Self-Protection in a Clustered Distributed System
اطلاع رسانیSelf-protection refers to the ability for a system to detect illegal behaviors and to fight-back intrusions with countermeasures. This article presents the design, the implementation, and the evaluation of a self-protected system which targets clustered distributed applications. Our approach is based on the structural knowledge of the cluster and of the distributed applications. This knowledge allows to detect known and unknown attacks if an illegal communication channel is used. The current prototype is a selfprotected JEE infrastructure (Java 2 Enterprise Edition) with firewall-based intrusion detection. Our prototype induces low- performancepenalty for applications.
Distributed Economic Dispatch for Smart Grids With Random Wind Power
اطلاع رسانیIn this paper, we present a distributed economic dispatch (ED) strategy based on projected gradient and finitetime average consensus algorithms for smart grid systems. Both conventional thermal generators and wind turbines are taken into account in the ED model. By decomposing the centralized optimization into optimizations at local agents, a scheme is proposed for each agent to iteratively estimate a solution of the optimization problem in a distributed manner with limited communication among neighbors. It is theoretically shown that the estimated solutions of all the agents reach consensus of the optimal solution asymptomatically. This scheme also brings some advantages, such as plug-and-play property. Different from most existing distributed methods, the private confidential information, such as gradient or incremental cost of each generator, is not required for the information exchange, which makes more sense in real applications. Besides, the proposed method not only handles quadratic, but also nonquadratic convex cost functions with arbitrary initial values. Several case studies implemented on six-bus power system, as well as the IEEE 30-bus
power system, are discussed and tested to validate the proposed method.
Asymmetric Threat Modeling Using HMMs: Bernoulli Filtering and Detectability Analysis
اطلاع رسانیThere is good reason to model an asymmetric threat (a structured action such as a terrorist attack) as an HMM whose observations are cluttered. Within this context this paper presents two important contributions. The first is a Bernoulli filter that can process cluttered observations and is capable of detecting if there is an HMM present, and if so, estimate the state of the HMM. The second is an analysis of the problem that, for a given HMM model, is able to make statements regarding the minimum complexity that an HMM would need to involve in order that it be detectable with reasonable fidelity, as well as upper bounds on the level of clutter (expected number of false measurements) and probability of miss of a relevant observation. In a simulation study the Bernoulli filter is shown to give good performance provided that the probability of observation is larger than the probability of an irrelevant clutter observation. Further, the results show that the longer the delays are between the HMM state transitions, the larger the probability margin must be. The feasibility prediction shows that it is possible to predict the boundary between poor performance and good performance for the Bernoulli filter, i.e., it is possible to predict when the Bernoulli filter will be useful, and when it will not be.
International Cooperation in Cyber Space to combat Cyber crime and terrorism
اطلاع رسانیCyber crime and terrorism is an international problem which does not respect national borders. Cyber criminals operate from relatively safe territories beyond the easy reach of the law enforcement agencies of the countries in which their victims reside. Collaboration between governments, intelligence agencies and law enforcement officers is critical to prosecuting cybercrime, and new organizations have been created to enable this. However, this co-operation seems to have run into roadblocks by the leak of large scale national level data snooping secrets by whistleblower Edward Snowden. The paper attempts to derive insights from ongoing initiatives reported in open source and recommend options available to charter the path for sustainable international cooperation in evolving secure cyber infrastructure.
Energy Efficient Green Routing Protocol for Internet of Multimedia Things
اطلاع رسانیInternet of Things (IoT) envisions the notion of ubiquitous connectivity of ‘everything’. However, the current esearch and development activities have been restricted to scalar sensor data based IoT systems, thus leaving a gap to benefit from services and application enabled by ‘multimedia things’ or Internet of Multimedia Things (IoMT). Moreover, a crucial issue for Information and Communication Technology (ICT) community is the steer increase in CO2 emissions, which mandates green communication to reduce energy consumption and carbon footprint emissions. Recently, IETF ROLL working group standardized an IPv6 Routing Protocol for Low-Power and Lossy Networks (RPL) for resource constrained devices. RPL builds a tree-like network topology based on some network metric optimization using RPL Objective Functions. Previous RPL implementations for scalar sensor data communication are not feasible for IoMT, since multimedia traffic pose distinct network requirements. The goal of this paper is to design an enhanced version of RPL for IoMT in which the sensed information is essentially provided by the multimedia devices. Our proposed RPL implementation minimizes carbon footprint emissions and energy consumption, along with the incorporation of application specific Quality of Service requirements. To evaluate the performance of the proposed scheme a simulation study is carried out in Cooja simulator for Contiki-OS, which suggests significant gains in terms of energy efficiency and delay.
A hybrid evolutionary algorithm for attribute selection in data mining
اطلاع رسانیReal life data sets are often interspersed with noise, making the subsequent data mining process difficult. The task of the classifier could be simplified by eliminating attributes that are deemed to be redundant for classification, as the retention of only pertinent attributes would reduce the size of the dataset and subsequently allow more comprehensible analysis of the extracted patterns or rules. In this article, a new hybrid approach comprising of two conventional machine learning algorithms has been proposed to carry out attribute selection. Genetic algorithms (GAs) and support vector machines (SVMs) are integrated effectively based on a wrapper approach. Specifically, the GA component searches for the best attribute set by applying the principles of an evolutionary process. The SVM then classifies the patterns in the reduced datasets, corresponding to the attribute subsets represented by the GA chromosomes. The proposed GA- SVM hybrid is subsequently validated using datasets obtained from the UCI machine learning repository. Simulation results demonstrate that the GA-SVM hybrid produces good classification accuracy and a higher level of consistency that is comparable to other established algorithms. In addition, improvements are made to the hybrid by using a correlation measure between attributes as a fitness measure to replace the weaker members in the population with newly formed chromosomes. This injects greater diversity and increases the overall fitness of the population. Similarly, the improved mechanism is also validated on the same data sets used in the first stage. The results justify the improvements in the classification accuracy and demonstrate its potential to be a good classifier for future data mining purposes.
Grey wolf optimization applied to economic load dispatch problems
اطلاع رسانیThis article presents a new evolutionary optimization approach named grey wolf optimization (GWO), which is based on the behaviour of grey wolves, for the optimal operating strategy of economic load dispatch (ELD). Nonlinear characteristics of generators like ramp rate limits, valve point discontinuities and prohibited operating zones are considered in the problem. GWO method does not require any information about the gradient of the objective function, while searching for an optimum solution. The GWO algorithm concept, appears to be a robust and reliable optimization algorithm is applied to the nonlinear ELD problems. The proposed algorithm is implemented and tested on four test systems having 10, 40, 80 and 140 units. The results confirm the potential and effectiveness of the proposed algorithm compared to various other methods available in the literature. The outcome is very encouraging and proves that the GWO is a very effective optimization technique for solving various ELD problems.
Gender, Policy, Politics, and Work: Feminist Comparative and Transnational Research
اطلاع رسانیThis article reviewsfeminist comparative and transnational research on workplace policy, politics and the state. The first section examines a range of theoretical approaches to the topic. W e then present a variety of methodologiesfor conducting comparative and transnational research on policy developments. Informed by a number of case studies included in the symposium, we explore the dynamics and determinants, both national and supranational, of policy formation and its impacts. Finally, we tease out the implicit and explicit notions of gender equityfor future policy analysis. The last two decades of the twentieth century saw the rise of new policies, ranging from equal opportunities and parental and family leave to regulation of working time and sexual relations, that have made the workplace more hospitable to women workers. The collected articles explore the dynamics and determinants, both national and supranational, of such feminist policy formation and its impacts. This symposium contributes to comparative and transnational research on workplace policy, politics, and the state, using feminist perspectives.
ارائه روشی جدید جهت بالا بردن امنیت در سیستم عامل لینوکس
اطلاع رسانیامنیت پیکر بندي فایل ها در سیستم عامل لینوکس به عوامل زیادي بستگی دارد که می توان به سطح سیستم و سطح کاربردي اشاره نمود. مهم ترین نکته درباره امنیت سیستم عامل هاي لینوکس پویا بودن آن است، مثلا زمانی که شما سیستم لینوکس خود را امن می کنید براي همیشه امن باقی نمی ماند زیرا برنامه هاي کاربردي و سیستی که از طریق تهدیدات و یا سوء استفاده هاي جدیدي که براي بسته هاي سیستمی یا برنامه هاي کاربردي ساخته می شوند باعث نا امن شدن سیستم عامل می شود به این دلیل نیازمند یک سیستم عامل امن هستیم. هدف اصلی از انجام این مقاله ارائه روشی جدید جهت بالا بردن امنیت در سیستم عامل لینوکس می باشد. بدین منظور این که چگونه می توان به سادگی، مداوم و عملی محیط لینوکس را امن کرد، راهکارهایی ارائه شد، همچنین بر اساس تجزیه و تحلیل عملکرد روش پیشنهادي و نیز پارامتر هاي ارزیابی براي سیستم هاي موجود در مقابل سیستم پیشنهادي، برتري این روش معرفی می گردد.
Reflections and interpretations on life in academia: a mentee speaks
اطلاع رسانیUsing personal autobiographical data collected over the course of an academic year, this article reflects the experiences of a new teacher educator entering higher education. Emergent patterns are examined and illuminated using the discourse of mentoring, and this discourse is, in turn, challenged, in part for the imbalance in the voices recorded, and at times for its masculine nature. The notion of a mentee’s role being in any way passive is dismissed, and the relationship between mentor and mentee is examined for reciprocity and negotiation within a structured, supportive framework. Questions are posed regarding the benefits and costs to mentors, citing research that exposes how even the most successful women in academia may suffer negative emotions. In analysing one mentee’s journey through a year in academia, a struggle with a changing and contradictory selfimage is exposed. Having a sense of ownership in a learner-driven mentoring process is acknowledged, and some suggestions on the qualities of a successful mentee are offered. The paradox of who mentors the mentors is also examined. The process of mentoring is viewed as an investment in staff and the constantly evolving institution.