• Title/Summary/Keyword: Measurement and assessment

Search Result 1,988, Processing Time 0.029 seconds

A Study for the Measurement System Assessment (측정시스템 평가에 관한 연구)

  • 백재욱
    • Journal of Korean Society for Quality Management
    • /
    • v.26 no.4
    • /
    • pp.124-142
    • /
    • 1998
  • It is essential to have a correct measurement system assessment to help improve process or quality. In this paper, we emphasize that a confidence interval a, pp.oach for the parameters of measurement error study and GR&R is crucial and a simple a, pp.oach for constructing them is presented. We also discuss on the issue of linearity of the gauge. Next, we try to reveal the relationship between measurement error and the process capability index. Finally some aspects of conducting the measuring experiment concerning the number of parts, number of measurements per part, and recommendations on how the experiment is to be performed will be considered.

  • PDF

DESIGN OF A VIBRATION AND STRESS MEASUREMENT SYSTEM FOR AN ADVANCED POWER REACTOR 1400 REACTOR VESSEL INTERNALS COMPREHENSIVE VIBRATION ASSESSMENT PROGRAM

  • Ko, Do-Young;Kim, Kyu-Hyung
    • Nuclear Engineering and Technology
    • /
    • v.45 no.2
    • /
    • pp.249-256
    • /
    • 2013
  • In accordance with the US Nuclear Regulatory Commission (US NRC), Regulatory Guide 1.20, the reactor vessel internals comprehensive vibration assessment program (RVI CVAP) has been developed for an Advanced Power Reactor 1400 (APR1400). The purpose of the RVI CVAP is to verify the structural integrity of the reactor internals to flow-induced loads prior to commercial operation. The APR1400 RVI CVAP consists of four programs (analysis, measurement, inspection, and assessment). Thoughtful preparation is essential to the measurement program, because data acquisition must be performed only once. The optimized design of a vibration and stress measurement system for the RVI CVAP is essential to verify the integrity of the APR1400 RVI. We successfully designed a vibration and stress measurement system for the APR1400 RVI CVAP based on the design materials, the hydraulic and structural analysis results, and performance tests of transducers in an extreme environment. The measurement system designed in this paper will be utilized for the APR1400 RVI CVAP as part of the first construction project in Korea.

Assessment of London underground tube tunnels - investigation, monitoring and analysis

  • Wright, Peter
    • Smart Structures and Systems
    • /
    • v.6 no.3
    • /
    • pp.239-262
    • /
    • 2010
  • Tube Lines has carried out a "knowledge and investigation programme" on the deep tube tunnels comprising the Jubilee, Northern and Piccadilly lines, as required by the PPP contract with London Underground. Many of the tunnels have been in use for over 100 years, so this assessment was considered essential to the future safe functioning of the system. This programme has involved a number of generic investigations which guide the assessment methodology and the analysis of some 5,000 individual structures. A significant amount of investigation has been carried out, including ultrasonic thickness measurement, detection of brickwork laminations using radar, stress measurement using magnetic techniques, determination of soil parameters using CPT, pressuremeter and laboratory testing, installation of piezometers, material and tunnel segment testing, and trialling of remote photographic techniques for inspection of large tunnels and shafts. Vibrating wire, potentiometer, electro level, optical and fibre-optic monitoring has been used, and laser measurement and laser scanning has been employed to measure tunnel circularity. It is considered that there is scope for considerable improvements in non-destructive testing technology for structural assessment in particular, and some ideas are offered as a "wish-list". Assessment reports have now been produced for all assets forming Tube Lines' deep tube tunnel network. For assets which are non-compliant with London Underground standards, the risk to the operating railway has to be maintained as low as reasonably practicable (ALARP) using enhanced inspection and monitoring, or repair where required. Monitoring techniques have developed greatly during recent years and further advances will continue to support the economic whole life asset management of infrastructure networks.

A Development and Performance Test of Voltage Measurement Accuracy Assessment System for Distribution Equipment (배전기기 전압계측 정밀도 평가시스템 개발 및 성능시험)

  • Cho, Jin-Tae;Kim, Ju-Yong;Lee, Hak-Ju;Kim, Jae-Han
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
    • /
    • v.27 no.9
    • /
    • pp.83-89
    • /
    • 2013
  • Power distribution system has been changed from radial system to closed loop or mesh system due to connection of distributed generation growth. Data from distribution equipments which are installed at distribution line is required to be accurate for the performance of DMS(Distribution Management System). This paper analyzes the voltage measurement data from distribution equipment. However, the results of the analysis are confirmed to have some errors in voltage measurement data from distribution equipment. These errors come from aging of voltage sensor in distribution equipment and inaccurate data transfer to FRTU(feeder remote terminal unit) through the controller. The main problem is that the voltage measurement data of distribution equipment can not be assessed after it's first installation at the distribution line. The voltage measurement accuracy assessment system is to assess the voltage measurement data from distribution equipment on hot-line. This study had a field test to verify the performance of system.

Consideration of Nano-Measurement Strategy (나노물질의 측정전략의 주요 쟁점)

  • Yoon, Chung-Sik
    • Journal of Environmental Health Sciences
    • /
    • v.37 no.1
    • /
    • pp.73-79
    • /
    • 2011
  • The growing interest in nanotechnology has resulted in increasing concern and a number of published environmental and workplace measurements for assessing occupational exposure to engineered nanomaterials. However, the amount of previous exposure data remains limited. Furthermore the data available was collected with extensive variation in terms of exposure measurement strategy, which limits the ability to pool the data in the future. In response, this paper reviewed several pertinent issues related to exposure measurement strategy to suggest a harmonized measurement strategy which would make exposure data more useful in the future, e.g. correlation between exposure metrics, relationship between activity and exposure, task-based or shift-based assessment, background concentration, limitation of personal exposure monitoring and other determinants of exposure/modeling. An improved sampling strategy for nanomaterial exposure assessment should be considered in order to maximize the use of the data from various real time monitoring instruments.

Revised PPC Measurement Method considering Interfering Float Weight of Task

  • Jung-Sook Yun;Hyung-il Kim;Jung-Ho Yu;Chang-Duk Kim
    • International conference on construction engineering and project management
    • /
    • 2009.05a
    • /
    • pp.1479-1484
    • /
    • 2009
  • It is commonly recognized to need performance management for successful construction project. PPC measurement of Last Planner System is one of construction project measurement method. PPC measurement is quantitatively assessment to go through construction, and that is not completely to be trusted when compare a project with another or an individual case work with another in same project. According to, purpose of this study is comparison indicator establishment that compare project with another or an individual case work with another it is not use PPC measurement for quantitatively assessment to go through construction. The procedure of this study is derive of the point at issue of existing PPC measurement for a aim PPC measurement in this study expenditure and select weight about that and it is applied to actually construction.

  • PDF

Development of an Performance Evaluation Method for Vehicle Detector Speed Measurement Applying Uncertainty in Measurement (측정불확도를 적용한 차량검지기 속도측정 성능평가방법 개발)

  • Lee, Hwan-Pil;Kim, Yong-Man;Kang, Dong-Yun
    • International Journal of Highway Engineering
    • /
    • v.14 no.2
    • /
    • pp.165-174
    • /
    • 2012
  • In this study, a method for evaluating the performance of speed measurements was developed to assess the qualities of a vehicle detector. The evaluation method considers measurement errors that are reflected in a reference speed. For this, the concept of uncertainty in measurement was applied to the development method. Other factors such as precedent study, statistical processing techniques, and speed measurement performance method of traffic enforcement equipment and vehicle detection systems were also reviewed. Through this process, the problems of the existing evaluation methods were derived and developed for the new performance evaluation method. Vehicle detectors that are installed in the field were evaluated using the traditional assessment methods and the developed method. As a result, for traditional assessment methods, it was found that evaluation criteria are acceptable, while developed method's criteria are not acceptable. This means that traditional assessment methods do not sufficiently consider errors in measurement, so it has potential to over-estimate for performance of evaluation equipment. On the other hand, it was represented that the developed method should include variable factor such as errors in measurement and more precise compared to traditional assessment methods.

Measurement Uncertainty Assessment of Altitude Performance Test for a Turboshaft Engine (터보샤프트 엔진 고공성능시험의 측정 불확도 평가)

  • Yang, In-Young;Lee, Bo-Hwa
    • Journal of the Korean Society of Propulsion Engineers
    • /
    • v.14 no.4
    • /
    • pp.59-64
    • /
    • 2010
  • Measurement uncertainty assessment was performed for altitude performance test for a turboshaft engine. Mathematical models of measurement were suggested for major performance parameters such as shaft horse power, fuel flow, specific fuel consumption, and airflow. The procedure was compared with the test of turbojet or turbofan engines. Uncertainty involved with the test condition measurement was assessed. Influence of the test condition measurement uncertainty on the corrected performance data was discussed. Uncertainty assessment result was provided for a example test case using a real altitude test facility. For major performance parameters, measurement uncertainties were assessed as 0.65~1.09% including the test condition measurement uncertainty, 0.36~0.94% not including it.

Efficient Data Management for Hull Condition Assessment

  • Jaramillo, David;Cabos, Christian;Renard, Philippe
    • International Journal of CAD/CAM
    • /
    • v.6 no.1
    • /
    • pp.9-17
    • /
    • 2006
  • Performing inspections for Hull Condition Monitoring and Assessment as stipulated in IACS unified requirements and IMO's Condition Assessment Scheme (CAS) IMO Resolution MEPC.94(46), 2001, Condition Assessment Scheme, IMO Resolution MEPC.111(50), 2003, Amendments to regulation 13G, addition of new regulation 13H involves a huge amount of measurement data to be collected, processed, analysed and maintained. Information to be recorded consists of thickness measurements and visual assessment of coating and cracks. The amount of data and increasing requirements with respect to condition assessment demand efficient computer support. Currently, due to the lack of standardization for this kind of data, the thickness measurements are recorded manually on ship drawings or tables. In this form, handling of the measurements is tedious and error-prone and assessment is difficult. Data reporting and analysis takes a long time, leading to some repairs being performed only at the next docking of the ship or making an additional docking necessary. The recently started ED funded project CAS addresses this topic and develops-as a first step-a data model for Hull Condition Monitoring and Assessment (HCMA) based on XML-technology. The model includes simple geometry representation to facilitate a graphically supported data collection as well as an easy visualisation of the measurement results. In order to ensure compatibility with the current way of working, the content of the data model is strictly confined to the requirements of the measurement process. Appropriate data interfaces to classification software will enable rapid assessment by the classification societies, thus improving the process in terms of time and cost savings. In particular, decision-making can be done while the ship is still in the dock for maintenance.

Selection Criteria of Measurement Locations for Advanced Power Reactor 1400 Reactor Vessel Internals Comprehensive Vibration Assessment Program (APR1400 원자로내부구조물 종합진동평가 측정위치 선정 기준)

  • Ko, Do-Young;Kim, Kyu-Hyung;Kim, Sung-Hwan
    • Transactions of the Korean Society for Noise and Vibration Engineering
    • /
    • v.21 no.8
    • /
    • pp.708-713
    • /
    • 2011
  • U.S. nuclear regulatory commission(NRC) regulatory guide(RG) 1.20 requires a comprehensive vibration assessment program(CVAP) for use in verifying the structural integrity of reactor vessel internals(RVI) for flow-induced vibrations prior to commercial operation. The CVAP program consist of vibration and fatigue analysis, a vibration measurement program, an inspection program, and a correlation of their results. One of the main purposes of the analysis program is to select measurement locations, however measurement locations can not be determined by only analysis results, therefore we developed selection criteria of measurement locations for advanced power reactor 1400(APR1400) RVI CVAP, It will be used to select measurement locations and instrument types for APR1400 RVI CVAP.