University of Toronto

Displaying 1-40 of 224 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

    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 // 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 // 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 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

    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 // 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 // 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

    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 // Dec 2010

    Network Coding: The Case of Multiple Unicast Sessions

    In this paper, the authors investigate the benefit of network coding over routing for multiple independent unicast transmissions. They compare the maximum achievable throughput with network coding and that with routing only. They show that the result depends crucially on the network model. In directed networks, or in undirected networks...

    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

    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 // Dec 2009

    SigNet: Network-on-Chip Filtering for Coarse Vector Directories

    Scalable cache coherence is imperative as systems move into the many-core era with cores counts numbering in the hundreds. Directory protocols are often favored as more scalable in terms of bandwidth requirements than broadcast protocols; however, directories incur storage overheads that can become prohibitive with large systems. In this paper,...

    Provided By University of Toronto

  • White Papers // Aug 2010

    AutoFuzz: Automated Network Protocol Fuzzing Framework

    Assessing software security involves steps such as code review, risk analysis, penetration testing and fuzzing. During the fuzzing phase, the testeras goal is to find flaws in software by sending unexpected input to the target application and monitoring its behavior. In this paper, the authors introduce the AutoFuzz - extendable,...

    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 // 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 // Dec 2009

    A Secondary Market for Spectrum

    Dynamic spectrum trading amongst small cognitive users is fundamentally different along two axes: temporal variation, and spatial variation of user demands and channel conditions. The authors advocate that a spectrum secondary market, analogous to the stock market, is to be established to dynamically trade among users their channel holdings obtained...

    Provided By University of Toronto

  • White Papers // Jan 2011

    Seen as Stable Marriages

    In this paper, the authors advocate the use of stable matching framework in solving networking problems, which are traditionally solved using utility-based optimization or game theory. Born in economics, stable matching efficiently resolves conflicts of interest among selfish agents in the market, with a simple and elegant procedure of deferred...

    Provided By University of Toronto

  • 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

    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 // 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 // Apr 2009

    Denial of Service Attacks in Networks With Tiny Buffers

    Recently, several papers have studied the possibility of shrinking buffer sizes in Internet core routers to just a few dozen packets under certain constraints. If proven right, these results can open doors to building all-optical routers, since a major bottleneck in building such routers is the lack of large optical...

    Provided By University of Toronto

  • White Papers // Feb 2009

    Adding the Easy Button to the Cloud With SnowFlock and MPI

    Cloud computing promises to provide researchers with the ability to perform parallel computations using large pools of Virtual Machines (VMs), without facing the burden of owning or maintaining physical infrastructure. However, with ease of access to hundreds of VMs, comes also an increased management burden. Cloud users today must manually...

    Provided By University of Toronto

  • White Papers // May 2009

    Computer Meteorology: Monitoring Compute Clouds

    Cloud computing environments allow customers to execute arbitrary code on hardware owned by a cloud provider. While cloud providers use virtualization to ensure isolation between customers, they face additional security challenges. Malicious customers may leverage the provider's hardware to launch attacks, either from VMs they own or by compromising VMs...

    Provided By University of Toronto

  • White Papers // Jan 2009

    Passive Loss Inference in Wireless Sensor Networks Based on Network Coding

    The highly stochastic nature of wireless environments makes it desirable to monitor link loss rates in wireless sensor networks. This paper studies the loss inference problem in sensor networks with network coding. Unlike traditional transmission protocols, network coding offers reliable communication without using control messages for individual packets. The paper...

    Provided By University of Toronto

  • White Papers // May 2009

    Blackboards, PowerPoint, and Tablet PCs in the Classroom

    Research into eye movements of subjects who are reading provides a window into the reader's cognitive processes. This paper uses some conclusions of that research to guide a discussion of the delivery of visual information in the classroom. The paper will briefly review some of the highlights of the research...

    Provided By University of Toronto

  • White Papers // Dec 2009

    Haste: Practical Online Network Coding in a Multicast Switch

    The use of network coding has been shown to improve throughput in input-queued multicast switches, but not without costs of computational complexity and delays. This paper investigates the design of efficient online network coding algorithms in a switch with multicast traffic. The paper presents Haste, an online opportunistic coding algorithm...

    Provided By University of Toronto

  • White Papers // Jan 2010

    Learning Mixture Models With the Latent Maximum Entropy Principle

    The paper presents a new approach to estimating mixture models based on a new inference principle the author has proposed: the Latent Maximum Entropy principle (LME). LME is different both from Jaynes' maximum entropy principle and from standard maximum likelihood estimation. The paper demonstrates the LME principle by deriving new...

    Provided By University of Toronto

  • White Papers // Sep 2010

    SnowFlock: Rapid Virtual Machine Cloning for Cloud Computing

    Virtual Machine (VM) fork is a new cloud computing abstraction that instantaneously clones a VM into multiple replicas running on different hosts. This paper focuses on the primitive of VM fork and the Xen-based implementation SnowFlock. Virtualization provides many benefits such as security, performance isolation, ease of management, and flexibility...

    Provided By University of Toronto

  • White Papers // Nov 2008

    Visualizing Data using t-SNE

    This paper presents a new technique called "t-SNE" that visualizes high-dimensional data by giving each datapoint a location in a two or three-dimensional map. The technique is a variation of Stochastic Neighbor Embedding (Hinton and Roweis, 2002) that is much easier to optimize, and produces significantly better visualizations by reducing...

    Provided By University of Toronto

  • White Papers // Jun 2010

    Repatriation Taxes And Foreign Direct Investment: Evidence From Tax Treaties

    This paper examines the effects on foreign direct investment of worldwide versus territorial tax systems. Canada operates a hybrid system of international taxation, under which dividends repatriated from affiliates located in tax treaty partner countries are exempt from domestic taxation, while repatriations from non-treaty countries are subject to a foreign...

    Provided By University of Toronto

  • White Papers // Jul 2010

    BPM in Cloud Architectures: Business Process Management With SLAs and Events

    Applications are becoming increasingly distributed and loosely coupled in terms of their development processes, software architectures, deployment platforms, and other aspects. For example, in Web mashups, utility or cloud computing environments, and Service-Oriented Architectures (SOA) applications are developed by orchestrating reusable services using high level workflows or business processes. Application...

    Provided By University of Toronto

  • White Papers // Jan 2009

    Dynamic Resource Allocation for Database Servers Running on Virtual Storage

    This paper introduces a novel multi-resource allocator to dynamically allocate resources for database servers running on virtual storage. Multi-resource allocation involves proportioning the database and storage server caches, and the storage bandwidth between applications according to overall performance goals. The problem is challenging due to the interplay between different resources,...

    Provided By University of Toronto

  • White Papers // Jan 2010

    QoS-Aware Adaptive Services in Mobile Ad-Hoc Networks

    Ad-hoc wireless networks consist of mobile nodes interconnected by multi-hop wireless paths. Unlike conventional wireless networks, ad-hoc networks have no fixed network infrastructure or administrative support. Because of the dynamic nature of the network topology and limited bandwidth of wireless channels, Quality-of-Service (QoS) provisioning is an inherently complex and difficult...

    Provided By University of Toronto

  • White Papers // Jan 2010

    Constructing Complex Semantic Mappings Between XML Data and Ontologies

    Much data is published on the Web in XML format satisfying schemas, and to make the Semantic Web a reality, such data needs to be interpreted with respect to ontologies. Interpretation is achieved through a semantic mapping between the XML schema and the ontology. The authors present work on the...

    Provided By University of Toronto

  • White Papers // Jan 2010

    Content-Based Routing in Mobile Ad Hoc Networks

    The publish/subscribe model of communication provides sender/receiver decoupling and selective information dissemination that is appropriate for mobile environments characterized by scarce resources and a lack of ?xed infrastructure. The authors propose and evaluate three content-based routing protocols: CBR is an adaptation of existing distributed publish/subscribe protocols for wired networks, FT-CBR...

    Provided By University of Toronto

  • White Papers // Sep 2008

    How Video Games Benefit Your Brain

    After more than three decades of development, video games are now increasingly used for purposes other than entertainment. These games play a role in fields as diverse as education, cognitive training, physical exercise, and rehabilitation. Developing a good game for meaningful purposes requires a comprehensive understanding of the critical characteristics...

    Provided By University of Toronto

  • White Papers // Jan 2010

    Distributed Cross-Layer Optimization of Wireless Sensor Networks: A Game Theoretic Approach

    This paper proposes a distributed optimization framework for wireless multihop sensor networks base on a game theoretic approach. The authors show that the cross-layer optimization problem can be decomposed into two subproblems corresponding to two separate layers (the physical and the application layers) of the overall system. By modelling each...

    Provided By University of Toronto

  • White Papers // Jan 2010

    Wireless Communication Systems

    Wireless communications networks to provide telephone service to mobile users have been rapidly developed in the past 15 years. Beginning with the first generation analog systems which provide voice service the authors are now on the verge of the standardization of 3rd generation systems which will have the capability to...

    Provided By University of Toronto

  • White Papers // Sep 2008

    CodeOR: Opportunistic Routing in Wireless Mesh Networks With Segmented Network Coding

    Opportunistic routing significantly increases unicast throughput in wireless mesh networks by effectively utilizing the wireless broadcast medium. With network coding, opportunistic routing can be implemented in a simple and practical way without resorting to a complicated scheduling protocol. Due to constraints of computational complexity, a protocol utilizing network coding needs...

    Provided By University of Toronto

  • White Papers // Jul 2009

    Teaching Old Caches New Tricks: RegionTracker and Predictor Virtualization

    On-chip last-level caches are increasing to tens of megabytes to accommodate applications with large memory footprints and to compensate for high memory latencies and limited off-chip bandwidth. This paper reviews two on-going research efforts that exploit such large caches: coarse-grain cache management, and predictor virtualization. Coarse-grain cache management collects and...

    Provided By University of Toronto

  • White Papers // Sep 2010

    The Sarbanes-Oxley Act And Exit Strategies Of Private Firms

    The costs and benefits of the Sarbanes-Oxley Act of 2002 (SOX) have been oft-debated since the inception of the Act. Much of the extant literature has assessed the costs and benefits of SOX to publicly-traded companies. The authors focus on the costs of SOX compliance for private firms wanting to...

    Provided By University of Toronto

  • White Papers // May 2010

    Dude, Where's That IP? Circumventing Measurement-Based IP Geolocation

    Many applications of IP geolocation can benefit from geolocation that is robust to adversarial clients. These include applications that limit access to online content to a specific geographic region and cloud computing, where some organizations must ensure their virtual machines stay in an appropriate geographic region. This paper studies the...

    Provided By University of Toronto