University of North Carolina

Displaying 1-40 of 75 results

  • White Papers // Jan 2014

    A Hybrid Real-Time Scheduling Approach for Large-Scale Multicore Platforms

    The authors propose a hybrid approach for scheduling real-time tasks on large-scale multicore platforms with hierarchical shared caches. In this approach, a multicore platform is partitioned into clusters. Tasks are statically assigned to these clusters, and scheduled within each cluster using the preemptive global EDF scheduling algorithm. They show that...

    Provided By University of North Carolina

  • White Papers // Jul 2013

    Fair Lateness Scheduling: Reducing Maximum Lateness in G-EDF-Like Scheduling

    In this paper, the authors discuss the Soft Real-Time (SRT) multiprocessor scheduling, tardiness bounds have been derived for a variety of scheduling algorithms, most notably, the Global Earliest-Deadline-First (G-EDF) algorithm. In this paper, the authors devise G-EDF-Like (GEL) schedulers, which have identical implementations to G-EDF and therefore the same overheads,...

    Provided By University of North Carolina

  • White Papers // Apr 2013

    Supporting Soft Real-Time Parallel Applications on Multiprocessors

    The prevalence of multicore processors has resulted in the wider applicability of parallel programming models such as OpenMP and MapReduce. A common goal of running parallel applications implemented under such models is to guarantee bounded response times while maximizing system utilization. Unfortunately, little previous work has been done that can...

    Provided By University of North Carolina

  • White Papers // Feb 2013

    Mixed-Criticality Scheduling Upon Unreliable Processors

    An unreliable processor is characterized by two execution speeds: a normal speed and a degraded speed. Under normal circumstances it will execute at its normal speed; unexpected conditions may occur during run-time that causes it to execute more slowly (but no slower than at its degraded speed). The problem of...

    Provided By University of North Carolina

  • White Papers // Oct 2012

    An Optimal K-Exclusion Real-Time Locking Protocol Motivated by Multi-GPU Systems

    Graphics Processing Units (GPUs) are becoming increasingly important in today's platforms as their growing generality allows for them to be used as powerful co-processors. In previous work, the authors showed that GPUs may be integrated into real-time systems by treating GPUs as shared resources, allocated to real-time tasks through mutual...

    Provided By University of North Carolina

  • White Papers // Aug 2012

    Effects of Dissatisfaction on Customer Repurchase Decisions in E-Commerce - An Emotion-Based Perspective

    Dissatisfaction is one of the factors that drive customers' decisions to reduce repurchase intention. Repurchase is crucial to the success of online stores. The present paper attempts to examine what coping behavior will be triggered by negative emotion in e-commerce and examines the potential influence of coping behavior on customer...

    Provided By University of North Carolina

  • White Papers // Jul 2012

    Topology Design in Time-Evolving Delay-Tolerant Networks With Unreliable Links

    With possible participation of a large number of wireless devices in Delay Tolerant Networks (DTNs), how to maintain efficient and dynamic topology becomes crucial. In this paper, the authors study the topology design problem in a predictable DTN where the time-evolving network topology is known a priori or can be...

    Provided By University of North Carolina

  • White Papers // Jul 2012

    Routing With Multi-Level Social Groups in Mobile Opportunistic Networks

    Mobile Opportunistic Networks (MONs) are intermittently connected networks, such as pocket switched networks formed by human-carried mobile devices. Routing in MONs is very challenging as it must handle network partitioning, long delays, and dynamic topology. Flooding is a possible solution but with high costs. Most existing routing methods for MONs...

    Provided By University of North Carolina

  • White Papers // Jul 2012

    Nokia Mobile Data Challenge: Predicting Semantic Place and Next Place Via Mobile Data

    The appearance of Smartphones equipped with various sensors enables pervasive monitoring of mobile users' behaviors and mobility. The Nokia Mobile Data Challenge (MDC) gives one a great opportunity to study the users' mobility models and location pro les from a rich mobile dataset. The realistic data analysis may benefit a...

    Provided By University of North Carolina

  • White Papers // Jun 2012

    Efficient Identity-Based and Authenticated Key Agreement Protocol

    Several identity based and implicitly authenticated key agreement protocols have been proposed in recent years and none of them has achieved all required security properties. It remains an open question to design secure identity based and implicitly authenticated key agreement protocols. In this paper, the authors propose an efficient identity-based...

    Provided By University of North Carolina

  • White Papers // Jun 2012

    Distributed Load Balancing Mechanism for Detouring Routing Holes in Sensor Networks

    Well known "Hole" problem is hardly avoided in wireless sensor networks because of various actual geographical environments. Existing geographic routing protocols (such as GFG and GPSR) use perimeter routing strategies to find a detour path around the boundary of holes when they encounter the "Local minimum" during greedy forwarding. However,...

    Provided By University of North Carolina

  • White Papers // Jun 2012

    Hybrid Position-Based and DTN Forwarding in Vehicular Ad Hoc Networks

    Efficient data delivery in Vehicular Ad hoc NETworks (VANETs) is still a challenging research issue. Position-based routing protocols have been proven to be more suitable for dynamic VANETs than traditional ad hoc routing protocols. However, position-based routing assumes that intermediate nodes can always be found to setup an end-to-end connection...

    Provided By University of North Carolina

  • White Papers // Mar 2012

    Password Protected Smart Card and Memory Stick Authentication Against Off-Line Dictionary Attacks

    The authors study the security requirements for remote authentication with password protected smart card. In recent years, several protocols for password-based authenticated key exchange have been proposed. These protocols are used for the protection of password based authentication between a client and a remote server. In this paper, they will...

    Provided By University of North Carolina

  • White Papers // Jan 2012

    Energy-Balanced Cooperative Routing in Multihop Wireless Ad Hoc Networks

    Cooperative Communication (CC) allows multiple nodes to simultaneously transmit the same packet to the receiver so that the combined signal at the receiver can be correctly decoded. Since the cooperative communication can reduce the transmission power and extend the transmission coverage, it has been considered in minimum energy routing protocols...

    Provided By University of North Carolina

  • White Papers // Nov 2011

    An Overview of Penetration Testing

    Penetration testing is a series of activities undertaken to identify and exploit security vulnerabilities. It helps confirm the effectiveness or ineffectiveness of the security measures that have been implemented. This paper provides an overview of penetration testing. It discusses the benefits, the strategies and the methodology of conducting penetration testing....

    Provided By University of North Carolina

  • White Papers // Sep 2011

    Localized Topologies With Bounded Node Degree for Three Dimensional Wireless Sensor Networks

    Three Dimensional (3D) wireless sensor networks have attracted a lot of attention due to its great potential usages in both commercial and civilian applications. Topology control in 3D sensor networks has been studied recently. Different 3D geometric topologies were proposed to be the underlying network topologies to achieve the sparseness...

    Provided By University of North Carolina

  • White Papers // Sep 2011

    Globally Scheduled Real-Time Multiprocessor Systems with GPUs

    Graphics Processing Units (GPUs) are powerful processors that can offer significant performance advantages over traditional CPUs. The last decade has seen rapid advancement in GPU computational power and generality. Recent technologies make it possible to use GPUs as coprocessors to CPUs. The performance advantages of GPUs can be great, often...

    Provided By University of North Carolina

  • White Papers // Sep 2011

    Generating Program Inputs for Database Application Testing

    Testing is essential for quality assurance of database applications. Achieving high code coverage of the database application is important in testing. In practice, there may exist a copy of live databases that can be used for database application testing. Using an existing database state is desirable since it tends to...

    Provided By University of North Carolina

  • White Papers // Aug 2011

    Detection of Fabricated CTS Packet Attacks in Wireless LANs

    IEEE 802.11 standard employs the RTS/CTS handshake procedure to avoid transmission collision and to improve network throughput. However, such an exchange may become a system vulnerability when malicious nodes send fabricated control messages such as CTS to make false claims of channel reservation. To the best of the authors' knowledge,...

    Provided By University of North Carolina

  • White Papers // Jul 2011

    Adaptive Information Coding for Secure and Reliable Wireless Telesurgery Communications

    Telesurgical Robot Systems (TRSs) have been the focus of research in academic, military, and commercial domains for many years. Contemporary TRSs address mission critical operations emerging in extreme fields such as battlefields, underwater, and disaster territories. The lack of wire-lined communication infrastructure in such fields makes the use of wireless...

    Provided By University of North Carolina

  • White Papers // Jul 2011

    The Investment Returns Of Nonprofit Organizations

    Nonprofit charities and foundations hold endowments and other investments. How do their investments perform? Some high-profile nonprofit endowments, importantly those of colleges and universities, have been studied before. This is the first paper, to the authors' knowledge, that looks at a large number of many different types of nonprofits. They...

    Provided By University of North Carolina

  • White Papers // Jun 2011

    Towards Effective Collaborative Analysis for Distributed Intrusion Detection

    This paper addresses the problem of collaborative analysis in a distributed setting via a network security application. Network security analysis often requires accurate and timely results, which is very challenging to achieve in large dynamic networks with a single user. To address this issue, the authors design and develop a...

    Provided By University of North Carolina

  • White Papers // Jun 2011

    Supporting Graph-Based Real-Time Applications in Distributed Systems

    The Processing Graph Method (PGM) is a widely used framework for modeling applications with producer/ consumer precedence constraints. PGM was originally developed by the U.S. Navy to model signal-processing applications where data communications exist among connected tasks. Prior paper has shown how to schedule PGM-specified systems on uniprocessors and globally-scheduled...

    Provided By University of North Carolina

  • White Papers // Apr 2011

    Line Orthogonality in Adjacency Eigenspace With Application to Community Partition

    Different from Laplacian or normal matrix, the properties of the adjacency eigenspace received much less attention. Recent work showed that n-odes projected into the adjacency eigenspace ex-hibit an orthogonal line pattern and nodes from the same community locate along the same line. In this paper, the authors conduct theoretical studies...

    Provided By University of North Carolina

  • White Papers // Apr 2011

    Efficient, Compromise Resilient and Append-Only Cryptographic Constructions for Digital Forensics

    Due to the forensic value of the audit logs, it is vital to provide forward-secure integrity and append-only properties in a logging system to prevent attackers who have gained control of the system from modifying or selectively deleting log entries generated before they took control. Existing forward-secure logging solutions are...

    Provided By University of North Carolina

  • White Papers // Apr 2011

    Multiprocessor Extensions to Real-Time Calculus

    Many embedded platforms consist of a heterogeneous collection of processing elements, memory modules, and communication subsystems. These components often implement different scheduling/arbitration policies, have different interfaces, and are supplied by different vendors. Hence, compositional techniques for modeling and analyzing such platforms are of interest. In this paper, the real-time calculus...

    Provided By University of North Carolina

  • White Papers // Apr 2011

    Phonotactic Reconstruction of Encrypted VoIP Conversations: Hookt on fon-iks

    In this paper, the authors unveil new privacy threats against Voice-over-IP (VoIP) communications. Although prior work has shown that the interaction of variable bit-rate codecs and length-preserving stream ciphers leaks information, they show that the threat is more serious than previously thought. In particular, they derive approximate transcripts of encrypted...

    Provided By University of North Carolina

  • White Papers // Jan 2011

    Cooperative Energy Spanners: Energy-Efficient Topology Control in Cooperative Ad Hoc Networks

    Cooperative Communication (CC) allows multiple nodes to simultaneously transmit the same packet to the receiver so that the combined signal at the receiver can be correctly decoded. Since CC can reduce the transmission power and extend the transmission coverage, it has been considered in topology control protocols. However, prior research...

    Provided By University of North Carolina

  • White Papers // Jan 2011

    Evolutionary Dynamics on Small-World Networks

    The authors study how the outcome of evolutionary dynamics on graphs depends on randomness on the graph structure. They gradually change the underlying graph from completely regular (e.g. a square lattice) to completely random. They find that the fixation probability increases as the randomness increases; nevertheless, the increase is not...

    Provided By University of North Carolina

  • White Papers // Jan 2011

    Achieving Direct Volume Visualization With Interactive Semantic Region Selection

    Interactive direct visualization of 3D data requires fast update rates and the ability to extract regions of interest from the surrounding data. The authors have implemented Multi-Valued Classification volume renderers on a general purpose multiprocessor graphics platform (Pixel-Planes 5) that are faster than any yet reported (2 -15 frames per...

    Provided By University of North Carolina

  • White Papers // Jan 2011

    Evaluation of Short-Term Traffic Forecasting Algorithms in Wireless Networks

    The authors goal is to characterize the traffic load in an IEEE802.11 infrastructure. This can be beneficial in many domains, including coverage planning, resource reservation, network monitoring for anomaly detection, and producing more accurate simulation models. They conducted an extensive measurement study of wireless users on a major university campus...

    Provided By University of North Carolina

  • White Papers // Jan 2011

    Multiprocessor Scheduling in Processor-Based Router Platforms: Issues and Ideas

    Two important trends are expected to guide the design of next-generation networks. First, with the commercialization of the Internet, providers will use value-added services to differentiate their service offerings from other providers; such services require the use of sophisticated resource scheduling mechanisms in routers. Second, to enable extensibility and the...

    Provided By University of North Carolina

  • White Papers // Jan 2011

    Modeling Client Arrivals at Access Points in Wireless Campus-Wide Networks

    The authors' goal is to model the arrival of wireless clients at the Access Points (APs) in a production 802.11 infrastructure. Such models are critical for benchmarks, simulation studies, design of capacity planning and resource allocation, and the administration and support of wireless infrastructures. Their contributions include a novel methodology...

    Provided By University of North Carolina

  • White Papers // Aug 2010

    Stepping Stone Versus "Dead End" Jobs: Occupational Pathways Out Of Working Poverty In The United States, 1996-2007

    In this paper the authors test for the existence of pathways of upward mobility for low wage workers by studying patterns of mobility in the 1996, 2001, and 2004 panels of the Survey of Income and Program Participation (SIPP). Based on a theoretical model of skill sorting versus learning, they...

    Provided By University of North Carolina

  • White Papers // Jul 2010

    Spin-Based Reader-Writer Synchronization for Multiprocessor Real-Time Systems

    With the transition to multicore architectures by most major chip manufacturers, multiprocessors are now a standard deployment platform for (soft) real-time applications. Reader preference, writer preference, and task-fair reader-writer locks are shown to cause undue blocking in multiprocessor real-time systems. Phase-fair reader writer locks, a new class of reader-writer locks,...

    Provided By University of North Carolina

  • White Papers // Jun 2010

    Considerations for Supporting Faculty in Transitioning a Course to Online Format

    The move toward offering more online instruction at many academic institutions frequently takes the form of conversion of a traditional course to online format. Despite its prevalence, this special form of course development has received little research attention. This paper presents the results of an exploratory study of the faculty...

    Provided By University of North Carolina

  • White Papers // May 2010

    Energy-Efficient Restricted Greedy Routing for Three Dimensional Random Wireless Networks

    In this paper, the authors investigate how to design energy-efficient localized routing in a large-scale Three-Dimensional (3D) wireless network. Several 3D localized routing protocols were proposed to seek either energy efficiency or delivery guarantee in 3D wireless networks. However, recent results showed that there is no deterministic localized routing algorithm...

    Provided By University of North Carolina

  • White Papers // Apr 2010

    Minimum Cost Localization Problem in Wireless Sensor Networks

    Localization is a fundamental problem in wireless sensor networks. Current localization algorithms mainly focus on checking the localizability of a network and/or how to localize as many nodes as possible given a static set of anchor nodes and distance measurements. In this paper, the authors study a new optimization problem,...

    Provided By University of North Carolina

  • White Papers // Apr 2010

    Improving the Schedulability of Sporadic Self-Suspending Soft Real-Time Multiprocessor Task Systems

    In many real-time systems, tasks self-suspend due to interactions with external devices such as disks and network cards. The suspension delays introduced by such behaviors can quite negatively impact schedulability if deadline misses cannot be tolerated. In work on globally-scheduled soft real-time multiprocessor systems, analysis has been presented for dealing...

    Provided By University of North Carolina

  • White Papers // Mar 2010

    Challenges in Genomic Data Processing I - Multiple Small Files

    Advances in the field of Genomics have made more data on the very building blocks of life available than ever before. When coupled with the burgeoning fields of Bioinformatics and Statistical Genomics, there is significant information that has been heretofore hidden in those simple chemical bonds. Unfortunately, bridging the divide...

    Provided By University of North Carolina

  • White Papers // Apr 2002

    How Representative Are Cross-Listed Firms? An Analysis of Firm Performance and Accounting Quality

    This article provides evidence on the characteristics of local-GAAP reported earnings for firms choosing to cross list in US markets relative to both a matched sample of foreign firms currently not cross listing in the US and a matched sample of US firms. The goal is to investigate the extent...

    Provided By University of North Carolina

  • White Papers // Mar 2010

    Challenges in Genomic Data Processing I - Multiple Small Files

    Advances in the field of Genomics have made more data on the very building blocks of life available than ever before. When coupled with the burgeoning fields of Bioinformatics and Statistical Genomics, there is significant information that has been heretofore hidden in those simple chemical bonds. Unfortunately, bridging the divide...

    Provided By University of North Carolina

  • White Papers // Jan 2010

    A Performance Study of Loss Detection/Recovery in Real-World TCP Implementations

    TCP is the dominant transport protocol used in the Internet and its performance fundamentally governs the performance of Internet applications. It is well-known that packet losses can adversely affect the connection duration of TCP connections-however, what is not fully understood is how well does the TCP design deal with losses....

    Provided By University of North Carolina

  • White Papers // Aug 2009

    Joint Opportunities for Real-Time Linux and Real-Time Systems Research

    Based on lessons learned in developing and maintaining LITMUSRT, arguments in favor of an intensified collaboration between the academic and the open-source real-time communities are presented, and several ways in which ongoing efforts in these two communities may benefit each other are outlined. Some (unfortunately) commonly-encountered sources of friction and...

    Provided By University of North Carolina

  • White Papers // Dec 2009

    FloVis: Leveraging Visualization to Protect Sensitive Network Infrastructure

    Computer networks have become critical to NATO operations. Much of NATO's computer traffic runs over civilian networks, and NATO computers are accessible to a wide variety of malicious activities. The scale of the network traffic involved makes monitoring and analysis difficult, and the rapid deployment of computer systems to new...

    Provided By University of North Carolina

  • White Papers // Aug 2009

    Building a Dark Piconet Upon Bluetooth Interfaces of Computers

    With the fast development of pervasive computing applications, Bluetooth devices have quickly gained popularity because of several highly desirable properties. Their uniform interfaces remove any concerns of users about the compatibility issues. With the low power consumption from 1mw to 100mw and decent transmission speed up to 3 Mbits/sec for...

    Provided By University of North Carolina

  • White Papers // Aug 2009

    Increasing Access To Capital: Could Better Measurement Of Social And Environmental Outcomes

    The role of capital in promoting growth is more apparent than ever as communities across the country struggle to bolster sagging economies and stem job losses brought on by the credit crunch. Although it may seem now that all markets are undercapitalized, some areas are chronically undercapitalized, including inner-city urban...

    Provided By University of North Carolina

  • White Papers // Jun 2010

    Considerations for Supporting Faculty in Transitioning a Course to Online Format

    The move toward offering more online instruction at many academic institutions frequently takes the form of conversion of a traditional course to online format. Despite its prevalence, this special form of course development has received little research attention. This paper presents the results of an exploratory study of the faculty...

    Provided By University of North Carolina

  • White Papers // Apr 2009

    What's The Use Of Arguing? European Union Strategies For The Promotion Of Human Rights In The United Nations

    This paper explores two themes raised by the recent ECFR Audit of European Power in the UN, where it is argued that a group of states constituting an 'Axis of Sovereignty' is frustrating European efforts to promote human rights in the multilateral framework of the UN. The first is the...

    Provided By University of North Carolina

  • White Papers // Jun 2009

    Prohibitions Versus Constraints: The 2008 Short Sales Regulations

    The author shows the effects of the short sales regulations issued during the financial crisis of 2008. Specifically, They study the emergency order that effectively restricted naked short selling for nineteen stocks, and the outright ban on all short selling of financial stocks. They document that both regulations were effective...

    Provided By University of North Carolina

  • White Papers // Apr 2009

    Did Structured Credit Fuel The LBO Boom?

    The authors demonstrate a link between the twin storms underlying the current financial crisis - the market for Collateralized Debt Obligations (CDOs) and the market for leveraged loans. The authors show that structural changes in credit markets that led to the explosion in CDOs created an increased supply of bank...

    Provided By University of North Carolina

  • White Papers // Jan 2011

    Achieving Direct Volume Visualization With Interactive Semantic Region Selection

    Interactive direct visualization of 3D data requires fast update rates and the ability to extract regions of interest from the surrounding data. The authors have implemented Multi-Valued Classification volume renderers on a general purpose multiprocessor graphics platform (Pixel-Planes 5) that are faster than any yet reported (2 -15 frames per...

    Provided By University of North Carolina

  • White Papers // Jan 2011

    Evolutionary Dynamics on Small-World Networks

    The authors study how the outcome of evolutionary dynamics on graphs depends on randomness on the graph structure. They gradually change the underlying graph from completely regular (e.g. a square lattice) to completely random. They find that the fixation probability increases as the randomness increases; nevertheless, the increase is not...

    Provided By University of North Carolina

  • White Papers // Jul 2011

    The Investment Returns Of Nonprofit Organizations

    Nonprofit charities and foundations hold endowments and other investments. How do their investments perform? Some high-profile nonprofit endowments, importantly those of colleges and universities, have been studied before. This is the first paper, to the authors' knowledge, that looks at a large number of many different types of nonprofits. They...

    Provided By University of North Carolina

  • White Papers // Jan 2011

    Evaluation of Short-Term Traffic Forecasting Algorithms in Wireless Networks

    The authors goal is to characterize the traffic load in an IEEE802.11 infrastructure. This can be beneficial in many domains, including coverage planning, resource reservation, network monitoring for anomaly detection, and producing more accurate simulation models. They conducted an extensive measurement study of wireless users on a major university campus...

    Provided By University of North Carolina

  • White Papers // Oct 2009

    On the Development of an Internetwork-Centric Defense for Scanning Worms

    Studies of worm outbreaks have found that the speed of worm propagation makes manual intervention ineffective. Consequently, many automated containment mechanisms have been proposed to contain worm outbreaks before they grow out of control. These containment systems, however, only provide protection for hosts within networks that implement them. Such a...

    Provided By University of North Carolina

  • White Papers // Jan 2011

    Modeling Client Arrivals at Access Points in Wireless Campus-Wide Networks

    The authors' goal is to model the arrival of wireless clients at the Access Points (APs) in a production 802.11 infrastructure. Such models are critical for benchmarks, simulation studies, design of capacity planning and resource allocation, and the administration and support of wireless infrastructures. Their contributions include a novel methodology...

    Provided By University of North Carolina

  • White Papers // Nov 2011

    An Overview of Penetration Testing

    Penetration testing is a series of activities undertaken to identify and exploit security vulnerabilities. It helps confirm the effectiveness or ineffectiveness of the security measures that have been implemented. This paper provides an overview of penetration testing. It discusses the benefits, the strategies and the methodology of conducting penetration testing....

    Provided By University of North Carolina

  • White Papers // Aug 2010

    Stepping Stone Versus "Dead End" Jobs: Occupational Pathways Out Of Working Poverty In The United States, 1996-2007

    In this paper the authors test for the existence of pathways of upward mobility for low wage workers by studying patterns of mobility in the 1996, 2001, and 2004 panels of the Survey of Income and Program Participation (SIPP). Based on a theoretical model of skill sorting versus learning, they...

    Provided By University of North Carolina

  • White Papers // Jun 2009

    Occupations And The Structure Of Wage Inequality In The United States, 1980s-2000s

    Occupations have long been regarded as central to the stratification systems of industrial countries, but have played little role in empirical attempts to explain the well-documented increases in wage inequality that occurred in the United States in the 1980s and 1990s. The authors address this deficiency by assessing occupation-level effects...

    Provided By University of North Carolina

  • White Papers // Oct 2009

    The Causal Impact Of Media In Financial Markets

    It is challenging to disentangle the causal impact of media reporting from the impact of the events being reported. The authors solve this problem by comparing the behaviors of investors with access to different media coverage of the same information event. They use zip codes to identify 19 mutually exclusive...

    Provided By University of North Carolina

  • White Papers // Sep 2011

    Generating Program Inputs for Database Application Testing

    Testing is essential for quality assurance of database applications. Achieving high code coverage of the database application is important in testing. In practice, there may exist a copy of live databases that can be used for database application testing. Using an existing database state is desirable since it tends to...

    Provided By University of North Carolina

  • White Papers // Apr 2011

    Line Orthogonality in Adjacency Eigenspace With Application to Community Partition

    Different from Laplacian or normal matrix, the properties of the adjacency eigenspace received much less attention. Recent work showed that n-odes projected into the adjacency eigenspace ex-hibit an orthogonal line pattern and nodes from the same community locate along the same line. In this paper, the authors conduct theoretical studies...

    Provided By University of North Carolina

  • White Papers // Nov 2009

    Privacy Preserving Categorical Data Analysis With Unknown Distortion Parameters

    Randomized Response techniques have been investigated in privacy preserving categorical data analysis. However, the released distortion parameters can be exploited by attackers to breach privacy. In this paper, the authors investigate whether data mining or statistical analysis tasks can still be conducted on randomized data when distortion parameters are not...

    Provided By University of North Carolina

  • White Papers // Jun 2009

    Load Balancing Routing With Bounded Stretch

    Routing in wireless networks has been heavily studied in the last decade. Many routing protocols are based on classic shortest path algorithms. However, shortest path-based routing protocols suffer from uneven load distribution in the network, such as crowed center effect where the center nodes have more load than the nodes...

    Provided By University of North Carolina

  • White Papers // Apr 2010

    Minimum Cost Localization Problem in Wireless Sensor Networks

    Localization is a fundamental problem in wireless sensor networks. Current localization algorithms mainly focus on checking the localizability of a network and/or how to localize as many nodes as possible given a static set of anchor nodes and distance measurements. In this paper, the authors study a new optimization problem,...

    Provided By University of North Carolina

  • White Papers // Jan 2011

    Cooperative Energy Spanners: Energy-Efficient Topology Control in Cooperative Ad Hoc Networks

    Cooperative Communication (CC) allows multiple nodes to simultaneously transmit the same packet to the receiver so that the combined signal at the receiver can be correctly decoded. Since CC can reduce the transmission power and extend the transmission coverage, it has been considered in topology control protocols. However, prior research...

    Provided By University of North Carolina

  • White Papers // May 2010

    Energy-Efficient Restricted Greedy Routing for Three Dimensional Random Wireless Networks

    In this paper, the authors investigate how to design energy-efficient localized routing in a large-scale Three-Dimensional (3D) wireless network. Several 3D localized routing protocols were proposed to seek either energy efficiency or delivery guarantee in 3D wireless networks. However, recent results showed that there is no deterministic localized routing algorithm...

    Provided By University of North Carolina

  • White Papers // Dec 2009

    Capacity of Data Collection in Arbitrary Wireless Sensor Networks

    How to efficiently collect sensing data from all sensor nodes is critical to the performance of wireless sensor networks. In this paper, the authors aim to understand the theoretical limitations of data collection in terms of possible and achievable maximum capacity. Previously, the study of data collection capacity has only...

    Provided By University of North Carolina

  • White Papers // Jun 2009

    Order-Optimal Data Collection in Wireless Sensor Networks: Delay and Capacity

    Data collection is one of the most important functions provided by wireless sensor networks. In this paper, the authors study theoretical limitations of data collection and data aggregation in terms of delay and capacity for a wireless sensor network where n sensors are randomly deployed. They consider different communication scenarios...

    Provided By University of North Carolina

  • White Papers // Jul 2009

    Efficient Fault Tolerant Topology Control for Three-Dimensional Wireless Networks

    Fault tolerant topology control in wireless networks has been studied recently. In order to achieve both sparseness (i.e., the number of links is linear with the number of nodes) and fault tolerance (i.e., can survive certain level of node/link failures), different geometric topologies were proposed and used as the underlying...

    Provided By University of North Carolina

  • White Papers // Aug 2009

    Data Collection Capacity of Random-Deployed Wireless Sensor Networks

    Data collection is one of the most important functions provided by wireless sensor networks. In this paper, the authors study the theoretical limitations of data collection and data aggregation in terms of delay and capacity for a wireless sensor network where n sensors are randomly deployed. They consider two different...

    Provided By University of North Carolina

  • White Papers // Apr 2011

    Phonotactic Reconstruction of Encrypted VoIP Conversations: Hookt on fon-iks

    In this paper, the authors unveil new privacy threats against Voice-over-IP (VoIP) communications. Although prior work has shown that the interaction of variable bit-rate codecs and length-preserving stream ciphers leaks information, they show that the threat is more serious than previously thought. In particular, they derive approximate transcripts of encrypted...

    Provided By University of North Carolina

  • White Papers // Apr 2009

    Supporting Pipelines in Soft Real-Time Multiprocessor Systems

    With the advent of multicore technologies, it is important that real-time scheduling theory be extended so that commonly-used multiprocessor programming techniques can be supported in systems with timing constraints. One technique of particular utility is pipelined execution, which is used to increase throughput by leveraging the parallelism inherent on multiprocessor...

    Provided By University of North Carolina

  • White Papers // May 2009

    Supporting Sporadic Pipelined Tasks with Early-Releasing in Soft Real-Time Multiprocessor Systems

    With the advent of multicore technologies, it is important for programming frameworks for real-time applications to provide support for commonly-used multiprocessor programming techniques. One such technique is pipelined execution, which is used to increase throughput by leveraging the parallelism inherent on multiprocessor platforms. Soft real-time sporadic multiprocessor task systems are...

    Provided By University of North Carolina

  • White Papers // Jun 2011

    Supporting Graph-Based Real-Time Applications in Distributed Systems

    The Processing Graph Method (PGM) is a widely used framework for modeling applications with producer/ consumer precedence constraints. PGM was originally developed by the U.S. Navy to model signal-processing applications where data communications exist among connected tasks. Prior paper has shown how to schedule PGM-specified systems on uniprocessors and globally-scheduled...

    Provided By University of North Carolina

  • White Papers // Apr 2010

    Improving the Schedulability of Sporadic Self-Suspending Soft Real-Time Multiprocessor Task Systems

    In many real-time systems, tasks self-suspend due to interactions with external devices such as disks and network cards. The suspension delays introduced by such behaviors can quite negatively impact schedulability if deadline misses cannot be tolerated. In work on globally-scheduled soft real-time multiprocessor systems, analysis has been presented for dealing...

    Provided By University of North Carolina

  • White Papers // Nov 2009

    TimeCapsule: Secure Recording of Accesses to a Protected Datastore

    The authors present an approach for transparently recording accesses to protected storage. In particular, they provide a framework for data monitoring in a virtualized environment using only the abstractions exposed by the hypervisor. To achieve their goals, they explore techniques for efficiently harvesting application code pages resident in memory at...

    Provided By University of North Carolina

  • White Papers // Feb 2013

    Mixed-Criticality Scheduling Upon Unreliable Processors

    An unreliable processor is characterized by two execution speeds: a normal speed and a degraded speed. Under normal circumstances it will execute at its normal speed; unexpected conditions may occur during run-time that causes it to execute more slowly (but no slower than at its degraded speed). The problem of...

    Provided By University of North Carolina

  • White Papers // Nov 2007

    Examination of Infomediary Roles in B2C E-Commerce

    In this paper, the authors provide a parsimonious research model that assists in the study of infomediary roles in B2C E-commerce, their level of integration and sophistication, and their impact on infomediary performance and customers' satisfaction. After an extensive literature review, discovery, facilitation, and support roles were identified as the...

    Provided By University of North Carolina