• 한국유체기계학회 논문집
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• 제10권2호
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• pp.22-31
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• 2007

This paper describes the shape optimization of rotor blade in a transonic axial compressor rotor. Three surrogate models, Kriging, radial basis neural network and response surface methods, are introduced to find optimum blade shape and to compare the characteristics of object function at each optimal design condition. Blade sweep, lean and skew are considered as design variables and adiabatic efficiency is selected as an objective function. Throughout the shape optimization of the compressor rotor, the predicted adiabatic efficiency has almost same value for three surrogate models. Among the three design variables, a blade sweep is the most sensitive on the object function. It is noted that the blade swept to backward and skewed to the blade pressure side is more effective to increase the adiabatic efficiency in the axial compressor Flow characteristics of an optimum blade are also compared with the results of reference blade.

• 한국정보과학회논문지:데이타베이스
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• 제30권4호
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• pp.397-407
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• 2003

이동 클라이언트를 이용한 공간 데이타의 변경 트랜잭션은 서버와 통신을 단절한 상태에서 사용자와의 상호 연산을 통하여 수정하는 긴 트랜잭션이다. 따라서 트랜잭션의 동시성 제어를 위해 잠금을 이용한 비관적 기법을 사용하면 이동 클라이언트가 잠금을 획득하기 위해 오랜 시간동안 대기해야 하므로 일반적으로 검증 작업을 이용한 낙관적 기법이 적합하다. 본 논문에서는 이동 클라이언트를 이용해 공간 데이타를 변경하는데 적합한 S-S-M(서버-대리 PC-이동 클라이언트) 구조를 위한 대리 트랜잭션 모델을 제안하고 모델에 따른 관리자클 구현한다. 서버와 이동 클라이언트가 대리 PC를 통해 통신하는 이 구조에서 대리 트랜잭션의 동시성 제어를 위해 공간 객체간의 위상 관계인 공간 관련성을 고려하며 기존의 검증 조건을 확장한다. 또한, 충돌이 발생한 트랜잭션의 완료 비용을 최소화하기 위해 대리 PC에서 충돌이 발생한 객체에 대하여 조정 작업을 수행하며 이를 지원하기 위한 확장된 완료 프로토콜을 제시한다.

• 융합신호처리학회논문지
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• 제10권4호
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• pp.256-261
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• 2009

최근의 웹환경은 닷넷과 자바로 양분되어 있다. 닷넷은 웹환경에서 원격의 객체를 호출하는 방법으로서 리모팅이라는 기술이 있다. 리모팅 기술 방식은 HTTP(Hypertext Transport Protocol)환경에서 데이터를 주고받는 원격호출의 한 형태로 SOAP(Simple Object Application Protocol)형태의 확장기술이다. 본 연구는 ERP(Enterprise Resource Planning)와 같은 잡한 업무의 웹프로그램에서 많이 사용하는 닷넷 리모팅 기술에서 ERP에 최적화한 응용계층 보안 적용, 리모팅 모듈과 암호화 모듈에서 중복되어 발생하는 직렬화 작업제거, 닷넷에서 사용되는 데이터 객체에 불필요한 데이터 제거를 통해 성능을 향상시키는 보안모듈 적용 방법을 제시하였다. 제시한 방법은 구현 및 실험을 통해 일반적인 보안적용에서 보다 약 2배의 속도 향상이 있음을 확인하였다. 향후 이와 관련된 컴포넌트 기반의 프레임워크 연구를 통해 편리한 개발자 환경 제공이 필요하다.

• 유체기계공업학회:학술대회논문집
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• 유체기계공업학회 2006년 제4회 한국유체공학학술대회 논문집
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• pp.543-544
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• 2006

Shape optimization of a transonic axial compressor rotor operating at the design flow condition has been performed using three-dimensional Navier-Stokes analysis and three different surrogate models: i.e.., Response Surface Method(RSM), Kriging Method, and Radial Basis Function(RBF). Three design variables of blade sweep, lean and skew are introduced to optimize the three-dimensional stacking line of the rotor blade. The object function of the shape optimization is selected as an adiabatic efficiency. Throughout the shape optimization of the rotor blade, the adiabatic efficiency is increased for the three different surrogate models. Detailed flow characteristics at the optimal blade shape obtained by different optimization method are drawn and discussed.

• Tribology and Lubricants
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• 제30권1호
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• pp.36-45
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• 2014

Understanding steel/skin contact phenomena is important for the study of object manipulation in robotics and has been a topic of great interest. In this study, pig skin was taken as a surrogate model for human skin, and its adhesive, friction, and deformation behaviors were measured under various exposure times to air. Indentation, friction, and scratch tests were performed at $25^{\circ}C$ and 45% relative humidity. The influences of adhesion and deformation on the coefficient of friction were characterized; the pig skin was found to be sensitive to the sliding velocity and normal load under the controlled experimental conditions.

• 한국정보시스템학회지:정보시스템연구
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• 제12권1호
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• pp.87-116
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• 2003

One of the important applications for business-to-business electronic commerce is in procurement and inventory management using electronic data interchange(EDI). Using online catalogs and approved supplier lists, firms can easily create requisitions and purchasing documents. The emerging trend in EDI technology is changed from VAN(Value Added Network) based EDI to XML based EDI. This paper intends to suggest a component-based XML/EDI system using Unified Modeling Language(UML), as an application system for automobile part industry. Applying component based XML/EDI systems designed with UML methodology, we analyzed the workflow and the document on procurement process between trading partners and implemented a prototype of efficient XML/EDI system, as a surrogate of existing VAN/EDI. The result of applying object-oriented CBD(Component Based Development) technique is to minimize the risk of life cycle and facilitate the reuse of software as mentioned to limitation of information engineering methodology. It enables the interoperability with corporate legacy systems such as ERP(Enterprise Resource Planning), SCM(Supply Chain Management). This system proposes a solution to apply analysis phase and design phase in implementation of XML/EDI system. The implementation of XML/EDI system using CBD shows the ease of use in software reuse and the interoperability with corporate internal information system. The purchasing department with XML/EDI system can electronically communicate purchase orders, delivery schedules to external suppliers and interoperate with other application systems.

• 한국정보시스템학회지:정보시스템연구
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• 제12권2호
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• pp.129-149
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• 2003

One of the important applications in Enterprise Resource Planning(ERP) systems is the Manufacturing Resource Planning(MRPII) system using Bill of Material(BOM). The manufacturing resource planning determines the quantity and timing of the production or purchase of subassemblies and raw materials needed to support the Master Production Scheduling(MPS). The bill of material is the recipe, a list of the materials needed to make a product. This paper intends to suggest a component-based materials management system using Unified Modeling Language(UML), as an application system for automobile part industry. Applying component based materials management systems designed with UML methodology, we analyzed the workflow and the document on materials management process from production planning to inventory management, and implemented a prototype of efficient materials management system, as a surrogate of existing material requirement planning(MRPI) system. To produce many other assemblies for a automobile part firm, component parts are assembled into subassemblies that are joined to assemble the finished product. Through the system suggested in this study, the level of inventory has cut down and the cost of inventory management has decreased. Also, the development method using UML makes the analysis and design phase to shorten in implementation period of MRPII system. The implementation of materials management system using CBD shows the ease of use in software reuse and the interoperability with corporate Internal information system. The result of applying object-oriented CBD technique is to minimize the risk of life cycle and facilitate the reuse of software as mentioned to limitation of information engineering methodology.