基于Silverlight的富数据输入研究

针对站点中经常需要用户输入各类数据的现状,讨论了实现开发RIA应用的Silverlight技术以及ASP.NET/SilverlightWeb应用程序的N层逻辑设计,并在此基础上利用Silverlight技术较好地实现了电子商务RIA平台中一个富数据输入界面功能,提高了用户的体验。     

SVPWM三相电压型逆变器的仿真研究

以三相电压型逆变器为基础,根据空间矢量脉宽调制（SVPWM）基本原理详细分析研究了电压矢量作用时间和扇区分配问题,以α-β坐标为基础,建立了互差π/3的x-y-z时间坐标系,提出了不同扇区矢量作用时间长短根据期望极值判断的原则。介绍了MATLAB中M文件编程的仿真方法,建立了MATLAB程序嵌入式主要功能模块,逆变器采用数字PID控制,利用Simulink对系统进行了综合仿真分析及试验,给出了仿真及实验波形,为实现SVPWM逆变器的数字控制提供参考。     

Three-dimensional subwavelength components utilizing THz surface plasmons

Since surface plasmons(SPs)are not constrained by the diraction limit,they have important potential applications in the optical,terahertz(THz),and microwave components.In this paper,we firstly present a review of three-dimensional(3D) bidirectional and multi-directional THz SP splitters based on the rectangular metallic groove gratings with finite thickness,in which a metallic wire was used to excite the THz SPs.The experimental verifications of such splitters have been implemented in the microwave frequencies,and the measurement results have excellent agreements to the full-wave simulations.To improve the performance,a 3D bidirectional THz SP splitter with the transverse confinement and a 3D bidirectional bending THz SP splitter are then proposed,which have shown very good splitting performance,compact sizes,and better transverse confinement of EM fields.Finally,a broadband slow-wave system of subwavelength thickness is reviewed and a new bending slow-wave system utilizing THz SPs is proposed.Experiments and simulations in microwave frequencies have good agreements,showing the validity of these components.     

A new algorithm for fast mining frequent itemsets using N-lists

Mining frequent itemsets has emerged as a fundamental problem in data mining and plays an essential role in many important data mining tasks.In this paper,we propose a novel vertical data representation called N-list,which originates from an FP-tree-like coding prefix tree called PPC-tree that stores crucial information about frequent itemsets.Based on the N-list data structure,we develop an efficient mining algorithm,PrePost,for mining all frequent itemsets.Efficiency of PrePost is achieved by the following three reasons.First,N-list is compact since transactions with common prefixes share the same nodes of the PPC-tree.Second,the counting of itemsets’ supports is transformed into the intersection of N-lists and the complexity of intersecting two N-lists can be reduced to O(m + n) by an efficient strategy,where m and n are the cardinalities of the two N-lists respectively.Third,PrePost can directly find frequent itemsets without generating candidate itemsets in some cases by making use of the single path property of N-list.We have experimentally evaluated PrePost against four state-of-the-art algorithms for mining frequent itemsets on a variety of real and synthetic datasets.The experimental results show that the PrePost algorithm is the fastest in most cases.Even though the algorithm consumes more memory when the datasets are sparse,it is still the fastest one.     

Multi-channel SAR imaging based on distributed compressive sensing

The rapid development of compressive sensing(CS)shows that it is possible to recover a sparse signal from very limited measurements.Synthetic aperture radar(SAR)imaging based on CS can reconstruct the target scene with a reduced number of collected samples by solving an optimization problem.For multi-channel SAR imaging based on CS,each channel requires sufficient samples for separate imaging and the total number of samples could still be large.We propose an imaging algorithm based on distributed compressive sensing(DCS)that reconstructs scenes jointly under multiple channels.Multi-channel SAR imaging based on DCS not only exploits the sparsity of the target scene,but also exploits the correlation among channels.It requires significantly fewer samples than multi-channel SAR imaging based on CS.If multiple channels offer different sampling rates,DCS joint processing can reconstruct target scenes with a much more flexible allocation of the number of measurements offered by each channel than that used in separate CS processing.     

基于游程编码思想的条码定位与识别方法

在复杂背景中的定位条码是图像式条码识别系统中的一个关键步骤,如何在复杂的背景中快速、白动地检测出条形码是该文的主要研究内容。首先介绍了条型码的编码结构,然后提出了一种基于游程编码思想的条码定位与识别方法,最后通过给出相关实验结果,验证了该算法的可行性和实用性。     

基于MSP430的低功耗近距无线图像传输系统设计与实现

近距无线图像传输系统主要用于无线传感器网络中的图像采集、传输、处理和显示,本文设计并实现了一种具有较强实用性的近距无线图像传输系统。采用OV7670图像传感器作为图像数据采集器,高速低功耗的nRF24L01射频模块作为无线收发器,采用MSP430F14916位超低功耗单片机作为微处理器,所构成的系统具有功耗低、图像传输速度快等优点。作者详细阐述了该系统的硬件结构和软件设计。     

新媒体时代的物联网信息设计与展望

在互联网发展的基础上,物联网可将信息的交流与沟通扩展到任何物体与物体之间,故其将成为新媒体时代改变人类生活的新变量。在探索智能化信息交互与设计的过程中,文章紧跟物联网的发展趋势,不断思索物联网的崛起给新媒体时代的文化、生产与生活带来的需求、挑战与可能性,同时指出了在这样的背景下,物联网这个新媒体时代的新形势对信息设计所带来的新启示。