• Journal of the Korean Society of Marine Environment & Safety
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• v.20 no.1
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• pp.113-119
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• 2014

Recently, R.O.K. Navy is increasing re-usability of design data and application of M&S(Modeling and Simulation) through the establishment of collaborative product development environment focused on Naval Ship Product Model(NSPM). As a result, the reliability of the result of design is getting better, and furthermore, a study to improve quality of construction through simulation of production/operation is in progress. Accordingly, the database construction of design data and the DB(Database) quality become important, but there was not research related to those or it was just initial state. This paper conducted research about system of the quality verification process of shape elements which compose NSPM based on the quality verification guideline of NSPM as the result of the precedent study. The hull surface was limited as verification object. The study to verify two things that application of basic drawing by the cad model of hull surface, and whether there is error in the geometric quality of cad model was progressed. To achieve this goal, the verification criteria and algorithm were defined and the prototype system which is based on was developed.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.34 no.4
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• pp.179-188
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• 2011

This paper outlines a systematic guideline for remanufacturing process using the Failure Mode and Effect Analysis (FMEA) method in order to estimate the reliability and quality of the remanufactured alternator. The method is just a tool to help, but the remanufacturer must determine the optimal remanufacturing process and specific inspection and production that will turn the alternator as-good-as new and place the product into the market with reliability and quality equal to a new product. FMEA is a method that is widely used in industry and has shown its value and effectiveness in the above remanufacturing case study. Actions taken often result in a lower severity, occurrence or detection rating. Redesign may result in lower severity and occurrence ratings while inserting validation controls and maintenance can reduce the detection rating. The revised ratings are recorded with the originals on the FMEA template form. After these corrective actions and revisions have been established, evaluation of the ranks can be repeated, until the redesign and control parameters comply with safety standards.

• Fire Science and Engineering
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• v.30 no.5
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• pp.67-73
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• 2016

This paper examined the structure, fire resistance of brass fittings type CSST employed in gas appliances and the reliability verification. Brass fittings of type CSST consisted of cladding, tubing, nut, clamp ring, socket, and ball valve. The applicable JIA standard regulates the maximum working pressure to be 4.2 kPa, which is the highest pressure of the relevant standards and the KS D 3625 stipulates the maximum pressure to be 3.24 kPa. With a normal product, the average resistance within the confidence interval was found to be $7.36m{\Omega}$. The average resistance within the confidence interval was $6.67m{\Omega}$ after the fire resistance tests. The analysis indicated that the AD was 1.584 and the standard deviation was 0.3972 with respect of a normal product. Compared to the normal product, however, the damaged product after the fire resistance test showed better features, such as an AD of 1.145 and a standard deviation of 0.2467. Moreover, the average resistance of the normal product was $7.359m{\Omega}$ and the standard deviation in histogram analysis was 0.3972. The average resistance of the damaged product after the fire resistance test in the histogram was $6.67m{\Omega}$ and the standard deviation was 0.2467.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.21 no.5
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• pp.413-419
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• 2008

Deterministic design optimization (DO) does not explicitly deal with a variety of factors from inherent randomness and uncertainties. Reliability based design optimization(RBDO) is necessary to use in engineering systems in order to guarantee quality and performance of product. In this paper, design variables are considered as random variables. Standard deviation according to change of design variables have changed as much as coefficient of variation. And, if the standard deviation is error of manufacturing, standard deviation-mean relation is concave form. We obtain reliability index using advanced first order second moment method(AFOSM). This paper is examined by solving two examples and the results are compares with DO, RBDO and suggested RBDO.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.35 no.2
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• pp.212-219
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• 2012

This study focus on what methods of MOT are needed and utilized to solve a technical problem in the MOT leading company. We first classified the MOT methods by project life cycle and R&D job quality based on the several discussion with working group. In order to study, the survey was carried out by 168 experts working on MOT practices. Our main research findings are as follows. The level of utilized MOT methods was above average because MOT sector was beginning to represent an increasing share of total R&D business. But the satisfaction level on the MOT majors was below average. The more utilized MOT methods in practices were 'environment analysis and opportunity research,' 'business feasibility,' 'roadmapping,' 'portfolio,' 'technology tree,' 'scheduling,' 'risk management,' 'six sigma,' 'design of experiment,' 'quality control,' 'cost analysis' etc. And the subjects of product realization process were also needed to MOT practice such as 'design for reliability,' 'design for cost,' 'design for performance,' 'design for safety' deeply involved to product quality. Finally, the capability requested to University students were 'problem define and solving,' 'technology planning and strategy,' 'creative thinking.'

• Journal of Korean Society for Quality Management
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• v.44 no.2
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• pp.321-340
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• 2016

Purpose: In this study, we revealed the influence of customer buying factors in the purchase process of eco-friendly product. Especially, we focused on the information acquisition, alternative evaluation, and after-purchase activity process based on Korea-China customer's survey. Methods: In the information acquisition process, we investigate the channels of information acquisition about eco-friendly product, a reliability of information, and an impediment of acquiring product information. At the stage of alternative evaluation, we extract various causes that affects pre-purchasing process and perform the AHP analysis to identify critical causes. At last, we compare several factors which affects before and after purchasing process. Results: Especially, an average utilization and cognition score of eco-friendly products of Chinese consumers is higher than Korean consumers' score. In addition, critical buying factors of Korean consumers are a product quality, an evaluation of existing users. However, that of Chinese consumers are safety of products and environmental benefits of products. Conclusion: In recent years, as the rapid economic development of China, environment pollutions like heavy smog and yellow dust have been occurred frequently. In that manner, Chinese consumer's environmental consciousness is rapidly increasing; not only try to be active participant in eco-friendly activities, but also eco-friendly purchasing activities. In addition, Chinese consumers recognize eco-friendly products as good products made with advanced technology.

• Fire Science and Engineering
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• v.34 no.3
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• pp.35-42
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• 2020

The accurate prediction of fire detector activation time is required to ensure the reliability of fire modeling during the safety assessment of performance-based fire safety design. The main objective of this study is to determine the activation temperature and the response time index (RTI) of a fixed heat detector, which are the main input factors of a fixed-temperature heat detector applied to the fire dynamics simulator (FDS), a typical fire model. Therefore, a fire detector evaluator, which is a fire detector experimental apparatus, was applied, and 10 types of domestic fixed-temperature heat detectors were selected through a product recognition survey. It was found that there were significant differences in the activation temperature and RTI among the detectors. Additionally, the detector activation time of the FDS with the measured DB can be predicted more accurately. Finally, the DB of the activation temperature and RTI of the fixed-temperature heat detectors with reliability was provided.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.3046-3051
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• 2011

The third-rail system is an important device supplying power directly to the Maglev train through physical contact with the collecting shoe. It is directly related to safety and reliability for the running of Maglev. However, most the third-rail system used in Korea depend on foreign product or technologies, Korea Urban Maglev in the development of appropriate power feeding is urgent. In particular, the turnout section is the weakness point in the system because bending force by turnout section movement and fatigue caused by repetitive motion as well as the expansion by temperature, the forces by Maglev collecting shoe is added th the third-rail. Therefore, this paper proposes the third-rail system appropriate for Korean Urban Maglev of turnout section. To verify the structural stability of POSCO ICT third-rail system, the finite element analysis and physical testing was performed. The third-rail is fixed on each side of the turn-out section steel structure by epoxy insulation supporter and the integral behaviors are occurred. Therefore, the maximum horizontal displacements of each support are investigated and then, it is applied to finite element model of the third-rail to investigate the moments and stress. Also, the bending test about one million times and Expansion Joint for the third-rail was performed. The third-rail system safety and reliability was identified by test line on Korea Institute of Machinery & Materials in Deajeon for under the actual usage environment such as the Maglev and turn-out operation.

• Journal of Internet Computing and Services
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• v.4 no.5
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• pp.31-41
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• 2003

At present, the market size of electronic commerce has increased and also the construction of internet shopping mall has expended. But it raises question about issue that the manpower who develope user interface lack of the comprehensive and systematic approach. For that reason this study identified the main factor of the user interface contents in internet shopping mall and suggested the contents item based on the reliability, safety and ease of uses for the customer. Eventually, the developed basic contents items are company information, the protection policy of private information, user agreement. product information, settlement information, order process, delivery process and customer support.

• Journal of the Korea Safety Management & Science
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• v.21 no.1
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• pp.1-7
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• 2019

Along with industrial development, various architectural structures have become bigger and higher, leading to an expansion in the size and capacity of construction equipment. And with the development of public transportation, the use of subways as a means of transportation in the city center is increasing, so that vibrations and structural noises are emerging as a new environmental issue. Considering that architectural structures may be used from several decades to hundreds of years after the time of construction, they can be seen as semi-permanent. Due to changes in the vibration-proof polyurethane mats installed in the foundation of these structures, settling may occur and vibration reduction may become inadequate. Therefore, in view of service life, it is necessary to have a high-level standard of reliability and stability. In accordance with this, the Floating Floor System, which uses soft polyurethane foam and can be constructed within a relatively short period of time, has excellent vibration resistant characteristics. It is presented as a great alternative solution to the issue of vibrations caused by subways, railways and building structures. At present, vibration-proof polyurethane mats have been developed up to the same product level as in other advanced countries. However, in the construction of structure foundations, the physical properties of this product and its shape incur changes. If they are installed as such in the structure of a building, it may cause significant impact on stability, requiring that this cause be urgently identified and improved.