• Journal of Ubiquitous Convergence Technology
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• v.2 no.1
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• pp.1-11
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• 2008

An effective solution to the problems caused by the explosive growth of World Wide Web is a web caching that employing an additional server, called proxy cache, between the clients and main server for caching the popular web objects near the clients. However, a single proxy cache can easily become the bottleneck. Deploying groups of cooperative caches provides scalability and robustness by eliminating the limitations caused by a single proxy cache. Two common architectures to implement the cooperative caching are hierarchical and distributed caching systems. Unfortunately, both architectures suffer from performance limitations. We propose an efficient hybrid caching architecture eliminating these limitations by using both the hierarchical and same level caches. Our performance evaluation with our investigated simulator shows that the proposed architecture offers the best of both existing architectures in terms of cache hit rate, the number of query messages from clients, and response time.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.10a
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• pp.1093-1094
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• 2015

Due to the use of the responsive web, representation of the web in a variety of devices is to be implemented in a more unified look. In this paper, we suggest how to implement fluid layout. We explain how to configure the fluid layout with the latest technology, flexible box and confirmed its advantages and disadvantages. In addition, we propose ways to solve the problem occurred by applying the flexible box.

• Proceedings of the Korea Institutes of Information Security and Cryptology Conference
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• 2003.12a
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• pp.686-690
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• 2003

웹 응용프로그램에 대한 위협이 점차 확산되면서 오늘날 많은 Web Application Firewall들이 등장하고 있다. 하지만, 대부분의 기관에서 웹 서버 자체의 변조는 기관의 미지 실추를 제외하면 업무상 큰 문제를 유발하지 않는다. 웹 서버에 대한 보안을 고려하는 이유는 웹 서버가 침입을 당할 경우 DB 서버의 내용에 손상이 가해질 수 있기 때문이다. 본 고에서는 Web Application Firewall과 연동하여 허용되는 SQL 질의패턴을 자동으로 생성하여 불법적인 SQL 질의를 차단하는 DB Application Firewall을 제안한다. 이를 통해 웹 응용프로그램의 취약점으로 인해 SQL 질의가 변조되더라도 DB 서버에 해당SQL질의가 전달되는 것을 차단할 수 있다.

• Proceedings of the KSRS Conference
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• 2003.11a
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• pp.396-398
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• 2003

Recently as users' requests for geographic information systems are being more various, several new functions are being added to existing geographic information systems. One of them is linkage of spatial geographic data and video / image data to offer more realistic information of geographic objects to users. Geographic information systems implementing this function are called video geographic information system. In this paper, we design and implement a video geographic information system for providing map data, video data and link information of them to web applications. We 1) design system architecture of a video geographic information system, 2) analyze some processes to construct link information of map data and video data, 3) design database schema to store map data, video data, and link information, and 4) design some XML/GML schema used to query and retrieve these data for web applications.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.12 no.2
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• pp.69-76
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• 2012

This paper proposes a novel way of personalized web search through re-ranking the search results with user profiles of concept-network structure. Basically, personalized search systems need to be based on user profiles that contain users' search patterns, and they actively use the user profiles in order to expand initial queries or to re-rank the search results. The proposed method is a sort of a re-ranking personalized search method integrated with query expansion facility. The method identifies some documents which occur commonly among a set of different search results from the expanded queries, and re-ranks the search results by the degree of co-occurring. We show that the proposed method outperforms the conventional ones by performing the empirical web search with a number of actual users who have diverse information needs and query intents.

• Journal of KIISE:Databases
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• v.27 no.2
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• pp.227-237
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• 2000

A Web database System is a large-scaled multimedia application system that has multimedia processing facilities and cooperates with relational/Object-Oriented DBMS. Conventional hypertext modeling methods and DB gateway have limitations for Web database because of their restricted versatile presentation abilities and inefficient concurrency control caused by bottleneck in cooperation processing. Thus, we suggest a Dynamic Navigation Model & Virtual Graph Structure. The Dynamic Navigation Model supports implicit query processing and dynamic creation of navigation spaces, and introduce node-link creation rule considering navigation styles. We propose a mapping methodology between the suggested hypertext model and the relational data model, and suggest a dynamic allocation scheduling technique for query processing server based on weighted value. We show that the proposed technique enhances the retrieval performance of Web database systems in processing complex queries concurrently.

• The Journal of Korean Association of Computer Education
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• v.6 no.2
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• pp.137-146
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• 2003

The Web programming techniques like CGI and server-sided script languages such as ASP, PHP and JSP have been used for developing on-line Web-based learning systems on SQL. But, the systems developed by using those techniques are dependent on the platforms on which the target DBMS's are located. Therefore, they can be hardly reused and maintained. In addition, it is not easy for them to provide a learner with the feedback information on processing his/her query and to give a teacher an opportunity of monitoring and guiding learner's learning process. In this paper, we propose an SQL learning system on the Web by using Java Applet and JDBC, which is independent on the target DBMS's. Moreover, it gives feedback information on learner's queries so that a teacher can monitor the learning process and teach them efficiently.

• The Journal of the Korea Contents Association
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• v.13 no.4
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• pp.8-16
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• 2013

Active studies are under way on telemedicine and medical support based on mobile devices in order to vitalize U-Healthcare. Especially when the medical law is revised to allow a remote prescription system, studies on a mobile prescription system will rapidly increase. And yet since mobile apps have less compatibility due to the nature of mobile platform, there is a restriction that they have to be redeveloped to be compatible with the platform. To compensate this problem, this study designs a mobile web prescription interface by using HLTML5, the standard language of mobile web development and jQuery Mobile, a JavaScript Library. It also adds a feature of converting to a form of standard protocol HL7-based messages to share data with existing hospital information system. This interface makes it possible to be interlocked with the existing hospital information system through the transmission of the HL7 messages. The advantage of the proposed system is that it can be used in various environments since it is independent of mobile platforms and compatible with general computers.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.18 no.5
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• pp.135-148
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• 2008

The expansion of the internet has made web applications become a part of everyday lift. As a result the number of incidents which exploit web application vulnerabilities are increasing. A large percentage of these incidents are SQL Injection attacks which are a serious security threat to databases with potentially sensitive information. Therefore, much research has been done to detect and prevent these attacks and it resulted in a decline of SQL Injection attacks. However, there are still methods to bypass them and these methods are too complex to implement in real web applications. This paper proposes a simple and effective SQL Query attribute value removal method which uses Static and Dynamic Analysis and evaluates the efficiency through various experiments.

• Proceedings of the Korean Information Science Society Conference
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• 2007.10a
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• pp.21-22
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• 2007