Biblio

This paper studies Wireless Information-Theoretic Security for low-speed mobility in autonomic networks. More specifically, the impact of user movement on the Probability of Non-Zero Secrecy Capacity and Outage Secrecy Capacity for different channel conditions has been investigated. This is accomplished by establishing a link between different user locations and the boundaries of information-theoretic secure communication. Human mobility scenarios are considered, and its impact on physical layer security is examined, considering quasi-static Rayleigh channels for the fading phenomena. Simulation results have shown that the Secrecy Capacity depends on the relative distance of legitimate and illegitimate (eavesdropper) users in reference to the given transmitter.

Resilience is regarded nowadays as the ideal solution that can be envisaged by sociotechnical systems for coping with potential threats and crises. This being said, gaining and maintaining this ability is not always easy, given the multitude of risks driving the adverse and challenging events. This paper aims to propose a method consecrated to the assessment of risks directly affecting resilience. This work is conducted within the framework of risk assessment and resilience engineering approaches. A 5×5 matrix, dedicated to the identification and assessment of risk factors that constitute threats to the system resilience, has been elaborated. This matrix consists of two axes, namely, the impact on resilience metrics and the availability and effectiveness of resilience planning. Checklists serving to collect information about these two attributes are established and a case study is undertaken. In this paper, a new method for identifying and assessing risk factors menacing directly the resilience of a given system is presented. The analysis of these risks must be given priority to make the system more resilient to shocks.

In this paper, the physical layer (PHY)security performance of a dual-hop cooperative relaying in a cognitive-radio system in the presence of an eavesdropper is investigated. The dual-hop transmission is composed of an asymmetric radio frequency (RF)link and a free space optical (FSO)link. In the considered system, an unlicensed secondary user (SU)uses the spectrum which is shared by a licensed primary user (PU)in a controlled manner to keep the interference at PU receiver, below a predefined value. Furthermore, among M available relays, one relay with the best end-to-end signal-to-noise-ratio (SNR)is selected for transmission. It is assumed that all of the RF links follow Rayleigh fading and all of the FSO links follow Gamma-Gamma distribution. Simulations results for some important security metrics, such as the average secrecy capacity (SC), and secrecy outage probability (SOP)are presented, where some practical issues of FSO links such as atmospheric turbulence, and pointing errors are taken into consideration.

Multipath fading as well as shadowing is liable for the leakage of confidential information from the wireless channels. In this paper a solution to this information leakage is proposed, where a source transmits signal through a α-μ/α-μ composite fading channel considering an eavesdropper is present in the system. Secrecy enhancement is investigated with the help of two fading parameters α and μ. To mitigate the impacts of shadowing a α-μ distribution is considered whose mean is another α-μ distribution which helps to moderate the effects multipath fading. The mathematical expressions of some secrecy matrices such as the probability of non-zero secrecy capacity and the secure outage probability are obtained in closed-form to analyze security of the wireless channel in light of the channel parameters. Finally, Monte-Carlo simulations are provided to justify the correctness of the derived expressions.

We develop a contingency planning methodology for how a firm would build a global supply chain network with reserve manufacturing capacity which can be strategically deployed by the firm in the event actual demand exceeds forecast. The contingency planning approach is comprised of: (1) a strategic network design model for finding the profit maximizing plant locations, manufacturing capacity and inventory investments, and production level and product distribution; and (2) a scenario planning and risk assessment scheme to analyze the costs and benefits of alternative levels of manufacturing capacity and inventory investments. We develop an efficient heuristic procedure to solve the model. We show numerically how a firm would use our approach to explore and weigh the potential upside benefits and downside risks of alternative strategies.

This paper addresses the need for standard communication protocols for IoT devices with limited power and computational capabilities. The world is rapidly changing with the proliferation and deployment of IoT devices. This will bring in new communication challenges as these devices are connected to Internet and need to communicate with each other in real time. The paper provides an overview of IoT system architecture and the forthcoming challenges it will bring. There is an urging need to establish standards for communication in the IoT world. With the recent development of new protocols like CoAP, 6LowPAN, IEEE 802.15.4 and Thread in different layers of OSI model, additional challenges also present themselves. Performance and data management is becoming more critical than ever before due to the complexity of connecting raging number of IoT devices. The performance of the systems dealing with IoT devices will require appropriate capacity planning the associated development of data centers. Finally, the paper also presents some reasonable approaches to address the above issues in the IoT world.

In distributed wireless storage systems, failed recovery probability depends on not only wireless channel conditions but also storage size of each distributed storage node. For efficient utilization of limited storage capacity, we asymptotically analyze the failed recovery probability of a distributed wireless storage system with a sum storage capacity constraint when signal-to-noise ratio goes to infinity, and find the optimal storage allocation strategy across distributed storage nodes in terms of the asymptotic failed recovery probability. It is also shown that when the number of storage nodes is sufficiently large the storage size required at each node is not so large for high exponential order of the failed recovery probability.