21,608 research outputs found

    Bayesian Network Analysis for Diagnostics and Prognostics of Engineering Systems

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    Bayesian networks have been applied to many different domains to perform prognostics, reduce risk and ultimately improve decision making. However, these methods have not been applied to military field and human performance data sets in an industrial environment. Methods frequently rely on a clear understanding of causal connections leading to an undesirable event and detailed understanding of the system behavior. Methods may also require large amount of analyst teams and domain experts, coupled with manual data cleansing and classification. The research performed utilized machine learning algorithms (such as Bayesian networks) and two existing data sets. The primary objective of the research was to develop a diagnostic and prognostic tool utilizing Bayesian networks that does not require the need for detailed causal understanding of the underlying system. The research yielded a predictive method with substantial benefits over reactive methods. The research indicated Bayesian networks can be trained and utilized to predict failure of several important components to include potential malfunction codes and downtime on a real-world Navy data set. The research also considered potential error within the training data set. The results provided credence to utilization of Bayesian networks in real field data – which will always contain error that is not easily quantified. Research should be replicated with additional field data sets from other aircraft. Future research should be conducted to solicit and incorporate domain expertise into subsequent models. Research should also consider incorporation of text based analytics for text fields, which was considered out of scope for this research project

    MFIRE-2: A Multi Agent System for Flow-based Intrusion Detection Using Stochastic Search

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    Detecting attacks targeted against military and commercial computer networks is a crucial element in the domain of cyberwarfare. The traditional method of signature-based intrusion detection is a primary mechanism to alert administrators to malicious activity. However, signature-based methods are not capable of detecting new or novel attacks. This research continues the development of a novel simulated, multiagent, flow-based intrusion detection system called MFIRE. Agents in the network are trained to recognize common attacks, and they share data with other agents to improve the overall effectiveness of the system. A Support Vector Machine (SVM) is the primary classifier with which agents determine an attack is occurring. Agents are prompted to move to different locations within the network to find better vantage points, and two methods for achieving this are developed. One uses a centralized reputation-based model, and the other uses a decentralized model optimized with stochastic search. The latter is tested for basic functionality. The reputation model is extensively tested in two configurations and results show that it is significantly superior to a system with non-moving agents. The resulting system, MFIRE-2, demonstrates exciting new network defense capabilities, and should be considered for implementation in future cyberwarfare applications

    A Multi Agent System for Flow-Based Intrusion Detection Using Reputation and Evolutionary Computation

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    The rising sophistication of cyber threats as well as the improvement of physical computer network properties present increasing challenges to contemporary Intrusion Detection (ID) techniques. To respond to these challenges, a multi agent system (MAS) coupled with flow-based ID techniques may effectively complement traditional ID systems. This paper develops: 1) a scalable software architecture for a new, self-organized, multi agent, flow-based ID system; and 2) a network simulation environment suitable for evaluating implementations of this MAS architecture and for other research purposes. Self-organization is achieved via 1) a reputation system that influences agent mobility in the search for effective vantage points in the network; and 2) multi objective evolutionary algorithms that seek effective operational parameter values. This paper illustrates, through quantitative and qualitative evaluation, 1) the conditions for which the reputation system provides a significant benefit; and 2) essential functionality of a complex network simulation environment supporting a broad range of malicious activity scenarios. These results establish an optimistic outlook for further research in flow-based multi agent systems for ID in computer networks

    The internet as a relationship marketing tool - some evidence from Irish companies

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    This article explores the strategies underlying the use of the internet as a marketing tool by Irish businesses. Three different approaches to internet Marketing are described: the ornamental, the informational and the relational. It is shown that, theoretically, the internet offers a unique opportunity for marketers to build up and maintain relationships with their clients. However, data collected through a mail survey and a content analysis of web sites reveal that currently the most frequent use of the internet by Irish companies still follows an ornamental or, at most, informational pattern. The authors discuss whether this discrepancy between internet potential and practice is due to the social basis of market relationships or whether it can be seen as evidence that the adaptation of a new marketing tool follows an incremental pattern

    First-Passage Time and Large-Deviation Analysis for Erasure Channels with Memory

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    This article considers the performance of digital communication systems transmitting messages over finite-state erasure channels with memory. Information bits are protected from channel erasures using error-correcting codes; successful receptions of codewords are acknowledged at the source through instantaneous feedback. The primary focus of this research is on delay-sensitive applications, codes with finite block lengths and, necessarily, non-vanishing probabilities of decoding failure. The contribution of this article is twofold. A methodology to compute the distribution of the time required to empty a buffer is introduced. Based on this distribution, the mean hitting time to an empty queue and delay-violation probabilities for specific thresholds can be computed explicitly. The proposed techniques apply to situations where the transmit buffer contains a predetermined number of information bits at the onset of the data transfer. Furthermore, as additional performance criteria, large deviation principles are obtained for the empirical mean service time and the average packet-transmission time associated with the communication process. This rigorous framework yields a pragmatic methodology to select code rate and block length for the communication unit as functions of the service requirements. Examples motivated by practical systems are provided to further illustrate the applicability of these techniques.Comment: To appear in IEEE Transactions on Information Theor

    Review of Universal Salt Iodation in East Central and Southern Africa (ACSA)

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    \ud This paper presents a regional position on Universal Salt Iodation (USI) intervention in 14 countries ill the East, Central and Southern Africa( ECSA) region,namely;Botswana,Kenya,Malawi,Mauritius,Mozambique,Namibia,bells,South Africa, Swaziland, Tanzania, Uganda, Zambia and Zimbabwe The is a follow-up to a resolution on the need to develop a regional position on USI intervention which was made at the Commonwealth Regional Health Community 25th Health Ministers Conference in Port Louis, Mauritius from November;29,1996. The overall objective was to get views on the implementation of USI intervention in order to identify areas requiring facilitation, harmonization , coordination and collaboration at nation and regional levels in the ECSA. The preparation of paper involved reviewing of USI legislation regulations plans of action, survey reports and workshop papers. To substantiate the literature review, individual interviews were held with USI stakeholders in Malawi, Namibia, Tanzania, Zambia, and Zimbabwe from July 10-21, 1997 In respect of the findings, all the CRHC mainland member states are implementing USI intervention as a long term strategy for virtual elimination of the year 2000. The evaluation results of some of the national programmes have shown improvement of indicators of adequacy of iodine in the body. For example there is crease in levels of urinary iodine and reduction of goiter in countries where the intervention has been implemented actively over the past few years. In order to enforce the marketing of iodated salt, more than half of the CRHC member states have legislated USI where those who have not passed legislation yet are promoting USI through extensive advocacy and marketing strategy. These national USI programmes are being augmented by technical, financial and material support from United Nations and multilateral agencies, and the cooperation and compliance of the salt industry in iodating and packaging salt in line with USI legislation of country in the ECSA region. There are obstacles and constraints that impinge on the progress of USI in the entire ECSA region: The national USI legislation and regulations are not harmonized. The role of other sub-sector such as agriculture, trade and industry, and issues related to quality assurance are not spelt out in the regulations. There is still disparity in level of awareness of USI and its importance at all levels. Except Malawi, the rest of CRHC member states have no USI legislation for all salt intended for animal consumption. This is threatening sustenance of USI as there some leakages of uniodated salt from livestock sub-sector to people. Further threat emerges from communities who produce uniodated salt on a small scale for their own consumption and sale in their localities. The export and import duty for iodated and uniodate salt are the same. This does not deter traders and consumers to market and use uniodated salt because its price is either low or similar to the price of iodated salt. The challenge is, therefore, how to place the USI high on the agenda of relevant national and ECSA regional sub-sectors which formulate, implement and coordinate policy in order to strengthen and harmonize the intervention as well as deploying regionally acceptable measures to overcome the constraints. The CRHC should facilitate the harmonization of the USI regulations in the ECSA region including the reduction of the present high iodine levels to the levels (20-40ppm iodine[30-66ppm Potassium iodate]) that are recommended by the WHO. The CRHC should ensure that quality assurance issues are made mandatory in order to promote quality of salt iodations during production and packaging. The CRHC should facilitate development of guidelines regarding the roles of all sub-sectors such as ministries of Agriculture, Health and Trade and Industry, Departments of customs (Revenue Collection Authorities) and Bureaus of Standards in the USI which should issued under the directive of the Southern Africa Development Community and Common Market for Eastern and Southern Africa trade agreement. The CRHC should facilitate and support promotion of USI through regional networking,development and production of information, education and communication(IEC) material, designation of a regional IDD/USI day establishment of IIDD newsletter. The CRHC should ensure that member states consider making uniodated salt for whatever use a controlled commodity and impose deterrent export and import duty in order to protect, support and promote use of iodated salt for human and animal consumption in the region. The CRHC should facilitate establishment of at least one regional micronutrients reference laboratory and improvement of the national laboratories. The CHRC should strengthen the Department of Food Security and Nutrition of personnel in order to enhance capacity to accomplish the suggested activities listed below along with other planned work in the Department. The CHRC should endeavor to mobilize technical, financial and resources for support of salt iodations in the region especially in countries which are lagging behind and small salt procedure. Facilitating and supporting the evaluation of selected national USI programmes in order to confirm the case for reduction of iodine levels in the ECSA region. Facilitating review and harmonization of USI legislation and relevant Standards Act in the ECSA region. Initiating and supporting the collaboration on the proposed imposition of deterrent export and import duty on uniodated salt in order to protect and promote use of iodated salt. Facilitating and supporting the guide for role vital sub-sector such as Bureaus of Standard, Chamber of Commerce, and Ministries of Trade and Industry, Agriculture, departments of Customs and Excise, in the promotion, supporting, protecting and monitoring USI in the ECSA region. Facilitating network and all aspects of IEC and designation of an IDD day in ECSA. Conducting ECSA regional conferences on USI policy direction and review with consideration of SADC and COMESA trade agreements. Establishing a regional data bank on USI and micronutrient in order to enhance and facilitate regional networking. Establishing a regional micronutrients reference laboratory for improvement of micronutrients laboratory services whilst on one hand, supporting devolution of some the services to the provinces in order to easy congestion in national laboratories. Collecting, documenting and disseminating USI current information and technology in the ECSA member states through newsletter, bulletins and regional workshops. Conducting and supporting training on: Micronutrients, food security and nutrition in order to develop and capacity for execution of intervention and Programme-driven (operational) research on micronutrient, food security and nutrition. \u
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