• Title/Summary/Keyword: defective systems

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Measurement of noise characteristics of an image sensor (화상센서의 잡음 특성 측정)

  • Lee, Tae-Kyoung;Hahn, Jae-Won
    • Transactions of the Society of Information Storage Systems
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    • v.5 no.2
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    • pp.89-95
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    • 2009
  • We setup the system to measure the noise characteristics of the 5M complementary metal-oxide semiconductor (CMOS) image sensor by generic measurement indicator of Standard mobile imaging architecture (SMIA) which is one of internal standard of mobile imaging architecture. To evaluate the effect of environment and setting parameters, such as temperature and integration time, we measure the variation of the dark signal, dynamic range and fixed pattern noise of image sensor. We also detect the number of defective pixels and cluster defects defined as adjacent single defect pixels at 5M CMOS image sensor. Then, we find the existence of some cluster defects in experiment, which are not expected in calculation.

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A Comparative Study on the Buyer's Right to Withhold Performance for the Seller's Delivery of Defective Goods and Documents in International Sales within the CISG, English law and Korean law

  • Lee, Byung-Mun
    • THE INTERNATIONAL COMMERCE & LAW REVIEW
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    • v.17
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    • pp.251-293
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    • 2002
  • The study is a comparative and analytical study which comprises of the analysis of the rules of the buyer's right to withhold performance where the seller delivers defective goods or documents of three legal systems; the CISG, English law and Korean law. The purposes underlying this study are twofold. The first is to clarify the current position as to the right of withholding performance in the event of the seller's tender of defective goods or documents in Korean law, CISG and English law so that it may assist the parties in drafting the buyer's right to withhold performance in their own contract. The second is to compare the rules of one jurisdiction with those of other jurisdictions and to evaluate the rules in light of the practical functions and benefits of the right to withhold performance and the discipline of comparative law the basic question of which is whether a solution from one jurisdiction may facilitate the systematic development and reform of another jurisdiction. It shows that each jurisdiction does not have any provision or case law specifically dealing with the buyer's right to withhold performance where the seller delivers the goods which are defective in terms of quality or quantity. The absence of such provision or case in each jurisdiction has resulted in either disputes or uncertainty. However, the study executed in light of the primary functions and benefits of the right in practice and the discipline of comparative law reveals that, first, the view in English law which is against recognizing the right may not be justified when one considers the practical importance of having the right and the position taken by the CISG as a well developed and modernized law, second, the view in Korean law which argues that the principle of specific goods dogma on which it is based is extended even to substitutable or repairable goods cannot be also justified on the ground of one's ordinary expectation and the position under the CISG and English law which imposes a contractual duty to deliver non-defective goods on the seller insofar as the buyer's payment is deemed to be made in exchange for the seller's delivery of non-defective goods and they are substitutable or repairable. Regarding the right to withhold performance in the event of the seller's tender of defective documents, the study shows that the relatively detailed rules in English law may be utilized as a guideline to fill the gap in the CISG and Korean law in terms of the practicability and appropriateness to govern documentary sales. Furthermore, it is found that the position in English law which confers on the buyer the right to withhold performance for a trivial defect in documents may be unreasonable in terms of one's need to enable justice to be done in individual cases.

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Estimation of Process Parameters Using QFD and Neural Networks in Injection Molding (품질기능전개와 신경망 회로를 이용한 사출성형 공정변수의 예측)

  • Koh, Bum-Wok;Kim, Jong-Seong;Choi, Hoo-Gon
    • IE interfaces
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    • v.21 no.2
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    • pp.221-228
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    • 2008
  • The injection molding process is able to produce high precision manufactures as a single process with fast speed. However, the prices of both the mold and the molding machine are expensive, and the single process is very complex and difficult to compose of the exact relationship between the process setting conditions and the product quality. Therefore, the quality of a molded product often depends on a skillful engineer's operations in the design of both parts and molds. In this paper, the relationship between the process conditions and the defectiveness is built for better manufactures under settings of the appropriate parameters, and so it can reduce the setup time in the injection molding process. Quality Function Deployment (QFD) provides severe defectiveness factors along with the related process parameters. Also, neural networks estimate the relationship between defective factors and process setting parameters, and lead to reduce the defectiveness of molded parts.

Analysis and Probability of Overestimation by an Imperfect Inspector with Errors of Triangular Distributions (삼각 과오 분포를 가진 불완전한 검사원의 과대 추정 확률과 분석)

  • Yang, Moon Hee;Cho, Jae Hyung
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.41 no.2
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    • pp.117-132
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    • 2018
  • There always exist nonzero inspection errors whether inspectors are humans or automatic inspection machines. Inspection errors can be categorized by two types, type I error and type II error, and they can be regarded as either a constant or a random variable. Under the assumption that two types of random inspection errors are distributed with the "uniform" distribution on a half-open interval starting from zero, it was proved that inspectors overestimate any given fraction defective with the probability more than 50%, if and only if the given fraction defective is smaller than a critical value, which depends upon only the ratio of a type II error over a type I error. In addition, it was also proved that the probability of overestimation approaches one hundred percent as a given fraction defective approaches zero. If these critical phenomena hold true for any error distribution, then it might have great economic impact on commercial inspection plans due to the unfair overestimation and the recent trend of decreasing fraction defectives in industry. In this paper, we deal with the same overestimation problem, but assume a "symmetrical triangular" distribution expecting better results since our triangular distribution is closer to a normal distribution than the uniform distribution. It turns out that the overestimation phenomenon still holds true even for the triangular error distribution.

Vibration analysis of defected and pristine triangular single-layer graphene nanosheets

  • Mirakhory, M.;Khatibi, M.M.;Sadeghzadeh, S.
    • Current Applied Physics
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    • v.18 no.11
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    • pp.1327-1337
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    • 2018
  • This paper investigates the vibration behavior of pristine and defected triangular graphene sheets; which has recently attracted the attention of researchers and compare these two types in natural frequencies and sensitivity. Here, the molecular dynamics method has been employed to establish a virtual laboratory for this purpose. After measuring the different parameters obtained by the molecular dynamics approach, these data have been analyzed by using the frequency domain decomposition (FDD) method, and the dominant frequencies and mode shapes of the system have been extracted. By analyzing the vibration behaviors of pristine triangular graphene sheets in four cases (right angle of 45-90-45 configuration, right angle of 60-90-30 configuration, equilateral triangle and isosceles triangle), it has been demonstrated that the natural frequencies of these sheets are higher than the natural frequency of a square sheet, with the same number of atoms, by a minimum of 7.6% and maximum of 26.6%. Therefore, for increasing the resonance range of sensors based on 2D materials, nonrectangular structures, and especially the triangular structure, can be considered as viable candidates. Although the pristine and defective equilateral triangular sheets have the highest values of resonance, the sensitivity of defective (45,90,45) triangular sheet is more than other configurations and then, defective (45,90,45) sheet is the worst choice for sensor applications.

The Liability System and the Legal Nature of the Seller's Liability for Defective Goods under Korean Law and the PELS (유럽매매법원칙과 한국법상 결함상품에 대한 매도인의 책임의 법적성격과 책임제도)

  • Lee, Byung-Mun
    • THE INTERNATIONAL COMMERCE & LAW REVIEW
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    • v.44
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    • pp.31-55
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    • 2009
  • This study attempts to provide a comparative overview of the liability systems Korean law and the PELS adopt, that is, the approaches taken by Korean law and the PELS to deal with various irregularities of contractual performance. In addition, it examines in a comparative way the questions of what is the position of the seller's liability for his delivery of defective goods under the chosen liability system and what is the legal nature of the seller's liability. The study finds that the dual liability system taken by Korean law has caused some complexities as to the matter of which liability is applicable in some borderline cases. The problem in such complexities is originated in that the remedies available and the limitation period applicable are differentiated in accordance with one's different categorization among three types of default under the general liability and defective performance under the seller's guarantee liability. In this light, the study argues that the unified liability system under the PELS is superior because its concept of non-performance embraces in a unitary manner all the aspects of default including defects in quality, quantity and title. In addition, it finds that Korean law has suffered endless debates on the question of what are the true contents of the same remedies of rescission and damages provided under the seller's guarantee liability as under the general liability. The debates have been come along on the basis of the traditional presumption among some of civil law jurisdictions that two liabilities be different in terms of not only their legal nature but also their contents of remedies. The study argues that the problem may be circumvented, first, by another way of thinking that the unified liability in Korean law is inferred from the specification of the identical remedies for both the general liability and the seller's guarantee liability under the KCC, second, by the preposition that the requirement of fault be depended upon what remedy the buyer seeks to claim rather than what liability he does to rely on.

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Long-Term Performance of Geomembranes by Oxidative Induction Time

  • Jeon, Han-Yong;Kim, Hong-Kwan;Keum, Jae-Ho;Jang, Yong-Chea;Lyoo, Won-Seok;Ghim, Han-Do
    • Journal of the Korean Geosynthetics Society
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    • v.2 no.3
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    • pp.19-24
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    • 2003
  • Long-term performance of smooth and textured type HDPE geomembranes which were used to the liner and slope systems of waste landfills was examined. Artificial surface defects were added to the surface of geomembranes by scratch addition apparatus specially designed. The mechanical and frictional properties, chemical and ultra violet light resistances and oxidative induction time(OIT) of geomembranes were examined for the cases of defective/non-defective surfaces. Frictional properties of textured type geomembranes showed more excellent than those of smooth type geomembranes. Finally, it was known that the long-term performance of non-defective and textured geomembranes was better than that of defective geomembranes through chemical and UV resistance and OIT tests etc.

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A Control Chart for the Improvement of Low Defective Process (저수준 불량 공정의 개선을 위한 관리도)

  • 박기주
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.21 no.45
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    • pp.375-381
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    • 1998
  • For products that are subject to inspections that lead to either acceptance or rejection, the p chart or control chart for proportion defective is applicable. The charting technique approach to quality control aims at alerting its user to any presentations in the properties of a manufactured product. This article presents an important tool available for quality control of a production process at the occurrence of defects in manufactured products at view low levels to improve the efficiency of the manufacturing productivity and to satisfy customer through the reduction of defect rates. To understand the consequences of the level of quality on competitive position, a more technical perspective is needed.

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Design for a Defective Product Inspection Device for the Curved Glass used in Smart-phones (스마트폰 곡면 강화유리의 불량품 검사장치 설계)

  • Kim, Han-Sol;Lee, Kyung-Jun;Jung, Dong-Yean;Lee, Yeon-Hyeong;Park, Jea-Hyun;Kim, Gab-Soon
    • Journal of Institute of Control, Robotics and Systems
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    • v.21 no.8
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    • pp.794-800
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    • 2015
  • This paper describes the design for a defective product inspection device for the curved glass used in smart-phone. Cameras are used as inspection devices to find cracks in LCDs (Liquid Crystal Displays), PDPs (Plasma Display Panels), etc. The devices used to inspect the curved glass used in smart-phone consist of a camera, two back-light apparatus, an inspection apparatus main body, and an image processing program. Camera image calibration was performed to smooth an image taken with the camera, and as a result, the average error was less than 0.12 pixels. And the image of a smart-phone's curved glass taken with the camera was processed using the produced program. As a result, the program could correctly extract the cracks on the curved glass. Thus, it is thought that the designed inspection device can successful detect cracks in curved tempered glass.

Systems Engineering Approach to Develop Intelligent Production Planning Scheduling Model linked to Machine and Quality Data (설비 및 품질 데이터 연계 지능형 생산계획 스케줄링 모델 개발을 위한 시스템엔지니어링 접근 방법)

  • Park, Jong Hee;Kim, Jin Young;Hong, Dae Geun
    • Journal of the Korean Society of Systems Engineering
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    • v.17 no.2
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    • pp.1-8
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    • 2021
  • This study proposes a systems engineering approach for the development of an advanced planning & scheduling (APS) system for a cosmetic case manufacturing factory. The APS system makes production plans and schedules based on the injection process, which consists of 27 plastic injection machines in parallel to control recommended inventory of products. The system uses machine operation/failure information and defective product/work-in-process tracking information to support intelligent scheduling. Furthermore, a genetic algorithm model is applied to handle the complexity of heuristic rules and machine/quality constraints in this process. As a result of the development, the recommended inventory compliance rate is improved by scheduling the 30-day production plan for 15 main products.