基于SVM分类机的入侵检测系统

本文设计并实现了一种基于SVM分类机的入侵检测系统。它收集并计算除服务器端口之外TCP／IP的流量特征，使用SVM算法进行分类，从而识别出该连接的服务类型，通过与该,连接服务器端口所表明服务类型的比较，检测出异常的TCP连接，在此基础上，本文深入探讨了TCP连接的观察时间、所取特征数目和SVM的核函数的选取对检测效果的影响。实验结果表明，本系统能够有效地检测出异常TCP连接。     

Discrete optimal stochastic controller and its forms

An approach to obtain the optimal controller From an optimal criterion is presented. The controller is very general in the sense that it is multivariable, it compensates Tor process delay and it allows a penalty on the input variable variance. The controller can be obtained in two forms: the state-space model form with the steady-state Kalman filter that separates the control algorithm in distinctive steps to provide an insight into the control problem, while the transfer function form is very convenient for implementation.     

Decentralized control for two time-scale discrete-time systems

Output feedback design of discrete-time decentralized systems with slow and fast modes is considered. Conditions for the complete separation of slow and fast subsystems are given. The slow and fast subsystem outputs, which are obtained by applying the slow and fast subcontrollers to the corresponding subsystems, will be shown to approximate those of the original system. Also, the composite control, when being applied to the original system, will place the eigenvalues sufficiently close to the desired locations.     

异常检测中查全率和查准率的控制

在使用支持向量机分类技术的异常检测系统中，提出控制查全率和查准率的方法，该方法采用遗传算法优化特征选择和训练模型，其中染色体由特征选择和训练模型组成，适应度是用ξα-estimate方法计算的查全率和查准率的组合，通过设置其中一个参数η达到控制查全率和查准率的目的，实验中采用异常检测标准数据分析该方法的使用效果，结果表明随着η增大，查全率也增大，而查准率却减小，使得用户可以通过设置η的值控制查全率和查准率。     

CALCULATION OF SHALLOW SHELL SUBJECT TO INFLUENCE OF LOAD LOCAL EFFECT BY THE DIFFERENCE TECHNIQUE ON IRREGULAR NETWORKS

In this paper, a methodology for the calculation of shallow shell with positive Gauss radius, and boundaries supported on the rectangular plane subject to influence of uniform load and concentrated forces has been considered. In order to solve differential equations (written in the form that assumes deflections as unknowns) of bending shallow shell theory, the author has used the finite difference technique on irregular networks. A detailed algorithm has been formulated that enables to solve the problem by computer. By the above algorithm, the author has obtained numerical results in the form of internal forces and deflections diagrams. © 1997 by John Wiley & Sons, Ltd.     

Heat Capacity and Structural Relaxation of Mixed-Alkali Glasses

Heat capacities of a series of mixed-alkali glasses of composition (in mol%) 24.4(Na₂O + K₂O)-75.6SiO₂ were measured in the transition region by differential scanning calorimetry. The glass heat capacities at 700 K and the equilibrium liquid heat capacities are the same for all glasses on a per-g atom basis and equal, respectively, to 5.6 ± 0.1 and 6.8 ± 0.1 cal/g atom K. The glass transition temperatures exhibited negative deviations from additivity, but the heat capacity curves in the transition region of all the glasses for identical heating rates and thermal histories could be superimposed on the same reduced plot. This behavior indicates that the shapes of the structural relaxation functions are the same for all the glasses. These results support Shelby's conclusion that there is no unique "mixed-alkali effect" on thermodynamic or structural relaxation properties and that the term should be reserved for properties relating to ionic transport.     

诱导物对猴头菇子实体生长发育及产量的影响

本文选用了7种诱导物（壳聚糖、茉莉酸甲酯、赤霉素、萘乙酸、三十烷醇、吲哚乙酸和2,4-二氯苯氧乙酸（2,4-D））设定不同浓度,采用喷湿方法对猴头菇生长发育影响进行研究,结果表明0.5、1.0 mg/kg的茉莉酸甲酯和0.05、0.5 mg/kg的吲哚乙酸能显著缩短猴头菇的生长周期（p<0.05）;1.5、2.0 mg/kg的赤霉素、1.0 mg/kg的萘乙酸及0.5、1.5、2.0 mg/kg的吲哚乙酸能显著提高猴头菇的产量（p<0.05）。其中,0.5 mg/kg吲哚乙酸既能缩短猴头菇生长周期（缩短4 d）又能提高产量（比对照组提高22.18%）,有望进一步应用到生产中。      

滤波器对新型换流变压器运行参数的影响分析

新型换流变压器及其滤波器具有特殊的绕组接线方案,所以对其运行参数如视在功率、功率因数、网侧电流、负载电压、网侧电流的畸变率等的研究尤为重要。首先建立反映网侧电流和负载电流、负载电压和网侧电压、网侧谐波电流和负载谐波电流关系的数学模型。理论分析表明,未投滤波器时,新型换流变压器跟传统换流变压器的运行参数特性一致;而投滤波器时,新型换流变压器可以有效地降低网侧视在功率,提高网侧功率因数,减少网侧电流、增加负载电压及改善网侧电流的畸变率。最后通过对比理论计算值、仿真结果和实验结果,验证了所推导的新型换流变压器的数学模型的正确性。     

咖啡中丙烯酰胺检测方法及含量研究进展

由于丙烯酰胺对人体有神经毒性和潜在的致癌性,在美国,咖啡烘焙、咖啡粉末和速溶咖啡中丙烯酰胺都有限量。目前测定咖啡中丙烯酰胺的方法较多,每种方法各有利弊。主要介绍测定咖啡中丙烯酰胺的4种方法:气相色谱法,高效液相色谱法,气相色谱串联质谱法和液相色谱串联质谱法。总结在各种类咖啡中丙烯酰胺含量检测方法的最新进展。     

Polyvinyl alcohol–potassium iodide gel probe to monitor the distribution of reactive species generation around atmospheric-pressure plasma jet

This study proposes polyvinyl alcohol–potassium iodide (PVA–KI) as a novel gel chemical probe. The probe uses the reactions among PVA, KI, water, borax, and oxidative species to visualize the distribution of reactive species. This method provides information regarding the distribution of reactive species by coloration on the gel surface. The effects of the surrounding gas phase on the distribution and diffusion of the reactive species are also investigated using the PVA–KI gel probe. Further, the relationship between the irradiation distance and reactive species diffusion is determined on the surface of the PVA–KI probe with and without plastic shielding. Adjusting the irradiation distance appropriately leads to an increase in the modified area as detected by the PVA–KI gel probe analysis. The relative concentration distributions of the reactive species are also obtained from visualized color distributions measured using a colorimeter. Furthermore, reactive species generation by long-scale line plasma is confirmed by the color reaction on the PVA–KI gel surface, with a greater area being covered by an atmospheric-pressure pulsed microwave line plasma source.