基于CC1100的无线视频监控系统设计

为了对特定场合进行安全监控,采用CC1100无线传输模块和PTC08串口摄像头模块设计并实现了一种无线视频监控系统。利用摄像头模块对视频进行数据采集、压缩、串口传输,并利用微控制器通过无线传输模块进行拍摄控制、数据传输。经测试表明,该系统具有操作简便、运行稳定的特点,达到了设计要求。     

基于ZigBee煤矿井下无线传感器节点设计

针对目前煤矿井下有线监控系统存在的问题,在此设计了一种无线传感器节点,其特点是无线的、移动性强、可靠性高、低功耗、实时性强等,能够实时监测煤矿井下的环境参数,包括温度、湿度和瓦斯浓度,并将采集到的信息通过ZigBee无线传输方式进行发送。以CC2430作为无线网络处理器,负责建立网络和传输数据,采用SHT11温湿度传感器和MJC4／3．0L瓦斯浓度传感器采集煤矿井下数据,用CC2591芯片作为无线发送前端,增强无线发送功率;软件架构采用Z-Stack协议栈,它是基于一个轮转查询式操作系统。最后通过实验测试表明,该无线传感器节点能实时准确地采集环境参数,有效地实现实时监测煤矿井下的环境情况。     

多输入多输出CCⅡ电压模式滤波器

提出了两种 CC (第二代电流传输器 )多输入多输出的电压模式滤波器电路。第一种电路为三输入二输出滤波器电路 ,由 2个 CC +(同相 CC )及 4个 RC元件构成 ,能实现 1 0个不同条件下的滤波器 ,并能实现4种具有同时两端输出的滤波器 ;第二种电路为四输入两输出滤波器电路 ,由 1个 CC +、1个 CC -(反相CC )及 5个 RC元件构成 ,能实现 2 2个不同条件下的滤波器 ,并能实现 6种具有同时两端输出的滤波器。与同类电路比较 ,电路结构简单、功能更强。文中还给出了 CC +及 CC -的实现电路 ,并对提出的滤波器电路进行了硬件实验。     

Benchmark calculations of 29Si–1H spin–spin coupling constants across double bond

Benchmark calculations of geminal and vicinal ²⁹Si–¹H spin–spin coupling constants across double bond in three reference alkenylsilanes have been carried out at both DFT and SOPPA levels in comparison with experiment. At the former, four density functionals, B3LYP, B3PW91, PBE0 and KT3, were tested in combination with five representative basis sets. At the latter, three main SOPPA‐based methods, SOPPA, SOPPA(CC2) and SOPPA(CCSD), were examined in combination with the same series of basis sets. On the whole, the wavefunction methods showed much better results as compared to DFT, with the most efficient combination of SOPPA/cc‐pVTZ‐su2 characterized by a mean absolute error of only 0.4 Hz calculated for a set of nine coupling constants in three compounds with a sample span of around 40 Hz. Copyright © 2012 John Wiley & Sons, Ltd.     

基于Android的汽车TPMS实现

随着汽车行业的快速发展,以及车联网的逐渐渗透,人们在享受丰富的车载用户体验的同时,对汽车安全性能的要求越来越高,而胎压是汽车安全隐患因素之一,所以实时监测胎压必不可少。其次,由于Win CE系统的CPU效率以及对网络支持能力的瓶颈,越来越不能满足人们的需求,而当今主流的Android操作系统很好地解决了这些难题,所以基于Android车载设备必将是未来车载系统的发展趋势。该系统是基于有源式的汽车胎压监测系统(TPMS),通过相关传感器设备能实时采集汽车轮胎胎压、温度和加速度等运行状态的数据,并通过CC1101射频模块将数据传送至胎压监视中心,由胎压监视中心显示这些参数值,并能够对异常情况发出警报提示信息。     

The Osofsky–Smith Theorem for Modular Lattices and Applications (I)

The aim of this article is to present a latticial version of the renown module theoretical Osofsky–Smith Theorem.     

Evaluation of Region-of-Interest coders using perceptual image quality assessments

A perceptual measure emulates the human vision for image quality assessment. This paper illustrates the evaluation of Region-of-Interest (ROI) coders using perceptual image quality assessments. The goal of this evaluation is to characterize the coder performance by controlling the ROI quality. Perceptual measures are taken into account for evaluation since they behave as a human-made evaluation. Moreover, a perceptual assessment named Wavelet Quality Index (WQI), is introduced as another image coder evaluator. Proposed assessment aims at emulating the human vision by a weighted linear combination of three wavelet-based perceptual measures. We evaluate the following types of ROI-coders: those preserving the quality of ROI by coarse compression of background (Max-Shift coder), and those balancing the quality between ROI and background (SCM-Shift, and BbB-Shift coders). Using considered assessments for the performance evaluation of coders, results show a variation of evaluation by nature of measurement.     

Turbo Decoding of Super-Orthogonal Space-Time Trellis Codes in Rayleigh Fading Channels

Space-time trellis codes have shown to provide a good performance in Rayleigh fading channels. Recently Super-orthogonal space-time trellis codes have shown to outperform these codes, and also provide a systematic design method to maximize diversity and coding gain in quasi-static Rayleigh fading channels. We investigate the performance of these new codes in rapid Rayleigh fading channels and further propose two concatenated versions of these codes. We further investigate the effect of imperfect channel state information on one of the concatenated versions. Some simulation results of the various concatenated schemes in quasi-static and rapid Rayleigh fading channels are presented. Jayesh N. Pillai received the B.Tech degree in Electrical and Electronic Engineering from the University of Calicut, Kerala, India in 2001. He is currently pursuing an MScEng degree in Electronic Engineering at the School of Electrical, Electronic and Computer Engineering at the University of KwaZulu-Natal, Durban, South Africa. His research interests are in the area of wireless communications, including multiple-antenna systems, space-time coding and channel coding. Stanley Henry Mneney obtained his B.Sc.(Hons) Eng. Degree from the University of Science and Technology, Kumasi in Ghana in 1976. In 1979 he completed his M.A.Sc. from the University of Toronto in Canada. In a Nuffic funded project by the Netherlands government he embarked on a sandwich Ph.D. programme between the Eindhoven Univesity of Technology and the University of Dar es Salaam, the latter awarding the degree in 1988. His co-supervisors were Prof Jens Arnbak and Prof Ramje Prasad representing the two Universities. The research area was on the application satellite technology to provide low cost systems and services to the rural population in the developing countries.Prof Mneney has taught at the Universities of Dar es Salaam, Nairobi, Durban Westville and he is currently an Associate Professor and Deputy Head of School of Electrical, Electronic and Computer Engineering at the University of KwaZulu-Natal in South Africa. His research interest includes Signal and Image processing, radio propagation and communication systems.     

无线收发芯片比较与选择

本文比较了nRF401、nRF903和CCl000三款无线收发芯片的特性，详细介绍了它们的结构原理、特性及应用电路。     

基于全集成收发芯片CC1000的无线数据传输设计

CC1000是CHIPCON公司生产的一种低功耗全集成收发芯片,工作于315/433/868/915 MHz工业、科学和医疗(ISM)短距离设备频段.文中介绍了芯片功能,给出了基于RS-232接口的PC机之间无线数据传输电路和PC机端接口程序、单片机控制端控制程序,实现两PC机之间的无线数据传输.系统结构简单,具有节能模式,对短距离无线数据通信提供了一种实例.