The Experts below are selected from a list of 16995 Experts worldwide ranked by ideXlab platform
Alexander Varshavsky - One of the best experts on this subject based on the ideXlab platform.
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vis a vis privacy preserving online social networking via virtual Individual Servers
Communication Systems and Networks, 2011Co-Authors: Amre Shakimov, Harold Lim, Ramon Caceres, Landon P Cox, Dongtao Liu, Alexander VarshavskyAbstract:Online social networks (OSNs) are immensely popular, but their centralized control of user data raises important privacy concerns. This paper presents Vis-a-Vis, a decentralized framework for OSNs based on the privacy-preserving notion of a Virtual Individual Server (VIS). A VIS is a personal virtual machine running in a paid compute utility. In Vis-a-Vis, a person stores her data on her own VIS, which arbitrates access to that data by others. VISs self-organize into overlay networks corresponding to social groups. This paper focuses on preserving the privacy of location information. Vis-a-Vis uses distributed location trees to provide efficient and scalable operations for sharing location information within social groups. We have evaluated our Vis-a-Vis prototype using hundreds of virtual machines running in the Amazon EC2 compute utility. Our results demonstrate that Vis-a-Vis represents an attractive complement to today's centralized OSNs.
Amin Vahdat - One of the best experts on this subject based on the ideXlab platform.
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maintaining high bandwidth under dynamic network conditions
USENIX Annual Technical Conference, 2005Co-Authors: Dejan Kostic, Ryan Braud, Charles Killian, Erik Vandekieft, James W Anderson, Alex C Snoeren, Amin VahdatAbstract:The need to distribute large files across multiple wide-area sites is becoming increasingly common, for instance, in support of scientific computing, configuring distributed systems, distributing software updates such as open source ISOs or Windows patches, or disseminating multimedia content. Recently a number of techniques have been proposed for simultaneously retrieving portions of a file from multiple remote sites with the twin goals of filling the client's pipe and overcoming any performance bottlenecks between the client and any Individual Server. While there are a number of interesting tradeoffs in locating appropriate download sites in the face of dynamically changing network conditions, to date there has been no systematic evaluation of the merits of different protocols. This paper explores the design space of file distribution protocols and conducts a detailed performance evaluation of a number of competing systems running in both controlled emulation environments and live across the Internet. Based on our experience with these systems under a variety of conditions, we propose, implement and evaluate Bullet' (Bullet prime), a mesh based high bandwidth data dissemination system that outperforms previous techniques under both static and dynamic conditions.
Xue Liu - One of the best experts on this subject based on the ideXlab platform.
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towards optimal electric demand management for internet data centers
IEEE Transactions on Smart Grid, 2012Co-Authors: Kui Ren, Xue LiuAbstract:Electricity cost is becoming a major portion of Internet data center (IDC)'s operation cost and large-scale IDCs are becoming important consumers of regional electricity markets. IDC's energy efficiency is gaining more attention by data center operators and electricity market operators. Effective IDC electric demand management solutions are eagerly sought by all stakeholders. In this paper, a mixed-integer programming model based IDC electric demand management solution is proposed, which integrates both the impacts of locational marginal electricity prices and power management capability of IDC itself. Dynamic voltage/frequency scaling of Individual Server, cluster Server ON/OFF scheduling, and dynamic workload dispatching are optimized while complying with all the IDC system-wide and Individual heterogeneous Servers' operation constraints according to the IDC applications' temporal variant workload. Reduced electricity cost can be achieved together with guaranteed QoS requirement and reliability consideration by using the proposed model. World Cup '98 data is utilized to evaluate the effectiveness of the proposed solution. According to the experimental evaluation, electricity cost could be cut by more than 20% in a peak workload period and by more than 80% in a light workload period. Besides, more than 6% electricity cost could be cut by considering the impact of electricity price difference. Experimental results also reveal that higher QoS requirement and reliability consideration could result in higher electricity cost.
Jeffrey S Chase - One of the best experts on this subject based on the ideXlab platform.
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ensemble level power management for dense blade Servers
International Symposium on Computer Architecture, 2006Co-Authors: Parthasarathy Ranganathan, Phillip A Leech, David Irwin, Jeffrey S ChaseAbstract:One of the key challenges for high-density Servers (e.g., blades) is the increased costs in addressing the power and heat density associated with compaction. Prior approaches have mainly focused on reducing the heat generated at the level of an Individual Server. In contrast, this work proposes power efficiencies at a larger scale by leveraging statistical properties of concurrent resource usage across a collection of systems ("ensemble"). Specifically, we discuss an implementation of this approach at the blade enclosure level to monitor and manage the power across the Individual blades in a chassis. Our approach requires low-cost hardware modifications and relatively simple software support. We evaluate our architecture through both prototyping and simulation. For workloads representing 132 Servers from nine different enterprise deployments, we show significant power budget reductions at performances comparable to conventional systems.
Amre Shakimov - One of the best experts on this subject based on the ideXlab platform.
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vis a vis privacy preserving online social networking via virtual Individual Servers
Communication Systems and Networks, 2011Co-Authors: Amre Shakimov, Harold Lim, Ramon Caceres, Landon P Cox, Dongtao Liu, Alexander VarshavskyAbstract:Online social networks (OSNs) are immensely popular, but their centralized control of user data raises important privacy concerns. This paper presents Vis-a-Vis, a decentralized framework for OSNs based on the privacy-preserving notion of a Virtual Individual Server (VIS). A VIS is a personal virtual machine running in a paid compute utility. In Vis-a-Vis, a person stores her data on her own VIS, which arbitrates access to that data by others. VISs self-organize into overlay networks corresponding to social groups. This paper focuses on preserving the privacy of location information. Vis-a-Vis uses distributed location trees to provide efficient and scalable operations for sharing location information within social groups. We have evaluated our Vis-a-Vis prototype using hundreds of virtual machines running in the Amazon EC2 compute utility. Our results demonstrate that Vis-a-Vis represents an attractive complement to today's centralized OSNs.