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cmp-lg/9807006
A Maximum-Entropy Partial Parser for Unrestricted Text
cmp-lg cs.CL
This paper describes a partial parser that assigns syntactic structures to sequences of part-of-speech tags. The program uses the maximum entropy parameter estimation method, which allows a flexible combination of different knowledge sources: the hierarchical structure, parts of speech and phrasal categories. In effe...
cmp-lg/9807007
Chunk Tagger - Statistical Recognition of Noun Phrases
cmp-lg cs.CL
We describe a stochastic approach to partial parsing, i.e., the recognition of syntactic structures of limited depth. The technique utilises Markov Models, but goes beyond usual bracketing approaches, since it is capable of recognising not only the boundaries, but also the internal structure and syntactic category of...
cmp-lg/9807008
A Linguistically Interpreted Corpus of German Newspaper Text
cmp-lg cs.CL
In this paper, we report on the development of an annotation scheme and annotation tools for unrestricted German text. Our representation format is based on argument structure, but also permits the extraction of other kinds of representations. We discuss several methodological issues and the analysis of some phenomen...
cmp-lg/9807009
A Projection Architecture for Dependency Grammar and How it Compares to LFG
cmp-lg cs.CL
This paper explores commonalities and differences between \dachs, a variant of Dependency Grammar, and Lexical-Functional Grammar. \dachs\ is based on traditional linguistic insights, but on modern mathematical tools, aiming to integrate different knowledge systems (from syntax and semantics) via their coupling to an...
cmp-lg/9807010
Automatically Creating Bilingual Lexicons for Machine Translation from Bilingual Text
cmp-lg cs.CL
A method is presented for automatically augmenting the bilingual lexicon of an existing Machine Translation system, by extracting bilingual entries from aligned bilingual text. The proposed method only relies on the resources already available in the MT system itself. It is based on the use of bilingual lexical templ...
cmp-lg/9807011
Statistical Models for Unsupervised Prepositional Phrase Attachment
cmp-lg cs.CL
We present several unsupervised statistical models for the prepositional phrase attachment task that approach the accuracy of the best supervised methods for this task. Our unsupervised approach uses a heuristic based on attachment proximity and trains from raw text that is annotated with only part-of-speech tags and...
cmp-lg/9807012
Character design for soccer commmentary
cmp-lg cs.CL
In this paper we present early work on an animated talking head commentary system called {\bf Byrne}\footnote{David Byrne is the lead singer of the Talking Heads.}. The goal of this project is to develop a system which can take the output from the RoboCup soccer simulator, and generate appropriate affective speech an...
cmp-lg/9807013
Improving Data Driven Wordclass Tagging by System Combination
cmp-lg cs.CL
In this paper we examine how the differences in modelling between different data driven systems performing the same NLP task can be exploited to yield a higher accuracy than the best individual system. We do this by means of an experiment involving the task of morpho-syntactic wordclass tagging. Four well-known tagge...
cmp-lg/9808001
An Empirical Evaluation of Probabilistic Lexicalized Tree Insertion Grammars
cmp-lg cs.CL
We present an empirical study of the applicability of Probabilistic Lexicalized Tree Insertion Grammars (PLTIG), a lexicalized counterpart to Probabilistic Context-Free Grammars (PCFG), to problems in stochastic natural-language processing. Comparing the performance of PLTIGs with non-hierarchical N-gram models and P...
cmp-lg/9808002
Indexing with WordNet synsets can improve Text Retrieval
cmp-lg cs.CL
The classical, vector space model for text retrieval is shown to give better results (up to 29% better in our experiments) if WordNet synsets are chosen as the indexing space, instead of word forms. This result is obtained for a manually disambiguated test collection (of queries and documents) derived from the Semcor...
cmp-lg/9808003
Parallel Strands: A Preliminary Investigation into Mining the Web for Bilingual Text
cmp-lg cs.CL
Parallel corpora are a valuable resource for machine translation, but at present their availability and utility is limited by genre- and domain-specificity, licensing restrictions, and the basic difficulty of locating parallel texts in all but the most dominant of the world's languages. A parallel corpus resource not...
cmp-lg/9808004
Word Length Frequency and Distribution in English: Observations, Theory, and Implications for the Construction of Verse Lines
cmp-lg cs.CL
Recent observations in the theory of verse and empirical metrics have suggested that constructing a verse line involves a pattern-matching search through a source text, and that the number of found elements (complete words totaling a specified number of syllables) is given by dividing the total number of words by the...
cmp-lg/9808005
Combining Expression and Content in Domains for Dialog Managers
cmp-lg cs.CL
We present work in progress on abstracting dialog managers from their domain in order to implement a dialog manager development tool which takes (among other data) a domain description as input and delivers a new dialog manager for the described domain as output. Thereby we will focus on two topics; firstly, the cons...
cmp-lg/9808006
Isometric Lineation in English Texts: An Empirical and Mathematical Examination of its Character and Consequences
cmp-lg cs.CL
In this paper we build on earlier observations and theory regarding word length frequency and sequential distribution to develop a mathematical characterization of some of the language features distinguishing isometrically lineated text from unlineated text, in other words the features distinguishing isometrical vers...
cmp-lg/9808007
Some Properties of Preposition and Subordinate Conjunction Attachments
cmp-lg cs.CL
Determining the attachments of prepositions and subordinate conjunctions is a key problem in parsing natural language. This paper presents a trainable approach to making these attachments through transformation sequences and error-driven learning. Our approach is broad coverage, and accounts for roughly three times t...
cmp-lg/9808008
Deriving the Predicate-Argument Structure for a Free Word Order Language
cmp-lg cs.CL
In relatively free word order languages, grammatical functions are intricately related to case marking. Assuming an ordered representation of the predicate-argument structure, this work proposes a Combinatory Categorial Grammar formulation of relating surface case cues to categories and types for correctly placing th...
cmp-lg/9808009
How to define a context-free backbone for DGs: Implementing a DG in the LFG formalism
cmp-lg cs.CL
This paper presents a multidimensional Dependency Grammar (DG), which decouples the dependency tree from word order, such that surface ordering is not determined by traversing the dependency tree. We develop the notion of a \emph{word order domain structure}, which is linked but structurally dissimilar to the syntact...
cmp-lg/9808010
Letter to Sound Rules for Accented Lexicon Compression
cmp-lg cs.CL
This paper presents trainable methods for generating letter to sound rules from a given lexicon for use in pronouncing out-of-vocabulary words and as a method for lexicon compression. As the relationship between a string of letters and a string of phonemes representing its pronunciation for many languages is not tr...
cmp-lg/9808011
Primitive Part-of-Speech Tagging using Word Length and Sentential Structure
cmp-lg cs.CL
It has been argued that, when learning a first language, babies use a series of small clues to aid recognition and comprehension, and that one of these clues is word length. In this paper we present a statistical part of speech tagger which trains itself solely on the number of letters in each word in a sentence.
cmp-lg/9808012
Separating Surface Order and Syntactic Relations in a Dependency Grammar
cmp-lg cs.CL
This paper proposes decoupling the dependency tree from word order, such that surface ordering is not determined by traversing the dependency tree. We develop the notion of a \emph{word order domain structure}, which is linked but structurally dissimilar to the syntactic dependency tree. The proposal results in a lex...
cmp-lg/9808013
Partial Evaluation for Efficient Access to Inheritance Lexicons
cmp-lg cs.CL
Multiple default inheritance formalisms for lexicons have attracted much interest in recent years. I propose a new efficient method to access such lexicons. After showing two basic strategies for lookup in inheritance lexicons, a compromise is developed which combines to a large degree (from a practical point of view...
cmp-lg/9808014
Spotting Prosodic Boundaries in Continuous Speech in French
cmp-lg cs.CL
A radio speech corpus of 9mn has been prosodically marked by a phonetician expert, and non expert listeners. this corpus is large enough to train and test an automatic boundary spotting system, namely a time delay neural network fed with F0 values, vowels and pseudo-syllable durations. Results validate both prosodic ...
cmp-lg/9808015
Error-Driven Pruning of Treebank Grammars for Base Noun Phrase Identification
cmp-lg cs.CL
Finding simple, non-recursive, base noun phrases is an important subtask for many natural language processing applications. While previous empirical methods for base NP identification have been rather complex, this paper instead proposes a very simple algorithm that is tailored to the relative simplicity of the task....
cmp-lg/9808016
Segregatory Coordination and Ellipsis in Text Generation
cmp-lg cs.CL
In this paper, we provide an account of how to generate sentences with coordination constructions from clause-sized semantic representations. An algorithm is developed to generate sentences with ellipsis, gapping, right-node-raising, and non-constituent coordination constructions. Various examples from linguistic lit...
cmp-lg/9808017
A Variant of Earley Parsing
cmp-lg cs.CL
The Earley algorithm is a widely used parsing method in natural language processing applications. We introduce a variant of Earley parsing that is based on a ``delayed'' recognition of constituents. This allows us to start the recognition of a constituent only in cases in which all of its subconstituents have been fo...
cmp-lg/9809001
Towards an implementable dependency grammar
cmp-lg cs.CL
The aim of this paper is to define a dependency grammar framework which is both linguistically motivated and computationally parsable. See the demo at http://www.conexor.fi/analysers.html#testing
cmp-lg/9809002
Some Ontological Principles for Designing Upper Level Lexical Resources
cmp-lg cs.CL
The purpose of this paper is to explore some semantic problems related to the use of linguistic ontologies in information systems, and to suggest some organizing principles aimed to solve such problems. The taxonomic structure of current ontologies is unfortunately quite complicated and hard to understand, especially...
cmp-lg/9809003
A Comparison of WordNet and Roget's Taxonomy for Measuring Semantic Similarity
cmp-lg cs.CL
This paper presents the results of using Roget's International Thesaurus as the taxonomy in a semantic similarity measurement task. Four similarity metrics were taken from the literature and applied to Roget's The experimental evaluation suggests that the traditional edge counting approach does surprisingly well (a c...
cond-mat/0002331
From naive to sophisticated behavior in multiagents based financial market models
cond-mat.stat-mech cond-mat.dis-nn cs.CE nlin.AO physics.data-an q-fin.TR
We discuss the behavior of two magnitudes, physical complexity and mutual information function of the outcome of a model of heterogeneous, inductive rational agents inspired in the El Farol Bar problem and the Minority Game. The first is a measure rooted in Kolmogorov-Chaitin theory and the second one a measure relat...
cond-mat/0009165
Occam factors and model-independent Bayesian learning of continuous distributions
cond-mat cs.LG nlin.AO physics.data-an
Learning of a smooth but nonparametric probability density can be regularized using methods of Quantum Field Theory. We implement a field theoretic prior numerically, test its efficacy, and show that the data and the phase space factors arising from the integration over the model space determine the free parameter of...
cond-mat/0010337
Optimization with Extremal Dynamics
cond-mat.stat-mech cs.NE math.OC
We explore a new general-purpose heuristic for finding high-quality solutions to hard optimization problems. The method, called extremal optimization, is inspired by self-organized criticality, a concept introduced to describe emergent complexity in physical systems. Extremal optimization successively replaces extrem...
cond-mat/0104066
Beyond the Zipf-Mandelbrot law in quantitative linguistics
cond-mat.stat-mech cs.CL nlin.AO
In this paper the Zipf-Mandelbrot law is revisited in the context of linguistics. Despite its widespread popularity the Zipf--Mandelbrot law can only describe the statistical behaviour of a rather restricted fraction of the total number of words contained in some given corpus. In particular, we focus our attention on...
cond-mat/0104214
Extremal Optimization for Graph Partitioning
cond-mat.stat-mech cs.NE math.OC
Extremal optimization is a new general-purpose method for approximating solutions to hard optimization problems. We study the method in detail by way of the NP-hard graph partitioning problem. We discuss the scaling behavior of extremal optimization, focusing on the convergence of the average run as a function of run...
cond-mat/0109121
Coordination of Decisions in a Spatial Agent Model
cond-mat.stat-mech cs.MA
For a binary choice problem, the spatial coordination of decisions in an agent community is investigated both analytically and by means of stochastic computer simulations. The individual decisions are based on different local information generated by the agents with a finite lifetime and disseminated in the system wi...
cond-mat/0109218
Entropic analysis of the role of words in literary texts
cond-mat.stat-mech cs.CL
Beyond the local constraints imposed by grammar, words concatenated in long sequences carrying a complex message show statistical regularities that may reflect their linguistic role in the message. In this paper, we perform a systematic statistical analysis of the use of words in literary English corpora. We show tha...
cond-mat/0110165
Jamming Model for the Extremal Optimization Heuristic
cond-mat.stat-mech cs.NE physics.comp-ph
Extremal Optimization, a recently introduced meta-heuristic for hard optimization problems, is analyzed on a simple model of jamming. The model is motivated first by the problem of finding lowest energy configurations for a disordered spin system on a fixed-valence graph. The numerical results for the spin system exh...
cond-mat/0201139
Long-range fractal correlations in literary corpora
cond-mat.stat-mech cs.CL nlin.AO
In this paper we analyse the fractal structure of long human-language records by mapping large samples of texts onto time series. The particular mapping set up in this work is inspired on linguistic basis in the sense that is retains {\em the word} as the fundamental unit of communication. The results confirm that be...
cond-mat/0202190
Threshold Disorder as a Source of Diverse and Complex Behavior in Random Nets
cond-mat.dis-nn cs.NE q-bio.NC
We study the diversity of complex spatio-temporal patterns in the behavior of random synchronous asymmetric neural networks (RSANNs). Special attention is given to the impact of disordered threshold values on limit-cycle diversity and limit-cycle complexity in RSANNs which have `normal' thresholds by default. Surpris...
cond-mat/0202383
Extended Comment on Language Trees and Zipping
cond-mat.stat-mech cs.CL cs.LG
This is the extended version of a Comment submitted to Physical Review Letters. I first point out the inappropriateness of publishing a Letter unrelated to physics. Next, I give experimental results showing that the technique used in the Letter is 3 times worse and 17 times slower than a simple baseline. And finally,...
cond-mat/0203436
Entropy estimation of symbol sequences
cond-mat.stat-mech cs.CL cs.IT math.IT physics.data-an stat.ML
We discuss algorithms for estimating the Shannon entropy h of finite symbol sequences with long range correlations. In particular, we consider algorithms which estimate h from the code lengths produced by some compression algorithm. Our interest is in describing their convergence with sequence length, assuming no lim...
cond-mat/0203591
Anticorrelations and subdiffusion in financial systems
cond-mat.dis-nn cond-mat.stat-mech cs.CE q-fin.ST
Statistical dynamics of financial systems is investigated, based on a model of a randomly coupled equation system driven by a stochastic Langevin force. Anticorrelations of price returns, and subdiffusion of prices is found from the model, and and compared with those calculated from historical $/EURO exchange rates.
cond-mat/0208414
Winner-Relaxing Self-Organizing Maps
cond-mat.dis-nn cs.NE nlin.AO q-bio.NC
A new family of self-organizing maps, the Winner-Relaxing Kohonen Algorithm, is introduced as a generalization of a variant given by Kohonen in 1991. The magnification behaviour is calculated analytically. For the original variant a magnification exponent of 4/7 is derived; the generalized version allows to steer the...
cond-mat/0301307
Nonextensive statistical mechanics and economics
cond-mat.stat-mech cs.CE q-fin.ST
Ergodicity, this is to say, dynamics whose time averages coincide with ensemble averages, naturally leads to Boltzmann-Gibbs (BG) statistical mechanics, hence to standard thermodynamics. This formalism has been at the basis of an enormous success in describing, among others, the particular stationary state correspond...
cond-mat/0301459
Collectives for the Optimal Combination of Imperfect Objects
cond-mat.dis-nn cond-mat.stat-mech cs.MA nlin.AO
In this letter we summarize some recent theoretical work on the design of collectives, i.e., of systems containing many agents, each of which can be viewed as trying to maximize an associated private utility, where there is also a world utility rating the behavior of that overall system that the designer of the colle...
cond-mat/0303089
Multiplicative point process as a model of trading activity
cond-mat.stat-mech cs.CE math.SP nlin.AO nlin.CD q-fin.TR
Signals consisting of a sequence of pulses show that inherent origin of the 1/f noise is a Brownian fluctuation of the average interevent time between subsequent pulses of the pulse sequence. In this paper we generalize the model of interevent time to reproduce a variety of self-affine time series exhibiting power sp...
cond-mat/0304132
Causalities of the Taiwan Stock Market
cond-mat.stat-mech cs.CE q-fin.ST
Volatility, fitting with first order Landau expansion, stationarity, and causality of the Taiwan stock market (TAIEX) are investigated based on daily records. Instead of consensuses that consider stock market index change as a random time series we propose the market change as a dual time series consists of the index...
cond-mat/0305508
Neural network modeling of data with gaps: method of principal curves, Carleman's formula, and other
cond-mat.dis-nn cs.NE physics.data-an
A method of modeling data with gaps by a sequence of curves has been developed. The new method is a generalization of iterative construction of singular expansion of matrices with gaps. Under discussion are three versions of the method featuring clear physical interpretation: linear - modeling the data by a sequence ...
cond-mat/0305527
Back-propagation of accuracy
cond-mat.dis-nn cs.NA cs.NE math.NA
In this paper we solve the problem: how to determine maximal allowable errors, possible for signals and parameters of each element of a network proceeding from the condition that the vector of output signals of the network should be calculated with given accuracy? "Back-propagation of accuracy" is developed to solve ...
cond-mat/0305681
Seven clusters in genomic triplet distributions
cond-mat.dis-nn cs.CV physics.bio-ph physics.data-an q-bio.GN
In several recent papers new gene-detection algorithms were proposed for detecting protein-coding regions without requiring learning dataset of already known genes. The fact that unsupervised gene-detection is possible closely connected to existence of a cluster structure in oligomer frequency distributions. In this ...
cond-mat/0307083
Generation of Explicit Knowledge from Empirical Data through Pruning of Trainable Neural Networks
cond-mat cs.NE physics.data-an
This paper presents a generalized technology of extraction of explicit knowledge from data. The main ideas are 1) maximal reduction of network complexity (not only removal of neurons or synapses, but removal all the unnecessary elements and signals and reduction of the complexity of elements), 2) using of adjustable ...
cond-mat/0307630
Product Distribution Field Theory
cond-mat.stat-mech cond-mat.dis-nn cs.MA nlin.AO
This paper presents a novel way to approximate a distribution governing a system of coupled particles with a product of independent distributions. The approach is an extension of mean field theory that allows the independent distributions to live in a different space from the system, and thereby capture statistical d...
cond-mat/0312019
A theoretical investigation of ferromagnetic tunnel junctions with 4-valued conductances
cond-mat.mes-hall cond-mat.mtrl-sci cs.CE physics.ins-det quant-ph
In considering a novel function in ferromagnetic tunnel junctions consisting of ferromagnet(FM)/barrier/FM junctions, we theoretically investigate multiple valued (or multi-level) cell property, which is in principle realized by sensing conductances of four states recorded with magnetization configurations of two FMs...
cond-mat/0402508
Information Theory - The Bridge Connecting Bounded Rational Game Theory and Statistical Physics
cond-mat.stat-mech cond-mat.dis-nn cs.GT cs.MA nlin.AO
A long-running difficulty with conventional game theory has been how to modify it to accommodate the bounded rationality of all real-world players. A recurring issue in statistical physics is how best to approximate joint probability distributions with decoupled (and therefore far more tractable) distributions. This ...
cond-mat/0402581
Dictionary based methods for information extraction
cond-mat.stat-mech cond-mat.other cs.IR q-bio.GN q-bio.OT
In this paper we present a general method for information extraction that exploits the features of data compression techniques. We first define and focus our attention on the so-called "dictionary" of a sequence. Dictionaries are intrinsically interesting and a study of their features can be of great usefulness to in...
cond-mat/0403233
Artificial Sequences and Complexity Measures
cond-mat.stat-mech cs.CL cs.IR cs.IT math.IT
In this paper we exploit concepts of information theory to address the fundamental problem of identifying and defining the most suitable tools to extract, in a automatic and agnostic way, information from a generic string of characters. We introduce in particular a class of methods which use in a crucial way data com...
cond-mat/0407439
A Theoretical Study on Spin-Dependent Transport of "Ferromagnet/Carbon Nanotube Encapsulating Magnetic Atoms/Ferromagnet" Junctions with 4-Valued Conductances
cond-mat.mes-hall cond-mat.mtrl-sci cs.CE physics.chem-ph
As a novel function of ferromagnet (FM)/spacer/FM junctions, we theoretically investigate multiple-valued (or multi-level) cell property, which is in principle realized by sensing conductances of four states recorded with magnetization configurations of two FMs; (up,up), (up,down), (down,up), (down,down). In order to...
cond-mat/0408190
From spin glasses to hard satisfiable formulas
cond-mat.stat-mech cond-mat.dis-nn cs.AI
We introduce a highly structured family of hard satisfiable 3-SAT formulas corresponding to an ordered spin-glass model from statistical physics. This model has provably "glassy" behavior; that is, it has many local optima with large energy barriers between them, so that local search algorithms get stuck and have dif...
cond-mat/0410270
On uniqueness theorems for Tsallis entropy and Tsallis relative entropy
cond-mat.stat-mech cs.IT math.IT
The uniqueness theorem for Tsallis entropy was presented in {\it H.Suyari, IEEE Trans. Inform. Theory, Vol.50, pp.1783-1787 (2004)} by introducing the generalized Shannon-Khinchin's axiom. In the present paper, this result is generalized and simplified as follows: {\it Generalization}: The uniqueness theorem for Tsal...
cond-mat/0410271
A generalized Faddeev's axiom and the uniqueness theorem for Tsallis entropy
cond-mat.stat-mech cs.IT math.IT
The uniequness theorem for the Tsallis entropy by introducing the generalized Faddeev's axiom is proven. Our result improves the recent result, the uniqueness theorem for Tsallis entropy by the generalized Shannon-Khinchin's axiom in \cite{Suy}, in the sence that our axiom is simpler than his one, as similar that Fad...
cond-mat/0410460
A Computational Study of Rotating Spiral Waves and Spatio-Temporal Transient Chaos in a Deterministic Three-Level Active System
cond-mat.other cs.NE nlin.CG
Spatio-temporal dynamics of a deterministic three-level cellular automaton (TLCA) of Zykov-Mikhailov type (Sov. Phys. - Dokl., 1986, Vol.31, No.1, P.51) is studied numerically. Evolution of spatial structures is investigated both for the original Zykov-Mikhailov model (which is applicable to, for example, Belousov-Zh...
cond-mat/0410594
A model of student's dilemma
cond-mat.other cond-mat.stat-mech cs.MA physics.soc-ph
Each year perhaps millions of young people face the following dilemma: should I continue my education or rather start working with already acquired skills. Right decision must take into account somebody's own abilities, accessibility to education institutions, competition, and potential benefits. A multi-agent, evolu...
cond-mat/0412460
Exact Maxwell-Boltzmann, Bose-Einstein and Fermi-Dirac Statistics
cond-mat.stat-mech cs.IT math.IT quant-ph
The exact Maxwell-Boltzmann (MB), Bose-Einstein (BE) and Fermi-Dirac (FD) entropies and probabilistic distributions are derived by the combinatorial method of Boltzmann, without Stirling's approximation. The new entropy measures are explicit functions of the probability and degeneracy of each state, and the total num...
cond-mat/0412587
Spin dependent transport of ``nonmagnetic metal/zigzag nanotube encapsulating magnetic atoms/nonmagnetic metal'' junctions
cond-mat.mes-hall cond-mat.mtrl-sci cs.CE physics.chem-ph quant-ph
Towards a novel magnetoresistance (MR) device with a carbon nanotube, we propose ``nonmagnetic metal/zigzag nanotube encapsulating magnetic atoms/nonmagnetic metal'' junctions. We theoretically investigate how spin-polarized edges of the nanotube and the encapsulated magnetic atoms influence on transport. When the on...
cond-mat/0412723
Modelling financial markets by the multiplicative sequence of trades
cond-mat.stat-mech cs.CE math.SP physics.data-an q-fin.ST
We introduce the stochastic multiplicative point process modelling trading activity of financial markets. Such a model system exhibits power-law spectral density S(f) ~ 1/f**beta, scaled as power of frequency for various values of beta between 0.5 and 2. Furthermore, we analyze the relation between the power-law auto...
cond-mat/0504025
Point process model of 1/f noise versus a sum of Lorentzians
cond-mat.stat-mech astro-ph cond-mat.dis-nn cs.CE math.ST nlin.AO physics.data-an q-bio.NC stat.TH
We present a simple point process model of $1/f^{\beta}$ noise, covering different values of the exponent $\beta$. The signal of the model consists of pulses or events. The interpulse, interevent, interarrival, recurrence or waiting times of the signal are described by the general Langevin equation with the multiplic...
cond-mat/0506037
Diagnosis of weaknesses in modern error correction codes: a physics approach
cond-mat.stat-mech cond-mat.dis-nn cs.IT math.IT
One of the main obstacles to the wider use of the modern error-correction codes is that, due to the complex behavior of their decoding algorithms, no systematic method which would allow characterization of the Bit-Error-Rate (BER) is known. This is especially true at the weak noise where many systems operate and wher...
cond-mat/0506652
The theoretical capacity of the Parity Source Coder
cond-mat.dis-nn cond-mat.stat-mech cs.IT math.IT
The Parity Source Coder is a protocol for data compression which is based on a set of parity checks organized in a sparse random network. We consider here the case of memoryless unbiased binary sources. We show that the theoretical capacity saturate the Shannon limit at large K. We also find that the first correction...
cond-mat/0508216
Cluster Variation Method in Statistical Physics and Probabilistic Graphical Models
cond-mat.stat-mech cs.IT math.IT
The cluster variation method (CVM) is a hierarchy of approximate variational techniques for discrete (Ising--like) models in equilibrium statistical mechanics, improving on the mean--field approximation and the Bethe--Peierls approximation, which can be regarded as the lowest level of the CVM. In recent years it has ...
cond-mat/0511159
Learning by message-passing in networks of discrete synapses
cond-mat.dis-nn cs.LG q-bio.NC
We show that a message-passing process allows to store in binary "material" synapses a number of random patterns which almost saturates the information theoretic bounds. We apply the learning algorithm to networks characterized by a wide range of different connection topologies and of size comparable with that of bio...
cond-mat/0512017
Combinatorial Information Theory: I. Philosophical Basis of Cross-Entropy and Entropy
cond-mat.stat-mech cs.IT math-ph math.IT math.MP physics.data-an
This study critically analyses the information-theoretic, axiomatic and combinatorial philosophical bases of the entropy and cross-entropy concepts. The combinatorial basis is shown to be the most fundamental (most primitive) of these three bases, since it gives (i) a derivation for the Kullback-Leibler cross-entropy...
cond-mat/0601021
Characterizing correlations of flow oscillations at bottlenecks
cond-mat.stat-mech cs.MA
"Oscillations" occur in quite different kinds of many-particle-systems when two groups of particles with different directions of motion meet or intersect at a certain spot. We present a model of pedestrian motion that is able to reproduce oscillations with different characteristics. The Wald-Wolfowitz test and Gillis...
cond-mat/0601487
Loop Calculus in Statistical Physics and Information Science
cond-mat.stat-mech cond-mat.dis-nn cs.IT math.IT
Considering a discrete and finite statistical model of a general position we introduce an exact expression for the partition function in terms of a finite series. The leading term in the series is the Bethe-Peierls (Belief Propagation)-BP contribution, the rest are expressed as loop-contributions on the factor graph ...
cond-mat/0601573
Amorphous packings of hard spheres in large space dimension
cond-mat.stat-mech cond-mat.dis-nn cs.IT math.GM math.IT
In a recent paper (cond-mat/0506445) we derived an expression for the replicated free energy of a liquid of hard spheres based on the HNC free energy functional. An approximate equation of state for the glass and an estimate of the random close packing density were obtained in d=3. Here we show that the HNC approxima...
cond-mat/0602183
Nonlinear parametric model for Granger causality of time series
cond-mat.dis-nn cond-mat.stat-mech cs.LG physics.med-ph q-bio.QM
We generalize a previously proposed approach for nonlinear Granger causality of time series, based on radial basis function. The proposed model is not constrained to be additive in variables from the two time series and can approximate any function of these variables, still being suitable to evaluate causality. Usefu...
cond-mat/0602345
Numerical Modeling of Coexistence, Competition and Collapse of Rotating Spiral Waves in Three-Level Excitable Media with Discrete Active Centers and Absorbing Boundaries
cond-mat.other cs.NE nlin.CG
Spatio-temporal dynamics of excitable media with discrete three-level active centers (ACs) and absorbing boundaries is studied numerically by means of a deterministic three-level model (see S. D. Makovetskiy and D. N. Makovetskii, on-line preprint cond-mat/0410460 ), which is a generalization of Zykov- Mikhailov mode...
cond-mat/0602661
On the high density behavior of Hamming codes with fixed minimum distance
cond-mat.stat-mech cond-mat.dis-nn cs.IT math.IT
We discuss the high density behavior of a system of hard spheres of diameter d on the hypercubic lattice of dimension n, in the limit n -> oo, d -> oo, d/n=delta. The problem is relevant for coding theory. We find a solution to the equations describing the liquid up to very large values of the density, but we show th...
cond-mat/0603189
Loop series for discrete statistical models on graphs
cond-mat.stat-mech cond-mat.dis-nn cs.IT math.IT
In this paper we present derivation details, logic, and motivation for the loop calculus introduced in \cite{06CCa}. Generating functions for three inter-related discrete statistical models are each expressed in terms of a finite series. The first term in the series corresponds to the Bethe-Peierls (Belief Propagatio...
cond-mat/0604267
Survey propagation for the cascading Sourlas code
cond-mat.stat-mech cs.IT math.IT
We investigate how insights from statistical physics, namely survey propagation, can improve decoding of a particular class of sparse error correcting codes. We show that a recently proposed algorithm, time averaged belief propagation, is in fact intimately linked to a specific survey propagation for which Parisi's r...
cond-mat/0606125
Microscopic activity patterns in the Naming Game
cond-mat.dis-nn cs.MA physics.soc-ph
The models of statistical physics used to study collective phenomena in some interdisciplinary contexts, such as social dynamics and opinion spreading, do not consider the effects of the memory on individual decision processes. On the contrary, in the Naming Game, a recently proposed model of Language formation, each...
cond-mat/0606696
Statistical mechanics of error exponents for error-correcting codes
cond-mat.dis-nn cond-mat.stat-mech cs.IT math.IT
Error exponents characterize the exponential decay, when increasing message length, of the probability of error of many error-correcting codes. To tackle the long standing problem of computing them exactly, we introduce a general, thermodynamic, formalism that we illustrate with maximum-likelihood decoding of low-den...
cond-mat/0608312
On Cavity Approximations for Graphical Models
cond-mat.stat-mech cond-mat.dis-nn cs.IT math.IT
We reformulate the Cavity Approximation (CA), a class of algorithms recently introduced for improving the Bethe approximation estimates of marginals in graphical models. In our new formulation, which allows for the treatment of multivalued variables, a further generalization to factor graphs with arbitrary order of i...
cond-mat/0611567
Generalized Statistics Framework for Rate Distortion Theory
cond-mat.stat-mech cs.IT math.IT
Variational principles for the rate distortion (RD) theory in lossy compression are formulated within the ambit of the generalized nonextensive statistics of Tsallis, for values of the nonextensivity parameter satisfying $ 0 < q < 1 $ and $ q > 1 $. Alternating minimization numerical schemes to evaluate the nonextens...
cond-mat/0611717
Non-equilibrium phase transition in negotiation dynamics
cond-mat.stat-mech cs.MA physics.soc-ph q-bio.PE
We introduce a model of negotiation dynamics whose aim is that of mimicking the mechanisms leading to opinion and convention formation in a population of individuals. The negotiation process, as opposed to ``herding-like'' or ``bounded confidence'' driven processes, is based on a microscopic dynamics where memory and...
cond-mat/0701218
Generalized Statistics Framework for Rate Distortion Theory with Bregman Divergences
cond-mat.stat-mech cs.IT math.IT
A variational principle for the rate distortion (RD) theory with Bregman divergences is formulated within the ambit of the generalized (nonextensive) statistics of Tsallis. The Tsallis-Bregman RD lower bound is established. Alternate minimization schemes for the generalized Bregman RD (GBRD) theory are derived. A com...
cond-mat/0703351
Error Correction and Digitalization Concepts in Biochemical Computing
cond-mat.soft cond-mat.dis-nn cond-mat.mtrl-sci cs.CE q-bio.BM quant-ph
We offer a theoretical design of new systems that show promise for digital biochemical computing, including realizations of error correction by utilizing redundancy, as well as signal rectification. The approach includes information processing using encoded DNA sequences, DNAzyme biocatalyzed reactions and the use of...
cond-mat/9703183
Finite size scaling of the bayesian perceptron
cond-mat.stat-mech cond-mat.dis-nn cs.AI cs.LG
We study numerically the properties of the bayesian perceptron through a gradient descent on the optimal cost function. The theoretical distribution of stabilities is deduced. It predicts that the optimal generalizer lies close to the boundary of the space of (error-free) solutions. The numerical simulations are in g...
cond-mat/9810144
Relaxation in graph coloring and satisfiability problems
cond-mat.dis-nn cs.AI
Using T=0 Monte Carlo simulation, we study the relaxation of graph coloring (K-COL) and satisfiability (K-SAT), two hard problems that have recently been shown to possess a phase transition in solvability as a parameter is varied. A change from exponentially fast to power law relaxation, and a transition to freezing ...
cond-mat/9902011
Cortical Potential Distributions and Cognitive Information Processing
cond-mat.dis-nn adap-org cond-mat.stat-mech cs.NE math-ph math.MP nlin.AO physics.bio-ph q-bio
The use of cortical field potentials rather than the details of spike trains as the basis for cognitive information processing is proposed. This results in a space of cognitive elements with natural metrics. Sets of spike trains may also be considered to be points in a multidimensional metric space. The closeness of ...
cond-mat/9906206
Ocular dominance patterns in mammalian visual cortex: A wire length minimization approach
cond-mat.soft cond-mat.dis-nn cs.NE physics.bio-ph q-bio
We propose a theory for ocular dominance (OD) patterns in mammalian primary visual cortex. This theory is based on the premise that OD pattern is an adaptation to minimize the length of intra-cortical wiring. Thus we can understand the existing OD patterns by solving a wire length minimization problem. We divide all ...
cs/0001002
Minimum Description Length and Compositionality
cs.CL cs.AI
We present a non-vacuous definition of compositionality. It is based on the idea of combining the minimum description length principle with the original definition of compositionality (that is, that the meaning of the whole is a function of the meaning of the parts). The new definition is intuitive and allows us to...
cs/0001004
Multiplicative Algorithm for Orthgonal Groups and Independent Component Analysis
cs.LG
The multiplicative Newton-like method developed by the author et al. is extended to the situation where the dynamics is restricted to the orthogonal group. A general framework is constructed without specifying the cost function. Though the restriction to the orthogonal groups makes the problem somewhat complicated, a...
cs/0001006
Compositionality, Synonymy, and the Systematic Representation of Meaning
cs.CL cs.LO
In a recent issue of Linguistics and Philosophy Kasmi and Pelletier (1998) (K&P), and Westerstahl (1998) criticize Zadrozny's (1994) argument that any semantics can be represented compositionally. The argument is based upon Zadrozny's theorem that every meaning function m can be encoded by a function \mu such that (i...
cs/0001008
Predicting the expected behavior of agents that learn about agents: the CLRI framework
cs.MA cs.LG
We describe a framework and equations used to model and predict the behavior of multi-agent systems (MASs) with learning agents. A difference equation is used for calculating the progression of an agent's error in its decision function, thereby telling us how the agent is expected to fare in the MAS. The equation rel...
cs/0001010
A Real World Implementation of Answer Extraction
cs.CL
In this paper we describe ExtrAns, an answer extraction system. Answer extraction (AE) aims at retrieving those exact passages of a document that directly answer a given user question. AE is more ambitious than information retrieval and information extraction in that the retrieval results are phrases, not entire docu...
cs/0001012
Measures of Distributional Similarity
cs.CL
We study distributional similarity measures for the purpose of improving probability estimation for unseen cooccurrences. Our contributions are three-fold: an empirical comparison of a broad range of measures; a classification of similarity functions based on the information that they incorporate; and the introductio...
cs/0001015
Multi-Agent Only Knowing
cs.AI cs.LO
Levesque introduced a notion of ``only knowing'', with the goal of capturing certain types of nonmonotonic reasoning. Levesque's logic dealt with only the case of a single agent. Recently, both Halpern and Lakemeyer independently attempted to extend Levesque's logic to the multi-agent case. Although there are a numbe...
cs/0001018
Adaptive simulated annealing (ASA): Lessons learned
cs.MS cs.CE
Adaptive simulated annealing (ASA) is a global optimization algorithm based on an associated proof that the parameter space can be sampled much more efficiently than by using other previous simulated annealing algorithms. The author's ASA code has been publicly available for over two years. During this time the autho...
cs/0001020
Exploiting Syntactic Structure for Natural Language Modeling
cs.CL
The thesis presents an attempt at using the syntactic structure in natural language for improved language models for speech recognition. The structured language model merges techniques in automatic parsing and language modeling using an original probabilistic parameterization of a shift-reduce parser. A maximum likel...
cs/0001021
Refinement of a Structured Language Model
cs.CL
A new language model for speech recognition inspired by linguistic analysis is presented. The model develops hidden hierarchical structure incrementally and uses it to extract meaningful information from the word history - thus enabling the use of extended distance dependencies - in an attempt to complement the local...
cs/0001022
Recognition Performance of a Structured Language Model
cs.CL
A new language model for speech recognition inspired by linguistic analysis is presented. The model develops hidden hierarchical structure incrementally and uses it to extract meaningful information from the word history - thus enabling the use of extended distance dependencies - in an attempt to complement the local...