[bmIm]OH: an efficient basic catalyst for the synthesis of 4H-benzo[d][1,3-]oxazin-4-one derivatives in solvent-free conditions

Reusable [bmIm]OH was found to be a highly efficient renewable homogenous catalyst for the rapid and convenient synthesis of benzoxazine-4-one derivatives from o-iodobenzoic-acid and benzonitrile at 75 °C in moderate to good yields. This methodology provides a facile and straightforward path to construct other related heterocycles in an eco-compatible fashion.     

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.     

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.     

基于MAC序列的相位编码准连续波的研究与应用

本文在讨论用二相编码信号构成的准连续波的数学模型和模糊函数的基础上,引入新的二元序列--MAC序列,并对其产生以及自相关特性进行了详细研究。通过对采用该序列编码的准连续波信号的周期单码重复时和多码重复的模糊函数进行仿真,其结果具有很好的图钉状,即有较高的距离和多普勒分辨率;并将MAC序列的相位编码准连续波应用在波形设计中,脉压仿真结果表明相比较m序列码,MAC序列更适用于目标检测。     

华为OLT下“流氓ONU”的故障处理

众所周知,EPON系统光传输机制是:下行广播方式,上行TDMA方式。所谓TDMA方式就是将上行总带宽分成若干个时隙,各个ONU通过占用不同的时隙来传送业务。上行时隙的分配由OLT来完成,并由OLT通知各个ONU,各ONU只能在分配的时隙内发光。若某个ONU持续长时间发光,它就会占用OLT分配给其他ONU的发光时间,从而与其它ONU的发光信号发生冲突,造成了其它ONU的离线。这种不按照分配的时间戳向上发送光信号的ONU,即是我们通常说的"流氓ONU"。     

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.