624 research outputs found

    Decidability properties for fragments of CHR

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    We study the decidability of termination for two CHR dialects which, similarly to the Datalog like languages, are defined by using a signature which does not allow function symbols (of arity >0). Both languages allow the use of the = built-in in the body of rules, thus are built on a host language that supports unification. However each imposes one further restriction. The first CHR dialect allows only range-restricted rules, that is, it does not allow the use of variables in the body or in the guard of a rule if they do not appear in the head. We show that the existence of an infinite computation is decidable for this dialect. The second dialect instead limits the number of atoms in the head of rules to one. We prove that in this case, the existence of a terminating computation is decidable. These results show that both dialects are strictly less expressive than Turing Machines. It is worth noting that the language (without function symbols) without these restrictions is as expressive as Turing Machines

    The State of Utah v. Joshua Jacob St. Clair : Brief of Appellant

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    APPEAL FROM JUDGMENT, SENTENCE (COMMITMENT) OF THIRD JUDICIAL DISTRICT COURT OF TOOELE COUNTY HONORABLE JOHN A. ROKIC

    Detection of genetically modified plant products by protein strip testing: an evaluation of real-life samples

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    The determination of the presence of genetically modified plant material by the detection of expressed genetically engineered proteins using lateral flow protein strip tests has been evaluated in different matrices. The presence of five major genetically engineered proteins (CP4-EPSPS, CryIAb, Cry9C, PAT/pat and PAT/bar protein) was detected at low levels in seeds, seed/leaf powder and leaf tissue from genetically modified soy, maize or oilseed rape. A comparison between &quot;protein strip test&quot; (PST) and &quot;polymerase chain reaction&quot; (PCR) analysis of genetically modified food/feed samples demonstrates complementarities of both techniques. -® Springer-Verlag 2007</p

    Improving the Outcome of a Probabilistic Logic Music System Generator by Using Perlin Noise

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    APOPCALEAPS is a logic-based music generation program that uses high level probabilistic rules. The music produced by APOPCALEAPS is controlled by parameters that can be customized by a user to create personalized songs. Perlin noise is a type of gradient noise algorithm which generates smooth and controllable variations of random numbers. This paper introduces the idea of using a Perlin noise algorithm on songs produced by APOPCALEAPS to alter their melody. The noise system modifies the song’s melody with noise values that fluctuate as measures change in a song. Songs with more notes and more elaborate differences between the notes are modified by the system more than simpler songs. The output of the system is a different but similar song. This research can be used for generation of music with structure where one would need to generate variants on a theme

    The impact of scholarships on students’ performance: a study on five Italian universities

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    This paper estimates the effect of receiving a need-based grant on the performance of university students in Italy. We perform both cross-sectional (between-universities) and within-universities propensity score matching analyses in order to evaluate the effect of grants on several students’ performance indicators as first year credits, dropout, and study efficiency. The findings suggest that financial aid positively affects students’ performances and completion in a substantial and statistically robust way. The positive impact is heterogeneous across universities, while few differences are detected for subgroups of students within them. Reinforcing the financial aid policy can simultaneously help disadvantaged students and foster the overall academic performance of Italian universities

    CHR(PRISM)-based Probabilistic Logic Learning

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    PRISM is an extension of Prolog with probabilistic predicates and built-in support for expectation-maximization learning. Constraint Handling Rules (CHR) is a high-level programming language based on multi-headed multiset rewrite rules. In this paper, we introduce a new probabilistic logic formalism, called CHRiSM, based on a combination of CHR and PRISM. It can be used for high-level rapid prototyping of complex statistical models by means of "chance rules". The underlying PRISM system can then be used for several probabilistic inference tasks, including probability computation and parameter learning. We define the CHRiSM language in terms of syntax and operational semantics, and illustrate it with examples. We define the notion of ambiguous programs and define a distribution semantics for unambiguous programs. Next, we describe an implementation of CHRiSM, based on CHR(PRISM). We discuss the relation between CHRiSM and other probabilistic logic programming languages, in particular PCHR. Finally we identify potential application domains

    Extreme Wave Storms and Atmospheric Variability at the Spanish Coast of the Bay of Biscay

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    This paper examines the characteristics and long-term variability of storminess for the Spanish coast of the Bay of Biscay for the period 1948 to 2015, by coupling wave (observed and modelled) and atmospheric datasets. The diversity of atmospheric mechanisms that are responsible for wave storms are highlighted at different spatial and temporal scales: synoptic (cyclone) and low frequency (teleconnection patterns) time scales. Two types of storms, defined mostly by wave period and storm energy, are distinguished, resulting from the distance to the forcing cyclones, and the length of the fetch area. No statistically significant trends were found for storminess and the associated atmospheric indices over the period of interest. Storminess reached a maximum around the decade of the 1980s, while less activity occurred at the beginning and end of the period of study. In addition, the results reveal that only the WEPI (West Europe Pressure Anomaly Index), EA (Eastern Atlantic), and EA/WR (Eastern Atlantic/Western Russia) teleconnection patterns are able to explain a substantial percentage of the variability in storm climate, suggesting the importance of local factors (W-E exposition of the coast) in controlling storminess in this region.This paper has been possible within the framework of the research project 17.JU11.64661 “Climatología Histórica de temporales en el área cantábrica (1851–2015)”, funded by SODERCAN S.A. (Sociedad para el Desarrollo Regional de Cantabria) and Programa Operativo FEDER, and the support of Biodiversity Foundation of the Ministry for Ecological Transition of Spain

    Validation of the performance of a GMO multiplex screening assay based on microarray detection

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    A new screening method for the detection and identification of GMO, based on the use of multiplex PCR followed by microarray, has been developed and is presented. The technology is based on the identification of quite ubiquitous GMO genetic target elements first amplified by PCR, followed by direct hybridisation of the amplicons on a predefined microarray (DualChip® GMO, Eppendorf, Germany). The validation was performed within the framework of a European project (Co-Extra, contract no 007158) and in collaboration with 12 laboratories specialised in GMO detection. The present study reports the strategy and the results of an ISO complying validation of the method carried out through an inter-laboratory study. Sets of blind samples were provided consisting of DNA reference materials covering all the elements detectable by specific probes present on the array. The GMO concentrations varied from 1% down to 0.045%. In addition, a mixture of two GMO events (0.1% RRS diluted in 100% TOPAS19/2) was incorporated in the study to test the robustness of the assay in extreme conditions. Data were processed according to ISO 5725 standard. The method was evaluated with predefined performance criteria with respect to the EC CRL method acceptance criteria. The overall method performance met the acceptance criteria; in particular, the results showed that the method is suitable for the detection of the different target elements at 0.1% concentration of GMO with a 95% accuracy rate. This collaborative trial showed that the method can be considered as fit for the purpose of screening with respect to its intra- and inter-laboratory accuracy. The results demonstrated the validity of combining multiplex PCR with array detection as provided by the DualChip® GMO (Eppendorf, Germany) for the screening of GMO. The results showed that the technology is robust, practical and suitable as a screening too
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