• Title/Summary/Keyword: process variability

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Process Effect on the RMS Roughness of CuInSe2 Thin Films Grown by MOMBE

  • Ko, Young-Don;Moon, Pyung;Yun, Il-Gu;Ham, Moon-Ho;Myoung, Jae-Min
    • Transactions on Electrical and Electronic Materials
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    • v.8 no.2
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    • pp.58-66
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    • 2007
  • In this paper, the process effect on the RMS roughness of the $HfO_2$ thin films grown by metal organic molecular beam epitaxy was investigated. The measured RMS roughness is examined to characterize the surface morphology. In order to analyze the factor effects, the significant factors of both the main and the interaction effects were extracted through the effect analysis. In order to compare the regression model with the variable transformation, the effect of each factor and the model efficiency are calculated. The methodology can allow us to analyze the effects between the process parameters related to the process variability.

Development of a Robust Design Process Using a Robustness Index (강건성 지수를 이용한 강건설계 기법의 개발)

  • Hwang, Kwang-Hyeon;Park, Gyung-Jin
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.27 no.8
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    • pp.1426-1435
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    • 2003
  • Design goal is to find the one that has the highest probability of success and the smallest variation. A robustness index has been proposed to satisfy these conditions. The two-step optimization process of the target problem requires a scaling factor. The search process of a scaling factor is replaced with the making of the decoupled design between the mean and the standard deviation. The decoupled design matrix is formed from the sensitivity or the sum of squares. After establishing the design matrix, the robust design process has a new three-step one. The first is ″reduce variability,″ the second is ″make the candidate designs that satisfy constraints and move the mean on the target,″ and the final is ″select the best robust design using the proposed robustness index.″ The robust design process is verified by three examples and the results using the robustness index are compared with those of other indices.

Multiresponse Optimization Through A New Desirability Function Considering Process Parameter Fluctuation (공정변수의 변동을 고려한 호감도 함수를 통한 다중반응표면 최적화)

  • Kwon Jun-Bum;Lee Jong-Seok;Lee Sang-Ho;Jun Chi-Hyuck;Kim Kwang-Jae
    • Journal of the Korean Operations Research and Management Science Society
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    • v.30 no.1
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    • pp.95-104
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    • 2005
  • A desirability function approach to a multiresponse problem is proposed considering process parameter fluctuation which may amplify the variance of response. It is called POE (propagation of error), which is defined as the standard deviation of the transmitted variability in the response as a function of process parameters. In order to obtain more robust process parameter setting, a new desirability function is proposed by considering POE as well as distance-to-target of response and response variance. The proposed method is illustrated using a rubber product case in Ribeiro et al. (2000).

EWM-MR chart for individual measurements in start-up process (초기공정에서 개별관측치를 이용한 EWM-MR 관리도)

  • 지선수
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.21 no.47
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    • pp.211-218
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    • 1998
  • In start-up process control applications it may be necessary to limit the sample size to one measurement. A control chart for individual measurements is used whenever it is desirable to examine each individual value from the process immediately. A possible option would be to use an exponential weighted moving(EWM), using modifying statistics with individual measurement, chart for monitoring the process center, and using a moving range (MR) chart for monitoring process variability. In this paper it is shown that there is scheme in using the EWM procedure based on average run length. An expression for the ARL is given in terms of an integral equation, approximated using numerical quadrature. In this case, where it is reasonable to assume normality and negligible autocorrelation in the observations, provide graphs that simplify the design of EWM-MR chart and taking method of exponential smoothing constant(λ) and constant(K) are suggested. The charts suggested above evaluate using the conditional probability.

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A Method to Manage Requirements Analyzing the Commonality and Variability in Product Line (프로덕트 라인에서 공통성과 가변성 분석을 통한 요구사항 관리방법)

  • Park, Dong-Su;Kim, Dong-Kyu;Chong, Ki-Won
    • The KIPS Transactions:PartD
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    • v.13D no.7 s.110
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    • pp.909-922
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    • 2006
  • The core assets include all properties which consist of an application in Product Line Engineering. The requirement, one of the core assets, is a basis of other core assets and commonality and variability of other core assets are classified by the requirement. accordingly, commonality and variability of the domain requirement should be managed objectively and it is necessary to make a process to reuse the domain requirements. However the requirement is analyzed by domain experts or developers without proper process. In this paper, we proposed the 4 activities: (1)the domain scoping, (2)the extraction and generalization of the domain requirement, (3)the domain requirement analyzing and modeling, (4)the change management, and sub activities. For all reasons given previously, it is possible to reduce the development time and cost by reusing the architectures and components related to the domain requirement. In addition, it is possible to increase the quality of the artifacts produced based on the requirements by managing them systematically.

A PC-Based System for Gear Pitch Analysis and Monitoring in Gear Manufacturing Process (기어피치분석 및 공정관측을 위한 PC기반시스템 구축)

  • 김성준;지용수
    • Journal of Korean Society for Quality Management
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    • v.30 no.3
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    • pp.111-119
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    • 2002
  • Gears are essential elements for mechanical power transmission. Geometric precision is the main factor for characterizing gear grade and qualify. Gear pitch is one of the crucial measurements, which is defined as a distance between two adjacent gear teeth. It is well-known that variability in gear pitches may causes wear-out and vibration noise. Therefore maintaining pitch errors at a low level plays a key role in assuring the gear quality to customers. This paper is concerned with a case study, which presents a computerized system for Inspecting pitch errors in a gear machining process. This system consists of a PC and window-based programs. Although the start and stop is manually accomplished, the process of measuring and analyzing pitch data is automatically conducted in this system. Our purpose lies in reducing inspection cost and time as well as Increasing test reliability. Its operation is briefly illustrated by example. Sometimes a strong autocorrelation is observed from pitch data. We also discuss a process monitoring scheme taking account of autocorrelations.

Aligning Executive Scanning with Strategic Management : The Stages of Executive Scanning Process in Healthcare Organizations

  • Suh, Won-S.
    • Korea Journal of Hospital Management
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    • v.12 no.2
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    • pp.93-111
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    • 2007
  • The thrust in this paper is to discuss the dimensions of executive scanning process (ESP) that support continuous scanning activities by executives. Executive scanning is especially important for the healthcare organizations in these days since the environment they are faced with is extremely complex and dynamic. While much has been written about ESP, two important aspects have been underemphasized in the past. The first is a link to the strategic management process (SMP) or the issue of strategy-scanning alignment. The second is a feedback loop to verify the quality of information generated through scanning process. This paper discusses the improved ESP by adding these two features.

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Optical In-Situ Plasma Process Monitoring Technique for Detection of Abnormal Plasma Discharge

  • Hong, Sang Jeen;Ahn, Jong Hwan;Park, Won Taek;May, Gary S.
    • Transactions on Electrical and Electronic Materials
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    • v.14 no.2
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    • pp.71-77
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    • 2013
  • Advanced semiconductor manufacturing technology requires methods to maximize tool efficiency and improve product quality by reducing process variability. Real-time plasma process monitoring and diagnosis have become crucial for fault detection and classification (FDC) and advanced process control (APC). Additional sensors may increase the accuracy of detection of process anomalies, and optical monitoring methods are non-invasive. In this paper, we propose the use of a chromatic data acquisition system for real-time in-situ plasma process monitoring called the Plasma Eyes Chromatic System (PECS). The proposed system was initially tested in a six-inch research tool, and it was then further evaluated for its potential to detect process anomalies in an eight-inch production tool for etching blanket oxide films. Chromatic representation of the PECS output shows a clear correlation with small changes in process parameters, such as RF power, pressure, and gas flow. We also present how the PECS may be adapted as an in-situ plasma arc detector. The proposed system can provide useful indications of a faulty process in a timely and non-invasive manner for successful run-to-run (R2R) control and FDC.

Volume Transport on the Texas-Louisiana Continental Shelf

  • Cho Kwang-Woo
    • Fisheries and Aquatic Sciences
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    • v.1 no.1
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    • pp.48-62
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    • 1998
  • Seasonal volume transport on the Texas-Louisiana continental shelf is investigated in terms of objectively fitted transport streamfunction fields based on the current meter data of the Texas­Louisiana Shelf Circulation and Transport Processes Study. Adopted here for the objective mapping is a method employing a two-dimensional truncated Fourier representation of the streamfunction over a domain, with the amplitudes determined by least square fit of the observation. The fitting was done with depth-averaged flow rather than depth-integrated flow to reduce the root-mean-square error. The fitting process filters out $11\%$ of the kinetic energy in the monthly mean transport fields. The shelf-wide pattern of streamfunction fields is similar to that of near-surface velocity fields over the region. The nearshore transport, about 0.1 to 0.3 Sv $(1 Sv= 10^6\;m^3/sec)$, is well correlated with the seasonal signal of along-shelf wind stress. The spring transport is weak compared to other seasons in the inner shelf region. The transport along the shelf break is large and variable. In the southwestern shelf break, transport amounts up to 4.7 Sv, which is associated with the activities of the encroaching of energetic anticyclonic eddies originated in Loop Current of the eastern Gulf of Mexico. The first empirical orthogonal function (EOF) of streamfunction variability contains $67.3\%$ of the variance and shows a simple, shelf-wide, along-shelf pattern of transport. The amplitude evolution of the first EOF is highly correlated (correlation coefficient: 0.88) with the evolution of the along-shelf wind stress. This provides strong evidence that the large portion of seasonal variation of the shelf transport is wind-forced. The second EOF contains $23.7\%$ of the variance and shows eddy activities at the southwestern shelf break. The correlation coefficient between the amplitudes of the second EOF and wind stress is 0.42. We assume that this mode is coupled a periodic inner shelf process with a non-periodic eddy process on the shelf break. The third EOF (accounting for $7.2\% of the variance) shows several cell structures near the shelf break associated with the variability of the Loop Current Eddies. The amplitude time series of the third EOF show little correlation with the along-shelf wind.

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Development of a Tool for Modeling the Variabilities of Business Process (비즈니스 프로세스의 가변성 모델링 지원 도구 개발)

  • Hong, Min-Woo;Moon, Mi-Kyeong;Yeom, Keun-Hyuk
    • Journal of KIISE:Computing Practices and Letters
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    • v.14 no.7
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    • pp.733-737
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    • 2008
  • Business process modeling is to represent the business activities in a graphical notation that enterprises use to achieve their customer's requirements. Nowadays, lots of requirements are changed quickly and variously. Therefore, business process models should provide the means which can prepare for changes by analyzing (pointing) elements of business process that are likely to alter. In this paper, we propose a business process family model (BPFM) which represents the commonalities and the variabilities of a set of business processes. In addition, we propose the process which develops the tools for BPFM based on Eclipse Plug-In Graphical Modeling Framework (GMF). The variabilities of Business Process are modeled by using expanded model elements of UML2.0 activity diagram.