• Journal of Power System Engineering
• /
• 제14권4호
• /
• pp.63-67
• /
• 2010

This paper introduces the eddy current signal characteristic of magnetic and non-magnetic gas turbine rotor. In the past, Magnetic particle inspection method was used in magnetic material for qualitative defect evaluation and the ultrasonic test method was used for quantitative evaluation. Nowadays, eddy current method is used in magnetic gas turbine rotor inspection due to advanced sensor design technology. We are studying on the magnetic gas turbine rotor by using eddy current method. We prepared diverse depth specimens made by magnetic and non-magnetic materials. We select optimum frequency according to material standard penetration data and experiment results. We got the signal on magnetic and non-magnetic material about 0.2 mm, 05 mm, 1.0 mm, 1.5 mm 2.0 mm and 2.5 mm depth defects and compare the signal amplitude and signal trend according to defect depth and frequency. The results show that signal amplitudes of magnetic are bigger than non-magnetic material and the trends are similar on every defect depth and frequency. The detection and resolution capabilities of eddy current are more effective in magnetic material than in non-magnetic materials. So, the eddy current method is effective inspection method on magnetic gas turbine rotor. And it has the merits of time saving and simple procedure by elimination of the ultrasonic inspection in traditional inspection method.

• Journal of the Ergonomics Society of Korea
• /
• 제29권4호
• /
• pp.435-444
• /
• 2010

To identify and evaluate the risk factors in WMSD work, a number of ergonomic workload evaluation methods have been developed. In the legal examination of WMSD risk factors, simple observational workload evaluation methods are widely used instead of using costly measurement equipments such as EMG and motion analyzer. The simple workload evaluation methods can be categorized into three groups; risk factor checklist methods, posture observation methods, and manual material handling task evaluation methods. In terms of the categories, this survey summarized several representative workload evaluation methods and compared them each other. Then some industrial application cases referring each the workload evaluation methods were surveyed. Due to the characteristics of each method, the selection and application procedure of workload evaluation method should be appropriate for the corresponding work. Therefore, some guidelines for the selection and application procedure of workload evaluation method were suggested.

• Journal of the Korea Concrete Institute
• /
• 제22권6호
• /
• pp.787-796
• /
• 2010

The main reason of the earth global warming is $CO_2$ and the regulation about it in the whole world has been reinforced to reduce $CO_2$ emission. It is needed that we should reduce it in the process at the production of concrete generated much of $CO_2$ emission as the primary material of construction industry recognized unfriendly environment industry. Based on a concrete, this study was constructed the system to evaluate $CO_2$ emission generated in the stage of material production, transportation, manufacture and developed the program to reduce and evaluate it efficiently. As a result, most of $CO_2$ emission is generated in the stage of material and it is quantitatively evaluated $CO_2$ emission generated in the stage of materials, transportation and manufacture. Moreover, the evaluation system of the volume of $CO_2$ emission which has the friendly environment technology about reduction of $CO_2$ emission at each stage is suggested for quantitatively evaluation $CO_2$ emission generated in the process at the production of concrete and remicon production company could use it to evaluation $CO_2$ emission.

• Journal of the Society of Disaster Information
• /
• 제17권4호
• /
• pp.747-754
• /
• 2021

Purpose: Seismic safety evaluation of a curved bridge must be performed since the curved bridges exhibit the complex behavior rather than the straight bridges, due to geometrical characteristics. In order to conduct the probabilistic seismic assessment of the curved bridge, Seismic fragility evaluation was performed using the uncertainty of the steel material properties of a curved bridge girde, in this study. Method: The finite element (FE) model using ABAQUS platform of the curved bridge girder was constructed, and the statistical parameters of steel materials presented in previous studies were used. 100 steel material models were sampled using the Latin Hypercube Sampling method. As an input ground motion in this study, seismic fragility evaluation was performed by the normalized scale of the Gyeongju earthquake to 0.2g, 0.5g, 0.8g, 1.2g, and 1.5g. Result: As a result of the seismic fragility evaluation of the curved girder, it was found that there was no failure up to 0.03g corresponding to the limit state of allowable stress design, but the failure was started from 0.11g associated with using limit state design. Conclusion: In this study, seismic fragility evaluation was performed considering steel materials uncertainties. Further it must be considered the seismic fragility of the curved bridge using both the uncertainties of input motions and material properties.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 한국정밀공학회 2012년도 춘계학술대회 논문집
• /
• pp.1117-1118
• /
• 2012

• Proceedings of the Korean Fiber Society Conference
• /
• 한국섬유공학회 2007년도 학술발표회 논문집
• /
• pp.327-328
• /
• 2007

• Journal of the Korean Society for Heat Treatment
• /
• 제18권2호
• /
• pp.126-133
• /
• 2005

• Proceedings of the International Microelectronics And Packaging Society Conference
• /
• 한국마이크로전자및패키징학회 2004년도 추계 기술심포지움 초록집
• /
• pp.24-24
• /
• 2004

• 한국전자현미경학회:학술대회논문집
• /
• 한국현미경학회 2004년도 제35차 춘계학술대회
• /
• pp.94-96
• /
• 2004

• The Journal of Sustainable Design and Educational Environment Research
• /
• 제12권2호
• /
• pp.1-10
• /
• 2013

This study evaluates the relationship among the evaluation structure of morphological elements, the satisfaction on exterior elements, and the image evaluation for the campus landmarks by campus type. The investigation results are summarized as follows. 1) The university headquarter was nominated as the university landmark, and the main reason for the nomination was the building's historic and locational value. 2) Of the morphological elements of the campus landmark, 'proportion and balance' and 'harmony and order' were deemed important, while 'diversity' was deemed less important. 3) For the satisfaction on the facility's exterior elements, the evaluation structure was different for each university. However, the factor of 'location of the facility' was deemed the biggest factor for satisfaction for all universities, while the facility's 'color and material' were found to be the most dissatisfying factors. 4) The image evaluation on the facility was different for each university. Although there was a strong skeptical image about 'liveliness', there was a very positive image about 'elegance' and 'scale'. 5) On the relationship between the satisfaction on exterior elements and the image evaluation, there was a different evaluation structure for each university. 'Facility's color and exterior material' were the main elements which improved the overall image of the facility. Thus, the study results strongly suggest that an important task is to determine the maintenance direction through the emphasis on the relationship between exterior elements and image satisfaction for each university.