Table of Content

20 September 1998, Volume 34 Issue 5

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Law of Iterated Logarithms of MLE for Non-homogeneous Poisson Processes

FANG Xiangzhong

1998, 34(5):  563-573. 

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This paper study the law of iterated logarithms of maximum likelihood estimate for general non-homogeneous Poisson processes. Suppose{N(t), t≥0} is a Poisson process on probability space{Ω, F, Pθ}, where θ=(θ₁,...,θ_m) is unknown parameter. Let θ^﹡=(θ₁^﹡,...,θ_m^﹡) be the true value of θ, θ^＾(T)=(θ₁^＾(T),...,θ_m^＾(T)) be the MLE of θ and (a_ij)_i,j=1,...,m the inverse martrix of the information matrix, then under some conditions, for any i(1≤i≤m), the following equation hold

New Characterization of Pseudo-holomorphic Curves in CPⁿ in Terms of the A_n-Toda Equations

MO Xiaohuan

1998, 34(5):  574-580. 

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The relation between solutions of the Toda equations for SU(n+1) and pseudo-holomorphicity of the harmonic surfaces in CPⁿ are given. We show that any harmonic two-spheres in CPⁿ give a solution to the A_n-Toda equations.

New Approaches of Immunity from Computer Viruses

CHEN Lijun

1998, 34(5):  581-587. 

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The concept of immunity from computer viruses is strictly defined, the function and the role of immunity in the information confrontation against computer viruses is also expounded. Two methods for immunity from viruses through enhancing the discretionary access control and setting up the protection region for the disks are offered in this article.

The Bifurcation Phenomena of Polycycle S⁽³⁾ of Hamiltonian System Under Small Perturbations

LI Baoyi,ZHANG Zhifen

1998, 34(5):  588-596. 

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By means of finitely-smooth normal form theory and the method of infinitesimal analysis, it is proved that the cyclicity of polycycle S⁽³⁾ of planar Hamiltonian system under small perturbations with certain nondegenerate condition is 3, thus the results of A.Mourtada about the cyclicity of isolated S⁽³⁾ is generalized.

Retrieval of Atmospheric Precipitable Water with GMS-5 Infrared Measurements

LI Wanbiao,LIU Yinghui,ZHU Yuanjing,ZHAO Bolin

1998, 34(5):  631-638. 

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The split window statistical method for retrieval of atmospheric precipitable water is developed by GMS-5 infrared brightness temperatures measurements. The preliminary test shows that the RMS error of the method is 0.37g.cm^-2. The precision is superior to that of GOES split window retrieval method. And it not only comes up to but also is superior to that of AVHRR split window estimations. The comparison of the monthly mean precipitable water distribution shows that the retrieval U field is in good agreement with that of the conventional radiosonde observation.

The Numerical Simulation on Dust-Storm over East Asia
II A Case Analysis

JI Fei,QIN Yu

1998, 34(5):  639-645. 

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In this paper, the dust forecasting model developed in the reference 1 has been used to simulate a dust-storm case over the East Asia. The detail characters of dust-storm outbreaking, transport and deposition have been simulated. And the temporal variation of dust concentration and influencing factors of dust-storm were analyzed.

Room Temperature Linearly Polarized Light Transmission Properties in TiO₂ Nanoclusters

WANG Dehuang,CHENG Humin,MA Jiming,LIANG Ruisheng,TANG Zhelie

1998, 34(5):  597-599. 

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The experimental results on transmission properties of linearly polarized light in TiO₂ nanoclusters at room temperature are reported. It was found that the transmission change as increasing wavelength nonlinearly varied. The measured value for band-gap wavelength is about 396nm and it is less than that for bulk crystals. The result is in conformity with the blue-shift phenomena given by the quantum-size effect.

Diabatic Waves in the Baroclinic Model

FU Zuntao,LIU Shikuo,FU Caixia

1998, 34(5):  646-655. 

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A baroclinic 2-layer model, including diabatic facter, was established to analyse the effects of diabatic factor on ultra-long waves in the tropical atmosphere. The results showed that each of diabatic facters could change the characteristics of adiabatic ultra-long waves, this could be seen in two ways: 1. the stability. 2. the propagating characteristics (including propagating direction and phase velocity). Thus, a conclusion could be obtained that low-frequency oscillation, such as intra-seasonal oscillation et al., is a kind of diabatic waves generated by diabatic factors in common. This kind of diabatic waves is an important factor to generate the long-and medium range variations and short-range climatic anomalies.

Stimulated Raman Effects in Bi-directional Transmission WDM Systems with Cascaded EDFAs

ZHANG Kan,XU Anshi,WU Deming,XIE Linzhen

1998, 34(5):  656-662. 

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SRS effects in bi-directional WDM transmission systems with cascaded EDFAs are studied in this paper. Uni-and bi-directional Systems are considered and compared. The result showed that SRS effects in a bi-directional system is equal to that of a corresponding uni-directional system if the EDFAs are symmetrically located.

Multiple Access Interference and Noise in FWM Optical Correlation Systems

ZHAO Liang,CAI Yuemin,WU Deming,XU Anshi

1998, 34(5):  663-669. 

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This paper reports our research on bipolar optical correlator using four wave mixing (FWM) effect. With analytical reduce and numerical calculation, after analysis on the multiple access interference(MAI) and other noises including amplified spontaneous emission(ASE), shot noise, receiver noise, and etc., signal to noise ratio and bit error rate are given as the evaluation of the system performance.

Adaptive CDMA Matched-filtering Receiver

CAI Yuemin,LIU Tie

1998, 34(5):  670-680. 

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This paper presents an adaptive matched-filtering receiver for DS/CDMA signals. Under MMSE criterion, the adaptive receiver converges to a conventional single user matched filter for an AWGN channel. For interference and multipath channels, the adaptive receiver achieves optimal detection by interference suppression and multipath combination. This paper presents the analytical and simulation results of the receiver in synchronous and asynchronous multi-user channels. The results show that the adaptive matched-filtering receiver is near-far resistant. By only improving the SNR of expected user, the BER can be decreased to any expected level.

A New Power Control Algorithm in CDMA System Using Fuzzy Logic

XU Dayong,LIANG Qinglin

1998, 34(5):  681-688. 

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A new power control algorithm in CDMA system is proposed in this paper, based on the analysis of the traditional algorithm's shortcoming, the parameters optimization in the fuzzy control system are considered. The simulation results show that the control precision can be improved by 0.6-1.1dB with 3-path diversity and 5 fuzzy sets distribution. The performance of the proposed algorithm under different limited word length condition are also analyzed.

A Hierarchical Model for Instructional Software Production

WANG Qiong,ZHU Wansen,YANG Fuqing

1998, 34(5):  689-693. 

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"How to raise instructional software's quality while raising its quantity" is one of the most important research topics in CAI. This article firs analysis some educational software development models at present, then proposes a hierarchical model for instructional software production. It gives the task lists of each level and the organization to make it come true.

A NC Algorithm for Graph Augmentation Problems

QU Wanling,YUAN Chongyi

1998, 34(5):  696-699. 

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k-edge connectivity augmentation problems in graph theory are bringing to more and more attention along with extensive applications of parallel computing and network technology. Early research has proved that general augmentation problems are NP-hard, but there are polynomial-time sequential algorithms for some subproblems, in which k=2 and weights of all edges in edge set of complement of graph are equal. In this paper a parallel algorithm for above subproblems running in O(log(n)) time and using O(n+m) processors on SIMD PRAM CRCW is presented.

The Yale Shooting Problem: A Case Study in Non-monotonic Reasoning

SUN Yong,FANG Ming

1998, 34(5):  700-706. 

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Non-monotonic reasoning is often used in daily life, e.g. lacking evidence to the contrary of β we infer β. This kind of logic has applications in queries to knowledge bases, very large databases and deductive bases. This case study uses the "Yale Shooting" problem to present non-monotonic reasoning from a proof-theoretic standpoint. Basic knowledge of first order logic and many-sorted algebra is assumed.

The Theory of X-Ray Pulsars

QIAO Guojun,XU Renxin

1998, 34(5):  608-620. 

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The evolution of interaction binary star has been discussed in this paper. Lipunov et al.have concluded that there is at lest one pulsar-black hole system among about 700 pulsars, hence it is on the near future that this kind of pulsar should be discovered. The periods of the X-ray pulsars are much longer than that of radio pulsars, and this long-period-problem is also introduced.

The Effect of Supercool on Liquid Phase Epitaxy Growth of III-IV Quinary AlGaInPAs

XU Ziliang,XU Wanjin,LI Li,YANG Chengqing,LIU Hongdu

1998, 34(5):  600-603. 

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The contour of the energy bandgap of III-V quinary, AlGaInPAs, lattice matched to GaAs has been calculated, and the segregation coefficient of Al in the solution used for growing AlGaInPAs/GaAs has been analysised. The effect of supercool on the solid composition of AlGaInPAs on GaAs, resulted from Al's segregating from the solution, has been demonstrated experimentally, no effect on other characteres was found.

Factorization of the Radial Schrodinger Equation of A Hydrogen Atom and Closeness of Classical Orbits

HUO Wujun,ZENG Jinyan

1998, 34(5):  604-607. 

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By using the Runge-Lenz vector and angular momentum, three kinds of raising and lowering operators(Δ(l)=±l, Δ(m)=0, ±1)conserving the energy(Δ(n)=0)are constructed. It is demonstrated that these operators are equivalent to the angular momentum raising and lowering operators(Δ(l)=±1)derived from the factorization of the radial Schrodinger equation.

The Observations of the X-ray Pulsars

QIAO Guojun,XU Renxin

1998, 34(5):  621-630. 

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The basic observations of the X-ray pulsars have been reviewed, including the binary star systems, the strong magnetic fields of neutron stars, the determination of the masses of neutron star and its company, etc. Usually, the X-ray pulsars have been found in the High Mass X-ray Binaries(HMXB), and the X-ray bursts have been found in the Low Mass X-ray Binaries(LMXB). However, as an X-ray pulsar, GRO J1744-28, discovered by the Compton (gama)-ray Observatory in the December 2(1995), acts also as an X-ray burster. This new discovery has been introduced in this paper.