University of Maryland

Displaying 1-40 of 190 results

  • White Papers // Feb 2012

    Deaf Cooperation for Secrecy With Multiple Antennas at the Helper

    In this paper, the authors investigate the roles of Cooperative Jamming (CJ) and Noise Forwarding (NF) in improving the achievable secrecy rates of a Gaussian WireTap channel (GWT) when the helper node is equipped with multiple antennas. They decompose the channel from the helper to the eavesdropper into two orthogonal...

    Provided By University of Maryland

  • White Papers // Feb 2012

    Deaf Cooperation and Relay Selection Strategies for Secure Communication in Multiple Relay Networks

    In this paper, the authors investigate the roles of Cooperative Jamming (CJ) and Noise Forwarding (NF) in improving the achievable secrecy rates of a Gaussian WireTap channel (GWT). In particular, they study the role of a deaf helper in confusing the eavesdropper in a GWT channel by either transmitting white...

    Provided By University of Maryland

  • White Papers // Jan 2012

    Secure Communication in Multiple Relay Networks Through Decode-and-Forward Strategies

    In this paper, the authors first study the Decode-and-Forward strategy for secrecy in a single-relay network. They propose a suboptimal Decode-and-Forward with Zero Forcing (DF/ZF) strategy for which they obtain the optimal power control policy. Next, they consider the multiple relay problem. They propose three different strategies based on DF/ZF....

    Provided By University of Maryland

  • White Papers // Jan 2012

    Towards an Optimal Strategy for WLAN Location Determination Systems

    This paper presents a general analysis for the performance of WLAN location determination systems. In particular, the authors present an analytical method for calculating the average distance error and probability of error of WLAN location determination systems. These expressions are obtained with no assumptions regarding the distribution of signal strength...

    Provided By University of Maryland

  • White Papers // Jan 2012

    Formal Specification and Analysis of PCF Protocol in the 802.11 Standard Using Systems of Communicating Machines

    With the widespread usage of the 802.11 protocol, it becomes important to study the protocol operation. In this paper, the authors propose a formal model for the point coordination function of the 802.11 MAC layer using systems of communicating machines. Their goal is to analyze the protocol for safety and...

    Provided By University of Maryland

  • White Papers // Jan 2012

    Kitsune: Efficient, General-Purpose Dynamic Software Updating for C

    Dynamic Software Updating (DSU) systems allow programs to be updated while running, thereby allowing developers to add features and fix bugs without downtime. This paper introduces Kitsune, a new DSU system for C whose design has three notable features. First, Kitsune's updating mechanism updates the whole program, not individual functions....

    Provided By University of Maryland

  • White Papers // Jan 2012

    Jamming Games for Power Controlled Medium Access With Dynamic Traffic

    Due to the broadcast nature of the wireless medium, wireless networks are highly susceptible to jamming attacks. Such attacks are often studied in a game theoretic framework under the assumption of uninterrupted traffic subject to continuous jamming opportunities. The authors analyze the effect of dynamically changing traffic on jamming games...

    Provided By University of Maryland

  • White Papers // Jan 2012

    Universally-Composable Two-Party Computation in Two Rounds

    Round complexity is a central measure of efficiency, and characterizing the round complexity of various cryptographic tasks is of both theoretical and practical importance. The authors show here a Universally Composable (UC) protocol (in the common reference string model) for two-party computation of any functionality, where both parties receive output,...

    Provided By University of Maryland

  • White Papers // Dec 2011

    Neighbor Discovery in a Wireless Sensor Network: Multipacket Reception Capability and Physical-Layer Signal Processing

    In randomly deployed networks, such as sensor networks, an important problem for each node is to discover its neighbor nodes so that the connectivity amongst nodes can be established. In this paper, the authors consider this problem by incorporating the physical layer parameters in contrast to the most of the...

    Provided By University of Maryland

  • White Papers // Dec 2011

    Chinese Restaurant Game - Part II: Applications to Wireless Networking, Cloud Computing, and Online Social Networking

    In this paper, the authors proposed a new game, called Chinese restaurant game, to analyze the social learning problem with negative network externality. The best responses of agents in the Chinese restaurant game with imperfect signals are constructed through a recursive method, and the influence of both learning and network...

    Provided By University of Maryland

  • White Papers // Oct 2011

    Wiretap Channels: Implications of the More Capable Condition and Cyclic Shift Symmetry

    Characterization of the rate-equivocation region of a general wiretap channel involves two auxiliary random variables: U, for rate splitting and V, for channel prefixing. Evaluation of regions involving auxiliary random variables is generally difficult. In this paper, the authors explore specific classes of wiretap channels for which the expression and...

    Provided By University of Maryland

  • White Papers // Oct 2011

    The Network Stack Trace: Performance Diagnosis for Networked Systems

    Transient network stalls that degrade application performance are frustrating to users and developers alike. Software bugs, network congestion, and intermittent connectivity all have the same symptoms - low throughput, high latency, and user-level timeouts. In this paper, the authors show how an end host can identify the sources of network...

    Provided By University of Maryland

  • White Papers // Sep 2011

    ITree: Efficiently Discovering High-Coverage Configurations Using Interaction Trees

    Software configurability has many benefits, but it also makes programs much harder to test, as in the worst case the program must be tested under every possible configuration. One potential remedy to this problem is Combinatorial Interaction Testing (CIT), in which typically the developer selects a strength t and then...

    Provided By University of Maryland

  • White Papers // Sep 2011

    Evaluating Dynamic Software Update Safety Using Systematic Testing

    Dynamic Software Updating (DSU) systems patch programs on the fly without incurring downtime. To avoid failures due to the updating process itself, many DSU systems employ timing restrictions. However, timing restrictions are theoretically imperfect, and their practical effectiveness is an open question. This paper presents the first significant empirical evaluation...

    Provided By University of Maryland

  • White Papers // Sep 2011

    Bandwidth Management for Mobile Media Delivery

    Mobile broadband networks such as 3G and WiMAX present unique challenges to media delivery. Rich media applications require high throughput and low end-to-end delay in order to maintain good quality. Due to the inherent noise in congestion signals (delay / loss) on mobile networks, existing bandwidth management approaches are unable...

    Provided By University of Maryland

  • White Papers // Aug 2011

    A Demo of Coco: A Compiler for Monadic Coercions in ML

    Combining monadic computations may induce a significant syntactic overhead. To allow monadic programming in direct style, the authors have developed Coco, a type-based tool that automatically rewrites ML code inserting necessary binds, unit, and morphisms between monads. This tool demonstration will show how to take advantage of Coco to facilitate...

    Provided By University of Maryland

  • White Papers // Aug 2011

    MultiOtter: Multiprocess Symbolic Execution

    Symbolic execution can be an effective technique for exploring large numbers of program paths, but it has generally been applied to programs running in isolation, whose inputs are files or command-line arguments. Programs that take inputs from other programs-servers, for example-have been beyond the reach of symbolic execution. To address...

    Provided By University of Maryland

  • White Papers // Jul 2011

    Motif-Based Topology Design for Efficient Performance by Networks of Mobile Autonomous Vehicles

    Networked systems of autonomous agents have emerged in a variety of applications such as collaborative robotics, mobile sensor networks and disaster relief operations. Complex phenomena are often observed in these systems due to the large number of agents, nonlinear interactions, locality of information transmission, and changes in the connectivity of...

    Provided By University of Maryland

  • White Papers // Jun 2011

    History-Free Sequential Aggregate Signatures

    Aggregation schemes allows to combine several cryptographic values like message authentication codes or signatures into a shorter value such that, despite compression, some notion of unforgeability is preserved. Recently, Eikemeier et al. (SCN 2010) considered the notion of history-free sequential aggregation for message authentication codes, where the sequentially-executed aggregation algorithm...

    Provided By University of Maryland

  • White Papers // Jun 2011

    Towards Shrink-Wrapped Security: Practically Incorporating Context Into Security Services

    The mobile workforce is rapidly increasing, and technological advances make it feasible for these workers to have ubiquitous access to a variety of resources with various protection requirements. The dynamic computing environment of these workers mandates a security paradigm in which security is tightly coupled with a user's current situation....

    Provided By University of Maryland

  • White Papers // Jun 2011

    Universally Composable Synchronous Computation

    In synchronous networks, protocols can achieve security guarantees that are not possible in an asynchronous world: i.e., they can simultaneously achieve input completeness (all honest parties' inputs are included in the computation) and guaranteed termination (honest parties do not "Hang" indefinitely). In practice, truly synchronous networks rarely exist, but synchrony...

    Provided By University of Maryland

  • White Papers // Jun 2011

    Directed Symbolic Execution

    In this paper, the authors study the problem of automatically finding program executions that reach a particular target line. This problem arises in many debugging scenarios; for example, a developer may want to confirm that a bug reported by a static analysis tool on a particular line is a true...

    Provided By University of Maryland

  • White Papers // Jun 2011

    Optimal Packet Scheduling in a Multiple Access Channel With Energy Harvesting Transmitters

    In this paper, the authors investigate the optimal packet scheduling problem in a two-user multiple access communication system, where the transmitters are able to harvest energy from the nature. Under a deterministic system setting, they assume that the energy harvesting times and harvested energy amounts are known before the transmission...

    Provided By University of Maryland

  • White Papers // Jun 2011

    Multi-Receiver Wiretap Channel With Public and Confidential Messages

    The authors study the multi-receiver wiretap channel with public and confidential messages. In this channel, there is a transmitter that wishes to communicate with two legitimate users in the presence of an external eavesdropper. The transmitter sends a pair of public and confidential messages to each legitimate user. While there...

    Provided By University of Maryland

  • White Papers // May 2011

    Round Optimal Blind Signatures

    All known round optimal (i.e., two-move) blind signature schemes either need a common reference string, rely on random oracles, or assume the hardness of some interactive assumption. At Eurocrypt 2010, Fischlin and Schr?der showed that a broad class of three-move blind signature scheme cannot be instantiated in the standard model...

    Provided By University of Maryland

  • White Papers // May 2011

    Secure Multi-Party Computation of Boolean Circuits With Applications to Privacy in On-Line Marketplaces

    Protocols for generic secure Multi-Party Computation (MPC) come in two forms: they either represent the function being computed as a Boolean circuit or as an arithmetic circuit over a large field. Either type of protocol can be used for any function, but the choice of which type of protocol to...

    Provided By University of Maryland

  • White Papers // May 2011

    Analysis of Explanatory and Predictive Architectures and the Relevance in Explaining the Adoption of IT in SMEs

    This paper critiques the explanatory and predictive architectures of six prominent innovation adoption theories with a view to unraveling their individual capabilities in providing lenses to the understanding of the social and idiosyncratic components of Small and Medium Enterprise (SMEs) in adopting Information Technology (IT). The analysis unravels that the...

    Provided By University of Maryland

  • White Papers // May 2011

    Adaptive Transmission Policies for Energy Harvesting Wireless Nodes in Fading Channels

    In this paper, the authors consider a single-user communication system, where an energy harvesting transmitter communicates with a receiver over a fading wireless channel. They design adaptive transmission policies that adapt to the random energy arrivals at the transmitter and random fluctuations in the channel, in order to maximize the...

    Provided By University of Maryland

  • White Papers // May 2011

    LeechLock: Preventing Selfish Clients in the BitTorrent Protocol

    Although the BitTorrent protocol incentivizes sharing by increasing a peer's download rate, tools have demonstrated that the tit-for-tat mechanism alone is insufficient to prevent peers from downloading content without reciprocation. The authors propose an enhancement to the BitTorrent protocol, called Leechlock, which uses globally shared tables to track peers' ratings...

    Provided By University of Maryland

  • White Papers // Apr 2011

    CloudFuice: A flexible Cloud-Based Data Integration System

    The advent of cloud computing technologies shows great promise for web engineering and facilitates the development of flexible, distributed, and scalable web applications. Data integration can notably benefit from cloud computing because integrating web data is usually an expensive task. This paper introduces CloudFuice, a data integration system that follows...

    Provided By University of Maryland

  • White Papers // Apr 2011

    Dynamic Enforcement of Knowledge-Based Security Policies

    This paper explores the idea of knowledge-based security policies, which are used to decide whether to answer queries over secret data based on an estimation of the querier's (possibly increased) knowledge given the results. Limiting knowledge is the goal of existing information release policies that employ mechanisms such as noising,...

    Provided By University of Maryland

  • White Papers // Apr 2011

    Neural Network to Identify Individuals at Health Risk

    The risk of diseases such as heart attack and high blood pressure could be reduced by adequate physical activity. However, even though majority of general population claims to perform some physical exercise, only a minority exercises enough to keep a healthy living style. Thus, physical inactivity has become one of...

    Provided By University of Maryland

  • White Papers // Apr 2011

    Virtual MeshTest - Improving Wireless Network Testbed Using Virtualization and Migration Algorithm

    There are several laboratory-based mobile wireless testbeds such as the MeshTest and the CMU wireless emulator. These testbeds provide powerful computing network platforms for users who want to perform controlled, repeatable, mobile experiments in the lab. However, such systems can only use 10-15 nodes in an experiment. The Virtual Mesh...

    Provided By University of Maryland

  • White Papers // Mar 2011

    Image Ranking and Retrieval Based on Multi-Attribute Queries

    The authors propose a novel approach for ranking and retrieval of images based on multi-attribute queries. Existing image retrieval methods train separate classifiers for each word and heuristically combine their outputs for retrieving multiword queries. Moreover, these approaches also ignore the interdependencies among the query terms. In contrast, they propose...

    Provided By University of Maryland

  • White Papers // Mar 2011

    Constructing Inverted Files on a Cluster of Multicore Processors Near Peak I/O Throughput

    The authors develop a new strategy for processing a collection of documents on a cluster of multicore processors to build the inverted files at almost the peak I/O throughput of the underlying system. The algorithm is based on a number of novel techniques including: A high-throughput pipelined strategy that produces...

    Provided By University of Maryland

  • White Papers // Feb 2011

    Partitioning Detection and Connectivity Restoration Algorithm for Wireless Sensor Actor Networks

    Recently, Wireless Sensor and Actor Networks have been receiving a growing attention from the research community because of their suitability for critical applications. Maintaining inter-actor connectivity becomes extremely crucial in such situations where actors have to quickly plan optimal coordinated response to detected events. Failure of critical actor partitions the...

    Provided By University of Maryland

  • White Papers // Feb 2011

    Managing the Quality of Virtualized Services

    Managing the quality of virtualized services that are delivered on the cloud is very challenging. Such services are often composed of smaller components that are assembled on an as-needed basis. In this paper, the authors propose a framework to measure and semi-automatically track quality delivered by a Virtualized service delivery...

    Provided By University of Maryland

  • White Papers // Jan 2011

    Retrofitting Security in COTS Software With Binary Rewriting

    The authors present a practical tool for inserting security features against low-level software attacks into third-party, proprietary or otherwise binary-only software. They are motivated by the inability of software users to select and use low-overhead protection schemes when source code is unavailable to them, by the lack of information as...

    Provided By University of Maryland

  • White Papers // Jan 2011

    Position Paper: Dynamically Inferred Types for Dynamic Languages

    Over the past few years the authors have been developing Diamondback Ruby (DRuby), a tool that brings static type inference to Ruby, a dynamically typed, object-oriented language. Developing DRuby required creating a Ruby front-end, which was extremely challenging: like other dynamic languages, Ruby has a complex, yet poorly documented syntax...

    Provided By University of Maryland

  • White Papers // Jan 2011

    Using Data for Systemic Financial Risk Management

    The recent financial collapse has laid bare the inadequacies of the information infrastructure supporting the US financial system. Technical challenges around large-scale data systems interact with significant economic forces involving innovation, transparency, confidentiality, complexity, and organizational change, to create a very difficult problem. The post-crisis reform legislation has created a...

    Provided By University of Maryland

  • White Papers // Jul 2006

    Design And Construction Of A Floating Living Machine

    A number of different types of ecosystems have been created for wastewater treatment including microbial reactors, algal tanks and scrubbers and constructed wetlands. Treatment is performed by these ecosystems through physical/chemical processes such as soil absorption and through metabolic processes such as denitrification. A set of constructed ecosystems that is...

    Provided By University of Maryland

  • White Papers // Mar 2007

    The Negotiation And Design Of Strategic Access Agreements

    Since the time of the ancient Greeks and Romans, powerful political actors have pursued access to strategic foreign and overseas territory primarily through the use of military force and the imposition of colonial rule.1 However, the end of World War II in 1945 and the onset of a new wave...

    Provided By University of Maryland

  • White Papers // Jan 2009

    MPLS Traffic Engineering Using Enhanced Minimum Interference Routing: An Approach Based on Lexicographic Max-Flow

    The main contribution of this paper is a new algorithm for dynamic routing of bandwidth guaranteed tunnels. The algorithm is a generalization of the "minimum-interference" based algorithm. The routing objective is to satisfy as many potential future requests as possible in an environment where requests arrive one-by-one, and there is...

    Provided By University of Maryland

  • White Papers // Jan 2009

    Fighting Spam With the NeighborhoodWatch DHT

    This paper presents DHTBL, an anti-spam blacklist built upon a novel secure Distributed Hash Table (DHT). They show how DHTBL can be used to replace existing DNS-based Blacklists (DNSBLs) of IP addresses of mail relays that forward spam. Implementing a blacklist on a DHT improves resilience to DoS attacks and...

    Provided By University of Maryland

  • White Papers // Nov 2010

    VMCrypt - Modular Software Architecture for Scalable Secure Computation

    Garbled circuits play a key role in secure computation. Unlike previous work, which focused mainly on efficiency and automation aspects of secure computation, in this paper the authors focus on software modularity and scalability, considering very large circuits. The main contribution is a virtual machine that dynamically loads hardware descriptions...

    Provided By University of Maryland

  • White Papers // Nov 2009

    Secure Network Coding Over the Integers

    Network coding has received significant attention in the networking community for its potential to increase throughput and improve robustness without any centralized control. Unfortunately, network coding is highly susceptible to "Pollution attacks" in which malicious nodes modify packets in a way that prevents the reconstruction of information at recipients; such...

    Provided By University of Maryland

  • White Papers // Apr 2011

    Neural Network to Identify Individuals at Health Risk

    The risk of diseases such as heart attack and high blood pressure could be reduced by adequate physical activity. However, even though majority of general population claims to perform some physical exercise, only a minority exercises enough to keep a healthy living style. Thus, physical inactivity has become one of...

    Provided By University of Maryland

  • White Papers // May 2009

    Topological Ordering of Function Words in Hierarchical Phrase-Based Translation

    Hierarchical phrase-based models are attractive because they provide a consistent framework within which to characterize both local and long-distance reorderings, but they also make it difficult to distinguish many implausible reorderings from those that are linguistically plausible. Rather than appealing to annotation-driven syntactic modeling, the authors address this problem by...

    Provided By University of Maryland

  • White Papers // Dec 2009

    Choosing a Network Management Solution for a Converged Internet Protocol Network

    The coming of age of IP convergence has streamlined to delivery of voice, video, and data. Midsized companies and governmental organizations are collapsing their disparate networks into one, allowing the similar consolidation of network management functions. This research paper seeks to educate the reader on the factors that must be...

    Provided By University of Maryland

  • White Papers // Jun 2009

    Prioritizing Component Compatibility Tests Via User Preferences

    Many software systems rely on third-party components during their build process. Because the components are constantly evolving, quality assurance demands that developers perform compatibility testing to ensure that their software systems build correctly over all deployable combinations of component versions, also called configurations. However, large software systems can have many...

    Provided By University of Maryland

  • White Papers // Jul 2009

    On Computing Compression Trees for Data Collection in Sensor Networks

    The authors address the problem of efficiently gathering correlated data from a wired or a wireless sensor network, with the aim of designing algorithms with provable optimality guarantees, and understanding how close they can get to the known theoretical lower bounds. The proposed approach is based on finding an optimal...

    Provided By University of Maryland

  • White Papers // Jul 2009

    Introducing a Test Suite Similarity Metric for Event Sequence-Based Test Cases

    Most of today's Event Driven Software (EDS) systems are tested using test cases that are carefully constructed as sequences of events; they test the execution of an event in the context of its preceding events. Because sizes of these test suites can be extremely large, researchers have developed techniques, such...

    Provided By University of Maryland

  • White Papers // Jan 2011

    Designing and Comparing Automated Test Oracles for GUI-Based Software Applications

    Test designers widely believe that the overall e effectiveness and cost of software testing depends largely on the type and number of test cases executed on the software. This paper shows that the test oracle, a mechanism that determines whether a software executed correctly for a test case, also significantly...

    Provided By University of Maryland

  • White Papers // Oct 2010

    A Utility-Aware and Holistic Approach for Privacy Preserving Distributed Mining With Worst Case Privacy Guarantee

    Organizations often want to predict some attribute values collaboratively. However, they are often unwilling or not allowed to directly share their private data. Thus there is great need for distributed privacy preserving techniques. There exists a rich body of work based on Secure Multi-Party Computation techniques. However, most such techniques...

    Provided By University of Maryland

  • White Papers // Jan 2011

    On Expected Constant-Round Protocols for Byzantine Agreement

    When designing cryptographic protocols, it is often convenient to abstract away various details of the underlying communication network. As one noteworthy example, it is often convenient to assume the existence of a broadcast channel which allows any party to send the same message to all other parties (and all parties...

    Provided By University of Maryland

  • White Papers // Jan 2011

    Faults' Context Matters

    When choosing a testing technique, practitioners want to know which one will detect the faults that matter most to them in the programs that they plan to test. Do empirical evaluations of testing techniques provide this information? More often than not, they report how many faults in a carefully chosen...

    Provided By University of Maryland

  • White Papers // Jan 2011

    Using GUI Run-Time State as Feedback to Generate Test Cases

    This paper presents a new automated model-driven technique to generate test cases by using feedback from the execution of a "Seed test suite" on an Application Under Test (AUT). The test cases in the seed suite are designed to be generated automatically and executed very quickly. During their execution, feedback...

    Provided By University of Maryland

  • White Papers // Mar 2011

    Constructing Inverted Files on a Cluster of Multicore Processors Near Peak I/O Throughput

    The authors develop a new strategy for processing a collection of documents on a cluster of multicore processors to build the inverted files at almost the peak I/O throughput of the underlying system. The algorithm is based on a number of novel techniques including: A high-throughput pipelined strategy that produces...

    Provided By University of Maryland

  • White Papers // Oct 2010

    Memory Performance Analysis for Parallel Programs Using Concurrent Reuse Distance

    Performance on multicore processors is determined largely by on-chip cache. Computer architects have conducted numerous studies in the past that vary core count and cache capacity as well as problem size to understand impact on cache behavior. These studies are very costly due to the combinatorial design spaces they must...

    Provided By University of Maryland

  • White Papers // Jul 2010

    Optimization of Linked List Prefix Computations on Multithreaded GPUs Using CUDA

    The authors present a number of optimization techniques to compute prefix sums on linked lists and implement them on multithreaded GPUs using CUDA. Prefix computations on linked structures involve in general highly irregular fine grain memory accesses that are typical of many computations on linked lists, trees, and graphs. While...

    Provided By University of Maryland

  • White Papers // May 2010

    Effective Strategies for Temporally Anchored Information Retrieval

    A number of emerging large scale applications such as web archiving and time-stamped web objects generated through information feeds involve time-evolving objects that can be most effectively explored through search within a temporal context. The authors develop in this paper a new approach to handle the temporal text search of...

    Provided By University of Maryland

  • White Papers // Nov 2009

    Scaling Single-Program Performance on Large-Scale Chip Multiprocessor

    Due to power constraints, computer architects will exploit TLP instead of ILP for future performance gains. Today, 4 - 8 state-of-the-art cores or 10s of smaller cores can fit on a single die. For the foreseeable future, the number of cores will likely double with each successive processor generation. Hence,...

    Provided By University of Maryland

  • White Papers // Jan 2011

    Collective Classification in Network Data

    Numerous real-world applications produce networked data such as web data (hypertext documents connected via hyperlinks) and communication networks (people connected via communication links). A recent focus in machine learning research has been to extend traditional machine learning classification techniques to classify nodes in such data. In this paper, the authors...

    Provided By University of Maryland

  • White Papers // Jan 2011

    Matching Jobs to Resources in Distributed Desktop Grid Environments

    Desktop grids use opportunistic sharing to exploit large collections of personal computers and workstations across the Internet and can achieve tremendous computing power with low cost. However, current systems are typically based on a traditional client-server architecture, which has inherent shortcomings with respect to robustness, reliability and scalability. In this...

    Provided By University of Maryland

  • White Papers // Jan 2011

    Efficient Geographic Routing in Multihop Wireless Networks

    The authors propose a new link metric called Normalized ADVance (NADV) for geographic routing in multihop wireless networks. NADV selects neighbors with the optimal trade-off between proximity and link cost. Coupled with the local next hop decision in geographic routing, NADV provides an adaptive and efficient cost-aware routing strategy. Depending...

    Provided By University of Maryland

  • White Papers // Jan 2011

    Ranking Search Results in P2P Systems

    P2P deployments are a natural infrastructure for building distributed search networks. Proposed systems support locating and retrieving all results, but lack the information necessary to rank them. Users, however, are primarily interested in the most relevant, and not all possible results. Using random sampling, the authors extend a class of...

    Provided By University of Maryland

  • White Papers // Jan 2011

    Studying the Characteristics of a "Good" GUI Test Suite

    The widespread deployment of Graphical-User Interfaces (GUIs) has increased the overall complexity of testing. A GUI test designer needs to perform the daunting task of adequately testing the GUI, which typically has very large input interaction spaces, while considering tradeoffs between GUI test suite characteristics such as the number of...

    Provided By University of Maryland

  • White Papers // Jan 2011

    Using Data for Systemic Financial Risk Management

    The recent financial collapse has laid bare the inadequacies of the information infrastructure supporting the US financial system. Technical challenges around large-scale data systems interact with significant economic forces involving innovation, transparency, confidentiality, complexity, and organizational change, to create a very difficult problem. The post-crisis reform legislation has created a...

    Provided By University of Maryland

  • White Papers // Jan 2011

    KeyChains: A Decentralized Public-Key Infrastructure

    A Certification Authority (CA) can be used to certify keys and build a Public-Key Infrastructure (PKI) when all users trust the same CA. A decentralized PKI trades off absolute assurance on keys for independence from central control and improved scalability and robustness. The PGP "Web of trust" model has been...

    Provided By University of Maryland

  • White Papers // Jan 2011

    Indexing Cached Multidimensional Objects in Large Main Memory Systems

    Semantic caches allow queries into large datasets to leverage cached results either directly or through transformations, using semantic information about the data objects in the cache. As the price of main memory continues to drop and its size increases, the size of semantic caches grows proportionately, and it is becoming...

    Provided By University of Maryland

  • White Papers // Jan 2011

    Using Content-Addressable Networks for Load Balancing in Desktop Grids

    Desktop grids combine Peer-to-Peer and Grid computing techniques to improve the robustness, reliability and scalability of job execution infrastructures. However, efficiently matching incoming jobs to available system resources and achieving good load balance in a fully decentralized and heterogeneous computing environment is a challenging problem. In this paper, the authors...

    Provided By University of Maryland

  • White Papers // Sep 2010

    Integrating DFM With CAD Through Design Critiquing

    The increasing focus on Design For Manufacturability (DFM) in research in concurrent engineering and engineering design is expanding the scope of traditional design activities in order to identify and eliminate manufacturing problems during the design stage. Manufacturing a product generally involvesmany different kinds of manufacturing activities, each having different characteristics....

    Provided By University of Maryland

  • White Papers // Dec 2009

    Network Connectivity and Related Optimization Problems on Random Graphs

    Network connectivity and propagation problems arise naturally in many social networks. The authors examine problems where some property, such as an infection or influence, starts from some initially seeded set of nodes and every affected node transmits the property to its neighbors with a probability determined by the connecting edge....

    Provided By University of Maryland

  • White Papers // Aug 2009

    Passive Aggressive Measurement With MGRP

    The authors present the Measurement Manager Protocol (MGRP), an in-kernel service that schedules and transmits probes on behalf of active measurement tools. Unlike prior measurement services, MGRP transparently piggybacks application packets inside the often significant amounts of empty padding contained in typical probes. Using MGRP thus combines the modularity, flexibility,...

    Provided By University of Maryland

  • White Papers // Jan 2011

    Resilient Multicast Using Overlays

    This paper introduces PRM (Probabilistic Resilient Multicast): a multicast data recovery scheme that improves data delivery ratios while maintaining low end-to-end latencies. PRM has both a proactive and a reactive components; this paper describes how PRM can be used to improve the performance of application-layer multicast protocols, especially when there...

    Provided By University of Maryland

  • White Papers // Jan 2011

    Distribution of Path Durations in Mobile Ad-Hoc Networks - Palm's Theorem to the Rescue

    The authors first study the distribution of path duration in multi-hop wireless networks. This paper shows that as the number of hops along a path increases, the path duration distribution can be accurately approximated by an exponential distribution under a set of mild conditions, even when the link duration distributions...

    Provided By University of Maryland

  • White Papers // Jan 2011

    Ontology-Driven Adaptive Sensor Networks

    A wireless sensor network deployed in an area of interest is affected by variations in environmental conditions associated with that area. It must adapt to these variations in order to continue functioning as desired by the user. The authors present a novel, two-phase solution to the wireless sensor network adaptivity...

    Provided By University of Maryland

  • White Papers // Mar 2009

    Towards Dynamic Adaptive Automated Test Generation for Graphical User Interfaces

    Graphical User Interfaces (GUIs) present an enormous number of potential event sequences to users. During testing it is necessary to cover this space, however the complexity of modern GUIs has made this an increasingly difficult task. The past work has demonstrated that it is important to incorporate "Context" into GUI...

    Provided By University of Maryland

  • White Papers // Jan 2009

    An Initial Characterization of Industrial Graphical User Interface Systems

    To date the authors have developed and applied numerous model-based GUI testing techniques; however, they are unable to provide definitive improvement schemes to real-world GUI test planners, as the data was derived from open source applications, small compared to industrial systems. This paper presents a study of three industrial GUI-based...

    Provided By University of Maryland

  • White Papers // Mar 2009

    An Extensible Heuristic-Based Framework for GUI Test Case Maintenance

    Graphical User Interfaces (GUIs) make up a large portion of the code comprising many modern software applications. However, GUI testing differs significantly from testing of traditional software. One respect in which this is true is test case maintenance. Due to the way that GUI test cases are often implemented, relatively...

    Provided By University of Maryland