先进微处理器体系结构及其发展趋势*

为了进一步提高微处理器性能,提出了多种新颖的体系结构,如多核、流处理、PIM、可重构、多态等.这些新的体系结构从不同角度对微处理器发展中的问题提出了解决方法.概述了这些体系结构的特点,并对未来体系结构的发展趋势进行了预测.     

机动车辆装载问题的一种混合遗传算法实现*

针对货物装载地和运送目的地均已确定情况下的车辆装载问题,给出了基于遗传算法求解的数学模型,并对基本遗传算法的各个算子针对问题的特点提出了改进方法,同时引入启发式策略,形成了一种混合遗传算法.该算法的特点是各个算子都以提高算法收敛速度和解的最优性为目标,同时种群大小是动态变化的,以求在保证群体多样性的同时加快收敛速度.实验结果表明,该算法对求解此类问题是有效的.     

分布式PACS通信服务中间层构造方法研究

基于目前分布式PACS中存在的问题,提出一个通信服务中间层的构造方法,分别进行了基于设计模式通信框架的构造、DICOM图像互操作和分布式PACS可复用构件的研究.通信服务中间层的构造不仅提高了分布式PACS在网络异构环境中的可移植性、可扩展性以及相关QoS性能,还满足了PACS今后发展中提出的较高的互连互操作性的要求.     

A vacuum ultraviolet laser with a submicrometer spot for spatially resolved photoemission spectroscopy

Vacuum ultraviolet(VUV)lasers have demonstrated great potential as the light source for various spectroscopies,which,if they can be focused into a small beam spot,will not only allow investigation of mesoscopic materials and structures but also find application in the manufacture of nano-objects with excellent precision.In this work,we report the construction of a 177 nm VUV laser that can achieve a record-small(〜0.76 μm)focal spot at a long focal length(~45 mm)by using a flat lens without spherical aberration.The size of the beam spot of this VUV laser was tested using a metal grating and exfoliated graphene flakes,and we demonstrated its application in a fluorescence spectroscopy study on pure and Tm3+-doped NaYF4 microcrystals,revealing a new emission band that cannot be observed in the traditional up-conversion process.In addition,this laser system would be an ideal light source for spatially and angleresolved photoemission spectroscopy.     

真空渗流法制备泡沫铝及其动态力学性能的研究

以真空渗流法制备陶瓷中空球泡沫铝,研究了应变率对吸能量和吸能效率的影响、相对密度对屈服强度的影响,并与普通泡沫铝进行比较。结果表明,工艺简单可行,所制备的泡沫铝的动态压缩应力-应变曲线只有弹性变形区和塑性变形区;随应变率的增大,屈服强度和吸能效率变化规律不明显,吸能量增大;随相对密度的增大,屈服强度增大,吸能量增大,吸能效率也增大;动态压缩时两种泡沫铝的吸能效率均较高,最大吸能效率大于0.9,是良好的吸能材料。     

无机天线罩材料的研究进展

对高马赫数导弹天线罩材料的性能要求进行了评述，综述了国外天线罩材料的研究进展，特别是重点介绍了美国等军事强国近年来研制的天线罩材料的温度、强度、介电特性以及工艺性能。分析了我国在该领域的研究现状，并提出了今后的发展方向。     

基于鲁棒一步集的Tube不变集鲁棒模型预测控制

针对一类干扰有界的输入和状态受约束线性离散系统,提出了一种基于鲁棒一步集的Tube不 变集鲁棒模型预测控制方法.首先采用多面体不变集离线设计方法得到基于多面体不变集序列的扩 展终端约束集;然后为了扩大鲁棒模型预测控制的初始状态允许区域,并提高系统的鲁棒性,在扩展终端约束集的基础上,通过引入鲁棒一步集并借助Tube不变集控制策略,设计了基于鲁棒一步集的鲁棒模型预测控制方法,并给出了算法的存在性和稳定性证明. 该方法不仅极大地扩大了初始状态允许区域,而且对有界干扰具有有效的抑制作用,使得受扰系统收敛到以原点为中心的最小鲁棒正不变集内.最后仿真验证了算法的有效性.     

Action recognition by hidden temporal models

We focus on the recognition of human actions in uncontrolled videos that may contain complex temporal structures. It is a difficult problem because of the large intra-class variations in viewpoint, video length, motion pattern, etc. To address these difficulties, we propose a novel system in this paper that represents each action class by hidden temporal models. In this system, we represent the crucial action event per category by a video segment that covers a fixed number of frames and can move temporally within the sequences. To capture the temporal structures, the video segment is described by a temporal pyramid model. To capture large intra-class variations, multiple models are combined using Or operation to represent alternative structures. The index of model and the start frame of segment are both treated as hidden variables. We implement a learning procedure based on the latent SVM method. The proposed approach is tested on two difficult benchmarks: the Olympic Sports and HMDB51 data sets. The experimental results reveal that our system is comparable to the state-of-the-art methods in the literature.     

Fabrication of Porous SiC Ceramics with Special Morphologies by Sacrificing Template Method

Sacrificial template technique is widely used in producing porous materials with controlled morphologies and tailored properties. In this paper, unique templates such as filters, carbon nanotube, carbon fiber and silica were used to make porous SiC ceramic with special morphologies. Template derived porous ceramic plates, SiC nano-net, fiber-inverse and bead-inverse porous SiC ceramic were successfully prepared from the preceramic precursor, polymethylsilane (PMS). The synthesis procedures were involved with the infiltration of the templates with appropriate concentration of the preceramic polymer, their curing, pyrolysis and subsequent template removal. The synthesized porous SiC was characterized by SEM, TEM, XRD and BET methods.     

Beyond ubiquitous computing: The Malaysian HoneyBee project for Innovative Digital Economy

In the proposed advanced computing environment, known as the HoneyBee Platform, various computing devices using single or multiple interfaces and technologies/standards need to communicate and cooperate efficiently with a certain level of security and safety measures. These computing devices may be supported by different types of operating systems with different features and levels of security support. In order to ensure that all operations within the environment can be carried out seamlessly in an ad-hoc manner, there is a need for a common mobile platform to be developed. The purpose of this long-term project is to investigate and implement a new functional layered model of the common mobile platform with secured and trusted ensemble computing architecture for an innovative Digital Economic Environment in the Malaysian context. This mobile platform includes a lightweight operating system to provide a common virtual environment, a middleware for providing basic functionalities of routing, resource and network management, as well as to provide security, privacy and a trusted environment. A generic application programming interface is provided for application developers to access underlying resources. The aim is for the developed platform to act as the building block for an ensemble environment, upon which higher level applications could be built. Considered as the most essential project in a series of related projects towards a more digital socio-economy in Malaysia, this article presents the design of the target computational platform as well as the conceptual framework for the HoneyBee project.