• Proceedings of the Korean Information Science Society Conference
• /
• 2003.10b
• /
• pp.58-60
• /
• 2003

기존의 웹 문서나 컨텐츠의 한계를 극복하기 위해 메타데이터에 대한 연구가 활발히 이루어진 가운데 그 산물로 등장한 XML은 현재 다양한 분야에서 그 활용에 관한 연구가 활발히 진행되고 있다. 그리고 그 중에서 XML문서 자체를 저장 및 검색하는 부분에 대한 연구도 많은 성과가 있었다. XML의 대표적인 특징은 기존의 다른 컨텐츠와는 달리 문서의 구조를 기술할 수 있다는 것이며 이런 구조적 정보는 활용 방법에 따라 XML문서의 다양한 처리에 있어 성능을 향상시키는 핵심적인 요소가 될 수 있다. 이에 본 논문에서는 기존의 비트맵 인덱스(Bitmap Index)를 확장하여 역파일 색인 방법과 결합시켜 P_INDEX를 제안하고, P_INDEX를 활용한 다양한 경로 중심의 검색 방법을 제시한다.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2004.11a
• /
• pp.39-42
• /
• 2004

공간 질의 및 색인에 관한 기존 연구는 주로 실외 환경에 기반을 두고 있다. 실내 환경은 실외 환경과는 달리 질의 특성 및 환경적 요소가 다르다. 실내 환경 질의의 대표적인 특징은 객체의 현재 위치를 파악하고 즉시 응답해야하며, 질의 범위도 지역적으로 제한되어 있는 점이다. 본 논문에서는 기존 연구가 가진 문제점을 해결하기 위해 메인 메모리 기반의 DBMS를 사용하며, 실내 환경에서 객체의 위치 탐색시 효율적으로 적응할 수 있는 비트맵 인덱스 기법을 제안한다.

• Journal of Information Technology Applications and Management
• /
• v.10 no.2
• /
• pp.19-31
• /
• 2003

We propose an indexing technique and an index selection algorithm for optimal OLAP query processing in object database systems, Although there are many research results on the relational database systems for OLAP Query processing, few researches have been done on the object database systems. Since OLAP queries represent complex business logic on a huge data ware-house, object database systems supporting the OLAP queries should have higher performance. Proposed bitmap index structure is an extension of conventional bitmap indexes for adapting object databases and provides higher performance with lower space overhead. We also propose a linear time solution of the index selection problem that will be used in the OLAP query optimization process.

• Journal of KIISE:Databases
• /
• v.35 no.2
• /
• pp.143-154
• /
• 2008

RFID events are large volume of stream data which come out continuously. Many studies have been done to detect a business event in RFID stream. However, the existing methods have many problems which increase unnecessary operations when business events do not satisfy minimum conditions. In this paper, to remove unnecessary operations, we define the minimum condition of business events and propose an efficient method that detects business events only when the minimum condition is satisfied. To check the minimum condition of business events, we register business queries in a query index. We detect business events using the query index and bitmap. It is shown through various experiment that the proposed method outperforms the existing methods.

• Journal of KIISE:Databases
• /
• v.27 no.1
• /
• pp.13-21
• /
• 2000

Online analytical processing (OLAP) systems are introduced to support decision support systems. Many researches focussed on efficient processing of aggregate functions that usually occur in OLAP queries. However, most previous researches in the literature are deal with the situation in which aggregate functions arc applied to all the values in a given range. Since those approaches utilize characteristic of aggregate functions applied to a range, they are difficult to be applied to a muitipoint query that is a query considering only some points in a given range. In this paper, we propose the Ranking Index and the flanking Decision Tree (RDT) for efficient evaluation of multipoints MAX/MIN queries. The ranking of possible MAX/MIN values are computed with RDT Then MAX/MIN values can be acquired from the Ranking Index. We show through experiments that our method provides high performance in most situations. In other words, the proposed method is robust as well as efficient. A single common set of precomputed results for both MAX and MIN values is another advantage of the proposed method.

• The KIPS Transactions:PartD
• /
• v.16D no.2
• /
• pp.191-200
• /
• 2009

Location based services (LBSs) have drawn huge attention as the growing number mobile devices and wireless technology demand more pervasive information access. In LBSs, Constraint nearest neighbor queries are one of the important queries of human to fulfill his desired quickly through wireless technology. We propose new query processing of constrained nearest neighbor query on the air to support mobile clients which demand optimal uses of wireless broadcast channel and using minimum battery power of client. First we proposed NN query processing with constrained region and then explain the novel NN query processing with various types of constraints. We have proposed novel algorithms to support Constrained Nearest Neighbor queries on the air based on Distributed Spatial Index and Bitmap-based Spatial Index.