scholarly journals Breeding Theorem Proving Heuristics with Genetic Algorithms

10.29007/gms9 ◽  
2018 ◽  
Author(s):  
Simon Schäfer ◽  
Stephan Schulz

First-order theorem provers have to search for proofs in an infinitespace of possible derivations. Proof search heuristics play a vitalrole for the practical performance of these systems. In the currentgeneration of saturation-based theorem provers like SPASS, E,Vampire or Prover~9, one of the most important decisions is theselection of the next clause to process with the given clausealgorithms. Provers offer a wide variety of basic clause evaluationfunctions, which can often be parameterized and combined in manydifferent ways. Finding good strategies is usually left to the usersor developers, often backed by large-scale experimentalevaluations. We describe a way to automatize this process usinggenetic algorithms, evaluating a population of different strategieson a test set, and applying mutation and crossover operators to goodstrategies to create the next generation. We describe the design andexperimental set-up, and report on first promising results.

1996 ◽  
Vol 76 (06) ◽  
pp. 0939-0943 ◽  
Author(s):  
B Boneu ◽  
G Destelle ◽  

SummaryThe anti-aggregating activity of five rising doses of clopidogrel has been compared to that of ticlopidine in atherosclerotic patients. The aim of this study was to determine the dose of clopidogrel which should be tested in a large scale clinical trial of secondary prevention of ischemic events in patients suffering from vascular manifestations of atherosclerosis [CAPRIE (Clopidogrel vs Aspirin in Patients at Risk of Ischemic Events) trial]. A multicenter study involving 9 haematological laboratories and 29 clinical centers was set up. One hundred and fifty ambulatory patients were randomized into one of the seven following groups: clopidogrel at doses of 10, 25, 50,75 or 100 mg OD, ticlopidine 250 mg BID or placebo. ADP and collagen-induced platelet aggregation tests were performed before starting treatment and after 7 and 28 days. Bleeding time was performed on days 0 and 28. Patients were seen on days 0, 7 and 28 to check the clinical and biological tolerability of the treatment. Clopidogrel exerted a dose-related inhibition of ADP-induced platelet aggregation and bleeding time prolongation. In the presence of ADP (5 \lM) this inhibition ranged between 29% and 44% in comparison to pretreatment values. The bleeding times were prolonged by 1.5 to 1.7 times. These effects were non significantly different from those produced by ticlopidine. The clinical tolerability was good or fair in 97.5% of the patients. No haematological adverse events were recorded. These results allowed the selection of 75 mg once a day to evaluate and compare the antithrombotic activity of clopidogrel to that of aspirin in the CAPRIE trial.


10.29007/87vl ◽  
2018 ◽  
Author(s):  
Guillaume Bury ◽  
Raphaël Cauderlier ◽  
Pierre Halmagrand

Extending first-order logic with ML-style polymorphism allows to definegeneric axioms dealing with several sorts. Until recently, mostautomated theorem provers relied on preprocess encodings intomono/many-sorted logic to reason within such theories. In this paper, wediscuss the implementation of polymorphism into thefirst-order tableau-based automated theorem prover Zenon. Thisimplementation leads to slightly modify some basic parts of the code,from the representation of expressions to the proof-search algorithm.


2011 ◽  
Vol 346 ◽  
pp. 419-425
Author(s):  
Shu Qiang Yu ◽  
Xu Dong Cheng ◽  
Peng Ju Qin

In the process of tunnel excavation, due to the complexity of geological and geomorphic conditions etc, in the given tunnel heading shape conditions, it is more important to determine the tunnel location near tunnel portal. The large-scale finite numerical simulation software ANSYS is adopted to analyze that stress and displacement of tunnel surrounding rock vary with unsymmetrical location, including burial depth, slope angle and thickness of overburden layer. The analysis results show that: Under the condition of reinforcement in advance, it is proper for the tunnel excavation to reduce burial depth and thickness of overburden layer. This paper provides the theory basis for rational selection of support types and parameters and proper determination of tunnel location.


2019 ◽  
Vol 2 (179) ◽  
pp. 5-27
Author(s):  
Myroslav PAVLYUK ◽  
Volodymyr SHLAPINSKY ◽  
Olesya SAVCHAK ◽  
Myroslav TERNAVSKY

Here the Cretaceous and Paleogene flysh of the Duklya-Chornohora, Burkut, Magura, Marmarosh and Pieniny covers was studied that in the north-western sector of the Ukrainian Carpathians near the border of Poland and Slovakia (Lemkivsky segment) distinguish themselves by very inclined thrusts. Spatially the given tectonic units are within the limits of so called hydrothermal field unfavourable as a whole, as to the presence of hydrocarbons on a large scale here. But there were distinguished small plots with prevalence of hydrocarbons in the gas composition. Prospects of the potential for gas presence in the region should be connected with the areas that spatially gravitate towards Transcarpathian deep. Studied area consists of several tectonic units of the first order. These are covers located farther south-west of Krosno cover: Duklya-Chornohora, Burkut (Porkulets), Magura, Marmarosh and Pieniny covers, in the south-west the studied terrane is limited by the Transcarpathian deep, and farther west – by the state border of Ukraine and Slovakia, in the south-east – by the Rika Rriver, in the north-east – by the zone of joining of Duklya-Chornohora and Krosno covers. Prospects of the potential for oil end gas presence in the given area, as in the Folded Carpathians on the whole, should be determined by the complex of all accompanying parameters: structural, collecting and covering, hadrochemical and geochemical. For the given area of the Carpathians the geochemical factor is the most important.


10.29007/ftc2 ◽  
2018 ◽  
Author(s):  
Guillaume Burel

The λΠ-calculus modulo is a proof language that has been proposed as a proof standardfor (re-)checking and interoperability. Resolution and superposition are proof-search methods that are used in state-of-the-art first-order automated theorem provers. We provide a shallow embedding of resolution and superposition proofs in the λΠ-calculus modulo, thus offering a way to check these proofs in a trusted setting, and to combine them with other proofs. We implement this embedding as a backend of the prover iProver Modulo.


2003 ◽  
Vol 93 ◽  
pp. 212-294
Author(s):  
Richard Gordon ◽  
Joyce Reynolds

The intention of this survey, as of its predecessors, is to assess the contribution to Roman studies of recent progress in epigraphy. Its aim is to draw attention to the more important newly-published inscriptions, to known or familiar texts whose significance has been reinterpreted, to the progress of publishing projects, and to a selection of recent work based upon epigraphic sources. It is mainly, but not exclusively, concerned with the implications of new work for Roman history and for that reason does not consider a number of otherwise interesting Hellenistic texts. It hardly needs to be said that there has been no publication remotely as significant as theSC de Cn. Pisone patre, which was reported in the previous survey, and to which we devote some further space here. But there are plenty of new or revised texts of sufficient interest: an honorific decree from Pergamon for a member of the city élite who clearly played a key part in the negotiations with the Romans at the time of the war with Aristonicus; the uncle of Cicero initiated into the Samothracian mysteries in 100B.C.; Octavian honoured at Klaros on account of his ‘quasi-divine exploits’; theTessera Paemeiobrigensisoraes Bergidense, which appears to be an edict by Augustus of 15 B.C. alluding to a hitherto unknown Spanish province of this period — ‘Transduria(na)’; a startling re-interpretation of the significance of the ‘Tiberiéum’ inscription set up by Pontius Pilate at Caesarea Maritima; the splendid replacement for Henzen'sActa Arvalium; the foundation inscription of Sarmizegetusa; one of the very earliest references to waterwheels, calledhydromēchanai(a word unknown to LSJ), in a long-known second-century A.D. text from Macedonia, where they were evidently employed on a large scale to produce income for the city; the transport by ‘barbarians’ of a Roman votive inscription, besides more obviously valuable booty, more than 200 km from the Roman frontier into what is now the Ukraine; and a re-reading suggesting that the well-known ‘milestone’ from Phoenicia honouring Julian astemplorum restauratorwas indeed, as Bowersock argued, erected immediately before the Persian expedition.


2014 ◽  
Vol 10 (1) ◽  
pp. 1-15
Author(s):  
Z. Láng

The possible effect of shaker harvest on root damage of 10-year-old cherry trees was studied on a simple tree structure model. The model was composed of elastic trunk and rigid main roots, the ends of which were connected to the surrounding soil via springs and dumping elements. Equations were set up to be able to calculate the relation between shaking height on the trunk and strain in the roots. To get the data for root break and their elongation at different shaking heights on the trunk, laboratory and field experiments were carried out on cherry trees and on their roots. Having evaluated the measured and calculated data it could be concluded that root damage is to be expected even at 3.6% strain and the risk of it increases with increased trunk amplitudes, i.e.with the decrease of shaking heightat smaller stem diameters (i.e. in younger plantation), andif the unbalanced mass of the shaker machine is too large for the given tree size.


At production of fabrics, including fabrics for agricultural purpose, an important role is played by the cor-rect adjustment of operation of machine main regulator. The quality of setup of machine main controller is determined by the proper selection of rotation angle of warp beam weaving per one filling thread. In the pro-cess of using the regulator as a result of mistakes in adjustment, wear of transmission gear and backlashes in connections of details there are random changes in threads length. The purpose of the article is the research of property of random errors of basis giving by STB machine regulator. Mistakes can be both negative, and positive. In case of emergence only negative or only positive mistakes operation of the machine becomes im-possible as there will be a consecutive accumulation of mistakes. As a result of experimental data processing for stable process of weaving and the invariable diameter of basis threads winding of threads it is revealed that the random error of giving is set up as linear function of the accidental length having normal distribution. Measurements of accidental deviations in giving of a basis by the main regulator allowed to construct a curve of normal distribution of its actual length for one pass of weft thread. The presented curve of distribution of random errors in giving of a basis is the displaced curve of normal distribution of the accidental sizes. Also we define the density of probability of normal distribution of basis giving errors connected with a margin er-ror operation of the main regulator knowing of which allows to plan ways of their decrease that is important for improvement of quality of the produced fabrics.


2014 ◽  
Vol 31 (2) ◽  
Author(s):  
Mariela Gabioux ◽  
Vladimir Santos da Costa ◽  
Joao Marcos Azevedo Correia de Souza ◽  
Bruna Faria de Oliveira ◽  
Afonso De Moraes Paiva

Results of the basic model configuration of the REMO project, a Brazilian approach towards operational oceanography, are discussed. This configuration consists basically of a high-resolution eddy-resolving, 1/12 degree model for the Metarea V, nested in a medium-resolution eddy-permitting, 1/4 degree model of the Atlantic Ocean. These simulations performed with HYCOM model, aim for: a) creating a basic set-up for implementation of assimilation techniques leading to ocean prediction; b) the development of hydrodynamics bases for environmental studies; c) providing boundary conditions for regional domains with increased resolution. The 1/4 degree simulation was able to simulate realistic equatorial and south Atlantic large scale circulation, both the wind-driven and the thermohaline components. The high resolution simulation was able to generate mesoscale and represent well the variability pattern within the Metarea V domain. The BC mean transport values were well represented in the southwestern region (between Vitória-Trinidade sea mount and 29S), in contrast to higher latitudes (higher than 30S) where it was slightly underestimated. Important issues for the simulation of the South Atlantic with high resolution are discussed, like the ideal place for boundaries, improvements in the bathymetric representation and the control of bias SST, by the introducing of a small surface relaxation. In order to make a preliminary assessment of the model behavior when submitted to data assimilation, the Cooper & Haines (1996) method was used to extrapolate SSH anomalies fields to deeper layers every 7 days, with encouraging results.


1979 ◽  
Vol 44 (7) ◽  
pp. 2064-2078 ◽  
Author(s):  
Blahoslav Sedláček ◽  
Břetislav Verner ◽  
Miroslav Bárta ◽  
Karel Zimmermann

Basic scattering functions were used in a novel calculation of the turbidity ratios for particles having the relative refractive index m = 1.001, 1.005 (0.005) 1.315 and the size α = 0.05 (0.05) 6.00 (0.10) 15.00 (0.50) 70.00 (1.00) 100, where α = πL/λ, L is the diameter of the spherical particle, λ = Λ/μ1 is the wavelength of light in a medium with the refractive index μ1 and Λ is the wavelength of light in vacuo. The data are tabulated for the wavelength λ = 546.1/μw = 409.357 nm, where μw is the refractive index of water. A procedure has been suggested how to extend the applicability of Tables to various refractive indices of the medium and to various turbidity ratios τa/τb obtained with the individual pairs of wavelengths λa and λb. The selection of these pairs is bound to the sequence condition λa = λ0χa and λb = λ0χb, in which b-a = δ = 1, 2, 3; a = -2, -1, 0, 1, 2, ..., b = a + δ = -1, 0, 1, 2, ...; λ0 = λa=0 = 326.675 nm; χ = 546.1 : 435.8 = 1.2531 is the quotient of the given sequence.


Sign in / Sign up

Export Citation Format

Share Document