21,151 research outputs found

    (1S)-1-phenylethanaminium 4-{[(1S,2S)-1-hydroxy-2,3-dihydro-1H,1'H-[2,2'-biinden]-2-yl]methyl}benzoate

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    Copyright 2012 © International Union of Crystallography.The title molecular salt, C8H12N+·C26H21O3-, contains a dimeric indane pharmacophore that demonstrates potent anti-inflammatory activity. The indane group of the anion exhibits some disorder about the [alpha]-C atom, which appears common to many structures containing this group. A model to account for the slight disorder was attempted, but this was deemed unsuccessful because applying bond-length constraints to all the bonds about the [alpha]-C atom led to instability in the refinement. The absolute configuration was determined crystallographically as S,S,S by anomalous dispersion methods with reference to both the Flack parameter and Bayesian statistics on Bijvoet differences. The configuration was also determined by an a priori knowledge of the absolute configuration of the (1S)-1-phenylethanaminium counter-ion. The molecules pack in the crystal structure to form an infinite two-dimensional hydrogen-bond network in the (100) plane of the unit cell

    Bending behavior of shape memory polymer based laminates

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    ArticleCOMPOSITE STRUCTURES. 78(2): 153-161 (2007)journal articl

    A rule-based assistive control algorithm for safe navigation for a powered wheelchair

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    This paper addresses the problem of safe navigation in an environment with randomly placed static obstacles. We convert a commercial powered wheelchair into a semiautonomous vehicle with limited sight (environment awareness), by instrumenting it using off-the-shelf ultrasonic sensors and associated electronic boards (Arduino). In the continuity of our previous work where we had used stochastic dynamic programming to formulate optimization problems which led to relatively large size look-up tables that can be used as supervisory control, here we propose to extract rules using those results (that data). The advantage of this approach is a lowcomputational cost for future online implementation, and the drawback is a suboptimal policy. The feasibility is assessed by running simulations in a fairly realistic environment (Unity3D)

    A genetic polymorphism and its genetic effects on goat myogenin gene in intron 1

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    Single nucleotide polymorphisms (SNPs) of the myogenin (MyoG) gene were tested using primer induced restriction fragment length polymorphism assay-polymerase chain reaction (PIRA-PCR) from Bore goat and its upgrading offspring to Tangshan diary goat (including F1, F2 and F3). The effects of the myogenin gene on the birth weight, 1-month body weight and the weaning weight were also analyzed. On the basis of the DNA sequence of the goat myogenin gene (FJ607135), primers were designed to amplify myogenin gene. The result showed that one polymorphism (transition of g.558C>T) was found in intron 1 of goat myogenin gene, in which two alleles (A and B) and three genotypes (AA, AB and BB) were examined. The distributions of three genotypes were basically identical in four goat populations, and allele A was the dominant gene. The effect of the myogenin genotypes on the birth weight, 1-month body weight and the weaning weight were all not significant (P > 0.05) due to the small number of BB gaots; however, the values of AA genotype goats and AB genotype goats were obviously higher than those of BB genotype goats for three growth traits, in the order of AA > AB > BB. These results suggest that the myogenin genotype has some effects on partial growth traits of goat, and selecting the individuals with A allele could be favorable to the birth weight, 1-month body weight and the weaning weight.Key words: goats, myogenin gene, primer induced restriction fragment length polymorphism assay-polymerase chain reaction (PIRA-PCR), genetic polymorphisms, genetic effects

    Problem Specific MOEA/D for Barrier Coverage with Wireless Sensors

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    Barrier coverage with wireless sensors aims at detecting intruders who attempt to cross a specific area, where wireless sensors are distributed remotely at random. This paper considers limited-power sensors with adjustable ranges deployed along a linear domain to form a barrier to detect intruding incidents. We introduce three objectives to minimize: 1) total power consumption while satisfying full coverage; 2) the number of active sensors to improve the reliability; and 3) the active sensor nodes' maximum sensing range to maintain fairness. We refer to the problem as the tradeoff barrier coverage (TBC) problem. With the aim of obtaining a better tradeoff among the three objectives, we present a multiobjective optimization framework based on multiobjective evolutionary algorithm (MOEA)/D, which is called problem specific MOEA/D (PS-MOEA/D). Specifically, we define a 2-tuple encoding scheme and introduce a cover-shrink algorithm to produce feasible and relatively optimal solutions. Subsequently, we incorporate problem-specific knowledge into local search, which allows search procedures for neighboring subproblems collaborate each other. By considering the problem characteristics, we analyze the complexity and incorporate a strategy of computational resource allocation into our algorithm. We validate our approach by comparing with four competitors through several most-used metrics. The experimental results demonstrate that PS-MOEA/D is effective and outperforms the four competitors in all the cases, which indicates that our approach is promising in dealing with TBC

    International diversification with factor funds

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    We propose a new investment strategy employing "factor funds" to systematically enhance the meanvariance efficiency of international diversification. Our approach is motivated by the increasing evidence that size (SMB), book-to-market (HML), and momentum (MOM) factors, along with the market factor, adequately describe international stock returns, and by the direct link between investors' portfolio choice problems and international asset pricing theories and tests. Using data from 10 developed countries during the period 1981-2008, we show that the "augmented" optimal portfolio involving local factor funds substantially outperforms the "benchmark" optimal portfolio comprising country market indices only as measured by their portfolio Sharpe ratios. This strongly rejects the intersection hypothesis which posits that the local factor funds do not span investment opportunities beyond what country market indices do. Among the three classes of factor funds, HML funds contribute most to the efficiency gains. In addition, the local version of factor funds outperforms the global factor funds. The added gains from local factor diversification are significant for both in-sample and out-of-sample periods, and for a realistic range of additional investment costs for factor funds, and remain robust over time. Copyright © 2010 INFORMS.preprin

    Characterization of carbohydrate fractions and fermentation quality in ensiled alfalfa treated with different additives

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    This experiment was carried out to evaluate the effects of adding fast-sile (FS), previous fermented juice (PFJ), sucrose (S) or fast-sile + sucrose (FS + S) on the fermentation characteristics and carbohydrates fractions of alfalfa silages by the Cornell net carbohydrates and proteins systems (CNCPS). Silages quality were well preserved determined by pH, lactic acid (LA), acetic acid (AA), propionic acid (PA), butyric acid (BA) and (NH3-N, % of TN). Except for the silage with no addition of (CK), all other silages were well preserved. FS + S addition showed the lowest pH and contents of AA, PA, BA, and the highest contents of LA. The contents of WSC (Water soluble carbohydrate) in all alfalfa silages decreased with the extension of ensiling time, especially in the former 15 days and decreased sharply in the first 2 days. The content of sucrose in all alfalfa silages in the residual mono and disaccharides was highest, and the content of fructose was the least. The contents of all these sugars decreased sharply in the first 2 days. The content of hemicellulose decreased during ensiling, while no obvious change on content of cellulose. The content of ADL (acid detergent lignin) in alfalfa silages increased during ensiling. The content of starch in silages reduced rapidly in the former days, and then had not obvious change.Key words: Carbohydrate fractions, alfalfa silage, additives, water soluble carbohydrate (WSC)
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