• Proceedings of the Computational Structural Engineering Institute Conference
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• 1996.10a
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• pp.304-312
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• 1996

Concepts, methods and tools for interactive CAD-based concurrent engineering design optimization of mechanical/structural systems and components which are critical in terms of cost development time, functionality and quality, are presented. The emphasis is on implementation of methods and capabilities for the optimization of composite structural system, and the integration of design process and manufacturing process of composite structures into standard CAD-based concurrent engineering environment The optimization of composite fuselage structures are performed under concurrent engineering environment for the example.

• Proceedings of the Korean Society For Composite Materials Conference
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• 1999.11a
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• pp.272-276
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• 1999

The present paper proposes design and manufacturing methods of the carbon/epoxy square grid structure with near zero-CTE in three geometrical principal directions. Bonding strength of the grid structure is examined for different bonding methods. Numerical examples show that maximum displacement of the composite grid structure is almost zero comparing with that of aluminum grid structure with same dimension under thermal loading.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.23 no.58
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• pp.49-58
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• 2000

In order to resolve a deadlock problem in manufacturing systems, three main methods have been proposed-prevention, avoidance, and recovery. The prevention and avoidance methods require predicting deadlocks in advance in order to prohibit them. In contrast, the recovery method allows a system to enter a deadlock state, then resolves it usually using a common buffer. In this paper, a deadlock recovery method considering the impact of flexible job routings is proposed. This method is based on capacity-designated directed graph (CDG) model representing current requesting and occupying relations between Jobs and resources in order to detect a deadlock and then recovers it.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2004.10a
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• pp.10-15
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• 2004

A machining processes for flange panel has been introduced. Contrary to the conventional methods like forming and welding, roll-seaming method has been utilized for better quality and less cost. Several measurement methods including digital image processing have been used to confirm the product quality assurance.

• Ceramist
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• v.21 no.2
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• pp.83-88
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• 2018

There is close relation between the heat generation and the performance of electronic device. The durability and efficiency of the device are degraded due to heat generation. It is necessary to release the generated heat from an electronic device. Based on demands of the printed circuit board (PCB) manufacturing, the robust and reliable plating technique of PCB is necessary. In this study, we review various methods for improving the heat sink property. These methods were considered to enhance the adhesion between ceramic substrate as heat sink and metal layer as electrode.

• Proceedings of the Membrane Society of Korea Conference
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• 1991.10a
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• pp.4-8
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• 1991

The characterization of pore properties (mean pore size and pore size distribution) of the active layer in a UF membrane is important not only in order to obtain information about the factors affecting pore formation during membrane manufacturing but also to understand deeply the mechanism of solute and solvent transport through pores. Many methods of characterizing quantitatively the pore properties of UF membranes have been suggested in the literature: solvent and gas flow measurement, bubble point determination, electron microscopy, gas adsorption/desorption measurement, rejection measurement etc. But most of these methods involve time-consuming procedures and involve some wellknown problems and uncertainties.

• International Journal of Korean Welding Society
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• v.4 no.1
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• pp.1-9
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• 2004

Continuously welded tracks, first introduced on train lines, are being used increasingly in Europe. And the different arc welding methods are only used on minor lines, private tracks and in the manufacturing of switches and crossings. Mobile flash butt welding belongs the future in rail welding on side if new tracks have to be erected. The following contribution reviews the processes available, usual test methods for welded rail joints and various applications.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.18 no.3
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• pp.185-188
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• 2008

Objectives: The purpose of this study is to analyze the occupational safety and health(OSH) state of precarious employee. Methods: The questionnaire of this survey is composed of 9 categories that are the workplace general information and the state of occupational injury and disease, OSH organization, OSH education and training. The subjects of this survey were the Manufacturing. The hypothesis of this study is where the proportion of precarious employee is higher, the OSH state is worse. To verify this hypothesis, we grouped the subjects into three categories by the proportion of precarious employee like as 0%(all standard employee), less than 30% and 30% or more. Using the SPSS 12.0 program to analyze the data, logistic regression analysis were implemented to find affective factors for the rate of occupational injury and disease. Results: 2,633 manufacturing workplaces were included for subjects. The proportions of precarious employee were 9.6 %. In manufacturing industry, about 70 % companies had no precarious employee. 16.8 % companies were in less than 30 % group, 13.2 % companies were in 30% or more group. For the rate of occupational injury and disease, the precarious group were 0.85(${\pm}1.8$), 1.19(${\pm}2.9$), 0.59(${\pm}1.1$). There was a trend that the higher precarious proportion groups was the higher rate of occupational injury and disease by the logistic regression analysis. It is more strong relationship than company size and OSH committee. Conclusions: We could find a significant result there was a positive relationship between the hiring proportion of precarious employee and the rate of occupational injury and disease in manufacturing industry with 50 employees and more.

• Korean Journal of Health Education and Promotion
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• v.23 no.2
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• pp.121-140
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• 2006

Objectives: Safety is a primary health promotion issue in worksite because injury induces multi-fold loss of the human and economic resources to profit organization. The purposes of this study were to describe worksite health and safety education and management status in Korean manufacturing companies. Methods: The original population size of Korean manufacturing industry in 2004 was 74,398 and 2,960 factories were selected by the multiple stratified sampling method for this study. The health and safety manager or representatives of the selected 2,960 companies successfully finished in the face-to-face interview survey about company's general characteristics, health and safety management style, health and safety education hours conducted by the Korean Occupational Safety and Health Agency. Results: The manufacturing companies in Seoul and Kyunggi areas, small size, and clothes and press industries were related to low health and safety management and education status. The companies which assigned at least one safety manager were 70.5% and which had a health and safety room within the company were only 9.3%. The companies which took the health and safety education for their regular blue-collar employees more than the legal education hours were under 56.1% and the percentage of the companies which took their health and safety education for newcomers less than the legal limits was lower than any other types of health and safety education in workplace. The significant strong workplace health and safety management variables in predicting employee health and safety education were psycho-social variables such as the company own health and safety regulation and the workplace health and safety management committee organization. rather than physical variables such as health manager employment, safety manager employment. Conclusions: Systematic and legal approaches are effective to encourage workplace health and safety education, specifically, through sustaining health and safety managers and building the company-wide health and safety management system. Furthermore, theses approaches should primarily focus on the small companies of which sizes were under 50.

• Journal of Applied Reliability
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• v.18 no.1
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• pp.87-94
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• 2018

Purpose: In this study, the defect quantification of thin metal plate was evaluated by using lock-in infrared thermography. Methods: A STS304 standard specimens, which had the artificial-defects of different size, were used. The focal distance between the infrared camera and the specimen was set to 500mm, and the distance between the lump and the specimen was set to 200mm. One halogen lamp with a maximum capacity of 1kW was used, and phase-lock infrared thermal images with a frequency of 1Hz were captured and analyzed. Result: Objectively quantified data values were obtained by analyzing the contrast ratio and signal-to-noise ratio. Conclusion: The possibility of defect diagnosis for thin metal plate was confirmed by using the lock-in infrared thermography technique.