University of Wisconsin

Displaying 1-40 of 104 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

    Dynamic Interference Adaptation for Wireless Mesh Networks

    Most wireless meshes will have to operate within the crowded unlicensed spectrum that is also shared by numerous uncoordinated 802.11 hotspots. This creates an unpredictable and variable spectrum space that mesh networks need to co-exist within. The authors propose a novel method for adapting to such external interference by dynamically...

    Provided By University of Wisconsin

  • White Papers // Jan 2011

    Updates for Structure Indexes

    The problem of indexing path queries in semistructured/XML databases has received considerable attention recently, and several proposals have advocated the use of structure indexes as supporting data structures for this problem. In this paper, the authors investigate efficient update algorithms for structure indexes. They study two kinds of updates-the addition...

    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

    Matchmaking: Distributed Resource Management for High Throughput Computing

    Conventional resource management systems use a system model to describe resources and a centralized scheduler to control their allocation. The authors argue that this paradigm does not adapt well to distributed systems, particularly those built to support high-throughput computing. Obstacles include heterogeneity of resources, which make uniform allocation algorithms difficult...

    Provided By University of Wisconsin

  • White Papers // Jan 2011

    On Generalized Authorization Problems

    This paper defines a framework in which one can formalize a variety of authorization and policy issues that arise in access control of shared computing resources. Instantiations of the framework address such issues as privacy, recency, validity, and trust. The paper presents an efficient algorithm for solving all authorization problems...

    Provided By University of Wisconsin

  • White Papers // Jan 2011

    Formalizing Sensitivity in Static Analysis for Intrusion Detection

    A key function of a host-based intrusion detection system is to monitor program execution. Models constructed using static analysis have the highly desirable feature that they do not produce false alarms; however, they may still miss attacks. Prior work has shown a trade-off between efficiency and precision. In particular, the...

    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 // Jan 2011

    Change of Representation for Statistical Relational Learning

    Statistical Relational learning (SRL) algorithms learn statistical models from relational data, such as that stored in a relational database. The authors previously introduced view learning for SRL, in which the view of a relational database can be automatically modified, yielding more accurate statistical models. The present paper presents SAYU-VISTA, an...

    Provided By University of Wisconsin

  • White Papers // Jan 2011

    Semantics-Preserving Procedure Extraction

    Procedure extract ion is an important program transformation that can be used to make programs easier to understand and maintain, to facilitate code reuse, and to convert "Monolithic" code to modular or object - oriented code. Procedure extraction involves the following steps: The statements to be extracted are identified (by...

    Provided By University of Wisconsin

  • White Papers // Jan 2011

    Tracking the Role of Adversaries in Measuring Unwanted Traffic

    Measurements related to security are being carried out on many sites on the Internet at network ingress points, between specific points on the Internet, and across the wide area Internet. The goals range from identifying sources of and possibly filtering unwanted traffic, to characterizing and coming up with new mechanisms...

    Provided By University of Wisconsin

  • White Papers // Jan 2011

    View Learning for Statistical Relational Learning: With an Application to Mammography

    Statistical Relational Learning (SRL) constructs probabilistic models from relational databases. A key capability of SRL is the learning of arcs (In the Bayes net sense) connecting entries in different rows of a relational table, or in different tables. Nevertheless, SRL approaches currently are constrained to use the existing database schema....

    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

    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

    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

    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

    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

    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 // Jul 2009

    Light Field Video Stabilization

    The authors describe a method for producing a smooth, stabilized video from the shaky input of a hand-held light field video camera - specifically, a small camera array. Traditional stabilization techniques dampen shake with 2D warps, and thus have limited ability to stabilize a significantly shaky camera motion through a...

    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 // Jul 2009

    An Efficient Algorithm for Co-Segmentation

    This paper is focused on the Co-segmentation problem - where the objective is to segment a similar object from a pair of images. The background in the two images may be arbitrary; therefore, simultaneous segmentation of both images must be performed with a requirement that the appearance of the two...

    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 // Mar 2010

    Peeking Into the Cloud: Toward User-Driven Cloud Management

    The emergence and growing popularity of cloud computing signals an evolution in the way IT infrastructure and services are delivered and consumed. Cloud services have a number of essential characteristics, such as self-service on-demand consumption, location independence, and rapid elasticity. There are also evolving cloud delivery models, including Infrastructure-as-a-Service (IaaS),...

    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 // Jan 2011

    Tracking the Role of Adversaries in Measuring Unwanted Traffic

    Measurements related to security are being carried out on many sites on the Internet at network ingress points, between specific points on the Internet, and across the wide area Internet. The goals range from identifying sources of and possibly filtering unwanted traffic, to characterizing and coming up with new mechanisms...

    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

    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

    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 // Sep 2010

    Towards Automatically Checking Thousands of Failures With Micro-Specifications

    Recent data-loss incidents have shown that existing large distributed systems are still vulnerable to failures. To improve the situation, the authors propose two new testing approaches: Failure Testing Service (FTS) and Declarative Testing Specification (DTS). FTS enables one to systematically push a system into thousands of failure scenarios, leading to...

    Provided By University of Wisconsin

  • White Papers // Jan 2011

    Matchmaking: Distributed Resource Management for High Throughput Computing

    Conventional resource management systems use a system model to describe resources and a centralized scheduler to control their allocation. The authors argue that this paradigm does not adapt well to distributed systems, particularly those built to support high-throughput computing. Obstacles include heterogeneity of resources, which make uniform allocation algorithms difficult...

    Provided By University of Wisconsin

  • White Papers // Jan 2011

    On Generalized Authorization Problems

    This paper defines a framework in which one can formalize a variety of authorization and policy issues that arise in access control of shared computing resources. Instantiations of the framework address such issues as privacy, recency, validity, and trust. The paper presents an efficient algorithm for solving all authorization problems...

    Provided By University of Wisconsin

  • White Papers // Dec 2009

    Protecting Commodity Operating System Kernels From Vulnerable Device Drivers

    Device drivers on commodity operating systems execute with kernel privilege and have unfettered access to kernel data structures. Several recent attacks demonstrate that such poor isolation exposes kernel data to exploits against vulnerable device drivers, for example through buffer overruns in packet processing code. Prior architectures to isolate kernel data...

    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

    Model Checking X86 Executables With CodeSurfer/x86 and WPDS++

    This paper presents a toolset for model checking x86 executables. The members of the toolset are CodeSurfer/x86, WPDS++, and the Path Inspector. CodeSurfer/x86 is used to extract a model from an executable in the form of a weighted pushdown system. WPDS++ is a library for answering generalized reachability queries on...

    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 // Aug 2009

    Verifying Information Flow Control Over Unbounded Processes

    Decentralized Information Flow Control (DIFC) systems enable programmers to express a desired DIFC policy, and to have the policy enforced via a reference monitor that restricts interactions between system objects, such as processes and les. Past research on DIFC systems focused on the reference-monitor implementation, and assumed that the desired...

    Provided By University of Wisconsin

  • White Papers // Mar 2010

    Cheap and Large CAMs for High Performance Data-Intensive Networked Systems

    The authors show how to build cheap and large CAMs, or CLAMs, using a combination of DRAM and flash memory. These are targeted at emerging data-intensive networked systems that require massive hash tables running into a hundred GB or more, with items being inserted, updated and looked up at a...

    Provided By University of Wisconsin

  • White Papers // Aug 2009

    Static Verification of Data-Consistency Properties

    To leverage the increased processing power of modern multicore processors, programmers are left with the burden of writing concurrent programs. A popular language for writing concurrent programs is Java. In Java, a concurrent program consists of multiple threads that execute in parallel and communicate through shared memory. Because the number...

    Provided By University of Wisconsin

  • White Papers // Jan 2011

    Program Analysis Via Graph Reachability

    This paper describes how a number of program-analysis problems can be solved by transforming them to graph-reachability problems. Some of the program-analysis problems that are amenable to this treatment include program slicing, certain dataflow-analysis problems, one version of the problem of approximating the possible "Shapes" that heap-allocated structures in a...

    Provided By University of Wisconsin

  • White Papers // Mar 2010

    A Decision Procedure for Detecting Atomicity Violations for Communicating Processes With Locks

    The problem of interest is to verify data consistency of a concurrent Java program. In particular, the authors present a new decision procedure for verifying that a class of data races caused by inconsistent accesses on multiple fields of an object cannot occur (So-called atomic-set serializability). Atomic-set serializability generalizes the...

    Provided By University of Wisconsin

  • White Papers // Jan 2011

    An Incremental Algorithm for Maintaining the Dominator Tree of a Reducible Flowgraph

    The authors present a new incremental algorithm for the problem of maintaining the dominator tree of a reducible flowgraph as the flowgraph undergoes changes such as the insertion and deletion of edges. Such an algorithm has applications in incremental dataflow analysis and incremental compilation. The contribution of this paper is...

    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

    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

    Change of Representation for Statistical Relational Learning

    Statistical Relational learning (SRL) algorithms learn statistical models from relational data, such as that stored in a relational database. The authors previously introduced view learning for SRL, in which the view of a relational database can be automatically modified, yielding more accurate statistical models. The present paper presents SAYU-VISTA, an...

    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

    Semantics-Preserving Procedure Extraction

    Procedure extract ion is an important program transformation that can be used to make programs easier to understand and maintain, to facilitate code reuse, and to convert "Monolithic" code to modular or object - oriented code. Procedure extraction involves the following steps: The statements to be extracted are identified (by...

    Provided By University of Wisconsin

  • White Papers // Dec 2009

    Toward the Practical Use of Network Tomography for Internet Topology Discovery

    Accurate and timely identification of the router-level topology of the Internet is one of the major unresolved problems in Internet research. Topology recovery via tomographic inference is potentially an attractive complement to standard methods that use TTL-limited probes. In this paper, the authors describe new techniques that aim toward the...

    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