3,670 research outputs found
A Portable High-Quality Random Number Generator for Lattice Field Theory Simulations
The theory underlying a proposed random number generator for numerical
simulations in elementary particle physics and statistical mechanics is
discussed. The generator is based on an algorithm introduced by Marsaglia and
Zaman, with an important added feature leading to demonstrably good statistical
properties. It can be implemented exactly on any computer complying with the
IEEE--754 standard for single precision floating point arithmetic.Comment: pages 0-19, ps-file 174404 bytes, preprint DESY 93-13
Type-Based Termination, Inflationary Fixed-Points, and Mixed Inductive-Coinductive Types
Type systems certify program properties in a compositional way. From a bigger
program one can abstract out a part and certify the properties of the resulting
abstract program by just using the type of the part that was abstracted away.
Termination and productivity are non-trivial yet desired program properties,
and several type systems have been put forward that guarantee termination,
compositionally. These type systems are intimately connected to the definition
of least and greatest fixed-points by ordinal iteration. While most type
systems use conventional iteration, we consider inflationary iteration in this
article. We demonstrate how this leads to a more principled type system, with
recursion based on well-founded induction. The type system has a prototypical
implementation, MiniAgda, and we show in particular how it certifies
productivity of corecursive and mixed recursive-corecursive functions.Comment: In Proceedings FICS 2012, arXiv:1202.317
Foundational Extensible Corecursion
This paper presents a formalized framework for defining corecursive functions
safely in a total setting, based on corecursion up-to and relational
parametricity. The end product is a general corecursor that allows corecursive
(and even recursive) calls under well-behaved operations, including
constructors. Corecursive functions that are well behaved can be registered as
such, thereby increasing the corecursor's expressiveness. The metatheory is
formalized in the Isabelle proof assistant and forms the core of a prototype
tool. The corecursor is derived from first principles, without requiring new
axioms or extensions of the logic
Estimating nonparametric mixed logit models via EM algorithm
The aim of this paper is to describe a Stata routine for the nonparametric estimation of mixed logit models using a Expectation-Maximisation algorithm. We also compare the performance of our estimator with respect to more typical parametric mixed logit models estimated by means of Simulated Maximum Likelihood.EM algorithm; latent class; mixed logit model; unobserved heterogeneity
Overview of Hydra: a concurrent language for synchronous digital circuit design
Hydra is a computer hardware description language that integrates several kinds of software tool (simulation, netlist generation and timing analysis) within a single circuit specification. The design language is inherently concurrent, and it offers black box abstraction and general design patterns that simplify the design of circuits with regular structure. Hydra specifications are concise, allowing the complete design of a computer system as a digital circuit within a few pages. This paper discusses the motivations behind Hydra, and illustrates the system with a significant portion of the design of a basic RISC processor
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