• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.1831-1832
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• 2007

WWW(World Wide Web)의 개발 이래 내 컴퓨터 안에만 존재하는 워드와 한글 등의 문서들은 네트워크를 타고 지구 어딘가에 있는 누군가의 모니터에 디스플레이되고 있다. 그러나 컴퓨터 기술은 이와 같은 단순한 HTML파일을 보여주기보다 방명록이나 동영상처럼 동적으로, 실시간으로 정보를 보여주는 수준으로 진화해야 했다. 이러한 기술을 처음으로 가능하게 한 것이 CGI 기술이다. 초기의 CGI 기술은 성능상의 문제로 개발과 발전을 거듭해 현재의 FastCGI나 mod_perl과 같은 기술이 제안되었다. 그러나 FastCGI나 mod_perl도 아직은 동적 정보를 제공하는 완벽한 기술은 아니며 각각 장단점을 지니고 있다. 본 논문에서는 각 기술의 장단점을 살펴보고 이들의 장점을 통합한 개선된 CGI기술을 제안한다.

• 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.

• Proceedings of the Korean Information Science Society Conference
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• 2005.07a
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• pp.304-306
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• 2005

CGI 프로그래밍 기법이후에 동적 웹 페이지 기술은 CGI 프로그래밍 기법을 개선하기 위해 활발히 연구되었고, 그 결과 Fast-CGI, 서버 사이드 스크립트 그리고 확장 서버 사이드 스크립트 기법이 제안되었다. 본 논문에서는 이러한 동적 웹 페이지 기술을 고찰함과 동시에 벤치마크 테스트를 통해 확장된 서버 사이드 스크립트 기법과 서버 사이드 스크립트 기법의 성능을 비교분석하였다. 벤치마크 테스트 결과에 의하면 확장 서버 사이드 스크립트 기법이 성능과 프로그램 개발 및 유지보수 비용을 함께 고려할 때 2-계층구조와 3-계층구조에서 우수하다는 것을 알 수 있었다. 특히, 대부분의 웹 시스템이 데이터베이스에 의존하는 전형적인 3-계층구조를 따르고 있기 때문에 웹 환경에서 확장 서버 사이드 스크립트 기법은 다른 기법에 비해 우수한 효율성을 나타내리라 기대된다.

• Journal of the Korean Society of Radiology
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• v.11 no.5
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• pp.303-312
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• 2017

The central goal of Gamma Knife radiosurgery(GKRS) is to maximize the conformity of the prescription isodose surface, and to minimize the radiation effect of the normal tissue surrounding the target volume. There are the various kinds of indices related with the quality of treatment plans such as conformity index, coverage, selectivity, beam-on time, gradient index(GI), and conformity/gradient index(CGI). As the best treatment plan evaluation tool, we must check by all means conformity index, GI, and CGI among them. Specially, GI and CGI related with complication of healthy normal tissue is more indispensible than conformity index. Then author calculated and statistically analysed CGI, the newly defined conformity/gradient index as well as GI being applied widely using the treatment planning system Leksell GammaPlan(LGP) and the verification method Variable Ellipsoid Modeling Technique(VEMT). In the study 10 patients with intracranial lesion treated by GKRS were included. Author computed the indices from LGP and VEMT requiring only four parameters: the prescribed isodose volume, the volume with dose > 30%, the target volume, and the volume of half the prescription isodose. All data were analyzed by paired t-test, which is statistical method used to compare two different measurement techniques. No statistical significance in GI at 10 cases was observed between LGP and VEMT. Differences in GI ranged from -0.14 to 0.01. The newly defined gradient index calculated by two methods LGP and VEMT was not statistically significant either. Author did not find out the statistical difference for the prescribed isodose volume between LGP and VEMT. CGI as the evaluation index for determining the best treatment plan is not significant statistically also. Differences in CGI ranged from -4 to 3. Similarly newly defined Conformity/Gradient index for GKRS was also estimated as the metric for the evaluation of the treatment plans through statistical analysis. Statistical analyses demonstrated that VEMT was in excellent agreement with LGP when considering GI, new gradient index, CGI, and new CGI for evaluating the best plans of GKRS. Due to the application of the fast and easy evaluation tool through LGP and VEMT author hopes CGI and newly defined CGI as well as gradient indices will be widely used.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.5 no.3
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• pp.493-501
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• 2001

As a web technology is generalized, the IT environment has been changed into an e-business system. An e business system requires web interface technology that can be integrated in a database and be applied to a server-side programming. Traditionally, a CGI technology has been used a web interface. But the CGI technology has many difficulties in connection and delay in processing. So, it is necessary to introduce a new methods as ISAPI Extension and JDBC. These methods provide advantages as reduce of memory and fast process. This paper proposes a comparing study on the JDBC-ODBC Bridge and the ISAPI Extension method. It will suggest more efficient technology with these methods for a web interface development.

• Journal of the Korean Data and Information Science Society
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• v.10 no.2
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• pp.501-510
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• 1999

We have seen a rapid development of multimedia intustry as computer evolves and the internet has changed our way of life dramatically in these days. There we several attempts to teach elementary statistics on the web but most of them are based on commercial products. The need for statistical data analysis and decision making based on those analysis is growing. In this article we try to show one way of reaching that goal by using a server side scripting language PHP3 toghether with extra graphical module and statistical distribution module on the web. We showed some elementary exploratory graphical data analysis and statistical inferences. There are plenty of room of improvements to make it a full blown statistical analysis tool on the web in the new future. All the programs and databases used in our article we public programs. The main engine PHP3 is included as an apache web server module so it is very light and fast. It will be much better when the PHP4(ZEND) will be officially out in terms of processing speed.