• 제목/요약/키워드: Quality control parameters

검색결과 1,044건 처리시간 0.03초

Diagnosis of Thickness Quality Using Multivariate Statistical Analysis in Hot Finishing Mill

  • Kim, Heung-Mook
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2001년도 ICCAS
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    • pp.116.3-116
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    • 2001
  • A diagnosis methodology for thickness quality in hot finishing mill is proposed based on multivariate statistical analysis. The thickness of hot strip is a key quality factor that is measured by x-ray thickness gauge. Currently, the thickness quality is guaranteed by upper and lower limit of thickness deviation from target thickness. But if any over-limit is occurred, there is no in-line method to identify the causes. In this paper, many parameters are extracted from the thickness deviation signal such as mean deviation(top, middle, tail), rms deviation(top, middle, tail) and peak deviation(top, middle, tail) as time domain parameters ...

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퍼지신경망을 이용한 도로 영상의 양불량 판정 (Determination of Road Image Quality Using Fuzzy-Neural Network)

  • 이운근;백광렬;이준웅
    • 제어로봇시스템학회논문지
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    • 제8권6호
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    • pp.468-476
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    • 2002
  • The confidence of information from image processing depends on the original image quality. Enhancing the confidence by an algorithm has an essential limitation. Especially, road images are exposed to lots of noisy sources, which makes image processing difficult. We, in this paper, propose a FNN (fuzzy-neural network) capable oi deciding the quality of a road image prior to extracting lane-related information. According to the decision by the FNN, road images are classified into good or bad to extract lane-related information. A CDF (cumulative distribution function), a function of edge histogram, is utilized to construct input parameters of the FNN, it is based on the fact that the shape of the CDF and the image quality has large correlation. Input pattern vector to the FNN consists of ten parameters in which nine parameters are from the CDF and the other one is from intensity distribution of raw image. Correlation analysis shows that each parameter represents the image quality well. According to the experimental results, the proposed FNN system was quite successful. We carried out simulations with real images taken by various lighting and weather conditions and achieved about 99% successful decision-making.

포장 인쇄의 인쇄적성 향상에 관한 연구 (The Study of Quality Control for Package Printing)

  • 이만교;하영백;윤종태
    • 한국인쇄학회지
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    • 제23권1호
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    • pp.53-63
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    • 2005
  • The quality of the print can be specified through the quality of the coloring, the reproduction of fine structures and the range of tone values. Also, package printed quality are controlled by this points. In this paper, densitometry method was used for printed quality. By densitometry we can get the print density and the parameters of each conditions that characterize halftone printing, such as dot gain and relative printing contrast. Also, we have proposed the optimizes range of the parameters such as density, dot gain etc. to the package printed printability control.

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품질 기능 전개법과 위험 부담 관리법을 조합한 설계 최적화 기법의 용접 품질 감시 시스템 개발 응용 (Weld Quality Monitoring System Development Applying A design Optimization Approach Collaborating QFD and Risk Management Methods)

  • 손중수;박영원
    • 제어로봇시스템학회논문지
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    • 제6권2호
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    • pp.207-216
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    • 2000
  • This paper introduces an effective system design method to develop a customer oriented product using a design optimization process and to select a set of critical design paramenters,. The process results in the development of a successful product satisfying customer needs and reducing development risk. The proposed scheme adopted a five step QFD(Quality Function Deployment) in order to extract design parameters from customer needs and evaluated their priority using risk factors for extracted design parameters. In this process we determine critical design parameters and allocate them to subsystem designers. Subsequently design engineers develop and test the product based on these parameters. These design parameters capture the characteristics of customer needs in terms of performance cost and schedule in the process of QFD, The subsequent risk management task ensures the minimum risk approach in the presence of design parameter uncertainty. An application of this approach was demonstrated in the development of weld quality monitoring system. Dominant design parameters affect linearity characteristics of weld defect feature vectors. Therefore it simplifies the algorithm for adopting pattern classification of feature vectors and improves the accuracy of recognition rate of weld defect and the real time response of the defect detection in the performance. Additionally the development cost decreases by using DSP board for low speed because of reducing CPU's load adopting algorithm in classifying weld defects. It also reduces the cost by using the single sensor to measure weld defects. Furthermore the synergy effect derived from the critical design parameters improves the detection rate of weld defects by 15% when compared with the implementation using the non-critical design parameters. It also result in 30% saving in development cost./ The overall results are close to 95% customer level showing the effectiveness of the proposed development approach.

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신경회로망을 이용한 비드폭 예측 (Prediction of the Bead Width Using an Artificial Neural Network)

  • 김일수;손준식;박창언;하용훈;성백섭
    • Journal of Welding and Joining
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    • 제18권4호
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    • pp.48-54
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    • 2000
  • Adaptive control in the robotic GMA(Gas Metal Arc) welding is employed to monitor information about weld characteristics and process parameters as well; as t modify those parameters to hold weld. The objectives of this paper are to realize the mapping characteristics of bead width through the neural network and multiple regression method as well as to select the most accurate model in order to control the weld quality(bead width0. The experimental results show that the proposed neural network estimator can predict bead width with reasonable accuracy, and guarantee the uniform weld quality.

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Quality Control of Majoon-e-Nisyan and its Acute Oral Toxicity Study in Experimental Rats

  • Shaikh, Masud;Husain, Gulam M.;Naikodi, Mohammed Abdul Rasheed;Kazmi, Munawwar H.;Viquar, Uzma
    • 셀메드
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    • 제11권1호
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    • pp.2.1-2.8
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    • 2021
  • The clinical condition Amnesia causes difficulty in learning new information and the inability to recall past events. It is primarily concerned with recent memory loss. Majoon-e-Nisyan (MJN) is a polyherbal Unani formulation, present in a semi-solid form. It is widely used potent drug of the Unani System of Medicine (USM) for treating Nisyan (amnesia). In the present study polyherbal Unani formulation, MJN has been studied for its quality control and acute toxicity. Standardization (quality control) of drugs deals with drug identity, drug quality and purity determination. Standardization of MJN had been done as per the Unani pharmacopoeial parameters approved by World Health Organization (WHO) - Pharmacognostical parameters, Physico-chemical parameters, high-performance thin-layer chromatography (HPTLC), microbial load, aflatoxin, and heavy metals. Solvents and chemicals used in the study were of analytical grade and used instrument were calibrated. By conducting an acute oral toxicity study in rats, the safety of MJN was assessed. The limit test method of OECD guideline 425 was followed in the study. Results of standardization and standard operating procedures (SOPs) for preparation of MJN may serve as the standard reference in the future. The data generated in the study for the quality control of MJN proved the quality of formulation and shows that MJN is not toxic in rats following acute dosing up to 2000 mg/kg bw. The data obtained in the paper for MJN may be used as a standard guideline for preparation of the formulation which can save time, cost, and resources for future research endeavours.

토모테라피에서 선량품질보증 분석을 위한 통계적공정관리의 타당성 (Feasibility on Statistical Process Control Analysis of Delivery Quality Assurance in Helical Tomotherapy)

  • 장경환
    • 대한방사선기술학회지:방사선기술과학
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    • 제45권6호
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    • pp.491-502
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    • 2022
  • The purpose of this study was to retrospectively investigate the upper and lower control limits of treatment planning parameters using EBT film based delivery quality assurance (DQA) results and to analyze the results of statistical process control (SPC) in helical tomotherapy (HT). A total of 152 patients who passed or failed DQA results were retrospectively included in this study. Prostate (n = 66), rectal (n = 51), and large-field cancer patients, including lymph nodes (n = 35), were randomly selected. The absolute point dose difference (DD) and global gamma passing rate (GPR) were analyzed for all patients. Control charts were used to evaluate the upper and lower control limits (UCL and LCL) for all the assessed treatment planning parameters. Treatment planning parameters such as gantry period, leaf open time (LOT), pitch, field width, actual and planning modulation factor, treatment time, couch speed, and couch travel were analyzed to provide the optimal range using the DQA results. The classification and regression tree (CART) was used to predict the relative importance of variables in the DQA results from various treatment planning parameters. We confirmed that the proportion of patients with an LOT below 100 ms in the failure group was relatively higher than that in the passing group. SPC can detect QA failure prior to over dosimetric QA tolerance levels. The acceptable tolerance range of each planning parameter may assist in the prediction of DQA failures using the SPC tool in the future.

적외선 센서를 이용한 용접선 추적 및 용접품질 모니터링에 관한 연구 (A Study on the Seam tracking and Control of the Welding Quality Using a Infrared sensor)

  • 김일수;손준식;김학형;서주환;김인주
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2006년도 춘계학술대회 논문집
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    • pp.301-302
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    • 2006
  • In this paper, the possibilities of the Infra-red sensor in sensing and control of the bead geometry in the automated welding process are presented. Infra-red sensor is a well-known method to deal with the problems with a high degree of fuzziness so that the sensor is employed to build the relationship between process variables and the quality characteristic the proposed above respectively. Based on several neural networks, the mathematical models are derived from extensive experiments with different welding parameters and complex geometrical features. The developed system enables to select the optimal welding parameters and control the desired weld dimensions during arc welding process.

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디스플레이 장치에서 인쇄원고의 컬러 재현특성에 관한 연구 (A Study on the Color Reproduction Characteristic of Original Copy in Display Device)

  • 조가람;구철회
    • 한국인쇄학회지
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    • 제23권1호
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    • pp.65-75
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    • 2005
  • An accurate characterization of the display device is essential for better color matching. The calibration and characterization process in display device is needed to transform the device dependent color to the device independent color. The process of characterization performs a linearization and transforms the linearized values into the CIE XYZ tristimulus values. The purposes of this paper is to propose optimal color transformation method for accurate reproduction of original copy in display device and to explain the propriety of transformation method using specific variable for the power of gradation expression.

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Analysis and Compare for Control Charts Under the Changed Alarm Rule

  • Haiyu Wang;Jichao Xu;Park, Young H.
    • International Journal of Quality Innovation
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    • 제4권2호
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    • pp.65-72
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    • 2003
  • This paper mainly studies to build control charts under different alarm rule. For different alarm rule, the control limit parameters of a control chart should be changed, then some kinds of control schemes under different alarm rule were compared and the methods of calculating ARL for different control schemes were given.