Duke University

Displaying 1-40 of 97 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

    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

    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

    Sharing Networked Resources With Brokered Leases

    This paper presents the design and implementation of Shirako, a system for on-demand leasing of shared networked resources. Shirako is a prototype of a service-oriented architecture for resource providers and consumers to negotiate access to resources over time, arbitrated by brokers. It is based on a general lease abstraction: a...

    Provided By Duke University

  • White Papers // Jan 2011

    Service Level Agreement Based Distributed Resource Allocation for Streaming Hosting Systems

    The trend to outsourcing network services to third parties in a utility model has resulted in a new distributed application model where the hosting service, service providers and end clients constitute a co-dependent profit ecosystem. SLAs provide a means for the service provider to specify the target levels of performance...

    Provided By Duke University

  • White Papers // Jan 2011

    Supporting Better Scalability and Richer Subscription Models in Wide-Area Publish/Subscribe

    With the advent of Web 2.0 and the Digital Age, everyone is witnessing an unprecedented increase in the amount of information collected, and in the number of users interested in different types of information. This growth means that traditional techniques, where interested users poll data sources for information they are...

    Provided By Duke University

  • White Papers // Jan 2011

    Scalability in Adaptive Multi-Metric Overlays

    Increasing application requirements have placed heavy emphasis on building overlay networks to efficiently deliver data to multiple receivers. A key performance challenge is simultaneously achieving adaptivity to changing network conditions and scalability to large numbers of users. In addition, most current algorithms focus on a single performance metric, such as...

    Provided By Duke University

  • White Papers // Jan 2011

    Combined Guard Channel and Mobile Assisted Handoff for Cellular Networks

    For cellular communication systems, mobility and limited radio coverage of a cell require calls to be handed over from one Base Station System (BSS) to an another BSS. Due to the limited bandwidth available in various cells, there is a finite probability that an ongoing call while being handed off...

    Provided By Duke University

  • White Papers // Jan 2011

    Pocket Hypervisors: Opportunities and Challenges

    In recent years, hypervisors for commodity operating systems have helped address problems in such diverse systems domains as secure-logging, honeypots, kernel-debugging, and cluster-computing. Hypervisors' popularity across domains is a result of their ability to encapsulate the state of a running system, mediate all interactions between the hardware and software, and...

    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 // Jan 2010

    The Missing Link: Putting the Network in Networked Cloud Computing

    The backbone of IT infrastructure is evolving towards a service-oriented model, in which distributed resources, either software or hardware, can be composed as a customized IT service on demand. In particular, cloud computing infrastructure services manage a shared "Cloud" of servers as a unified hosting substrate for diverse applications, using...

    Provided By Duke University

  • White Papers // Jan 2011

    Combined Guard Channel and Mobile Assisted Handoff for Cellular Networks

    For cellular communication systems, mobility and limited radio coverage of a cell require calls to be handed over from one Base Station System (BSS) to an another BSS. Due to the limited bandwidth available in various cells, there is a finite probability that an ongoing call while being handed off...

    Provided By Duke University

  • White Papers // Jan 2011

    Supporting Better Scalability and Richer Subscription Models in Wide-Area Publish/Subscribe

    With the advent of Web 2.0 and the Digital Age, everyone is witnessing an unprecedented increase in the amount of information collected, and in the number of users interested in different types of information. This growth means that traditional techniques, where interested users poll data sources for information they are...

    Provided By Duke University

  • White Papers // Jan 2011

    Scalability in Adaptive Multi-Metric Overlays

    Increasing application requirements have placed heavy emphasis on building overlay networks to efficiently deliver data to multiple receivers. A key performance challenge is simultaneously achieving adaptivity to changing network conditions and scalability to large numbers of users. In addition, most current algorithms focus on a single performance metric, such as...

    Provided By Duke University

  • White Papers // Jan 2011

    Pocket Hypervisors: Opportunities and Challenges

    In recent years, hypervisors for commodity operating systems have helped address problems in such diverse systems domains as secure-logging, honeypots, kernel-debugging, and cluster-computing. Hypervisors' popularity across domains is a result of their ability to encapsulate the state of a running system, mediate all interactions between the hardware and software, and...

    Provided By Duke University

  • White Papers // Nov 2010

    SocialFilter: Introducing Social Trust to Collaborative Spam Mitigation

    This paper proposes SocialFilter, a trust-aware collaborative spam mitigation system. SocialFilter enables nodes with no email classification functionality to query the network on whether a host is a spammer. It employs trust inference to weigh the reports concerning spamming hosts that collaborating spam-detecting nodes (Reporters) submit to the system. Subsequently,...

    Provided By Duke University

  • White Papers // Jun 2010

    CloudCmp: Shopping for a Cloud Made Easy

    Cloud computing has gained much popularity recently, and many companies now offer a variety of public cloud computing services, such as Google AppEngine, Amazon AWS, and Microsoft Azure. These services differ in service models and pricing schemes, making it challenging for customers to choose the best suited cloud provider for...

    Provided By Duke University

  • White Papers // Jan 2011

    Sharing Networked Resources With Brokered Leases

    This paper presents the design and implementation of Shirako, a system for on-demand leasing of shared networked resources. Shirako is a prototype of a service-oriented architecture for resource providers and consumers to negotiate access to resources over time, arbitrated by brokers. It is based on a general lease abstraction: a...

    Provided By Duke University

  • White Papers // Jan 2011

    Anypoint: Extensible Transport Switching on the Edge

    Anypoint is a new model for one-to-many communication with ensemble sites-aggregations of end nodes that appear to the external Internet as a unified site. Policies for routing Any-point traffic are defined by application-layer plugins residing in extensible routers at the ensemble edge. Anypoint's switching functions operate at the transport layer...

    Provided By Duke University

  • White Papers // Jan 2011

    Service Level Agreement Based Distributed Resource Allocation for Streaming Hosting Systems

    The trend to outsourcing network services to third parties in a utility model has resulted in a new distributed application model where the hosting service, service providers and end clients constitute a co-dependent profit ecosystem. SLAs provide a means for the service provider to specify the target levels of performance...

    Provided By Duke University

  • White Papers // Oct 2009

    The Duality Between Message Routing and Epidemic Data Replication

    Several domains of networking such as Delay Tolerant Networks (DTNs), Mobile Ad hoc NETworks (MANETs), and Peer-to-Peer (P2P) networks have the common goal of transporting messages to their intended destinations. These networking domains share many requirements and employ routing protocols that are often composed of similar mechanisms. This paper explores...

    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 // Dec 2010

    Avoiding the Rush Hours: WiFi Energy Management Via Traffic Isolation

    WiFi continues to be a prime source of energy consumption in mobile devices. This paper observes that, despite a rich body of research in WiFi energy management, there is room for improvement. The key finding is that WiFi energy optimizations have conventionally been designed with a single AP in mind....

    Provided By Duke University

  • White Papers // Oct 2010

    The Case for Context-Aware Compression

    The proliferation of pictures and videos in the Internet is imposing heavy demands on mobile data networks. This demand is expected to grow rapidly and a one-fit-all solution is unforeseeable. While researchers are approaching the problem from different directions, the authors identify a human-centric opportunity to reduce content size. The...

    Provided By Duke University

  • White Papers // Dec 2009

    Towards Mobile Phone Localization Without War-Driving

    This paper identifies the possibility of using electronic compasses and accelerometers in mobile phones, as a simple and scalable method of localization without war-driving. The idea is not fundamentally different from ship or air navigation systems, known for centuries. Nonetheless, directly applying the idea to human-scale environments is non-trivial. Noisy...

    Provided By Duke University

  • White Papers // Jul 2010

    BytesToGo: Offloading 3G Via WiFi Prioritization

    The growing number of sensors on mobile phones is enabling a closer look into the micro-behavior of human users. The authors envision that such behavioral insights can help deliver enhanced network services. While behavior-aware networking is a broad research theme, they take up a narrower problem in the space of...

    Provided By Duke University

  • White Papers // Dec 2010

    Using Mobile Phones to Write in Air

    Numerous sensors in modern mobile phones enable a range of people-centric applications. This paper envisions a system called PhonePoint Pen that uses the in-built accelerometer in mobile phones to recognize human writing. By holding the phone like a pen, a user should be able to write short messages or draw...

    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

    Toward Self-Healing Multitier Services

    Are self-healing database-centric multitier services utopia or just a hard puzzle? The authors argue for the latter and aim to identify the missing pieces of this puzzle. They advocate robust and scalable learning-based approaches to self-healing that they expect to work well for a large class of multitier services. The...

    Provided By Duke University

  • White Papers // Jan 2011

    Managing Mixed-Use Clusters With Cluster-on-Demand

    Although clusters offer inexpensive computing power, they are difficult and expensive to manage, particularly for user communities with diverse software needs. This paper presents Cluster-On-Demand (COD), a cluster operating system framework for mixed-use clusters. COD interposes on standard network management services - DHCP, NIS, and DNS - to partition a...

    Provided By Duke University

  • White Papers // Jan 2011

    ConSil: Low-Cost Thermal Mapping of Data Centers

    Several projects involving high-level thermal management - such as eliminating "Hot spots" or reducing cooling costs through intelligent workload placement - require ambient air temperature readings at a fine granularity. Unfortunately, current thermal instrumentation methods involve installing a set of expensive hardware sensors. Modern motherboards include multiple on-board sensors, but...

    Provided By Duke University

  • White Papers // Jan 2011

    Virtual Machine Hosting for Networked Clusters: Building the Foundations for "Autonomic" Orchestration

    Virtualization technology offers powerful resource management mechanisms, including performance-isolating resource schedulers, live migration, and suspend/resume. But how should networked virtual computing systems use these mechanisms? A grand challenge is to devise practical policies to drive these mechanisms in a self-managing or "Autonomic" system, without relying on human operators. This paper...

    Provided By Duke University

  • White Papers // Jan 2011

    Making Scheduling "Cool": Temperature-Aware Workload Placement in Data Centers

    Trends towards consolidation and higher-density computing configurations make the problem of heat management one of the critical challenges in emerging data centers. Conventional approaches to addressing this problem have focused at the facilities level to develop new cooling technologies or optimize the delivery of cooling. In contrast to these approaches,...

    Provided By Duke University

  • White Papers // Jan 2011

    Learning Application Models for Utility Resource Planning

    Shared computing utilities allocate compute, network, and storage resources to competing applications on demand. An awareness of the demands and behaviors of the hosted applications can help the system to manage its resources more effectively. This paper proposes an active learning approach that analyzes performance histories to build predictive models...

    Provided By Duke University

  • White Papers // Jan 2011

    Dynamic Virtual Clusters in a Grid Site Manager

    This paper presents new mechanisms for dynamic resource management in a cluster manager called Cluster-On-Demand (COD). COD allocates servers from a common pool to multiple virtual clusters (vclusters), with independently configured software environments, name spaces, user access controls, and network storage volumes. The authors' present experiments using the popular Sun...

    Provided By Duke University

  • White Papers // Jan 2011

    Weatherman: Automated, Online, and Predictive Thermal Mapping and Management for Data Centers

    Recent advances have demonstrated the potential benefits of coordinated management of thermal load in data centers, including reduced cooling costs and improved resistance to cooling system failures. A key unresolved obstacle to the practical implementation of thermal load management is the ability to predict the effects of workload distribution and...

    Provided By Duke University

  • White Papers // Jan 2011

    Fa: A System for Automating Failure Diagnosis

    Failures of Internet services and enterprise systems lead to user dissatisfaction and considerable loss of revenue. Since manual diagnosis is often laborious and slow, there is considerable interest in tools that can diagnose the cause of failures quickly and automatically from system-monitoring data. This paper identifies two key data-mining problems...

    Provided By Duke University

  • White Papers // Jan 2011

    Empirical Comparison of Techniques for Automated Failure Diagnosis

    Failures of Internet services and enterprise systems lead to user dissatisfaction and considerable loss of revenue. Manual diagnosis of these failures can be laborious, slow, and expensive. This problem has received considerable attention recently from researchers in systems, databases, machine learning and knowledge discovery, computer architecture, and other areas. The...

    Provided By Duke University

  • White Papers // Aug 2010

    NetFence: Preventing Internet Denial of Service From Inside Out

    Denial of Service (DoS) attacks frequently happen on the Internet, paralyzing Internet services and causing millions of dollars of financial loss. This work presents NetFence, a scalable DoS-resistant network architecture. NetFence uses a novel mechanism, secure congestion policing feedback, to enable robust congestion policing inside the network. Bottleneck routers update...

    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

    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

    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 // 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

    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 // 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

    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