name stringlengths 5 6 | title stringlengths 8 144 | abstract stringlengths 0 2.68k | fulltext stringlengths 1.78k 95k | keywords stringlengths 22 532 |
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368450 | Efficient techniques for accurate modeling and simulation of substrate coupling in mixed-signal IC''s. | Industry trends aimed at integrating higher levels of circuit functionality have triggered a proliferation of mixed analog-digital systems. Magnified noise coupling through the common chip substrate has made the design and verification of such systems an increasingly difficult task. In this paper we present a fast eige... | Introduction
Industry trends aimed at integrating higher levels of circuit functionality resulting from an
emphasis on compactness in consumer electronic products and a widespread growth and interest
in wireless communications, have triggered a proliferation of mixed analog-digital systems. Single
chip mixed-signal des... | Discrete Cosine Transform;mixed-signal;eigenfunction;substrate coupling;Fast Fourier Transform;eigenvalue;eigenpair |
369138 | Slicing Software for Model Construction. | Applying finite-state verification techniques (e.g., model checking) to software requires that program source code be translated to a finite-state transition system that safely models program behavior. Automatically checking such a transition system for a correctness property is typically very costly, thus it is necess... | Introduction
Modern software systems are highly complex, yet they must
be extremely reliable and correct. In recent years, finite-state
verification techniques, including model checking tech-
niques, have received much attention as a software validation
method. These techniques have been effective in validating
crucial... | software verification;program slicing;state-space reduction;linear temporal logic;program dependence graph;model-checking |
369187 | Optimal sequencing by hybridization in rounds. | Sequencing by hybridization (SBH) is a method for reconstructing a sequence over a small finite alphabet from a collection of probes (substrings). Substring queries can be arranged on an array (SBH chip) and then a combinatorial method is used to construct the sequence from its collection of probes. Technological const... | Introduction
Consider the following problem. Let be an alphabet with letters. Given
a string s drawn uniformly at random from n and the ability to ask queries
of the type: "Is x a substring of s?". What is the minimum set of such
questions one can ask such that with high probability one can reconstruct s.
The proble... | sequencing by hybridization;probabilistic analysis;DNA sequencing |
369220 | Fast and simple character classes and bounded gaps pattern matching, with application to protein searching. | The problem of fast searching of a pattern that contains Classes of characters and Bounded size Gaps (CBG) in a text has a wide range of applications, among which a very important one is protein pattern matching (for instance, one PROSITE protein site is associated with the CBG [RK] x(2, where the brackets match any o... | Introduction
This paper deals with the problem of fast searching of patterns that contain Classes of characters
and Bounded size Gaps (CBG) in texts. This problem occurs in various elds, like information
retrieval, data mining and computational biology. We are particularly interested in the latter one.
In computational... | bit-parallelism;information retrieval;PROSITE;pattern matching;computational biology |
369880 | Enlarging the Margins in Perceptron Decision Trees. | Capacity control in perceptron decision trees is typically performed by controlling their size. We prove that other quantities can be as relevant to reduce their flexibility and combat overfitting. In particular, we provide an upper bound on the generalization error which depends both on the size of the tree and on the... | Introduction
Perceptron Decision Trees (PDT) have been introduced by a number of authors under different
names [17, 6, 7, 8, 10, 11, 27, 18]. They are decision trees in which each internal
node is associated with a hyperplane in general position in the input space. They have been
used in many real world pattern classif... | perceptron;learning theory;capacity control;decision trees;learning algorithm |
369881 | Cascade Generalization. | Using multiple classifiers for increasing learning accuracy is an active research area. In this paper we present two related methods for merging classifiers. The first method, Cascade Generalization, couples classifiers loosely. It belongs to the family of stacking algorithms. The basic idea of Cascade Generalization i... | Introduction
The ability of a chosen classification algorithm to induce a good generalization depends
on the appropriateness of its representation language to express generalizations
of the examples for the given task. The representation language for a standard
decision tree is the DNF formalism that splits the instanc... | combining classifiers;multiple models;merging classifiers;constructive induction |
369882 | Markov Processes on Curves. | We study the classification problem that arises when two variablesone continuous (x), one discrete (s)evolve jointly in time. We suppose that the vector x traces out a smooth multidimensional curve, to each point of which the variable s attaches a discrete label. The trace of s thus partitions the curve into different ... | Introduction
The automatic segmentation of continuous trajectories poses a challenging
problem in machine learning. The problem arises whenever a multi-dimensional
trajectory fx(t)jt 2 [0; ]g must be mapped into a sequence
of discrete labels segmentation performs this mapping by
specifying consecutive time intervals s... | automatic speech recognition;markov processes on curves;hidden Markov models |
370225 | Simplicial Properties of the Set of Planar Binary Trees. | Planar binary trees appear as the the main ingredient of a new homology theory related to dialgebras, cf.(J.-L. Loday, i>C.R. Acad. Sci. Paris 321 (1995), 141146.) Here I investigate the simplicial properties of the set of these trees, which are independent of the dialgebra context though they are reflected in the dial... | Introduction
The planar binary trees have been widely studied for their combinatorial properties, which relate
them to permutations, partition of closed strings and other finite sets. In fact, the cardinality
of the set Y n of planar binary trees with leaves and one root is the Catalan number
n!(n+1)! , which is well k... | almost-simplicial sets;planar binary trees |
370338 | Partial Evaluation of Views. | Many database applications and environments, such as mediation over heterogeneous database sources and data warehousing for decision support, lead to complex queries. Queries are often nested, defined over previously defined views, and may involve unions. There are good reasons why one might want to remove pieces (sub-... | Introduction
1.1 Motivation and Objectives
Many current database applications and environments, as mediation over heterogeneous database sources
and data warehousing for decision support, incur complex queries. Queries are often nested, defined over
previously defined views, and may involve unions. special type of such... | query rewrite;query optimization;relational databases;database mediation;TPC/D benchmark;database security;data warehousing |
371036 | Verification of Large State/Event Systems Using Compositionality and Dependency Analysis. | A state/event model is a concurrent version of Mealy machines used for describing embedded reactive systems. This paper introduces a technique that uses compositionality and dependency analysis to significantly improve the efficiency of symbolic model checking of state/event models. It makes possible automated verifica... | Introduction
Symbolic model checking is a powerful technique for formal verification of finite-state
concurrent systems. The technique was initially developed to verify digital
systems and for this class of systems, it has proven very efficient: hardware
systems with an extremely large number of reachable states has be... | embedded software;symbolic model checking;formal verification;backwards reachability |
371431 | Parametric Design Synthesis of Distributed Embedded Systems. | AbstractThis paper presents a design synthesis method for distributed embedded systems. In such systems, computations can flow through long pipelines of interacting software components, hosted on a variety of resources, each of which is managed by a local scheduler. Our method automatically calibrates the local resourc... | Introduction
An embedded system's intrinsic real-time constraints are imposed on its external inputs and out-
puts, from the perspective of its environment. At the same time, the computation paths between
these end-points may flow through a large set of interacting components, hosted on a variety of
resources - and man... | distributed systems;embedded systems;soft real-time;statistical performance;design synthesis |
371529 | Implementing E-Transactions with Asynchronous Replication. | AbstractThis paper describes a distributed algorithm that implements the abstraction of e-Transaction: a transaction that executes exactly-once despite failures. Our algorithm is based on an asynchronous replication scheme that generalizes well-known active-replication and primary-backup schemes. We devised the algorit... | Introduction
Until very recently, three-tier architectures were at the leading edge of development. Only a few
tools supported them, and only a small number of production-level applications implemented them.
Three-tier applications are now becoming mainstream. They match the logical decomposition of
applications (prese... | transactions;exactly-once semantics;replication;fault-tolerance;end-to-end reliability |
371884 | The role of commutativity in constraint propagation algorithms. | Constraing propagation algorithms form an important part of most of the constraint programming systems. We provide here a simple, yet very general framework that allows us to explain several constraint propagation algorithms in a systematic way. In this framework we proceed in two steps. First, we introduce a generic ... | Introduction
Constraint programming in a nutshell consists of formulating and solving so-called
constraint satisfaction problems. One of the most important techniques developed in this
area is constraint propagation that aims at reducing the search space while maintaining
equivalence.
Constraint propagation is a very w... | constraint propagation;generic algorithms;commutativity |
372075 | Total System Energy Minimization for Wireless Image Transmission. | In this paper, we focus on the total-system-energy minimization of a wireless image transmission system including both digital and analog components. Traditionally, digital power consumption has been ignored in system design, since transmit power has been the most significant component. However, as we move to an era of... | Introduction
There is widespread use of portable wireless technology in the form of cellular phones, wireless
networks, wireless surveillance systems and other wireless devices. In order to avoid frequent
recharging and possible down-time, the power consumption of these systems must be minimized.
Currently, most low-po... | energy minimization;low power;joint source-channel coding;indoor wireless transmission |
372085 | Exploring Hypermedia Processor Design Space. | Distributed hypermedia systems that support collaboration are important emerging tools for creation, discovery, management and delivery of information. These systems are becoming increasingly desired and practical as other areas of information technologies advance. A framework is developed for efficiently exploring the... | Introduction
In the last decade multimedia services have found increase use in application systems such as education and
training, office and business, information and point of sales [26]. In the recent years, the wide spread use of the
World Wide Web has produced a fertile ground for multimedia services [4, 5].
Hyperm... | hypermedia processor;synthesis framework;workload characterization;instruction-level parallelism |
372816 | Rationalising the Renormalisation Method of Kanatani. | The renormalisation technique of Kanatani is intended to iteratively minimise a cost function of a certain form while avoiding systematic bias inherent in the common method of minimisation due to Sampson. Within the computer vision community, the technique has generally proven difficult to absorb. This work presents an... | Introduction
Many problems in computer vision are readily formulated as the need to minimise a
cost function with respect to some unknown parameters. Such a cost function will
often involve (known) covariance matrices characterising uncertainty of the data and
will take the form of a sum of quotients of quadratic forms... | maximum likelihood;covariance matrix;surface fitting;conic fitting;renormalisation;statistical methods;fundamental matrix estimation |
373294 | A model of OASIS role-based access control and its support for active security. | OASIS is a role-based access control architecture for achieving secure interoperation of services in an open, distributed environment. Services define roles and implement formally specified policy for role activation and service use; users must present the required credentials, in the specified context, in order to act... | INTRODUCTION
The growing interest in role-based access control (RBAC)
as an eective means of replacing traditional discretionary
and mandatory access control has led to the development of
several models over the past few years [20, 8, 16]. Besides
the basic structure of subject, role and privilege, they all
include a n... | RBAC;service level agreements;certificates;OASIS;policy;role based access control |
373399 | Hierarchical GUI Test Case Generation Using Automated Planning. | AbstractThe widespread use of GUIs for interacting with software is leading to the construction of more and more complex GUIs. With the growing complexity come challenges in testing the correctness of a GUI and its underlying software. We present a new technique to automatically generate test cases for GUIs that exploi... | Introduction
G RAPHICAL User Interfaces (GUIs) have become an
important and accepted way of interacting with to-
day's software. Although they make software easy to use
from a user's perspective, they complicate the software development
process [1], [2]. In particular, testing GUIs is
more complex than testing conventi... | GUI regression testing;automated test case generation;software testing;generating alternative plans;GUI testing;application of AI planning |
373425 | Robust Classification for Imprecise Environments. | In real-world environments it usually is difficult to specify target operating conditions precisely, for example, target misclassification costs. This uncertainty makes building robust classification systems problematic. We show that it is possible to build a hybrid classifier that will perform at least as well as the ... | Introduction
Traditionally, classification systems have been built by experimenting with many different classifiers, comparing
their performance and choosing the best. Experimenting with different induction algorithms, parameter settings,
and training regimes yields a large number of classifiers to be evaluated and com... | uncertainty;evaluation;classification;learning;multiple models;comparison;cost-sensitive learning;skewed distributions |
373433 | Margins for AdaBoost. | Recently ensemble methods like ADABOOST have been applied successfully in many problems, while seemingly defying the problems of overfitting.ADABOOST rarely overfits in the low noise regime, however, we show that it clearly does so for higher noise levels. Central to the understanding of this fact is the margin distrib... | Introduction
An ensemble is a collection of neural networks or other types of classifiers
(hypotheses) that are trained for the same task. Boosting and other ensemble
learning methods have been used recently with great success for
several applications, e. g. OCR [29, 16]. So far the reduction of the generalization
erro... | classification;support vectors;arcing;ADABOOST;soft margin;large margin |
373623 | Customer Retention via Data Mining. | ``Customer Retention'' is an increasingly pressing issue in today's ever-competitive commercial arena. This is especially relevant and important for sales and services related industries. Motivated by a real-world problem faced by a large company, we proposed a solution that integrates various techniques of data mi... | Introduction
In the last decade, the increased dependency and widespread use of
databases in almost every business, scientific and government organization
has led to an explosive growth of data. Instead of being blessed with
more information to aid decision making, the overwhelming amounts of
data have inevitably resul... | data mining;deviation analysis;customer retention;multiple level association rules;feature selection |
373655 | Cryptography in Quadratic Function Fields. | We describe several cryptographic schemes in quadratic function fields of odd characteristic. In both the real and the imaginary representation of such a field, we present a Diffie-Hellman-like key exchange protocol as well as a public-key cryptosystem and a signature scheme of ElGamal type. Several of these schem... | Introduction
Since the introduction of the well-known Diffie-Hellman key exchange protocol [16], many cryptographic
schemes based on discrete logarithms in a variety of groups (and even semi-groups) have been developed.
Among them, the signature scheme due to ElGamal [17], now the basis of the U.S. Digital Signature St... | ElGamal signature scheme;quadratic function field;public key cryptosystem;diffie-hellman key exchange protocol;discrete logarithm |
375420 | Slicing concurrent java programs. | Program slicing is an important approach to testing, understanding and maintaining programs. The paper presents a slicing algorithm for concurrent Java programs. Because the execution process of concurrent programs is unpredictable, there are many problems to be solved when slicing. To slice concurrent Java programs, w... | Introduction
Java is a new object-oriented programming language
and has achieved widespread acceptance because it emphasizes
portability. Java has multithreading capabilities
for concurrent programming. To provide synchronization
between asynchronously running threads, the
Java language and runtime system uses monitors... | program slicing;concurrent program dependence graph;concurrent control flow graph |
375508 | Efficient Detection of Vacuity in Temporal Model Checking. | The ability to generate a counter-example is an important feature of model checking tools, because a counter-example provides information to the user in the case that the formula being checked is found to be non-valid. In this paper, we turn our attention to providing similar feedback to the user in the case that the f... | Introduction
The ability to generate a counter-example is an important feature of model checking
tools, because a counter-example provides information to the user in the case that the
formula being checked is found to be non-valid. In this paper, we turn our attention
to providing similar feedback to the user in the ca... | model checking;interesting witness;formal verification;vacuity;temporal logic |
375681 | Main-memory index structures with fixed-size partial keys. | The performance of main-memory index structures is increasingly determined by the number of CPU cache misses incurred when traversing the index. When keys are stored indirectly, as is standard in main-memory databases, the cost of key retrieval in terms of cache misses can dominate the cost of an index traversal. Yet i... | INTRODUCTION
Following recent dramatic reductions, random access memory
(RAM) is competitive in price with the disk storage of a few years
ago. With multi-gigabyte main memories easily affordable and expandable
(on 64-bit architectures), applications with as much as 1
or 2 GB of data in main memory can be built with re... | key compression;b-trees;cache coherence;main-memory indices;t-tree |
375684 | Efficient and effective metasearch for text databases incorporating linkages among documents. | Linkages among documents have a significant impact on the importance of documents, as it can be argued that important documents are pointed to by many documents or by other important documents. Metasearch engines can be used to facilitate ordinary users for retrieving information from multiple local sources (text datab... | The Internet has become a vast information resource in recent years. To help ordinary users find
desired data in this environment, many search engines have been created. Each search engine has
a text database that is defined by the set of documents that can be searched by the search engine.
Usually, an inverted file in... | metasearch;linkages among documents;information retrieval;distributed collection |
375760 | Causality representation and cancellation mechanism in time warp simulations. | The Time Warp synchronization protocol allows causality errors and then recovers from them with the assistance of a cancellation mechanism. Cancellation can cause the rollback of several other simulation objects that may trigger a cascading rollback situation where the rollback cycles back to the original simulation ob... | Introduction
Rollback is an inherent operation in the Time Warp
mechanism. Rollback restores the state of an LP to a
causally consistent state from which normal event processing
can continue. During cancellation, rollbacks occurring
in one LP can propagate to other LPs to cancel out causally
incorrect event computation... | time warp;logical time;vector clocks;virtual time |
375847 | Concurrent threads and optimal parallel minimum spanning trees algorithm. | This paper resolves a long-standing open problem on whether the concurrent write capability of parallel random access machine (PRAM) is essential for solving fundamental graph problems like connected components and minimum spanning trees in O(logn) time. Specifically, we present a new algorithm to solve these problems ... | INTRODUCTION
Given a weighted undirected graph G with n vertices and m edges, the minimum
spanning tree (MST) problem is to nd a spanning tree (or spanning forest) of G
with the smallest possible sum of edge weights. This problem has a rich history.
A preliminary version of this paper appeared in the proceedings of the... | minimum spanning trees;parallel algorithms;EREW PRAM;connected components |
375862 | An Efficient Algorithm for Aggregating PEPA Models. | AbstractPerformance Evaluation Process Algebra (PEPA) is a formal language for performance modeling based on process algebra. It has previously been shown that, by using the process algebra apparatus, compact performance models can be derived which retain the essential behavioral characteristics of the modeled system. ... | Introduction
In recent years several Markovian process algebras (MPAs) have been presented
in the literature. These include PEPA [1], MTIPP [2], and EMPA [3].
As with classical process algebras, these formalisms allow models of systems
to be constructed which are amenable to functional or behavioural analysis
by a vari... | stochastic process algebras;performance modeling;performance evaluation tools;model aggregation |
376307 | Social role awareness in animated agents. | This paper promotes {\itshape social role awareness\/} as a desirable capability of animated agents, that are by now strong affective reasoners, but otherwise often lack the social competence observed with humans. In particular, humans may easily adjust their behavior depending on their respective role in a socio-organ... | INTRODUCTION
Ever since Bates and Reilly promoted believable agents in
their 'Oz project' [2], there has been continued interest to
give animated agents the illusion of life. It is now widely accepted
that emotion expression and personality are key components
of believable agents. Moreover, Cassell and her co-workers
r... | social dimension in communication;believability;human-like qualities of synthetic agents;affective reasoning and emotion expression;social agents |
376477 | A knowledge level software engineering methodology for agent oriented programming. | Our goal in this paper is to introduce and motivate a methodology, called \emph{Tropos}, for building agent oriented software systems. Tropos is based on two key ideas. First, the notion of agent and all the related mentalistic notions (for instance: beliefs, goals, actions and plans) are used in all phases of software... | INTRODUCTION
Agent oriented programming (AOP, from now on) is most
often motivated by the need of open architectures that continuously
change and evolve to accommodate new components
and meet new requirements. More and more, software
must operate on different platforms, without recompilation,
and with minimal assumptio... | agent-based software engineering;design methodologies |
376519 | A Maximum-Likelihood Strategy for Directing Attention during Visual Search. | AbstractA precise analysis of an entire image is computationally wasteful if one is interested in finding a target object located in a subregion of the image. A useful attention strategy can reduce the overall computation by carrying out fast but approximate image measurements and using their results to suggest a promi... | Introduction
Object recognition algorithms often have two phases: a selection phase where a region (or a subset of image
features) is chosen, and a verication phase where the algorithm veries whether the object is present in the
chosen region. The algorithm speed depends on the strategy used for selecting regions. We c... | object recognition;visual search;attention |
377018 | A Cost Model for Selecting Checkpoint Positions in Time Warp Parallel Simulation. | AbstractRecent papers have shown that the performance of Time Warp simulators can be improved by appropriately selecting the positions of checkpoints, instead of taking them on a periodic basis. In this paper, we present a checkpointing technique in which the selection of the positions of checkpoints is based on a chec... | the execution of events at each LP (this is also referred to as causality). These mechanisms are,
in general, conservative or optimistic. The conservative ones enforce causality by requiring LPs to
block until certain safety criteria are met. Instead, in the optimistic mechanisms, events may be
executed in violation of... | rollback-recovery;checkpointing;time warp;performance optimization;optimistic synchronization;cost models;parallel discrete-event simulation |
377030 | A Framework for Integrating Data Alignment, Distribution, and Redistribution in Distributed Memory Multiprocessors. | AbstractParallel architectures with physically distributed memory provide a cost-effective scalability to solve many large scale scientific problems. However, these systems are very difficult to program and tune. In these systems, the choice of a good data mapping and parallelization strategy can dramatically improve t... | Introduction
The increasing availability of massively parallel computers composed of a large number
of processing nodes is far from being matched by the availability of programming models
and software tools that enable users to get high levels of performance out of these systems.
The proliferation of small and medium-s... | loop parallelization;linear 0-1 integer programming;distribution;distributed-memory multiprocessor;automatic data mapping;performance prediction;redistribution;alignment |
377264 | Local Encoding Transformations for Optimizing OBDD-Representations of Finite State Machines. | Ordered binary decision diagrams are the state-of-the-art representation of switching functions. In order to keep the sizes of OBDDs tractable, heuristics and dynamic reordering algorithms are applied to optimize the underlying variable order. When finite state machines are represented by OBDDs the state encoding can b... | Introduction
Ordered binary decision diagrams (OBDDs) which have been introduced by Bryant [Bry86]
provide an efficient graph-based data structure for switching functions. The main optimization
parameter of OBDDs is the underlying variable order. In order to find a good order
two techniques were applied so far: the use... | local transformation;OBDD;state encoding;finite state machine;ordered binary decision diagram |
377806 | Data locality enhancement by memory reduction. | In this paper, we propose memory reduction as a new approach to data locality enhancement. Under this approach, we use the compiler to reduce the size of the data repeatedly referenced in a collection of nested loops. Between their reuses, the data will more likely remain in higher-speed memory devices, such as the cac... | INTRODUCTION
Compiler techniques, such as tiling [29, 30], improves temporal
data locality by interchanging the nesting order of time-
iterative loops and array-sweeping loops. Unfortunately,
data dependences in many programs often prevent such loop
interchange. Therefore, it is important to seek locality enhancement
t... | loop fusion;data locality;loop shifting;array contraction |
377895 | Optimizing threaded MPI execution on SMP clusters. | Our previous work has shown that using threads to execute MPI programs can yield great performance gain on multiprogrammed shared-memory machines. This paper investigates the design and implementation of a thread-based MPI system on SMP clusters. Our study indicates that with a proper design for threaded MPI execution,... | INTRODUCTION
With the commercial success of SMP architectures, SMP
clusters with commodity components have been widely deployed
for high performance computing due to the great
economic advantage of clustering [1, 2]. MPI is a message-passing
standard [14] widely used for high-performance parallel
applications and has b... | SMP clusters;multi-threading;communication optimization;MPI |
377896 | Demonstrating the scalability of a molecular dynamics application on a Petaflop computer. | The IBM Blue Gene project has endeavored into the development of a cellular architecture computer with millions of concurrent threads of execution. One of the major challenges of this project is demonstrating that applications can successfully exploit this massive amount of parallelism. Starting from the sequential ver... | INTRODUCTION
Now that several Teraflop-scale machines have been deployed in
various industrial, governmental, and academic sites, the high performance
computing community is starting to look for the next
big step: Petaflop-scale machines. At least two very different approaches
have been advocated for the development of... | massively parallel computing;performance evaluation;blue gene;cellular architecture;molecular dynamics |
377938 | Analysis of the Xedni Calculus Attack. | The xedni calculus attack on the elliptic curve discrete logarithm problem (ECDLP) involves lifting points from the finite field{\Bbb F}_p to the rational numbers {\Bbb Q} and then constructing an elliptic curve over {\Bbb Q} that passes through them. If the lifted points are linearly dependent, then the ECDLP is solve... | Introduction
At the Second Elliptic Curve Cryptography Workshop (University of Waterloo, September 14-16,
1998), Joseph Silverman announced a new attack on the elliptic curve discrete logarithm problem
(ECDLP) over a prime field F p . He called his method "xedni calculus" because it "stands index
calculus on its head."... | xedni calculus;discrete logarithm;elliptic curve |
377993 | Weak alternating automata are not that weak. | Automata on infinite words are used for specification and verification of nonterminating programs. Different types of automata induce different levels of expressive power, of succinctness, and of complexity. Alternating automata have both existential and universal branching modes and are particularly suitable for speci... | INTRODUCTION
Finite automata on innite objects were rst introduced in the 60's. Motivated
by decision problems in mathematics and logic, Buchi, McNaughton, and Rabin
developed a framework for reasoning about innite words and innite trees [Buchi
1962; McNaughton 1966; Rabin 1969]. The framework has proved to be very pow... | weak alternating automata;complementation |
378045 | Fast and Accurate Algorithms for Projective Multi-Image Structure from Motion. | AbstractWe describe algorithms for computing projective structure and motion from a multi-image sequence of tracked points. The algorithms are essentially linear, work for any motion of moderate size, and give accuracies similar to those of a maximum-likelihood estimate. They give better results than the Sturm/Triggs f... | Introduction
This paper extends our previous multi-image structure-from-motion (SFM) algorithms [18][26][16] [24] from
the Euclidean to the projective context. Previously, we assumed that the camera calibration was known and
fixed; the new versions of our algorithms handle sequences with varying and unknown calibration... | structure from motion;linear algorithms;bundle adjustment;shape from X;sturm/triggs factorization;low level vision;dominant plane;factorization;projective geometry;projective multiframe structure from motion |
378060 | Dimensionality Reduction in Unsupervised Learning of Conditional Gaussian Networks. | AbstractThis paper introduces a novel enhancement for unsupervised learning of conditional Gaussian networks that benefits from feature selection. Our proposal is based on the assumption that, in the absence of labels reflecting the cluster membership of each case of the database, those features that exhibit low correl... | Introduction
One of the basic problems that arises in a great variety of elds, including pattern
recognition, machine learning and statistics, is the so-called data clustering problem
[1, 2, 10, 11, 18, 22]. Despite the dierent interpretations and expectations it gives rise
to, the generic data clustering problem invol... | data clustering;edge exclusion tests;conditional Gaussian networks;feature selection |
378472 | An efficient algorithm for finding the CSG representation of a simple polygon. | We consider the problem of converting boundary representations of polyhedral objects into constructive-solid-geometry (CSG) representations. The CSG representations for a polyhedron P are based on the half-spaces supporting the faces of P. For certain kinds of polyhedra this problem is equivalent to the corresponding p... | desirable that such representations be compact and support efficient simulation of real-world
operations on the objects. Over the years two different styles of representation have
emerged; these are used by nearly all geometric modeling systems currently in existence.
The first style of representation describes an obje... | boundary-to-CSG conversion algorithms;solid modeling;simple polygons;constructive solid geometry |
378636 | Nice point sets can have nasty Delaunay triangulations. | We consider the complexity of Delaunay triangulations of sets of point s in $\Real^3$ under certain practical geometric constraints. The \emph{spread} of a set of points is the ratio between the longest and shortest pairwise distances. We show that in the worst case, the Delaunay triangulation of $n$ points in~$\Real^... | Introduction
Delaunay triangulations and Voronoi diagrams are used as a fundamental tool in several geometric
application areas, including nite-element mesh generation [17, 25, 37, 40], deformable surface
modeling [16], and surface reconstruction [1, 3, 4, 5, 12, 35]. Many algorithms in these application
domains begin ... | delaunay triangulation;sample measure;sample;spread;lower bounds;surface reconstruction |
378824 | The structural cause of file size distributions. | We propose a user model that explains the shape of the distribution of file sizes in local file systems and in the World Wide Web. We examine evidence from 562 file systems, 38 web clients and 6 web servers, and find that the model is a good description of these systems. These results cast doubt on the widespread view ... | Introduction
Numerous studies have reported traffic patterns in the Internet
that show characteristics of self-similarity (see [17]
for a survey). Most proposed explanations are based on the
assumption that the distribution of transfer times in the net-work
is long-tailed [19] [18] [22] [12]. In turn, this assumption
i... | file sizes;long-tailed distributions;self-similarity |
379527 | Performance and fluid simulations of a novel shared buffer management system. | We consider a switching system that has multiple ports that share a common buffer, in which there is a FIFO logical queue for each port. Each port may support a large number of flows or connections, which are approximately homogeneous in their statistical characteristics, with common QoS requirements in cell loss and m... | Introduction
This paper considers a model of a switching node shown
in
Figure
1, which has multiple(N ) ports with bandwidths
that share a common buffer of size B. In the
shared buffer there is a FIFO logical queue implemented as
a linked-list for each port. Each port may support a large
number of flows or connection... | buffer management;fluid simulations;virtual partitioning |
379528 | Estimating small cell-loss ratios in ATM switches via importance sampling. | The cell-loss ratio at a given node in an ATM switch, defined as the steady-state fraction of packets of information that are lost at that node due to buffer overflow, is typically a very small quantity that is hard to estimate by simulation. Cell losses are rare events, and importance sampling is sometimes the appropr... | INTRODUCTION
An Asynchronous Transfer Mode (ATM) communication switch can be modeled as
a network of queues with finite bu#er sizes. Packets of information (called cells)
join the network from several sources according to stochastic processes, and some
cells may be lost due to bu#er overflow. The long-term (or steady-s... | variance reduction;importance sampling;ATM;rare events |
379727 | Creating trading networks of digital archives. | Digital archives can best survive failures if they have made several c opies of their collections at remote sites. In this paper, we discuss how autonomous sites can cooperate to provide preservation by trading data. We examine the decisions that an archive must make when forming trading networks, such as the amount of... | INTRODUCTION
Digital materials are vulnerable to a number of different
kinds of failures, including decay of the digital media, loss
due to hackers and viruses, accidental deletions, natural dis-
asters, and bankruptcy of the institution holding the collec-
tion. Archives can protect digital materials by making several... | digital archiving;replication;data trading;preservation;fault tolerance |
379790 | Parallel Implementation of a Central Decomposition Method for Solving Large-Scale Planning Problems. | We use a decomposition approach to solve three types of realistic problems: block-angular linear programs arising in energy planning, Markov decision problems arising in production planning and multicommodity network problems arising in capacity planning for survivable telecommunication networks. Decomposition is an al... | Introduction
Despite all recent progresses in optimization algorithms and in hardware, model builders
keep on generating larger and larger optimization models that challenge the best existing
technology. This is particularly true in the area of planning problems where the quest for
more realism in the description of th... | cutting plane method;parallel computation;analytic center;decomposition;real-life problems |
380322 | Efficient Local Search for DAG Scheduling. | AbstractScheduling DAGs to multiprocessors is one of the key issues in high-performance computing. Most realistic scheduling algorithms are heuristic and heuristic algorithms often have room for improvement. The quality of a scheduling algorithm can be effectively improved by a local search. In this paper, we present a... | Introduction
Scheduling computations onto processors is one of the crucial components of a parallel processing
environment. They can be performed at compile-time or runtime. Scheduling performed
at compile-time is called static scheduling; scheduling performed at runtime is called dynamic
scheduling. The
exibility inhe... | multiprocessors;fast local search;complexity;quality;DAG scheduling |
380864 | On optimal slicing of parallel programs. | Optimal program slicing determines for a statement S in a program &pgr; whether or not S affects a specified set of statements, given that all conditionals in &pgr; are interpreted as non-deterministic choices.Only recently, it has been shown that reachability of program points and hence also optimal slicing is undecid... | INTRODUCTION
Static program slicing [27] is an established program reduction
technique that has applications in program under-
standing, debugging, and testing [26]. More recently, it has
also been proposed as a technique for ameliorating the state-explosion
problem when formally verifying software or hardware
[13, 10,... | parallel programs;undecidability;complexity;interprocedural analysis;slicing |
381455 | A polynomial-time approximation scheme for base station positioning in UMTS networks. | We consider the following optimization problem for UMTS networks: For a specified teletraffic demand and possible base station locations, choose positions for base stations such that the construction costs are below a given limit, as much teletraffic as possible is supplied, the ongoing costs are minimal, and the intr... | Introduction
1.1 CDMA Networks
During the planning stage for a new cellular network, one of the main tasks for a provider is
to decide where to place the base stations (i.e., the antennas). In order to accomplish this, data
about the expected teletrac demand is needed. A widely accepted way of describing phone trac
qua... | approximation algorithms;network design |
381497 | Encoding program executions. | Dynamic analysis is based on collecting data as the program runs. However, raw traces tend to be too voluminous and too unstructured to be used directly for visualization and understanding. We address this problem in two phases: the first phase selects subsets of the data and then compacts it, while the second phase en... | KEYWORDS
Software understand, Program tracing, Dynamic program
analysis
Software understanding requires inferring the behavior of
software systems. Static techniques do this by analyzing the
program's code, while dynamic techniques are based on running
the program, collecting data as it runs, and then analyzing
the res... | program tracing;software understand;dynamic program analysis |
382913 | Role-based authorization constraints specification. | Constraints are an important aspect of role-based access control (RBAC) and are often regarded as one of the principal motivations behind RBAC. Although the importance of contraints in RBAC has been recogni zed for a long time, they have not recieved much attention. In this article, we introduce an intuitive formal lan... | INTRODUCTION
Role-based access control (RBAC) has emerged as a widely accepted alternative to
classical discretionary and mandatory access controls [Sandhu et al. 1996]. Several
models of RBAC have been published and several commercial implementations are
available. RBAC regulates the access of users to information and... | authorization constraints;constraints specification;access control models;role-based access control |
383040 | Query-based sampling of text databases. | The proliferation of searchable text databases on corporate networks and the Internet causes a database selection problem for many people. Algorithms such as gGLOSS and CORI can automatically select which text databases to search for a given information need, but only if given a set of resource descriptions that accura... | Table
1.
Size, Size,
Name in bytes in documents
CACM 2MB 3,204
Test corpora.
Size, Size,
in unique in total
terms terms Variety
6,468 117,473 homogeneous
122,807 9,723,528 heterogeneous
very heterogenenous
of these choices is deferred to later sections of the paper.
How best to represent a large document database is a... | resource selection;resource ranking;server selection;distributed information retrieval;query-based sampling |
383081 | Extending equation-based congestion control to multicast applications. | In this paper we introduce TFMCC, an equation-based multicast congestion control mechanism that extends the TCP-friendly TFRC protocol from the unicast to the multicast domain. The key challenges in the design of TFMCC lie in scalable round-trip time measurements, appropriate feedback suppression, and in ensuring that ... | Introduction
It is widely accepted that one of several factors inhibiting the
usage of IP multicast is the lack of good, deployable, well-tested
multicast congestion control mechanisms. To quote
[10]:
The success of the Internet relies on the fact that best-effort
traffic responds to congestion on a link by reducing
th... | feedback;TCP-friendliness;single-rate;congestion control;suppression;multicast |
383193 | Hash based parallel algorithms for mining association rules. | In this paper, we propose four parallel algorithms (NPA, SPA, HPA and HPA-ELD) for mining association rules on shared-nothing parallel machines to improve its performance. In NPA, candidate itemsets are just copied amongst all the processors which can lead to memory overflow for large transaction databases. The remain... | Introduction
Recently, "Database Mining" has begun to attract
strong attention. Because of the progress of bar-code
technology, point-of-sales systems in retail company
become to generate large amount of transaction data,
but such data being archived and not being used effi-
ciently. The advance of microprocessor and s... | memory overflow;shared nothing environment;SPA;memory space;performance evaluations;knowledge acquisition;hash function;broadcasting;candidate itemsets;large transaction databases;HPA;NPA;HPA-ELD;hash based parallel algorithms;shared nothing parallel machines;association rule mining |
383198 | Querying the World Wide Web. | The World Wide Web is a large, heterogeneous, distributed collection of documents connected by hypertext links. The most common technology currently used for searching the Web depends on sending information retrieval requests to index servers. One problem with this is that these queries cannot exploit the structure and... | Introduction
The World Wide Web[BLCL + 94] is a large, heteroge-
neous, distributed collection of documents connected by
hypertext links. Current practice for finding documents
of interest depends on browsing the network by following
links and searching by sending information retrieval
requests to "index servers" that ... | hypermedia;web searching;query cost;query locality;WebSQL query language;large heterogeneous distributed document collection;hypertext links;formal semantics;information retrieval requests;textual retrieval;virtual graph model;document network;topology-based queries;multiple index servers;calculus;World Wide Web queryi... |
383204 | The Strobe algorithms for multi-source warehouse consistency. | A warehouse is a data repository containing integrated information for efficient querying and analysis. Maintaining the consistency of warehouse data is challenging, especially if the data sources are autonomous and views of the data at the warehouse span multiple sources. Transactions containing multiple updates at on... | Introduction
A data warehouse is a repository of integrated information
from distributed, autonomous, and possibly
heterogeneous, sources. Figure 1 illustrates the
basic warehouse architecture. At each source, a monitor
collects the data of interest and sends it to the
warehouse. The monitors are responsible for identi... | strobe algorithms;batch updates;overlapping update stream;incremental algorithms;integrated information;multi-source warehouse consistency;continuous update stream;transaction processing scenarios;efficient querying;multiple updates;efficient analysis;warehouse data consistency maintenance;very large databases;data rep... |
383205 | Making views self-maintainable for data warehousing. | A data warehouse stores materialized views over data from one or more sources in order to provide fast access to the integrated data, regardless of the availability of the data sources. Warehouse views need to be maintained in response to changes to the base data in the sources. Except for very simple views, maintainin... | Introduction
The problem of materialized view maintenance has
received increasing attention recently [6, 7, 11], particularly
due to its application to data warehousing
[3, 14]. A view is a derived relation defined in
terms of base relations. A view is said to be materialized
when it is stored in the database, rather
t... | select-project-join view;warehouse view;materialized views;data integrity;key integrity constraints;auxiliary data storage;materialized view maintenance;fast integrated data access;referential integrity constraints;data source querying;auxiliary views;self-maintainable views;data warehousing |
383209 | Scrambling query plans to cope with unexpected delays. | Accessing data from numerous widely-distributed sources poses significant new challenges for query optimization and execution. Congestion and failures in the network can introduce highly-variable response times for wide-area data access. This paper is an initial exploration of solutions to this variability. We introduc... | Introduction
Ongoing improvements in networking technology
and infrastructure have resulted in a dramatic increase
in the demand for accessing and collating data
from disparate, remote data sources over wide-area
networks such as the Internet and intranets. Query
optimization and execution strategies have long been
stu... | run time query plan modification techniques;highly variable response times;query optimization;wide area data access;remote sources;missing data;query plan scrambling;unexpected delays;data access;initial requested tuples;widely distributed sources;query processing |
383210 | Building regression cost models for multidatabase systems. | A major challenge for performing global query optimization in a multidatabase system (MDBS) is the lack of cost models for local database systems at the global level. In this paper we present a statistical procedure based on multiple regression analysis for building cost models for local database systems in an MDBS. Ex... | Introduction
A multidatabase system (MDBS) integrates information
from pre-existing local databases managed by
heterogeneous database systems (DBS) such as OR-
ACLE, DB2 and EMPRESS. A key feature of an
MDBS is the local autonomy that each local database
retains to manage its data and serve its existing ap-
plications.... | cost estimation;cost model;global query optimization;multidatabase system;multiple regression |
383258 | Integrated test of interacting controllers and datapaths. | In systems consisting of interacting datapaths and controllers and utilizing built-in self test (BIST), the datapaths and controllers are traditionally tested separately by isolating each component from the environment of the system during test. This work facilitates the testing of datapath/controller pairs in an integ... | INTRODUCTION
Systems consisting of interacting datapaths and controllers are typically designed by
synthesizing and testing the datapath and controller independently, even though
the two operate as an inseparable pair. This separation can cause difficulties in
even if the datapath and controller are designed such that ... | built-in self-test;register transfer level;synthesis-for-testability |
383271 | A signal-processing framework for inverse rendering. | Realism in computer-generated images requires accurate input models for lighting, textures and BRDFs. One of the best ways of obtaining high-quality data is through measurements of scene attributes from real photographs by inverse rendering. However, inverse rendering methods have been largely limited to settings with ... | Introduction
To create a realistic computer-generated image, we need both
an accurate, physically-based rendering algorithm and a detailed
model of the scene including light sources and objects specified
by their geometry and material properties-texture and reflectance
(BRDF). There has been substantial progress in the... | light field;irradiance;inverse rendering;illumination;BRDF;radiance;spherical harmonics;signal processing |
383321 | Synthesizing sounds from physically based motion. | This paper describes a technique for approximating sounds that are generated by the motions of solid objects. The technique builds on previous work in the field of physically based animation that uses deformable models to simulate the behavior of the solid objects. As the motions of the objects are computed, their surf... | Figure
1: The top image shows a multi-exposure image from an
animation of a metal bowl falling onto a hard surface. The lower
image shows a spectrogram of the resulting audio for the first five
impacts.
Although the field of computer graphics traditionally focuses on
generating visuals, our perception of an environmen... | animation techniques;finite element method;physically based modeling;sound modeling;simulation;dynamics;surface vibrations |
383594 | Stochastic control of path optimization for inter-switch handoffs in wireless ATM networks. | One of the major design issues in wireless ATM networks is the support of Inter-switch handoffs. An inter-switch handoff occurs when a mobile terminal moves to a new base station connecting a different switch. Apart from resource allocation at the new base station, inter-switch handoff also requires connection rerouti... | Figure
1 (b), the switch chosen to perform this function is usually referred to as the crossover switch
[5]. Depending on the performance criteria of the crossover switch discovery algorithms [5]-[6], the end-
to-end path after rerouting may not be optimal. In this paper, we define an optimal path as the best path
amo... | path optimization;inter-switch bandoff;connection rerouting;wireless ATM |
383741 | A recursive formulation of Cholesky factorization of a matrix in packed storage. | A new compact way to store a symmetric or triangular matrix called RPF for Recursive Packed Format is fully described. Novel ways to transform RPF to and from standard packed format are included. A new algorithm, called RPC for Recursive Packed Cholesky, that operates on the RPG format is presented. ALgorithm RPC is ba... | Introduction
A very important class of linear algebra problems are those in which the coefcient
matrix A is symmetric and positive denite [5, 11, 23]. Because of the
symmetry it is only necessary to store either the upper or lower triangular part
of the matrix.
Lower triangular caseB
7 14 21 28
Upper triangular caseB
4... | complex Hermitian matrices;cholesky factorization and solution;real symmetric matrices;recursive algorithms;novel packed matrix data structures;BLAS;positive definite matrices |
383755 | Flexible network support for mobile hosts. | Fueled by the large number of powerful light-weight portable computers, the expanding availability of wireless networks, and the popularity of the Internet, there is an increasing demand to connect portable computers to the Internet at any time and in any place. However, the dynamic nature of a mobile host's connectivi... | Introduction
Light-weight portable computers, the spread of wireless networks and services, and the popularity of
the Internet combine to make mobile computing an attractive goal. With these technologies, users should
be able to connect to the Internet at any time and in any place, to read email, query databases, retri... | multiple packet delivery methods;multiple network interfaces;mobility support;mobile IP;mobile policy table |
383761 | A distributed mechanism for power saving in IEEE 802.11 wireless LANs. | The finite battery power of mobile computers represents one of the greatest limitations to the utility of portable computers. Furthermore, portable computers often need to perform power consuming activities, such as transmitting and receiving data by means of a random-access, wireless channel. The amount of power consu... | Introduction
The finite battery power of mobile computers represents one of the greatest limitations to the
utility of portable computers [10, 17]. Projections on the expected progress in battery technology
show that only a 20% improvement in the battery capacity is likely to occur over the next 10 years
[14]. Despite ... | power saving;IEEE 80211;analytical modelling;simulation;wireless networks |
383762 | Transmission-efficient routing in wireless networks using link-state information. | The efficiency with which the routing protocol of a multihop packet-radio network uses transmission bandwidth is critical to the ability of the network nodes to conserve energy. We present and verify the source-tree adaptive routing (STAR) protocol, which we show through simulation experiments to be far more efficient ... | Introduction
Multi-hop packet-radio networks, or ad-hoc networks, consist of mobile hosts interconnected by routers
that can also move. The deployment of such routers is ad-hoc and the topology of the network is very
dynamic, because of host and router mobility, signal loss and interference, and power outages. In addit... | mobile wireless networks;source routing tree;link-state routing protocol |
383773 | ad hoc multicast routing with mobility prediction. | An ad hoc wireless network is an infrastructureless network composed of mobile hosts. The primary concerns in ad hoc networks are bandwidth limitations and unpredictable topology changes. Thus, efficient utilization of routing packets and immediate recovery of route breaks are critical in routing and multicasting proto... | Introduction
An ad hoc network is a dynamically reconfigurable
wireless network with no fixed infrastructures. Each
host acts as a router and moves in an arbitrary man-
ner. Ad hoc networks are deployed in applications such
as disaster recovery and distributed collaborative com-
puting, where routes are mostly multihop... | ad hoc networks;mobile computing;multicast and routing protocols;mobility prediction |
383780 | On knowledge-based programming with sensing in the situation calculus. | We consider a class of knowledge-based Golog programs with sense actions. These programs refer explicitly to an agent's knowledge, and are designed to execute on-line, and under a dynamic closed-world assumption on knowledge. On-line execution of sense actions dynamically updates the background axioms with sentences as... | INTRODUCTION
Our concern will be with knowledge-based programs, specically, Golog programs
[Levesque et al. 1997] that appeal to knowledge and actions, including sense actions.
As an example, we consider the blocks world, and a program that explicitly refers to
an agent's knowledge, and to the sense actions she can per... | situation calculus;situation calculus programming languages;dynamic closed-world assumption;theorem-proving;sensing and knowledge |
383892 | Querying ATSQL databases with temporal logic. | We establish a correspondence between temporal logic and a subset of ATSQL, a temporal extension of SQL-92. In addition, we provide an effective translation from temporal logic to ATSQL that enables a user to write high-level queries which are then evaluated against a space-efficient representation of the database. A r... | Introduction
This paper brings together two research directions in temporal databases. The first direction is concerned
with temporal extensions to practical query languages such as SQL [Gad93, NA93, Sar93].
The issues addressed include space-efficient storage, effective implementation techniques and handling
of large ... | first-order temporal logic;ATSQL;query translation;temporal databases |
384000 | The do-all problem in broadcast networks. | The problem of performing t tasks in a distributed system on p failure-prone processors is one of the fundamental problems in distributed computing. If the tasks are similar and independent and the processors communicate by sending messages then the problem is called Do-All. In our work the communication is over a mult... | INTRODUCTION
We consider a distributed system in which p processors need
to perform t tasks. If the processors communicate by exchanging
messages, are prone to failures, and the tasks are
similar and independent then this problem is called Do-All .
In this paper we consider a setting in which the processors
are station... | fail-stop failures;independent tasks;multiple-access channel;lower bound;adversary;distributed algorithm |
384010 | On scalable and efficient distributed failure detectors. | Process groups in distributed applications and services rely on failure detectors to detect process failures completely, and as quickly, accurately, and scalably as possible, even in the face of unreliable message deliveries. In this paper, we look at quantifying the optimal scalability, in terms of network load, (in m... | INTRODUCTION
Failure detectors are a central component in fault-tolerant
distributed systems based on process groups running over
unreliable, asynchronous networks eg., group membership
protocols [3], supercomputers, computer clusters [13], etc.
The ability of the failure detector to detect process failures
completely ... | scalability;failure detectors;efficiency;distributed systems;accuracy |
384052 | A framework for semantic reasoning about Byzantine quorum systems. | We have defined a class of shared variables called TS-variables that includes those implemented by the various Byzantine quorum system constructions of Malkhi and Reiter, and developed a number of definitions and theorems enabling us to reason about these variables abstractly. Using these tools, we have reduced the pro... | Introduction
Byzantine quorum systems [MR98a] are a promising approach to the problem of e-ciently implementing
Byzantine fault-tolerant data services. There are several variations on this approach [Baz97, MRWr97,
MRW97, MR98a], but the basic concept is the same for all of them: data are maintained simultaneously
at mu... | distributed data services;atomic variable semantics;byzantine fault tolerance;quorum systems |
384178 | Combined tuning of RF power and medium access control for WLANS. | Mobile communications, such as handhelds and laptops, still suffer from short operation time due to limited battery capacity. We exploit the approach of protocol harmonization to extend the time between battery charges in mobile devices using an IEEE 802.11 network interface. Many known energy saving mechanisms only co... | Introduction
Reduction of energy consumption for mobile devices
is an emerging eld of research and engineering. The
driving factors are the weight and time in operation of
mobile devices, which should be small and should allow
for a long operation time, respectively. The weight
is determined to a large extent by the ba... | power saving;MAC;IEEE 80211;retransmission;protocol harmonization;energy saving;power control;vertical optimization;WLAN |
384218 | Compiler Design for an Industrial Network Processor. | One important problem in code generation for embedded processors is the design of efficient compilers for ASIPs with application specific architectures. This paper outlines the design of a C compiler for an industrial ASIP for telecom applications. The target ASIP is a network processor with special instructions for bi... | INTRODUCTION
The use of application specic instruction set processors
(ASIPs) in embedded system design has become quite com-
mon. ASIPs are located between standard "o-the-shelf"
programmable processors and custom ASICs. Hence, ASIPs
represent the frequently needed compromise between high
e-ciency of ASICs and low dev... | compilers;embedded processors;network processors |
384245 | Improving memory performance of sorting algorithms. | Memory hierarchy considerations during sorting algorithm design and implementation play an important role in significantly improving execution performance. Existing algorithms mainly attempt to reduce capacity misses on direct-mapped caches. To reduce other types of cache misses that occur in the more common set-associ... | INTRODUCTION
Sorting operations are fundamental in many large scale scientific and commercial
applications. Sorting algorithms are highly sensitive to the memory hierarchy of
the computer architecture on which the algorithms are executed, as well as sensitive
to the types of data sets. Restructuring standard and algori... | mergesort;memory performance;quicksort;caches;TLB |
384248 | Finding the right cutting planes for the TSP. | Given an instance of the Traveling Salesman Problem (TSP), a reasonable way to get a lower bound on the optimal answer is to solve a linear programming relaxation of an integer programming formulation of the problem. These linear programs typically have an exponential number of constraints, but in theory they can be so... | Introduction
Given some set of locations and a distance function, the Traveling Salesman
Problem (TSP) is to find the shortest tour, i.e., simple cycle through all of the
locations. This problem has a long history (see, e.g. [11]) and is a famous example
of an NP-hard problem. Accordingly, there is also a long history ... | combinatorial optimization;performance;experimentation;algorithms;minimum cut;traveling salesman problem;cutting plane |
384249 | Fast priority queues for cached memory. | The cache hierarchy prevalent in todays high performance processors has to be taken into account in order to design algorithms that perform well in practice. This paper advocates the adaption of external memory algorithms to this purpose. This idea and the practical issues involved are exemplified by engineering a fast... | Introduction
The mainstream model of computation used by algorithm designers in the last
half century [18] assumes a sequential processor with unit memory access cost.
However, the mainstream computers sitting on our desktops have increasingly
deviated from this model in the last decade [10, 11, 13, 17, 19]. In particu... | implementation;data structure;external memory;priority queue;cache;cache efficiency;multi way merging;secondary storage |
500150 | Motion-based segmentation and contour-based classification of video objects. | The segmentation of objects in video sequences constitutes a prerequisite for numerous applications ranging from computer vision tasks to second-generation video coding.We propose an approach for segmenting video objects based on motion cues. To estimate motion we employ the 3D structure tensor, an operator that provid... | INTRODUCTION
Video object segmentation is required by numerous applications
ranging from high-level vision tasks to second-generation
video coding [25]. The MPEG-4 video coding
standard [10] provides functionality for object-based video
coding. Video information can be encoded in a number of
arbitrarily shaped video ob... | space;structure tensor;curvature scale;object classification;motion segmentation |
500486 | A Survey of Energy Efficient Network Protocols for Wireless Networks. | Wireless networking has witnessed an explosion of interest from consumers in recent years for its applications in mobile and personal communications. As wireless networks become an integral component of the modern communication infrastructure, energy efficiency will be an important design consideration due to the limit... | Introduction
The rapid expansion of wireless services such as cellular voice, PCS
(Personal Communications Services), mobile data and wireless LANs
in recent years is an indication that signicant value is placed on accessibility
and portability as key features of telecommunication (Salkintzis and Mathiopoulos (Guest Ed... | mobile computing;network protocols;low-power design;energy efficient design;wireless networks;power aware protocols |
500504 | Frozen development in graph coloring. | We define the 'frozen development' of coloring random graphs. We identify two nodes in a graph as frozen if they are of the same color in all legal colorings and define the collapsed graph as the one in which all frozen pairs are merged. This is analogous to studies of the development of a backbone or spine in SAT (the... | Introduction
A phase transition has been identied for many NP-complete problems and is
frequently correlated with a high frequency of hard instances. This contrasts
with randomly chosen instances from other regions of the problem space, where
most often such instances are easy. Recently the techniques of statistical me... | spine;threshold phenomena;frozen development;graph coloring;backbone |
500505 | Constructing an asymptotic phase transition in random binary constraint satisfaction problems. | The standard models used to generate random binary constraint satisfaction problems are described. At the problem sizes studied experimentally, a phase transition is seen as the constraint tightness is varied. However, Achlioptas et al. showed that if the problem size (number of variables) increases while the remaining... | Introduction
Following the paper by Cheeseman, Kanefsky and Taylor [2] in 1991, phase transition
phenomena in NP-complete problems, including constraint satisfaction problems
(CSPs), have been widely studied. In CSPs, using randomly-generated in-
stances, a phase transition is seen as the tightness of the constraints i... | random problems;constraint satisfaction;phase transitions |
500605 | Learning one-variable pattern languages very efficiently on average, in parallel, and by asking queries. | A pattern is a finite string of constant and variable symbols. The langauge generated by a pattern is the set of all strings of constant symbols which can be obtained from the pattern by substituting non-empty strings for variables. We study the learnability of one-variable pattern languages in the limit with respect t... | Introduction
A pattern is a string of constant symbols and variable symbols. The language
generated by a pattern - is the set of all strings obtained by substituting strings
of constants for the variables in - (cf. [1]). Pattern languages and variations
thereof have been widely investigated (cf., e.g., [17, 18, 19]). T... | average-cae analysis;inductive learning;parallelization;one-variable pattern languages |
501056 | The Invariants of the Clifford Groups. | The automorphism group of the Barnes-Wall lattice L_m in dimension 2^m(m \neq 3 ) is a subgroup of index 2 in a certain Clifford group \mathcal{C}_m of structure 2_+^{1+2m} . O^+(2m,2). This group and its complex analogue \mathcal{X}_m of structure (2_+^{1+2m}{\sf Y}Z_8) . Sp(2m, 2) have arisen in recent years in conne... | Introduction
In 1959 Barnes and Wall [2] constructed a family of lattices in dimensions 2
They distinguished two geometrically similar lattices Lm #
. The automorphism
investigated in a series of papers by Bolt, Room and Wall [8], [9],
[50]. Gm is a subgroup of index 2 in a certain group Cm of structure 2 1+2m
We follo... | invariants;spherical designs;self-dual codes;barnes-wall lattices;clifford groups |
501419 | Neighborhood aware source routing. | A novel approach to source routing in ad hoc networks is introduced that takes advantage of maintaining information regarding the two-hop neighborhood of a node. The neighborhood aware source routing (NSR) protocol is presented based on this approach, and its performance is compared by simulation with the peformance of... | INTRODUCTION
On-demand routing protocols have been shown to be very
eective for ad hoc networks. The success of a caching algorithm
for an on-demand routing protocol depends of the
strategies used for the deletion of links from the routing
cache [5]. DSR has been shown to incur less routing overhead
when utilizing a ca... | ad hoc networks;wireless mobile networks;source routing;on-demand routing;link-state information |
501469 | Bounding Cache-Related Preemption Delay for Real-Time Systems. | AbstractCache memory is used in almost all computer systems today to bridge the ever increasing speed gap between the processor and main memory. However, its use in multitasking computer systems introduces additional preemption delay due to the reloading of memory blocks that are replaced during preemption. This cache-... | Introduction
In a real-time computing system, tasks have timing constraints in terms of deadlines that
must be met for correct operation. To guarantee such timing constraints, extensive research
has been performed on schedulability analysis [1, 2, 3, 4, 5, 6]. In these studies, various
assumptions are usually made to s... | cache memory;fixed-priority scheduling;preemption;schedulability analysis;real-time system |
501975 | The complexity of the exponential output size problem for top-down and bottom-up tree transducers. | The exponential output size problem is to determine whether the size of output trees of a tree transducer grows exponentially in the size of input trees. In this paper the complexity of this problem is studied. It is shown to be NL-complete for total top-down tree transducers, DEXPTIME-complete for general top-down tre... | Introduction
Top-down and bottom-up tree transducers were introduced in the late sixties
by Rounds and Thatcher [13, 16, 17, 18] as a generalisation of finite-state transducers
on strings. The main motivation was to provide a simple formal model
of syntax-directed transformational grammars in mathematical linguistics a... | complexity;tree transducer;output size;completeness |
501982 | The architecture and performance of security protocols in the ensemble group communication system. | Ensemble is a Group Communication System built at Cornell and the Hebrew universities. It allows processes to create process groups within which scalable reliable fifo-ordered multicast and point-to-point communication are supported. The system also supports other communication properties, such as causal and total mult... | Introduction
Group Communication Systems (GCSs) are used today in industry where reliability and high-availability
are required. Group Communication is a subject of ongoing research and many GCSs
have been built [1, 2, 3, 4, 5, 6, 7], some of them commercial products [8]. Example GCS applications
include: group-confere... | security;group communication |
502094 | Efficient generation of shared RSA keys. | We describe efficient techniques for a number of parties to jointly generate an RSA key. At the end of the protocol an RSA modulus publicly known. None of the parties know the factorization of N. In addition a public encryption exponent is publicly known and each party holds a share of the private exponent that enables... | Introduction
We present e-cient protocols for a number of parties to jointly generate an RSA modulus
where p; q are prime. At the end of the computation the parties are convinced that N is indeed a
product of two large primes. However, none of the parties know the factorization of N . We then
show how the parties can p... | primality testing;threshold cryptography;RSA;multiparty computation |
502097 | Quantum lower bounds by polynomials. | We examine the number of queries to input variables that a quantum algorithm requires to compute Boolean functions on {0,1}N in the black-box model. We show that the exponential quantum speed-up obtained for partial functions (i.e., problems involving a promise on the input) by Deutsch and Jozsa, Simon, and Shor cannot... | Introduction
The black-box model of computation arises when one is given a black-box containing
an N -tuple of Boolean variables The box is equipped
to output the bit x i on input i . We wish to determine some property of X , accessing
the x i only through the black-box. Such a black-box access is called a query.
A pro... | query complexity;quantum computing;lower bounds;black-box model;polynomial method |
502099 | Extractors and pseudorandom generators. | We introduce a new approach to constructing extractors. Extractors are algorithms that transform a "e;weakly random"e; distribution into an almost uniform distribution. Explicit constructions of extractors have a variety of important applications, and tend to be very difficult to obtain.We demonstrate an unsusp... | Introduction
An extractor is an algorithm that converts a \weak source of randomness" into an almost uniform
distribution by using a small number of additional truly random bits. Extractors have several
important applications (see e.g. [Nis96]). In this paper we show that pseudorandom generator
constructions of a certa... | error-correcting codes;extractors;pseudorandomness |
502105 | Improved implementations of binary universal operations. | We present an algorithm for implementing binary operations (of any type) from unary load-linked (LL) and store-conditional (SC) operations. The performance of the algorithm is evaluated according to its sensitivity, measuring the distance between operations in the graph induced by conflicts, which guarantees that they ... | Introduction
An algorithm is non-blocking if a processor is delayed only when some other processor is making
progress. Non-blocking algorithms avoid performance bottlenecks due to processors' failures
or delay. In asynchronous shared memory systems, non-blocking algorithms require the use of
universal operations such a... | universal operations;deterministic coin tossing;load-linked/store-conditional operations;wait-free algorithms;asynchronous shared-memory systems;contention-sensitive algorithms |
502111 | A fully sequential procedure for indifference-zone selection in simulation. | We present procedures for selecting the best or near-best of a finite number of simulated systems when best is defined by maximum or minimum expected performance. The procedures are appropriate when it is possible to repeatedly obtain small, incremental samples from each simulated system. The goal of such a sequential ... | Introduction
In a series of papers (Boesel and Nelson 1999, Goldsman and Nelson 1998ab, Nelson and
Banerjee 1999, Nelson and Goldsman 1998, Nelson, Swann, Goldsman and Song 1998, Miller,
Nelson and Reilly 1996, 1998ab), we have addressed the problem of selecting the best simulated
system when the number of systems is f... | variance reduction;multiple comparisons;ranking and selection;output analysis |
502522 | Data mining criteria for tree-based regression and classification. | This paper is concerned with the construction of regression and classification trees that are more adapted to data mining applications than conventional trees. To this end, we propose new splitting criteria for growing trees. Conventional splitting criteria attempt to perform well on both sides of a split by attempting... | Introduction
Tree methods can be applied to two kinds of predictive problems. Regression trees
are used to predict a continuous response, while classification trees are used to
predict a class label.
The goal of tree methods is to partition data into small buckets such that a
response value (regression tree) or a class... | CART;boston housing data;splitting criteria;Pima Indians Diabetes data |
502523 | Probabilistic modeling of transaction data with applications to profiling, visualization, and prediction. | Transaction data is ubiquitous in data mining applications. Examples include market basket data in retail commerce, telephone call records in telecommunications, and Web logs of individual page-requests at Web sites. Profiling consists of using historical transaction data on individuals to construct a model of each ind... | INTRODUCTION
Large transaction data sets are common in data mining ap-
plications. Typically these data sets involve records of transactions
by multiple individuals, where a transaction consists
of selecting or visiting among a set of items, e.g., a market
basket of items purchased or a list of which Web pages an
indiv... | EM algorithm;mixture models;profiles;transaction data |
502525 | Mining the network value of customers. | One of the major applications of data mining is in helping companies determine which potential customers to market to. If the expected profit from a customer is greater than the cost of marketing to her, the marketing action for that customer is executed. So far, work in this area has considered only the intrinsic valu... | INTRODUCTION
Direct marketing is one of the major applications of KDD.
In contrast to mass marketing, where a product is promoted
indiscriminately to all potential customers, direct marketing
attempts to rst select the customers likely to be protable,
Permission to make digital or hard copies of all or part of this wor... | collaborative filtering;direct marketing;viral marketing;markov random fields;social networks;dependency networks |
502527 | Proximal support vector machine classifiers. | Instead of a standard support vector machine (SVM) that classifies points by assigning them to one of two disjoint half-spaces, points are classified by assigning them to the closest of two parallel planes (in input or feature space) that are pushed apart as far as possible. This formulation, which can also be interpre... | INTRODUCTION
Standard support vector machines (SVMs) [36, 6, 3, 5,
20], which are powerful tools for data classification, classify
points by assigning them to one of two disjoint halfspaces.
These halfspaces are either in the original input space of
the problem for linear classifiers, or in a higher dimensional
feature... | support vector machines;data classification;linear equations |
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