• 제목/요약/키워드: quality measurement

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자동차용 Poewer steering unit 의 자동측정시스템 개발에 관한 연구 (A Study on the Development of the measurement system of the Power steering unit for Automobile)

  • 기창두;김상묵
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 1995년도 추계학술대회 논문집
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    • pp.925-928
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    • 1995
  • Recently, the system of the industry demands quick and accurate measurement for the mass production and high quality. Also, we need to improve the accuracy to decrease the failure rate in automatic assembly processing and improve the confidence, durability and the compatibility of parts. To answer this tendency and requirement, we have developed many accrate measuring instruments and methods. In this paper, we develop the whidows program using the DSP board(TMS320C25) which is used the data acquisition and the Visual C $^{++}$ , a windows programming language. We perform the measurement, analysis and output process in GUI(Graphic User Interface)environment. By using system, we will save the time required for the hand-worked measurement and avoid the useless iterative measurement. Furthermore, we expect to improve the productivity through automotive quality control in manufacturing process.s.

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측정오차를 고려한 최적 공정평균의 경제적 설정 - 축차검사의 활용 (Economic Selection of the Optimal Process Mean Using Sequential Inspection to Reduce the Effect of Measurement Errors)

  • 박환수;장영순
    • 품질경영학회지
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    • 제34권2호
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    • pp.12-21
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    • 2006
  • This paper considers the problem of selecting the most profitable process mean for production processes where measurement errors exist in inspection systems. For such situations, a sequential inspection procedure is proposed to reduce measurement errors. The decision to accept, reject, or take an additional inspection of an item is made at every measurement point until the number of repeated measurements reaches its upper bound. An expected profit model is constructed and the optimal process mean, the cut-off values, and the upper bound of the number of repeated measurements are obtained when accepted(rejected) items are sold at regular(reduced) price. A numerical study is performed to investigate the performance of the proposed procedure.

기둥형 로드셀 감지부의 설계변수에 따른 비선형 거동해석 (Finite Element Analysis of Nonlinear Behavior of a Column Type Sensing Element for Load Cell According to Design Parameters)

  • 이춘열;강대임
    • 대한기계학회논문집A
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    • 제24권6호
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    • pp.1540-1546
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    • 2000
  • Recently, force measurement systems are commonly used in many industrial fields and the precision of the measurement system is getting more important as the industry needs more precise tools and in struments to make high quality products. However, a high precision force measurement system is hard to make unless we know precisely the causes, quality and quantity of measurement errors in advance. In this work, many possible mechanical causes of measurement errors are reviewed including ratio of length to diameter of sensing part, radius of contact area, radius of bearing part, ratio of material properties and change of boundary conditions. Also, the measurement errors are analyzed by nonlinear finite element method and the nonlinear behavior of the errors are investigated. The results can be used to design force measurement systems and expected to be very useful especially for compact type load cells.

기상계측 시스템을 이용한 머시닝센터의 기하오차 모델링 및 오차측정 (Modeling and Measurement of Geometric Errors for Machining Center using On-Machine Measurement System)

  • 이재종;양민양
    • 한국정밀공학회지
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    • 제16권2호통권95호
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    • pp.201-210
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    • 1999
  • One of the major limitations of productivity and quality in metal cutting is the machining accuracy of machine tools. The machining accuracy is affected by geometric and thermal errors of the machine tools. Therefore, a key requirement for improving te machining accuracy and product quality is to reduce the geometric and thermal errors of machine tools. This study models geometric error for error analysis and develops on-machine measurement system by which the volumetric erors are measured. The geometric error is modeled using form shaping function(FSF) which is defined as the mathematical relationship between form shaping motion of machine tool and machined surface. The constant terms included in the error model are found from the measurement results of on-machine measurement system. The developed on-machine measurement system consists of the spherical ball artifact (SBA), the touch probe unit with a star type stylus, the thermal data logger and the personal computer. Experiments, performed with the developed measurement system, show that the system provides a high measuring accuracy, with repeatability of ${\pm}2{\mu}m$ in X, Y and Z directions.

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IoT에 의한 순환여과식 양식장 자동 수질 측정 시스템 구현 (Implementation of an Automated In-line Water Quality Measurement System of Recirculation Fish Farm with IoT)

  • 김선우;최연성
    • 한국전자통신학회논문지
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    • 제12권3호
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    • pp.477-484
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    • 2017
  • 기존의 순환여과식 양식장에서는 전문 인력의 부족, 수입 측정 장비에 대한 높은 의존도 등으로 인하여 많은 어려움을 격고 있다. 이에 본 논문에서는 최신 IoT기술을 적용한 광학식 센서(pH, DO)를 이용하여 양식장 수조 내 오염도를 빠른 시간내에 측정할 수 있는 자동 수질 측정 시스템을 구현하고자 한다. 기존 시스템의 문제점은 양식장 수조를 사람이 일일이 확인하거나, 측정 장비를 수조 속에 넣고 직접 측정을 하여 물고기의 생육에 좋지 않은 영향을 주는 것이다. 본 논문에서는 시스템은 측정 장비를 수조 속에 담그지 않고 간접 측정을 하는 방식을 제안하고 염분 및 다수의 오염 물질이 포함된 환경에서도 양식장 내의 물고기의 생육에 영향을 주지 않고 지속적인 측정이 가능한 시스템을 개발하였다.

Uncertainty Assessment: Relative versus Absolute Point Dose Measurement for Patient Specific Quality Assurance in EBRT

  • Mahmood, Talat;Ibrahim, Mounir;Aqeel, Muhammad
    • 한국의학물리학회지:의학물리
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    • 제28권3호
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    • pp.111-121
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    • 2017
  • Verification of dose distribution is an essential part of ensuring the treatment planning system's (TPS) calculated dose will achieve the desired outcome in radiation therapy. Each measurement have uncertainty associated with it. It is desirable to reduce the measurement uncertainty. A best approach is to reduce the uncertainty associated with each step of the process to keep the total uncertainty under acceptable limits. Point dose patient specific quality assurance (QA) is recommended by American Association of Medical Physicists (AAPM) and European Society for Radiotherapy and Oncology (ESTRO) for all the complex radiation therapy treatment techniques. Relative and absolute point dose measurement methods are used to verify the TPS computed dose. Relative and absolute point dose measurement techniques have a number of steps to measure the point dose which includes chamber cross calibration, electrometer reading, chamber calibration coefficient, beam quality correction factor, reference conditions, influences quantities, machine stability, nominal calibration factor (for relative method) and absolute dose calibration of machine. Keeping these parameters in mind, the estimated relative percentage uncertainty associated with the absolute point dose measurement is 2.1% (k=1). On the other hand, the relative percentage uncertainty associated with the relative point dose verification method is estimated to 1.0% (k=1). To compare both point dose measurement methods, 13 head and neck (H&N) IMRT patients were selected. A point dose for each patient was measured with both methods. The average percentage difference between TPS computed dose and measured absolute relative point dose was 1.4% and 1% respectively. The results of this comparative study show that while choosing the relative or absolute point dose measurement technique, both techniques can produce similar results for H&N IMRT treatment plans. There is no statistically significant difference between both point dose verification methods based upon the t-test for comparing two means.

관광호텔 식음료상품 서비스품질 평가 (Service Quality assessment for Food & Beverage Product of Hotel)

  • 김승희
    • 한국조리학회지
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    • 제5권2호
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    • pp.447-467
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    • 1999
  • Most published work on product quality focuses on manufactured goods. The subject of service quality has received less attention. This distinction is important because some of the quality-improving strategies avaliable to manufacturers may be inappropriate for service firms. Services are performances, not objects. They are often produced in the presence of the customer, as in the cause of hotel restaurant services, quality occurs during service delivery, usually in an interaction between the customer and contact personnel of service firm. for this reason, service quality is highly dependent on the performance of employees, an organizational resource that cannot be controlled to the degree that components of tangible goods can be engineered. The study has begun as a basic study for customer satisfaction-oriented management in understanding the service quality of food & beverage products and through a systematic analysis of it. The major purpose of the study was to examine the relationship of the customer satisfaction and service quality in consideration of reliability, empathy, responsiveness, tangibility and assurance. An empirical research was conducted based on the previous theoretical studies. 286 customer at first class hotels in Seoul were selected as samples of this study. The time period of research was from February through March 1999, and answers were processed by SAS to yield frequency analysis, multivariate statistical analysis and regression analysis. The finding of the statistical treatment are frequencies, factor analysis, multiple regression analysis, path analysis. SERVQUAL method was used the service quality evaluation methods. After factor analysis, it was resulted to 3 factors. those were factor 1(assurance.empathy.responsiveness), factor 2(reliability), factor 3(tangibility). The findings of the statistical treatment are as follows. First, the attribute measurement of performance service quality was affected by customer satisfaction. Second, the attribute measurement of performance service qualify was affected by repurchase intention. Third, The attribute measurement of performance customer satisfaction was affected by repurchase intention. The result of study model was followed, service quality was affected repurchase intention than customer satisfaction. indirected effect through, service duality and customer satisfaction was affected repurchase intention.

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국외 문헌고찰을 기초로 정신건강의 측면에서 본 한국주거의 질 측정요소에 관한 연구 (Measuring Inventory of Korean Housing Quality Related to Mental Health through Foreign Literature Reviews)

  • 박정아;최병숙
    • 한국주거학회논문집
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    • 제23권6호
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    • pp.1-9
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    • 2012
  • This study is to organize the frame of measuring inventory for housing quality related to mental health in foreign literature reviews. In the first step, many housing quality contents or items are extracted from empirical studies, including housing environment quality and mental health. In the next step, extracted contents and items are classified by space scope (house and neighborhood unit) and WHO housing properties (safety & security, health & sanitation, efficiency/convenience, comfort/amenity). Almost all housing properties follow the WHO standard, but some properties, sustainability and economic characteristics, do not follow the standard. These reflect on current Korean housing environment. They are energy saving and environment friendly effort, property value and economic burden, identity expression, and school district. So they need to be added to the Korean housing quality measurement related to mental health.

비만과 건강관련 삶의 질 (The Health-related Quality of Life of Obesity)

  • 권영달
    • 한방비만학회지
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    • 제4권1호
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    • pp.125-137
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    • 2004
  • Objective: The purpose of this study is to investigate how to use the Quality of Life(QoL) of obesity and to study the report cases which measure QoL on obesity. Method: This study investigate the definition of Health-related Quality of Life(HRQoL), the measurement of Health-related Quality of Life, and the papers of Health-related Quality of Life on obesity through the books and medicine journals of HRQoL and obesity. Conclusions: 1. The QoL includes role functional ability, the degree and quality of social and community interaction, psychological state, somatic feeling, and life satisfaction than personal health and social well-being. 2. The investigator needs to evaluate the reliability, validity and sensitivity of the scale, and the appropriateness of the instrument for the target population When he decides measurement. 3. The investigator have the well-drilled supporter or himself managed the data and study population to prevent missing data. 4. The investigator should decide which is needed on obesity a obesity-specific or broad-ranging instrument, or both.

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Automatic Display Quality Measurement by Image Processing

  • Chen, Bo-Sheng;Heish, Chen-Chiung
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
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    • pp.1228-1231
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    • 2009
  • This paper presented an automatic system for display quality measurement by image processing. The goal is to replace human eyes for display quality evaluation by computer vision and get the objective quality review for consumer to make purchase of monitor or TV. Color, contrast, brightness, sharpness and motion blur are the main five factors to affect display quality that could be measured by supplying patterns and analyzing the corresponding images captured from webcam. The scores are calculated by image processing techniques. Linear regression model is then adopted to find the relation between human score and the measured display performance.

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