• 제목/요약/키워드: measurement systems

검색결과 4,992건 처리시간 0.033초

정보시스템 신뢰성 향상을 위한 위험점수 측정모델 연구 (A Risk Point Measuring Model for Improvement of the Information System Reliability)

  • 조두호;서장훈
    • 대한안전경영과학회지
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    • 제7권3호
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    • pp.47-61
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    • 2005
  • Many researchers have proved that risk measurement of information systems is a very effective tool for improving confidence of information systems. However, information system risk in Korea still includes many subjective judgements. This study deals with applying a quantitative model to improve risk measurement of information system quality. First of all, we have come up with solutions to improve the evaluation efficiency on risk measurement. We have merged the risk guidelines of COBIT and CMM, and developed a quantified evaluation scheme that call by risk point. We have proved the validity of this model by interviews with experts and by case studies.

Ball link bar를 이용한 CNC 공작 기계의 정밀도 계측과 해석에 관한 연구 (Measurement and analysis of CNC machine tool errors using ball link bar system)

  • 권혁동
    • 제어로봇시스템학회논문지
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    • 제3권3호
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    • pp.289-296
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    • 1997
  • In this paper, a method has been proposed for error measurement/diagnosis of CNC machine tools using the ball link bar on three dimensional space. For the circular motion error measurement, deviation between the desired and actual test path has been measured and analysed using a new type of ball link which incorporates ideal three point contact between reference balls and sockets. Computer program for the error evaluation has been developed and implemented under PC environment. Using the developed program, the circular test data on a CNC machine tool have been analysed, and thus, machine tool errors were effectively evaluated.

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Application of the Through-Transmitted Ultrasonic Signal for the Identification of Two-Phase Flow Patterns in a Simulated High Temperature Vertical Channel

  • Chu In-Cheol;Song Chul-Hwa;Baek Won-Pil
    • Nuclear Engineering and Technology
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    • 제36권1호
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    • pp.12-23
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    • 2004
  • In the present study a new measurement technique has been developed, which uses an ultrasonic transmission signal in order to identify the vertical two phase flow pattern. The ultrasonic measurement system developed in the present study not only provides the information required for the identification of vertical two phase flow patterns but also makes real time identification possible. Various vertical two phase flow patterns such as bubbly, slug, churn, annular flow etc. have been accurately identified with the present ultrasonic measurement system under atmospheric condition. In addition, the present test apparatus can practically simulate the ultrasonic propagation characteristics under high temperature and high pressure systems. Therefore, it is expected that the present ultrasonic flow pattern identification technique could be applicable to the vertical two phase flow systems under high temperature and high pressure conditions.

로봇 작업측정을 위한 컴퓨터 지원 시스템의 개발 (-The Development of a Computer Aided System for Robot Work Measurement-)

  • 권규식
    • 산업경영시스템학회지
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    • 제24권62호
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    • pp.49-58
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    • 2001
  • In recent years, a number of robot work measurement systems have been developed. This study discusses CARS (Computer Aided Romum System) which is to computerize the existed manual version ROMUM (RObot Modularization of the Unit Motion) method as the predetermined time system for robot work measurement. The ROMUM was developed to establish the standard time of work through modularize the unit motions in robot tasks. The CARS is designed on a menu driven form by computer assist for user interface and then interacts with user effectively. Therefore, the system can provide the convenience of use and minimization of analysis time and degree of judgement for establishing standard time.

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AHP에 의한 한국자동차부품제조사의 제조성과기준의 중요도 평가 (An AHP Approach to Evaluate the priorities of Manufacturing Performance Criteria in Korean Automobile Parts Manufacturing Company)

  • 김태수
    • 산업경영시스템학회지
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    • 제34권3호
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    • pp.115-122
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    • 2011
  • The critical role played by manufacturing performance measurement systems in achieving competitive success is increasingly recognized. Developing an integrated performance measurement model is significant for strategic management. This study consist of several principal steps. Performance criteria from the literature and an questionnaire were utilized prior to building the performance model. The AHP(Analytic Hierarchy Process) is utilized to evaluate the weight of each criterion when generating the performance measurement model for Korea automobile parts manufacturing company. AHP analysis showed clear difference in the priority between 5 criteria and 24 sub-criteria in terms of manufacturing performance of Korean automobile parts manufacturing company. The result of priority evaluation in the 5 criteria of 2nd level was ranked quality, cost, delivery, employee, flexibility. And the critical sub-criteria in the 24 sub-criteria of 3rd level was ranked claim rate, process defect rate, outsourcing parts defect rate, ability to quality management innovation, claim cost, etc.

엔진 흡기계에 쓰이는 다공형 직조관의 음향특성 측정 및 성능예측 (Measurement of Acoustic Properties and Prediction of Acoustic Performance of Porous Woven Hoses for Engine Intake Systems)

  • 박철민;이정권
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2000년도 추계학술대회논문집
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    • pp.182-186
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    • 2000
  • The porous woven hose is recently considered as an effective element of automotive intake systems. In order to predict the acoustic performance of an intake system with a porous woven hose, the information on the acoustic wall impedance is required. In this article, a measurement technique that is valid over the low frequency range and without mean flow condition is presented. The measurement is performed in a cylindrical chamber with a concentric layout of the sample and the resistance is estimated from measured reactance and transmission loss data. It is observed that the measured transmission loss for a porous woven hose with an arbitrary length agrees well with the predicted one that uses the estimated impedance for a small sample length.

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Software Reliability of Safety Critical FPGA-based System using System Engineering Approach

  • Pradana, Satrio;Jung, Jae Cheon
    • 시스템엔지니어링학술지
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    • 제14권2호
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    • pp.49-57
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    • 2018
  • The main objective of this paper is come up with methodology approach for FPGA-based system in verification and validation lifecycle regarding software reliability using system engineering approach. The steps of both reverse engineering and re-engineering are carried out to implement an FPGA-based of safety critical system in Nuclear Power Plant. The reverse engineering methodology is applied to elicit the requirements of the system as well as gain understanding of the current life cycle and V&V activities of FPGA based-system. The re-engineering method is carried out to get a new methodology approach of software reliability, particularly Software Reliability Growth Model. For measure the software reliability of a given FPGA-based system, the following steps are executed as; requirements definition and measurement, evaluation of candidate reliability model, and the validation of the selected system. As conclusion, a new methodology approach for software reliability measurement using software reliability growth model is developed.

산업용 무선온도측정 시스템 개발 (Development of industrial wireless temperature System)

  • 류정탁;차부상;김연보;문병현
    • 한국산업정보학회논문지
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    • 제14권1호
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    • pp.90-94
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    • 2009
  • 본 연구에서는 산업현장에서 직접적으로 활용할 수 있는 시스템에 중심을 둔다. 따라서 본 논문은 산업 실내 환경에 적합한 무선 기반의 원격 측정 시스템 설계에 관한 기초 연구로서 비교적 간단한 실내 온도 측정 시스템을 설계하고 제작하였다. 또한 실내 환경에서의 응용 가능성을 검토하기 위해 측정거리에 따른 특성 분석과 안테나 변경에 따른 성능 차이에 대해 논한다.

Residual Stress Measurement on T-type Welded Specimen by Neutron Diffraction

  • Jang, D.Y.;Park, M.J.;Choi, H.D.;Kim, J.P.
    • International Journal of Korean Welding Society
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    • 제1권2호
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    • pp.45-50
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    • 2001
  • This paper presents application of neutron diffraction technique to the measurement of residual stresses in the T-type 20 m thick welded stainless steel plates(100$\times$50 $mm^2$ and 50$\times$50 $mm^2$). The High Resolution Powder Diffractormeter of the Korea Atomic Research Institute was utilized in the measurement. The power of nuclear reactor was 24 MWt and the measured reflection in the 220 plane (2$\theta$)was $92.66^{\circ}$. Poisson ratio of 0.265 and elastic constant of 211 GPa were applied to the calculation of stresses and strains. Three directional components such as normal, transverse, and longitudinal stresses were measured. The results showed that three components were tensile and became compressive along the y axis in the zone away from the welded center. The compressive stresses became tensile in the zone away from the center line of x axis. This may be due to the balance effect caused by the net stress to keep the specimen shape flat.

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Time Synchronization Error and Calibration in Integrated GPS/INS Systems

  • Ding, Weidong;Wang, Jinling;Li, Yong;Mumford, Peter;Rizos, Chris
    • ETRI Journal
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    • 제30권1호
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    • pp.59-67
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    • 2008
  • The necessity for the precise time synchronization of measurement data from multiple sensors is widely recognized in the field of global positioning system/inertial navigation system (GPS/INS) integration. Having precise time synchronization is critical for achieving high data fusion performance. The limitations and advantages of various time synchronization scenarios and existing solutions are investigated in this paper. A criterion for evaluating synchronization accuracy requirements is derived on the basis of a comparison of the Kalman filter innovation series and the platform dynamics. An innovative time synchronization solution using a counter and two latching registers is proposed. The proposed solution has been implemented with off-the-shelf components and tested. The resolution and accuracy analysis shows that the proposed solution can achieve a time synchronization accuracy of 0.1 ms if INS can provide a hard-wired timing signal. A synchronization accuracy of 2 ms was achieved when the test system was used to synchronize a low-grade micro-electromechanical inertial measurement unit (IMU), which has only an RS-232 data output interface.

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