• 제목/요약/키워드: Quality control sample

검색결과 846건 처리시간 0.03초

Bayesian Reliability Estimation for a Two-unit Hot Standby System

  • Kim, Hee-Jae;Moon, Young-Gil;Lee, Chang-Soo
    • Journal of the Korean Data and Information Science Society
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    • 제8권1호
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    • pp.31-39
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    • 1997
  • we shall propose some Bayes estimators and some generalized maximum likelihood estimators for reliability of a two-unit hot standby system with perfect switch based upon a complete sample of failure times observed from the exponential model and compare the peformances of the proposed estimators in terms of mean squared error.

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Rank tests for Conparing several treatments with a control in a Randomized Block experiment

  • Park, Sang-Gue;kim, Jeong-il;Lee, Eun-Koo
    • 품질경영학회지
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    • 제19권1호
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    • pp.16-27
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    • 1991
  • Propose three rank tests based on different kinds of ranking methods for comparing several treatments with a control in a randomized block experiment. Monte Carlo power simulation study is examined in some small sample sizes and configurations to recommend a better test for applications.

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POSITION RECOGNITION AND QUALITY EVALUATION OF TOBACCO LEAVES VIA COLOR COMPUTER VISION

  • Lee, C. H.;H. Hwang
    • 한국농업기계학회:학술대회논문집
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    • 한국농업기계학회 2000년도 THE THIRD INTERNATIONAL CONFERENCE ON AGRICULTURAL MACHINERY ENGINEERING. V.III
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    • pp.569-577
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    • 2000
  • The position of tobacco leaves is affluence to the quality. To evaluate its quality, sample leaves was collected according to the position of attachment. In Korea, the position was divided into four classes such as high, middle, low and inside positioned leaves. Until now, the grade of standard sample was determined by human expert from korea ginseng and tobacco company. Many research were done by the chemical and spectrum analysis using NIR and computer vision. The grade of tobacco leaves mainly classified into 5 grades according to the attached position and its chemical composition. In high and low positioned leaves shows a low level grade under grade 3. Generally, inside and medium positioned leaf has a high level grade. This is the basic research to develop a real time tobacco leaves grading system combined with portable NIR spectrum analysis system. However, this research just deals with position recognition and grading using the color machine vision. The RGB color information was converted to HSI image format and the sample was all investigated using the bundle of tobacco leaves. Quality grade and position recognition was performed through well known general error back propagation neural network. Finally, the relationship about attached leaf position and its grade was analyzed.

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현미 Sourdough을 이용한 찐빵의 품질특성 (Quality Characteristics of Steamed Bread with Brown Rice Sourdough)

  • 최동순;박향숙;이명호
    • 한국조리학회지
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    • 제22권5호
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    • pp.1-12
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    • 2016
  • 본 연구에서는 찐빵의 영양성과 품질을 향상시키기 위한 현미발효액, 현미 sourdough을 만든 후, 첨가량을 달리하여 찐빵을 제조한 다음 이화학적, 관능적 특성을 측정하였다. 반죽의 pH 및 적정산도를 측정한 결과는 현미 sourdough 첨가량에 따라 유의적으로 낮아지는 경향을 보였으며, 대조구의 적정산도는 시료간의 유의한 차이가 있었다. 발효시간에 따른 반죽의 부피는 대조구와 각 시료간의 유의적인 차이가 없었으며, 발효 15분에는 대조구에서 가장 크게 부피가 증가하였고, D시료에서 가장 낮은 부피를 보였다. 찐빵의 부피 및 비용적의 경우, B 시료에서 3.34로 가장 높았고, 각각의 시료에서 발효시간에 따른 유의한 차이를 보였다. 지름은 B 시료에서 88.11로 가장 높았고, D 시료에서 79.04로 가장 낮았으며, 시료간의 유의한 차이가 나타났다. 찐빵의 높이는 대조구에서 42.91로 가장 높았고, D 시료에서 41.87로 가장 낮았으며, 시료간의 유의한 차이를 보였다. 찐빵의 단면구조를 살펴본 결과, 부피와 비용적이 가장 높게 나타난 B 시료의 기공이 가장 크고 조직의 결이 일정하게 분포되어 있었다. L값은 대조구보다 첨가구에서 높은 경향을 보였고, a값은 현미 sourdough의 첨가량이 증가할수록 높게 나타났고, b값은 찐빵의 부피와 비용적이 클수록 낮게 나타나 L값과 유사한 경향을 보였다. 경도, 점착성, 씹힘성에서 D 시료에서 가장 높았고, B 시료에서 가장 낮았으며, 시료간의 유의한 차이가 나타났다. 전체적인 선호도를 측정한 결과, 향, 맛, 외형 및 질감에서 가장 높은 선호도를 나타낸 B 시료에서 가장 높았고, 맛, 외형 및 질감 등에서 가장 낮은 선호도를 나타낸 D 시료에서가장 낮았으며, 각 시료간의 유의한 차이를 보였다.

계량형 샘플링 검사에서의 경험적 베이즈 추정 (Empirical Bayes Estimation on Sampling Inspection by Variables)

  • 신민웅;신기일
    • 품질경영학회지
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    • 제23권3호
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    • pp.45-56
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    • 1995
  • The method of lot by lot quality protection for sampling inspection by variables is widely used in quality control. In case of sampling inspection being done repeatedly, one can use the information from the previous sampling inspection to improve current estimates. This article shows that empirical Bayes estimator is superior to the usual sample mean in repeated sampling inspection by variables.

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Demerit-CUSUM 관리도와 해석방법에 관한 연구 (A Study of Demerit-CUSUM Control Chart and Interpretation Method)

  • 나상민;강창욱;심성보
    • 품질경영학회지
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    • 제31권1호
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    • pp.132-141
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    • 2003
  • As the technology has improved and demands of customers have varied, a lot of products are getting diverse and intricate. Consequently, the enterprise that produce products have to simultaneously consider the various variables for the very products. There are some scheme, such as Multivariate control chart and Demerit control chart, designed to simultaneously monitor the variables in the process. In this paper, we present an effective method for process control using the Demerit-CUSUM control chart in the process where nonconforming units or nonconformities are occured by various types. In addition, we show interpretation method for abnormal signal in order to quickly detect the assignable causes as Demerit-CUSUM control chart signals abnormality. we compare performance of Demerit control chart and Demerit-CUSUM control chart using example again used in the existing studies, and present result of performance accoriding to changing sample size and parameter.

패턴 분야의 국가직무능력표준 개발에 관한 연구 (Study on Development of National Competency Standards (NCS) of Pattern)

  • 곽연신;서승희
    • 패션비즈니스
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    • 제18권5호
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    • pp.144-158
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    • 2014
  • National Competency Standards(NCS) is to systemize the competency that is necessary for performing duties in industrial fields and to utilize synthetically duty, vocational education training, and qualification at the national level. The purpose of this study is to analyze the process of NCS development and verification, which systemizes competency units and competency unit elements through the analysis of duty in pattern field. It is to cultivate competent people to be able to promote the development of pattern industry ultimately through being a complementary to educational circles and industry then to give them practical knowledge that is demanded in the field. Furthermore, it is to be utilized as a fundamental data for reforming the system of duty competency evaluation so as to manage personnel career systematically and to improve their competency. Focus Group Interview(FGI) was adapted as the method of this study, which was proceeded 3 times, and validity of the drawn result is verified through expert questionnaire survey. Research result, which is competency units, is 10 as follows; Fit trend analysis, Analysis of sample garment Specification sheet, Pattern making for sample garment, Pattern making for manufacturing garment, Creation of sewing specification, Instruction of manufacturing technique, Sample garment Inspection for quality control, Grading, Calculation of the required material quantities, Quality control.

Sensing Technology for Rapid Detection of Phosphorus in Water: A Review

  • Islam, Sumaiya;Reza, Md Nasim;Jeong, Jin-Tae;Lee, Kyeong-Hwan
    • Journal of Biosystems Engineering
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    • 제41권2호
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    • pp.138-144
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    • 2016
  • Purpose: Phosphorus is an essential element for water quality control. Excessive amounts of phosphorus causes algal bloom in water, which leads to eutrophication and a decline in water quality. It is necessary to maintain the optimum amount of phosphorus present. During the last decades, various studies have been conducted to determine phosphorus content in water. In this study, we present a comprehensive overview of colorimetric, electrochemical, fluorescence, microfluidic, and remote sensing technologies for the measurement of phosphorus in water, along with their working principles and limitations. Results: The colorimetric techniques determine the concentration of phosphorus through the use of color-generating reagents. This is specific to a single chemical species and inexpensive to use. The electrochemical techniques operate by using a reaction of the analyte of interest to generate an electrical signal that is proportional to the sample analyte concentration. They show a good linear output, good repeatability, and a high detection capacity. The fluorescence technique is a kind of spectroscopic analysis method. The particles in the sample are excited by irradiation at a specific wavelength, emitting radiation of a different wavelength. It is possible to use this for quantitative and qualitative analysis of the target analyte. The microfluidic techniques incorporate several features to control chemical reactions in a micro device of low sample volume and reagent consumption. They are cheap and rapid methods for the detection of phosphorus in water. The remote sensing technique analyzes the sample for the target analyte using an optical technique, but without direct contact. It can cover a wider area than the other techniques mentioned in this review. Conclusion: It is concluded that the sensing technologies reviewed in this study are promising for rapid detection of phosphorus in water. The measurement range and sensitivity of the sensors have been greatly improved recently.

볶은 잡곡 종류를 달리하여 제조한 별미장의 품질 특성 (Quality Characteristics of Byeolmijang Prepared by Different Variety of Roasted Grain Powders)

  • 엄현주;권누리;강혜정;박혜진;김소영;김주형
    • 한국식품영양학회지
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    • 제35권2호
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    • pp.106-115
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    • 2022
  • The purpose of this study was to examine the quality characteristics of byeolmijang prepared several roasted whole grain powders (oat, brown rice, black soybean, corn) for eight weeks. As the fermentation progressed, the pH decreased from 6.10~6.12 to 4.48~4.92 and the total acidity increased dramatically from 0.41~0.48% to 1.67~2.24%. There were no differences in the moisture content. The content of reducing sugar decreased, in particular, brown rice sample(C) decreased significantly than the other samples during fermentation. In color, L and b-value decreased all samples, whereas a-value showed a tendency to slightly increase. The total cell counts and lactic acid bacteria revealed an increasing tendency during fermentation. In case of the amino-type nitrogen contents, it increased significantly during the fermentation period, especially control sample (A) showed the highest content significantly. The total polyphenol of all samples increased in the fermentation period. ABTS and DPPH radical scavenging activities also increased, especially corn sample (E) had the highest levels. In by electronic tongue analysis, corn sample (E) revealed higher umami and sourness than the control. So, by adding roasted corn powder, it can enhance function and taste of byeolmijang.

Switching performances of multivarite VSI chart for simultaneous monitoring correlation coefficients of related quality variables

  • Chang, Duk-Joon
    • Journal of the Korean Data and Information Science Society
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    • 제28권2호
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    • pp.451-459
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    • 2017
  • There are many researches showing that when a process change has occurred, variable sampling intervals (VSI) control chart is better than the fixed sampling interval (FSI) control chart in terms of reducing the required time to signal. When the process engineers use VSI control procedure, frequent switching between different sampling intervals can be a complicating factor. However, average number of samples to signal (ANSS), which is the amount of required samples to signal, and average time to signal (ATS) do not provide any control statistics about switching performances of VSI charts. In this study, we evaluate numerical switching performances of multivariate VSI EWMA chart including average number of switches to signal (ANSW) and average switching rate (ASWR). In addition, numerical study has been carried out to examine how to improve the performance of considered chart with accumulate-combine approach under several different smoothing constant and sample size. In conclusion, process engineers, who want to manage the correlation coefficients of related quality variables, are recommended to make sample size as large and smoothing constant as small as possible under permission of process conditions.