University of Virginia

Displaying 1-40 of 97 results

  • White Papers // Feb 2014

    Extra Bits on SRAM and DRAM Errors - More Data from the Field

    Several recent publications have shown that memory errors are common in high-performance computing systems, due to hardware faults in the memory subsystem. With exascale-class systems predicted to have 100-350x more DRAM and SRAM than current systems, these faults are predicted to become more common. Therefore, further study of the faults...

    Provided By University of Virginia

  • White Papers // Jul 2013

    PCF: A Portable Circuit Format for Scalable Two-Party Secure Computation

    A secure computation protocol for a function f (x; y) must leak no information about inputs x; y during its execution; thus it is imperative to compute the function f in a data-oblivious manner. Traditionally, this has been accomplished by compiling f into a Boolean circuit. Previous approaches, however, have...

    Provided By University of Virginia

  • White Papers // May 2012

    A Model and Decision Procedure for Data Storage in Cloud Computing

    Cloud computing offers many possibilities for prospective users; there are however many different storage and compute services to choose from between all the cloud providers and their multiple datacenters. In this paper, the authors focus on the problem of selecting the best storage services according to the application's requirements and...

    Provided By University of Virginia

  • White Papers // Mar 2012

    A Systematic Study of Automated Program Repair: Fixing 55 Out of 105 Bugs for $8 Each

    There are more bugs in real-world programs than human programmers can realistically address. This paper evaluates two research questions: "What fraction of bugs can be repaired automatically?" and "How much does it cost to repair a bug automatically?" In previous work, the authors presented GenProg, which uses genetic programming to...

    Provided By University of Virginia

  • White Papers // Mar 2012

    Synthesizing API Usage Examples

    Key program interfaces are sometimes documented with usage examples: concrete code snippets that characterize common use cases for a particular data type. While such documentation is known to be of great utility, it is burdensome to create and can be incomplete, out of date, or not representative of actual practice....

    Provided By University of Virginia

  • White Papers // Dec 2011

    Relationship Between Career Program Characteristics and Job Satisfaction in a City Based Local Authority

    According to the human resource development literature, career program has two salient characteristics: career planning and career management. Recent studies in this area reveal that the ability of management to properly implement such career program characteristics may have a significant impact on job satisfaction. Although the nature of this relationship...

    Provided By University of Virginia

  • White Papers // Dec 2011

    Assessing the Value of Cloudbursting: A Case Study of Satellite Image Processing on Windows Azure

    To perform computational experiments at greater scale and in less time, enterprises are increasingly looking to dynamically expand their computing capabilities through the temporary addition of cloud resources (aka "Cloud-bursting"). Computational infrastructure can be dismantled in minutes with no long-term capital investments. However, research is needed to identify which properties...

    Provided By University of Virginia

  • White Papers // Jun 2011

    GuardRails: A Data-Centric Web Application Security Framework

    Modern web application frameworks have made it easy to create powerful web applications. Developing a secure web application, however, still requires a developer to posses a deep understanding of security vulnerabilities and attacks. Even for experienced developers it is tedious, if not impossible, to find and eliminate all vulnerabilities. This...

    Provided By University of Virginia

  • White Papers // Jun 2011

    Kicking The Dog: Korea's Bureaucratic Resistance To Globalization In Reaction To Democratization

    Seven years have passed since the Korean economy was engulfed by the 1997 Asian Financial Crisis. Arguably, the country is still not fully recovered from the catastrophe almost a decade later. In those intervening years, numerous books and papers have attempted to diagnose the origins of the extraordinarily sharp downturn...

    Provided By University of Virginia

  • White Papers // May 2011

    Private Editing Using Untrusted Cloud Services

    The authors present a general methodology for protecting the confidentiality and integrity of user data for a class of on-line editing applications. The key insight is that many of these applications are designed to perform most of their data-dependent computation on the client side, so it is possible to maintain...

    Provided By University of Virginia

  • White Papers // Apr 2011

    Feasibility of Dynamic Binary Parallelization

    This paper proposes DBP, an automatic technique that transparently parallelizes a sequential binary executable while it is running. A prototype implementation in simulation was able to increase sequential execution speeds by up to 1.96x, averaged over three benchmarks suites. Fundamental issues in microprocessor technologies have led designers to increase the...

    Provided By University of Virginia

  • White Papers // Apr 2011

    Interest Rates And Inflation

    For some time now the author have been intrigued by the apparent relationship between the behavior of various interest rates and that of inflation. As a physicist, the author views economics the same way the author views physical systems. Namely, describe them by a model which is amenable to mathematical...

    Provided By University of Virginia

  • White Papers // Mar 2011

    An Analysis of Using High-Frequency Sinusoidal Illumination to Measure the 3D Shape of Translucent Objects

    Using optical triangulation methods to measure the shape of translucent objects is difficult because subsurface scattering contaminates measurements of the "Direct" reflection at the surface. A number of recent papers have shown that high-frequency sinusoidal illumination patterns allow isolating this direct component, which in turn enables accurate estimation of the...

    Provided By University of Virginia

  • White Papers // Mar 2011

    Analytic Error Modeling for Imprecise Arithmetic Circuits

    Imprecise hardware challenges the traditional notion that correctness is an immutable priority, by systematically trading off efficacy (precision) against efficiency (power, area, performance, and cost). Evaluating the impact of such tradeoffs on output quality using, e.g., Monte Carlo simulations is a time-consuming and non-deterministic process. This paper presents two analytic...

    Provided By University of Virginia

  • White Papers // Mar 2011

    Extending SAT Solvers to Cryptographic Problems

    Cryptography ensures the con confidentiality and authenticity of information but often relies on unproven assumptions. SAT solvers are a powerful tool to test the hardness of certain problems and have successfully been used to test hardness assumptions. This paper extends a SAT solver to efficiently work on cryptographic problems. The...

    Provided By University of Virginia

  • White Papers // Feb 2011

    Where Is the Data? Why You Cannot Debate CPU Vs. GPU Performance Without the Answer

    General Purpose GPU Computing (GPGPU) has taken off in the past few years, with great promises for increased desktop processing power due to the large number of fast computing cores on high-end graphics cards. Many publications have demonstrated phenomenal performance and have reported speedups as much as 1000x over code...

    Provided By University of Virginia

  • White Papers // Feb 2011

    Improving Region Selection Through Loop Completion

    Dynamic binary translation is a powerful technique for program analysis and modification that operates on binary code as it executes, thus availing itself of information only available at run-time. However, by intervening between the software and hardware, a significant slowdown may be introduced into program execution, which can hinder widespread...

    Provided By University of Virginia

  • White Papers // Feb 2011

    Improving Indirect Branch Translation in Dynamic Binary Translators

    Dynamic Binary Translators (DBTs) have a wide range of applications including program instrumentation, dynamic optimization, and security. One of the main issues with DBTs is their performance overhead. A significant part of this overhead is caused by Indirect Branch (IB) translation. In this paper, the authors show that the percentage...

    Provided By University of Virginia

  • White Papers // Feb 2011

    Distributed Uplink Resource Allocation in Cognitive Radio Networks - Part II: Equilibria and Algorithms for Joint Access Point Selection and Power Allocation

    The main objective of this two part paper is to formulate and address the problem of distributed uplink resource allocation in multi-carrier Cognitive Radio Networks (CRN) with multiple Access Points (APs). When the APs operate on non-overlapping spectrum bands, such problem is essentially a joint spectrum decision and spectrum sharing...

    Provided By University of Virginia

  • White Papers // Feb 2011

    Joint Distributed Access Point Selection and Power Allocation in Cognitive Radio Networks

    Spectrum management has been identified as a crucial step towards enabling the technology of the Cognitive Radio Network (CRN). Most of the current works dealing with spectrum management in the CRN focus on a single task of the problem, e.g., spectrum sensing, spectrum decision, spectrum sharing or spectrum mobility. In...

    Provided By University of Virginia

  • White Papers // Feb 2011

    Efficient Privacy-Preserving Biometric Identification

    The authors present an efficient matching protocol that can be used in many privacy-preserving biometric identification systems in the semi-honest setting. The most general technical contribution is a new backtracking protocol that uses the byproduct of evaluating a garbled circuit to enable efficient oblivious information retrieval. They also present a...

    Provided By University of Virginia

  • White Papers // Feb 2011

    A Sub-0.5V Lattice-Based Public-Key Encryption Scheme for RFID Platforms in 130nm CMOS

    Implementing public-key cryptography on passive RFID tags is very challenging due to the limited die size and power available. Typical public-key algorithms require complex logical components such as modular exponentiation in RSA. The authors demonstrate the feasibility of implementing public-key encryption on low-power, low cost passive RFID tags to large-scale...

    Provided By University of Virginia

  • White Papers // Jan 2011

    Bandwidth Allocation in Hexagonal Wireless Sensor Networks for Real-Time Communications

    This paper presents an algorithm for bandwidth allocation for delay-sensitive traffic in multi-hop wireless sensor networks. The solution considers both periodic as well as a periodic real-time traffic in an unified manner. The authors also present a distributed MAC protocol that conforms to the bandwidth allocation and thus satisfies the...

    Provided By University of Virginia

  • White Papers // Jan 2011

    Accelerating Compute-Intensive Applications With GPUs and FPGAs

    Accelerators are special purpose processors designed to speed up compute-intensive sections of applications. Two extreme endpoints in the spectrum of possible accelerators are FPGAs and GPUs, which can often achieve better performance than CPUs on certain workloads. FPGAs are highly customizable, while GPUs provide massive parallel execution resources and high...

    Provided By University of Virginia

  • White Papers // Jan 2011

    A Performance Study of General Purpose Applications on Graphics Processors

    Graphic Processors Unit (GPUs), with many light-weight data-parallel cores, can provide substantial parallel computational power to accelerate general purpose applications. To best utilize the GPU's parallel computing resources, it is crucial to understand how GPU architectures and programming models can be applied to different categories of traditionally CPU applications. In...

    Provided By University of Virginia

  • White Papers // Jan 2011

    Thunder: Towards Practical, Zero Cost Acoustic Localization for Outdoor Wireless Sensor Networks

    Localization for outdoor wireless sensor networks has been a challenge for real applications. Although many solutions have been proposed, few of them can be used in real applications because of their high cost, low accuracy or infeasibility due to practical issues. In this paper, the authors propose a practical acoustic...

    Provided By University of Virginia

  • White Papers // Jan 2011

    Enviro-Track: Towards an Environmental Computing Paradigm for Distributed Sensor Networks

    Distributed sensor networks are quickly gaining recognition as viable embedded computing platforms. Current techniques for programming sensor networks are cumbersome, inflexible, and low-level. This paper introduces EnviroTrack, an object-based distributed middleware system that raises the level of programming abstraction by providing a convenient and powerful interface to the application developer...

    Provided By University of Virginia

  • White Papers // Jan 2011

    CMP Design Space Exploration Subject to Physical Constraints

    This paper explores the multi-dimensional design space for chip multiprocessors, exploring the inter-related variables of core count, pipeline depth, superscalar width, L2 cache size, and operating voltage and frequency, under various area and thermal constraints. The results show the importance of joint optimization. Thermal constraints dominate other physical constraints such...

    Provided By University of Virginia

  • White Papers // Jan 2011

    Heterogeneous Chip Multiprocessor Design for Virtual Machines

    Multi-core architectures provide an alternative to increasing clock frequencies to improve performance of modern processors. The best design for these chip multiprocessors, including structure sizes or whether to use homogeneous or heterogeneous cores, remains open for exploration. One potential design path involves using heterogeneous cores that are specialized for a...

    Provided By University of Virginia

  • White Papers // Jan 2011

    An Entity Maintenance and Connection Service for Sensor Networks

    In this paper, the authors present a middleware architecture for coordination services in sensor networks that facilitates interaction between groups of sensors which monitor different environmental events. It sits on top of the native routing infrastructure and exports the abstraction of mobile communication endpoints maintained at the locations of such...

    Provided By University of Virginia

  • White Papers // Jan 2011

    A Communication Architecture and Programming Abstractions for Real-Time Embedded Sensor Networks

    Data distribution in embedded real-time sensor networks requires new protocols and programming environments that achieve time-sensitive message delivery and provide useful abstractions to the application programmer. Attainment of these goals requires changes to multiple layers of the communication protocol stack. In this paper, the authors review a protocol suite developed...

    Provided By University of Virginia

  • White Papers // Dec 2010

    Modeling and Analyzing NBTI in the Presence of Process Variation

    With continuous scaling of transistors in each technology generation, NBTI and Process Variation (PV) have become very important silicon reliability problems for the microprocessor industry. In this paper, the authors develop an analytical model to capture the impact of NBTI in the presence of PV for use in architecture simulations....

    Provided By University of Virginia

  • White Papers // Dec 2010

    Looking For Local-Labor-Market Effects Of NAFTA

    Using US Census data for 1990 and 2000, the authors estimate effects of the NAFTA agreement on the US wages. They look for any indication of effects of the agreement on the local labor markets dependent on industries vulnerable to import competition from Mexico, and the workers employed in industries...

    Provided By University of Virginia

  • White Papers // Dec 2010

    Looking For Local Labor-Market Effects Of The NAFTA

    Using US Census data for 1990 and 2000, the authors estimate effects of the NAFTA agreement on the US wages. They look for any indication of effects of the agreement on local labor markets dependent on industries vulnerable to import competition from Mexico, and workers employed in industries competing with...

    Provided By University of Virginia

  • White Papers // Dec 2010

    Applicability of the Willow Architecture for Cloud Management

    The differences between grids and clouds arguably include objectives, organization, scale, and workload. By examining these fundamental characteristics and requirements in detail, the authors assess the degree to which a generic management infrastructure for grid computing can be applied to cloud infrastructures. The analysis is further refined by considering a...

    Provided By University of Virginia

  • White Papers // Dec 2010

    Relaxing Non-Volatility for Fast and Energy-Efficient STT-RAM Caches

    Spin-Transfer Torque RAM (STT-RAM) is an emerging non-volatile memory technology that is a potential universal memory that could replace SRAM in processor caches. This paper presents a novel approach for redesigning STT-RAM memory cells to reduce the high dynamic energy and slow write latencies. The authors lower the retention time...

    Provided By University of Virginia

  • White Papers // Dec 2010

    Fault Tolerance and Scaling in e-Science Cloud Applications: Observations From the Continuing Development of MODISAzure

    It can be natural to believe that many of the traditional issues of scale have been eliminated or at least greatly reduced via cloud computing. That is, if one can create a seemingly well-functioning cloud application that operates correctly on small or moderate-sized problems, then the very nature of cloud...

    Provided By University of Virginia

  • White Papers // Dec 2010

    CSAL: A Cloud Storage Abstraction Layer to Enable Portable Cloud Applications (work-in-Progress)

    One of the large impediments for adoption of cloud computing is perceived vendor lock-in with respect to both low-level resource management and application level storage services. Application portability is essential to both avoid lock-in as well as leverage the ever changing landscape of cloud offerings. The authors present a storage...

    Provided By University of Virginia

  • White Papers // Dec 2010

    Shouting To Be Heard In Advertising

    Advertising competes for consumer attention, but attention is scarce. More profitable senders send more messages to break through the clutter. There may be multiple equilibria: more messages in aggregate induce more "Shouting to be heard" among senders trying to break through the advertising clutter, which creates a "Lottery ticket" dimension...

    Provided By University of Virginia

  • White Papers // Oct 2010

    A Human Study of Fault Localization Accuracy

    Localizing and repairing defects are critical software engineering activities. Not all programs and not all bugs are equally easy to debug, however. They present formal models, backed by a human study involving 65 participants (from both academia and industry) and 1830 total judgments, relating various software- and defect-related features to...

    Provided By University of Virginia

  • Presentations // Jan 2003

    Post-Merger Integration: Dos Donts And Due Diligence

    This presentation highlights the concept of post merger integration. The various aspects, which have been discussed in this, include: Purpose of the project and framework for assessing mergers, three companies and their stories, and mergers due diligence. Also, are discussed some do?s and don?ts of mergers. These are planning the...

    Provided By University of Virginia

  • White Papers // May 2004

    A Nuclear Weaponization Program

    This document provides a presentation on nuclear weaponization program, which involves a set of activities and facilities aimed at manufacturing and maintaining nuclear weapons. It does not include the manufacturing complex to make separated plutonium or highly enriched uranium, or "fissile material. For the purposes of verification, such a program...

    Provided By University of Virginia

  • White Papers // Apr 2011

    Interest Rates And Inflation

    For some time now the author have been intrigued by the apparent relationship between the behavior of various interest rates and that of inflation. As a physicist, the author views economics the same way the author views physical systems. Namely, describe them by a model which is amenable to mathematical...

    Provided By University of Virginia

  • White Papers // Jun 2010

    An Approach on Hardware Design for Computationally Intensive Image Processing Applications Based on Light Field Refocusing Algorithm

    This paper describes the performance analysis of the light field refocusing algorithm running on different hardware specifications, including the Intel Pentium 4, SSE2(Streaming SIMD Extensions), GPU, and also Cell Broadband Engine. The hardware chosen has unique features, making it interesting to compare their performance on such an application with each...

    Provided By University of Virginia

  • White Papers // Apr 2011

    Feasibility of Dynamic Binary Parallelization

    This paper proposes DBP, an automatic technique that transparently parallelizes a sequential binary executable while it is running. A prototype implementation in simulation was able to increase sequential execution speeds by up to 1.96x, averaged over three benchmarks suites. Fundamental issues in microprocessor technologies have led designers to increase the...

    Provided By University of Virginia

  • White Papers // Jun 2010

    African Export Successes: Surprises, Stylized Facts, And Explanations

    High quality coffee is achieved by maintaining consistency and tight quality control of processing. The central washing stations can (and in this case, do) achieve this. The stations separate processing from dwellings, which is crucial for both elements of quality, and is also more efficient. Central washing stations also help...

    Provided By University of Virginia

  • White Papers // Jan 2010

    Gravity In International Finance

    The past decade has witnessed an explosion of papers estimating gravity equations for cross-border financial holdings. While traditionally the territory of the international trade literature, this recent application of gravity to international finance is driven by new data, a good empirical fit of financial gravity equations and a plethora of...

    Provided By University of Virginia

  • White Papers // Dec 2010

    Shouting To Be Heard In Advertising

    Advertising competes for consumer attention, but attention is scarce. More profitable senders send more messages to break through the clutter. There may be multiple equilibria: more messages in aggregate induce more "Shouting to be heard" among senders trying to break through the advertising clutter, which creates a "Lottery ticket" dimension...

    Provided By University of Virginia

  • White Papers // Oct 2010

    Economic Effects Of Health Care Reform On Virginia

    This paper estimates the impact of the 2010 health care reform law (the Patient Protection and Affordable Care Act/Health Care and Education Reconciliation Act) on Virginia's economy. Health care reform is a complex and multifaceted law that was enacted with the joint goals of improving health insurance coverage for U.S....

    Provided By University of Virginia

  • White Papers // Jun 2011

    Kicking The Dog: Korea's Bureaucratic Resistance To Globalization In Reaction To Democratization

    Seven years have passed since the Korean economy was engulfed by the 1997 Asian Financial Crisis. Arguably, the country is still not fully recovered from the catastrophe almost a decade later. In those intervening years, numerous books and papers have attempted to diagnose the origins of the extraordinarily sharp downturn...

    Provided By University of Virginia

  • White Papers // Mar 2011

    An Analysis of Using High-Frequency Sinusoidal Illumination to Measure the 3D Shape of Translucent Objects

    Using optical triangulation methods to measure the shape of translucent objects is difficult because subsurface scattering contaminates measurements of the "Direct" reflection at the surface. A number of recent papers have shown that high-frequency sinusoidal illumination patterns allow isolating this direct component, which in turn enables accurate estimation of the...

    Provided By University of Virginia

  • White Papers // Dec 2010

    Looking For Local Labor-Market Effects Of The NAFTA

    Using US Census data for 1990 and 2000, the authors estimate effects of the NAFTA agreement on the US wages. They look for any indication of effects of the agreement on local labor markets dependent on industries vulnerable to import competition from Mexico, and workers employed in industries competing with...

    Provided By University of Virginia

  • White Papers // Apr 2010

    Early Observations on the Performance of Windows Azure

    A significant open issue in cloud computing is performance. Few, if any, cloud providers or technologies offer quantitative performance guarantees. Regardless of the potential advantages of the cloud in comparison to enterprise-deployed applications, cloud infrastructures may ultimately fail if deployed applications cannot predictably meet behavioral requirements. In this paper, the...

    Provided By University of Virginia

  • White Papers // Dec 2010

    Fault Tolerance and Scaling in e-Science Cloud Applications: Observations From the Continuing Development of MODISAzure

    It can be natural to believe that many of the traditional issues of scale have been eliminated or at least greatly reduced via cloud computing. That is, if one can create a seemingly well-functioning cloud application that operates correctly on small or moderate-sized problems, then the very nature of cloud...

    Provided By University of Virginia

  • White Papers // Dec 2010

    Applicability of the Willow Architecture for Cloud Management

    The differences between grids and clouds arguably include objectives, organization, scale, and workload. By examining these fundamental characteristics and requirements in detail, the authors assess the degree to which a generic management infrastructure for grid computing can be applied to cloud infrastructures. The analysis is further refined by considering a...

    Provided By University of Virginia

  • White Papers // Aug 2010

    Cloud Auto-Scaling With Deadline and Budget Constraints

    Clouds have become an attractive computing platform which offers on-demand computing power and storage capacity. Its dynamic scalability enables users to quickly scale up and scale down underlying infrastructure in response to business volume, performance desire and other dynamic behaviors. However, challenges arise when considering computing instance non-deterministic acquisition time,...

    Provided By University of Virginia

  • White Papers // Jun 2010

    Event Detection in Wireless Sensor Networks - Can Fuzzy Values Be Accurate?

    Event detection is a central component in numerous Wireless Sensor Network (WSN) applications. In spite of this, the area of event description has not received enough attention. The majority of current event description approaches rely on using precise values to specify event thresholds. However, the authors believe that crisp values...

    Provided By University of Virginia

  • White Papers // Jun 2010

    Robust Data and Event Services in Real-Time Embedded Sensor Network Systems

    The majority of event detection in real-time embedded sensor network systems is based on data fusion that uses noisy sensor data collected from complicated real-world environments. Current research has produced several excellent low-level mechanisms to collect sensor data and perform aggregation. However, solutions that enable these systems to provide real-time...

    Provided By University of Virginia

  • White Papers // Apr 2010

    Design of an Architecture for Multiple Security Levels in Wireless Sensor Networks

    With the increased application of Wireless Sensor Networks (WSNs) in military, commercial, and home environments, securing the data in the network is a critical issue. Several security mechanisms, such as TinySec have been introduced to address the need for security in WSNs. There are many applications, however, which require more...

    Provided By University of Virginia

  • White Papers // Jun 2009

    Event-Based Location Dependent Data Services in Mobile WSNs

    Mobile sensors are widely deployed in Wireless Sensor Networks (WSNs) to satisfy emerging application requirements. Specifically, processing location dependent queries in mobile WSNs is still a challenging problem due to sensor mobility. The authors present an Event-based Location Dependent Query (ELDQ) model that continuously aggregate data in specific areas around...

    Provided By University of Virginia

  • White Papers // May 2009

    Traffic-Aware Channel Assignment in Wireless Sensor Networks

    Existing frequency assignment efforts in wireless sensor network research focus on balancing available physical frequencies among neighboring nodes, without paying attention to the fact that different nodes have different traffic volumes. Ignoring the different traffic requirements in different nodes in frequency assignment design leads to poor MAC performance. Therefore, in...

    Provided By University of Virginia

  • White Papers // Jun 2009

    An Analysis of Mac OS X Leopard

    Here is an exhaustive study of Mac OS X Leopard along a specific set of metrics. The metrics include the overhead of kernel calls, context switches, page allocation, and file I/O. This operating system has shown to be the most user friendly, non-intimidating, and commercially successful distribution of a Unix...

    Provided By University of Virginia

  • White Papers // May 2010

    A PDA-Based Counseling Tool for Improving Medical Student Smoking Cessation Counseling

    The authors' demonstrated improvement of SCC skills by third-year medical students using a workshop combined with a supplemental reference tool. However, a PDA-based tool did not increase key SCC behaviors compared with a paper-based reminder. For a PDA intervention to be effective in this setting the tool must be simplified...

    Provided By University of Virginia

  • White Papers // Oct 2009

    A Quantitative Analysis of High Performance Computing With Amazon's EC2 Infrastructure: The Death of the Local Cluster?

    The introduction of affordable infrastructure on demand, specifically Amazon's Elastic Compute Cloud (EC2), has had a significant impact in the business IT community and provides reasonable and attractive alternatives to locally-owned infrastructure. For scientific computation however, the viability of EC2 has come into question due to its use of virtualization...

    Provided By University of Virginia

  • White Papers // Jan 2011

    An Entity Maintenance and Connection Service for Sensor Networks

    In this paper, the authors present a middleware architecture for coordination services in sensor networks that facilitates interaction between groups of sensors which monitor different environmental events. It sits on top of the native routing infrastructure and exports the abstraction of mobile communication endpoints maintained at the locations of such...

    Provided By University of Virginia

  • White Papers // Jan 2011

    A Communication Architecture and Programming Abstractions for Real-Time Embedded Sensor Networks

    Data distribution in embedded real-time sensor networks requires new protocols and programming environments that achieve time-sensitive message delivery and provide useful abstractions to the application programmer. Attainment of these goals requires changes to multiple layers of the communication protocol stack. In this paper, the authors review a protocol suite developed...

    Provided By University of Virginia

  • White Papers // Oct 2009

    Transforming the Corps into a Risk Managing Organization

    The Corps' reliance on engineering design standards, a hierarchical decision structure and strong link to congressional budget priorities may have been appropriate for the past but not for the future. The increasing recognition by the agency and by the public of the limits of prediction (uncertainty) and in the limits...

    Provided By University of Virginia

  • White Papers // Dec 2011

    Relationship Between Career Program Characteristics and Job Satisfaction in a City Based Local Authority

    According to the human resource development literature, career program has two salient characteristics: career planning and career management. Recent studies in this area reveal that the ability of management to properly implement such career program characteristics may have a significant impact on job satisfaction. Although the nature of this relationship...

    Provided By University of Virginia

  • White Papers // Mar 2011

    Extending SAT Solvers to Cryptographic Problems

    Cryptography ensures the con confidentiality and authenticity of information but often relies on unproven assumptions. SAT solvers are a powerful tool to test the hardness of certain problems and have successfully been used to test hardness assumptions. This paper extends a SAT solver to efficiently work on cryptographic problems. The...

    Provided By University of Virginia

  • White Papers // May 2012

    A Model and Decision Procedure for Data Storage in Cloud Computing

    Cloud computing offers many possibilities for prospective users; there are however many different storage and compute services to choose from between all the cloud providers and their multiple datacenters. In this paper, the authors focus on the problem of selecting the best storage services according to the application's requirements and...

    Provided By University of Virginia

  • White Papers // Dec 2011

    Assessing the Value of Cloudbursting: A Case Study of Satellite Image Processing on Windows Azure

    To perform computational experiments at greater scale and in less time, enterprises are increasingly looking to dynamically expand their computing capabilities through the temporary addition of cloud resources (aka "Cloud-bursting"). Computational infrastructure can be dismantled in minutes with no long-term capital investments. However, research is needed to identify which properties...

    Provided By University of Virginia

  • White Papers // Mar 2012

    A Systematic Study of Automated Program Repair: Fixing 55 Out of 105 Bugs for $8 Each

    There are more bugs in real-world programs than human programmers can realistically address. This paper evaluates two research questions: "What fraction of bugs can be repaired automatically?" and "How much does it cost to repair a bug automatically?" In previous work, the authors presented GenProg, which uses genetic programming to...

    Provided By University of Virginia

  • White Papers // Mar 2012

    Synthesizing API Usage Examples

    Key program interfaces are sometimes documented with usage examples: concrete code snippets that characterize common use cases for a particular data type. While such documentation is known to be of great utility, it is burdensome to create and can be incomplete, out of date, or not representative of actual practice....

    Provided By University of Virginia

  • White Papers // Oct 2010

    A Human Study of Fault Localization Accuracy

    Localizing and repairing defects are critical software engineering activities. Not all programs and not all bugs are equally easy to debug, however. They present formal models, backed by a human study involving 65 participants (from both academia and industry) and 1830 total judgments, relating various software- and defect-related features to...

    Provided By University of Virginia

  • White Papers // Sep 2009

    Syntactic Regression Testing for Tree-Structured Output

    Regression testing is used by software developers to ensure that program modifications have not negatively impacted the correctness of code. While regression testing has been successfully applied in many domains, programs such as web applications, XML processors, and compilers remain expensive to test because harmless program evolutions make the tests...

    Provided By University of Virginia

  • White Papers // Aug 2010

    University Of Virginia Equal Opportunity Report 2010

    The University of Virginia's 2010 Equal Opportunity Report contains information and data from the October 2008 to October 2009 reporting period that provides a broad range of undertakings and good faith efforts taken by schools and departments to ensure equal opportunity for faculty and staff. The units have increased their...

    Provided By University of Virginia

  • White Papers // Jan 2010

    ControlWare: A Middleware Architecture for Feedback Control of Software Performance

    Attainment of software performance assurances in open, largely unpredictable environments has recently become an important focus for real-time research. Unlike closed embedded systems, many contemporary distributed real-time applications operate in environments where offered load and available resources suffer considerable random fluctuations, thereby complicating the performance assurance problem. Feedback control theory...

    Provided By University of Virginia

  • White Papers // Jan 2010

    QoS Support for Real-Time Databases

    The confluence of computers, communications and databases is quickly creating a global virtual database where many applications require real-time access to both temporally accurate and multimedia data. The authors are developing a global virtual database, called BeeHive, which is enterprise specific and offers features along real-time, fault tolerance, quality of...

    Provided By University of Virginia

  • White Papers // Jan 2010

    ALARM-NET: Wireless Sensor Networks for Assisted-Living and Residential Monitoring

    This paper describes ALARM-NET, a wireless sensor network for assisted-living and residential monitoring. It integrates environmental and physiological sensors in a scalable, heterogeneous architecture. A query protocol allows real-time collection and processing of sensor data by user interfaces and back-end analysis programs. One such program determines circadian activity rhythms of...

    Provided By University of Virginia

  • White Papers // Jan 2010

    STAR: Secure Real-Time Transaction Processing With Timeliness Guarantees

    Real-time databases are needed in security-critical applications, e.g., e-commerce, agile manufacturing, and military applications. In these applications, transactions and data items can be classified into several security levels according to their clearance and sensitivity levels. It is essential for real-time databases to prevent illegal direct/indirect transfer of sensitive data, e.g.,...

    Provided By University of Virginia