Resource Space Grid: model,method and platform

A Resource Space Grid is a virtual Grid that aims at effectively sharing, using and managing versatile resources across the Internet. The kernel of the Resource Space Grid includes a Resource Space Model (RSM) and a uniform Resource Using Mechanism (RUM). This paper presents the Resource Space Grid's core scientific issues and methodology, architecture, model and theory, design criteria and method, and practice. A normal form theory is proposed to normalize the resource space—a coordinate system for uniformly specifying and organizing resources. The RUM provides not only the end‐users with an operable resource browser to operate resources using the built‐in Resource Operation Language (ROL), but also the application developers with the ROL‐based programming environment. The prototype platform based on the proposed model and method has been implemented and used for sharing and managing resources in distributed research teams. Operations on Resource Spaces can constitute the virtual communities of Resource Space Grids—a platform independent resource sharing environment. Copyright © 2004 John Wiley & Sons, Ltd.     

立体视觉测量系统的三维空间重构

】三维空间重构是立体视觉测量系统工作过程中十分重要的一部分。在本文所提出的三维空间重构方法中,摄象机模型所含参数的物理意义明确,考虑了镜头的畸变,算法简单,计算量小。实验证明：这种三维空间重构方法是可行的。     

驾驶员座椅半主动空气悬架系统振动特性实验研究

构建了座椅半主动悬架振动特性测试实验系统,将带附加气室的空气弹簧、比例流量阀及磁流变减振器同时应用于座椅悬架,通过控制比例流量阀输入电压和磁流变减振器输入电流调节座椅悬架系统的刚度和阻尼,对不同参变量下座椅悬架系统的振动特性进行了实验研究。研究结果表明,在共振区,比例阀输入电压和磁流变输入电流的变化对系统位移传递率和加速度均方根值影响较大,而在低频振动区和隔振区影响较小;比例阀电压的增大可以降低系统的共振频率,磁流变电流的增大可以减小系统在共振区的位移传递率和加速度均方根值。     

可见光与红外图像融合质量评价指标分析

目的 客观评价作为图像融合的重要研究领域,是评价融合算法性能的有力工具。目前,已有几十种不同类型的评价指标,但各应用领域包括可见光与红外图像融合,仍缺少统一的选择依据。为了方便比较不同融合算法性能,提出一种客观评价指标的通用分析方法并应用于可见光与红外图像融合。方法 将可见光与红外图像基准数据集中的客观评价指标分为两类,分别是基于融合图像的评价指标与基于源图像和融合图像的评价指标。采用Kendall相关系数分析融合指标间的相关性,聚类得到指标分组;采用Borda计数排序法统计算法的综合排序,分析单一指标排序和综合排序的相关性,得到一致性较高的指标集合;采用离散系数分析指标均值随不同算法的波动程度,选择充分体现不同算法间差异的指标;综合相关性分析、一致性分析及离散系数分析,总结具有代表性的建议指标集合。结果 在13对彩色可见光与红外和8对灰度可见光与红外两组图像源中,分别统计分析不同图像融合算法的客观评价数据,得到可见光与红外图像融合的建议指标集(标准差、边缘保持度),作为融合算法性能评估的重要参考。相较于现有方法,实验覆盖20种融合算法和13种客观评价指标,并且不依赖主观评价结果。结论...     

Analysis and Implementation of an Open Programmable Router Based on Forwarding and Control Element Separation

A router architecture based upon ForCES (Forwarding and Control Element Separation), which is being standardized by IETF ForCES working group, gains its competitive advantage over traditional router architectures in flexibility, programmability, and cost-effectiveness. In this paper, design and implementation of a ForCES-based router (ForTER) is illustrated. Firstly, the implementation architecture of ForTER is discussed. Then, a layered software model, which well illustrates ForCES features, is proposed. Based on the model, design and implementation of Control Element (CE) and Forwarding Element (FE) in ForTER are introduced in detail. Moreover, security for ForTER is considered and an algorithm to prevent DoS attacks is presented. Lastly, experiments of ForTER are illustrated for routing and running routing protocols, network management, DoS attack prevention, etc. The experimental results show the feasibility of the ForTER design. Consequently, the ForTER implementation basically testifies the feasibility of ForCES architecture and some IETF ForCES specifications.     

High-Performance Si Nanowire Transistors on Fully Si Bulk Substrate From Top-Down Approach: Simulation and Fabrication

A new method to fabricate high-performance gate-all-around silicon (Si) nanowire transistors (SNWTs) based on fully Si bulk (FSB) substrate is proposed and demonstrated by both simulation and experiments in this paper. Due to the large fan-out and deep junction of Si source/drain (S/D) region connecting with the bulk substrate, the FSB SNWTs can effectively alleviate the self-heating effects with technology scaling. Thermal behavior of multiwire SNWTs is investigated and FSB SNWTs show superior self-heating immunity to SNWTs based on Si-on-insulator (SOI) substrate (SOI SNWTs). In addition, the bottom parasitic transistor can be well suppressed in this structure. Although FSB SNWTs have larger gate parasitic capacitance, the CV/ $I$ is found to be comparable to the SOI SNWTs. With self-aligned, fully epi-free compatible CMOS processes, this new architecture was successfully fabricated, which exhibit high on–off current ratio of $hbox{2.6} times hbox{10}^{8}$ due to better heat dissipation and low S/D resistance realized in this structure.      

Fire performance of composite laminates embedded with multi-ply carbon nanofiber sheets

In this study, free-standing carbon nanofiber sheets (CNS) were incorporated into glass fiber reinforced polyester composites through resin transfer molding (RTM) process. These sheets were made of vapor grown carbon nanofibers. The composite laminates consisted of eight plies of CNS and eight plies of glass fiber mats. The fire retarding performance of the laminates was evaluated with cone calorimeter tests with an external radiated heat flux of $50\text{kW}/{\text{m}}^2$. The test results indicated that there was significant improvement in the fire retardancy of composite laminates due to the incorporation of CNS. It was found that the CNS plies survived the test except the one on the top surface of the laminates. The formation of compact char materials was observed on the surface of the CNS residues. The improvement in fire retarding performance was achieved through the barrier and insulator effects of the CNS and charred materials by restricting the migration of flammable products to the top surface of the laminates and preventing the transmission of external heat to the underlying polyester resin.     

Structural and magnetic properties of transition metal doped ZnO films

Structural and magnetic properties have been studied for polycrystalline Zn_1 − xTM_xO films where transition metal (TM) = Fe, Cr. The Zn_1 − xTM_xO films were prepared by the radio frequency magnetron sputtering technique on Al₂O₃ (001) substrates. The microstructures of the films are characterized by X-ray diffraction and X-ray photoelectron spectroscopy. TM in the films exists mainly in the form of TM²⁺, and the TM²⁺ ions have substituted for the Zn²⁺ ions bonded in TM-O in the ZnO lattice and do not change the wurtzite structure of ZnO. The result of magnetic measurement shows that the Zn_1 − xTM_xO films are ferromagnetic at 5 K and 300 K respectively. Subsequently, we discuss the origin of the ferromagnetism in the films.     

Three-dimensional near-field MIMO array imaging using range migration techniques

This paper presents a 3-D near-field imaging algorithm that is formulated for 2-D wideband multiple-input-multiple-output (MIMO) imaging array topology. The proposed MIMO range migration technique performs the image reconstruction procedure in the frequency-wavenumber domain. The algorithm is able to completely compensate the curvature of the wavefront in the near-field through a specifically defined interpolation process and provides extremely high computational efficiency by the application of the fast Fourier transform. The implementation aspects of the algorithm and the sampling criteria of a MIMO aperture are discussed. The image reconstruction performance and computational efficiency of the algorithm are demonstrated both with numerical simulations and measurements using 2-D MIMO arrays. Real-time 3-D near-field imaging can be achieved with a real-aperture array by applying the proposed MIMO range migration techniques.     

Isolation and sequence analysis of the gene URA3 encoding the orotidine-5'-phosphate decarboxylase from Candida glycerinogenes WL2002-5, an industrial glycerol producer

The URA3 gene of Candida glycerinogenes WL2002-5, an industrial glycerol producer encoding orotidine-5'-phosphate decarboxylase enzyme, was isolated by complementation cloning in Saccharomyces cerevisiae. DNA sequence analysis revealed the presence of an open reading frame (ORF) of 786 bp, encoding a 262 amino acid protein, which shares 71.65% amino acid sequence similarity to the S. cerevisiae URA3 protein. Furthermore, the cloned ORF fully complemented the ura3 mutation of S. cerevisiae, confirming that it encodes for the C. glycerinogenes Ura3 (CgUra3) protein.