General study of jitter mechanisms for metric-based wireless routing protocols

To ameliorate high collision, a nefarious side effect of route discovery stage of reactive routing protocols in wireless networks, jitter mechanisms are proposed which enforce wireless nodes to postpone their transmission for a random amount of time so as to reduce probability of simultaneous transmission. Although it has been shown that jitter mechanisms can dramatically improve reactive routing protocols, it was not until recently that jitter mechanisms have been subjected to study. In this paper, different random distributions are proposed for jittering mechanisms and also shaping function, with the aim of which a simple routing protocol like AODV becomes sensitive to any arbitrary metric, is defined. Comprehensive simulation of routing metrics and jitter mechanisms have revealed that simple modification of a jitter mechanism, which can be even implemented independent of a routing protocol, greatly improves routes discovered by any routing protocol.     

Fast Two-Output Secure Computation with Optimal Error Probability

Cut-and-choose paradigm makes Yao's protocol for two-party computation secure in malicious model with an error probability.In CRYPTO 2013,based on multi-phase cut-and-choose,Lindell reduced this probability to the optimal value.However,this work can only compute single-output functions with optimal error probability.We transform multi-phase cut-and-choose for singleoutput case into one that can deal with two-output functions,meanwhile maintaining the optimal error probability.Based on this new paradigm,we propose an efficient two-output secure computation protocol.Besides,by utilizing the specific property of the output garbled keys,we solve the authenticity issue of the generator's output with only symmetric cryptographic operations linear in the output length of the generator,which is the most efficient method so far in standard model without Random oracle (Ro).     

Analytical modeling of Transmission Control Protocol NewReno using Generalized Stochastic Petri Nets

This paper presents a novel analytical model of Transmission Control Protocol (TCP) using a generalized stochastic Petri net (GSPN). Extensive simulation work has been done for the performance evaluation of TCP NewReno protocol. In view of the limitations of the simulation technique, we present an analytical approach using GSPN. A GSPN is a useful mathematical tool that solves continuous time Markov chains for complex systems and evaluates the stationary behavior. In this paper, we analyze the slow‐but‐steady variant of TCP NewReno. The model captures the behavioral aspects of the slow start and the congestion avoidance phase together with the fast retransmit and recovery capabilities of TCP NewReno. Performance metrics such as throughput, goodput, and task completion time of the system are obtained. The effect of variation in the model parameters on the performance is studied. The results are validated using the network simulator, and their accuracy is verified by evaluating the confidence interval. The performance of the proposed model is compared with that of TCP Reno. The performance of the proposed model is also compared with one of the previous models. The numerical illustrations and comparison of the proposed technique with simulation validates the accuracy, efficiency, and competence of the GSPN technique. While GSPN modeling for TCP is investigated in depth for the TCP NewReno and TCP Reno variant in this paper, other protocols could be also analyzed similarly. Copyright © 2013 John Wiley & Sons, Ltd.     

Adaptive multimedia streaming using a simulation test bed

The major purpose of this paper is to transmit an existing video above a complete simulated video streaming architecture based on Network Simulator (NS2). Thanks to our architecture, the visual quality evaluation of the distributed streaming platform under various conditions is simplified. Indeed, the received video can be easily visualized using a classic video client or be compared using the Peak Signal-Noise Ratio (PSNR) value and the Structural SIMilarity (SSIM) value. In the case study, we compare adaptive video congestion strategies using a transcoder, Datagram Congestion Control Protocol (DCCP) and TCP-Friendly Rate Control (TFRC).     

基于不均等分层分簇的无线传感器网络协议

针对不均等分簇协议中节点竞选半径和簇头的选取机制存在缺陷问题,提出了不均等分层分簇协议,将网络覆盖区域进行分层处理,降低了簇头簇内负担,提高了能量使用效率,并采用Matlab软件进行了仿真实验。仿真结果表明,UHC协议有效降低了簇内节点密度,且延长了网络使用寿命。     

Synthesis,Characterization, and Catalytic Behavior of Bamboo Rice Husk Ash

In this paper, we report the use of bamboo rice husk ash as an efficient, greener, reusable, and biodegradable heterogeneous catalyst for the synthesis of tetrahydro‐4H ‐chromene‐3‐carbonitriles via the one‐pot three‐component reaction of malononitrile with aromatic aldehydes and dimedone or 1,3‐cyclohexanedione. The formation of bamboo rice husk ash‐silica has been confirmed by several analytical techniques.     

一种基于串行通信接口的采样速率测试方法

串行接口在工业控制领域得到广泛的应用,而且对串口的功能进行验证具有较为完善的测试设备和方法。另一方面,如何简化并快速进行串口模块的功能验证具有重要的意义。基于此观点,在研究了模块自身的功能特性的基础上,提出一种具有一定通用性的设计思想,即利用通信速率和采样速率之间的关系,将串口收/发送器速率与串口接收器采样速率配置成一定配比关系,从而实现用于测试串口接收器的任意帧结构数据。     

基于USB2.0接口的PCM数据采集器设计与实现

为满足X型飞机飞行试验的需求,设计了基于USB2.0接口的PCM数据采集器,该采集器实现了对机载环境下振动参数的采集、记录和实时监控功能,具备对100%及部分机载环境振动参数的PCM、RS422数据流记录功能,通过USB接口实现了上位机对100%PCM数据、可选RS422数据流的加载及实时监控功能。     

基于嵌入式处理器STM32的抽油机井实时监控系统设计

为了解决抽油机井生产过程中的实时监控问题,本文提出了一种基于嵌入式处理器STM32的抽油机井实时监控系统设计方案,并完成系统的软硬件设计.该系统能够测量抽油机并的油压、油温、三相电流电压、功率、有功、无功、功率因数以及示功图等参数,以此来实现对抽油机井的实时监控.系统各部分与上位机使用RS485总线连接,上位机通过Modbus协议与各模块通信.该系统具有操作简便、测量准确的特点,实现了数据的实时接收和远程监控功能.     

基于TS201的实时图像处理系统链路口通信设计

在图像处理系统中,为了实时获取数据图像及解决多DSP之间的数据传输,在以FPGA加3个DSP为核心模块的硬件平台上,论文通过对DSP链路口发送、接收时序设计以及对存储器直接访问控制块、链路口接收控制寄存器、发送控制寄存器进行编程设置,实现了以Analog Device公司的DSP(TS201)为核心器件的链路口图像接收技术及链路口数据传输技术。