Cross-layer design for resource allocation in 3G wireless networks and beyond

Cross-layer design approaches are critical for efficient utilization of the scarce radio resources with QoS provisioning in the third-generation wireless networks and beyond. Better system performance can be obtained from information exchanges across protocol layers, which may not be available in the traditional layering architecture. This article provides an overview of cross-layer design approaches for resource allocation in 3G CDMA networks, summarizes state-of-the-art research results, and suggests further research issues. In addition, a cross-layer design approach for real-time video over time-varying CDMA channels is proposed, where link layer resource allocation benefits from information in both the application and physical layers. Simulations results are given to demonstrate the effectiveness of the proposed approach.     

一种改进的旋转式微机械结构

给出了一种改进的旋转式微机械薄膜残余应变测试结构．与已有的普通微旋转结构相比,改进的微旋转结构执行梁的宽度都保持一致．改进的微旋转结构在旋转变形之后,整个执行梁都会发生弯曲变形,所以在变形之后结构的残余应力非常小且分布均匀,没有普通微旋转结构的高应力集中,因此测量精度高于传统微旋转结构,更适合于高残余应变薄膜的测试．文中详细推导了改进微旋转结构的力学模型,并用有限元软件进行了模拟分析,同时详细地给出了改进的微旋转结构与传统微旋转结构的性能对比,最后用实验对改进微旋转结构的理论模型进行了验证．     

GaN/AlGaN超晶格透射电镜分析

用MOCVD法生长了120周期的GaN/Al0.14Ga0.86N超晶格,激光剥离技术被有效地用于GaN/AlGaN超晶格截面透射电镜样品的制作.用透射电子显微镜观察到了清晰的超晶格及晶胞周期结构,电子衍射也表明生长的超晶格样品质量较好.在透射电镜图中看到了Al,Ga原子的聚居点,这些聚居点达到应力临界时将可能成为新缺陷的起点.同时观察到GaN缓冲层中的线缺陷大多呈现弯曲的弧形,这是外延生长导致的.     

自主机器人直线行进过程的数字PID控制

针对自主机器人的直线行进过程，提出一种通过硬件电路确定直流电机模型的方法，即利用光电编码器测得机器人驱动轮电机转速信号，经硬件电路将每个周期时间内的脉冲数记录下来，从而得到电机输出转速响应曲线，确定电机的数学模型。在电机模型确定的基础上，实现了自主机器人直线行进过程的数字PID控制。数字PID参数的确定采用Ziegler—Nichols法，同时借助Matlab／Simulink仿真软件对所得PID参数进行了进一步的整定，取得了良好的控制效果。     

TC4钛合金表面激光熔覆原位制备TiB陶瓷涂层的微观组织特征与硬度特性

为提高钛合金表面力学性能,利用钛合金基体与TiB2粉末之间的原位反应,在TC4钛合金表面激光熔覆原位制备了TiB陶瓷涂层。采用扫描电镜(SEM)和X射线衍射仪(XRD)分析了熔覆层的形貌、显微组织与陶瓷相分布,并用硬度计测试了显微硬度。结果表明,在实验优化的工艺参数下,可制备出无气孔、无裂纹与表面质量较好的熔覆层。熔覆层的显微组织由表及里从块状颗粒转变为细针状组织;TiB2陶瓷相由表及里逐渐减少,而TiB陶瓷相由表及里逐渐增多;熔层表面显微硬度高,并由表及里呈现出梯度变化。     

K-PSO: An improved PSO-based container scheduling algorithm for big data applications

In recent years, Docker container technology is being applied in the field of cloud computing at an explosive speed. The scheduling of Docker container resources has gradually become a research hotspot. Existing big data computing and storage platforms apply with traditional virtual machine technology, which often results in low resource utilization, a long time for flexible scaling and expanding clusters. In this paper, we propose an improved container scheduling algorithm for big data applications named Kubernetes-based particle swarm optimization(K-PSO). Experimental results show that the proposed K-PSO algorithm converges faster than the basic PSO algorithm, and the running time of the algorithm is cut in about half. The K-PSO container scheduling algorithm and algorithm experiment for big data applications are implemented in the Kubernetes container cloud system. Our experimental results show that the node resource utilization rate of the improved scheduling strategy based on K-PSO algorithm is about 20% higher than that of the Kube-scheduler default strategy, balanced QoS priority strategy, ESS strategy, and PSO strategy, while the average I/O performance and average computing performance of Hadoop cluster are not degraded.     

氮化硅基陶瓷材料抗穿甲破坏实验研究

陶瓷复合材料是轻型装甲战斗车辆的装甲材料之一 ,介绍了氮化硅陶瓷材料靶板的制备工艺和方法 ,以及使用其进行穿甲试验的全过程 ,试验和计算结果表明 ,氮化硅陶瓷靶以其良好的抗穿甲破坏能力成为了一种很有发展前途的装甲防护材料     

Zn(II) Complex Catalyzed Coupling Aquathermolysis of Water-Heavy Oil-Methanol at Low Temperature

A Zn(II) coordination complex was synthesized, characterized, and used for catalytic aquathermolysis of heavy oil at low temperatures for the first time. The effects of water content and catalyst concentration on aquathermolysis were investigated. And then a tri-component coupling aquathermolysis of waterheavy oil-methanol was designed and the reaction conditions were investigated. With the catalyst and methanol, the reaction occurred at temperatures as low as 180°C. The viscosity of the product was also substantially reduced from around 24 400 to 6420 mPa s by the decomposition of the large hydrocarbon molecules.     

高栅压下超薄栅nMOSFET的RTS噪声

在深入研究SMIC 90nm工艺1.4nm栅厚度nMOS器件RTS噪声时域特性的基础上,提出了该类噪声电子隧穿栅介质的物理起源,并对高栅压下RTS噪声机理作了深入阐述.结合IMEC和TSMC的研究,建立了栅压与RTS噪声时间参数的物理模型,实验结果和模型模拟结果的一致说明了模型的有效性.该研究为边界陷阱动力学和此类器件可靠性提供了新的研究手段.     

以面向市场的科技创新体制推进企业转型

上海市电信有限公司在对中国电信集团公司提出的转型战略深入思考和探索后,提出自身实施科技创新的立足点:面向市场、服务转型.本文介绍了上海电信进行以市场为导向的科技创新工作的4个方向,其中总结了上海电信在近几年所获得的成绩以及未来贯彻落实集团转型战略的具体工作措施.