Massachusetts Institute of Technology

Displaying 161-200 of 381 results

  • White Papers // Jan 2011

    Delay in Random Access Wireless Networks With Controlled Mobility

    This paper considers dynamic wireless networks where messages arriving randomly (in time and space) are collected by a mobile receiver. The messages are transmitted to the mobile receiver according to a random access scheme and the receiver dynamically adjusts its position in order to receive these messages in the least...

    Provided By Massachusetts Institute of Technology

  • White Papers // Jan 2011

    The Click Modular Router

    Click is a new software architecture for building flexible and configurable routers. A Click router is assembled from packet processing modules called elements. Individual elements implement simple router functions like packet classification, queuing, scheduling, and interfacing with network devices. A router configuration is a directed graph with elements at the...

    Provided By Massachusetts Institute of Technology

  • White Papers // Jan 2011

    Securing the Borealis Data Stream Engine

    As Data Stream Management Systems (DSMSs) become more and more popular, there is an increasing need to protect such systems from adversaries. In this paper the authors present an approach to secure DSMSs. They propose a general security framework and an access control model to secure DSMSs. The authors implement...

    Provided By Massachusetts Institute of Technology

  • White Papers // Jan 2011

    Detecting BGP Configuration Faults With Static Analysis

    The Internet is composed of many independent Autonomous Systems (ASes) that exchange reachability information to destinations using the Border Gateway Protocol (BGP). Network operators in each AS configure BGP routers to control the routes that are learned, selected, and announced to other routers. Faults in BGP configuration can cause forwarding...

    Provided By Massachusetts Institute of Technology

  • White Papers // Jan 2011

    Guidelines for Interdomain Traffic Engineering

    Network operators must have control over the flow of traffic into, out of, and across their networks. However, the Border Gateway Protocol (BGP) does not facilitate common traffic engineering tasks, such as balancing load across multiple links to a neighboring AS or directing traffic to a different neighbor. Solving these...

    Provided By Massachusetts Institute of Technology

  • White Papers // Jan 2011

    Practical Verification Techniques for Wide-Area Routing

    Protocol and system designers use verification techniques to analyze a system's correctness properties. Network operators need verification techniques to ensure the "Correct" operation of BGP. BGP's distributed dependencies cause small configuration mistakes or oversights to spur complex errors, which sometimes have devastating effects on global connectivity. These errors are often...

    Provided By Massachusetts Institute of Technology

  • White Papers // Jan 2011

    An Empirical Study of "Bogo" Route Advertisements

    An important factor in the robustness of the inter-domain routing system is whether the routers in Autonomous Systems (ASes) filter routes for "Bogon" address space - i.e., private address space and address space that has not been allocated by the Internet Assigned Numbers Authority (IANA). This paper presents an empirical...

    Provided By Massachusetts Institute of Technology

  • White Papers // Jan 2011

    Middleboxes No Longer Considered Harmful

    Intermediate network elements, such as Network Address Translators (NATs), firewalls, and transparent caches are now commonplace. The usual reaction in the network architecture community to these so-called middleboxes is a combination of scorn (because they violate important architectural principles) and dismay (because these violations make the Internet less flexible). While...

    Provided By Massachusetts Institute of Technology

  • White Papers // Jan 2011

    How to Construct a Correct and Scalable IBGP Configuration

    The Internet's current interdomain routing protocol, BGP (Border Gateway Protocol), has two modes of operation: eBGP (external BGP), used to exchange routing information between autonomous systems, and iBGP (internal BGP), used to propagate that information within an Autonomous System (AS). In a "Full mesh" iBGP configuration, every router has a...

    Provided By Massachusetts Institute of Technology

  • White Papers // Jan 2011

    Energy-Efficient Dynamic Source Routing in Ad-Hoc Wireless Networks

    The authors present Span-DSR and DSR-PSM, two power-saving algorithms designed for ad-hoc wireless networks using source routing. Span-DSR reduces power consumption and has desirable fairness properties, while maintaining a connected backbone of nodes to route packets. Span-DSR's power saving protocol increases system lifetime by a factor of two better than...

    Provided By Massachusetts Institute of Technology

  • White Papers // Jan 2011

    Network-Wide BGP Route Prediction for Traffic Engineering

    The Internet consists of about 13,000 Autonomous Systems (AS's) that exchange routing information using the Border Gateway Protocol (BGP). The operators of each AS must have control over the flow of traffic through their network and between neighboring AS's. However, BGP is a complicated, policy-based protocol that does not include...

    Provided By Massachusetts Institute of Technology

  • White Papers // Jan 2011

    Mobilized Ad-Hoc Networks: A Reinforcement Learning Approach

    With the cost of wireless networking and computational power rapidly dropping, mobile ad-hoc networks will soon become an important part of the society's computing structures. While there is a great deal of research from the networking community regarding the routing of information over such networks, most of these techniques lack...

    Provided By Massachusetts Institute of Technology

  • White Papers // Dec 2010

    Demonstration of Multi-Robot Search and Secure

    The authors consider the search and secure problem, where intruders are to be detected in a bounded area without allowing them to escape. The problem is tackled by representing the area to be searched as a traversability graph, which is reduced to a tree graph by placing stationary robots to...

    Provided By Massachusetts Institute of Technology

  • Webcasts // Dec 2010

    Mathematics, Common Sense, And Good Luck: My Life And Careers

    Don't expect to glean any market tips or trading secrets from the author, who steadfastly refuses to disclose the method behind his remarkable record in investing. Instead, listen to this mathematician, hedge fund manager and philanthropist sum up a remarkably varied and rich career, and offer some "Guiding principles" distilled...

    Provided By Massachusetts Institute of Technology

  • White Papers // Dec 2010

    Heracles: Fully Synthesizable Parameterized MIPS-Based Multicore System

    Heracles is an open-source complete multicore system written in Verilog. It is fully parameterized and can be reconfigured and synthesized into different topologies and sizes. Each processing node has a 7-stage pipeline, fully bypassed, microprocessor running the MIPS-III ISA, a 4-stage input-buffer, virtual-channel router, and a local variable-size shared memory....

    Provided By Massachusetts Institute of Technology

  • Webcasts // Dec 2010

    Perceptive Mobile Robots Working Safely Alongside Humans

    Although we are still far from the moment of singularity, or even Star Wars 'Droids, we can anticipate robot colleagues in the near future, believes by the author. The author is developing 'Situationally aware' machines to help out humans in those "Unstructured environments?where we live, work and recreate."

    Provided By Massachusetts Institute of Technology

  • Webcasts // Dec 2010

    Relaunching Growth In Europe

    The presenter finds it difficult to witness the calamitous decline of Spain, a nation he led to robust economic health as prime minister from 1996 to 2004. The gains during his administration have vanished following the international financial crisis. But the economic misfortunes of Spain and other European nations are...

    Provided By Massachusetts Institute of Technology

  • White Papers // Dec 2010

    Compressive Sensing Over Networks

    In this paper, the authors demonstrate some applications of compressive sensing over networks. They make a connection between compressive sensing and traditional information theoretic techniques in source coding and channel coding. The results provide an explicit trade-off between the rate and the decoding complexity. The key difference of compressive sensing...

    Provided By Massachusetts Institute of Technology

  • White Papers // Dec 2010

    Price Of Airline Frequency Competition

    Frequency competition influences capacity allocation decisions in airline markets and has important implications to airline profitability and airport congestion. Market share of a competing airline is a function of its frequency share and the relationship between the two is pivotal for understanding the impacts of frequency competition on airline business....

    Provided By Massachusetts Institute of Technology

  • White Papers // Nov 2010

    Scalable Directoryless Shared Memory Coherence Using Execution Migration

    The authors introduce the concept of deadlock-free migration-based coherent shared memory to the NUCA family of architectures. Migration-based architectures move threads among cores to guarantee sequential semantics in large multicores. Using an Execution Migration (EM) architecture, the authors achieve performance comparable to directory-based architectures without using directories: avoiding automatic data...

    Provided By Massachusetts Institute of Technology

  • White Papers // Nov 2010

    How to Tell if Your Cloud Files Are Vulnerable to Drive Crashes

    This paper presents a new challenge - verifying that a remote server is storing a file in a fault-tolerant manner, i.e., such that it can survive hard-drive failures. The authors describe an approach called the Remote Assessment of Fault Tolerance (RAFT). The key technique in a RAFT is to measure...

    Provided By Massachusetts Institute of Technology

  • White Papers // Nov 2010

    "Whither Industrial Relations: Does It Have A Future In Post-Industrial Society"

    Industrial relations are in trouble. It is in trouble both as a set of institutions and practices, linked to trade unions and collective bargaining and as a scholarly endeavor. The title of talk here, which the author was obliged to provide long in advance, is essentially a place holder for...

    Provided By Massachusetts Institute of Technology

  • White Papers // Nov 2010

    Whither Industrial Relations: Does It Have A Future In Post-Industrial Society

    Industrial relations are in trouble. It is in trouble both as a set of institutions and practices, linked to trade unions and collective bargaining and as a scholarly endeavor. The title of talk here, which the author was obliged to provide long in advance, is essentially a place holder for...

    Provided By Massachusetts Institute of Technology

  • Webcasts // Nov 2010

    Communications In Slow-Moving Crises

    What's a journalist to do when a major story must be coaxed reluctantly into public view, or emerges on what seems like a geological time scale? These panelists discuss how to approach slowly evolving but urgent stories at a time when news coverage has shifted inexorably from print and its...

    Provided By Massachusetts Institute of Technology

  • White Papers // Nov 2010

    Algebraic Watchdog: Mitigating Misbehavior in Wireless Network Coding

    The authors propose a secure scheme for wireless network coding, called the algebraic watchdog. By enabling nodes to detect malicious behaviors probabilistically and use overheard messages to police their downstream neighbors locally, the algebraic watchdog delivers a secure global self-checking network. Unlike traditional Byzantine detection protocols which are receiver based,...

    Provided By Massachusetts Institute of Technology

  • Webcasts // Nov 2010

    The Financial Crisis, The Recession, And The American Political Economy: A Systemic Perspective

    The author shows how useful a varied background in math, political science and business can be, as he dissects the complexities and recent crisis of the U.S. financial system. In a lecture that distills many of the arguments of his recent film, Inside Job, the author conveys dispassionately yet persuasively...

    Provided By Massachusetts Institute of Technology

  • Webcasts // Nov 2010

    The Future Is Gray, Small & Female: Disruptive Demographics And Transportation Tomorrow

    If the prospect of aging and infirmity seems remote, you could use some time with AGNES (Age Gain Now Empathy System), a wearable apparatus that approximates "What it feels like to be a 75-year-old woman."

    Provided By Massachusetts Institute of Technology

  • White Papers // Nov 2010

    Mixed Context and Privacy

    Users engaging Online Service Providers (OSPs) such as Google, Amazon, and Facebook encounter environments architected by a single actor (the OSP), but comprised of content and executable elements potentially provided by multiple actors. For the ten OSPs analyzed, privacy policies only cover content provided directly by the OSP. Content provided...

    Provided By Massachusetts Institute of Technology

  • White Papers // Oct 2010

    Consistent and Efficient Reconstruction of Latent Tree Models

    The authors study the problem of learning a latent tree graphical model where samples are available only from a subset of variables. They propose two consistent and computationally efficient algorithms for learning minimal latent trees, that is, trees without any redundant hidden nodes. Their first algorithm, recursive grouping, builds the...

    Provided By Massachusetts Institute of Technology

  • Webcasts // Oct 2010

    Negotiating The Gulf Disaster

    The Gulf Oil spill hurt many individuals and businesses, and there is broad agreement that they deserve compensation. But working out the nuances of damage payment is no simple matter, as the presenter describes in conversation with an MIT Museum audience.

    Provided By Massachusetts Institute of Technology

  • Webcasts // Oct 2010

    Toward Efficient Airport Operations

    Few of us would elect to spend countless hours at the airport watching planes arrive, depart and sit at gates. But what constitutes a punishment for some actually energizes the presenter, whose research focuses on improving airport operations. Her goal is to make air travel more efficient, robust and green.

    Provided By Massachusetts Institute of Technology

  • White Papers // Oct 2010

    A Simple Message-Passing Algorithm for Compressed Sensing

    Recovery of a vector x from measurements of the form y = Ax has been of central interest in the compressed sensing literature. When restricted to binary vectors, this has been of interest in the context of binary linear error-correcting codes. In essence, both desire a matrix A and an...

    Provided By Massachusetts Institute of Technology

  • White Papers // Oct 2010

    Using DVB-S2 Over Asymmetric Heterogeneous Optical to Radio Frequency Satellite Links

    The DVB-S2 coding standard has seen widespread use in many Radio Frequency (RF) communications applications. The availability of Commercial-Off-The-Shelf (COTS) Intellectual Property (IP) that can be used to rapidly prototype and field communications systems makes this well-performing, standards-based approach to Forward Error Correction (FEC) coding extremely attractive. In this paper,...

    Provided By Massachusetts Institute of Technology

  • White Papers // Oct 2010

    On the Role of Queue Length Information in Network Control

    In this paper, the authors study the role played by queue length information in the operation of flow control and server allocation policies. They first consider a simple model of a single server queue with congestion-based flow control. The input rate at any instant is decided by a flow control...

    Provided By Massachusetts Institute of Technology

  • Webcasts // Oct 2010

    Humanities In The Digital Age

    Reports of the demise of the humanities are exaggerated, suggest these panelists, but there may be reason to fear its loss of relevance. Three scholars whose work touches a variety of disciplines and with wide knowledge of the worlds of academia and publishing ponder the meaning and mission of the...

    Provided By Massachusetts Institute of Technology

  • Webcasts // Oct 2010

    Open Payment, A New Approach To Public Transportation Fare Collection

    Soon, a ticket to ride won't require paper coupons, tokens, human vendors, or even Boston's CharlieCard. Urban transit is abandoning a century old payment system for sophisticated digital payment technology, says the author. The author has been toiling for a decade on technology and methods that will enable transit industry...

    Provided By Massachusetts Institute of Technology

  • White Papers // Oct 2010

    Survivable Network Design Problems in Wireless Networks

    Survivable network design is an important suite of algorithmic problems where the goal is to select a minimum cost network subject to the constraint that some desired connectivity property has to be satisfied by the network. Traditionally, these problems have been studied in a model where individual edges (and sometimes...

    Provided By Massachusetts Institute of Technology

  • White Papers // Oct 2010

    Dynamic Pricing Through Sampling Based Optimization

    In this paper the authors develop an approach to dynamic pricing that combines ideas from data-driven and robust optimization to address the uncertain and dynamic aspects of the problem. In this setting, a firm offers multiple products to be sold over a fixed discrete time horizon. Each product sold consumes...

    Provided By Massachusetts Institute of Technology

  • White Papers // Oct 2010

    Post-2008 Crisis In Labor Standards: Prospects For Labor Regulation Around The World

    Over the course of the last thirty years, government policy has been increasingly dominated by neoclassical economic thought and neoliberal public policies. This has been especially true in the United States, but the trends are evident in one way or another in every part of the world. They reflect in...

    Provided By Massachusetts Institute of Technology

  • Webcasts // Oct 2010

    The Art Of Science Communication

    You wouldn't know that the moderator felt nervous in advance of addressing this audience of neuroscientists. In his trademark style, moderator chats up the crowd like an old friend, sharing anecdotes involving one of his great pursuits: "I love to talk to scientists," moderator says.

    Provided By Massachusetts Institute of Technology

  • Webcasts // Mar 2007

    Is There A Black Architect In The House?

    "If there is any kind of profession that's gotten away with a kind of benign neglect of diversifying itself over the course of last 30 years, it's architecture," says the presenter. With one chart after another, he plots the dismal record of design schools, firms and professional associations in modifying...

    Provided By Massachusetts Institute of Technology

  • White Papers // Sep 2010

    Legal Challenges and Strategies for Comparison Shopping and Data Reuse

    New technologies have been continuously emerging to enable effective reuse of an ever-growing amount of data on the Web. Innovative firms can leverage the available technologies and data to provide useful services. Comparison-shopping services are an example of reusing existing data to make bargain-finding easier. Certain reuses have caused conflicts...

    Provided By Massachusetts Institute of Technology

  • White Papers // Jun 2010

    Optimizing MapReduce for Multicore Architectures

    MapReduce is a programming model for data-parallel programs originally intended for data centers. MapReduce simplifies parallel programming, hiding synchronization and task management. These properties make it a promising programming model for future processors with many cores, and existing MapReduce libraries such as Phoenix have demonstrated that applications written with MapReduce...

    Provided By Massachusetts Institute of Technology

  • White Papers // Dec 2009

    Scheduling Policies for Single-Hop Networks With Heavy-Tailed Traffic

    The area of control of communication networks is one of the most active and fruitful fields of research in recent years, including several elaborate and interconnected forms of control, such as congestion control, routing, scheduling and power control. Much of the theoretical foundation regarding network stability was laid out in...

    Provided By Massachusetts Institute of Technology

  • White Papers // Sep 2009

    The Impact of Queue Length Information on Buffer Overflow in Parallel Queues

    The authors consider a system consisting of N parallel queues, served by one server. Time is slotted, and the server serves one of the queues in each time slot, according to some scheduling policy. In the first part of the paper, they characterize the buffer overflow exponents and the likeliest...

    Provided By Massachusetts Institute of Technology

  • White Papers // Dec 2009

    Optimal Control of Wireless Networks With Finite Buffers

    Design of low delay wireless networks that optimally utilize the network capacity is one of the most important problems in network theory and engineering. Since the seminal paper of Tassiulas and Ephremides which proposed a joint routing and scheduling algorithm that achieves the maximum network throughput, significant efforts have been...

    Provided By Massachusetts Institute of Technology

  • White Papers // Dec 2009

    Network Reliability With Geographically Correlated Failures

    Fiber-optic networks are vulnerable to natural disasters, such as tornadoes or earthquakes, as well as to physical failures, such as an anchor cutting underwater fiber cables. Such real-world events occur in specific geographical locations and disrupt specific parts of the network. Therefore, the geography of the network determines the effect...

    Provided By Massachusetts Institute of Technology

  • White Papers // Jan 2011

    Analysis and Algorithms for Partial Protection in Mesh Networks

    Mesh networks supporting data rates of multiple gigabytes per second are being deployed to meet the increasing demands of the telecom industry. As data rates continue to increase, the failure of a network line element or worse, a fiber cut, can result in severe service disruptions and large data loss,...

    Provided By Massachusetts Institute of Technology

  • White Papers // Jan 2011

    Queue Length Asymptotics for Generalized Max-Weight Scheduling in the Presence of Heavy-Tailed Traffic

    Traditionally, traffic in telecommunication networks has been modeled using Poisson and Markov-modulated processes. These simple traffic models exhibit 'Local randomness', in the sense that much of the variability occurs in short time scales, and only an average behavior is perceived at longer time scales. With the spectacular growth of packet-switched...

    Provided By Massachusetts Institute of Technology

  • White Papers // Jan 2011

    A Robust Optimization Approach to Backup Network Design With Random Failures

    This paper presents a scheme in which a dedicated backup network is designed to provide protection from random link failures. Upon a link failure in the primary network, traffic is rerouted through a preplanned path in the backup network. The authors introduce a novel approach for dealing with random link...

    Provided By Massachusetts Institute of Technology

  • White Papers // Jan 2011

    A State Action Frequency Approach to Throughput Maximization Over Uncertain Wireless Channels

    The authors consider scheduling over a wireless system, where the channel state information is not available a priori to the scheduler, but can be inferred from the past. Specifically, the wireless system is modeled as a network of parallel queues. They assume that the channel state of each queue evolves...

    Provided By Massachusetts Institute of Technology

  • White Papers // Aug 2009

    Autonomous Routing Algorithms for Networks With Wide-Spread Failures

    The authors study end-to-end delay performance of different routing algorithms in networks with random failures. Specifically, they compare delay performances of Differential Backlog (DB) and Shortest Path (SP) routing algorithms and show that DB routing outperforms SP routing in terms of throughput when the network is heavily loaded and/or the...

    Provided By Massachusetts Institute of Technology

  • White Papers // Apr 2010

    Minimizing Transmission Energy in Sensor Networks Via Trajectory Control

    Energy optimization is a significant component of Wireless Sensor Network (WSN) design. In this paper the authors consider transmission energy optimization in WSNs where messages are collected by a mobile receiver (collector). The collector is responsible for gathering data messages by choosing the optimal path that minimizes the total transmit...

    Provided By Massachusetts Institute of Technology

  • White Papers // Aug 2010

    Dynamic Vehicle Routing for Data Gathering in Wireless Networks

    There has been a significant amount of interest in performance analysis of mobility assisted wireless networks in the last decade (e.g., [15], [24] - [28]). Typically, throughput and delay performance of networks were analyzed where nodes moving according to a random mobility model were utilized for relaying data (e.g., [14],...

    Provided By Massachusetts Institute of Technology

  • White Papers // Jan 2011

    Scheduling in Parallel Queues With Randomly Varying Connectivity and Switchover Delay

    The authors consider a dynamic server control problem for two parallel queues with randomly varying connectivity and server switchover delay between the queues. At each time slot the server decides either to stay with the current queue or switch to the other queue based on the current connectivity and the...

    Provided By Massachusetts Institute of Technology

  • White Papers // Feb 2010

    Wealth Accumulation And Factors Accounting For Success

    The authors use detailed income, balance sheet, and cash flow statements constructed for households in a long monthly panel in an emerging market economy, and some recent contributions in economic theory, to document and better understand the factors underlying success in achieving upward mobility in the distribution of net worth....

    Provided By Massachusetts Institute of Technology

  • White Papers // Sep 2010

    Throughput Optimal Scheduling in the Presence of Heavy-Tailed Traffic

    The authors investigate the tail behavior of the steady-state queue occupancies under throughput optimal scheduling in the presence of heavy-tailed traffic. They consider a system consisting of two parallel queues, served by a single server. One of the queues receives traffic that is heavy-tailed (the "Heavy queue"), and the other...

    Provided By Massachusetts Institute of Technology

  • White Papers // Jan 2011

    Delay in Random Access Wireless Networks With Controlled Mobility

    This paper considers dynamic wireless networks where messages arriving randomly (in time and space) are collected by a mobile receiver. The messages are transmitted to the mobile receiver according to a random access scheme and the receiver dynamically adjusts its position in order to receive these messages in the least...

    Provided By Massachusetts Institute of Technology

  • White Papers // Mar 2010

    Whanau: A Sybil-Proof Distributed Hash Table

    Decentralized systems on the Internet are vulnerable to the "Sybil attack", in which an adversary creates numerous false identities to influence the system's behavior. This problem is particularly pernicious when the system is responsible for routing messages amongst nodes, as in the Distributed Hash Tables (DHT) which underlie many peer-to-peer...

    Provided By Massachusetts Institute of Technology

  • White Papers // Jan 2010

    Secure Storage of Fingerprint Biometrics Using Slepian-Wolf Codes

    This paper describes a method to encode fingerprint biometrics securely for use, e.g., in encryption or access control. The system is secure because the stored data suffices to validate a probe fingerprint but not to recreate the original fingerprint biometric. Therefore, a breach in database security does not lead to...

    Provided By Massachusetts Institute of Technology

  • White Papers // Aug 2010

    Immersive Journalism: Immersive Virtual Reality for the First-Person Experience of News

    This paper introduces the concept and discusses the implications of immersive journalism, which is the production of news in a form in which people can gain first person experiences of the events or situation described in news stories. The fundamental idea of immersive journalism is to allow the participant, typically...

    Provided By Massachusetts Institute of Technology

  • White Papers // Nov 2009

    Design and Performance of Multipath MIN Architecture

    In this paper, the authors discuss the use of multipath Multistage Interconnection Networks (MINs) in the design of a fault-tolerant parallel computer. Multipath networks have multiple paths between any input and any output. In particular, they examine networks with either the property of expansion or maximal-fanout. The authors present a...

    Provided By Massachusetts Institute of Technology

  • Webcasts // Apr 2011

    Technology: Do Kids Need More or Less?

    The ultimate questions for this Sandbox 2011 panel, posed by the presenter, are "Where is technology not working? When is technology not the answer?" That's a bold agenda for a panel of children's media creators and a roomful of other producers in the industry, from Sesame Workshop, WGBH, 360 Kid,...

    Provided By Massachusetts Institute of Technology

  • Webcasts // Apr 2011

    Learning 3.0: Why Technology Belongs in Every Classroom

    The Obama Administration's recently unveiled plan for transforming American education through technology does not envision "Plugging kids in and making them smarter," declares the presenter. Instead, it focuses on leveraging aspects of digital technology "To create way more compelling environments in schools," and to address educational inequities and the larger...

    Provided By Massachusetts Institute of Technology

  • White Papers // Jan 2010

    Dos and Don'ts of Client Authentication on the Web

    Client authentication has been a continuous source of problems on the web. Although many well-studied techniques exist for authentication, websites continue to use extremely weak authentication schemes, especially in non-enterprise environments such as store fronts. These weaknesses often result from careless use of authenticators within Web cookies. Of the twenty-seven...

    Provided By Massachusetts Institute of Technology

  • White Papers // Apr 2011

    Gasping for AIR - Why We Need Linked Rules and Justifications on the Semantic Web

    The Semantic Web is a distributed model for publishing, utilizing and extending structured information using Web protocols. One of the main goals of this technology is to automate the retrieval and integration of data and to enable the inference of interesting results. This automation requires logics and rule languages that...

    Provided By Massachusetts Institute of Technology

  • White Papers // Mar 2011

    BOOM: Broadcast Optimizations for On-Chip Meshes

    Future many-core chips will require an on-chip network that can support broadcasts and multicasts at good power-performance. A vanilla on-chip network would send multiple unicast packets for each broadcast packet, resulting in latency, throughput and power overheads. Recent research in on-chip multicast support has proposed forking of broadcast/multicast packets within...

    Provided By Massachusetts Institute of Technology

  • White Papers // Feb 2011

    Decomposing Broadcast Algorithms Using Abstract MAC Layers

    In much of the theoretical literature on global broadcast algorithms for wireless networks, issues of message dissemination are considered together with issues of contention management. This combination leads to complicated algorithms and analysis, and makes it difficult to extend the work to more difficult communication problems. In this paper, the...

    Provided By Massachusetts Institute of Technology

  • White Papers // Mar 2011

    Remote Oblivious Storage: Making Oblivious RAM Practical

    Remote storage of data has become an increasingly attractive and advantageous option, especially due to cloud systems. While encryption protects the data, it does not hide the access pattern to the data. A natural solution is to access remote storage using an Oblivious RAM (ORAM) which provably hides all access...

    Provided By Massachusetts Institute of Technology

  • White Papers // Oct 2010

    SEEC: A Framework for Self-aware Computing

    As the complexity of computing systems increases, application programmers must be experts in their application domain and have the systems knowledge required to address the problems that arise from parallelism, power, energy, and reliability concerns. One approach to relieving this burden is to make use of self-aware computing systems, which...

    Provided By Massachusetts Institute of Technology

  • White Papers // Dec 2010

    Heracles: Fully Synthesizable Parameterized MIPS-Based Multicore System

    Heracles is an open-source complete multicore system written in Verilog. It is fully parameterized and can be reconfigured and synthesized into different topologies and sizes. Each processing node has a 7-stage pipeline, fully bypassed, microprocessor running the MIPS-III ISA, a 4-stage input-buffer, virtual-channel router, and a local variable-size shared memory....

    Provided By Massachusetts Institute of Technology

  • White Papers // Nov 2010

    Scalable Directoryless Shared Memory Coherence Using Execution Migration

    The authors introduce the concept of deadlock-free migration-based coherent shared memory to the NUCA family of architectures. Migration-based architectures move threads among cores to guarantee sequential semantics in large multicores. Using an Execution Migration (EM) architecture, the authors achieve performance comparable to directory-based architectures without using directories: avoiding automatic data...

    Provided By Massachusetts Institute of Technology

  • White Papers // Aug 2010

    The Abstract MAC Layer

    A diversity of possible communication assumptions complicates the study of algorithms and lower bounds for radio networks. The authors address this problem by defining an abstract MAC layer. This service provides reliable local broadcast communication, with timing guarantees stated in terms of a collection of abstract delay functions applied to...

    Provided By Massachusetts Institute of Technology

  • White Papers // Aug 2010

    MAC Design for Analog Network Coding

    Most medium access control mechanisms discard collided packets and consider interference harmful. Recent work on Analog Network Coding (ANC) suggests a different approach, in which multiple interfering transmissions are strategically scheduled. The received collisions are collected and then used in a decoding process, such as the ZigZag decoding process, where...

    Provided By Massachusetts Institute of Technology

  • White Papers // Jun 2010

    Broadcasting in Unreliable Radio Networks

    Practitioners agree that unreliable links, which fluctuate between working and not working, are an important characteristic of wireless networks. In contrast, most theoretical models of radio networks fix a static set of links and assume that these links work reliably throughout an execution. This gap between theory and practice motivates...

    Provided By Massachusetts Institute of Technology

  • White Papers // May 2010

    Dynamic Knobs for Power-Aware Computing

    The authors present PowerDial, a system for dynamically adapting application behavior to execute successfully in the face of load and power fluctuations. PowerDial transforms static configuration parameters into dynamic knobs that the PowerDial control system can manipulate to dynamically trade off the accuracy of the computation in return for reductions...

    Provided By Massachusetts Institute of Technology

  • White Papers // Feb 2010

    The Cost of Global Broadcast Using Abstract MAC Layers

    The authors analyze greedy algorithms for broadcasting messages throughout a multi-hop wireless network, using a slot-based model that includes message collisions without collision detection. The algorithms are split formally into two pieces: A high-level piece for broadcast and a low-level piece for contention management. They accomplish the split using abstract...

    Provided By Massachusetts Institute of Technology

  • White Papers // Feb 2010

    SWIFT: A Narrowband-Friendly Cognitive Wideband Network

    Wideband technologies in the unlicensed spectrum can satisfy the ever-increasing demands for wireless bandwidth created by emerging rich media applications. The key challenge for such systems, however, is to allow narrowband technologies that share these bands (say, 802.11 a/b/g/n, Zigbee) to achieve their normal performance, without compromising the throughput or...

    Provided By Massachusetts Institute of Technology

  • White Papers // Nov 2009

    Distributed Computation in Dynamic Networks

    In this paper the authors investigate distributed computation in dynamic networks in which the network topology changes from round to round. They consider a worst-case model in which the communication links for each round are chosen by an adversary, and nodes do not know who their neighbors for the current...

    Provided By Massachusetts Institute of Technology

  • White Papers // Apr 2010

    Robust Routing for Local Area Optical Access Networks

    One approach to providing the benefits of the high data rates afforded by optics is to attempt to implement traditional electronic and electro-optic approaches using optical technologies. In electronics, operations such as buffering, adding packets and dropping packets, or merging packet streams, are done with ease. In optics, however, buffering...

    Provided By Massachusetts Institute of Technology