试析电子营销对企业发展的影响

本文主要论述了与电子商务有关的电子营销,分析其特点和运行机制,同时将新型的电子营销与传统营销相对比,总结其不同和发展。以电子营销为主体,讨论了当代电子营销的竞争策略和竞争方法,将电子交流、电子科研和电子交易进行综合,而电子营销除了大量使用电子广告之外,还应该具备丰富的、有意义的产品推广,将电子商务的优势加以利用,建立具有特殊性、独立性的电子营销,为企业的进一步发展带来更高的经济效益和社会效益。     

Accuracy of the zero crossings of the second directional derivative as an edge detector

In this paper the accuracy of the second directional derivative edge detector is analyzed, based on a number of idealized edge models. The results are compared with those for the Laplacian edge detector. Errors are shown to be small under a number of conditions. These conditions are less severe for the second directional derivative than for the Laplacian edge detector. Spurious or phantom edges can be removed by checking the sign of the third directional derivative, though this is not enough to remove all large errors. Indeed, it is also shown that large errors will be obtained if no threshold is set on the magnitude of a third order derivative.This work was supported by the Belgian National Fund for Scientific Research (NFWO).     

Asymptotic behavior of fluctuations for the 1D Ising model in zero-temperature limit

Fluctuation of the average spin for one-dimensional Ising spins with nearest neighbor interactions are studied. The distribution function for the average spin is calculated for a finite volume, finite temperature, and finite magnetic field. As the volume increases and the temperature diminishes at zero magnetic field, there are two limits in which the probability distribution shows quite different behaviors: in the thermodynamic limit as the volume goes to infinity for finite temperature, small deviations of the fluctuations are described by a Gaussian distribution, and in the limit as the temperature vanishes for a finite volume, the ground states are realized with probability one. The crossover between these limits is analyzed via a ratio of the correlation length to the volume. The helix-coil transition in a polypeptide is discussed as an application.     

Fast vectorized algorithm for the Monte Carlo simulation of the random field Ising model

An algorithm for the simulation of the 3-dimensional random field Ising model with a binary distribution of the random fields is presented. It uses multi-spin coding and simulates 64 physically different systems simultaneously. On one processor of a Cray YMP it reaches a speed of 184 million spin updates per second. For smaller field strength we present a version of the algorithm that can perform 242 million spin updates per second on the same machine.     

Ising model in a quasiperiodic transverse field,percolation, and contact processes in quasiperiodic environments

Quantum Ising models in a transverse field are related to continuous-time percolation processes whose oriented percolation versions are contact processes. We study such models in the presence of quasiperiodic disorder and prove localization in the ground state, no percolation, and extinction, respectively, for sufficiently large disorder.     

光源场熵的计算与性质研究

本文利用Karhunen—Loeve展开,在光源空域内对光源场互谱密度进行量子谐振子模分解,发展了一种计算光源场熵的新方法,并精确计算了高斯Schell模光源场的熵,讨论了光源场熵与光源全相干度,光源场模数的关系。     

大鼠缺血性卒中光化学模型研究

本文基于光化学反应机理，对大鼠缺血性卒中光化学模型进行研究，指出光化学反应诱导ＶＥＣ功能异常，从而加速了血小板聚集，导致血管栓塞。该模型制作简单，相对非侵害，有可能替代大脑动脉闭塞的缺血性卒中模型。     

关于逻辑函数化简的行为诊断的研究

本文以逻辑函数化简的行为诊断为研究背景，提出了一种适合于解题ＩＣＡＩ系统中学生行为的、符合人类思维特征的认识诊断系统模型，详细论述了逻辑函数化简过程中，学生行为认识诊断的具体实现，在准确捕捉学生行为中的错误及错误原因等重要问题上取得了意义的研究成果。     

Robust Non-Fragile Guaranteed Cost Control for Nonlinear Time Delay Discrete-Time Systems Based on T-S Model

This paper concerns the robust non-fragile guaranteed cost control for nonlinear time delay discrete-time systems based on Takagi-Sugeno （T-S） model. The problem is to design a guaranteed cost state feedback controller which can tolerate uncertainties from both models and gain variation. Sufficient conditions for the existence of such controller are given based on the linear matrix inequality （LMI） approach combined with Lyapunov method and inequality technique. A numerical example is given to illustrate the feasibility and effectiveness of our result.     

柱边边缘扫描检出模型的研究

本文建立了两种通用的柱边边缘扫描（白光扫描和激光扫描）检出的理论模型，给出了这两种模型的计算机仿真曲线，分析了影响边缘检出灵敏度的因素，并通过三种边缘检出方法验证了这两种模型的正确性。