University of Maryland

Displaying 1-40 of 179 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

    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

    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

    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 // Aug 2009

    Semantic Web Service Composition in Social Environments

    This paper describes how to generate compositions of semantic Web services using social trust information from user ratings of the services. The authors present taxonomy of features, such as interoperability, availability, privacy, security, and others. The authors describe a way to compute social trust in OWL-S style semantic Web services....

    Provided By University of Maryland

  • White Papers // Jan 2010

    Semi-Automatic Composition of Web Services Using Semantic Descriptions

    As web services become more prevalent, tools will be needed to help users find, filter and integrate these services. Composing existing services to obtain new functionality will prove to be essential for both business-to-business and business-to-consumer applications. The authors have developed a prototype that guides a user in the dynamic...

    Provided By University of Maryland

  • White Papers // May 2010

    COSI: Cloud Oriented Subgraph Identification in Massive Social Networks

    Subgraph matching is a key operation on graph data. Social Network (SN) providers may want to find all subgraphs within their social network that "Match" certain query graph patterns. Unfortunately, subgraph matching is NP-complete, making its application to massive SNs a major challenge. Past work has shown how to implement...

    Provided By University of Maryland

  • White Papers // Jan 2010

    Multiscale Analysis for Wireless LAN Traffic Characterization

    In this paper, the author's overview the various network traffic models, especially focusing on the multiscale analysis. By multiscale analysis the authors mean wavelet-based self-similar and multifractal analysis. Multiscale analysis is advantageous in that it can reveal the scaling behavior of the traffic on large time scale; at the same...

    Provided By University of Maryland

  • White Papers // Jan 2010

    An Accurate Technique for Measuring the Wireless Side of Wireless Networks

    Wireless Monitoring (WM) is a passive approach for capturing wireless-side traffic with rich MAC/PHY layer information. WM can suffer, however, from low capture performance, i.e., high measurement loss, due to the unreliable wireless medium. This paper experimentally shows that WM can perform reliable and accurate measurements on wireless traffic, in...

    Provided By University of Maryland

  • White Papers // Jan 2010

    Admission Control for Multihop Wireless Backhaul Networks With QoS Support

    Despite improvements in wireless access technologies such as 3G or 802.11x, ubiquitous data access has remained a challenge, mainly due to the lack of inexpensive, pervasive backhaul connections from access points to the Internet. With the recent WiMAX standard for high-speed, non-line-of-sight xed wireless links, multihop wireless backhauls might now...

    Provided By University of Maryland

  • White Papers // Jan 2010

    Design and Evaluation of a Common Access Point for Bluetooth, 802.11 and Wired LANs

    Devices using wireless technologies like Bluetooth and 802.11b will be ubiquitous in the near future. The technologies supporting these devices will need to co-exist in order to support smooth exchange of information. This paper envisions the existence of an Access Point (AP) that can support all these wireless technologies and...

    Provided By University of Maryland

  • White Papers // Dec 2009

    Sectored Random Projections for Cancelable Iris Biometrics

    Privacy and security are essential requirements in practical biometric systems. In order to prevent the theft of biometric patterns, it is desired to modify them through revocable and non invertible transformations called Cancelable Biometrics. This paper proposes an efficient algorithm for generating a Cancelable Iris Biometric based on Sectored Random...

    Provided By University of Maryland

  • White Papers // Jan 2010

    Maximizing Path Durations in Mobile Ad-Hoc Networks

    The authors study the problem of path selection in mobile ad-hoc networks. Based on the earlier results the authors propose a novel scheme that maximizes the expected durations of selected paths and performs local path recovery by computing the probability a cached alternative path is still available in the event...

    Provided By University of Maryland

  • White Papers // Jan 2010

    Secure Spaces: Location-Based Secure Wireless Group Communication

    This paper defines "Secure Space" as an enclosed area within which wireless devices can participate in secure group communication. A device is able to join a secure space group by the virtue of its location within the enclosure. The devices communicate with each other using IEEE 802.11 wireless LAN or...

    Provided By University of Maryland

  • White Papers // Mar 2009

    A Quick Read On The State Of Small Business And The Small Business Success Index

    Competitiveness in this context is defined as the level of success a small business achieves in conducting the organizational activities critical to its short and long term viability. The more competitive a small business is, the more likely it is to meet the personal and business goals of its owners...

    Provided By University of Maryland

  • White Papers // Jun 2010

    Using Virtualization and Live Migration in a Scalable Mobile Wireless Testbed

    Laboratory-based mobile wireless testbeds such as MeshTest and the CMU Wireless Emulator are powerful platforms that allow users to perform controlled, repeatable, mobile wireless experiments in the lab. Unfortunately such systems can only accommodate 10-20 nodes in an experiment. The authors have designed and built a prototype of a system...

    Provided By University of Maryland

  • White Papers // May 2009

    Cloud-Based Decision Support Systems and Availability Context: The Probability of Successful Decision Outcomes

    In an age of cloud computing, mobile users, and wireless networks, the availability of decision support related computing resources can no longer guarantee five-nines (99.999%) availability but the dependence on decision support systems is ever increasing. If not already, the likelihood of obtaining accurate deterministic advice from these systems will...

    Provided By University of Maryland

  • White Papers // Jan 2011

    Coinonia: Privacy-Aware Meeting Scheduler Based on Location-Based Services for Mobile Users

    The location based service has been attracted more and more in recent years with the advance of wireless communication technologies. Some mobile applications are designed to provide users with their current location information shared by a group of people where a user might be reluctant to reveal the private information....

    Provided By University of Maryland

  • White Papers // May 2009

    Improving Graph Drawing Readability by Incorporating Readability Metrics: A Software Tool for Network Analysts

    Designing graph drawings that effectively communicate the underlying network is challenging as for every network there are many potential unintelligible or even misleading drawings. Automated graph layout algorithms have helped, but frequently generate ineffective drawings. In order to build awareness of effective graph drawing strategies, the authors detail readability metrics...

    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 // Mar 2010

    Informal Sector, Government Policy And Institutions

    The authors document cross-country differences in informal activity, government policies and institutions using a data set covering 118 countries. Five key facts emerge from this data set. Better institutions are associated with lower inflation, higher income tax rates and less informal activity. Related to these, they also find that higher...

    Provided By University of Maryland

  • White Papers // Mar 2010

    Improving Communications: Awareness And Management Of Perceiving Disagreement

    Interpersonal communications often fail to communicate the intended message. Language, contextual, and cultural differences between the sender and receiver of the message influence the receipt of the intended message exacerbates a lack of understanding when the message contains inexact words and phrases. The resultant message obtained by the receiver may...

    Provided By University of Maryland

  • White Papers // Jan 2011

    Adapting Transmission Power for Optimal Energy Reliable Multi-Hop Wireless Communication

    The authors define a transmission power adaptation-based routing technique that finds optimal paths for minimum energy reliable data transfer in multi-hop wireless networks. This optimal choice of the transmission power depends on the link distance between the two nodes and the channel characteristics. Typical energy efficient routing techniques use a...

    Provided By University of Maryland

  • White Papers // Jan 2010

    Your House Or Your Credit Card, Which Would You Choose? Personal Delinquency Tradeoffs And Precautionary Liquidity Motives

    This paper presents evidence that precautionary liquidity concerns lead many individuals to pay credit card bills even at the cost of mortgage delinquencies and foreclosures. While the popular press and some recent literature have suggested that this choice may emerge from steep declines in housing prices, the authors find evidence...

    Provided By University of Maryland

  • White Papers // Jul 2010

    Wireless Jamming Attacks Under Dynamic Traffic Uncertainty

    The authors analyze the effects of dynamic packet traffic on jamming attacks in wireless networks. For random access over collision channels, the jamming problem is formulated as a non-cooperative game in which nodes choose their transmission probabilities under energy and delay constraints. They relax the standard assumption of backlogged nodes...

    Provided By University of Maryland

  • White Papers // Sep 2010

    Distributed Topology Control for Stable Path Routing in Multi-Hop Wireless Networks

    In this paper, the authors introduce the topology control problem for stable path routing in mobile multi-hop networks. They formulate the topology control problem of selective link-state broadcast as a graph pruning problem with restricted local neighborhood information. They develop a multi-agent optimization framework where the decision policies of each...

    Provided By University of Maryland

  • White Papers // Oct 2009

    Auction-Based Dynamic Spectrum Trading Market - Spectrum Allocation and Profit Sharing

    The authors study the problem of designing a new trading market for dynamic spectrum sharing when there are multiple sellers and multiple buyers. First, they study the interaction among homogeneous buyers of spectrum as a non-cooperative game and show the existence of Symmetric Mixed-Strategy Nash Equilibrium (SMSNE). Second, they assume...

    Provided By University of Maryland

  • White Papers // Jan 2011

    Stability of a Rate Control System With Averaged Feedback and Network Delay

    The authors study the stability of a variant of Kelly's rate control scheme in a simple setting with a single flow and a single resource. The feedback signals from the resource is a function of an average rate of the flow obtained using a low pass filter. They derive a...

    Provided By University of Maryland

  • White Papers // Aug 2009

    Ant-Based Adaptive Message Forwarding Scheme for Challenged Networks With Sparse Connectivity

    The authors propose a new class of message routing schemes for mobile wireless networks with intermittent network connectivity. The proposed schemes are based on Swarm Intelligence (SI) and exploit the statistical properties of time-varying network connectivity for opportunistic message forwarding. They also consider a special form of the proposed schemes...

    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 // Aug 2010

    Locksmith: Practical Static Race Detection for C

    Locksmith is a static analysis tool for automatically detecting data races in C programs. In this paper, the authors describe each of Locksmith's component analyses precisely, and present systematic measurements that isolate interesting tradeoffs between precision and efficiency in each analysis. Using a benchmark suite comprising standalone applications and Linux...

    Provided By University of Maryland

  • White Papers // Jul 2010

    Dynamic Inference of Static Types for Ruby

    There have been several efforts to bring static type inference to object-oriented dynamic languages such as Ruby, Python, and Perl. In authors' experience, however, such type inference systems are extremely difficult to develop, because dynamic languages are typically complex, poorly specified, and include features, such as eval and reflection, that...

    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