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# Tsinghua Science and Technology

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Displaying Results 1 - 21 of 21
• ### [Front cover]

Publication Year: 2004, Page(s): c1
| PDF (162 KB)
• ### Contents

Publication Year: 2004, Page(s): 1
| PDF (90 KB)
• ### Challenge and methods of synchronous disk I/O

Publication Year: 2004, Page(s):1 - 8
| | PDF (327 KB)

At present, I/O is the performance bottleneck limiting the speed of computer systems. A large number of I/O operations are synchronous readlwrite operations of only small data blocks. However, reducing the latency of synchronous I/O operation is a non-trivial problem. In this paper, we propose two methods to address this problem. The first method, FastSync, uses a cache disk optimized for write op... View full abstract»

• ### Use of global behavior tree for conformance testing of OSPF protocol LSDB synchronization

Publication Year: 2004, Page(s):9 - 16
| | PDF (305 KB)

Protocol formalization is one of a class of hard problems in testing routing protocols and characterized by dynamic, concurrent and distributed behavior. For the purpose of performing conformance testing of the open shortest path first protocol link-state database (LSDB) synchronization process, the authors propose a formal model called global behavior tree, which describes global interactions amo... View full abstract»

• ### Elastic wave propagation simulation in heterogeneous anisotropic media on non-uniform grids

Publication Year: 2004, Page(s):17 - 23
| | PDF (586 KB)

A finite-difference method with spatially non-uniform grids was developed to simulate elastic wave propagation in heterogeneous anisotropic media. The method is very simple and requires less compution time. Complicated geometric structures, such as low-velocity layers, cased boreholes and nonplanar interfaces, are treated with fine non-uniform grids. Unlike the multi-grid scheme, this method does ... View full abstract»

• ### Wavelet neural networks for adaptive equalization by using the orthogonal least square algorithm

Publication Year: 2004, Page(s):24 - 29
| | PDF (309 KB)

Equalizers are widely used in digital communication systems for corrupted or time varying channels. To overcome performance decline for noisy and nonlinear channels, many kinds of neural network models have been used in nonlinear equalization. In this paper, we propose a new nonlinear channel equalization, which is structured by wavelet neural networks. The orthogonal least square algorithm is app... View full abstract»

• ### High-performance broadcasting algorithms on cluster

Publication Year: 2004, Page(s):30 - 37
| | PDF (380 KB)

In many clusters connected by high-speed communication networks, the exact structure of the underlying communication network and the latency difference between different sending and receiving pairs may be ignored when they broadcast, such as in the approach adopted by the broadcasting method in MPICH, a widely used MPI implementation. However, the underlying network cluster topologies are becoming... View full abstract»

• ### Single-user blind channel equalization using modified constant modulus algorithm

Publication Year: 2004, Page(s):38 - 44
| | PDF (433 KB)

A modified constant modulus algorithm (MCMA) for blind channel equalization is proposed by modifying the constant modulus error function. The MCMA is compared with the conventional constant modulus algorithm (CMA) for symbol-spaced equalization of 4PSK signals. The result shows that the performance of the MCMA is superior to that of the CMA in both convergence rate and intersymbol interference for... View full abstract»

• ### Reducing inconsistent rules based on irregular decision table

Publication Year: 2004, Page(s):45 - 50
| | PDF (268 KB)

In this paper, we study the problem of rule extraction from data sets using the rough set method. For inconsistent rules due to improper selection of split-points during discretization, and/or to lack of information, we propose two methods to remove their inconsistency based on irregular decision tables. By using these methods, inconsistent rules are eliminated as far as possible, without affectin... View full abstract»

• ### Stability and accuracy analysis for Taylor series numerical method

Publication Year: 2004, Page(s):51 - 56
| | PDF (341 KB)

The Taylor series numerical method (TSNM) is a time integration method for solving problems in structural dynamics. In this paper, a detailed analysis of the stability behavior and accuracy characteristics of this method is given. It is proven by a spectral decomposition method that TSNM is conditionally stable and belongs to the category of explicit time integration methods. By a similar analysis... View full abstract»

• ### Large eddy simulation of particle-laden turbulent flow over a backward-facing step

Publication Year: 2004, Page(s):57 - 63
| | PDF (646 KB)

Particle diffusion in large eddy structures with various Stokes number was analyzed numerically for the two-dimensional gas-particle turbulent flow over a backward-facing step. The continuous phase simulation was analyzed using the large eddy simulation (LES) method while the particle phase was analyzed by the Lagrangian method. The spatial and temporal results were used to analyze the evolution o... View full abstract»

• ### Effect of new O-superfamily conotoxin on voltage-activated currents of hippocampal neurons

Publication Year: 2004, Page(s):64 - 68
| | PDF (323 KB)

The effects of a new O-superfamily conotoxin, S03, on sodium current (INa), transient A-type potassium currents (IA), and delayed rectified potassium currents (IK), were examined in cultured rat hippocampal neurons using the whole-cell patch clamp technique. Addition of S03 caused a concentration-dependent, rapidly developing, and reversible inhibition of voltage-a... View full abstract»

• ### Contributions of DPOR at low light intensity to chlorophyll biosynthesis and growth in the Synechocystis sp. PCC 6803

Publication Year: 2004, Page(s):69 - 75
| | PDF (329 KB)

The chlL gene encoding one component of light-independent (dark) protochlorophyllide oxido reductase (DPOR) was deleted in cyanobacterium Synechocystis sp. PCC 6803 (S.6803). The resulting chlL mutant lost DPOR activity. No significant differences of chlorophyll (Chi) content and growth rate were observed between the wild and the mutant strains grown at 50 μE · m... View full abstract»

• ### Low temperature induced conformation changes of aminoacylase

Publication Year: 2004, Page(s):76 - 80
| | PDF (310 KB)

Control of aggregation, by lowering temperature and protein concentrations, can enhance the extent of successful refolding. The low temperature has been used in protein folding studies, as undesired aggregations often occur at higher temperatures. Therefore, it is very important to study the effects of low temperature on the native enzyme to help understand the factors that affect the structure of... View full abstract»

• ### Electroporation transfection as an effective tool to trace transplanted NSCs in adult central nervous system

Publication Year: 2004, Page(s):81 - 87
| | PDF (782 KB)

Neural stem cells, which are clonogenic cells with self-renewal and multilineage differentiation properties, are currently considered as powerful candidates for cell replacement therapy in neurodegenerative disorders such as Parkinson's disease. A key issue is whether stem cells can survive, migrate and differentiate following transplantation into the adult central nervous system. This research sh... View full abstract»

• ### Apoptosis induced by high concentrations of nicotinamide in tobacco suspension cells

Publication Year: 2004, Page(s):88 - 93
| | PDF (493 KB)

As an inhibitor of poly(ADP-ribose) polymerase (PARP), nicotinamide has a restraining effect on apoptosis at certain low concentrations. In our present study, apoptosis induced by high concentrations of nicotinamide was observed in tobacco suspension cells. When cells were preincubated with 250 mmol/L nicotinamide for 24 h, the hallmarks of apoptosis were detected, including DNA fragments increasi... View full abstract»

• ### Kinetics of inhibition of polyphenol oxidase obtained from tobacco nicotiana tobacum

Publication Year: 2004, Page(s):94 - 97
| | PDF (279 KB)

In this study, the kinetics of inhibition of polyphenol oxidase by L-cysteine has been investigated. The inhibition of tobacco polyphenol oxidase was studied using the progress-of-substrate-reaction method proposed by Tsou, following the substrate reaction during irreversible inhibition of the enzyme activity. Analysis of the inhibition kinetics shows that inhibition occurs by an irreversible and ... View full abstract»

• ### Exploring codon usage patterns of alternatively spliced genes in human chromosome 1

Publication Year: 2004, Page(s):98 - 107
| | PDF (345 KB)

In this study, 414 whole protein-coding sequences (238 004 codons) of alternatively spliced genes of human chromosome 1 have been employed to explore the patterns of codon usage bias among genes. Overall codon usage data analysis indicates that G- and C-ending codons are predominant in the genes. The base usage in all three codon positions suggests a selection-mutation balance. Multivariate statis... View full abstract»

• ### Applied ecotechnical research on lübao slow-release water-fertilizer-nutrition agent

Publication Year: 2004, Page(s):108 - 115
| | PDF (260 KB)

Lubao slow-release water-fertilizer-nutrition agent (LSWA) is a new and proven highly effective soil additive. This nutrient absorbent polymer dramatically conserves water and reduces fertilizer usage while significantly increasing plant and crop yield. There are numerous benefits that LSWA is engineered to produce, and moreover, with every new application new benefits are discovered. The versatil... View full abstract»

• MATHEMATICS
• ### Quasi-conformally flat submanifolds with parallel mean curvature vector

Publication Year: 2004, Page(s):116 - 120
| | PDF (294 KB)

This paper studied the conditions such that an n-dimensional complete space-like submanifold M with a parallel mean curvature vector field in an indefinite space form Sn+p (c)(p ≥ 2, n≥ 3) is a totally umbilical submanifold. By means of Laplacian estimation and the choice of a diagonal frame field, the following theorem is proved: if Mis quasi-conformally flat and H... View full abstract»

• ### Julia sets of skew products for class MAp

Publication Year: 2004, Page(s):121 - 124
| | PDF (312 KB)

Let fj∊M (j = 1,2,…, m; m≥1 and $tilde{f}$ be the skew product associated with the generator system ${f_{1}, f_{2}, ldots, f_{m}}. Then$F(tilde{f})$is completely invariant under$(tilde{f});J(tilde{f})$is completely invariant under$tilde{f}; J(tilde{f})$is perfect;$J(tilde{f})\$ has interi... 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