Boston University

Displaying 1-40 of 164 results

  • White Papers // Jun 2014

    Distributed Real-Time Fault Tolerance on a Virtualized Multi-Core System

    In this paper, the authors present different approaches for real-time fault tolerance using redundancy methods for multi-core systems. Using hardware virtualization, a distributed system on a chip is created, where the cores are isolated from one another except through explicit communication channels. Using this system architecture, redundant tasks that would...

    Provided By Boston University

  • White Papers // May 2014

    Learning Modular Structures from Network Data and Node Variables

    A standard technique for understanding underlying dependency structures among a set of variables posits a shared conditional probability distribution for the variables measured on individuals within a group. This approach is often referred to as module networks, where individuals are represented by nodes in a network, groups are termed modules,...

    Provided By Boston University

  • White Papers // Mar 2014

    Profiling EEMBC MultiBench Programs Using Full-System Simulations

    In this paper, the authors present the profiling of EEMBC parallel benchmark programs that is designed for the evaluation and future development of scalable SMP architectures. Modern Multi-Processor System-on-Chip (MPSoC) includes tens of IP blocks, such as CPUs, memories, input/output devices, and HW accelerators,. Figure 1 shows an example of...

    Provided By Boston University

  • White Papers // Jan 2014

    Strategies for Anticipating Risk in Heterogeneous System Design

    Heterogeneous design presents an opportunity to improve energy efficiency but raises a challenge in resource management. Prior design methodologies aim for performance and efficiency, yet a deployed system may miss these targets due to run-time effects, which the authors denote as risk. They propose design strategies that explicitly aim to...

    Provided By Boston University

  • White Papers // Jan 2014

    Mutable Protection Domains: Towards a Component-based System for Dependable and Predictable Computing

    The increasing complexity of software poses significant challenges for real-time and embedded systems beyond those based purely on timeliness. With embedded systems and applications running on everything from mobile phones, PDAs, to automobiles, aircraft and beyond, an emerging challenge is to ensure both the functional and timing correctness of complex...

    Provided By Boston University

  • White Papers // Jan 2014

    On the Integration of Real-time Asynchronous Event Handling Mechanisms with Existing Operating System Services

    In this paper, the authors present an asynchronous event handling mechanism for real-time applications that leverages existing system services in COTS systems. In their implementation, event dispatching is initiated within bottom-half interrupt handling routines, in order to support predictable, safe, and efficient event handling functionality at user-level. They compare their...

    Provided By Boston University

  • White Papers // Jan 2014

    Quest-V: A Virtualized Multikernel for High-Confidence Systems

    In this paper, the authors outline the design of 'Quest-V', which is implemented as a collection of separate kernels operating together as a distributed system on a chip. Quest-V uses virtualization techniques to isolate kernels and prevent local faults from affecting remote kernels. This leads to a high-confidence multikernel approach,...

    Provided By Boston University

  • White Papers // Oct 2013

    The Quest-V Separation Kernel for Mixed Criticality Systems

    Embedded systems are increasingly featuring multi and many-core processors, due in part to their power, performance and price benefits. These processors offer new opportunities for an increasingly significant class of mixed criticality systems. In mixed criticality systems, there is a combination of application and system components with different safety and...

    Provided By Boston University

  • White Papers // Sep 2013

    Optimizing Communication and Cooling Costs in HPC Data Centers via Intelligent Job Allocation

    Nearly half of the energy in the computing clusters today is consumed by the cooling infrastructure. It is possible to reduce the cooling cost by allowing the data center temperatures to rise; however, component reliability constraints impose thermal thresholds as failure rates are exponentially dependent on the processor temperatures. Existing...

    Provided By Boston University

  • White Papers // Aug 2013

    Autonomous Resource Sharing for Multi-Threaded Workloads in Virtualized Servers

    Multi-threaded applications from many application domains have started to appear on the cloud resources. Multi-threaded applications bring additional challenges to the management of the cloud resources, due to characteristics such as inter/intra-thread communication. In tandem, as the energy spent on computing continues to increase, the ability to provide energy-performance tradeoffs...

    Provided By Boston University

  • White Papers // Aug 2013

    Dynamic Server Power Capping for Enabling Data Center Participation in Power Markets

    Today's US power markets offer new opportunities for the energy consumers to reduce their energy costs by first promising an average consumption rate for the next hour and then by following a regulation signal broadcast by the Independent System Operators (ISOs), who need to match supply and demand in real...

    Provided By Boston University

  • White Papers // Jul 2013

    Dynamic Cache Pooling for Improving Energy Efficiency in 3D Stacked Multicore Processors

    Resource pooling, where multiple architectural components are shared among multiple cores, is a promising technique for improving the system energy efficiency and reducing the total chip area. 3D stacked multicore processors enable efficient pooling of cache resources owing to the short interconnect latency between vertically stacked layers. This paper introduces...

    Provided By Boston University

  • White Papers // Jun 2013

    vCap: Adaptive Power Capping for Virtualized Servers

    Power capping on server nodes has become an essential feature in data centers for controlling energy costs and peak power consumption. More than half of the server nodes are virtualized in today's data centers; thus, providing a practical power capping technique for consolidated virtual environments is a significant research problem....

    Provided By Boston University

  • White Papers // Jun 2013

    Navigating Heterogeneous Processors with Market Mechanisms

    As datacenters proliferate and access to them is democratized, increasingly diverse cloud applications will demand computation. To accommodate the rise in demand, traditional datacenter servers have relied on Moore's Law. This strategy is insufficient as Dennard scaling ends and constrains the power efficiency of processor servers. Instead of relying on...

    Provided By Boston University

  • White Papers // Feb 2013

    Intra-Car Wireless Sensors Data Collection: A Multi-Hop Approach

    The authors experimentally investigate the benefits of multi-hop networking for intra-car data aggregation under the current state-of-the-art Collection Tree Protocol (CTP). They show how this protocol actively adjusts collection routes according to channel dynamics in various practical car environments, resulting in performance gains over single-hop aggregation. Throughout their experiments, they...

    Provided By Boston University

  • White Papers // Jan 2013

    Real-Time USB Communication in the Quest Operating System

    In this paper, the authors describe a real-time USB 2 subsystem for the quest operating system. Quest is designed for real-time embedded systems. Such systems need to interact with their environment using sensors and actuators. On many embedded platforms today there is support for basic serial, USB 2.0 and 100...

    Provided By Boston University

  • White Papers // Jan 2013

    CCM: Scalable, On-Demand Compute Capacity Management for Cloud Datacenters

    Multi-tenant cloud computing datacenters run diverse workloads with time varying resource demands. This continuously leads to areas of high and low resource utilization throughout the cloud infrastructure. The authors present CCM (Cloud Capacity Manager) - a prototype system, and, methods for dynamically multiplexing the compute capacity of cloud datacenters at...

    Provided By Boston University

  • White Papers // Jan 2013

    Probabilistic Indoor Tracking of Mobile Wireless Nodes Relative to Landmarks

    The profile-based approach is known to be advantageous when it comes to inferring positions of mobile wireless devices in complex indoor environments. The past decade has seen a significant body of work that explores different implementations of this approach, with varying degrees of success. Here, the authors cast the profile-based...

    Provided By Boston University

  • White Papers // Jan 2013

    Spatio-Temporal Network Anomaly Detection by Assessing Deviations of Empirical Measures

    The authors introduce an Internet traffic anomaly detection mechanism based on large deviations results for empirical measures. Using past traffic traces they characterize network traffic during various time-of-day intervals, assuming that it is anomaly-free. They present two different approaches to characterize traffic: a model-free approach based on the method of...

    Provided By Boston University

  • White Papers // Dec 2012

    Verifying Search Results Over Web Collections

    Web searching accounts for one of the most frequently performed computations over the Internet as well as one of the most important applications of outsourced computing, producing results that critically affect users' decision-making behaviors. As such, verifying the integrity of Internet-based searches over vast amounts of web contents is essential....

    Provided By Boston University

  • White Papers // Sep 2012

    A Two Phase Hybrid RSS/AoA Algorithm for Indoor Device Localization Using Visible Light

    A two phase hybrid algorithm for estimating the location of a mobile node, which has the capability of measuring signal strength, azimuth, and elevation, in a smart space environment over the visible light channel is proposed. In contrast to conventional triangulation approaches which are performed in a simplified plane, the...

    Provided By Boston University

  • White Papers // Sep 2012

    Dynamic Pricing of Preemptive Service for Elastic Demand

    The authors consider a service provider that accommodates two classes of users: Primary Users (PUs) and Secondary Users (SUs). SU demand is elastic to price whereas PU demand is inelastic. When a PU arrives to the system and finds all channels busy, it preempts an SU unless there are no...

    Provided By Boston University

  • White Papers // Aug 2012

    Scheduling Mobile Nodes for Cooperative Data Transport in Sensor Networks

    Message Ferrying has been shown to be an effective approach to support routing in sparse ad hoc or sensor networks. Considering a generic network model where each node in the network wishes to send data to some (or possibly all) other nodes with known (and possibly different) rates, the authors...

    Provided By Boston University

  • White Papers // Aug 2012

    Optimal Admission Control in Two-Class Preemptive Loss Systems

    The authors study optimal admission control in a two-class preemptive loss system. A class-1 customer arrival aborts service of a class-2 customer if the system is full upon arrival. Each successfully serviced class-2 customer leads to a reward, whereas each aborted class-2 customer incurs a cost. Using dynamic programming, they...

    Provided By Boston University

  • White Papers // Aug 2012

    Online Pricing of Secondary Spectrum Access With Unknown Demand Function

    The authors consider a wireless provider who caters to two classes of customers, namely Primary Users (PUs) and Secondary Users (SUs). PUs has long term contracts while SUs are admitted and priced according to current availability of excess spectrum. The average rate at which SUs attempt to access the spectrum...

    Provided By Boston University

  • White Papers // Aug 2012

    Competition in Secondary Spectrum Markets: Price War or Market Sharing?

    Recent initiatives allow cellular providers to offer spot service of their licensed spectrum, paving the way to dynamic secondary spectrum markets. This paper characterizes market outcomes when multiple providers are drawn into competition for secondary demand. The authors study a game-theoretic model in which each provider aims to enhance its...

    Provided By Boston University

  • White Papers // Aug 2012

    Prioritized Data Synchronization for Disruption Tolerant Networks

    The authors consider the problem of synchronizing prioritized data on two distinct hosts in Disruption-Tolerant Networks (DTNs). To this effect, they propose and analyze a new interactive protocol for priority-oriented synchronization, called P-CPI that is especially efficient in terms of bandwidth usage. This middleware protocol has features that are particularly...

    Provided By Boston University

  • White Papers // Jul 2012

    Profit-Robust Policies for Dynamic Sharing of Radio Spectrum

    The authors investigate profitability from secondary spectrum provision under unknown relationships between price charged for spectrum use and demand drawn at the given price. They show that profitability is governed by the applied admission policy and the price charged to secondary users. They explicitly identify a critical price (market entry...

    Provided By Boston University

  • White Papers // Jul 2012

    Economic Viability of Private Commons: Framework and Guidelines for Profitability

    Ongoing regulatory reforms have led to several novel spectrum sharing models under the general umbrella of dynamic spectrum sharing. The private commons model introduced by FCC in 2004 allows spectrum licensees to provide secondary access to spectrum on an opportunistic basis while retaining ownership. Since wireless communication systems are typically...

    Provided By Boston University

  • White Papers // Jul 2012

    Jamming-Resistant Rate Control in Wi-Fi Networks

    Recent experimental studies reveal that several well-known and widely deployed Rate Adaptation Algorithms (RAAs) in 802.11 WLANs are vulnerable to selective jamming attacks. However, previous work resorts to complex jamming strategies that are hard to implement and does not provide applicable solutions to this problem. In this paper, the authors...

    Provided By Boston University

  • White Papers // Jun 2012

    Posit: A Lightweight Approach for IP Geolocation

    Location-specific Internet services are predicated on the ability to identify the geographic position of IP hosts accurately. Fundamental to current state-of-the-art geolocation techniques is reliance on heavyweight traceroute-like probes that put a significant traffic load on networks. In this paper, the authors introduce a new lightweight approach to IP geolocation...

    Provided By Boston University

  • White Papers // Jun 2012

    Adaptive Energy-Efficient Resource Sharing for Multi-threaded Workloads in Virtualized Systems

    Computational demand on today's data centers is continuously increasing, as computing trends are shifting towards the cloud. The corresponding increases in energy consumption and management complexity remain as major challenges for data centers. Server virtualization provides opportunities to improve energy efficiency by reducing the number of physical servers through workload...

    Provided By Boston University

  • White Papers // Jun 2012

    Time Management in the Quest-V RTOS

    Quest-V is a new system currently under development for multicore processors. It comprises a collection of separate kernels operating together as a distributed system on a chip. Each kernel is isolated from others using virtualization techniques, so that faults do not propagate throughout the entire system. This multikernel design supports...

    Provided By Boston University

  • White Papers // Apr 2012

    Optimal Admission Control of Secondary Users in Preemptive Cognitive Radio Networks

    The authors study optimal admission control of Secondary Users (SUs) in Cognitive Radio (CR) networks in presence of preemption. In this model, when a Primary User (PU) arrives to the system and finds all the channels busy, it preempts an SU unless all the users in the system are PUs....

    Provided By Boston University

  • White Papers // Apr 2012

    Universally Composable Security With Local Adversaries

    The traditional approach to formalizing ideal-model based definitions of security for multi-party protocols model adversaries (both real and ideal) as centralized entities that control all parties that deviate from the protocol. While this centralized-adversary modeling suffices for capturing basic security properties such as secrecy of local inputs and correctness of...

    Provided By Boston University

  • White Papers // Apr 2012

    On Delay-Minimized Data Harvesting With Mobile Elements in Wireless Sensor Networks

    The authors consider the problem of routing and scheduling a set of mobile elements that act as mechanical carriers of data, harvesting them from sensor nodes and delivering them to a sink. The objective is to minimize the data delivery latency. Most of the existing work has focused on designing...

    Provided By Boston University

  • White Papers // Mar 2012

    Connected Identifying Codes

    The authors consider the problem of generating a connected identifying code for an arbitrary graph. After a brief motivation, they show that the decision problem regarding the existence of such a code is NP-complete, and they propose a novel polynomial-time approximation ConnectID that transforms any identifying code into a connected...

    Provided By Boston University

  • White Papers // Mar 2012

    Performance and Power Analysis of RCCE Message Passing on the Intel Single-Chip Cloud Computer

    The number of cores integrated on a single chip increases with each generation of computers. Traditionally, a single Operating System (OS) manages all the cores and resource allocation on a multi-core chip. Intel's Single-chip Cloud Computer (SCC), a manycore processor built for research use with 48 cores, is an implementation...

    Provided By Boston University

  • White Papers // Feb 2012

    Reliable Rateless Wireless Broadcasting With Near-Zero Feedback

    The authors examine the problem of minimizing feedback in reliable wireless broadcasting, by pairing rateless coding with extreme value theory. Their key observation is that, in a broadcast environment, this problem resolves into estimating the maximum number of packets dropped among many receivers rather than for each individual receiver. With...

    Provided By Boston University

  • White Papers // Feb 2012

    Scheduling Algorithms and Bounds for Rateless Data Dissemination in Dense Wireless Networks

    Many applications in wireless cellular networks rely on the ability of the network to reliably and efficiently disseminate data to a large client audience. The stochastic nature of packet loss across receivers and channel interference constraints between cells complicate this task, however. In this paper, the authors analyze the problem...

    Provided By Boston University

  • White Papers // Jan 2011

    iJoin: Importance-Aware Join Approximation Over Data Streams

    The authors consider approximate join processing over data streams when memory limitations cause incoming tuples to overflow the available space, precluding exact processing. Selective eviction of tuples (load-shedding) is needed, but is challenging since data distributions and arrival rates are unknown a priori. Also, in many real-world applications such as...

    Provided By Boston University

  • White Papers // Feb 2010

    Scale Invariant Properties Of Public Debt Growth

    Public debt is one of the important economic variables that quantitatively describe a nation's economy. Because bankruptcy is a risk faced even by institutions as large as governments (e.g. Iceland), national debt should be strictly controlled with respect to national wealth. Also, the problem of eliminating extreme poverty in the...

    Provided By Boston University

  • White Papers // Dec 2009

    The Structure And Growth Of Weighted Networks

    The authors develop a simple theoretical framework for the evolution of weighted networks that is consistent with a number of stylized features of real-world data. In the framework, the Barabasi-Albert model of network evolution is extended by assuming that link weights evolve according to a geometric Brownian motion. The model...

    Provided By Boston University

  • White Papers // Oct 2010

    Communicating Technical Knowledge

    In patent theory, the cost of communicating technical knowledge is small. In human capital theory, it is large. But evidence suggests that these costs are actually endogenous. Firms invest in reducing communication costs, but only when technology is sufficiently advanced. This can make competition different for early stage technologies: patents...

    Provided By Boston University

  • White Papers // Feb 2011

    Quantifying And Modeling Long-range Cross-correlations In Multiple Time Series With Applications To World Stock Indices

    The authors propose a modified time lag random matrix theory in order to study time lag cross-correlations in multiple time series. They apply the method to 48 world indices, one for each of 48 different countries. They find long-range power-law cross-correlations in the absolute values of returns that quantify risk,...

    Provided By Boston University

  • White Papers // Mar 2011

    A Copula Approach On The Dynamics Of Statistical Dependencies In The US Stock Market

    The authors analyze the statistical dependency structure of the S&P 500 constituents in the 4-year period from 2007 to 2010 using intraday data from the New York Stock Exchange's TAQ database. With a copula-based approach, they find that the statistical dependencies are very strong in the tails of the marginal...

    Provided By Boston University

  • White Papers // May 2011

    A Domain-Specific Language for the Incremental and Modular Design of Large-Scale Verifiably-Safe Flow Networks

    Flow networks are inductively defined, assembled from small networks or modules to produce arbitrarily large ones, with interchangeable functionally-equivalent parts. The authors carry out this induction formally using a Domain-Specific Language (DSL). Associated with the authors' DSL is a typing system (or static semantics), a system of formal annotations that...

    Provided By Boston University

  • White Papers // Feb 2011

    The Filter-Placement Problem and Its Application to Content De-Duplication

    In many information networks, data items - such as updates in social networks, news flowing through interconnected RSS feeds and blogs, measurements in sensor networks, route updates in ad-hoc networks, etc. - propagate in an uncoordinated manner: nodes often relay information they receive to neighbors, independent of whether or not...

    Provided By Boston University

  • White Papers // Jan 2011

    Basis Token Consistency: Supporting Strong Web Cache Consistency

    With web caching and cache-related services like CDNs and edge services playing an increasingly significant role in the modern Internet, the problem of the weak consistency and coherence provisions in current web protocols is drawing increasing attention. Toward this end, the authors differentiate definitions of consistency and coherence for web-like...

    Provided By Boston University

  • White Papers // Nov 2010

    Bankruptcy Risk Model And Empirical Tests

    The authors analyze the size-dependence and temporal stability of firm bankruptcy risk in the US economy by applying Zipf scaling techniques. They focus on a single risk factor - the debt-to-asset ratio R - in order to study the stability of the Zipf distribution of R over time. They find...

    Provided By Boston University

  • White Papers // Apr 2010

    Virtualization and Programming Support for Video Sensor Networks With Application to Wireless and Physical Security

    Network Security Systems are heavily anchored in the digital plane of "Cyber Space" and hence cannot be used effectively to derive the physical identity of an intruder in order to prevent further malicious wireless broadcasts (i.e., Escorting an Intruder off the Premises Based on Physical Evidence). Embedded Sensor Networks (SNs)...

    Provided By Boston University

  • White Papers // Jan 2011

    Programming With Dependently Typed Data Structures

    The mechanism for declaring datatypes in functional programming languages such as ML and Haskell is of great use in practice. This mechanism, however, often suffers from its imprecision in capturing various invariants inherent in data structures. The introduction of dependent datatypes in Dependent ML (DML) can partly remedy the situation,...

    Provided By Boston University

  • White Papers // Jan 2011

    Dependent Types for Program Termination Verification

    Program termination verification is a challenging research subject of significant practical importance. While there is already a rich body of literature on this subject, it is still undeniably a difficult task to design a termination checker for a realistic programming language that supports general recursion. In this paper, the authors...

    Provided By Boston University

  • White Papers // Jan 2011

    Dependent ML: An Approach to Practical Programming With Dependent Types

    The authors present an approach to enriching the type system of ML with a restricted form of dependent types, where type index terms are required to be drawn from a given type index language that is completely separate from run-time programs, leading to the DML language schema. This enrichment allows...

    Provided By Boston University

  • White Papers // Aug 2009

    Principles of Safe Policy Routing Dynamics

    This paper introduces the Dynamic Policy Routing (DPR) model that captures the propagation of route updates under arbitrary changes in topology or path preferences. DPR introduces the notion of causation chains where the route flap at one node causes a flap at the next node along the chain. Using DPR,...

    Provided By Boston University

  • White Papers // Aug 2010

    International Risk Cycles

    This paper presents a two-country real business cycle model with two novel features: exogenous shocks to worldwide uncertainty, heterogeneous exposures to the world aggregate shock. The authors show that these two features lead to significant progress in tackling international finance puzzles. When world risk increases, investment decreases and a worldwide...

    Provided By Boston University

  • White Papers // Jan 2011

    Authenticated Index Structures for Outsourced Databases

    In an Outsourced DataBase (ODB) system the database owner publishes data through a number of remote servers, with the goal of enabling clients at the edge of the network to access and query the data more efficiently. As servers might be untrusted or can be compromised, query authentication becomes an...

    Provided By Boston University

  • White Papers // Jan 2011

    Characterizing and Exploiting Reference Locality in Data Stream Applications

    In this paper, the authors investigate a new approach to process queries in data stream applications. They show that reference locality characteristics of data streams could be exploited in the design of superior and flexible data stream query processing techniques. They identify two different causes of reference locality: popularity over...

    Provided By Boston University

  • White Papers // Oct 2009

    Safe Compositional Network Sketches: Tool & Use Cases

    NetSketch is a tool that enables the specification of network-flow applications and the certification of desirable safety properties imposed thereon. NetSketch is conceived to assist system integrators in two types of activities: modeling and design. As a modeling tool, it enables the of an existing system while retaining sufficient information...

    Provided By Boston University

  • White Papers // Jan 2011

    An Information Theoretic Framework for Field Monitoring Using Autonomously Mobile Sensors

    The authors consider a mobile sensor network monitoring a spatio-temporal field. Given limited caches at the sensor nodes, the goal is to develop a distributed cache management algorithm to efficiently answer queries with a known probability distribution over the spatial dimension. First, they propose a novel distributed information theoretic approach...

    Provided By Boston University

  • White Papers // Jan 2011

    MORPHOSYS: Efficient Colocation of QoS-Constrained Workloads in the Cloud

    In hosting environments such as IaaS clouds, desirable application performance is usually guaranteed through the use of Service Level Agreements (SLAs), which specify minimal fractions of resource capacities that must be allocated for unencumbered use for proper operation. Arbitrary colocation of applications with different SLAs on a single host may...

    Provided By Boston University

  • White Papers // Feb 2011

    Safe Compositional Network Sketches: NetSketch Tool Implementation

    NetSketch is a tool that enables the specification of network-flow applications and the certification of desirable safety properties imposed thereon. NetSketch is conceived to assist system integrators in two types of activities: Modeling and design. As a modeling tool, it enables an existing system so as to retain sufficient enough...

    Provided By Boston University

  • White Papers // Feb 2010

    A Type-Theoretic Framework for Efficient and Safe Colocation of Periodic Real-Time Systems

    Desirable application performance is typically guaranteed through the use of Service Level Agreements (SLAs) that specify fixed fractions of resource capacities that must be allocated for unencumbered use by the application. The mapping between what constitutes desirable performance and SLAs is not unique: multiple SLA expressions might be functionally equivalent....

    Provided By Boston University

  • White Papers // Aug 2010

    Angels in the Cloud a Peer-Assisted Bulk-Synchronous Content Distribution Service

    Leveraging client upload capacity through peer-assisted content distribution was shown to decrease the load on content providers, while also improving average distribution times. These benefits, however, are limited by the disparity between client upload and download speeds, especially in scenarios requiring a Minimum Distribution Time (MDT) of a piece of...

    Provided By Boston University

  • White Papers // Jan 2011

    A Typed Model for Encoding-Based Protocol Interoperability

    Documentation of the HTTP protocol includes precise descriptions of the syntax of the protocol, but lacks similarly precise specification of the semantics of messages and message bodies. Semantics are stated in English prose; while this makes the document more intuitively accessible, it makes any sort of formal claims of correctness...

    Provided By Boston University

  • White Papers // Oct 2009

    Safe Compositional Network Sketches: The Formal Framework

    NetSketch is a tool for the specification of constrained-flow applications and the certification of desirable safety properties imposed thereon. NetSketch is conceived to assist system integrators in two types of activities: Modeling and design. As a modeling tool, it enables the of an existing system while retaining sufficient information about...

    Provided By Boston University

  • White Papers // Aug 2009

    Angels: In-Network Support for Minimum Distribution Time in P2P Overlays

    This paper proposes the use of in-network caches (which the authors call Angels) to reduce the Minimum Distribution Time (MDT) of a file from a seeder - a node that possesses the file - to a set of leechers - nodes who are interested in downloading the file. An Angel...

    Provided By Boston University

  • White Papers // Mar 2010

    The Relationship Between Mobile and Fixed Line Communications: A Survey

    While a dramatic worldwide increase in mobile communication to above 4 billion users has occurred, wealthy countries in the last few years have experienced a significant decline in fixed network subscriptions. Such Fixed-to-Mobile Substitution (FMS) is at the center of this literature survey. Theoretical models explaining FMS are scarce and...

    Provided By Boston University

  • White Papers // Jan 2011

    A Geometric Approach to Slot Alignment in Wireless Sensor Networks

    Traditionally, slotted communication protocols have employed guard times to delineate and align slots. These guard times may expand the slot duration significantly, especially when clocks are allowed to drift for longer time to reduce clock synchronization overhead. Recently, a new class of lightweight protocols for statistical estimation in wireless sensor...

    Provided By Boston University

  • White Papers // Aug 2009

    PreDA: Predicate Routing for DTN Architectures Over MANET

    The authors consider a Delay Tolerant Network (DTN) whose users (Nodes) are connected by an underlying Mobile Ad hoc NETwork (MANET) substrate. Users can declaratively express high-level policy constraints on how "Content" should be routed. For example, content can be directed through an intermediary DTN node for the purposes of...

    Provided By Boston University

  • White Papers // Dec 2010

    Assessing the Security of a Clean-Slate Internet Architecture

    The TCP/IP architecture was originally designed without taking security measures into consideration. Over the years, it has been subjected to many attacks, which has led to many patches to counter them. The investigations into the fundamental principles of networking have shown that carefully following an abstract model of Inter-Process Communication...

    Provided By Boston University

  • White Papers // Jul 2009

    Brief Announcement: Cloud Computing Games: Pricing Services of Large Data Centers

    Organizations opt to reduce costs by contracting their day-to-day computing needs to service providers who offer large-scale data centers and cloud computing services. Like other computing commodities, data centers provide paid services that require careful pricing. Using a Stackelberg game formulation, this paper presents a demand-based pricing model for maximizing...

    Provided By Boston University

  • White Papers // Jan 2011

    Cross Layer Design to Multi-Thread a Data-Pipelining Application on a Multi-Processor on Chip

    Data-Pipelining is a widely used model to represent streaming applications. Incremental decomposition and optimization of a data-pipelining application onto a multi-processor platform spans multiple design layers, including the application layer, the system software layer, the architecture layer and the micro-architecture layer. For best results, designers have to consider multiple design...

    Provided By Boston University

  • White Papers // Feb 2006

    Optimal Mechanism For Selling Substitutes

    In this paper we study a problem of a multiproduct monopolist selling substitutable goods to a buyer with unknown valuations. Under the standard distributional assumptions we find that in the optimal menu every nontrivial contract delivers some good with certainty. Using this result we apply control-theoretic tools to the case...

    Provided By Boston University

  • White Papers // Jan 2010

    Wireless Infrared Communications

    Wireless infrared communications refers to the use of free-space propagation of light waves in the near infrared band as a transmission medium for communication. The communication can be between one portable communication device and another or between a portable de-vice and a tethered device, called an access point or base...

    Provided By Boston University

  • White Papers // Sep 2010

    Trade & Cap: A Customer-Managed, Market-Based System for Trading Bandwidth Allowances at a Shared Link

    This paper proposes Trade & Cap (T&C), an economics-inspired mechanism that incentivizes users to voluntarily coordinate their consumption of the bandwidth of a shared network link so as to converge on what they perceive to be an equitable allocation, while ensuring efficient resource utilization. Under T&C, rather than acting as...

    Provided By Boston University

  • White Papers // Apr 2010

    Specialization, Productivity And Financing Constraints

    The authors analyze financial contracting when the specificity of investments is endogenous. Specialization decreases the liquidation value of assets, but it also improves a firm's long term productivity. While the first effect is known to make financing more difficult, the authors show that the second effect can ease financing constraints...

    Provided By Boston University

  • White Papers // Aug 2010

    Private Equity Fund Returns: Do Managers Actually Leave Money On The Table?

    Evidence indicates that private equity funds, unlike mutual funds, deliver persistent abnormal returns and that top performing funds are often oversubscribed. Why do private equity funds appear to leave money on the table, rather than, say, increasing fund size and/or fees? The authors argue that private equity funds are fundamentally...

    Provided By Boston University

  • White Papers // Dec 2010

    Monetary Policy, Leverage, And Bank Risk-Taking

    The recent global financial crisis has ignited a debate on whether easy monetary conditions can lead to greater bank risk-taking. The authors study this issue in a model of leveraged financial intermediaries that endogenously choose the riskiness of their portfolios. When banks can adjust their capital structures, monetary easing unequivocally...

    Provided By Boston University

  • White Papers // Mar 2011

    A Token Based Approach to Distributed Computation in Sensor Networks

    The authors consider distributed algorithms for data aggregation and function computation in sensor networks. The algorithms perform pairwise computations along edges of an underlying communication graph. A token is associated with each sensor node, which acts as a transmission permit. Nodes with active tokens have transmission permits; they generate messages...

    Provided By Boston University