Massachusetts Institute of Technology

Displaying 161-200 of 445 results

  • White Papers // Jan 2011

    Targeting The Poor: Evidence From A Field Experiment In Indonesia

    This paper reports an experiment in 640 Indonesian villages that investigated three approaches to targeting the poor: Proxy-Means Tests (PMT), where a census of assets is used to predict consumption; community targeting, where villagers rank everyone from richest to poorest; and a hybrid. Defining poverty based on PPP$2 per-capita consumption,...

    Provided By Massachusetts Institute of Technology

  • White Papers // Jan 2011

    The Portuguese High Speed Rail Network; Relating Financing To Strategic And Operating Issues

    This paper describes the implementation of the Portuguese High Speed Rail (HSR) Network. The business model developed by RAVE for the PPP's related with the HSR infrastructure is described and discussed. Following a recently awarded research project (EXPRESS) aimed at studying the strategic aspects related with the implementation of HSR...

    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 // 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 // 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 // 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

  • 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

    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

  • 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

    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

  • 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

  • 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

  • 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

  • Webcasts // Oct 2010

    From Experimental Physics To Internet Entrepreneurship: One Scientist?s Journey

    Few better personify the vitality and ambition fueling China's economic surge than the author. In this energetic and revelatory talk, the author relates his personal evolution from MIT physicist to leading Chinese entrepreneur. An industrious student from a poor family, the author was one of the fortunate few in his...

    Provided By Massachusetts Institute of Technology

  • Webcasts // Oct 2010

    Engineering Smarter Drivers

    While automakers market increasingly intelligent cars, they may be missing the point. No matter how sophisticated the vehicle's brain, suggests by the author, the smartest element on the road is still the human driver. In search of safe, responsive vehicles, designers should not think of separate components - machine and...

    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 // Jun 2013

    On Analyzing and Improving COPE Performance

    COPE is a new architecture for unicasts in wireless mesh networks that employs opportunistic network coding to improve total throughput. Katti et al. showed through experiments that this system significantly improves the throughput of wireless networks with UDP traffic, and several attempts have been made to analyze the COPE performance....

    Provided By Massachusetts Institute of Technology

  • White Papers // Apr 2012

    Random Access Compressed Sensing Over Fading and Noisy Communication Channels

    Random Access Compressed Sensing (RACS) is an efficient method for data gathering from a network of distributed sensors with limited resources. RACS relies on integrating random sensing with the communication architecture, and achieves overall efficiency in terms of the energy per bit of information successfully delivered. To address realistic deployment...

    Provided By Massachusetts Institute of Technology

  • White Papers // May 2012

    On Reliability Functions for Single-Message Unequal Error Protection

    Single-message Unequal Error Protection (UEP) is a channel coding scheme that protects one special message differently from other (regular) messages. This induces three different types of errors in the system: miss (where the authors decode the special codeword as a regular codeword), false alarm (where they decode a regular codeword...

    Provided By Massachusetts Institute of Technology

  • White Papers // Dec 2012

    Saddle Point in the Minimax Converse for Channel Coding

    A mini-max meta-converse has recently been proposed as a simultaneous generalization of a number of classical results and a tool for the non-asymptotic analysis. In this paper it is shown that the order of optimizing the input and output distributions can be interchanged without affecting the bound. In the course...

    Provided By Massachusetts Institute of Technology

  • White Papers // May 2013

    Quasi-Static SIMO Fading Channels at Finite Blocklength

    The authors investigate the maximal achievable rate for a given block-length and error probability over quasi-static Single-Input Multiple-Output (SIMO) fading channels. Under mild conditions on the channel gains, it is shown that the channel dispersion is zero regardless of whether the fading realizations are available at the transmitter and/or the...

    Provided By Massachusetts Institute of Technology

  • White Papers // Jun 2012

    Diversity Versus Channel Knowledge at Finite Block-Length

    The authors study the maximal achievable rate for a given block-length n and block error probability over Rayleigh block-fading channels in the non-coherent setting and in the finite block-length regime. Their results show that for a given block-length and error probability, is not monotonic in the channel's coherence time, but...

    Provided By Massachusetts Institute of Technology

  • White Papers // Jul 2012

    The Adversarial Joint Source-Channel Problem

    This paper introduces the problem of joint source-channel coding in the setup where channel errors are adversarial and the distortion is worst case. Unlike the situation in the case of stochastic source-channel model, the separation principle does not hold in adversarial setup. This surprising observation demonstrates that designing good distortion-correcting...

    Provided By Massachusetts Institute of Technology

  • White Papers // Feb 2012

    On Asynchronous Capacity and Dispersion

    Recently Tchamkerten et al. proposed a mathematical formulation of the problem of joint synchronization and error-correction in noisy channels. A variation of their formulation in this paper considers a strengthened requirement that the decoder estimate both the message and the location of the codeword exactly. It is shown that the...

    Provided By Massachusetts Institute of Technology

  • White Papers // May 2010

    Learning Gaussian Tree Models: Analysis of Error Exponents and Extremal Structures

    The problem of learning tree-structured Gaussian graphical models from independent and identically distributed (i.i.d.) samples is considered. The influence of the tree structure and the parameters of the Gaussian distribution on the learning rate as the number of samples increases is discussed. Specifically, the error exponent corresponding to the event...

    Provided By Massachusetts Institute of Technology

  • White Papers // Mar 2011

    Sample Complexity for Topology Estimation in Networks of LTI Systems

    In this paper, the authors propose a consistent and computationally efficient FFT-based algorithm for inferring the network topology where each node in the network is associated to a widesense stationary, ergodic, Gaussian process. Each edge of the tree network is characterized by a linear, time-invariant dynamical system and additive white...

    Provided By Massachusetts Institute of Technology

  • White Papers // Jul 2011

    The Sender-Excited Secret Key Agreement Model: Capacity Theorems

    The authors consider the fundamental limits of the secret key generation problem when the sources are excited by the sender. In many practical communication settings, the channel may be influenced by the parties involved. Similar to recent works on probing capacity and channels with action-dependent states, their system model captures...

    Provided By Massachusetts Institute of Technology

  • White Papers // Jun 2011

    Rank Minimization Over Finite Fields

    The problem of matrix completion has been well studied in recent years. Essentially, one is given a (small) subset of entries of a low-rank matrix and one is required to estimate all the the remaining entries. In this paper, the authors establish information-theoretic limits in estimating a finite field low-rank...

    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

  • 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 // 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 // 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

    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 // 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 // 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 // Dec 2009

    Cache Replacement Policies for Multicore Processors

    Almost all of the modern computers use multiple cores, and the number of cores is expected to increase as hardware prices go down, and Moore's law fails to hold. Most of the theoretical algorithmic work so far has focused on the setting where multiple cores are performing the same task....

    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 // Jun 2010

    Detecting Evolving Patterns of Self-Organizing Networks by Flow Hierarchy Measurement

    Hierarchies occur widely in evolving self-organizing ecological, biological, technological and social networks, but detecting and comparing hierarchies is difficult. Here the authors present a metric and technique to quantitatively assess the extent to which self-organizing directed networks exhibit a flow hierarchy. Flow hierarchy is a commonly observed but theoretically overlooked...

    Provided By Massachusetts Institute of Technology

  • White Papers // Apr 2010

    Arguments for an Information-Centric Internetworking Architecture

    The current Internet architecture focuses on communicating entities, largely leaving aside the information to be exchanged among them. However, trends in communication scenarios show that WHAT is being exchanged becoming more important than WHO are exchanging information. Van Jacobson describes this as moving from interconnecting machines to interconnecting information. Any...

    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 // 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 // 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 // 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 // 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 // Mar 2007

    Low-Cost Airports For Low-Cost Airlines: Flexible Design To Manage The Risks

    The paradigm of airport planning and design is changing fundamentally. Low-cost airlines have become significant drivers of airport planning, along with aircraft size and other technical factors. They have different requirements than the "Legacy" carriers. They focus on cost and on alternative ways to handle passengers. Now being sizeable participants...

    Provided By Massachusetts Institute of Technology

  • White Papers // May 2010

    Report: NSF Workshop on Future Wireless Communication Research

    The wireless communication industry is a trillion-dollar, worldwide business that represents a substantial fraction of the global Gross Domestic Product. Over the past two decades, it has had a transformative impact on the society and has revolutionized almost all aspects of human interaction. These networks are inescapably intertwined with the...

    Provided By Massachusetts Institute of Technology

  • White Papers // Apr 2009

    Minimum Energy Transmission Over a Wireless Channel With Deadline and Power Constraints

    The authors consider optimal rate-control for energy-efficient transmission of data, over a time-varying channel, with packet deadline constraints. Specifically, the problem scenario consists of a wireless transmitter with B units of data that must be transmitted by deadline T over a fading channel. The transmitter can control the transmission rate...

    Provided By Massachusetts Institute of Technology

  • White Papers // Mar 2010

    Throughput Optimization in Mobile Backbone Networks

    This paper describes new algorithms for throughput optimization in a mobile backbone network. This hierarchical communication framework combines mobile backbone nodes, which have superior mobility and communication capability, with regular nodes, which are constrained in mobility and communication capability. An important quantity of interest in mobile backbone networks is the...

    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 // 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