George Washington University

Displaying 1-40 of 56 results

  • White Papers // Apr 2014

    Joint Latency and Cost Optimization for Erasure-coded Data Center Storage

    Modern distributed storage systems offer large capacity to satisfy the exponentially increasing need of storage space. They often use erasure codes to protect against disk and node failures to increase reliability, while trying to meet the latency requirements of the applications and clients. This paper provides an insightful upper bound...

    Provided By George Washington University

  • White Papers // Feb 2014

    NetVM: High Performance and Flexible Networking using Virtualization on Commodity Platforms

    NetVM brings virtualization to the network by enabling high bandwidth network functions to operate at near line speed, while taking advantage of the flexibility and customization of low cost commodity servers. NetVM allows customizable data plane processing capabilities such as firewalls, proxies, and routers to be embedded within virtual machines,...

    Provided By George Washington University

  • White Papers // Mar 2013

    Mortar: Filling the Gaps in Data Center Memory

    Data center servers are typically over provisioned, leaving spare memory and CPU capacity idle to handle unpredictable workload bursts by the virtual machines running on them. While this allows for fast hotspot mitigation, it is also wasteful. Unfortunately, making use of spare capacity without impacting active applications is particularly difficult...

    Provided By George Washington University

  • White Papers // Mar 2013

    CacheDriver: Hypervisor Managed Data Storage in RAM and Flash

    Application and OS-level caches are crucial for hiding the I/O latency and improving application performance. However, caches are designed to greedily consume memory, which can cause problems in virtualized data centers since the hypervisor cannot tell what a virtual machine uses its memory for. To improve this situation, the authors...

    Provided By George Washington University

  • White Papers // Feb 2013

    Benefits and Challenges of Managing Heterogeneous Data Centers

    Today's businesses have a wealth of options available to them for running their applications. They can use proprietary infrastructures, private data centers, co-location facilities, or public clouds. Applications can be deployed on native hardware or virtualization can be used to improve consolidation and manageability. Public cloud platforms are growing in...

    Provided By George Washington University

  • White Papers // Jan 2013

    OPFKA: Secure and Efficient Ordered-Physiological-Feature-Based Key Agreement for Wireless Body Area Networks

    Body Area Networks (BANs) are expected to play a major role in patient health monitoring in the near future. Providing an efficient key agreement with the prosperities of plug-in-play and transparency to support secure inter-sensor communications is critical especially during the stages of network initialization and reconfiguration. In this paper,...

    Provided By George Washington University

  • White Papers // Jan 2013

    Cooperative Multi-Hop Relaying Via Network Formation Games in Cognitive Radio Networks

    The cooperation between the primary and the secondary users has attracted a lot of attention in cognitive radio networks. However, most existing research mainly focuses on the single-hop relay selection for a primary transmitter-receiver pair, which might not be able to fully explore the benefit brought by cooperative transmissions. In...

    Provided By George Washington University

  • White Papers // Jan 2013

    Channel Quality Prediction Based on Bayesian Inference in Cognitive Radio Networks

    The problem of channel quality prediction in cognitive radio networks is investigated in this paper. First, the spectrum sensing process is modeled as a Non-Stationary Hidden Markov Model (NSHMM), which captures the fact that the channel state transition probability is a function of the time interval the primary user has...

    Provided By George Washington University

  • White Papers // Nov 2012

    Improving Hybrid FSO/RF Network Reliability Through Transceiver Reconfiguration

    Despite the increasing popularity of Free-Space Optics (FSO) in wireless mesh networks, reliability is still a major concern. Due to the strong dependence of FSO link availability on weather conditions (e.g., fog, cloud, air turbulence) using RF links is inevitable, both for backup and signaling. In addition, reconfiguration of FSO...

    Provided By George Washington University

  • White Papers // Nov 2012

    Software Selection based on Quantitative Security Risk Assessment

    In this paper, the authors present a software product evaluation method using such a quantitative security risk assessment model. This method utilizes prior research in quantitative security risk assessment, which is based on empirical data from the National Vulnerability Database (NVD), and compares the security risk levels of the products...

    Provided By George Washington University

  • White Papers // Sep 2012

    Spectrum Assignment and Sharing for Delay Minimization in Multi-Hop Multi-Flow CRNs

    This paper investigates the problem of spectrum assignment and sharing to minimize the total delay of multiple concurrent flows in multi-hop cognitive radio networks. The authors first analyze the expected per-hop delay, which incorporates the sensing delay and transmission delay characterizing the PU activities and spectrum capacities. Then they formulate...

    Provided By George Washington University

  • White Papers // Sep 2012

    Towards Efficient GPU Sharing on Multicore Processors

    Scalable systems employing a mix of GPUs with CPUs are becoming increasingly prevalent in high-performance computing. The presence of such accelerators introduces significant challenges and complexities to both language developers and end users. This paper provides a close study of efficient coordination mechanisms to handle parallel requests from multiple hosts...

    Provided By George Washington University

  • White Papers // Jul 2012

    Achievable Transmission Capacity of Cognitive Radio Networks With Cooperative Relaying

    Previous research on cognitive networks argues that secondary users can only work under a low transmission power condition in an underlay spectrum sharing model. Motivated by the idea of cooperative communications, in this paper the authors investigate the achievable transmission capacity of a cognitive network that provides cooperative relaying to...

    Provided By George Washington University

  • White Papers // Jun 2012

    RePRAM: Re-cycling PRAM Faulty Blocks for Extended Lifetime

    As main memory systems begin to face the scaling challenges from DRAM technology, future computer systems need to adapt to the emerging memory technologies like Phase-Change Memory (PCM). While these newer technologies offer advantages such as storage density, non-volatility, and low energy consumption, they are constrained by limited write endurance...

    Provided By George Washington University

  • White Papers // Jun 2012

    Enterprise-Ready Virtual Cloud Pools: Vision, Opportunities and Challenges

    Cloud computing platforms such as Amazon EC2 provide customers with flexible, on-demand resources at low cost. However, while existing offerings are useful for providing basic computation and storage resources, they have not provided the transparency, security and network controls that many enterprise customers would like. While cloud computing has a...

    Provided By George Washington University

  • White Papers // May 2012

    Cross-Layer RWA in Translucent Optical Networks

    Wavelength Division Multiplexing (WDM)-based optical networks are ideal candidates for core backbone networks because of their ability to carry large amounts of traffic. Optical amplification has increased the reach of long-haul optical links. Nevertheless, it is impossible today to construct a truly optical network without converting optical signals to electrical...

    Provided By George Washington University

  • White Papers // May 2012

    Verifiable Multi-Secret Sharing Based on LFSR Sequences

    In Verifiable Multi-Secret Sharing schemes (VMSSs), many secrets can be shared but only one share is kept by each user and this share is verifiable by others. In this paper, the authors propose two secure, efficient, and verifiable (t; n) multi-secret sharing schemes, namely Scheme-I and Scheme-II. Scheme-I is based...

    Provided By George Washington University

  • White Papers // May 2012

    Model based Testing for Software Systems: An Application of Markov Modulated Markov Process

    Software systems require the validation of design features through regression testing. Two primary challenges in system validation are ensuring that test suites reflect actual system usage, and managing the test suite size to keep testing costs low while keeping testing results meaningful. To create a test environment that is close...

    Provided By George Washington University

  • White Papers // Feb 2012

    Providing Reliability as an Elastic Service in Cloud Computing

    Modern day data centers coordinate hundreds of thousands of heterogeneous tasks and aim at delivering highly reliable cloud computing services. Although offering equal reliability to all users benefits everyone at the same time, users may find such an approach either too inadequate or too expensive to fit their individual requirements,...

    Provided By George Washington University

  • White Papers // Jan 2012

    Maximizing Throughput When Achieving Time Fairness in Multi-Rate Wireless LANs

    This paper focuses on designing a distributed medium access control algorithm that aims at achieving time fairness among contending stations and throughput maximization in an 802.11 wireless LAN. The core idea of the authors' proposed algorithm lies in that each station needs to select an appropriate contention window size so...

    Provided By George Washington University

  • White Papers // Jan 2012

    Achievable Transmission Capacity of Cognitive Mesh Networks With Different Media Access Control

    Spectrum sharing is an emerging mechanism to resolve the conflict between the spectrum scarcity and the growing demands for the wireless broadband access. In this paper, the authors investigate the achievable transmission capacity of a wireless backhaul mesh network that shares the spectrums of the underutilized cellular uplink over the...

    Provided By George Washington University

  • White Papers // Jan 2012

    A Statistical Approach for Target Counting in Sensor-Based Surveillance Systems

    Target counting in sensor-based surveillance systems is an interesting task that potentially could have many important applications in practice. In such a system, each sensor outputs the number of targets in its sensing region, and the problem is how one can combine all the reported numbers from sensors to provide...

    Provided By George Washington University

  • White Papers // Jan 2012

    Traffic Clustering and Online Traffic Prediction in Vehicle Networks: A Social Influence Perspective

    In this paper, the authors investigate the dynamic traffic relationship characterized by a similarity value from one road point to another in vehicle networks. Due to the regularity of human mobility, traffic exhibits strong correlations in both temporal domain and spatial domain. By exploiting the similarity values, they derive application-specific...

    Provided By George Washington University

  • White Papers // Jan 2012

    Joint VM Placement and Routing for Data Center Traffic Engineering

    Today's data centers need efficient traffic management to improve resource utilization in their networks. In this paper, the authors study a joint tenant (e.g., server or virtual machine) placement and routing problem to minimize traffic costs. These two complementary degrees of freedom - placement and routing - are mutually-dependent, however,...

    Provided By George Washington University

  • White Papers // Dec 2011

    The Need for Power Debugging in the Multi-Core Environment

    Multi-core processors have fueled computing performance to greater scales by offering parallelism on chip. Debugging an application for power has a wide array of benefits ranging from minimizing the thermal hotspots to reducing the likelihood of CPU malfunction. In this paper, the authors justify the need for power debugging, and...

    Provided By George Washington University

  • White Papers // Nov 2011

    TRACON: Interference-Aware Scheduling for Data-Intensive Applications in Virtualized Environments

    Large-scale data centers leverage virtualization technology to achieve excellent resource utilization, scalability, and high availability. Ideally, the performance of an application running inside a Virtual Machine (VM) shall be independent of co-located applications and VMs that share the physical machine. However, adverse interference effects exist and are especially severe for...

    Provided By George Washington University

  • White Papers // Aug 2011

    RPRAM: Exploring Redundancy Techniques to Improve Lifetime of PCM-Based Main Memory

    Future main memory systems will confront the scaling challenges posed by DRAM technology and should adapt themselves to use the emerging memory technologies like Phase Change Memory (PCM, or PRAM). PCM offers advantages such as storage density, non-volatility, and lower energy consumption. However, they are constrained by limited write endurance...

    Provided By George Washington University

  • White Papers // Apr 2011

    Exploiting Concurrent Kernel Execution on Graphic Processing Units

    Graphics Processing Units (GPUs) have been accepted as a powerful and viable coprocessor solution in high-performance computing domain. In order to maximize the benefit of GPUs for a multicore platform, a mechanism is needed for CPU threads in a parallel application to share this computing resource for efficient execution. NVIDIA's...

    Provided By George Washington University

  • White Papers // Apr 2011

    Performance Modeling and Analysis of Flash-Based Storage Devices

    Flash-based Solid-State Drives (SSDs) will become key components in future storage systems. An accurate performance model will not only help understand the state-of-the-art of SSDs, but also provide the research tools for exploring the design space of such storage systems. Although over the years many performance models were developed for...

    Provided By George Washington University

  • White Papers // Mar 2011

    A Monte Carlo Method for Mobile Target Counting

    This paper addresses the problem of target counting based on the Monte Carlo simulation. The authors rely on an Accept-Reject process to guide the placement of virtual targets in a virtual sensor field, which has exactly the same sensor layout as the real one. The objective of this construction is...

    Provided By George Washington University

  • White Papers // Jan 2011

    Sparse Target Counting and Localization in Sensor Networks Based on Compressive Sensing

    In this paper, the authors propose a novel Compressive Sensing (CS) based approach for sparse target counting and positioning in wireless sensor networks. While this is not the first work on applying CS to count and localize targets, it is the first to rigorously justify the validity of the problem...

    Provided By George Washington University

  • White Papers // Jan 2011

    Predictive Scheduling in Multi-Carrier Wireless Networks With Link Adaptation

    Channel-aware scheduling and link adaptation methods are widely considered to be crucial for realizing high data rates in wireless networks. However, predicting the future channel states, and adjusting the transmission schedules and parameters accordingly, may consume valuable system resources, such as bandwidth, time, and power. This paper considers the trade-offs...

    Provided By George Washington University

  • White Papers // Feb 2010

    How China's Employment Problems Became Trade Problems: China, Labour Law And The Rule Of Law

    In this paper, the author focuses on the potential trade spillovers of Chinese policies to maintain employment. Chinese leaders are determined to maintain employment and have long ignored employment laws that could empower workers. But in 2007, China reformed its labor laws and allowed wide public comment. The new laws...

    Provided By George Washington University

  • White Papers // Jan 2010

    Innovation Project Participants Interaction Optimization Models

    Based on the game theory principles and approaches, this paper suggests mathematical and computer simulation models of innovation process participants interaction to effectively stimulate creativeinnovative activity of innovation project implementers. The optimal solutions of the problem of innovation project profit sharing are determined for the situations of uncertainty of participants'...

    Provided By George Washington University

  • White Papers // Jan 2010

    Efficient Alarm Management in Optical Networks

    As the capacity of optical transport networks increases, rapid fault identification and localization become increasingly important. These problems are more challenging than in traditional electronic networks because of optical transparency. In a transparent optical network which does not regenerate optical signals, a fault may propagate to various parts of the...

    Provided By George Washington University

  • White Papers // Jan 2010

    Survivability for All-Optical Network Against Optical Attacks

    The use of optical technology, in particular Wavelength Division Multiplexing (WDM), has revolutionized the transmission of voice and data. An enormous and easily accessible bandwidth is available today with the utilization of the considerable optical capacity of the fiber. On the other hand, the optical domain introduces its own set...

    Provided By George Washington University

  • White Papers // Jan 2010

    Hardware-Aware Communication Protocols in Low Energy Wireless Sensor Networks

    As the energy consumption in sensor nodes is dominated by the radio transmission/reception circuitry, communication protocols must be designed for economy in radio communications. Sensor nodes are generally equipped with short-range radios that have various characteristics including data rate, power consumption in transmit, receive, and sleep modes, and time to...

    Provided By George Washington University

  • White Papers // Aug 2009

    3DLoc2: Three Dimensional Localization and Locking Toolkits for Tracing Anonymous Wireless Criminals

    Network forensics plays a crucial role for public safety and homeland security. A critical challenge, however, is the fact that criminals may leverage the open wireless networks provided by many hotels, restaurants, libraries, etc to hide their physical locations even when their network identities are revealed. Motivated by the pressing...

    Provided By George Washington University

  • White Papers // Aug 2009

    HiCloud: Taming Clouds on the Clouds

    In this paper, the authors aim to extend current computationally-intensive weather forecasting research on geographically distributed resources for faster results delivery and improved scalability. To achieve this goal they take advantage of the emerging cloud computing paradigm to enable very large-scale weather forecasting applications in the proposed cloud infrastructure. Such...

    Provided By George Washington University

  • White Papers // Aug 2009

    Two Hundred Years Of Financial Integration: Latin America Since Independence

    The author collects a new database on Latin America's international issuance from 1820 to 1931 in the major financial centers of that time: London, Paris, Berlin, Frankfurt, and New York. This database includes individual sovereign bonds and loans as well as bonds, loans, and equities issued by private corporations. The...

    Provided By George Washington University

  • White Papers // Mar 2004

    Developing Greater Flexibility and Resolution in Aviation Accident Analyses

    Priorities in aviation safety have been largely influenced by a few published safety summaries compiled from the worldwide objective fatal accident data record which tend to aggregate data into broad categories that cross regional, aircraft and operational boundaries. Derived safety concerns are often interpreted as being representative of (and transferable...

    Provided By George Washington University

  • White Papers // Jan 2010

    Efficient Alarm Management in Optical Networks

    As the capacity of optical transport networks increases, rapid fault identification and localization become increasingly important. These problems are more challenging than in traditional electronic networks because of optical transparency. In a transparent optical network which does not regenerate optical signals, a fault may propagate to various parts of the...

    Provided By George Washington University

  • White Papers // Jan 2010

    Survivability for All-Optical Network Against Optical Attacks

    The use of optical technology, in particular Wavelength Division Multiplexing (WDM), has revolutionized the transmission of voice and data. An enormous and easily accessible bandwidth is available today with the utilization of the considerable optical capacity of the fiber. On the other hand, the optical domain introduces its own set...

    Provided By George Washington University

  • White Papers // Jan 2010

    Hardware-Aware Communication Protocols in Low Energy Wireless Sensor Networks

    As the energy consumption in sensor nodes is dominated by the radio transmission/reception circuitry, communication protocols must be designed for economy in radio communications. Sensor nodes are generally equipped with short-range radios that have various characteristics including data rate, power consumption in transmit, receive, and sleep modes, and time to...

    Provided By George Washington University

  • White Papers // Jan 2010

    Innovation Project Participants Interaction Optimization Models

    Based on the game theory principles and approaches, this paper suggests mathematical and computer simulation models of innovation process participants interaction to effectively stimulate creativeinnovative activity of innovation project implementers. The optimal solutions of the problem of innovation project profit sharing are determined for the situations of uncertainty of participants'...

    Provided By George Washington University

  • White Papers // Apr 2009

    Alternate Multihop Routing in Limited Reconfigurable Optical Networks

    In this paper, authors investigate the performance of limited reconfigurable optical networks when multihopping is used. Multihopping is achieved by dropping a wavelength at an intermediate node and transmitting on another wavelength at that node (O-E-O). A route can consist of several such hops each obeying the wavelength continuity constraint...

    Provided By George Washington University

  • White Papers // Feb 2009

    Developing ERP Systems Success Model For The Construction Industry

    Recently, a significant number of major construction companies embarked on the implementation of integrated information technology solutions such as enterprise resource planning ERP systems to better integrate various business functions. However, these integrated systems in the construction sector present a set of unique challenges, different from those in the manufacturing...

    Provided By George Washington University

  • White Papers // Dec 2008

    Electricity Transmission Sector In Brazil - Analysis Of The Auctions' Results And The Public And Private Firms' Costs

    In Brazil, most of the electricity used by households and industries is supplied by hydropower plants. In general these plants are built on rivers with natural waterfalls that are usually very far from Brazilian consumers. Such technical constraint requires a high-power transmission infrastructure to convey the electricity produced to the...

    Provided By George Washington University

  • White Papers // Mar 2009

    CAP: A Context-Aware Privacy Protection System for Location-Based Services

    The authors address issues related to privacy protection in Location-Based Services (LBS). Most existing research in this field either requires a trusted third-party or uses oblivious protocols which are computationally and communicationally expensive. The design of privacy-preserving techniques is principled on not requiring a trusted third-party while being highly efficient...

    Provided By George Washington University

  • White Papers // Mar 2009

    The Digital Marauder's Map: A New Threat to Location Privacy

    The Marauder's Map is a magical map in J. K. Rowling's fantasy series, "Harry Potter and the Prisoner of Azkaban". It shows all moving objects within the "Hogwarts School of Witchcraft and Wizardry". This paper introduces a similar attack to location privacy in wireless networks. The system, namely the digital...

    Provided By George Washington University

  • White Papers // Aug 2009

    3DLoc2: Three Dimensional Localization and Locking Toolkits for Tracing Anonymous Wireless Criminals

    Network forensics plays a crucial role for public safety and homeland security. A critical challenge, however, is the fact that criminals may leverage the open wireless networks provided by many hotels, restaurants, libraries, etc to hide their physical locations even when their network identities are revealed. Motivated by the pressing...

    Provided By George Washington University

  • White Papers // Jun 2009

    Using the PGAS Programming Paradigm for Biological Sequence Alignment on a Chip Multi-Threading Architecture

    The Partitioned Global Address Space (PGAS) programming paradigm offers ease-of-use in expressing parallelism through a global shared address space while emphasizing performance by providing locality awareness through the partitioning of this address space. Therefore, the interest in PGAS programming languages is growing and many new languages have emerged and are...

    Provided By George Washington University

  • White Papers // Aug 2009

    Two Hundred Years Of Financial Integration: Latin America Since Independence

    The author collects a new database on Latin America's international issuance from 1820 to 1931 in the major financial centers of that time: London, Paris, Berlin, Frankfurt, and New York. This database includes individual sovereign bonds and loans as well as bonds, loans, and equities issued by private corporations. The...

    Provided By George Washington University

  • White Papers // Feb 2010

    How China's Employment Problems Became Trade Problems: China, Labour Law And The Rule Of Law

    In this paper, the author focuses on the potential trade spillovers of Chinese policies to maintain employment. Chinese leaders are determined to maintain employment and have long ignored employment laws that could empower workers. But in 2007, China reformed its labor laws and allowed wide public comment. The new laws...

    Provided By George Washington University

  • White Papers // Jan 2011

    Predictive Scheduling in Multi-Carrier Wireless Networks With Link Adaptation

    Channel-aware scheduling and link adaptation methods are widely considered to be crucial for realizing high data rates in wireless networks. However, predicting the future channel states, and adjusting the transmission schedules and parameters accordingly, may consume valuable system resources, such as bandwidth, time, and power. This paper considers the trade-offs...

    Provided By George Washington University

  • White Papers // Mar 2011

    A Monte Carlo Method for Mobile Target Counting

    This paper addresses the problem of target counting based on the Monte Carlo simulation. The authors rely on an Accept-Reject process to guide the placement of virtual targets in a virtual sensor field, which has exactly the same sensor layout as the real one. The objective of this construction is...

    Provided By George Washington University

  • White Papers // Jan 2011

    Sparse Target Counting and Localization in Sensor Networks Based on Compressive Sensing

    In this paper, the authors propose a novel Compressive Sensing (CS) based approach for sparse target counting and positioning in wireless sensor networks. While this is not the first work on applying CS to count and localize targets, it is the first to rigorously justify the validity of the problem...

    Provided By George Washington University

  • White Papers // Nov 2011

    TRACON: Interference-Aware Scheduling for Data-Intensive Applications in Virtualized Environments

    Large-scale data centers leverage virtualization technology to achieve excellent resource utilization, scalability, and high availability. Ideally, the performance of an application running inside a Virtual Machine (VM) shall be independent of co-located applications and VMs that share the physical machine. However, adverse interference effects exist and are especially severe for...

    Provided By George Washington University

  • White Papers // Apr 2011

    Performance Modeling and Analysis of Flash-Based Storage Devices

    Flash-based Solid-State Drives (SSDs) will become key components in future storage systems. An accurate performance model will not only help understand the state-of-the-art of SSDs, but also provide the research tools for exploring the design space of such storage systems. Although over the years many performance models were developed for...

    Provided By George Washington University

  • White Papers // Jan 2012

    Achievable Transmission Capacity of Cognitive Mesh Networks With Different Media Access Control

    Spectrum sharing is an emerging mechanism to resolve the conflict between the spectrum scarcity and the growing demands for the wireless broadband access. In this paper, the authors investigate the achievable transmission capacity of a wireless backhaul mesh network that shares the spectrums of the underutilized cellular uplink over the...

    Provided By George Washington University

  • White Papers // Jan 2012

    A Statistical Approach for Target Counting in Sensor-Based Surveillance Systems

    Target counting in sensor-based surveillance systems is an interesting task that potentially could have many important applications in practice. In such a system, each sensor outputs the number of targets in its sensing region, and the problem is how one can combine all the reported numbers from sensors to provide...

    Provided By George Washington University

  • White Papers // Jan 2012

    Traffic Clustering and Online Traffic Prediction in Vehicle Networks: A Social Influence Perspective

    In this paper, the authors investigate the dynamic traffic relationship characterized by a similarity value from one road point to another in vehicle networks. Due to the regularity of human mobility, traffic exhibits strong correlations in both temporal domain and spatial domain. By exploiting the similarity values, they derive application-specific...

    Provided By George Washington University

  • White Papers // Jan 2012

    Maximizing Throughput When Achieving Time Fairness in Multi-Rate Wireless LANs

    This paper focuses on designing a distributed medium access control algorithm that aims at achieving time fairness among contending stations and throughput maximization in an 802.11 wireless LAN. The core idea of the authors' proposed algorithm lies in that each station needs to select an appropriate contention window size so...

    Provided By George Washington University

  • White Papers // Feb 2012

    Providing Reliability as an Elastic Service in Cloud Computing

    Modern day data centers coordinate hundreds of thousands of heterogeneous tasks and aim at delivering highly reliable cloud computing services. Although offering equal reliability to all users benefits everyone at the same time, users may find such an approach either too inadequate or too expensive to fit their individual requirements,...

    Provided By George Washington University

  • White Papers // Aug 2011

    RPRAM: Exploring Redundancy Techniques to Improve Lifetime of PCM-Based Main Memory

    Future main memory systems will confront the scaling challenges posed by DRAM technology and should adapt themselves to use the emerging memory technologies like Phase Change Memory (PCM, or PRAM). PCM offers advantages such as storage density, non-volatility, and lower energy consumption. However, they are constrained by limited write endurance...

    Provided By George Washington University

  • White Papers // Apr 2009

    Time-Synchronization Free Localization in Large Scale Underwater Acoustic Sensor Networks

    The authors introduce and study the localization problem in large scale underwater acoustic sensor networks. Considering that depth information is typically available for underwater sensors, they transform the 3D underwater positioning problem into its two-dimensional counterpart via a projection technique. They, then introduce a localization scheme specifically designed for large...

    Provided By George Washington University

  • White Papers // May 2012

    Verifiable Multi-Secret Sharing Based on LFSR Sequences

    In Verifiable Multi-Secret Sharing schemes (VMSSs), many secrets can be shared but only one share is kept by each user and this share is verifiable by others. In this paper, the authors propose two secure, efficient, and verifiable (t; n) multi-secret sharing schemes, namely Scheme-I and Scheme-II. Scheme-I is based...

    Provided By George Washington University

  • White Papers // Nov 2012

    Software Selection based on Quantitative Security Risk Assessment

    In this paper, the authors present a software product evaluation method using such a quantitative security risk assessment model. This method utilizes prior research in quantitative security risk assessment, which is based on empirical data from the National Vulnerability Database (NVD), and compares the security risk levels of the products...

    Provided By George Washington University

  • White Papers // Nov 2012

    Improving Hybrid FSO/RF Network Reliability Through Transceiver Reconfiguration

    Despite the increasing popularity of Free-Space Optics (FSO) in wireless mesh networks, reliability is still a major concern. Due to the strong dependence of FSO link availability on weather conditions (e.g., fog, cloud, air turbulence) using RF links is inevitable, both for backup and signaling. In addition, reconfiguration of FSO...

    Provided By George Washington University

  • White Papers // May 2012

    Model based Testing for Software Systems: An Application of Markov Modulated Markov Process

    Software systems require the validation of design features through regression testing. Two primary challenges in system validation are ensuring that test suites reflect actual system usage, and managing the test suite size to keep testing costs low while keeping testing results meaningful. To create a test environment that is close...

    Provided By George Washington University

  • White Papers // Jun 2012

    Enterprise-Ready Virtual Cloud Pools: Vision, Opportunities and Challenges

    Cloud computing platforms such as Amazon EC2 provide customers with flexible, on-demand resources at low cost. However, while existing offerings are useful for providing basic computation and storage resources, they have not provided the transparency, security and network controls that many enterprise customers would like. While cloud computing has a...

    Provided By George Washington University

  • White Papers // Jan 2012

    Joint VM Placement and Routing for Data Center Traffic Engineering

    Today's data centers need efficient traffic management to improve resource utilization in their networks. In this paper, the authors study a joint tenant (e.g., server or virtual machine) placement and routing problem to minimize traffic costs. These two complementary degrees of freedom - placement and routing - are mutually-dependent, however,...

    Provided By George Washington University

  • White Papers // Sep 2012

    Spectrum Assignment and Sharing for Delay Minimization in Multi-Hop Multi-Flow CRNs

    This paper investigates the problem of spectrum assignment and sharing to minimize the total delay of multiple concurrent flows in multi-hop cognitive radio networks. The authors first analyze the expected per-hop delay, which incorporates the sensing delay and transmission delay characterizing the PU activities and spectrum capacities. Then they formulate...

    Provided By George Washington University

  • White Papers // Jan 2013

    Cooperative Multi-Hop Relaying Via Network Formation Games in Cognitive Radio Networks

    The cooperation between the primary and the secondary users has attracted a lot of attention in cognitive radio networks. However, most existing research mainly focuses on the single-hop relay selection for a primary transmitter-receiver pair, which might not be able to fully explore the benefit brought by cooperative transmissions. In...

    Provided By George Washington University

  • White Papers // Jan 2013

    OPFKA: Secure and Efficient Ordered-Physiological-Feature-Based Key Agreement for Wireless Body Area Networks

    Body Area Networks (BANs) are expected to play a major role in patient health monitoring in the near future. Providing an efficient key agreement with the prosperities of plug-in-play and transparency to support secure inter-sensor communications is critical especially during the stages of network initialization and reconfiguration. In this paper,...

    Provided By George Washington University

  • White Papers // Jan 2013

    Channel Quality Prediction Based on Bayesian Inference in Cognitive Radio Networks

    The problem of channel quality prediction in cognitive radio networks is investigated in this paper. First, the spectrum sensing process is modeled as a Non-Stationary Hidden Markov Model (NSHMM), which captures the fact that the channel state transition probability is a function of the time interval the primary user has...

    Provided By George Washington University

  • White Papers // Aug 2009

    HiCloud: Taming Clouds on the Clouds

    In this paper, the authors aim to extend current computationally-intensive weather forecasting research on geographically distributed resources for faster results delivery and improved scalability. To achieve this goal they take advantage of the emerging cloud computing paradigm to enable very large-scale weather forecasting applications in the proposed cloud infrastructure. Such...

    Provided By George Washington University

  • White Papers // Nov 2001

    Modeling Risk in the Dynamic Environment of Maritime Transportation

    The Washington State Ferries are one of the largest ferry systems in the world. Accidents involving Washington State Ferries are rare events. Due to the infrequent occurrence of such accidents, large accident databases are not available for a standard statistical analysis of the contribution of perceived risk factors to accident...

    Provided By George Washington University

  • White Papers // Jul 2012

    Achievable Transmission Capacity of Cognitive Radio Networks With Cooperative Relaying

    Previous research on cognitive networks argues that secondary users can only work under a low transmission power condition in an underlay spectrum sharing model. Motivated by the idea of cooperative communications, in this paper the authors investigate the achievable transmission capacity of a cognitive network that provides cooperative relaying to...

    Provided By George Washington University

  • White Papers // May 2012

    Cross-Layer RWA in Translucent Optical Networks

    Wavelength Division Multiplexing (WDM)-based optical networks are ideal candidates for core backbone networks because of their ability to carry large amounts of traffic. Optical amplification has increased the reach of long-haul optical links. Nevertheless, it is impossible today to construct a truly optical network without converting optical signals to electrical...

    Provided By George Washington University