University of Alberta

Displaying 1-36 of 36 results

  • White Papers // Jul 2012

    Centralized and Distributed Power Allocation in Multi-User Wireless Relay Networks

    Optimal power allocation for multi-user amplify-and-forward wireless relay networks in which multiple source-destination pairs are assisted by a set of relays is investigated. Two relay power allocation strategies based on maximization of either the minimum rate among all users or the weighted sum of rates are developed. A distributed implementation...

    Provided By University of Alberta

  • White Papers // Apr 2012

    Simulating Service-Oriented Systems: A Survey and the Services-Aware Simulation Framework

    The service-oriented architecture style supports desirable qualities, including distributed, loosely-coupled systems spanning organizational boundaries. Such systems and their configurations are challenging to understand, reason about, and test. Improved understanding of these systems will support activities such as autonomic run-time configuration, application deployment, and development/testing. Simulation is one way to understand...

    Provided By University of Alberta

  • White Papers // Oct 2011

    Moving Text Analysis Tools to the Cloud

    Text analysis is an important computational task, as unstructured data including text abound and can potentially provide interesting information and knowledge in a variety of areas. In the authors' collaboration with Digital Humanists, they have started to examine the opportunities that the cloud offers to improving the response times of...

    Provided By University of Alberta

  • White Papers // Sep 2011

    Code Convention Adherence in Evolving Software

    Maintainability is a desired property of software, and a variety of metrics have been proposed for measuring it, focusing on different notions of complexity and code readability. Many practices have been proposed to improve maintainability through code re-factorings: improving the cohesion, simplification of interfaces, re-namings to improve understandability. Code conventions...

    Provided By University of Alberta

  • White Papers // Jul 2011

    Maintaining and Evolving Service Level Agreements: Motivation and Case Study

    Inter-organization service-oriented compositions are governed by Service Level Agreements (SLAs). While the software is maintained and evolved in response to changing business requirements or technology, the governing SLA and software configuration designed to meet this SLA do not always change in step. SLAs are negotiated and may have legal standing,...

    Provided By University of Alberta

  • White Papers // Jul 2011

    Automated State-Space Exploration for Configuration Management of Service-Oriented Applications

    Configuration management is a complex task, even for experienced system administrators, which makes self-managing systems a desirable solution. Self-management implies the need for a model based on which configuration changes may be decided. In previous work, the authors described a method for constructing a state-transition model of application behavior, by...

    Provided By University of Alberta

  • White Papers // Jun 2011

    Autonomic Configuration Adaptation Based on Simulation-Generated State-Transition Models

    Configuration management is a complex task, even for experienced system administrators, which makes self-managing systems a particularly desirable solution. This paper describes a novel contribution to self-managing systems, including an autonomic configuration self-optimization methodology. The authors' solution involves a systematic simulation method that develops a state-transition model of the behavior...

    Provided By University of Alberta

  • White Papers // Feb 2011

    Optimal Multiuser Zero Forcing With Per-Antenna Power Constraints for Network MIMO Coordination

    The authors consider a multicell Multiple-Input Multiple-Output (MIMO) coordinated downlink transmission, also known as network MIMO, under per-antenna power constraints. They investigate a simple multiuser Zero-Forcing (ZF) linear precoding technique known as Block Diagonalization (BD) for network MIMO. The optimal form of BD with per-antenna power constraints is proposed. It...

    Provided By University of Alberta

  • White Papers // Feb 2011

    Histogram and Other Aggregate Queries in Wireless Sensor Networks

    Wireless Sensor Networks (WSNs) are typically used to collect values of some phenomena in a monitored area. In many applications, users are interested in summaries of the observed data, e.g., a histogram reflecting the distribution of the collected values. However, processing a histogram query efficiently on top of WSN is...

    Provided By University of Alberta

  • White Papers // Jan 2011

    Structure Learning of Causal Bayesian Networks: A Survey

    Causality is a fundamental concept in reasoning. The effectiveness of many reasoning tasks depends on the understanding of the underlying cause-effect relationships. Therefore, the notion of causality has been explored in a wide range of disciplines. Causal discovery, however, was not modeled as a machine learning task until recently. Many...

    Provided By University of Alberta

  • White Papers // Jan 2011

    Reviving a Tangible Interface Affording 3D Spatial Interaction

    Tangible interfaces offer natural means of human computer interaction and have already been shown to simplify existing computerized applications and offer solutions for tasks that were considered to be "Out of the scope" of human-computer interaction. The authors are currently perusing new applications for 3D geometry defining tangible interfaces. In...

    Provided By University of Alberta

  • White Papers // Jan 2011

    Aggregation Convergecast Scheduling in Wireless Sensor Networks

    The authors consider the problem of aggregation convergecast scheduling in wireless sensor networks. Aggregation convergecast differs from regular convergecast in that it accommodates transmission dependencies that allow in-network aggregation to be performed. They formulate the abstract problem of aggregation convergecast and review the existing literature. They observe that existing schemes...

    Provided By University of Alberta

  • White Papers // Jan 2011

    Optimal Traffic-Oblivious Energy-Aware Routing for Multihop Wireless Networks

    Energy efficiency is an important issue in multi-hop wireless networks with energy concerns. Usually it is achieved with accurate knowledge of the traffic pattern and/or the current network information such as the remaining energy level. The authors investigate the problem of designing a routing scheme to minimize the maximum energy...

    Provided By University of Alberta

  • White Papers // Oct 2010

    Using Support Vector Machines to Learn How to Compile a Method

    The question addressed in this paper is what subset of code transformations should be attempted for a given method in a Just-in-Time compilation environment. The solution proposed is to use a Support Vector Machine (SVM) to learn a model based on method features and on the measured compilation and execution...

    Provided By University of Alberta

  • White Papers // Aug 2010

    Using RFID to Enhance Security in Off-Site Data Storage

    Off-site data storage is one of the most widely used strategies in enterprises of all sizes to improve business continuity. In medium-to-large size enterprises, the off-site data storage processes are usually outsourced to specialized providers. However, outsourcing the storage of critical business information assets raises serious security considerations, some of...

    Provided By University of Alberta

  • White Papers // Jul 2010

    A Simple Construction of 16-QAM Codewords With Low PMEPR for OFDM Signals

    Golay sequences have been introduced to construct 16-QAM (Quaternary Amplitude Modulation) code for the Orthogonal Frequency Division Multiplexing (OFDM), reducing the Peak-to-Mean Envelope Power Ratio (PMEPR). As an alternative way to construct Golay sequences, the construction of 16- QAM using Rudin-Shapiro Polynomials (RSP) was also reported recently in several literatures....

    Provided By University of Alberta

  • White Papers // Jul 2010

    Superimposed Pilot Based Joint CFO and Channel Estimation for CP-OFDM Modulated Two-Way Relay Networks

    This paper proposes a superimposed training strategy to estimate the individual frequency and channel parameters in an Amplify-and-Forward (AF) Two-Way Relay Network (TWRN). Two efficient suboptimal estimation algorithms and an iterative process to further improve the performance are proposed. The estimation Cramer-Rao Bound (CRB) on the proposed estimation strategy is...

    Provided By University of Alberta

  • White Papers // Jul 2010

    Feedback Delay Effect on Dual-Hop MIMO AF Relaying With Antenna Selection

    In this paper, the effect of feedback delays on the performance of multiple-input multiple-output antenna amplify-and-forward relay networks with the best transmit/receive antenna pair selection over Rayleigh fading is studied. The cumulative distribution function and the moment generating function of the end-to-end Signal-to-Noise Ratio (SNR) are derived. Closed-form expressions for...

    Provided By University of Alberta

  • White Papers // Jul 2010

    Generalized Singular Value Decomposition for Coordinated Beamforming in MIMO Systems

    In this paper, the authors examine the use of Generalized Singular Value Decomposition (GSVD) for coordinated beamforming in MIMO systems. GSVD facilitates joint decomposition of a class of matrices arising inherently in source-to-2 destination MIMO broadcast scenarios. GSVD allows two channels of suitable dimensionality to be jointly diagonalized, i.e. to...

    Provided By University of Alberta

  • White Papers // Jul 2010

    Transmit Antenna Selection Strategies for Cooperative MIMO AF Relay Networks

    In this paper, an analytical framework is developed for the performance analysis of three Transmit Antenna Selection (TAS) strategies for dual-hop multiple-input multiple-output Channel-Assisted Amplify-and-Forward (CA-AF) relay networks over Rayleigh fading. The cumulative distribution function of a lower bound of the end-to-end Signal-to-Noise Ratio (SNR) of the optimal TAS strategy...

    Provided By University of Alberta

  • White Papers // Jul 2010

    Opportunistic Relaying in Two-Way Networks

    This paper is on opportunistic relaying for networks with two-way communications. For a network with two users that exchange information with each other through multiple amplify-and-forward relays, the authors propose a single-relay selection scheme. Since the communication is two-way, the proposed scheme aims at optimizing the worse performance of the...

    Provided By University of Alberta

  • White Papers // Jul 2010

    BEM-Based Estimation for Time-Varying Channels and Training Design in Two-Way Relay Networks

    In this paper, channel estimation for Two-Way Relay Networks (TWRNs) over time-varying channels is investigated. The authors consider the Amplify-and-Forward (AF) relaying scheme and adopt the Complex-Exponential Basis Expansion Model (CE-BEM) that represents the time-varying channel by a finite number of parameters. They develop the estimation methods for both the...

    Provided By University of Alberta

  • White Papers // Jul 2010

    Local And Global Merchant Networks: Accounting Across Space And Time

    The authors' paper has three main objectives. First, they build upon the earlier research of the Guide du Commerce (1773) and French trade to examine business networks emanating from eighteenth-century Nantes. Second, through the use of techniques drawn from social theory, they analyse these networks in terms of their linkages...

    Provided By University of Alberta

  • White Papers // Jun 2010

    Multi-Hop Relay Networks With Multiple-Antenna Equipped Source and Destination

    The performance of a multi-hop amplify-and-forward relay network is analyzed. The source and destination terminals are equipped with multiple-antennas and the relays with single-antennas. The cumulative distribution function and the moment generating function of two tight upper bounds of the end-to-end signal-to-noise ratio are derived. The lower bounds for the...

    Provided By University of Alberta

  • White Papers // May 2010

    Superimposed Pilots Aided Joint CFO and Channel Estimation for ZP-OFDM Modulated Two-Way Relay Networks

    Existing works on joint Carrier Frequency Offset (CFO) and channel estimation in Two-Way Relay Networks (TWRN) only deal with the convoluted channel parameters and the mixed CFO values. In this paper, the authors design a superimposed pilot based training strategy from the relay node such that the individual frequency and...

    Provided By University of Alberta

  • White Papers // May 2010

    The Capitalization Of Taxes In Bond Prices: Evidence From The Market For Government Of Canada Bonds

    This paper provides estimates of the extent to which corporate and personal income taxes are capitalized in bond prices. The methodology yields estimates of the degree of tax capitalization, rather than an implied tax rate. This makes it straightforward to identify the marginal investor and test for changes in tax...

    Provided By University of Alberta

  • White Papers // Jan 2010

    Visualizing Web Navigation Data With Polygon Graphs

    As the volume of digitally accessible information grows, there is increasing pressure on the development of data visualization methods to enable humans to interpret that data. This paper provides a description of the WebViz system, as a tool to visualize both the structure and usage of web sites. It illustrates...

    Provided By University of Alberta

  • White Papers // Nov 2009

    Predicting Object-Oriented Software Quality: A Case Study

    Software quality lags far behind the quality of any other engineered product that humans create, and yet software systems are essential to the modern world. Software engineers have long proposed reusing existing software components to improve overall system quality. As part of a reuse process, the reliability of a component...

    Provided By University of Alberta

  • White Papers // Jun 2009

    Disjoint LDPC Coding for Gaussian Broadcast Channels

    Low-Density Parity-Check (LDPC) codes have been used for communication over a two-user Gaussian broadcast channel. It has been shown in the literature that the optimal decoding of such system requires joint decoding of both user messages at each user. Also, a joint code design procedure should be performed. The authors...

    Provided By University of Alberta

  • White Papers // Jun 2009

    Generalized Agency Problems

    Agency problems in economics virtually always entail self-interested agency exhibiting "Insufficient" loyalty to principal. Social psychology also has a literature, mainly derived from work by Stanley Milgram, on issues of agency, but this emphasizes excessive loyalty - people undergoing a so-called "Agentic shift" and forsaking rationality for loyalty to a...

    Provided By University of Alberta

  • White Papers // May 2009

    Optimizing XML Compression

    The eXtensible Markup Language (XML) provides a powerful and flexible means of encoding and exchanging data. As it turns out, its main advantage as an encoding format (namely, its requirement that all open and close markup tags are present and properly balanced) yield also one of its main disadvantages: Verbosity....

    Provided By University of Alberta

  • White Papers // Apr 2009

    Resource Allocation and QoS Provisioning for Wireless Relay Networks

    Emerging broadband wireless applications in most wireless networks require increasingly high throughput and more stringent Quality-of-Service (QoS) requirements. In this respect, multiple-antenna technologies have been recognized as important solutions for future high-speed wireless networks. Particularly, employment of multiple antennas at transmitter and/or receiver sides can provide significant multiplexing and/or diversity...

    Provided By University of Alberta

  • White Papers // Feb 2009

    To Bundle Or Not To Bundle: On The Profitability Of Multi-Item Auctions

    Bundling, a strategy of selling two or more distinct products as a package for a single price, is widely practiced in today's marketplace. The paper investigates under what conditions it is more profitable to auction two items jointly as a bundle vs. separately, and examines how this is determined by...

    Provided By University of Alberta

  • White Papers // Jan 2009

    Cooperative Decision-Making in Decentralized Multiple-Robot Systems: The Best-of-N Problem

    Multiple-Robot Systems (MRS) that is decentrally organized has many benefits over centralized systems. Decentralized systems are less affected by computational and communicative bottlenecks, and they are more robust to the loss of individual member robots. System-level cognitive operations, though, are much more difficult to implement in decentralized systems. One example...

    Provided By University of Alberta

  • White Papers // Jan 2009

    On Reliable Transmission of Data Over Simple Wireless Channels

    Standard protocols for reliable data transmission over unreliable channels are based on various Automatic Repeat reQuest (ARQ) schemes, whereby the sending node receives feedback from the receiver and retransmits the missing data. The authors discuss this issue in the context of one-way data transmission over simple wireless channels characteristic of...

    Provided By University of Alberta

  • White Papers // Jan 2008

    Option Introduction, Short Sale Constraints And The Speed Of Stock Price Adjustment To Negative News

    This paper investigates the effect of option introduction on short sale constraints. The author finds that post option improvement in adjustment efficiency is isolated to short sale constrained (low institutional ownership) stocks responding to negative information. No significant improvement in adjustment efficiency is found in response to positive information, across...

    Provided By University of Alberta

  • White Papers // Jan 2010

    Visualizing Web Navigation Data With Polygon Graphs

    As the volume of digitally accessible information grows, there is increasing pressure on the development of data visualization methods to enable humans to interpret that data. This paper provides a description of the WebViz system, as a tool to visualize both the structure and usage of web sites. It illustrates...

    Provided By University of Alberta

  • White Papers // Feb 2009

    To Bundle Or Not To Bundle: On The Profitability Of Multi-Item Auctions

    Bundling, a strategy of selling two or more distinct products as a package for a single price, is widely practiced in today's marketplace. The paper investigates under what conditions it is more profitable to auction two items jointly as a bundle vs. separately, and examines how this is determined by...

    Provided By University of Alberta

  • White Papers // Jun 2009

    Generalized Agency Problems

    Agency problems in economics virtually always entail self-interested agency exhibiting "Insufficient" loyalty to principal. Social psychology also has a literature, mainly derived from work by Stanley Milgram, on issues of agency, but this emphasizes excessive loyalty - people undergoing a so-called "Agentic shift" and forsaking rationality for loyalty to a...

    Provided By University of Alberta

  • White Papers // Jan 2011

    Reviving a Tangible Interface Affording 3D Spatial Interaction

    Tangible interfaces offer natural means of human computer interaction and have already been shown to simplify existing computerized applications and offer solutions for tasks that were considered to be "Out of the scope" of human-computer interaction. The authors are currently perusing new applications for 3D geometry defining tangible interfaces. In...

    Provided By University of Alberta

  • White Papers // Jan 2009

    Cooperative Decision-Making in Decentralized Multiple-Robot Systems: The Best-of-N Problem

    Multiple-Robot Systems (MRS) that is decentrally organized has many benefits over centralized systems. Decentralized systems are less affected by computational and communicative bottlenecks, and they are more robust to the loss of individual member robots. System-level cognitive operations, though, are much more difficult to implement in decentralized systems. One example...

    Provided By University of Alberta

  • White Papers // May 2010

    The Capitalization Of Taxes In Bond Prices: Evidence From The Market For Government Of Canada Bonds

    This paper provides estimates of the extent to which corporate and personal income taxes are capitalized in bond prices. The methodology yields estimates of the degree of tax capitalization, rather than an implied tax rate. This makes it straightforward to identify the marginal investor and test for changes in tax...

    Provided By University of Alberta

  • White Papers // May 2009

    Optimizing XML Compression

    The eXtensible Markup Language (XML) provides a powerful and flexible means of encoding and exchanging data. As it turns out, its main advantage as an encoding format (namely, its requirement that all open and close markup tags are present and properly balanced) yield also one of its main disadvantages: Verbosity....

    Provided By University of Alberta

  • White Papers // Jun 2009

    Disjoint LDPC Coding for Gaussian Broadcast Channels

    Low-Density Parity-Check (LDPC) codes have been used for communication over a two-user Gaussian broadcast channel. It has been shown in the literature that the optimal decoding of such system requires joint decoding of both user messages at each user. Also, a joint code design procedure should be performed. The authors...

    Provided By University of Alberta

  • White Papers // Jul 2010

    Local And Global Merchant Networks: Accounting Across Space And Time

    The authors' paper has three main objectives. First, they build upon the earlier research of the Guide du Commerce (1773) and French trade to examine business networks emanating from eighteenth-century Nantes. Second, through the use of techniques drawn from social theory, they analyse these networks in terms of their linkages...

    Provided By University of Alberta

  • White Papers // Jul 2010

    A Simple Construction of 16-QAM Codewords With Low PMEPR for OFDM Signals

    Golay sequences have been introduced to construct 16-QAM (Quaternary Amplitude Modulation) code for the Orthogonal Frequency Division Multiplexing (OFDM), reducing the Peak-to-Mean Envelope Power Ratio (PMEPR). As an alternative way to construct Golay sequences, the construction of 16- QAM using Rudin-Shapiro Polynomials (RSP) was also reported recently in several literatures....

    Provided By University of Alberta

  • White Papers // Jul 2010

    Opportunistic Relaying in Two-Way Networks

    This paper is on opportunistic relaying for networks with two-way communications. For a network with two users that exchange information with each other through multiple amplify-and-forward relays, the authors propose a single-relay selection scheme. Since the communication is two-way, the proposed scheme aims at optimizing the worse performance of the...

    Provided By University of Alberta

  • White Papers // Jul 2010

    BEM-Based Estimation for Time-Varying Channels and Training Design in Two-Way Relay Networks

    In this paper, channel estimation for Two-Way Relay Networks (TWRNs) over time-varying channels is investigated. The authors consider the Amplify-and-Forward (AF) relaying scheme and adopt the Complex-Exponential Basis Expansion Model (CE-BEM) that represents the time-varying channel by a finite number of parameters. They develop the estimation methods for both the...

    Provided By University of Alberta

  • White Papers // Jul 2010

    Feedback Delay Effect on Dual-Hop MIMO AF Relaying With Antenna Selection

    In this paper, the effect of feedback delays on the performance of multiple-input multiple-output antenna amplify-and-forward relay networks with the best transmit/receive antenna pair selection over Rayleigh fading is studied. The cumulative distribution function and the moment generating function of the end-to-end Signal-to-Noise Ratio (SNR) are derived. Closed-form expressions for...

    Provided By University of Alberta

  • White Papers // Jul 2010

    Generalized Singular Value Decomposition for Coordinated Beamforming in MIMO Systems

    In this paper, the authors examine the use of Generalized Singular Value Decomposition (GSVD) for coordinated beamforming in MIMO systems. GSVD facilitates joint decomposition of a class of matrices arising inherently in source-to-2 destination MIMO broadcast scenarios. GSVD allows two channels of suitable dimensionality to be jointly diagonalized, i.e. to...

    Provided By University of Alberta

  • White Papers // Jul 2010

    Superimposed Pilot Based Joint CFO and Channel Estimation for CP-OFDM Modulated Two-Way Relay Networks

    This paper proposes a superimposed training strategy to estimate the individual frequency and channel parameters in an Amplify-and-Forward (AF) Two-Way Relay Network (TWRN). Two efficient suboptimal estimation algorithms and an iterative process to further improve the performance are proposed. The estimation Cramer-Rao Bound (CRB) on the proposed estimation strategy is...

    Provided By University of Alberta

  • White Papers // Jul 2010

    Transmit Antenna Selection Strategies for Cooperative MIMO AF Relay Networks

    In this paper, an analytical framework is developed for the performance analysis of three Transmit Antenna Selection (TAS) strategies for dual-hop multiple-input multiple-output Channel-Assisted Amplify-and-Forward (CA-AF) relay networks over Rayleigh fading. The cumulative distribution function of a lower bound of the end-to-end Signal-to-Noise Ratio (SNR) of the optimal TAS strategy...

    Provided By University of Alberta

  • White Papers // Jun 2010

    Multi-Hop Relay Networks With Multiple-Antenna Equipped Source and Destination

    The performance of a multi-hop amplify-and-forward relay network is analyzed. The source and destination terminals are equipped with multiple-antennas and the relays with single-antennas. The cumulative distribution function and the moment generating function of two tight upper bounds of the end-to-end signal-to-noise ratio are derived. The lower bounds for the...

    Provided By University of Alberta

  • White Papers // May 2010

    Superimposed Pilots Aided Joint CFO and Channel Estimation for ZP-OFDM Modulated Two-Way Relay Networks

    Existing works on joint Carrier Frequency Offset (CFO) and channel estimation in Two-Way Relay Networks (TWRN) only deal with the convoluted channel parameters and the mixed CFO values. In this paper, the authors design a superimposed pilot based training strategy from the relay node such that the individual frequency and...

    Provided By University of Alberta

  • White Papers // Apr 2009

    Resource Allocation and QoS Provisioning for Wireless Relay Networks

    Emerging broadband wireless applications in most wireless networks require increasingly high throughput and more stringent Quality-of-Service (QoS) requirements. In this respect, multiple-antenna technologies have been recognized as important solutions for future high-speed wireless networks. Particularly, employment of multiple antennas at transmitter and/or receiver sides can provide significant multiplexing and/or diversity...

    Provided By University of Alberta

  • White Papers // Jan 2011

    Aggregation Convergecast Scheduling in Wireless Sensor Networks

    The authors consider the problem of aggregation convergecast scheduling in wireless sensor networks. Aggregation convergecast differs from regular convergecast in that it accommodates transmission dependencies that allow in-network aggregation to be performed. They formulate the abstract problem of aggregation convergecast and review the existing literature. They observe that existing schemes...

    Provided By University of Alberta

  • White Papers // Jan 2011

    Structure Learning of Causal Bayesian Networks: A Survey

    Causality is a fundamental concept in reasoning. The effectiveness of many reasoning tasks depends on the understanding of the underlying cause-effect relationships. Therefore, the notion of causality has been explored in a wide range of disciplines. Causal discovery, however, was not modeled as a machine learning task until recently. Many...

    Provided By University of Alberta

  • White Papers // Feb 2011

    Histogram and Other Aggregate Queries in Wireless Sensor Networks

    Wireless Sensor Networks (WSNs) are typically used to collect values of some phenomena in a monitored area. In many applications, users are interested in summaries of the observed data, e.g., a histogram reflecting the distribution of the collected values. However, processing a histogram query efficiently on top of WSN is...

    Provided By University of Alberta

  • White Papers // Jan 2008

    Option Introduction, Short Sale Constraints And The Speed Of Stock Price Adjustment To Negative News

    This paper investigates the effect of option introduction on short sale constraints. The author finds that post option improvement in adjustment efficiency is isolated to short sale constrained (low institutional ownership) stocks responding to negative information. No significant improvement in adjustment efficiency is found in response to positive information, across...

    Provided By University of Alberta

  • White Papers // Feb 2011

    Optimal Multiuser Zero Forcing With Per-Antenna Power Constraints for Network MIMO Coordination

    The authors consider a multicell Multiple-Input Multiple-Output (MIMO) coordinated downlink transmission, also known as network MIMO, under per-antenna power constraints. They investigate a simple multiuser Zero-Forcing (ZF) linear precoding technique known as Block Diagonalization (BD) for network MIMO. The optimal form of BD with per-antenna power constraints is proposed. It...

    Provided By University of Alberta

  • White Papers // Jan 2011

    Optimal Traffic-Oblivious Energy-Aware Routing for Multihop Wireless Networks

    Energy efficiency is an important issue in multi-hop wireless networks with energy concerns. Usually it is achieved with accurate knowledge of the traffic pattern and/or the current network information such as the remaining energy level. The authors investigate the problem of designing a routing scheme to minimize the maximum energy...

    Provided By University of Alberta

  • White Papers // Jan 2009

    On Reliable Transmission of Data Over Simple Wireless Channels

    Standard protocols for reliable data transmission over unreliable channels are based on various Automatic Repeat reQuest (ARQ) schemes, whereby the sending node receives feedback from the receiver and retransmits the missing data. The authors discuss this issue in the context of one-way data transmission over simple wireless channels characteristic of...

    Provided By University of Alberta

  • White Papers // Oct 2010

    Using Support Vector Machines to Learn How to Compile a Method

    The question addressed in this paper is what subset of code transformations should be attempted for a given method in a Just-in-Time compilation environment. The solution proposed is to use a Support Vector Machine (SVM) to learn a model based on method features and on the measured compilation and execution...

    Provided By University of Alberta

  • White Papers // Nov 2009

    Predicting Object-Oriented Software Quality: A Case Study

    Software quality lags far behind the quality of any other engineered product that humans create, and yet software systems are essential to the modern world. Software engineers have long proposed reusing existing software components to improve overall system quality. As part of a reuse process, the reliability of a component...

    Provided By University of Alberta

  • White Papers // Jul 2012

    Centralized and Distributed Power Allocation in Multi-User Wireless Relay Networks

    Optimal power allocation for multi-user amplify-and-forward wireless relay networks in which multiple source-destination pairs are assisted by a set of relays is investigated. Two relay power allocation strategies based on maximization of either the minimum rate among all users or the weighted sum of rates are developed. A distributed implementation...

    Provided By University of Alberta

  • White Papers // Apr 2012

    Simulating Service-Oriented Systems: A Survey and the Services-Aware Simulation Framework

    The service-oriented architecture style supports desirable qualities, including distributed, loosely-coupled systems spanning organizational boundaries. Such systems and their configurations are challenging to understand, reason about, and test. Improved understanding of these systems will support activities such as autonomic run-time configuration, application deployment, and development/testing. Simulation is one way to understand...

    Provided By University of Alberta

  • White Papers // Jun 2011

    Autonomic Configuration Adaptation Based on Simulation-Generated State-Transition Models

    Configuration management is a complex task, even for experienced system administrators, which makes self-managing systems a particularly desirable solution. This paper describes a novel contribution to self-managing systems, including an autonomic configuration self-optimization methodology. The authors' solution involves a systematic simulation method that develops a state-transition model of the behavior...

    Provided By University of Alberta

  • White Papers // Jul 2011

    Maintaining and Evolving Service Level Agreements: Motivation and Case Study

    Inter-organization service-oriented compositions are governed by Service Level Agreements (SLAs). While the software is maintained and evolved in response to changing business requirements or technology, the governing SLA and software configuration designed to meet this SLA do not always change in step. SLAs are negotiated and may have legal standing,...

    Provided By University of Alberta

  • White Papers // Jul 2011

    Automated State-Space Exploration for Configuration Management of Service-Oriented Applications

    Configuration management is a complex task, even for experienced system administrators, which makes self-managing systems a desirable solution. Self-management implies the need for a model based on which configuration changes may be decided. In previous work, the authors described a method for constructing a state-transition model of application behavior, by...

    Provided By University of Alberta

  • White Papers // Sep 2011

    Code Convention Adherence in Evolving Software

    Maintainability is a desired property of software, and a variety of metrics have been proposed for measuring it, focusing on different notions of complexity and code readability. Many practices have been proposed to improve maintainability through code re-factorings: improving the cohesion, simplification of interfaces, re-namings to improve understandability. Code conventions...

    Provided By University of Alberta

  • White Papers // Oct 2011

    Moving Text Analysis Tools to the Cloud

    Text analysis is an important computational task, as unstructured data including text abound and can potentially provide interesting information and knowledge in a variety of areas. In the authors' collaboration with Digital Humanists, they have started to examine the opportunities that the cloud offers to improving the response times of...

    Provided By University of Alberta

  • White Papers // Aug 2010

    Using RFID to Enhance Security in Off-Site Data Storage

    Off-site data storage is one of the most widely used strategies in enterprises of all sizes to improve business continuity. In medium-to-large size enterprises, the off-site data storage processes are usually outsourced to specialized providers. However, outsourcing the storage of critical business information assets raises serious security considerations, some of...

    Provided By University of Alberta