• International Journal of Quality Innovation
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• 제7권2호
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• pp.141-156
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• 2006

This study describes a novel algorithm for optimizing the quality yield of silicon wafer slicing. 12 inch wafer slicing is the most difficult in terms of semiconductor manufacturing yield. As silicon wafer slicing directly impacts production costs, semiconductor manufacturers are especially concerned with increasing and maintaining the yield, as well as identifying why yields decline. The criteria for establishing the proposed algorithm are derived from a literature review and interviews with a group of experts in semiconductor manufacturing. The modified Delphi method is then adopted to analyze those results. The proposed algorithm also incorporates the analytic hierarchy process (AHP) to determine the weights of evaluation. Additionally, the proposed algorithm can select the evaluation outcomes to identify the worst machine of precision. Finally, results of the exponential weighted moving average (EWMA) control chart demonstrate the feasibility of the proposed AHP-based algorithm in effectively selecting the evaluation outcomes and evaluating the precision of the worst performing machines. So, through collect data (the quality and quantity) to judge the result by AHP, it is the key to help the engineer can find out the manufacturing process yield quickly effectively.

• 한국품질경영학회:학술대회논문집
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• 한국품질경영학회 1998년도 The 12th Asia Quality Management Symposium* Total Quality Management for Restoring Competitiveness
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• pp.189-197
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• 1998

The axiomatic hypothesis of the objective distribution of evaluation subjection will be proposed in this paper. On the basis of that, set up the random response model of the expert evaluation system and the quality control principle of expert base. Under this principle, develop the statistical quality control theory of expert base, further; provide the quality improvement technology for expert base.

• 한국산림과학회지
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• 제103권2호
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• pp.258-263
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• 2014

본 연구는 임도의 재해위험 등급을 구분하기 위한 평가표를 제시하고자 수행되었으며, 이를 위해 임도의 재해에 영향을 미치는 인자들을 선정하고 산림공학 전문가들을 대상으로 AHP 설문조사를 실시하였다. 평가항목은 전문가집단의 자문을 통해 크게 자연환경, 인문 사회환경, 임도의 구성요소로 구분하였으며, 총 21개의 평가인자로 구성하였다. 설문조사결과를 바탕으로 각 평가항목에 대한 가중치 분석을 실시하였으며, 분석결과 임도의 구성요소 항목 중 배수시설이 가장 높은 가중치를 점하고 있는 것으로 나타났다. 한편, AHP 분석결과를 바탕으로 각각의 평가항목에 대한 평가기준과 평가점수를 부여하여 평가표를 작성하였다. 도출된 평가표를 현장조사에 적용시킨 결과 최고점은 78.8점, 최저점은 42.7점, 평균점수는 61.8점으로 나타났다. 산정된 점수를 바탕으로 전문가 집단의 회의를 통해 임도의 재해위험 등급을 4등급으로 구분하여 제시하였다.

• 한국산업경영시스템학회:학술대회논문집
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• 한국산업경영시스템학회 2002년도 춘계학술대회
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• pp.359-364
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• 2002

In case of pn control chart often used in mass production system of plant industry and so on, we could evaluate it's performance by the approximation to normal distribution. It has many differences according to sample sizes and defective fraction, and have disadvantage that needs much samples to use the normal distribution approximation. Existent control charts can not detect the cause of process something wrong because it is taking the sampling intervals of fixed length about all times from the process. Therefore, to overcome this shortcoming we use VSI(variable sampling intervals) techniques in this paper. This technique takes a long sampling interval to have the next sampling point if the sample point is in stable state, and if the sample point is near control lines, it takes short sampling interval because the probability to escape control limit is high. To analyze performance of pn control charts that have existent fixed sampling intervals(FSI) and that use VSI technique, we compare ATS of two charts, and analyze the performance of each control chart by the sample sizes, process fraction defective and control limits that Ryan and Schwertman had proposed.

• Industrial Engineering and Management Systems
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• 제6권1호
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• pp.11-21
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• 2007

The PDCA (Plan, Do, Check and Act) cycle is often used in the field of quality management. Recently, business environments have become more competitive, and the due time of products has shortened. In a short production run process, to increase efficiency of management, the necessity for distinguishing the PDCA design that starts with PLAN and the CAPD design that starts with CHECK has been clarified. Starting from Duncan (1956), there have been a number of papers dealing with the economic design of control charts from the viewpoint of production run. Some authors (Gibra, 1971; Ladany and Bedi, 1976; etc.) have studied the economic design for finite-length runs; other authors (Crowder, 1992; Del Castillo and Montgomery, 1996; etc.) have studied the economic design for short runs. However, neither the PDCA nor the CAPD design of control charts has been considered. In this paper, both the PDCA and CAPD designs of the $\bar{\x}$ chart are defined based on Del Castillo and Montgomery's design (1996), and their mathematical formulations are shown. Then from an economic viewpoint, the optimal values of the sample size per each sampling, control limits width, and the sampling interval of the two designs are studied. Finally, by numerically analyzing the relations between the key parameters and the total expected cost per unit time, the comparisons between the two designs are considered in detail.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 제37회 하계학술대회 논문집 A
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• pp.22-24
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• 2006

The installations of power quality monitoring system have increased drastically over the past several decades. These systems have been effectively used to monitor, analyze and diagnose the conditions of power system, and furthermore can be used to improve the present asset maintenance policy, scheduled (time-based) method, into the advanced, cost-effective and labor-effective maintenance methods, such as condition-based maintenance, predictive maintenance and reliability centered maintenance. As an approach to this, this paper introduces the statistical methods, three kinds of control charts (Shewhart chart, CUSUM chart and EWMA chart), and discusses the applicability of these methods to recognize the changing trends of power quality indices and to estimate the system's condition, using Matlab.

• KIEAE Journal
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• 제12권2호
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• pp.15-24
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• 2012

The purpose of this study is to understand children's participating behavior on the environment-improving process of a community child center, and to develop participating technique and tools that can be appliable. For this, a workshop, constructions, and an evaluation research were done on the premise that children participate in process of designing a community child center. The result of study is as follows. (1) A survey chart, questionaries, preference image chart, and attitude measurement chart used in this study were easy to understand, simple, and thus found to be a useful technique and tool that could make children participate more active and interested. (2) As children participated more on the environment-improving process of community child centers, their demands became more diverse and specific, and their levels of satisfaction were high. (3) The change of satisfaction level before construction and after, and consistent demands for the separation of studying space between upper and lower graders show that children understand their physical environment changes well, and have clear ideas on how their studying space should be composed.

• 한국정보과학회논문지:소프트웨어및응용
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• 제36권7호
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• pp.571-579
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• 2009

차트 파싱 알고리즘에서 left-corner와 look-ahead 정보를 이용하여 불필요한 중간 구조가 생성되지 않도록 함으로써 파싱 속도를 향상시키는 방법이 제안된 바 있다. left-corner와 look-ahead 정보를 이용할 경우 불필요한 중간 구조가 생성되지 않으므로 파싱 속도가 빨라지겠지만 이러한 정보를 유지 관리하고 참조하는 데 따른 추가 비용이 발생한다. 이러한 추가 비용이 발생함에도 불구하고 대규모 문법을 사용하여 파싱을 할 때에는 파싱 속도가 상당한 많이 향상되었다는 연구 결과가 있었다. 본 논문에서 는 소규모 문법을 사용했을 때 파싱 속도가 어느 정도 향상되는가를 관찰하는 실험을 하였다. 실험 결과 소규모의 문법에서는 파싱 속도 향상 정도가 상대적으로 낮았으며 left-corner 정보는 파싱 속도를 향상 시키는 것이 아니라 오히려 저해한다는 사실을 알 수 있었다.

• 한국방재학회 논문집
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• 제4권1호
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• pp.57-64
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• 2004

최근의 엘리뇨와 라니냐 등 이상기온현상과 이에 따른 산불발생빈도의 증가는 산지사면의 안정성에 대한 산불의 영향을 고려해보게 되는 계기가 되고 있다. 본 논문에서는 산불로 인한 식생의 파괴에 따른 자연사면 안정성에 미치는 정도를 규명하고, 산불에 따른 사면의 안정성을 평가하는 방법을 제시하여 산불로 인하여 발생될 수 있는 피해를 최소화하는데 그 목적이 있다. 본 논문에서는 산불로 인한 산지사면 식생의 변화가 사면 안정성에 미치는 영향을 정량적으로 분석하였고, 그 결과로 산불의 영향을 고려한 사면안정도표를 제안하였다.

• 한국지반환경공학회 논문집
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• 제20권9호
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• pp.5-11
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• 2019

최근 국내 도심지 지반침하 및 함몰이 빈번히 발생함에 따라 지반침하에 대한 불안감 또한 증가하고 있다. 그로 인해 GPR를 통한 지하 공동 탐지 지반함몰 모사실험 지반의 거동을 확인하기 위한 수치해석 등의 연구가 진행되고 있다. 국내의 경우 공동위험도 평가를 최근에 마련하였으나 현재의 지반상태 파악에 초점을 두었기 때문에 향후 발생할 수 있는 지반침하 및 함몰에 대한 예측을 정량적으로 하기 힘들다. 따라서 본 연구에서는 지반침하/함몰의 기하학적 변수인 공동크기와 토피두께를 변화시키며 총 30개의 case에 대한 수치해석을 수행하였다. 이 결과를 바탕으로 현재의 상태 뿐 아니라 향후 발생할 시기를 정량적으로 예측할 수 있는 방법을 제시하였다.