure web gateway is easy to implement, it is not suitable for processing a large number of on-line retrival requests. When considering the growth of the Internet and WWW, it is very important to develop a web gateway efficiently supporting a large number of concurrent users. In this paper, we propose a 3-tier client-server structure web gateway for the KRISTAL-II information system. We also evaluate the performance of the proposed web gateway through experiments.

• The KIPS Transactions:PartC
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• v.12C no.1 s.97
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• pp.147-156
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• 2005

CGI is a standard interface rule between web server and gateway devised for the gateway's standard output to replace a static web document in UNIX environment. So, it is common to use standard I/O statements provided by the programming language for the CGI gateway. But the standard I/O mechanism is one of buffer strategies that are designed transparently to operating system and optimized for generic cases. This means that it nay be useful to apply another optimization to the standard I/O environment in CGI gateway. In this paper, we introduced standard output method and file output method as the two output optimization areas for CGI gateways written in C language in the UNIX/LINUX systems, and applied the proposed methods of each area to Debian LINUX, IBM AIX, SUN Solaris, Digital UNIX respectively. Then we analyzed the effect of them focused on execution time. The results were different from operating system to operating system. Compared to normal situation, the best case of standard output area showed about $10{\%}$ improvement and the worst case showed $60{\%}$ degradation in file output area where some performance improvements were expected.

• Journal of KIISE:Computing Practices and Letters
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• v.10 no.1
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• pp.66-74
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• 2004

To get changing data or retrieved information in a web service environment, we need the CGI method in which we designate an executable file and receive the output of the executable file as a document. But the original CGI method has some performance pitfalls caused by the native condition that a process for the requested executable file should be created every time it is requested. Several approaches that make the process as a daemon wholly or partly have been made to solve those problems and they have exclusive strength and weakness. So, many developers are confused when they have to choose which of the CGI methods. We proposed an efficient CGI gateway design called SendFD that the main part of CGI gateway was separated as a daemon and taken over the communication channel by the other small part forked whenever it was requested. Then we testified the efficiency of SendFD styled CGI gateway in real web service environment and it showed about 3% performance improvement compared to the conventional socket pipe method.

• The Journal of the Korea Contents Association
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• v.10 no.8
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• pp.73-83
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• 2010

This paper investigates protocol architecture of a Web-ZigBee gateway for interconnecting TCP/IP-based networks and ZigBee/IEEE802.15.4-based wireless sensor networks. The Web-ZigBee gateway delivers data between the TCP/IP network and the ZigBee network. Since those two networks have different communication protocols, a protocol translation mechanism is needed. Herein, we propose a method to deliver query messages from the Internet to the sensor network and receive data from sensors. The protocol translation is performed in the translation layer that is placed above the two application layers, i.e., the Internet application layer and ZigBee application layer. Among various interfaces, we use CGI programming to take care of translation functions efficiently. The CGI manages query information from a client on the Internet and data from the ZigBee sensor network. Whereas the TCP/IP enabled sensor network overlays two heterogeneous communication protocols, overlaying layers increase the complexity and cost of implementing the sensor network. On the contrary, the sensors in our gateway-based system are not only light (because each communication protocol works independently without overlaying), but also efficient because the translation layer mostly alleviates header overloading.

• Journal of KIISE:Computing Practices and Letters
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• v.5 no.1
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• pp.1-13
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• 1999

웹의 등장은 인터넷 인구의 엄청난 성장을 가져왔다. 이와 더불어 최근에는 가상 금융 및 전자 상거래 시장등을 지원하는 웹 상의 데이터베이스 관련 상품들이 속속 등장하고 있다. 이에 기존의 데이터베이스 시스템과 클라이언트-서버 방식으로 동작하던 응용 프로그램들은 웹 환경에 적합한 상호 연동방식을 요구한다. 본 논문에서는 관계형 DBMS인 SRP를 웹상에서 동작시키기 위한 통로인 SWeS를 제시한다. SWes는 CGI를 이용한 응용서버 방식으로 구현하였으며, 동적 서버 교체와 페이지 단위의 결과 전송 기법등을 사용해 가용성 및 동시성,확장성을 높이는 구조를 갖는다.