超高压系统的电控设计

研究超高压系统的增压原理,建立了系统数学模型,并在此基础上通过仿真分析了影响系统压力波动的主要因素.设计了超高压系统的主电路及控制电路.通过仿真分析研究了该系统的特性与各主要参数之间的关系.对系统的推广应用具有一定意义.     

基于RFID和无线传感的矿井实时定位预警系统

为了实现对矿山生产过程中三维定位和灾害预警监测,设计了一种基于RFID和无线传感的矿山实时定位预警系统,硬件包括无线射频标识模块、实时三维定位模块、监测数据采集与分析模块、灾害预警模块、灾害分析模块和地面远程控制主机。实际应用表明,该系统平台铺设灵活性强,监控范围广泛,可以三维全方位监控,有效提高矿山安全监测效率。     

一种基于模糊控制的推力变向机构控制仿真

为了适应越来越恶劣的飞机作战环境,在原有的轴对称矢量喷管的数学模型的基础上,提出一种基于模糊控制的推力变向机构的构想.建立AVEN的数学模型,并进行模糊控制设计,通过Matlab的仿真说明该控制器可以有效地追踪输入信号的变化,同时进一步分析比较量化因子Ke、Kde和比例因子Ku对控制结果的影响,在此基础上设计模糊PID控制器,与单纯的PID控制器和模糊控制器进行比较.分析结果表明:该模糊控制器能够较为理想地跟踪输入,较为准确地分析各量化因子对输出结果的影响,为推力变向机构的工程实践提供理论参考.     

利用无线物联网技术实现智能电力计量

为了实现对分散接入电力计量系统的终端智能电表实施数据读取和有效管理,文中提出了采用低功率无线网(LPWAN)技术,将终端智能电表接入数据网关和电力私有云实现智能电力计量的技术方案。该方案采用了LoRa无线模块实现电力计量数据的双向交互,具有运行可靠、低成本、低功耗、远程接入等优势。此外,文中还重点介绍将如何利用新兴的LPWAN技术帮助构建智能电能无线接入的解决方案,展示了用于智能电表端到端LoRa连接的系统实现。     

一种基于Zigbee技术在大面积农场管理中组网的方法

为了实现大面积农场管理,文中提供了一种使用Zigbee无线传感器网络组网的系统,包括第一网关、第二网关、至少一个Zigbee无线传感器网以及RS485有线网络。实际应用表明,本系统利用大面积农场管理系统已有的RS485有线网络．大大降低了组网的成本、提高了管理对象和拓扑的灵活性。     

Crowd counting in complex scenes based on an attention aware CNN network

Crowd counting with density estimation has been an active research community due to its significant applications in the fields of public security, video surveillance, traffic monitoring. However, Crowd counting for congested scenes often suffers from some obstacles including severe occlusions, large scale variations, noise interference, etc. In this paper, using the first ten layers of a modified VGG16 and dilated convolution layers as the framework, we have proposed a CNN based crowd counting and density estimation model improved by the attention aware modules with residual connections. To tackle the problem of noise interference, convolutional block attention modules have been introduced into the deep network to segment the foreground and background to focus on interest information, refining deeper features of the input image. To improve information transmission and reuse, residual connections are utilized to link 3 attention blocks. Meanwhile, dilated convolution layers keep larger reception fields and obtain high-resolution density maps. The proposed method has been evaluated on three public benchmarks, i.e. Shanghai Tech A & B, UCF-QNRF and MALL, achieving the mean absolute errors of 64.6 & 8.3, 113.8 and 1.68, respectively. The results outperform some existing excellent approaches. This indicates that the proposed model has high accuracy and better robustness, which is suitable for crowd counting and density estimation in various congested scenes.     

A reflective semiconductor optical amplifier based all-optical header separator

An all-optical header extraction scheme based on the reflective semiconductor optical amplifier (RSOA) is presented, which can be used to process variable-length and bit-rate transparent packets. Through selecting the appropriate carrier-lifetime of the RSOA, the payload pulses obtain smaller gains than header pulses and are considered to be compressed. By using the reflective structure, the header pulses can acquire larger gains than the payload twice, and the contrast radio (CR) is improved. The simulation results show that the CRs can reach 22.8 dB and 18 dB for the packets with header pulses at the rates of 2.5 Gb/s and 10 Gb/s, respectively, and these values can be optimized through properly selecting the structure parameters, such as the small-signal gain and saturation energy.     

基于PMU的电力系统监控体系结构优化设计

文中提出了一种利用有限数量的相量测量单元(PMU)和相量数据集中器(PDC)设计最优监控结构的方法.通过在大量的设定值场景下,使电力系统可观测性曲线的期望值最大化,同时使通信基础设施成本最小化,最终确定PMU和PDC的最佳位置.提出了一种非线性动态扩展卡尔曼滤波(EFK)状态观测器.这种状态观测器可以将暂态行为转换为由...     

面向无人机自组网和车联网的媒体接入控制协议研究综述

随着移动通信技术的迭代更新,车联网(VANET)和无人机自组网(FANETs)已成为通信网络的重要组成部分,而媒体接入控制(MAC)协议则是移动自组织网络未来发展的核心研究内容之一。安全控制信息和用户业务信息是自组织网络最主要的两类信息,而两者不同的服务质量(QoS)需求对MAC机制的设计带来了严峻的考验。该文主要考虑车联网和无人机自组网,针对其网络特征,从不同的优化目标出发,对其使用的MAC协议进行分析与归纳,并对下一步的研究方向进行了思考与展望。     

基于物联网的矿井温、湿度检测系统设计

为了实现对矿井温、湿度检测,提出了一种基于物联网的矿井温、湿度检测系统,并完成了系统的软硬件测试。硬件包括由分布在矿井中的测量节点组成的无线传感网络,由基站节点和监控终端设备相连接形成的监控装置,软件采用MSP430进行编程,并实现了温湿度信号检测。实际应用表明,该系统具有体积小,部署方便,成本低廉等优点。