• Title/Summary/Keyword: 로트

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An intelligent system for semiconductor yield classification with soft computing techniques (소프트컴퓨팅 기법을 활용하는 지능적인 반도체 수율 분류 시스템)

  • Lee, Jang-Hee;Ha, Sung-Ho
    • The Journal of Information Systems
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    • v.19 no.1
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    • pp.19-33
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    • 2010
  • 생산 수율은 비선형관계를 지닌 여러 요인들에 의해 영향을 받기 때문에 반도체 생산의 경우 예측이 어렵다. 본 논문에서 저자들은 사례기반추론과 자기조직화신경망 기반의 데이터마이닝 기법을 활용하여 수율의 높고 낮음을 밝히는 지능화된 수율예측시스템을 제시한다. 이 시스템은 자기조직회신경망을 사용하여 생산 로트의 공정파라미터 패턴을 파악하고 속성가중치 기반의 사례기반추론을 통해 신규 로트의 수율 수준을 예측한다. 이때 속성가중치는 역전파인공신경망을 통해 계산된다. 웹기반 시스템이 개발되고, 반도체 생산 기업의 실제 자료를 적용하여 본 시스템의 효율을 검증하고 평가한다.

Determination of Inspection LOT size for Flexural Strength of Concrete Pavement by Statical Analysis (통계적 품질관리기법에 의한 포장콘크리트의 휨강도 검사 로트의 적정성 검토)

  • Kim, Jin-Cheol;Kim, Hong-Sam;Ahn, Tae-Ho;Han, Seung-Woo;Ahn, Tae-Song
    • Proceedings of the Korea Concrete Institute Conference
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    • 2010.05a
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    • pp.453-454
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    • 2010
  • Statical analysis for determination of LOT size was performed to make inspection standards on concrete pavement site applied correspondingly to KS Q 0001. As a result, minimum sampling frequency of strength inspection to certify the required flexural strength was analysed once for each $300m^3$ or once per day, nor less than.

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A Case Study on the Change of Sampling inspection method for the Small Depth Charge Fuze (소형폭뢰용 수압식 신관의 품질검사방법 전환사례 연구)

  • Jee, Jae-Yong
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.18 no.10
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    • pp.531-538
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    • 2017
  • In the case of hydraulic pressure type fuse, we accept or reject certain product lots by considering the number of defective products in the operating pressure test. Generally, this procedure, known as 'The inspection by attributes', has been most commonly used in the field of quality assurance of products. However, the method of inspection by attributes suffers because it tests more samples than inspection by variables. Even though the quality of the products has remained stable in the process condition, the same number of samples is required for every lot, which wastes time and money. This paper suggests that the lot acceptance procedure is changed from inspection by attributes to inspection by variables. We can calculate the statistical tolerance percent of defectives and compare this to the Acceptable Quality Level (AQL) in order to save money and time. It is also easier to monitor and control the quality of products by using the process capability index and x-bar charts. In conclusion, the procedure delivers mutual benefit to both the customer and the producer by securing high quality products and reference data.

The Locking Protocol using Identifier in an Object-Oriented Database Systems (객체지향 데이타베이스 시스템에서 식별자를 이용한 로킹 프로토콜)

  • Bae, Seok-Chan;Hwang, Bu-Hyeon
    • The Transactions of the Korea Information Processing Society
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    • v.1 no.2
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    • pp.154-162
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    • 1994
  • In this paper, a new locking protocol which can increase the concurrency in an Object Oriented Database Systems is proposed. The proposed locking protocol uses the Root object identifier to identify the root of a component object in a composite object. The transaction that requests a lock on the component object checks whether the Rid of the component object has been locked by another transaction. Even though the class of the component object is locked by one transaction, other transactions can concurrently access other instances in the class, if each Rid of them is not locked by any other transactions. This can increase the degree of concurrency.

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A Compact Rotman Lens with Wide Angle Steering Characteristics (광각 빔조향 특성을 갖는 소형 로트만 렌즈)

  • 이광일;김인선;오승엽
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.13 no.5
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    • pp.500-506
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    • 2002
  • This paper presents a design of wide angle steering microstrip Rotman lens operating over broadband frequency range for Electronic Warfare equipments. It has a compact and simple structure which it is easy to manufacture repetitively. The lens is modelled as a 2-dimension planar circuit, the contour integral method is performed over entire lens contour and the transmission coefficients from 8 beam ports to 8 array ports are found. The measured results are well agreed with those of analysis. Prediction of the multibeam array pattern fed by linear array antenna shows $\pm$65$^{\circ}$ of beam steering and $\pm$5 dB insertion loss deviation over 3:1 frequency range.

A quantitative test method for assessing solder joint reliability of FCBGA packages (FCBGA의 솔더조인트 신뢰성 보증을 위한 정량적인 시험법)

  • Go, Byeong-Gak;Park, Bu-Hui;Kim, Gang-Dong;Jang, Jung-Sun
    • Proceedings of the Korean Operations and Management Science Society Conference
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    • 2005.05a
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    • pp.933-937
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    • 2005
  • FCBGA가 마더보드에 실장된 후 솔더 조인트에 균열이 생기면 단선이 발생한다. 솔더 조인트의 신뢰성을 평가하기 위한 방법 중 전단강도시험(shear test)은 약한 솔더 조인트를 판별하기 어려워 양품 로트와 불량 로트를 구별할 수 없으며, 인장강도시험(pull test)은 솔더 볼의 위치별 산포가 크고, peel test는 품질을 정량적으로 나타낼 수 없는 등의 문제가 있다. 새로운 시험 방법은 Area Pull Test(이하 APT)라 명명했으며 peel test와 pull test를 합한 개념으로서, 시험 샘플을 만드는 과정은 peel test와 동일하다. 솔더 조인트의 인장강도 측정은 지그를 만들어서 FCBGA 전체를 당겨서 측정하였다. 샘플은 Ni도금 두께를 3, 5, 8 ${\mu}m$로 제작하여 불량(3${\mu}m$), 양품으로 구분하였고, 양품 또한 품질 수준을 두가지(5,8${\mu}m$)로 나누었다. 그 결과 peel test 기준에 의거한 불량, 양품을 정량적인 수치(인장강도)로 판별할 수 있었으며, 솔더 조인트의 파괴모드별 인장강도를 구분 할 수 있었다.

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A Case Study on the Next Generation Library Catalogs (차세대 도서관 목록 사례의 고찰)

  • Yoon, Cheong-Ok
    • Journal of Korean Library and Information Science Society
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    • v.41 no.1
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    • pp.5-28
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    • 2010
  • The purpose of this study is to investigate the major features of Next Generation Library Catalogs. 'Next Generation Melvyl Pilot' of University of California Library System and 'SearchWorks' of Stanford University Library are examined. While the former is developed, based on OCLC WorldCat Local, the latter is based on the Blacklight, an Open Source Catalog Software. Both commonly provide the features, including enriched contents, facet navigation, keyword searching, relevancy ranking of search results, and user contribution, etc., but some functions vary in scopes and contents. Also, it seems that both are in process of development rather than complete implementations.

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