University of Mary Washington

Displaying 1-40 of 142 results

  • White Papers // May 2014

    Efficient Implementation of Hyperspectral Anomaly Detection Techniques on GPUs and Multicore Processors

    Anomaly detection is an important task for hyperspectral data exploitation. Although many algorithms have been developed for this purpose in recent years, due to the large dimensionality of hyperspectral image data, fast anomaly detection remains a challenging task. In this paper, the authors exploit the computational power of commodity Graphics...

    Provided By University of Mary Washington

  • White Papers // Mar 2014

    Oblivious Data Structures

    The authors are among the first to systematically investigate (memory-trace) oblivious data structures. They propose a framework for constructing a variety of oblivious data structures, achieving asymptotic performance gains in comparison with generic Oblivious RAM (ORAM). They evaluate the performance of their oblivious data structures in terms of their bandwidth...

    Provided By University of Mary Washington

  • White Papers // Mar 2014

    Verifiable Oblivious Storage

    The authors formalize the notion of Verifiable Oblivious Storage (VOS), where a client outsources the storage of data to a server while ensuring data confidentiality, access pattern privacy, and integrity and freshness of data accesses. VOS generalizes the notion of Oblivious RAM (ORAM) in that it allows the server to...

    Provided By University of Mary Washington

  • White Papers // Jan 2014

    Hierarchical Interconnects for On-Chip Clustering

    In the sub-micron technology era, wire delays are becoming much more important than gate delays, making it particularly attractive to go for clustered designs. A common form of clustering adopted in processors is to replace the centralized instruction scheduler with multiple smaller schedulers that work in parallel within a single...

    Provided By University of Mary Washington

  • White Papers // Dec 2013

    Practical Dynamic Searchable Encryption with Small Leakage

    Dynamic Searchable Symmetric Encryption (DSSE) enables a client to encrypt their document collection in a way that it is still searchable and efficiently updatable. However, all DSSE constructions that have been presented in the literature so far come with several problems: Either they leak a significant amount of information (e.g.,...

    Provided By University of Mary Washington

  • White Papers // Nov 2013

    Optimal Locally Repairable Codes and Connections to Matroid Theory

    Petabyte-scale distributed storage systems are currently transitioning to erasure codes to achieve higher storage efficiency. Classical codes like reed-solomon are highly sub-optimal for distributed environments due to their high overhead in single-failure events. Locally Repairable Codes (LRCs) form a new family of codes that are repair efficient. In particular, LRCs...

    Provided By University of Mary Washington

  • White Papers // Aug 2013

    Schema Extraction for Tabular Data on the Web

    Tabular data is an abundant source of information on the web, but remains mostly isolated from the latter are interconnections since tables lack links and computer-accessible descriptions of their structure. In other words, the schemas of these tables - attribute names, values, data types, etc. - are not explicitly stored...

    Provided By University of Mary Washington

  • White Papers // Aug 2013

    Hone: \"Scaling Down\" Hadoop on Shared-Memory Systems

    The underlying assumption behind Hadoop and, more generally, the need for distributed processing is that the data to be analyzed cannot be held in memory on a single machine. Today, this assumption needs to be re-evaluated. Although petabyte-scale data-stores are increasingly common, it is unclear whether \"Typical\" analytics tasks require...

    Provided By University of Mary Washington

  • White Papers // Jun 2013

    Efficient Secure Two-Party Computation Using Symmetric Cut-and-Choose

    Beginning with the work of Lindell and Pinkas, researchers have proposed several protocols for secure two-party computation based on the cut-and-choose paradigm. In existing instantiations of this paradigm, one party generates K garbled circuits; some fraction of those is \"Checked\" by the other party, and the remaining fraction is evaluated....

    Provided By University of Mary Washington

  • White Papers // May 2013

    Optimal Scheduling for Energy Harvesting Transmitters With Hybrid Energy Storage

    The authors consider data transmission with an energy harvesting transmitter which has a hybrid energy storage unit composed of a perfectly efficient Super-Capacitor (SC) and an inefficient battery. The SC has finite space for energy storage while the battery has unlimited space. The transmitter can choose to store the harvested...

    Provided By University of Mary Washington

  • White Papers // May 2013

    Binary Energy Harvesting Channel With Finite Energy Storage

    The authors consider the capacity of an energy harvesting communication channel with a finite-sized battery. As an abstraction of this problem, they consider a system where energy arrives at the encoder in multiples of a fixed quantity, and the physical layer is modeled accordingly as a finite discrete alphabet channel...

    Provided By University of Mary Washington

  • White Papers // May 2013

    An Improved Sub-Packetization Bound for Minimum Storage Regenerating Codes

    Distributed storage systems employ codes to provide resilience to failure of multiple storage disks. Specifically, an (n, k) MDS code stores k symbols in n disks such that the overall system is tolerant to a failure of up to n-k disks. However, access to at least k disks is still...

    Provided By University of Mary Washington

  • White Papers // May 2013

    Non-Asymptotic and Second-Order Achievability Bounds for Source Coding with Side-Information

    In this paper, the authors proved a new non-asymptotic bound on the error probability for the WAK problem. They present a novel achievability bound for the Wyner-Ahlswede-Korner (WAK) problem of lossless source coding with rate-limited side-information. This bound is proved using ideas from channel simulation and channel resolvability. The bound...

    Provided By University of Mary Washington

  • White Papers // May 2013

    An Implementation of Binomial Method of Option Pricing using Parallel Computing

    The Binomial method of option pricing is based on iterating over discounted option payoffs in a recursive fashion to calculate the present value of an option. Implementing the Binomial method to exploit the resources of a parallel computing cluster is non-trivial as the method is not easily parallelizable. The authors...

    Provided By University of Mary Washington

  • White Papers // Apr 2013

    Making Space for Values: Communication & Values Levers in a Virtual Team

    The infrastructure underlying the Internet continues to evolve, with ramifications for not only the technical protocols that govern network functions, but also implications for social, economic, and legal issues. This paper uses ethnography to examine how and why ethical and social issues arise during the design of Named Data Networking,...

    Provided By University of Mary Washington

  • White Papers // Apr 2013

    Memory Trace Oblivious Program Execution

    Cloud computing allows users to delegate data and computation to cloud service providers, at the cost of giving up physical control of their computing infrastructure. An attacker with physical access to the computing platform can perform various physical attacks, including probing memory buses and cold-boot style attacks. Previous work on...

    Provided By University of Mary Washington

  • White Papers // Mar 2013

    Access vs. Bandwidth in Codes for Storage

    Erasure-correcting codes are the basis for widely used storage systems, where disks (nodes) correspond to symbols in the code. An important family of codes is the Maximum Distance Separable (MDS) codes, which provide an optimal resiliency to erasures for a given amount of redundancy. Namely, an MDS code with r...

    Provided By University of Mary Washington

  • White Papers // Mar 2013

    On Sharing Private Data with Multiple NonColluding Adversaries

    The authors present SPARSI, a novel theoretical framework for partitioning sensitive data across multiple non-colluding adversaries. Most work in privacy-aware data sharing has considered disclosing summaries where the aggregate information about the data is preserved, but sensitive user information is protected. Nonetheless, there are applications, including online advertising, cloud computing...

    Provided By University of Mary Washington

  • White Papers // Mar 2013

    Technical Report: Does Malware Detection Improve with Diverse AntiVirus Products? an Empirical Study

    The authors present results of an empirical study to evaluate the detection capability of diverse Anti-Virus products (AVs). They have used malware samples that have been collected in a geographically distributed honeypot deployment in several different countries and organizations. The malware have been collected in August 2012; therefore the results...

    Provided By University of Mary Washington

  • White Papers // Mar 2013

    Spread Identity : A New Dynamic Address Remapping Mechanism for Anonymity and DDoS Defense

    The authors present and experimentally evaluate Spread Identity (SI) - a new dynamic network address remapping mechanism that provides anonymity and DDoS defense capabilities for Internet communications. For each session between a source and destination host, the trusted source gateway dynamically and randomly assigns an IP address for the source...

    Provided By University of Mary Washington

  • White Papers // Feb 2013

    Secure Degrees of Freedom of the Gaussian Wiretap Channel With Helpers and No Eavesdropper CSI: Blind Cooperative Jamming

    Wyner introduced the wiretap channel in which a legitimate transmitter wants to have secure communications with a legitimate receiver in the presence of an eavesdropper, and determined its capacity-equivocation region for the degraded case. Csiszar and Korner extended this result to the general, not necessarily degraded, wiretap channel. Leung-Yan-Cheong and...

    Provided By University of Mary Washington

  • White Papers // Feb 2013

    Energy Cooperation in Energy Harvesting Two-Way Communications

    In this paper, the authors investigate a two-way communication channel where users can harvest energy from nature and energy can be transferred in one-way from one of the users to the other. Energy required for data transmission is randomly harvested by the users throughout the communication duration and users have...

    Provided By University of Mary Washington

  • White Papers // Jan 2013

    An Outer Bound for Multiple Access Channels with Correlated Sources

    The capacity region of the multiple access channel with correlated sources remains an open problem. Cover, El Gamal and Salehi gave an achievable region in the form of single-letter entropy and mutual information expressions, without a single-letter converse. Cover, El Gamal and Salehi also suggested a converse in terms of...

    Provided By University of Mary Washington

  • White Papers // Jan 2013

    The Capacity Region of a Class of Discrete Degraded Interference Channels

    The authors provide a single-letter characterization for the capacity region of a class of Discrete Degraded Interference Channels (DDICs). The class of DDICs considered includes the Discrete Additive Degraded Interference Channel (DADIC) studied by Benzel. They show that for the class of DDICs studied, encoder cooperation does not increase the...

    Provided By University of Mary Washington

  • White Papers // Jan 2013

    Optimization Based Rate Control for Multirate Multicast Sessions

    Multi-rate multicasting, where the receivers of a multicast group can receive service at different rates, is an efficient mode of data delivery for many real-time applications. In this paper, the authors address the problem of achieving rates that maximize the total receiver utility for multi-rate multicast sessions. This problem not...

    Provided By University of Mary Washington

  • White Papers // Jan 2013

    A Simple Rate Control Algorithm for Maximizing Total User Utility

    In this paper, the authors consider the rate control problem with the objective of maximizing the total user utility. It takes into account the possible differences in user requirements, and also provides a framework for achieving a wide range of fairness objectives. They propose a simple algorithm for achieving the...

    Provided By University of Mary Washington

  • White Papers // Dec 2012

    Technology Comparison for Large Last-Level Caches (L3Cs): Low-Leakage SRAM, Low Write-Energy STT-RAM, and Refresh-Optimized eDRAM

    Large Last-Level Caches (L3Cs) are frequently used to bridge the performance and power gap between processor and memory. Although traditional processors implement caches as SRAMs, technologies such as STT-RAM Magnetoresistive Random-Access Memory (MRAM), and eDRAM have been used and/or considered for the implementation of L3Cs. Each of these technologies has...

    Provided By University of Mary Washington

  • White Papers // Dec 2012

    Two-Way and Multiple-Access Energy Harvesting Systems With Energy Cooperation

    The authors study the capacity regions of the Gaussian Two-Way Channel (TWC) and the Gaussian two-user Multiple Access Channel (MAC) with one-way energy transfer. In both scenarios, there are two users powered by energy harvesting devices communicating messages to each other or to an access point. They model these scenarios...

    Provided By University of Mary Washington

  • White Papers // Dec 2012

    Runtime Optimizations for Prediction with Tree-Based Models

    Tree-based models have proven to be an effective solution for web ranking as well as other problems in diverse domains. This paper focuses on optimizing the runtime performance of applying such models to make predictions, given an already trained model. Although exceedingly simple conceptually, most implementations of tree-based models do...

    Provided By University of Mary Washington

  • White Papers // Dec 2012

    An Efficient CCA2-Secure Variant of the McEliece Cryptosystem in the Standard Model

    Recently, a few Chosen Ciphertext Attacks secure (CCA2-secure) variants of the McEliece Public-Key Encryption (PKE) scheme in the standard model were introduced. All the proposed schemes are based on encryption repetition paradigm and use general transformation from CPA-secure scheme to a CCA2- secure one. Therefore, the resulting encryption scheme needs...

    Provided By University of Mary Washington

  • White Papers // Dec 2012

    Verifiable Data Streaming

    In a verifiable data streaming protocol, the client streams a long string to the server who stores it in its database. The stream is verifiable in the sense that the server can neither change the order of the elements nor manipulate them. The client may also retrieve data from the...

    Provided By University of Mary Washington

  • White Papers // Nov 2012

    Anti Error Propagation Methods for Wireless Uplink Using Network Coding

    Wireless network coding suffers the error propagation issues that may severely degrade the diversity performance. In this paper, the authors develop two power scaling schemes at the relay side and two detection schemes at the receiver side, respectively, to mitigate error propagation in network-coded uplink channel and thus achieve full...

    Provided By University of Mary Washington

  • White Papers // Nov 2012

    Probabilistic Computation for Information Security

    Probabilistic computation is a convenient means of mechanically reasoning about a variety of information security problems. At its core, information security concerns itself with measuring or limiting the knowledge an adversary might attain from interacting with a protected system. Probabilistic inference lets one compute this knowledge explicitly as long as...

    Provided By University of Mary Washington

  • White Papers // Oct 2012

    Multi-View Constrained Clustering with an Incomplete Mapping Between Views

    Multi-view learning algorithms typically assume a complete bipartite map-ping between the different views in order to exchange information during the learning process. However, many applications provide only a partial mapping between the views, creating a challenge for current methods. To address this problem, the authors propose a multi-view algorithm based...

    Provided By University of Mary Washington

  • White Papers // Oct 2012

    Systematic Integration of Flowgraph- and Module-Level Parallelism in Implementation of DSP Applications on Multiprocessor Systems-on-Chip

    Increasing use of Multi-Processor System-on-Chip (MPSoC) technology is an important trend in the design and implementation of signal processing systems. However, the design of efficient DSP software for MPSoC platforms involves complex inter-related steps, including data decomposition, memory management, and inter-task and inter-thread synchronization. These design steps are challenging, especially...

    Provided By University of Mary Washington

  • White Papers // Sep 2012

    Secure Degrees of Freedom of the Gaussian Wiretap Channel With Helpers

    The secrecy capacity of the canonical Gaussian wiretap channel does not scale with the transmit power, and hence, the secure d.o.f. of the Gaussian wiretap channel with no helpers is zero. It has been known that a strictly positive secure d.o.f. can be obtained in the Gaussian wiretap channel by...

    Provided By University of Mary Washington

  • White Papers // Sep 2012

    Secure Degrees of Freedom of One-Hop Wireless Networks

    The authors study the secure Degrees of Freedom (DoF) of one-hop wireless networks by considering four fundamental wireless network structures: Gaussian wiretap channel, Gaussian broadcast channel with confidential messages, Gaussian interference channel with confidential messages, and Gaussian multiple access wiretap channel. The secrecy capacity of the canonical Gaussian wiretap channel...

    Provided By University of Mary Washington

  • White Papers // Sep 2012

    Cluster-Based Instance Consolidation for Subsequent Matching

    Instance consolidation is a way to merge instances that are thought to be the same or closely related that can be used to support co-reference resolution and entity linking. For Semantic Web data, consolidating instances can be as simple as relating instances using owl: sameAs, as is the case in...

    Provided By University of Mary Washington

  • White Papers // Jul 2012

    Gaussian Wiretap Channel With a Batteryless Energy Harvesting Transmitter

    The authors study the Gaussian wiretap channel with an energy harvesting transmitter which does not have a battery to save energy. In the absence of a battery, the necessary transmission energy is maintained by an i.i.d. energy arrival process. They observe that this channel is an instance of the state-dependent...

    Provided By University of Mary Washington

  • White Papers // Jul 2012

    Gaussian Wiretap Channel With an Amplitude Constraint

    The authors consider the Gaussian wiretap channel with an amplitude constraint, i.e., a peak power constraint, on the channel input. They show that the entire rate-equivocation region of the Gaussian wiretap channel with an amplitude constraint is obtained by discrete input distributions with finite support. They prove this result by...

    Provided By University of Mary Washington

  • White Papers // Dec 2012

    Technology Comparison for Large Last-Level Caches (L3Cs): Low-Leakage SRAM, Low Write-Energy STT-RAM, and Refresh-Optimized eDRAM

    Large Last-Level Caches (L3Cs) are frequently used to bridge the performance and power gap between processor and memory. Although traditional processors implement caches as SRAMs, technologies such as STT-RAM Magnetoresistive Random-Access Memory (MRAM), and eDRAM have been used and/or considered for the implementation of L3Cs. Each of these technologies has...

    Provided By University of Mary Washington

  • White Papers // May 2012

    Optimal Frequency Selection for Energy Efficient Underwater Acoustic Networks

    The underwater acoustic channel is characterized by a path loss that is dependent on both the distance and the frequency of communication. Given this dependence, it has been previously demonstrated that for a given communication distance, there is an optimal operating frequency, where conditions for signal propagation and noise are...

    Provided By University of Mary Washington

  • White Papers // Aug 2011

    Secure Lossy Transmission of Vector Gaussian Sources

    The authors explain the secure lossy transmission of a vector Gaussian source to a legitimate user in the presence of an eavesdropper, where both the legitimate user and the eavesdropper have vector Gaussian side information. The aim of the transmitter is to describe the source to the legitimate user in...

    Provided By University of Mary Washington

  • White Papers // Nov 2012

    Anti Error Propagation Methods for Wireless Uplink Using Network Coding

    Wireless network coding suffers the error propagation issues that may severely degrade the diversity performance. In this paper, the authors develop two power scaling schemes at the relay side and two detection schemes at the receiver side, respectively, to mitigate error propagation in network-coded uplink channel and thus achieve full...

    Provided By University of Mary Washington

  • White Papers // Dec 2012

    Runtime Optimizations for Prediction with Tree-Based Models

    Tree-based models have proven to be an effective solution for web ranking as well as other problems in diverse domains. This paper focuses on optimizing the runtime performance of applying such models to make predictions, given an already trained model. Although exceedingly simple conceptually, most implementations of tree-based models do...

    Provided By University of Mary Washington

  • White Papers // May 2012

    A Binary Classification Framework for Two-Stage Multiple Kernel Learning

    With the advent of kernel methods, automating the task of specifying a suitable kernel has become increasingly important. In this context, the Multiple Kernel Learning (MKL) problem of finding a combination of pre-specified base kernels that is suitable for the task at hand has received significant attention from researchers. In...

    Provided By University of Mary Washington

  • White Papers // Jul 2010

    Applying Internal Customer Relationship Management (IntCRM) Principles to Improving Business / IT Integration and Performance

    Ever since the arrival of general purpose computers into the business environment, tension has existed between the departments who implement and manage the technology and those responsible for the business functions and processes. This struggle to integrate business and IT functions becomes increasingly important as technology becomes so entrenched in...

    Provided By University of Mary Washington

  • White Papers // Jan 2010

    Perfect Omniscience, Perfect Secrecy and Steiner Tree Packing

    The authors consider perfect secret key generation for a "Pair-wise independent network" model in which every pair of terminals share a random binary string, with the strings shared by distinct terminal pairs being mutually independent. The terminals are then allowed to communicate interactively over a public noiseless channel of unlimited...

    Provided By University of Mary Washington

  • White Papers // Jun 2009

    Performance Studies for Multithreading in Matlab With Usage Instructions on HPC

    This report explores the use of multiple computational cores by multithreading in the software package Matlab on a compute node with two dual-core AMD Opteron processors. After testing the built-in functions of Matlab for a small test problem, the authors consider a classical test problem resulting from a finite difference...

    Provided By University of Mary Washington

  • White Papers // May 2013

    An Implementation of Binomial Method of Option Pricing using Parallel Computing

    The Binomial method of option pricing is based on iterating over discounted option payoffs in a recursive fashion to calculate the present value of an option. Implementing the Binomial method to exploit the resources of a parallel computing cluster is non-trivial as the method is not easily parallelizable. The authors...

    Provided By University of Mary Washington

  • White Papers // Feb 2012

    Understanding Issues in Cloud Forensics: Two Hypothetical Case Studies

    The inevitable vulnerabilities and criminal targeting of cloud environments demand an understanding of how digital forensic investigations of the cloud can be accomplished. The authors present two hypothetical case studies of cloud crimes; child pornography being hosted in the cloud, and a compromised cloud-based website. Their cases highlight shortcomings of...

    Provided By University of Mary Washington

  • White Papers // May 2012

    Throughput and Stability for Relay-Assisted Wireless Broadcast with Network Coding

    The throughput and stability properties of wireless network coding are evaluated for an arbitrary number of terminals exchanging broadcast traffic with the aid of a relay. First, coding and scheduling schemes are derived that minimize the number of transmissions needed for each node to broadcast one packet. For stochastically varying...

    Provided By University of Mary Washington

  • White Papers // Aug 2010

    Wireless Jamming Attacks Under Dynamic Trafc Uncertainty

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

    Provided By University of Mary Washington

  • White Papers // Aug 2011

    Cellular Traffic Offloading Through WiFi Networks

    Cellular networks are currently facing the challenges of mobile data explosion. High-end mobile phones and laptops double their mobile data traffic every year and this trend is expected to continue given the rapid development of mobile social applications. It is imperative that novel architectures be developed to handle such voluminous...

    Provided By University of Mary Washington

  • White Papers // Apr 2010

    A Semantic Similarity Analysis for Data Mappings Between Heterogeneous XML Schemas

    One of the most critical steps to integrating heterogeneous e-Business applications using different XML schemas is schema mapping, which is known to be costly and error-prone. Past research on schema mapping has not made full use of semantic information imbedded in the hierarchical structure of the XML schema. In this...

    Provided By University of Mary Washington

  • White Papers // May 2013

    Binary Energy Harvesting Channel With Finite Energy Storage

    The authors consider the capacity of an energy harvesting communication channel with a finite-sized battery. As an abstraction of this problem, they consider a system where energy arrives at the encoder in multiples of a fixed quantity, and the physical layer is modeled accordingly as a finite discrete alphabet channel...

    Provided By University of Mary Washington

  • White Papers // Oct 2010

    Secure Broadcasting Using Multiple Antennas

    The authors consider three different secure broadcasting scenarios: Broadcast Channels with Common and confidential messages (BCC), multi-receiver wiretap channels with public and confidential messages, and compound wiretap channels. The BCC is a broadcast channel with two users, where in addition to the common message sent to both users, a private...

    Provided By University of Mary Washington

  • White Papers // May 2013

    Non-Asymptotic and Second-Order Achievability Bounds for Source Coding with Side-Information

    In this paper, the authors proved a new non-asymptotic bound on the error probability for the WAK problem. They present a novel achievability bound for the Wyner-Ahlswede-Korner (WAK) problem of lossless source coding with rate-limited side-information. This bound is proved using ideas from channel simulation and channel resolvability. The bound...

    Provided By University of Mary Washington

  • White Papers // Apr 2009

    Secrecy Capacity Region of the Gaussian Multi-Receiver Wiretap Channel

    The authors consider the Gaussian multi-receiver wiretap channel and evaluate its secrecy capacity region. This evaluation requires the identification of underlying auxiliary random variables. For this purpose, they first visit the converse proof of the scalar Gaussian broadcast channel, and show that this proof cannot be extended to this secrecy...

    Provided By University of Mary Washington

  • White Papers // Apr 2009

    On the Rate-Limited Gelfand-Pinsker Problem

    The authors study a rate-limited version of the well known problem of coding for channels with random parameters which was studied by Gelfand and Pinsker. In particular, they consider a state-dependent channel when the transmitter is supplied with the state information at a rate Re. They obtain a new upper...

    Provided By University of Mary Washington

  • White Papers // Apr 2010

    Gaussian MIMO Broadcast Channels with Common and Confidential Messages

    The authors study the two-user Gaussian Multiple-Input Multiple-Output (MIMO) broadcast channel with common and confidential messages. In this channel, the transmitter sends a common message to both users, and a confidential message to each user which is kept perfectly secret from the other user. They obtain the entire capacity region...

    Provided By University of Mary Washington

  • White Papers // Apr 2010

    On Gaussian MIMO Broadcast Channels with Common and Private Messages

    The authors study the Gaussian Multiple-Input Multiple-Output (MIMO) broadcast channel with common and private messages. They first obtain an outer bound for the capacity region of the two-user discrete memoryless broadcast channel with common and private messages. They next show that if jointly Gaussian random variables are sufficient to evaluate...

    Provided By University of Mary Washington

  • White Papers // Apr 2010

    Delay Minimization With a General Pentagon Rate Region

    The authors consider a communication channel with two transmitters and one receiver, with an underlying rate region which is approximated as a general pentagon. Different from the Gaussian Multiple Access Channel (MAC) capacity region, the sum-rate on the dominant face of this pentagon is not a constant. They allocate rates...

    Provided By University of Mary Washington

  • White Papers // Apr 2010

    Diamond Channel with Partially Separated Relays

    The authors considered several variations of the diamond channel with an orthogonal multiple access component. They established the capacity for the case when the broadcast channel is deterministic. They next provided an upper bound on the capacity when the broadcast channel is physically degraded. This upper bound was shown to...

    Provided By University of Mary Washington

  • White Papers // May 2011

    Secrecy Games on the One-Sided Interference Channel

    In this paper, the authors study the two-user one-sided interference channel with confidential messages. In this interference channel, in addition to the usual selfishness of the users, the relationship between the two pairs of users is further adversarial in the sense of both receivers' desires to eavesdrop on the communication...

    Provided By University of Mary Washington

  • White Papers // May 2012

    An Outer Bound for the Vector Gaussian CEO Problem

    The authors study the vector Gaussian CEO problem, and provide an outer bound for its rate-distortion region. They obtain their outer bound by evaluating an outer bound for the multi-terminal source coding problem by means of a technique relying on the de Bruijn identity and the properties of the Fisher...

    Provided By University of Mary Washington

  • White Papers // May 2012

    On the Sum Secure Degrees of Freedom of Two-Unicast Layered Wireless Networks

    The authors consider a two-unicast layered network where two transmitters wish to have reliable and secure communication with their respective receivers simultaneously, by utilizing a layered network between the transmitters and receivers. The single-layer version of this network is an interference channel, whose capacity is unknown in general; it is...

    Provided By University of Mary Washington

  • White Papers // Jun 2010

    Transmission of Common, Public and Confidential Messages in Broadcast Channels with Multiple Antennas

    The authors study the Gaussian Multiple-Input Multiple-Output (MIMO) wiretap channel, which consists of a transmitter, a legitimate user, and an eavesdropper. In this channel, the transmitter sends a common message to both the legitimate user and the eavesdropper. Moreover, the legitimate user receives a private message, which is desired to...

    Provided By University of Mary Washington

  • White Papers // Sep 2010

    Capacity of a Class of Semi-Deterministic Primitive Relay Channels

    The authors characterize the capacity of a class of primitive relay channels. The primitive relay channel considered in this paper consists of a semi-deterministic broadcast channel to the relay and the decoder. The relay can help the message transmission through an orthogonal finite capacity link to the decoder. They show...

    Provided By University of Mary Washington

  • White Papers // Sep 2010

    Real Interference Alignment for the K-User Gaussian Interference Compound Wiretap Channel

    The authors study the K-user Gaussian interference wiretap channel with N external eavesdroppers. All the transmitters, receivers and eavesdroppers have a single antenna each. They propose an achievable scheme to lower bound the secure degrees of freedom (d.o.f.) for each transmitter-receiver pair. Their approach is based on the (real) interference...

    Provided By University of Mary Washington

  • White Papers // Jan 2013

    An Outer Bound for Multiple Access Channels with Correlated Sources

    The capacity region of the multiple access channel with correlated sources remains an open problem. Cover, El Gamal and Salehi gave an achievable region in the form of single-letter entropy and mutual information expressions, without a single-letter converse. Cover, El Gamal and Salehi also suggested a converse in terms of...

    Provided By University of Mary Washington

  • White Papers // Feb 2010

    Transmission Completion Time Minimization in an Energy Harvesting System

    The authors consider the transmission completion time minimization problem in a single-user energy harvesting wireless communication system. In this system, both the data packets and the harvested energy are modeled to arrive at the source node randomly. Their goal is to adaptively change the transmission rate according to the traffic...

    Provided By University of Mary Washington

  • White Papers // Feb 2010

    On Gaussian MIMO Compound Wiretap Channels

    The authors study the two-user one-eavesdropper discrete memoryless compound wiretap channel, where the transmitter sends a common confidential message to both users, which needs to be kept perfectly secret from the eavesdropper. They provide a new achievable secrecy rate which is shown to be potentially better than the best known...

    Provided By University of Mary Washington

  • White Papers // Feb 2012

    Deaf Cooperation for Secrecy with a Multi-Antenna Helper

    In this paper, the authors investigate the roles of Cooperative Jamming (CJ) and Noise Forwarding (NF) in improving the achievable secrecy rates of a Gaussian WireTap channel (GWT) when the helper node is equipped with multiple antennas. They decompose the channel from the helper to the eavesdropper into two orthogonal...

    Provided By University of Mary Washington

  • White Papers // Feb 2013

    Secure Degrees of Freedom of the Gaussian Wiretap Channel With Helpers and No Eavesdropper CSI: Blind Cooperative Jamming

    Wyner introduced the wiretap channel in which a legitimate transmitter wants to have secure communications with a legitimate receiver in the presence of an eavesdropper, and determined its capacity-equivocation region for the degraded case. Csiszar and Korner extended this result to the general, not necessarily degraded, wiretap channel. Leung-Yan-Cheong and...

    Provided By University of Mary Washington

  • White Papers // Sep 2011

    Deaf Cooperation for Secrecy in Multiple-Relay Networks

    In this paper, the authors investigate the roles of Cooperative Jamming (CJ) and Noise Forwarding (NF) in improving the achievable secrecy rates of a Gaussian WireTap channel (GWT). In particular, they study the role of a deaf helper in confusing the eavesdropper in a GWT channel by either transmitting white...

    Provided By University of Mary Washington

  • White Papers // Feb 2010

    Ergodic Secret Alignment for the Fading Multiple Access Wiretap Channel

    In this paper, the authors provide a new achievable ergodic secrecy rate region for the multiple access wiretap channel in fading. Their achievable scheme is based on repeating each symbol at two fading instances, as in the original ergodic interference alignment technique of Nazer et. al. They choose the channel...

    Provided By University of Mary Washington

  • White Papers // Feb 2011

    Optimal Packet Scheduling in a Multiple Access Channel With Rechargeable Nodes

    In this paper, the authors investigate the optimal packet scheduling problem in a two-user multiple access communication system, where the transmitters are able to harvest energy from the nature. Under a deterministic system setting, they assume that the energy harvesting times and harvested energy amounts are known before the transmission...

    Provided By University of Mary Washington

  • White Papers // Apr 2009

    Outer Bounds for User Cooperation

    The authors obtain a dependence balance based outer bound on the capacity region of the two-user Multiple Access Channel with Generalized Feedback (MAC-GF). They investigate a Gaussian MAC with User-Cooperation (MAC-UC), where each transmitter receives an additive white Gaussian noise corrupted version of the channel input of the other transmitter....

    Provided By University of Mary Washington

  • White Papers // May 2009

    Delay Minimization in Multiple Access Channels

    The authors investigate a delay minimization problem in a multiple access wireless communication system. They consider a discrete-time non-fading Additive White Gaussian Noise (AWGN) multiple access channel. In each slot, bits arrive at the transmitters randomly according to some distribution, which is i.i.d. from user to user and from slot...

    Provided By University of Mary Washington