• 제목/요약/키워드: testing and calibration

검색결과 241건 처리시간 0.028초

Objective Bayesian testing for the location parameters in the half-normal distributions

  • Kang, Sang-Gil;Kim, Dal-Ho;Lee, Woo-Dong
    • Journal of the Korean Data and Information Science Society
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    • 제22권6호
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    • pp.1265-1273
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    • 2011
  • This article deals with the problem of testing the equality of the location parameters in the half-normal distributions. We propose Bayesian hypothesis testing procedures for the equality of the location parameters under the noninformative prior. The non-informative prior is usually improper which yields a calibration problem that makes the Bayes factor to be defined up to arbitrary constants. This problem can be deal with the use of the fractional Bayes factor or intrinsic Bayes factor. So we propose the default Bayesian hypothesis testing procedures based on the fractional Bayes factor and the intrinsic Bayes factors under the reference priors. Simulation study and an example are provided.

Default Bayesian testing for the equality of shape parameters in the inverse Weibull distributions

  • Kang, Sang Gil
    • Journal of the Korean Data and Information Science Society
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    • 제25권6호
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    • pp.1569-1579
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    • 2014
  • This article deals with the problem of testing for the equality of the shape parameters in two inverse Weibull distributions. We propose Bayesian hypothesis testing procedures for the equality of the shape parameters under the noninformative prior. The noninformative prior is usually improper which yields a calibration problem that makes the Bayes factor to be defined up to a multiplicative constant. So we propose the default Bayesian hypothesis testing procedures based on the fractional Bayes factor and the intrinsic Bayes factors under the reference priors. Simulation study and an example are provided.

Objective Bayesian Testing for Effect Size in Paired Study

  • Kang, Sang-Gil;Kim, Dal-Ho;Lee, Woo-Dong
    • Journal of the Korean Data and Information Science Society
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    • 제19권4호
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    • pp.1477-1489
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    • 2008
  • This article deals with the problem of testing whether the effect size in paired study exists. We propose Bayesian hypothesis testing procedures for the effect size in paired study under the noninformative prior. The noninformative prior is usually improper which yields a calibration problem that makes the Bayes factor to be defined up to a multiplicative constant. So we propose the objective Bayesian hypothesis testing procedures based on the fractional Bayes factor and the intrinsic Bayes factor under the reference prior. Simulation study and a real data example are provided.

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Default Bayesian testing for normal mean with known coefficient of variation

  • Kang, Sang-Gil;Kim, Dal-Ho;Le, Woo-Dong
    • Journal of the Korean Data and Information Science Society
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    • 제21권2호
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    • pp.297-308
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    • 2010
  • This article deals with the problem of testing mean when the coefficient of variation in normal distribution is known. We propose Bayesian hypothesis testing procedures for the normal mean under the noninformative prior. The noninformative prior is usually improper which yields a calibration problem that makes the Bayes factor to be defined up to a multiplicative constant. So we propose the objective Bayesian hypothesis testing procedures based on the fractional Bayes factor and the intrinsic Bayes factor under the reference prior. Specially, we develop intrinsic priors which give asymptotically same Bayes factor with the intrinsic Bayes factor under the reference prior. Simulation study and a real data example are provided.

다축 시뮬레이터의 변위-하중 보정에 관한 연구 (A study on Displacement-Load Calibration of Multi-Axis Simulator)

  • 정상화;류신호;신현성;김상석;박용래
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2000년도 춘계학술대회 논문집
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    • pp.591-594
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    • 2000
  • In the recent day, fatigue life prediction techniques play a major role in the design of components in the ground vehicle industry. Full scale durability testing in the laboratory is an essential of any fatigue life evaluation of components or structure of the automotive vehicle. Component testing is particulary important in today's highly competitive industries where the design to reduce weight and production costs must be balanced with the necessity to avoid expensive service failure. Generally, 3-axis durability testing device is used to carry out the fatigue test. In this paper, The operation software for simultaneously driving 3-axis vibration testing device is developed and the displacement of the 3-axis actuator is separately calibrated by LDT Moreover, the input and output data are displayed in windows of PC controller with real time.

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금속압력용기의 사용 전 음향방출시험 (Pre-service Acoustic Emission Testing for Metal Pressure Vessel)

  • 이종오;윤운하;이태희;이종규
    • 비파괴검사학회지
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    • 제23권3호
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    • pp.280-284
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    • 2003
  • 사용하지 않은 새 금속 압력용기에 대하여, 사용 전 음향방출시험을 수행할 때 장비점검, 탐촉자간 거리, 탐촉자 위치, 전 측정 시스템 점검, 가압방법, 잡음 제거법 및 시험 결과의 평가 등에 대한 절차를 수립하고 현장 응용시험이 수행되었다. 일반적으로 음향방출 시험은 많은 잡음을 포함하는데 시험동안 관찰결과를 기록하여 평가 시 시간 필터링함으로서 잡음을 제거할 수 있었다.

Calibration Chamber System을 이용한 KICT-type LPT 장비의 거동분석 (Evaluation of KICT-type Large Penetration Test using Calibration Chamber System)

  • 김영석;김영진;이우진;안신환
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2008년도 추계 학술발표회
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    • pp.1359-1364
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    • 2008
  • It is well known that the standard penetration test (SPT) has been used in all over the world to get geotechnical properties of the ground. However, it is difficult to apply the SPT to the dense sand, gravel, weathered rock, etc. For the application of the SPT in these grounds, it is necessary to change in the diameter and the impact energy of the SPT. For the improvement of site investigation technology, Large Penetration Testing device (KICT-type LPT) was developed and applied to the in situ condition. The drop height and weight of the hammer in developed system were decided as 760mm and 150kg, respectively. And the developed sampler has the inner diameter of 63 mm and the length of 500 mm with the adjustment of energy ratio to the SPT of 1.5. In this study, the performance of KICT-type LPT was evaluated by using a calibration chamber system and pile driving analyzer (PDA)

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Automatic RF Input Power Level Control Methodology for SAR Measurement Validation

  • Kim, Ki-Hwea;Choi, Dong-Geun;Gimm, Yoon-Myoung
    • Journal of electromagnetic engineering and science
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    • 제15권3호
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    • pp.181-184
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    • 2015
  • Evaluation of radiating radiofrequency fields from hand-held and body-mounted wireless communication devices to human bodies are conducted by measuring the specific absorption rate (SAR). The uncertainty of system validation and probe calibration in SAR measurement depend on the variation of RF power used for the validation and calibration. RF input power for system validation or probe calibration is controlled manually during the test process of the existing systems in the laboratories. Consequently, a long time is required to reach the stable power needed for testing that will cause less uncertainty. The standard uncertainty due to this power drift is typically 2.89%, which can be obtained by applying IEC 62209 in a normal operating condition. The principle of the Automatic Input Power Level Control System (AIPLC), which controls the equipment by a program that maintains a stable input power level, is suggested in this paper. The power drift is reduced to less than ${\pm}1.16dB$ by AIPLC, which reduces the standard uncertainty of power drift to 0.67%.

적외선 카메라를 이용한 표면온도측정의 왜곡 보정 (Distortion Correction of Surface Temperature Measurement Using an Infrared Camera)

  • 이성민;김익현;이종국;변영환;박기수
    • 한국항공우주학회지
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    • 제44권7호
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    • pp.545-551
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    • 2016
  • 적외선 열화상 방식을 사용하여 초음속 풍동모델 표면온도를 측정하였다. 표면온도를 정량적으로 파악하기 위해 적외선 카메라 감지신호의 흑체 보정, 카메라와 렌즈의 불완전한 평형 등으로 야기되는 왜곡 보정, 그리고 모델표면 시야각에 따른 방사율 보정을 수행하였다. 본 연구를 통해 적외선 카메라를 이용한 표면온도측정의 왜곡보정 기술을 확보하였으며, 공력특성 실험을 통해 통상적으로 사용되는 이차원 시험모델 사용시 정성적일 뿐만 아니라 정량적인 계측을 위해서는 왜곡보정이 고려되어야 함을 입증하였다.