826 research outputs found
Evolving Lucene search queries for text classification
We describe a method for generating accurate, compact, human
understandable text classifiers. Text datasets are indexed using Apache Lucene and Genetic Programs are used to construct
Lucene search queries. Genetic programs acquire fitness by
producing queries that are effective binary classifiers for a
particular category when evaluated against a set of training
documents. We describe a set of functions and terminals and
provide results from classification tasks
A Duhamel Integral Based Approach to Identify an Unknown Radiation Term in a Heat Equation with Non-linear Boundary Condition
In this paper, we consider the determination of an unknown radiation term in the nonlinear boundary condition of a linear heat equation from an overspecified condition. First we study the existence and uniqueness of the solution via an auxiliary problem. Then a numerical method consisting of zeroth-, first-, and second-order Tikhonov regularization method to the matrix form of Duhamel\u27s principle for solving the inverse heat conduction problem (IHCP) using temperature data containing significant noise is presented. The stability and accuracy of the scheme presented is evaluated by comparison with the Singular Value Decomposition (SVD) method. Some numerical experiments confirm the utility of this algorithm as the results are in good agreement with the exact data
BIT-VO: visual odometry at 300 FPS using binary features from the focal plane
Focal-plane Sensor-processor (FPSP) is a next-generation camera technology which enables every pixel on the sensor chip to perform computation in parallel, on the focal plane where the light intensity is captured. SCAMP-5 is a general-purpose FPSP used in this work and it carries out computations in the analog domain before analog to digital conversion. By extracting features from the image on the focal plane, data which is digitised and transferred is reduced. As a consequence, SCAMP-5 offers a high frame rate while maintaining low energy consumption. Here, we present BITVO, which is the first 6-Degrees of Freedom visual odometry algorithm which utilises the FPSP. Our entire system operates at 300 FPS in a natural environment, using binary edges and corner features detected by the SCAMP-5
Synthesis and Optimization of Reversible Circuits - A Survey
Reversible logic circuits have been historically motivated by theoretical
research in low-power electronics as well as practical improvement of
bit-manipulation transforms in cryptography and computer graphics. Recently,
reversible circuits have attracted interest as components of quantum
algorithms, as well as in photonic and nano-computing technologies where some
switching devices offer no signal gain. Research in generating reversible logic
distinguishes between circuit synthesis, post-synthesis optimization, and
technology mapping. In this survey, we review algorithmic paradigms ---
search-based, cycle-based, transformation-based, and BDD-based --- as well as
specific algorithms for reversible synthesis, both exact and heuristic. We
conclude the survey by outlining key open challenges in synthesis of reversible
and quantum logic, as well as most common misconceptions.Comment: 34 pages, 15 figures, 2 table
Influence of Hydroxypropyl Methylcellulose Molecular Weight Grade on Water Uptake, Erosion and Drug Release Properties of Diclofenac Sodium Matrix Tablets
Purpose: To comparatively evaluate the effect of two hydroxylpropyl methylcellulose (HPMC) molecular weight grades (K4M and K15M) on drug release from diclofenac sodium matrix tablets.Methods: Tablets containing diclofenac sodium were prepared by direct compression method at various drug/HPMC ratios and evaluated in vitro for their water uptake, erosion and dissolution characteristics over a period of 8 h. Their release data were analyzed according to various release kinetic models.Results: The release rate of diclofenac decreased with increase in polymer content and was dependent on the HPMC type used, with the lower release rate observed in formulations containing the higher molecular weight grade HPMC K15M. Formulations containing the higher molecular weight HPMC (F4, F5 and F6) showed higher water uptake than those containing the lower molecular weight polymer (F1, F2 and F3) (p < 0. 001). The formulations incorporating the lower molecular weight HPMC K4M (F1, F2 and F3) showed higher erosion than those that contained HPMC K15M (F4, F5 and F6) (p < 0.001). Kinetic data based on the release exponent, n, in Peppas model, showed that n values were between 0.14 and 0.55, indicating that drug release from HPMC matrices was predominantly by diffusion.Conclusion: This study demonstrates that the molecular weight (MW) of HPMC does affect the water uptake and erosion as well as the rate of drug release from of HPMC matrices.Keywords: Matrix, Diclofenac sodium, HPMC, Erosion, Water uptake
Head circumference in Iranian infants
Background: Head circumference (HC) measurement is an important parameter in the diagnosis of neurological and developmental disorders as well as dysmorphic syndromes. Recognition of different disorders requires an understanding of the normal variation of the HC size, especially during infancy which is a period of rapid brain growth. Regarding the differences in the international and interracial standard charts of anthropometric indices, local and generational diversities, changes in the ethnic mix of the population and socioeconomic factors, periodic re-evaluations need to be done on the size of HC. This study aimed to represent a local HC standard for an Iranian infant population in comparison with the charts of the American National Center of Health Statistics (NCHS) approved by the World Health Organization (WHO). Methods: About 1003 neonates were randomly enrolled in this cross-sectional study. They were ageing from 3 days to 24 months and were apparently in normal condition. The HC size of these infants was measured and recorded. Tables and graphs were diagramed by Excel Microsoft Office 2007 software and two-tailed Student's t-test was used for statistical analysis of data. Results: According to the findings of this study, the mean of the HC size in male infants was larger than the female ones. Based on a visual comparison, the curves followed a pattern similar to that of the NCHS's. Overall, our subjects in both genders were found to have a smaller HC size at birth compared to the NCHS charts. However, infants of other ages had a larger HC size compared to that of the NCHS's. Conclusion: With respect to the international and interracial differences in the HC size, it is recommended that local anthropometric indices be constructed and used clinically across the world. In addition, extensive and longitudinally designed studies are required in this regard
Development and Evaluation of Mucoadhesive Chlorhexidine Tablet Formulations
Purpose: To formulate mucoadhesive chlorhexidine tablets and evaluate their drug release characteristics and mechanism.Methods: Chlorhexidine buccal adhesive tablets were prepared by direct compression using a blend of hydroxypropyl methylcellulose (HPMC) and chitosan as the bioadhesive polymers. Their dissolutionproperties were assessed according to USP 24 (paddle method). In order to determine the mode of drug release from the tablets, the release data were subjected to various release kinetic models. Thebioadhesive strength of the tablets was also evaluated. Results: The results showed that as the proportion of HPMC in the blend increased, drug release rate decreased, with the lowest release rate observed when HPMC alone was used as the bioadhesive polymer (p < 0.001). Both the type and ratio of the polymers used influenced release kinetics. Also,bioadhesion force increased with increasing proportion of HPMC in the tablets, with the highest adhesion force shown when HPMC was the only polymer used, and lowest when chitosan was used alone (p < 0.01). Conclusion: The chlorhexidine formulations developed showed promise as a bioadhesive delivery system for the drug.Keywords: Mucoadhesive tablets; Chlorhexidine; HPMC; Chitosan; Release properties; Bioadhesive strength
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