University of California

Displaying 161-200 of 738 results

  • 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 // Feb 2011

    A Stateless Traceback Technique for Identifying the Origin of Attacks From a Single Packet

    Anonymity is one of the main motivations for conducting denial-of-service attacks. Currently, there is no mechanism to either identify the true source of an IP packet or to prove its authenticity. In this paper, the authors propose a stateless IP traceback technique that identifies the origin network of each individual...

    Provided By University of California

  • White Papers // Feb 2011

    An Empirical Analysis of XSS Sanitization in Web Application Frameworks

    Filtering or sanitization is the predominant mechanism in today's applications to defend against cross-site scripting (XSS) attacks. XSS sanitization can be difficult to get right as it ties in closely with the parsing behavior of the browser. This paper explains some of the subtleties of ensuring correct sanitization, as well...

    Provided By University of California

  • White Papers // Feb 2011

    Peer-to-Peer Multimedia Sharing Based on Social Norms

    Empirical data shows that in the absence of incentives, a peer participating in a Peer-to-Peer (P2P) network wishes to download content, while avoiding to contribute content in return. This phenomenon, known as free-riding, has been actively studied in the literature and incentives have been proposed to compel self-interested peers to...

    Provided By University of California

  • White Papers // Feb 2011

    Reduced-Bandwidth Multithreaded Algorithms for Sparse Matrix-Vector Multiplication

    On multicore architectures, the ratio of peak memory bandwidth to peak floating-point performance (byte: flop ratio) is decreasing as core counts increase, further limiting the performance of bandwidth limited applications. Multiplying a sparse matrix (as well as its transpose in the un-symmetric case) with a dense vector is the core...

    Provided By University of California

  • White Papers // Feb 2011

    Towards a Societal Scale, Mobile Sensing System

    With the proliferation of sensor equipped smart phones, and augmented reality applications fast appearing, the mobile phone is becoming something much more than a scaled-down, connected IO and processing device. In addition to these standard PC traits, a cell phone is situated in an environment, mobile, and typically co-located with...

    Provided By University of California

  • White Papers // Jan 2011

    Traffic Characterization and Internet Usage in Rural Africa

    While Internet connectivity has reached a significant part of the world's population, those living in rural areas of the developing world are still largely disconnected. Recent efforts have provided Internet connectivity to a growing number of remote locations, yet Internet traffic demands cause many of these networks to fail to...

    Provided By University of California

  • White Papers // Jan 2011

    A Unified CAD-PLM Architecture for Improving Electronics Design Productivity Through Automation, Collaboration, and Cloud Computing

    In electronics design, Computer Aided Design (CAD) tools manage part data in a logical schematic view (a part symbol) and a physical PCB view (a part footprint). Yet, a part has a third view, which CAD tools ignore - its supply data (manufacturer part number, variant, distributor, etc). To manage...

    Provided By University of California

  • White Papers // Jan 2011

    PoX: Protecting Users From Malicious Facebook Applications

    Online social networks such as Facebook, MySpace, and Orkut store large amounts of sensitive user data. While a user can legitimately assume that a social network provider adheres to strict privacy standards, the authors argue that it is unwise to trust third-party applications on these platforms in the same way....

    Provided By University of California

  • White Papers // Jan 2011

    Temporal Traffic Dynamics Improve the Connectivity of Ad Hoc Cognitive Radio Networks

    In an ad hoc cognitive radio network, secondary users access channels temporarily unused by primary users and the existence of a communication link between two secondary users depends on the transmitting and receiving activities of nearby primary users. Using theories and techniques from continuum percolation and ergodicity, the authors analytically...

    Provided By University of California

  • White Papers // Jan 2011

    Enhancing Data Privacy in the Cloud

    Due to its low cost, robustness, flexibility and ubiquitous nature, cloud computing is changing the way entities manage their data. However, various privacy concerns arise whenever potentially sensitive data is outsourced to the cloud. This paper presents a novel approach for coping with such privacy concerns. The proposed scheme prevents...

    Provided By University of California

  • White Papers // Jan 2011

    Rubik's for Cryptographers

    Hard mathematical problems are at the core of security arguments in cryptography. In this paper, the authors study mathematical generalizations of the famous Rubik's cube puzzle, namely the factorization, representation and balance problems in non-Abelian groups. These problems arise naturally when describing the security of Cayley hash functions, a class...

    Provided By University of California

  • White Papers // Jan 2011

    The Theory of Intervention Games for Resource Sharing in Wireless Communications

    This paper develops a game-theoretic framework for the design and analysis of a new class of incentive schemes called intervention schemes. The authors formulate intervention games, propose a solution concept of intervention equilibrium, and prove its existence in a finite intervention game. They apply the framework to resource sharing scenarios...

    Provided By University of California

  • White Papers // Jan 2011

    The SQL-Based All-Declarative FORWARD Web Application Development Framework

    The vast majority of database-driven web applications perform, at a logical level, fundamentally simple Insert/Update/Delete commands. In response to a user action on the browser, the web application executes a program that transitions the old state to a new state. The state is primarily persistent and often captured in a...

    Provided By University of California

  • White Papers // Jan 2011

    Latin Square Based Channel Access Scheduling in Large-Scale WLAN Systems

    WLAN systems based on the IEEE 802.11 could contain hundreds even up to thousands of wireless access points nowadays. However, IEEE 802.11 MAC protocols, including DCF, PCF and EDCA mechanisms, are unable to meet the challenges to provide collision freedom, especially in distributed large scale WLAN systems. The authors propose...

    Provided By University of California

  • White Papers // Jan 2011

    Flow-Sensitive Pointer Analysis for Millions of Lines of Code

    Many program analyses benefit, both in precision and performance, from precise pointer analysis. An important dimension of pointer analysis precision is flow-sensitivity, which has been shown to be useful for applications such as program verification and static analysis of binary code, among many others. However, flow-sensitive pointer analysis has historically...

    Provided By University of California

  • White Papers // Jan 2011

    Sound and Complete Monitoring of Sequential Consistency for Relaxed Memory Models

    The authors present a technique for verifying that a program has no executions violating Sequential Consistency (SC) when run under the relaxed memory models Total Store Order (TSO) and Partial Store Order (PSO). The technique works by monitoring sequentially consistent executions of a program to detect if similar program executions...

    Provided By University of California

  • White Papers // Jan 2011

    Detecting MAC Layer Back-Off Timer Violations in Mobile Ad Hoc Networks

    In IEEE 802.11 based ad hoc networks, by simply manipulating the back-off timers and/or wait times prior to transmission, malicious nodes can cause a drastically reduced allocation of bandwidth to well-behaved nodes. This can result in causing bandwidth starvation and hence, a denial of service to legitimate nodes. The authors...

    Provided By University of California

  • White Papers // Jan 2011

    Layered Media Multicast Control (LMMC): Real-Time Error Control

    The authors study the problem of real-time error control in layered and replicated media systems. They formulate an optimization problem aimed at minimizing a cost metric defined over the wasted bandwidth of redundancy in such systems. They also provide an analytical solution to the problem in the context of Layered...

    Provided By University of California

  • White Papers // Jan 2011

    Routing and Multicast in Multihop, Mobile Wireless Networks

    In this paper, the authors present a multicast protocol which builds upon a cluster based wireless network infrastructure. First, they introduce the network infrastructure which includes several innovative features such as: minimum change cluster formation; dynamic priority token access protocol, and; distributed hierarchical routing. Then, for this infrastructure they propose...

    Provided By University of California

  • White Papers // Jan 2011

    Asymptotically Efficient Multi-Channel Estimation for Opportunistic Spectrum Access

    The problem of estimating the parameters of multiple independent continuous-time Markov on-off processes is considered. The objective is to minimize the total Mean Square Error (MSE) under a constraint on the total sensing time. The Fisher information matrix for the primary traffic model and the maximum likelihood estimator are obtained...

    Provided By University of California

  • White Papers // Jan 2011

    Spectrum Opportunity Detection: How Good Is Listen-Before-Talk?

    The authors consider spectrum opportunity detection in cognitive radio networks for spectrum overlay. They highlight the differences between detecting primary signals and detecting spectrum opportunities. They show that besides noise and fading, the geographic distribution and traffic pattern of primary users have significant impact on the performance of spectrum opportunity...

    Provided By University of California

  • White Papers // Jan 2011

    Toward a Definition of and Linguistic Support for Partial Quiescence

    The global quiescence of a distributed computation (or distributed termination detection) is an important problem. Some concurrent programming languages and systems provide global quiescence detection as a built-in feature so that programmers do not need to write special synchronization code to detect quiescence. This paper introduces Partial Quiescence (PQ), which...

    Provided By University of California

  • White Papers // Jan 2011

    ASCENT: Adaptive Self-Configuring SEnsor Networks Topologies

    Advances in micro-sensor and radio technology will enable small but smart sensors to be deployed for a wide range of environmental monitoring applications. The low per-node cost will allow these wireless networks of sensors and actuators to be densely distributed. The nodes in these dense networks will coordinate to perform...

    Provided By University of California

  • White Papers // Jan 2011

    On the Throughput Capacity of Random Wireless Networks

    The authors consider the problem of how throughput in a wireless network with randomly located nodes scales as the number of users n grows. Their results rely on percolation theory arguments. When the node density is too high the network is fully connected but generates excessive interference. In the low...

    Provided By University of California

  • White Papers // Jan 2011

    Distributed Channel Access Scheduling for Ad Hoc Networks

    In this paper, the authors present and analyze protocols for Time-Division Multiple Access (TDMA) scheduling in ad hoc networks with omni-directional antennas. These protocols use a Neighbor-aware Contention Resolution (NCR) algorithm to elect deterministically one or multiple winners in a given contention context based on the topology information within two...

    Provided By University of California

  • White Papers // Jan 2011

    Joint Design of Scheduling and Routing Based on Connected Coverage for Optimal Sensor Network Lifetime

    The authors consider information retrieval in a wireless sensor network deployed to monitor a spatially corrected random led. The measured data are sent to an access point through multi-hop transmissions. They address the joint design of sensor scheduling and information routing in each data collection to optimize a performance measure:...

    Provided By University of California

  • White Papers // Jan 2011

    Coverage-Based Information Retrieval for Lifetime Maximization in Sensor Networks

    The authors consider information retrieval in a wireless sensor network deployed to monitor a spatially correlated random field. They address sensor scheduling in each data collection under the performance measure of network lifetime. They formulate this problem as an energy constrained coverage problem and proposal a scheduling algorithm based on...

    Provided By University of California

  • White Papers // Jan 2011

    A Self-Healing and Optimizing Routing Technique for Ad Hoc Networks

    On demand routing protocols provide scalable and cost-effective solutions for packet routing in wireless ad hoc networks. The paths generated by these protocols may deviate far from the optimal because of the lack of knowledge about the global topology and the mobility of nodes. Routing optimality affects network performance, especially...

    Provided By University of California

  • White Papers // Jan 2011

    Efficient Remote Profiling for Resource-Constrained Devices

    The widespread use of ubiquitous, mobile, and continuously-connected computing agents has inspired software developers to change the way they test, debug, and optimize software. Users now play an active role in the software evolution cycle by dynamically providing valuable feedback about the execution of a program to developers. Software developers...

    Provided By University of California

  • White Papers // Jan 2011

    Guiding Architectural SRAM Models

    Caches, block memories, predictors, state tables, and other forms of on-chip memory are continuing to consume a greater portion of processor designs with each passing year. Making good architectural decisions early in the design process requires a reasonably accurate model for these important structures. Dealing with continuously changing SRAM design...

    Provided By University of California

  • White Papers // Jan 2011

    Quantifying the Potential of Program Analysis Peripherals

    As programmers are asked to manage more complicated parallel machines, it is likely that they will become increasingly dependent on tools such as multi-threaded data race detectors, memory bounds checkers, dynamic data flow trackers, and various performance profilers to understand and maintain their software. As these tools continue to grow...

    Provided By University of California

  • White Papers // Jan 2011

    Degenerate 3D Tensors

    Topological analysis of 3D tensor fields starts with the identification of degeneracies in the tensor field. In this paper, the authors present a new, intuitive and numerically stable method for finding degenerate tensors in symmetric second order 3D tensors. This method is formulated based on a description of a tensor...

    Provided By University of California

  • White Papers // Jan 2011

    Power Conservation and Quality of Surveillance in Target Tracking Sensor Networks

    Target tracking is an important application of wireless sensor networks. In this application, the sensor nodes collectively monitor and track the movement of an event or target object. The network operations have two states: the surveillance state during the absence of any event of interest, and the tracking state which...

    Provided By University of California

  • White Papers // Jan 2011

    Comparison: ASR is a Variant of ANODR

    Recently, on-demand routing approach has been embraced by several anonymous routing schemes to protect Mobile Ad hoc NETworks (MANETs) from traffic analysts' attacks. ANODR is the first in literature an on-demand anonymous routing protocol proposed for MANETs, followed by SDAR, ASR and MASK which use the same on-demand approach. While...

    Provided By University of California

  • White Papers // Jan 2011

    The Case for Efficient File Access Pattern Modeling

    Most modern I/O systems treat each file access independently. However, events in a computer system are driven by programs. Thus, accesses to files occur in consistent patterns and are by no means independent. The result is that modern I/O systems ignore useful information. Using traces of file system activity the...

    Provided By University of California

  • White Papers // Jan 2011

    Pseudo-IP: Providing a Thin Network Layer Protocol for Semi-IntelligentWireless Devices

    In the near future users will be able to move freely and still have seamless network and Internet connectivity. The authors envision that the Internet of the future will interconnect mobile or stationary clouds into the existing IP infrastructure. While many of the Internet protocols are immensely successful in traditional...

    Provided By University of California

  • White Papers // Jan 2011

    Energy Conservation in Datacenters Through Cluster Memory Management and Barely-Alive Memory Servers

    As a result of current resource provisioning schemes in Internet services, servers end up less than 50% utilized almost all the time. At this level of utilization, the servers' energy efficiency is less than half their efficiency at peak utilization. A solution to this problem could be consolidating workloads into...

    Provided By University of California

  • White Papers // Jan 2011

    External Double Hashing With Choice

    A novel extension to external double hashing providing significant reduction to both successful and unsuccessful search lengths is presented. The experimental and analytical results demonstrate the reductions possible. This method does not restrict the hashing table configuration parameters and utilizes very little additional storage space per bucket. The runtime performance...

    Provided By University of California

  • White Papers // Jan 2011

    Looking for Diamonds in the Desert - Extending Automatic Protocol Generation to Three-Party Authentication and Key Agreement Protocols

    The current process of designing a security protocol is usually ad-hoc and involves little formalism and mechanical assistance. Such a design process is not only slow but also error-prone. Evidence shows that even when security protocols are designed with care and examined intensely,they can still be fundamentally flawed. A classic...

    Provided By University of California

  • White Papers // May 2011

    Exploring the Relationship BetweenWeb Application Development Tools and Security

    How should software engineers choose which tools to use to develop secure web applications? Different developers have different opinions regarding which language, framework, or vulnerability-finding tool tends to yield more secure software than another; some believe that there is no difference at all between such tools. This paper adds quantitative...

    Provided By University of California

  • White Papers // May 2011

    Phishing on Mobile Devices

    The authors assess the risk of phishing on mobile platforms. Mobile operating systems and browsers lack secure application iden-tity indicators, so the user cannot always identify whether a link has taken her to the expected application. They conduct a systematic analysis of ways in which mobile applications and web sites...

    Provided By University of California

  • White Papers // Mar 2011

    Defeating UCI: Building Stealthy and Malicious Hardware

    In previous work Hicks et al. proposed a method called Unused Circuit Identification (UCI) for detecting malicious backdoors hidden in circuits at design time. The UCI algorithm essentially looks for portions of the circuit that go unused during design-time testing and flags them as potentially malicious. In this paper, the...

    Provided By University of California

  • White Papers // Apr 2010

    Lazy Annotation for Program Testing and Verification

    The authors describe an interpolant-based approach to test generation and model checking for sequential programs. The method generates Floyd/Hoare style annotations of the program on demand, as a result of failure to achieve goals, in a manner analogous to conflict clause learning in a DPLL style SAT solver. The DPLL...

    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 // Jan 2011

    ASCENT: Adaptive Self-Configuring SEnsor Networks Topologies

    Advances in micro-sensor and radio technology will enable small but smart sensors to be deployed for a wide range of environmental monitoring applications. The low per-node cost will allow these wireless networks of sensors and actuators to be densely distributed. The nodes in these dense networks will coordinate to perform...

    Provided By University of California

  • White Papers // Dec 2010

    GeoServ: A Distributed Urban Sensing Platform

    Urban sensing where mobile users continuously gather, process, and share location-sensitive sensor data (e.g., street images, road condition, traffic flow) is emerging as a new network paradigm of sensor information sharing in urban environments. The key enablers are the smartphones (e.g., iPhones and Android phones) equipped with onboard sensors (e.g.,...

    Provided By University of California

  • White Papers // Aug 2010

    VAPR: Void Aware Pressure Routing Protocol

    UnderWater Acoustic Sensor Networks (UW-ASNs) have lately been suggested as a potent means of supporting aquatic applications ranging from environmental monitoring to intrusion detection. A bevy of mobile sensor nodes each equipped with a variety of sensors and a low bandwidth acoustic modem (e.g. Drogues) can be deployed the region...

    Provided By University of California

  • White Papers // Mar 2010

    A Path Loss Model for Non-Line-of-Sight Ultraviolet Multiple Scattering Channels

    An UltraViolet (UV) signal transmission undergoes rich scattering and strong absorption by atmospheric particulates. The authors develop a path loss model for a Non-Line-Of-Sight (NLOS) link. The model is built upon probability theory governing random migration of photons in free space, undergoing scattering, in terms of angular direction and distance....

    Provided By University of California

  • White Papers // May 2011

    On the Sum-Capacity With Successive Decoding in Interference Channels

    In this paper, the authors investigate the sum-capacity of the two-user Gaussian interference channel with Gaussian superposition coding and successive decoding. They first examine an approximate deterministic formulation of the problem, and introduce the complementarity conditions that capture the use of Gaussian coding and successive decoding. In the deterministic channel...

    Provided By University of California

  • White Papers // Jan 2011

    On the Throughput Capacity of Random Wireless Networks

    The authors consider the problem of how throughput in a wireless network with randomly located nodes scales as the number of users n grows. Their results rely on percolation theory arguments. When the node density is too high the network is fully connected but generates excessive interference. In the low...

    Provided By University of California

  • White Papers // Mar 2011

    To Preempt or Not: Tackling Bid and Time-Based Cheating in Online Spectrum Auctions

    Online spectrum auctions offer ample flexibility for bidders to request and obtain spectrum on-the-fly. Such flexibility, however, opens up new vulnerabilities to bidder manipulation. Aside from rigging their bids, selfish bidders can falsely report their arrival time to game the system and obtain unfair advantage over others. Such time-based cheating...

    Provided By University of California

  • White Papers // Jun 2009

    Performance Evaluation of Link Quality Estimation Metrics for Static Multihop Wireless Sensor Networks

    The lossy nature of wireless communication leads to many challenges while designing multihop networks. As an integral part of reliable communication in wireless networks, effective link estimation is essential for routing protocols. Recent studies have shown that link reliability-based metrics like ETX have better performance than traditional metrics such as...

    Provided By University of California

  • White Papers // Feb 2010

    Opportunistic Routing With Congestion Diversity and Tunable Overhead

    This paper considers the problem of routing packets across a multi-hop network consisting of multiple sources of traffic and wireless links with stochastic reliability and a broadcast nature. Opportunistic routing relies on the following principle. Each packet transmission can be overheard by a random subset of receiver nodes among which...

    Provided By University of California

  • White Papers // Dec 2010

    Variable-Length Coding With Noiseless Feedback and Finite Messages

    This paper considers the problem of zero-rate (fixed number of messages) variable-length coding over a memoryless noisy channel with noiseless feedback. This problem is considered from a control theoretic point of view and is modeled as a special case of active sequential hypothesis testing. Techniques from dynamic programming are applied...

    Provided By University of California

  • White Papers // Oct 2009

    A Class of Throughput Optimal Routing Policies

    This paper considers the problem of routing packets across a multi-hop wireless network while ensuring throughput optimality. One of the main challenges in the design of throughput optimal routing policies is identifying an appropriate Lyapunov function with negative expected drift. The only known throughput optimal routing policies in the literature,...

    Provided By University of California

  • White Papers // Aug 2009

    Opportunistic Routing With Congestion Diversity in Wireless Multi-Hop Networks

    This paper considers the problem of routing packets across a multi-hop network consisting of multiple sources of traffic and wireless links with stochastic reliability while ensuring bounded expected delay. Each packet transmission can be overheard by a random subset of receiver nodes among which the next relay/router is selected opportunistically....

    Provided By University of California

  • White Papers // Jan 2011

    Distributed Channel Access Scheduling for Ad Hoc Networks

    In this paper, the authors present and analyze protocols for Time-Division Multiple Access (TDMA) scheduling in ad hoc networks with omni-directional antennas. These protocols use a Neighbor-aware Contention Resolution (NCR) algorithm to elect deterministically one or multiple winners in a given contention context based on the topology information within two...

    Provided By University of California

  • White Papers // Jan 2010

    Distributed Learning in Cognitive Radio Networks: Multi-Armed Bandit With Distributed Multiple Players

    The authors consider a cognitive radio network with distributed multiple secondary users, where each user independently searches for spectrum opportunities in multiple channels without exchanging information with others. The occupancy of each channel is modeled as an i.i.d. Bernoulli process with unknown mean. Users choosing the same channel collide, and...

    Provided By University of California

  • White Papers // Jan 2011

    Joint Design of Scheduling and Routing Based on Connected Coverage for Optimal Sensor Network Lifetime

    The authors consider information retrieval in a wireless sensor network deployed to monitor a spatially corrected random led. The measured data are sent to an access point through multi-hop transmissions. They address the joint design of sensor scheduling and information routing in each data collection to optimize a performance measure:...

    Provided By University of California

  • White Papers // Jan 2011

    Coverage-Based Information Retrieval for Lifetime Maximization in Sensor Networks

    The authors consider information retrieval in a wireless sensor network deployed to monitor a spatially correlated random field. They address sensor scheduling in each data collection under the performance measure of network lifetime. They formulate this problem as an energy constrained coverage problem and proposal a scheduling algorithm based on...

    Provided By University of California

  • White Papers // Jan 2011

    A Self-Healing and Optimizing Routing Technique for Ad Hoc Networks

    On demand routing protocols provide scalable and cost-effective solutions for packet routing in wireless ad hoc networks. The paths generated by these protocols may deviate far from the optimal because of the lack of knowledge about the global topology and the mobility of nodes. Routing optimality affects network performance, especially...

    Provided By University of California

  • White Papers // May 2010

    Beyond Multi-Hop: Optimal Cooperation in Large Wireless Networks

    Multi-hop is the communication architecture of current wireless networks such as mesh or ad hoc networks. Packets are sent from each source to its destination via multiple point-to-point transmissions between relaying nodes. The origins of this approach are rooted in the practice of traditional wire-line networks. Today, the increasing need...

    Provided By University of California

  • White Papers // Aug 2009

    Distributed Authentication for Randomly Compromised Networks

    The authors introduce a simple, practical approach with probabilistic information-theoretic security to solve one of quantum key distribution's major security weaknesses: the requirement of an authenticated classical channel to prevent man-in-the-middle attacks. Their scheme employs classical secret sharing and partially trusted intermediaries to provide arbitrarily high confidence in the security...

    Provided By University of California

  • White Papers // Mar 2009

    Online Learning in Autonomic Multi-Hop Wireless Networks for Transmitting Mission-Critical Applications

    In this paper, the authors study how to optimize the transmission decisions of nodes aimed at supporting mission-critical applications, such as surveillance, security monitoring, and military operations, etc. They focus on a network scenario where multiple source nodes transmit simultaneously mission-critical data through relay nodes to one or multiple destinations...

    Provided By University of California

  • White Papers // Mar 2012

    Static Detection of Loop-Invariant Data Structures

    As a culture, object-orientation encourages programmers to create objects, both short- and long-lived, without concern for cost. Excessive object creation and initialization can cause severe runtime bloat, which degrades significantly application performance and scalability. A frequently-occurring coding pattern that may lead to large volumes of (temporary) objects is the creation...

    Provided By University of California

  • White Papers // Feb 2012

    Uncovering Performance Problems in Java Applications With Reference Propagation Profiling

    Many applications suffer from run-time bloat: excessive memory usage and work to accomplish simple tasks. Bloat significantly affects scalability and performance, and exposing it requires good diagnostic tools. The authors present a novel analysis that profiles the run-time execution to help programmers uncover potential performance problems. The key idea of...

    Provided By University of California

  • White Papers // Apr 2009

    From Tests to Proofs

    The authors describe the design and implementation of an automatic invariant generator for imperative programs. While automatic invariant generation through constraint solving has been extensively studied from a theoretical viewpoint as a classical means of program verification, in practice existing tools do not scale even to moderately sized programs. This...

    Provided By University of California

  • White Papers // Aug 2011

    Application Architecture Discovery - Towards Domain-Driven, Easily-Extensible Code Structure

    The architecture of a software system and its code structure have a strong impact on its maintainability - the ability to fix problems, and make changes to the system efficiently. To ensure maintainability, software systems are usually organized as subsystems or modules, each with atomically defined responsibilities. However, as the...

    Provided By University of California

  • White Papers // Mar 2012

    OnController Initialization in Multivariable Switching Systems

    The authors consider a class of switched systems which consists of a linear MIMO and possibly unstable process in feedback interconnection with a multi-controller whose dynamics switch. It is shown how one can achieve significantly better transient performance by selecting the initial condition for every controller when it is inserted...

    Provided By University of California

  • White Papers // Sep 2009

    Jump Control of Probability Densities With Applications to Autonomous Vehicle Motion

    The authors investigate the problem of controlling the probability density of the state of a process that is observed by the controller via a fixed but unknown function of the state. The goal is to control the process so that its probability density at a point in the state space...

    Provided By University of California

  • White Papers // Sep 2010

    L2-Induced Gains of Switched Systems and Classes of Switching Signals

    This paper addresses the L2-induced gain analysis for switched linear systems. The authors exploit non-conservative necessary and sufficient conditions for the induced gain to lie below a prescribed positive constant and discuss on the induced gains of switched systems obtained for different classes of switching signals, which distinct regularity assumptions...

    Provided By University of California

  • White Papers // Sep 2010

    Impulsive Systems Triggered by Superposed Renewal Processes

    The authors consider impulsive systems with several reset maps triggered by independent renewal processes, i.e., the intervals between jumps associated with a given reset map are identically distributed and independent of the other jump intervals. Considering linear dynamic and reset maps, they establish that mean exponential stability is equivalent to...

    Provided By University of California

  • White Papers // Nov 2010

    The Equivalence of the Random Oracle Model and the Ideal Cipher Model, Revisited

    The authors consider the cryptographic problem of constructing an invertible random permutation from a public random function (i.e., which can be accessed by the adversary). This goal is formalized by the notion of indifferentiability of Maurer et al. (TCC 2004). This is the natural extension to the public setting of...

    Provided By University of California

  • White Papers // Jan 2009

    Cooperative Multiplexing in the Multiple Antenna Half Duplex Relay Channel

    Cooperation between terminals has been proposed to improve the reliability and throughput of wireless communication. While recent work has shown that relay cooperation provides increased diversity, increased multiplexing gain over that offered by direct link has largely been unexplored. In this work the authors show that cooperative multiplexing gain can...

    Provided By University of California

  • White Papers // Jan 2009

    Automatic Analog Beamforming Transceiver for 60 GHz Radios

    The demand for high speed wireless communication systems has made it necessary to move to millimeter wave frequencies. Device scaling in CMOS technologies has enabled low cost communications systems in the unlicensed 57-64 GHz frequency band. However, the path loss at these frequencies becomes severe as the effective antenna area...

    Provided By University of California

  • White Papers // Feb 2009

    Efficient Implementation of Linear Programming Decoding

    Linear Programming (LP) decoding, originally proposed by Feldman et al. as an approximation to the Maximum-Likelihood (ML) decoding of binary linear codes, solves a linear optimization problem formed by relaxing each of the finite-field parity-check constraints into a number of linear constraints. While providing a number of advantages over Iterative...

    Provided By University of California

  • White Papers // Dec 2009

    Correlated Sources Over Broadcast Channels

    The problem of reliable transmission of correlated sources over the broadcast channel, originally studied by Han and Costa, is revisited. An alternative characterization of their sufficient condition for reliable transmission is given, which includes results of Marton for channel coding over broadcast channels and of Gray and Wyner for distributed...

    Provided By University of California

  • White Papers // Nov 2010

    Correlated Resource Models of Internet End Hosts

    Understanding and modelling resources of Internet end hosts is essential for the design of desktop software and Internet-distributed applications. In this paper the authors develop a correlated resource model of Internet end hosts based on real trace data taken from the SETI@home project. This data covers a 5-year period with...

    Provided By University of California

  • White Papers // Nov 2010

    Distributed High Accuracy Peer-to-Peer Localization in Mobile Multipath Environments

    In this paper the authors consider the problem of high accuracy localization of mobile nodes in a multipath-rich environment where sub-meter accuracies are required. They employ a peer to peer framework where the vehicles/nodes can get pairwise multipath-degraded ranging estimates in local neighborhoods together with a fixed number of anchor...

    Provided By University of California