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The calculi of emergence: Computation, dynamics, and induction
 Physica D 1994
"... SFI Working Papers contain accounts of scientific work of the author(s) and do not necessarily represent the views of the Santa Fe Institute. We accept papers intended for publication in peerreviewed journals or proceedings volumes, but not papers that have already appeared in print. Except for pap ..."
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Cited by 108 (15 self)
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SFI Working Papers contain accounts of scientific work of the author(s) and do not necessarily represent the views of the Santa Fe Institute. We accept papers intended for publication in peerreviewed journals or proceedings volumes, but not papers that have already appeared in print. Except for papers by our external faculty, papers must be based on work done at SFI, inspired by an invited visit to or collaboration at SFI, or funded by an SFI grant. ©NOTICE: This working paper is included by permission of the contributing author(s) as a means to ensure timely distribution of the scholarly and technical work on a noncommercial basis. Copyright and all rights therein are maintained by the author(s). It is understood that all persons copying this information will adhere to the terms and constraints invoked by each author's copyright. These works may be reposted only with the explicit permission of the copyright holder. www.santafe.edu
The Dimensions of Individual Strings and Sequences
 INFORMATION AND COMPUTATION
, 2003
"... A constructive version of Hausdorff dimension is developed using constructive supergales, which are betting strategies that generalize the constructive supermartingales used in the theory of individual random sequences. This constructive dimension is used to assign every individual (infinite, binary ..."
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Cited by 101 (11 self)
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A constructive version of Hausdorff dimension is developed using constructive supergales, which are betting strategies that generalize the constructive supermartingales used in the theory of individual random sequences. This constructive dimension is used to assign every individual (infinite, binary) sequence S a dimension, which is a real number dim(S) in the interval [0, 1]. Sequences that
Model checking one million lines of C code
 In Proceedings of the 11th Annual Network and Distributed System Security Symposium (NDSS
, 2004
"... Implementation bugs in securitycritical software are pervasive. Several authors have previously suggested model checking as a promising means to detect improper use of system interfaces and thereby detect a broad class of security vulnerabilities. In this paper, we report on our practical experienc ..."
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Cited by 89 (3 self)
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Implementation bugs in securitycritical software are pervasive. Several authors have previously suggested model checking as a promising means to detect improper use of system interfaces and thereby detect a broad class of security vulnerabilities. In this paper, we report on our practical experience using MOPS, a tool for software model checking securitycritical applications. As examples of security vulnerabilities that can be analyzed using model checking, we pick five important classes of vulnerabilities and show how to codify them as temporal safety properties, and then we describe the results of checking them on several significant Unix applications using MOPS. After analyzing over one million lines of code, we found more than a dozen new security weaknesses in important, widelydeployed applications. This demonstrates for the first time that model checking is practical and useful for detecting security weaknesses at large scale in real, legacy systems. 1.
Reconciling simplicity and likelihood principles in perceptual organization
 Psychological Review
, 1996
"... Two principles of perceptual organization have been proposed. The likelihood principle, following H. L. E yon Helmholtz ( 1910 / 1962), proposes that perceptual organization is chosen to correspond to the most likely distal layout. The simplicity principle, following Gestalt psychology, suggests tha ..."
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Cited by 86 (17 self)
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Two principles of perceptual organization have been proposed. The likelihood principle, following H. L. E yon Helmholtz ( 1910 / 1962), proposes that perceptual organization is chosen to correspond to the most likely distal layout. The simplicity principle, following Gestalt psychology, suggests that perceptual organization is chosen to be as simple as possible. The debate between these two views has been a central topic in the study of perceptual organization. Drawing on mathematical results in A. N. Kolmogorov's ( 1965)complexity heory, the author argues that simplicity and likelihood are not in competition, but are identical. Various implications for the theory of perceptual organization and psychology more generally are outlined. How does the perceptual system derive a complex and structured description of the perceptual world from patterns of activity at the sensory receptors? Two apparently competing theories of perceptual organization have been influential. The first, initiated by Helmholtz ( 1910/1962), advocates the likelihood principle: Sensory input will be organized into the most probable distal object or event consistent with that input. The second, initiated by Wertheimer and developed by other Gestalt psychologists, advocates what Pomerantz and Kubovy (1986) called the simplicity principle: The perceptual system is viewed as finding the simplest, rather than the most likely, perceptual organization consistent with the sensory input '. There has been considerable theoretical nd empirical controversy concerning whether likelihood or simplicity is the governing principle of perceptual organization (e.g., Hatfield, &
Equivalence of Measures of Complexity Classes
"... The resourcebounded measures of complexity classes are shown to be robust with respect to certain changes in the underlying probability measure. Specifically, for any real number ffi ? 0, any uniformly polynomialtime computable sequence ~ fi = (fi 0 ; fi 1 ; fi 2 ; : : : ) of real numbers (biases ..."
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Cited by 74 (24 self)
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The resourcebounded measures of complexity classes are shown to be robust with respect to certain changes in the underlying probability measure. Specifically, for any real number ffi ? 0, any uniformly polynomialtime computable sequence ~ fi = (fi 0 ; fi 1 ; fi 2 ; : : : ) of real numbers (biases) fi i 2 [ffi; 1 \Gamma ffi], and any complexity class C (such as P, NP, BPP, P/Poly, PH, PSPACE, etc.) that is closed under positive, polynomialtime, truthtable reductions with queries of at most linear length, it is shown that the following two conditions are equivalent. (1) C has pmeasure 0 (respectively, measure 0 in E, measure 0 in E 2 ) relative to the cointoss probability measure given by the sequence ~ fi. (2) C has pmeasure 0 (respectively, measure 0 in E, measure 0 in E 2 ) relative to the uniform probability measure. The proof introduces three techniques that may be useful in other contexts, namely, (i) the transformation of an efficient martingale for one probability measu...
Quantum Algorithm For Hilberts Tenth Problem
 Int.J.Theor.Phys
, 2003
"... We explore in the framework of Quantum Computation the notion of Computability, which holds a central position in Mathematics and Theoretical Computer Science. A quantum algorithm for Hilbert’s tenth problem, which is equivalent to the Turing halting problem and is known to be mathematically noncomp ..."
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Cited by 61 (10 self)
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We explore in the framework of Quantum Computation the notion of Computability, which holds a central position in Mathematics and Theoretical Computer Science. A quantum algorithm for Hilbert’s tenth problem, which is equivalent to the Turing halting problem and is known to be mathematically noncomputable, is proposed where quantum continuous variables and quantum adiabatic evolution are employed. If this algorithm could be physically implemented, as much as it is valid in principle—that is, if certain hamiltonian and its ground state can be physically constructed according to the proposal—quantum computability would surpass classical computability as delimited by the ChurchTuring thesis. It is thus argued that computability, and with it the limits of Mathematics, ought to be determined not solely by Mathematics itself but also by Physical Principles. 1
Verification of Concurrent Programs: The AutomataTheoretic Framework
 Annals of Pure and Applied Logic
, 1987
"... We present an automatatheoretic framework to the verification of concurrent and nondeterministic programs. The basic idea is that to verify that a program P is correct one writes a program A that receives the computation of P as input and diverges only on incorrect computations of P . Now P is c ..."
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Cited by 56 (3 self)
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We present an automatatheoretic framework to the verification of concurrent and nondeterministic programs. The basic idea is that to verify that a program P is correct one writes a program A that receives the computation of P as input and diverges only on incorrect computations of P . Now P is correct if and only if a program PA , obtained by combining P and A, terminates. We formalize this idea in a framework of !automata with a recursive set of states. This unifies previous works on verification of fair termination and verification of temporal properties. 1 Introduction In this paper we present an automatatheoretic framework that unifies several trends in the area of concurrent program verification. The trends are temporal logic, model checking, automata theory, and fair termination. Let us start with a survey of these trends. In 1977 Pnueli suggested the use of temporal logic in the verification of concurrent programs [Pn77]. The basic motivation is that in the verificat...
The pitfalls of verifying floatingpoint computations
 ACM Transactions on programming languages and systems
"... Current critical systems often use a lot of floatingpoint computations, and thus the testing or static analysis of programs containing floatingpoint operators has become a priority. However, correctly defining the semantics of common implementations of floatingpoint is tricky, because semantics ma ..."
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Cited by 56 (3 self)
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Current critical systems often use a lot of floatingpoint computations, and thus the testing or static analysis of programs containing floatingpoint operators has become a priority. However, correctly defining the semantics of common implementations of floatingpoint is tricky, because semantics may change according to many factors beyond sourcecode level, such as choices made by compilers. We here give concrete examples of problems that can appear and solutions for implementing in analysis software. 1