University of Toronto

Displaying 1-40 of 195 results

  • White Papers // Jun 2012

    Cost Efficient Datacenter Selection for Cloud Services

    Many cloud services nowadays are running on top of geographically distributed infrastructures for better reliability and performance. They need an effective way to direct the user requests to a suitable datacenter, in a cost efficient manner. Previous work focused mostly on the electricity cost of datacenters. The approaches favor datacenters...

    Provided By University of Toronto

  • White Papers // May 2012

    MixApart: Decoupled Analytics for Shared Storage Systems

    Data analytics and enterprise applications have very different storage functionality requirements. For this reason, enterprise deployments of data analytics are on a separate storage silo. This may generate additional costs and inefficiencies in data management, e.g., whenever data needs to be archived, copied, or migrated across silos. The authors introduce...

    Provided By University of Toronto

  • White Papers // May 2012

    Oruta: Privacy-Preserving Public Auditing for Shared Data in the Cloud

    With cloud storage services, it is commonplace for data to be not only stored in the cloud, but also shared across multiple users. However, public auditing for such shared data - while preserving identity privacy - remains to be an open challenge. In this paper, the authors propose the first...

    Provided By University of Toronto

  • White Papers // May 2012

    A General and Practical Datacenter Selection Framework for Cloud Services

    Many cloud services nowadays are running on top of geographically distributed infrastructures for better reliability and performance. They need an effective way to direct the user requests to a suitable datacenter, depending on factors including performance, cost, etc. Previous work focused on efficiency and invariably considered the simple objective of...

    Provided By University of Toronto

  • White Papers // Apr 2012

    Postcard: Minimizing Costs on Inter-Datacenter Traffic With Store-and-Forward

    It is typical for cloud providers to operate a number of geographically distributed datacenters, where inter-datacenter traffic constitutes a large portion of a cloud provider's traffic demand over the Internet. Though such inter-datacenter traffic incurs substantial operational costs that are charged by ISPs, it varies significantly across different overlay links,...

    Provided By University of Toronto

  • White Papers // Apr 2012

    Towards Optimal Capacity Segmentation With Hybrid Cloud Pricing

    Cloud resources are usually priced in multiple markets with different service guarantees. For example, Amazon EC2 prices virtual instances under three pricing schemes - the subscription option (a.k.a., Reserved Instances), the pay-as-you-go offer (a.k.a., On-Demand Instances), and an auction-like spot market (a.k.a., Spot Instances) - simultaneously. There arises a new...

    Provided By University of Toronto

  • White Papers // Mar 2012

    Bargaining Towards Maximized Resource Utilization in Video Streaming Datacenters

    Datacenters can be used to host large-scale video streaming services with better operational efficiency, as the multiplexing achieved by virtualization technologies allows different videos to share resources at the same physical server. Live migration of videos from servers that are overloaded to those that are under-utilized may be a solution...

    Provided By University of Toronto

  • White Papers // Mar 2012

    Distributional Measures of Semantic Distance: A Survey

    The ability to mimic human notions of semantic distance has widespread applications. Some measures rely only on raw text (distributional measures) and some rely on knowledge sources such as WordNet. Although extensive studies have been performed to compare WordNet-based measures with human judgment, the use of distributional measures as proxies...

    Provided By University of Toronto

  • White Papers // Feb 2012

    Maximizing Revenue With Dynamic Cloud Pricing: The Infinite Horizon Case

    The authors study the infinite horizon dynamic pricing problem for an infrastructure cloud provider in the emerging cloud computing paradigm. The cloud provider, such as Amazon, provides computing capacity in the form of virtual instances and charges customers a time-varying price for the period they use the instances. The provider's...

    Provided By University of Toronto

  • White Papers // Jan 2012

    Quality-Assured Cloud Bandwidth Auto-Scaling for Video-on-Demand Applications

    There has been a recent trend that Video-on-Demand (VoD) providers such as Netflix are leveraging resources from cloud services for multimedia streaming. In this paper, the authors consider the scenario that a VoD provider can make reservations for bandwidth guarantees from cloud service providers to guarantee the streaming performance in...

    Provided By University of Toronto

  • White Papers // Jan 2012

    A Theory of Cloud Bandwidth Pricing for Video-on-Demand Providers

    Current-generation cloud computing is offered with usage-based pricing, with no bandwidth capacity guarantees, which is however unappealing to bandwidth-intensive applications such as Video-on-Demand (VoD). The authors consider a new type of service where VoD providers, such as Netflix and Hulu, make reservations for bandwidth guarantees from the cloud at negotiable...

    Provided By University of Toronto

  • White Papers // Jan 2012

    Jointly Optimal Bit Loading, Channel Pairing and Power Allocation for Multi-Channel Relaying

    The authors aim to enhance the end-to-end rate of a general dual-hop relay network with multiple channels and finite modulation formats, by jointly optimizing channel pairing, power allocation, and integer bit loading. Such an optimization problem has both a discrete feasible region, due to the combinatoric nature of channel pairing,...

    Provided By University of Toronto

  • White Papers // Jan 2012

    Truthful Spectrum Auction Design for Secondary Networks

    Opportunistic wireless channel access by non-licensed users has emerged as a promising solution for addressing the bandwidth scarcity challenge. Auctions represent a natural mechanism for allocating the spectrum, generating an economic incentive for the licensed user to relinquish channels. A severe limitation of existing spectrum auction designs lies in the...

    Provided By University of Toronto

  • White Papers // Jan 2012

    Supporting Efficient Collective Communication in NoCs

    Across many architectures and parallel programming paradigms, collective communication plays a key role in performance and correctness. Hardware support is necessary to prevent important collective communication from becoming a system bottleneck. Support for multicast communication in Networks-on-Chip (NoCs) has achieved substantial throughput improvements and power savings. In this paper, the...

    Provided By University of Toronto

  • White Papers // Jan 2012

    MANET Extensions to Ns2

    This is a set of software modules providing additional models for the simulation of multi-hop Mobile Ad hoc NETworks (MANETs) in the ns2 simulator. The authors provide implementations of the CM and Shell mobility models, and the AF and LOS radio propagation models described in. They also provide instrumentation tools...

    Provided By University of Toronto

  • White Papers // Jan 2012

    SFlow: Towards Resource-Efficient and Agile Service Federation in Service Overlay Networks

    Existing research work towards the composition of complex federated services has assumed that service requests and deliveries flow through a particular service path or tree. In this paper, the authors extend such a service model to a directed acyclic graph, allowing services to be delivered via parallel paths and interleaved...

    Provided By University of Toronto

  • White Papers // Jan 2012

    A High-Throughput Overlay Multicast Infrastructure With Network Coding

    Network coding has been recently proposed in information theory as a new dimension of the information multicast problem that helps achieve optimal transmission rate or cost. End hosts in overlay networks are natural candidates to perform network coding, due to its available computational capabilities. In this paper, the authors seek...

    Provided By University of Toronto

  • White Papers // Jan 2012

    ToX - The Toronto XML Engine

    The authors present ToX - the Toronto XML Engine - a repository for XML data and metadata, which supports real and virtual XML documents. Real documents are stored as files or mapped into relational or object databases, depending on their structuredness; indices are defined according to the storage method used....

    Provided By University of Toronto

  • White Papers // Jan 2012

    Linear Processing for the Downlink in Multiuser MIMO Systems With Multiple Data Streams

    In this paper, the authors solve the problem of linear precoding for the downlink in multiuser Multiple-Input Multiple-Output (MIMO) systems. The transmitter and the receivers may be equipped with multiple antennas and each user may receive multiple data streams. Their objective is to jointly optimize the power allocation and transmit-receive...

    Provided By University of Toronto

  • White Papers // Jan 2012

    Automated Data Analysis Techniques for a Modern Silicon Debug Environment

    With the growing size of modern designs and more strict time-to-market constraints, design errors unavoidably escape pre-silicon verification and reside in silicon prototypes. As a result, silicon debug has become a necessary step in the digital integrated circuit design flow. Although embedded hardware blocks, such as scan chains and trace...

    Provided By University of Toronto

  • White Papers // Jan 2012

    From RTL to Silicon: The Case for Automated Debug

    Computer-aided design tools are continuously improving their scalability and efficiency to mitigate the high cost associated with designing and fabricating modern VLSI systems. A key step in the design process is the root-cause analysis of detected errors. Debugging may take months to close, introduce high cost and uncertainty ultimately jeopardizing...

    Provided By University of Toronto

  • White Papers // Dec 2011

    Distributed Optimal TXOP Control for Throughput Requirements in IEEE 802.11e Wireless LAN

    This paper designs a distributed Transmission OPportunity (TXOP) adaptation algorithm for IEEE802.11e Enhanced Distributed Channel Access (EDCA). Each node measures its throughput in a window and compares it with a target value. If the measured throughput is higher than the target value, the node reduces its TXOP, otherwise if the...

    Provided By University of Toronto

  • White Papers // Dec 2011

    Non-Solution Implications Using Reverse Domination in a Modern SAT-Based Debugging Environment

    With the growing complexity of VLSI designs, functional debugging has become a bottleneck in modern CAD flows. To alleviate this cost, various SAT-based techniques have been developed to automate bug localization in the RTL. In this paper, dominance relationships between circuit blocks have been recently shown to reduce the number...

    Provided By University of Toronto

  • White Papers // Dec 2011

    Leveraging Reconfigurability to Raise Productivity in FPGA Functional Debug

    The authors propose new hardware and software techniques for FPGA functional debug that leverage the inherent re-configurability of the FPGA fabric to reduce functional debugging time. The functionality of an FPGA circuit is represented by a programming bit-stream that specifies the configuration of the FPGA's internal logic and routing. The...

    Provided By University of Toronto

  • White Papers // Nov 2011

    On Error Tolerance and Engineering Change With Partially Programmable Circuits

    The growing size, density and complexity of modern VLSI chips are contributing to an increase in hardware faults and design errors in the silicon, decreasing manufacturing yield and increasing the design cycle. The use of Partially Programmable Circuits (PPCs) has been recently proposed for yield enhancement with very small overhead....

    Provided By University of Toronto

  • White Papers // Nov 2011

    Joint Power Control and Beamforming Codebook Design for MISO Channels under the Outage Criterion

    This paper investigates the joint design of power control and beamforming codebooks for limited-feedback Multiple-Input Single-Output (MISO) wireless systems. The problem is formulated as the minimization of the outage probability subject to the transmit power constraint and cardinality constraints on the beamforming and power codebooks. The authors show that the...

    Provided By University of Toronto

  • White Papers // Nov 2011

    Efficient Debugging of Multiple Design Errors

    After functional verification detects a failure, design debugging aims to find all locations in the design that could be responsible for the observed error. The task of debugging becomes more difficult in modern designs because of the presence of multiple design errors. Multiple design errors exponentially increase the solution space...

    Provided By University of Toronto

  • White Papers // Oct 2011

    Propelling SAT-Based Debugging Using Reverse Domination

    With the growing complexity of VLSI designs, functional debugging has become a bottleneck in modern CAD flows. To alleviate this cost, various SAT-based techniques have been developed to automate bug localization in the RTL. In this paper, dominance relationships between circuit blocks have been recently shown to reduce the number...

    Provided By University of Toronto

  • White Papers // Sep 2011

    Modeling on Quicksand

    Researchers studying the inter-domain routing system, its properties and new protocols, face many challenges in performing realistic evaluations and simulations. Modeling decisions with respect to AS-level topology, routing policies and traffic matrices are complicated by a dearth of ground truth for each of these components. Moreover, scalability is-sues arise when...

    Provided By University of Toronto

  • White Papers // Jul 2011

    Collaborative Caching for Video Streaming Among Selfish Wireless Service Providers

    Video streaming is now at the fingertips of mobile users with recent advances in wireless communications and mobile networking. Caching has been widely deployed by Wireless Service Providers (WSPs) to facilitate video content dissemination. Yet, capacity provisioning of cache servers is challenging given dynamic user demands and limited wireless bandwidth...

    Provided By University of Toronto

  • White Papers // Jul 2011

    YMMV: Multiple Session Multicast With MIMO

    Multicast is an important application in cellular networks. The 4G technologies, including WiMAX and LTE, invariably adopt Multiple-Input-Multiple-Output (MIMO) to facilitate spatial multiplexing and fundamentally increase channel capacity. However, state-of-the-art multicast protocols are designed to perform in single-hop mode with a single session, leading to under-utilization of the scarce spectrum...

    Provided By University of Toronto

  • White Papers // Jul 2011

    Completion Delay Reduction in Lossy Feedback Scenarios for Instantly Decodable Network Coding

    In this paper, the authors study the effect of packet feedback loss events on the broadcast completion delay performance of instantly decodable network coding. These feedback loss events result in a continuous lack of knowledge about the reception status at different subsets of receivers. This lack of knowledge creates a...

    Provided By University of Toronto

  • White Papers // Jul 2011

    Jointly Optimal Channel Pairing and Power Allocation for Multi-Channel Multi-Hop Relaying

    The authors study the problem of channel pairing and power allocation in a multi-channel multi-hop relay network to enhance the end-to-end data rate. Both Amplify-and-Forward (AF) and Decode-and-Forward (DF) relaying strategies are considered. Given fixed power allocation to the channels, they show that channel pairing over multiple hops can be...

    Provided By University of Toronto

  • White Papers // Jun 2011

    Latch-Based Performance Optimization for FPGAs

    The authors explore using pulsed latches for timing optimization - a first in the FPGA community. Pulsed latches are transparent latches driven by a clock with a non-standard (non-50%) duty cycle. They exploit existing functionality within commercial FPGA chips to implement latch-based optimizations that do not have the power or...

    Provided By University of Toronto

  • White Papers // Jun 2011

    Usury, Calvinism, And Credit In Protestant England: From The Sixteenth Century To The Industrial Revolution

    This paper analyzes the impact of Protestantism on interest rates in England from the 16th century to the Industrial Revolution. One of many myths about the usury doctrine - the prohibition against demanding anything above the principal in a loan (mutuum) - is that it ceased to be observed in...

    Provided By University of Toronto

  • White Papers // Jun 2011

    Low-Cost Hardware Profiling of Run-Time and Energy in FPGA Embedded Processors

    Field-Programmable Gate Arrays (FPGAs) are a widely used technology in the design of embedded systems due to their improving speed, density and power, steadily decreasing cost, and their programmability which reduces a product's time-to-market. The advent of FPGA soft processors permits the creation of hybrid systems within a single FPGA...

    Provided By University of Toronto

  • White Papers // Jun 2011

    Reducing FPGA Router Run-Time Through Algorithm and Architecture

    The authors propose a new FPGA routing approach that, when combined with a low-cost architecture change, results in a 34% reduction in router run-time, at the cost of a 3% area overhead, with no increase in critical path delay. Their approach begins with traditional Path-Finder-style routing, which they run on...

    Provided By University of Toronto

  • White Papers // Jun 2011

    Canadian Monetary Policy And Real And Nominal Exchange Rates [Revised]

    This study undertakes an analysis of the relationship between Canadian monetary policy and the movements of Canada's real and nominal exchange rates with respect to the United States and, less directly, with respect to the rest of the world. It encompasses, extends and broadens a range of more narrowly-focused rigorous...

    Provided By University of Toronto

  • White Papers // Jun 2011

    Linking Semistructured Data on the Web

    Many Web data sources and APIs make their data available in XML, JSON, or a domain-specific semi-structured format, with the goal of making the data easily accessible and usable by Web application developers. Although such data formats are more machine-processable than pure text documents, managing and analyzing such data in...

    Provided By University of Toronto

  • White Papers // May 2011

    Non-Coherent Capacity of Secret-Key Agreement With Public Discussion

    The authors study the non-coherent capacity of secret-key agreement with public discussion over i.i.d. Rayleigh Fading wireless channels, where neither the sender nor the receivers have access to instantaneous Channel State Information (CSI). They present two results. At high Signal-to-Noise Ratio (SNR), the secret-key capacity is bounded in SNR, regardless...

    Provided By University of Toronto

  • White Papers // Jan 2011

    Scaling and Continuous Availability in Database Server Clusters Through Multiversion Replication

    In this paper, the authors study replication techniques for scaling and continuous operation for a dynamic content server. The focus is on supporting transparent and fast reconfiguration of its database tier in case of overload or failures. They show that the data persistence aspects can be decoupled from reconfiguration of...

    Provided By University of Toronto

  • White Papers // Sep 2010

    Revisiting Defenses Against Large-Scale Online Password Guessing Attacks

    Brute force and dictionary attacks on password-only remote login services are now widespread and ever increasing. Enabling convenient login for legitimate users while preventing such attacks is a difficult problem. Automated Turing Tests (ATTs) continue to be an effective, easy-to-deploy approach to identify auto-mated malicious login attempts with reasonable cost...

    Provided By University of Toronto

  • White Papers // Jun 2009

    Face Recognition With Biometric Encryption for Privacy-Enhancing Self-Exclusion

    Face recognition has been employed in various security-related applications such as surveillance, mugshot identification, e-passport, and access control. Despite its recent advancements, privacy concern is one of several issues preventing its wider deployment. In this paper, the authors address the privacy concern for a self-exclusion scenario of face recognition, through...

    Provided By University of Toronto

  • White Papers // Nov 2009

    Delay Bounds for Networks With Heavy-Tailed and Self-Similar Traffic

    The authors provide upper bounds on the end-to-end backlog and delay in a network with heavy-tailed and self-similar traffic. The analysis follows a network calculus approach where traffic is characterized by envelope functions and service is described by service curves. A key contribution of this paper is the derivation of...

    Provided By University of Toronto

  • White Papers // Jan 2010

    Understanding Latent Sector Errors and How to Protect Against Them

    Latent Sector Errors (LSEs) refer to the situation where particular sectors on a drive become inaccessible. LSEs are a critical factor in data reliability, since a single LSE can lead to data loss when encountered during RAID reconstruction after a disk failure. LSEs happen at a significant rate in the...

    Provided By University of Toronto

  • White Papers // Jun 2011

    Linking Semistructured Data on the Web

    Many Web data sources and APIs make their data available in XML, JSON, or a domain-specific semi-structured format, with the goal of making the data easily accessible and usable by Web application developers. Although such data formats are more machine-processable than pure text documents, managing and analyzing such data in...

    Provided By University of Toronto

  • White Papers // Aug 2009

    Indeterminacy Of Competitive Equilibrium With Risk Of Default

    The authors prove indeterminacy of competitive equilibrium in sequential economies, where limited commitment requires the endogenous determination of solvency constraints preventing debt repudiation (Alvarez and Jermann). In particular, they show that, for any arbitrary value of social welfare in between autarchy and (constrained) optimality, there exists an equilibrium at which...

    Provided By University of Toronto

  • White Papers // May 2011

    Learning Better Image Representations Using 'Flobject Analysis'

    Unsupervised learning can be used to extract image representations that are useful for various and diverse vision tasks. After noticing that most biological vision systems for interpreting static images are trained using disparity information, the authors developed an analogous framework for unsupervised learning. The output of their method is a...

    Provided By University of Toronto

  • White Papers // Apr 2011

    On Deep Generative Models With Applications to Recognition

    The most popular way to use probabilistic models in vision is first to extract some descriptors of small image patches or object parts using well-engineered features, and then to use statistical learning tools to model the dependencies among these features and eventual labels. Learning probabilistic models directly on the raw...

    Provided By University of Toronto

  • White Papers // Aug 2010

    Awareness Requirements for Adaptive Systems

    Recently, there has been a growing interest in self-adaptive systems. Roadmap papers in this area point to feedback loops as a promising way of operationalizing adaptivity in such systems. In this paper, the authors present a new type of requirement - called Awareness Requirement - that can refer to other...

    Provided By University of Toronto

  • White Papers // Sep 2010

    Inequality And Growth In A Knowledge Economy

    The authors develop a two sector growth model to understand the relation between inequality and growth. Agents, who are endowed with different levels of knowledge, select either into a retail or a manufacturing sector. Agents in the manufacturing sector match to carry out production. A by-product of production is creation...

    Provided By University of Toronto

  • White Papers // Jan 2011

    Trading Frenzies And Their Impact On Real Investment

    The authors study a model where a capital provider learns from the price of a firm's security in deciding how much capital to provide for new investment. This feedback effect from the financial market to the investment decision gives rise to trading frenzies, where speculators all wish to trade like...

    Provided By University of Toronto

  • White Papers // Apr 2011

    Asset Returns And Volatility Clustering In Financial Time Series

    An analysis of the stylized facts in financial time series is carried out. The authors find that, instead of the heavy tails in asset return distributions, the slow decay behaviour in autocorrelation functions of absolute returns is actually directly related to the degree of clustering of large fluctuations within the...

    Provided By University of Toronto

  • White Papers // Jan 2011

    Finding A Path Among The Concrete: Work-Life Narratives Of Urban Aboriginal Young Adults

    Aboriginal peoples are the fastest growing population in Canada (Statistics Canada, 2008). Over half of the Aboriginal population is under the age of 24 and, according to Human Resources and Skills Development Canada (2008), Aboriginal young adults are two to three times more likely to be unemployed than their non-Aboriginal...

    Provided By University of Toronto

  • White Papers // Jun 2011

    Usury, Calvinism, And Credit In Protestant England: From The Sixteenth Century To The Industrial Revolution

    This paper analyzes the impact of Protestantism on interest rates in England from the 16th century to the Industrial Revolution. One of many myths about the usury doctrine - the prohibition against demanding anything above the principal in a loan (mutuum) - is that it ceased to be observed in...

    Provided By University of Toronto

  • White Papers // Feb 2010

    Portfolio Choice, Attention Allocation, And Price Comovement

    This paper models the attention allocation of portfolio investors. Investors choose the composition of their information subject to an information flow constraint. Given their expected investment strategy in the next period, which is to hold a diversified portfolio, in equilibrium investors choose to observe one linear combination of asset payoffs...

    Provided By University of Toronto

  • White Papers // Mar 2009

    Credit Risk, Default Loss, And The Economics Of Bankruptcy

    The negotiating strategies of parties to a corporate bankruptcy are shaped by the rules and procedures of bankruptcy law. The rules have an asymmetric impact on the debtor and its creditors. To analyze the effect of this asymmetry, the paper develops a model of bankruptcy negotiation based on a binomial...

    Provided By University of Toronto

  • White Papers // Jan 2010

    Communication, Timing, And Common Learning

    The authors study the effect of stochastically delayed communication on common knowledge acquisition (common learning). If messages do not report dispatch times, communication prevents common learning under general conditions even if common knowledge is acquired without communication. If messages report dispatch times, communication can destroy common learning under more restrictive...

    Provided By University of Toronto

  • White Papers // May 2011

    Canadian Monetary Policy And Real And Nominal Exchange Rates

    This study undertakes an analysis of the relationship between Canadian monetary policy and the movements of Canada's real and nominal exchange rates with respect to the United States and, less directly, with respect to the rest of the world. It encompasses, extends and broadens a range of more narrowly-focused rigorous...

    Provided By University of Toronto

  • White Papers // Jun 2011

    Canadian Monetary Policy And Real And Nominal Exchange Rates [Revised]

    This study undertakes an analysis of the relationship between Canadian monetary policy and the movements of Canada's real and nominal exchange rates with respect to the United States and, less directly, with respect to the rest of the world. It encompasses, extends and broadens a range of more narrowly-focused rigorous...

    Provided By University of Toronto

  • White Papers // Jan 2011

    MP-DSR: A QoS-Aware Multi-Path Dynamic Source Routing Protocol for Wireless Ad-Hoc Networks

    Routing in wireless ad-hoc networks has received significant attention from recent literature due to the fact that the dynamic behavior of these networks poses many technical challenges on the design of an effective routing scheme. Though on-demand routing approaches have been shown to perform well, they generally lack the support...

    Provided By University of Toronto

  • White Papers // May 2011

    Accelerating the Cloud With Heterogeneous Computing

    Heterogeneous multiprocessors that combine multiple CPUs and GPUs on a single die are posed to become commonplace in the market. As seen recently from the high performance computing community, leveraging a GPU can yield performance increases of several orders of magnitude. The authors propose using GPU acceleration to greatly speed...

    Provided By University of Toronto

  • White Papers // Jan 2011

    Simplified Simulation Models for Indoor MANET Evaluation Are Not Robust

    The authors evaluate the robustness of simplified mobility and radio propagation models for indoor MANET simulations. A robust simplification allows researchers to extrapolate simulation results and reach reliable conclusions about the expected performance of protocols in real life. They show that common simplified mobility and radio propagation models are not...

    Provided By University of Toronto

  • White Papers // Feb 2011

    Multicell Coordination Via Joint Scheduling, Beamforming and Power Spectrum Adaptation

    The mitigation of intercell interference is a central issue for future generation wireless cellular networks where frequencies are reused aggressively and where hierarchical cellular structures may heavily overlap. The paper examines the benefit of coordinating transmission strategies and resource allocation schemes across multiple cells for interference mitigation. For a multicell...

    Provided By University of Toronto

  • White Papers // Jun 2010

    Interference Mitigation With Joint Beamforming and Common Message Decoding in Multicell Systems

    Conventional multicell wireless systems operate with out-of-cell interference treated as noise - interference detection is infeasible as intercell interference is typically weak. This paper considers the benefit of designing decodable interference signals by allowing common-private message splitting at the transmitter and common message decoding by users in adjacent cells. In...

    Provided By University of Toronto

  • White Papers // May 2010

    Network Coding in Relay-Based Networks

    Since its inception in information theory, network coding has attracted a significant amount of research attention in recent years. Shortly after theoretical explorations in wired networks, the use of network coding in wireless networks towards improving throughput has been widely recognized. In this chapter, the authors present a survey of...

    Provided By University of Toronto

  • White Papers // Dec 2009

    Efficient Resource Allocation With Flexible Channel Cooperation in OFDMA Cognitive Radio Networks

    Recently, a cooperative paradigm for single-channel cognitive radio networks has been advocated, where primary users can leverage secondary users to relay their traffic. However, it is not clear how such cooperation can be exploited in multi-channel networks effectively. Conventional cooperation entails that data on one channel has to be relayed...

    Provided By University of Toronto

  • White Papers // Sep 2009

    Herding, Contrarianism And Delay In Financial Market Trading

    Herding and contrarian behavior are often cited features of real-world financial markets. Theoretical models of continuous trading that study herding and contrarianism, however, usually do not allow traders to choose when to trade or to trade more than once. The authors present a large-scale experiment to explore these features within...

    Provided By University of Toronto

  • White Papers // Sep 2010

    Publishing Bibliographic Data on the Semantic Web Using BibBase

    The authors present BibBase, a system for publishing and managing bibliographic data available in BibTeX files on the Semantic Web. BibBase uses a powerful yet light-weight approach to transform BibTeX files into rich Linked Data as well as custom HTML and RSS code that can readily be integrated within a...

    Provided By University of Toronto

  • White Papers // Mar 2010

    Copernicus: Face-to-Face Web-Based Sharing and Collaboration

    Mobile devices are increasingly being used to access web applications. Unfortunately, the usage model for web applications today is still desktop-centric, in which users work in isolation. As a result, using mobile devices to find or share data, or collaborate while in a social setting is cumbersome at best, and...

    Provided By University of Toronto

  • White Papers // Jan 2011

    An Empirical Evaluation of the Student-Net Delay Tolerant Network

    Radio equipped mobile devices have enjoyed tremendous growth in the past few years. The authors observe that in the near future it might be possible to build a network that routes delay-tolerant packets by harnessing user mobility and the pervasive availability of wireless devices. Such a delay-tolerant network could be...

    Provided By University of Toronto

  • White Papers // Jun 2010

    Securing Script-Based Extensibility in Web Browsers

    Web browsers are increasingly designed to be extensible to keep up with the Web's rapid pace of change. This extensibility is typically implemented using script-based extensions. Script extensions have access to sensitive browser APIs and content from untrusted web pages. Unfortunately, this powerful combination creates the threat of privilege escalation...

    Provided By University of Toronto

  • White Papers // Apr 2011

    Optimal Multi-Server Allocation to Parallel Queues With Independent Random Queue-Server Connectivity

    The authors investigate an optimal scheduling problem in a discrete-time system of L parallel queues that are served by K identical, randomly connected servers. Each queue may be connected to a subset of the K servers during any given time slot. This model has been widely used in studies of...

    Provided By University of Toronto

  • White Papers // Jan 2010

    Universal Secure Error-Correcting Schemes for Network Coding

    This paper considers the problem of securing a linear network coding system against an adversary that is both an eavesdropper and a jammer. The network is assumed to transport n packets from source to each receiver, and the adversary is allowed to eavesdrop on ? arbitrarily chosen links and also...

    Provided By University of Toronto

  • White Papers // Nov 2010

    A Comparative Study of the Usability of Two Object-Oriented Concurrent Programming Languages

    Concurrency has been rapidly gaining importance in general-purpose computing, caused by the recent turn towards multicore processing architectures. As a result, an increasing number of developers have to learn to write concurrent programs, a task that is known to be hard even for the expert. Language designers are therefore working...

    Provided By University of Toronto

  • White Papers // Mar 2009

    Relay Selection and Power Allocation in Cooperative Cellular Networks

    The authors consider a system with a single base station communicating with multiple users over orthogonal channels while being assisted by multiple relays. Several recent works have suggested that, in such a scenario, selection, i.e., a single relay helping the source, is the best relaying option in terms of the...

    Provided By University of Toronto

  • White Papers // Jul 2010

    A Foundation for Stochastic Bandwidth Estimation of Networks With Random Service

    The authors develop a stochastic foundation for bandwidth estimation of networks with random service, where bandwidth availability is expressed in terms of bounding functions with a defined violation probability. Exploiting properties of a stochastic max-plus algebra and system theory, the task of bandwidth estimation is formulated as inferring an unknown...

    Provided By University of Toronto

  • White Papers // Apr 2009

    Projective Space Codes for the Injection Metric

    In the context of error control in random linear network coding, it is useful to construct codes that comprise well-separated collections of subspaces of a vector space over a finite field. In this paper, the metric used is the so-called "Injection distance," introduced by Silva and Kschischang. A Gilbert-Varshamov bound...

    Provided By University of Toronto

  • White Papers // Mar 2011

    Verifiable Delegation of Computation over Large Datasets

    The authors study the problem of computing on large datasets that are stored on an untrusted server. They follow the approach of amortized verifiable computation introduced by Gennaro, Gentry, and Parno in CRYPTO 2010. They present the first practical verifiable computation scheme for high degree polynomial functions. Such functions can...

    Provided By University of Toronto

  • White Papers // May 2009

    Sparse Network Coding With Overlapping Classes

    This paper presents a novel approach to network coding for distribution of large files. Instead of the usual approach of splitting packets into disjoint classes (also known as generations) the authors propose the use of overlapping classes. The overlapping allows the decoder to alternate between Gaussian elimination and back substitution,...

    Provided By University of Toronto