• 대한전기학회논문지:전력기술부문A
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• 제48권10호
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• pp.1198-1205
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• 1999

This study is focused on the reliability evaluation for distribution system based on deterministic evaluation technique. Average failure rates, average outage time, and average annual outage time of electrical parts and load points are calculated through network reduction method and failure mode & effective analysis method. And reliability indices of distribution system are calculated. Finally, by employing analytic hierarchy process method, unique index which evaluates and improves the distribution system is calculated. As a result, finding weak points and expansion schedule of the system is possible. The usefulness of this method is verified by applying it to the Inchon International Airport.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 추계학술대회논문집A
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• pp.222-227
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• 2001

Nonlinear acoustic effect has been considered as an effective tool for the evaluation of material degradation. In this paper, the applicability of nonlinear acoustic effect to the evaluation of degradation of 2.25Cr-1Mo steel is investigated. Firstly, a number of 2.25Cr-1Mo steel samples were heat-treated, and their damage mechanism was examined. Secondly, Ultrasonic nonlinear parameter was measured. Nonlinear acoustic parameter was found to be clearly sensitive to the material degradation.

• 한국CDE학회논문집
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• 제6권2호
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• pp.140-146
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• 2001

A nuclear Power Plant is composed of a number of mechanical components. Maintaining the integrity of these components is one of the most critical issues in nuclear industry. In order to evaluate the integrity of these mechanical components, a lot of data are required including inspection data, geometrical data, material properties, etc. Therefore, an effective database system is essential to manage the integrity of nuclear power plant. For this purpose, an internet based virtual reality environment and web database system was proposed. The developed virtual reality environment provides realistic geometrical configurations of mechanical components using VRML (Virtual Reality Modeling Language). The virtual reality environment was linked with the web database, which can manage the required data for the integrity evaluation. The proposed system is able to share the information regarding the integrity evaluation through internet, and thus, will be suitable for an integrated system for the maintenance of mechanical components.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2010년도 춘계학술대회 논문집
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• pp.609-614
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• 2010

In this paper, the structural integrity and fatigue strength for the bogie frame of Monorail being developed in domestic was evaluated. Presently, the standard of evaluation for the bogie frame of monorail was not regulated. Therefore, the evaluation of the structural integrity and fatigue strength for the bogie frame was performed on the basis of the UIC 615-4 standard. The structural integrity of the designed bogie frame was evaluated by displacement and Von-Mises stress under each load conditions. And the fatigue strength was evaluated by combined main in-service load conditions specified at UIC 615-4 standard and it was compared with result of fatigue analysis using winLIFE v3.1 with the function of batch processing. The results shows that the structural integrity and fatigue strength of the designed bogie frame was satisfied, and the fatigue analysis using batch processing was more effective than conventional fatigue analysis using combined load conditions.

• 품질경영학회지
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• 제40권3호
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• pp.306-315
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• 2012

Purpose: To ensure good quality munitions, we require quantitative risk management and optimal risk management of system characteristics. Methods: Failure mode and effects analysis (FMEA) is a widely used technique to assess or to improve reliability of products at early stage of design and development. Traditionally, the prioritization of failures for corrective actions is performed by developing a risk priority number (RPN). Results: This paper reestablishes an effective methodology for prioritization of failure modes in FMEA procedure. Revised evaluation criteria of RPN are devised. Conclusion: To verify the proposed methodology, it is applied to RPN evaluation for K21 infantry combat vehicle.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2000년도 춘계학술대회논문집
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• pp.1675-1680
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• 2000

Recently the uncertainty has been made rapid progress in various fields of industry but the uncertainty measurement method of acoustical test (i.e. Insertion loss, Absorption ratio, Transmission loss etc,) hasn't been established. In this study, the uncertainty of measurement method for ducted silencers is carried out according to ISO 7235. The standard uncertainty factors are composed of sound pressure level, microphone sensitivity and pistonphone calibration in this measurement. Sound pressure level is type A evaluation of uncertainty, microphone sensitivity and pistonphone calibration are type B evaluation of uncertainty. The combined standard uncertainty is calculated by two type evaluation. The expanded uncertainty is expressed by the combined standard uncertainty multiply k value which is yield the effective degree of freedom.

• 한국윤활학회:학술대회논문집
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• 한국윤활학회 1998년도 제28회 추계학술대회
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• pp.175-180
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• 1998

This paper describes evaluation of oxidation stability for diesel engine oils by Hot-tube oxidation tester at high temperature. Evaluation was rated by visual inspection of lacquer in capillary glass tube and TAN determination of used oil. Air, NO$_2$-air and SO$_2$-air mixed gases were used as oxidizing gas. One oil which has low oxidation stability is selected and reformulated by addition of some additives such as antioxidant, detergent and disperant to improve oxidation stability. As a results of reformulation, antioxidant and detergent was effective for improvement of high temperture oxidation stability on diesel engine oil.

• Journal of the Korean Wood Science and Technology
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• 제42권5호
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• pp.590-596
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• 2014

Wooden cultural heritages of Korea have been destroyed by fire in many cases. As a result, a number of methods to protect wooden cultural properties against fire were introduced. A way of protecting wooden cultural properties installations of fire equipments such as sprinkler, fire alarm system, or fire extinguisher. Another way of protecting wooden cultural properties is to treat them with flame retardants for their safety. Development of a very effective flame retardant with a good performance without affecting danchung and wood quality is required. At the same time, methods of evaluating flame retardant treated woods should be devised to assess their efficacy. In this study, combustion characteristics using cone-calorimeter, limit oxygen index, moisture absorption, iron corrosive and weathering were analyzed to evaluate the flame resistance efficacy and performance of flame retardants treated woods. The evaluation methods of flame retardants for wooden cultural heritage were suggested.

• 대한임베디드공학회논문지
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• 제5권2호
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• pp.67-76
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• 2010

Although both functional verification and performance evaluation are necessary for the development of effective and reliable communication systems, they have been often performed independently; by functional modeling with formal language tools and by performance modeling with professional network performance evaluation tools, respectively. Separate and repeated modeling of one system, however, would often result in cost increase and inconsistency between the models. This paper proposes an integrated model design approach in order to overcome this problem that evaluates the performance of a communication protocol designed in SDL with SDL-OPNET model conversion. The proposed technique generates OPNET skeleton code from Tau-generated C code of the SDL model by analyzing the relations between SDL and OPNET models. IEEE 802.2 LLC protocol was used as an example of model conversion to show the applicability and effectiveness of the proposed technique.

• 한국정보과학회논문지:시스템및이론
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• 제36권5호
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• pp.380-386
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• 2009

중요 IT 자산에 대한 보안성 강화를 위해서는 관련 위협(또는 취약점)의 식별 및 이에 대한 보안 대비책의 적정성 분석이 선행되어야 한다. 이를 위해 본 논문에서는 자산 및 위협에 기반한 보안 위험도 평가기법을 제안한다. 제안한 기법은 식별된 자산 및 위협 관련 공격시도 탐지와 취약점 점검 등의 대응 범위 및 수준의 사전 점검과 정량적인 위험도 평가를 제공함으로써 기존 연구에 비해 효과적으로 위협관리 업무에 활용될 것으로 기대된다.