基于K-L散度的恶意代码模型聚类检测方法

在云计算应用环境下,由于服务系统越来越复杂,网络安全漏洞和被攻击情况急剧增加,传统的恶意代码检测技术和防护模式已无法适应云存储环境的需求。为此,通过引入高斯混合模型,建立恶意代码的分层检测机制,使用信息增益和文档频率等方法分析和提取样本数据特征值,结合K-L散度特性,提出基于K-L散度的恶意代码模型聚类检测方法。采用KDDCUP99数据集,使用Weka开源软件完成数据预处理和聚类分析。实验结果表明,在结合信息增益和文档频率进行特征分析的前提下,与贝叶斯算法相比,该方法在虚拟环境中恶意代码的平均检测时间降低16.6%,恶意代码的平均检测率提高1.05%。     

Coupling geometric analysis and viability theory for system exploration: Application to a living food system

This paper addresses the issue of studying a food complex system in a reverse engineering manner with the aim of identifying the set of all possible actions that makes it reach a quality target with respect to manufacturing constraints. Once the set of actions is identified, several criteria can be considered to identify interesting trajectories and control policies. A viability approach, coupling the viability theory and a geometric approach of robustness, is proposed to study complex dynamical systems. It can be implemented for several types of systems, from linear to non linear or hybrid systems. The proposed framework was adapted to a living food system: a ripening model of Camembert cheese to identify the set of states and actions (capture basin) from which it is possible to reach a predefined quality target. Within the set of viable trajectories, particular trajectories that improve the Camembert cheese ripening process are identified using the proposed approach. The results are applied at a pilot scale and are discussed in this paper.     

Web交互模型的形式化验证研究

Web交互模型的形式化验证是对Web事件属性进行校验的十分可信的方法。通过一系列的系统模型建立、系统行为分析以及对于模型中关心属性的相关验证,能够让交互模型在设计阶段就能使形式化模型暴露出其所存在的缺陷,而不至于让缺陷保留到编码阶段或者更后面才能被真正地暴露出来,这样使系统模型的生存能力更加强大,同时避免了因后期缺陷暴露而出现的大代价修复。通过对Web系统的交互应用服务的过程模型化的体系进行研究,通过模型本身具有的属性进行相关正确性的校验,主要通过使用数学推理实现系统逻辑上的服务交互进程,从而进行过程的推演,并对系统服务的正确性进行过程的形式化验证,从而使系统服务模块的属性正确性可以通过逻辑上的演进来发现服务问题的存在,而不再是系统通过编码实现后才发现。对Web交互模型的形式化验证是基于IMWSC模型语义形成的IMWSC模型的验证机制。     

Progressive events in supervisory control and compositional verification

This paper investigates some limitations of the nonblocking property when used for supervisor synthesis in discrete event systems. It is shown that there are cases where synthesis with the nonblocking property gives undesired results. To address such cases, the paper introduces progressive events as a means to specify more precisely how a synthesised supervisor should complete its tasks. The nonblocking property is modified to take progressive events into account, and appropriate methods for verification and synthesis are proposed. Experiments show that progressive events can be used in the analysis of industrial-scale systems, and can expose issues that remain undetected by standard nonblocking verification.     

基于SVM模型的妫水河叶绿素a浓度的遥感反演

以北京市妫水河为研究区,基于2011年9月25日和2012年9月30日的两期叶绿素a浓度实测数据和准同步的环境一号卫星(HJ-1A)多光谱数据,分别构建一元线性和多元支持向量机模型(SVMM),通过决定系数R²和平均相对误差对模型的精度进行检验,用模型进行水体叶绿素a浓度的反演,并分析其时空分布特征。研究表明:在样本数较少的情况下,SVM具有很强的非线性映射能力,能够取得较好的预测结果,更适用于反演叶绿素a浓度。时间分布上,研究区叶绿素a浓度呈增加趋势,均值上升了6.86 μg/L;空间分布上,深水区叶绿素a浓度值低于浅水区,上游高于下游。国产HJ-1A CCD2多光谱数据以其4 d的时间分辨率,在水质动态变化监测方面具有优势。     

Practical Design Model for Calculating Bubble Diffuser Contactor Ozone Transfer Efficiency

Ozone transfer to water or wastewater is necessary before desirable, effective ozone reactions occur. Several factors affect ozone transfer efficiency, including water quality characteristics, contactor configuration, and applied ozone characteristics. The design model presented in this paper addresses all factors affecting ozone transfer. The model was used to compare measured transfer efficiency with predicted transfer efficiency at four full-scale wastewater ozone disinfection facilities. A relatively good prediction was obtained at each plant.

The paper presents an example calculation of ozone transfer efficiency. Also, the effect of changes to some of the factors affecting transfer efficiency is presented, such as changes in diffuser depth, plant elevation, ozone concentration, water quality (i.e., ozone demand), pH, detention time, temperature, and acombination of factors. The design model may be used to evaluate the effect of changes in plant design on transfer efficiency, but cannot provide an absolute value for transfer efficiency until difficult-to-measure parameters, such as bubble diameter, are known.     

基于中国电信CEP协议的组件服务应用

面对复杂多变的需求,需要我们梳理出业务的本质,并设计一套与之相适应、易扩展的框架结构,让业务组件化,组件服务化,通过灵活的服务组装,来满足灵活多样的业务需求。本文旨在通过对中国电信CEP协议的剖析,指引如何通过对整个CEP层次结构进行归纳总结,体系化实现服务能力的封装与开放。     

Computational fluid dynamics (CFD) analysis and experimental study for toxic hazardous waste destruction in the cavity incinerator

We undertook numerical and experimental studies to develop a better incineration method for the destruction of CC1₄. A phenomenological model for the turbulent reaction of CC1₄, including a flame inhibition feature, has been successfully incorporated into a commercial code, simulating the incineration processes of this compound. The gaseous flow solution was obtained using SIMPLEST, a derivative of Patankar’s SIMPLE algorithm, with a k-ε turbulence model. A modified fast chemistry turbulent reaction model was developed to describe the flame inhibition due to the presence of CC1₄, considering the corresponding burning velocity data of these mixtures. An experiment was carried out on a 5.2 kW laboratory scale, transportable, cavity-type incinerator, which warrants a sufficient residence time and effective turbulent mixing by the formation of a strong recirculation region in a combustor. To this end, the specific configuration of the incinerator was manufactured to consist of two opposing jets and a rearward facing step. The calculated data were in close agreement with the experimental data for the concentrations of major species, such as CCI₄ and HCl, together with the temperature profiles. The experimental test gave the desired DRE of above 99.99%.     

玻纤增强聚脂弯管应变导纳试验研究及其动应力分析

探讨了测定玻纤增强聚脂弯管应变导纳的试验方法。给出了力通道和应变通道的标定曲线。确定了玻纤聚脂弯管的第一、第二阶模态频率和阻尼比以及单位力幅下的动应变值。借助应变导纳的幅频特性和相频特性分析了弯管动应力。还用静态试验验证了动态测试的正确性     

浅谈计算机管理信息系统的发展及其经济效益

在社会各行各业竞争日趋激烈的形势下,有效、科学的管理是企业生存的必备条件.其中以信息管理为重要手段,数据的收集处理的快速准确化,为企业降低成本,带来更好的经济收益,也使得企业在生产过程中对组织内部进行更合理有效的调整,对组织外部的各类企业有更好的交流,而本身的重大决策,也有了更加科学的依据.本文介绍了信息系统的发展,以及如何带来经济收益.