University of Texas

Displaying 241-280 of 303 results

  • White Papers // Jul 2009

    Block Diagonalization in the MIMO Broadcast Channel With Delayed CSIT

    This paper investigates the impact of delayed Channel State Information at the Transmitter (CSIT) on the MIMO broadcast channel with Block Diagonalization (BD) pre-coding. First, an upper bound for the achievable throughput is provided, which shows that BD is more robust to imperfect CSIT than zero-forcing pre-coding as it has...

    Provided By University of Texas

  • White Papers // Jul 2009

    Position Paper for Workshop on Future Directions in Cyber-Physical Systems Security

    Cyber-Physical System (CPS) security presents new problems inasmuch as cyber-physical systems are different from either information systems (IS) or Physical Control Systems (PCS) in that there are interactions between the information processing elements and the physical control elements that neither IS nor PCS alone may incur. In computational terms, CPS...

    Provided By University of Texas

  • White Papers // Jul 2009

    Transfer Learning From Minimal Target Data by Mapping Across Relational Domains

    A central goal of transfer learning is to enable learning when training data from the domain of interest is limited. Yet, work on transfer across relational domains has so far focused on the case where there is a significant amount of target data. This paper bridges this gap by studying...

    Provided By University of Texas

  • White Papers // Jun 2009

    PAQ: Adapting Query Fidelity in Dynamic Networks

    Ubiquitous computing applications have been enabled by a tight embedding of computation to the environment, support for dynamic networks, and the physical distribution of application components. Applications respond to frequent changes, detected through persistent monitoring of the environment in domains such as construction sites, where maintaining safety is essential; in...

    Provided By University of Texas

  • White Papers // Jun 2009

    Towards Adaptive Resource-Driven Routing

    In pervasive computing environments, applications find themselves in constantly changing operating conditions. Such applications often need to discover locally available resources on-demand. Communication protocols have been developed that base discovery not on the unique address of the destination but on application-level characteristics of the destination host. Previous work has focused...

    Provided By University of Texas

  • White Papers // Jun 2009

    Resolving and Mediating Ambiguous Contexts for Pervasive Care Environments

    Ubiquitous (or smart) healthcare applications envision sensor rich computing and networking environments that can capture various types of contexts of patients (or inhabitants of the environment), such as their location, activities and vital signs. Such context information is useful in providing health related and wellness management services in an intelligent...

    Provided By University of Texas

  • White Papers // Jun 2009

    Web 2.0 and Semantic Web Portal for Annotation and Discovery of Web Services in Geosciences

    With the rapid development of e-Science and scientific workflow technologies, geosciences Web portals are becoming even more important to support geoscientists in their research and discovery. While existing portals provide convenient means for humans to share and search for scientific data and services, they provide little support for automated agents...

    Provided By University of Texas

  • White Papers // Jun 2009

    A Location-Determination Application in WirelessHART

    WirelessHART is an emerging wireless communication standard that is targeted at the real-time process control industry. An example application of wireless communication in an industrial process control plant is the location of field engineers. The capability to locate personnel is a safety critical issue in process control plants because of...

    Provided By University of Texas

  • White Papers // Jun 2009

    A Framework for Modeling Security Measures

    This paper introduces a framework that provides a model for describing security measures and their relative effectiveness as well as importance. This model enhances computer security training and educational curriculum by providing experimental data and analysis to educators and students. Business environments will benefit from this model by enabling more...

    Provided By University of Texas

  • White Papers // Jun 2009

    Graphical Models of Separation Logic

    Graphs are used to model control and data flow among events occurring in the execution of a concurrent program. The authors' treatment of data flow covers both shared storage and external communication. Nevertheless, the laws of Hoare and Jones correctness reasoning remain valid when interpreted in this general model. In...

    Provided By University of Texas

  • White Papers // May 2009

    Security Threat and Vulnerability Mitigation Patterns: A Case of Credit Card Theft Mitigation

    Most attacks on computer and software systems are caused by threats to known vulnerabilities. Part of the reason is that one needs a lot of knowledge in developing secure systems, but it is difficult to obtain sufficient knowledge and use it correctly as security incident reports and security standards are...

    Provided By University of Texas

  • White Papers // May 2009

    On the Secrecy Rate of Interference Networks Using Structured Codes

    This paper shows that structured transmission schemes are a good choice for secret communication over interference networks with an eavesdropper. Structured transmission is shown to exploit channel asymmetries and thus perform better than randomly generated codebooks for such channels. For a class of interference channels, the authors show that an...

    Provided By University of Texas

  • White Papers // May 2009

    ODON: An On-Demand Security Overlay for Mission-Critical Applications

    In this paper, the authors consider the construction of a large-scale, highly available and secure overlay network to enable mission-critical communication between emergency personnel at a disaster area and their coordinating agencies across the Internet. This network is designed to be secure against network-based failures and external attacks including Denial...

    Provided By University of Texas

  • White Papers // May 2009

    Coverage in Multi-Antenna Two-Tier Networks

    In two-tier networks comprising a conventional cellular network overlaid with shorter range hotspots (e.g. femtocells, distributed antennas, or wired relays)with universal frequency reuse, the near-far effect from cross-tier interference creates dead spots where reliable coverage cannot be guaranteed to users in either tier. Equipping the macrocell and femtocells with multiple...

    Provided By University of Texas

  • White Papers // May 2009

    SOAR: Simple Opportunistic Adaptive Routing Protocol for Wireless Mesh Networks

    Multihop wireless mesh networks are becoming a new attractive communication paradigm owing to their low cost and ease of deployment. Routing protocols are critical to the performance and reliability of wireless mesh networks. Traditional routing protocols send traffic along predetermined paths and face difficulties in coping with unreliable and unpredictable...

    Provided By University of Texas

  • White Papers // May 2009

    Target Debt Ratios, Adverse Selection Costs, And Equity Mis-Pricing

    Previous studies disagree on the speed at which firms adjust their leverage toward a target. The authors argue that a portion of this variance is caused by two factors. First, firms face a 'Hard' boundary when over levered. This is due to the present value of bankruptcy costs increasing at...

    Provided By University of Texas

  • White Papers // Apr 2009

    Quicklink Selection for Navigational Query Results

    Quicklinks for a website are navigational shortcuts displayed below the website homepage on a search results page, and that let the users directly jump to selected points inside the website. Since the real-estate on a search results page is constrained and valuable, picking the best set of quicklinks to maximize...

    Provided By University of Texas

  • White Papers // Apr 2009

    Inputs of Coma: Static Detection of Denial-of-Service Vulnerabilities

    As networked systems grow in complexity, they are increasingly vulnerable to Denial-of-Service (DoS) attacks involving resource exhaustion. A single malicious input of coma can trigger high-complexity behavior such as deep recursion in a carelessly implemented server, exhausting CPU time or stack space and making the server unavailable to legitimate clients....

    Provided By University of Texas

  • White Papers // Apr 2009

    Mode Switching for the Multi-Antenna Broadcast Channel Based on Delay and Channel Quantization

    Imperfect channel state information degrades the performance of Multiple-Input Multiple-Output (MIMO) communications; its effects on Single-User (SU) and MultiUser (MU) MIMO transmissions are quite different. In particular, MU-MIMO suffers from residual interuser interference due to imperfect channel state information while SU-MIMO only suffers from a power loss. This paper compares...

    Provided By University of Texas

  • White Papers // Apr 2009

    Images Of Europeans: In-Group Trust And Support For European Integration

    Prior research on citizen support for European integration does not consider how individuals' evaluations of European nationalities are associated with support. This paper fills this gap by developing a political cohesion model based on social identity theory. The author claims that the probability of supporting integration increases with greater levels...

    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

  • White Papers // Apr 2009

    Social Network Classification Incorporating Link Type Values

    Classification of nodes in a social network and its applications to security informatics have been extensively studied in the past. However, previous paper generally does not consider the types of links (e.g., whether a person is friend or a close friend) that connect social networks members for classification purposes. Here,...

    Provided By University of Texas

  • White Papers // Mar 2009

    PADS: A Policy Architecture for Distributed Storage Systems

    This paper presents PADS, a policy architecture for building distributed storage systems. A policy architecture has two aspects. First, a common set of mechanisms that allow new systems to be implemented simply by defining new policies. Second, a structure for how policies, themselves, should be specified. In the case of...

    Provided By University of Texas

  • White Papers // Mar 2009

    Detection and Prevention Methods of Botnet-Generated Spam

    Although anti-spam measures are improving, the spam volume is increasing due to the use of Botnets. Botnets facilitate an efficient generation and guaranteed delivery of large volumes of spam. Spambots, or spam-generating bots, use different transmission methods based on the network settings of the infected host. These methods include relaying,...

    Provided By University of Texas

  • White Papers // Mar 2009

    Tactical Synthesis of Efficient Global Search Algorithms

    Algorithm synthesis transforms a formal specification into an efficient algorithm to solve a problem. Algorithm synthesis in Specware combines the formal specification of a problem with a high-level algorithm strategy. To derive an efficient algorithm, a developer must define operators that refine the algorithm by combining the generic operators in...

    Provided By University of Texas

  • White Papers // Mar 2009

    Synthesis of Fast Programs for Maximum Segment Sum Problems

    It is well-known that a naive algorithm can often be turned into an efficient program by applying appropriate semantic spreserving transformations. This technique has been used to derive programs to solve a variety of maximum-sum programs. One problem with this approach is that each problem variation requires a new set...

    Provided By University of Texas

  • White Papers // Mar 2009

    DexterNet: An Open Platform for Heterogeneous Body Sensor Networks and Its Applications

    The authors present an open-source platform for wireless body sensor networks called DexterNet. The system supports real-time, persistent human monitoring in both indoor and outdoor environments. The platform utilizes a three-layer architecture to control heterogeneous body sensors. The first layer called the Body Sensor Layer (BSL) deals with design of...

    Provided By University of Texas

  • White Papers // Mar 2009

    Religious Beliefs, Gambling Attitudes, And Financial Market Outcomes

    The authors use religion as a proxy for gambling and investigate whether geographical variation in religion-induced gambling norms affects aggregate market outcomes. Motivated by the evidence from gambling studies, they conjecture that gambling propensity would be higher in regions with higher concentration of Catholics relative to Protestants. They consider four...

    Provided By University of Texas

  • White Papers // Feb 2009

    Transmission Capacity of Two-Way Communication in Wireless Ad Hoc Networks

    Wireless ad hoc networks require bidirectional data transmission to support two-way traffic and control functions like packet acknowledgement. Most prior work on the capacity of wireless ad hoc networks, however, has focused only on one-way communication. In this paper, the authors develop the concept of transmission capacity of two-way communication...

    Provided By University of Texas

  • White Papers // Feb 2009

    Throughput Scaling Laws for Wireless Ad Hoc Networks With Relay Selection

    Determining the capacity of uncoordinated wireless ad hoc networks is one of the most general and challenging problems in network information theory. The current mainstream approach consists of deriving sum rate bounds and asymptotic capacity scaling laws, which describe important aspects of the capacity region. In their seminal work, Gupta...

    Provided By University of Texas

  • White Papers // Feb 2009

    Dynamic Coexistence of Frequency Hopping Networks Using Parallel and Gaussian Allocations

    This paper studies the coexistence of several independent and dynamic wireless networks using the frequency hopping technique in the unlicensed radio band. The authors propose a new hopping scheme that allows more networks to collocate effectively, but does not violate federal restrictions regarding frequency constraint (related to the minimum number...

    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 // Feb 2009

    Discovering and Representing Systematic Code Changes

    Software engineers often inspect program differences when reviewing others' code changes, when writing check-in comments, or when determining why a program behaves differently from expected behavior after modification. Program differencing tools that support these tasks are limited in their ability to group related code changes or to detect potential inconsistencies...

    Provided By University of Texas

  • White Papers // Feb 2009

    Uplink Capacity and Interference Avoidance for Two-Tier Femtocell Networks

    Two-tier femtocell networks - comprising a conventional cellular network plus embedded femtocell hotspots - offer an economically viable solution to achieving high cellular user capacity and improved coverage. With universal frequency reuse and DS-CDMA transmission however, the ensuing cross-tier interference causes unacceptable outage probability. This paper develops an uplink capacity...

    Provided By University of Texas

  • White Papers // Feb 2009

    A Framework for Evaluating DTN Mobility Models

    The field of delay tolerant networking is rich with protocols that exploit node mobility to overcome unpredictable or otherwise bad connectivity. The performance of many of these protocols is highly sensitive to the underlying mobility model which determines the nodes' movements, and the characteristics of these mobility models are not...

    Provided By University of Texas

  • White Papers // Feb 2009

    An Online Learning Framework for Link Adaptation in Wireless Networks

    Current and future wireless networks require the selection of a plurality of parameters at different layers of the communication system to optimize network throughput while satisfying certain reliability constraints. In prior work, mathematical input/output models along with system performance expressions have been used to perform the parameter selection. In practice,...

    Provided By University of Texas

  • White Papers // Feb 2009

    Strategic Planning Related To Business Management And Competitive Collegiate Chess: A Comparative Analysis

    This study provides a comparative analysis relating to various strategies utilized within both the field of business management and within the field of collegiate level competitive chess. Related implications regarding the benefit of including access to the development of chess mastery within the extra-curricular portion of Business Administration programs are...

    Provided By University of Texas

  • White Papers // Feb 2009

    Auction Pricing: A Case Study Assessing The Price Elasticity Of Demand Based On Supply And The Revenue Equivalence Theorem

    This paper addresses the price elasticity of demand related to various categories of goods sold within the consignment auction-marketing environment. An actual ongoing non-traditional business organization specializing in the nation-wide distribution of merchandise via consignment auctions provides data for this case study. Originally developed and initiated in 1993 in response...

    Provided By University of Texas

  • White Papers // Feb 2009

    The Formative Evaluation Of Free Trade Agreements: Assessing The Consequences Of The North American Free Trade Agreement

    This paper attempts to contribute toward the ongoing formative evaluation of free trade agreements. A review of various data sources, as well as of the literature regarding the consequences of the North American Free Trade Agreement (NAFTA) upon the country of Mexico, provides the specific focus for this study. Free...

    Provided By University of Texas

  • White Papers // Feb 2009

    Low-Rank Kernel Learning With Bregman Matrix Divergences

    In this paper, the authors study low-rank matrix nearness problems, with a focus on learning low-rank positive semi-definite (Kernel) matrices for machine learning applications. They propose efficient algorithms that scale linearly in the number of data points and quadratically in the rank of the input matrix. Existing algorithms for learning...

    Provided By University of Texas

  • White Papers // Jun 2009

    PAQ: Adapting Query Fidelity in Dynamic Networks

    Ubiquitous computing applications have been enabled by a tight embedding of computation to the environment, support for dynamic networks, and the physical distribution of application components. Applications respond to frequent changes, detected through persistent monitoring of the environment in domains such as construction sites, where maintaining safety is essential; in...

    Provided By University of Texas

  • White Papers // Sep 2009

    Modeling Delivery Delay for Flooding in Mobile Ad Hoc Networks

    Mobile Ad hoc NETworks (MANETs) can have widely varying characteristics under different deployments, and previous studies show that the characteristics impact the behavior of routing protocols for MANETs. To deploy applications successfully in MANETs, application developers need to comprehend the potential behavior of any underlying protocol used. In mobile networks,...

    Provided By University of Texas

  • White Papers // Sep 2009

    Blurring Snapshots: Temporal Inference of Missing and Uncertain Data

    Many pervasive computing applications continuously monitor state changes in the environment by acquiring, interpreting and responding to information from sensors embedded in the environment. However, it is extremely difficult and expensive to obtain a continuous, complete, and consistent picture of a continuously evolving operating environment. One standard technique to mitigate...

    Provided By University of Texas

  • White Papers // Sep 2010

    Depot: Cloud Storage With Minimal Trust

    The paper describes the design, implementation, and evaluation of Depot, a cloud storage system that minimizes trust assumptions. Depot tolerates buggy or malicious behavior by any number of clients or servers, yet it provides safety and liveness guarantees to correct clients. Depot provides these guarantees using a two-layer architecture. First,...

    Provided By University of Texas

  • White Papers // Dec 2009

    Edge-Based Cloud Computing as a Feasible Network Paradigm

    The term edge based cloud computing refers to a network of edge systems that provide the services currently provided by data center clouds. In this paper the authors present modifications to MRPerf, an existing tool used to simulate MapReduce in data center clouds, enabling it to simulate Hadoop MapReduce jobs...

    Provided By University of Texas

  • White Papers // Feb 2009

    Strategic Planning Related To Business Management And Competitive Collegiate Chess: A Comparative Analysis

    This study provides a comparative analysis relating to various strategies utilized within both the field of business management and within the field of collegiate level competitive chess. Related implications regarding the benefit of including access to the development of chess mastery within the extra-curricular portion of Business Administration programs are...

    Provided By University of Texas

  • White Papers // Feb 2009

    Auction Pricing: A Case Study Assessing The Price Elasticity Of Demand Based On Supply And The Revenue Equivalence Theorem

    This paper addresses the price elasticity of demand related to various categories of goods sold within the consignment auction-marketing environment. An actual ongoing non-traditional business organization specializing in the nation-wide distribution of merchandise via consignment auctions provides data for this case study. Originally developed and initiated in 1993 in response...

    Provided By University of Texas

  • White Papers // Feb 2009

    The Formative Evaluation Of Free Trade Agreements: Assessing The Consequences Of The North American Free Trade Agreement

    This paper attempts to contribute toward the ongoing formative evaluation of free trade agreements. A review of various data sources, as well as of the literature regarding the consequences of the North American Free Trade Agreement (NAFTA) upon the country of Mexico, provides the specific focus for this study. Free...

    Provided By University of Texas

  • White Papers // May 2010

    Foreign Portfolio Investment Inflows To The United States: The Impact Of Investor Risk Aversion And US Stock Market Performance

    This paper examines the relationship of net foreign portfolio investment inflows, namely corporate bonds and stocks, to two pull factors; investor risk aversion and the US stock market. Using a vector autoregressive model, we find that positive shocks to the stock market elicit an insignificant response to the net corporate...

    Provided By University of Texas

  • White Papers // Apr 2009

    Images Of Europeans: In-Group Trust And Support For European Integration

    Prior research on citizen support for European integration does not consider how individuals' evaluations of European nationalities are associated with support. This paper fills this gap by developing a political cohesion model based on social identity theory. The author claims that the probability of supporting integration increases with greater levels...

    Provided By University of Texas

  • White Papers // Dec 2010

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

    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 // Jul 2009

    Transfer Learning From Minimal Target Data by Mapping Across Relational Domains

    A central goal of transfer learning is to enable learning when training data from the domain of interest is limited. Yet, work on transfer across relational domains has so far focused on the case where there is a significant amount of target data. This paper bridges this gap by studying...

    Provided By University of Texas

  • White Papers // Feb 2009

    Low-Rank Kernel Learning With Bregman Matrix Divergences

    In this paper, the authors study low-rank matrix nearness problems, with a focus on learning low-rank positive semi-definite (Kernel) matrices for machine learning applications. They propose efficient algorithms that scale linearly in the number of data points and quadratically in the rank of the input matrix. Existing algorithms for learning...

    Provided By University of Texas

  • White Papers // Jan 2010

    Orthogonalization to Reduce Interference Alignment Overhead in the MIMO Interference Channel

    Interference channels are useful analytical models for distributed wireless communication networks with multiple simultaneously transmitting users. The degrees-of-freedom optimal transmit strategy for interference channels are interference alignment, which requires substantial channel state knowledge throughout the network. As the network grows, the sum capacity, theoretically, increases linearly. This result, however, neglects...

    Provided By University of Texas

  • White Papers // Feb 2009

    Transmission Capacity of Two-Way Communication in Wireless Ad Hoc Networks

    Wireless ad hoc networks require bidirectional data transmission to support two-way traffic and control functions like packet acknowledgement. Most prior work on the capacity of wireless ad hoc networks, however, has focused only on one-way communication. In this paper, the authors develop the concept of transmission capacity of two-way communication...

    Provided By University of Texas

  • White Papers // Nov 2009

    Feasibility of Interference Alignment of Measured MIMO-OFDM Channels

    Interference Alignment (IA) has been shown to provide all users of an interference channel with half the capacity achievable in an interference free point-to-point link resulting in linear sum capacity scaling with the number of users in the high SNR regime. The linear scaling is achieved by cooperatively precoding transmitted...

    Provided By University of Texas

  • White Papers // Feb 2009

    An Online Learning Framework for Link Adaptation in Wireless Networks

    Current and future wireless networks require the selection of a plurality of parameters at different layers of the communication system to optimize network throughput while satisfying certain reliability constraints. In prior work, mathematical input/output models along with system performance expressions have been used to perform the parameter selection. In practice,...

    Provided By University of Texas

  • White Papers // Feb 2011

    On Secure and Resilient Telesurgery Communications Over Unreliable Networks

    Telesurgical Robot Systems (TRSs) address mission critical operations emerging in extreme fields such as battlefields, underwater, and disaster territories. The lack of wire-lined communication infrastructure in such fields makes the use of wireless technologies including satellite and ad-hoc networks inevitable. TRSs over wireless environments pose unique challenges such as preserving...

    Provided By University of Texas

  • White Papers // Feb 2010

    Open Vs. Closed Access Femtocells in the Uplink

    Femtocells are assuming an increasingly important role in the coverage and capacity of cellular networks. In contrast to existing cellular systems, femtocells are end-user deployed and controlled, randomly located, and rely on third party backhaul (e.g., DSL or cable modem). Femtocells can be configured to be either open access or...

    Provided By University of Texas

  • White Papers // Sep 2011

    AOVis: A Model-Driven Multiple-Graph Approach to Program Fact Extraction for AspectJ/Java Source Code

    AspectJ reverse engineering and visualization remains a challenge at the architectural and design levels, with fewer tools available for reverse engineers compared to other languages such as Java. Prior work on AspectJ modeling focused on forward engineering or detailed-design reverse engineering, or required special instrumentation to identify cross-cutting relationships. Effective...

    Provided By University of Texas

  • White Papers // Jan 2010

    An Adaptive Algorithm for Dynamic Tuning of MAC Parameters in IEEE 802.15.4/ZigBee Sensor Networks

    Recent studies have highlighted that IEEE 802.15.4 based Wireless Sensor Networks (WSNs) suffer from a severe unreliability problem due to the default MAC parameters setting suggested by the standard, although with a more appropriate choice it is possible to achieve the desired reliability and better energy efficiency. However, such setting...

    Provided By University of Texas

  • White Papers // Jul 2010

    Fast Neighbor Discovery With Lightweight Termination Detection in Heterogeneous Cognitive Radio Networks

    An important step in the initialization of a wireless ad hoc network is neighbor discovery in which every node attempts to determine the set of nodes it can communicate with in one wireless hop. In recent years, cognitive radio technology has gained attention as an attractive approach to alleviate the...

    Provided By University of Texas

  • White Papers // Dec 2010

    ASSERT: A Wireless Networking Testbed

    As wireless networking is becoming more pervasive, there has been a greater desire to develop communication hardware and protocol stacks that have a number of desirable properties like increased throughput, reduced latency, reduced energy consumption, quality of service, security, etc. Consequently, several academic and industrial research groups are actively working...

    Provided By University of Texas

  • White Papers // Aug 2008

    An Asynchronous Neighbor Discovery Algorithm for Cognitive Radio Networks

    Cognitive Radio (CR) technology is a promising emerging technology that enables a more efficient usage of already assigned spectrum. However, before CR networks can be deployed, new algorithms and protocols need to be developed. When forming an ad-hoc Cognitive Radio Network (CRN), one of the fundamental tasks is to determine...

    Provided By University of Texas

  • White Papers // Jan 2012

    A Lightweight Algorithm for Causal Message Ordering in Mobile Computing Systems

    Causally ordered message delivery is a required property for several distributed applications particularly those that involve human interactions (such as teleconferencing and collaborative work). In this paper, the authors present an efficient protocol for causal ordering in mobile computing systems. This protocol requires minimal resources on mobile hosts and wireless...

    Provided By University of Texas

  • White Papers // Jul 2012

    Frankenstein: Stitching Malware From Benign Binaries

    This paper proposes a new self-camouflaging malware propagation system, Frankenstein, that overcomes shortcomings in the current generation of metamorphic malware. Specifically, although mutants produced by current state-of-the-art metamorphic engines are diverse, they still contain many characteristic binary features that reliably distinguish them from benign software. Frankenstein forgoes the concept of...

    Provided By University of Texas

  • White Papers // May 2012

    AnonymousCloud: A Data Ownership Privacy Provider Framework in Cloud Computing

    A means of reliably concealing ownership of cloud data without impeding computation over the data is presented and evaluated. This facilitates information privacy enforcement in cloud environments by withholding data ownership information from cloud nodes that compute using the data. As a result, nodes that have access to private data...

    Provided By University of Texas

  • White Papers // May 2012

    Hatman: Intra-Cloud Trust Management for Hadoop

    Data and computation integrity and security are major concerns for users of cloud computing facilities. Many production-level clouds optimistically assume that all cloud nodes are equally trustworthy when dispatching jobs; jobs are dispatched based on node load, not reputation. This increases their vulnerability to attack, since compromising even one node...

    Provided By University of Texas

  • White Papers // Aug 2012

    Offloading in Heterogeneous Networks: Modeling, Analysis and Design Insights

    Pushing data traffic from cellular to Wi-Fi is an example of inter-Radio Access Technology (RAT) offloading. While this clearly alleviates congestion on the over-loaded cellular network, the ultimate potential of such offloading and its effect on overall system performance is not well understood. To address this, the authors develop a...

    Provided By University of Texas

  • White Papers // Jan 2012

    Optimal Surface Deployment Problem in Wireless Sensor Networks

    Sensor deployment is a fundamental issue in a wireless sensor network, which often dictates the overall network performance. Previous studies on sensor deployment mainly focused on sensor networks on 2D plane or in 3D volume. In this paper, the authors tackle the problem of optimal sensor deployment on 3 surfaces,...

    Provided By University of Texas

  • White Papers // Jul 2001

    Product Costing And Pricing Under Long Term Capacity Commitment

    This white paper discusses about a model that is developed to analyze optimal product costing and pricing decisions when a firm must make long term commitments to some activity resource capacities. The problem is complex because of interactions between the initial capacity choices and adjustments in product costs and prices...

    Provided By University of Texas

  • White Papers // Nov 2010

    Cooperative Spectral Covariance Sensing Under Correlated Shadowing

    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 between the sensors and this makes sensing the presence of a signal difficult, even with...

    Provided By University of Texas

  • White Papers // Apr 2010

    An Upper Bound on Multi-Hop Transmission Capacity With Dynamic Multipath Routing

    This paper develops upper bounds on the end-to-end transmission capacity of multi-hop wireless networks. Potential source-destination paths are dynamically selected from a pool of randomly located relays, from which a closed-form lower bound on the outage probability is derived in terms of the expected number of potential paths. This is...

    Provided By University of Texas

  • White Papers // Jul 2011

    Capacity Bounds on Multiuser MIMO Transmission in Random Wireless Networks

    The authors consider a large wireless ad hoc network in which each multi-antenna transmitting node sends multiple independent streams to different receivers in a Poisson field of interferers. They provide exact expressions and simplified approximations on the outage probability, contention density, and transmission capacity for dirty paper coding with perfect...

    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 // 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 // Feb 2011

    A New Model for Coverage With Fractional Frequency Reuse in OFDMA Cellular Networks

    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. To date, FFR techniques have been typically been evaluated through system-level simulations using a hexagonal grid for the base station locations. This paper...

    Provided By University of Texas

  • White Papers // Jul 2011

    Multiuser Zero-Forcing Beamforming With Limited Feedback in Wireless Ad Hoc Networks

    The effect of limited feedback on point-to-multipoint communication is investigated in multi-antennas wireless ad hoc networks. The authors consider zero-forcing beamforming with quantized channel direction information and derive new closed-form expressions for the outage probability, throughput, transmission capacity, and average user rate. Expressions for the performance degradation due to finite...

    Provided By University of Texas

  • 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 // 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