# Tsinghua Science and Technology

## Filter Results

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

Publication Year: 2001, Page(s): c1
| |PDF (2066 KB)
• ### Contents

Publication Year: 2001, Page(s): 1
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• ### Editor of science visits the editorial board of journal of Tsinghua university (Sci. & Tech.)

Publication Year: 2001, Page(s): 325
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• ### Tsinghua-1 Micro-satellite power system architecture and design

Publication Year: 2001, Page(s):289 - 293
Cited by:  Papers (1)
| |PDF (847 KB)

The Tsinghua-1 Micro-satellite, the first satellite made by Tsinghua University, was launched in 2000. The power system of the Tsinghua-1 Micro-satellite is one of the most important subsystems. It provides all the power for the satellite platform and the payloads. The power system design includes the regulation, protection and distribution of a 4 × 35 W solar array and 7 Ah NiCd batteries.... View full abstract»

• ### Fuzzy control method with application for functional neuromuscular stimulation system

Publication Year: 2001, Page(s):294 - 297
Cited by:  Papers (1)
| |PDF (818 KB)

A fuzzy control technique is applied to a functional neuromuscular stimulation (FNS) physical multiarticular muscle control system. The FNS multiarticular muscle control system based on the fuzzy controller was developed with the fuzzy control rule base. Simulation experiments were then conducted for the joint angle trajectories of both the elbow flexion and the wrist flexion usi ng the proposed f... View full abstract»

• ### Microminiature inertial measurement system and its applications

Publication Year: 2001, Page(s):298 - 303
| |PDF (1012 KB)

The microminiature inertial measurement system, a new style of inertial measurement system, has many advantages compared with traditional systems, such as small size, low mass, low cost, low power consumption, high bearing capacity, and long life. Undoubtedly, it will have wide applications in military and commercial fields. However, current micro inertial sensors do not have sufficient accuracy, ... View full abstract»

• ### Key problems of mechanically dithered system of RLG

Publication Year: 2001, Page(s):304 - 309
| |PDF (1006 KB)

Mechanical dither is widely applied to reduce lock-in of the ring laser gyroscope(RLG) based on the principle proposed by Sagnac in 1913. This article reviews recent developments in the field for the optimal design of the dither mechanism that decides the effect of bias to some extent. The proper dither signal and its control directly influence dither efficiercy. Stable and accurate error compensa... View full abstract»

• ### Interfacial evaporation of falling liquid films with wall heating

Publication Year: 2001, Page(s):310 - 313
| |PDF (7839 KB)

The interfacial evaporation of falling water films with wall heating was experimentally studied and analyzed. The results presented in this paper showed that the capillary-induced interfacial evaporation played an important role in heat transfer of a falling liquid film. It would be independent of the wall heat flux and somewhat lower than that without wall heating for impure fluids such as water-... View full abstract»

• ### Modeling of sulfur retention in circulating fluidized bed coal combustors

Publication Year: 2001, Page(s):314 - 318
| |PDF (980 KB)

A comprehensive model for predicting the sulfur retention performance in circulating fluidized bed combustors was developed which involves the different residence times, the wide particle size distribution and the different forms of sulfur in the coal. In addition, the reductive decomposition of CaSO4 is highlighted. The simulation results from the model show that the sulfur contents, t... View full abstract»

• ### Comprehensive mathematical model for coal combustion in a circulating fluidized bed combustor

Publication Year: 2001, Page(s):319 - 325
| |PDF (1111 KB)

Char combustion is on a special reducing condition in the dense bed of a circulating fluidized bed combustor. Experimental findings were used to develop a comprehensive mathematical model to simulate the hydrodynamic and combustion processes in a circulating fluidized bed combustor. In the model, gas-solid interaction was used to account for the mass transfer between the bubble phase and the emuls... View full abstract»

• ### Shakedown and limit analysis of defective pressure vessels

Publication Year: 2001, Page(s):326 - 330
| |PDF (934 KB)

This paper presents a failure analysis of pressure vessels with defects by a direct method of limit and shake down analysis. The defects considered are part-through slots with various geometric configurations. The engineering situation considered here has practical importance in the pressure vessel industry. The results are compared with those obtained by a step-by-step procedure using the profess... View full abstract»

• ### One-dimensional simulation of the pressure wave near the exit of a high-speed train tunnel

Publication Year: 2001, Page(s):331 - 334
| |PDF (783 KB)

The one-dimensional (1-D) unsteady flow induced by a high-speed train entering a tunnel is numerically studied by the method of characteristics. The tube area is dependent on time and distance. The energy equation used by Kage et al is corrected to avoid the conflict with the isentropic assumption. The effect of the tunnel hood on the pressure wave is studied near the tunnel exit Results show that... View full abstract»

• ### Nonlinear vibration of rotor rubbing stator caused by initial perturbation

Publication Year: 2001, Page(s):335 - 339
| |PDF (784 KB)

The vibration of a rotor rubbing a stator caused by an initial perturbation was studied analytically. The analytical model consists of a simple disc-shaft rotor and a fixed stator. The perturbation is an instantaneous change of the radial velocity when the rotor is operating in its normal steady state. The analysis showed that the rotor may continue rubbing the stator for small clearance, even if ... View full abstract»

• ### Computation of load flow problems with homotopy methods

Publication Year: 2001, Page(s):340 - 343
| |PDF (1049 KB)

Load flow comptations are the basis for voltage security assessments in power systems. All of the flow equation solutions must be computed to explore the mechanisms of voltage instability and voltage collapse. Conventional algorithms, such as Newton's methods and its variations, are not very desirable because they cannot be easily used to find all of the solutions. This paper investigate homotopy ... View full abstract»

• ### Isometric spacelike immersions of space forms in indefinite space forms

Publication Year: 2001, Page(s):344 - 346
| |PDF (765 KB)

Let M be a connected n-dimensional space form spacelike isometrically immersed in a (2n −1) dimensional indefinite space form. If M is maximal, we prove that either M is totally geodesic or M is a piece of the n-dimensional hyperbolic cylinder in the (2n −1)-dimensionaal pseudo-hyperbolic space. View full abstract»

• ### Isometry between two indefinite metrics

Publication Year: 2001, Page(s):347 - 349
| |PDF (575 KB)

This paper solves the isometry problem between two indefinite metrics by using exterior differential systems. We prove that an indefinite metric is either rigid, admits a one-parameter group of isometries (rotation-ike surfaces), or admits a three parameter group of isometries (K = constant). View full abstract»

• MATHEMATICAL SCIENCE
• ### Spectral radius of hamiltonian planar graphs and outerplanar graphs

Publication Year: 2001, Page(s):350 - 354
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The spectral radius is an important parameter of a graph related to networks. A method for estimating the spectral radius of each spanning subgraph is used to prove that the spectral radius of a Hamiltonian planar graph of order n ≥ 4 is less than or equal to $2 +quad overline{3n-11}$ and the spectral radius of the outer planar graph of order n ≥ 6 is less than or equal to... View full abstract»

• ### A new implementation of the post-stage tasks of motion estimation timation using SIMD architecture

Publication Year: 2001, Page(s):355 - 360
| |PDF (1172 KB)

Usually a single MPEG2 video ercoder chip realizes the multiple post-stage tasks of motion estimation, such as motion vector refinement and prediction error generation, using multiple hardware modules. This paper proposes a new architecture using only a single module to implement the post-stage tasks of motion estimation, which has a single instruction stream over multiple data streams (SIMD). The... View full abstract»

• ### Efficient and low-latency systolic array architecture for full searches in block-matching motion estimation

Publication Year: 2001, Page(s):361 - 368
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This paper describes an efficient, low-latency systolic array architecture for full searches in block-matching motion estimation. Conventional one-dimensional systolic array architecture is used to develop a novel ring-like systolic array architecture through operator rescheduling considering the symmetry of the data flow. High-latency delay due to stuffing of the array pipeline in the conventiona... View full abstract»

• ### Chinese speech recognition model based on activation of the state feedback neural network

Publication Year: 2001, Page(s):369 - 373
| |PDF (817 KB)

This paper proposes a simplified novel speech recognition model, the state feedback neural network activation model (SFNNAM), which is developed based on the characteristics of Chinese speech structure. The model assumes that the current state of speech is only a correction of the last previous state. According to the C-V (Consonant-Vowel) structure of the Chinese language, a speech segmentation m... View full abstract»

• ### Multi-band UV decision making method based on LPC analysis

Publication Year: 2001, Page(s):374 - 376
| |PDF (656 KB)

A simple ultraviolet (UV) decision making method using sub-bands can greatly reduce the computational complexity and the memory requirements in the MBE-LPC algorithm and can reduce the difficulties in DSP real-time fixed-point in Plementation and integrated circuit chips. The frequency waveform of each sub-band of the linear-prediction coding (LPC) residue is used to calculate the autocorrelation ... View full abstract»

• ### A scalable data-distributed algorithm for volume rendering on parallel virtual machines

Publication Year: 2001, Page(s):377 - 382
| |PDF (1281 KB)

An algorithm is presented for volume rendering in environments of parallel virtual machines. To reduce the communication cost, as well as to guarantee the locality of all subtasks, the volume data is divided into and organized as a series of slices. The task subdivision algorithm produces acceptable load balancing by maintaining and employing a database of performance indices. An asynchronous bina... View full abstract»

• ### Road identification for anti-lock brake systems equipped with only wheel speed sensors

Publication Year: 2001, Page(s):383 - 385
Cited by:  Patents (2)
| |PDF (520 KB)

Anti-Lock brake systems (ABS) are now widely used on motor vehicles. To reduce product cost and to use currently available technologies, standard ABS uses only wheel speed sensors to detect wheel angular velocities, which is not enough to directly obtain wheel slip ratios needed by the contrd unit, but can be used to calculate reference slip ratios with measured wheel angular velocities and the es... View full abstract»

• ### Replacement policy for caching World-Wide Web documents based on site-graph model

Publication Year: 2001, Page(s):386 - 390
Cited by:  Papers (1)
| |PDF (947 KB)

The hit rate, a major metric for evaluating proxy caches, is mostly limited by the replacement strategy of proxy caches. However, in traditional proxy caches, the hit rate does not usually successfully predict how well a proxy cache will perform because the proxy cache counts any hit in its caching space which has many pages without useful information, so its replacement strategy fails to determin... View full abstract»

• ### Agile information system supporting virtual enterprise operation

Publication Year: 2001, Page(s):391 - 395
| |PDF (1134 KB)

Dynamic collaboration is a relationship of companies working together formutual benefit to bring a complementary set of competencies to gain a market opportunity. A mechanism to manage and control information flow among collaborating partners is described in this paper Analysis of the virtual infomation system requirements was used to develop an agile manufacturing infomation system (AMIS) to crea... View full abstract»

## 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