Efficient Wireless Security Through Jamming, Coding and Routing

There is a rich recent literature on how to assist secure communication between a single transmitter and receiver at the physical layer of wireless networks through techniques such as cooperative jamming. In this paper, we consider how these single-hop physical layer security techniques can be extended to multi-hop wireless networks and show how to augment physical layer security techniques with higher layer network mechanisms such as coding and routing. Specifically, we consider the secure minimum energy routing problem, in which the objective is to compute a minimum energy path between two network nodes subject to constraints on the end-to-end communication secrecy and goodput over the path. This problem is formulated as a constrained optimization of transmission power and link selection, which is proved to be NP-hard. Nevertheless, we show that efficient algorithms exist to compute both exact and approximate solutions for the problem. In particular, we develop an exact solution of pseudo-polynomial complexity, as well as an epsilon-optimal approximation of polynomial complexity. Simulation results are also provided to show the utility of our algorithms and quantify their energy savings compared to a combination of (standard) security-agnostic minimum energy routing and physical layer security. In the simulated scenarios, we observe that, by jointly optimizing link selection at the network layer and cooperative jamming at the physical layer, our algorithms reduce the network energy consumption by half

Optimal Caching and Routing in Hybrid Networks

Hybrid networks consisting of MANET nodes and cellular infrastructure have been recently proposed to improve the performance of military networks. Prior work has demonstrated the benefits of in-network content caching in a wired, Internet context. We investigate the problem of developing optimal routing and caching policies in a hybrid network supporting in-network caching with the goal of minimizing overall content-access delay. Here, needed content may always be accessed at a back-end server via the cellular infrastructure; alternatively, content may also be accessed via cache-equipped "cluster" nodes within the MANET. To access content, MANET nodes must thus decide whether to route to in-MANET cluster nodes or to back-end servers via the cellular infrastructure; the in-MANET cluster nodes must additionally decide which content to cache. We model the cellular path as either i) a congestion-insensitive fixed-delay path or ii) a congestion-sensitive path modeled as an M/M/1 queue. We demonstrate that under the assumption of stationary, independent requests, it is optimal to adopt static caching (i.e., to keep a cache's content fixed over time) based on content popularity. We also show that it is optimal to route to in-MANET caches for content cached there, but to route requests for remaining content via the cellular infrastructure for the congestion-insensitive case and to split traffic between the in-MANET caches and cellular infrastructure for the congestion-sensitive case. We develop a simple distributed algorithm for the joint routing/caching problem and demonstrate its efficacy via simulation.Comment: submitted to Milcom 201

DESIGN, ANALYSIS AND OPTIMIZATION OF CACHE SYSTEMS

The increase in data traffic over the past years is predicted to continue more aggressively in the years to come. However, traditional methods such as increasing the amount of spectrum or deploying more base stations are no longer sufficient to cope with the traffic growth. Caching is hence recognized as one of the most effective means to improve the performance of Internet services by bringing content closer to the end-users. Although the benefits of in-network content caching has been demonstrated in various contexts, they introduce new challenges in terms of modeling and analyzing network performance. Building on analytical results for Time-To-Live caches and the flexibility they provide in modeling caches, this thesis investigates various aspects in which caching affects network design and performance. The complexity of making optimal routing and content placement decisions is studied first. Showing the infeasibility of implementing the optimal strategy, low-complexity techniques are developed to achieve near-optimal performance in terms of the delay observed by end-users. The problem of differentiated cache services is studied next with the question ``how can Content Distribution Networks implement caching policies to provide differentiated services to different content providers?\u27\u27. A utility-maximization framework is formulated to design caching policies with fairness considerations and implications on market economy for cache service providers and content publishers. An online algorithm is also developed with the purpose of implementing the utility-based cache policies with no a priori information on the number of contents and file popularities. This thesis also analyzes caches in conjunction with data structures, e.g. Pending Interest Table, proposed in the future Internet architecture designs such as Named Data Networking. The analysis provides the means to understand system performance under different circumstances, and develop techniques to achieve optimal performance

Mortality rate and immune responses of rainbow trout (Oncorhynchus mykiss) infected with Yersinia ruckeri subsequent to feeding on diet supplemented with Ducrosia anethifolia essential oil

Application of the immunostimulant is the most promising method for controlling diseases in aquaculture. In this study, the mortality rate and immune responses of rainbow trout (Oncorhynchus mykiss) fed on diet supplemented with Ducrosia anethifolia essential oil was investigated after challenging with Yersinia ruckeri. The essential oil mixed with sunflower oil at different concentrations (0.001, 0.01 and 0.1%) and the commercial food was coated with this oil. Fish were fed with diets for 8 weeks and infected with Y. ruckeri at the ending of feeding trial. Serum protein, albumin, globulin and lysozyme and bactericidal activity of challenged fish were evaluated one week after injection and mortality were counted till day 10. The results showed that albumin had not differed among treatments. The highest level of the protein and globulin were found in control group. Serum lysozyme activity showed no difference between groups. The highest and lowest serum bactericidal activity was observed in 0.001% and control group, respectively. The mortality rates in infected fish were as 55% in control group, 40% in 0.001%, 70% in 0.01% and 70% in 0.1% treatment. Lowest rate of mortality was observed in group 0.001%, while began two days earlier than other groups

THE LINK BETWEEN ALLERGIC RHINITIS AND RHEUMATIC DISORDERS: FROM AVICENNA'S VIEW TO RECENT FINDINGS

Allergic rhinitis (AR) is one of the most prevalent allergic disorder across the globe which has significant socioeconomic costs. In addition to direct and indirect costs, the disease also has hidden direct costs related to comorbid conditions. AR can result in several complications such as pharyngitis, sinusitis, asthma, otitis media, eczema and lymphoid hypertrophy. Although associations between AR and other airway disorders have been investigated for years, less attention has been focused on the association of this disease with non-respiratory disorders. Cosidering the fact that AR is rarely found in isolation and reprts of traditional Persian medical literatures on the relationship between rhinitis and joint disorders, this study aimed to investigate the link between AR and rheumatic disorders. In this regard, Avicenna’s Canon of Medicine which was a well known medical textbook until 17th century was reviewed. Modern medical databases were searched as well. The results of this study showed that as mentioned in the teachings of Avicenna, allergic rhinitis may have association with some rheumatic disorders such as rheumatoid arthritis, low back pain and gout. Findings that support this hypothesis include the wide range of symptoms and complications of allergic rhinitis, emphasizing the association by prominent medical scholars of the past like Rhazes and Avicenna, studies found an association between AR or chronic rhnosinusitis with rheumatic diseases and common cytokines and inflammatory biomarkers that serve similar roles in both allergic rhinitis and rheumatic diseases like IL-4, IL-6, IL-8, IL-17 and TNF-alpha. It is suggested that studies be conducted with the main aim of investigating the relationship between these diseases and evaluating underlying mechanisms. The result of such research can be helpful in finding new treatment modalities in both groups. Keywords: allergic rhinitis; rheumatic disorder; comorbidity, traditional medicine; Persian medicine; Avicenn

Exploring society responsibilities in promoting Islamic ethics standards

ABSTRACT This research was aimed at exploring society responsibilities in promoting Islamic ethics standards and has been pathologically formulated to institutionalize what the existential nature and identity-orientedness is with regards to men and women' responsibilities and also those of the Islamic government separately. Attempts have been made to explain why the bases of moral virtues in the Koran which are worship, justice and righteousness have been observed. Later, the research refers to guidelines for reaching and fulfillment of moral standards in the society and specifically from a sociological point of view. The results found indicated that moral perfection could through man's psychological innate and bound and strong religious basis bring about some exhilarating moral standards within the existence, conscience and essence of humans. The man's perfection and superiority is instituted in regard to the knowledge of identity and understanding inner values and the goal of creation of humans

An approximate analysis of heterogeneous and general cache networks

In this paper, we propose approximate models to assess the performance of a cache network with arbitrary topology where nodes run the Least Recently Used (LRU), First-In First-Out (FIFO), or Random (RND) replacement policies on arbitrary size caches. Our model takes advantage of the notions of cache characteristic time and Time-To-Live (TTL)-based cache to develop a unified framework for approximating metrics of interest of interconnected caches. Our approach is validated through event-driven simulations; and when possible, compared to the existing a-NET model [23].Dans ce travail, nous proposons des modèles approximatifs pour évaluer les performances d'un réseau de caches ayant une topologie arbitraire où les noeuds exécutent les politiques Least Recently Used (LRU), First In First Out (FIFO), ou Random replacement (RND) sur des caches de taille quelconque. Notre modèle tire parti des notions de temps caractéristique d'un cache et des modèles Time-To-Live (TTL) de cache pour développer une approche unifiée pour l'approximation des métriques de performance sur des caches interconnectés. Notre approche est validée par des simulations événementielles; et, si possible, comparée au modèle existant a-NET [23]