University of California

Displaying 321-360 of 582 results

  • White Papers // Aug 2010

    Interactive Visual Analysis of Hierarchical Enterprise Data

    In this paper, the authors present an interactive visual technique for analyzing and understanding hierarchical data, which they have applied to analyzing a corpus of technical reports produced by a corporate research laboratory. The analysis begins by selecting a known entity, such as a topic, a report, or a person,...

    Provided By University of California

  • White Papers // Aug 2010

    Quantitative Evaluation of Secure Network Coding

    Network coding has gained significant attention by improving throughput and reliability in disruptive MANETs. Yet, it is vulnerable to attacks from malicious nodes. In order to prevent this attack, the authors have explored the use of secure network coding schemes based on homomorphic properties of cryptographic systems. While the method...

    Provided By University of California

  • White Papers // Aug 2010

    Bayesian Inference for Queueing Networks and Modeling of Internet Services

    Modern Internet services, such as those at Google, Yahoo!, and Amazon, handle billions of requests per day on clusters of thousands of computers. Because these services operate under strict performance requirements, a statistical understanding of their performance is of great practical interest. Such services are modeled by networks of queues,...

    Provided By University of California

  • White Papers // Aug 2010

    System Problem Detection by Mining Console Logs

    The console logs generated by an application contain information that the developers believed would be useful in debugging or monitoring the application. Despite the ubiquity and large size of these logs, they are rarely exploited because they are not readily machine-parsable. The authors propose a fully automatic methodology for mining...

    Provided By University of California

  • White Papers // Aug 2010

    Towards Cooperative Grids: Sensor/Actuator Networks for Renewables Integration

    Faced with an uncertain path forward to Renewables Portfolio Standard (RPS) goals and the high cost of energy storage, the authors believe that deep demand side management must be a central strategy to achieve widespread penetration of renewable energy sources. They examine the variability of wind as a source of...

    Provided By University of California

  • White Papers // Jul 2010

    Code Generation for Embedded Java With Ptolemy

    Code generation from models is the ultimate goal of model-based design. For real-time systems the generated code must be analyzable for the worst-case execution time (WCET). This paper evaluates Java code generation from Ptolemy II for embedded real-time Java. The target system is the time-predictable Java processor JOP. The quality...

    Provided By University of California

  • White Papers // Jul 2010

    On Developing Smart Applications for VANETs: Where Are We Now? Some Insights on Technical Issues and Open Problems

    The advances in research on ad hoc networks, the availability of cheap radio interfaces (e.g. Wi-Fi) and the increasing amount of electronic devices installed in vehicles have set the path for vehicular ad hoc networks. In the past few years, Vehicular Ad hoc NETwork (VANET) research has addressed all layers,...

    Provided By University of California

  • White Papers // Jul 2010

    An Adaptive Multi-Channel P2P Video-on-Demand System Using Plug-and-Play Helpers

    They authors present a multi-channel P2P Video-on-Demand (VoD) system using "plug-and-play" helpers. Helpers are heterogeneous "micro-servers" with limited storage, bandwidth and number of users they can serve simultaneously. The proposed system has the following salient features: it minimizes the server load; it is distributed, and requires little or no maintenance...

    Provided By University of California

  • White Papers // Jul 2010

    Fine-Grained Incremental Learning and Multi-Feature Tossing Graphs to Improve Bug Triaging

    Software bugs are inevitable and bug fixing is a difficult, expensive, and lengthy process. One of the primary reasons why bug fixing takes so long is the difficulty of accurately assigning a bug to the most competent developer for that bug kind or bug class. Assigning a bug to a...

    Provided By University of California

  • White Papers // Jul 2010

    Cross-Language, Type-Safe, and Transparent Object Sharing for Co-Located Managed Runtimes

    As software becomes increasingly complex and difficult to analyze, it is more and more common for developers to use high-level, type-safe, Object-Oriented (OO) programming languages and to architect systems that comprise multiple components. Different components are often implemented in different programming languages. In state-of-the-art multi-component, multi-language systems, cross-component communication relies...

    Provided By University of California

  • White Papers // Jul 2010

    Security Exercises for the Online Classroom With DETER

    Creating high-quality homework with an emphasis on creativity and open-ended learning is challenging. This is especially true for online classes, which must be both accessible via the Internet and comparable in quality and value to projects that could be used in a traditional classroom. UCLA recently began offering an online...

    Provided By University of California

  • White Papers // Jul 2010

    Comprehending Environmental And Economic Sustainability: Comparative Analysis Of Stability Principles In The Biosphere And Free Market Economy

    Using the formalism of Lyapunov potential function it is shown that the stability principles for biomass in the ecosystem and for employment in economics are mathematically similar. The ecosystem is found to have a stable and an unstable stationary state with high (forest) and low (grasslands) biomass, respectively. In economics,...

    Provided By University of California

  • White Papers // Jul 2010

    A Novel Delay-And Reliability-Aware Inter-Vehicle Routing Protocol

    Intelligent transportation systems could improve transportation safety, driving assistance and traffic management system. Vehicular Ad hoc NETwork (VANET) is an emerging field of technology, embedding wireless communication networks into vehicles to achieve intelligent transportation systems. The development of such systems pose many unique challenges like designing routing protocols that not...

    Provided By University of California

  • White Papers // Jul 2010

    EEFSim: Energy Efficiency Simulator

    Nowadays Cloud computing has emerged as one of the most promising computer paradigms. The idea of selling software as a service has promoted IT enterprises to bet for this new paradigm. Cloud computing aims to power the next generation data centers not only offering software as a service but virtual...

    Provided By University of California

  • White Papers // Jul 2010

    Provenance Based Information Trustworthiness Evaluation in Multi-Hop Networks

    In this paper, the authors present a trust model to evaluate the trustworthiness of information as well as the information publishing nodes based on the information provenance. They consider two factors in evaluating the provenance based information trust: path similarity and information similarity. In multihop networks, information can flow through...

    Provided By University of California

  • White Papers // Jul 2010

    New Advances in Self-Policing Cloud Computing

    Cloud computing is a style of computing in which dynamically scalable and often virtualized resources e.g., CPU, memory, storage, and network bandwidth are provided as a service over the Internet. This model is considered affordable for cloud users as they avoid the significant financial overheads associated with deploying, maintaining, and...

    Provided By University of California

  • White Papers // Jul 2010

    Assessing the VANET's Local Information Storage Capability Under Different Traffic Mobility

    Wireless networking enabled vehicles can form Vehicular Ad hoc Mesh Networks (VMesh). By cooperative communication among VMeshes, a local transient information could be "Retained" within a given geographic region for a certain period of time, without any infrastructure help. In this paper, the authors study this "Storage Capability" of VMesh....

    Provided By University of California

  • White Papers // Jul 2010

    Frequency Quorum Rendezvous for Fast and Resilient Key Establishment Under Jamming Attack

    Jamming attacks have been recently studied as wireless security threats disrupting reliable RF communication in a wireless network. Existing countermeasures often make use of spread-spectrum techniques such as Frequency Hopping Spread Spectrum and Direct Sequence Spread Spectrum. Communication parties rely on a pre-shared common key (hopping sequence or spread code)...

    Provided By University of California

  • White Papers // Jul 2010

    Knowledge Transfers From Multinational To Domestic Firms: Evidence From Worker Mobility

    Labor turnover is a commonly-cited mechanism for the transmission of technology from multinational to domestic firms, but until now there has been little direct evidence for this mechanism. Using a novel matched establishment-worker database from Brazil, the author presents evidence consistent with the existence of positive multinational wage spillovers through...

    Provided By University of California

  • White Papers // Jun 2010

    Does Tariff Liberalization Kick The Good Apples Out? Theory And Evidence

    This paper examines the liberalization of a common tariff when imported varieties vary in quality and cost. Varieties of higher quality and/or lower costs are imported at lower absolute demand elasticities and also to earn higher revenues. By virtue of larger demand elasticities, low revenue varieties benefit the most from...

    Provided By University of California

  • White Papers // Jun 2010

    Readers Behaving Badly Reader Revocation in PKI-Based RFID Systems

    Recent emergence of RFID tags capable of performing public key operations motivates new RFID applications, including electronic travel documents, identification cards and payment instruments. In this context, public key certificates form the cornerstone of the overall system security. In this paper, the authors argue that one of the prominent challenges...

    Provided By University of California

  • White Papers // Jun 2010

    A Novel SLA Framework for Time-Differentiated Resilience in Optical Mesh Networks

    Telecom customers may have specific time periods during which they require extra resilience. However, these time-differentiated resilience requirements are not effectively addressed by current SLA frameworks. To satisfy these high priority periods, a generic SLA framework typically provides upgraded protection over the entire service duration, which is unnecessary and expensive....

    Provided By University of California

  • White Papers // Jun 2010

    Efficient Computation of Queueing Delay at a Network Port From Output Link Packet Traces

    Current Internet core routers provide enough buffer capacity at each output port to keep the link busy for 250 msec. to avoid disrupting TCP flows because of dropped packets. Since link speeds are rising much more quickly than the availability and cost-effectiveness of large high-speed memories, there is now significant...

    Provided By University of California

  • White Papers // Jun 2010

    Organizing Large Scale Hacking Competitions

    Computer security competitions and challenges are a way to foster innovation and educate students in a highly-motivating setting. In recent years, a number of different security competitions and challenges were carried out, each with different characteristics, configurations, and goals. From 2003 to 2007, the authors carried out a number of...

    Provided By University of California

  • White Papers // Jun 2010

    Cross-Language, Type-Safe, and Transparent Object Sharing for Co-Located Managed Runtimes UCSB Technical Report #2010-11 June, 2010

    As software becomes increasingly complex and difficult to analyze, it is more and more common for developers to use high-level, type-safe, Object-Oriented (OO) programming languages and to architect systems that comprise multiple components. Different components are often implemented in different programming languages. In state-of-the-art multi-component, multi-language systems, cross-component communication relies...

    Provided By University of California

  • White Papers // Jun 2010

    Coexistence-Aware Scheduling for Wireless System-on-a-Chip Devices

    Today's mobile devices support many wireless technologies to achieve ubiquitous connectivity. Economic and energy constraints, however, drive the industry to implement multiple technologies into a single radio. This system-on-a-chip architecture leads to competition among networks when devices toggle across different technologies to communicate with multiple networks. In this paper, authors...

    Provided By University of California

  • White Papers // Jun 2010

    Multinational Firms And Trade: Gravity Versus Market Power In A Ricardian World

    Are multinational firms good for consumer welfare? The authors build a model of foreign direct investment and trade that exploits both firm heterogeneity and strategic pricing behavior, embodying direct exporting and multinational production for both export and local sale in one framework. They show that improved efficiency in target firms...

    Provided By University of California

  • White Papers // Jun 2010

    Gibbs Sampling in Open-Universe Stochastic Languages

    Languages for Open-Universe Probabilistic Models (OUPMs) can represent situations with an unknown number of objects and identity uncertainty. While such cases arise in a wide range of important real-world applications, existing general purpose inference methods for OUPMs are far less efficient than those available for more restricted languages and model...

    Provided By University of California

  • White Papers // Jun 2010

    Protecting a Moving Target: Addressing Web Application Concept Drift

    Because of the ad hoc nature of web applications, intrusion detection systems that leverage machine learning techniques are particularly well-suited for protecting websites. The reason is that these systems are able to characterize the applications' normal behavior in an automated fashion. However, anomaly-based detectors for web applications suffer from false...

    Provided By University of California

  • White Papers // Jun 2010

    Analyzing and Detecting Malicious Flash Advertisements

    The amount of dynamic content on the web has been steadily increasing. Scripting languages such as JavaScript and browser extensions such as Adobe's Flash have been instrumental in creating web-based interfaces that are similar to those of traditional applications. Dynamic content has also become popular in advertising, where Flash is...

    Provided By University of California

  • White Papers // Jun 2010

    Examining Energy Use in Heterogeneous Archival Storage Systems

    Controlling energy usage in data centers, and storage in particular, continues to rise in importance. Many systems and models have examined energy efficiency through intelligent spin-down of disks and novel data layouts, yet little work has been done to examine how power usage over the course of months to years...

    Provided By University of California

  • White Papers // Jun 2010

    FIRE: FInding Rogue nEtworks

    For many years, online criminals have been able to conduct their illicit activities by masquerading behind disreputable Internet Service Providers (ISPs). For example, organizations such as the Russian Business Network (RBN), Atrivo (a.k.a., Intercage),McColo, and most recently, the Triple Fiber Network (3FN) operated with impunity, providing a safe haven for...

    Provided By University of California

  • White Papers // Jun 2010

    Rate-Optimal Video Transmission Over MIMO Channels

    In this paper, the authors propose a low complexity method for optimal video transmission over a quasi-static Rayleigh fading channel utilizing multiple transmit and receive antennas. Under the assumption that the total transmission bandwidth is fixed, their method jointly selects the optimal Space-Time Code (STC) with fixed and finite signal...

    Provided By University of California

  • White Papers // Jun 2010

    Accelerating Viola-Jones Face Detection to FPGA-Level Using GPUs

    Face detection is an important aspect for biometrics, video surveillance and human computer interaction. The authors present a multi-GPU implementation of the Viola-Jones face detection algorithm that meets the performance of the fastest known FPGA implementation. The GPU design offers far lower development costs, but the FPGA implementation consumes less...

    Provided By University of California

  • White Papers // Jun 2010

    Towards Practical Taint Tracking

    This paper proposes several technical measures that significantly improve performance and largely limit kernel taint explosion in a XEN- and QEMU-based taint tracking system. Full-system, fine-grained taint tracking is a fundamental primitive that can be used for a number of purposes, most notably for tracking the flow of information through...

    Provided By University of California

  • White Papers // Jun 2010

    Data Privacy With Multi-Function Printers, Printers and Copiers

    Hard drives have become prevalent temporary or static storage components within many print devices. In fact, most copiers and multi-function printers manufactured since 2005 have hard drives. While the campus Cyber-safety program has, to date, focused on computer and network security, the focus needs to be expanded to include hard...

    Provided By University of California

  • White Papers // Jun 2010

    Financial Constraints And Innovation: Why Poor Countries Dont Catchup

    The authors examine micro-level channels of how financial development can affect macroeconomic outcomes like the level of income and export intensity. They investigate theoretically and empirically how financial constraints affect a firm's innovation and export activities, using unique firm survey data which provides direct measures for innovations and firm-specific financial...

    Provided By University of California

  • White Papers // May 2010

    P4P: Practical Large-Scale Privacy-Preserving Distributed Computation Robust Against Malicious Users

    In this paper the authors introduce a framework for privacy preserving distributed computation that is practical for many real-world applications. The framework is called Peers for Privacy (P4P) and features a novel heterogeneous architecture and a number of efficient tools for performing private computation and ensuring security at large scale....

    Provided By University of California

  • White Papers // May 2010

    Mesos: A Platform for Fine-Grained Resource Sharing in the Data Center

    This paper present Mesos, a platform for sharing commodity clusters between multiple diverse cluster computing frameworks, such as Hadoop and MPI 1. Sharing improves cluster utilization and avoids per-framework data replication. Mesos shares resources in a fine-grained manner, allowing frameworks to achieve data locality by taking turns reading data stored...

    Provided By University of California

  • White Papers // May 2010

    Measuring Online Service Availability Using Twitter

    Real-time micro-blogging services such as Twitter are widely recognized for their social dynamics - how they both encapsulate a social graph and propagate information across it. However, the content of this information is equally interesting since it frequently reflects individual experiences with a broad variety of real-time events. Indeed, events...

    Provided By University of California

  • White Papers // Nov 2011

    How to Lower Congestion With Cross-Layer MPR-PHY/MAC Design?

    In this paper, the authors introduce a cross-layer design between PHY and MAC for Multiple Packet Reception (MPR). Based on the simulation results, three phases of operation has been identified for MPR-PHY/MAC design depending on the offered load to the network. The design is suitable for multihop ad-hoc networks. The...

    Provided By University of California

  • White Papers // Oct 2011

    CLA-MAC: A Cooperative Extension of Load Adaptive MAC Protocol

    The use of cooperative communications techniques has proven to significantly improve network performance via cooperation among network nodes. In this paper, the authors propose a cooperative extension of Load Adaptive MAC (LA-MAC) protocol proposed earlier by one as a hybrid CSMA-TDMA protocol for MANETs. They describe the design and GNU...

    Provided By University of California

  • White Papers // Jun 2009

    Future Directions in Cognitive Radio Network Research

    Wireless technology is proliferating rapidly, and the vision of pervasive wireless computing and communications offers the promise of many societal and individual benefits. While consumer devices such as cell phones, PDAs and laptops receive a lot of attention, the impact of wireless technology is much broader, e.g., through sensor networks...

    Provided By University of California

  • White Papers // Feb 2012

    Mitigate Funnel Effect in Sensor Networks With Multi-Interface Relay Nodes

    Overlay network architectures that use orthogonal channels have been known to provide effective additional resources to underlying networks in high demand. Overlays are composed of relay nodes provided with rich computational resources and multiple wireless interfaces that make them capable of establishing several non-interfering networks. These networks can be used...

    Provided By University of California

  • White Papers // Aug 2011

    Timely and Robust Key Establishment Under Jamming Attack in Critical Wireless Networks

    Jamming attacks are security threats disrupting RF communications in wireless networks. Traditionally, spread spectrum has been proposed as a countermeasure. However, spread spectrum requires secure pre-key establishment before data transmission, with considerable time investment and thus limited functionality. This paper proposes a Frequency Quorum Rendezvous (FQR) scheme. In FQR, nodes...

    Provided By University of California

  • White Papers // Aug 2011

    MPR-Aware Performance Improvement for Inter-Domain Routing in MANETs

    Inter-domain routing for MANETs (Mobile Ad Hoc NETworks) draws increasing attention in military and civil application. It works on heterogeneous networking protocols, including different MAC layer protocols and routing layer protocols. It elects gateways within each domain, which in turn connect to other domains. In this paper, the authors propose...

    Provided By University of California

  • White Papers // Mar 2012

    Primary User Traffic Estimation for Dynamic Spectrum Access

    Accurate estimation of licensed channel Primary User's (PU) temporal statistics is important for Dynamic Spectrum Access (DSA) systems. With accurate estimation of the mean duty cycle, u, and the mean off- and on-times of PUs, DSA systems can more efficiently assign PU resources to its subscribers, thus, increasing channel utilization....

    Provided By University of California

  • White Papers // Dec 2011

    Alleviate Cellular Congestion Through Opportunistic Through Filling

    The demand for cellular data service has been skyrocketing since the debut of data-intensive smart phones and touch-pads. However, not all data are created equal. Many popular applications on mobile devices, such as email synchronization and social network updates, are delay tolerant. In addition, cellular load varies significantly in both...

    Provided By University of California

  • White Papers // Dec 2009

    PACE Yourself: Power Aware Collaborative Execution on Mobile Phones

    In this paper, the authors propose a framework for Power Aware Collaborative Execution (PACE) for mobile phones. Mobile phones have scarce resources, such as battery power and bandwidth. In the context of mobile phones, collaborative execution is a way to pool resources together to give the abstraction to the end...

    Provided By University of California

  • White Papers // Apr 2010

    Network Coding-Aware Queue Management for Unicast Flows Over Coded Wireless Networks

    The authors are interested in unicast flows over wireless networks with intersession network coding (such as COPE). TCP flows over coded wireless networks do not fully exploit network coding opportunities due to their bursty behavior and to the fact that TCP is agnostic to the underlying network coding. In this...

    Provided By University of California

  • White Papers // Jan 2012

    On Detecting Pollution Attacks in Inter-Session Network Coding

    Network coding involves packets being combined at intermediate nodes inside the network. Depending on whether packets from the same or different sessions are combined, network coding is classified as intra-session or inter-session, respectively. Inter-session coding, that is the focus of this paper, has been implemented in practice, such as in...

    Provided By University of California

  • White Papers // Sep 2011

    Cooperative Video Streaming on Smartphones

    Video applications are increasingly popular over smartphones. However, in current cellular systems, the downlink data rate fluctuates and the loss rate can be quite high. The authors are interested in the scenario where a group of smartphone users, within proximity of each other, are interested in viewing the same video...

    Provided By University of California

  • White Papers // Feb 2010

    Delay-Optimized Network Coding for Video Streaming Over Wireless Networks

    In this paper, the authors study delay-optimized network coding for video streaming over wireless networks with network coding capabilities. It has been demonstrated that network coding can increase throughput in wireless networks, by mixing packets from different flows into a single packet, thus increasing the information content per transmission. However,...

    Provided By University of California

  • White Papers // Jun 2011

    Fisher-Information-Matrix Based Analysis of Semiblind MIMO Frequency Selective Channel Estimation

    The authors present a study of Semi-Blind (SB) estimation for a Frequency-Selective (FS) Multiple-Input Multiple-Output (MIMO) wireless channel using a novel Fisher-Information Matrix (FIM) based approach. The frequency selective MIMO system is modeled as a matrix Finite Impulse Response (FIR) channel, and the transmitted data symbols comprise of a sequence...

    Provided By University of California

  • White Papers // May 2010

    Is the Internet for Porn? an Insight Into the Online Adult Industry

    The online adult industry is among the most profitable business branches on the Internet, and its web sites attract large amounts of visitors and traffic. Nevertheless, no study has yet characterized the industry's economical and security-related structure. As cyber-criminals are motivated by financial incentives, a deeper understanding and identification of...

    Provided By University of California

  • White Papers // Jan 2012

    Proactive Resource Provisioning

    Allocating resources in communication networks to QoS flows can require an undesirable delay or cost. As demand churns readjusting wavelength allocation in optical networks, Label Switched Path (LSP) reservations in MPLS networks, QoS connections in two-tier ad hoc networks, and Service Level Agreements (SLAs) between peering autonomous systems are just...

    Provided By University of California

  • White Papers // Jan 2012

    Efficient Synthesis of Networks on Chip

    The authors propose an efficient heuristic for the Constraint-Driven Communication Synthesis (CDCS) of on-chip communication networks. The complexity of the synthesis problems comes from the number of constraints that have to be considered. In this paper, they propose to cluster constraints to reduce the number that needs to be considered...

    Provided By University of California

  • White Papers // Oct 2010

    A Tool-Based Approach to Teaching Parallel and Concurrent Programming

    Today, multicore computers are commonplace and university curricula are lagging behind. The authors need to work concurrency and parallelism into introductory courses, while also maintaining upper-level specialized courses on the topic. Since teachers may themselves require education on the topic, they feel that it is important to make course materials...

    Provided By University of California

  • White Papers // Feb 2011

    Heuristic Evaluation of Programming Language Features

    Usability is an important feature for programming languages. However, user studies which compare programming languages or systems are both very expensive and typically inconclusive. In this paper, the authors posit that discount usability methods can be successfully applied to programming languages concepts such as language features. They give examples of...

    Provided By University of California

  • White Papers // Dec 2009

    Reducing Seek Overhead With Application-Directed Prefetching

    An analysis of performance characteristics of modern disks finds that prefetching can improve the performance of non-sequential read access patterns by an order of magnitude or more, far more than demonstrated by prior work. Using this analysis, the authors design prefetching algorithms that make effective use of primary memory, and...

    Provided By University of California

  • White Papers // Apr 2010

    DP-FAIR: A Simple Model for Understanding Optimal Multiprocessor Scheduling

    The authors consider the problem of optimal real-time scheduling of periodic and sporadic tasks for identical multiprocessors. A number of recent papers have used the notions of fluid scheduling and deadline partitioning to guarantee optimality and improve performance. In this paper, they develop a unifying theory with the DP-FAIR scheduling...

    Provided By University of California

  • White Papers // Oct 2010

    User Evaluation of Correctness Conditions: A Case Study of Cooperability

    In order to find and fix concurrency bugs, programmers must reason about different possible thread inter-leavings - context switches may occur at any program point, all with the potential for thread interference. To reduce the number of thread interference points to consider, the correctness criterion of co-operability ensures that code...

    Provided By University of California

  • White Papers // Aug 2010

    Interactive Visual Analysis of Hierarchical Enterprise Data

    In this paper, the authors present an interactive visual technique for analyzing and understanding hierarchical data, which they have applied to analyzing a corpus of technical reports produced by a corporate research laboratory. The analysis begins by selecting a known entity, such as a topic, a report, or a person,...

    Provided By University of California

  • White Papers // Jun 2010

    Organizing Large Scale Hacking Competitions

    Computer security competitions and challenges are a way to foster innovation and educate students in a highly-motivating setting. In recent years, a number of different security competitions and challenges were carried out, each with different characteristics, configurations, and goals. From 2003 to 2007, the authors carried out a number of...

    Provided By University of California

  • White Papers // Jan 2012

    BugFix: A Learning-Based Tool to Assist Developers in Fixing Bugs

    The authors present a tool called BugFix that can assist developers in fixing program bugs. Their tool automatically analyzes the debugging situation at a statement and reports a prioritized list of relevant bug-fix suggestions that are likely to guide the developer to an appropriate fix at that statement. BugFix incorporates...

    Provided By University of California

  • White Papers // Jan 2012

    Identifying the Root Causes of Memory Bugs Using Corrupted Memory Location Suppression

    The authors present a general approach for automatically isolating the root causes of memory-related bugs in software. Their approach is based on the observation that most memory bugs involve uses of corrupted memory locations. By iteratively suppressing (nullifying) the effects of these corrupted memory locations during program execution, their approach...

    Provided By University of California

  • White Papers // Jan 2012

    Enhancing LRU Replacement Via Phantom Associativity

    In this paper, the authors propose a novel cache design, Phantom Associative Cache (PAC), that alleviates cache thrashing in L2 caches by keeping the in-cache data blocks for a longer time period. To realize PAC, they introduce the concept of phantom lines. A phantom line works like a real cache...

    Provided By University of California

  • White Papers // Jan 2012

    Power Adaptive Broadcasting With Local Information in Ad Hoc Networks

    Network wide broadcasting is an energy intensive function. In this paper, the authors propose a new method that performs transmission power adaptations based on information available locally, to reduce the overall energy consumed per broadcast. In most of the prior work on energy efficient broadcasting it is assumed that the...

    Provided By University of California

  • White Papers // Jan 2012

    Effective and Efficient Localization of Multiple Faults Using Value Replacement

    The authors previously presented a fault localization technique called Value Replacement that repeatedly alters the state of an executing program to locate a faulty statement. The technique searches for program statements involving values that can be altered during runtime to cause the incorrect output of a failing run to become...

    Provided By University of California

  • White Papers // Apr 2010

    Covariance Based Signaling and Feedback Data Parameterization for the TimeVarying MIMO Broadcast Channel

    Linear precoding (beamforming) techniques that maximize the sum rate in the multi-antenna broadcast channel often suffer severe performance degradation when the channel state information at the transmitter is erroneous or outdated. This paper presents a linear precoding algorithm that uses the channel statistics rather than channel state to provide more...

    Provided By University of California

  • White Papers // Apr 2010

    Spatial Multiplexing in Random Wireless Networks

    The authors consider a network of transmitters, each with a receiver at a fixed distance, and locations drawn independently according to a homogeneous Poisson Point Process (PPP). The transmitters and the receivers are equipped with multiple antennas. Under a channel model that includes Rayleigh fading and path-loss, and an outage...

    Provided By University of California

  • White Papers // Jan 2010

    Outage-Optimal Transmission in Multiuser-MIMO Kronecker Channels

    In this paper, the authors look at single user and multiuser Multiple-Input Multiple-Output (MIMO) beamforming networks with Channel Distribution Information (CDI). CDI does not need to be updated every time the channel changes, but only when the statistics of the channel change. Thus, feedback in the network is significantly reduced...

    Provided By University of California

  • White Papers // Sep 2010

    Line and Lattice Networks Under Deterministic Interference Models

    Capacity bounds are compared for four different deterministic models of wireless networks, representing four different ways of handling broadcast and superposition in the physical layer. In particular, the transport capacity under a multiple unicast traffic pattern is studied for a one-dimensional network of regularly spaced nodes on a line and...

    Provided By University of California

  • White Papers // Feb 2012

    A Flexible In-Network IP Anonymization Service

    User privacy on the Internet has been an increasing concern in recent years. With the proliferation and sophistication of information services, data mining, and search engines, a simple network address may be used to reveal a great deal of information about a user, including location, identity, and behavior. Existing approaches...

    Provided By University of California

  • White Papers // Sep 2010

    The Case for Using Traffic Forecasting in Schedule-Based Channel Access

    In this paper, the authors explore the idea of using traffic forecasting to improve the delay performance of a schedule-based medium access control protocol. Schedule-based channel access has been shown to utilize network and energy resources efficiently but is often hindered by the extra delay that scheduling introduces. They explore...

    Provided By University of California

  • White Papers // Aug 2009

    Collision-Free Asynchronous Multi-Channel Access in Ad Hoc Networks

    In this paper, the authors present a collision-free asynchronous multi-channel access protocol for Ad Hoc wireless networks using a single transceiver. Their protocol, dubbed AMMAC for Asynchronous Multi-channel Medium Access Control, targets low-cost and low-power deployments where nodes are equipped with a single transceiver. Other distinguishing features of AM-MAC include...

    Provided By University of California

  • White Papers // Jan 2012

    Weighted Fair Queuing With Differential Dropping

    Weighted Fair Queuing (WFQ) allows Internet operators to define traffic classes and then assign different bandwidth proportions to these classes. Unfortunately, the complexity of efficiently allocating the buffer space to each traffic class turns out to be overwhelming, leading most operators to vastly overprovision buffering - resulting in a large...

    Provided By University of California

  • White Papers // Jan 2012

    BlueSky: A Cloud-Backed File System for the Enterprise

    The authors present BlueSky, a network file system backed by cloud storage. BlueSky stores data persistently in a cloud storage provider such as Amazon S3 or Windows Azure, allowing users to take advantage of the reliability and large storage capacity of cloud providers and avoid the need for dedicated server...

    Provided By University of California

  • White Papers // Dec 2011

    Limitations of Scanned Human Copresence Encounters for Modelling Proximity-Borne Malware

    Patterns of human encounters, which are difficult to observe directly, are fundamental to the propagation of mobile malware aimed at infecting devices in spatial proximity. The authors investigate errors introduced by using scanners that detect the presence of devices on the assumption that device co-presence at a scanner corresponds to...

    Provided By University of California

  • White Papers // May 2012

    Analysis of Ecrime in Crowd-Sourced Labor Markets: Mechanical Turk Vs. Freelancer

    Research in the economics of security has contributed more than a decade of empirical findings to the understanding of the microeconomics of (in) security, privacy, and ecrime. Here, the authors build on insights from previous macro-level research on crime, and microeconomic analyses of ecrime to develop a set of hypotheses...

    Provided By University of California