• Title/Summary/Keyword: Quality Process

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A Study on the New Rolling Stock Vehicle Maintenance Technology and Discussion on Quality Assurance Measures (신규 도입차량 유지관리 기술과 품질보증 대책에 대한 고찰)

  • Choi, Seog-Jung;Kim, Moon-Hong;Kim, Bong-Rae
    • Proceedings of the KSR Conference
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    • 2011.10a
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    • pp.27-37
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    • 2011
  • Currently, in the course of introducing rolling stocks, RAMS standard and management by system engineering method apply to rolling stock system. Technical elements and results applied in system introduction phase are just used in acquisition stage, and these are not applied to the standard in railway site. Therefore, it is difficult to apply to standardized technology and quality assurance measure. Due to the establishment of the EU, railway operation system is internationalized and the international railway standards are being discussed in various ways. In addition, standardization is expanded from manufacture to operation and maintenance. It is to provide consistent standard in quality, cost calculation of maintenance technology, maintenance technology and quality assurance in case of international railway safety incidents. Therefore, this study is to find technology, quality and cost management model to be used for choosing railway-operation guidance by considering how technologies & quality have changed in system life cycle, compared with estimated standards, based on the technologies & quality-related result in the process of getting new rolling stocks and management guidance for operation & maintenance process.

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Framework of micro level e-Learning quality dimensions

  • Cho, Eun-Soon
    • International Journal of Contents
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    • v.5 no.2
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    • pp.1-5
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    • 2009
  • This study was to analyze important dimensions and its factors of micro level of e-learning determining the quality of e-learning. E-learning dimensions and their factors were identified and developed from the analytical review of related researches. From literature review and survey as well as expert interview, six categories of e-learning identified from this study were: 1) curriculum content, 2) usability, 3) instructional design, 4) evaluation -both process and results, 5) management, and 6) refinement and improvement. A total of thirty-seven factors determining the quality of the e-learning six categories were identified. The rank order and contribution rates for each categories and factors were calculated to explain how importantly they contribute to the quality of e-learning. Also three dimensions such as controlling the e-learning quality, e-learning fundamental dimension e-learning process dimension, and e-learning product dimension, were explained. This study suggests a useful guidance for e-learning quality and evaluation framework for better results.

The Study of Distributed Disturbance Recording System (분산형 사고파형저장 시스템에 대한 연구)

  • Park, Jong-Chan;Lee, Se-In
    • The Transactions of the Korean Institute of Electrical Engineers P
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    • v.57 no.1
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    • pp.30-35
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    • 2008
  • In this paper, the application of power Quality monitoring based on Sampled Value(SV) which is introduced in the IEC61850 International Standard for substation communication are discussed. Firstly, while Merging Unit(MU) is designed as a process level device transmitting sensor data, the practical problems such as time delay compensation and optical fiber communication are encountered. Secondly, the Sampled Value message which is proper to a power quality monitoring system is presented. Because the power quality monitoring system requests less time-critical service compared to protection and control applications, the Sampled Value service message structure is introduced to improve efficiency. Lastly, the power quality monitoring server having various power quality analysis functions is suggested to verify the performance of Merging Unit With the diverse experiments, it is proved that the process bus distributed solution is flexible and economic for the power quality monitoring.

Standardization of the Construction Process and Development of the Process Management Software for Spatial Database Quality Maintenance (공간데이터베이스 품질유지를 위한 구축 공정 표준화 및 공정관리 소프트웨어 개발)

  • 최병길;김성수;조광희
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.21 no.1
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    • pp.89-97
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    • 2003
  • This study is aimed at standardizing the process of spatial database construction and developing a software tool for process management. Knowhow of five GIS firms and provisions of NGI(National Geography Institute) was analyzed. In this study, the process of spatial database construction was standardized. The system from this study has the capability to manage the process of construction database using GIS and to deal with the metadata of unit map, generated from the process, systematically and continuously. The process was also shown by using either Gantt chart or PERT chart after developing an interface for "MS Project". A software "Visual Basic for Application" was used for this study.

Better Statistical Test for Process Capability Index $C_p$ (공정능력지수 $C_p$에 대한 효율적인 가설검정)

  • Cho, Joong-Jae;Lim, Soo-Duck
    • Journal of Korean Society for Quality Management
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    • v.34 no.3
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    • pp.66-72
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    • 2006
  • The process capability indices are widely used to measure the capability of the process to manufacture items within the specified tolerance. Most evaluations on process capability indices focus on point estimates, which may result in unreliable assessments of process performance. The index $C_p$ has been widely used in various industries to assess process performance. In this paper, we propose new testing procedure on assessing $C_p$ index for practitioners to use in determining whether a given process is capable. The provided approach is easy to use and the decision making is more reliable. Whether a process is clearly normal or nonnormal, our bootstrap testing procedure could be applied effectively without the complexity of calculation. A numerical result based on the proposed approach is illustrated.

Copper thickness and thermal reliability of microvias produced by laser-assisted seeding (LAS) process in printed circuit board (PCB) manufacture

  • Leung, E. S.W.;Yung, W. K.C.
    • International Journal of Quality Innovation
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    • v.2 no.2
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    • pp.69-92
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    • 2001
  • The laser-assisted seeding (LAS) process has potential to replace conventional electroless copper plating in Printed Circuit Board (PCB) manufacturing since it combines the steps of laser drilling and plating into one single process. In the LAS process, the single extra LAS step can metallize a microvia. Thus, the process steps can be greatly reduced and the productivity enhanced, but also the high aspect ratio microvias can be metallized. The objectives of this paper are to study the LAS copper thickness within PCB microvias and the thermal reliability of the microvias produced by this process. It was found that results were satisfactory in both the reliability test and also the LAS copper thickness which both comply with IPC standard, the copper thickness produced by the LAS process is sufficient for subsequent electro-plating process. The reliability of the microvias produced by LAS process is acceptable which are free from any voids, corner cracks, and distortion in the plated copper.

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Economic Performance of an EWMA Chart for Monitoring MMSE-Controlled Processes

  • Lee, Jae-Heon;Yang, Wan-Youn
    • Journal of the Korean Data and Information Science Society
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    • v.15 no.2
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    • pp.285-295
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    • 2004
  • Statistical process control(SPC) and engineering process control(EPC) are two complementary strategies for quality improvement. An integrated process control(IPC) can use EPC to reduce the effect of predictable quality variations and SPC to monitor the process for detection of special causes. In this paper we assume an IMA(1,1) model as a disturbance process and an occurrence of a level shift in the process, and we consider the economic performance for applying an EWMA chart to monitor MMSE-controlled processes. The numerical results suggest that the IPC scheme in an IMA(1,1) disturbance model does not give additional advantages in the economic aspect.

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A Study on the manufacturing process using the sensitivity analysis of stochastic network (감도분석에 의한 제조공정연구)

  • 박기주
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.24 no.63
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    • pp.65-77
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    • 2001
  • A more technical perspective is needed in estimating the effect of the Manufacturing Process for improving the Productivity, there are many statistical evaluation methods, convenience sampling, frequencies, histogram, QC seven tools, control chart etc. It is more important for the companies to use six sigma to reduce defective and improve the process control than the technical definition as a disciplined quantitative approach for improvement of process control and a new way of quality innovation. Process network analysis is a technique which has the potentiality for a wide use to improve the manufacturing process which other techniques can't be used to analyze effectively. It has some problems to analyze the process with feedback loops. The branch probabilities during quality inspections depend upon the number of times the product has been rejected. This paper presents how to improve the manufacturing process by statistical process control using branch probabilities, Moment Generating Function(MGF) and Sensitivity Equation.

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Manufacture of Squid-Jeotgal by the Improved Process (개선된 제조기법에 의한 오징어젓갈 제조)

  • YOON Ji-Hye;LEE Won-Dong;KANG Ji-Hee;LEE Ji-Sun;LEE Myung-Suk
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.36 no.4
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    • pp.333-339
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    • 2003
  • New manufacturing process was applied to manufacture the low salted Squid-Jeotgal to improve the quality variation salty taste and shelf-life. It's optimum salting and sugaring process was made by the addition of $17\%$ NaCl for 3 hr and $15\%$ corn syrup for 4 hr with 10 rpm agitation. Quality variations of Squid-Jeotgal produced by the improved and the conventional process were packed by jar, polyethylene lerephthalatefpolyethyleneilinear low density polyethylene (PET) and low density polyethylene (PE). And then quality variations of them were investigated at storage temperature of 10, 20, and $30^{\circ}C.$ Decreasing rate of pH, increasing rates of VBN and viable cell counts of Squid-Jeotgal produced by the improved process were slower than those of the conventional process at all storage temperature. Sensory evaluation indicated that the production of Squid-Jeotgal by the improved process extended the shelf-life about 10-20 days.

Evaluation of punching process variables influencing micro via-hole quality of LTCC green sheet (LTCC 기판의 미세 비아홀 펀칭 중 공정 변수의 영향 평가)

  • Baek S. W.;Rhim S. H.;Oh S. I.;Yoon S. M.;Lee S.;Kim S. S.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2004.11a
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    • pp.260-265
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    • 2004
  • LTCC(Low temperature co-fired ceramic) is being recognized as a significant packaging material of electrical devices for the advantages such as relatively low temperature being needed for process, low conductor resistance and high printing resolution. In the process of LTCC electrical devices, the punched via-hole quality is one of the most important factors on the performance of the device. However, its mechanism is very complicated and optimization of the process seems difficult. In this paper, to clarify the process, via-hole punching experiments were carried out and the punched holes were examined in terms of their burr formation. The effects of thickness of PET sheet and ceramic sheet and punch-to-die clearance on via-hole quality were also discussed. Optimum process conditions are proposed and a factor k is introduced to express effect of the process variables.

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