By Topic

Tsinghua Science and Technology

Issue 2 • Date April 2003

Filter Results

Displaying Results 1 - 25 of 26
  • [Front cover]

    Publication Year: 2003, Page(s): c1
    IEEE is not the copyright holder of this material | PDF file iconPDF (432 KB)
    Freely Available from IEEE
  • Contents

    Publication Year: 2003, Page(s): 1
    IEEE is not the copyright holder of this material | PDF file iconPDF (250 KB)
    Freely Available from IEEE
  • Low-power CMOS VCO with dual-band local oscillating signal outputs for 5/2.5-ghz wlan transceivers

    Publication Year: 2003, Page(s):121 - 125
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (1074 KB)

    The paper describes a novel low-power CMOS voltage-controlled oscillator (VCO) with dual-band local oscillating (LO) signal outputs for 5/2.5-GHz wireless local area network (WLAN) transceivers. The VCO is based on an on-chip symmetrical spiral inductor and a differential varactor. The 2.5-GHz quadrature LO signals are generated using the injection-locked frequency divider (ILFD) technique. The IL... View full abstract»

    Open Access
  • Surface micromachining of bulk acoustic wave filters

    Publication Year: 2003, Page(s):126 - 129
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (1418 KB)

    The most common typical bulk acoustic wave (BAW) filters are fabricated using bulk micromachining technology, but they have several disadvantages. This paper describes a new structure for front end passband BAW filters manufactured using surface micromachining. Porous silicon is used as a thick sacrificial layer. The structure reduces the influence of the support film on the filter to improve the ... View full abstract»

    Open Access
  • HV/CVD grown grown relaxed SiGe buffer layers for SiGe HMOSFETs

    Publication Year: 2003, Page(s):130 - 134
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (1310 KB)

    High-vacuum/chemical-vapor deposition (HV/CVD) system was used to grow relaxed SiGe buffer layers on Si substrates. Several methods were then used to analyze the quality of the SiGe films. X-ray diffraction and Raman spectroscopy showed that the upper layer was almost fully relaxed. Second ion mass spectroscopy showed that the Ge compositions were step-graded. Transmission electron microscopy show... View full abstract»

    Open Access
  • Optimization of PZT-based radio-frequency filters

    Publication Year: 2003, Page(s):135 - 138
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (969 KB)

    Analytical solutions are presented for the wave equation for the electrode-piezoelectric-electrode sandwich structure in film bulk acoustic resonators (FBAR). The impedance for lead-zirconate-titanate (PZT)-based FBAR was derived using the proper boundary conditions and material parameters. A method is presented to adjust the resonant frequency based on the process and material properties. Ferroel... View full abstract»

    Open Access
  • Implementation of WPDL conforming workflow model

    Publication Year: 2003, Page(s):139 - 144
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (1604 KB)

    Workflow process definition language (WPDL) facilitates the transfer of workflow process definitions between separate workflow products. However, much work is still needed to transfer the specific workflow model to a WPDL conforming model. CIMFlow is a workflow management system developed by the National CIMS Engineering Research Center. This paper discusses the methods by which the CIMFlow model ... View full abstract»

    Open Access
  • Accurate parallel algorithm for adini nonconforming finite element

    Publication Year: 2003, Page(s):145 - 150
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (1172 KB)

    Multi-parameter asymptotic expansions are interesting since they justify the use of multi-parameter extrapolation which can be implemented in parallel and are well studied in many papers for the conforming finite element methods. For the nonconforming finite element methods, however, the work of the multi-parameter asymptotic expansions and extrapolation have seldom been found in the literature. T... View full abstract»

    Open Access
  • Efficient error recovery techniques in a novel multimedia streaming framework with peer-paired collaboration

    Publication Year: 2003, Page(s):151 - 155
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (1527 KB)

    Research on application-level multicast seeks to combine the merits of unicast and IP multicast while avoiding their drawbacks. Efficient error recovery in such a system is still a difficult problem. Current research is primarily focused on developing local error recovery techniques, but these techniques would not work with shared losses, which often occur in application-level multicast. This pape... View full abstract»

    Open Access
  • Robust voice command understanding and error tolerance algorithm based on word graph expansion

    Publication Year: 2003, Page(s):156 - 160
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (1111 KB)

    A novel word graph expansion algorithm for voice command understanding is presented as the basis of a more accurate and robust voice command system. Tests show that the algorithm has much better performance than the generally-adopted N-best algorithm while maintaining high computational efficiency. Also the error tolerance method used to improve the robustness of the voice command understanding mo... View full abstract»

    Open Access
  • Analog module placement design using genetic algorithm

    Publication Year: 2003, Page(s):161 - 168
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (2037 KB)

    This paper presents a novel genetic algorithm for analog module placement based on a generalization of the two-dimensional bin packing problem. The genetic encoding and operators assure that all problem constraints are always satisfied. Thus the potential problems of adding penalty terms to the cost function are eliminated so that the search configuration space is drastically decreased. The dedica... View full abstract»

    Open Access
  • Operational gesture segmentation and recognition

    Publication Year: 2003, Page(s):169 - 173
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (2351 KB)

    Gesture analysis by computer is an important part of the human computer interface (HCI) and a gesture analysis method was developed using a skin-color-based method to extract the area representing the hand in a single image with a distribution feature measurement designed to describe the hand shape in the images. A hidden Markov model (HMM) based method was used to analyze the temporal variation a... View full abstract»

    Open Access
  • MC-tree: Dynamic index structure for partially clustered multi-dimensional database

    Publication Year: 2003, Page(s):174 - 180
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (1531 KB)

    Index structure that enables efficient similarity queries in high-dimensional space is crucial for many applications. This paper discusses the indexing problem in dataset composed of partially clustered data, which exists in many applications. Current index methods are inefficient with partially clustered datasets. The dynamic and adaptive index structure presented here, called a multi-cluster tre... View full abstract»

    Open Access
  • Rough class on a completely distributive lattice

    Publication Year: 2003, Page(s):181 - 184
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (907 KB)

    This paper generalizes the Pawlak rough set method to a completely distributive lattice. The concept of a rough set has many applications in data mining. The approximation operators on a completely distributive lattice are studied, the rough class on a completely distributive lattice is defined and the expressional theorems of the rough class are proven. These expressional theorems are used to pro... View full abstract»

    Open Access
  • Congestion control algorithm for resilient packet ring

    Publication Year: 2003, Page(s):185 - 191
    Cited by:  Papers (1)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (1570 KB)

    A congestion control algorithm is proposed for resilient packet ring (RPR) in this paper. In this algorithm, nonlinear explicit rate feedback control is used to ensure fast convergence and smooth equilibrium behavior. The algorithm combines explicit rate control with a deficit round robin (ORR) scheduler, which not only ensures fairness, but also avoids the implementation difficulties of explicit ... View full abstract»

    Open Access
  • Conceptual framework and curriculum for networked agile manufacturing

    Publication Year: 2003, Page(s):192 - 197
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (1272 KB)

    Networked agile manufacturing (NAM) is a new manufacturing paradigm for the 21st century. Manufacturing businesses based on NAM are characterized by virtual organization, innovation, global sourcing of materials and production centered on the workforce. Therefore, NAM requires a knowledgeable, motivated workforce. This paper reviews the literature related to developing an NAM curriculum to: (1) re... View full abstract»

    Open Access
  • Cryptanalysis and improvement of piveteau signature scheme with message recovery

    Publication Year: 2003, Page(s):198 - 200
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (767 KB)

    Piveteau signature scheme allows message recovery but the methodology differs from that of the Nyberg-Rueppel schemes. This paper analyzes the security of the Piveteau scheme by designing some attacks. Two improved methods to Piveteau signature scheme and Nyberg-Rueppel schemes were developed to avoid these weaknesses. Analyses of the security of the improved schemes prove that the improved method... View full abstract»

    Open Access
  • Aerostatic stability of long-span cable-stayed bridges: Parametric study

    Publication Year: 2003, Page(s):201 - 205
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (1040 KB)

    The increasing span of cable-stayed bridges has focused more attention on the aerostatic stability of the design and construction of such bridges. This paper presents a new method to analyze the nonlinear aerostatic stability of cable-stayed bridges including all three components of the wind load and the geometric nonlinearity. The analysis was used to investigate the effects of the wind angle of ... View full abstract»

    Open Access
  • Triangular differential quadrature for bending analysis of reissner plates with curved boundaries

    Publication Year: 2003, Page(s):206 - 214
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (1664 KB)

    The recently proposed concept of the triangular differential quadrature method (TDQM) is applied to the bending analysis of Reissner plates with various curvilinear geometries subjected to various combinations of boundary conditions. A unit isosceles right triangle is used as the standard triangle for all the derivatives expressed using the triangular differential quadrature rule. Geometric transf... View full abstract»

    Open Access
  • MECHANICAL ENGINEERING 
  • Vorticity measurements using a 6-sensor hot-wire probe in a tangentially fired furnace

    Publication Year: 2003, Page(s):215 - 223
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (2055 KB)

    Vorticity, which represents the rotation of a fluid element, is an important characteristic of turbulence. Various methods have been used to measure vorticity. A hot-wire/hot-film anemometer (HWA) was used here to measure the vorticity in turbulent flows. The velocity components and their partial derivatives were simultaneously measured with a new 6-sensor hot-wire (HW) probe assuming ideal yaw an... View full abstract»

    Open Access
  • Modeling and control of active susnensions for MDOF vehicle

    Publication Year: 2003, Page(s):224 - 230
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (997 KB)

    The conventional method for analyzing active suspension control for a vehicle is only to analyze a quarter or half car with a lower order degree-of-freedom (DOF) model, but such models do not actually model practical applications. Accurate models of a suspension control system require a multi-degree-of-freedom (MDOF) vehicle model with a detailed model of the controller. An MDOF model was develope... View full abstract»

    Open Access
  • Reduction method for reachability analysis of Petri nets

    Publication Year: 2003, Page(s):231 - 235
    Cited by:  Papers (16)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (878 KB)

    Reachability analysis is an important approach for acquiring Petri net (PN) properties. The reachability tree and the solution of the state equation are two commonly used methods for reachability analysis. but they can result in state explosion and spurious solutions in some cases. As a significant complementary method. the PN reduction technique simplifies the reachability analysis by reducing th... View full abstract»

    Open Access
  • MECHANICAL ENGINEERING 
  • Laser texturing of rolled surfaces

    Publication Year: 2003, Page(s):236 - 240
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (1509 KB)

    To reduce friction and improve clarity of steel surfaces. laser texturing was used to produce known surface roughness profile on rolled surfaces using a Nd:YAG laser. Laser texturing process was analyzed to select the laser parameters. The surface roughness hardness and abrasion resistance were then measured and analyzed. The results show that the surface roughness is harder than the matrix, which... View full abstract»

    Open Access
  • Carbon nanometer tube threads

    Publication Year: 2003, Page(s): 125
    IEEE is not the copyright holder of this material | PDF file iconPDF (292 KB)
    Open Access
  • Highlight of 2002 at tsinghum university

    Publication Year: 2003, Page(s): 191
    IEEE is not the copyright holder of this material | PDF file iconPDF (347 KB)
    Open Access

Aims & Scope

Tsinghua Science and Technology (Tsinghua Sci Technol) aims to highlight scientific achievements in computer science, electronic engineering, and other IT fields. Contributions all over the world are welcome.

Full Aims & Scope

Meet Our Editors

Editor-in-Chief
Professor Jiaguang Sun
School of Software
Tsinghua University
Beijing  100084 China
journal@tsinghua.edu.cn
Phone:86-10-62771385