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Tsinghua Science and Technology

Issue 4 • Date Dec. 1999

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

    Publication Year: 1999, Page(s): c1
    IEEE is not the copyright holder of this material | PDF file iconPDF (2671 KB)
    Freely Available from IEEE
  • Contents

    Publication Year: 1999, Page(s):1 - 2
    IEEE is not the copyright holder of this material | PDF file iconPDF (1662 KB)
    Freely Available from IEEE
  • Universal adaptive observer for nonlinear time-varying deterministic systems

    Publication Year: 1999, Page(s):1597 - 1601
    Cited by:  Papers (1)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (993 KB)

    Designing adaptive observers for MIMO nonlinear time varying deterministic systems is an open problem. In this paper a novel solution on to this problem is given by use of a “strong tracking fiIter (STF)”. First, the STF is outlined, then some technical points of view to use the STF as an adaptive observer are discussed. Finally, two typical examples are presented to illustrate the e... View full abstract»

    Open Access
  • Point pattern matching using irreducible matrix and relative invariant

    Publication Year: 1999, Page(s):1602 - 1605
    Cited by:  Papers (1)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (726 KB)

    Point pattern matching is an important problem in the fields of computer vision and pattern recognition. In this paper, new algorithms based on irredcible matrix and relative invariant for matching two sets of points with the same cardinality are proposed Thei r fundamental idea is transforming the two dimensional point sets with n points into the vectors in n-dimensional space. Considering these ... View full abstract»

    Open Access
  • A new framework for Intranet-based group decision support system

    Publication Year: 1999, Page(s):1606 - 1609
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (947 KB)

    The burgeoning Intranet is becoming a standard platform for the new generation of IS (Information System) applications. This paper gives a brief survey of Group Decision Support Systems (GDSS). Then the influence of Intranet on GDSS and limitations of Intranet as a platform for GDSS are analyzed. A new framework for Intranet based GDSS is proposed, which extends the two tier browser/server archite... View full abstract»

    Open Access
  • Fuzzy adaptive variable structure guidance with application to space interception

    Publication Year: 1999, Page(s):1610 - 1614
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (968 KB)

    The adaptive variable structure guidance (AVSG) is robust to target maneuvers, but apt to induce unwanted chattering. Fuzzy technique is used to implerrent the AVSG for eliminating chattering, and then a new guidance method called fuzzy AVSG is produced. The fuzzy AVSG is applied to the space interception problem Simulation results demonstrate the effectiveness of the new gui dance method. View full abstract»

    Open Access
  • Dynamic classifier combination method based on minimum cost criterion

    Publication Year: 1999, Page(s):1615 - 1619
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (896 KB)

    This paper presents a novel method for multi-classifier dynamic corrbinati on based on minimum cost criterion. Different from common combination methods, the proposed dynamic combination selects the most suitable group of classifiers according to the Performance Predication Feature (PPF) extracted from the input sample. PPFs are the features of sample that have great influence on the performance o... View full abstract»

    Open Access
  • Request dispatching algorithms for web server clusters based on load balancing

    Publication Year: 1999, Page(s):1620 - 1623
    Cited by:  Patents (1)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (725 KB)

    Web server clusters has become a popular solution to achieve high performance due to their low price, high reliability, and good scalability. One of the key technologies is “request dispatching”, which is to centrally accept all the incoming HTTP requests and dispatch them to the servers in the cluster to achieve parallelism The research shows that the efficiency of request dispatchi... View full abstract»

    Open Access
  • Dispersion compensation of 50 km SMF optical transmission systems with a linearly chirped fiber grating

    Publication Year: 1999, Page(s):1624 - 1627
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (629 KB)

    A linearly chi rped fiber grating was written by tilting the fiber with a uniform phase mask. A bandwidth of 0. 25 nm was produced. Dispersion compensation over 50 km of standard single mode fiber (SMF) was demonstrated using this chirped fiber grating. A figure of merit of 0.88 was achieved with near perfect recompresson. View full abstract»

    Open Access
  • Progressive failure simulation for damaged composite laminates using nonlinear finite element method

    Publication Year: 1999, Page(s):1628 - 1631
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (591 KB)

    A nonlinear finite element program taking into account of the nonlinear shear stress-strain relation is used to simulate the progressive damage of composite laminates with a circular hole subjected to tensile loading. Stress, strain, and ultimate strength of the laminate are analyzed. Comparison between calculated result and test data shows that the nonlinear approach gives more accurate result, e... View full abstract»

    Open Access
  • An integrated application of neural network, fuzzy and expert systems for machining operation sequencing

    Publication Year: 1999, Page(s):1632 - 1637
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (1117 KB)

    A part is described using features. A reuro fuzzy system then determines the machining sequerce for each feature. Previous process plans were utilized to build, test, and validate the Neuro Fuzzy Network (NFN). Parts having simlar manufacturing sequences are grouped into families, also using an NFN. A standard manufacturing sequence is obtained for each family comprising all the operations applica... View full abstract»

    Open Access
  • 233U Breeding in accelerator sub-critical fast reactor

    Publication Year: 1999, Page(s):1638 - 1641
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (671 KB)

    Accelerator driven Sub-critical Fast Reactor (ADFR) is chosen as fissile material breeding reactor. (U Pu) Ox is chosen as fuel in the core and ThO2 as fertile material in the blanket zone to breed 233U. Molten lead is chosen as coolant because of its better neutronic and chemical characteristics over sodium. The program system used for neutronics study consists of... View full abstract»

    Open Access
  • Optimal treatment cost allocation methods in pollution control

    Publication Year: 1999, Page(s):1642 - 1646
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (859 KB)

    Total emission control is an effective pollution control strategy. However, Chinese application of total emission control lacks reasonable and fair methods for optimal treatment cost allocation, a critical issue in total emission control. This paper considers four approaches to allocate treatment costs. The first approach is to set up a multiple-objective planning model and to solve the model usin... View full abstract»

    Open Access
  • Completeness of the higher order harmonics

    Publication Year: 1999, Page(s):1647 - 1651
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (846 KB)

    Applications using higher order harmonics (HOH) require knowledge of the corrpleteness of the HOH for the diffusion difference equation. This paper shows that the set of HOH for the fission source is complete, but that the set for the flux using the multi-group model is not complete. This paper uses the assumption that the set of flux vectors of HOH for every group is complete. This assumption can... View full abstract»

    Open Access
  • R&D and reliability analysis of a digital protection system for nuclear heating reactors

    Publication Year: 1999, Page(s):1652 - 1655
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (670 KB)

    This paper discusses a scheme of digital Reactor Protection System (RPS). Advanced parallel processing channels, consisting of a microprocessor based unit and a General Array Logic (GAL)-based unit have been configured in each of the redundant trains to eliminate the risk of common mode failure of digital RPSs through the way of diversified equipment. Also several digital techniques are also appli... View full abstract»

    Open Access
  • A Multi-purpose electro-heat cogeneration plant

    Publication Year: 1999, Page(s):1656 - 1660
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (3958 KB)

    In China a test heating reactor has been built and a commercial demonsration heat plant is under construction. In order to increase the thermal efficiency of the existing heating reactor, an electro-heat cogeneration plant concept is presented. The cogeneration plant keeps the advantages of the existing heating reactor: compact arrangement (smaller sizes than ordinary facility), simpler systems, g... View full abstract»

    Open Access
  • Dynamic model for the control system simulation and design of a 200 MW nuclear heating reactor

    Publication Year: 1999, Page(s):1661 - 1665
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (954 KB)

    The paper develops a nonlinear dynamc model used in a wide range control system simulation for a 200 MW Nuclear Heating Reactor (NHR 200). Besides a one point neutron kinetics equation and terrperature feedback based on the lumped fuel and coolant terrperature, which are the usual methods used in modeling of PWR, two other factors are also considered in order to suit the wide range operation. The ... View full abstract»

    Open Access
  • Licensing of the construction permit of the NHR-200

    Publication Year: 1999, Page(s):1666 - 1671
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (1162 KB)

    The nuclear heating reactor (NHR) was developed by the Institute of Nuclear Energy Technology (INET), Tsinghua University. The main design features and safety concepts of the NHR200, the criteria and principles that were followed in licensing the construction permit of the NHR 200 are discussed. Licensing activities and procedures are described. Some of the main safety licensing safety issues incl... View full abstract»

    Open Access
  • Numerical calculation of flows in turbomachinery with three dimensional viscous codes

    Publication Year: 1999, Page(s):1672 - 1677
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (1094 KB)

    A fast and accurate three dimensional (3-D) viscous code for calculating flows in turbomachinery has been established. In this code, H meshes are adopted to build the discrete equations, and the conservation equations are solved on grid nodes at the corners of cuboid elements. In order to acceler ate convergence, local time stepping, residual smoothing and multigrid method are also applied, and th... View full abstract»

    Open Access
  • Numerical investigation of a high-speed centrifugal compressor impeller

    Publication Year: 1999, Page(s):1678 - 1682
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (911 KB)

    High speed centrifuga compresrors are widely used in industry. It is important to understand its internal flow field in order to design higher efficiency and pressure ratio impellers. In this paper, a 3-D viscous code to solve the simplified Reynolds averaged Navier Stokes equations has been developed. The viscocs effect is simulated by viscous body force method. The governing equations are spatia... View full abstract»

    Open Access
  • Future applications of power plant simulators — Total plant solution system

    Publication Year: 1999, Page(s):1683 - 1687
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (1003 KB)

    Over the past three decades, power plant simulators have gone through several major phases of evolution and they have been widely used as a valuable tod for training plant operational personnel. Looking forward, the simulators will again prove their value far beyond the traditional training applications Simulators will serve as the engine of the envisioned “Total Plant Solution Sysem”... View full abstract»

    Open Access
  • Full-function numerical method for flow over a self-excited vibrating body

    Publication Year: 1999, Page(s):1688 - 1691
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (819 KB)

    This paper presents the concept of a fult-function numerical method for flow over a self excited vibrating body. It contains three dimensional (3-D) numerical analysis of unsteady aerodynamic force for a self excited vibrating body, calculation of the work done by unsteady aerodyramc force and damping, determination of the equili brium amplitude and dynamic stress as well as corresponding life eva... View full abstract»

    Open Access
  • Analysis of passivity and disturbance attenuationfor a class of power systems

    Publication Year: 1999, Page(s):1692 - 1694
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (5099 KB)

    This paper investigates the dissipative performance of a class of power systems with disturbances, when viewed from a fixed set of inputs and outputs. A passivity result is obtained for a special regulation output, and the Hamilton-Jacobi inequality is solved by means of variable-gradient approach so that the power system has finite L2-gain less than or equal to a prescribed value. View full abstract»

    Open Access
  • Observation of the metallic vapor from a plasma focus

    Publication Year: 1999, Page(s):1695 - 1697
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (789 KB)

    Although many scientists suggested that the ionized metallic vapor produced in plasma focus plays a significant role in the X-ray emission, they did not give a visual image of the metallic vapor. In this paper the evolution of plasma sheath above the anode was recorded with a laser differential interferometer and the metallic vapor produced on the target surface by bombardment of an intense electr... View full abstract»

    Open Access
  • Calculation of three dimensional electrostatic field in potential transformers

    Publication Year: 1999, Page(s):1698 - 1700
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (723 KB)

    The electrostatic field in 500 kV potential transformers has been simulated with three dimensianal (3-D) models. The main purpose of calculating the electrostatic field is to investigate the effect of electrostatic shiel ding in transformers and to see if the shielding can be removed. The conclusions are that the shielding on the middle of the winding is not clearly profitable to the maximum elect... View full abstract»

    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.

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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