20,181 research outputs found

    Cost-Efficient Data Backup for Data Center Networks against {\epsilon}-Time Early Warning Disaster

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    Data backup in data center networks (DCNs) is critical to minimize the data loss under disaster. This paper considers the cost-efficient data backup for DCNs against a disaster with ε\varepsilon early warning time. Given geo-distributed DCNs and such a ε\varepsilon-time early warning disaster, we investigate the issue of how to back up the data in DCN nodes under risk to other safe DCN nodes within the ε\varepsilon early warning time constraint, which is significant because it is an emergency data protection scheme against a predictable disaster and also help DCN operators to build a complete backup scheme, i.e., regular backup and emergency backup. Specifically, an Integer Linear Program (ILP)-based theoretical framework is proposed to identify the optimal selections of backup DCN nodes and data transmission paths, such that the overall data backup cost is minimized. Extensive numerical results are also provided to illustrate the proposed framework for DCN data backup

    Economic and Workforce Development Task Force Report, August 2008

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    The 2008 disasters devastated businesses, farms, homes, schools, non-profit institutions, entire communities, and people’s lives across the state of Iowa. The Rebuild Iowa Advisory Commission (RIAC) is charged by the Governor to guide the state’s recovery and reconstruction process. The Economic and Workforce Development Task Force is respectfully submitting this report to be included and considered in the deliberations of the RIAC. While economic and workforce development are two issues that are inextricably linked and critical to Iowa’s rebuilding strategies, each also requires extraordinary attention in determining what needs to be considered in the very immediate and longer-term recovery

    Optimizing the Structure and Scale of Urban Water Infrastructure: Integrating Distributed Systems

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    Large-scale, centralized water infrastructure has provided clean drinking water, wastewater treatment, stormwater management and flood protection for U.S. cities and towns for many decades, protecting public health, safety and environmental quality. To accommodate increasing demands driven by population growth and industrial needs, municipalities and utilities have typically expanded centralized water systems with longer distribution and collection networks. This approach achieves financial and institutional economies of scale and allows for centralized management. It comes with tradeoffs, however, including higher energy demands for longdistance transport; extensive maintenance needs; and disruption of the hydrologic cycle, including the large-scale transfer of freshwater resources to estuarine and saline environments.While smaller-scale distributed water infrastructure has been available for quite some time, it has yet to be widely adopted in urban areas of the United States. However, interest in rethinking how to best meet our water and sanitation needs has been building. Recent technological developments and concerns about sustainability and community resilience have prompted experts to view distributed systems as complementary to centralized infrastructure, and in some situations the preferred alternative.In March 2014, the Johnson Foundation at Wingspread partnered with the Water Environment Federation and the Patel College of Global Sustainability at the University of South Florida to convene a diverse group of experts to examine the potential for distributed water infrastructure systems to be integrated with or substituted for more traditional water infrastructure, with a focus on right-sizing the structure and scale of systems and services to optimize water, energy and sanitation management while achieving long-term sustainability and resilience

    Alpha Entanglement Codes: Practical Erasure Codes to Archive Data in Unreliable Environments

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    Data centres that use consumer-grade disks drives and distributed peer-to-peer systems are unreliable environments to archive data without enough redundancy. Most redundancy schemes are not completely effective for providing high availability, durability and integrity in the long-term. We propose alpha entanglement codes, a mechanism that creates a virtual layer of highly interconnected storage devices to propagate redundant information across a large scale storage system. Our motivation is to design flexible and practical erasure codes with high fault-tolerance to improve data durability and availability even in catastrophic scenarios. By flexible and practical, we mean code settings that can be adapted to future requirements and practical implementations with reasonable trade-offs between security, resource usage and performance. The codes have three parameters. Alpha increases storage overhead linearly but increases the possible paths to recover data exponentially. Two other parameters increase fault-tolerance even further without the need of additional storage. As a result, an entangled storage system can provide high availability, durability and offer additional integrity: it is more difficult to modify data undetectably. We evaluate how several redundancy schemes perform in unreliable environments and show that alpha entanglement codes are flexible and practical codes. Remarkably, they excel at code locality, hence, they reduce repair costs and become less dependent on storage locations with poor availability. Our solution outperforms Reed-Solomon codes in many disaster recovery scenarios.Comment: The publication has 12 pages and 13 figures. This work was partially supported by Swiss National Science Foundation SNSF Doc.Mobility 162014, 2018 48th Annual IEEE/IFIP International Conference on Dependable Systems and Networks (DSN

    We need to use the words...

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    Sometimes it’s important to simply say the words … as it is in the beginning of wisdom that is the definition of terms. When historians look at the world of project management, what will they say that we have said about climate change? Certainly more general—but absolutely legitimate—terms such as ‘sustainability’ have been used, but in a basic term search in the 3 oldest project management journals, I was surprised to see only a few dozen uses of ‘climate change’ as a specific term. Theconversation started a long time ago using those words, and PMRP would like to encourage more with this commentary on one of the central topics of this journal … climate change

    Resource capability for local government in mainstreaming gender into disaster risk reduction: evidence from Indonesia

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    Understanding how local government responds to gender vulnerability and gender capacity is important to make cities safer both for women and for men. However, little is known on how local government is empowered in terms of provision of capacity, resources and abilities to mainstreaming gender into disaster risk reduction and community resilience. The case of Indonesia pinpoints district government capability is vital to promote gender equality within local disaster risk reduction and resilience. The district government capability means the ability of local government to organise resources, competence and knowledge to meet the needs and concerns of women and men within disaster risk reduction process. This capability has been transformed into their ability in institutional and human resources policy and for providing financial, technical and leadership capabilities to promote gender equality into local disaster risk reduction and resilience. Experience of Bantul earthquake reconstruction shows a significant achievement has been made by this district in terms of local capability in mainstreaming gender. Among the most important factors related to district capability are women leadership, support from non-government organisations, women participation, financial resources and capacity of local gender institutions
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