39,660 research outputs found

    Converting Natural Language Phrases in Lambda Calculus to Generalized Constraint Language

    Get PDF
    This study explores one aspect of bridging Computing with Words with Natural Language Processing, to connect the extraction capabilities of Natural Language Processing with the inference capabilities of Computing with Words. Computing with Words uses Generalized Constraint Language to show the logical proposition of a given expression. A program was written to convert a logic-based lambda calculus representation of any English natural language expression into Generalized Constraint Language. The scope of this project is set to tagging parts of speech in simplistic expressions and is a foundation for expanding upon more complex lambda calculus expressions into Generalized Constraint Language. This program tags the parts of speech from the lambda calculus expression and outputs the Generalized Constraint Language of the expression, showing the constraint on an idea in the original sentence. This project establishes an entry point and is designed with further improvements and modifications in mind. The output from this project is useful in providing an understanding of bridging Natural Language Processing and Computing with Words, as the program creates a baseline of extracting parts of speech from a sentence to highlighting significant meaning of the given sentence.https://openriver.winona.edu/urc2019/1030/thumbnail.jp

    Combining Graph-Based and Deduction-Based Information-Flow Analysis

    Get PDF
    Information flow control (IFC) is a category of techniques for ensuring system security by enforcing information flow properties such as non-interference. Established IFC techniques range from fully automatic approaches with much over-approximation to approaches with high pre- cision but potentially laborious user interaction. A noteworthy approach mitigating the weaknesses of both automatic and interactive IFC tech- niques is the hybrid approach, developed by Küsters et al., which – how- ever – is based on program modifications and still requires a significant amount of user interaction. In this paper, we present a combined approach that works without any program modifications. It minimizes potential user interactions by apply- ing a dependency-graph-based information-flow analysis first. Based on over-approximations, this step potentially generates false positives. Pre- cise non-interference proofs are achieved by applying a deductive theorem prover with a specialized information-flow calculus for checking that no path from a secret input to a public output exists. Both tools are fully integrated into a combined approach, which is evaluated on a case study, demonstrating the feasibility of automatic and precise non-interference proofs for complex programs

    On Role Logic

    Full text link
    We present role logic, a notation for describing properties of relational structures in shape analysis, databases, and knowledge bases. We construct role logic using the ideas of de Bruijn's notation for lambda calculus, an encoding of first-order logic in lambda calculus, and a simple rule for implicit arguments of unary and binary predicates. The unrestricted version of role logic has the expressive power of first-order logic with transitive closure. Using a syntactic restriction on role logic formulas, we identify a natural fragment RL^2 of role logic. We show that the RL^2 fragment has the same expressive power as two-variable logic with counting C^2 and is therefore decidable. We present a translation of an imperative language into the decidable fragment RL^2, which allows compositional verification of programs that manipulate relational structures. In addition, we show how RL^2 encodes boolean shape analysis constraints and an expressive description logic.Comment: 20 pages. Our later SAS 2004 result builds on this wor

    A type system for components

    Get PDF
    In modern distributed systems, dynamic reconfiguration, i.e., changing at runtime the communication pattern of a program, is chal- lenging. Generally, it is difficult to guarantee that such modifications will not disrupt ongoing computations. In a previous paper, a solution to this problem was proposed by extending the object-oriented language ABS with a component model allowing the programmer to: i) perform up- dates on objects by means of communication ports and their rebinding; and ii) precisely specify when such updates can safely occur in an object by means of critical sections. However, improper rebind operations could still occur and lead to runtime errors. The present paper introduces a type system for this component model that extends the ABS type system with the notion of ports and a precise analysis that statically enforces that no object will attempt illegal rebinding

    Modified Regge calculus as an explanation of dark energy

    Full text link
    Using Regge calculus, we construct a Regge differential equation for the time evolution of the scale factor a(t)a(t) in the Einstein-de Sitter cosmology model (EdS). We propose two modifications to the Regge calculus approach: 1) we allow the graphical links on spatial hypersurfaces to be large, as in direct particle interaction when the interacting particles reside in different galaxies, and 2) we assume luminosity distance DLD_L is related to graphical proper distance DpD_p by the equation DL=(1+z)DpDpD_L = (1+z)\sqrt{\overrightarrow{D_p}\cdot \overrightarrow{D_p}}, where the inner product can differ from its usual trivial form. The modified Regge calculus model (MORC), EdS and Λ\LambdaCDM are compared using the data from the Union2 Compilation, i.e., distance moduli and redshifts for type Ia supernovae. We find that a best fit line through log(DLGpc)\displaystyle \log{(\frac{D_L}{Gpc})} versus logz\log{z} gives a correlation of 0.9955 and a sum of squares error (SSE) of 1.95. By comparison, the best fit Λ\LambdaCDM gives SSE = 1.79 using HoH_o = 69.2 km/s/Mpc, ΩM\Omega_{M} = 0.29 and ΩΛ\Omega_{\Lambda} = 0.71. The best fit EdS gives SSE = 2.68 using HoH_o = 60.9 km/s/Mpc. The best fit MORC gives SSE = 1.77 and HoH_o = 73.9 km/s/Mpc using R=A1R = A^{-1} = 8.38 Gcy and m=1.71×1052m = 1.71\times 10^{52} kg, where RR is the current graphical proper distance between nodes, A1A^{-1} is the scaling factor from our non-trival inner product, and mm is the nodal mass. Thus, MORC improves EdS as well as Λ\LambdaCDM in accounting for distance moduli and redshifts for type Ia supernovae without having to invoke accelerated expansion, i.e., there is no dark energy and the universe is always decelerating.Comment: 15 pages text, 6 figures. Revised as accepted for publication in Class. Quant. Gra

    Adaptable processes

    Get PDF
    We propose the concept of adaptable processes as a way of overcoming the limitations that process calculi have for describing patterns of dynamic process evolution. Such patterns rely on direct ways of controlling the behavior and location of running processes, and so they are at the heart of the adaptation capabilities present in many modern concurrent systems. Adaptable processes have a location and are sensible to actions of dynamic update at runtime; this allows to express a wide range of evolvability patterns for concurrent processes. We introduce a core calculus of adaptable processes and propose two verification problems for them: bounded and eventual adaptation. While the former ensures that the number of consecutive erroneous states that can be traversed during a computation is bound by some given number k, the latter ensures that if the system enters into a state with errors then a state without errors will be eventually reached. We study the (un)decidability of these two problems in several variants of the calculus, which result from considering dynamic and static topologies of adaptable processes as well as different evolvability patterns. Rather than a specification language, our calculus intends to be a basis for investigating the fundamental properties of evolvable processes and for developing richer languages with evolvability capabilities

    W(h)ither calculus?

    Get PDF

    Cell Cycle Control in Eukaryotes: a BioSpi model

    Get PDF
    This paper presents a stochastic model of the cell cycle control in eukaryotes. The framework used is based on stochastic process algebras for mobile systems. The automatic tool used in the simulation is the BioSpi. We compare our approach with classical ODE specications

    A logic programming framework for modeling temporal objects

    Get PDF
    Published versio
    corecore