• Proceedings of the Korean Nuclear Society Conference
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• 1998.05b
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• pp.795-801
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• 1998

Metallic fatigue of Pressurized Water Reactor(PWR) materials is a generic safety issue for commercial nuclear power plants. It is very important to obtain the fatigue usage factor for component integrity and life extension. In this paper, fatigue usage was obtained at the inside surface of Kori unit 2, 3 and 4 RCP casing weld, based on the design transient. And it was intended to establish the procedure and the detailed method of fatigue evaluation in accordance with ASME Section III Code. According to this code rule, two methods to determine the stress cycle and the number of cycles could be applied. One method is the superposition of cycles of various design transients and the other is based on the assumption that a stress cycle correspond to only one design transient. Both method showed almost same fatigue usage in the RCP casing weld.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.05a
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• pp.783-791
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• 2000

Increasing demands in productivity are propelling the development of new manufacturing methods like hard machining, high speed cutting (HSC) or machining of difficult to machine materials. In these processes the toois are subjected to very severe mechanical, tribological and thermal loads. They fail prematurely by abrasion, cratering, edge breakage and cold welding. The performance of such tools will be enhanced by better and more wear resistant coatings. The development of these new coatings shows a clear trend towards complex multi-component and multi-layer configurations. TiAIN multilayer coating belongs to these coatings for the new cutting tool generation. This paper tries to explain the benefits of the new coatings. TiAIN multilayer coating offers the following advantages: reduction of manufacturing costs. boost productivity, and lower coolant procurement, conditioning and disposal costs.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 1999.08a
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• pp.349-355
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• 1999

The texture inhomogeniety during rolling is one of the greatest problems. Especially, shear texture develops more easily during ferritic rolling of steel sheets at high temperatures due to friction between rolls and the material. In this study, the influence of front and back tensions on the texture development during ferritic rolling has been studied. The rolling textures were simulated using the full constrains Taylor-Bishiop-Hill model with the strain history obtained from finite element analysis. The calculated textures showed that the back tension rolling could reduce the shear component more effectively than front tension or rolling without tension. However, the experimental results showed that the lension effect was very small compared to our prediction. It might be attributed to initial texture and difference in frictions between simulation and experiments.

• Proceedings of the Korea Concrete Institute Conference
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• 1997.10a
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• pp.97-102
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• 1997

In this study, a predictive method which was modified from KIshi's model for the temperature development of concrete was developed by using mineral compounds of clinker and pozzolans. Temperature dependent heat generation of reaction was also considered. Specific heat considering the effect of mix proportion and temperature was calculated with experimental data in the literatures. Thermal conductivity considering the effect of mix proportion and temperature was experimentally investigated. Through this research it was found that the developed method considering thermal properties accurately predicted adiabatic temperature rise of concrete without the experiment. It was also found that the thermal conductivity of concrete could be predicted by the volume ratio of each component of mix proportion and was independent of temperature within the normal climatic range.

• KCI Concrete Journal
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• v.12 no.2
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• pp.31-43
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• 2000

The extensive usage of pretensioned prestressed concrete component in modem construe- tion as structural members mandates precise understanding of its mechanism. Especially, an adequate transfer of prestressing force from steel tendons to concrete around the end regions of the member is a critical issue. Due to the importance of the topic, several investigators have formulated equations modeling the transfer bond length based on various bonding mechanism between steel and concrete. However, the existing models are still inadequate in predicting the bond development in pretensioned prestressed concrete members. Therefore, this study presents a model of transfer bond length based on rational theory that can simulate experimental results. The model is developed into solid mechanics based structural analysis computer program. The program is validated by comparing the analysis results with experimental results of bond stress distribution, concrete strain profiles, and transfer length in pretensioned prestressed concrete members. The proposed analytical procedure in this study can be utilized as a useful tool for realistic evaluation of transfer length in pretensioned prestressed concrete members.

• Convergence Security Journal
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• v.7 no.3
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• pp.25-30
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• 2007

CC ver.3 is widening evaluation range extent about Security product. As a result, The security product evaluation research need more definite standard that serves to evaluate composition style product. The paper propose a development guide for composition style TOE. This research is suitable in evaluation basis of CC ver.3, and presents Korean-made composition style product estimation plan. This paper used European ITSEM component guide and TOE analysis to present estimation guide method of composition style product.

• Proceedings of the KIEE Conference
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• 1996.07c
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• pp.1407-1408
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• 1996

The development of MCFC is going to the second stage of development and recent studies have been focusing on long-term durability of cell component. Systematic investigation on corrosion behavior of Fe-based alloys has been done in (62+38) mol % (Li+K) $CO_3$ melt at 923K by using steady-state polarization and electrochemical impedance spectroscopy method. It was found that the corrosion current t of these Fe-based alloys decreased with increasing Cr, Al content.

• Proceedings of the Korean Information Science Society Conference
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• 2000.10a
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• pp.451-453
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• 2000

소프트웨어의 경제성, 시장 경쟁력 확보를 위한 소프트웨어의 재사용은 소프트웨어 공학의 주요 이슈가 되고 있다. 그 중 컴포넌트와 컴포넌트 기반의 소프트웨어 개발은 재사용성을 확보할 수 있는 가장 주목받는 방안으로 제시되고 있으며 많은 기법이나 지침들이 제안되고 있다. 기존의 캡슐화와 정보은폐를 핵심 개념으로 하는 OOD(Object Oriented Development)에 의한 소프트웨어 개발방법은 이미 재사용성, 유지보수성, 무결성, 안정성 등의 많은 장점으로 인해 학계와 산업계에서 이미 많이 보편화되어 있고 널리 이용되어 지고 있다. 하지만 CBD(Component Based Development)와 EJB(Enterprise Java Beans)에 기반하여 컴포넌트 어플리케이션을 개발하는데 있어서는 그 적용사례가 드물고 활요성 또한 검증된 바가 거의 없다. 따라서 본 논문에서는 대형 분산 시스템이라 할 수 있는 뱅킹 시스템에 CBD, EJB, UML(Unified Modeling Language)을 적용해 봄으로써 소프트웨어 개발시의 그 실무적인 유용성을 검증해 본다.

• Proceedings of the Korean Information Science Society Conference
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• 2010.06d
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• pp.190-195
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• 2010

Vehicular ad hoc networks (VANETs) have a number of interesting applications to preserve road safety, notify users about changed road/traffic condition, handling post accident hazards and moreover service oriented applications to make the travel convenient to the drivers. Use of common information format for diverse applications enables the application developers to easily design flexible information dissemination system for new applications or add new features to existing application. This paper introduces a common information format for various applications in VANETs. The main goal of the paper is to design generalized distributed architectures for vehicular networks, which considers diverse application development scenarios and uses common information format. The proposed architectures enable the application developers to flexibly disseminate information to affected or interested user. In this paper, we have given a detail description of each component of the architectures and how they communicate with each other. In future, we will implement the proposed architecture using suitable simulator.

• Journal of Power System Engineering
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• v.14 no.1
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• pp.40-46
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• 2010

This paper shows the development process for measuring three-dimensional flow velocity components in a web-browser. The system is developed in an embeddable C/C++ interpreter Ch and Ch-CGI toolkit. The interface for the web-based measurement system consists of a set of web HTML files and Ch files for CGI. All of data in web browser are passed to Ch-CGI script to generate the output of new HTML file. PC-Server and PC-Client can submit measurement parameters and receive the text/graphical results each other. PC-Client can control the test equipment by using a parameters that received from PC-Server. It also can pass the test results between the web-based measurement system. In summary, the designed measurement system is evaluated, the outputs shown well on the web browser.