39,245 research outputs found

    Design-time Models for Resiliency

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    Resiliency in process-aware information systems is based on the availability of recovery flows and alternative data for coping with missing data. In this paper, we discuss an approach to process and information modeling to support the specification of recovery flows and alternative data. In particular, we focus on processes using sensor data from different sources. The proposed model can be adopted to specify resiliency levels of information systems, based on event-based and temporal constraints

    Dynamic resiliency analysis of key predistribution in wireless sensor networks

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    Wireless sensor networks have been analyzed for more than a decade from operational and security points of view. Several key predistribution schemes have been proposed in the literature. Although valuable and state-of-the-art proposals have been made, their corresponding security analyses have not been performed by considering the dynamic nature of networking behavior and the time dimension. The sole metric used for resiliency analysis of key predistribution schemes is "fraction of links compromised" which is roughly defined as the ratio of secure communication links that the adversary can compromise over all secure links. However, this metric does not consider the dynamic nature of the network; it just analyzes a snapshot of the network without considering the time dimension. For example, possible dead nodes may cause change of routes and some captured links become useless for the attacker as time goes by. Moreover, an attacker cannot perform sensor node capturing at once, but performs over time. That is why a methodology for dynamic security analysis is needed in order to analyze the change of resiliency in time a more realistic way. In this paper, we propose such a dynamic approach to measure the resiliency of key predistribution schemes in sensor networks. We take the time dimension into account with a new performance metric, "captured message fraction". This metric is defined as the percentage of the messages generated within the network to be forwarded to the base station (sink) that are captured and read by the attacker. Our results show that for the cases where the static fraction of links compromised metric indicates approximately 40% of the links are compromised, our proposed captured message fraction metric shows 80% of the messages are captured by the attacker. This clearly proves the limitations of the static resiliency analysis in the literature

    Harmonizing Climate Change Mitigation and Adaptation in Transportation and Land-Use Planning in California Cities

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    Abstract: Recent extreme weather events in California—wildfires, drought, and flooding—make abundantly clear the need to plan effective responses to both the causes and the consequences of climate change. A central challenge for climate planning efforts has been identifying transportation and land-use (TLU) strategies that simultaneously reduce greenhouse gas emissions (“mitigation”) and adapt communities so that they will be less affected by the adverse impacts of climate change (“adaptation”). Sets of policies that collectively address both mitigation and adaptation are known as “integrated actions.” This study explores municipal climate planning in California to determine whether cities incorporate integrated actions into their plans, assess the potential drivers of conflict between mitigation and adaptation in municipal plans, and identify ways the State of California can help cities more effectively incorporate integrated actions. The study methods consisted of a detailed analysis of climate planning documents from 23 California cities with particularly long histories of climate planning, plus interviews with 25 local, regional, and state officials who work on municipal climate planning. The authors found that some cities did adopt packages of integrated actions, and, promisingly, two cities with recently updated climate plans explicitly focused on the need for integrated actions. However, most cities addressed climate mitigation and adaptation in separate efforts, potentially reducing synergies between the two types of action and even creating conflicts. Since the first generation of climate action plans focused primarily on mitigation of greenhouse gases (GHGs), adaptation strategies have not yet been effectively or fully combined into mitigation plans in many cities. Also, a cross-comparison of plan content and interview data suggests that cities often had sets of policies that could potentially create conflicts—mitigation policies that would undermine adaptation capacity, and vice versa. In addition, where a city did adopt integrated actions, these efforts are typically not labeled as such, nor do the policies appear within the same policy document. The study findings suggest promising steps that both municipal and state governments can take to support integrated TLU actions at the local level. For example, cities can proactively link the content in climate mitigation and adaptation plans—a process that will require building the capacity for cross-collaboration between the various departments in charge of developing, implementing, and monitoring climate-related plans. As for the state government, it can provide funding specifically for planning and implementing integrated actions, offer technical support to help municipalities adopt programs and projects that produce integrated mitigation and adaptation benefits, and fund research in the area of integrated actions

    Robust Energy Management for Green and Survivable IP Networks

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    Despite the growing necessity to make Internet greener, it is worth pointing out that energy-aware strategies to minimize network energy consumption must not undermine the normal network operation. In particular, two very important issues that may limit the application of green networking techniques concern, respectively, network survivability, i.e. the network capability to react to device failures, and robustness to traffic variations. We propose novel modelling techniques to minimize the daily energy consumption of IP networks, while explicitly guaranteeing, in addition to typical QoS requirements, both network survivability and robustness to traffic variations. The impact of such limitations on final network consumption is exhaustively investigated. Daily traffic variations are modelled by dividing a single day into multiple time intervals (multi-period problem), and network consumption is reduced by putting to sleep idle line cards and chassis. To preserve network resiliency we consider two different protection schemes, i.e. dedicated and shared protection, according to which a backup path is assigned to each demand and a certain amount of spare capacity has to be available on each link. Robustness to traffic variations is provided by means of a specific modelling framework that allows to tune the conservatism degree of the solutions and to take into account load variations of different magnitude. Furthermore, we impose some inter-period constraints necessary to guarantee network stability and preserve the device lifetime. Both exact and heuristic methods are proposed. Experimentations carried out with realistic networks operated with flow-based routing protocols (i.e. MPLS) show that significant savings, up to 30%, can be achieved also when both survivability and robustness are fully guaranteed

    Working with parents to support their disabled children’s social and school inclusion. An exploratory counseling study

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    This article synthesizes the long-lasting counseling process of a family with a child suffering from a chronic illness. The provided intervention model draws on a series of principles from various theoretical approaches, namely systemic, psychodynamic, and resiliency. Family functioning and support is considered a catalytic parameter in assisting children with disabilities to fully develop their potential. This project is based on a family and child-centered integrative counseling model adopting the nonmedical conception of disability. Through the presentation of a case study of a couple who faced a critical situation in the life of their child, this article briefly describes the way the family dynamics were readdressed through this intervention counseling model. In addition, this work attempts to give a picture of the complex and confusing emotional states parents may go through when dealing with physical and psychological health-threatening situations and present guidelines for integrated counseling models. © 2015 Taylor & Francis Group, LL

    A highly resilient and zone-based key predistribution protocol for multiphase wireless sensor networks

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    Pairwise key distribution among the sensor nodes is an essential problem for providing security in Wireless Sensor Networks (WSNs). The common approach for this problem is random key predistribution, which suffers from resiliency issues in case of node captures by adversaries. In the literature, the resiliency problem is addressed by zone-based deployment models that use prior deployment knowledge. Another remedy in the literature, which is for multiphase WSNs, aims to provide self-healing property via periodic deployments of sensor nodes with fresh keys over the sensor field. However, to the best of our knowledge, these two approaches have never been combined before in the literature. In this paper, we propose a zone-based key predistribution approach for multiphase WSNs. Our approach combines the best parts of these approaches and provides self-healing property with up to 9-fold more resiliency as compared to an existing scheme. Moreover, our scheme ensures almost 100% secure connectivity, which means a sensor node shares at least one key with almost all of its neighbors
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