• Journal of the Korean Society of Manufacturing Process Engineers
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• v.20 no.5
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• pp.35-46
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• 2021

The purpose of this study is to establish effective quality control activities to maintain proper operation rates and improve the performance of research and development weapon systems. Quality control improvement measures suitable for the actual conditions of our military were identified by comparing the operational methods and advantages/disadvantages of the domestic quality control systems Defense Quality Management System and Defense Quality mark with those of the systems employed in the US(QPL and QML). In order to ensure the reliability of the weapon system, it is imperative to operate a design-oriented self-quality management system through manufacturing-oriented government-led inspection and to expand and reorganize the certification system divided into manufacturing items and companies.

• Transactions of the Korean Society of Automotive Engineers
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• v.13 no.5
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• pp.90-95
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• 2005

Most of mechanical structures are composed of many substructures connected to one another by various types of mechanical joints with various shapes of cutouts. It is important to study these connected structures under dynamic forces for evaluation of stress concentration. In this paper, a FQI(fatigue quality index) analysis using the concept of SF(severity factor) is performed to various shape of elliptical hole. The SF is affected by the location of cutout in plate and radius ratio, static SF is analyzed with finite element analysis and the equation of FQI for predicting a dynamic SF is formed.

• International Journal of Precision Engineering and Manufacturing
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• v.8 no.4
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• pp.10-15
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• 2007

Taguchi methods have been used for a long time to improve the product quality and process performance of a manufacturing system, Few researchers have applied this methodology in laser beam cutting (LBC) of sheet metals and found the considerable improvement in cut qualities. In all experimental investigations of LBC so far, the objective was to optimize the single quality characteristic at a time. In this paper the simultaneous optimization of multiple quality characteristics such as Kerf width and material removal rate (MRR) during pulsed Nd:YAG LBC of thin sheet of magnetic material (high Silicon-steel) has been presented using Taguchi's quality loss function. The results show the considerable improvement in multiple S/N ratio as compared to initial cutting condition. Also, the comparison of results from single and multi-objective optimization have been presented and it was found that the loss in quality is always possible shifting from single quality to multiple quality optimization.

• Journal of Mechanical Science and Technology
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• v.19 no.4
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• pp.1001-1005
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• 2005

This paper evaluates the performance of ventilation for the removal of indoor pollutants as a function of ventilation rate and the number of occupants in a test room and school classroom. An experimental apparatus consists of a test room, a tracer gas supply system, a gas detector, and a fan for ventilation air supply with a controller. The ventilation performance is evaluated in a step-down method based on ASTM Standard E741-83 using $CO_{2}$ gas as a tracer gas in the test room of 35 $m^{3}.$ For the ventilation air flow rate of 1.0 ACH, a recommended ventilation flow rate of Korea school standard for acceptable indoor air quality in the case of one person, CO_{2}$ gas concentration decreases up to $55{\%}$ within 50 minutes without occupancy and increases up to $75{\%}$ in the case of one occupant. Also indoor air quality at the school classroom is investigated experimentally.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.25 no.3
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• pp.141-149
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• 2015

In this study, there is an investigation about the sound quality of automotive horn that attached to luxury sedans. In order to define a questionnaire of horn sound quality the factor analysis is conducted. Ten automotive horns are selected for this research and ten passenger cars(nine is luxury sedan and one economy class car). Luxury is used for the questionnaire as an attribute for the sound quality of car horn. The interior noises for ten test cars are recorded and used for the subjective analysis of car horn sound. In the paper, new sound metric for the car horn sound is presented. The new sound metric is used for the objective sound index for the prediction of subjective sound quality of car horn.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2006.11a
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• pp.29-34
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• 2006

In this paper, the mechanical characteristics of ultrasonic cold forged technology (UCFT) used for the trimming knife and the effects of ultrasonic vibration energy (UVE) into the trimming process on the state of the strip cutting face were studied. And a diagnosis system to quality control for trimming knife and strip cutting face was developed and installed in plant. By the plant application of UCFT, service life of knife was more increased over 100% than that of conventional knife. And using the developed diagnosis system, the knife breakage and saw ear have been perfectly detected and quality control of trimming face is obtained effectively.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2005.05a
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• pp.473-476
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• 2005

Today's manufacturing industry is facing challenges from advanced difficult-to-machine materials (WC-Co alloys, ceramics, and composites), stringent design requirements (high precision, complex shapes, and high surface quality), and machining costs. Advanced materials play an increasingly important role in modem manufacturing industries, especially, in aircraft, automobile, tool, die and mold making industries. The greatly-improved thermal, chemical, and mechanical properties of the material (such as improved strength, heat resistance, wear resistance, and corrosion resistance), while having yielded enormous economic benefits to manufacturing industries through improved product performance and product design, are making traditional machining processes unable to machine them or unable to machine them economically. In this paper, mechanical characteristic evaluation test of fine powder type WC-Co alloy was accomplished to obtain clear data for miniaturized special die parts machining with high reliability and high quality.

• International Journal of Safety
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• v.8 no.2
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• pp.5-8
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• 2009

Fusing process of laser printer is the step to fuse toner on the paper and it has a great effect on fast printing speed, decrease in waiting time and improvement of printing quality. In order to improve the quality of fusing, a study on the fusion region is required. Recently, various researches are progressing in this field. In this study, the research about the temperature distribution of fusing region is performed through numerical analysis because fusing region is one of the important factors influencing fusing quality. According to results, it is ascertained that the temperature of fusing region is relative to velocity of the paper under print and has a regular distribution to width direction of the paper.

• International Journal of Quality Innovation
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• v.7 no.1
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• pp.98-111
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• 2006

The paper presents the design of an optical profilometer, a device used for the reconstruction of the micro-geometry of mechanical parts in applications where high precision is needed. The design is based on Robust Design, a major' methodology for quality improvement of engineering systems. Several design solutions, namely different hardware and software setups of the device, are compared in order to select a configuration realising a desired trade-off between performance and cost. The peculiarity of the design strategy is the use of a computer model of the measurement process where the physical part of the process is simulated. This allows for an extensive exploration of the design space, thus opening the way to product innovation.

• International Journal of Quality Innovation
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• v.10 no.2
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• pp.57-76
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• 2009

Although many adherents openly praise the importance of quality management practices (QMP) in organisations, others have identified significant costs and implementation obstacles. Some recent studies showed that QMP have failed due to the ignorance of quality cultures. How to improve the success rate of QMP in organisations has become a critical issue both in the academy and in practice. This paper discusses the common enablers of and cultural impacts on QMP. It explores the dimensions of national versus organisational culture, and identifies the main features of four quality culture models as advocated in the literature in relation to facilitating QMP in organisations. It was found that flat structures, decentralised functions, empowerment, flexibility, innovation, limited rules and regulations and teamwork favor the QMP implementation. For facilitating culture changes for QMP, values associated with low power distance, low uncertainty avoidance and collectivism would have to be nurtured. Further research is needed to incorporate the findings and develop a practical quality culture approach for real applications in industry.