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991.
A virtual system for vision based SPC (Statistical Process Control) is explored and constructed in this article for the purpose of the preliminary tests. Its performance is compared with that of a real vision system in a case study. The similarity between the virtual and real systems is examined with a chi-square test and an X chart experiment. The results suggest that the virtual system can be used to replace the real system in the preliminary test. The virtual system has many advantages, such as low cost, easy setup, wide adaptability, and being heuristic in nature. The use of the virtual system may help promote the applications of vision system to SPC. 相似文献
992.
对国内两套MINI-MPM连轧管机组(Φ159mm和Φ180mm)的结构(连轧管机、再加热炉、穿孔机、定径机及换辊机构等)和性能特点进行了分析比较,指出了各自的特点,可供新建MINI-MPM连轧管机组时参考. 相似文献
993.
The fracture behavior of a composite/adhesive/steel bonded joint was investigated by using double cantilever beam specimens. A starter crack is embedded at the steel/adhesive interface by inserting Teflon tape. The composite adherend is a random carbon fiber reinforced vinyl ester resin composite while the other adherend is cold rolled steel. The adhesive is a one-part epoxy that is heat cured. The Fernlund-Spelt mixed mode loading fixture was employed to generate five different mode mixities. Due to the dissimilar adherends, crack turning into the adhesive (or crack kinking) associated with joint failure, was observed. The bulk fracture toughness of the adhesive was measured separately by using standard compact tension specimens. The strain energy release rates for kinking cracks at the critical loads were calculated by a commercial finite element analysis software ABAQUS in conjunction with the virtual crack closure technique. Two fracture criteria related to strain energy release rates were examined. These are (1) maximum energy release rate criterion (Gmax) and, (2) mode I facture criterion (GII = 0). They are shown to be equivalent in this study. That is, crack kinking takes place at the angle close to maximum G or GI (also minimum GII, with a value that is approximately zero). The average value of GIC obtained from bulk adhesive tests using compact tension specimens is shown to be an accurate indicator of the mode I fracture toughness of the kinking cracks within the adhesive layer. It is concluded that the crack in tri-material adhesively bonded joint tends to initiate into the adhesive along a path that promotes failure in pure mode I, locally. 相似文献
994.
Abstract: The thermal properties of a micro-electromechanical system sensor were analysed by a novel digital moiré method. A double-layer micro-cantilever sensor (60 μ m long, 10 μ m width and 2 μ m thick) was prepared by focused ion beam milling. A grating with frequency of 5000 lines mm−1 was etched on the cantilever. The sensor was placed into a scanning electron microscope system with a high temperature device. The observation and recording of the thermal deformation of the grating were realised in real-time as the temperature rose from room temperature to 300 °C at intervals of 50 °C. Digital moiré was generated by interference of the deformed grating and a digital virtual grating. The thermal properties including strain distribution of the sensor and the linear expansion coefficient of polysilicon were accurately measured by the phase-shifted moiré patterns. 相似文献
995.
996.
997.
TMS320C28x模数转换器的精度校正 总被引:5,自引:0,他引:5
TMS320C28x系列DSP内部集成ADC转换模块,为提高ADC转换精度,对TMS320F2812的ADC模块转换误差及其影响进行分析测试,提出一种用于提高ADC模块精度的校正算法。实际应用证明使用该方法补偿效果良好,有效改善ADC的转换精度,并具有普遍性。 相似文献
998.
阐述了一种在水电厂机组监控系统中PLC与PC串行通信的实现方法,给出了PLC与PC的硬件接口方法及基于Windows和VB环境下的通信程序。 相似文献
999.
高性能混凝土配合比设计的试验研究 总被引:2,自引:0,他引:2
从对HPC组成、结构的认识出发,借鉴利用拨开系数求砂率的方法,提出了一种新的HPC配制方法,并通过试验证实该方法是完全可行的. 相似文献
1000.
基于AHP法的信息熵模糊物元模型在地基处理方案评价中的应用 总被引:7,自引:2,他引:7
将信息论和模糊物元分析理论相结合 ,建立地基处理方案评价的信息熵模糊物元分析模型 ,运用层次分析法建立指标层次结构 ,确定指标权重 ,消除了专家权重分配困难的缺陷 ,提高了方案评价的可信度 ,并通过具体实例说明了模型的实际应用 . 相似文献