Abstract: In analog electronic systems, characteristic information required for fault prognosis is achieved by test points of a board, so the selection and optimization of test points is an important topic for PHM research of electronic products. Current methods for selection of test points generally rely on functional simulation analysis or testability modeling analysis. Based on this, FMMEA method is introduced to find failure susceptibility components in this paper, moreover, through simulating and calculating the predictability of test points, the final test points are determined. As an example, a board level system is presented to validate this approach.
Abstract: The resistivity characteristics of sediments are important to analyze marine sedimental environment and material source. A kind of penetration multiple parameter micro-probe which is designed to measure the resistivity of sediment sample in the northwestern of South Yellow Sea. In this paper, shelf sediment resistivity property off northwest of the South Yellow Sea is studied by analyzing the influence factors and relations, for providing valuable information to the marine sedimental environment around this area.
Abstract: During the drilling process of shale gas horizontal well, wellbore instability problem happens frequently. Especially in the horizontal interval, shale which has high levels of gamma is more likely to collapse which lead to delays, and exist certainly collapse period. The development of shale gas is restricted seriously. Research on the formation process of cracks network around the wellbore by CT chromatographic technique. The result reveals that under the condition of uniaxial compression, the cracks initiated inside the shale formation around the wellbore, with the propagation of cracks, between the orientation of cracks and the maximum stress direction will emerge a certain deviated angle. The drilling fluid filtrates into the formation and reduce the strength of rock which will prompt crack propagation and form crack network. Finally the wellbore will collapse with drilling fluid continuous invasion, because the invasion have altered the stress intensity factor at fracture tip, and changed the propagating direction of crack and the friction coefficient of fracture plane, which will reduce the strength of rock and the effective stress of the rock around the wellbore. Crack network dominates the mechanism of instability; mud weight increases do not necessarily lead to a more stable borehole and can further destabilize the wellbore.
Abstract: To ensure the safety of bridge bearing replacement procedure, the project introduces the real-time monitoring technology. Collects displacement data, stress data, elevation and temperature are collected by displacement sensor, stress sensor and so on. Data processing and analyzing by the computer provides guidance for replacement procedure. The results of the monitoring and timely analysis of data collation provide guidance for the replacement process. Engineering practice results show that real-time monitoring technology is an important means to ensure the bearing replacement safe, but it should develop a reasonable scientific monitoring program.
Abstract: The advantages of fiber optic sensors in contrast to conventional electrical ones make them popular in different applications. In the field of strength of materials, structure curvature is an important parameter. The limitations of traditional curvature measurement technology and the characters of fiber optic sensors are analyzed. The research status and characters of curvature measurement of different type fiber optic sensors are introduced. Potential and some successful applications of fiber optic sensors in high voltage switching are presented. It is reasonable to believe that the fiber optic sensing technology is a hot research topic in high voltage equipment fields for next a long time.
Abstract: This paper investigates a miniature rectangular triplate-printed antenna, which acts as a magnetic field probe to estimate amplitude of the RF Electromagnetic Interference current by non-contact measurement. To characterize the probe, a current transfer factor defined as the ratio of the probed voltage over the current is investigated by measuring the frequency-dependent S-parameter. Moving and rotating the probe will change the current transfer factor, and then significantly affect the estimation of the RF current under detection. To specify the application of the probe, the spatial dependences of the current transfer factor are systematically studied, and in agreement with the calculation of the magnetic field generated by the RF current.
Abstract: The supporting structure in foundation pit is very important in civil engineering and is used to support the whole foundation pit. Its diaplacement is directly related to the safety of buildings. White light digital image analysis in frequency domain has the advantages of whole-field, non-contact measurement and the simple measuring system and can obtain displacements by frequency domination correlation arithmetic. In this paper, the method was introduced to measure the displacements of supporting structure. The experimental results show the usability of the method for supporting structure in foundation pit.
Abstract: The purpose of this study is to develop an internet system for cognitive diagnosis assessment. The theoretical foundation of this cognitive diagnosis model is mixed scoring student-problem chart (S-P chart) which is beyond the limitation of traditional S-P chart. Therefore, one contribution of this study is to construct the cloud computing for analyzing measurement data. Another contribution is to extend the traditional S-P chart and accomplish an internet system. In addition to the theory and system, this paper also gives an empirical data to interpret utility of the internet system. The results show the feasibility of this internet system of cognitive diagnosis measurement. Based on the findings of this study, some suggestions and recommendations are discussed for future research.
Abstract: Lithium battery coating thickness is measured by sensor using laser triangulation. The algorithm based on threshold judgment and multi-scale wavelet is realized for noise high-frequency reduction of lithium battery film thickness systems. The result shows that compared with the unique multi-scale wavelet de-noising, the method applies to different lengths and discontinuous of coating thickness measurement. .