University of Wisconsin

Displaying 1-40 of 98 results

  • White Papers // Feb 2014

    Honey Encryption: Security Beyond the Brute-Force Bound

    "The authors introduce Honey Encryption (HE), a simple, general approach to encrypting messages using low min-entropy keys such as passwords. HE is designed to produce a cipher text which, when decrypted with any of a number of incorrect keys, yields plausible-looking but bogus plaintexts called honey messages. A key benefit...

    Provided By University of Wisconsin

  • White Papers // Aug 2012

    Towards Energy-Efficient Database Cluster Design

    Energy is a growing component of the operational cost for many "Big data" deployments, and hence has become increasingly important for practitioners of large-scale data analysis who require scale-out clusters or parallel DBMS appliances. Although a number of recent studies have investigated the energy efficiency of DBMSs, none of these...

    Provided By University of Wisconsin

  • White Papers // Jun 2012

    Reducing Memory Reference Energy With Opportunistic Virtual Caching

    Most modern cores perform a highly-associative Translation Look aside Buffer (TLB) lookup on every memory access. These designs often hide the TLB lookup latency by overlapping it with L1 cache access, but this overlap does not hide the power dissipated by TLB lookups. It can even exacerbate the power dissipation...

    Provided By University of Wisconsin

  • White Papers // May 2012

    A Passive Measurement System for Network Testbeds

    The ability to capture and process packet-level data is of intrinsic importance in network testbeds that offer broad experimental capabilities to researchers. In this paper, the authors describe the design and implementation of a passive measurement system for network testbeds called GIMS. The system enables users to specify and centrally...

    Provided By University of Wisconsin

  • White Papers // May 2012

    Obtaining Representative Measurements of Cellular Network Performance

    Network service providers, and other parties, require an accurate understanding of the performance cellular networks deliver to users. In particular, they often seek a measure of the network performance users experience solely when they are interacting with their device - a measure the authors call representative. Acquiring such measures is...

    Provided By University of Wisconsin

  • White Papers // Jan 2012

    Phantom: Physical Layer Cooperation for Location Privacy Protection

    Localization techniques that allow inferring the location of wireless devices directly from received signals have exposed mobile users to new threats. Adversaries can easily collect required information (such as signal strength) from target users, however, techniques securing location information at the physical layer of the wireless communication systems have not...

    Provided By University of Wisconsin

  • White Papers // Nov 2011

    Design and Performance of Distributed Mechanisms for Flow Admission in Wireless Adhoc Networks

    Given a wireless network where some pairs of communication links interfere with each other, the authors study sufficient conditions for determining whether a given set of minimum bandwidth Quality-of-Service (QoS) requirements can be satisfied. They are especially interested in algorithms which have low communication overhead and low processing complexity. The...

    Provided By University of Wisconsin

  • White Papers // Oct 2011

    Polymorphic Type Inference for Scripting Languages With Object Extensions

    This paper presents a polymorphic type inference algorithm for a small subset of JavaScript. The goal is to prevent accessing undefined members of objects. The authors define a type system that allows explicit extension of objects through add operation and implicit extension through method calls. The type system also permits...

    Provided By University of Wisconsin

  • White Papers // Jul 2011

    Optimal Scheduling Policies With Mutual Information Accumulation in Wireless Networks

    In this paper, the authors aim to develop scheduling policies to maximize the stability region of a wireless network under the assumption that mutual information accumulation is implemented at the physical layer. This enhanced physical layer capability enables the system to accumulate information even when the link between two nodes...

    Provided By University of Wisconsin

  • White Papers // May 2011

    How National And International Financial Development Affect Industrial R&D

    The authors examine the impacts of both domestic and international financial market development on R&D intensities in 22 manufacturing industries in 18 OECD countries for the period 1990- 2003. They take account of such industry characteristics as the need for external financing and the amount of tangible assets. Multiple forms...

    Provided By University of Wisconsin

  • White Papers // Mar 2011

    Flexible Traffic and Host Profiling Via DNS Rendezvous

    The ability to accurately classify network traffic and to perform timely detection of the presence of unwanted classes of traffic has important implications for network operations and security. In recent years, classification has become more challenging due to applications that use ports that are not well-known that overload or masquerade...

    Provided By University of Wisconsin

  • White Papers // Mar 2011

    Power-Awareness Extensions for Network Testbeds

    The escalation in power consumption of networking and communications equipment is of concern to technologists and environmentalists alike. Understanding how and when networking devices consume power is complicated by their lack of instrumentation. Furthermore, standard networking devices are not typically flexible enough to support experiments with new techniques for reducing...

    Provided By University of Wisconsin

  • White Papers // Mar 2011

    Fingerprinting 802.11 Rate Adaptation Algorithms

    The effectiveness of rate adaptation algorithms is an important determinant of 802.11 wireless network performance. The diversity of algorithms that has resulted from efforts to improve rate adaptation has introduced a new dimension of variability into 802.11 wireless networks, further complicating the already difficult task of understanding and debugging 802.11...

    Provided By University of Wisconsin

  • White Papers // Mar 2011

    PIE in the Sky: Online Passive Interference Estimation for Enterprise WLANs

    Trends in enterprise WLAN usage and deployment point to the need for tools that can capture interference in real time. A tool for interference estimation can not only enable WLAN managers to improve network performance by dynamically adjusting operating parameters like the channel of operation and transmit power of access...

    Provided By University of Wisconsin

  • White Papers // Feb 2011

    Secret Key Generation Through OFDM Multipath Channel

    The authors analyze the fundamental limits of key generation and describe an implementation based on error correcting codes. They show that key extraction based on channel coefficients significantly outperforms key extraction based on Received Signal Strength Indicators (RSSI). The development in this paper is based on an IEEE 802.11a Orthogonal...

    Provided By University of Wisconsin

  • White Papers // Jan 2011

    DomainImpute: Inferring Unseen Components in the Internet

    Despite many efforts over the past decade, the ability to generate topological maps of the Internet at the router-level accurately and in a timely fashion remains elusive. Mapping campaigns commonly involve traceroute-like probing that are usually non-adaptive and incomplete, thus revealing only a portion of the underlying topology. In this...

    Provided By University of Wisconsin

  • White Papers // Jan 2011

    Analysis of SPKI/SDSI Certificates Using Model Checking

    SPKI/SDSI is a framework for expressing naming and authorization issues that arise in a distributed-computing environment. In this paper, the authors establish a connection between SPKI/SDSI and a formalism known as Pushdown Systems (PDSs). They show that the SPKI/SDSI-to-PDS connection provides a framework for formalizing a variety of certificate-analysis problems....

    Provided By University of Wisconsin

  • White Papers // Jan 2011

    Efficient Context-Sensitive Intrusion Detection

    Model-based intrusion detection compares a process's execution against a program model to detect intrusion attempts. Models constructed from static program analysis have historically traded precision for efficiency. The authors address this problem with the Dyck model, the first efficient statically-constructed context-sensitive model. This model species both the correct sequences of...

    Provided By University of Wisconsin

  • White Papers // Jan 2011

    Implementing OKBC Knowledge Model Using Object Relational Capabilities of Oracle 8

    PERK is a storage system that loads Knowledge Bases (KB) from the Oracle DBMS. Its current limitation is the inability to do client-side memory flushing out. In this paper, the authors present a new architecture, named PERK-II, which utilizes the object relational capabilities provided by Oracle 8. It can do...

    Provided By University of Wisconsin

  • White Papers // Jan 2011

    Static Program Analysis Via 3-Valued Logic

    This paper reviews the principles behind the paradigm of "Abstract interpretation via 3-valued logic," discusses recent work to extend the approach, and summarizes ongoing research aimed at overcoming remaining limitations on the ability to create program analysis algorithms fully automatically. Static analysis concerns techniques for obtaining information about the possible...

    Provided By University of Wisconsin

  • White Papers // Jan 2011

    Automatic Verification of Strongly Dynamic Software Systems

    Strongly dynamic software systems are difficult to verify. By strongly dynamic, the authors mean that the actors in such systems change dynamically, that the resources used by such systems are dynamically allocated and deallocated, and that for both sets, no bounds are statically known. In this position paper, they describe...

    Provided By University of Wisconsin

  • White Papers // Jan 2011

    A Non-Blocking Parallel Spatial Join Algorithm

    Interest in incremental and adaptive query processing has led to the investigation of equijoin evaluation algorithms that are non-blocking. This investigation has yielded a number of algorithms, including the symmetric hash join, the XJoin, the Ripple Join, and their variants. However, to the knowledge no one has proposed a non-blocking...

    Provided By University of Wisconsin

  • White Papers // Jan 2011

    HijackGL: Reconstructing From Streams for Stylized Rendering

    This work shows that intercepting a low-level graphics library command stream and reconstructing a declarative representation is practical and useful, especially for exploring new rendering styles. The authors show not only how the basic mechanics of intercepting an OpenGL command stream lead to a non-invasive extension mechanism for graphics applications,...

    Provided By University of Wisconsin

  • White Papers // Jan 2011

    Locking Protocols for Materialized Aggregate Join Views

    The maintenance of materialized aggregate join views is a well-studied problem. However, to date the published literature has largely ignored the issue of concurrency control. Clearly immediate materialized view maintenance with transactional consistency, if enforced by generic concurrency control mechanisms, can result in low levels of concurrency and high rates...

    Provided By University of Wisconsin

  • White Papers // Jan 2011

    The Design, Implementation, and Evaluation of mpiBLAST

    mpiBLAST is an open-source parallelization of BLAST that achieves superlinear speed-up by segmenting a BLAST database and then having each node in a computational cluster search a unique portion of the database. Database segmentation permits each node to search a smaller portion of the database, eliminating disk I/O and vastly...

    Provided By University of Wisconsin

  • White Papers // Jan 2011

    Multiprocessor Scheduling Using Dynamic Performance Measurement and Analysis

    In this paper the authors address using dynamic performance metrics when making scheduling decisions. The focus is on the problem of cache affinity in multiprocessor CPU schedulers. The Linux 2.4 kernel uses a simplistic method to determine cache affinity, one that does not take into account the working set size...

    Provided By University of Wisconsin

  • White Papers // Jan 2011

    Program Generalization for Software Reuse: From C to C++

    The authors consider the problem of software generalization: Given a program component C, create a parameterized program component C' such that C' is usable in a wider variety of syntactic contexts than C. Furthermore, C' should be a semantically meaningful generalization of C; namely, there must exist an instantiation of...

    Provided By University of Wisconsin

  • White Papers // Jan 2011

    Modeling Congestion in Backbone Routers

    Traffic engineering models based on end-to-end loss probabilities and delays do not scale well to fast backbone links. In this paper, the authors investigate the nature of congestion events in highly aggregated flows. An examination of congestion events shows distinct phases of queue buildup, packet dropping followed later by TCP...

    Provided By University of Wisconsin

  • White Papers // Jan 2011

    Inferring Regulatory Networks From Time Series Expression Data and Relational Data Via Inductive Logic Programming

    In this paper, the authors are interested in learning rules that will reveal the causal genes for the expression variation from various relational data sources in addition to gene expression data. Following the previous work where they showed that time series gene expression data could potentially uncover causal effects, they...

    Provided By University of Wisconsin

  • White Papers // Jan 2011

    Two Formal Analyses of Attack Graphs

    An attack graph is a succinct representation of all paths through a system that end in a state where an intruder has successfully achieved his goal. Today Red Teams determine the vulnerability of networked systems by drawing gigantic attack graphs by hand. Constructing attack graphs by hand is tedious, error-prone,...

    Provided By University of Wisconsin

  • White Papers // Jan 2011

    Towards Automatic Generation of Vulnerability-Based Signatures

    In this paper the authors explore the problem of creating vulnerability signatures. A vulnerability signature matches all exploits of a given vulnerability, even polymorphic or metamorphic variants. The work departs from previous approaches by focusing on the semantics of the program and vulnerability exercised by a sample exploit instead of...

    Provided By University of Wisconsin

  • White Papers // Jan 2011

    Efficient Filtering in Publish-Subscribe Systems Using Binary Decision Diagrams

    Implicit invocation or publish-subscribe has become an important architectural style for large-scale system design and evolution. The publish-subscribe style facilitates developing large-scale systems by composing separately developed components because the style permits loose coupling between various components. One of the major bottlenecks in using publish-subscribe systems for very large scale...

    Provided By University of Wisconsin

  • White Papers // Jan 2011

    High Throughput Data Transfers Using the Tornado Transport Protocol

    The need to transfer extremely large files over very high bandwidth network paths is becoming more and more common. Current window based transport protocols often limit throughput to a level well below what might otherwise be achievable. In this paper the authors describe and evaluate the Tornado Transport Protocol (TTP)...

    Provided By University of Wisconsin

  • White Papers // Jan 2011

    Evaluating and Modeling Window Synchronization in Highly Multiplexed Flows

    In this paper, the authors investigate issues of synchronization in highly aggregated flows such as would be found in the Internet backbone. Understanding this phenomenon is important since it leads to reduced network utilization. The hypothesis is that regularly spaced loss events lead to window synchronization in long lived flows....

    Provided By University of Wisconsin

  • White Papers // Jan 2011

    Failure Analysis of SGI XFS File System

    Commodity file systems expect a fail stop disk. But to-days disks fail in unexpected ways. Disks exhibit latent sector errors, silent corruption and transient failures to name a few. In this paper the authors study the behavior of SGI XFS to such errors. File systems play a key role in...

    Provided By University of Wisconsin

  • White Papers // Jan 2011

    Resource Deployment Based on Autonomous System Clustering

    Effective placement of resources used to support distributed services in the Internet depends on an accurate representation of Internet topology and routing. Representations of Autonomous System (AS) level topology derived solely from BGP tables show only a subset of the connections that actually get used. However, in many cases, missing...

    Provided By University of Wisconsin

  • White Papers // Jan 2011

    Using Slicing to Identify Duplication in Source Code

    Programs often have a lot of duplicated code, which makes both understanding and maintenance more difficult. This problem can be alleviated by detecting duplicated code, extracting it into a separate new procedure, and replacing all the clones (The instances of the duplicated code) by calls to the new procedure. This...

    Provided By University of Wisconsin

  • White Papers // Jan 2011

    Caching for Multi-Dimensional Data Mining Queries

    Multi-dimensional data analysis and online analytical processing are standard querying techniques applied on today's data warehouses. Data mining algorithms, on the other hand, are mostly run in stand-alone, batch mode on at les extracted from relational databases. In this paper the authors propose a general querying model combining the power...

    Provided By University of Wisconsin

  • White Papers // Jan 2011

    Adaptive Control for Anonymous Network-Attached Storage

    The authors describe techniques for building an anonymous network-attached storage system. Central to the design is adaptation, which enables higher performance without administrative tuning. Via a range of simulation experiments and a prototype implementation, they quantify the costs of providing anonymous storage and explore the parameters to which system performance...

    Provided By University of Wisconsin

  • White Papers // Jan 2011

    Design and Evaluation of Alternative Selection Placement Strategies in Optimizing Continuous Queries

    In this paper, the authors design and evaluate alternative selection placement strategies for optimizing a very large number of continuous queries in an Internet environment. Two grouping strategies, PushDown and PullUp, in which selections are either pushed below, or pulled above, joins are proposed and investigated. While the earlier research...

    Provided By University of Wisconsin

  • White Papers // Nov 2009

    Cloud Computing: The Changing Face of Computer Science

    The way people use computers is changing. Instead of data and programs being contained on the device of users, they will be held on servers in a server farm, and users will access the content via the Internet for a fee. Computer usage will become a service, with the benefits...

    Provided By University of Wisconsin

  • White Papers // Jan 2010

    Laying the Foundation for the Investigation of the Quality of Service for Resource Management in Grid Computing

    By pooling the resources of virtually any functional machine, grids have quickly become a powerful, low-cost, attractive solution in a number of application domains. As a result of the surge in interest in grid computing, a variety of implementations have emerged. The availability of grid systems in commercial industry is...

    Provided By University of Wisconsin

  • White Papers // Jan 2010

    Scientific Workflow Management by Database Management

    In several working environments, production involves repeated executions of certain procedures. A workflow describes the individual tasks performed in these procedures and their interrelationships. Current Workflow Management Systems (WFMSs) use a Database Management System (DBMS) to store task descriptions, and implement all workflow functionality in modules that run on top...

    Provided By University of Wisconsin

  • White Papers // Apr 2010

    Extensible and Scalable Network Monitoring Using OpenSAFE

    Administrators of today's networks are highly interested in monitoring traffic for purposes of collecting statistics, detecting intrusions, and providing forensic evidence. Unfortunately, network size and complexity can make this a daunting task. Aside from the problems in analyzing network traffic for this information - an extremely difficult task itself -...

    Provided By University of Wisconsin

  • White Papers // Jan 2010

    A DBMS Engine Simulator to Assist in Classroom Understanding of Oracle Query Execution

    Oracle's DBMS query execution process consists of a complicated series of steps which can be difficult for many students and professionals to understand. It is also difficult to find resources which provide a compiled description of this process and all of the components involved. The authors have researched Oracle's DBMS...

    Provided By University of Wisconsin

  • White Papers // Oct 2009

    Impact of Disk Corruption on Open-Source DBMS

    Despite the best intentions of disk and RAID manufacturers, on-disk data can still become corrupted. This paper examines the effects of corruption on database management systems. Through injecting faults into the MySQL DBMS, the authors find that in certain cases, corruption can greatly harm the system, leading to untimely crashes,...

    Provided By University of Wisconsin

  • White Papers // Jan 2010

    Nest - A Grid Enabled Storage Appliance

    This paper describes NeST, a flexible software-only storage appliance designed to meet the storage needs of the Grid. NeST has three key features that make it well suited for deployment in a Grid environment. First, NeST provides a generic data transfer architecture that supports multiple data transfer protocols including GridFTP...

    Provided By University of Wisconsin

  • White Papers // Jan 2010

    Phase III: Data Recovery and Mitigation

    Data recovery may be undertaken as a form of mitigation at an archeological site determined eligible for listing on the National Register of Historic Places and that will be impacted by a proposed federal undertaking. Data recovery is undertaken when neither preservation in place nor avoidance through project redesign is...

    Provided By University of Wisconsin

  • White Papers // Jan 2011

    Analysis of SPKI/SDSI Certificates Using Model Checking

    SPKI/SDSI is a framework for expressing naming and authorization issues that arise in a distributed-computing environment. In this paper, the authors establish a connection between SPKI/SDSI and a formalism known as Pushdown Systems (PDSs). They show that the SPKI/SDSI-to-PDS connection provides a framework for formalizing a variety of certificate-analysis problems....

    Provided By University of Wisconsin

  • White Papers // Jan 2011

    Efficient Context-Sensitive Intrusion Detection

    Model-based intrusion detection compares a process's execution against a program model to detect intrusion attempts. Models constructed from static program analysis have historically traded precision for efficiency. The authors address this problem with the Dyck model, the first efficient statically-constructed context-sensitive model. This model species both the correct sequences of...

    Provided By University of Wisconsin

  • White Papers // Jan 2011

    Implementing OKBC Knowledge Model Using Object Relational Capabilities of Oracle 8

    PERK is a storage system that loads Knowledge Bases (KB) from the Oracle DBMS. Its current limitation is the inability to do client-side memory flushing out. In this paper, the authors present a new architecture, named PERK-II, which utilizes the object relational capabilities provided by Oracle 8. It can do...

    Provided By University of Wisconsin

  • White Papers // Jan 2011

    Static Program Analysis Via 3-Valued Logic

    This paper reviews the principles behind the paradigm of "Abstract interpretation via 3-valued logic," discusses recent work to extend the approach, and summarizes ongoing research aimed at overcoming remaining limitations on the ability to create program analysis algorithms fully automatically. Static analysis concerns techniques for obtaining information about the possible...

    Provided By University of Wisconsin

  • White Papers // Jan 2011

    Automatic Verification of Strongly Dynamic Software Systems

    Strongly dynamic software systems are difficult to verify. By strongly dynamic, the authors mean that the actors in such systems change dynamically, that the resources used by such systems are dynamically allocated and deallocated, and that for both sets, no bounds are statically known. In this position paper, they describe...

    Provided By University of Wisconsin

  • White Papers // Jan 2011

    A Non-Blocking Parallel Spatial Join Algorithm

    Interest in incremental and adaptive query processing has led to the investigation of equijoin evaluation algorithms that are non-blocking. This investigation has yielded a number of algorithms, including the symmetric hash join, the XJoin, the Ripple Join, and their variants. However, to the knowledge no one has proposed a non-blocking...

    Provided By University of Wisconsin

  • White Papers // Jan 2011

    HijackGL: Reconstructing From Streams for Stylized Rendering

    This work shows that intercepting a low-level graphics library command stream and reconstructing a declarative representation is practical and useful, especially for exploring new rendering styles. The authors show not only how the basic mechanics of intercepting an OpenGL command stream lead to a non-invasive extension mechanism for graphics applications,...

    Provided By University of Wisconsin

  • White Papers // May 2010

    Garuda: A Cloud-Based Job Scheduler

    The authors present the design and implementation details of Garuda, a cloud based job scheduler using Google App Engine as the underlying cloud provider. The goal of the project is to demonstrate the concept of a centralized cloud based job scheduler that manages a pool of worker machines and schedules...

    Provided By University of Wisconsin

  • White Papers // Jun 2010

    Dynamic Processors Demand Dynamic Operating Systems

    The rise of multicore processors has lead to techniques that dynamically vary the set and characteristics of cores or threads available to the operating system. For example, Core Fusion merges multiple cores for faster processing. While the mechanics of the change, such as merging two cores into a more powerful...

    Provided By University of Wisconsin

  • White Papers // Dec 2009

    WrtVMM: A Virtual Machine Monitor for Embedded Devices

    The authors built a virtual machine monitor for the Linksys WRT54GL wireless router to run Embedded Xinu as a guest OS within OpenWrt. The system uses a kernel module and signal handlers to support the virtualization of the guest OS. Sufficient support is provided to allow Xinu to startup, handle...

    Provided By University of Wisconsin

  • White Papers // Dec 2009

    E-Mobile: A Heterogeneous Agent-Based, Remote Off-Loading Framework for Efficient Energy Management of Mobile Devices

    Web applications are becoming increasingly popular on mobile/wireless devices. As more desktop applications that are inherently computational intensive and resource-demanding are being ported to the mobile platforms, the energy consumption of the devices is shooting up, thereby decreasing the battery life. An alternate approach is to off-load the resource intensive...

    Provided By University of Wisconsin

  • White Papers // Dec 2009

    Multi-View 3D Geometry Reconstruction: Exploiting Massive Parallelism

    3D geometric reconstruction from digital images captured from consumer cameras is an inexpensive, but computationally demanding application. In this experimental study, the authors have explored parallelism in the best known public domain software (Bundler and PMVS2) and found that massive parallelism exists at various levels that can be exploited on...

    Provided By University of Wisconsin

  • White Papers // Jun 2010

    The Case for Fine-Grained Traffic Engineering in Data Centers

    In recent years, several techniques have been suggested for routing and traffic engineering in data centers. However, not much is known about how these techniques perform relative to each other under realistic data center traffic patterns. The preliminary study reveals that existing techniques can only achieve 80% to 85% of...

    Provided By University of Wisconsin

  • White Papers // Mar 2010

    Model Evolution: An Incremental Approach to Non-Rigid Structure From Motion

    In this paper, the authors present a new framework for Non-Rigid Structure From Motion (NRSFM) that simultaneously addresses three significant challenges: severe occlusion, perspective camera projection, and large non-linear deformation. They introduce a concept called a model graph, which greatly reduces the computational cost of discovering groups of input images...

    Provided By University of Wisconsin

  • White Papers // Jan 2011

    Locking Protocols for Materialized Aggregate Join Views

    The maintenance of materialized aggregate join views is a well-studied problem. However, to date the published literature has largely ignored the issue of concurrency control. Clearly immediate materialized view maintenance with transactional consistency, if enforced by generic concurrency control mechanisms, can result in low levels of concurrency and high rates...

    Provided By University of Wisconsin

  • White Papers // Aug 2009

    Reducing Concurrent Analysis Under a Context Bound to Sequential Analysis

    This paper addresses the analysis of concurrent programs with shared memory. Such an analysis is undecidable in the presence of multiple procedures. One approach used in recent work obtains decidability by providing only a partial guarantee of correctness: the approach bounds the number of context switches allowed in the concurrent...

    Provided By University of Wisconsin

  • White Papers // Jan 2011

    The Design, Implementation, and Evaluation of mpiBLAST

    mpiBLAST is an open-source parallelization of BLAST that achieves superlinear speed-up by segmenting a BLAST database and then having each node in a computational cluster search a unique portion of the database. Database segmentation permits each node to search a smaller portion of the database, eliminating disk I/O and vastly...

    Provided By University of Wisconsin

  • White Papers // Jan 2011

    Multiprocessor Scheduling Using Dynamic Performance Measurement and Analysis

    In this paper the authors address using dynamic performance metrics when making scheduling decisions. The focus is on the problem of cache affinity in multiprocessor CPU schedulers. The Linux 2.4 kernel uses a simplistic method to determine cache affinity, one that does not take into account the working set size...

    Provided By University of Wisconsin

  • White Papers // Jan 2011

    Program Generalization for Software Reuse: From C to C++

    The authors consider the problem of software generalization: Given a program component C, create a parameterized program component C' such that C' is usable in a wider variety of syntactic contexts than C. Furthermore, C' should be a semantically meaningful generalization of C; namely, there must exist an instantiation of...

    Provided By University of Wisconsin

  • White Papers // Jan 2011

    Modeling Congestion in Backbone Routers

    Traffic engineering models based on end-to-end loss probabilities and delays do not scale well to fast backbone links. In this paper, the authors investigate the nature of congestion events in highly aggregated flows. An examination of congestion events shows distinct phases of queue buildup, packet dropping followed later by TCP...

    Provided By University of Wisconsin

  • White Papers // Sep 2009

    Network Anomaly Confirmation, Diagnosis and Remediation

    Identifying and diagnosing network traffic anomalies, and rectifying their effects are standard, daily activities of network operators. While there is a large and growing literature on techniques for detecting network anomalies, there has been little or no treatment of what to do after a candidate anomaly has been identified. In...

    Provided By University of Wisconsin

  • White Papers // Jan 2011

    Inferring Regulatory Networks From Time Series Expression Data and Relational Data Via Inductive Logic Programming

    In this paper, the authors are interested in learning rules that will reveal the causal genes for the expression variation from various relational data sources in addition to gene expression data. Following the previous work where they showed that time series gene expression data could potentially uncover causal effects, they...

    Provided By University of Wisconsin

  • White Papers // Dec 2010

    Identifying Activity

    Identification of active constraints in constrained optimization is of interest from both practical and theoretical viewpoints, as it holds the promise of reducing an inequality-constrained problem to an equality-constrained problem, in a neighborhood of a solution. The authors study this issue in the more general setting of composite nonsmooth minimization,...

    Provided By University of Wisconsin

  • White Papers // Dec 2010

    Tuffy: Scaling Up Statistical Inference in Markov Logic Networks

    Markov Logic Networks (MLNs) have emerged as a powerful framework that combines statistical and logical reasoning; they have been applied to many data intensive problems including information extraction, entity resolution, and text mining. Current implementations of MLNs do not scale to real-world data sets, which is preventing their wide-spread adoption....

    Provided By University of Wisconsin

  • White Papers // Aug 2010

    Accelerated Block-Coordinate Relaxation for Regularized Optimization

    The authors discuss minimization of a smooth function to which is added a regularization function that induces structure in the solution. A block-coordinate relaxation approach with proximal linearized subproblems yields convergence to stationary points, while identification of the optimal manifold (Under a nondegeneracy condition) allows acceleration techniques to be applied...

    Provided By University of Wisconsin

  • White Papers // Jan 2011

    Two Formal Analyses of Attack Graphs

    An attack graph is a succinct representation of all paths through a system that end in a state where an intruder has successfully achieved his goal. Today Red Teams determine the vulnerability of networked systems by drawing gigantic attack graphs by hand. Constructing attack graphs by hand is tedious, error-prone,...

    Provided By University of Wisconsin

  • White Papers // Jan 2011

    Towards Automatic Generation of Vulnerability-Based Signatures

    In this paper the authors explore the problem of creating vulnerability signatures. A vulnerability signature matches all exploits of a given vulnerability, even polymorphic or metamorphic variants. The work departs from previous approaches by focusing on the semantics of the program and vulnerability exercised by a sample exploit instead of...

    Provided By University of Wisconsin

  • White Papers // Jan 2011

    Efficient Filtering in Publish-Subscribe Systems Using Binary Decision Diagrams

    Implicit invocation or publish-subscribe has become an important architectural style for large-scale system design and evolution. The publish-subscribe style facilitates developing large-scale systems by composing separately developed components because the style permits loose coupling between various components. One of the major bottlenecks in using publish-subscribe systems for very large scale...

    Provided By University of Wisconsin

  • White Papers // Jan 2011

    High Throughput Data Transfers Using the Tornado Transport Protocol

    The need to transfer extremely large files over very high bandwidth network paths is becoming more and more common. Current window based transport protocols often limit throughput to a level well below what might otherwise be achievable. In this paper the authors describe and evaluate the Tornado Transport Protocol (TTP)...

    Provided By University of Wisconsin

  • White Papers // Jan 2011

    Evaluating and Modeling Window Synchronization in Highly Multiplexed Flows

    In this paper, the authors investigate issues of synchronization in highly aggregated flows such as would be found in the Internet backbone. Understanding this phenomenon is important since it leads to reduced network utilization. The hypothesis is that regularly spaced loss events lead to window synchronization in long lived flows....

    Provided By University of Wisconsin

  • White Papers // Oct 2009

    A Learning-Based Approach for IP Geolocation

    The ability to pinpoint the geographic location of IP hosts is compelling for applications such as on-line advertising and network at-tack diagnosis. While prior methods can accurately identify the location of hosts in some regions of the Internet, they produce erroneous results when the delay or topology measurement on which...

    Provided By University of Wisconsin

  • White Papers // Jan 2011

    Failure Analysis of SGI XFS File System

    Commodity file systems expect a fail stop disk. But to-days disks fail in unexpected ways. Disks exhibit latent sector errors, silent corruption and transient failures to name a few. In this paper the authors study the behavior of SGI XFS to such errors. File systems play a key role in...

    Provided By University of Wisconsin