The three-party authenticated key agree-ment protocol is a significant cryptographic mechanism for secure communication,which encourages two entities to authent
In the field of robust audio watermarking,how to seek a good trade-off between robustness and imperceptibility is challenging.The existing studies use the same
为研究最优的、低成本圆弧型的汽车圆锥滚子轴承的滚子母线修形方案,本文应用MASTA作为计算分析工具,计算出不同圆弧、不同圆弧-直线的母线修形方案下的轴承中各粒滚子的应力;并借助正交试验法找出纯圆弧修形方案和圆弧-直线修形方案中各个几何参数对于轴承滚子最大应力的影响机制;最后,根据正交试验的结果找出圆弧型滚子母线和圆弧-直线型滚子母线的最优几何参数组合。
随着移动通信系统的高速建设和发展,射频信号的包络信号带宽越来越宽,功率峰均比越来越大,恒定电压供电的基站功放效率越来越低。针对该问题,论文设计了一种电源调制电路。该电路输出的电压根据峰值检测后的电压值对功率放大器的供电端进行实时控制,保持功率放大器工作状态一直在最高效率点上,从而提高功率放大器的效率。实验表明:在原电路负载不变的情况下,设计的电源调制电路的工作效率提高了30%以上,为使用包络跟踪技术提高功率放大器的效率提供了理论支持与实验支撑。
Density peak clustering (DPC) can identify cluster centers quickly,without any prior knowledge.It is supposed that the cluster centers have a high density and l
Keyword extraction by Term frequency-Inverse document frequency (TF-IDF) is used for text information retrieval and mining in many domains,such as news text,soc
The fast development and the rapid spread of information technology have raised the issue of digital-image copyright protection,which was mostly addressed throu
Software safety requirements are crucial for safety assurance of safety-critical software systems.A novel accident causality model,Systems-theoretic accident mo
临兴区块近年来发现马家沟组低渗低温碳酸盐岩储层赋存天然气,需通过酸压技术进行储层开发。针对55℃低温的问题,通过室内实验,采用正交实验方法,优选研发形成了适用于50~60℃储层条件的低温酸基压裂液体系,其中盐酸浓度20%,岩心溶蚀率71%,体系黏度8~10 mPa·s,55℃条件下黏度下降率20%,腐蚀速率2.062 g/(m2·h),铁离子稳定能力220 mg/mL,防膨率94.67%。采用该酸基压裂液体系配合液氮伴注的闭合酸压工艺技术,完成了海油内部第一口井的酸压矿场施工,施工共入井液体121.3 m
Essential proteins are integral parts of living organisms.The prediction of essential proteins facilitates to discover disease genes and drug targets.The predic