• Journal of Internet Computing and Services
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• v.15 no.4
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• pp.125-133
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• 2014

The column-oriented database storage is a very advanced model for large-volume data analysis systems because of its superior I/O performance. Traditional data storages exploit row-oriented storage where the attributes of a record are placed contiguously in hard disk for fast write operations. However, for search-mostly datawarehouse systems, column-oriented storage has become a more proper model because of its superior read performance. Recently, solid state drive using MLC flash memory is largely recognized as the preferred storage media for high-speed data analysis systems. The features of non-volatility, low power consumption, and fast access time for read operations are sufficient grounds to support flash memory as major storage components of modern database servers. However, we need to improve traditional transaction management scheme due to the relatively slow characteristics of column compression and flash operation as compared to RAM memory. In this research, we propose a new scheme called Column-aware Multi-Version Locking (CaMVL) scheme for efficient transaction processing. CaMVL improves transaction performance by using compression lock and multi version reads for efficiently handling slow flash write/erase operation in lock management process. We also propose a simulation model to show the performance of CaMVL. Based on the results of the performance evaluation, we conclude that CaMVL scheme outperforms the traditional scheme.

• Journal of KIISE:Software and Applications
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• v.26 no.5
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• pp.604-612
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• 1999

데이터웨어하우스는 데이터분석을 위한 특수 목적의 데이터베이스로, 주로 데이터분석을 위한 질의(이하 OLAP 질의)가 던져진다. 그런데 OLAP질의는 수백만개의 레코드를 가지 테이블에 대해 하나 이상의 aggregation 함수와 group-by 연산자가 포함되므로, 질의 처리 시간은 수 분에서 수 시간이 걸린다. 이를 개선하기위하여 데이터 큐브를 구현함에 있어서의 문제는 디스크 공간이 한정되어 있기 때문에 평균 질의 처리 시간이 훨씬 짧아진다하더라도 모든 셀들을 실체화할수 없다. 따라서 한정된 디스크 공간을 최대한 활용하면서 가능한 빠른 평균 질의 처리 시간을 얻을 수 있도록 데이터 큐브의 일부만을 실체화 시켜야한다. 본 논문의 주제와 관련된 연구로는 Harinarayan[4] 이 제안한 greedy 알고리즘이 있다. 이 알고리즘은 1) 데이터 큐브를 격자구조로 표현한후, 2) 격자의 위에서부터 아래로 차례로 뷰들을 방문하면서 방문한 뷰가 실체화되 경우 데이터 큐브에 주는 이익을 계산한다. 3) 그 중 가장 이익이 큰 것을 선택한다. 3) 그중 가장 이익이 큰 것을 선택한다. 2)와 3)의 과정은 k개의 뷰를 선택할 경우, k번 반복된다. 이 알고리즘의 운영 시간은 데이터 큐브를 구성하는 뷰의 개수가 n개이고 그 중에서 k개를 실체화할 경우에 O(kn2)이다. 본 논문에서는 운영 시간을 향상시킨 수정된 greedy 알고리즘을 제안한다. 알고리즘 내부에서 실체화할 뷰를 선택할 때 격자를 단순화시킨 트리를 사용함으로써, 알고리즘 운영시간을 O(kn2)에서 O(kn)으로 향상시켰다.

• Proceedings of the Korea Contents Association Conference
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• 2007.11a
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• pp.490-494
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• 2007

The chemical process plant information is used and updated during design, construction, operation, and maintenance of plant. This special type of information should be utilized as the DW(datawarehouse) which conforms to the standard format. The DW should be design in consideration of connectivity to application softwares. The application softwares are different from each other in the context of their objects such as design, management, decision-making, and so on. In this paper, some considerable facts in dealing with chemical process plant information on the framework of developing application software including datawarehousing, model building, interfacing. As a case study, the development of decision-making support system for environmental policy is illustrated for the related discussion.

• The KIPS Transactions:PartD
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• v.10D no.6
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• pp.917-926
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• 2003

More views in data warehouse, can respond to the users more rapidly because the user's requests may be processed by utilizing only the materialized views with higher probabilities rather than accessing base relations. But, more views cause longer update duration of all the materialized views. During the update time, queries of users can not be processed because accesses to the datawarehouse are blocked. Thus, the update durations of the materialized views are necessary to be reduced. In this paper, we propose algorithm the update duration of the materialized views owing to managing by distinguishing insecton/deletion operations. Though there might overheads for distinguishing insertion/deletion, we concluded that the proposed algorithm could be excellent than others.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.32 no.4
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• pp.25-37
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• 2009

This Study constructs a dashboard system to synthetically and systematically monitor national R&D information based on data warehouse. Managing the national R&D statistics and trend is important since it provides data for policies and decision making for national R&D. Many agencies related to national R&D information collect the basic R&D statistic data which provides the basis of logical decision making and R&D policies. The data has not well been used. The data has not been consistently collected nor managed. The raw data has not been organized nor processed to meet various demands. The needs has been arisen for a consistent national R&D monitoring system to increase the relevance, accessibility and efficiency of data for various users. This study selects 25 key indicators based on the user requirements and designs data warehouse for supporting the indicators using star schema. The dashboard system is developed in this study provides the infrastructure of monitoring national R&D information and analytic environment of supporting statistical analysis and time-series data analysis.

• The KIPS Transactions:PartD
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• v.11D no.4
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• pp.967-974
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• 2004

An OLAP system is the decision support tool with which a user can analyze the information interactively in the various aspects. However, the traditional existing construction of an OLAP system has the inefficiency problem of increasing the time and cost caused by the frequent changes of the users requirements. In this paper, we analyse existing construction procedure of OLAP systems and propose a prototyping OLAP View based on the star schema which can help and guide the designer In supporting efficiently of users requirements. Through an implementation of S shopping mall using the OLAP View, we show that our proposal is able to support OLAP construction strategy and provide accurate understanding of data resources. With an OLAP View, we can reduce the required time and cost of implementing OLAP system.

• Annual Conference of KIPS
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• 2007.05a
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• pp.88-90
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• 2007

수집 및 가공된 교통자료와 시스템 운영 자료의 체계적인 분석 수단으로 사용될 교통 이력자료 관리 시스템의 요구 기능을 정의하는 것은 매우 중요하다. 시스템 구축을 위한 사용자 요구사항을 구체적으로 정의, 설명함으로써 시스템 완성도와 활용도를 높인다. 본 논문에서는 교통 이력자료 관리시스템의 주요 기능으로 '자료 저장 기능', '자료 분석 기능', '자료 보고 기능' 을 제안한다. 이러한 시스템의 사용자 요구 기능은 Rational Rose tool 을 이용하여 Use Case 다이어그램으로 시각화 되어지며 이후 교통정보 이력자료 통합데이터베이스 구축을 위한 개발자들에게 더욱 쉬운 이해를 제공할 수 있다.

• The Journal of the Korea Contents Association
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• v.9 no.2
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• pp.106-114
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• 2009

In this study, we are analysing adverse drug events and proposing a technical structure of "adverse drug event surveillance system" using business intelligence technology, hoping that we can use the system commonly and actively. It is the recent trend to adopt both of electronic review and manual review process to surveil adverse drug events and this study construct CDW applying ETL in BI Technology. As the result of analysis, the data pool included 701 doctors who prescribed and 3059 patients(1528 male, 1531 female), of total 318,222 cases, 2,086cases(0.6%) were suspected as having adverse drug events. And the single type of T.bilirubin> 3mg/dL(ADE type-LabR0005) was the most common(548 among 2085 cases) within the framework of signals.

• Journal of Korean Society for Geospatial Information Science
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• v.17 no.1
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• pp.121-129
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• 2009

Today, it is difficult to re-use and share spatial information, because of the explosive growth of heterogeneous information and specific characters of spatial information accumulated by diverse local agency. A spatial analysis of subsurface spatial informa-tion, one of the National Spatial Data Infrastructure, needs related spatial information such as, topographical map, geologic map, underground facility map, etc. However, current methods using standard format or spatial datawarehouse cannot consider a se-mantic hetergenity. In this paper, the layered ontology model which consists of generic concept, measuremnt scale, spatial model, and subsurface spatial information has developed. Also, the current ontology building method pertained to human experts is a expensive and time-consuming process. We have developed the MDA-based metamodel(UML Profile) of ontology that can be a easy under-standing and flexiblity of environment change. The semantic quality of devleoped ontology model has evaluated by reasoning engine, Pellet. We expect to improve a semantic sharing, and strengthen capacities for developing GIS experts system using knowledge representation ability of ontology.

• Journal of Korea Society of Industrial Information Systems
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• v.15 no.2
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• pp.115-126
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• 2010

Modern society can be described as ubiquitous computing over the concept of information. Information technology(IT) has been developing in a way that relative technologies are integrated to each other. Especially in ubiquitous environment, medical information industry shows significant interest in the U-healthcare service area. This paper will first look into U-healthcare service environment and component of Integrated Medical Information Systems(IMIS). Secondly, it examines the basic technological factors for integrated medical information systems, which is datawarehouse, network, communication standards and technology related U-healthcare service. Finally it proposes how to implement and operate new integrated medical information system for ubiquitous health care service. The system will do point of care(POC) for customers by real time and diagnose them using their various and personal medical data. The information will be communicated back to the customers, which will improve their satisfaction.