• Asia pacific journal of information systems
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• v.2 no.1
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• pp.57-76
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• 1992

Material Requirement Planning(MRP) has been the most widely implemented large scale production management system in the manufacturing industry. Computerization of MRP systems involves, in general, Bill Of Material(BOM) explosion algolithms which usually takes heavy computation time. In order to improve the effectiveness of the MRP systems, we propose to build a logical BOM database in advance, which reflects the Join operations for the BOM explosion. It reduces the response time for the BOM indented explosion. It reduces the MRP processing time. It also increased main memory utilization.

• The Transactions of the Korea Information Processing Society
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• v.4 no.2
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• pp.325-337
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• 1997

This paper introduces the basic concepts and requirements of database system based on the object-oriented paradigm,and presents the overview of the design of an object-oriented data base system which refects those conceprs and requirements . The system imolemented on C++,consists of three structure layers.The inner layer, which is in fact a storage system,performs file I/O,while the inermediate layer is responisible for most of the functions except the ones rerated to the user interface, such as the transaction management,the schema manage-ment,and the management of buffers in main memory etc.The outer layer,designed mainly for the uwerunteface,mot only privides the functions for graphical user interface,preprocessor,and interpreter etc,but also supports extended SQL for object-oriented features.

• Journal of Information Processing Systems
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• v.4 no.1
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• pp.9-16
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• 2008

This paper describes the design and implementation of a two-tier DBMS for handling massive data and providing faster response time. In the present day, the main requirements of DBMS are figured out using two aspects. The first is handling large amounts of data. And the second is providing fast response time. But in fact, Traditional DBMS cannot fulfill both the requirements. The disk-oriented DBMS can handle massive data but the response time is relatively slower than the memory-resident DBMS. On the other hand, the memory-resident DBMS can provide fast response time but they have original restrictions of database size. In this paper, to meet the requirements of handling large volumes of data and providing fast response time, a two-tier DBMS is proposed. The cold-data which does not require fast response times are managed by disk storage manager, and the hot-data which require fast response time among the large volumes of data are handled by memory storage manager as snapshots. As a result, the proposed system performs significantly better than disk-oriented DBMS with an added advantage to manage massive data at the same time.

• Journal of Korea Spatial Information System Society
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• v.8 no.1 s.16
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• pp.1-16
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• 2006

Recently, human based computing environment for supporting users to concentrate only user task without sensing other changes from users is being progressively researched and developed. But middleware deletes steream data processed for reducing process load of massive information from RFID sensor in this computing. So, this kind of middleware have problems when user demands probability or statistics needed for data warehousing or data mining and when user demands very important stream data repeatedly but already discarded in the middleware every former time. In this paper, we designs Sensor Middleware Architecture on Multi Level Spatial DBMS with Snapshot and manage repeatedly required stream datas to solve reusing problems of historical stream data in current middleware. This system uses disk databse that manages historical stream datas filtered in middleware for requiring services using historical stream information as data mining or data warehousing from user, and uses memory database that mamages highly reuseable data as a snapshot when stream data storaged in disk database has high reuse frequency from user. For the more, this system processes memory database management policy in a cycle to maintain high reusement and rapid service for users. Our paper system solves problems of repeated requirement of stream datas, or a policy decision service using historical stream data of current middleware. Also offers variant and rapid data services maintaining high data reusement of main memory snapshot datas.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.8 no.5
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• pp.1035-1041
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• 2004

Currently users are tend to use multimedia data types in their applications. Main features of multimedia data types are large amount of data compared to conventional data types. In this reason, it's hard to load data into main memory and to search. That is the cause of occur disk input and output frequently, and decrease the system performance. In this paper, we describe to have fast and efficient access to multimedia data using index technique. Index method presented by paper consists of two parts : one is index file part for keywords and the other is posting file part for the list of file names. Of course, we use keyword. But user is not charge of memory for the keywords. Users just use natural language to insert, delete and search data what he or she wants. Internally, System makes keywords from natural language to get access to multimedia data. It provides convenience to users. Using this study to develop one's application for multimedia, one may have a chance for advanced performance of a system and getting a result speedily.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.7B
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• pp.605-619
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• 2003

The main memory DBMS(MMDBMS) efficiently supports various database applications that require high performance since it employs main memory rather than disk as a primary storage. In this paper, we discuss the index manager of the Tachyon, a next-generation MMDBMS. Recently, the gap between the CPU processing and main memory access times is becoming much wider due to rapid advance of CPU technology. By devising data structures and algorithms that utilize the behavior of the cache in CPU, we are able to enhance the overall performance of MMDBMSs considerably. In this paper, we address the practical implementation issues and our solutions for them obtained in developing the cache-conscious index manager of the Tachyon. The main issues touched are (1) consideration of the cache behavior, (2) compact representation of the index entry and the index node, (3) support of variable-length keys, (4) support of multiple-attribute keys, (5) support of duplicated keys, (6) definition of the system catalog for indexes, (7) definition of external APIs, (8) concurrency control, and (9) backup and recovery. We also show the effectiveness of our approach through extensive experiments.

• Journal of KIISE:Computing Practices and Letters
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• v.6 no.5
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• pp.468-476
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• 2000

Binding the object-oriented programming language C++ with a database management system provides a persistency to C++ programming objects so that objects can persist after program termina~,on. In such a binding system, we can manage a persistent object same as that we use a transient object and also use database management facilities such as transaction management and concurrency control. This paper presents a method providing the persistency to C++ programming objects in the binding system. We propose an improved interface based on C++ binding of ODMG-97 and present the design and implementation technique of it. The proposed interface provides a seamless interface for creating objects of the persistent capable class. We can create a persistent object without its class name as we do not give a class name when creating a transient object. Also, we guarantee the type compatibilty between the obiect created in database and the obiect created in main memory.

• Journal of KIISE:Databases
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• v.35 no.1
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• pp.17-28
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• 2008

Recently, main memory access is a performance bottleneck for many computer applications. Cache memory is introduced in order to reduce memory access latency. However, it is possible for cache memory to reduce memory access latency, when desired data are located on cache. EST tree is proposed to solve this problem by improving T tree. However, when doing a range search, EST tree has to search unnecessary nodes. Therefore, this paper proposes $CST^+$ tree which has the merit of CST tree and is possible to do a range search by linking data nodes with linked lists. By experiments, we show that $CST^+$ is $4{\sim}10$ times as fast as CST and $CSB^+$. In addition, rebuilding an index Is an essential step for the database recovery from system failure. In this paper, we propose a fast tree index rebuilding algorithm called MaxPL. MaxPL has no node-split overhead and employs a parallelism for reading the data records and inserting the keys into the index. We show that MaxPL is $2{\sim}11$ times as fast as sequential insert and batch insert.

• Proceedings of the Korean Information Science Society Conference
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• 2004.10b
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• pp.73-75
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• 2004

최근에 무선 인터넷과 이동 컴퓨팅 기술이 발전하고, 휴대 전화, PDA와 같은 이동 단말기가 보편화됨에 따라 사용자의 위치 정보를 활용하는 위치 기반 서비스(LBS: Location Based Service)가 다양한 분야에서 제공되고 있다. 모바일 환경에서 위치 기반 서비스를 제공하기 위해서는 모바일 장치에서 대용량의 공간 데이타를 신속하게 처리하고 효과적으로 관리하기 위한 공간 MMDBMS(Main Memory Database Management System)가 필요하다. 이에 본 논문에서는 기존의 PC용 MMDBMS인 HSQLDB를 확장하여 모바일 장치에서 공간 데이타를 효율적으로 관리할 수 있는 공간 MMDBMS를 설계 및 구현하였다. 공간 MMDBMS는 OGC의 공간 데이타 모델을 따르며, 공간 데이타 특성에 적합한 압축 기법인 산술 코딩 기법을 제공하고, 모바일 장치에 적합한 MBR 압축 및 해슁 기법을 이용한 공간 인덱스를 지원한다. 그리고, 모바일 장치의 낮은 성능의 프로세서에서 공간 데이타 디스플레이 기능을 제공하고, 모바일 장치와 디스크 기반 GIS인 ZEUS 사이에서 공간 데이타 import/export의 성능 향상을 위한 데이타 캐쉬 기능을 지원한다.

• Proceedings of the Korea Information Processing Society Conference
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• 2002.11c
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• pp.1883-1886
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• 2002

본 논문은 많은 종류의 인터넷 정보시스템에서 데이터의 고속 검색과 저장 및 처리를 지원하는 주기억장치 데이터베이스 시스템을 중복하여 관리할 수 있는 중복 주기억장치 데이터베이스 시스템의 요구사항에 대해 알아본다. 아울러, 자료의 고속처리라는 측면을 주로 고려하여 중복되어 관리되는 주기억장치 데이터베이스 시스템의 아키텍쳐 및 트랜잭션 수행구조를 설계한다.