7,460 research outputs found

    Adaptive text mining: Inferring structure from sequences

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    Text mining is about inferring structure from sequences representing natural language text, and may be defined as the process of analyzing text to extract information that is useful for particular purposes. Although hand-crafted heuristics are a common practical approach for extracting information from text, a general, and generalizable, approach requires adaptive techniques. This paper studies the way in which the adaptive techniques used in text compression can be applied to text mining. It develops several examples: extraction of hierarchical phrase structures from text, identification of keyphrases in documents, locating proper names and quantities of interest in a piece of text, text categorization, word segmentation, acronym extraction, and structure recognition. We conclude that compression forms a sound unifying principle that allows many text mining problems to be tacked adaptively

    The Use of Chloride, Citric and Ascorbic Acid Dip and Packaged Film to Extend the Shelf Life of Pejerrey (Odonthested bonaerensis) during Storage at Different Temperatures

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    The objective of this study was to analyze the effect of chloride, citric and ascorbic acid dip treatments in conjunction with two types of packaging films (with high and low gas permeability) on microbial growth in samples of pejerrey fillets (Odonthestes bonaerensis) at three storage temperatures (4˚C, 0˚C and −1.5˚C). Colour, pH, texture modification and chemical changes were also studied. Psychrotrophic microorganisms, sp. were modelled by the Gompertz’ equation. Lag phase duration, specific growth rate and maximum population density were calculated. The activation energy (E() was calculated reaching values of 147 and 177 kJ/mol when the low permeability packaging films were employed. We used psychrotrophic microorganisms, sp., as a predictor of the shelf life of product. The application of treatment with chloride, citric and ascorbic acids, extended 1 - 2 days the storage life of the product (time to reach 106 CFU/g) when the packaging material used was polyethylene. The use of chloride, citric and ascorbic acids and vacuum packaging produced shelf life values of 7.7, >25 and >25 days at 4˚C, 0˚C and −1.5˚C respectively. The products had very good organoleptic characteristics, maintained their colour and texture appropriate, and absence of pathogenic microorganisms. These values indicated that the growth models were acceptable for expressing the growth of microorganisms on pejerrey fillets, which can be applied to ensure the safety of fish and to establish standards for avoiding microbial contamination.Fil: Copes, Julio Alberto. Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias; ArgentinaFil: Pellicer, Karina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias; ArgentinaFil: Bigeon, Gisela. Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias; ArgentinaFil: Giannuzzi, Leda. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos; Argentin

    Screening analysis and selection of emission reduction concepts for intermittent combustion aircraft engines

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    An analysis was conducted to screen, evaluate, and select three engine exhaust emission reduction concepts from a group of 14 candidate alternatives. A comprehensive literature search was conducted to survey the emission reduction technology state-of-the-art and establish contact with firms working on intermittent combustion engine development and pollution reduction problems. Concept development, advantages, disadvantages, and expected emission reduction responses are stated. A set of cost effectiveness criteria was developed, appraised for relative importance, and traded off against each concept so that its merit could be determined. A decision model was used to aid the evaluators in managing the criteria, making consistent judgements, calculating merit scores, and ranking the concepts. An Improved Fuel Injection System, Improved Cooling Combustion Chamber, and a Variable Timing Ignition System were recommended to NASA for approval and further concept development. An alternate concept, Air Injection, was also recommended

    Automatic Correction of Arabic Dyslexic Text

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    This paper proposes an automatic correction system that detects and corrects dyslexic errors in Arabic text. The system uses a language model based on the Prediction by Partial Matching (PPM) text compression scheme that generates possible alternatives for each misspelled word. Furthermore, the generated candidate list is based on edit operations (insertion, deletion, substitution and transposition), and the correct alternative for each misspelled word is chosen on the basis of the compression codelength of the trigram. The system is compared with widely-used Arabic word processing software and the Farasa tool. The system provided good results compared with the other tools, with a recall of 43%, precision 89%, F1 58% and accuracy 81%

    Effects of Optaflexx alone or in combination with BoVantage on the performance and carcass merit of finishing heifers

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    Beta agonists, including Optaflexx (Elanco Animal Health, Greenfield, IN), are now routinely fed to finishing cattle as a means of increasing carcass weight and efficiency of carcass weight gain during the final 20 to 42 days on feed. BoVantage, a product recently introduced by Kent Nutrition Group (Muscatine, IA) for use in feedlot cattle, has been observed to improve efficiency of gain late in the finishing phase. This study was conducted to determine if the actions of BoVantage and Optaflexx are synergistic

    Optimizing Filter-Probe Diffusion Weighting in the Rat Spinal Cord for Human Translation

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    Diffusion tensor imaging (DTI) is a promising biomarker of spinal cord injury (SCI). In the acute aftermath, DTI in SCI animal models consistently demonstrates high sensitivity and prognostic performance, yet translation of DTI to acute human SCI has been limited. In addition to technical challenges, interpretation of the resulting metrics is ambiguous, with contributions in the acute setting from both axonal injury and edema. Novel diffusion MRI acquisition strategies such as double diffusion encoding (DDE) have recently enabled detection of features not available with DTI or similar methods. In this work, we perform a systematic optimization of DDE using simulations and an in vivo rat model of SCI and subsequently implement the protocol to the healthy human spinal cord. First, two complementary DDE approaches were evaluated using an orientationally invariant or a filter-probe diffusion encoding approach. While the two methods were similar in their ability to detect acute SCI, the filter-probe DDE approach had greater predictive power for functional outcomes. Next, the filter-probe DDE was compared to an analogous single diffusion encoding (SDE) approach, with the results indicating that in the spinal cord, SDE provides similar contrast with improved signal to noise. In the SCI rat model, the filter-probe SDE scheme was coupled with a reduced field of view (rFOV) excitation, and the results demonstrate high quality maps of the spinal cord without contamination from edema and cerebrospinal fluid, thereby providing high sensitivity to injury severity. The optimized protocol was demonstrated in the healthy human spinal cord using the commercially-available diffusion MRI sequence with modifications only to the diffusion encoding directions. Maps of axial diffusivity devoid of CSF partial volume effects were obtained in a clinically feasible imaging time with a straightforward analysis and variability comparable to axial diffusivity derived from DTI. Overall, the results and optimizations describe a protocol that mitigates several difficulties with DTI of the spinal cord. Detection of acute axonal damage in the injured or diseased spinal cord will benefit the optimized filter-probe diffusion MRI protocol outlined here

    Electricity powering combustion: hydrogen engines

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    Hydrogen is ameans to chemically store energy. It can be used to buffer energy in a society increasingly relying on renewable but intermittent energy or as an energy vector for sustainable transportation. It is also attractive for its potential to power vehicles with (near-) zero tailpipe emissions. The use of hydrogen as an energy carrier for transport applications is mostly associated with fuel cells. However, hydrogen can also be used in an internal combustion engine (ICE). When converted to or designed for hydrogen operation, an ICE can attain high power output, high efficiency and ultra low emissions. Also, because of the possibility of bi-fuel operation, the hydrogen engine can act as an accelerator for building up a hydrogen infrastructure. The properties of hydrogen are quite different from the presently used hydrocarbon fuels, which is reflected in the design and operation of a hydrogen fueled ICE (H2ICE). These characteristics also result in more flexibility in engine control strategies and thus more routes for engine optimization. This article describes the most characteristic features of H2ICEs, the current state of H2ICE research and demonstration, and the future prospects
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