Virginia Polytechnic Institute and State University

Displaying 1-40 of 56 results

  • White Papers // May 2011

    An Optimal Link Layer Model for Multi-Hop MIMO Networks

    The rapid advances of MIMO to date have mainly stayed at the physical layer. Such fruits have not been fully benefited at the network layer mainly due to the computational complexity associated with the matrix-based model that MIMO involves. Recently, there are some efforts to simplify link layer model for...

    Provided By Virginia Polytechnic Institute and State University

  • White Papers // May 2011

    On Capacity Scaling Law of Cognitive Radio Ad Hoc Networks

    Cognitive radio is envisioned to be an enabling radio technology for future wireless networks. In this paper, the authors study the capacity scaling laws for Cognitive Radio ad hoc Networks (CRNs), i.e., how each individual node's capacity scales as the number of nodes in the network increases. This effort is...

    Provided By Virginia Polytechnic Institute and State University

  • White Papers // Feb 2011

    On Renewable Sensor Networks With Wireless Energy Transfer

    Traditional wireless sensor networks are constrained by limited battery energy. Thus, finite network lifetime is widely regarded as a fundamental performance bottleneck. Recent breakthrough in the area of wireless energy transfer offers the potential of removing such performance bottleneck, i.e., allowing a sensor network remain operational forever. In this paper,...

    Provided By Virginia Polytechnic Institute and State University

  • White Papers // Feb 2011

    Efficient OFDM Denial: Pilot Jamming and Pilot Nulling

    Orthogonal Frequency Division Multiplexing (OFDM) uses pilot tones to estimate the channel's frequency response and perform equalization. It is commonly known that jamming pilot tones is more efficient than broadband attacks against an entire OFDM signal. This paper builds on this idea and introduces the pilot nulling attack, which is...

    Provided By Virginia Polytechnic Institute and State University

  • White Papers // Feb 2011

    Achievable Rate Analysis in Network-Coded Cooperative Communications With Multiple Relay Nodes

    Network-Coded Cooperative Communications (NCCC) refers to the use of Network Coding (NC) in Cooperative Communications (CC). Prior studies have shown that NC has the potential to improve the performance of CC when there are multiple sessions in the wireless network. These studies were done for the case when multiple sessions...

    Provided By Virginia Polytechnic Institute and State University

  • White Papers // Feb 2011

    Parallel Load Balancing Strategies for Ensembles of Stochastic Biochemical Simulations

    The evolution of biochemical systems where some chemical species are present with only a small number of molecules, is strongly influenced by discrete and stochastic effects that cannot be accurately captured by continuous and deterministic models. The budding yeast cell cycle provides an excellent example of the need to account...

    Provided By Virginia Polytechnic Institute and State University

  • White Papers // Jan 2011

    Optimizing Network-Coded Cooperative Communications Via Joint Session Grouping and Relay Node Selection

    Network-Coded Cooperative Communications (NCCC) is a new paradigm in wireless networks that employs Network Coding (NC) to improve the performance of CC. The core mechanism to harness the benefits of NC-CC is to appropriately combine sessions into separate groups, and then have each group select the most beneficial relay node...

    Provided By Virginia Polytechnic Institute and State University

  • White Papers // Jan 2011

    Designing Energy Efficient Communication Runtime Systems for Data Centric Programming

    The insatiable demand of high performance computing is being driven by the most computationally intensive applications such as computational chemistry, climate modeling, nuclear physics, etc. The last couple of decades have observed a tremendous rise in supercomputers with architectures ranging from traditional clusters to system-on-a-chip in order to achieve the...

    Provided By Virginia Polytechnic Institute and State University

  • White Papers // Jan 2011

    On Optimal Throughput-Energy Curve for Multi-Hop Wireless Networks

    Network throughput and energy consumption are two important performance metrics for a multi-hop wireless network. Current state-of-the-art is limited to either maximizing throughput under some energy constraint or minimizing energy consumption while satisfying some throughput requirement. In this paper, the authors take a multicriteria optimization approach to offer a systematic...

    Provided By Virginia Polytechnic Institute and State University

  • White Papers // Jan 2011

    Architecting Network-Centric Software Systems: A Style-Based Beginning

    With the advent of potent network technology, software development has evolved from traditional platform-centric construction to network-centric evolution. This change involves largely the way the authors reason about systems as evidenced in the introduction of Network-Centric Operations (NCO). Unfortunately, it has resulted in conflicting interpretations of how to map NCO...

    Provided By Virginia Polytechnic Institute and State University

  • White Papers // Dec 2010

    Load-Varying LINPACK: A Benchmark for Evaluating Energy Efficiency in High-End Computing

    For decades, performance has driven the High-End Computing (HEC) community. However, as highlighted in recent exascale studies that chart a path from petascale to exascale computing, power consumption is fast becoming the major design constraint in HEC. Consequently, the HEC community needs to address this issue in future petascale and...

    Provided By Virginia Polytechnic Institute and State University

  • White Papers // Nov 2010

    Storytelling Security: User-Intention Based Traffic Sanitization

    Malicious software (malware) with decentralized communication infrastructure, such as peer-to-peer botnets, is difficult to detect. In this paper, the authors describe a traffic-sanitization method for identifying malware-triggered outbound connections from a personal computer. The solution correlates user activities with the content of outbound traffic. The key observation is that user-initiated...

    Provided By Virginia Polytechnic Institute and State University

  • White Papers // Nov 2010

    Mobilizar: Capturing User Behavior With Mobile Digital Diaries

    One of the major challenges in the Information Retrieval field is handling the massive amount of information available to Internet users. Existing ranking techniques and strategies that govern the retrieval process fall short of expected accuracy. Often relevant documents are buried deep in the list of documents returned by the...

    Provided By Virginia Polytechnic Institute and State University

  • White Papers // Oct 2010

    On the Maximum Sum-Rate of Cognitive MIMO Interference Channels

    In this paper, the authors address the problem of maximizing the ergodic sum-rate of an N-user cognitive MIMO Interference Channel (IC) formed by unlicensed (or secondary) users. They assume that N secondary users coexist in the same area and try to access the same set of frequency bands. In such...

    Provided By Virginia Polytechnic Institute and State University

  • White Papers // Sep 2010

    Multicast Communications in Multi-Hop Cognitive Radio Networks

    The authors study a multicast communication problem in a multi-hop ad hoc network where each node is equipped with a Cognitive Radio (CR). The goal is to minimize the required network-wide resource to support a set of multicast sessions, with a given bit rate requirement for each multicast session. The...

    Provided By Virginia Polytechnic Institute and State University

  • White Papers // Jun 2010

    Cross-Layer Optimization for Wireless Sensor Network With Multi-Packet Reception

    In this paper, the authors consider how to exploit Multi-Packet Reception (MPR) to increase the capacity for a wireless sensor network. Since MPR behavior at the physical layer affects link layer scheduling, it is necessary to follow a cross-layer approach to obtain an optimal solution. Due to the complexity of...

    Provided By Virginia Polytechnic Institute and State University

  • White Papers // Jun 2010

    Understanding External Firm Factors Impacting Innovation In The Hardwood Veneer Industry

    Innovation research in the wood products industry has historically focused on factors that the firm can influence or control (i.e. climate for innovation, organizational culture, job satisfaction, etc.) (Hovgaard and Hansen, 2004), as opposed to factors external to the firm that it may not be able to directly influence or...

    Provided By Virginia Polytechnic Institute and State University

  • White Papers // May 2010

    Is Network Coding Always Good for Cooperative Communications?

    Network Coding (NC) is a promising approach to reduce time-slot overhead for Cooperative Communications (CC) in a multi-session environment. Most of the existing works take advantage of the benefits of NC in CC but do not fully recognize its potential adverse effect. In this paper, the authors show that employing...

    Provided By Virginia Polytechnic Institute and State University

  • White Papers // Mar 2010

    Teachers' Perceptions Of The Importance Of Identified Servant Leadership Characteristics For High School Principals In Two Diverse Communities

    The purpose of this paper was to determine whether there are differences in the perceptions of the importance of identified servant leadership characteristics for high school principals held by teachers in schools located in two diverse communities. Servant leadership is a practical philosophy supporting people who serve first in their...

    Provided By Virginia Polytechnic Institute and State University

  • White Papers // Mar 2010

    Coding-Aware Routing for Unicast Sessions in Wireless Mesh Networks

    The selection of routes is an important issue in wireless networks when network coding is used. Existing research formulate network-coding-aware routing as a linear optimization program. However, deploying such method in real wireless networks is impractical. To solve this issue, in this paper, a practical network-coding aware routing protocol is...

    Provided By Virginia Polytechnic Institute and State University

  • White Papers // Feb 2010

    Wireless Sensor Network Radio Power Management and Simulation Models

    Wireless Sensor Networks (WSNs) create a new frontier in collecting and processing data from remote locations. The IEEE 802.15.4 Wireless Personal Area Network-Low Rate (WPAN-LR) WSNs rely on hardware simplicity to make sensor field deployments both affordable and long-lasting without maintenance support. WSN designers strive to extend network lifetimes while...

    Provided By Virginia Polytechnic Institute and State University

  • White Papers // Jan 2010

    Lightweight Data Management for Compositional Modeling in Problem Solving Environments

    The paper outlines various design considerations and implementation options pertaining to lightweight data management in Problem Solving Environments (PSEs). The emphasis is on compositional modeling, in the context of a PSE for wireless communications System Design (S W). By focusing on a restrictive subset of markup languages, the paper describes...

    Provided By Virginia Polytechnic Institute and State University

  • White Papers // Jan 2010

    Adaptive QoS Control Based on Benefit Optimization for Video Servers Providing Differentiated Services

    This paper proposes and analyzes Quality of Service (QoS) control algorithms for video servers designed to provide differentiated video streaming services. The design concepts are based on resource reservation and benefit optimization so that resources are reserved dynamically and adaptively for different QoS levels in response to the changing workload...

    Provided By Virginia Polytechnic Institute and State University

  • White Papers // Oct 2009

    Power Saving Experiments for Large Scale Global Optimization

    Green computing, an emerging field of research that seeks to reduce excess power consumption in High Performance Computing (HPC), is gaining popularity among researchers. Research in this field often relies on simulation or only uses a small cluster, typically 8 or 16 nodes, because of the lack of hardware support....

    Provided By Virginia Polytechnic Institute and State University

  • White Papers // Sep 2009

    Effects of Wi-Fi and Bluetooth Battery Exhaustion Attacks on Mobile Devices

    This paper provides insight into the ramifications of battery exhaustion Denial of Service (DoS) attacks on battery-powered mobile devices. Several IEEE 802.11 Wi-Fi, IEEE 802.15.1 Bluetooth, and blended attacks are studied to understand their effects on device battery lifetimes. In the worst case, DoS attacks against mobile devices were found...

    Provided By Virginia Polytechnic Institute and State University

  • White Papers // Aug 2009

    A Comparison of Channel Assignment Techniques With Power Control in Ad Hoc Networks

    Multi-channel operation in an ad hoc network can improve robustness and reliability by efficiently managing interference and reducing contention. In this paper, the authors model four dynamic channel assignment techniques under the same set of assumptions, comparing the efficiency of their power and channel allocations. As the number of channels...

    Provided By Virginia Polytechnic Institute and State University

  • White Papers // Aug 2009

    A Tractable and Accurate Cross-Layer Model for Multi-Hop MIMO Ad Hoc Networks

    MIMO-based communications have great potential to improve network capacity for wireless ad hoc networks. Although there has been significant progress on MIMO at the physical layer or single-hop communication over the years, advances in the theory of MIMO for multi-hop ad hoc networks remain limited. This stagnation is mainly due...

    Provided By Virginia Polytechnic Institute and State University

  • White Papers // Aug 2009

    A Flexible Design Flow for Software IP Binding in Commodity FPGA

    SoftWare Intellectual Property (SWIP) is a critical component of increasingly complex FPGA based System On Chip (SOC) designs. As a result, developers want to ensure that their SWIP sources are protected from being exposed to an unauthorized party and are restricted to run only on a trusted FPGA platform. This...

    Provided By Virginia Polytechnic Institute and State University

  • White Papers // Aug 2009

    CFlood: A Constrained Flooding Protocol for Real-Time Data Delivery in Wireless Sensor Networks

    Real-time performance is critical for many time-sensitive applications of wireless sensor networks. The authors present a constrained flooding protocol, called CFlood that enhances the deadline satisfaction ratio per unit energy consumption of time-sensitive packets in sensor networks. CFlood improves real-time performance by flooding, but effectively constrains energy consumption by controlling...

    Provided By Virginia Polytechnic Institute and State University

  • White Papers // Aug 2009

    On Selfishness, Local Information, and Network Optimality: A Topology Control Example

    Topology control of ad hoc and mesh networks specifies how to assign per-node transmission parameters (such as power level, frequency etc.) so as to achieve energy efficiency, while maintaining certain desirable properties such as connectivity. In autonomous networks, nodes may act in their self-interest and improve their performance, perhaps at...

    Provided By Virginia Polytechnic Institute and State University

  • White Papers // Jun 2009

    Battery-Sensing Intrusion Protection System Validation Using Enhanced Wi-Fi and Bluetooth Attack Correlation

    This paper discusses mobile device security and extends the original Battery-Sensing Intrusion Protection System (B-SIPS) design by introducing the Multi-Vector Portable - Intrusion Detection System (MVP-IDS). MVP-IDS validate reported anomalous battery depletion from B-SIPS clients with real-time Wi-Fi and Bluetooth traffic using attack signature detection modules. To correlate Instantaneous Current...

    Provided By Virginia Polytechnic Institute and State University

  • White Papers // Jun 2009

    The Green500 List: Year One

    The latest release of the Green500 List in November 2008 marked its one-year anniversary. As such, this paper aims to provide an analysis and retrospective examination of the Green500 List in order to understand how the list has evolved and what trends have emerged. In addition, the authors present community...

    Provided By Virginia Polytechnic Institute and State University

  • White Papers // Jun 2009

    Shortening Time-to-Discovery With Dynamic Software Updates for Parallel High Performance Applications

    Despite using multiple concurrent processors, a typical high performance parallel application is long-running, taking hours, even days to arrive at a solution. To modify a running high performance parallel application, the programmer has to stop the computation, change the code, redeploy, and enqueue the updated version to be scheduled to...

    Provided By Virginia Polytechnic Institute and State University

  • White Papers // May 2009

    Multi-Dimensional Characterization of Temporal Data Mining on Graphics Processors

    Through the algorithmic design patterns of data parallelism and task parallelism, the Graphics Processing Unit (GPU) offers the potential to vastly accelerate discovery and innovation across a multitude of disciplines. For example, the exponential growth in data volume now presents an obstacle for high-throughput data mining in fields such as...

    Provided By Virginia Polytechnic Institute and State University

  • White Papers // Apr 2009

    Theoretical Results on Base Station Movement Problem for Sensor Network

    The benefits of using mobile base station to prolong sensor network lifetime have been well recognized. However, due to the complexity of the problem (time-dependent network topology and traffic routing), theoretical performance limit and provably optimal algorithms remain difficult to develop. This paper fills this important gap by contributing theoretical...

    Provided By Virginia Polytechnic Institute and State University

  • White Papers // Apr 2009

    Evaluation of Online Resources in Assisting Phishing Detection

    Phishing is an attempt to fraudulently acquire users' sensitive information, such as passwords or financial information, by masquerading as a trustworthy entity in online transactions. Recently, a number of researchers have proposed using external online resources like the Google PageRank system to assist phishing detection. The advantage of such an...

    Provided By Virginia Polytechnic Institute and State University

  • White Papers // Mar 2009

    Compatibility Study for Optimal Tree-Based Broadcast Routing

    Broadcast routing is a critical component in the routing design. While there are plenty of routing metrics and broadcast routing schemes in current literature, it remains an unsolved problem as to which metrics are compatible to a specific broadcast routing scheme. In particular, in the wireless broadcast routing context where...

    Provided By Virginia Polytechnic Institute and State University

  • White Papers // Feb 2009

    ScALPEL: A Scalable Adaptive Lightweight Performance Evaluation Library for Application Performance Monitoring

    As supercomputers continue to grow in scale and capabilities, it is becoming increasingly difficult to isolate processor and system level causes of performance degradation. Over the last several years, a significant number of performance analysis and monitoring tools have been built/proposed. However, these tools suffer from several important shortcomings, particularly...

    Provided By Virginia Polytechnic Institute and State University

  • White Papers // Feb 2009

    Network Interface Cards as First-Class Citizens

    Network performance has improved by over an order-of-magnitude in the past decade. While, the overall system architecture itself has made modification attempts to match such growth, these changes are mostly "Incremental enhancements, tweaks and adjustments" that try to keep the hardware control hierarchy away from the network communication path. However,...

    Provided By Virginia Polytechnic Institute and State University

  • White Papers // Jan 2009

    A Distributed Optimization Algorithm for Multi-Hop Cognitive Radio Networks

    Cognitive Radio (CR) is a revolution in radio technology and is viewed as an enabling technology for dynamic spectrum access. This paper investigates how to design distributed algorithm for a future multi-hop CR network, with the objective of maximizing data rates for a set of user communication sessions. The authors...

    Provided By Virginia Polytechnic Institute and State University

  • White Papers // Feb 2011

    Parallel Load Balancing Strategies for Ensembles of Stochastic Biochemical Simulations

    The evolution of biochemical systems where some chemical species are present with only a small number of molecules, is strongly influenced by discrete and stochastic effects that cannot be accurately captured by continuous and deterministic models. The budding yeast cell cycle provides an excellent example of the need to account...

    Provided By Virginia Polytechnic Institute and State University

  • White Papers // Dec 2010

    Load-Varying LINPACK: A Benchmark for Evaluating Energy Efficiency in High-End Computing

    For decades, performance has driven the High-End Computing (HEC) community. However, as highlighted in recent exascale studies that chart a path from petascale to exascale computing, power consumption is fast becoming the major design constraint in HEC. Consequently, the HEC community needs to address this issue in future petascale and...

    Provided By Virginia Polytechnic Institute and State University

  • White Papers // Nov 2010

    Storytelling Security: User-Intention Based Traffic Sanitization

    Malicious software (malware) with decentralized communication infrastructure, such as peer-to-peer botnets, is difficult to detect. In this paper, the authors describe a traffic-sanitization method for identifying malware-triggered outbound connections from a personal computer. The solution correlates user activities with the content of outbound traffic. The key observation is that user-initiated...

    Provided By Virginia Polytechnic Institute and State University

  • White Papers // Nov 2010

    Mobilizar: Capturing User Behavior With Mobile Digital Diaries

    One of the major challenges in the Information Retrieval field is handling the massive amount of information available to Internet users. Existing ranking techniques and strategies that govern the retrieval process fall short of expected accuracy. Often relevant documents are buried deep in the list of documents returned by the...

    Provided By Virginia Polytechnic Institute and State University

  • White Papers // Aug 2009

    A Flexible Design Flow for Software IP Binding in Commodity FPGA

    SoftWare Intellectual Property (SWIP) is a critical component of increasingly complex FPGA based System On Chip (SOC) designs. As a result, developers want to ensure that their SWIP sources are protected from being exposed to an unauthorized party and are restricted to run only on a trusted FPGA platform. This...

    Provided By Virginia Polytechnic Institute and State University

  • White Papers // Sep 2008

    Two Phase Spectrum Sharing for Frequency-Agile Radio Networks

    Modern frequency-agile radios are capable of dynamically changing the spectrum width and central frequency of its channels. Existing spectrum sharing algorithms often fail to exploit this characteristic to realize efficient spectrum utilization. In this paper, the authors present a theoretical framework that capitalizes on the frequency agility of modern radios....

    Provided By Virginia Polytechnic Institute and State University

  • White Papers // May 2011

    An Optimal Link Layer Model for Multi-Hop MIMO Networks

    The rapid advances of MIMO to date have mainly stayed at the physical layer. Such fruits have not been fully benefited at the network layer mainly due to the computational complexity associated with the matrix-based model that MIMO involves. Recently, there are some efforts to simplify link layer model for...

    Provided By Virginia Polytechnic Institute and State University

  • White Papers // Jan 2011

    On Optimal Throughput-Energy Curve for Multi-Hop Wireless Networks

    Network throughput and energy consumption are two important performance metrics for a multi-hop wireless network. Current state-of-the-art is limited to either maximizing throughput under some energy constraint or minimizing energy consumption while satisfying some throughput requirement. In this paper, the authors take a multicriteria optimization approach to offer a systematic...

    Provided By Virginia Polytechnic Institute and State University

  • White Papers // Jan 2009

    A Distributed Optimization Algorithm for Multi-Hop Cognitive Radio Networks

    Cognitive Radio (CR) is a revolution in radio technology and is viewed as an enabling technology for dynamic spectrum access. This paper investigates how to design distributed algorithm for a future multi-hop CR network, with the objective of maximizing data rates for a set of user communication sessions. The authors...

    Provided By Virginia Polytechnic Institute and State University

  • White Papers // May 2011

    On Capacity Scaling Law of Cognitive Radio Ad Hoc Networks

    Cognitive radio is envisioned to be an enabling radio technology for future wireless networks. In this paper, the authors study the capacity scaling laws for Cognitive Radio ad hoc Networks (CRNs), i.e., how each individual node's capacity scales as the number of nodes in the network increases. This effort is...

    Provided By Virginia Polytechnic Institute and State University

  • White Papers // Feb 2011

    Achievable Rate Analysis in Network-Coded Cooperative Communications With Multiple Relay Nodes

    Network-Coded Cooperative Communications (NCCC) refers to the use of Network Coding (NC) in Cooperative Communications (CC). Prior studies have shown that NC has the potential to improve the performance of CC when there are multiple sessions in the wireless network. These studies were done for the case when multiple sessions...

    Provided By Virginia Polytechnic Institute and State University

  • White Papers // Dec 2008

    A Cross-Layer Approach to Multi-Hop Networking With Cognitive Radios

    Cognitive Radio (CR) is an enabling technology for efficient use of available spectrum and promises unprecedented flexibility in multi-hop wireless networking. This paper explores networking related issues associated with CRs. Specifically the authors consider how to maximize the rates of a set of user communication sessions in a multi-hop CR-based...

    Provided By Virginia Polytechnic Institute and State University

  • White Papers // Sep 2009

    Effects of Wi-Fi and Bluetooth Battery Exhaustion Attacks on Mobile Devices

    This paper provides insight into the ramifications of battery exhaustion Denial of Service (DoS) attacks on battery-powered mobile devices. Several IEEE 802.11 Wi-Fi, IEEE 802.15.1 Bluetooth, and blended attacks are studied to understand their effects on device battery lifetimes. In the worst case, DoS attacks against mobile devices were found...

    Provided By Virginia Polytechnic Institute and State University

  • White Papers // Jun 2009

    Battery-Sensing Intrusion Protection System Validation Using Enhanced Wi-Fi and Bluetooth Attack Correlation

    This paper discusses mobile device security and extends the original Battery-Sensing Intrusion Protection System (B-SIPS) design by introducing the Multi-Vector Portable - Intrusion Detection System (MVP-IDS). MVP-IDS validate reported anomalous battery depletion from B-SIPS clients with real-time Wi-Fi and Bluetooth traffic using attack signature detection modules. To correlate Instantaneous Current...

    Provided By Virginia Polytechnic Institute and State University

  • White Papers // Jun 2010

    Understanding External Firm Factors Impacting Innovation In The Hardwood Veneer Industry

    Innovation research in the wood products industry has historically focused on factors that the firm can influence or control (i.e. climate for innovation, organizational culture, job satisfaction, etc.) (Hovgaard and Hansen, 2004), as opposed to factors external to the firm that it may not be able to directly influence or...

    Provided By Virginia Polytechnic Institute and State University

  • White Papers // Aug 2009

    CFlood: A Constrained Flooding Protocol for Real-Time Data Delivery in Wireless Sensor Networks

    Real-time performance is critical for many time-sensitive applications of wireless sensor networks. The authors present a constrained flooding protocol, called CFlood that enhances the deadline satisfaction ratio per unit energy consumption of time-sensitive packets in sensor networks. CFlood improves real-time performance by flooding, but effectively constrains energy consumption by controlling...

    Provided By Virginia Polytechnic Institute and State University

  • White Papers // Aug 2008

    Optimal Downlink Power Allocation and Scheduling for MIMO-Based WiMAX Access Networks

    Recently, mobile WiMAX equipped with MIMO technology has attracted much attention and has emerged as a leading solution for broadband wireless access networks. However, study on optimal resource management for such networks is still in its infancy and results in this area remain limited. In this paper, the authors study...

    Provided By Virginia Polytechnic Institute and State University

  • White Papers // Aug 2009

    A Tractable and Accurate Cross-Layer Model for Multi-Hop MIMO Ad Hoc Networks

    MIMO-based communications have great potential to improve network capacity for wireless ad hoc networks. Although there has been significant progress on MIMO at the physical layer or single-hop communication over the years, advances in the theory of MIMO for multi-hop ad hoc networks remain limited. This stagnation is mainly due...

    Provided By Virginia Polytechnic Institute and State University

  • White Papers // Oct 2008

    Power Spectrum Optimization of Multi-Carrier MIMO Ad Hoc Networks: A Dual Stochastic Approximation Approach

    Multi-Carrier MIMO (MC-MIMO) has emerged as a promising technology to provide significant capacity gain for broadband wireless ad hoc networks. However, due to the non-convex and large-scale problem structure, little work has been done on power spectrum optimization to harvest MC-MIMO's capacity gain for broadband ad hoc networks. The authors'...

    Provided By Virginia Polytechnic Institute and State University

  • White Papers // Aug 2009

    A Comparison of Channel Assignment Techniques With Power Control in Ad Hoc Networks

    Multi-channel operation in an ad hoc network can improve robustness and reliability by efficiently managing interference and reducing contention. In this paper, the authors model four dynamic channel assignment techniques under the same set of assumptions, comparing the efficiency of their power and channel allocations. As the number of channels...

    Provided By Virginia Polytechnic Institute and State University

  • White Papers // Aug 2009

    On Selfishness, Local Information, and Network Optimality: A Topology Control Example

    Topology control of ad hoc and mesh networks specifies how to assign per-node transmission parameters (such as power level, frequency etc.) so as to achieve energy efficiency, while maintaining certain desirable properties such as connectivity. In autonomous networks, nodes may act in their self-interest and improve their performance, perhaps at...

    Provided By Virginia Polytechnic Institute and State University

  • White Papers // Jan 2011

    Optimizing Network-Coded Cooperative Communications Via Joint Session Grouping and Relay Node Selection

    Network-Coded Cooperative Communications (NCCC) is a new paradigm in wireless networks that employs Network Coding (NC) to improve the performance of CC. The core mechanism to harness the benefits of NC-CC is to appropriately combine sessions into separate groups, and then have each group select the most beneficial relay node...

    Provided By Virginia Polytechnic Institute and State University

  • White Papers // May 2010

    Is Network Coding Always Good for Cooperative Communications?

    Network Coding (NC) is a promising approach to reduce time-slot overhead for Cooperative Communications (CC) in a multi-session environment. Most of the existing works take advantage of the benefits of NC in CC but do not fully recognize its potential adverse effect. In this paper, the authors show that employing...

    Provided By Virginia Polytechnic Institute and State University

  • White Papers // Feb 2011

    Efficient OFDM Denial: Pilot Jamming and Pilot Nulling

    Orthogonal Frequency Division Multiplexing (OFDM) uses pilot tones to estimate the channel's frequency response and perform equalization. It is commonly known that jamming pilot tones is more efficient than broadband attacks against an entire OFDM signal. This paper builds on this idea and introduces the pilot nulling attack, which is...

    Provided By Virginia Polytechnic Institute and State University

  • White Papers // Oct 2010

    On the Maximum Sum-Rate of Cognitive MIMO Interference Channels

    In this paper, the authors address the problem of maximizing the ergodic sum-rate of an N-user cognitive MIMO Interference Channel (IC) formed by unlicensed (or secondary) users. They assume that N secondary users coexist in the same area and try to access the same set of frequency bands. In such...

    Provided By Virginia Polytechnic Institute and State University

  • White Papers // Jan 2011

    Designing Energy Efficient Communication Runtime Systems for Data Centric Programming

    The insatiable demand of high performance computing is being driven by the most computationally intensive applications such as computational chemistry, climate modeling, nuclear physics, etc. The last couple of decades have observed a tremendous rise in supercomputers with architectures ranging from traditional clusters to system-on-a-chip in order to achieve the...

    Provided By Virginia Polytechnic Institute and State University

  • White Papers // May 2002

    Critical Infrastructures--Virginia's Challenge for the New Millennium

    This paper outlines some of the issues in power sector, and seeks to identify initial steps to develop a holistic approach at the state level in Virginia. At the state level, this demand is manifested in the call for higher levels of primary energy services, particularly electricity and natural gas,...

    Provided By Virginia Polytechnic Institute and State University

  • White Papers // Apr 2004

    Critical Programmatic Success Factors of Select Arts Programs for Older Adults

    The purpose of this study is to identify the pivotal factors contributing to programmatic success of arts programs for people, age sixty-five and older, in the United States. This study examines select programs within five arts disciplines: Elders Share the Arts (theatre), Museum One (visual art), Liz Lerman Dance Exchange...

    Provided By Virginia Polytechnic Institute and State University

  • White Papers // Jul 2002

    Zoomorphic Architecture: The Carolina Coastal Museum

    Throughout the evolution of man, the ocean has played an integral part in his survival. As technology has advanced so has man's use of the ocean. In order to preserve the history of these advancements for future generations, museums have been erected. The Carolina Coastal Museum is dedicated to the...

    Provided By Virginia Polytechnic Institute and State University

  • White Papers // Sep 2000

    Satellite Rural Telephone Network Design: A Methodology for Performance Optimization

    Rural telephony has historically been a recurring subject of concern for most large developing countries. It is generally considered that rural telephone users do not generate the same level of telephone traffic and, thus, revenue as urban users, lowering the incentives to invest in rural telecommunications. The financial implications of...

    Provided By Virginia Polytechnic Institute and State University

  • White Papers // Sep 2001

    The Sensory and Analytical Analyses of Nonfat Milk Formulations: Stability to Light Oxidation and Pasteurization

    Liquid sweet buttermilk used at relatively high percentages, 75%, in the formulation of a nonfat dairy beverage, does not contribute enough volatile compounds to improve the flavor of the beverage, as compared to the traditional nonfat milk formulated with cream and skim milk. The research explained in this paper concludes...

    Provided By Virginia Polytechnic Institute and State University

  • White Papers // Jul 2001

    Antibacterial Activity of Hydrogen Peroxide Against Escherichia Coli O157:H7 and Salmonella Spp. in Fruit Juices, Both Alone and in Combination With Organic Acids

    Fresh, unpasteurized fruit juices hold a favorable appeal to many consumers due to their distinct flavor characteristics and perceived nutritional superiority. Producers of unpasteurized juice have traditionally relied upon a juice's inherent acidity to render their product microbiologically safe. However, documented outbreaks of Salmonella and Escherichia. Coli O157:H7 associated with...

    Provided By Virginia Polytechnic Institute and State University

  • White Papers // May 2009

    Multi-Dimensional Characterization of Temporal Data Mining on Graphics Processors

    Through the algorithmic design patterns of data parallelism and task parallelism, the Graphics Processing Unit (GPU) offers the potential to vastly accelerate discovery and innovation across a multitude of disciplines. For example, the exponential growth in data volume now presents an obstacle for high-throughput data mining in fields such as...

    Provided By Virginia Polytechnic Institute and State University

  • White Papers // Nov 2008

    Overview of Emerging Broadband Wireless Technologies for Transportation

    Departments of Transportation depend considerably on communications between Intelligent Transportation Systems (ITS) field devices and Transportation Operations Centers (TOC). The future of transportation operations is expected to grow beyond just fixed devices to incorporate vehicle-to-vehicle and vehicle-to-roadside wireless communications. The interaction between vehicles, roadway management and critical roadway infrastructure will...

    Provided By Virginia Polytechnic Institute and State University

  • White Papers // Apr 2009

    Evaluation of Online Resources in Assisting Phishing Detection

    Phishing is an attempt to fraudulently acquire users' sensitive information, such as passwords or financial information, by masquerading as a trustworthy entity in online transactions. Recently, a number of researchers have proposed using external online resources like the Google PageRank system to assist phishing detection. The advantage of such an...

    Provided By Virginia Polytechnic Institute and State University

  • White Papers // Feb 2009

    Network Interface Cards as First-Class Citizens

    Network performance has improved by over an order-of-magnitude in the past decade. While, the overall system architecture itself has made modification attempts to match such growth, these changes are mostly "Incremental enhancements, tweaks and adjustments" that try to keep the hardware control hierarchy away from the network communication path. However,...

    Provided By Virginia Polytechnic Institute and State University

  • White Papers // Jan 2010

    Lightweight Data Management for Compositional Modeling in Problem Solving Environments

    The paper outlines various design considerations and implementation options pertaining to lightweight data management in Problem Solving Environments (PSEs). The emphasis is on compositional modeling, in the context of a PSE for wireless communications System Design (S W). By focusing on a restrictive subset of markup languages, the paper describes...

    Provided By Virginia Polytechnic Institute and State University

  • White Papers // Jun 2009

    The Green500 List: Year One

    The latest release of the Green500 List in November 2008 marked its one-year anniversary. As such, this paper aims to provide an analysis and retrospective examination of the Green500 List in order to understand how the list has evolved and what trends have emerged. In addition, the authors present community...

    Provided By Virginia Polytechnic Institute and State University

  • White Papers // Jan 2010

    Adaptive QoS Control Based on Benefit Optimization for Video Servers Providing Differentiated Services

    This paper proposes and analyzes Quality of Service (QoS) control algorithms for video servers designed to provide differentiated video streaming services. The design concepts are based on resource reservation and benefit optimization so that resources are reserved dynamically and adaptively for different QoS levels in response to the changing workload...

    Provided By Virginia Polytechnic Institute and State University

  • White Papers // Feb 2010

    Wireless Sensor Network Radio Power Management and Simulation Models

    Wireless Sensor Networks (WSNs) create a new frontier in collecting and processing data from remote locations. The IEEE 802.15.4 Wireless Personal Area Network-Low Rate (WPAN-LR) WSNs rely on hardware simplicity to make sensor field deployments both affordable and long-lasting without maintenance support. WSN designers strive to extend network lifetimes while...

    Provided By Virginia Polytechnic Institute and State University