19,767 research outputs found

    Exploiting Data Parallelism in the yConvex Hypergraph Algorithm for Image Representation using GPGPUs

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    To define and identify a region-of-interest (ROI) in a digital image, the shape descriptor of the ROI has to be described in terms of its boundary characteristics. To address the generic issues of contour tracking, the yConvex Hypergraph (yCHG) model was proposed by Kanna et al [1]. In this work, we propose a parallel approach to implement the yCHG model by exploiting massively parallel cores of NVIDIA's Compute Unified Device Architecture (CUDA). We perform our experiments on the MODIS satellite image database by NASA, and based on our analysis we observe that the performance of the serial implementation is better on smaller images, but once the threshold is achieved in terms of image resolution, the parallel implementation outperforms its sequential counterpart by 2 to 10 times (2x-10x). We also conclude that an increase in the number of hyperedges in the ROI of a given size does not impact the performance of the overall algorithm.Comment: 1 page, 1 figure published in Proceedings of the 27th ACM International Conference on Supercomputing, ICS 2013, Eugene, Oregon, US

    Extended Riemann-Liouville fractional derivative operator and its applications

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    Many authors have introduced and investigated certain extended fractional derivative operators. The main object of this paper is to give an extension of the Riemann-Liouville fractional derivative operator with the extended Beta function given by Srivastava et al. [22] and investigate its various (potentially) useful and (presumably) new properties and formulas, for example, integral representations, Mellin transforms, generating functions, and the extended fractional derivative formulas for some familiar functions

    Semantic categories underlying the meaning of ‘place’

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    This paper analyses the semantics of natural language expressions that are associated with the intuitive notion of ‘place’. We note that the nature of such terms is highly contested, and suggest that this arises from two main considerations: 1) there are a number of logically distinct categories of place expression, which are not always clearly distinguished in discourse about ‘place’; 2) the many non-substantive place count nouns (such as ‘place’, ‘region’, ‘area’, etc.) employed in natural language are highly ambiguous. With respect to consideration 1), we propose that place-related expressions should be classified into the following distinct logical types: a) ‘place-like’ count nouns (further subdivided into abstract, spatial and substantive varieties), b) proper names of ‘place-like’ objects, c) locative property phrases, and d) definite descriptions of ‘place-like’ objects. We outline possible formal representations for each of these. To address consideration 2), we examine meanings, connotations and ambiguities of the English vocabulary of abstract and generic place count nouns, and identify underlying elements of meaning, which explain both similarities and differences in the sense and usage of the various terms

    Stress tests on cylinders and aluminum panels

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    An optimization study of composite stiffened cylinders is discussed. The mathematical model for the buckling has been coupled successfully with the optimization program AESOP. The buckling analysis is based on the use of the smeared theory for the buckling of stiffened orthotropic cylindrical shells. The loading, radius, and length of the cylinder are assumed to be known parameters. An optimum solution gives the value of cross-sectional dimensions and laminate orientations. The different types of buckling modes are identified. Mathematical models are developed to show the relationships of the parameters

    Range Queries on Uncertain Data

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    Given a set PP of nn uncertain points on the real line, each represented by its one-dimensional probability density function, we consider the problem of building data structures on PP to answer range queries of the following three types for any query interval II: (1) top-11 query: find the point in PP that lies in II with the highest probability, (2) top-kk query: given any integer k≤nk\leq n as part of the query, return the kk points in PP that lie in II with the highest probabilities, and (3) threshold query: given any threshold τ\tau as part of the query, return all points of PP that lie in II with probabilities at least τ\tau. We present data structures for these range queries with linear or nearly linear space and efficient query time.Comment: 26 pages. A preliminary version of this paper appeared in ISAAC 2014. In this full version, we also present solutions to the most general case of the problem (i.e., the histogram bounded case), which were left as open problems in the preliminary versio

    An investigation into the nutritional status of patients receiving an Enhanced Recovery After Surgery (ERAS) protocol versus standard care following Oesophagectomy

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    Enhanced Recovery After Surgery (ERAS) protocols have been effectively expanded to various surgical specialities including oesophagectomy. Despite nutrition being a key component, actual nutrition outcomes and specific guidelines are lacking. This cohort comparison study aims to compare nutritional status and adherence during implementation of a standardised post-operative nutritional support protocol, as part of ERAS, compared to those who received usual care.Two groups of patients undergoing resection of oesophageal cancer were studied. Group 1 (n = 17) underwent oesophagectomy between Oct 2014 and Nov 2016 during implementation of an ERAS protocol. Patients in group 2 (n = 16) underwent oesophagectomy between Jan 2011 and Dec 2012 prior to the implementation of ERAS. Demographic, nutritional status, dietary intake and adherence data were collected. Ordinal data was analysed using independent t tests, and categorical data using chi-square tests.There was no significant difference in nutrition status, dietary intake or length of stay following implementation of an ERAS protocol. Malnutrition remained prevalent in both groups at day 42 post surgery (n = 10, 83% usual care; and n = 9, 60% ERAS). A significant difference was demonstrated in adherence with earlier initiation of oral free fluids (p
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