North Carolina State University

Displaying 81-120 of 217 results

  • White Papers // Nov 2011

    Time-Traveling Forensic Analysis of VM-Based High-Interaction Honeypots

    Honeypots have proven to be an effective tool to capture computer intrusions (or malware infections) and analyze their exploitation techniques. However, forensic analysis of compromised honeypots is largely an ad-hoc and manual process. In this paper, the authors propose Timescope, a system that applies and extends recent advances in deterministic...

    Provided By North Carolina State University

  • White Papers // Oct 2011

    AutoGeneration of Communication Benchmark Traces

    Benchmarks are essential for evaluating HPC hardware and software for petascale machines and beyond. But benchmark creation is a tedious manual process. As a result, benchmarks tend to lag behind the development of complex scientific codes. The authors' paper automates the creation of communication benchmarks. Given an MPI application, they...

    Provided By North Carolina State University

  • White Papers // Sep 2011

    A Tunable, Software-based DRAM Error Detection and Correction Library for HPC

    Proposed exascale systems will present a number of considerable resiliency challenges. In particular, DRAM soft-errors, or bit-flips, are expected to greatly increase due to the increased memory density of these systems. Current hardware-based fault-tolerance methods will be unsuitable for addressing the expected soft error frequency rate. As a result, additional...

    Provided By North Carolina State University

  • White Papers // Sep 2011

    Hybrid Resource Allocation Scheme in Two-Hop Relaying WiMAX Networks

    In this paper, the authors consider resource allocation schemes in two-hop relaying WiMAX networks in order to maximize cell throughput, while serving the Subscriber Stations (SSs) in a fair manner. First they present two well-known schemes, namely, orthogonal and overlapped, according to the frequency reuse during the access zone intervals...

    Provided By North Carolina State University

  • White Papers // Sep 2011

    CloudScale: Elastic Resource Scaling for Multi-Tenant Cloud Systems

    Elastic resource scaling lets cloud systems meet application Service Level Objectives (SLOs) with minimum resource provisioning costs. In this paper, the authors present CloudScale, a system that automates finegrained elastic resource scaling for multi-tenant cloud computing infrastructures. CloudScale employs online resource demand prediction and prediction error handling to achieve adaptive...

    Provided By North Carolina State University

  • White Papers // Aug 2011

    Memory Trace Compression and Replay for SPMD Systems using Extended PRSDs

    Concurrency levels in large-scale supercomputers are rising exponentially, and shared-memory nodes with hundreds of cores and non-uniform memory access latencies are expected within the next decade. However, even current petascale systems with tens of cores per node suffer from memory bottlenecks. As core counts increase, memory issues will become critical...

    Provided By North Carolina State University

  • White Papers // Aug 2011

    Distributed Spectrum-Aware Clustering in Cognitive Radio Sensor Networks

    A novel Distributed Spectrum-Aware Clustering (DSAC) scheme is proposed in the context of Cognitive Radio Sensor Networks (CRSN). DSAC aims at forming energy efficient clusters in a self-organized fashion while restricting interference to Primary User (PU) systems. The spectrum-aware clustered structure is presented where the communications consist of intra-cluster aggregation...

    Provided By North Carolina State University

  • White Papers // Jul 2011

    A Flow-Based Centrality Measure Through Resistance Distances in Smart-Grid Networks

    The authors propose methods to estimate centrality in Smart-Grid Networks (SGNs) from the view of a flow-based approach. In several network categories, centrality metrics, such as degree, closeness and betweenness, have provided ways to investigate the importance or weakness of components. These well-known metrics utilize either non-global or shortest-path information....

    Provided By North Carolina State University

  • White Papers // Jul 2011

    Evaluation of SIP Proxy Server Performance: Packet-Level Measurements and Queuing Model

    The growing number of applications that use the Session Initiation Protocol (SIP) to manage media sessions over IP is placing increasing demands on the SIP Proxy Servers (SPS) that make up the core of the SIP network. In this paper, the authors investigate the performance of OpenSIPS, an open source...

    Provided By North Carolina State University

  • White Papers // Jul 2011

    Optimal Max-Min Fair Resource Allocation in Multihop Relay-Enhanced WiMAX Networks

    In this paper, an optimal resource allocation scheme is proposed for WiMAX networks enhanced with non-transparent Relay Stations (RSs). The authors first focus on two-hop relaying networks, since this scenario has the largest throughput gain. Furthermore, many researchers have proposed different resource allocation schemes in two-hop relaying networks, and, thus,...

    Provided By North Carolina State University

  • White Papers // Jul 2011

    IEEE 802.11 Saturation Throughput Analysis in the Presence of Hidden Terminals

    Due to its usefulness and wide deployment, IEEE 802.11 has been the subject of numerous studies but still lacks a complete analytical model. Hidden terminals are common in IEEE 802.11 and cause the degradation of throughput. Despite the importance of the hidden terminal problem, there have been a relatively small...

    Provided By North Carolina State University

  • White Papers // Jun 2011

    On the Expressiveness of Return-Into-Libc Attacks

    Return-Into-LibC (RILC) is one of the most common forms of code-reuse attacks. In this attack, an intruder uses a buffer overflow or other exploit to redirect control flow through existing (libc) functions within the legitimate program. While dangerous, it is generally considered limited in its expressive power since it only...

    Provided By North Carolina State University

  • White Papers // Jun 2011

    GStream: A General-Purpose Data Streaming Framework on GPU Clusters

    Emerging accelerating architectures, such as GPUs, have proved successful in providing significant performance gains to various application domains. However, their viability to operate on general streaming data is still ambiguous. In this paper, the authors propose GStream, a general-purpose, scalable data streaming framework on GPUs. The contributions of GStream are...

    Provided By North Carolina State University

  • White Papers // Jun 2011

    A Fault Observant Real-Time Embedded Design for Network-on-Chip Control Systems

    Performance and time to market requirements cause many real-time designers to consider Components, Off The Shelf (COTS) for real-time systems. Massive multi-core embedded processors with Network-on-Chip (NoC) designs to facilitate core-to-core communication are becoming common in COTS. These architectures benefit real-time scheduling, but they also pose predictability challenges. In this...

    Provided By North Carolina State University

  • White Papers // Jun 2011

    EMFS: Email-Based Personal Cloud Storage

    Though a variety of cloud storage services have been offered recently, they have not yet provided users with transparent and cost-effective personal data storage. Services like Google Docs offer easy file access and sharing, but tie storage with internal data formats and specific applications. Meanwhile, services like Dropbox offer general-purpose...

    Provided By North Carolina State University

  • White Papers // May 2011

    Detecting Concurrency-Related Problematic Activity Arrangement in WS-BPEL Programs

    A composite web service often interacts with several partner web services hosted in different servers. These partner web services are represented as activities in a WS-BPEL program describing the composite web service. Invoking the maximal number of these activities concurrently is essential for improving its performance. But complex message coupling...

    Provided By North Carolina State University

  • White Papers // Apr 2011

    Static Task Partitioning for Locked Caches in Multi-Core Real-Time Systems

    Massive multi-core architectures with tens of cores are becoming more prevalent in embedded systems. However, their acceptance in the real-time systems domain is rather low due to challenges in system analysis and predictability. Recent real-time systems research has focused on shared cache architectures. In such systems, tasks across all cores...

    Provided By North Carolina State University

  • White Papers // Mar 2011

    RWA in WDM Rings: An Efficient Formulation Based on Maximal Independent Set Decomposition

    WDM rings are now capable of supporting more than 100 wavelengths over a single fiber. Conventional link and path formulations for the RWA problem are inefficient due to the inherent symmetry in wavelength assignment and the fact that the problem size increases fast with the number of wavelengths. Although a...

    Provided By North Carolina State University

  • White Papers // Mar 2011

    From Jammer to Gambler: Modeling and Detection of Jamming Attacks Against Time-Critical Traffic

    Time-critical wireless applications in emerging network systems, such as e-healthcare and smart grids, have been drawing increasing attention in both industry and academia. The broadcast nature of wireless channels unavoidably exposes such applications to jamming attacks. However, existing methods to characterize and detect jamming attacks cannot be applied directly to...

    Provided By North Carolina State University

  • White Papers // Mar 2011

    Probabilistic Communication and I/O Tracing With Deterministic Replay at Scale

    With today's petascale supercomputers, applications often exhibit low efficiency, such as poor communication and I/O performance that can be diagnosed by analysis tools. However, these tools either produce extremely large trace files that complicate performance analysis, or sacrifice accuracy to collect high-level statistical information using crude averaging. This work contributes...

    Provided By North Carolina State University

  • White Papers // Feb 2011

    Self-Sustaining, Efficient and Forward-Secure Cryptographic Constructions for Unattended Wireless Sensor Networks

    Unattended Wireless Sensor Networks (UWSNs) operating in hostile environments face great security and performance challenges due to the lack of continuous real-time communication with the final data receivers (e.g., mobile data collectors). The lack of real-time communication forces sensors to accumulate sensed data possibly for long time periods, along with...

    Provided By North Carolina State University

  • White Papers // Feb 2011

    Hybrid FRR/p-Cycle MPLS Link Protection Design

    Survivable MPLS technologies are crucial in ensuring reliable communication services. The Fast ReRoute (FRR) mechanism has been standardized to achieve fast local repair of Label Switched Paths (LSPs). The authors present a hybrid survivability scheme for MPLS networks that combines the well-known p-cycle method with FRR technology. While with pure...

    Provided By North Carolina State University

  • White Papers // Feb 2011

    Exploiting Heterogeneity to Prolong the Lifetime of Large-Scale Wireless Sensor Networks

    In Wireless Sensor Networks (WSNs), sensor nodes are typically power-constrained with limited lifetime, and thus it is necessary to know how long the network sustains its networking operations. The authors consider the network lifetime as the time until that a majority of functional nodes remains connected of one another, forming...

    Provided By North Carolina State University

  • White Papers // Feb 2011

    Transmission Throughput of Decentralized Overlaid Networks With Outage Constraints

    Overlaid networks, typically composed of primary and secondary networks, are emerging as a viable candidate to resolve the conflict between increasing demand for spectrum and spectrum shortage. The essential purpose of overlaid networks is to improve the network spectrum efficiency, which, however, may not be achieved if the secondary network...

    Provided By North Carolina State University

  • White Papers // Jan 2011

    Time-Ordered Event Traces: A New Debugging Primitive for Concurrency Bugs

    Non-determinism makes concurrent bugs extremely difficult to reproduce and to debug. In this paper, the authors propose a new debugging primitive to facilitate the debugging process by exposing this non-deterministic behavior to the programmer. The key idea is to generate a time-ordered trace of events such as function calls/returns and...

    Provided By North Carolina State University

  • White Papers // Jan 2011

    HAQu: Hardware-Accelerated Queueing for Fine-Grained Threading on a Chip Multiprocessor

    Queues are commonly used in multithreaded programs for synchronization and communication. However, because software queues tend to be too expensive to support fine grained parallelism, hardware queues have been proposed to reduce overhead of communication between cores. Hardware queues require modifications to the processor core and need a custom interconnect....

    Provided By North Carolina State University

  • White Papers // Jan 2011

    Access Map Pattern Matching for High Performance Data Cache Prefetch

    Hardware data prefetching is widely adopted to hide long memory latency. A hardware data pre-fetcher predicts the memory address that will be accessed in the near future and fetches the data at the predicted address into the cache memory in advance. To detect memory access patterns such as a constant...

    Provided By North Carolina State University

  • White Papers // Jan 2011

    Eigen-Inference for Multi-Source Power Estimation

    At a time when radio resources become scarce, the alternative offered by flexible radios is gaining more and more interest. This paper introduces a new method to estimate the power transmitted by multiple signal sources, when the number of sensing devices and the available samples are sufficiently large compared to...

    Provided By North Carolina State University

  • White Papers // Jan 2011

    Smart Sleep: Sleep More to Reduce Delay in Duty-Cycled Wireless Sensor Networks

    A Simple Random Walk (SRW) has been considered as an effective forwarding method for many applications in Wireless Sensor Networks (WSNs) due to its desirable properties. However, a critical downside of SRW - slow diffusion or exploration over the space, typically leads to longer packet delay and undermines its own...

    Provided By North Carolina State University

  • White Papers // Jan 2011

    Impact of Data Sharing on CMP Design: A Study Based on Analytical Modeling

    Over the past few years, Chip Multi Processor (CMP) architecture has become the dominating hardware architecture across a spectrum of computing machinery - personal computing devices, workstations, commercial and scientific servers, and warehouse scale computers. The sheer complexity involved in the design and verification of each unit in a CMP...

    Provided By North Carolina State University

  • White Papers // Jan 2011

    ExMin: A Routing Metric for True Opportunity Gain in Delay Tolerant Networks

    DTNs have emerged as an attractive networking paradigm for mobile networks where transmission links among mobile nodes are dynamically established or torn down and communication is accomplished through multi-hop message relaying. Such environments are becoming increasingly prevalent due to the rapid growth of heterogeneous mobile devices and delay-insensitive applications. A...

    Provided By North Carolina State University

  • White Papers // Jan 2011

    Optimal Resource Allocation in Multihop Relay-Enhanced WiMAX Networks

    Multihop relaying in WiMAX networks is considered an increasingly attractive technology for providing throughput enhancement, coverage extension, or both. In this paper, the authors consider deploying non-transparent Relay Stations (RSs) that transmit on the same carrier frequency as the Base Station (BS) for the purpose of coverage extension. Since it...

    Provided By North Carolina State University

  • White Papers // Jan 2011

    Retrofitting Unit Tests for Parameterized Unit Testing

    Recent advances in software testing introduced Parameterized Unit Tests (PUT), which accept parameters, unlike Conventional Unit Tests (CUT), which do not accept parameters. PUTs are more beneficial than CUTs with regards to fault detection capability, since PUTs help describe the behaviors of methods under test for all test arguments. In...

    Provided By North Carolina State University

  • White Papers // Jan 2011

    PRESS: PRedictive Elastic ReSource Scaling for Cloud Systems

    Cloud systems require elastic resource allocation to minimize resource provisioning costs while meeting Service Level Objectives (SLOs). In this paper, the authors present a novel PRedictive Elastic reSource Scaling (PRESS) scheme for cloud systems. PRESS unobtrusively extracts fine-grained dynamic patterns in application resource demands and adjusts their resource allocations automatically....

    Provided By North Carolina State University

  • White Papers // Jan 2011

    A New Internet Architecture to Enable Software Defined Optics and Evolving Optical Switching Models

    The design of the SILO network architecture of fine-grain services was based on three fundamental principles. First, SILO generalizes the concept of layering and decouples layers from services, making it possible to introduce easily new functionality and innovations into the architecture. Second, cross-layer interactions are explicitly supported by extending the...

    Provided By North Carolina State University

  • White Papers // Jan 2011

    Trustworthy Service Caching: Cooperative Search in P2P Information Systems

    The authors are developing an approach for P2P information systems, where the peers are modeled as autonomous agents. Agents provide services or give referrals to one another to help find trustworthy services. They consider the important case of information services that can be cached. Agents request information services through high-level...

    Provided By North Carolina State University

  • White Papers // Jan 2011

    Analyzing the Energy-Time Tradeoff in High-Performance Computing Applications

    Although users of high-performance computing are most interested in raw performance, both energy and power consumption have become critical concerns. One approach to lowering energy and power is to use high-performance cluster nodes that have several power-performance states, so that the energy-time tradeoff can be dynamically adjusted. This paper analyzes...

    Provided By North Carolina State University

  • White Papers // Jan 2011

    Bounding Preemption Delay Within Data Cache Reference Patterns for Real-Time Tasks

    Caches have become invaluable for higher-end architectures to hide, in part, the increasing gap between processor speed and memory access times. While the effect of caches on timing predictability of single real-time tasks has been the focus of much research, bounding the overhead of cache warm-ups after preemptions remains a...

    Provided By North Carolina State University

  • White Papers // Jan 2011

    Using Prime Numbers for Cache Indexing to Eliminate Conflict Misses

    Using alternative cache indexing/hashing functions is a popular technique to reduce conflict misses by achieving a more uniform cache access distribution across the sets in the cache. Although various alternative hashing functions have been demonstrated to eliminate the worst case conflict behavior, no study has really analyzed the pathological behavior...

    Provided By North Carolina State University

  • White Papers // Jan 2011

    The Incremental Deployability of RTT-Based Congestion Avoidance for High Speed TCP Internet Connections

    The research focuses on end-to-end congestion avoidance algorithms that use Round Trip Time (RTT) fluctuations as an indicator of the level of network congestion. The algorithms are referred to as delay-based congestion avoidance or DCA. Due to the economics associated with deploying change within an existing network, the authors are...

    Provided By North Carolina State University

  • White Papers // Feb 2011

    Self-Sustaining, Efficient and Forward-Secure Cryptographic Constructions for Unattended Wireless Sensor Networks

    Unattended Wireless Sensor Networks (UWSNs) operating in hostile environments face great security and performance challenges due to the lack of continuous real-time communication with the final data receivers (e.g., mobile data collectors). The lack of real-time communication forces sensors to accumulate sensed data possibly for long time periods, along with...

    Provided By North Carolina State University

  • White Papers // Oct 2009

    BAF: An Efficient Publicly Verifiable Secure Audit Logging Scheme for Distributed Systems

    Audit logs, providing information about the current and past states of systems, are one of the most important parts of modern computer systems. Providing security for audit logs on an untrusted machine in a large distributed system is a challenging task, especially in the presence of active adversaries. In such...

    Provided By North Carolina State University

  • White Papers // Apr 2010

    A Survey of Network Design Problems and Joint Design Approaches in Wireless Mesh Networks

    Over the last decade, the paradigm of Wireless Mesh Networks (WMNs) has matured to a reasonably commonly understood one, and there has been extensive research on various areas related to WMNs such as design, deployment, protocols, performance, etc. The quantity of research being conducted in the area of wireless mesh...

    Provided By North Carolina State University

  • White Papers // Mar 2010

    CentMesh: Modular and Extensible Wireless Mesh Network Testbed

    In this paper, the authors present the design of their wireless mesh network testbed (CentMesh) which facilitates experimentation as a service. CentMesh differs from other testbeds in terms of its modular, flexible and extensible design. The CentMesh software suite provides a modular programming library using which users can implement their...

    Provided By North Carolina State University

  • White Papers // Nov 2009

    Impact of Power Control on Relay Load Balancing in Wireless Sensor Networks

    When shortest path routing is employed in large scale multi-hop wireless networks, nodes located near the center of the network have to perform disproportional amount of relaying for others. In energy-constrained networks like sensor, such unfair forwarding results into early depletion of batteries of these congested nodes. To solve the...

    Provided By North Carolina State University

  • White Papers // Mar 2012

    Packet Aggregation Based Back-Pressure Scheduling in Multi-Hop Wireless Networks

    The back-pressure based scheduling policy originally proposed by Tassiulas et al. in has shown the potential of solving many fairness and network utilization related problems of wireless multi-hop networks. Recently, the scheduling policy has been adapted in random medium access protocols such as CSMA/CA using prioritization of MAC layer transmissions....

    Provided By North Carolina State University

  • White Papers // Mar 2012

    Energy Efficient Iterative Waterfilling for the MIMO Broadcasting Channels

    Optimizing Energy Efficiency (EE) for the MIMO Broadcasting Channels (BC) is considered in this paper, where a practical power model is taken into account. Although the EE of the MIMO BC is non-concave, the authors reformulate it as a quasi-concave function based on the uplink-downlink duality. After that, an energy...

    Provided By North Carolina State University

  • White Papers // May 2012

    Communication Theory Perspective on Antenna Selection for Compact Transceivers

    Traditional antenna selection applied to MIMO systems ignores the presence of unselected (or inactive) antennas. However, compact arrays offer a unique advantage in that mutual coupling can be exploited to improve the system performance. Previous studies on selection with coupling have not considered the effects of the inactive-antenna terminations and...

    Provided By North Carolina State University

  • White Papers // May 2012

    Fundamental Capacity Limits on Compact MIMO-OFDM Systems

    The authors undertake an information-theoretic approach to characterize the optimal design of a broadband multi-antenna system in the presence of mutual coupling. It was shown recently that mutual coupling effectively decomposes otherwise spectrally identical spatial modes of an antenna array into spectrally non-identical eigen-modes. They shall use Shannon's information theory...

    Provided By North Carolina State University

  • White Papers // May 2012

    An Algorithm for Joint Guidance and Power Control for Electric Vehicles in the Smart Grid

    A massive amount of energy consumption currently stems from the transportation sector. Therefore, improvements in power usage by commuting vehicles are being studied and becoming an increasingly popular research topic. In particular, there is a growing need to model the envisioned smart infrastructure, including charging stations, some of which might...

    Provided By North Carolina State University

  • White Papers // May 2012

    Enabling Adaptive Rate and Relay Selection for 802.11 Mobile Ad Hoc Networks

    Mobile Ad hoc NETworks (MANETs) are self-configuring wireless networks that lack permanent infrastructure and are formed among mobile nodes on demand. Rapid node mobility results in dramatic channel variation, or fading, that degrades MANET performance. Employing Channel State Information (CSI) at the transmitter can improve the throughput of routing and...

    Provided By North Carolina State University

  • White Papers // Apr 2012

    Beyond Random Walk and Metropolis-Hastings Samplers: Why You Should Not Backtrack for Unbiased Graph Sampling

    Graph sampling via crawling has been actively considered as a generic and important tool for collecting uniform node samples so as to consistently estimate and uncover various characteristics of complex networks. The so-called Simple Random Walk with re-weighting (SRW-rw) and Metropolis-Hastings (MH) algorithm have been popular in the literature for...

    Provided By North Carolina State University

  • White Papers // May 2012

    Efficient Intranode Communication in GPU-Accelerated Systems

    Current implementations of MPI are unaware of accelerator memory (i.e., GPU device memory) and require programmers to explicitly move data between memory spaces. This approach is inefficient, especially for intranode communication where it can result in several extra copy operations. In this paper, the authors integrate GPU-awareness into a popular...

    Provided By North Carolina State University

  • White Papers // Mar 2012

    Inferring Method Specifications From Natural Language API Descriptions

    Application Programming Interface (API) documents are a typical way of describing legal usage of reusable software libraries, thus facilitating software reuse. However, even with such documents, developers often overlook some documents and build software systems that are inconsistent with the legal usage of those libraries. Existing software verification tools require...

    Provided By North Carolina State University

  • White Papers // Mar 2012

    Making Exceptions on Exception Handling

    The exception-handling mechanism has been widely adopted to deal with exception conditions that may arise during program executions. To produce high-quality programs, developers are expected to handle these exception conditions and take necessary recovery or resource-releasing actions. Failing to handle these exception conditions can lead to not only performance degradation,...

    Provided By North Carolina State University

  • White Papers // Mar 2012

    Isolating Failure-Inducing Combinations in Combinatorial Testing Using Test Augmentation and Classification

    Combinatorial Testing (CT) is a systematic way of sampling input parameters of the Software Under Test (SUT). A t-way combinatorial test set can exercise all behaviors of the SUT caused by interactions between t input parameters or less. Although combinatorial testing can provide fault detection capability, it is often desirable...

    Provided By North Carolina State University

  • White Papers // Mar 2012

    Gossip-Based Information Spreading in Mobile Networks

    Mobile networks receive increasing research interest recently due to their increasingly wide applications in various areas; Mobile Ad hoc NETworks (MANET) and Vehicular Ad hoc NETworks (VANET) are two prominent examples. Mobility introduces challenges as well as opportunities: it is known to improve the network throughput as shown in. In...

    Provided By North Carolina State University

  • White Papers // Feb 2012

    On the Capacity Region for Cognitive Multiple Access Over White Space Channels

    Cognitive Radio (CR) has stirred great interest with its potential to exploit the already scarce spectrum resource. The Cognitive Multiple Access Channels (CogMAC) are commonly seen in many applications, such as the Cognitive Radio Sensor Networks (CRSN), and the 802.22 cognitive Wireless Regional Area Networks (WRAN). In this paper, the...

    Provided By North Carolina State University

  • White Papers // Jan 2012

    Fundamental Limits of Passive Attacks on Wireless Link Signatures

    The goal of this paper is to gain a fundamental understanding of the potential vulnerability of existing wireless link schemes subject to passive eavesdropping and inference. From the adversary's perspective, the feasibility and fundamental limit of this new attack is explored. In addition, how the theoretical results are instantiated in...

    Provided By North Carolina State University

  • White Papers // Aug 2011

    Distributed Spectrum-Aware Clustering in Cognitive Radio Sensor Networks

    A novel Distributed Spectrum-Aware Clustering (DSAC) scheme is proposed in the context of Cognitive Radio Sensor Networks (CRSN). DSAC aims at forming energy efficient clusters in a self-organized fashion while restricting interference to Primary User (PU) systems. The spectrum-aware clustered structure is presented where the communications consist of intra-cluster aggregation...

    Provided By North Carolina State University

  • White Papers // Feb 2011

    Transmission Throughput of Decentralized Overlaid Networks With Outage Constraints

    Overlaid networks, typically composed of primary and secondary networks, are emerging as a viable candidate to resolve the conflict between increasing demand for spectrum and spectrum shortage. The essential purpose of overlaid networks is to improve the network spectrum efficiency, which, however, may not be achieved if the secondary network...

    Provided By North Carolina State University

  • White Papers // Jan 2011

    Eigen-Inference for Multi-Source Power Estimation

    At a time when radio resources become scarce, the alternative offered by flexible radios is gaining more and more interest. This paper introduces a new method to estimate the power transmitted by multiple signal sources, when the number of sensing devices and the available samples are sufficiently large compared to...

    Provided By North Carolina State University

  • White Papers // Sep 2011

    CloudScale: Elastic Resource Scaling for Multi-Tenant Cloud Systems

    Elastic resource scaling lets cloud systems meet application Service Level Objectives (SLOs) with minimum resource provisioning costs. In this paper, the authors present CloudScale, a system that automates finegrained elastic resource scaling for multi-tenant cloud computing infrastructures. CloudScale employs online resource demand prediction and prediction error handling to achieve adaptive...

    Provided By North Carolina State University

  • White Papers // Oct 2012

    HadISD: A Quality-Controlled Global Synoptic Report Database for Selected Variables at Long-Term Stations From 1973 - 2011

    In this paper, the authors describes the creation of HadISD: an automatically quality-controlled synoptic resolution dataset of temperature, dewpoint temperature, sea-level pressure, wind speed, wind direction and cloud cover from global weather stations for 1973 - 2011. The full dataset consists of over 6000 stations, with 3427 long-term stations deemed...

    Provided By North Carolina State University

  • White Papers // Jan 2011

    Optimal Resource Allocation in Multihop Relay-Enhanced WiMAX Networks

    Multihop relaying in WiMAX networks is considered an increasingly attractive technology for providing throughput enhancement, coverage extension, or both. In this paper, the authors consider deploying non-transparent Relay Stations (RSs) that transmit on the same carrier frequency as the Base Station (BS) for the purpose of coverage extension. Since it...

    Provided By North Carolina State University

  • White Papers // Sep 2011

    Hybrid Resource Allocation Scheme in Two-Hop Relaying WiMAX Networks

    In this paper, the authors consider resource allocation schemes in two-hop relaying WiMAX networks in order to maximize cell throughput, while serving the Subscriber Stations (SSs) in a fair manner. First they present two well-known schemes, namely, orthogonal and overlapped, according to the frequency reuse during the access zone intervals...

    Provided By North Carolina State University

  • White Papers // Apr 2012

    Advertising Cached Contents in the Control Plane: Necessity and Feasibility

    A key feature of Information-Centric Networking architectures is universal caching where anyone can cache any content and users can obtain the content from anywhere as long as the content itself is intact. This powerful feature benefits the content providers, the Internet Service Providers (ISPs) as well as end users since...

    Provided By North Carolina State University

  • White Papers // Feb 2010

    Parallel All Pairs Similarity Search

    In this paper, the authors present the first scalable parallel solution for the All Pairs Similarity Search (APSS) problem, which involves finding all pairs of data records that have a similarity score above the specified threshold. With exponentially growing datasets and modern multi-processor/multi-core system architectures, serial nature of all existing...

    Provided By North Carolina State University

  • White Papers // Jul 2011

    A Flow-Based Centrality Measure Through Resistance Distances in Smart-Grid Networks

    The authors propose methods to estimate centrality in Smart-Grid Networks (SGNs) from the view of a flow-based approach. In several network categories, centrality metrics, such as degree, closeness and betweenness, have provided ways to investigate the importance or weakness of components. These well-known metrics utilize either non-global or shortest-path information....

    Provided By North Carolina State University

  • White Papers // Oct 2009

    Social Distance Aware Resource Allocation in Wireless Networks

    Social connectivity networks and the associated socio-technical context are an important determinant of a user's resource requirements. Despite the recent attention on wireless network design, little quantitative work has been done in order to combine purely technical design methods with explicit dependencies on the social or business connectivity and utility...

    Provided By North Carolina State University

  • White Papers // Jun 2011

    On the Expressiveness of Return-Into-Libc Attacks

    Return-Into-LibC (RILC) is one of the most common forms of code-reuse attacks. In this attack, an intruder uses a buffer overflow or other exploit to redirect control flow through existing (libc) functions within the legitimate program. While dangerous, it is generally considered limited in its expressive power since it only...

    Provided By North Carolina State University

  • White Papers // Jan 2013

    QuickSense: Fast and Energy-Efficient Channel Sensing for Dynamic Spectrum Access Networks

    Spectrum sensing, the task of discovering spectrum usage at a given location, is a fundamental problem in dynamic spectrum access networks. While sensing in narrow spectrum bands is well studied in previous work, wideband spectrum sensing is challenging since a wideband radio is generally too expensive and power consuming for...

    Provided By North Carolina State University

  • White Papers // Jan 2013

    Characterizing Link Connectivity for Opportunistic Mobile Networking: Does Mobility Suffice?

    With recent drastic growth in the number of users carrying smart mobile devices, it is not hard to envision opportunistic ad-hoc communications taking place with such devices carried by humans. This leads to, however, a new challenge to the conventional link-level metrics, solely defined based on user mobility, such as...

    Provided By North Carolina State University

  • White Papers // Jun 2012

    From Glauber Dynamics to Metropolis Algorithm: Smaller Delay in Optimal CSMA

    Since the seminal work by Tassiulas and Ephremides on throughput-optimal scheduling, referred to as Max-Weight, a huge array of research has been made to develop distributed MAC scheduling with high performance guarantee and low complexity. The tradeoff between complexity and efficiency has been, however, observed in many cases, or even...

    Provided By North Carolina State University

  • White Papers // Jan 2011

    The Incremental Deployability of RTT-Based Congestion Avoidance for High Speed TCP Internet Connections

    The research focuses on end-to-end congestion avoidance algorithms that use Round Trip Time (RTT) fluctuations as an indicator of the level of network congestion. The algorithms are referred to as delay-based congestion avoidance or DCA. Due to the economics associated with deploying change within an existing network, the authors are...

    Provided By North Carolina State University

  • White Papers // Apr 2010

    DARTS: Techniques and Tools for Predictably Fast Memory Using Integrated Data Allocation and Real-Time Task Scheduling

    Hardware-managed caches introduce large amounts of timing variability, complicating real-time system design. One alternative is a memory system with scratchpad memories which improve system performance while eliminating such timing variability. Prior work introduced the DARTS approach, which combines static allocation of data into scratchpad memories, with task scheduling for preemptive...

    Provided By North Carolina State University

  • White Papers // Apr 2010

    Towards Quantitative Analysis of Proofs of Authorization: Applications, Framework, and Techniques

    Although policy compliance testing is generally treated as a binary decision problem, the evidence gathered during the trust management process can actually be used to examine these outcomes within a more continuous space. In this paper, the authors develop a formal model that allows them to quantitatively reason about the...

    Provided By North Carolina State University

  • White Papers // May 2010

    Informative Middleman Service, Variety-Expansion And Long Run Growth

    In reality, the intermediate firms not only conduct R&D but also provide informative middleman services to overcome the information cost generated by technological advancements. The author incorporates the informative middleman services such as consulting, advertising, technical supporting, repair and maintenance into a variety-expansion model. The author finds that: Activities of...

    Provided By North Carolina State University

  • White Papers // May 2010

    Schumpeterian Growth, Trade, And Dynamic Comparative Advantage

    The authors study the effects of trade on economic growth in a Schumpeterian framework. The model excludes scale effects and technology transfer, the two usual channels in the literature through which trade affects growth, leaving only comparative advantage. Comparative advantage and the trading pattern are determined endogenously. Endogeneity of production...

    Provided By North Carolina State University

  • White Papers // Jan 2011

    Design and Applications of a Smooth Mobility Model for Mobile Ad Hoc Networks

    Existing mobility models used in the simulation tools have two major limitations. First, these models invoke unrealistic moving behaviors, such as sudden stop and sharp turn during the simulation. Hence, the study of Mobile Ad-hoc NETworks (MANETs) based on these models could lead to wrong conclusions. Second, because the node...

    Provided By North Carolina State University