• Journal of KIISE:Databases
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• v.34 no.4
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• pp.328-342
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• 2007

We propose a new cache conscious indexing structure for processing frequently updated data efficiently. Our proposed index structure is based on a KDB-Tree, one of the representative index structures based on space partitioning techniques. In this paper, we propose a data compression technique and a pointer elimination technique to increase the utilization of a cache line. To show our proposed index structure's superiority, we compare our index structure with variants of the CR-tree(e.g. the FF CR-tree and the SE CR-tree) in a variety of environments. As a result, our experimental results show that the proposed index structure achieves about 85%, 97%, and 86% performance improvements over the existing index structures in terms of insertion, update and cache-utilization, respectively.

• Journal of Korean Library and Information Science Society
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• v.30 no.3
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• pp.427-456
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• 1999

This paper deals with the problems of information retrieval through full-test database which arise from both the deficiency of searching strategies or methods by information searcher and the difficulties of query representation, generation, extension, etc. In oder to solve these problems, we should use automatic retrieval instead of manual retrieval in the past. One of the ways to make the gap narrow between the terms by the writers and query by the searchers is that the query should be searched with the terms which the writers use. Thus, the preconditions which should be taken one accorded way to solve the problems are that all areas of information retrieval such as should taken one accorded way to solve the problems are that all areas of information retrieval such as contents analysis, information structure, query formation, query evaluation, etc. should be solved as a coherence way. We need to deal all the ares of automatic information retrieval for the efficiency of retrieval thought this paper is trying to solve the design of thesaurus browser. Thus, this paper shows the theoretical analyses about the form of information retrieval, automatic indexing, clustering technique, establishing and expressing thesaurus, and information retrieval technique. As the result of analyzing them, this paper shows us theoretical model, that is to say, the thesaurus browser by clustering algorithm. The result in the paper will be a theoretical basis on new retrieval algorithm.

• The KIPS Transactions:PartD
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• v.12D no.2 s.98
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• pp.189-198
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• 2005

XML is rapidly becoming the standard for data representation and exchange, and XML documents are being adopted in various applications. Since the late 1990s, some native XML database management systems(DBMSs) have been developed. More recently, commercial relational DBMS vendors try to incorporate full functionalities of XML into their products, such as Oracle, MS SQL and IBM DB2. In this paper, we implement a well-known RDBMS-based XML data storage and indexing technique, called XPath Accelerator, and tune it in an industry-leading RDBMS. Our contributions are two-folds: 1) an in-depth implementation of the XPath Accelerator technique and 2) its tuning to exploit the advanced query processing techniques of an RDBMS.

• Journal of Korea Water Resources Association
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• v.46 no.1
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• pp.35-45
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• 2013

The aim of study is to present how to estimate and use the FRI (Flood Risk Index) for classifying area zones based on regional flooding risk in terms of the integrated flood risk management. To estimate the FRI at a spatial resolution of city/county/town units for the Nakdong River Watershed, the 17 representative flood indexing factors are carefully selected for the three flood indexes, such as PI (Pressure Index), SI (State Index), and RI (Response Index) under the P-S-R (Pressure-State-Response) classification system. Because flood indexing factors are measured at different scales and units, they are transformed into a common domain by the T-Score normalization technique. The entropy weight coefficient method is also applied to calculate the weight of flood indexing factors in order to reduce subjective judgement on the effect of weight coefficients. The three flood indexes of PI, SI, and RI are integrated for an overall value of the FRI to evaluate the flood risk of districts. To examine the practical application of the proposed FRI, the FRI results with/without the weight coefficients are compared with flooding zones of natural disaster risk areas officially announced in 2010. It is expected that the FRI ensured by full verification can make regional protection plans against flooding disasters with respect to causes and characteristics of past floods.

• Journal of Korea Society of Digital Industry and Information Management
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• v.6 no.1
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• pp.131-142
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• 2010

In this paper, we propose a web GPS based logistics vehicle control management system using MVC design patterns. The proposed system is designed by applying design patterns of object oriented modeling called mini-architecture to enhance reliability of software as well as promote stability of overall system design. In addition, we can get a position information by means of the GPS embedded in PDA and communicate between client and monitoring server using CDMA network so that the position of client can be identified directly by the map service. The system provides an moving object indexing technique which extends the existing TB-tree to manage and retrieve a transporting trajectory of logistics efficiently. Finally, with development of the logistics vehicle control service called WG-LOGICS system, we can verify the usefulness of our system which is able for monitoring a vehicle preparation, allocating registration, loading a burden, transfer path, and destination arrival in real world.

• Journal of Institute of Control, Robotics and Systems
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• v.11 no.12
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• pp.1083-1087
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• 2005

As development of digital technology, many kinds of multimedia data are used variously and requirements for effective use by user are increasing. In order to transfer information fast and precisely what user wants, effective retrieval method is required. As existing multimedia data are impossible to apply the MPEG-1, MPEG-2 and MPEG-4 technologies which are aimed at compression, store and transmission. So MPEG-7 is introduced as a new technology for effective management and retrieval of multimedia data. In this paper, we extract content-based features using color descriptor among the MPEG-7 standardization visual descriptor, and reduce feature data applying PCA(Principal Components Analysis) technique. We model the cerebral cortex and hippocampal neural network in engineering domain, and team content-based feature vectors fast and apply the hippocampal neural network algorithm to compose of optimized feature. And then we present fast and precise retrieval effect when indexing and retrieving.

• Proceedings of the Korean Information Science Society Conference
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• 2002.04a
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• pp.586-588
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• 2002

본 논문에서는 높은 대역폭(Bandwidth)을 가지는 싱글채널(Single Channel)로 결합될 수 없는 낮은 대역폭의 멀티채널(Multi Channel) 환경에서의 브로드캐스트(Broadcast)를 위한 효과적인 인덱스 방법을 제안한다. 최근에 들어 멀티채널에서 데이터 브로드캐스트의 인덱스 방법에 대한 많은 연구가 행하여 졌는데, 트리구조의 사용 여부에 따라 두 가지 방법으로 구분해 볼 수 있다. 트리 구조를 이용한 방법은 서버의 부담을 증가시키지만 트리 구조를 이용하지 않은 방법보다 모바일 유저에게 낮은 대기시간을 제공할 수 있다. 이 논문에서는 기존의 방법들이 가지는 채널의 수나 데이터의 크기에 제한을 두는 단점을 해결하고 접근 빈도가 높은 데이터에 대한 인덱스들의 반복 정도를 높여서 모든 인덱스에 대한 대기시간(Latency)의 평균값을 현저하게 줄일 수 있는 효과적인 인덱스 스케줄 생성 방법을 제시한다.

• Proceedings of the Korean Information Science Society Conference
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• 2006.10c
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• pp.205-209
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• 2006

무선 네트워크의 기술 발달과 이동기기들의 많은 보급에 따라 GIS, LBS 등의 위치기반 서비스 등이 널리 사용되고 있다. 이러한 서비스를 수행하기위하여 방대한 양의 이동 객체들의 효율적인 관리, 검색에 대한 연구가 많이 이루어지고 있으며 이동 객체들의 특성과 사용목적에 따라 다양한 연구결과가 제시되고 있다. 본 논문에서는 시간에 따라 다양한 속도와 방향으로 이동하는 다차원 이동 공간 데이터를 위한 효율적인 색인 기법을 제시한다. 제안된 방법은 KDB-Tree와 QSF-Tree에 기반을 두고 있으며 색인 구조의 검색 성능을 향상시키기 위한 분할, 갱신 방법을 제시하여 시간에 따라 현재 속도와 방향이 다양하게 변화하는 데이터를 신속히 데이터를 색인하고 영역 질의 뿐만 아니라 미래 예측 질의에 대하여 현재 보유한 데이터 정보를 기반으로 미래 예측 결과를 신속히 산출할 수 있도록 한다.

• Journal of KIISE:Computing Practices and Letters
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• v.16 no.8
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• pp.878-882
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• 2010

DaaS model that surrogates their data has a problem of privacy leakage by service provider. In this paper, we analyze inference attack that can occur on encrypted data that consist of multiple column through index, and we suggest b-anonymity to protect data against inference attack. We use R+-tree technique to minimize false-positive that can happen when we use an index for efficiency of data processing.

• International Journal of Contents
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• v.11 no.1
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• pp.69-72
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• 2015

Generally, existing parallel main-memory spatial index structures to avoid the trade-off between query freshness and CPU cost uses light-weight locking techniques. However, still, the lock based methods have some limits such as thrashing which is a well-known problem in lock based methods. In this paper, we propose a distributed index structure for moving objects exploiting the parallelism in multiple machines. The proposed index is a lock free multi-version concurrency technique based on the D-Stream model of Spark Stream. The proposed method exploits the multiversion nature of D-Stream of Spark Streaming.