Massachusetts Institute of Technology

Displaying 321-360 of 457 results

  • 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 // Nov 2009

    What?s New At The MIT Center For Future Civic Media?

    The moderator of this webcast presents the Landman Report Card, a tool for helping communities contend with oil and gas companies eager to lease private land for energy drilling. In these deals, a salesman comes by with a pitch and a contract, leaving some property owners to deal with disastrous...

    Provided By Massachusetts Institute of Technology

  • White Papers // Nov 2009

    Collections, Cardinalities, and Relations

    Logics that involve collections (sets, multisets), and cardinality constraints are useful for reasoning about unbounded data structures and concurrent processes. To make such logics more useful in verification this paper extends them with the ability to compute direct and inverse relation and function images. The authors establish decidability and complexity...

    Provided By Massachusetts Institute of Technology

  • White Papers // Nov 2009

    A Fast and Secure Software Solution [ss7.0] That Counters Shoulder Surfing Attack

    Shoulder Surfing is a direct observation technique, such as looking over someone's shoulder to trap the information. It is relatively easy to stand next to someone and watch, what data the user types as an information to authenticate himselfherself to enter into a particular system. Often users are unaware of...

    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 // Oct 2009

    Experiences and Challenges With Using CERT Data to Analyze International Cyber Security

    With the increasing interconnection of computer networks and sophistication of cyber attacks, it is important to understand the dynamics of such situations, especially in regards to cyber international relations. The Explorations in Cyber International Relations (ECIR) Data Dashboard Project is an initiative to gather worldwide cyber security data publicly provided...

    Provided By Massachusetts Institute of Technology

  • White Papers // Oct 2009

    Coherent Optical Communication Over the Turbulent Atmosphere with Spatial Diversity and Wavefront Predistortion

    Optical communication through the atmosphere has the potential to provide data transmission over a distance of 1 to 100km at very high rates. The deleterious effects of turbulence can severely limit the utility of such a system, however, causing outages of up to 100ms. In this paper, the authors investigate...

    Provided By Massachusetts Institute of Technology

  • Webcasts // Oct 2009

    Carbon And Energy Efficient Supply Chains

    Consumers will soon be able to quantify the carbon footprint of products they consume, and that could begin to change consumer behavior. The common banana you buy, say organic or not, is probably labeled by the country or origin. Increasingly, you might see a second sticker adorning your beloved yellow...

    Provided By Massachusetts Institute of Technology

  • Webcasts // Oct 2009

    Education Across Borders: The India Perspective

    Rickshaw drivers in India are frequent victims of tuberculosis after just a few years inhaling traffic fumes. This near-epidemic went unacknowledged until the author demanded a solution. The fix, now gaining traction across the country, is a solar-powered vehicle that eliminates pedaling. But what began as a project to assist...

    Provided By Massachusetts Institute of Technology

  • Webcasts // Oct 2009

    Leadership Amidst Crisis

    In thirty years. S. D. Shibulal has seen his share of economic crises, but in thinking hard about the role of crises in the future for today's students he predicts: they will occur more frequently and will be less predictable, longer lasting and more costly.

    Provided By Massachusetts Institute of Technology

  • Webcasts // Oct 2009

    America~s Leadership In Clean Energy

    In welcoming President Obama, MIT President Susan Hockfield summarizes the vast array of energy innovation at MIT, including the MIT Energy Initiative and the student-led 1700 member Energy Club, and declares, "We share President Obama's view that clean energy is the defining challenge of this era."

    Provided By Massachusetts Institute of Technology

  • Webcasts // Oct 2009

    Transportation Policy: Thinking Globally, Acting Locally And Walking The Talk

    Why do so many sustainable transportation programs turn out, like the Alice in the Wonderland parable to lead us down unexpected paths? The presenter observes that true sustainable transport requires making more than short-term fixes. A sustainable transportation program is built upon the pyramid of three "E"s: equity, environmental benefit,...

    Provided By Massachusetts Institute of Technology

  • Webcasts // Oct 2009

    Leadership And Entrepreneurship

    While their ventures couldn't be more dissimilar - engineering high tech defense gear for soldiers, and running an exclusive online boutique - this entrepreneurs share some common experiences and lessons. Moderator would "Love to tell you I'm wicked brilliant, analytical, clairvoyant, but I'm not."

    Provided By Massachusetts Institute of Technology

  • White Papers // Oct 2009

    Genetic Variation In Financial Decision Making

    Individuals differ in how they compose their investment portfolios, yet empirical models of portfolio risk typically only account for a small portion of the cross-sectional variance. This paper asks if genetic variation can explain some of these individual differences. Following a major pension reform Swedish adult had to compose a...

    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

  • Webcasts // Oct 2009

    Improving Your Commute

    In this webcast, the presenter describes three challenges hat need to be met in using data to help commuters - pedestrians, bicyclists, drivers - reduce the time (and fuel) spent stuck in traffic: accurate modeling of traffic delays while conserving energy and protecting user privacy, accurate predictions of future traffic...

    Provided By Massachusetts Institute of Technology

  • White Papers // Oct 2009

    Financial Development, Gender And Entrepreneurship

    Female entrepreneurs are much less frequent than male entrepreneurs. In this paper the authors investigate a possible culprit: access to financial services. They use a dataset with entrepreneurship rates by opportunity and by need from the Global Entrepreneurship Monitor and indicators of financial institutions from Beck, Demirguc-Kunt and Levine (2000)...

    Provided By Massachusetts Institute of Technology

  • Webcasts // Sep 2009

    The Role Of Information Technology In Improving Transit Systems

    This ditty about tram car ticketing made famous by Mark Twain might spring to mind during the author's talk. Technology unimaginable in Twain's day is spurring a global shift in urban transit, the author says, from manual to automatic systems.

    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 // Sep 2009

    Whanaungatanga: Sybil-Proof Routing With Social Networks

    Decentralized systems, such as distributed hash tables, are subject to the Sybil attack, in which an adversary creates many false identities to increase its influence. This paper proposes a routing protocol for a distributed hash table that is strongly resistant to the Sybil attack. This is the first solution to...

    Provided By Massachusetts Institute of Technology

  • Webcasts // Sep 2009

    Financial Services: Prospects For Your Future

    In a lively discussion with the authors deconstructs the near collapse of the banking system and points out the multiple factors that have contributed to the financial crisis. Topics in the discussion include the banks that did not fail, how Canadian and other countries' banking systems also did not fail,...

    Provided By Massachusetts Institute of Technology

  • Webcasts // Sep 2009

    Financial Services: Prospect For Your Future

    In a lively discussion with Simon Johnson, Lawrence Fish deconstructs the near collapse of the banking system and points out the multiple factors that have contributed to the financial crisis.

    Provided By Massachusetts Institute of Technology

  • Webcasts // Sep 2009

    U.S.-Cuba Relations: The Beginning Of A Long Thaw?

    To the dismay of these seasoned Cuba specialists, the Obama administration is not pursuing a rapid thaw in relations with the Castro regime. While there appears no speedy end to 50 years of icy antipathy toward Cuba, the speakers detect a few hopeful signs of warming in recent times.

    Provided By Massachusetts Institute of Technology

  • Webcasts // Sep 2009

    Entrepreneurship, Government, And Development In Africa

    After centuries of insufferable oppression by colonial powers, bloody independence struggles, and corrupt home-grown regimes, "Africa today is quickly awakening, and determined to mainstream itself in the phenomenon of the globalization process," says the author, who served as Ghana's president for two terms starting in 2000.

    Provided By Massachusetts Institute of Technology

  • White Papers // Sep 2009

    Inferring Friendship Network Structure by Using Mobile Phone Data

    Data collected from mobile phones have the potential to provide insight into the relational dynamics of individuals. This paper compares observational data from mobile phones with standard self-report survey data. The authors find that the information from these two data sources is overlapping but distinct. For example, self-reports of physical...

    Provided By Massachusetts Institute of Technology

  • White Papers // Sep 2009

    Broadband Microfoundations: The Need for Traffic Data

    To date, most of the empirical effort to understand broadband service markets has focused on availability and adoption metrics and data. Data of this sort is indeed valuable when the dominant policy questions concern penetration and uptake. However, as broadband availability and penetration saturate, such data will become less informative....

    Provided By Massachusetts Institute of Technology

  • White Papers // Sep 2009

    Hybrid Wireless Broadband

    Wireless access networks are evolving rapidly and hold the promise of significantly altering the landscape for broadband competition. In a companion paper, the authors explained why wireless networks are unlikely to converge toward the sort of broadband platform network exemplified by wired Next Generation Access Networks. In this paper the...

    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 // Aug 2009

    The Evolution of Internet Congestion

    This paper discusses the evolution of the congestion controls that govern all Internet traffic. In particular the authors chronicle and discuss the implications of the fact that the most significant "Congestion Signals" are increasingly coming from network operators, not the TCP stack. Providers now nudge users into different traffic patterns...

    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 // Aug 2009

    On the Convergence of Wired and Wireless Access Network Architectures

    Wired and wireless access networks continue to evolve toward higher-capacity, multi-service systems. Recent wireless broadband networks such as 3G LTE and WiMax provide a general-purpose IP platform with over-the-top services at the application layer, which is similar to the design of wired IP platform networks. This paper examines whether wired...

    Provided By Massachusetts Institute of Technology

  • White Papers // Aug 2009

    Understanding Broadband Speed Measurements

    Broadband speed has emerged as the single most commonly cited metric for characterizing the quality of broadband offerings. However speed measurements for the same service can vary significantly. These differences arise from a complex set of factors including different test methodologies and test conditions. For any testing methodology, teasing apart...

    Provided By Massachusetts Institute of Technology

  • White Papers // Aug 2009

    Lightpath Routing and Capacity Assignment for Survivable IP-Over-WDM Networks

    In IP-over-WDM networks the logical topology consists of a set of lightpaths that are routed on top of the physical fiber topology. Hence a single fiber cut can lead to multiple logical link failures. The authors study the impact of lightpath routing on network survivability and spare capacity requirements. They...

    Provided By Massachusetts Institute of Technology

  • White Papers // Aug 2009

    Caching in Wireless Networks

    The authors consider the problem of delivering content cached in a wireless network of n nodes randomly located on a square of area n. They provide an inner bound on this caching capacity region, and, in the high path-loss regime, a matching (in the scaling sense) outer bound. For large...

    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 // Aug 2009

    MapperMania: A Framework for Native Multi-Tenancy Business Object Mapping to a Persistent Data Store

    Enterprise resource planning software mainly occurs in large enterprises. Nevertheless, processes conducted by Small and Midsize Enterprises (SMEs) do have the same complexity. The Software-as-a-Service delivery model bears new challenges for application developers. Especially in the context of enterprise resource planning software targeting the SME market, new problems arise. Most...

    Provided By Massachusetts Institute of Technology

  • 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

    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

    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

    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

  • Webcasts // Sep 2010

    Moving Ahead: Engineering Challenges Of Deep Water Drilling And Future Oil Resource Recovery

    To keep up with demand, the oil industry ventures increasingly farther and deeper offshore, extracting resources as fast as possible in often hazardous conditions with newly minted technology. So to these panelists, the BP Deepwater Horizon accident did not come as a complete surprise. However, they view the disaster from...

    Provided By Massachusetts Institute of Technology

  • Webcasts // Sep 2010

    Democracy After Citizens United

    Just when it seemed the corrosive influence of big money on American politics could not be greater, the Supreme Court gave corporations full license to exercise 'Free speech' during campaign season. The author and his respondents debate the most effective response to the 2010 Citizens United ruling, which, the author...

    Provided By Massachusetts Institute of Technology

  • Webcasts // Sep 2010

    Energy Innovation At Scale

    The United States urgently needs a transformation of its energy supply both to address climate change and for reasons of energy security. To meet this immense challenge, the nation requires not just technological breakthroughs, but heavy lifting from big industry as well as government guidance, says the author.

    Provided By Massachusetts Institute of Technology

  • Webcasts // May 2010

    TV Or Not TV: That?s Not The Question

    While the moderator cites evidence that traditional TV viewing is alive and well, her panelists line up to describe a TV industry under siege by digital competitors, and in the throes of major change. In the course of this session, this focuses on how television engages a young(er) audience, a...

    Provided By Massachusetts Institute of Technology

  • Webcasts // Sep 2010

    Washington Rules: America's Path To Permanent War

    Washington stubbornly sticks to national security policies that don't work, are devoid of moral considerations, sap the Treasury and rob future generations, says the author. In a brief talk that leads to a candid and sometimes impassioned give and take with his audience, the author describes a national security consensus...

    Provided By Massachusetts Institute of Technology

  • Webcasts // May 2010

    Disrupting Class: How Disruptive Innovation Will Change The Way The World Learns

    The author describes how the idea of disruptive innovation, developed by management researcher and author Clayton M. Christensen, can provide a fresh perspective on struggling education systems, and perhaps offer some solutions. Business history, the author tells his audience, is littered with cases of unlikely triumphs, when a smaller firm...

    Provided By Massachusetts Institute of Technology

  • Webcasts // Apr 2010

    International Media Flows: Global Media And Culture

    The moderator introduces five graduates of the Comparative Media Studies Program - in this final webcast, who share their views and experiences about the international/global dimension of the program. 'Comparative' can be interpreted across time - media through history, media in times of transition or across media - across platforms,...

    Provided By Massachusetts Institute of Technology

  • Webcasts // Apr 2010

    Creativity And Collaboration In The Digital Age

    In a panel moderated by the presenter of this webcast, five former Comparative Media Studies (CMS) students discuss their personal experiences within the CMS program and the impact it has had on their understanding, interpretation, and implementation of creativity in the digital age.

    Provided By Massachusetts Institute of Technology

  • Webcasts // May 2010

    Visual Overviews For Cultural Heritage: Interactive Exploration For Scholars In The Humanities, Arts, And Beyond

    A focus on designing technologies that allow the "Visualization of things not visible" has been at the center of the presenter's work over the past two decades. The presenter advocates the discovery of temporal patterns, relationships and clusters via an empowering user experience which enables discovery at a customizable pace...

    Provided By Massachusetts Institute of Technology

  • Webcasts // Jun 2010

    Innovation In Energy Storage: What I Learned In 3.091 Was All I Needed To Know

    In a lecture that could have been titled, Better Education through Chemistry, the author begins with solar energy, grid-level storage, and liquid metal batteries and moves into education innovation, sharing creative ways to teach chemistry.

    Provided By Massachusetts Institute of Technology

  • Webcasts // May 2010

    Humanistic Approaches To The Graphical Expression Of Interpretation

    It is in sharp contrast to a period of enlightenment and empirical science that a re-humanization of digital activities may now take place, says the author. Humanistic approaches are the motif against which she frames her assertion that "Interpretation" introduces an epistemological shift - which she identifies by the rubric...

    Provided By Massachusetts Institute of Technology

  • Webcasts // Jun 2010

    Capitalism 3.0: An Institutional Revolution In The Making

    The author points to what he calls a "Blind spot" in contemporary leadership research: the organization and management of attention. The author argues that there are different kinds of awareness or attentiveness, that different problems require different qualities of or approaches to awareness.

    Provided By Massachusetts Institute of Technology

  • Webcasts // Jun 2010

    Shaped By Booms And Busts: How The Economy Impacts CEO Management Style

    If you read the press or talk to practitioners, according to the author, the worst thing for an entrepreneur [is] to be one who grew up in a boom time. These entrepreneurs never learn to manage finances or build efficient firms because they're so used to having ample availability of...

    Provided By Massachusetts Institute of Technology

  • Webcasts // Jun 2010

    MIT?s Entrepreneurial Development And Impact Over The Past 50 Years

    The author reviews the effects of entrepreneurship within MIT and the relation of MIT entrepreneurship to larger communities. The webcast polled MIT alumni about companies they had started or co-founded and which were still in business.

    Provided By Massachusetts Institute of Technology

  • Webcasts // Apr 2010

    Denialism: Media In The Age Of Disinformation

    A few hundred years after the Enlightenment, western civilization is rushing back to the Dark Ages. The causes are debatable, but, argue these science journalists, the public increasingly rejects the findings of science, from climate change to evolution, and is turning away from rationality and reason in general.

    Provided By Massachusetts Institute of Technology

  • Webcasts // Apr 2010

    Transportation, The Built Environment And Greenhouse Gas Emissions In Developing Cities

    It seems that income and travel are inextricably linked. As communities gain wealth and prosperity, their travel footprint increases. Global population is projected to increase by nearly 2 billion people by 2030. If this newly added population drove just 3,000 kilometers a year, they would emit more tonnes of C02...

    Provided By Massachusetts Institute of Technology

  • Webcasts // May 2010

    The Interaction Between Poverty, Growth And Democracy

    The presenter has remained a passionate advocate of reform since departing the presidency of Peru in 2006. In his home country, the presenter embodied the possibility of transformation, having risen from poverty in an Andean village to top political power, where he initiated a process of economic and social change...

    Provided By Massachusetts Institute of Technology

  • Webcasts // Apr 2010

    Civics In Difficult Places

    Moderator wonders if these new digital forms are fundamentally liberating, providing users access to public spaces they might otherwise be denied. Moderator pursues this line of inquiry in a series of internet conversations with correspondents covering some of the world's most ravaged or oppressed regions.

    Provided By Massachusetts Institute of Technology

  • Webcasts // Apr 2010

    From Relief To Reconstruction ? Practical And Policy Challenge

    As the United Nations and worldwide NGOs face the challenges of providing basic services to the survivors of the January 2010 Haitian earthquake, the author scrutinizes what will ultimately be "Crucial to the outcome, in the Haitian context, of a successful recovery and rehabilitation by the Haitian people and for...

    Provided By Massachusetts Institute of Technology

  • Webcasts // Apr 2010

    Giving Back: Finding The Best Way To Make A Difference

    The world's most intractable problems might be cracked if more of the "Brightest minds" could be tempted to work on them, asserts Bill Gates. Too many graduates of top universities like MIT find it infinitely more satisfying to deal in derivatives, he says, or lucrative areas of medical science like...

    Provided By Massachusetts Institute of Technology

  • Webcasts // Apr 2010

    The Gutenberg Parenthesis: Oral Tradition And Digital Technologies

    In this webcast, the author makes the deliberately provocative case for a Gutenberg "Parenthesis" - a period marked by the reign of the printing press and isolated from the largely oral culture that came before, and the digitally shaped culture emerging today. The author, who finds an upside in society's...

    Provided By Massachusetts Institute of Technology

  • Webcasts // Mar 2010

    Transportation In Contemporary Society: A Complex Systems Approach

    In the nineteen fifties and sixties, students of transportation focused on building infrastructure and applied lessons from the physical sciences to designing mobility. Mobility was facilely linked to the engines of economic growth and expanding GDP. In time, that perspective was replaced by a focus on transportation systems and networks....

    Provided By Massachusetts Institute of Technology

  • Webcasts // Mar 2010

    Modeling Human Mobility

    Researchers who wish to study mobility patterns might be reaching for your phone. Increasingly, cell phones are equipped with locational receivers (Global Positioning Systems or GPS) and their bread crumb trails are opening up entirely new ways to study and predict the dynamics of travel.

    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 // 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 // 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 // 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

  • 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

    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 // 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

  • 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

    No Bits Left Behind

    One of the key tenets of database system design is making efficient use of storage and memory resources. However, existing database system implementations are actually extremely wasteful of such resources; for example, most systems leave a great deal of empty space in tuples, index pages, and data pages, and spend...

    Provided By Massachusetts Institute of Technology