Abstract:The method of differential cipher analysis was presented by E. biham and A. Shamir in 1990. It constitutes a realistic threat to DES and DES-like systems. This paper deeply analyzes its principles and presents seven methods to improve the performance of DES. It is then possible for DES to prevent the attack of differential cipher analysis.

Abstract:This paper discusses a method of 86S-box design which considers the diffusibility and the homogeneity. It also gives the flow scheme of the program and the demonstration of nonlinear intensity and radomization.

Abstract:This paper introduces the location principle and a tracking algorithm WMEKF (Weighted Modified Extended Kalman Filter) for bistatic radar systems with an independent receiver. An adaptive tracking algorithm AWMEKF (Adaptive WMEKF) of maneuvering targets is proposed in the paper. Its tracking performance for typical maneuvering target paths is evaluated by means of computer simulation.

Abstract:In this paper.a kind of waveguide Gunn effect oscillator at 1.25cm is discussed. Its main cavity uses the structure of adjustable coaxial height reduced waveguide. This makes the circuit match the diode well. The paper puts stress on discussing the influence of the size of each part on the characteristic of the oscillator. High Q H₀₁₁ mode cylindrical cavity is used as the steady-frequence cavity and metal materials with different line-expand coefficients for temperature compensation is also used. These improve the frequience stead degree. In 23GH₂-25GH₂ band, using WT55 Gunn effect diode, the output power of the oscillator is larger than 30mw, the frequence stead degree is 5×10^-5.

Abstract:Continuous system simulation language is a non-procedural programming language. The written order of the statements bears no relation to the execution order. The statements must be sorted (or re-arranged) automatically by the compiler so as to generate the object codes with correct executing order. Based on analysing the characteristics of the dynamic section of simulation programs, the algorithms of auto-sorter implemented in the simulation language PARCSSL compiler of the software for parallel simulation PARSIM are given in this paper.

Abstract:ISO-proposed ASN.1 (Abstract Syntax Notation One) and ASN-BER (Basic Encoding Rules for ASN.1) proved to be highly powerful and flexible，but with low efficiency and large overheads in normal implementations. This paper first discusses general methods to improve the encoding efficiency and speed, then describes the design and implementation techniques of a fast transfer syntax.

Abstract:The binary-to-decimal (BTD) conversion is often used in computer.It is the key problem to calculate D first for converting the binary floating point number (BFPN) O.B₁B₂…B_n*2^B into the decimal 0.D₁D₂…D_m*10^D. In this paper，we comprehensively studied the nature of BFPNand inferred an important conclusion for calculating D precisely. Based on the conclusion we constructed a high efficient formula which can not only calculate D but also keep the total error minimum in application.

Abstract:Branch-delay is one of the RISC (Reduced Instruction Set Computer)technology characters. According to our simulation to scalar programs on Cray-l-Like supercomputer，about 10～20%CPU time is occupied by branch inst. In this paper，the implementation method of branch-delay technology in i860 microprocessor is deeply analyzed. The method of introducing branch-delay technology into Cray-l-Like prototype is studied. Simulation results and theoretical analysis show that reducing one cp execute time for each branch inst will increase system pertormance by 4～5 percent.

Abstract:The paper extends the concept of logical device of UNIX and introduces the supercomputer logical disk. The method for implementing the ligical disk is described according to the given architecture of supercomputer system then. The concept of logical disk makes it possible that the size of file system is independent of the capacity of the physical disk and that the logical disk supports the super file or super file system.

Abstract:The most popular methods to solve large sparse problems are based on projection techniques on appropriate subspaces. The main attraction of these methods is that they only require using the matrix by vector multiplications. We give the implementations of PCG、GMRES、Lanczos's method and Davidson's method on YH-1.We then compare their advantages and disadvantages. Finally we discuss the parallel implementations as possible as we can.

Abstract:In this paper, a new type of coloring method of creating living picture is presented. It is different from the old single color or mode method. It's coloring method by gradually changing the color. Using this method to creatl computer Art picture which is living, it has been used in the creation of computer animation. In this paper, some program in C language have been given.

Abstract:Image processing is an important field of the application for neural network. In this paper，the models of neural network，learning rule and the capabilities of message processing are introduced，Then，the applications of neural network for image processing is described. The emphasis of this paper is put on the classificator of neural network and Hopfield network for solving optimum problems in image processing.

Abstract:A process was studied to make continuous silicon carbide fiber from polycarbosilane (PC) served as precursor. The manufacture process includes the synthesis of PC，and melt spinning in an equipment with a nozzle of 100 holes to produce 10-15μm diameter fibers. These fibers were cured single ply yarn, and were coutinuously pyrolyzed to 1200℃ in an inert environment. They then undergo siziug，dry and drum reel to produce amorphous high performance ceramic fiber. The fibers have a tansile strength of 2-2.3GPa and an elastic moduli of 178GPa. Their length>100m. The effect between structure and properties of SiC fiber made by various technical parameters has been studied in this paper.

Abstract:In this paper, the research results of reducing interferences and attenuations of solid rocker motor exhaust plume to microwave and laser guidance signal have been reported. The results include: reduced smoke HTPB propellants with good ignition properties at low pressure and good steadiness of combustions, which make the transmissivities of both microwave and laser to exhaust plumes increase by a factor of 3.

Abstract:Two kinds of new macrocyclic chelates have been synthesized via a (2+2)condensation of O-phenylenediamine with O-phthalicaldehyde in absolute ethanol using CoCl₂?6H₂O and NiCl₂?6H₂O as template respectively. The composition and structure of cited chelates have been determined by elemental analysis，molar conductance and magnetic susceptibility measurements，IR Spectrophotometry. The electrochromism of the chelates have been observed by uv-visible spectra，the electrochromic mechanism are preliminary investigated.

Abstract:An active area of research in supercomputing is concerned with mapping certain sums, such as discrete Fourier transforms (DFT) and discrete cosine transforms (DCT) to multi-processor arrays. This paper presents two kinds of systolic arrays for 2D-DFT using the flow diagram of row-column de composition algorithm. One is a linear array of N₁ processors (if the DFT is N₁×N₂), and it takes O(N₁N₂)time steps. The speed-up of this array over the sequential implementation of the row-column decomposition algorithm on a single processor is O(N)(IF N₁=N₂=N). This result is currently optimal not only in PE numbers, but a1so in time cost. The other is a rectagular array of N₁×N₂ processors and it takes O(N₁+N₂)steps. The specdup of it over the sequential implementation of the row-cotumn decomposition algorithm on a single processor is O(N²)(IF N= N₁=N₂). At last, the paper gives two systolic arrays of 2D-DCT,which are similar to that of 2D-DFT. Furthermore, these systolic arrays can be easily generalized to multi-dimensional cases.

Abstract:This paper is concerned with the existence of positive solutions for the following problem: -div(|Du|^p-2Du)+k (x) u^P-1=K(x)u^P-1+g(x,u)，u∈W^1,P (R^N),4≤P²≤N,P=NP/N-p，where g (x,u) is a lower-order perturbation of u^p-1. It is the continuation of the zero-perturbation case.

Abstract:The method of mathematical model construction for mobile vehicle has been created in this paper. The dynamic model of Mobile Robot KDM-1 as the special case has been deduced in detail, and the authors try to use the dynamical mechanics of nonholonomic systems as the analytical instruments. The data of the model are obtained by experiment and checked by real vehicle driving，and several parameters are inspected by simulation testing. It is revealed that the satisfactory result of simulation with dynamic model consists with that of driving experiments of vehicle inside the room. The paper has presented a useful way for other vehicle carrying mobile robot to build up he mathematical model.

Abstract:In this paper an analytical solution of the unsteady flow of non-Newtanian fluids in annular pipes was found by using the integral transform method. Numerical simulation was carried out. On the basis of these，a detailed analysis was made to the effects of non-Newtonian coefficient H_c and the shape factor η on the flow. The obtained conclusions may provide the engineering projection with higher reliability.

Abstract:This article makes a deep study on layer potential developed in reference[l]. The curves that describe the relation between U and e1ectron density N⁰_e，and the relation between Cu-O plane number 1 and U，are traced. Furthermore，this article studies the micromechanism of layer potential-effective Hamiltonian for Cu-O layer，Effective Hamiltonian for Cu-O layer is obtained. The condition for holes (slave-fermions) to be condensed to Cooper pairs is dicussed.

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