Massachusetts Institute of Technology

Displaying 361-400 of 424 results

  • White Papers // Aug 2009

    Service Objects: Adaptable, Metadata-Based Services for Multi-Tenant On-Demand Enterprise Applications

    An adaptive, standardized service layer is a key feature of a multi-tenant on-demand enterprise application. Custom business logic and data need to be exposed via services that are tailored to the respective customer organization. Ideally, this layer of web services can be automatically derived from the underlying domain model. This...

    Provided By Massachusetts Institute of Technology

  • White Papers // Aug 2009

    Automatically Patching Errors in Deployed Software

    The authors present ClearView, a system for automatically patching errors in deployed software. ClearView works on stripped Windows x86 binaries without any need for source code, debugging information, or other external information, and without human intervention. ClearView observes normal executions to learn invariants that characterize the application's normal behavior, uses...

    Provided By Massachusetts Institute of Technology

  • White Papers // Aug 2009

    Bandwidth Extension of Low Noise Fractional-N Synthesizers

    In this paper, the authors examine issues with extending the bandwidth of fractional-N synthesizers. Quantization noise is shown to be the limiting factor in state-of-the-art fractional-N synthesis. A re-framing of the noise model used to analyze synthesizer phase noise leads directly to a methodology to enable high bandwidth synthesis. They...

    Provided By Massachusetts Institute of Technology

  • White Papers // Aug 2009

    ESD And Health Care Systems: Some Strategic Considerations

    Proper health care delivery to a growing but aging population is becoming one of the most challenging tasks of the time. It becomes also one of the most complexes. Although many tools are at hand, grand designs and implementation systems are mostly lacking. In the industrialized countries, requests for optimal...

    Provided By Massachusetts Institute of Technology

  • White Papers // Aug 2009

    The 24-Hour Knowledge Factory Paradigm: The Evolving Model For Offshoring Based On Strategic, Economic, Legal, Health, Technical, And Other Considerations

    The 24-Hour Knowledge Factory paradigm involves 3 (or more) collaborating centers, each located in a different continent. Individuals at each center work from 9 am to 5 pm in that country, and then pass the work-in-progress to the next collaborating center to enable round-the clock performance in a manner somewhat...

    Provided By Massachusetts Institute of Technology

  • White Papers // Jul 2009

    ATAC: On-Chip Optical Networks for Multicore Processors

    ˆe trend in modern microprocessor architectures is clear: multicore is here. As silicon resources become increasingly abundant, processor designers are able to place more and more cores on a chip: AMD and Intel have released 2-core chips with 4-core offerings coming soon. Forecasts show that by 2014, processors may contain...

    Provided By Massachusetts Institute of Technology

  • White Papers // Jul 2009

    Designing Energy-Efficient Low-Diameter On-Chip Networks with Equalized Interconnects

    In a power and area constrained multicore system, the on-chip communication network needs to be carefully designed to maximize the system performance and programmer productivity while minimizing energy and area. In this paper, the authors explore the design of energy-efficient low-diameter networks (flattened butterfly and Clos) using equalized on-chip interconnects....

    Provided By Massachusetts Institute of Technology

  • White Papers // Jul 2009

    Multiple Experiments For The Causal Link between The Quantity And Quality Of Children

    A longstanding question in the economics of the family is the relationship between family size and subsequent human capital formation and welfare. If there is a causal "Quantity-quality trade-off," then policies that discourage large families should lead to increased human capital and higher earnings. Ordinary least squares estimates and a...

    Provided By Massachusetts Institute of Technology

  • White Papers // Jul 2009

    Electricity Transmission Policy For America: Enabling A Smart Grid, End-to-End

    This paper proposes a framework of policies to guide the future development of America's electric transmission grid so that the electric power industry will be able to serve more effectively the changing needs of the U.S. economy and society. The paper provides a factual overview of the American electric power...

    Provided By Massachusetts Institute of Technology

  • White Papers // Jul 2009

    Productivity Differences Between And Within Countries

    The authors document substantial within-country (cross-municipality) differences in incomes for a large number of countries in the Americas. A significant fraction of the within-country differences cannot be explained by observed human capital. They conjecture that the sources of within-country and between-country differences are related. As a first step towards a...

    Provided By Massachusetts Institute of Technology

  • White Papers // Jun 2009

    Programming Manifolds

    Many programming domains involve the manipulation of values distributed through a manifold - examples include sensor networks, smart materials, and biofilms. This paper describes a programming semantics for manifolds based on the amorphous medium abstraction, which places a computational device at every point in the manifold. This abstraction enables the...

    Provided By Massachusetts Institute of Technology

  • White Papers // Jun 2009

    Interactive Visual Histories for Vector Graphics

    Presentation and graphics software enables users to experiment with variations of illustrations. They can revisit recent editing operations using the ubiquitous undo command, but they are limited to sequential exploration. The authors propose a new interaction metaphor and visualization for operation history. While editing, a user can access a history...

    Provided By Massachusetts Institute of Technology

  • White Papers // Jun 2009

    A Distributed Wearable, Wireless Sensor System for Evaluating Professional Baseball Pitchers and Batters

    This paper introduces a compact, wireless, wearable system that measures signals indicative of forces, torques and other descriptive and evaluative features that the human body undergoes during bursts of extreme physical activity (such as during athletic performance). Standard approaches leverage high-speed camera systems, which need significant infrastructure and provide limited...

    Provided By Massachusetts Institute of Technology

  • White Papers // Jun 2009

    Efficient Cache Attacks on AES, and Countermeasures

    The authors describe several software side-channel attacks based on inter-process leakage through the state of the CPU's memory cache. This leakage reveals memory access patterns, which can be used for cryptanalysis of cryptographic primitives that employ data-dependent table lookups. The attacks allow an unprivileged process to attack other processes running...

    Provided By Massachusetts Institute of Technology

  • Webcasts // Jun 2009

    Critical Issues And Grand Challenges

    The panelists use the lens of systems engineering to focus sharply on some signature global challenges in finance, healthcare, energy and IT. The system failure that undid the small but influential financial services industry was a few decades in the making, says one of the presenter.

    Provided By Massachusetts Institute of Technology

  • Webcasts // Jun 2009

    Grand Challenges And Engineering Systems: Inspiring And Educating The Next Generation

    It's a good thing for a world increasingly beset by mammoth challenges that universities are responding with new engineering systems programs. These initiatives, as one of the presenter attests, are swiftly proliferating in the U.S. and abroad to equip students to address such complex issues as health care, sustainable energy,...

    Provided By Massachusetts Institute of Technology

  • White Papers // Jun 2009

    Competition, Market Coverage, and Quality Choice in Interconnected Platforms

    The authors study duopoly competition between two interconnected Internet Service Providers (ISP) that compete in quality and prices for both Content Providers (CP) and consumers. They develop a game theoretic model using a two-sided market framework, where ISP's are modeled as interconnected plat-forms with quality bottlenecks; a consumer on a...

    Provided By Massachusetts Institute of Technology

  • Webcasts // Jun 2009

    Global And Domestic Imbalances: Why Rural China Is The Key

    China owes its astonishing economic expansion not to far-sighted government policy but to hundreds of millions of entrepreneurial peasants. Yasheng Huang's research reveals not only how small-scale rural businesses created China's miracle but how that nation's recovery from the global recession and righting the massive East-West trade imbalance depend on...

    Provided By Massachusetts Institute of Technology

  • Webcasts // Jun 2009

    The Power Of Competition: How To Focus The World's Brains On Your Innovation Challenges

    Cooperation may be making us "A little bit too nice" when it comes to innovation, suggests Fiona Murray. She believes there's nothing like competition for injecting energy into the process of solving key innovation problems, whether in business or society.

    Provided By Massachusetts Institute of Technology

  • White Papers // Jun 2009

    Modeling Radio Networks

    The authors describe a modeling framework and collection of foundational composition results for the study of probabilistic distributed algorithms in synchronous radio networks. Existing results in this setting rely on informal descriptions of the channel behavior and therefore lack easy comparability and are prone to error caused by definition subtleties....

    Provided By Massachusetts Institute of Technology

  • White Papers // Jun 2009

    Wishbone: Profile-Based Partitioning for Sensornet Applications

    The ability to partition sensor network application code across sensor nodes and backend servers is important for running complex, data-intensive applications on sensor platforms that have CPU, energy, and bandwidth limitations. This paper presents Wishbone, a system that takes a dataflow graph of operators and produces an optimal partitioning. With...

    Provided By Massachusetts Institute of Technology

  • White Papers // Jun 2009

    Income And Health Spending: Evidence From Oil Price Shocks

    Health expenditures as a share of GDP have more than tripled over the last half century. A common conjecture is that this is primarily a consequence of rising real per capita income, which more than doubled over the same period. The authors investigate this hypothesis empirically by instrumenting for local...

    Provided By Massachusetts Institute of Technology

  • White Papers // Jun 2009

    VPriv: Protecting Privacy in Location-Based Vehicular Services

    A variety of location-based vehicular services are currently being woven into the national transportation infrastructure in many countries. These include usage- or congestion-based road pricing, traffic law enforcement, traffic monitoring, "Pay-as-you-go" insurance, and vehicle safety systems. Although such applications promise clear benefits, there are significant potential violations of the location...

    Provided By Massachusetts Institute of Technology

  • White Papers // Jun 2009

    Wishbone: Profile-Based Partitioning for Sensor net Applications

    The ability to partition sensor network application code across sensor nodes and back-end servers is important for running complex, data-intensive applications on sensor platforms that have CPU, energy, and bandwidth limitations. This paper presents Wishbone, a system that takes a data flow graph of operators and produces an optimal partitioning....

    Provided By Massachusetts Institute of Technology

  • White Papers // Jun 2009

    Disciplined Agility For Process Control & Automation

    Process Automation systems can impact the operating cost of manufacturing equipment, the safe control of large quantities of energy and the safety of dangerous substances used during manufacturing. The manufacturing segment expects greater automation of larger processes, increased capability of process automation systems, and higher quality of those systems. At...

    Provided By Massachusetts Institute of Technology

  • White Papers // Jun 2009

    Lean Visual Management In An ERP/MES-Controlled Production Cell

    As a company grows, more and more effort is needed to control and coordinate operations. Typically, this is accomplished through an evolving collection of systems and processes, such as an Enterprise Resource Planning (ERP) system, but such systems also influence how a company does business, reviews performance, and communicate results....

    Provided By Massachusetts Institute of Technology

  • White Papers // Jun 2009

    Mitigating The Risk Of A New Workforce By Reducing Rework And Rightsizing On Hand Inventory

    Dramatically increasing the hourly workforce at a rapid pace to support accelerated product demand in an aircraft manufacturing facility in a short amount of time resulted in: increased rework, and increased part damage during assembly. The majority of rework results from simple workmanship mistakes from the new workforce. The approach...

    Provided By Massachusetts Institute of Technology

  • White Papers // Jun 2009

    Understanding Enterprise Behavior Using Hybrid Simulation Of Enterprise Architecture

    Today, the design of business enterprises is much more art than science. The complex structure and behavior of enterprises makes it difficult to untangle cause and effect amidst its components and their relationships. In order for managers to understand how an enterprise's architecture affects its behavior, they need tools and...

    Provided By Massachusetts Institute of Technology

  • White Papers // Jun 2009

    Enabling Cultural Shifts: An Enterprise Approach Toward Lean Thinking

    The Supply Planning Operations team, in a large manufacturing firm, faced a future where their complexity of scope was increasing without an increase in resource levels. As an effort to improve both efficiency and effectively within the organization, they chose to adopt Lean Thinking as a method to streamline and...

    Provided By Massachusetts Institute of Technology

  • White Papers // May 2009

    Gradient Clock Synchronization in Dynamic Networks

    Establishing coordination between participants is at the core of many algorithmic challenges in distributed computing. A fundamental coordination task, and a basic prerequisite for many applications, is achieving a common notion of time. Typically every node in the network has access to a local hardware clock, but the hardware clocks...

    Provided By Massachusetts Institute of Technology

  • White Papers // May 2009

    Oblivious Routing in On-Chip Bandwidth-Adaptive Networks

    Oblivious routing can be implemented on simple router hardware, but network performance suffers when routes become congested. Adaptive routing attempts to avoid hot spots by re-routing flows, but requires more complex hardware to determine and configure new routing paths. The authors propose on-chip bandwidth-adaptive networks to mitigate the performance problems...

    Provided By Massachusetts Institute of Technology

  • White Papers // May 2009

    A Screening Model To Explore Planning Decisions In Automotive Manufacturing Systems Under Demand Uncertainty

    Large-scale, complex engineering systems, as for automotive manufacturing, often require significant capital investment and resources for systems configuration. Furthermore, these systems operate in environments that are constantly changing due to shifts in macroeconomic, market demand and regulations, which can significantly influence systems' performance. It is often very difficult or prohibitively...

    Provided By Massachusetts Institute of Technology

  • Webcasts // May 2009

    Energy Entrepreneurship And Innovation: Today's Challenges, Tomorrow's Opportunities

    There are sample opportunities for new energy entrepreneurs, these panelists agree, but motivation and certain kinds of know how play key roles in bringing new ventures to fruition. Idealism led Christina Lampe-Onnerud to "Go into the energy space" at 23, but "Inertia" surrounding the energy business may intimidate today's entrepreneurs.

    Provided By Massachusetts Institute of Technology

  • Webcasts // May 2009

    U.S.-Iran Relations

    While Barrack Obama has rejected the Bush administration's harsh stance toward Iran, the authors warn that they're far from the start of fruitful relations, and that achieving real diplomacy will paradoxically require both patience and a sense of urgency.

    Provided By Massachusetts Institute of Technology

  • White Papers // May 2009

    ATAC: A Manycore Processor With On-Chip Optical Network

    Ever since industry has turned to parallelism instead of frequency scaling to improve processor performance, multicore processors have continued to scale to larger and larger numbers of cores. Some believe that multicores will have 1000 cores or more by the middle of the next decade. However, their promise of increased...

    Provided By Massachusetts Institute of Technology

  • White Papers // May 2009

    Spectrum Pooling for Next Generation Public Safety Radio Systems

    The Dynamic Spectrum Access (DSA) research and development community is maturing technologies that will enable radios to share RF spectrum much more intensively. Adoption of DSA technologies by the public safety community can better align systems with the future of wireless services more generally and can contribute to making next...

    Provided By Massachusetts Institute of Technology

  • Webcasts // May 2009

    Engineering For The Ecological Age: Lessons From History

    The author, a structural engineer, "Fell in love with archaeology" during college. The senior thesis at Cornell involved a 600-year-old Incan suspension bridge made entirely out of grass. The author learned that this apparently primitive structure owed its astonishing longevity to regular rebuilds by the locals (during a community festival),...

    Provided By Massachusetts Institute of Technology

  • White Papers // May 2009

    Measuring And Understanding Hierarchy As An Architectural Element In Industry Sectors

    Hierarchy is a generic structure in which levels are asymmetrically ordered. In an industry setting, classic supply chains display strict hierarchy, whereas clusters of firms have linkages going in many different directions. The empirical measurement and model analysis together indicate that it is the low transaction specificity that drives down...

    Provided By Massachusetts Institute of Technology

  • Webcasts // Apr 2009

    Ethics And Enlightened Leadership

    His Holiness the Dalai Lama spoke at an inaugural event for a new institute in his name, the Dalai Lama Center for Ethics and Transformative Values. He tempered his provocative ideas about promoting ethics in a secular society with a stream of lively banter.

    Provided By Massachusetts Institute of Technology

  • Webcasts // Apr 2009

    The Future Of Science Journalism

    The authors states that science journalism "Is now, and in the decades ahead, absolutely indispensable." As they confront global warming and health pandemics, science reporting must be sustained, the author says, "In its rightful place, at the top of the profession and in the thick of the national conversation." But...

    Provided By Massachusetts Institute of Technology

  • White Papers // Feb 2011

    SoftCast: Clean-Slate Scalable Wireless Video

    Video broadcast and mobile video challenge the conventional wireless design. In broadcast and mobile scenarios the bit rate supported by the channel differs across receivers and varies quickly over time. The conventional design however forces the source to pick a single bit rate and degrades sharply when the channel cannot...

    Provided By Massachusetts Institute of Technology

  • White Papers // Feb 2010

    Core Count Vs Cache Size for Manycore Architectures in the Cloud

    The number of cores which fit on a single chip is growing at an exponential rate while off-chip main memory bandwidth is growing at a linear rate at best. This core count to off-chip bandwidth disparity causes per-core memory bandwidth to decrease as process technology advances. Continuing per-core off-chip bandwidth...

    Provided By Massachusetts Institute of Technology

  • White Papers // Nov 2009

    A Unified Operating System for Clouds and Manycore: Fos

    Single chip processors with thousands of cores will be available in the next ten years and clouds of multicore processors afford the operating system designer thousands of cores today. Constructing operating systems for manycore and cloud systems face similar challenges. This paper identifies these shared challenges and introduces them solution:...

    Provided By Massachusetts Institute of Technology

  • White Papers // Oct 2009

    Understanding and Supporting Directed Content Sharing on the Web

    To find interesting, personally relevant web content, the authors often rely on friends and colleagues to pass links along as they encounter them. This paper studies and augments link-sharing via e-mail, the most popular means of sharing web content today. Armed with survey data indicating that active sharers of novel...

    Provided By Massachusetts Institute of Technology

  • White Papers // Mar 2011

    Deterministic Network Model Revisited: An Algebraic Network Coding Approach

    The capacity of multiuser networks has been a longstanding problem in information theory. Recently, Avestimehr et al. have proposed a deterministic network model to approximate multiuser wireless networks. This model, known as the ADT network model, takes into account the broadcast nature of wireless medium and interference. The authors show...

    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 // Jan 2011

    Co-Designing Multi-Packet Reception, Network Coding, and MAC Using a Simple Predictive Model

    The authors design a cross-layer approach to optimize the joint use of multi-packet reception and network coding, in order to relieve congestion. The authors construct a model for the behavior of the 802.11 MAC and apply it to several key canonical topology components and their extensions to any number of...

    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 // 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

  • White Papers // Apr 2009

    Security Impact Ratings Considered Harmful

    In this paper, the authors question the common practice of assigning security impact ratings to OS updates. Specifically, they present evidence that ranking updates by their perceived security importance, in order to defer applying some updates, exposes systems to significant risk. They argue that OS vendors and security groups should...

    Provided By Massachusetts Institute of Technology

  • Webcasts // Sep 2010

    Crowds and Clouds: Data, Sheep, and Collaboration in the Works of Aaron Koblin

    Where others see just data points and fodder for bar graphs, presenter visualizes dynamic systems where information assumes forms both abstract and familiar. In this talk, presenter shares recent projects that meld statistical science and art to convey a really big picture, while often inviting the viewer to partake in...

    Provided By Massachusetts Institute of Technology

  • Webcasts // Mar 2011

    Data-Driven Traffic Modeling, Prediction, and Planning

    Some professors work primarily in labs and others mainly at desks. Presenter conducts her research on the bustling streets of Singapore, where she is helping to design a "Future mobility project" Whose goal is to "Marry information technology with the transportation industry."

    Provided By Massachusetts Institute of Technology

  • Webcasts // Nov 2009

    Network-Driven Transportation

    Today, cell phones are a menace to safe driving, as they distract operators who should otherwise focus on the road. Tomorrow, cell phones could actually improve the driving, and help drivers avoid traffic congestion, use the road system more effectively, and manage the parking supply.

    Provided By Massachusetts Institute of Technology

  • White Papers // Jun 2009

    Efficient Cache Attacks on AES, and Countermeasures

    The authors describe several software side-channel attacks based on inter-process leakage through the state of the CPU's memory cache. This leakage reveals memory access patterns, which can be used for cryptanalysis of cryptographic primitives that employ data-dependent table lookups. The attacks allow an unprivileged process to attack other processes running...

    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 // Aug 2009

    Training-Based Schemes Are Suboptimal for High Rate Asynchronous Communication

    Synchronization and information transmission of virtually all practical communication systems are performed separately, on the basis of different communication bits. Moreover, in general, the rate of these strategies is computed with respect to the information transmission time period, ignoring the delay overhead caused by various hand-shake protocols used to guarantee...

    Provided By Massachusetts Institute of Technology

  • White Papers // Jun 2009

    VPriv: Protecting Privacy in Location-Based Vehicular Services

    A variety of location-based vehicular services are currently being woven into the national transportation infrastructure in many countries. These include usage- or congestion-based road pricing, traffic law enforcement, traffic monitoring, "Pay-as-you-go" insurance, and vehicle safety systems. Although such applications promise clear benefits, there are significant potential violations of the location...

    Provided By Massachusetts Institute of Technology

  • White Papers // Jun 2009

    Wishbone: Profile-Based Partitioning for Sensor net Applications

    The ability to partition sensor network application code across sensor nodes and back-end servers is important for running complex, data-intensive applications on sensor platforms that have CPU, energy, and bandwidth limitations. This paper presents Wishbone, a system that takes a data flow graph of operators and produces an optimal partitioning....

    Provided By Massachusetts Institute of Technology

  • White Papers // Jan 2011

    How to Construct a Correct and Scalable IBGP Conguration

    The Internet's current inter domain 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...

    Provided By Massachusetts Institute of Technology

  • White Papers // Mar 2011

    Robust Distributed Routing in Dynamical Flow Networks - Part I: Locally Responsive Policies and Weak Resilience

    Robustness of distributed routing policies is studied for dynamical flow networks, with respect to adversarial disturbances that reduce the link flow capacities. A dynamical flow network is modeled as a system of ordinary differential equations derived from mass conservation laws on a directed acyclic graph with a single origin-destination pair...

    Provided By Massachusetts Institute of Technology

  • Webcasts // Oct 2007

    Process Improvement In The Rarefied Environment Of Academic Medicine

    In this webcast the author says, "Medicine for the most part remains a cottage industry," then how can you impose system-wide improvements - especially if you're presiding over an academic hospital, where the culture rewards brilliant, independent, free-thinking doctors?

    Provided By Massachusetts Institute of Technology

  • White Papers // Mar 2011

    Fully Leakage-Resilient Signatures

    A signature scheme is fully leakage resilient (Katz and Vaikuntanathan, ASIACRYPT '09) if it is existentially unforgeable under an adaptive chosen-message attack even in a setting where an adversary may obtain bounded (yet arbitrary) leakage information on all intermediate values that are used throughout the lifetime of the system. This...

    Provided By Massachusetts Institute of Technology

  • White Papers // Mar 2011

    Improving Wireless Network Performance Using Sensor Hints

    With the proliferation of mobile wireless devices such as smartphones and tablets that are used in a wide range of locations and movement conditions, it has become important for wireless protocols to adapt to different settings over short periods of time. Network protocols that perform well in static settings where...

    Provided By Massachusetts Institute of Technology

  • White Papers // Mar 2011

    Accurate, Low-Energy Trajectory Mapping for Mobile Devices

    CTrack is an energy-efficient system for trajectory mapping using raw position tracks obtained largely from cellular base station fingerprints. Trajectory mapping, which involves taking a sequence of raw position samples and producing the most likely path followed by the user, is an important component in many location based services including...

    Provided By Massachusetts Institute of Technology

  • White Papers // Aug 2009

    Explorations in Cyber International Relations (ECIR) Data Dashboard Report #1: CERT Data Sources and Prototype Dashboard System

    Growing global interconnection and interdependency of computer networks, in combination with increased sophistication of cyber attacks over time, demonstrate the need for better understanding of the collective and cooperative security measures needed to prevent and respond to cyber-security emergencies. The Exploring Cyber International Relations (ECIR) Data Dashboard project is an...

    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 // Jan 2011

    Peer-to-Peer Communication Across Network Address Translators

    Network Address Translation (NAT) causes well-known difficulties for Peer-To-Peer (P2P) communication, since the peers involved may not be reachable at any globally valid IP address. Several NAT traversal techniques are known, but their documentation is slim, and data about their robustness or relative merits is slimmer. This paper documents and...

    Provided By Massachusetts Institute of Technology

  • White Papers // Sep 2010

    Nectar: Automatic Management of Data and Computation in Datacenters

    Managing data and computation is at the heart of datacenter computing. Manual management of data can lead to data loss, wasteful consumption of storage, and laborious bookkeeping. Lack of proper management of computation can result in lost opportunities to share common computations across multiple jobs or to compute results incrementally....

    Provided By Massachusetts Institute of Technology

  • White Papers // Apr 2011

    Exact Distance Oracles for Planar Graphs

    A fast shortest-path query data structure may be of use whenever an application needs to compute shortest path distances between some but not all pairs of nodes. Indeed, shortest-path query processing is an integral part of many applications, in particular in Geographic Information Systems (GIS) and intelligent transportation systems. These...

    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 // Jun 2011

    A Software Approach to Unifying Multicore Caches

    Multicore chips will have large amounts of fast on-chip cache memory, along with relatively slow DRAM interfaces. The on-chip cache memory, however, will be fragmented and spread over the chip; this distributed arrangement is hard for certain kinds of applications to exploit efficiently, and can lead to needless slow DRAM...

    Provided By Massachusetts Institute of Technology

  • White Papers // Nov 2011

    CPHASH: A Cache-Partitioned Hash Table

    CPHASH is a concurrent hash table for multicore processors. CPHASH partitions its table across the caches of cores and uses message passing to transfer lookups/inserts to a partition. CPHASH's message passing avoids the need for locks, pipelines batches of asynchronous messages, and packs multiple messages into a single cache line...

    Provided By Massachusetts Institute of Technology

  • White Papers // Jun 2010

    Reinventing Scheduling for Multicore Systems

    High performance on multicore processors requires that schedulers be reinvented. Traditional schedulers focus on keeping execution units busy by assigning each core a thread to run. Schedulers ought to focus, however, on high utilization of on-chip memory, rather than of execution cores, to reduce the impact of expensive DRAM and...

    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 // Mar 2010

    Characterizing Cyberspace: Past, Present and Future David Clark

    This paper is funded by the Office of Naval Research under award number N00014091059 and N000140810898. Any opinions, findings, and conclusions or recommendations expressed in this email are those of the author(s) and do not necessarily reflect the views of the Office of Naval Research. In general terms, most practitioners...

    Provided By Massachusetts Institute of Technology

  • White Papers // Jun 2011

    Probabilistically Accurate Program Transformations

    The standard approach to program transformation involves the use of discrete logical reasoning to prove that the applied transformation does not change the observable semantics of the program. This paper, in contrast, introduces a novel approach that uses probabilistic reasoning to justify transformations that may change the result that the...

    Provided By Massachusetts Institute of Technology

  • White Papers // May 2011

    Detecting and Escaping Infinite Loops With Jolt

    Infinite loops can make applications unresponsive. Potential problems include lost work or output, denied access to application functionality, and a lack of responses to urgent events. The authors present Jolt, a novel system for dynamically detecting and escaping infinite loops. At the user's request, Jolt attaches to an application to...

    Provided By Massachusetts Institute of Technology

  • White Papers // May 2011

    Manipulating Program Functionality to Eliminate Security Vulnerabilities

    Security vulnerabilities can be seen as excess undesirable functionality present in a software system. The authors present several mechanisms that can either excise or change system functionality in ways that may eliminate security vulnerabilities while, enabling the system to continue to deliver acceptable service. They discuss several automatic techniques for...

    Provided By Massachusetts Institute of Technology

  • Webcasts // Apr 2011

    Plays Well With Others: Leadership in Online Collaboration

    In this Webcast, the presenter finds the accomplishments of such online collaborations as Wikipedia, Apache and Firefox "Nothing less than astounding," and is both eagerly seeking and hoping to foster the next creative group Internet sensation. The presenter identifies some typical collaborative modes, including the remix (adapting someone else's project);...

    Provided By Massachusetts Institute of Technology

  • Webcasts // Apr 2011

    The Future of Learning

    In this Webcast, the presenter explains about the future of education. One of the assumptions on which the presenter has built is that the future of education is about learning, not about schooling. The companion assumption is that technology has a critical role to play, not as an end but...

    Provided By Massachusetts Institute of Technology