• Proceedings of the Korean Information Science Society Conference
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• 2003.04a
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• pp.773-775
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• 2003

이동성을 갖는 장치들의 위치 정보를 관리하기 위하여 이동체 데이터베이스에 관한 연구가 필요하게 되었다. 이동체 색인의 검색에서 영역 질의와 궤적 질의는 공간 근접성과 궤적 연결성과 같이 상반된 특징으로 인하여 함께 고려되지 않았다. 이동체 색인에서 영역 질의의 성능개선을 위해서는 노드간의 심한 중복과 사장 공간(Dead space)을 줄여야 하고, 궤적 질의의 성능 개선을 위해서는 이동체의 궤적 보전이 이루어져야 한다. 이와 같은 요구 조건을 만족하기 위해, 이 논문에서는 R-tree를 기반의 색인 구조에서 새로운 분할 정책을 제안한다. 제시하는 색인 구조에서 단말 노드의 엔트리는 궤적이며, 비단말 노드의 엔트리는 자식 노드이다. 단말 노드 분할 정책에서 동일 궤적을 그룹화해서 분할 하는 공간 축 분할 정책과 공간 활용도를 높이는 시간 축 분할 정책을 제안한다. 시간 축 분할 후 사장영역이 클 경우에는 다중 분할을 수행하여 사장 공간을 줄이고 노드간의 중복을 최소화한다. 비 단말 노드 분할 정책에서는 같은 궤적을 저장하는 노드들을 연결 노드(Connected Node)라고 정의하고, 엔트리의 궤적 연결성을 기준으로 분할한다.

• Journal of Internet Computing and Services
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• v.16 no.1
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• pp.75-82
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• 2015

Major corporations and portals have implemented a link server that connects Content Management Systems (CMS) to the physical address of content in a database (DB) to support efficient content use in web-based environments. In particular, a link server automatically connects the physical address of content in a DB to the content URL shown through a web browser screen, and re-connects the URL and the physical address when either is modified. In recent years, the number of users of digital content over the web has increased significantly because of the advent of the Big Data environment, which has also increased the number of link validity checks that should be performed in a CMS and a link server. If the link validity check is performed through an existing URL-based sequential method instead of petabyte or even etabyte environments, the identification rate of dead links decreases because of the degradation of validity check performance; moreover, frequent link checks add a large amount of workload to the DB. Hence, this study is aimed at providing a link server that can recognize URL link deletion or addition through analysis on the B-tree-based Information Identifier count per interval based on a large amount of URLs in order to resolve the existing problems. Through this study, the dead link check that is faster and adds lower loads than the existing method can be performed.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2014.05a
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• pp.254-256
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• 2014

In this paper, using the Android App to remote database monitoring system is proposed. Existing remote database monitoring scheme CS(Client / Server) based. Conventional CS based systems are space constraints and a plurality of administrator to access the database at that degrade performance disadvantages. The advantage of the proposed system first, because the web -based interface allows the application program, and also the ease of maintenance, through a web browser, if you have Internet access anytime, anywhere environment without restrictions of time and space monitoring. Second, the proposed system because the App -based technology due to an increase in connection session and query execution does not affect the performance of your database. Third, if there is a problem with the remote database through which social networks immediately notify the administrator of the smartphone in real time so that the administrator can identify the problem.

• Journal of the Korea Society of Computer and Information
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• v.11 no.6 s.44
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• pp.289-298
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• 2006

Many researches are going on with regard to issues and problems related to mobile database systems, which are caused by the weak connectivity of wireless networks, the mobility and the portability of mobile clients. Mobile computing satisfies user's demands for convenience and performance to use information at any time and in any place, but it has many problems to be solved in the aspect of data management. The purpose of our study is to design Mobile Continuous Query Processing System(MCQPS) to solve problems related to database hoarding, the maintenance of shared data consistency and the optimization of logging, which are caused by the weak connectivity and disconnection of wireless networks inherent in mobile database systems under mobile client server environments. We proved the superiority of the proposed MCQPS by comparing its performance to the C I S(Client-Intercept-Slaver) model. In Addition, we experiment on proposed index structure and methodology in various methods.

• Journal of Internet Computing and Services
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• v.10 no.4
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• pp.1-11
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• 2009

Recently there has arisen concern in both the database community and the graphics society about data retrieval from large motion databases because the high dimensionality of motion data implies high costs. In this circumstance, finding an effective distance measure and an efficient query processing method for such data is a challenging problem. This paper presents an elaborate motion query processing system, SMoFinder (Similar Motion Finder), which incorporates a novel kinematic distance measure and an efficient indexing strategy via adaptive frame segmentation. To this end, we regard human motions as multi-linkage kinematics and propose the weighted Minkowski distance metric. For efficient indexing, we devise a new adaptive segmentation method that chooses representative frames among similar frames and stores chosen frames instead of all frames. For efficient search, we propose a new search method that processes k-nearest neighbors queries over only representative frames. Our experimental results show that the size of motion databases is reduced greatly (${\times}1/25$) but the search capability of SMoFinder is equal to or superior to that of other systems.

• Journal of the Korea Society of Computer and Information
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• v.17 no.2
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• pp.13-21
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• 2012

Mobile data caching is usually used as an effective way to improve the speed of local transaction processing and reduce server load. In mobile database environment, due to its characters - low bandwidth, excessive latency and intermittent network, caching is especially crucial. A lot of mobile data caching strategies have been proposed to handle these problems over the last few years. However, with smart phone widely application these approaches cannot support vast data requirements efficiently. In this paper, to make full use of cache data, lower wireless transmission quantity and raise transaction success rate, we design a new mobile data caching synchronization strategy based on in-demand and replacement priority. We experimentally verify that our techniques significantly reduce quantity of wireless transmission and improve transaction success rate, especially when mobile client request a large amount of data.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.4B
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• pp.285-290
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• 2006

Various aspects should be taken into account while developing a distributed architecture based on a multi-tier model or an enterprise architecture. Among those, the separation of role between page designer and page developer, defining entity which is used for database connection and transaction processing are very much important. In this paper, we presented DONSL(Data Server of Non SQL query) architecture to solve these problems applying web tier object modelling. This architecture solves the above problems by simplifying tiers coupling and removing DAO(Data Access Object) and entity from programming logic. We concentrate upon these three parts. One is about how to develop the DAO not concerning the entity modification, another is automatic transaction processing technique including SQL generation and the other is how to use the AET/MET(Automated/Manual Execute d Transaction) effectively.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.22 no.9
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• pp.1867-1879
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• 1997

DREAM-S is a distributed main-memory database system for the real-time processing of shared operational datra in ATM switching systems. DREAM-S has a client-server architecture in which only the server has the diskstorage, and provides the T-Tree index structure for efficient accesses to the data. We propose a recovery technique for the T-Tree index structre in DREAM-S. Although main-memory database system offer efficient access performance, the database int he main-memory may be broken when system failure such as database transaction failure or power failure occurs. Therfore, a recovery technique that recovers the database (including index structures) is essential for fault tolerant ATM switching systems. Proposed recovery technique relieves the bottleneck of the server processors disk operations by maintaining the T-Tree index structure only in the main-memory. In addition, fast recovery is guaranteed even in large number of client systems since the T-Tree index structure(s) in each system can be recovered cncurrently.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.8 no.5
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• pp.394-399
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• 2015

This paper is a study related to connecting to medical device in IoT environment for e-Health Implementation. The implementation environment of this paper consists of sensing device node, gateway and its server. The information from medical devices on sensor node is transferred to gateway. The gateway transfers the information from their devices into the server and the server saves their transferred information. The medical information from medical devices is ready to use in making medical decision which is saved in database. In this paper, we connected the gateway to the commercial sensor node for implementing gateway functions. We studied and implemented how their network entities communicate each other.

• Proceedings of the Korean Information Science Society Conference
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• 2005.07b
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• pp.67-69
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• 2005

본 논문에서는 기 구축된 전자 카탈로그를 의미적 연결 관계에 기초한 확장된 전자 카탈로그로 변환하는 방법을 제안한다. 이를 통해 구축된 확장된 전자 카탈로그에서 의미적 태깅에 의한 확장된 어휘 인덱스 구축 방안과, 이를 이용한 검색 성능 향상 기법을 제안한다. 기존의 전자 카탈로그는 상품 정보가 분류별로 생성된 테이블에 저장되고 저장된 테이블로부터 생성된 키워드 인덱스로부터 검색이 이루어 졌다. 이러한 검색은 상품이 가지는 정보를 데이터베이스에 구축된 테이블에만 한정하게 되어 전자 카탈로그에 포함된 상품이나 분류간의 의미적 연결 관계들을 충분히 이용하지 못하였다 전자 카탈로그에 내재된 의미적 요소를 충분히 활용하기 위해서는 전자 카탈로그를 의미적 연결 관계에 기초한 모델로 구성할 필요가 있다. 본 논문에서는 의미적 모델 기반 전자 카탈로그 시스템으로의 전환 과정을 XML형태의 명세를 이용해 반자동적으로 전환할 수 있는 툴을 구현하며, 단순 키워드 어휘 인덱스 구축이 아닌, 어휘 인덱스의 의미적 확장을 제안하고, 이를 위한 태그 요소로써 어휘에 대한 형태소 분석 결과, 수치 환산 및 확장 요소, 속성간의 도메인 정보 등을 제시하였다. 이를 기반으로 최적의 검색 결과를 얻어 내도록 하는 인접도 평가 함수에 적용하는 방법을 제시한다.