网络蠕虫的传播与控制

近年来,蠕虫的快速传播已经成为因特网安全的主要威胁。本文分析了网络蠕虫的特征和工作原理,给出了蠕虫的传播模型,最后给出了蠕虫的检测、清除和控制方法。     

邮件蠕虫传播与防御的分析研究*

邮件蠕虫利用e-mail在具有power-law结构特点的网络中进行传播,使得传统的蠕虫防御策略失效。结合power-law网络拓扑结构的特点,引入节点免疫和邮件服务器参与两种防御策略,分别对重复感染与非重复感染两种类型的邮件蠕虫传播进行了实验仿真。结果表明,节点的优先免疫类型、免疫起始时间、邮件服务器参与防御时间及蠕虫邮件识别正确率都与邮件蠕虫的传播有着紧密联系。     

Pulse quarantine strategy of internet worm propagation: Modeling and analysis

Worms can spread throughout the Internet very quickly and are a great security threat. Constant quarantine strategy is a defensive measure against worms, but its reliability in current imperfect intrusion detection systems is poor. A pulse quarantine strategy is thus proposed in the current study. The pulse quarantine strategy adopts a hybrid intrusion detection system with both misuse and anomaly detection. Through analysis of corresponding worm propagation models, its stability condition is obtained: when the basic reproduction number is less than one, the model is stable at its infection-free periodic equilibrium point where worms get eliminated. Numerical and simulation experiments show that constant quarantine strategy is inefficient because of its high demand on the patching rate at “birth”, whereas the pulse quarantine strategy can lead to worm elimination with a relatively low value. As patching almost all hosts in the actual network is difficult, the pulse quarantine strategy is more effective in worm elimination.     

网络蠕虫的检测防治技术研究

随着网络系统应用的普及和其复杂多变性,网络蠕虫已对网络安全造成极其严重的威胁。本文介绍了网络蠕虫的定义和检测策略,对几种常用的网络蠕虫检测防御技术进行了比较,分析了它们的优点和不足,同时对未来网络蠕虫检测防治技术研究提出了几点建议。     

Combination of micro and cloud-based system to ambulance

Microsystem Technologies - This paper presents the integrated system of patients vital monitoring in the ambulance. It provides a real time cloud-based management platform of the ambulance tracking...     

Modeling and analyzing of the interaction between worms and antiworms during network worm propagation

Interaction of antiworms with a worm population of e.g. hosts of worm infected and hosts of antiworm infected must be considered as a dynamic process. This study is an attempt for the first time to understand how introduction of antiworm affects the dynamic of network worm propagation. In this paper, we create a mathematical model (SIAR model) using ordinary differential equations to describe the interaction of worms and antiworms. Although idealized, the model demonstrates how the combination of a few proposed nonlinear interaction rules between antiworms and worms is able to generate a considerable variety of different kinds of responses. Taking the Blaster and Nachi worms as an example, we give a brief analysis for designing a practical antiworm system. To the best of our knowledge, there is no model for the spread of an antiworm that employs the passive scan and the finite lifetime and we believe that this is the first attempt on understanding the interaction between worms and antiworms.     

Modeling and analysis of passive worm propagation in the P2P file-sharing network

A number of worms, named P2P (peer-to-peer) passive worms, have recently surfaced, which propagate in P2P file-sharing networks and have posed heavy threats to these networks. In contrast to the majority of Internet worms, it is by exploiting users’ legitimate activities instead of vulnerabilities of networks in which P2P passive worms propagate. This feature evidently slows down their propagation, which results in them not attracting an adequate amount of attention in literature. Meanwhile, this feature visibly increases the difficulty of detecting them, which makes it very possible for them to become epidemic. In this paper, we propose an analytical model for P2P passive worm propagation by adopting epidemiological approaches so as to identify their behaviors and predict the tendency of their propagation accurately. Compared with a few existing models, dynamic characteristics of P2P networks are taken into account. Based on this proposed model, the sufficient condition for the global stability of the worm free equilibrium is derived by applying epidemiological theories. Large scale simulation experiments have validated both the proposed model and the condition.     

存储技术安全性分析与对策研究

传输安全和存储安全是数据安全的两个方面。存储安全是指在数据保存上确保其安全性、完整性、可靠性和有效性。该文阐述了安全存储方案,并着重介绍了实现数据安全存储的各种技术,探讨了安全存储技术的发展方向。     

Correction to: An improvement of spectral clustering algorithm based on fast diffusion search for natural neighbor and affinity propagation

The Journal of Supercomputing -     

Information technology,the organizational capability of proactive corporate environmental strategy and firm performance: a resource-based analysis

The study of the relationships between information technology (IT), environmental organizational issues and firm performance is a cutting-edge research topic for the information systems (IS) community. However, at present we know very little about these relationships. Drawing on the perspective of IT-enabled organizational capabilities and the literature on organizations and the natural environment, our study introduces conceptually the construct organizational capability of proactive corporate environmental strategy to the IS field. We propose that IT capability may enable the implementation of a proactive environmental strategy and that this strategy could play a significant role in determining the business value of IT. Using structural equations modeling with data collected from 63 firms, we find that IT capability is an enabler of proactive environmental strategy and that this strategy plays a significant role in mediating the effects of IT on firm performance. Our study provides initial evidence on the role of IT in the implementation of proactive environmental practices. Our results suggest to IT executives that their decisions matter in shaping environmental sustainability, which in turn will generate business value from IT.     

智能卡COS的快速烧写技术研究与实现

对智能卡COS现有USB、串口读写器的烧写技术进行了研究与分析,提出了一种以ARM处理器为母片硬件平台,通过智能卡接口对其他智能卡COS进行快速烧写的片拷贝方法。该方法具有硬件设计简单、烧写速度快,稳定性、安全性高等优点,且易于扩展为批量智能卡COS烧写器平台。目前该技术已在贴片智能卡生产厂商得以全面应用,大大提高了COS的烧写效率,具有较好的应用前景。     

An improvement of spectral clustering algorithm based on fast diffusion search for natural neighbor and affinity propagation

The Journal of Supercomputing - Spectral clustering algorithm has become more popular in data clustering problems in recent years, due to the idea of optimally dividing the graph to solve the data...     

Exact analysis of the finite precision error generation and propagation in the FAEST and the fast transversal algorithms: A general methodology for developing robust RLS schemes

In this paper, an analysis for the actual and deeper cause of the finite precision error generation and accumulation in the FAEST-5p and the fast transversal filtering (FTF) algorithm is undertaken, on the basis of a new methodology and practice. In particular, it is proved that, in case where the input data in these algorithms is a white noise or a periodic sequence, then, out of all the formulas that constitute these two schemes, only four specific formulas generate an amount of finite precision error that consistently makes the algorithms fail after a certain number of iterations. If these formulas are calculated free of finite precision error, then all the results of the two algorithms are also computed error-free. In addition, it is shown that there is a very limited number of specific formulas that transmit the finite precision error generated by these four formulas. Moreover, a number of very general propositions is presented that allow for the calculation of the exact number of erroneous digits with which all the quantities of the FAEST and FTF schemes are computed, including the filter coefficients. Finally, a general methodology is introduced, based on the previous results, that allows for the development of new RLS algorithms that, intrinsically, suffer less of finite precision numerical problems and that therefore are, in practice, suitable for high quality fast Kalman filtering implementations.     

沙尘衰减对微波通信的影响

通过分析沙尘尺寸分布,在计算干沙和纯水的复介电常数的基础上,利用粒子散射理论给出了微波传输中的沙尘衰减的计算模型,该模型分析了爆炸沙尘、车扬沙尘和自然沙尘三种不同的沙尘的衰减。通过数值计算的结果,仿真了不同含水量下沙尘衰减率随微波频率的变化,最后给出了相关结论。     

Enhancing cognitive plausibility of uncertainty calculus: acommon-sense-based approach to propagation and aggregation

Uncertainty calculus overcomes many of the drawbacks affecting other well-known approaches to uncertain reasoning. Nevertheless, it suffers from other severe limitations and gives rise to counter-intuitive results. We show that common sense inconsistencies of uncertainty calculus originate from a scarce cognitive plausibility in the definition of propagation and aggregation operators, and we propose an improved version of Driankov's uncertainty calculus (1986) where the definition of such operators is substantially revised according to common sense criteria. Revised uncertainty calculus allows overcoming in a general and uniform way all the problems identified in uncertainty calculus and provides a substantial enhancement of cognitive plausibility. It has been successfully tested in the design and development of a real application concerning preventive diagnosis of power transformers     

上网迷恋之因探讨与对策思考

随着社会网络普及率越来越高,上网迷恋问题日益突出,已经成为社会性问题。了解网迷危害、确定网迷类型,找出迷恋上网原因,分析研究对策,对症下药。家庭、学校、社会、政府共同携手构建立体网迷防治模式,打造一个合理健康的网络社会。     

Interval propagation to reason about sets: Definition and implementation of a practical language

Local consistency techniques have been introduced in logic programming in order to extend the application domain of logic programming languages. The existing languages based on these techniques consider arithmetic constraints applied to variables ranging over finite integer domains. This makes difficult a natural and concise modelling as well as an efficient solving of a class of NP-complete combinatorial search problems dealing with sets. To overcome these problems, we propose a solution which consists in extending the notion of integer domains to that of set domains (sets of sets). We specify a set domain by an interval whose lower and upper bounds are known sets, ordered by set inclusion. We define the formal and practical framework of a new constraint logic programming language over set domains, called Conjunto. Conjunto comprises the usual set operation symbols (, , \), and the set inclusion relation (% MathType!MTEF!2!1!+-% feaafiart1ev1aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn% hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr% 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9% vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x% fr-xb9adbaqaaeaacaGaaiaabeqaamaabaabaaGcbaGaeyOHI0maaa!37EA!\[ \subseteq \]). Set expressions built using the operation symbols are interpreted as relations (s s ₁ = s ₂, ...). In addition, Conjunto provides us with a set of constraints called graduated constraints (e.g. the set cardinality) which map sets onto arithmetic terms. This allows us to handle optimization problems by applying a cost function to the quantifiable, i.e., arithmetic, terms which are associated to set terms. The constraint solving in Conjunto is based on local consistency techniques using interval reasoning which are extended to handle set constraints. The main contribution of this paper concerns the formal definition of the language and its design and implementation as a practical language.     

Teachers' perceptions of the barriers to technology integration and practices with technology under situated professional development

This case study examines 18 elementary school teachers' perceptions of the barriers to technology integration (access, vision, professional development, time, and beliefs) and instructional practices with technology after two years of situated professional development. Months after transitioning from mentoring to teacher-led communities of practice, teachers continued to report positive perceptions of several barriers and were observed engaging in desirable instructional practices. Interviews suggest that the situated professional development activities helped create an environment that supported teachers' decisions to integrate technology. Implications for teacher professional development and technology integration are discussed in conjunction with the strengths and limitations of the study.     

Ascent EM for fast and global solutions to finite mixtures: An application to curve-clustering of online auctions

In this paper we propose two new EM-type algorithms for model-based clustering. The first algorithm, Ascent EM, draws its ideas from the Monte Carlo EM algorithm and uses only random subsets from the entire database. Using only a subset rather than the entire database allows for significant computational improvements since many fewer data points need to be evaluated in every iteration. We also argue that one can choose the subsets intelligently by appealing to EMs highly-appreciated likelihood-ascent property. The second algorithm that we propose builds upon Ascent EM and incorporates ideas from evolutionary computation to find the global optimum. Model-based clustering can feature local, sub-optimal solutions which can make it hard to find the global optimum. Our algorithm borrows ideas from the Genetic Algorithm (GA) by incorporating the concepts of crossover, mutation and selection into EMs updating scheme. We call this new algorithm the GA Ascent EM algorithm. We investigate the performance of these two algorithms in a functional database of online auction price-curves gathered from eBay.com.