• Proceedings of the Computational Structural Engineering Institute Conference
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• 1995.10a
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• pp.87-94
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• 1995

In highway bridges robust damage detection exercises are mandatory to secure the safety of the structures from hostile environmental conditions such as fatigue earthquake, wind, and corrosion. This paper presents a damage detection practice in a full-scale highway bridge by utilizing modal response parameters of as-built and damaged states of the structure. first the test structure is described and modal testing procedures are outlined. Next, a damage detection model which yields information on the location of damage directly from changes in mode shapes is outlined. Finally, the damage detection model is implemented to predict the location of damage in the ten structure. From the results, it was found that the damage detection model accurately locates damage in the test structures for which modal parameters of only a single mode are available for pre-damage (as-built) and post-damage stages.

• Proceedings of the Korea Concrete Institute Conference
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• 2005.05b
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• pp.293-296
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• 2005

The tensile properties of GFRP(glass fiber reinforced polymer) rods with various surface deformation produced by RTM(resin transfer molding) process were analyzes experimentally. Two types of GFRP rods with different surface deformation manufactured by RTM process in domestic area and two types of GFRP rods imported were considered in this study. All testing procedures including specimens preparation, set-up of test equipments and measuring devices were made according to the ASTM D3916-02 recommendations. From the test results, it was found that wave-type GFRP rod made by RTM process showed the highest tensile strength due to the highest fiber volume ratio.

• Journal of the Korean Home Economics Association
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• v.30 no.1
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• pp.163-178
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• 1992

The purpose of this study was to test system model for family resources management developed by Deacon and Firebaugh. The data were collected by means of a questionnaire destributed to a stratified sample of 600 housewives living in Seoul. The questionnaires specially developed by the researchers contained of 118 items. the coefficient alpha reliability estimate for this instrument was conducted using Cronbach' procedures. The data were analyzed using frequency, percentile, mean, step wise multiple regression and path analysis. The results of path analysis showed that the level of the elements of satisfaction with the management was correlated with demands(the household size, the age of the last child, employment status of respondents), resources(marital satisfaction, health of respondents), and throughput(standard setting, reality in planning, the existence of facilitating conditions). A system model for family resource management received considerabel empirical support. This presumed that the components of demands lead to the lower satisfaction with management. The throughput components were also important in explaining satisfaction with management some of research and methodology issues for the advanced study were suggested.

• Proceedings of the KSME Conference
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• 2004.04a
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• pp.258-263
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• 2004

Mechanical property evaluation of micrometer-sized structures is necessary to help design reliable microelectromechanical systems(MEMS) devices. Most material properties are known to exhibit dependence on specimen size and such properties of microscale structures are not well characterized. This paper describes techniques developed for tensile testing of materials used in MEMS. Epi-polycrystalline silicon is currently the most widely used material, and its tensile strength has been measured as 1.52GPa. We have developed an uniaxial testing machine for testing microscale specimen using electro-magnetic actuator. The field magnet and the moving coil taken from an audio-speaker were utilized as the components of the actuator. Structure of specimen was designed and manufactured for easy handling and alignment. In addition to the static tensile tests, new techniques and procedures for measuring strength are described.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.31 no.6 s.261
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• pp.644-650
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• 2007

Mechanical property evaluation of micrometer-sized structures is necessary to help design reliable microelectromechanical systems(MEMS) devices. Most material properties are known to exhibit dependence on specimen size and such properties of microscale structures are not well characterized. This paper describes techniques developed for tensile testing of thin film used in MEMS. Epi-polycrystalline silicon is currently the most widely used material, and its tensile strength has been measured as 1.52GPa. We have developed a tensile testing machine for testing microscale specimen using electro-magnetic actuator. The field magnet and the moving coil taken from an audio-speaker were utilized as the components of the actuator. Structure of specimen was designed and manufactured for easy handling and alignment. In addition to the static tensile tests, it is described that new techniques and procedures can be adopted for high cycle fatigue test of a thin film.

• Proceedings of the KSR Conference
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• 2006.11b
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• pp.196-201
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• 2006

Due to the damage which is caused by with the smoke, in the analysis statistics of a fire accident smoke is becoming the important evaluation index of fire quality. We must follow the procedures to use interior material for railway car as stated the Safety regulation for the urban railway car. In this study, we compared the Smoke Density of the train seat by test between Cone-Calorimeter and Smoke Density-Chamber. The results showed that the smoke density by test between Cone-Calorimeter and Smoke Density-Chamber is visible a similar tendency.

• Journal of the Korean Data and Information Science Society
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• v.23 no.4
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• pp.843-850
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• 2012

The inferences of data obtained from periodic inspection and type I censoring for the three step stress accelerated life test are studied in this paper. The failure rate function that a log-quadratic relation of stress and the tampered failure rate model are considered under the exponential distribution. The optimal stress change times which minimize the asymptotic variance of maximum likelihood estimators of parameters is determined and the maximum likelihood estimators of the model parameters are estimated. A numerical example will be given to illustrate the proposed inferential procedures.

• Structural Engineering and Mechanics
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• v.30 no.4
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• pp.481-500
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• 2008

In this paper, a model updating technique in dynamics is used to identify elastic properties for pultruded GFRP-Glass Fiber Reinforced Plastic framed structural systems used in civil construction. Traditional identification techniques for composite materials may be expensive, while this alternative approach allows to identify several properties simultaneously, with very good precision. Furthermore, the procedure of a non-destructive type has a relatively simple implementation. Properties describing the mechanical behavior for beam and shell finite element modeling are identified. The used formulation is based on the minimization of eigensolution residuals. Important points concerning model updating procedures have been observed, such as the particular vibrational behavior of the test structure, the modeling strategies and the optimal placement of the sensors in the experimental procedure. Results obtained by experimental tests show the efficiency of the proposed procedure.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2018.05a
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• pp.181-182
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• 2018

2015년 6월 MSC 95차 위원회에서 e-navigation 소프트웨어 품질 보증 가이드라인이 회람문서로 정식 등재되었다. 이 가이드라인은 소프트웨어 개발 라이프사이클에 따라 소프트웨어를 개발하며 필요한 품질 보증 절차 활동과 사용자의 요구를 만족시킬 수 있는 제품의 개발을 위한 인간중심설계 절차를 제시한다. 본 논문에서는 e-navigation 소프트웨어 품질보증 가이드라인을 심층분석하여 해양 임베디드 응용 소프트웨어 품질보증을 위한 사용성평가 시험절차 개발에 필요한 연관된 국제표준 및 기존 연구를 조사 분석 후 연구하였다.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2009.05a
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• pp.259-262
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• 2009

IEC 61850 based substation automation system mainly consists of human machine interface and a various of IEDs in charge of protective and control functions of the substation. Both of them should require the performance verification of IEC 61850 communication services because their communication relation is the same as client and server throughout the digital network. This paper shows a research result on the testing method of basic communication interface of the IEC 61850 based client, which was implemented by the analysis of real communication between HMI and IED of IEC 61850 based substation automation system and refereed to IED IEC 61850 conformance test procedures.