617 research outputs found

    Lazy AC-Pattern Matching for Rewriting

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    We define a lazy pattern-matching mechanism modulo associativity and commutativity. The solutions of a pattern-matching problem are stored in a lazy list composed of a first substitution at the head and a non-evaluated object that encodes the remaining computations. We integrate the lazy AC-matching in a strategy language: rewriting rule and strategy application produce a lazy list of terms.Comment: In Proceedings WRS 2011, arXiv:1204.531

    Yield and quality response of drip-irrigated pepper under Mediterranean climatic conditions to various water regimes

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    This study examines the effects of different irrigation regimes on yield and water use of pepper irrigated by a drip system under field conditions during the 2004 growing season at the Soil and Water Resources Research Institute in Tarsus, Turkey under Mediterranean climatic conditions. The field trials consisted of three irrigation intervals (IF1:20±2, IF2:40±2 and IF3:60±2 mm of cumulative pan evaporation) and evaluated by three irrigation levels (DI1=0.50, DI2=0.75 and DI3=1.00). Both the irrigation levels (DI) and intervals (IF) had significantly different effects on pepper yields. The maximum and minimum yields were obtained from the IF1DI3 and IF3DI1 treatment plots as 35920 and 21390 kg ha-1, respectively. The yields and yield components decreased as irrigation levels decreased for each irrigation interval. However, the larger irrigation interval (IF3) resulted in lower yields with all irrigation levels. Pepper seasonal evapotranspiration varied from a low 327 mm in the more stressfull treatment (IF3DI1) to a high 517 mm in the well irrigated control (IF1DI3). Significant linear relations were found between the pepper yield and the total water use for each irrigation interval. Irrigation intervals resulted in similar water use in the treatments with the same irrigation level. Water use efficiency (WUE) and irrigation water use efficiency (IWUE) values were significantly influenced by the irrigation intervals and levels. WUE ranged from 6.0 kg m-3 in IF3DI2 to 7.8 kg m-3 in the IF1DI1. The maximum IWUE was observed in IF1DI1, and the minimum IWUE was in IF3DI3 treatment. Both irrigation levels and frequencies had significantly different effects on quality parameters such as the first and second quality yield, number of fruit, mean fruit weight, pepper length and width, as well as plant height at harvest. In conclusion, the IF1DI3 irrigation regime is recommended for field grown pepper in order to attain higher yields with improved quality. Economic evaluation revealed that full irrigation treatment (IF1DI3) generated the highest net income. However, under water scarcity conditions, IF1DI2 treatment can provide an acceptable net income.Key words: Pepper, deficit irrigation, water use efficiency, yield response factor, economic evaluation

    TYC 2675-663-1: A newly discovered W UMa system in an active state

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    The recently discovered eclipsing binary system TYC 2675-663-1 is a X-ray source, and shows properties in the optical that are similar to the W UMa systems, but are somewhat unusual compared to what is seen in other contact binary systems. The goal of this work is to characterize its properties and investigate its nature by means of detailed photometric and spectroscopic observations. We have performed extensive V-band photometric measurements with the INTEGRAL satellite along with ground-based multi-band photometric observations, as well as high-resolution spectroscopic monitoring from which we have measured the radial velocities of the components. These data have been analysed to determine the stellar properties, including the absolute masses and radii. Additional low-resolution spectroscopy was obtained to investigate spectral features. From the measured eclipse timings we determine an orbital period for the binary of P=0.4223576+-0.0000009 days. The light-curve and spectroscopic analyses reveal the observations to be well represented by a model of an overcontact system composed of main-sequence F5 and G7 stars (temperature difference of nearly 1000 K), with the possible presence of a third star. Low-resolution optical spectroscopy reveals a complex H alpha emission, and other features that are not yet understood. The unusually large mass ratio of q=0.81+-0.05 places it in the rare "H" (high mass ratio) subclass of the W UMa systems, which are presumably on their way to coalescence.Comment: 12 pages in double column format. Accepted for publication in Astronomy and Astrophysic

    Quantifying the optical properties and chromophore concentrations of turbid media by chemometric analysis of hyperspectral diffuse reflectance data collected using a fourier interferometric imaging system

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    A non-contact Fourier transform interferometric imaging system was used to collect hyperspectral images of the steady-state diffuse reflectance from a point source in turbid media for the spectral range of 550-850 nm. Steady-state diffuse reflectance profiles were generated from the hyperspectral images, and partial least-squares (PLS) regression was performed on the diffuse reflectance profiles to quantify absorption (mu (alpha)) and reduced scattering (mu (s)') properties of turbid media. The feasibility of using PLS regression to predict optical properties was examined for two different sets of spatially-resolved diffuse reflectance data. One set of data was collected from 40 turbid phantoms, while the second set was generated by convolving Monte Carlo simulations with the instrument response of the imaging system. Study results show that PLS prediction of mu (alpha) and mu (s)' was accurate to within +/-8% and +/-5%, respectively, when the model was trained on turbid phantom data. Moreover, PLS prediction of optical properties was considerably faster and more efficient than direct least-squares fitting of spatially-resolved profiles. When the PLS model was trained on Monte Carlo simulated data and subsequently used to predict mu (alpha) and mu (s)' from the diffuse reflectance of turbid phantom, the percent accuracies degraded to +/-12% and +/-5%, respectively. These accuracy values are applicable to homogenous, semi-infinite turbid phantoms with optical property ranges comparable to tissues

    Trauma Mechanisms and Injuries Associated with Go-Karting

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    Annually, approximately 600 patients seek medical attention after go-kart accidents in the Netherlands. A large variability in injury patterns can be encountered. Knowledge of the trauma mechanisms of go-kart accidents and insight into the associated injuries is limited and requires improvement. Such additional knowledge may lead to customized trauma protocols for patients with a high index of suspicion on go-kart injuries. Research into trauma mechanisms may also lead to implementation of improved or additional safety measures for go-karting, involving both the go-karts itself as well as prerequisites to the go-kart tracks and qualifications for the drivers. The main trauma mechanisms involved in go-kart accidents, and three cases to illustrate the variety of injuries are described in the current manuscript

    Tactics for Reasoning modulo AC in Coq

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    We present a set of tools for rewriting modulo associativity and commutativity (AC) in Coq, solving a long-standing practical problem. We use two building blocks: first, an extensible reflexive decision procedure for equality modulo AC; second, an OCaml plug-in for pattern matching modulo AC. We handle associative only operations, neutral elements, uninterpreted function symbols, and user-defined equivalence relations. By relying on type-classes for the reification phase, we can infer these properties automatically, so that end-users do not need to specify which operation is A or AC, or which constant is a neutral element.Comment: 16

    Football and exchange rates: Empirical support for behavioral economics

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    Recently, economic theory has been expanded to incorporate emotions, which have been assumed to play an important role in financial decisions. The present study illustrates this by showing a connection between the sports performance of popular national football teams (Besiktas, Fenerbahce, and Galatasaray) and performance of the Turkish economy. Specifically, a significant positive association was found between the success of three major professional Turkish football teams and the exchange rate of the Turkish lira against the U.S. dollar. The effect of the football success of several Turkish football teams on the exchange rate of the Turkish lira was examined using the simultaneous multiple regression model with predictor measures of wins, losses, and ties for different combinations of teams to predict the depreciation rate of the Turkish lira between the years 1987 and 2003. Wins by Turkish football teams against foreign (non-Turkish) rivals increased with exchange rate depreciation of the Turkish lira against the U.S. dollar. © Psychological Reports 2007

    Structural Synthesis for GXW Specifications

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    We define the GXW fragment of linear temporal logic (LTL) as the basis for synthesizing embedded control software for safety-critical applications. Since GXW includes the use of a weak-until operator we are able to specify a number of diverse programmable logic control (PLC) problems, which we have compiled from industrial training sets. For GXW controller specifications, we develop a novel approach for synthesizing a set of synchronously communicating actor-based controllers. This synthesis algorithm proceeds by means of recursing over the structure of GXW specifications, and generates a set of dedicated and synchronously communicating sub-controllers according to the formula structure. In a subsequent step, 2QBF constraint solving identifies and tries to resolve potential conflicts between individual GXW specifications. This structural approach to GXW synthesis supports traceability between requirements and the generated control code as mandated by certification regimes for safety-critical software. Synthesis for GXW specifications is in PSPACE compared to 2EXPTIME-completeness of full-fledged LTL synthesis. Indeed our experimental results suggest that GXW synthesis scales well to industrial-sized control synthesis problems with 20 input and output ports and beyond.Comment: The long (including appendix) version being reviewed by CAV'16 program committee. Compared to the submitted version, one author (out of her wish) is moved to the Acknowledgement. (v2) Corrected typos. (v3) Add an additional remark over environment assumption and easy corner case

    A catalog of chromospherically active binary stars (third edition)

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    Chromospherically Active Binaries (CAB) catalogue have been revised and updated. With 203 new identifications, the number of CAB stars is increased to 409. Catalogue is available in electronic format where each system has various number of lines (sub-orders) with a unique order number. Columns contain data of limited number of selected cross references, comments to explain peculiarities and position of the binarity in case it belongs to a multiple system, classical identifications (RS CVn, BY Dra), brightness and colours, photometric and spectroscopic data, description of emission features (Ca II H&K, HαH_{\alpha}, UV, IR), X-Ray luminosity, radio flux, physical quantities and orbital information, where each basic entry are referenced so users can go original sources.Comment: 5 pages, including 2 figures and 3 tables, accepted for publication in MNRA

    DNA bending by photolyase in specific and non-specific complexes studied by atomic force microscopy

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    Specific and non-specific complexes of DNA and photolyase are visualised by atomic force microscopy. As a substrate for photolyase a 1150 bp DNA restriction fragment was UV-irradiated to produce damaged sites at random positions. Comparison with a 735 bp undamaged DNA fragment made it possible to separate populations of specific and non-specific photolyase complexes on the 1150 bp fragment, relieving the need for highly defined substrates. Thus it was possible to compare DNA bending for specific and non-specific interactions. Non-specific complexes show no significant bending but increased rigidity compared to naked DNA, whereas specific complexes show DNA bending of on average 36°and higher flexibility. A model obtained by docking shows that photolyase can accommodate a 36°bent DNA in the vicinity of the active site
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