• Journal of the Korean Society of Combustion
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• v.22 no.3
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• pp.47-52
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• 2017

The propellant tile and crack which account for the greatest proportion of solid rockets are profoundly affected by viscosity and mechanical properties of solid propellant. In this paper HTPB/AP/Al system propellant has been researched for the viscosity, mechanical properties and burning properties with type and contents of bonding agents. The viscosity of propellant was changed significantly depending on the type and contents of bonding agents, and mechanical properties of HTPB/AP/Al system propellant were also varied. Considering both lower viscosity and stable mechanical properties, the optimum type and contents of bonding agents can be identified as the main factors to the HTPB/AP/Al system propellant.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.7
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• pp.347-352
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• 2019

This study focused on improving the cast quality of small-sized induction motor rotors during the die casting process. A new rotor core cast model was proposed based on previous research results and parametric studies. Numerical analyses using 3-dimensional half models were performed to evaluate the filling patterns of aluminum molten metals into a mold and on-site experiment performed to verify the newly proposed cast model. The following were obtained from numerical filling analyses and experimental results. First, molten metals started to fill the lower end ring, then moved on to fill the core slot and upper end ring and finally stopped to fill at the rotor core slot. Second, significant circulation of molten metals was not observed on the lower end ring, resulting in fewer defects at the section of the lower end ring from the experimental results. Third, the new shape of a rotor core cast was effective in producing rotors with sound cast quality, and reducing the end ring cast defect area by approximately 70 %.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2004.10a
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• pp.36-39
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• 2004

Glass molding is an advantageous method to manufacture glass micro optical components. However, it is difficult to make Tungsten Carbide core for glass microlens array. We have developed novel method to fabricate Tungsten Carbide core for micro glass components using pressure forming. Silicon masters were fabricated by micro machining. Tungsten Carbide core was fabricated by pressure forming and sintering. And we made high quality surface of Tungsten Carbide core by using the magnetic-field-assisted polishing process.

• Proceedings of the IEEK Conference
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• 2008.06a
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• pp.797-798
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• 2008

Visual quality of video telephony over 3G networks is not satisfactory due to limited bandwidths. Therefore, it is worthwhile to enhance subjective visual quality based on ROI coding. In this paper, we propose a rate-control algorithm for video telephony with ROI based H.264|AVC coding. The QP values are increasingly assigned in non-ROI away from the ROI so that graceful degradation of visual quality can be achieved, which is more visually pleasant.

• Journal of Korean Institute of Industrial Engineers
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• v.43 no.2
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• pp.120-126
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• 2017

This paper has proposed the development direction and R&D analysis approach that the diversity of defense R&D process and product should be mainly under consideration. It has shown that there is a fair possibility of the various quality assess to meet the R&D requirements in defense-based. Thus, the analysis on multiple quality elements is carried out with defense R&D characteristics. Especially, a quality management master planning based on the quality model of establishing defense R&D policy has proposed, identifying relevant quality characteristics on the R&D of weapon system and the R&D of core technology. That is, this paper is not only interested in determining an appropriate model for improving the quality of a R&D weapon system but also argued efforts in order to reap the best possible outcome and process on both the R&D of weapon system and quality of the R&D of core technology including present R&D activities.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.10
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• pp.115-120
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• 2018

This study examined the cast quality of small-sized induction motor rotors during the die casting process. Numerical analyses with 3-dimensional half models were performed to investigate the filling patterns of aluminum molten metals into a mold after high-speed injections. The following were obtained from numerical analyses and experimental results. First, molten metals started to fill the lower end ring, then moved horizontally to fill the core slot and upper end ring, and finally stopped to fill the rotor core slot. Second, circulation of molten metals occurred at the lower end ring, resulting considerable porosity at the section of lower end ring from the experimental results. Third, further work for obtaining sound quality of rotor core cast is required to develop a new shape of the rotor core cast or improve the die casting conditions.

• Journal of the Korean Society of Food Culture
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• v.23 no.2
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• pp.184-193
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• 2008

The purpose of this study was to determine the detailed customer satisfaction and dissatisfaction factors of family restaurants in Korea, and to then classify the factors into 3 groups, inlcuding core service, quality service, and basic service. ‘Core service’ represents the critical factors that generate both satisfaction and dissatisfaction; ‘quality service’ generates only satisfaction; and ‘basic service’ generates only dissatisfaction. This categorization is based on Herzberg’s motivation-hygiene theory (1976) as well as Cadotte & Turgeon (1988). Based on the characteristics of the three groups, differentiation strategies in managing customer service were suggested to the family restaurant managers. A qualitative research method, termed the critical incident technique (CIT), was used in the study. This method helps researchers find new factors or attributes by grouping key issues from the anecdotes (critical incidents) and then categorizing common factors from the key issues. This research categorized key satisfiers and dissatisfiers into 33 factors, which were from 402 critical incidents described by 261 respondents. Eleven factors (response to service failures, food taste and quality, attention paid to customers, coupon/mileage point/discount card, customer’s ordinary requests, waiting, food diversity, food price, facility sanitation, checking out, customer’s special requests) were classified into core service, which required maximum management not regarding the level of customer satisfaction. Six factors (employee attitude, event, education and explanation, complementary food, customer’s mistakes, attention paid to children) were classified into quality service, which required differentiation strategy management. Finally, nine factors (speed of food service, employee’s mistakes, food sanitation, atmosphere and interior, seating, forcing orders, parking, other customers, reservations) were classified into basic service, which required minimum management at the level of the industry standards.

• Journal of the Korea Furniture Society
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• v.12 no.1
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• pp.39-45
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• 2001

This study was carried out to evaluate the feasibility of using HDF as surface panels as well as core materials for flush door manufacturing. Several core compositions were developed and applied to manufacture door specimens. Core materials were tested under bending load, door manufacturing process was analysed to find better way of using HDF for door manufacturing, and door specimens were tested under bending, twisting and impact loads. From this study, it was concluded that HDF can be used to manufacture quality flush doors. And it was desirable to use light color HDF as surface panels because dark color HDF caused a problem in manufacturing process by shadow shown through finishing veneer. HDF doors were light, and showed good quality and higher resistance against bending twisting and impact loads.

• International Journal of Quality Innovation
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• v.9 no.1
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• pp.94-102
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• 2008

When facing the global severe competition, the enterprises all try their best to upgrade the quality, reduce the costs to reach the goal of customer satisfaction. Motorola was the earliest firm creating the term Six Sigma (6 ${\sigma}$); GE was the enterprise successfully fulfilling Six Sigma. The success of these two firms revealed the prominent effects and became the world-class model enterprises. The main purpose of promoting Six Sigma activity was to reduce the possible defects in the business process to the least through designing and monitoring business process in order to reach the goals such as the best quality and efficiency, the lowest costs, the shortest circular process time, maximum profits and customer satisfaction. This research used the Six Sigma technique to improve the business process of ceramics manufacturing plant and find out the major factors of slower core task time by the analytical process of Process Mapping, Pareto Chart, Simu18 simulation software and figures and proposed the improvement measures. Through the confirmation of the case companies, it successfully reduced the core process time and the organizational costs and increased the capacity.

• Journal of Korean Society for Quality Management
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• v.39 no.2
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• pp.337-348
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• 2011

To implement total quality management(TQM), firms and institutions have strategically used quality awards models. In this paper we analyzed the national quality awards of G-20 members such as United States, Europe, Japan, Canada, Australia and Korea. There are three main points to analysis; First, "which type of model is good for Korea?", even though Korea already has adopted MBNQA model. Second, "Are the core values really different from each models?". And third, "Is there any difference in the criteria structure and value points system?" This study aims to design a National Quality Award which is good for the Korean companies and organizations. After analyzing the current quality awards models, we propose some suggestion about core value setting Korean-specific criteria development and value points system change.