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51.
USB闪盘的软硬件开发技术 总被引:2,自引:0,他引:2
郑初华 《南昌航空工业学院学报》2002,16(4):65-69
本文重点介绍了一种在USB接口下的闪盘(闪存编程器)的软硬件开发技术,对USB和闪存做了简单介绍,闪存在计算机、智能仪器、通信设备等中使用非常广泛,用于存放相对固定及便于升级的内容,闪盘因其存储容量大、体积小便于携带等优点,很快会代软驱软盘成为主要的移动存储器。USB作为一种新型的接口技术,以其简单易用、速度快、兼容性强等特点而倍受青睐。 相似文献
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A study of long-term climatology of ionospheric irregularities by using GPS phase fluctuations at the Brazilian longitudes 总被引:1,自引:0,他引:1
F.D. Chu C.C. Lee W.S. Chen J.Y. Liu 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2008,41(4):645-649
We have examined the ionospheric plasma irregularities that were recorded by using three ground-based receivers of the global positioning system (GPS) located at Brazilian longitudes during the period of a complete solar cycle, 1995–2005. The statistic results show that ionospheric irregularities are very easy to occur in December solstice months but rare to occur in June solstice months. Besides, the occurrence rates of irregularities in both December and June solstice months are little dependent on solar activity. However, in equinoctial months, the development of irregularities is obviously dependent on solar activity. There is a new finding in this study that if strong irregularities are distinguished from moderate ones, their occurrence rates would increase with solar activity during the December solstice months. 相似文献
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Track association of multi-target has been recognized as one of the key technologies in distributed multiple-sensor data fusion system,and its accuracy directly impacts on the performance of the whole tracking system.A multi-sensor data association is proposed based on aftinity propagation(AP)algorithm.The proposed method needs an initial similarity,a distance between any two points,as a parameter,therefore,the similarity matrix is calculated by track position,velocity and azimuth of track data.The approach can automatically obtain the optimal classification of uncertain target based on clustering validity index.Furthermore,the same kind of data are fused based on the variance of measured data and the fusion result can be taken as a new measured data of the target.Finally,the measured data are classified to a certain target based on the nearest neighbor ideas and its characteristics,then filtering and target tracking are conducted.The experimental results show that the proposed method can effectively achieve multi-sensor and multi-target track association. 相似文献
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阵风发生器流场特性分析与试验验证 总被引:2,自引:0,他引:2
为了有效安排试验以及进行数据分析,需要事先获知阵风发生器扰动流场特性.基于某型叶片阵风发生装置,对影响阵风强度及其分布形态的各种因素进行了深入细致的讨论,重点分析了叶片摆角幅值、振荡频率、来流风速以及叶片侧向间距的作用.数值模拟结果显示:上述敏感参数不同程度地影响了中心线各点阵风幅值.侧向阵风速度幅值在叶片下游各截面具有相似的分布形态,且在小攻角范围与叶片摆角幅值保持线性变化.因此选定来流风速和振荡频率后,调节叶片摆角幅值较易获得期望的阵风强度.风洞试验表明:阵风发生器特性分析具有实用价值. 相似文献
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针对某大展弦比多控制面弹性机翼风洞模型,分别从频域和时域进行阵风响应分析和阵风响应减缓控制律设计。采用经典控制理论设计控制律,通过操纵位于0.6和0.8翼展处的内外侧控制面减小由正弦阵风引起的翼尖加速度(WTA)。低频段的阵风减缓的数值分析与风洞试验结果均表明:多控制面的阵风减缓效果优于单控制面。当来流速度为14 m/s时,针对频率为2~5 Hz的阵风,采用多控制面得到的WTA减小10%~24%;当来流速度在8~16 m/s时,针对频率为2 Hz的正弦阵风,闭环状态下的翼尖加速度减小10%~40%;结构有限元模型与真实模型存在工程允许的误差导致理论与试验结果存在一定的误差。本文的工作对工程实际中采用阵风减缓技术具有参考价值。 相似文献
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The long-wave perturbation method is employed to investigate the nonlinear hydromagnetic stability of a thin electrically-conductive pseudoplastic liquid film flowing down the surface of a vertical wall in a magnetic field. The validity of the numerical results is improved through the introduction of the flow index and the magnetic force into the governing equation. In contrast to most previous studies presented in the literature, the solution scheme employed in this study is based on a numerical approximation approach rather than an analytical method. The solution procedure commences by employing the normal mode approach to analyze the linear stability of the film flow. The multiple-scales method is then applied to obtain the weak nonlinear dynamics of the thin-film system for stability analysis. The modeling results reveal that the pseudoplastic film flow system may exhibit both subcritical instability and supercritical stability states. The flow stability can be enhanced by increasing the intensity of the magnetic field and the flow index, respectively. In general, the optimum conditions can be found through the use of a system to alter stability of the film flow by controlling the applied magnetic field. 相似文献