University of Texas

Displaying 41-80 of 316 results

  • White Papers // Jul 2011

    Downlink Femtocell Networks: Open or Closed?

    A fundamental choice in femtocell deployments is the set of users which are allowed to access each femtocell. Closed access restricts the set to specifically registered users, while open access allows any mobile subscriber to use any femtocell. The main results of the paper are lemmas which provide expressions for...

    Provided By University of Texas

  • White Papers // Jun 2011

    Fundamentals of Inter-Cell Overhead Signaling in Heterogeneous Cellular Networks

    Heterogeneous base stations (e.g. picocells, microcells, femtocells and distributed antennas) will become increasingly essential for cellular network capacity and coverage. Up until now, little basic research has been done on the fundamentals of managing so many infrastructures - much of it unplanned - together with the carefully planned macrocellular network....

    Provided By University of Texas

  • White Papers // Jun 2011

    Enhancing the Role of Inlining in Effective Interprocedural Parallelization

    The emergence of multi-core architectures makes it essential for optimizing compilers to automatically extract parallelism for large scientific applications composed of many subroutines residing in different files. Inlining is a well-known technique which can be used to erase procedural boundaries and enable more aggressive loop parallelization. However, conventional inlining cannot...

    Provided By University of Texas

  • White Papers // Jun 2011

    Average Rate Achievable in K-Tier Downlink Heterogeneous Cellular Networks

    Cellular networks are becoming increasingly heterogeneous due to the co-deployment of many disparate infrastructure elements, including micro, pico and femtocells, and distributed antennas. This introduces new challenges in the modeling, analysis, and design of these networks. While grid-based models have been quite popular in modeling classical macrocell networks, they are...

    Provided By University of Texas

  • White Papers // Jun 2011

    A Tractable Framework for Coverage and Outage in Heterogeneous Cellular Networks

    The authors develop a tractable, flexible, and accurate model for downlink heterogeneous cellular networks. It consists of K tiers of randomly-located Base Stations (BSs), where each tier may differ in terms of the average transmit power, the supported data rate and the BS density. This allows elements spanning traditional, micro,...

    Provided By University of Texas

  • White Papers // Jun 2011

    3G Meets the Internet: Understanding the Performance of Hierarchical Routing in 3G Networks

    The volume of Internet traffic over 3G wireless networks is sharply rising. In contrast to many Internet services utilizing replicated resources, such as Content Distribution Networks (CDN), the current 3G standard architecture employs hierarchical routing, where all user data traffic goes through a small number of aggregation points using logical...

    Provided By University of Texas

  • White Papers // Jun 2011

    Cloaking Malware With the Trusted Platform Module

    The Trusted Platform Module (TPM) is commonly thought of as hardware that can increase platform security. However, it can also be used for malicious purposes. The TPM, along with other hardware, can implement a cloaked computation, whose memory state cannot be observed by any other software, including the operating system...

    Provided By University of Texas

  • White Papers // Jun 2011

    A Framework for Resource-Aware Data Accumulation in Sparse Wireless Sensor Networks

    Wireless Sensor Networks (WSNs) have become an enabling technology for a wide range of applications. In contrast, with traditional scenarios where static sensor nodes are densely deployed, a sparse WSN architecture can also be used in many cases. In a sparse WSN, special Mobile Data Collectors (MDCs) are used to...

    Provided By University of Texas

  • White Papers // Jun 2011

    XML Query Optimization in Map-Reduce

    The authors present a novel query language for large-scale analysis of XML data on a map-reduce environment, called MRQL, that is expressive enough to capture most common data analysis tasks and at the same time is amenable to optimization. The authors' evaluation plans are constructed using a small number of...

    Provided By University of Texas

  • White Papers // Jun 2011

    Coverage in Two-Tier Cellular Networks With Fractional Frequency Reuse

    Fractional Frequency Reuse (FFR) is an interference management technique well-suited to OFDMA-based cellular networks wherein the cells are partitioned into spatial regions with different frequency reuse factors. These techniques are of further relevance when considered in the context of heterogeneous networks whose performance is often limited by intercell and inter-tier...

    Provided By University of Texas

  • White Papers // Jun 2011

    Network Control: A Rate-Distortion Perspective

    Today's networks are controlled assuming precompressed and packetized data. For video, this assumption of data packets abstracts out one of the key aspects - the lossy compression problem. Therefore, first, this paper develops a framework for network control that incorporates both source-rate and source-distortion. Next, it decomposes the network control...

    Provided By University of Texas

  • White Papers // May 2011

    Characterizing Decentralized Wireless Networks With Temporal Correlation in the Low Outage Regime

    Communication in decentralized wireless networks is limited by interference. Because transmissions typically last for more than a single contention time slot, interference often exhibits strong statistical dependence over time that results in temporally correlated communication performance. The temporal dependence in interference increases as user mobility decreases and/or the total transmission...

    Provided By University of Texas

  • White Papers // May 2011

    EVE: Verifying Correct Execution of Cloud-Hosted Web Applications

    The authors present a new approach to verifying that a completely untrusted, Platform-as-a-Service cloud is correctly executing an outsourced web application. Web applications such as blogs, wikis, and online social networks are increasingly hosted on third-party, "Platform-as-a-Service" (PaaS) clouds. The owner outsources the execution of his application to a cloud...

    Provided By University of Texas

  • White Papers // May 2011

    Broadcast Channels With Delayed Finite-Rate Feedback: Predict or Observe?

    Most multiuser pre-coding techniques require accurate Transmitter Channel State Information (CSIT) to maintain orthogonality between the users. Such techniques have proven quite fragile in time-varying channels because the CSIT is inherently imperfect due to estimation and feedback delay, as well quantization noise. An alternative approach recently proposed by Maddah-Ali and...

    Provided By University of Texas

  • White Papers // May 2011

    Architecture and Abstractions for Environment and Traffic Aware System-Level Coordination of Wireless Networks

    This paper presents a system level approach to interference management in an infrastructure based wireless network with full frequency reuse. The key idea is to use loose base station coordination that is tailored to the spatial load distribution and the propagation environment to exploit the diversity in a user population's...

    Provided By University of Texas

  • White Papers // May 2011

    Practical Adaptive User Association Policies for Wireless Systems With Dynamic Interference

    The authors study the impact of user association policies on flow-level performance in interference-limited wireless networks. Most research in this area has used static interference models (neighboring base stations are always active) and resorted to intuitive objectives such as load balancing. In this paper, they show that this can be...

    Provided By University of Texas

  • White Papers // May 2011

    Secure Data Processing in a Hybrid Cloud

    Cloud computing has made it possible for a user to be able to select a computing service precisely when needed. However, certain factors such as security of data and regulatory issues will impact a user's choice of using such a service. A solution to these problems is the use of...

    Provided By University of Texas

  • White Papers // May 2011

    Regret-Freedom Isn't Free

    Cooperative, Peer-To-Peer (P2P) services-distributed systems consisting of participants from Multiple Administrative Domains (MAD)|must deal with the threat of arbitrary (Byzan-tine) failures while incentivizing the cooperation of potentially selfish (rational) nodes that such services rely on to function. Although previous work has generally agreed that these types of participants need to...

    Provided By University of Texas

  • White Papers // May 2011

    Consistency, Availability, and Convergence

    The authors examine the limits of consistency in fault-tolerant distributed storage systems. In particular, they identify fundamental tradeoffs among properties of consistency, availability, and convergence, and the authors close the gap between what is known to be impossible (i.e. CAP) and known systems that are highly-available but that provide weaker...

    Provided By University of Texas

  • White Papers // Apr 2011

    Mechanizing the Expert Dense Linear Algebra Developer

    Sustained high performance on the fastest computers in the world has traditionally been accomplished by experts who carefully hand-code key routines. This quickly becomes unmanageable for large bodies of software and/or as architectures change enough that entire libraries need to be rewritten. The authors believe the problem is that a...

    Provided By University of Texas

  • White Papers // Apr 2011

    Towards Security-Aware Program Visualization for Analyzing In-Lined Reference Monitors

    In-lined Reference Monitoring frameworks are an emerging technology for enforcing security policies over untrusted, mobile, binary code. However, formulating correct policy specifications for such frameworks to enforce remains a daunting undertaking with few supporting tools. A visualization approach is proposed to aid in this task; preliminary results are presented in...

    Provided By University of Texas

  • White Papers // Apr 2011

    Get Off My Prefix! the Need for Dynamic, Gerontocratic Policies in Inter-Domain Routing

    Inter-domain routing in today's Internet is plagued by security and reliability issues (e.g., prefix hijacking), which are often caused by malicious or Byzantine misbehavior. The authors argue that route selection policies must move beyond static preferences that select routes on the basis of static attributes such as route length or...

    Provided By University of Texas

  • White Papers // Apr 2011

    Combating Channel Impairments and Impulsive Noise in Local Utility Powerline Communications

    A smart grid intelligently monitors and controls energy flow in order to improve the efficiency and reliability of power delivery. This monitoring and control requires low-delay, real-time, highly reliable communications between customers, local utilities and regional utilities. This paper focuses on PowerLine Communications (PLC) from the customer power meters to...

    Provided By University of Texas

  • White Papers // Apr 2011

    Repair From a Chair: Computer Repair as an Untrusted Cloud Service

    Today, when people need their computers repaired, their process is not very different from hiring someone to fix a television: they either bring the computer to a repair service, or they call a technician (or family member) and ask for a house call. This process is inconvenient. It also risks...

    Provided By University of Texas

  • White Papers // Apr 2011

    Toward Practical and Unconditional Verification of Remote Computations

    This paper revisits a classic question: how can a machine specify a computation to another one and then, without executing the computation, check that the other machine carried it out correctly? The applications of such a primitive include cloud computing (a computationally limited device offloads processing to the cloud but...

    Provided By University of Texas

  • White Papers // Apr 2011

    The K-Observer Problem in Computer Networks

    For any non-negative integer K, a K-observer P of a network N is a set of nodes in N such that each message, that travels at least K hops in N, is handled (and so observed) by at least one node in P. A K-observer P of a network N...

    Provided By University of Texas

  • White Papers // Apr 2011

    Dynamic Focusing of Awareness in Fuzzy Control Systems

    Adaptive fuzzy logic control systems with Gaussian membership functions are described. A systematic simulation study of 'Dynamic focusing of awareness' in fuzzy logic control systems is provided. This study shows how the final steady-state values of the membership functions change in response to varying initial membership functions, changing desired trajectory,...

    Provided By University of Texas

  • White Papers // Mar 2011

    A New Way of Computing Rate in Cellular Networks

    It is common practice to model the Base Station (BS) locations in a cellular system by a grid, such as a hexagonal or square lattice. This model is usually analytically intractable as well as quite idealized. Therefore, system designers resort to complex simulations to evaluate network performance. In this paper,...

    Provided By University of Texas

  • White Papers // Mar 2011

    Ergodic Transmission Capacity of Wireless Ad Hoc Networks With Interference Management

    Most work on wireless network throughput ignores the temporal correlation inherent to wireless channels because it degrades tractability. To better model and quantify the temporal variations of wireless network throughput, this paper introduces a metric termed Ergodic Transmission Capacity (ETC), which includes spatial and temporal ergodicity. All transmitters in the...

    Provided By University of Texas

  • White Papers // Mar 2011

    Secure Multidimensional Range Queries Over Outsourced Data

    In this paper the authors study the problem of supporting multidimensional range queries on encrypted data. The problem is motivated by secure data outsourcing applications where a client may store his/her data on a remote server in encrypted form and want to execute queries using server's computational capabilities. The solution...

    Provided By University of Texas

  • White Papers // Mar 2011

    Deterministic Public-Key Encryption Revisited

    One of the maxims of modern cryptography is that "Randomness is needed for good encryption," meaning the encryption algorithm of a scheme that should be randomized. Such an encryption scheme is called probabilistic. Indeed, probabilistic encryption is necessary to meet the fundamental notion of semantic security introduced by Goldwasser and...

    Provided By University of Texas

  • White Papers // Mar 2011

    Fuzzy Optimization for Mobile Ad Hoc Networks: A Bottom-up Cross-Layer Approach

    In this paper, the authors introduce a new method for cross-layer design in mobile ad hoc networks. They use Fuzzy Logic System (FLS) to coordinate physical layer, data-link layer and application layer for cross-layer design. Ground speed, average delay and packets successful transmission ratio are selected as antecedents for the...

    Provided By University of Texas

  • White Papers // Mar 2011

    Efficient Lattice (H)IBE in the Standard Model

    The authors construct an efficient identity based encryption system based on the standard Learning With Errors (LWE) problem. Their security proof holds in the standard model. The key step in the construction is a family of lattices for which there are two distinct trapdoors for finding short vectors. One trapdoor...

    Provided By University of Texas

  • White Papers // Mar 2011

    Outage Probability for Heterogeneous Cellular Networks With Biased Cell Association

    In this paper, the authors develop a tractable framework for SINR analysis in downlink Heterogeneous Cellular Networks (HCNs) with flexible cell association policies. The HCN is modeled as a multi-tier cellular network where each tier's BSs are randomly located and have a unique transmit power, path loss exponent, spatial density,...

    Provided By University of Texas

  • White Papers // Mar 2011

    TPP: The Two-Way Password Protocol

    The need for secure communication in the Internet has led to the widespread deployment of secure application-level protocols. The current state-of-the-art is to use TLS, in conjunction with a password protocol. The password protocol, which the authors call a One-way Password Protocol (OPP), authenticates the client to the server, using...

    Provided By University of Texas

  • White Papers // Mar 2011

    Modeling and Analysis of K-Tier Downlink Heterogeneous Cellular Networks

    Cellular networks are in a major transition from a carefully planned set of large tower-mounted BaseStations (BSs) to an irregular deployment of heterogeneous infrastructure elements that often additionally includes micro, pico, and femtocells, as well as distributed antennas. In this paper, the authors develop a tractable, flexible, and accurate model...

    Provided By University of Texas

  • White Papers // Mar 2011

    HartFi: An Energy-Efficient Localization System

    Location-Based Applications (LBAs) are emerging to be the killer applications on mobile devices. To know the where-abouts of devices, various interfaces (i.e., GPS, Wi-Fi or cellular) can be used to sense their locations. Ideally, localization should be done all the time. However, keeping any of these interfaces running continuously would...

    Provided By University of Texas

  • White Papers // Mar 2011

    Secure Friend Discovery in Mobile Social Networks

    Mobile social networks extend social networks in the cyberspace into the real world by allowing mobile users to discover and interact with existing and potential friends who happen to be in their physical vicinity. Despite their promise to enable many exciting applications, serious security and privacy concerns have hindered wide...

    Provided By University of Texas

  • White Papers // Mar 2011

    Downlink SDMA With Limited Feedback in Interference-Limited Wireless Networks

    The tremendous capacity gains promised by Space Division Multiple Access (SDMA) depend critically on the accuracy of the transmit channel state information. In the broadcast channel, even without any network interference, it is known that such gains collapse due to interstream interference if the feedback is delayed or low rate....

    Provided By University of Texas

  • White Papers // Mar 2011

    Cooperative Spectral Covariance Sensing: Properties and Analysis

    This paper investigates the theoretical limits of white space sensing in a Cognitive Radio (CR) network limited by channel correlation. In a log-normal shadowing channel, the received signal power is correlated based on the distance among the sensors and this makes sensing the presence of a signal difficult, even with...

    Provided By University of Texas

  • White Papers // Jan 2011

    Vertical Specialization, Intermediate Tariffs, And The Pattern Of Trade: Assessing The Role Of Tariff Liberalization To U.S. Bilateral Trade 1989-2001

    How important are intermediate tariffs in determining trade patterns? Empirical work measuring the impact of tariff liberalization most commonly focuses on the effects of barriers imposed by importers, but exporter trade policy should also matter when exports are produced with imported intermediates. Guided by extensions of the Eaton and Kortum...

    Provided By University of Texas

  • White Papers // Mar 2010

    Real-Time Head Pose Estimation on Mobile Platforms

    Many computer vision applications such as augmented reality require head pose estimation. As far as the real-time implementation of head pose estimation on relatively resource limited mobile platforms is concerned, it is required to satisfy real-time constraints while maintaining reasonable head pose estimation accuracy. The authors introduced head pose estimation...

    Provided By University of Texas

  • White Papers // Jan 2011

    Pseudorandom Financial Derivatives

    Arora, Barak, Brunnermeier, and Ge [ABBG] showed that taking computational complexity into account, a dishonest seller could dramatically increase the lemon costs of a family of financial derivatives. The authors show that if the seller is required to construct derivatives of a certain form, then this phenomenon disappears. In particular,...

    Provided By University of Texas

  • White Papers // Jan 2011

    Toward a Practical Packet Marking Approach for IP Traceback

    IP traceback is an important step in defending against Denial-of-Service (DoS) attacks. Probabilistic Packet Marking (PPM) has been studied as a promising approach to realize IP traceback. In this paper, the authors propose a new PPM approach that improves the current state of the art in two practical directions: it...

    Provided By University of Texas

  • White Papers // Dec 2010

    Design of the FutureGrid Experiment Management Framework

    FutureGrid provides novel computing capabilities that enable reproducible experiments while simultaneously supporting dynamic provisioning. This paper describes the Future-Grid experiment management framework to create and execute large scale scientific experiments for researchers around the globe. The experiments executed are performed by the various users of FutureGrid ranging from administrators, software...

    Provided By University of Texas

  • White Papers // Jun 2011

    A Framework for Resource-Aware Data Accumulation in Sparse Wireless Sensor Networks

    Wireless Sensor Networks (WSNs) have become an enabling technology for a wide range of applications. In contrast, with traditional scenarios where static sensor nodes are densely deployed, a sparse WSN architecture can also be used in many cases. In a sparse WSN, special Mobile Data Collectors (MDCs) are used to...

    Provided By University of Texas

  • White Papers // Jan 2011

    The Impact Of Financial Constraints On The Relation Between Shareholder Taxes And The Cost Of Equity Capital

    Using both the Tax Relief Act of 1997 (TRA) and the Jobs and Growth Tax Relief and Reconciliation Act of 2003 (JGTRRA), the authors conduct the first empirical investigation on how the tax cuts on dividends and/or capital gains affect the cost of equity differently for firms facing different degrees...

    Provided By University of Texas

  • White Papers // Jan 2011

    Corporate Taxes And Investment: The Cash Flow Channel

    Existing literature focuses on how corporate taxation affects firms' investment decisions by altering after-tax returns. This paper instead examines how corporate taxation affects investment by reducing the cash flow a firm has available to invest in the current period. The author uses a sharp nonlinearity in the mapping from pre-tax...

    Provided By University of Texas

  • White Papers // Sep 2009

    Why Are Firms Unlevered?

    In this paper, the authors examine the motivations for firms to remain debt free. Using a sample of firms that have no debt for three consecutive years, they find little support for the managerial entrenchment, flexibility, or the tax hypotheses. These firms do not have weak governance mechanisms, they payout...

    Provided By University of Texas

  • White Papers // Aug 2009

    Do Financial Intermediaries Help To Certify Firm Transparency? Effect Of Auditor Quality On SEO Transaction Costs

    The author empirically investigates the differing certification effects of a firm employing financial intermediaries of varying reputation. The author uses a treatment effects model to control for endogeneity in the selection of intermediary reputation, and the author demonstrates that the use of reputable financial intermediaries helps to mitigate transaction costs...

    Provided By University of Texas

  • White Papers // May 2010

    Query Processing in Connectivity-Challenged Environments

    This paper presents a discussion of issues that need to be addressed for processing relational queries in distributed environments where the connectivity is unstable and is changing continuously. Query processing over data across nodes that are collecting information is an example of such an environment. Traditional distributed query processing techniques...

    Provided By University of Texas

  • White Papers // Mar 2011

    Fuzzy Optimization for Mobile Ad Hoc Networks: A Bottom-up Cross-Layer Approach

    In this paper, the authors introduce a new method for cross-layer design in mobile ad hoc networks. They use Fuzzy Logic System (FLS) to coordinate physical layer, data-link layer and application layer for cross-layer design. Ground speed, average delay and packets successful transmission ratio are selected as antecedents for the...

    Provided By University of Texas

  • White Papers // Mar 2010

    Lightweight Checkpoint Mechanism and Modeling in GPGPU Environment

    While High Performance Computing (HPC) systems continue to scale in volume of computing elements and overall computing powers, the performance/cost benefit of these systems is subject to their abilities to provide high reliability, availability, and transparency in utilizing the underlying computing resources. This is evidenced by a recent announcement from...

    Provided By University of Texas

  • White Papers // Jan 2011

    A Parametric Model for the Distribution of the Angle of Arrival and the Associated Correlation Function and Power Spectrum at the Mobile Station

    One of the main assumptions in the Clarke's classic channel model is isotropic scattering, i.e. uniform distribution for the angle of arrival of multipath components at the mobile station. However, in many mobile radio channels the authors encounter non-isotropic scattering, which strongly affects the correlation function and power spectrum of...

    Provided By University of Texas

  • White Papers // Sep 2011

    Transmission Capacity of Ad-Hoc Networks With Multiple Antennas Using Transmit Stream Adaptation and Interference Cancelation

    The transmission capacity of an ad-hoc network is the maximum density of active transmitters per unit area, given an outage constraint at each receiver for a fixed rate of transmission. Assuming that the transmitter locations are distributed as a Poisson point process, this paper derives upper and lower bounds on...

    Provided By University of Texas

  • White Papers // Jan 2011

    Pilot Designs for Consistent Frequency Offset Estimation in OFDM Systems

    This paper presents pilot designs for consistent frequency offset estimation of OFDM systems in frequency-selective fading channels. The authors describe two design approaches, namely consistency in the probabilistic sense and absolute consistency. Existing preambles and pilot designs in the literature do not guarantee the absolute consistency. They derive general criteria...

    Provided By University of Texas

  • White Papers // Apr 2010

    Distributed Rate Allocation for Wireless Networks

    This paper develops a distributed algorithm for rate allocation in wireless networks that achieves the same throughput region as optimal centralized algorithms. This cross-layer algorithm jointly performs Medium Access Control (MAC) and physical-layer rate adaptation. The paper establishes that this algorithm is throughput-optimal for general rate regions. In contrast to...

    Provided By University of Texas

  • White Papers // Jul 2010

    Queue-Architecture and Stability Analysis in Cooperative Relay Networks

    An abstraction of the physical layer coding using bit pipes that are coupled through data-rates is insufficient to capture notions such as node cooperation in cooperative relay networks. Consequently, network-stability analyses based on such abstractions are valid for non-cooperative schemes alone and meaningless for cooperative schemes. Motivated from this, this...

    Provided By University of Texas

  • White Papers // Feb 2010

    On the Impact of Mobility on Multicast Capacity of Wireless Networks

    Analogous to the beneficial impact that mobility has on the throughput of unicast networks, this paper establishes that mobility can provide a similar gain in the order-wise growth-rate of the throughput for multicast networks. This paper considers an all-mobile multicast network, and characterizes its multicast capacity scaling. The scaling result...

    Provided By University of Texas

  • White Papers // Feb 2010

    Pilot Contamination Problem in Multi-Cell TDD Systems

    This paper considers a multi-cell multiple antenna system with precoding at the base stations for downlink transmission. To enable precoding, Channel State Information (CSI) is obtained via uplink training. This paper mathematically characterizes the impact that uplink training has on the performance of multi-cell multiple antenna systems. When non-orthogonal training...

    Provided By University of Texas

  • White Papers // Jun 2011

    Network Control: A Rate-Distortion Perspective

    Today's networks are controlled assuming precompressed and packetized data. For video, this assumption of data packets abstracts out one of the key aspects - the lossy compression problem. Therefore, first, this paper develops a framework for network control that incorporates both source-rate and source-distortion. Next, it decomposes the network control...

    Provided By University of Texas

  • White Papers // Jun 2010

    Sum Capacity of K User Gaussian Degraded Interference Channels

    This paper studies a family of genie-MAC (Multiple Access Channel) outer bounds for K-user Gaussian interference channels. This family is inspired by existing genie-aided bounding mechanisms, but differs from current approaches in its optimization problem formulation and application. The fundamental idea behind these bounds is to create a group of...

    Provided By University of Texas

  • White Papers // Aug 2009

    On the Stability Region of Amplify-and-Forward Cooperative Relay Networks

    This paper considers an amplify-and-forward relay network with fading states. Amplify-and-forward scheme (along with its variations) is the core mechanism for enabling cooperative communication in wireless networks, and hence understanding the network stability region under amplify-and-forward scheme is very important. However, in a relay network employing amplify-and-forward, the interaction between...

    Provided By University of Texas

  • White Papers // Dec 2010

    A Customizable Two-Step Framework for General Equipment Provisioning in Optical Transport Networks

    Optical Transport Network (OTN) is a standard approach to offering transport support to a variety of existing service technologies, e.g., ESCON, HDTV, GE, etc. Multiple service technologies can be concurrently multiplexed onto one common transport network, which offers hierarchical transmission rate wrappers physically supported by Wavelength Division Multiplexing (WDM) lambda...

    Provided By University of Texas

  • White Papers // Feb 2009

    Position Paper: BFT: the Time is Now

    Data centers strive to provide reliable access to the data and services that they host. This reliable access requires the hosted data and services hosted by the data center to be both consistent and available. Byzantine Fault Tolerance (BFT) replication offers the promise of services that are consistent and available...

    Provided By University of Texas

  • White Papers // Aug 2011

    Remote Batch Invocation for SQL Databases

    Batch services are a new approach to distributed computation in which clients send batches of operations for execution on a server and receive hierarchical results sets in response. In this paper, the authors show how batch services provide a simple and powerful interface to relational databases, with support for arbitrary...

    Provided By University of Texas

  • White Papers // Dec 2011

    Making Argument Systems for Outsourced Computation Practical (Sometimes)

    This paper describes the design, implementation, and evaluation of a system for performing verifiable outsourced computation. It has long been known that this problem can be solved in theory using Probabilistically Checkable Proofs (PCPs) coupled with modern cryptographic tools, and these solutions have wholly impractical performance, according to the conventional...

    Provided By University of Texas

  • White Papers // Apr 2011

    Toward Practical and Unconditional Verification of Remote Computations

    This paper revisits a classic question: how can a machine specify a computation to another one and then, without executing the computation, check that the other machine carried it out correctly? The applications of such a primitive include cloud computing (a computationally limited device offloads processing to the cloud but...

    Provided By University of Texas

  • White Papers // Apr 2011

    Repair From a Chair: Computer Repair as an Untrusted Cloud Service

    Today, when people need their computers repaired, their process is not very different from hiring someone to fix a television: they either bring the computer to a repair service, or they call a technician (or family member) and ask for a house call. This process is inconvenient. It also risks...

    Provided By University of Texas

  • White Papers // Dec 2009

    Adaptive Limited Feedback for Sum-Rate Maximizing Beamforming in Cooperative Multicell Systems

    Base station cooperation improves the sum-rates that can be achieved in cellular systems. Conventional cooperation techniques require sharing large amounts of information over finite-capacity backhaul links and assume that base stations have full Channel State Information (CSI) of all the active users in the system. In this paper, a new...

    Provided By University of Texas

  • White Papers // Jul 2010

    User Partitioning for Less Overhead in MIMO Interference Channels

    This paper presents a study on multiple-antenna interference channels, accounting for general overhead as a function of the number of users and antennas in the network. The model includes both perfect and imperfect channel state information based on channel estimation in the presence of noise. Three low-complexity methods are proposed...

    Provided By University of Texas

  • White Papers // Mar 2010

    A New Eclipse-Based JML Compiler Built Using AST Merging

    The Java Modeling Language (JML) is a formal interface specification language to document the behavior of Java program modules and has been used in many research and industrial projects. However, its inability to support Java 5 features such as generics is reducing its user base significantly. Besides, the JML compiler...

    Provided By University of Texas

  • White Papers // Jan 2012

    XML Query Routing in Structured P2P Systems

    This paper addresses the problem of data placement, indexing, and querying large XML data repositories distributed over an existing P2P service infrastructure. The authors' architecture scales gracefully to the network and data sizes, is fully distributed, fault tolerant and self-organizing, and handles complex queries efficiently, even those queries that use...

    Provided By University of Texas

  • White Papers // Jan 2011

    A Fully Pipelined XQuery Processor

    The authors present a high-performance, pull-based streaming processor for XQuery, called XQPull, that can handle many essential features of the language, including general predicates, recursive queries, backward axis steps, and function calls, using a very small amount of caching. Their framework is based on a new type of event streams,...

    Provided By University of Texas

  • White Papers // Sep 2011

    Supervised Learning for Insider Threat Detection Using Stream Mining

    Insider threat detection requires the identification of rare anomalies in contexts where evolving behaviors tend to mask such anomalies. This paper proposes and tests an ensemble-based stream mining algorithm based on supervised learning that addresses this challenge by maintaining an evolving collection of multiple models to classify dynamic data streams...

    Provided By University of Texas

  • White Papers // Nov 2011

    Insider Threat Detection Using Stream Mining and Graph Mining

    Evidence of malicious insider activity is often buried within large data streams, such as system logs accumulated over months or years. Ensemble-based stream mining leverages multiple classification models to achieve highly accurate anomaly detection in such streams even when the stream is unbounded, evolving, and unlabeled. This makes the approach...

    Provided By University of Texas

  • White Papers // Apr 2011

    Towards Security-Aware Program Visualization for Analyzing In-Lined Reference Monitors

    In-lined Reference Monitoring frameworks are an emerging technology for enforcing security policies over untrusted, mobile, binary code. However, formulating correct policy specifications for such frameworks to enforce remains a daunting undertaking with few supporting tools. A visualization approach is proposed to aid in this task; preliminary results are presented in...

    Provided By University of Texas

  • White Papers // Sep 2010

    Challenges and Future Directions of Software Technology: Secure Software Development

    Developing large scale software systems has major security challenges. This paper describes the issues involved and then addresses two topics: formal methods for emerging secure systems and secure services modeling. Large scale software development is one of the biggest challenges faced by corporations. Incorporating security into the software development process...

    Provided By University of Texas

  • White Papers // Oct 2009

    Model-Checking In-Lined Reference Monitors

    A technique for elegantly expressing In-lined Reference Monitor (IRM) certification as model-checking is presented and implemented. In-lined Reference Monitors (IRM's) enforce software security policies by in-lining dynamic security guards into untrusted binary code. Certifying IRM systems provide strong formal guarantees for such systems by verifying that the instrumented code produced...

    Provided By University of Texas

  • White Papers // Apr 2009

    Enforcing IRM Security Policies: Two Case Studies

    SPoX (Security Policy XML) is a declarative language for specifying application security policies for enforcement by In-lined Reference Monitors. Two case studies are presented that demonstrate how this language can be used to effectively enforce application-specific security policies for untrusted Java applications in the absence of source code. In-lined Reference...

    Provided By University of Texas