Carleton University

Displaying 1-40 of 147 results

  • White Papers // Jan 2014

    Consistent Query Answering in Data Warehouses

    A Data Warehouse (DW) is a data repository that organizes and physically integrates data from multiple sources under special kinds of schemas. A DW is composed by a set of dimensions that reflect the way the data is structured, and the facts that correspond to quantitative data related with the...

    Provided By Carleton University

  • White Papers // Sep 2013

    Writing Down Your Password: Does It Help?

    Users are able to remember their phone numbers and postal codes, their student numbers, PIN numbers, and social insurance numbers. Why, then, do users have trouble remembering their passwords? This paper considers the hypothesis that being able to access written notes when needed would eventually help users to memorize the...

    Provided By Carleton University

  • White Papers // Sep 2013

    Network Latency Impact on Performance of Software Deployed Across Multiple Clouds

    In cloud computing, an \"Edge cloud\" may be introduced close to some of the end users, to give faster service for very demanding applications. The transactions that require heavy processing capacity and longer processing times are seen as more suitable to be carried out at the \"Core\" cloud. Parts in...

    Provided By Carleton University

  • White Papers // Aug 2013

    CloudOpt: Incremental Optimal Deployment for Dynamic Management of Clouds

    Management of large service centers and clouds requires adaptation to changing conditions and workload, which is usually based on ad hoc strategies. To obtain deployments that are close to the best possible, this paper applies large-scale optimization techniques to minimize energy use or other costs. Constraints force the satisfaction of...

    Provided By Carleton University

  • White Papers // Jul 2013

    Password Advice Shouldn't Be Boring: Visualizing Password Guessing Attacks

    Users are susceptible to password guessing attacks when they create weak passwords. Despite an abundance of text-based password advice, it appears insufficient to help home users create strong memorable passwords. The authors propose that users would be empowered to make better password choices if they understood how password guessing attacks...

    Provided By Carleton University

  • White Papers // Jun 2013

    Cloud Security: Attacks and Current Defenses

    This paper presents a high-level classification of current research in cloud computing security. Unlike past work, this classification is organized around attack strategies and corresponding defenses. Specifically, the authors outline several threat models for cloud computing systems, discuss specific attack mechanisms, and classify proposed defenses by how they address these...

    Provided By Carleton University

  • White Papers // May 2013

    The Usability of Captchas on Smartphones

    Completely Automated Public Turing tests to tell Computers and Humans Apart (CAPTCHA) are challenge response tests used on the web to distinguish human users from automated bots. In this paper, the authors present an exploratory analysis of the results obtained from a user study and a heuristic evaluation of Captchas...

    Provided By Carleton University

  • White Papers // May 2013

    Optimum Transmission Through the Gaussian Multiple Access Channel

    In this paper, the authors study the optimality of particular points in the capacity region of Gaussian Multiple Access Channels (GMACs) with various power constraints. The points of interest maximize general rate objectives that arise in practical communication scenarios. Achieving these points constitutes the task of jointly optimizing time-sharing parameters,...

    Provided By Carleton University

  • White Papers // May 2013

    Information Technology and Supply Chain Governance: A Conceptual Model

    In this paper, the authors apply three theories of governance in proposing a conceptual model of the relationship between Information Technology (IT) and Supply Chain Governance (SCG) and its conceptions (contractual, transactional and relational). They argue, theoretically, that with contractual governance, IT is used to control activities and processes across...

    Provided By Carleton University

  • White Papers // Apr 2013

    Improving User Authentication on Mobile Devices: A Touchscreen Graphical Password

    Typing text passwords is challenging when using touchscreens on mobile devices and this is becoming more problematic as mobile usage increases. The authors designed a new graphical password scheme called Touchscreen Multi-layered Drawing (TMD) specifically for use with touchscreens. They conducted an exploratory user study of three existing graphical passwords...

    Provided By Carleton University

  • White Papers // Mar 2013

    Radio Resource Management in a Coordinated Cellular Distributed Antenna System by Using Particle Swarm Optimization

    In this paper, the authors consider a Coordinated Multi-Point transmission (CoMP) scheme used in a cellular system where antenna ports are distributed throughout the cell, instead of using a single base station. Two schemes are considered; either ports can be switched on and off (Binary Power Management, BPM) or their...

    Provided By Carleton University

  • White Papers // Mar 2013

    Coordinated Multi-Point (CoMP) Adaptive Estimation and Prediction Schemes Using Superimposed and Decomposed Channel Tracking

    Performance of future wireless technologies will depend heavily on cooperation between different transmission/reception nodes in the access network. CoMP (Coordinated Multi-Point) transmission increases the cell edge user performance by reducing the inter-cell interference. UEs (User Equipments) simultaneously receive data from multiple base stations (eNBs) grouped into a joint transmission cluster....

    Provided By Carleton University

  • White Papers // Mar 2013

    SSL and HTTPS: Revisiting Past Challenges and Evaluating Certificate Trust Model Enhancements

    Internet users today depend daily on HTTPS for secure communication with sites they intend to visit. Over the years, many attacks on HTTPS and the certificate trust model it uses have been hypothesized, executed, and/or evolved. Meanwhile the number of browser-trusted (and thus, de facto, user-trusted) certificate authorities has proliferated,...

    Provided By Carleton University

  • White Papers // Feb 2013

    A Pricing Based Algorithm for Cell Switching Off in Green Cellular Networks

    In this paper, the authors propose a pricing based algorithm that assigns User Terminals (UTs) to Base Stations (BSs) and optimizes the transmission powers in a way that minimizes the energy expenditure. The algorithm takes into account the fixed energy expenditure that occurs even if a BS does not transmit...

    Provided By Carleton University

  • White Papers // Dec 2012

    Similarity of Polygonal Curves in the Presence of Outliers

    The Frechet distance is a well studied and commonly used measure to capture the similarity of polygonal curves. Unfortunately, it exhibits a high sensitivity to the presence of outliers. Since the presence of outliers is a frequently occurring phenomenon in practice, a robust variant of Frechet distance is required which...

    Provided By Carleton University

  • White Papers // Nov 2012

    Dynamic Operation of BSs in Green Wireless Cellular Networks Powered by the Smart Grid

    There is great interest in considering the energy efficiency aspect of wireless cellular networks. When a wireless cellular network is powered by the smart grid, only considering energy efficiency in the cellular network is not enough. In this paper, the authors consider not only energy-efficient communications but also the dynamics...

    Provided By Carleton University

  • White Papers // Nov 2012

    Dynamic Energy-Efficient Resource Allocation in Cognitive Heterogeneous Wireless Networks With the Smart Grid

    Rapidly rising energy costs and increasingly rigid environmental standards have led to an emerging trend of addressing the "Energy efficiency" aspect of wireless cellular networks. In cellular networks, Base Stations (BSs) are Power-hungry elements and absorbing them in the smart grid can significantly increase power efficiency. However, this important perspective...

    Provided By Carleton University

  • White Papers // Nov 2012

    Grassmannian Signalling Achieves the Ergodic High SNR Capacity of the Non-Coherent MIMO Relay Channel Within an SNR-Independent Gap

    This paper considers the ergodic non-coherent capacity of a multiple-input multiple-output frequency-flat block Rayleigh fading relay channel. It is shown that for this channel restricting the input distribution to be isotropic on a compact Grassmann manifold maximizes an upper bound on the cutset bound at high Signal-to-Noise Ratios (SNRs). Furthermore,...

    Provided By Carleton University

  • White Papers // Oct 2012

    A Decoding Procedure for Compress-and-Forward and Quantize-and-Forward Relaying

    In this paper, a decoding procedure is developed for both the Compress-and-Forward (CF) and the Short Message Quantize-and-Forward (QF-SM) relaying schemes. This procedure is based on exploiting a common feature of the mapping used by both schemes to determine the relay output from the estimate of its input. Using this...

    Provided By Carleton University

  • White Papers // Sep 2012

    Optimal Tradeoff Between Efficiency and Jain's Fairness Index in Resource Allocation

    In several systems, including wireless communication ones, certain services, which are referred to as benefits, are provided to multiple users based on the allocation of shared resources that are typically scarce. The allocation of these resources typically encounters conflicting goals. For instance, favoring a certain class of users may increase...

    Provided By Carleton University

  • White Papers // Sep 2012

    Turbo Receiver Design for MIMO Relay ARQ Transmissions

    In this paper, the authors investigate practical turbo receiver design for throughput-efficient relay ARQ transmissions over broadband cooperative MIMO channels. Their setup is comprised of three multi-antenna nodes: a source, a destination, and a relay node operating under the amplify-and-forward half-duplex relaying mode. To attain higher system average throughput, they...

    Provided By Carleton University

  • White Papers // Sep 2012

    A Genetic Algorithm Based Cell Switch-Off Scheme for Energy Saving in Dense Cell Deployments

    The energy consumption of mobile networks is rapidly growing; operators have both economic and environmental incentives to increase the energy efficiency of their networks. One way of saving energy is to switch off cells during periods of light traffic. However, cell switch-off is a difficult problem to solve through conventional...

    Provided By Carleton University

  • White Papers // Sep 2012

    Efficiently Computable Bounds on the Rates Achieved by a Cross Layer Design With Binary Scheduling in Generic OFDMA Wireless Networks

    Future broadband communication networks are expected to be OFDMA-based with generic ad hoc topologies, wherein the wireless nodes play multiple roles, including transmission, reception and relaying. When the schedules by which the OFDMA sub-channels are assigned to wireless links are binary, obtaining a characterization of the maximum rates that can...

    Provided By Carleton University

  • White Papers // Aug 2012

    Preventing the Cluster Formation Attack Against the Hierarchical OLSR Protocol

    The Hierarchical Optimized Link State Routing (HOLSR) protocol enhances the scalability and heterogeneity of traditional OLSR-based Mobile Ad-Hoc NETworks (MANETs). It organizes the network in logical levels and nodes in clusters. In every cluster, it implements the mechanisms and algorithms of the original OLSR to generate and to distribute control...

    Provided By Carleton University

  • White Papers // Aug 2012

    Supporting Learning of an Unfamiliar Authentication Scheme

    Plaintext password systems have been the ubiquitous method of authentication for computer applications and online Internet services for many years. All the while, users have been coping with difficulties with plaintext passwords, such as a lack of user understanding and ability to create and remember secure passwords. In response, a...

    Provided By Carleton University

  • White Papers // Jul 2012

    Software diversity: Security, Entropy and Game Theory

    Although many have recognized the risks of software monocultures, it is not currently clear how much and what kind of diversity would be needed to address these risks. Here, the authors attempt to provide insight into this issue using a simple model of hosts and vulnerabilities connected in a bipartite...

    Provided By Carleton University

  • White Papers // Jun 2012

    Not Sealed But Delivered: The (Un)Usability of S/MIME Today

    Despite widespread concerns about email privacy and security, today virtually all email is sent without encryption or authentication. Past work has identified usability issues with encrypted and digitally signed email. The most recent work in this area, however, with the more significant work having been done over a decade ago....

    Provided By Carleton University

  • White Papers // May 2012

    A Literature Review of Code Clone Analysis to Improve Software Maintenance Process

    Software systems are getting more complex as the system grows where maintaining such system is a primary concern for the industry. Code clone is one of the factors making software maintenance more difficult. It is a process of replicating code blocks by copy-and-paste that is common in software development. In...

    Provided By Carleton University

  • White Papers // May 2012

    System and Application Knowledge Based Scheduling of Multiple Applications in a WSN

    The paper concerns a Wireless Sensor Network (WSN) hosting multiple applications. The applications vary in terms of their resource requirements such as the number of sensors required by the applications and the location of the required sensors relative to a sink node. The requests for the various applications need to...

    Provided By Carleton University

  • White Papers // May 2012

    MAC Performance Improvement in UAV Ad-Hoc Networks With Full-Duplex Radios and Multi-Packet Reception Capability

    Recent advances in interference cancellation and signal processing techniques can enable full-duplex radios and multi-packet reception (MPR) capability, which will have significant impacts on the medium access control (MAC) design. In this paper, the authors study the MAC design in UAV ad-hoc networks with full-duplex radios and MPR. To efficiently...

    Provided By Carleton University

  • White Papers // May 2012

    A Token-Based Connectivity Update Scheme for Unmanned Aerial Vehicle Ad Hoc Networks

    Code Division Multiple Access Mobile Ad hoc NETworks (CDMA-MANETs) are envisioned to be the next generation networking architecture for networking military platforms in a battlefield. In this paper, the authors consider a CDMA ad hoc network consisting of multiple Unmanned Aerial Vehicles (UAVs). They propose a token-based connectivity update scheme...

    Provided By Carleton University

  • White Papers // May 2012

    Service Availability Analysis in Communication-Based Train Control (CBTC) Systems Using WLANs

    Data communication technology is one of the key subsystem in Communication-Based Train Control (CBTC), which is an automated train control system for railways that ensures safe operation of rail vehicles using data communications. In CBTC systems, less service availability could cause train derailment, collision or even catastrophic loss of lives...

    Provided By Carleton University

  • White Papers // May 2012

    Network Coding Based Wideband Compressed Spectrum Sensing

    One of the fundamental components in Cognitive Radios (CRs) is spectrum sensing. For sensing the wide range of frequency bands, CRs need high sampling rate Analog to Digital Converters (ADCs) which have to operate at or above the Nyquist rate. The high operating rate constitutes a major implementation challenge. Compressive...

    Provided By Carleton University

  • White Papers // May 2012

    Flow Availability Analysis in Two-Layer Networks With Dedicated Path Protection at the Upper Layer

    The authors propose an analytical model that computes availability of upper-layer flows in two-layer networks with dedicated path protection deployed at the upper layer. Their proposed model reduces overestimation of the existing model caused by the ignorance of upper-layer failure correlations. They compute the flow availability by properly taking into...

    Provided By Carleton University

  • White Papers // May 2012

    Optimal Server Assignment in Multi-Server Parallel Queueing Systems With Random Connectivities and Random Service Failures

    The problem of assignment of K identical servers to a set of N symmetric parallel queues is investigated in this paper. The parallel queueing system is considered to be time slotted and the connectivity of each queue to each server is varying randomly over time and following Bernoulli distribution with...

    Provided By Carleton University

  • White Papers // May 2012

    Iterative Recovery Algorithms for Compressed Sensing of Wideband Block Sparse Spectrums

    In a wireless communication environment, many of the Primary Users (PUs) do not use their licensed frequency bands at all times. The surveys show that the maximum frequency utilization of the allocated spectrum is less than 10%. To increase the frequency utilization in such environments, Secondary Users (SUs) equipped with...

    Provided By Carleton University

  • White Papers // May 2012

    Bottom-Up Trie Structure for P2P Live Streaming

    By simultaneously providing live video and audio contents to millions of users around the world, Peer-To-Peer Live Video Streaming (P2P LVS) has become one of the most popular Internet applications in recent years. However, current P2P LVS software has problems such as non-smooth playback and long start-up delay for end...

    Provided By Carleton University

  • White Papers // May 2012

    Optimizing the Monitoring Path Design for Independent Dual Failures

    This paper proposes a new monitoring path design paradigm for independent dual link failures. Specifically, the new approach exploits the sequential arrival and departure property of independent failure events to uniquely localize failed links. Such property, however, cannot be captured by the existing approach, which is built upon the notion...

    Provided By Carleton University

  • White Papers // May 2012

    Broadcasting in Multihop Wireless Networks: the Case for Multi-Source Network Coding

    Network Coding, in particular Random Linear Network Coding, has been extensively researched for communication in multihop wireless networks, such as MANETs. A key aspect of random linear network coding is the definition of generations, the set of native data packets that can be coded together. To keep the decoding complexity...

    Provided By Carleton University

  • White Papers // May 2012

    Joint Routing, Scheduling and Power Allocation in OFDMA Wireless Ad Hoc Networks

    In this paper an OFDMA-based wireless ad hoc network is considered. In addition to the potential of being a source and/or a destination, each node is assumed to be capable of decoding and forwarding its received packets to other nodes in the network. The goal is to determine the optimal...

    Provided By Carleton University