• 한국재난정보학회 논문집
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• 제5권2호
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• pp.140-152
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• 2009

Recently the occurrence ratio of mechanical accidents in industrial disaster of korea is increased, but very little accident information has been given regarding the prevention of mechanical accidents. In this study, mechanical accidents by the analysis of industrial accident case was examined. And it was proposed the risk assessment method and building database for investigation of risk factors in mechanical accident. As a result, from mechanical accidents database, it was found that the occurrence ratio of mechanical accident by constriction and falling etc. is very high and death ratio by mechanical accident is larger than that of usual accident. And we applied the quantitative risk assessment method proposed by this study in the mechanical accident analysis of a domestic manufacturer. From the results, the risk factors due to constriction, curling, falling and scattering are principal causes of mechanical accidents. These result is similar to that of the analysis of mechanical accidents for recent 12 years in korea.

• 공학교육연구
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• 제13권3호
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• pp.18-33
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• 2010

This paper describes two capstone senior design courses for the Mechanical Engineering program at University of the Pacific. The first course taught in the Fall semester is entitled "Engineering Design/Senior Project I." The second course taught in the Spring semester is entitled "Engineering Design/Senior Project II." All Mechanical Engineering students with senior standing are required to take these two classes in this sequence. At the end of every Spring semester, industrial advisors are invited to assess the final senior projects during an annual Senior Project Day. This assessment is performed using the Program Outcomes and Program Educational Objectives established for Pacific's Mechanical Engineering program. Since all Mechanical Engineering students are required to complete senior projects, this is a 100% evaluation process. After the evaluations are done, the data sets are compiled and reviewed by the faculty for assessment purposes. It is important to note that the industrial advisors perform the evaluations, but the faculty members assess the information to determine if modifications need to be made to the program or courses. In addition to the senior project evaluations, general feedback from Mechanical Engineering Industrial Advisory Committee (MEIAC) members is also useful for the outcomes-based assessment process in addition to the definition and evaluation of Program Outcomes and Program Educational Objectives.

• 한국안전학회지
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• 제37권5호
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• pp.33-41
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• 2022

As the number of automobile registrations increases yearly, parking spaces that are located in downtown areas are increasing, and mechanical parking facilities are also increasing. Therefore, there is a high risk of accidents when installing and repairing a mechanical parking facility. In the preceding six years (from 2012 to 2018), the statistics that pertain to accidental disasters indicated that a total of 137 disaster victims were generated by the construction sector, 33 accidents occurred, and 10 people died. However, only the safety management items pertaining to accidents that occur during maintenance work and the use of the installed mechanical parking facilities are being studied; furthermore, there is no ongoing research with respect to the risk management that is conducted at the construction site. In 2017, the Korea Occupational Safety and Health Agency (KOSHA) announced the "Guidelines for Safe Installation and Maintenance of Mechanical Parking Equipment"; however, it is a safety guideline that is limited to the installation of basic protective equipment and to facility installation. There is no model for mechanical parking facilities that is indicated in the "Risk Assessment Model by Construction Industry Type", which is issued by the Safety and Health Corporation and is widely utilized for risk assessment in the construction industry; moreover, elevator installation work CODE N0: 22 is the only major example of a disaster. In this study, "risk assessment through a focus group interview" was performed, and data was derived from the "risk assessment of Article 41 (2) of the Industrial Safety and Health Act", which reflects the characteristics of the construction industry based on AHP analysis. The results of this study can be utilized for the risk assessment that is conducted during the construction stage of mechanical parking facilities.

• 공학교육연구
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• 제13권6호
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• pp.143-151
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• 2010

본 논문은 서울과학기술대학교(구 서울산업대학교) 기계설계자동화공학부에서 16년간의 캡스톤디자인 운영경험과 개선을 바탕으로 캡스톤디자인 교과목 기반의 프로그램 학습성과의 평가 사례에 대해 서술하였다. 우선, 캡스톤디자인 교과목과 관련된 프로그램 학습성과를 소개하였고, 평가 방법 및 항목에 대해서 설명하였다. 이를 바탕으로 하여 2008년도의 학습성과 평가 결과를 도출하였고, 이를 분석한 후 개선 전략을 수립하였다. 전략으로서 학생들에게 심사 기준과 모범사례를 온라인상에 미리 공개하였고, 그 결과 2009년도에는 전반적으로 약 3.3% 개선된 학습성과 평가 결과를 얻을 수 있었다. 마지막으로 코스 임베디드 평가 개념 측면에서 캡스톤디자인 교과목을 이용한 프로그램 학습성과 평가의 타당성, 효율성, 내실성, 그리고 지속가능성에 대해서도 논의하였다.

• 환경영향평가
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• 제9권4호
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• pp.257-269
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• 2000

This study is to investigate the methodology and applicability on emission control by both MECHANICAL Model and Fugitive Dust Model (FDM) through the comparison of field measurement data and calculated data. Comparing to the method of AP-42 emission fector on the production of flying dust the MECHANICAL Model was proved to be more applicable to the calculation emission rate on the various dust emission conditions on a unpaved road. The seperate calculation on annual mean emission amount and a 24working hours amount was undertaken for the easy management of fugitive dust. Dust concentration predicted by FDM is similar with a measurement value.

• 한국자동차공학회논문집
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• 제15권5호
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• pp.56-62
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• 2007

In order to compare subjective and objective assessments, a passenger car was driven at several speeds over several road profiles. To measure the acceleration signals experienced by the seated subject who provided an subjective assessment, four triaxial translational accelerometers and one triaxial gyro sensor were mounted on the steering wheel and on the passenger seat and floor, respectively. Correlations were determined between the measured accelerations and the subjective assessments of 3 expert subjects and 9 general subjects using psychophysical power law.

• Earthquakes and Structures
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• 제12권6호
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• pp.653-663
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• 2017

A seismic margin assessment evaluates how much margin exists for the system under beyond design basis earthquake events. Specifically, the seismic margin for the entire system is evaluated by utilizing a systems analysis based on the sub-system and component seismic fragility data. Each seismic fragility curve is obtained by using empirical, experimental, and/or numerical simulation data. The systems analysis is generally performed by employing a fault tree analysis. However, the current practice has clear limitations in that it cannot deal with the uncertainties of basic components and accommodate the newly observed data. Therefore, in this paper, we present a Bayesian-based seismic margin assessment that is conducted using seismic fragility data and fault tree analysis including Bayesian inference. This proposed approach is first applied to the pooltype nuclear research reactor system for the quantitative evaluation of the seismic margin. The results show that the applied approach can allow updating by considering the newly available data/information at any level of the fault tree, and can identify critical scenarios modified due to new information. Also, given the seismic hazard information, this approach is further extended to the real-time risk evaluation. Thus, the proposed approach can finally be expected to solve the fundamental restrictions of the current method.

• International Journal of Precision Engineering and Manufacturing
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• 제7권3호
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• pp.24-29
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• 2006

Pressurized gas pipelines are subject to harmful effects from both the surrounding environment and the materials passing through them. Reliable assessment procedures, including fracture mechanics analyses, are required to maintain their integrity. Currently, integrity assessments are performed using conventional deterministic approaches, even though there are many uncertainties to hinder rational evaluations. Therefore, in this study, a probabilistic approach was considered for gas pipeline evaluations. The objectives were to estimate the failure probability of a corroded pipeline in the gas and oil industries and to propose limited operating conditions for different types of loadings. To achieve these objectives, a probabilistic assessment program was developed using a reliability index and simulation techniques, and applied to evaluate the failure probabilities of a corroded API-5L-X52 gas pipeline subjected to internal pressures, bending moments, and combined loadings. The results demonstrated the potential of the probabilistic integrity assessment program.

• 대한기계학회논문집A
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• 제25권5호
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• pp.823-833
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• 2001

In recent years, the subject of remaining life assessment has drawn considerable attention in chemical plants, where various structural components typically operate at high temperature an pressure. Thus a life prediction methodology accounting for high temperature creep fracture is increasingly needed for the components. Critical defects in such structures are generally found in the form of semi-elliptical surface crack, and the analysis of which is consequently an important problem in engineering fracture mechanics. On this background, we first develop an auto mesh generation program for detailed 3-D finite element analyses of axial and circumferential semi-elliptical surface cracks in a piping system. A high temperature creep fracture parameter C-integral is obtained from the finite element analyses of generated 3-D models. Post crack growth module is further appended here to calculate the amount of crack growth. Finally the remaining lives of surface cracked pipes for various analytical parameters are assessed using the developed life assessment program.

• International Journal of Naval Architecture and Ocean Engineering
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• 제11권1호
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• pp.353-363
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• 2019

This paper presents a comprehensive simulation and assessment of gas dispersion above sea from a subsea release using a Computational Fluid Dynamics (CFD) approach. A 3D CFD model is established to evaluate the behavior of flammable gas above sea, and a jack-up drilling platform is included to illustrate the effect of flammable gas cloud on surface vessels. The simulations include a matrix of scenarios for different surface release rates, distances between surface gas pool and offshore platform, and wind speeds. Based on the established model, the development process of flammable gas cloud above sea is predicted, and the dangerous area generated on offshore platform is assessed. Additionally, the effect of some critical factors on flammable gas dispersion behavior is analyzed. The simulations produce some useful outputs including the detailed parameters of flammable gas cloud and the dangerous area on offshore platform, which are expected to give an educational reference for conducting a prior risk assessment and contingency planning.