• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.04a
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• pp.342-346
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• 1997

In the recent competitive market situation, the product development lead-time plays a significant role for the success of a manufacting company. One of the most important efforts required is reducing the design lead-time by managing all the necessary technical information related to the design process. In this paper,the data model for an engineering data management system for machine tools is described by applying object-oriented modeling technique. The design objects and their structure are defined regarding the functions such as version control, configuration management, and technical document management, and are implemented using an object-relational database management system. The suggested model takes into special account the characteristics of machining centers.

• The Journal of Information Technology and Database
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• v.3 no.1
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• pp.3-24
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• 1996

Databases are critical to business information systems, and RDBMS is most widely used for the database system. Normalization has been designed to control various anomalies(insert, update, and delete anomalies). However, normalized database design does not account for the tradeoffs necessary for the performance. In this research, we develop a model for database design by denormalization of duplicating attributes in order to reduce frequent join processes. In this mood, we consider insert, update, delete, and query costs. The anomaly and data inconsistency are removed by additional disk I/O which is necessary for each update and insert transaction. We propose a branch and bound method for this model, and show considerable cost reduction.

• Journal of the Korean Data and Information Science Society
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• v.12 no.1
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• pp.89-97
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• 2001

Chen and Chen(FSS, 1993, 159-168) presented a reasonable analytical model of fuzzy closed-loop systems and proposed a method to analyze the stability of fuzzy control by the relational matrix of fuzzy system. Chen, Lu and Chen(IEEE Trans. Syst. Man Cybern., 1995, 881-888) formulated the sufficient and necessary conditions on stability of fuzzy closed-loop control systems. Gang and Chen(FSS, 1996, 27-34) deduced a linguistic relation model of a fuzzy closed loop control system from the linguistic models of the fuzzy controller and the controlled process and discussed the linguistic stability of fuzzy closed loop system by a linguistic relation matrix. In this paper, we study more on their models. Indeed, we prove the existence and uniqueness of equilibrium state $X_e$ in which fuzzy system is stable and give closed form of $X_e$. The same examples in Chen and Chen and Gang and Chen are treated to analyze the stability of fuzzy control systems.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1998.10a
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• pp.342-351
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• 1998

The purpose of this study is to develop a central database and a database management system to store and manage information systematically from each module of an integrated structural design system. In order to efficiently express structural design process related to the data which is very complex, we used an object-oriented modeling methodology to propose the possibility to apply a database schema for application programs in an integrated system for reinforced concrete structural design. Based on this model, we developed an interface between each module and central database. After modeled by using object modeling technique, the database was mapped by the relational database table. Then the central database and the interface were programed by using Visual C/syo ++/, a windows environmental development tool.

• Proceedings of the Korean Information Science Society Conference
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• 1999.10a
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• pp.48-50
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• 1999

본 논문은 공간데이터와 비공간데이터를 통합처리하는 공간 데이터베이스 시스템에서 데이터의 의미적 무결성을 보장하는 확장된 공간 데이터 모델을 설계한다. 공간 데이터베이스 시스템에서 다루는 단순 객체가 아닌 추상화된 복합 객체로 다양한 유도 데이터에 대한 의미적 무결성을 데이터베이스 시스템 내부에서 효율적으로 유지해야 하며, 공간 데이터의 의미적 무결성 제약 조건을 사용자에 의해 정의할 수 있어야 한다. 본 논문에서는 공간 데이터베이스에서 사용하는 공간 데이터에 대한 무결성 정보를 술어 논리 형태로 표현하고 유지할 수 있는 무결성 공간 데이터 모델 (ISRDM: Integrity supported Spatial-Relational Data Model)을 제안한다. 제안된 공간 데이터 모델은 하부 단계 저장 구조, 개념적 데이터 표현 단계, 무결성 표현 단계가 독립적으로 구성되는 다단계 구조로 기존의 공간 데이터베이스 시스템을 용이하게 확장하고 다양한 응용 요구에 대해 유연하게 대처할 수 있도록 설계한다.

• Journal of the Korea Computer Industry Society
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• v.10 no.1
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• pp.1-12
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• 2009

In this thesis, founded on those considerings, plan the formula of media data for the information of drawing for the production of steel plate by establishing the concept of relational data model, plan the surroundings for query for the interface of user, and introduce the process materialized actually in detail as use the management system of drawing.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2001.10a
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• pp.151-158
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• 2001

This paper describes an example of developing an integrated design system, Integrated Structural Design System for Reinforced Concrete Buildings(INDECON). INDECON incorporates a central database and three design modules: a preliminary design module(PDM), a structural analysis module(SAM), and a detailed design module(DDM). The development of INDECON begins with the development of design models including Design Object Model(DOM) which describes design data during the structural design process. The Design Object Model is transformed to Design Table Model(DTM) for the central database, and is specified to be in detail for the three design modules. Then the central database is implemented and managed by relational database management system(RDBMS), and the three design modules are implemented using C++ programming language. The central database in the server computer communicates with the design modules in the client computers using TCP/IP internet protocol. The developing procedure for INDECON in this paper can be applied for developing more comprehensive integrated structural design systems.

• Journal of the Korea Society of Computer and Information
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• v.25 no.4
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• pp.123-131
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• 2020

The pattern query in graph database has advantages of easy query expression and high query processing performance compared to relational database SQL. However, unlike the relational database, the graph database may not utilize the advantages of pattern query depending on modeling because the methodology for building the logical data model is not defined. In this study, in the is-a node modeling method that appears during the graph modeling process, we experiment that there is a difference in performance between graph pattern query when designing with a generalization model and designing with a specialization model. As a result of the experiment, it was shown that better performance can be obtained when the is-a node is designed as a specialization model. In addition, when writing a pattern query, we show that if a variable is bound to a node or edge, performance may be better than that of the variable of not bounded. The experimental results can be presented as an is-a node modeling method for pattern query and a graph query writing method in the graph database.

• Journal of Korean Academy of Nursing
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• v.28 no.2
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• pp.380-391
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• 1998

This study was conducted to develop a theoretical model for the determinants of activities of daily living in Korean rural elderly people. The theoretical model was derived from Lawton's Ecological Model to explain human behavior. The model includes determinant variables for functional status such as age, sex, physical status, cognitive status, physical environment, social environment, and depression. Data for this study was collected from 189 elderly people in a rural district near Chonju City. The data was analyzed with SPSS PC/sup +/4.1 and LISREL 8. The analysis of the data showed that the first proposed theoretical model did not fit the collected data well. In order to increase the fit of the model to the data, the model was modified by deleting the exogenous variables of sex, physical environment, and social environment. The fit of the modified model to the data was increased and was move suitable. The results of this study show that the determinants of the activities of Korean rural elderly people were age, perceived physical condition, cognitive status, and depressional status. Age has a significant direct and indirect effect on the activities of daily living of rural elderly people. Perceived physical condition has a significant indirect effect through depression on activities of daily living. Cognitive status also has a significant indirect effect through depression on functional status. Depression has a significant direct effect on the functional status. Physical environment and social environment showed reversal relationships to functional status. In conclusion, the results of this study show that personal characteristic factors are more important than environmental characteristic factors for functional status of elderly people. However, the importance of depression to functional status in Korean rural elderly people and the reverse relationship between social environment and functional status, reflect Korean specificity. Korean nursing needs to focus more on this Korean specificity in order to develop nursing knowledge and practice appropriate to Korean people.

• Journal of Intelligence and Information Systems
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• v.5 no.1
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• pp.13-34
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• 1999

Building a knowledge base effectively has been an important research area in the expert systems field. A variety of approaches have been studied including rules, semantic networks, and frames to represent the knowledge base for expert systems. As the size and complexity of the knowledge base get larger and more complicated, the integration of knowledge based with database technology cecomes more important to process the large amount of data. However, relational database management systems show many limitations in handing the complicated human knowledge due to its simple two dimensional table structure. In this paper, we propose Object-Oriented Knowledge Store (OOKS), a knowledge base model on the basis of a frame sturcture using an object-oriented database. In the proposed model, managing rules for inferencing and facts about objects in one uniform structure, knowledge and data can be tightly coupled and the performance of reasoning can be improved. For building a knowledge base, a knowledge script file representing rules and facts is used and the script file is transferred into a frame structure in database systems. Specifically, designing a frame structure in the database model as it is, it can facilitate management and utilization of knowledge in expert systems. To test the appropriateness of the proposed knowledge base model, a prototype system has been developed using a commercial ODBMS called ObjectStore and C++ programming language.