SQL注入攻击原理及预防

从2007年底至今,SQL注入式攻击成为黑客犯罪的主要手段,利用Google搜索引擎来确定注入点,并插入指向恶意内容的链接,其造成的威胁是巨大的,通过了解其原理,建立有效的安全体系来防范SQL注入式攻击。     

数字虚拟图像与实拍影像的整合

数字虚拟图像与实拍影像的整合是现阶段动态影像创作的一种趋势,它突破了单一的影像形式,融会了两种不同形态的影像语言,不仅为创作者提供了无限的创作空间,并且开拓了新的审美情趣,使影像在创作观念与形式语言表现上发生了许多变化,值得我们思考与研究。本文通过对数字虚拟图像与实拍影像整合的含义、目的与价值三个方面的论述,希望可以引起对新的影像形式语言理论研究的思考,开拓影像形式语言的多元化。     

Discriminant subspace analysis: a Fukunaga-Koontz approach

The Fisher Linear Discriminant (FLD) is commonly used in pattern recognition. It finds a linear subspace that maximally separates class patterns according to the Fisher Criterion. Several methods of computing the FLD have been proposed in the literature, most of which require the calculation of the so-called scatter matrices. In this paper, we bring a fresh perspective to FLD via the Fukunaga-Koontz Transform (FKT). We do this by decomposing the whole data space into four subspaces with different discriminability, as measured by eigenvalue ratios. By connecting the eigenvalue ratio with the generalized eigenvalue, we show where the Fisher Criterion is maximally satisfied. We prove the relationship between FLD and FKT analytically, and propose a unified framework to understanding some existing work. Furthermore, we extend our our theory to Multiple Discriminant Analysis (MDA). This is done by transforming the data into intra- and extra-class spaces, followed by maximizing the Bhattacharyya distance. Based on our FKT analysis, we identify the discriminant subspaces of MDA/FKT, and propose an efficient algorithm, which works even when the scatter matrices are singular, or too large to be formed. Our method is general and may be applied to different pattern recognition problems. We validate our method by experimenting on synthetic and real data.     

计算机辅助图像分类信息挖掘与应用探讨*

以沿海地区TM图像应用为例,通过量化方法由计算机对训练区的分离度进行确定与比较,进行最佳信息维数的确定与最佳信息维组合的选择,并将信息维数对分类精度的影响进行探讨。结果证明,这种方法可以得到能满足工作需要的分类精度,组合维数以6维最佳。     

高温水采暖系统内部氧腐蚀

对阜康冶炼厂高温水采暖系统内部产生氧腐蚀的原因进行分析，采取相应的措施，收到良好的效果     

Experimental research on air film formation behavior of air cushion belt conveyor with stable load

In this paper, the air film formation behavior of air cushion belt conveyor with stable load is studied. The air cushion field is analyzed by means of theoretical derivation, numerical simulation and experimental research. An intelligent experiment platform is developed. Three dimensional pressure distribution of air film and the air film thickness distribution along the conveyor belt in the width direction are obtained. The experimental result is analyzed by comparing with theoretical calculation and numerical simulation. The numerical and theoretical results are in good agreement with those obtained from experiments. The air film formation behavior pattern of air cushion belt conveyor with stable load is presented. The optimized film thickness and pore distribution are obtained based on the comprehensive energy consumption. This study provides a basis for the optimization design of air cushion belt conveyor.     

Disruption of Synechocystis PCC 6803 for lipid extraction

In order to extract intracellular lipids from cyanobacterial Synechocystis PCC 6803 for biofuel production, seven cell-disruption methods - autoclaving, bead beating, freeze drying, French press, microwave, pulsed electric fields (PEF), and ultrasound - were tested prior to lipid extraction to make intracellular lipids more accessible by organic solvents. The different methods brought about distinct disruption effects to the cell envelope, plasma membrane, and thylakoid membranes that were related to extraction efficiency. Microwave, PEF, and ultrasound with temperature control had significant enhancement of lipid extraction (9-13% increases). Bead beating, freeze drying, and French press did not provide significant enhancement of lipid extraction. Furthermore, autoclaving, French press, and ultrasound treatments caused significant release of lipid into the medium, which may increase solvent usage and make medium recycling difficult. In order to minimize the cost of cell-disruption and lipid-extraction steps, microwave and PEF (with temperature control) might be best suited for large-scale cell disruption among all techniques investigated.     

单通道TD-SCDMA射频拉远单元

该文设计了一种单通道TD-SCDMA射频拉远单元。首先根据系统要达到的性能指标要求,设计了系统拓扑结构,接着从该系统拓扑结构出发,分析了整个系统的设计思路及实现方案,选择相应的电路模块。测试结果表明设计的系统达到了预期的指标,临近通道功率比小于-40.64 dBc和误差向量幅度为5.08%rms。     

NYP与我国高职院校公共基础课教学之对比剖析——以成都职业技术学院为例

通过我国高职院校(以成职院为例)与新加坡南洋理工学院在公共基础课的教学模式、课程设置、课程与专业结合的针对性以及学生全面素质培育方面,进行思考和分析,提出了结合我国高等职业教育实际情况的思考和建议。     

基于结构继承的贝叶斯网结构学习优化设计

采用遗传算法建立贝叶斯网络的优化学习结构,一直是贝叶斯网络研究倍受关注的课题.传统遗传算法的个体设计存在需要反复进行无环性检验的问题,降低了进化效率.针对这个问题,提出一种新的个体编码方式.考虑到进化过程中家族得分的可继承性,提出基于家族继承的结构评分改进算法,进而设计相应的改进遗传算法.实验结果表明,改进算法在BN建网精度与效率上都得到明显提升.