Evaluation method of electrical connector performance based on intermittent failure

2017 ◽  
Author(s):  
Qian Li ◽  
Kehong Lv ◽  
Jing Qiu ◽  
Guanjun Liu
Keyword(s):  
Evaluation Method ◽  
Electrical Connector ◽  
Intermittent Failure

scholarly journals Research on Residual Life Prediction for Electrical Connectors Based on Intermittent Failure and Hidden Semi-Markov Model

2018 ◽  
Vol 8 (8) ◽  
pp. 1373 ◽  
Author(s):  
Qian Li ◽  
Kehong Lv ◽  
Jing Qiu ◽  
Guanjun Liu
Keyword(s):  
Markov Model ◽  
Life Prediction ◽  
Evaluation Method ◽  
Residual Life ◽  
Dynamic Properties ◽  
Prediction Method ◽  
Electrical Connector ◽  
Residual Life Prediction ◽  
Intermittent Failure ◽  
Electrical Connectors

Based on the dynamic properties of electrical connector intermittent failure, the model and methods for residual life prediction for electrical connectors are studied in this paper. Firstly, the mechanism of electrical connector intermittent failure is analyzed, and the area enclosed by the contact resistance curve and the fault threshold is defined as the generalized severity of intermittent failure to describe how severe the electrical connector’s intermittent failure is. Then, the Hidden Semi-Markov Model (HSMM) is introduced to build the residual life prediction model of the electrical connector. Further, the evaluation method of using the state and prediction method for residual life are studied. Finally, by carrying out the residual life prediction test, the effectiveness of the residual life prediction method for electrical connectors based on intermittent failure and HSMM is verified.

Research on intermittent failure re-presentation of electrical connector based on accelerated test

2018 ◽  
Vol 233 (3) ◽  
pp. 317-327 ◽  
Author(s):  
Qian Li ◽  
Kehong Lyu ◽  
Jing Qiu ◽  
Guanjun Liu
Keyword(s):  
Goodness Of Fit ◽  
Failure Detection ◽  
Accelerated Test ◽  
Goodness Of Fit Test ◽  
Failure Frequency ◽  
Electrical Connector ◽  
Reaction Theory ◽  
Detection And Diagnosis ◽  
Anderson Darling ◽  
Intermittent Failure

The intermittent failure re-presentation is the basis of intermittent failure detection and diagnosis of electrical connectors. Recently, the method for intermittent failure re-presentation is applying the whole working stress to the electrical connector. To further shorten the re-present cycle, the research on intermittent failure re-presentation of electrical connector based on accelerated test is carried out in this article. First, the model of electric contact and the intermittent failure mechanism of electrical connector is analyzed, and the frequency of intermittent failure is selected as a signature of intermittent failure re-presentation. Then, the accelerated intermittent failure re-presentation model is constructed based on the reaction theory, and the intermittent failure acceleration factor is given. Subsequently, the distribution of intermittent failure frequency is determined using the method of Anderson–Darling goodness-of-fit test. Finally, taking the rectangular electrical connector as the example, the intermittent failure re-presentation based on accelerated test is implemented, and the intermittent failure frequency is obtained. By comparing the estimated value and the measured value, the validity and applicability of the intermittent failure re-presentation method based on accelerated test is verified.

Evaluation method for imaging plate resolution by means of phase contrast transfer function

1995 ◽  
Vol 53 ◽  
pp. 662-663 ◽  
Author(s):  
T. Oikawa ◽  
H. Kosugi ◽  
F. Hosokawa ◽  
D. Shindo ◽  
M. Kersker
Keyword(s):  
Transfer Function ◽  
Phase Contrast ◽  
Evaluation Method ◽  
Amorphous Film ◽  
Imaging Plate ◽  
X Rays ◽  
Special Shape ◽  
Contrast Transfer Function ◽  
Contrast Image ◽  
Specimen Shape

Evaluation of the resolution of the Imaging Plate (IP) has been attempted by some methods. An evaluation method for IP resolution, which is not influenced by hard X-rays at higher accelerating voltages, was proposed previously by the present authors. This method, however, requires truoblesome experimental preperations partly because specially synthesized hematite was used as a specimen, and partly because a special shape of the specimen was used as a standard image. In this paper, a convenient evaluation method which is not infuenced by the specimen shape and image direction, is newly proposed. In this method, phase contrast images of thin amorphous film are used.Several diffraction rings are obtained by the Fourier transformation of a phase contrast image of thin amorphous film, taken at a large under focus. The rings show the spatial-frequency spectrum corresponding to the phase contrast transfer function (PCTF). The envelope function is obtained by connecting the peak intensities of the rings. The evelope function is offten used for evaluation of the instrument, because the function shows the performance of the electron microscope (EM).

Combining Values

2002 ◽  
Vol 7 (2) ◽  
pp. 1-4, 12 ◽  
Author(s):  
Christopher R. Brigham
Keyword(s):  
Lower Extremity ◽  
Upper Extremity ◽  
Evaluation Method ◽  
Proximal Phalanx ◽  
Common Error ◽  
The Third ◽  
Whole Person ◽  
Impairment Ratings ◽  
Upper Extremity Impairment ◽  
The Individual

Abstract To account for the effects of multiple impairments, evaluating physicians must provide a summary value that combines multiple impairments so the whole person impairment is equal to or less than the sum of all the individual impairment values. A common error is to add values that should be combined and typically results in an inflated rating. The Combined Values Chart in the AMA Guides to the Evaluation of Permanent Impairment, Fifth Edition, includes instructions that guide physicians about combining impairment ratings. For example, impairment values within a region generally are combined and converted to a whole person permanent impairment before combination with the results from other regions (exceptions include certain impairments of the spine and extremities). When they combine three or more values, physicians should select and combine the two lowest values; this value is combined with the third value to yield the total value. Upper extremity impairment ratings are combined based on the principle that a second and each succeeding impairment applies not to the whole unit (eg, whole finger) but only to the part that remains (eg, proximal phalanx). Physicians who combine lower extremity impairments usually use only one evaluation method, but, if more than one method is used, the physician should use the Combined Values Chart.

A fuzzy evaluation method of road vehicle automatic weighing instrument in dynamic force metrological performance

2020 ◽  
Vol 64 (1-4) ◽  
pp. 1365-1372
Author(s):  
Xiaohui Mao ◽  
Liping Fei ◽  
Xianping Shang ◽  
Jie Chen ◽  
Zhihao Zhao
Keyword(s):  
Evaluation Method ◽  
Comprehensive Evaluation ◽  
Evaluation Model ◽  
Dynamic Performance ◽  
Dynamic Force ◽  
Fuzzy Evaluation ◽  
Road Vehicle ◽  
Evaluation Standard ◽  
The Road ◽  
Metrological Performance

The measurement performance of road vehicle automatic weighing instrument installed on highways is directly related to the safety of roads and bridges. The fuzzy number indicates that the uncertain quantization problem has obvious advantages. By analyzing the factors affecting the metrological performance of the road vehicle automatic weighing instrument, combined with the fuzzy mathematics theory, the weight evaluation model of the dynamic performance evaluation of the road vehicle automatic weighing instrument is proposed. The factors of measurement performance are summarized and calculated, and the comprehensive evaluation standard of the metering performance of the weighing equipment is obtained, so as to realize the quantifiable analysis and evaluation of the metering performance of the dynamic road vehicle automatic weighing instrument in use, and provide data reference for adopting a more scientific measurement supervision method.

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