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Search Results: 1 - 10 of 3546 matches for " Cindy Estéfany; Mateus-Pineda "
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Dise?o de controladores de tipo proporcional integral derivativo (PID) y difuso para la posición de un motor de corriente continua (DC)
Rairán-Antolines,José Danilo; Guerrero-Cifuentes,Cindy Estéfany; Mateus-Pineda,Jaime Alfredo;
Ingeniería y Universidad , 2010,
Abstract: the performance of pid and fuzzy controllers is compared in a commercial device normally used in model airplanes: the s3004 futaba servo. the controller circuit, the power amplifier and the sensor are modified, and then the motor is observed. next, a root-locus method is used to tune a pid for angular position control. simulations and control are made in matlab's simulink, and also a data acquisition card (pci 6024e) is used. results are analyzed at the end of the document: although the pid controller works better, the fuzzy controller shows a similar performance.
Dise o de controladores de tipo proporcional integral derivativo (PID) y difuso para la posición de un motor de corriente continua (DC)
José Danilo Rairán-Antolines,Cindy Estéfany Guerrero-Cifuentes,Jaime Alfredo Mateus-Pineda
Ingeniería y Universidad , 2010,
Abstract: The performance of PID and fuzzycontrollers is compared in a commercialdevice normally used in modelairplanes: the S3004 Futaba Servo.The controller circuit, the poweramplifier and the sensor are modified,and then the motor is observed. Next,a root-locus method is used to tunea PID for angular position control.Simulations and control are made inMatlab’s Simulink, and also a dataacquisition card (PCI 6024E) is used.Results are analyzed at the end of thedocument: although the PID controllerworks better, the fuzzy controllershows a similar performance.
The Structure of Pinus hartwegii at the Cofre de Perote, Veracruz, Mexico  [PDF]
Dulce María Murrieta-Hernández, María del Rosario Pineda-López, Juan Carlos Noa-Carrazana, Martín Mata-Rosas, Ramón Zulueta-Rodríguez, Norma Flores-Estévez
Open Journal of Forestry (OJF) , 2014, DOI: 10.4236/ojf.2014.44035
A study was conducted on the forest structure of Pinus hartwegii Lindl., located at the Cofre de Perote National Park. The density, diameter, height and wooded coverage were evaluated along an altitudinal gradient from 3500 to 4000 meters in 20 plots of 100 m2. The structure of the population was found to be in the form of an “inverted J”. No statistically significant differences were found for any of the above-mentioned variables evaluated in the altitudinal range. A high density of suppressed individuals was found to occur at 50% of the sites sampled. Given the suppression characteristics of the trees, shelterwood is suggested for a better development of the woodland mass, as well as the introduction of mycorrhizal plants.
Effect of Domestic Wastewater as Co-Substrate on Biological Stain Wastewater Treatment Using Fungal/Bacterial Consortia in Pilot Plant and Greenhouse Reuse  [PDF]
Pedroza-Camacho Lucas David, Lores-Acosta Juan Camilo, Rojas-Enríquez Johans Farid, Mateus-Maldonado Juan Felipe, Puentes Cindy Stephanie, Ramírez-Rodríguez Julio, Mendez-Casallas Francy Janeth, Salcedo-Reyes Juan Carlos, Díaz-Ariza Lucía Ana, Lozano-Puentes Hair Santiago, Pedroza-Rodríguez Aura Marina
Journal of Water Resource and Protection (JWARP) , 2018, DOI: 10.4236/jwarp.2018.103020
Abstract: In this study, a pilot wastewater treatment plant was used to evaluate the co-treatment of biological-staining residues and domestic wastewater under non-sterile conditions. A novel microbial consortia formed by Trametes versicolor, Trametes sp, Pleurotus ostreatus, Pseudomonas fluorescens, Pseudomonas azotoformans, Pseudomonas sp, Enterobacter xianfangensis and Bacillus subtillis was inoculated in an extended aeration type bio-reactor. The treatment units were operated during three consecutive cycles during a period of 147 h. After the last operating cycle, the concentrations of Chemical Oxygen Demand, Biochemical Oxygen Demand, Color Units, Total suspended solids, and the pH value were 1695 mg/L, 105 mg/L, 106 CU, <0.001 mg/L and 5.8 respectively. The initial values of wastewater were 6755 mg/L (COD), 2005 mg/L (BOD5), 1367 (CU), 566 mg/L (TSS) and 7.0 (pH) respectively. The reduction of pollutants load was related with the ratio of the two types of wastewater (3.5:0.5) combined to increase biodegradability, the concentration of fungi and bacteria used in the consortia (30 × 103 - 55 × 106 CUF/mL Total Fungi and 70 × 107 - 83 × 108 CFU/mL of Total Bacteria) and ligninolytic enzymes production, Laccase (13 - 96 U/L), MnP (9.8 - 39 U/L) and LiP (0.3 - 5.3 U/L). The post-treated effluent was used as irrigation water. Lolium perenne plants were watered during 60 days with post-treated effluent. The results of root weight showed that there are significant differences between the initial water and the effluent obtained after the operational cycles (p = 0.00470). The highest root weights (1 - 1.12 g) were found in plants irrigated with water obtained from the last treatment cycle.
Leverage and the Maturity Structure of Debt in Emerging Markets  [PDF]
Cesario Mateus, Paulo Terra
Journal of Mathematical Finance (JMF) , 2013, DOI: 10.4236/jmf.2013.33A005

The aim of this paper is to analyse for a multi-country large emerging market sample the choice between debt and equity simultaneously with the decision between short- and long-term debts. In order to investigate the joint decision among leverage and maturity, we examine an unique sample of 986 firms and 13,490 firm-year observations from Latin America and 686 firms and 7919 firm-year observations from Eastern Europe for the period 1990-2003. We employ dynamic panel data analysis using Generalized Method of moments. The empirical results support three main findings. First, the cross-effects between leverage and maturity behave exactly the opposite between Latin America and Eastern Europe sub-samples. Capital structure and debt maturity are policy complements in Latin America and substitutes in Eastern Europe. Second, there is a significant dynamic effects component in the determination of leverage and maturity. Finally, adjustment to the target, maturity is by no means costless and instantaneous with firm’s facing moderate adjustment costs.

Implied Idiosyncratic Volatility and Stock Return Predictability  [PDF]
Cesario Mateus, Worawuth Konsilp
Journal of Mathematical Finance (JMF) , 2014, DOI: 10.4236/jmf.2014.45032
Abstract: This paper investigates the role of volatility risk on stock return predictability. Using 596 stock options traded at the American Stock Exchange and the Chicago Board Options Exchange (CBOE) for the period from January 2001 to December 2010, it examines the relation between different idiosyncratic volatility measures and expected stock returns for a period that involves both the dotcom bubble and the recent financial crisis. First it is showed that implied idiosyncratic volatility is the best stock return predictor among the different volatility measures used. Second, cross-section firm-specific characteristics are important on stock returns forecast. Third, we provide evidence that higher short selling constraints impact negatively stock returns having liquidity the opposite effect.
Physical versus Synthetic Exchange Traded Funds. Which One Replicates Better?  [PDF]
Cesario Mateus, Yana Rahmani
Journal of Mathematical Finance (JMF) , 2017, DOI: 10.4236/jmf.2017.74054
Abstract: This paper investigates the tracking performance of physical and synthetic equity exchange traded funds listed (ETFs) on the London Stock Exchange (LSE) during the period 2008 to 2013. We examine the ETFs accuracy in replicating their benchmark returns, with different geographical focus, applying several tracking metrics and including the financial crisis period. First, we did not find evidence that synthetic ETFs outperformed physical ETFs in terms of lower daily tracking performance. Second, the results show that the ability of ETFs to replicate its benchmark index’s returns depends on characteristics of the securities composing the index. Third, we provide evidence that the 2008-2009 financial crises had negative impact on daily tracking performance for all ETFs. Fourth, the method to estimate the tracking error impacts the results.
A comparative study of two histological techniques for the identification of cytomegalovirus infection in colorectal biopsies from patients with chronic inflammatory bowel disease
Castro,M. L. de; Tardío,A.; Campo,V. del; Estévez,A.; Pineda,J. R.; Domínguez,F.; Hermo,J. A.; Clofent,J.;
Revista Espa?ola de Enfermedades Digestivas , 2009, DOI: 10.4321/S1130-01082009001000004
Abstract: background: the role that cytomegalovirus (cmv) plays in inflammatory bowel disease (ibd) is controversial. the diagnosis of cmv infection in ibd depends on viral identification with hematoxylin-eosin (he) or immunohistochemistry (ihc). our aim was to compare the sensitivity of he and ihc for this diagnosis in ibd patients. patients and methods: a case-control study. our database was searched for ibd patients with he- or ihc-based cmv-positivity from 1997 to 2007. controls were selected among ibd inpatients matched for age and year of diagnosis with cmv. their clinical characteristics were analyzed. he and ihc were performed on biopsies from cases and controls at 6 months before and after inclusion in the study. in the statistical analysis, p values below 0.05 were considered significant. results: ten ibd patients with cmv infection were identified. ibd-cmv patients were more steroid-resistant or steroid-dependent (p = 0.03), and underwent a higher number of colonic biopsies (p = 0.03). from 97 biopsies analyzed, 12 were he-negative and ihc-positive, and 3 showed reversed results. the sensitivity of he was 58.6%, 95% ci (38.9-78.3), and that of ihc was 89.7%, 95% ci (76.8-100). we did not find a good level of agreement between both techniques: kappa value 0.55, 95% ci (0.36-0.75). cmv positivity with ihc was associated with the use of more than one immunosuppressant drug, or 13.5, 95% ci (1.2-152.2). antiviral treatment was useful for cmv patients with steroid-dependent and steroid-refractory ibd. conclusions: ihc shows a 30% higher sensitivity than he for the diagnosis of cmv infection in ibd patients. there is no good level of agreement between both histological techniques.
Abstinence Education Changes Perceptions of Middle School Students  [PDF]
Tary J. Tobin, Cindy Bankston
Creative Education (CE) , 2017, DOI: 10.4236/ce.2017.815164
Abstract: Abstinence education lessons were designed to address teen pregnancy and sexually transmitted infection (STI) among adolescent youth. A community nonprofit organization with extensive experience in abstinence education trained youth leaders and high school students to collaborate with public school health education teachers. The lessons were based on Promoting Health Among Teens! [PHAT] Abstinence-Only, School Edition(Jemmott, Jemmott, & McCaffree, 2014). Originally developed for use in schools with a high proportion of African Americans, they were adapted for use in schools with a high proportion of Latinos. Over 1000 students from nine middle schools in the northwest part of the United States participated. Responses to pre- and post-intervention survey items were compared and indicated improvements in knowledge of the benefits of sexual abstinence and changes in attitudes toward abstinence. The outcomes of the It’s Legit II: Promoting Health Among Teens! Project indicated?that it was implemented well, received well, and had a beneficial effect.
Wireless Application Protocol (WAP)
Cindy Melzer
South African Journal of Information Management , 2009, DOI: 10.4102/sajim.v2i2/3.108
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