以物联网为牵引的复杂计算系统设计与开发能力培养

信息技术的快速发展催生了一种复杂计算系统——物联网,其是跨学科专业理论知识与技术应用的综合。具备设计与开发物联网式复杂计算系统能力是计算机类专业研究生的重要培养目标。为此,提出研究生物联网课程教学改革基本规划,从典型复杂计算系统的角度阐述物联网深层次认知、剖析物联网系统开发基本素养、凝练物联网架构;基于物联网典型应用场景,从技术路线的角度提出研究生物联网复杂计算系统设计与开发能力培养技术架构。实施改革后,研究生的综合平均成绩、基础性与综合性实验完成率,以及综合理解能力、设计与开发能力均得到提升。今后将继续加强教学改革力度,培养综合能力强的物联网人才。

基于ARM9的无线视频监控系统设计与实现

为实现视频监控系统的便携性和可移动性,提出以ARM920T-S3C2440为中央处理器的嵌入式系统设计方案。对系统分别进行软硬件设计,硬件系统主要是设计外围硬件设备的原理图和PCB图,对制作的电路板焊接并调试,针对调试过程中出现问题给予解决;软件系统中移植Linux操作系统并加载摄像头驱动程序。分别可以在Windows和Linux两个系统中实现视频监控,实验结果表明两种方案能实时实现视频的无线监控。

基于ARM9的视频监控系统设计

提出一种基于ARM9和GPRS网络的嵌入式安防报警系统。以S3C2440处理器作为控制核心,将摄像头采集的图像数据进行压缩,利用GSM模块向用户提供短信通知和彩信确认,用户根据情况发送命令,控制云台或者报警,实现对现场的实时监控。实验结果表明,该系统图像采集稳定,监控效果良好,具有较好的应用前景。

嵌入式Flash CISC/DSP微处理器的研究与实现

本文研究一种新的既具有微控制器功能 ,又有增强DSP功能的高性能微处理器的实现架构 .在统一的增强CISC指令集下 ,我们将基于哈佛和寄存器 寄存器结构的微处理器模块和单周期乘法 /累加器、桶形移位寄存器、无开销循环及跳转硬件支持模块、硬件地址产生器等DSP功能模块以及嵌入式FlashMemory和指令队列缓冲器有机的集成起来 ,在统一架构下通过单核实现CISC/DSP微处理器 ,有效地提高了处理器的性能 .该微处理器采用 0 35 μmCMOS工艺实现 ,芯片面积为 2 5mm2 .在 80M工作频率下 ,动态功耗为 4 2 5mW ,峰值数据处理能力可达 80MIPS .该处理器核可满足片上系统 (SOC)对高性能处理器的需求 .

并行CISC指令译码器的设计与实现

针对x86系列兼容微处理器串行译码速度慢、效率低的缺点,提出了一种并行译码器设计方案。该方案将整个译码过程分为长度译码和地址译码两个阶段进行流水译码,在指令不带前缀的情况下单拍完成长度译码,支持任意两条指令并行译码,提高了译码效率。其使用Verilog-HDL进行描述,SYNOPSYS-DV在SMIC CMOS0.18工艺库下进行综合。结果表明完全达到了设计要求。

MP-WFRFT and Constellation Scrambling Based Physical Layer Security System

In this paper, a multiple parameters weighted fractional Fourier transform(MPWFRFT) and constellation scrambling(CS) method based physical layer(PHY) security system is proposed. The proposed scheme is executed by two steps. In the first step, MPWFRFT, implemented as the constellation beguiling(CB) method, is applied to change the signal's identity. In the second step the additional pseudo random phase information, regarded as the encryption key, is attached to the original signal to enhance the security. Typically, the pseudo random phase information can be removed effectively by the legitimate receiver. In contrast to the cryptography based encryption algorithms and the conventional PHY secrecy techniques, the main contribution of the proposed scheme is concentrated on the variation in signal's characteristics. Simulation results show that the proposed scheme can prevent the exchanging signal from eavesdroppers' classifi cation or inception. Moreover, the proposed scheme can guarantee the BER performance at a tolerate increasing in computational complexity for the legitimate receivers.

Cast shadow detection for moving objects based on binocular stereo vision

A novel cast shadow detection approach was proposed.A stereo vision system was used to capture images instead of traditional single camera.It was based on an assumption that cast shadows were on a special plane.The image obtained from one camera was inversely projected to the plane and then transformed to the view from another camera.The points on the plane shared the same position between original image and the transformed image.As a result,the cast shadows can be detected.In order to improve the efficiency of cast shadow detection and decrease computational complexity,the obvious object areas in CIELAB color space were removed and the potential shadow areas were obtained.Experimental results demonstrate that the proposed approach can detect cast shadows accurately even under various illuminations.

Simulation calculation of solubility of insoluble compound M_mA_a in complex system

A simulation calculation model for the solubility of insoluble compound MmAa in complex system was established.According to coordination equilibrium principle,relevant dissociation reaction,complexation reaction,self-complexation reaction and protonation reaction during insoluble compound dissolving were considered and then the mass balance equations about solubility calculation were obtained.In the case analysis,the solubility of silver chloride in ammonia system was obtained by simulation calculation,and curved surface charts of thermodynamic equilibrium about the total concentration of silver ions,pH and concentration of ammonia ions were drawn correspondingly.The results show that under the conditions of room temperature and 6 mol/L ammonia concentration,the calculated solubility value of silver chloride(34 g/L) is close to the actual value(31 g/L),demonstrating that this model is suitable for solubility calculation of insoluble compound MmAa in the complex system.

VV&A and confidence assessment of a complex giant system simulation model

It is difficult or even impossible for a pure mathematical model to represent a complex giant system because of the complexity, activity, uncertainty in such a system. The meta-synthesis methodology and the generalized modelling method are used to model a complex giant system. This paper has an in-depth study on the confidence assessment of a complex giant system simulation model that is built based on the meta-synthesis methodology and the generalized modelling method. A new definition of VV&A for complex system is given, on which is based a 12-step reference model and proposed for VV&A purpose. Furthermore, the principle and method of intelligent boundary interval intermediate assessment is proposed for the harmonization of modelling and model-validation.

Two-stage DOA estimation method for passive radar based on sparse representation

In a GPS illuminator based passive radar system,estimation of direction of arriving(DOA) of multiple targets is a difficult problem due to strong interference.A two-stage method combining extensive cancellation algorithm(ECA) and sparse representation is proposed.In the first stage,ECA algorithm is used to eliminate the direct-path and multi-path interference.In the second stage,sparse representation of improved weight constraints based on L1 norm is adopted to estimate DOA and suppress the interference.Simulation results show that the proposed method can effectively estimate DOA in low computation complexity without estimating the disturbance parameter.

Efficient Broadcast Retransmission Based on Network Coding for InterPlaNetary Internet

In traditional wireless broadcast networks,a corrupted packet must be retransmitted even if it has been lost by only one receiver.Obviously,this is not bandwidth-efficient for the receivers that already hold the retransmitted packet.Therefore,it is important to develop a method to realise efficient broadcast transmission.Network coding is a promising technique in this scenario.However,none of the proposed schemes achieves both high transmission efficiency and low computational complexity simultaneously so far.To address this problem,a novel Efficient Opportunistic Network Coding Retransmission(EONCR)scheme is proposed in this paper.This scheme employs a new packet scheduling algorithm which uses a Packet Distribution Matrix(PDM)directly to select the coded packets.The analysis and simulation results indicate that transmission efficiency of EONCR is over 0.1,more than the schemes proposed previously in some simulation conditions,and the computational overhead is reduced substantially.Hence,it has great application prospects in wireless broadcast networks,especially energyand bandwidth-limited systems such as satellite broadcast systems and Planetary Networks(PNs).

A fast MPC algorithm for reducing computation burden of MIMO

The computation burden in the model-based predictive control algorithm is heavy when solving QR optimization with a limited sampling step, especially for a complicated system with large dimension. A fast algorithm is proposed in this paper to solve this problem, in which real-time values are modulated to bit streams to simplify the multiplication. In addition, manipulated variables in the prediction horizon are deduced to the current control horizon approximately by a recursive relation to decrease the dimension of QR optimization. The simulation results demonstrate the feasibility of this fast algorithm for MIMO systems.

Dynamical Criticality:Overview and Open Questions

Systems that exhibit complex behaviours are often found in a particular dynamical con- dition, poised between order and disorder. This observation is at the core of the so-called criticality hypothesis, which states that systems in a dynamical regime between order and disorder attain the highest level of computational capabilities and achieve an optimal trade-off between robustness and flexibility. Recent results in cellular and evolutionary biology, ueuroscience and computer science have revitalised the interest in the criticality hypothesis, emphasising its role as a viable candidate general law in adaptive complex systems. This paper provides an overview of the works on dynamical criticality that are -- To the best of our knowledge -- Particularly relevant for the criticality hypothesis. The authors review the main contributions concerning dynamics and information processing at the edge of chaos, and illustrate the main achievements in the study of critical dynamics in biological systems. Finally, the authors discuss open questions and propose an agenda for future work.

A new method of frequency-dependent network equivalence for power system

Electromagnetic transient simulation for large-scale power system is a time-consuming problem.A new frequency-dependent equivalence method is presented in the paper,which might significantly accelerate power system electromagnetic transient simulation.In the method,an effective algorithm is designed to directly transfer the port admittance determinant of external system's mixing matrix into admittance rational function;and the step-by-step strategy for the equivalence of actual large system is put forward,which further reduces the calculation quantities needed.Moreover,the study of multiple real root pole characteristics of admittance transfer function of two-port network is performed and a proposition is achieved.Based on the proposition and residue theorem,the equivalence system for external system corresponding to the admittance rational function is obtained.The computation complexity of the step-by-step equivalence method is about o(┌n/np×T┐)(┌┐ is upper integral operation,n is the total buses number of external system,N P is the total buses number of single step equivalence network,T is single step equivalence time),which indicates that the computation complexity of the method proposed has nearly linear relationship with the buses number of external system,and the method proposed has satisfactory computation speed.Since the mixing matrix of external system includes all the information of external system,therefore,port admittance rational function derived from it can reflect its full frequency characteristic and the equivalence network achieved has high equivalence precision.Moreover,since the port rational function is gained at the condition of the external system without source,which equals stable passive network,it could not show any unstable pole and need not extra measure to make the equivalence system stable.The test results of the samples and comparison with other methods demonstrate that the new method proposed is valid and effective.

SYSTEMATIC DESIGN OF SINGLE CARRIER OVERLAP FREQUENCY DOMAIN EQUALIZATION

This paper proposes a systematic design method of overlap frequency domain equalization(FDE) for single carrier (SC) transmission without a guard interval (GI).Based on the analysis of signal-to-interference-plus-noise ratio (SINR) of the equalizer output for each symbol,the authors adaptivelydetermine the block of the overlap FDE,where the block is defined as a set of symbols at the equalizeroutput with sufficiently low error rate,for a certain fixed sliding window size,which corresponds toa fast Fourier transform (FFT) window size.The proposed method takes advantage of the fact thatthe utility part of the equalized signal is localized around the center of the FFT window.In addition,the authors also propose to adjust the block size in order to control the computational complexity ofthe equalization per processed sample associating with the average bit error rate (BER) of the system.Simulation results show that the proposed scheme can achieve comparable BER performance to theconventional SC-FDE scheme with sufficient GI insertion for both the coded and uncoded cases withvarious modulation levels,while requiring lower computational complexity compared to the SC overlapFDE transmission with the fixed block.