Duke University

Displaying 1-40 of 114 results

  • White Papers // Apr 2014

    Experiences in Developing and Evaluating a Low-Cost Soft-Error-Tolerant Multicore Processor

    To tolerate soft errors - which requires both detecting the errors and recovering from their effects - industry and academia have developed a wide variety of approaches. Holistic approaches like N-Modulo Redundancy (NMR) are too expensive, in terms of power and area, for all but the most critical applications. The...

    Provided By Duke University

  • White Papers // Mar 2014

    A Throughput-Oriented Approach to Release Consistency on GPUs

    Graphics Processing Units (GPUs) have specialized throughput-oriented memory systems optimized for streaming writes with scratchpad memories to capture locality explicitly. Expanding the utility of GPUs beyond graphics encourages designs that simplify programming (e.g., using caches instead of scratchpads) and better support irregular applications with finer-grain synchronization. The authors' hypothesis is...

    Provided By Duke University

  • White Papers // Feb 2014

    Scalably Verifiable Dynamic Power Management

    Dynamic Power Management (DPM) is critical to maximizing the performance of systems ranging from multicore processors to datacenters. However, one formidable challenge with DPM schemes is verifying that the DPM schemes are correct as the number of computational resources scales up. In this paper, the authors develop a DPM scheme...

    Provided By Duke University

  • White Papers // Jan 2014

    Bayesian Conditional Density Filtering for Big Data

    The authors propose a Conditional Density Filtering (C-DF) algorithm for efficient online Bayesian inference. C-DF adapts Gibbs sampling to the online setting, sampling from approximations to conditional posterior distributions obtained by tracking of surrogate conditional sufficient statistics as new data arrive. This tracking eliminates the need to store or process...

    Provided By Duke University

  • White Papers // Jan 2014

    A Dynamic Approach to thread Scheduling in Hardware (DASH)

    As thread level parallelism in applications has continued to grow, research in Chip Multi-Processors (CMPs) has continued to expand. Recent calls by industry have led researchers to develop new techniques for writing multithreaded programs for non-server applications. In these programs thread level parallelism will no longer be at the embarrassingly...

    Provided By Duke University

  • White Papers // Dec 2013

    Exploiting Emerging Technologies for Nanoscale Photonic Networks-on-Chip

    In this paper, the authors explore the use of emerging molecular scale devices to construct nanophotonic networks - called molecular-scale Network-on-Chip (mNoC). They leverage quantum dot LEDs, which provide electrical to optical signal modulation, and chromophores, which provide optical signal filtering for receivers. These devices replace the ring resonators and...

    Provided By Duke University

  • White Papers // Jun 2013

    Understanding the Critical Path in Power State Transition Latencies

    Increasing demands on datacenter computing prompts research in energy-efficient warehouse scale systems. In one approach, server activation policies invoke low-power sleep states but the power state transition latency must be small to produce effective energy savings. Chrome OS and Arch Linux require 50ms and 650ms, respectively, to enter sleep states....

    Provided By Duke University

  • White Papers // Jun 2013

    Disintegrated Control for Energy-Efficient and Heterogeneous Memory Systems

    A mix of emerging technologies promises qualitatively new memory system capabilities. However, today's memory controllers and channels constrain heterogeneity. Today's integration of controllers on processor dies prevents systems from accommodating diverse, technology-specific protocols and schedulers in a modular manner; memory design decisions must be made during processor design. Moreover, today's...

    Provided By Duke University

  • White Papers // Jun 2013

    mNoC: Large Nanophotonic Network-on-Chip Crossbars with Molecular Scale Devices

    Moore's law and the continuity of device scaling have led to an increasing number of cores/nodes on a chip, creating a need for new mechanisms to achieve high-performance and power efficient Network-on-Chip (NoC). Nanophotonics based NoCs provide for higher bandwidth and more power efficient designs than electronic networks. Present approaches...

    Provided By Duke University

  • White Papers // Jun 2013

    Sequential Consistency for Heterogeneous-Race-Free Programmer-centric Memory Models for Heterogeneous Platforms

    Hardware vendors now provide heterogeneous platforms in commodity markets (e.g., integrated CPUs and GPUs), and are promising an integrated, shared memory address space for such platforms in future iterations. Because not all threads in a heterogeneous platform can communicate with the same latency, vendors are proposing synchronization mechanisms that allow...

    Provided By Duke University

  • White Papers // Apr 2013

    Data Secrecy in Distributed Storage Systems under Exact Repair

    The problem of securing data against eavesdropping in distributed storage systems is studied. The focus is on systems that use linear codes and implement exact repair to recover from node failures. The maximum file size that can be stored securely is determined for systems in which all the available nodes...

    Provided By Duke University

  • White Papers // Dec 2012

    Differential Privacy and Statistical Disclosure Risk Measures: An Investigation with Binary Synthetic Data

    The authors compare the disclosure risk criterion of ?-differential privacy with a criterion based on probabilities that intruders uncover actual values given the released data. To do so, they generate fully synthetic data that satisfy ?-differential privacy at different levels of ?, make assumptions about the information available to intruders,...

    Provided By Duke University

  • White Papers // Nov 2012

    Inferred Models for Dynamic and Sparse Hardware-Software Spaces

    Diverse software and heterogeneous hardware pose new challenges in systems and architecture management. Managers benefit from improving introspective capabilities, which provide data across a spectrum of platforms, from software and datacenter profilers to performance counters and canary circuits. Despite this wealth of data, management has become more difficult as sophisticated...

    Provided By Duke University

  • White Papers // Oct 2012

    Writing Cosets of a Convolutional Code to Increase the Lifetime of Flash Memory

    In this paper, the authors extend the lifetime of flash memory by reducing the frequency with which a given page of memory is erased. This is accomplished by increasing the number of writes that are possible before erasure is necessary. Redundancy is introduced into the write process to decrease the...

    Provided By Duke University

  • White Papers // May 2012

    The Limits of Concurrency in Cache Coherence

    In this paper, the authors has shown how to improve the performance of cache coherence protocols by using logical time to enable concurrency that would not be legal in physical time. They hypothesized that extending this prior work to enable even greater concurrency would further improve performance, and they developed...

    Provided By Duke University

  • White Papers // Jan 2012

    Efficient Peer-To-Peer Keyword Searching

    The recent file storage applications built on top of peer-to-peer distributed hash tables lack search capabilities. The authors believe that search is an important part of any document publication system. To that end, they have designed and analyzed a distributed search engine based on a distributed hash table. Their simulation...

    Provided By Duke University

  • White Papers // Sep 2011

    Algorithms for Constructing Overlay Networks for Live Streaming

    In this paper, the authors present a polynomial time approximation algorithm for constructing an overlay multicast network for streaming live media events over the Internet. The class of overlay networks constructed by their algorithm includes networks used by Akamai Technologies to deliver live media events to a global audience with...

    Provided By Duke University

  • White Papers // Sep 2011

    Assessing the Veracity of Identity Assertions via OSNs

    Anonymity is one of the main virtues of the Internet, as it protects privacy and enables users to express opinions more freely. However, anonymity hinders the assessment of the veracity of assertions that online users make about their identity attributes, such as age or profession. The authors propose FaceTrust, a...

    Provided By Duke University

  • White Papers // Sep 2011

    Confidant: Protecting OSN Data Without Locking It Up

    Online Social Networks (OSNs) are immensely popular, but participants are increasingly uneasy with centralized services' handling of user data. Decentralized OSNs offer the potential to address user's anxiety while also enhancing the features and scalability offered by existing, centralized services. In this paper, the authors present Confidant, a decentralized OSN...

    Provided By Duke University

  • White Papers // Jun 2011

    For Here or to Go: Predicting Client Dwell Time in WiFi Hotspots

    Modern mobile phones provide a plethora of sensors, enabling high-resolution measurement of the user's behavior. Further, user behaviors are not random-detailed measurements of current activities can be suggestive of the near future. The authors envision that such behavioral insights can help deliver enhanced network services. While behavior-aware networking is a...

    Provided By Duke University

  • White Papers // May 2011

    Frame Coherence and Sparse Signal Processing

    The sparse signal processing literature often uses random sensing matrices to obtain performance guarantees. Unfortunately, in the real world, sensing matrices do not always come from random processes. It is therefore desirable to evaluate whether an arbitrary matrix, or frame, is suitable for sensing sparse signals. To this end, the...

    Provided By Duke University

  • White Papers // May 2011

    Dealing Proactively With Data Corruption: Challenges and Opportunities

    The danger of production or backup data becoming corrupted is a problem that database administrators dread. This paper aims to bring this problem to the attention of the database research community, which, surprisingly, has by and large overlooked this problem. The authors begin by pointing out the causes and consequences...

    Provided By Duke University

  • White Papers // May 2011

    A Hierarchical Model to Evaluate Quality of Experience of Online Services Hosted by Cloud Computing

    As online service providers utilize cloud computing to host their services, they are challenged by evaluating the quality of experience and designing redirection strategies in this complicated environment. The authors propose a hierarchical modeling approach that can easily combine all components of this environment. Identifying interactions among the components is...

    Provided By Duke University

  • White Papers // Apr 2011

    Fast Level Set Estimation From Projection Measurements

    Estimation of the level set of a function (i.e., regions where the function exceeds some value) is an important problem with applications in digital elevation maps, medical imaging, and astronomy. In many applications, however, the function of interest is acquired through indirect measurements, such as tomographic projections, coded-aperture measurements, or...

    Provided By Duke University

  • White Papers // Mar 2011

    No Time to Countdown: Migrating Backoff to the Frequency Domain

    Conventional WiFi networks perform channel contention in time domain. This is known to be wasteful because the channel is forced to remain idle, while all contending nodes are backing off for multiple time slots. This paper proposes to break away from convention and recreate the backing off operation in the...

    Provided By Duke University

  • White Papers // Mar 2011

    Precise Indoor Localization Using PHY Layer Information

    This paper shows the viability of precise indoor localization using physical layer information in WiFi systems. The authors find that channel frequency responses across multiple OFDM subcarriers can be suitably aggregated into a location signature. While these signatures vary over time and environmental mobility, they notice that their core structure...

    Provided By Duke University

  • White Papers // Feb 2011

    On the Identification of Parametric Underspread Linear Systems

    Identification of time-varying linear systems, which introduce both time-shifts (delays) and frequency-shifts (Doppler-shifts), is a central task in many engineering applications. This paper studies the problem of identification of Under-spread Linear Systems (ULSs), defined as time-varying linear systems whose responses lie within a unit-area region in the delay - Doppler...

    Provided By Duke University

  • White Papers // Feb 2011

    Identification of Parametric Underspread Linear Systems and Super-Resolution Radar

    Identification of time-varying linear systems, which introduce both time-shifts (delays) and frequency-shifts (Doppler-shifts), is a central task in many engineering applications. This paper studies the problem of identification of Underspread Linear Systems (ULSs), whose responses lie within a unit-area region in the delay - Doppler space, by probing them with...

    Provided By Duke University

  • White Papers // Feb 2011

    Brand Names Act Like Marketing Placebos

    This paper illustrates the power of reputation, such as that embodied in brand names, demonstrating that names can enhance objective product efficacy. Study participants facing a glaring light were asked to read printed words as accurately and as quickly as they could, receiving compensation proportional to their performance. Those wearing...

    Provided By Duke University

  • White Papers // Jan 2011

    The Resilience of WDM Networks to Probabilistic Geographical Failures

    Telecommunications networks, and in particular optical WDM networks, are vulnerable to large-scale failures of their physical infrastructure, resulting from physical attacks (such as an Electromagnetic Pulse attack) or natural disasters (such as solar flares, earthquakes, and floods). Such events happen at specific geographical locations and disrupt specific parts of the...

    Provided By Duke University

  • White Papers // Jan 2011

    In-Vehicle Driver Detection Using Mobile Phone Sensors

    The authors present a mobile phone based sensing system to determine if a mobile user in an automobile is the driver or a passenger. This can help the mobile device to be aware of the user's attention span and control the delivery of notifications such as incoming calls and context...

    Provided By Duke University

  • White Papers // Jan 2011

    Automating Privacy Testing of Smartphone Applications

    Smartphones have revolutionized mobile computing, but have created concerns that many third-party mobile applications do not properly handle users' privacy-sensitive data. This paper proposes AppInspector, an automated privacy validation system that analyzes apps and generates reports of potential privacy risks. A key insight is that distinguishing acceptable disclosures from privacy...

    Provided By Duke University

  • White Papers // Jan 2011

    Computational Journalism: A Call to Arms to Database Researchers

    The digital age has brought sweeping changes to the news media. While online consumption of news is on the rise, fewer people today read newspapers. Newspaper advertising revenues fell by a total of 23% in 2007 and 2008, and tumbled 26% more in 2009. This continuing decline of the traditional...

    Provided By Duke University

  • White Papers // Jan 2011

    Starfish: A Selftuning System for Big Data Analytics

    Timely and cost-effective analytics over "Big Data" is now a key ingredient for success in many businesses, scientific and engineering disciplines, and government endeavors. The Hadoop software stack - which consists of an extensible MapReduce execution engine, pluggable distributed storage engines, and a range of procedural to declarative interfaces -...

    Provided By Duke University

  • White Papers // Jan 2011

    A Sampling-Based Approach to Optimizing Top-k Queries in Sensor Networks

    Wireless sensor networks generate a vast amount of data. This data, however, must be sparingly extracted to conserve energy, usually the most precious resource in battery powered sensors. When approximation is acceptable, a model-driven approach to query processing is effective in saving energy by avoiding contacting nodes whose values can...

    Provided By Duke University

  • White Papers // Jan 2011

    Many-to-Many Aggregation for Sensor Networks

    Wireless sensor networks have enormous potential to aid data collection in a number of areas, such as environmental and wildlife research. In this paper, the authors address the challenges of supporting many-to-many aggregation in a sensor network. An application of many-to-many aggregation is in-network control of sensors. For expensive sensing...

    Provided By Duke University

  • White Papers // Jan 2011

    On the Database/Network Interface in Large-Scale Publish/Subscribe Systems

    The work performed by a publish/subscribe system can conceptually be divided into subscription processing and notification dissemination. Traditionally, research in the database and networking community has focused on these aspects in isolation. The interface between the database server and the network is an aspect often overlooked by previous research. At...

    Provided By Duke University

  • White Papers // Jan 2011

    Query Suspend and Resume

    Suppose a long-running analytical query is executing on a database server and has been allocated a large amount of physical memory. A high-priority task comes in and people need to run it immediately with all available resources. The authors have several choices. They could swap out the old query to...

    Provided By Duke University

  • White Papers // Jan 2011

    Energy-Efficient Continuous Isoline Queries in Sensor Networks

    Environmental monitoring is a promising application for sensor networks. Many scenarios produce geographically correlated readings, making them visually interesting and good targets for the isoline query. This query depicts boundaries showing how values change in the network. Temporal and spatial suppression provide opportunities for reducing the cost of maintaining the...

    Provided By Duke University

  • White Papers // Jan 2011

    Compact Reachability Labeling for Graph-Structured Data

    Testing reachability between nodes in a graph is a well-known problem with many important applications, including knowledge representation, program analysis, and more recently, biological and ontology databases inferencing as well as XML query processing. Various approaches have been proposed to encode graph reachability information using node labeling schemes, but most...

    Provided By Duke University

  • White Papers // Feb 2011

    On the Identification of Parametric Underspread Linear Systems

    Identification of time-varying linear systems, which introduce both time-shifts (delays) and frequency-shifts (Doppler-shifts), is a central task in many engineering applications. This paper studies the problem of identification of Under-spread Linear Systems (ULSs), defined as time-varying linear systems whose responses lie within a unit-area region in the delay - Doppler...

    Provided By Duke University

  • White Papers // Jan 2009

    Vis-a-Vis: Online Social Networking via Virtual Individual Servers

    Online Social Networks (OSNs) are immensely popular, but their centralized control of sensitive user data raises important privacy concerns. This paper presents Vis-'a-Vis, a decentralized framework for online social networking based on the privacy-preserving notion of a Virtual Individual Server (VIS), a personal virtual machine running within a cloud-computing utility....

    Provided By Duke University

  • White Papers // Sep 2011

    Assessing the Veracity of Identity Assertions via OSNs

    Anonymity is one of the main virtues of the Internet, as it protects privacy and enables users to express opinions more freely. However, anonymity hinders the assessment of the veracity of assertions that online users make about their identity attributes, such as age or profession. The authors propose FaceTrust, a...

    Provided By Duke University

  • White Papers // Apr 2013

    Data Secrecy in Distributed Storage Systems under Exact Repair

    The problem of securing data against eavesdropping in distributed storage systems is studied. The focus is on systems that use linear codes and implement exact repair to recover from node failures. The maximum file size that can be stored securely is determined for systems in which all the available nodes...

    Provided By Duke University

  • White Papers // Jan 2014

    Bayesian Conditional Density Filtering for Big Data

    The authors propose a Conditional Density Filtering (C-DF) algorithm for efficient online Bayesian inference. C-DF adapts Gibbs sampling to the online setting, sampling from approximations to conditional posterior distributions obtained by tracking of surrogate conditional sufficient statistics as new data arrive. This tracking eliminates the need to store or process...

    Provided By Duke University

  • White Papers // Aug 2010

    Cost-Effective Integration of Three-Dimensional (3D) ICs Emphasizing Testing Cost Analysis

    Three-Dimensional (3D) ICs promise to overcome barriers in interconnect scaling by leveraging fast, dense inter-die vias, thereby offering benefits of improved performance, higher memory bandwidth, smaller form factors, and heterogeneous integration. However, when deciding to adopt this emerging technology as a mainstream design approach, designers must consider the cost of...

    Provided By Duke University

  • White Papers // Jun 2013

    Disintegrated Control for Energy-Efficient and Heterogeneous Memory Systems

    A mix of emerging technologies promises qualitatively new memory system capabilities. However, today's memory controllers and channels constrain heterogeneity. Today's integration of controllers on processor dies prevents systems from accommodating diverse, technology-specific protocols and schedulers in a modular manner; memory design decisions must be made during processor design. Moreover, today's...

    Provided By Duke University

  • White Papers // Mar 2010

    Cloud Network Infrastructure as a Service: An Exercise in Multi-Domain Orchestration

    Cloud computing is now a successful and well-understood example of the Infrastructure as a Service (IaaS) model. This paper explores how to extend IaaS clouds to other kinds of substrate resources beyond servers and storage, and to link these elements together in a coordinated, multi-provider "Web" of cloud infrastructure services....

    Provided By Duke University

  • White Papers // Apr 2010

    Sensor Assisted Wireless Communications

    The nature of human mobility demands that mobile devices become agile to diverse operating environments. Coping with such diversity requires the device to assess its environment, and trigger appropriate responses to each of them. While existing communication subsystems rely on in-band wireless signals for context-assessment and response, they explore a...

    Provided By Duke University

  • White Papers // Apr 2010

    Sensor Assisted Wireless Communication

    The nature of human mobility demands that mobile devices become agile to diverse operating environments. Coping with such diversity requires the device to assess its environment, and trigger appropriate responses to each of them. While existing communication subsystems rely on in-band wireless signals for context-assessment and response, the authors explore...

    Provided By Duke University

  • White Papers // Feb 2011

    Identification of Parametric Underspread Linear Systems and Super-Resolution Radar

    Identification of time-varying linear systems, which introduce both time-shifts (delays) and frequency-shifts (Doppler-shifts), is a central task in many engineering applications. This paper studies the problem of identification of Underspread Linear Systems (ULSs), whose responses lie within a unit-area region in the delay - Doppler space, by probing them with...

    Provided By Duke University

  • White Papers // May 2011

    Frame Coherence and Sparse Signal Processing

    The sparse signal processing literature often uses random sensing matrices to obtain performance guarantees. Unfortunately, in the real world, sensing matrices do not always come from random processes. It is therefore desirable to evaluate whether an arbitrary matrix, or frame, is suitable for sensing sparse signals. To this end, the...

    Provided By Duke University

  • White Papers // Apr 2011

    Fast Level Set Estimation From Projection Measurements

    Estimation of the level set of a function (i.e., regions where the function exceeds some value) is an important problem with applications in digital elevation maps, medical imaging, and astronomy. In many applications, however, the function of interest is acquired through indirect measurements, such as tomographic projections, coded-aperture measurements, or...

    Provided By Duke University

  • White Papers // Nov 2009

    Behavioral Finance: Capital Budgeting And Other Investment Decisions

    This paper surveys the literature on the effects of behavioral biases on capital budgeting. A large body of the psychology literature finds that people tend to be overconfident and overly optimistic. Because of self-selection, firm managers tend to be even more affected by these biases than the general population. Indeed,...

    Provided By Duke University

  • White Papers // Sep 2009

    Board Independence And Credit Ratings

    Using Sarbanes-OXley Act (SOX) as a natural experiment, the authors find evidence consistent with an optimal level of board independence for credit ratings. They test two hypotheses that could explain this optimality: Information Cost Hypothesis (ICH) that the effectiveness of independent boards increases with the private benefits of the management,...

    Provided By Duke University

  • White Papers // Jul 2010

    Autonomic Cloud Network Orchestration: A GENI Perspective

    Pervasive virtualization at the edge and in the network core drives the evolution of the IT infrastructure towards a service-oriented model. It permits a move from static arrangements of resources that persist over long periods of time to highly dynamic arrangements that respond to the needs of customers by dynamically...

    Provided By Duke University

  • White Papers // Aug 2010

    Quantifying Resiliency of IaaS Cloud

    Cloud based services may experience changes - internal, external, large, small - at any time. Predicting and quantifying the effects on the quality-of-service during and after a change are important in the resiliency assessment of a cloud based service. In this paper, the authors quantify the resiliency of Infrastructure-as-a-Service (IaaS)...

    Provided By Duke University

  • White Papers // Jan 2009

    Capital Gains Tax Overhang And Payout Policy

    Jin (2006) documents that tax-sensitive institutional investors with large embedded capital gains are reluctant to sell their shares, creating upward stock price pressure. This price pressure should reduce a firm's incentive to repurchase its shares. Consistent with this argument, the authors find that embedded capital gains of tax-sensitive institutional investors...

    Provided By Duke University

  • White Papers // Mar 2011

    No Time to Countdown: Migrating Backoff to the Frequency Domain

    Conventional WiFi networks perform channel contention in time domain. This is known to be wasteful because the channel is forced to remain idle, while all contending nodes are backing off for multiple time slots. This paper proposes to break away from convention and recreate the backing off operation in the...

    Provided By Duke University

  • White Papers // Mar 2011

    Precise Indoor Localization Using PHY Layer Information

    This paper shows the viability of precise indoor localization using physical layer information in WiFi systems. The authors find that channel frequency responses across multiple OFDM subcarriers can be suitably aggregated into a location signature. While these signatures vary over time and environmental mobility, they notice that their core structure...

    Provided By Duke University

  • White Papers // Jan 2009

    Mobicom Poster: SurroundSense: Mobile Phone Localization Using Ambient Sound and Light

    Proliferating mobile phones provide a foundation for revolutionary innovations in people-centric computing. Numerous applications are on the rise, many of which exploit the phone's location as the primary indicator of context. Existing physical localization schemes based on GPS/WiFi/GSM have been shown to achieve, at best, localization accuracy of several meters....

    Provided By Duke University

  • White Papers // Jun 2011

    For Here or to Go: Predicting Client Dwell Time in WiFi Hotspots

    Modern mobile phones provide a plethora of sensors, enabling high-resolution measurement of the user's behavior. Further, user behaviors are not random-detailed measurements of current activities can be suggestive of the near future. The authors envision that such behavioral insights can help deliver enhanced network services. While behavior-aware networking is a...

    Provided By Duke University

  • White Papers // May 2011

    A Hierarchical Model to Evaluate Quality of Experience of Online Services Hosted by Cloud Computing

    As online service providers utilize cloud computing to host their services, they are challenged by evaluating the quality of experience and designing redirection strategies in this complicated environment. The authors propose a hierarchical modeling approach that can easily combine all components of this environment. Identifying interactions among the components is...

    Provided By Duke University

  • White Papers // Aug 2009

    A Stochastic Model for Beaconless IEEE 802.15.4 MAC Operation

    IEEE 802.15.4 is a popular choice for MAC/PHY protocols in low power and low data rate wireless sensor networks. In this paper, the authors develop a stochastic model for the beaconless operation of IEEE 802.15.4 MAC protocol. Given the number of nodes competing for channel access and their packet generation...

    Provided By Duke University

  • White Papers // Jan 2011

    The Resilience of WDM Networks to Probabilistic Geographical Failures

    Telecommunications networks, and in particular optical WDM networks, are vulnerable to large-scale failures of their physical infrastructure, resulting from physical attacks (such as an Electromagnetic Pulse attack) or natural disasters (such as solar flares, earthquakes, and floods). Such events happen at specific geographical locations and disrupt specific parts of the...

    Provided By Duke University

  • White Papers // Jan 2012

    Efficient Peer-To-Peer Keyword Searching

    The recent file storage applications built on top of peer-to-peer distributed hash tables lack search capabilities. The authors believe that search is an important part of any document publication system. To that end, they have designed and analyzed a distributed search engine based on a distributed hash table. Their simulation...

    Provided By Duke University

  • White Papers // Oct 2008

    CoRRS: COnsistent and Responsive Routing with Safeguard

    The Internet uses a process called routing convergence to quickly find suitable forwarding paths after dynamic network changes such as failures. During routing convergence, routers may have inconsistent forwarding state that leads to massive packet loss or forwarding loops. Real-time applications are often sensitive to loss and delay, and may...

    Provided By Duke University

  • White Papers // Oct 2010

    Bootstrapping Accountability in the Internet We Have

    The lack of accountability makes the Internet vulnerable to numerous attacks, including prefix hijacking, route forgery, source address spoofing, and DoS flooding attacks. This paper takes a "Dirty-slate" approach to bring accountability to the present Internet with low-cost and deployable enhancements. The authors' design, IPA, uses the readily available top-level...

    Provided By Duke University

  • White Papers // Sep 2011

    Confidant: Protecting OSN Data Without Locking It Up

    Online Social Networks (OSNs) are immensely popular, but participants are increasingly uneasy with centralized services' handling of user data. Decentralized OSNs offer the potential to address user's anxiety while also enhancing the features and scalability offered by existing, centralized services. In this paper, the authors present Confidant, a decentralized OSN...

    Provided By Duke University

  • White Papers // Sep 2011

    Algorithms for Constructing Overlay Networks for Live Streaming

    In this paper, the authors present a polynomial time approximation algorithm for constructing an overlay multicast network for streaming live media events over the Internet. The class of overlay networks constructed by their algorithm includes networks used by Akamai Technologies to deliver live media events to a global audience with...

    Provided By Duke University

  • White Papers // May 2011

    Dealing Proactively With Data Corruption: Challenges and Opportunities

    The danger of production or backup data becoming corrupted is a problem that database administrators dread. This paper aims to bring this problem to the attention of the database research community, which, surprisingly, has by and large overlooked this problem. The authors begin by pointing out the causes and consequences...

    Provided By Duke University

  • White Papers // Apr 2009

    Automated Experiment-Driven Management of (Database) Systems

    In this paper, the authors argue that an important piece of the system administration puzzle has largely been left untouched by researchers. This piece involves mechanisms and policies to identify as well as collect missing instrumentation data; the missing data is essential to generate the knowledge required to address certain...

    Provided By Duke University

  • White Papers // Jan 2011

    A Sampling-Based Approach to Optimizing Top-k Queries in Sensor Networks

    Wireless sensor networks generate a vast amount of data. This data, however, must be sparingly extracted to conserve energy, usually the most precious resource in battery powered sensors. When approximation is acceptable, a model-driven approach to query processing is effective in saving energy by avoiding contacting nodes whose values can...

    Provided By Duke University

  • White Papers // May 2010

    MobiCom 2009 Poster: Wireless Network Coding and Concurrent MAC: Are These Approaches Complementary?

    The IEEE 802.11 MAC protocol precludes the possibility of concurrent transmissions by two neighboring nodes. There have been some MAC proposals such as CMAP for enabling concurrent transmissions. Wireless network coding schemes like COPE convey more information in one transmission by coding multiple packets together. Both CMAP and COPE have...

    Provided By Duke University

  • White Papers // Nov 2010

    Subscriber Assignment for Wide-Area Content-Based Publish/Subscribe

    The authors study the problem of assigning subscribers to brokers in a wide-area content-based publish/subscribe system. A good assignment should consider both subscriber interests in the event space and subscriber locations in the network space, and balance multiple performance criteria including bandwidth, delay, and load balance. The resulting optimization problem...

    Provided By Duke University

  • White Papers // Oct 2009

    I/O-Efficient Statistical Computing With RIOT

    Statistical analysis of massive data is becoming indispensable to science, commerce, and society today. Such analysis requires efficient, flexible storage support and special optimization techniques. In this paper, the authors present RIOT (R with I/O Transparency), a system that extends R, a popular computing environment for statistical data analysis. RIOT...

    Provided By Duke University

  • White Papers // Jan 2011

    Many-to-Many Aggregation for Sensor Networks

    Wireless sensor networks have enormous potential to aid data collection in a number of areas, such as environmental and wildlife research. In this paper, the authors address the challenges of supporting many-to-many aggregation in a sensor network. An application of many-to-many aggregation is in-network control of sensors. For expensive sensing...

    Provided By Duke University

  • White Papers // Jan 2011

    On the Database/Network Interface in Large-Scale Publish/Subscribe Systems

    The work performed by a publish/subscribe system can conceptually be divided into subscription processing and notification dissemination. Traditionally, research in the database and networking community has focused on these aspects in isolation. The interface between the database server and the network is an aspect often overlooked by previous research. At...

    Provided By Duke University

  • White Papers // Jan 2011

    Query Suspend and Resume

    Suppose a long-running analytical query is executing on a database server and has been allocated a large amount of physical memory. A high-priority task comes in and people need to run it immediately with all available resources. The authors have several choices. They could swap out the old query to...

    Provided By Duke University

  • White Papers // Jan 2011

    Energy-Efficient Continuous Isoline Queries in Sensor Networks

    Environmental monitoring is a promising application for sensor networks. Many scenarios produce geographically correlated readings, making them visually interesting and good targets for the isoline query. This query depicts boundaries showing how values change in the network. Temporal and spatial suppression provide opportunities for reducing the cost of maintaining the...

    Provided By Duke University