18,202 research outputs found

    Recreation, tourism and nature in a changing world : proceedings of the fifth international conference on monitoring and management of visitor flows in recreational and protected areas : Wageningen, the Netherlands, May 30-June 3, 2010

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    Proceedings of the fifth international conference on monitoring and management of visitor flows in recreational and protected areas : Wageningen, the Netherlands, May 30-June 3, 201

    Optical layer monitoring schemes for fast link failure localization in all-optical networks

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    Optical layer monitoring and fault localization serves as a critical functional module in the control and management of optical networks. An efficient monitoring scheme aims at minimizing not only the hardware cost required for 100{%} link failure localization, but also the number of redundant alarms and monitors such that the network fault management can be simplified as well. In recent years, several optical layer monitoring schemes were reported for fast and efficient link failure localization, including simple, non-simple monitoring cycle (m-cycle) and monitoring trail (m-trail). Optimal ILP (Integer Linear Program) models and heuristics were also proposed with smart design philosophy on flexibly trading off different objectives. This article summarizes those innovative ideas and methodologies with in-depth analysis on their pros and cons. We also provide insights on future research topics in this area, as well as possible ways for extending the new failure localization approaches to other network applications. © 2005 IEEE.published_or_final_versio

    Link Fault Localization using Bi-directional M-Trails in All-Optical Mesh Networks

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    Differentiated quality-of-recovery and quality-of-protection in survivable WDM mesh networks

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    In the modern telecommunication business, there is a need to provide different Quality-of-Recovery (QoR) and Quality-of-Protection (QoP) classes in order to accommodate as many customers as possible, and to optimize the protection capacity cost. Prevalent protection methods to provide specific QoS related to protection are based on pre-defined shape protection structures (topologies), e.g., p -cycles and p -trees. Although some of these protection patterns are known to provide a good trade-off among the different protection parameters, their shapes can limit their deployment in some specific network conditions, e.g., a constrained link spare capacity budget and traffic distribution. In this thesis, we propose to re-think the design process of protection schemes in survivable WDM networks by adopting a hew design approach where the shapes of the protection structures are decided based on the targeted QoR and QoP guarantees, and not the reverse. We focus on the degree of pre-configuration of the protection topologies, and use fully and partially pre-cross connected p -structures, and dynamically cross connected p -structures. In QoR differentiation, we develop different approaches for pre-configuring the protection capacity in order to strike different balances between the protection cost and the availability requirements in the network; while in the QoP differentiation, we focus on the shaping of the protection structures to provide different grades of protection including single and dual-link failure protection. The new research directions proposed and developed in this thesis are intended to help network operators to effectively support different Quality-of-Recovery and Quality-of-Protection classes. All new ideas have been translated into mathematical models for which we propose practical and efficient design methods in order to optimize the inherent cost to the different designs of protection schemes. Furthermore, we establish a quantitative relation between the degree of pre-configuration of the protection structures and their costs in terms of protection capacity. Our most significant contributions are the design and development of Pre-Configured Protection Structure (p-structure) and Pre-Configured Protection Extended-Tree (p -etree) based schemes. Thanks to the column generation modeling and solution approaches, we propose a new design approach of protection schemes where we deploy just enough protection to provide different quality of recovery and protection classe

    Recursive SDN for Carrier Networks

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    Control planes for global carrier networks should be programmable (so that new functionality can be easily introduced) and scalable (so they can handle the numerical scale and geographic scope of these networks). Neither traditional control planes nor new SDN-based control planes meet both of these goals. In this paper, we propose a framework for recursive routing computations that combines the best of SDN (programmability) and traditional networks (scalability through hierarchy) to achieve these two desired properties. Through simulation on graphs of up to 10,000 nodes, we evaluate our design's ability to support a variety of routing and traffic engineering solutions, while incorporating a fast failure recovery mechanism

    A comprehensive meta-analysis of cryptographic security mechanisms for cloud computing

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    The file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the DOI link.The concept of cloud computing offers measurable computational or information resources as a service over the Internet. The major motivation behind the cloud setup is economic benefits, because it assures the reduction in expenditure for operational and infrastructural purposes. To transform it into a reality there are some impediments and hurdles which are required to be tackled, most profound of which are security, privacy and reliability issues. As the user data is revealed to the cloud, it departs the protection-sphere of the data owner. However, this brings partly new security and privacy concerns. This work focuses on these issues related to various cloud services and deployment models by spotlighting their major challenges. While the classical cryptography is an ancient discipline, modern cryptography, which has been mostly developed in the last few decades, is the subject of study which needs to be implemented so as to ensure strong security and privacy mechanisms in today’s real-world scenarios. The technological solutions, short and long term research goals of the cloud security will be described and addressed using various classical cryptographic mechanisms as well as modern ones. This work explores the new directions in cloud computing security, while highlighting the correct selection of these fundamental technologies from cryptographic point of view

    High Peaks Back - country Trails Plan

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    The High Peaks Trails Plan is a regional vision for back-country trails in Maine\u27s High Peaks region. The plan identifies challenges and opportunities which face the trails community, and outlines several strategies for trails groups to move forward together to overcome mutual challenges
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