7,804 research outputs found
Henri Temianka Correspondence; (toth)
No full textThis collection contains material pertaining to the life, career, and activities of Henri Temianka, violin virtuoso, conductor, music teacher, and author. Materials include correspondence, concert programs and flyers, music scores, photographs, and books.https://digitalcommons.chapman.edu/temianka_correspondence/4215/thumbnail.jp
Application of empirical formulae and artificial neural networks for estimating bridge pier scour under clear-water and live-bed conditions
No full textIn the most recent years, the use of Artificial Neural Networks (ANN) models has been proposed in the literature for the prediction of scour depth around bridge piers, taking advantage of their capability to flexibly reproduce the highly non-linear nature of the relationship between input and output variables, also when such relationship is not explicitly known a priori. Nonetheless, so far, no attempt has been made to implement an ANN model that takes specifically into account the fact that profoundly different phenomena govern the formation of pier holes under clear-water and live-bed conditions. This study aims at further investigating the potentiality of the ANN approach: a wide set of both field and laboratory data is used to test different architectures of ANN for predicting the local scour depth as a function of the variables characterizing the flow, the sediments and the pier. In particular, special focus is given to the analysis of the scour depth under clear water and live bed conditions.
The work analyses the impact of the use of different training data sets on the performances of the model over an external, validation set, whose data are not used in any way in the calibration of the models.
As a standard of reference, the scour depths estimates predicted by the ANN models are compared to the estimates obtained by empirical formulae conventionally used in the literature and in the current engineering practic
Prediction of local scour depth at bridge piers under clear-water and live-bed conditions: comparison of literature formulae and artificial neural networks
No full textThe scouring effect of the flowing water around bridge piers may undermine the stability of the structure, leading to extremely high direct and indirect costs and, in extreme cases, the loss of human lives.
The use of Artificial Neural Networks (ANN) models has been recently proposed in the literature for estimating the maximum scour depth around bridge piers: this study aims at further investigating the potentiality of the ANN approach and, in particular, at analysing the influence of the experimental setting (laboratory or field data) and of the sediment transport mode (clear water or live bed) on the prediction performances.
A large database of both field and laboratory observations has been collected from the literature for predicting the maximum local scour depth as a function of a parsimonious set of variables characterizing the flow, the sediments and the pier. Neural networks with an increasing degree of specialization have been implemented - using different subsets of the calibration data in the training phase - and validated over an external validation dataset.
The results show that the ANN scour depths’ predictions outperform the estimates obtained by empirical formulae conventionally used in the literature and in the current engineering practice
Estimation of scour depth around bridge piers with artificial neural networks: the impact of training data
No full textAlex Toth and another Librarian examining a card catalog
No full textAlex Toth, who was a Librarian at Pacific University, and another Librarian (possibly Patricia Sobottka?), examining a card catalog in Pacific's Scott Library in July, 1978. This appears to be the Author catalog, which provided access to the books in Pacific's collections based on the last name of the author. This is one of a set of photographs that appears to have been posed in order to demonstrate the range of work that was taking place in the library
Elongate Twig Ant, Mexican Twig Ant (suggested common names), Pseudomyrmes gracilis (Fabricius) (Insecta: Hymenoptera: Formicidae: Pseudomyrmecinae)
No full textEENY-418, a 5-page illustrated fact sheet by Patricia L. Toth, is part of the Featured Creatures collection. It describes this neotropical, arboreal ant best known for its associations with plants and its terrible sting, its synonymy, distribution, description, life cycle, nests, hosts, damage, and management. Includes selected references. Published by the UF Department of Entomology and Nematology, September 2007.
EENY-418/IN752: Slender Twig Ant Pseudomyrmex gracilis (Fabricius) (Insecta: Hymenoptera: Formicidae: Pseudomyrmecinae) (ufl.edu
SPECTRAL MAXIMUM-LIKELIHOOD PARAMETERIZATION OF HYDROLOGICAL MODELS
No full textThis study considers the use of the maximum likelihood estimator proposed by Whittle for calibrating the
parameters of hydrological models. Whittle’s likelihood provides asymptotically consistent estimates for
Gaussian and non Gaussian data, even in the presence of long range dependence. This method may represent a valuable opportunity in the context of ungauged or scarcely gauged catchments. In fact, the only information required for model parameterization is the spectral density function of the actual process simulated by the model. When long series of calibration data are not available, the spectral density can be inferred by using old and sparse records, regionalization methods or information on the correlation properties of the process itself. The proposed procedure is applied to a case study referring to an Italian river basin, for which a lumped rainfall-runoff model is calibrated by emulating scarcely gauged situations. It is shown that the Whittle estimator can be applied in such a context with satisfactory results
Oral absorption enhancement of dipeptide L-Glu-L-Trp-OH by lipid and glycosyl conjugation
No full textIn recent years, the conjugation of sugar moieties and lipoamino acids has been extensively investigated as a mean to enhance the stability towards enzymatic degradation and the permeability across biological membranes of poorly orally available drugs, including peptides. In this prospect, a library of novel derivatives of the dipeptide L-Glu-L-Trp, a naturally occurring thymic immunomodulator with high hydrophilic character and low membrane permeability, was designed and synthesised by conjugating 2-amino-dodecanoic acid (C12) and/or 1-amino--D-glucuronic acid (GlcAN), -D-glucuronic acid (GlcA) and N--D-glucopyranosylamine succinamic acid (GlsNS) residues to the Glu-Trp scaffold, using an Fmoc solid-phase peptide synthesis strategy on trichlorotrityl resin. A cellobiose derivative was also prepared in solution. The synthesized peptides showed no sign of toxicity to red blood cells at 200 M (haemolysis assay) and their resistance against enzymatic hydrolysis, assessed in Caco-2 homogenates, was usually significantly increased, particularly for the C-terminal conjugates. Several derivatives also saw their apparent permeability values greatly enhanced and one of the conjugates tested proved to be able to release the initial dipeptide after penetrating Caco-2 monolayers. An initial in vivo experiment was then carried out in male Wistar rats to examine the effect of conjugation on the absorption rate and bioavailability. © 2008 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 90: 633-643, 2008
LINE WIDTHS OF AND
No full textAuthor Institution:Collision broadened line widths of and were determined from high resolution spectra covering the bands for both absorbing molecules. The line widths encompassed the spectral regions of the (1200), (2000), (0111), (0201), (1001) and (0002) bands. The band notation is . The and measurements were obtained for samples at room temperature and the spectra were obtained for samples at and . The ) values are compared to best-fit calculated values given in an earlier study by R. A. Toth, J. Mol. Spectrosc. 40, 605-615 (1971)
Data-driven streamflow simulation: the influence of exogenous variables and temporal resolution
No full textData-driven modelling approaches, like artificial neural networks, are particularly sensitive to the choice of input and output variables. This study focuses on the size of the temporal observation interval of input and output data in a river
flow prediction application, analysing the simulation performances when considering increasing time aggregations of different input variables. The analyses are carried out on the data registered in a medium-sized (1,050 km2) watershed located on the Apennine mountains, where hourly meteorological data and streamflow measurements are available over an 8-year period.
Four modelling approaches are considered for the prediction of river flow in the closure section: (1) without exogenous inputs, (2) with the additional input of past precipitation data, (3) with the additional input of past streamflow data measured in the upstream section, (4) with the additional input of both past precipitation and past upstream flow. For each modelling approach, using both (a) input data and output data at the same time scale and (b) input data at a temporal resolution finer than that of the output data, optimal modelling networks are identified and forecast performances
are compared. The results highlight how the simulation improves with the addition of exogenous inputs, in particular upstream flow data, and with the use of input data at a temporal resolution finer than that of the output data. The results also show how both such benefits increase for larger temporal aggregation of the forecast
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