• Proceedings of the Korea Database Society Conference
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• 1997.10a
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• pp.483-503
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• 1997

One important question that arises when dealing with temporal databases in context of object-oriented systems is the method that associates time with attributes relationship semantics. Results of previous work about attribute versioning, particularity extending flat(First Normal Form: FNF) or nested(Non-First Normal Form: NFNF) relational models. are not applicable to temporal object-oriented databases. This is because object-oriented models provide more powerful constructs than traditional models for structuring complex objects. Therefore, this paper presents an formal approach for incorporating temporal extension to object-oriented databases. Our goal in this paper is to study temporal object-oriented database representation according to generalization, aggregation and association among objects. We define tile concepts of attribute versioning in temporal object-oriented model, and we concentrate on the representation of temporal relationship among objects. Another contribution of this paper is to specify time constraints on relationship semantics and analyze our model based on representation criteria. By means of formalizing tile temporal object oriented model, this paper can not only provide tile robust operating functions that design algebraic operators, but also entrance the reuse of modules.

• Proceedings of the Korea Database Society Conference
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• 1999.10a
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• pp.183-189
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• 1999

오늘의 기업에게 정보기술이란 필수요소이다. 정보기술을 효과적으로 활용하기 위해서는 IT 인프라가 체계적으로 구축되어 있어야 한다. 해당 조직에 적합한 정보기술 기반구조를 설계하고 이의 도입을 위한 구체적인 계획을 수립하기 위해서는 체계적이고 효과적인 정보계획 수립(Information System Planning: ISP)이 필요하다. 그러나 정보계획수립 프로젝트의 상당수가 실패로 그치고 있다. 특히 정보기술의 지속적인 변화 때문에 수립한 정보기술 기반구조 계획안이 실제 구현되지 못하고 계획으로만 남는 경향이 있다. 이러한 ISP의 어려움을 해결하기 위해서는 정보기술 참조모델(reference model)을 적극적으로 활용할 필요가 있다. 즉, 조직의 정보시스템에 공통적으로 적용할 수 있는 IT 인프라나 표준 아키텍쳐를 바탕으로 정보계획수립을 수행해 나가는 방식이 필요하다. 이와 같은 참조모델 기반의 정보계획 수립은 새로운 아키텍쳐를 추출하고 표준화를 이룸으로써 프로젝트의 생산성을 높일 수 있다는 장점을 가지고 있다. 기존의 ISP 연구는 ISP의 필요성, 과정, 성공요인 등에 국한되어 왔으며, 방법론에 대한 연구는 미비한 편이다. 최근들어 ISP의 체계적인 분류나 참조모델 기반 계획수립의 필요성이 제기되었다. 그러나 아직까지 이와같은 접근에서 참조 모델을 어떻게 구축하고 활용해 나갈 것인가에 대한 연구는 부족한 실정이다. 따라서 본 논문에서는 참조모델을 구축하기 위한 다양한 접근방법과 각각의 특징을 제시한다. 나아가서 해당 조직의 상황이나 요구수준에 따라 적합한 접근방법을 선택할 수 있게 해주는 방안을 제시한다.타냈으며, 평가결과에 대해 여러 가지 방법으로 분석하였다. 첫째, 동종제품간 평가분석을 통하여 각각의 제품을 비교하였으며, 둘째 소프트웨어 종류별 평가로 제품을 응용소프트웨어, 응용개발도구, 시스템 소프트웨어로 분류하여 평균값으로 비교하였다. 셋째, 국내외 제품별 평가분석으로 전체 제품을 국내제품과 국외제품으로 분류하여 비교하였으며, 마지막으로 총괄분석을 통해 가중치를 적용하여 전 제품의 점수를 비교하였다. 여기에서는 각 제품의 평균점수에 대한 차이를 95%의 유의수준으로 T-Test를 실시하였다.uted to the society, and what the socioeconomic impacts are resulted from the program. It would be useful for the means of (ⅰ) fulfillment of public accountability to legitimate the program and to reveal the expenditure of pubic fund, and (ⅱ) managemental and strategical learning to give information necessary to improve the making. program and policy decision making, The objectives of the study are to develop the methodology of modeling the socioeconomic evaluation, and build up the practical socioeconomic evaluation mod

• Journal of KIISE:Computing Practices and Letters
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• v.14 no.2
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• pp.171-179
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• 2008

RBAC(Role based Access Control) is effective way of managing user's access to information object in enterprise level and e-government system. The concept of RBAC is that the access right to object in a system is not directly assigned o users but assigned by being a member of a role which is defined in a organization. RBAC is utilized for controling access range of privacy but it does not support the personal legal right of control over information and right of limited access to the self. Nor it contains the way of observation of privacy flow that is guided in a legal level. In this paper, extended RBAC model for protecting privacy will be suggested and discussed. Two components of Data Right and Assigning Data Right are added to existed RBAC and the definition of each component is redefined in aspect of privacy preservation. Data Right in extended RBAC represents the access right to privacy data. This component provides the way of control over who can access which privacy and ensures limitation of access quantity of privacy. Based on this extended RBAC, implemented examples are presented and the evaluation is discussed by comparing existed RBAC with extended RBAC.

• Journal of KIISE:Databases
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• v.30 no.3
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• pp.320-335
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• 2003

Location-Based Services(LBS) give rise to location-based queries of which results depend on the locations of moving objects. One of important applications of LBS is to examine tracks of continuously moving objects. Moving objects databases need to provide 3-dimensional indexing for efficiently processing range queries on the movement of continuously changing positions. An extension of the 2-dimensional R-tree to include time dimension shows low space utilization and poor search performance, because of high overlap of index nodes and their dead space. To solve these problems, we propose a new R-tree based indexing technique, namely TR-tree. To increase storage utilization, we assign more entries to the past node by using the unbalanced splitting policy. If two nodes are highly overlapped, these nodes are forcibly merged. It is the forced merging policy that reduces the dead space and the overlap of nodes. Since big line segments can also affect the overlap of index nodes to be increased, big line segments should be clipped by the clipping policy when splitting overfull nodes. The TR-tree outperforms the 3DR-tree and TB-tree in all experiments. Particularly, the storage utilization of the TR-tree is higher than the R-tree and R*-tree.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.18 no.2
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• pp.201-211
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• 2005

Due to the complex mechanism and various parameters that affect shear behavior of reinforced concrete (RC) members, models on shear tend to be complex and difficult to utilize for design of structural members, and empirical relationships formulated with limited test data often work lot members having a specific range of influencing parameters on shear. As an alternative approach tot solving this problem, artificial neural networks have been suggested by some researchers. In this paper, artificial neural networks were used to predict shear strengths of RC beams without shear reinforcement. Especially, a large database that consists of shear test results of 398 RC members without shear reinforcement was used for artificial neural network analysis. Three well known approaches for shear strength of RC members, ACI 318-02 shear provision, Zsutiy's equation, and Okamura's relationship, are also evaluated with test results in the shear database and compared with neural network approach. While ACI 318-02 provided inaccurate predictions for RC members without shear reinforcement, the empirical equations by Zsutty and Okamura provided more improved prediction of Shear strength than ACI 318-02. The artificial neural networks, however provided the best prediction of shear strengths of RC beams without shear reinforcement that was closest to test results.

• Journal of Korea Spatial Information System Society
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• v.8 no.2 s.17
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• pp.53-73
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• 2006

Recently, the need for Location-Based Services (LBS) has increased due to the development of mobile devices, such as PDAs, cellular phones and GPS. As a moving object database that stores and manages the positions of moving objects is the core technology of LBS, the scheme for maintaining the main memory DBMS to the server is necessary to store and process frequent reported positions of moving objects efficiently. However, previous works on a moving object database have studied mostly a disk based moving object index that is not guaranteed to work efficiently in the main memory DBMS because these indexes did not consider characteristics of the main memory. It is necessary to study the main memory index scheme for a moving object database. In this paper, we propose the main memory index scheme based on the R-tree for storing and processing positions of moving objects efficiently in the main memory DBMS. The proposed index scheme, which uses a growing node structure, prevents the splitting cost from increasing by delaying the node splitting when a node overflows. The proposed scheme also improves the search performance by using a MergeAndSplit policy for reducing overlaps between nodes and a LargeDomainNodeSplit policy for reducing a ratio of a domain size occupied by node's MBRs. Our experiments show that the proposed index scheme outperforms the existing index scheme on the maximum 30% for range queries.

• The KIPS Transactions:PartD
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• v.9D no.6
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• pp.1055-1062
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• 2002

Recently, the lesson plan document that is imported in the educational area is not provided to the educational information systematically, and the teachers are not easy to compose the lessen plan documentation. So, it needs additional time and effort to develope the lesson plan documents. Because of increasing the distributing network. web-based lesson plan system is required to all of the education area. Therefore, we need to compose the lesson plan that is possible to obtain the various teacher's requirement by providing creation, retrival, and reusability of document using the standard XML on web. In this paper, we developed the system for creating the common DTD (Document Type Definition), providing the standard XML document through the common DTD over the lesson plan analysis. In this system, it provides the editor to compose the lesson plan and supports the searching function to improvement of reusability on the existing lesson plan. We design the searching functions such as the structure base, facet and keyword. The composed lesson plans are interoperated with Database. Consequently, we can share the information on web by composing the lesson plan using the XML and save the time and cost by directly writing the lesson plan on web. We can also provide the improved learning environment.

• The Transactions of the Korea Information Processing Society
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• v.1 no.1
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• pp.114-128
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• 1994

It is very difficult for a nonprofessional programmer in Koera to write a program with very High Level Language such as, V,REFINE, GIST, and SETL, because the semantic primitives of these languages are based on predicate calculus, set, mapping, or testricted natural language. And it takes time to be familiar with these language. In this paper, we suggest a method to reduce such difficulties by programming with the declarative, procedural constructs, and aggregate constructs. And we design and implement an experimental knowledge-based automatic programming system. called HAPS(Hangul Automatic Program System). HAPS, whose input is specification such as Hangul abstract algorithm and datatype or Hangul procedural constructs, and whose output is C program. The method of operation is based on rule-based and program transformation technique, and the problem transformation technique. The problem area is general problem. The control structure of HAPS accepts the program specification, transforms this specification according to the proper rule in the rule-base, and stores the transformed program specification on the global data base. HAPS repeats these procedures until the target C program is fully constructed.

• Journal of KIISE:Computing Practices and Letters
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• v.14 no.2
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• pp.130-142
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• 2008

Different from other ontology languages, TopicMap is capable of integrating numerous amount of heterogenous information resources using the locational information without any information transformation. Although many conventional editors have been developed for topic maps, they are standalone-type only for writing XTM documents. As a result, these tools request too much time for handling large-scale data and provoke practical problems to integrate with legacy systems which are mostly based on relational database. In this paper, we model a large-scale topic map structure based on XTM 1.0 into RDB structure to minimize the processing time and build up the ontology in legacy systems. We implement a topic map platform called X-TOP that can enhance the efficiency of ontology construction and provide interoperability between XTM documents and database. Moreover, we can use conventional SQL tools and other application development tools for topic map construction in X-TOP. The X-TOP is implemented to have 3-tier architecture to support flexible user interfaces and diverse DBMS. This paper shows the usability of X-TOP by means of the comparison with conventional tools and the application to healthcare cancer ontology management.

• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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• 2010.06a
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• pp.185-185
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• 2010

문명 발전에 의해 생활공간이 더욱더 복잡해짐에 따라 현실 세계의 3차원 공간으로서의 이해가 필요해졌고, 3차원 공간을 효율적으로 관리 및 분석하기 위하여 3차원 GIS에 대한 중요성이 대두되기 시작하였다. 현재까지의 3차원 GIS는 1990년대에 들어서 3차원 가상도시의 등장으로 도시 모델의 3차원 가시화에 대해 많은 연구가 진행되어 왔다. 이러한 3차원 가상도시는 도시 관리 차원에서 도시공간의 표현, 분석, 모델링, 시뮬레이션 등을 통하여 도시정보의 체계적이고 효율적인 관리를 가능하게 한다. 3D GIS 기술의 활용 사례로는 3차원 도시 경관 분석 및 도시 계획, 3차원 시뮬레이션, 3차원 위치기반 서비스, 도시 행정 관리 등이 있다. 3차원 도시 경관 분석 및 도시 계획 활용 분야에서는 3차원 GIS를 활용하여 새롭게 건설되는 건물들이나 토지 이용 변경에 따른 경관 분석을 가상공간에서 시뮬레이션 분석함으로써 경관 변화 예측 및 적합한 경관 설계에 대한 분석을 한다. 3차원 시뮬레이션의 경우 환경오염도 분석, 최적의 입지선정, 개발 전후의 경관 차이, 각종 재난에 따른 위험도 분석, 경관과 일조량 분석 등을 미리 가상도시에 시뮬레이션 함으로서 불필요한 업무를 줄일 수 있고 발생할 수 있는 결과 값을 예상할 수 있다. 3차원 위치기반 서비스의 경우 자신의 위치를 비교적 정확히 측정함으로서 생소한 도시를 방문하거나 위치를 찾아갈 경우 최단 경로 및 최적 경로를 탐색할 수 있다. 앞으로의 3차원 GIS 기술 동향으로 유비쿼터스 환경에서의 시공간분석(Temporal GIS)과 3차원 실내공간인지 기술 개발 등으로 볼수있다. 시공간분석은 시공간 질의를 통한 공간정보의 시간에 다른 변화 계산 또는 예측된 결과를 분석할 수 있고, 시공간 분석에 사용되는 공간적, 시간적 정보의 조합은 적어도 3차원 이상의 정보를 나타내기 때문에 필요에 따라 다양한 결과를 산출 할 수 있다. 종합적으로 시공간분석은 GIS의 분석 범위를 넓혀 주며 실시간 GIS 응용시스템 개발을 위한 주요 과업이다. 3차원 실내공간정보 표현기법과 공간분석 및 공간인지 기법을 이용한 통한 유비쿼터스 환경에서의 3차원 실내공간인지 기술 개발을 통해 최근 공간정보를 기반으로 한 위치기반서비스내 u-서비스 즉, 인간 행태의 분석, 관리 및 응용을 지원하도록 한다 이는 위치기반서비스 사용자의 주변상황에 대한 인지능력을 향상시켜주고 최근 사회적 이슈가 되고 있는 U-City의 성공여부에 직접적인 영향을 미칠것이다. 이를 위해 다음과 같은 기술개발이 수행되어야 할것이다. 첫째로, 공간인지 기술을 위한 3차원 실내공간표현 방법 개발, 둘째로, 3차원 실내공간정보를 이용한 공간분석 및 공간인지 기법 개발, 마지막으로 유비쿼터스 환경에서 3차원 실내공간인지를 위한 미들웨어 개발을 통해서 공간정보의 활용을 macro-scale 공간에서 micro-scale로 확산될 것이다. 그러므로, 본 세미나를 통해서, 3차원 GIS의 활용의 보편화와 대중화를 위해서는 3차원 데이터 획득 및 처리 방법, 3차원 공간데이타베이스, 공간 분석 및 가시화에 대한 기술적 이슈들을 논하고자 한다.