University of Minnesota

Displaying 1-40 of 123 results

  • White Papers // May 2012

    Recovery of Low-Rank Plus Compressed Sparse Matrices With Application to Unveiling Traffic Anomalies

    Given the superposition of a low-rank matrix plus the product of a known fat compression matrix times a sparse matrix, the goal of this paper is to establish deterministic conditions under which exact recovery of the low-rank and sparse components becomes possible. This fundamental identifiability issue arises with traffic anomaly...

    Provided By University of Minnesota

  • White Papers // Apr 2012

    Dynamic Network Delay Cartography

    Path delays in IP networks are important metrics, required by network operators for assessment, planning, and fault diagnosis. Monitoring delays of all source-destination pairs in a large network is however challenging and wasteful of resources. The paper advocates a spatio-temporal Kalman filtering approach to construct network-wide delay maps using measurements...

    Provided By University of Minnesota

  • White Papers // Mar 2012

    Scalable Transaction Management With Snapshot Isolation on Cloud Data Management Systems

    Key-value based data storage systems such as HBase and Bigtable provide high scalability compared to traditional relational databases, however, they provide only limited transactional functionality, such as single-row transactions. The authors address the problem of building scalable transaction management mechanisms for multi-row transactions on key-value storage systems. They develop scalable...

    Provided By University of Minnesota

  • White Papers // Aug 2011

    Correlated Flooding in Low-Duty-Cycle Wireless Sensor Networks

    Flooding in low-duty-cycle wireless sensor networks is very costly due to asynchronous schedules of sensor nodes. To adapt existing flooding-tree-based designs for low-duty-cycle networks, the authors shall schedule nodes of common parents wake up simultaneously. Traditionally, energy optimality in a designated flooding-tree is achieved by selecting parents with the highest...

    Provided By University of Minnesota

  • White Papers // Jul 2011

    Safeguarding Schedule Updates in Wireless Sensor Networks

    Working in the duty cycling mode enables sensor nodes to utilize limited energy efficiently instead of unnecessary idle listening. In such networks, awareness of neighboring nodes' working schedules is essential, especially when each node sets up the schedule independently. Most traditional research assumes that a node can always share its...

    Provided By University of Minnesota

  • White Papers // Jun 2011

    Cross-Layer Design of Coded Multicast for Wireless Random Access Networks

    Joint optimization of network coding and Aloha-based Medium Access Control (MAC) for multi-hop wireless networks is considered. The multicast throughput with a power consumption-related penalty is maximized subject to flow conservation and MAC achievable rate constraints to obtain the optimal transmission probabilities. The relevant optimization problem is inherently non-convex and...

    Provided By University of Minnesota

  • White Papers // Jun 2011

    Credit Constraints And Generational Welfare Over The Great Recession

    The Great Recession of 2007-2009 has been one of the largest contractions in the United States since the Great Depression. However, the recession has not impacted all agents equally. Some have lost not only their jobs but also their homes, while others have made fortunes purchasing assets at depressed values....

    Provided By University of Minnesota

  • White Papers // May 2011

    Bubble Trace: Mobile Target Tracking Under Insufficient Anchor Coverage

    As an essential requirement for surveillance systems, target tracking has been studied extensively. Most of the tracking schemes are based on trilateration, which requires each point in the monitoring area to be covered by at least three anchors. However, due to the inadequate deployment of costly anchors and environment constraints,...

    Provided By University of Minnesota

  • White Papers // May 2011

    Sparsity-Aware Kalman Tracking of Target Signal Strengths on a Grid

    Tracking multiple moving targets is known to be challenged by the nonlinearity present in the measurement equation, and by the computationally burdensome data association task. This paper introduces a grid-based model of target signal strengths leading to linear state and measurement equations, that can afford state estimation via sparsity-aware Kalman...

    Provided By University of Minnesota

  • White Papers // Apr 2011

    Group Sparse Lasso for Cognitive Network Sensing Robust to Model Uncertainties and Outliers

    To account for variations in the frequency, time, and space dimensions, dynamic re-use of licensed bands under the Cognitive Radio (CR) paradigm calls for innovative network-level sensing algorithms for multi-dimensional spectrum opportunity awareness. Toward this direction, the present paper develops a collaborative scheme whereby CRs cooperate to localize active Primary...

    Provided By University of Minnesota

  • White Papers // Apr 2011

    Liquidsoap: A High-Level Programming Language for Multimedia Streaming

    Generating multimedia streams, such as in a netradio, is a task which is complex and difficult to adapt to every users' needs. The authors introduce a novel approach in order to achieve it, based on a dedicated high-level functional programming language, called Liquid-soap, for generating, manipulating and broadcasting multimedia streams....

    Provided By University of Minnesota

  • White Papers // Apr 2011

    Corporate Branding Effects On Consumer Purchase Preferences In Serbian Telecom Market

    This research is carried out to know the role of corporate branding in mobile phone network along with different influencing factors involved in the purchase of mobile telephone connections. This paper discusses corporate branding from consumer's point of view that how much they value it and what type of role...

    Provided By University of Minnesota

  • White Papers // Apr 2011

    The Natural Resource Decision Support System (NRDSS): Creation of a 9.2 ArcGIS Server Website and a SQL Server 2005 ArcSDE 9.2 Database for the Minnesota Board of Water and Soil Resources (BWSR)

    In the fall of 2007, GeoSpatial Services (GSS) accepted a contract from the Minnesota Board of Water and Soil Resources (BWSR) to develop a 9.2 ArcGIS Server application. This application was to be a web mapping site that would support Soils SURvey GeOgraphic Database (SSURGO) soils data interaction and allow...

    Provided By University of Minnesota

  • White Papers // Apr 2011

    The Routing Continuum From Shortest-Path to All-Path: A Unifying Theory

    Routing is a critical operation in many types of networks from communication networks to transportation networks. For instance, in modern IP-based data networks, shortest path routing is most commonly used. In traditional telecommunication networks, dynamic alternative routing strategies that employ paths that are longer than shortest paths have been also...

    Provided By University of Minnesota

  • White Papers // Apr 2011

    Flat Versus Metered Rates, Bundling, and "Bandwidth Hogs"

    The current push for bandwidth caps, tiered usage pricing, and other measures in both wireless and wireline communications is usually justified by invoking the specter of "Bandwidth hogs" consuming an unfair share of the transmission capacity and being subsidized by the bulk of the users. This paper presents a conventional...

    Provided By University of Minnesota

  • White Papers // Apr 2011

    Business Ethics Pedagogy: A Synthesis Of Paradigms, Philosophies, And Teaching Methods

    Is the job as educators to teach students how to make ethical decisions or is it to teach students how to become innately better people, thus becoming better ethical decision-makers on the job? This paper examines current teaching methods in business ethics. An argument for the necessity of ethics education...

    Provided By University of Minnesota

  • White Papers // Apr 2011

    Data Security in the Cloud

    Cloud computing is an emerging trend in the provision of computing resources. For economical reasons users are outsourcing applications and data storage to the cloud, a managed hardware infrastructure providing various services. As the cloud grows it becomes necessary to secure the data and applications from unwanted attackers. This paper...

    Provided By University of Minnesota

  • White Papers // Mar 2011

    Dynamic Outsourcing Mobile Computation to the Cloud

    Mobile devices are becoming the universal interface to online services and cloud computing applications. Since mobile phones have limited computing power and battery life, there is a potential to migrate computation intensive application components to external computing resources. The Cloud is an attractive platform for offloading due to elastic resource...

    Provided By University of Minnesota

  • White Papers // Feb 2011

    Simplifying Manageability, Scalability and Host Mobility in Large-Scale Enterprise Networks Using VEIL-Click

    The explosive growth in the network driven services and devices is causing existing networks to continually expand to accommodate the demands set by them. However, underlying network architecture can not sustain this continual expansion. As a result, several ad-hoc mechanisms are used as workarounds, which make the networks increasingly complicated...

    Provided By University of Minnesota

  • White Papers // Feb 2011

    A Geometric Approach to Robustness in Complex Networks

    Unlike traditional studies on network robustness, that typically treat networks as combinatoric objects and rely primarily on classical graph-theoretic concepts (e.g. minimum cuts) to characterize network robustness, the authors explore a geometric approach which enables one to employ more advanced theories and techniques, quantify and compare robustness of networks in...

    Provided By University of Minnesota

  • White Papers // Feb 2011

    i-Code: A New Approach to Practical Network Coding for Content Distribution

    This paper studies the practicality of network coding to facilitate cooperative content distribution. Network coding is a new data transmission technique which allows any nodes in a network to encode and distribute data. It is a good solution offering reliability and efficiency in distributing content, but network coding has not...

    Provided By University of Minnesota

  • White Papers // Feb 2011

    VIRO: A Scalable, Robust and Namespace Independent Virtual Id ROuting for Future Networks

    Today's Internet is increasingly strained to meet the demands and requirements of these Internet services and their users, such as scalability to accommodate the increasing number of network components and host devices, high availability, robustness, mobility and security. As the universal "Glue" that pieces together various heterogeneous physical networks, the...

    Provided By University of Minnesota

  • White Papers // Feb 2011

    Trade Liberalization With Endogenous Borrowing Constraints

    A recent empirical literature has documented that credit availability is a significant barrier for firm-level exports. The authors develop a dynamic general equilibrium trade model with heterogeneous monopolistic competitive firms and imperfect credit markets due to limited contract enforce-ability. They show that this model is consistent with the findings of...

    Provided By University of Minnesota

  • White Papers // Feb 2011

    Challenges In Demonstrating The Impact Of Overconfidence In M&A Activity

    One of the foundations of behavioral finance is the overconfidence hypothesis. Barberis and Thaler (2003) list it as one of the main beliefs that characterize study in the field. Simply put, the overconfidence hypothesis suggests that the subjects of study (investors or corporate managers) believe that they are more competent...

    Provided By University of Minnesota

  • White Papers // Jan 2011

    Efficient Data Collection From Wireless Nodes Under Two-Ring Communication Model

    Research on Wireless Sensor Networks (WSNs) has been very active in the last two decades with researchers focusing on issues ranging from deployments with coverage guarantees to the development of energy-efficient communication protocols to improve network lifetime. Consequently, the technology advanced to the level that WSNs are now being routinely...

    Provided By University of Minnesota

  • White Papers // Jan 2011

    Un-Zipping Cellular Infrastructure Locations Via User Geo-Intent

    Despite the rapid growth in cellular data traffic, the authors know very little about the (operational) Cellular Data Service Network (CDSN) infrastructure. A key step in the process of developing any such understanding is to first understand the locations and distribution of the base-stations in the CDSN infrastructure that serve...

    Provided By University of Minnesota

  • White Papers // Jan 2011

    Making Sense of Customer Tickets in Cellular Networks

    Effective management of large-scale cellular data networks is critical to meet customer demands and expectations. Customer calls for technical support provide direct indication as to the problems customers encounter. In this paper, the authors study the customer tickets - free-text recordings and classifications by customer support agents - collected at...

    Provided By University of Minnesota

  • White Papers // Jan 2011

    A First Look at Inter-Data Center Traffic Characteristics Via Yahoo! Datasets

    Recent years have seen unprecedented growth in the data center driven technologies and services. Various organizations are now sourcing their computing to "Cloud-based" infrastructures. Therefore, large scale data centers and associated cloud services are developed and deployed by various organizations and service providers to store massive amounts of data, and...

    Provided By University of Minnesota

  • White Papers // Jan 2011

    Deuteronomy: Transaction Support for Cloud Data

    The Deuteronomy system supports efficient and scalable ACID transactions in the cloud by decomposing functions of a database storage engine kernel into: a Transactional Component (TC) that manages transactions and their "Logical" concurrency control and undo/redo recovery, but knows nothing about physical data location and a Data Component (DC) that...

    Provided By University of Minnesota

  • White Papers // Jan 2011

    On-Demand Time Synchronization With Predictable Accuracy

    Time synchronization remains as a challenging task in wireless sensor networks that face severe resource constraints. Unlike previous work's aiming at pure clock accuracy, this paper proposes On-Demand Synchronization (ODS), a design to achieve efficient clock synchronization with customized performance. By carefully modeling the error uncertainty of skew detection and...

    Provided By University of Minnesota

  • White Papers // Jan 2011

    Heterogeneity-Aware Workload Distribution in Donation-Based Grids

    In this paper, the authors explore the tradeoffs and opportunities in porting a high-throughput Grid computing middleware to a high-performance service oriented environment. They present the limitations of the Grid computing middleware when operating in such a performance sensitive environment and suggest ways of overcoming these limitations. They focus on...

    Provided By University of Minnesota

  • White Papers // Jan 2011

    Practical Techniques for Eliminating Storage of Deleted Data

    The layered design of modern file systems hides the liveness of data from the underlying storage systems. In this paper, the authors define a generic "Purge" operation that can be used by a file system to pass liveness information to the storage system with minimal changes in the layer interfaces....

    Provided By University of Minnesota

  • White Papers // Jan 2011

    Proxy-Assisted Periodic Broadcast for Video Streaming With Multiple Servers

    Large scale video streaming over Internet requires a large amount of resources such as server I/O bandwidth, network bandwidth. A number of video delivery techniques can be used to lower these requirements. Periodic broadcast by a central server combined with proxy caching offers a significant reduction of the aggregate network...

    Provided By University of Minnesota

  • White Papers // Jan 2011

    Proxy-Assisted Periodic Broadcast Architecture for Large-Scale Video Streaming

    Many multimedia applications rely on video streaming techniques. However, large scale video delivery is still challenging since it requires a large amount of resources. This paper proposes a proxy-assisted periodic broadcast architecture for video delivery to a large number of clients over the Internet. The video delivery technique is based...

    Provided By University of Minnesota

  • White Papers // Dec 2010

    The Distributed Virtual Network for High Fidelity, Large Scale Peer to Peer Network Simulation

    The ability to analyze the behavior of large distributed systems can be limited by the modeling tools used. The Distributed Virtual Network (DVN) is a discrete event network simulator providing a platform for realistic, high fidelity, scalable and repeatable simulations of large distributed systems. With a global view of the...

    Provided By University of Minnesota

  • White Papers // Nov 2010

    Optimized Multi-Antenna Communication in Ad-Hoc Networks With Opportunistic Routing

    The authors consider the problem of using multiple antennas to maximize end-to-end performance in a multi-hop ad hoc wireless network with opportunistic routing. They find that when a single data stream is sent per-hop, performance is maximized by aggressively increasing spatial reuse, as opposed to increasing per-hop length or rate....

    Provided By University of Minnesota

  • White Papers // Nov 2010

    HOSPITAL: Host and Network System Profiler and Internet Traffic Analyzer

    The ever-increasing complexity and diversity of the Internet pose several challenges to network operators and administrators and, in general, Internet users. More specifically, because of the diversity in applications and usage patterns; the prevalence of dynamic IP addresses and applications that do not conform to standard configuration (e.g. VoIP to...

    Provided By University of Minnesota

  • White Papers // Oct 2010

    Dynamic Switching-Based Data Forwarding for Low-Duty-Cycle Wireless Sensor Networks

    In this paper, the authors introduce the concept of Dynamic Switch-based Forwarding (DSF) that optimizes the expected data delivery ratio, expected communication delay, or expected energy consumption for low-duty-cycle wireless sensor networks under unreliable communication links. DSF is designed for networks with possibly unreliable communication links and predetermined node communication...

    Provided By University of Minnesota

  • White Papers // Oct 2010

    VEIL-Click: Creating Advanced Large-Scale Ethernet Networks

    VEIL (Virtual Ethernet Identifier Layer) is a novel concept for below IP networking. It addresses the scalability, efficiency and reliability challenges facing the traditional Ethernet, while retaining its simplicity. Furthermore, it provides a uniform (Below IP) convergence layer to support a large, dynamic and heterogeneous (Layer-2) network that is capable...

    Provided By University of Minnesota

  • White Papers // Oct 2010

    Exact Hamming Distortion Analysis of Viterbi Encoded Trellis Coded Quantizers

    Let G be a finite strongly connected aperiodic directed graph in which each edge carries a label from a finite alphabet A. Then G induces a trellis coded quantizer for encoding an alphabet A memoryless source. A source sequence of long finite length is encoded by finding a path in...

    Provided By University of Minnesota

  • White Papers // Mar 2010

    Spatial Multiplexing With MMSE Receivers: Single-Stream Optimality in Ad Hoc Networks

    The performance of spatial multiplexing systems with linear minimum-mean-squared-error receivers is investigated in ad hoc networks. It is shown that single-stream transmission is preferable over multi-stream transmission, due to the weaker interference powers from the strongest interferers remaining after interference-cancelation. This result is obtained by new exact closed-form expressions the...

    Provided By University of Minnesota

  • White Papers // Dec 2009

    Multi-Antenna Communication in Ad Hoc Networks: Achieving MIMO Gains With SIMO Transmission

    The benefit of multi-antenna receivers is investigated in wireless ad hoc networks, and the main finding is that network throughput can be made to scale linearly with the number of receive antennas nR even if each transmitting node uses only a single antenna. This is in contrast to a large...

    Provided By University of Minnesota

  • White Papers // Mar 2010

    Opportunistic Routing in Ad Hoc Networks: How Many Relays Should There Be? What Rate Should Nodes Use?

    Opportunistic routing is a multi-hop routing scheme which allows for selection of the best immediately available relay. In blind opportunistic routing protocols, where transmitters blindly broadcast without knowledge of the surrounding nodes, two fundamental design parameters are the node transmission probability and the transmission spectral efficiency. In this paper, these...

    Provided By University of Minnesota

  • White Papers // Nov 2010

    Optimized Multi-Antenna Communication in Ad-Hoc Networks With Opportunistic Routing

    The authors consider the problem of using multiple antennas to maximize end-to-end performance in a multi-hop ad hoc wireless network with opportunistic routing. They find that when a single data stream is sent per-hop, performance is maximized by aggressively increasing spatial reuse, as opposed to increasing per-hop length or rate....

    Provided By University of Minnesota

  • White Papers // Jun 2011

    Cross-Layer Design of Coded Multicast for Wireless Random Access Networks

    Joint optimization of network coding and Aloha-based Medium Access Control (MAC) for multi-hop wireless networks is considered. The multicast throughput with a power consumption-related penalty is maximized subject to flow conservation and MAC achievable rate constraints to obtain the optimal transmission probabilities. The relevant optimization problem is inherently non-convex and...

    Provided By University of Minnesota

  • White Papers // Apr 2011

    Group Sparse Lasso for Cognitive Network Sensing Robust to Model Uncertainties and Outliers

    To account for variations in the frequency, time, and space dimensions, dynamic re-use of licensed bands under the Cognitive Radio (CR) paradigm calls for innovative network-level sensing algorithms for multi-dimensional spectrum opportunity awareness. Toward this direction, the present paper develops a collaborative scheme whereby CRs cooperate to localize active Primary...

    Provided By University of Minnesota

  • White Papers // Mar 2009

    Monetary Policy In India: Objectives, Reaction Function And Policy Effectiveness

    In the first part of this paper, the policy reaction functions of the Reserve Bank of India (RBI) have been modeled to see how policy stance decisions respond to the changes in the goal variables. In the second part, the transmission effects of RBI's policy stances on the goal variables...

    Provided By University of Minnesota

  • White Papers // Apr 2011

    Data Security in the Cloud

    Cloud computing is an emerging trend in the provision of computing resources. For economical reasons users are outsourcing applications and data storage to the cloud, a managed hardware infrastructure providing various services. As the cloud grows it becomes necessary to secure the data and applications from unwanted attackers. This paper...

    Provided By University of Minnesota

  • White Papers // Apr 2009

    Tracking With Unreliable Node Sequences

    Tracking mobile targets using sensor networks is a challenging task because of the impacts of in-the-field factors such as environment noise, sensing irregularity, etc. This paper proposes a robust tracking framework using node sequences, an ordered list extracted from unreliable sensor readings. Instead of estimating each position point separately in...

    Provided By University of Minnesota

  • White Papers // Feb 2011

    i-Code: A New Approach to Practical Network Coding for Content Distribution

    This paper studies the practicality of network coding to facilitate cooperative content distribution. Network coding is a new data transmission technique which allows any nodes in a network to encode and distribute data. It is a good solution offering reliability and efficiency in distributing content, but network coding has not...

    Provided By University of Minnesota

  • White Papers // Mar 2011

    Dynamic Outsourcing Mobile Computation to the Cloud

    Mobile devices are becoming the universal interface to online services and cloud computing applications. Since mobile phones have limited computing power and battery life, there is a potential to migrate computation intensive application components to external computing resources. The Cloud is an attractive platform for offloading due to elastic resource...

    Provided By University of Minnesota

  • White Papers // Jan 2011

    Efficient Data Collection From Wireless Nodes Under Two-Ring Communication Model

    Research on Wireless Sensor Networks (WSNs) has been very active in the last two decades with researchers focusing on issues ranging from deployments with coverage guarantees to the development of energy-efficient communication protocols to improve network lifetime. Consequently, the technology advanced to the level that WSNs are now being routinely...

    Provided By University of Minnesota

  • White Papers // Mar 2010

    Minimum Spanning Tree on Spatio-Temporal Networks

    Given a Spatio-Temporal network (ST network) whose edge properties vary with time, a Time-Sub-interval Minimum Spanning Tree (TSMST) is a collection of distinct minimum spanning trees of the ST network. The TSMST computation problem aims to identify a collection of distinct minimum spanning trees and their respective time-sub-intervals under the...

    Provided By University of Minnesota

  • White Papers // Aug 2010

    Keep Your Friends Close: Incorporating Trust Into Social Network-Based Sybil Defenses

    Social network-based Sybil defenses exploit the algorithmic properties of social graphs to infer the extent to which an arbitrary node in such a graph should be trusted. However, these systems do not consider the different amounts of trust represented by different graphs, and different levels of trust between nodes, though...

    Provided By University of Minnesota

  • White Papers // Dec 2010

    The Distributed Virtual Network for High Fidelity, Large Scale Peer to Peer Network Simulation

    The ability to analyze the behavior of large distributed systems can be limited by the modeling tools used. The Distributed Virtual Network (DVN) is a discrete event network simulator providing a platform for realistic, high fidelity, scalable and repeatable simulations of large distributed systems. With a global view of the...

    Provided By University of Minnesota

  • White Papers // Sep 2009

    Multi-Type Nearest Neighbor Queries Road Networks With Time Window Constraints

    A Multi-Type Nearest Neighbor (MTNN) query finds the shortest tour for a given query point and different types of spatial features such that only one instance of each feature is visited during the tour. In a real life MTNN query a user normally needs an answer with specific start time...

    Provided By University of Minnesota

  • White Papers // Sep 2009

    3D Reconstruction of Periodic Motion From a Single View

    Periodicity has been recognized as an important cue for tasks like activity recognition and gait analysis. However, most existing techniques analyze periodic motions only in image coordinates, making them very dependent on the viewing angle. In this paper, the authors show that it is possible to reconstruct a periodic trajectory...

    Provided By University of Minnesota

  • White Papers // Nov 2009

    Flexible Decision Support in Dynamic Inter-organizational Networks

    An effective Decision Support System (DSS) should help its users improve decision-making in complex, information-rich, dynamic environments. The authors present a feature gap analysis of current decision support technologies, and they identify a set of DSS Desiderata, properties that can contribute both effectiveness and flexibility to users in such environments....

    Provided By University of Minnesota

  • White Papers // Aug 2011

    Correlated Flooding in Low-Duty-Cycle Wireless Sensor Networks

    Flooding in low-duty-cycle wireless sensor networks is very costly due to asynchronous schedules of sensor nodes. To adapt existing flooding-tree-based designs for low-duty-cycle networks, the authors shall schedule nodes of common parents wake up simultaneously. Traditionally, energy optimality in a designated flooding-tree is achieved by selecting parents with the highest...

    Provided By University of Minnesota

  • White Papers // May 2010

    Bounding Communication Delay in Energy Harvesting Sensor Networks

    In energy-harvesting sensor networks, limited ambient energy from environment necessitates sensor nodes to operate at a low-duty-cycle, i.e., they communicate briefly and stay asleep most of time. Such low-duty-cycle operation leads to orders of magnitude longer communication delays in comparison with traditional always-active networks, imposing a new challenge in many...

    Provided By University of Minnesota

  • White Papers // Sep 2009

    Spatiotemporal Delay Control for Low-Duty-Cycle Sensor Networks

    Data delivery is a major function of sensor network applications. Many applications, such as military surveillance, require the detection of interested events to be reported to a command center within a specified time frame, and therefore impose a real-time bound on communication delay. On the other hand, to conserve energy,...

    Provided By University of Minnesota

  • White Papers // Sep 2009

    ESC: Energy Synchronized Communication in Sustainable Sensor Networks

    With advances in energy harvesting techniques, it is now feasible to build Sustainable Sensor Networks (SSN) to support long-term applications. Unlike battery-powered sensor networks, the objective of sustainable sensor networks is to effectively utilize a continuous stream of ambient energy. Instead of pushing the limits of energy conservation, the authors...

    Provided By University of Minnesota

  • White Papers // Oct 2009

    Virtual Scanning Algorithm for Road Network Surveillance

    This paper proposes a VIrtual Scanning Algorithm (VISA), tailored and optimized for road network surveillance. The authors' design uniquely leverages upon the facts that the movement of targets (e.g., vehicles) is confined within roadways and the road network maps are normally known. They guarantee the detection of moving targets before...

    Provided By University of Minnesota

  • White Papers // Jul 2011

    Safeguarding Schedule Updates in Wireless Sensor Networks

    Working in the duty cycling mode enables sensor nodes to utilize limited energy efficiently instead of unnecessary idle listening. In such networks, awareness of neighboring nodes' working schedules is essential, especially when each node sets up the schedule independently. Most traditional research assumes that a node can always share its...

    Provided By University of Minnesota

  • White Papers // Oct 2010

    Dynamic Switching-Based Data Forwarding for Low-Duty-Cycle Wireless Sensor Networks

    In this paper, the authors introduce the concept of Dynamic Switch-based Forwarding (DSF) that optimizes the expected data delivery ratio, expected communication delay, or expected energy consumption for low-duty-cycle wireless sensor networks under unreliable communication links. DSF is designed for networks with possibly unreliable communication links and predetermined node communication...

    Provided By University of Minnesota

  • White Papers // May 2009

    Exploring In-Situ Sensing Irregularity in Wireless Sensor Networks

    The circular sensing model has been widely used to estimate performance of sensing applications in existing analyses and simulations. While this model provides valuable high-level guidelines, the quantitative results obtained may not reflect the true performance of these applications, due to the sensing irregularity introduced by existence of obstacles in...

    Provided By University of Minnesota

  • White Papers // Apr 2009

    Impact of Fading on the Performance of ALOHA and CSMA

    This paper considers the performance of the ALOHA and CSMA MAC protocols in wireless ad hoc networks in the presence of fading. Increasing the rate of successful reception of packets is the authors' objective, and thus, outage probability is used as the performance evaluation metric. In their network model, packets...

    Provided By University of Minnesota

  • White Papers // Apr 2009

    Effects of Generic Types Specialization on Program Behavior

    Generic types are a language feature of Java that allows writing program code that is parameterized over types. The Java implementation of generic types uses a mechanism called type erasure. Type erasure creates a single instance of a generic class, removing all type specific usage information (e.g. whether it is...

    Provided By University of Minnesota

  • White Papers // Apr 2009

    Use of Profilers for Studying Java Dynamic Optimizations

    Java differs from many common programming languages in that Java programs are first compiled to platform-independent bytecode. Java bytecode is run by a program called the Java Virtual Machine (JVM). Because of this approach, Java programs are often optimized dynamically (i.e. at run-time) by the JVM. A Just-In-Time compiler (JIT)...

    Provided By University of Minnesota

  • White Papers // Aug 2009

    Extracting the Textual and Temporal Structure of Supercomputing Logs

    Supercomputers are prone to frequent faults that adversely affect their performance, reliability and functionality. System logs collected on these systems are a valuable resource of information about their operational status and health. However, their massive size, complexity, and lack of standard format makes it difficult to automatically extract information that...

    Provided By University of Minnesota

  • White Papers // Jan 2009

    Resource Bundles: Using Aggregation for Statistical Large-Scale Resource Discovery and Management

    Resource discovery is an important process for finding suitable nodes that satisfy application requirements in large loosely-coupled distributed systems. Besides inter-node heterogeneity, many of these systems also show a high degree of intra-node dynamism, so that selecting nodes based only on their recently observed resource capacities can lead to poor...

    Provided By University of Minnesota

  • White Papers // Jan 2011

    Heterogeneity-Aware Workload Distribution in Donation-Based Grids

    In this paper, the authors explore the tradeoffs and opportunities in porting a high-throughput Grid computing middleware to a high-performance service oriented environment. They present the limitations of the Grid computing middleware when operating in such a performance sensitive environment and suggest ways of overcoming these limitations. They focus on...

    Provided By University of Minnesota

  • White Papers // Jun 2009

    HiDRA: Statistical Multi-Dimensional Resource Discovery for Large-Scale Systems

    Resource discovery enables applications deployed in heterogeneous large-scale distributed systems to find resources that meet QoS requirements. In particular, most applications need resource requirements to be satisfied simultaneously for multiple resources (such as CPU, memory and network bandwidth). Due to dynamism in many large-scale systems, providing statistical guarantees on such...

    Provided By University of Minnesota

  • White Papers // Jan 2011

    Practical Techniques for Eliminating Storage of Deleted Data

    The layered design of modern file systems hides the liveness of data from the underlying storage systems. In this paper, the authors define a generic "Purge" operation that can be used by a file system to pass liveness information to the storage system with minimal changes in the layer interfaces....

    Provided By University of Minnesota

  • White Papers // Feb 2011

    Challenges In Demonstrating The Impact Of Overconfidence In M&A Activity

    One of the foundations of behavioral finance is the overconfidence hypothesis. Barberis and Thaler (2003) list it as one of the main beliefs that characterize study in the field. Simply put, the overconfidence hypothesis suggests that the subjects of study (investors or corporate managers) believe that they are more competent...

    Provided By University of Minnesota

  • White Papers // Aug 2010

    Capital Use Intensity And Productivity Biases

    Measures of productivity growth are often pro-cyclical. This paper focuses on measurement errors in capital inputs, associated with unobserved variations in capital utilization rates, as an explanation for the existence of pro-cyclical patterns in measures of productivity. Recently constructed national and state-specific indexes of inputs, outputs, and productivity in U.S....

    Provided By University of Minnesota

  • White Papers // Jul 2010

    Capital Services In U.S. Agriculture: Concepts, Comparisons, And The Treatment Of Interest Rates

    Measures of capital services are used in studies of production and to inform policies related to growth and development. A variety of methods have been used to measure capital stocks and service flows. The authors briefly review the methods commonly used to measure capital service flows, and the main assumptions....

    Provided By University of Minnesota

  • White Papers // Sep 2009

    Mendel Versus Malthus: Research, Productivity And Food Prices In The Long Run

    Over the past 50 years and longer, the supply of food commodities has grown faster than the effective market demand, in spite of increasing population and per capita incomes. Consequently, the real (deflated) prices of food commodities have steadily trended down. The past increases in agricultural productivity and production, and...

    Provided By University of Minnesota

  • White Papers // Aug 2010

    The Role Of Job Search Methods And Contacts On Commuting And Relocation Decisions

    This paper empirically explores the relationship between job finding and commuting outcomes and the relationship between job search and the commute and location outcomes of relocation decisions after finding employment. The relationship between commute outcomes when finding a new job and the job search method that one employs are explored...

    Provided By University of Minnesota

  • White Papers // Mar 2009

    Optimum Pilot Overhead in Wireless Communication: A Unified Treatment of Continuous and Block-Fading Channels

    The optimization of the pilot overhead in single-user wireless fading channels is investigated, and the dependence of this overhead on various system parameters of interest (e.g., fading rate, signal-to-noise ratio) is quantified. The achievable pilot-based spectral efficiency is expanded with respect to the fading rate about the no-fading point, which...

    Provided By University of Minnesota