169,902 research outputs found
The Euler-Type Universal Numerical Integrator (E-TUNI) with Backward Integration
No full textThe Euler-Type Universal Numerical Integrator (E-TUNI) is a discrete numerical structure that couples a first-order Euler-type numerical integrator with some feed-forward neural network architecture. Thus, E-TUNI can be used to model non-linear dynamic systems when the real-world plant’s analytical model is unknown. From the discrete solution provided by E-TUNI, the integration process can be either forward or backward. Thus, in this article, we intend to use E-TUNI in a backward integration framework to model autonomous non-linear dynamic systems. Three case studies, including the dynamics of the non-linear inverted pendulum, were developed to verify the computational and numerical validation of the proposed model
An Overview of the Euler-Type Universal Numerical Integrator (E-TUNI): Applications in Non-Linear Dynamics and Predictive Control
No full textA Universal Numerical Integrator (UNI) is a computational framework that combines a classical numerical integration method, such as Euler, Runge–Kutta, or Adams–Bashforth, with a universal approximator of functions, such as a feed-forward neural network (including MLP, SVM, RBF, among others) or a fuzzy inference system. The Euler-Type Universal Numerical Integrator (E–TUNI) is a particular case of UNI based on the first-order Euler integrator and is designed to model non-linear dynamic systems observed in real-world scenarios accurately. The UNI framework can be organized into three primary methodologies: the NARMAX model (Non-linear AutoRegressive Moving Average with eXogenous input), the mean derivatives approach (which characterizes E–TUNI), and the instantaneous derivatives approach. The E–TUNI methodology relies exclusively on mean derivative functions, distinguishing it from techniques that employ instantaneous derivatives. Although it is based on a first-order scheme, the E–TUNI achieves an accuracy level comparable to that of higher-order integrators. This performance is made possible by the incorporation of a neural network acting as a universal approximator, which significantly reduces the approximation error. This article provides a comprehensive overview of the E–TUNI methodology, focusing on its application to the modeling of non-linear autonomous dynamic systems and its use in predictive control. Several computational experiments are presented to illustrate and validate the effectiveness of the proposed method
Impaired sperm quality, delayed mating but no costs for offspring fitness in crickets winning a fight
No full textThe outcome of male-male contest competition is known to affect male mating success and is believed to confer fitness benefits to females through preference for dominant males. However, by mating with contest winners, females can incur significant costs spanning from decreased fecundity to negative effects on offspring. Hence identifying costs and benefits of male dominance on female fitness is crucial to unravel the potential for a conflict of interests between the sexes. Here we investigated males’ pre- and post-copulatory reproductive investment and its effect on female fitness after a single contest a using the field cricket Gryllus bimaculatus. We allowed males to fight, and immediately measured their mating behaviour, sperm quality, and offspring viability. We found that males experiencing a fight, independently of the outcome, delayed matings but their courtship effort was not affected. However, winners produced sperm of lower quality (viability) compared to losers and to males that did not experience fighting. Results suggest a trade-off in resource allocation between pre- and post-mating episodes of sexual selection. Despite lower ejaculate quality we found no fitness costs (fecundity and viability of offspring) for females mated to winners. Overall our findings highlight the importance of considering fighting ability when assessing male reproductive success, as winners may be impaired in their competitiveness at a post-mating level
Estudio hidrogeológico con fines de riego y uso poblacional en la comunidad de Tuni Grande y parcialidades de Colquejahua y Pacaje
No full textEstudio hidrogeológico con fines de riego y uso poblacional en la comunidad de Tuni Grande y parcialidades de Colquejahua y Pacaje.Tesi
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
A methodology to assess social sustainability of multi-tier supply chains in the textile industry
No full textSocial sustainability is a crucial aspect of Sustainable Supply Chain Management (SSCM), particularly in the textile industry, due to numerous disasters that have occurred in garment factories, often in developing countries. Furthermore, the textile supply chain presents critical working conditions that demand attention. Thus, fashion and textile companies are urged to implement social risk management practices. This work develops a MCDM model for Sustainable Supplier Selection (SSS) and Sustainable Supplier Evaluation (SSE) using the Analytic Hierarchy Process (AHP) and the Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS). The model presents a risk-based approach implementing both non-compensatory and compensatory techniques to assess the social sustainability of suppliers. The evaluation is based on the Higg Facility Social and Labor Module (Higg FSLM), which is the dominant social auditing program in the textile industry. Additionally, an Aggregation Methodology is developed to allocate the performance of sub-suppliers to higher-tier suppliers, from Tier-4 to Tier-1. The proposed method was applied to the case study of Benetton Group, an Italian fashion company. This method demonstrated its effectiveness in evaluating and ranking suppliers based on their social performance and it is expected to represent a useful tool for sustainability managers. A sensitivity analysis was performed to demonstrate the importance of choosing the appropriate weights and scores. Notably, this work develops the first methodology to quantitatively assess social sustainability in multi-tier supply chains in the textile industry. It also enables to combine a robust social sustainability assessment method based on the Higg FSLM with the internal sustainability risk strategies of focal companies
Mitomycin C in highly myopic eyes - Author reply
No full textOphthalmology. 2005 Feb;112(2):208-18; discussion 219.
Mitomycin C modulation of corneal wound healing after photorefractive keratectomy in highly myopic eyes.
Gambato C, Ghirlando A, Moretto E, Busato F, Midena E.
SourceRefractive Surgery Service and Antimetabolite Therapy Research Unit, Department of Ophthalmology, University of Padova, Padova, Italy.
Abstract
PURPOSE: To evaluate the role of topical mitomycin C in corneal wound healing (CWH) after photorefractive keratectomy (PRK) in highly myopic eyes.
DESIGN: Prospective, double-masked, randomized clinical trial.
PARTICIPANTS: Seventy-two eyes of 36 patients affected by high (>7 diopters) myopia.
METHODS: In each patient, one eye was randomly assigned to PRK with intraoperative topical 0.02% mitomycin C application, and the fellow eye was treated with a placebo. Postoperatively, mitomycin C-treated eyes received artificial tears (3 times daily, tapered in 3 months), whereas the fellow eye was treated with fluorometholone sodium 2% and artificial tears (3 times daily, tapered in 3 months).
MAIN OUTCOME MEASURES: Uncorrected visual acuity (UCVA) and best-corrected visual acuity (BCVA), contrast sensitivity, manifest refraction, and biomicroscopy. Contrast sensitivity was determined using the Pelli-Robson chart. Corneal confocal microscopy documented CWH.
RESULTS: Mean follow-up was 18 months (range, 12-36). No side effects or toxic effects were documented. At 12-month follow-up examination, UCVAs (logarithm of the minimum angle of resolution) were 0.4+/-0.48 and 0.5+/-0.53 (P = .03) in mitomycin C-treated eyes and corticosteroid-treated eyes, respectively. At 1 year, corneal haze developed in 20% of corticosteroid-treated eyes, versus 0% of mitomycin C-treated eyes. At 12, 24, and 36 months, corneal confocal microscopy showed activated keratocytes and extracellular matrix significantly more evident in untreated eyes (Ps = 0.004, 0.024, and 0.046, respectively).
CONCLUSION: Topical intraoperative application of 0.02% mitomycin C can reduce haze formation in highly myopic eyes undergoing PRK.
Comment in
Ophthalmology. 2006 Feb;113(2):357; author reply 357-8
Dispelling the Myths Behind First-author Citation Counts
No full textWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
Characterization of microsatellite loci in the subsocial spider Stegodyphus lineatus (Araneae: Eresidae)
No full textStegodyphus lineatus spiders live in groups consisting of closely related individuals. There appears to be no discrimination against related individuals as mates but females mate multiply, despite the fact that matings are shown to carry a cost. We have developed eight
polymorphic dinucleotide microsatellite markers that allow us to assess levels of heterozygosity and relatedness among individuals of this species. These molecular markers are likely to prove highly effective tools for estimating levels of inbreeding and thus allow us
to test hypotheses about the relationships between social structure, mating strategies and inbreeding avoidanc
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