857 resultados para non-parametric technique


Relevância:

80.00% 80.00%

Publicador:

Resumo:

El objetivo del presente estudio consiste en analizar el impacto que la publicación de la noticia de obtención de un certificado de calidad (ISO 9000) tiene sobre el valor de mercado de la empresa y sobre la volatilidad del precio de cotización de las acciones. Adicionalmente se examinan diversos factores determinantes del impacto de la obtención del certificado sobre la rentabilidad. La muestra utilizada incluye todas las empresas que, habiendo cotizado en el mercado continuo entre los años 1993 y 1999, han obtenido un certificado de calidad. Para medir el impacto de la obtención de un certificado de calidad sobre los resultados se ha analizado los excesos de rentabilidad, mientras que para medir la variación en la volatilidad se han realizado cuatro test, dos paramétricos, uno no paramétrico y una propuesta de test semiparamétrico. Los resultados indican que el mercado reacciona positivamente a la obtención de este certificado, provocando además un incremento en la volatilidad de los precios de cotización.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

Resumen del póster expuesto en el 6th EOS Topical Meeting on Visual and Physiological Optics (EMVPO 2012), Dublín, 20-22 Agosto 2012.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

Póster presentado en el 6th EOS Meeting on Visual and Physiological Optics (EMVPO 2012), Dublín, 20-22 Agosto 2012.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

The interaction of both natural conditions and anthropogenic environmental impacts can lead to different soft-bottom macrobenthic distribution patterns. Soft-bottom macrobenthic community was analysed at different taxonomic scales in order to evaluate whether diverse subset of organisms respond to the variability of the environmental pressures (natural and human induced) showing or not similar distribution patterns. Therefore, this long-term survey had been focused on a heterogeneous area, where both anthropogenic and natural stress may affect the community. Three perpendicular transects to the coast were established and stations at 4, 10 and 15 m depths were sampled at each transect twice a year (summer- winter) from 2004 to 2009. Non-parametric multivariate techniques were used to analyse soft-bottom macrobenthic community distribution and its relation to the environmental factors. Similar distribution patterns between investigated taxonomic levels were detected and they were mainly related to depth.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

Background and Study Aim: Understanding injury incidence rates will be a great help with regards to preventing potential future damages. It is for this reason that this study suggests studying a large number of variables. The purpose of research is the relationship of events (empirical variables) that are usually taken into account in developing injury prevention programs during the battles and training in judo tournament. Material and methods: In this research project, 57 male judokas taking part in the Spanish National University Championship in 2009 were asked to complete a retrospective questionnaire. We analysed the following events: the most commonly injured body regions, the medical diagnosis, how and when the injury happened, the type of injury, the side of the body and the type of medical attention received. For the statistical analysis, we used the SPSS statistics programme to apply the Chi-square test in order to determine the significance levels for non-parametric tests from p<.05. Results: Significant differences were found in the most commonly injured body region, the shoulder/clavicle (p<.05), and in the most common diagnosis, the sprain (p<.05). Impact injuries (p<.05) are the most common and training (p<.05) is the most dangerous time. About the type of injury, 78.38% are new injuries (p<.05) and 69.05% affect the right hand side of the body (p<.05). Doctors are the most consulted specialists, but the physiotherapists obtained the best marks. Have been out due to injury for over 21 days 36.36% of the participants, but not for the entire season. Conclusions: The most common diagnosis in university student judokas coincides with those of elite judokas, with the sprain being the most common. University student judokas have a higher rate of shoulder/clavicle injuries, while professional judokas are prone to a higher rate of knee injuries. Training is the most common moment in which injuries occur, both in university student judokas and professional judokas. New injuries are the most common types of injuries in university student judokas and, while doctors are the most consulted specialists, the physiotherapists obtained the best marks.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

El uso específico de la termografía infrarroja como técnica no destructiva permite el estudio de sistemas constructivos en edificios históricos (caracterización de materiales, disposición constructiva o identificación de elementos originales). Así, se muestra una aplicación práctica en templos en la provincia de Alicante construidos entre finales del siglo XVII y principios del xix, donde se analiza la complementariedad de las imágenes termográficas de 140 cúpulas (junto con datos recopilados in situ, dibujos originales y levantamiento de planos) como herramienta de estudio en fases de análisis previas a una restauración. En conclusión, la investigación detalla una aplicación termográfica al estudio de distintos aspectos como el reconocimiento de materiales empleados (90,71 % ladrillo macizo, 6,43 % ladrillo hueco y 2,86 % piedra), variaciones de espesor interior y exterior (75,71 % perfil apuntado, 17,86 % perfil semiesférico y 6,43 % perfil rebajado), caracterización de grietas/fisuras (estado de conservación) e identificación de cúpulas originales (96,43 %) o restauradas (3,57 %).

Relevância:

80.00% 80.00%

Publicador:

Resumo:

The study of digital competence remains an issue of interest for both the scientific community and the supranational political agenda. This study uses the Delphi method to validate the design of a questionnaire to determine the perceived importance of digital competence in higher education. The questionnaire was constructed from different framework documents in digital competence standards (NETS, ACLR, UNESCO). The triangulation of non-parametric techniques made it possible to consolidate the results obtained through the Delphi panel, the suitability of which was highlighted through the expert competence index (K). The resulting questionnaire emerges as a good tool for undertaking future national and international studies on digital competence in higher education.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

Trabalho Final do Curso de Mestrado Integrado em Medicina, Faculdade de Medicina, Universidade de Lisboa, 2013

Relevância:

80.00% 80.00%

Publicador:

Resumo:

A presente investigação pretende identificar os fatores que compõem a vantagem competitiva da cadeia de pronto-a-vestir Zara, contribuindo para a sua diferenciação do mercado. Pretende-se ainda perceber se esses fatores diferem de acordo com as caraterísticas sociodemográficas dos consumidores (idade, grau académico e rendimento), bem como se a frequência de realização de compras na loja influencia significativamente os fatores de diferenciação pela vantagem competitiva. Para tal, desenvolveu-se um estudo de caso, assente numa metodologia quantitativa, que contou com a aplicação de um questionário como método de recolha dos dados. O tratamento estatístico recorreu a técnicas descritivas e inferenciais como a análise fatorial e testes de comparação de médias. Os resultados demonstram haver quatro fatores que compõem a vantagem competitiva da Zara (atendimento, marca e produto, ambiente da loja e valor percebido), verificando-se uma influência maioritariamente do grau de escolaridade e da frequência de compras na loja.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

Os Portugueses desde imemoráveis tempos gostam de partir à descoberta de mundos novos, fazemo-lo pelas mais variadas razões, no entanto, neste trabalho iremos apenas analisar os riscos associados ao turismo de lazer. Os atentados de Nova Iorque em 11 Setembro 2001, Síndrome Respiratório Grave em HongKong em Fevereiro de 2003, o Tsunami no oceano Indico em Dezembro 2004, a erupção vulcânica na Islândia em Abril de 2010 ou os atentados de Paris em 13 de Novembro 2015, estas datas ficaram marcadas para sempre, lemos e relemos inúmeros depoimentos de pessoas que se encontravam de férias nestas cidades e pensamos e se fossemos nós? Os primeiros registos da atividade seguradora datam do ano 5.000 A.C. inicialmente seguravam transportes de mercadorias, hoje em dia podem cobrir “qualquer coisa”. Com a perceção dos riscos que hoje em dia podem ocorrer numa viagem, será que as Seguradoras estão preparadas para minimizar os mesmos? E qual a perceção dos riscos para quem viaja. Para o efeito realizou-se um estudo exploratório por suporte a uma amostra de conveniência que reuniu 152 observações. Análises descritivas e testes não paramétricos foram aplicados para definir quais os riscos mais percebidos e quais os que os turistas portugueses pretendem ver cobertos. Concluiu-se que as pessoas que dão maior importância aos Risco de Saúde e Financeiro são os que efetuam seguros de viagem, já as que dão maior importância aos Risco Equipamento, Risco Politico, Risco Psicológico e Risco de Satisfação são as que optam por não fazer seguro.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

Two different slug test field methods are conducted in wells completed in a Puget Lowland aquifer and are examined for systematic error resulting from water column displacement techniques. Slug tests using the standard slug rod and the pneumatic method were repeated on the same wells and hydraulic conductivity estimates were calculated according to Bouwer & Rice and Hvorslev before using a non-parametric statistical test for analysis. Practical considerations of performing the tests in real life settings are also considered in the method comparison. Statistical analysis indicates that the slug rod method results in up to 90% larger hydraulic conductivity values than the pneumatic method, with at least a 95% certainty that the error is method related. This confirms the existence of a slug-rod bias in a real world scenario which has previously been demonstrated by others in synthetic aquifers. In addition to more accurate values, the pneumatic method requires less field labor, less decontamination, and provides the ability to control the magnitudes of the initial displacement, making it the superior slug test procedure.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

Objective To determine the pharmacokinetics of doxorubicin in sulphur-crested cockatoos, so that its use in clinical studies in birds can be considered. Design A pharmacokinetic study of doxorubicin, following a single intravenous (IV) infusion over 20 min, was performed in four healthy sulphur-crested cockatoos (Cacatua galerita). Procedure Birds were anaesthetised and both jugular veins were cannulated, one for doxorubicin infusion and the other for blood collection. Doxorubicin hydrochloride (2 mg/kg) in normal saline was infused IV over 20 min at a constant rate. Serial blood samples were collected for 96 h after initiation of the infusion. Plasma doxorubicin concentrations were assayed using an HPLC method involving ethyl acetate extraction, reverse-phase chromatography and fluorescence detection. The limit of quantification was 20 ng/mL. Established non-parametric methods were used for the analysis of plasma doxorubicin data. Results During the infusion the mean +/- SD for the C-max of doxorubicin was 4037 +/- 2577 ng/mL. Plasma concentrations declined biexponentially immediately after the infusion was ceased. There was considerable intersubject variability in all pharmacokinetic variables. The terminal (beta-phase) half-life was 41.4 +/- 18.5 min, the systemic clearance (Cl) was 45.7 +/- 18.0 mL/min/kg, the mean residence time (MRT) was 4.8 +/- 1.4 min, and the volume of distribution at steady state (V-SS) was 238 131 mL/kg. The extrapolated area under the curve (AUC(0-infinity)) was 950 +/- 677 ng/mL.h. The reduced metabolite, doxorubicinol, was detected in the plasma of all four parrots but could be quantified in only one bird with the profile suggesting formation rate-limited pharmacokinetics of doxorubicinol. Conclusions and clinical relevance Doxorubicin infusion in sulphur-crested cockatoos produced mild, transient inappetence. The volume of distribution per kilogram and terminal half-life were considerably smaller, but the clearance per kilogram was similar to or larger than reported in the dog, rat and humans. Traces of doxorubicinol, a metabolite of doxorubicin, were detected in the plasma.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

The somatic growth dynamics of green turtles ( Chelonia mydas) resident in five separate foraging grounds within the Hawaiian Archipelago were assessed using a robust non-parametric regression modelling approach. The foraging grounds range from coral reef habitats at the north-western end of the archipelago, to coastal habitats around the main islands at the southeastern end of the archipelago. Pelagic juveniles recruit to these neritic foraging grounds from ca. 35 cm SCL or 5 kg ( similar to 6 years of age), but grow at foraging-ground-specific rates, which results in quite different size- and age-specific growth rate functions. Growth rates were estimated for the five populations as change in straight carapace length ( cm SCL year) 1) and, for two of the populations, also as change in body mass ( kg year) 1). Expected growth rates varied from ca. 0 - 2.5 cm SCL year) 1, depending on the foraging-ground population, which is indicative of slow growth and decades to sexual maturity, since expected size of first-time nesters is greater than or equal to 80 cm SCL. The expected size- specific growth rate functions for four populations sampled in the southeastern archipelago displayed a non-monotonic function, with an immature growth spurt at ca. 50 - 53 cm SCL ( similar to 18 - 23 kg) or ca. 13 - 19 years of age. The growth spurt for the Midway atoll population in the northwestern archipelago occurs at a much larger size ( ca. 65 cm SCL or 36 kg), because of slower immature growth rates that might be due to a limited food stock and cooler sea surface temperature. Expected age-at-maturity was estimated to be ca. 35 - 40 years for the four populations sampled at the south-eastern end of the archipelago, but it might well be > 50 years for the Midway population. The Hawaiian stock comprises mainly the same mtDNA haplotype, with no differences in mtDNA stock composition between foraging-ground populations, so that the geographic variability in somatic growth rates within the archipelago is more likely due to local environmental factors rather than genetic factors. Significant temporal variability was also evident, with expected growth rates declining over the last 10 - 20 years, while green turtle abundance within the archipelago has increased significantly since the mid-1970s. This inverse relationship between somatic growth rates and population abundance suggests a density-dependent effect on somatic growth dynamics that has also been reported recently for a Caribbean green turtle stock. The Hawaiian green turtle stock is characterised by slow growth rates displaying significant spatial and temporal variation and an immature growth spurt. This is consistent with similar findings for a Great Barrier Reef green turtle stock that also comprises many foraging-ground populations spanning a wide geographic range.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

Inactivity is associated with endothelial dysfunction and the development of cardiovascular disease. Exercise training has a favourable effect in the management of hypertension, heart failure and ischaemic heart disease. These beneficial effects are probably mediated through improvements of vascular function and, in this issue of Clinical Science, Hagg and co-authors propose a coronary artery effect. The use of a Doppler technique for non-invasive assessment of coronary flow reserve in a small animal model is an exciting aspect of this study. If feasible in the hands of other investigators, the availability of sequential coronary flow measurements in animal models may help improve our understanding of the mechanisms of disorders of the coronary circulation.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

Background: In early 2001 Australia experienced a sudden and unexpected disruption to heroin availability, know as the 'heroin shortage'. This 'shortage has been linked to a decrease in needle and syringe output and therefore possibly a reduction in injecting drug use. We aimed to examine changes, if any, in blood-borne viral infections and presentations for injecting related problems related to injecting drug use following the reduction heroin availability in Australia, in the context of widespread harm reduction measures. Methods: Time series analysis of State level databases on HIV, hepatitis B, hepatitis C notifications and hospital and emergency department data. Examination of changes in HIV, hepatitis B, hepatitis C notifications and hospital and emergency department admissions for injection-related problems following the onset of the heroin shortage; non-parametric curve-fitting of number of hepatitis C notifications among those aged 15 - 19 years. Results: There were no changes observed in hospital visits for injection-related problems. There was no change related to the onset heroin shortage in the number of hepatitis C notifications among persons aged 15 - 19 years, but HCV notifications have subsequently decreased in this group. No change occurred in HIV and hepatitis B notifications. Conclusion: A marked reduction in heroin supply resulted in no increase in injection-related harm at the community level. However, a delayed decrease in HCV notifications among young people may be related. These changes occurred in a setting with widespread, publicly funded harm reduction initiatives.