保护通信基础设施的安全(英文)

正Our world becomes more and more dependent on communications infrastructure such as computer resources,network connections and devices for communications.However,current security techniques do not provide adequate protection against cyber attackers for these systems and devices.The increasing complexity of     

面向精准农业的无线多媒体传感网设计(英文)

To satisfy the needs of modern precision agriculture, a Precision Agriculture Sensing System (PASS) is designed, which is based on wireless multimedia sensor network. Both hardware and software of PASS are tailored for sensing in wide farmland without human supervision. A dedicated single-chip sensor node platform is designed specially for wireless multi-media sensor network. To guarantee the bulky data transmission, a bitmap index reliable data transmission mechanism is proposed. And a battery-array switching system is design to power the sensor node to elongate the lifetime. The effectiveness and performance of PASS have been evaluated through comprehensive experiments and large-scale real-life deployment.     

FLIC文件的数据结构与显示软件的研究

ＦＬＩＣ文件是三维动画设计软件的动画输出文件或者称为动画存储文件事实上是对一个静止画面序列的描述，连续显示这一序列便可在屏幕上产生画效果。文中对ＦＬＩＳ文件的数据结构做了详细的剖析，而且在此基础上研究了ＦＬＩＣ文件的显示软件，编制出带有屏幕“明出”与“暗出”特技效果的动画演播程序。     

经济型数控铣床程序的输入与存储

经济型数控铣床程序的输入与存储成都前锋电子股份有限公司田际佳（６１００５１）为了满足生产的需要，我们先后改造了三台普通立式铣床为经济型数控铣床。普通立铣是长征机床厂生产的型号为Ｘ５０３２Ａ；控制柜采用的是西安微电机所研制的型号为ＢＫＸ—３Ｂ。执行环节...     

IaaS云中面向能源效率优化的虚拟机调度算法(英文)

In IaaS Cloud,different mapping relationships between virtual machines(VMs) and physical machines(PMs) cause different resource utilization,so how to place VMs on PMs to reduce energy consumption is becoming one of the major concerns for cloud providers.The existing VM scheduling schemes propose optimize PMs or network resources utilization,but few of them attempt to improve the energy efficiency of these two kinds of resources simultaneously.This paper proposes a VM scheduling scheme meeting multiple resource constraints,such as the physical server size(CPU,memory,storage,bandwidth,etc.) and network link capacity to reduce both the numbers of active PMs and network elements so as to finally reduce energy consumption.Since VM scheduling problem is abstracted as a combination of bin packing problem and quadratic assignment problem,which is also known as a classic combinatorial optimization and NP-hard problem.Accordingly,we design a twostage heuristic algorithm to solve the issue,and the simulations show that our solution outperforms the existing PM- or network-only optimization solutions.     

无线通信中物理层安全问题及其解决方案(英文)

The properties of broadcast nature, high densities of deployment and severe resource limitations of sensor and mobile networks make wireless networks more vulnerable to various attacks, including modification of messages, eavesdropping, network intrusion and malicious forwarding. Conventional cryptography-based security may consume significant overhead because of low-power devices, so current research shifts to the wireless physical layer for security enhancement. This paper is mainly focused on security is...     

一种基于软件定义网络的自治服务质量管理机制(英文)

With the increase of network complexity,the flexibility of network control and management becomes a nontrivial problem.Both Software Defined Network(SDN) and Autonomic Network technologies are sophisticated technologies for the network control and management.These two technologies could be combined together to construct a software defined self-managing solution for the future network.An autonomic QoS management mechanism in Software Defined Network(AQSDN) is proposed in this paper.In AQSDN,the various QoS features can be configured autonomically in an OpenFlow switch through extending the OpenFlow and OF-Config protocols.Based on AQSDN,a novel packet context-aware QoS model(PCaQoS) is also introduced for improving the network QoS.PCaQoS takes packet context into account when packet is marked and managed into forwarding queues.The implementation of a video application's prototype which evaluates the self-configuration feature of the AQSDN and the enhancement ability of the PCaQoS is presented in order to validate this design.     

视频传感器网络中面向特定场景的行人检测方法(英文)

Pedestrian detection is one of the most important problems in the visual sensor network. Considering that the visual sensors have limited cap ability, we propose a pedestrian detection method with low energy consumption. Our method contains two parts: one is an Enhanced Self-Organizing Background Subtraction (ESOBS) based foreground segmentation module to obtain active areas in the observed region from the visual sensors; the other is an appearance model based detection module to detect the pedestrians from the foreground areas. Moreover, we create our own large pedestrian dataset according to the specific scene in the visual sensor network. Numerous experiments are conducted in both indoor and outdoor specific scenes. The experimental results show that our method is effective.     

一种面向物联网的无线传感器网络优化部署策略(英文)

This paper proposes an open hierarchical network architecture for the Internet of Things (IoT), which can provide a unified network topology by using heterogeneous Wireless Sensor Networks (WSNs). With this proposed architecture, our research focuses on the optimal deployment strategy of the nodes on the convergence level. We aim at the maximization of the sub-network's lifetime while minimizing the deployment cost. Meanwhile, a novel metric named as the Ratio of Lifetime to Cost (RLC) is proposed to estima...     

面向轻载深包检测的应用负载特征自动挖掘(英文)

Automatic signature generation approaches have been widely applied in recent traffic classification.However,they are not suitable for LightWeight Deep Packet Inspection(LW_DPI) since their generated signatures are matched through a search of the entire application data.On the basis of LW_DPI schemes,we present two Hierarchical Clustering(HC) algorithms:HC_TCP and HC_UDP,which can generate byte signatures from TCP and UDP packet payloads respectively.In particular,HC_TCP and HC_ UDP can extract the positions of byte signatures in packet payloads.Further,in order to deal with the case in which byte signatures cannot be derived,we develop an algorithm for generating bit signatures.Compared with the LASER algorithm and Suffix Tree(ST)-based algorithm,the proposed algorithms are better in terms of both classification accuracy and speed.Moreover,the experimental results indicate that,as long as the application-protocol header exists,it is possible to automatically derive reliable and accurate signatures combined with their positions in packet payloads.     

基于软件定义网络的一种多控制器休眠模型(英文)

In order to improve the scalability and reliability of Software Defined Networking(SDN),many studies use multiple controllers to constitute logically centralized control plane to provide load balancing and fail over.In this paper,we develop a flexible dormant multi-controller model based on the centralized multi-controller architecture.The dormant multi-controller model allows part of controllers to enter the dormant state under light traffic condition for saving system cost.Meanwhile,through queueing analysis,various performance measures of the system can be obtained.Moreover,we analyze the real traffic of China Education Network and use the results as the parameters of computer simulation and verify the effects of parameters on the system characteristics.Finally,a total expected cost function is established,and genetic algorithm is employed to find the optimal values of various parameters to minimize system cost for the deployment decision making.     

软件过程改进与软件能力成熟度模型(SW-CMM)

软件产业是信息产业的核心，对诸多高新技术企业的发展起到不可估量的推动作用。虽然经过一段时间的发展，我国的软件产业进步了很多，但是由于开发过程不规范、质量测试体系不完善，软件产品的生产效率和生产质量一直没有得到很好的控制和解决，因此成为束缚软件产业进一步发展的瓶颈。本文通过对软件能力成熟度模型(CMM)的描述和剖析，总结出软件开发过程中的改进方法，可以很好地解决上述问题。     

节能与绿色通信专题(英文)

正Conventional communication technologies are targeted mainly at spectrum efficiency,but not energy efficiency and environmental friendliness.Recent efforts from both industry and academia have dedicated to reduce the energy consumption and carbon emissions of the information and communication technologies(ICTs).There are two ways to achieve this goal:one is to conserve energy through energy-aware operation optimiza-     

电磁兼容设计与应用专题(英文)

The ultra-high speed network is the latest trend of theinformation era that is expected to last a long time.This trend not only requires network development but alsopromotes the advancement of the related intersection     

单片机硬件、软件及其应用讲座(15)——第八讲 输入/输出端口(下)

<正> 输入/输出端口应用举例 硬件电路规划 针对本讲中介绍的端口功能,并且以“ICD在线调试器套件”中提供的演示板及其上面的现有硬件资源为基础,笔者设计了一个利用I/O端口实现数据输入和输出的应用实例。在该实例中将要用到的演示板上的部分硬件电路如图2和图3所示。 图2是端口RC外接的8条支路,由一只(8路封装在一起的)拨动开关SW3分别控制各路接通还是断开。这8条支路既构成了端口RC的输出负载电路,又构成了端口RC的输出     

单片机硬件、软件及其应用讲座(14)——第八讲 输入/输出端口(上)

<正> 输入/输出端口(也可简称为I/O口)是单片机内部电路与外部世界交换信息的通道。输入端口负责从外界接收检测信号、键盘信号等各种开关量信号。输出端口负责向外界输送由内部电路产生的处理结果、显示信息、控制命令、驱动信号等。如果将单片机看作是一个为人服务的“奴仆”的话,那么单片机的I/O口也就是“主-仆对话”或称“人-机对话”的渠道。由此可见,输入/输出端口对于单片机来说是一种极其重要的外围模块,以至于对任何一个厂家生产的任何一种型号的单片机来说,输入/输出端口模块都是必不可少的。     

软件辅助设计(CASE)方法与使用

介绍了CASE工具的基本应用方法,并以作者所使用的CASE工具为例,阐述它的组成与功能,并举例说明了它的应用。     

利用COMSOL软件对1D-BPM电极影响的仿真及分析(英文)

基于微机电系统(MEMS)微加工技术和Pb(Mg1/3Nb2/3)O3-PbTiO3(PMN-PT)电光材料设计的一维二进制码相位调制器(1D-BPM)可用于激光显示技术中的散斑消除。建立了1D-BPM数学模型,推导出电极在PMN-PT片内产生的电场和PMN-PT折射率变化导致通过的光束相位变化的关系。采用有限元分析方法仿真了电极几何尺寸对相位的影响,发现当电极尺寸在亚微米级时,两电极间相位分布不仅依赖于电极产生的电场大小,而且受到电极几何尺寸的影响。电极角效应是器件设计及优化时需考虑的重要因素。     

Si(100)表面的TCS研究(英文)

Total current spectroscopy (TCS) is a newly developed method in detecting electronic properties of solid surfaces. In this work, a chemically cleaned Si(100) wafer was cleaned and annealed "by heating the sample up to about 850℃ in a UHV chamber with a pressure less than 1×10-7pa then the surface appeared a sharp 2×1 LEED pattern.In the TCS spectra both on cleaned and uncleaned surfaces, four peaks labeled A, B, C aad D appeared in 3.5, 6.4, 9.3, and 13.5eV, respectively, with respect to vacuum level. Among them peaks A,C,D remain unchanged while peak B is quite sensitive to gas absorption and the surface temperature, mainly by changing its intensity. The phenomena are explained by assuming that inelastic scattering of incident eletrons dominates the process. Peaks A,C, D were caused by interband transitions and peak B was attributed to the surface state. Further studies are in consideration.     

智能终端PIN输入安全的要求与实现

本文介绍了一种基于Android智能终端上PIN输入的安全要求和设计方法,解决由于Android漏洞可能产生的PIN输入安全风险.