Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99


Any time

2019 ( 210 )

2018 ( 328 )

2017 ( 352 )

2016 ( 502 )

Custom range...

Search Results: 1 - 10 of 243325 matches for " Higor Vinicius dos R. Leite "
All listed articles are free for downloading (OA Articles)
Page 1 /243325
Display every page Item
Ant Colony Optimisation for Backward Production Scheduling
Leandro Pereira dos Santos,Guilherme Ernani Vieira,Higor Vinicius dos R. Leite,Maria Teresinha Arns Steiner
Advances in Artificial Intelligence , 2012, DOI: 10.1155/2012/312132
Abstract: The main objective of a production scheduling system is to assign tasks (orders or jobs) to resources and sequence them as efficiently and economically (optimised) as possible. Achieving this goal is a difficult task in complex environment where capacity is usually limited. In these scenarios, finding an optimal solution—if possible—demands a large amount of computer time. For this reason, in many cases, a good solution that is quickly found is preferred. In such situations, the use of metaheuristics is an appropriate strategy. In these last two decades, some out-of-the-shelf systems have been developed using such techniques. This paper presents and analyses the development of a shop-floor scheduling system that uses ant colony optimisation (ACO) in a backward scheduling problem in a manufacturing scenario with single-stage processing, parallel resources, and flexible routings. This scenario was found in a large food industry where the corresponding author worked as consultant for more than a year. This work demonstrates the applicability of this artificial intelligence technique. In fact, ACO proved to be as efficient as branch-and-bound, however, executing much faster. 1. Production Scheduling Still a Differential for Competitiveness The globalised world economic scenario makes entrepreneurial competitiveness unavoidable and being competitive has become an indispensable prerequisite to organisations that strive for success. Within this context, manufacturing activities become especially important for they decisively influence performance, directly affecting (and being affected by) forecast, planning, and scheduling decisions. Shop-floor production scheduling, which within the hierarchical production planning covers disaggregate and detailed decisions in short time frame, consists in allocating activities (production orders or jobs) to resources, by obeying sequencing and setup restrictions, with focus on getting the best possible results from limited available resources, and, at the same time, aiming at reducing production costs and meeting service levels as fast and efficiently as possible. To make all this happen in cases where production and financial resources are limited and restrictions are many, adequate algorithms techniques and intelligence are necessary. Almost four decades ago, Garey et al. [1] classified production scheduling problems as being NP-hard, which in practical ways means that it is very difficult for one to obtain an optimal solution through exact algorithms and also demand unacceptable execution (computer or effort) time. The
Prevalência de maloclus o e necessidade de tratamento ortod ntico em indivíduos adultos = Prevalence of malocclusion and orthodontic treatment needs in adult patients
Jalber Almeida dos Santos,Vinicius Gabriel Barros Florentino,Dmitry José de Santana Sarmento,Alessandro Leite Cavalcanti
Acta Scientiarum : Health Sciences , 2011,
Abstract: Os objetivos desse estudo foram determinar a prevalência de maloclus o e a necessidade de tratamento ortod ntico em pacientes de 18 a 50 anos de idade atendidos nas clínicas odontológicas da Universidade Estadual da Paraíba. A amostra compreendeu 156 pacientes (65,4% mulheres e 34,6% homens). O diagnóstico da maloclus o foi feito com o uso do índice de Estética Dental (DAI) por meio de dois examinadores calibrados (K = 0,71). A análise estatística utilizou os testes do Qui-quadrado e Exato de Fisher, com nível de significanciade 5%. A prevalência de maloclus o foi 63,5%. Observou-se diferen a estatisticamente significante entre a perda de elemento dentário na regi o anterior e a severidade da maloclus o (p = 0,000; OR = 21,06 [8,47-53,90]). Metade dos pacientes n o estava satisfeita com o sorriso, existindo diferen a estatisticamente significante entre a severidade da maloclus o e a satisfa o ao sorrir (p = 0,015; OR = 2,23 [1,16-4,71]). Conclui-se que a prevalência de maloclus o foi alta, sendo mais frequente o apinhamento no segmento incisal. Um ter o dos pacientes portava maloclus o muito severa/incapacitante, sendo verificada associa o entre a severidade da maloclus o e a satisfa o ao sorrir. The objectives of this study were to determine the prevalence of malocclusion and the orthodontic treatment needs in patients aged 18 to 50 years attending the dental clinics of the State University of Paraíba, Brazil. The sample was composed of 156 patients (65.4% females and 34.6% males). The diagnosis of malocclusion was established by two calibrated examiners (K = 0.71) using the Dental Aesthetics Index (DAI). The Chi-square and Fisher’s exact testswere used for statistical analysis of the data at 5% significance level. The prevalence of malocclusion was 63.5%. There was statistically significant difference between tooth loss in the anterior region and malocclusion severity (p = 0.000; OR = 21.06 [8.47-53.90]). Half of the patients were not satisfied with their smile, with statistically significant difference between malocclusion severity and satisfaction at smiling (p = 0.015; OR= 2.23 [1.16-4.71]). In conclusion, the prevalence of malocclusions was high, the most frequent being crowding in the incisal segment. One third of the patients presented very severe/incapacitating malocclusion, existing association between malocclusion severity and satisfaction at smiling.
Purifica??o parcial e caracteriza??o bioquímica de lipase extracelular produzida por nova linhagem de Rhizopus sp.
Pastore, Gláucia M.;Costa, Vinicius dos Santos R. da;Koblitz, Maria Gabriela B.;
Ciência e Tecnologia de Alimentos , 2003, DOI: 10.1590/S0101-20612003000200006
Abstract: lipases are enzymes capable of catalyzing a great variety of reactions that are interesting to food, pharmaceutical, chemical, and other industries. this versatility is also due to the different substrate specificity possibilities that lipases from various sources. for this reason, lipase producing microorganisms are being searched by research groups around the world. this paper presents the properties of a extracellular lipase produced by a newly isolated strain of rhizopus sp. the crude enzyme showed optimal activity at 40oc, between 6.0 and 6.5 ph values and kept 50% of it′s activity after treatment between 40oc and 55oc for 60 minutes. the hydrolytic activity of the crude extract was greater when coconut fat was used as substrate. this shows the affinity of the lipase to saturated medium chain fatty acids. the fractions i and ii, that were obtained after the partial purification of the lipase, showed biochemical characteristics similar to the crude extract.
Purifica o parcial e caracteriza o bioquímica de lipase extracelular produzida por nova linhagem de Rhizopus sp.
Pastore Gláucia M.,Costa Vinicius dos Santos R. da,Koblitz Maria Gabriela B.
Ciência e Tecnologia de Alimentos , 2003,
Abstract: Lipases s o enzimas capazes de catalizar uma grande gama de rea es de interesse para as indústrias alimentícia, farmacêutica, química, entre outras. Esta versatilidade se deve também às diversas possibilidades de especificidade quanto ao substrato que lipases de diferentes fontes apresentam. Por este motivo, microrganismos produtores desta enzima vêm sendo procurados por grupos de pesquisa no mundo todo. Este trabalho apresenta as propriedades de uma lipase produzida por nova linhagem fúngica de Rhizopus sp. A enzima bruta apresentou condi es ótimas de atividade a 40oC em valores de pH entre 6,0 e 6,5. e manteve 50% ou mais de sua atividade quando aquecida por 60 minutos à temperaturas entre 40oC e 55oC. A atividade hidrolítica da lipase bruta foi maior quando o substrato testado foi a gordura de coco, demonstrando afinidade por ácidos graxos saturados de cadeia média. As fra es I e II obtidas após purifica o parcial da enzima apresentaram características bioquímicas semelhantes as do extrato bruto.
Quasi-fermi levels, chemical and electric potential profiles of a semiconductor under illumination
Santos, A. M. dos;Beliaev, D.;Scolfaro, L. M. R.;Leite, J. R.;
Brazilian Journal of Physics , 1999, DOI: 10.1590/S0103-97331999000400034
Abstract: a theoretical semi-classical method to calculate the modulated field profile in a semiconductor is presented. the behavior of quasi-fermi levels and chemical potentials for the majority and minority carriers is investigated. systematic studies of the non-thermodynamic equilibrium electric potential profile as a function of the modulation light intensity are performed.
Quasi-fermi levels, chemical and electric potential profiles of a semiconductor under illumination
Santos A. M. dos,Beliaev D.,Scolfaro L. M. R.,Leite J. R.
Brazilian Journal of Physics , 1999,
Abstract: A theoretical semi-classical method to calculate the modulated field profile in a semiconductor is presented. The behavior of quasi-Fermi levels and chemical potentials for the majority and minority carriers is investigated. Systematic studies of the non-thermodynamic equilibrium electric potential profile as a function of the modulation light intensity are performed.
Emetofobia: revis?o crítica sobre um transtorno pouco estudado
Leite, Carlos Eduardo Paula;Vicentini, Henrique Cláudio;Neves, Joyce dos Santos;Torres, Albina R.;
Jornal Brasileiro de Psiquiatria , 2011, DOI: 10.1590/S0047-20852011000200007
Abstract: introduction: emetophobia or fear of vomit - which includes an excessive fear of vomiting or seeing other people vomiting and can be triggered by internal and external stimuli -is a complex and fairly unknown disorder. objective: this study aimed at reviewing the current knowledge about this condition. method: a conventional literature review of the previous 30 years, using as search strategy the following keywords: "emetophobia", "emetophobic", "fear of vomiting", "vomiting phobia", and "phobia of vomit". all articles about the epidemiology, phenomenology, differential diagnosis and treatment of emetophobia were included, as well as articles cited in these ones. results: there are no available data on the prevalence in the general population and little is known about the etiology of emetophobia. most studies describe predominance in females, early onset and chronic course. the avoidant behaviors can have a significant impact on occupational, social and family lives. the most important differential diagnoses are: panic disorder with agoraphobia, social phobia, anorexia nervosa and obsessive-compulsive disorder. treatment studies are mostly case reports and no controlled clinical trials have been published. cognitive-behavioral interventions, however, seem to be promising. conclusion: more studies are needed for a better understanding of the epidemiology, clinical picture, etiology, classification and treatment of emetophobia.
TRAINING COURSE FOR TRAINERS OF EDUCATIONAL ACTIVITIES related to social control in health in the Federal District
Tania Cristina dos R. L. Leite,Elioenai Dornelles Alves,Rosangela Conde Watanabe
Revista Gest?o & Saúde , 2010,
Abstract: The course used active learning methodologiesthrough official cytokines that lead to the construction of collectiveknowledge, considering the experience of the participantsas health counselors and participation inprevious training relating to social control. Thecourse, divided into two blocks, will have 48 hours / class is24 h for the didactic process andragogical and 24-hofi divided into six cytokines 4 hours, approaching contentsrelevant to social control in health. They were invitedtechnicians who act as instructors for deepeningspecifi c topics.
Serum laminin, type IV collagen and hyaluronan as fibrosis markers in non-alcoholic fatty liver disease
Santos V.N. dos,Leite-Mór M.M.B.,Kondo M.,Martins J.R.
Brazilian Journal of Medical and Biological Research , 2005,
Abstract: Hepatic fibrosis in patients with non-alcoholic fatty liver disease is associated with progression of the disease. In the present study, we analyzed the discriminative ability of serum laminin, type IV collagen and hyaluronan levels to predict the presence of fibrosis in these patients. In this preliminary report, we studied 30 overweight patients divided into two groups according to the absence (group I, N = 19) or presence (group II, N = 11) of fibrosis in a liver biopsy. Triglycerides, aspartate aminotransferase, alanine aminotransferase, gamma-glutamyltranspeptidade, hyaluronan (noncompetitive fluoroassay), type IV collagen, and laminin (ELISA) were determined. Group II presented significantly higher mean laminin, hyaluronan, type IV collagen, and aspartate aminotransferase values, which were due to the correlation between these parameters and the stage of fibrosis in the biopsy (Spearman's correlation coefficient, rS = 0.65, 0.62, 0.53, and 0.49, respectively). Analysis of the ROC curve showed that laminin values >282 ng/ml were those with the best diagnostic performance, with 87% accuracy. Association of laminin with type IV collagen showed improvement in the positive predictive value (100%), but with reduction in diagnostic sensitivity (64%). When compared with the criteria of Ratziu et al. [Gastroenterology (2000) 118: 1117-1123] for the diagnosis of septal fibrosis, laminin values presented a better diagnostic accuracy (83 vs 70%). Determination of extracellular matrix components in serum, especially of laminin, may identify patients with non-alcoholic fatty liver disease and fibrosis and these components may be used as indicators for liver biopsy in these patients.
Tiago Pinheiro Braga,Ant?,nio Narcí,sio Pinheiro,Edson R. Leite,Regina Clá,udia R. dos Santos,Antoninho Valentini
催化学报 , 2015, DOI: 10.1016/S1872-2067(14)60313-2
Abstract: ?Molybdenum-basedcatalystssupportedonAl2O3dopedwithNi,Cu,orFeoxideweresynthesizedandusedinethylbenzenedehydrogenationtoproducestyrene.Themolybdenumoxidewassupportedusinganunconventionalroutethatcombinedthepolymericprecursormethod(Pechini)andwetimpregnationoncommercialalumina.ThesampleswerecharacterizedbyX-raydiffraction(XRD),N2adsorption-desorptionisotherms,temperature-programmedreductionofH2(H2-TPR),andthermogravimetric(TG)analysis.XRDresultsshowedthattheaddedmetalswerewelldispersedonthealuminasupport.Theadditionofthemetaloxide(Ni,Cu,orFe)of2wt%bywetimpregnationdidnotaffectthetextureofthesupport.TPRresultsindicatedasynergisticeffectbetweenthedopantandmolybdenumoxide.Thecatalytictestsshowedethylbenzeneconversionof28%-53%andstyreneselectivityof94%-97%,indicatingthattheadditionofthedopantimprovedthecatalyticperformance,whichwasrelatedtotheredoxmechanism.Molybdenumoxidesplayafundamentalroleintheoxidativedehydrogenationofethylbenzenetostyrenebyitsredoxandacid-baseproperties.ThesamplecontainingCushowedanatypicalresultwithincreasingconversionduringthereaction,whichwasduetometalreduction.TheNi-containingsolidexhibitedthehighestamountofcarbondeposited,shownbyTGanalysisafterthecatalytictest,whichexplaineditslowercatalyticstabilityandselectivity.
Page 1 /243325
Display every page Item

Copyright © 2008-2017 Open Access Library. All rights reserved.