• Title/Summary/Keyword: 공정능력

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An Improved Process Incapability Index for the Evaluation of Process Capability (공정능력의 평가를 위한 개선된 비공정능력지수)

  • Shin, Kyung-seok;Kim, Seong-Jip;Kang, Chang-wook
    • Journal of Korean Society for Quality Management
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    • v.24 no.4
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    • pp.90-102
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    • 1996
  • Process incapability index which is intended to evaluate the process capability by measuring process incapability provides more detailed information by dividing information about the process mean and variance. But when the target value is not consistent with the center of specification, it is very difficult to evaluate the process capability accurately. Thus it is necessary to improve the existing process incapability index. The improved process incapability index can identify the variation of the process faster than other process capability indices when applied firstly, to the precision process which can be affected sensitively by the change of the process, secondly, to the ordinary process where cost difference from the change of process is noticeable. By using subindices such as inaccuracy index and imprecision index, it is easier for quality manager to find where the cause of the variation of process is, and to take necessary action in advance.

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A Study on Expression of Process Capability and Sigma Level (공정능력과 시그마 수준의 표시에 대한 연구 : 다수 위치측정에 대한 공정능력지수 기준)

  • Lee, Do-Kyung
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.32 no.1
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    • pp.111-116
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    • 2009
  • Process capability indices have been widely used in manufacturing industries to provide a quantitative measure of process performance. PCIs have been developed to represent process capability more exactly. In the previous studies, only one designated location on each part has been measured. But multiple measurement locations on each part are required to calculate the reliable process capability. In this paper, we propose a new process capability index dealing the multiple measurement locations on each part. Also we showed the relationship between the new index and sigma level according to the number of measurement locations.

Influence Factors of Critical Thinking Disposition and Core Basic Nursing Skills Achievement on Clinical Competence in Nursing Students (간호학생의 비판적 사고성향 및 핵심기본간호술 성취도가 간호수행능력에 미치는 영향)

  • Yi, Jee-Seon;Kim, Hyun-Ju;Park, Chang-Seung
    • Journal of the Korean Applied Science and Technology
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    • v.35 no.4
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    • pp.1359-1368
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    • 2018
  • The purpose of this study was to identify factors related to clinical competence of nursing students and to contribute to the education plan of the undergraduate course for the enhancement of clinical competence. The subjects of the study were 227 students in the 4th grade in the college of nursing. Clinical competence based on the general characteristics of the subject, critical thinking disposition, and core basic nursing skills achievement was conducted by an independent t-test, pearson's corelation coefficient, and linear regression model was used for statistical analysis to investigate factors influencing clinical competence. The results showed that intellectual fairness of critical thinking, achievement in middle and low level of core basic nursing skills had an effect on nursing students' clinical competence, and the higher score had the better clinical competence. Based on the results of this study, it is necessary to improve intellectual fairness and core basic nursing achievement of nursing students and to prepare an educational program to develop the achievement of high level.

Effects of B2B Transaction fairness Between Travel Agencies on Travel Franchisee's Relationship-orientation and Performance (여행사간 B2B 거래공정성이 가맹여행사의 관계지향성과 성과에 미치는 영향)

  • Seo, Sun
    • The Journal of the Korea Contents Association
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    • v.12 no.5
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    • pp.404-414
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    • 2012
  • B2B2C distribution channel between travel agencies, the travel franchiser's fairness become a big issue. So this study examines the effects of B2B transaction fairness between travel agencies on relationship-orientation and travel franchisee's performance. The research results are as follows: First, the most influential factor on the franchisee's performance was found as relationship-orientation factor. Second, among the 3 variable factors of B2B transaction fairness, the most influential factor on the franchisee's relationship-orientation was found as interactional fairness. And procedural fairness was found as next. Third, distributive fairness and interactional fairness were found to have a significant effect on franchisee's financial performance. And distributive fairness and procedural fairness were found to have a significant effect on franchisee's non-financial competency. Conclusively, excellent employees of travel franchiser' are the most valuable factors in B2B2C transactions due to the nature of the travel industry where human services are valued above everything else.

Research Results and Trends Analysis for EWMA Control Chart of Manufacturing Processes (제조공정에서 EWMA 관리도의 적용에 관한 연구동향 분석)

  • Kim, Jong-Gurl;Um, Sang-Jun;Choi, Sung-Won;Kim, Dong-Nyuk
    • Proceedings of the Safety Management and Science Conference
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    • 2013.04a
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    • pp.581-591
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    • 2013
  • 제조공정에서 사용되어 지는 SPC(Statistical Process Control)관리 기법은 가피원인을 탐지하여 변동을 감소시키는 통계적 공정관리 시스템이다. SPC의 대표적인 관리 기법으로는 Shewhart관리도, Cusum관리도, EWMA관리도가 있으며 이러한 관리 기법들은 공정을 보다 안정적으로 관리 할 수 있도록 유지 및 예측하는데 사용 되어 진다. 하지만 제조 공정의 유형에 따라 샘플링 방법, 관리한계선 등을 다양하게 설정하여 보다 효율적인 관리를 모색하고 있다. 공정 형태에 따라 다양한 관리 방법과 분석 결과가 나타난다. 일반적으로 Xbar-R 관리도와 같은 Shewhart 관리도를 사용하지만 Batch 단위의 공정, 연속 공정의 라인에서 사용되기에는 부분적인 한계를 보이고 있다. 본 논문에서는 일반적인 관리도와 공정 변화에 민감하게 반응 할 수 있는 누적합 관리도와 지수가중치이동평균 관리도를 비교해 보고 작은 변동에 대한 탐지 능력이 우수한 지수가중치이동평균 관리도에 대한 연구동향과 사례를 분석하여 제조 공정에 적합한 관리 방법을 모색하고자 한다.

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An Operating Methodology of SPC System in LCD Industries

  • Lee, Chang-Young;Nam, Ho-Soo
    • Journal of the Korean Data and Information Science Society
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    • v.16 no.3
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    • pp.507-514
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    • 2005
  • In this paper we consider an operating methodology of SPC(statistical process control) system in the TFT-LCD industries. The main contents are real time process monitoring, significant difference test, outlying glass analysis, process capability analysis and chart viewing.

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Study on the Improving Penetration Performance of Tungsten Heavy Alloy Penetrator by Heat Treatment (열처리 공정을 통한 텅스텐 중합금 관통자의 관통능력 향상에 관한 연구)

  • Kim, Myunghyun;Noh, Jooyoung;Lee, Youngwoo;An, Daehee
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.21 no.2
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    • pp.322-327
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    • 2020
  • An Armor Piercing Fin Stabilized Discarding Sabot (APFSDS), which penetrates and sabotages the target by physical energy, consists of a general penetrator using Depleted Uranium (DU) or Tungsten Heavy Alloy (THA) but THA is preferable because of manufacturing and environmental issues. On a THA penetrator, the penetration performance is determined mainly by self-sharpening depending on the hardness and toughness of materials. In particular, the tensile strength and impact strength work as key factors. The correlation coefficient for the penetration performance of the tensile strength was 0.721 and the impact strength was -0.599. The improved penetration performance by additional heat treatment was proven experimentally. Therefore, maintaining elongation over 9 % and tensile strength over 123 kg/㎟ is desirable, and the impact strength should be less than 6.8 kg·m/㎠ for good penetration performance.

A TFT-LCD Module Assembly Scheduler (TFT-LCD 모듈 조립 공정 스케줄러)

  • 김시원;정봉주
    • Proceedings of the Korean Operations and Management Science Society Conference
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    • 2000.04a
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    • pp.94-98
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    • 2000
  • 본 논문은 TFT-LCD 모듈 조립 공정에서의 스케줄링 시스템을 제안한다. TFT-LCD 모듈 조립 공정은 선행 공정인 액정 공정에서 넘어오는 LCD 판넬과 기타 부품들을 조립하여 최종 완제품을 만드는 공정이다. 본 연구에서 다루고 있는 문제는 주문량으로부터 구해지는 일일 생산 계획량이 주어졌을 때 각 라인에서 생산되어질 제품을 배정하는 문제이다. 본 논문의 목적은 주어진 실제 공정 환경에서 일일 생산 계획량을 최대로 만족하기 위한 스케줄링 휴리스틱을 개발하는 것이다. 이를 위해 relaxed LP 모형을 제시하였고 제시된 LP 모형을 이용한 알고리즘을 개발하였다. 제안된 알고리즘은 제품 우선 배정 조건, 현 보유 자재량과 대략적인 라인의 생산 능력을 고려한 LP 프로시져 부분과 제품 간 셋업 시간을 고려한 설비 배정 휴리스틱의 두 부분으로 구분된다. 알고리즘의 성능 검사를 위해 실제 TFT-LCD 모듈 공정에서의 데이터를 이용하여 과거에 실제 이루어진 생산 결과와 비교를 하였으며 제안된 알고리즘의 효율성을 실험 결과를 통해 보였다.

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A Study on the Machine Selection Problem Considering the Cost of Defective Products in the Machining Process (절삭가공에서의 불량가공비용을 고려한 기계선정에 관한 연구)

  • Park, Chan-Woong
    • Journal of Digital Convergence
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    • v.12 no.8
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    • pp.345-350
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    • 2014
  • The most important decision of process planning for the manufacturing system is the machine selection problem to minimize machining costs. Each machine has its own different machining performance indicating a different fraction of scrap, making the cost of scrap generated by machining is different for each machine. Therefore, when we decide on machine selection, we must consider the machining cost and the cost of scrap generated. This paper describes the statistical model for the fraction of scrap generated by machining and the machine selection algorithm considering the total cost including the machining cost and the cost of scrap generated.