943 resultados para Non-parametric Tests


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The strategy research have been widespread for many years and, more recently, the process of formation of the strategies in the individual perspective has also gained attention in academia. Confirming this trend, the goal of this study is to discuss the process of formation of the strategies from an individual perspective based on the three dimensions of the strategic process (change, thinking and formation) proposed by De Wit and Meyer (2004). To this end, this exploratory-descriptive study used the factor analysis techniques, non-parametric correlation and linear regression to analyze data collected from the decision makers of the 93 retail in the industry of construction supplies in the Natal and metropolitan area. As a result, we have that the formation factors of the dimensions investigated were identified in the majority, thus confirming the existence of paradoxes in the strategic process, and that there is a relationship between logical thinking and deliberate formation with the hierarchical level of decision makers.

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Academic demands, new social context, new routines and decrease of the parental control, are factors that may influence the sleep pattern of freshman students at the University. Medical students from the Federal University of Rio Grande do Norte (UFRN) have a full-time course, subjects with high-level content, and, at the first semester, classes begin at 7 a.m. This group composed by young adults who still suffering with delayed sleep phase, common in adolescence, indicating that this class schedule can be inappropriate at this age. The reduction of nocturnal sleep during school days, and the attempt to recover sleep on free days – social jet lag (JLS), suggests that in the first semester, students suffer from high sleep pressure. High sleep pressure may reflect on cognitive tasks and performance. Therefore, the aim of this study was to investigate the relationship between sleep pressure and the academic profile of medical students from the first semester of UFRN, characterizing this population socio-demographically and investigating possible impacts on therestactivity rhytm and academic performance. A sample of 88 students, healthy men and women awswered the following questionnaires: Pittsburgh Sleep Quality (PSQI), Epworth Sleepiness Scale (ESS), Horne & Ostberg Chronotype (HO), Munich Chronotype (MCTQ) and “Health and Sleep” adapted. Actigraphy was used during 14 days to make actogramas and obtain non-parametric variables of the rest-activity rhythm and the grades of the morning schedule were used as academic performance. The JLS was used as a measure of sleep pressure. Statistics significance level was 95%. The population was sociodemographic homogeneous. Most students have healthy lifestyle, practice physical activity, use car to go to the university and take between 15 and 30 minutes for this route. Regarding CSV, most were classify as intermediate (38.6%) and evening (32%) chronotypes, needs to nap during the week, suffer daytime sleepiness and have poor sleep quality. 83% of the sample has at least 1h JLS, which led us to divide into two groups: Group <2h JLS (N = 44) and Group ≥ 2h JLS (N = 44). The groups have differences only in chronotype, showing that most evening individuals have more JLS, however, no differences were found in relation to sociodemographic aspect, rest-activity rhythm or academic performance. The homogeneity of the sample was limited to compare the groups, however, is alarming that students already present in the first half: JLG, poor sleep quality and excessive daytime sleepiness, which can be accentuated through the university years, with the emergence of night shifts and increased academic demand. Interventionsaddressingthe importance of good sleep habits and the change of the class start time are strategies aimed to improve student’s health.

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This thesis stems from the project with real-time environmental monitoring company EMSAT Corporation. They were looking for methods to automatically ag spikes and other anomalies in their environmental sensor data streams. The problem presents several challenges: near real-time anomaly detection, absence of labeled data and time-changing data streams. Here, we address this problem using both a statistical parametric approach as well as a non-parametric approach like Kernel Density Estimation (KDE). The main contribution of this thesis is extending the KDE to work more effectively for evolving data streams, particularly in presence of concept drift. To address that, we have developed a framework for integrating Adaptive Windowing (ADWIN) change detection algorithm with KDE. We have tested this approach on several real world data sets and received positive feedback from our industry collaborator. Some results appearing in this thesis have been presented at ECML PKDD 2015 Doctoral Consortium.

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This paper proposes an allocation Malmquist index which is inspired by the work on the non-parametric cost Malmquist index. We first show that how to decompose the cost Malmquist index into the input-oriented Malmquist index and the allocation Malmquist index. An application in corporate management of the China securities industry with the panel data set of 40 securities companies during the period 2005–2011 shows the practicality of the propose model.

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Objective. The prevalence of smoking in Aboriginal Canadians is higher than non-Aboriginal Canadians, a behavior that also tends to alter dietary patterns. Compared with the general Canadian population, maternal smoking rates are almost twice as high. The aim of this study was to compare dietary adequacy of Inuvialuit women of childbearing age comparing smokers versus non-smokers. Research methods & procedures. A cross-sectional study, where participants completed a culturally specific quantitative food frequency questionnaire. Non-parametric analysis was used to compare mean nutrient intake, dietary inadequacy and differences in nutrient density among smokers and non-smokers. Multiple logistic regression analyses were performed for key nutrients inadequacy and smoking status. Data was collected from three communities in the Beaufort Delta region of the Northwest Territories, Canada from randomly selected Inuvialuit women of childbearing age (19-44 years). Results: Of 92 participants, 75% reported being smokers. There were no significant differences in age, BMI, marital status, education, number of people in household working and/or number of self employed, and physical activity between smokers and non-smokers. Non-parametric analysis showed no differences in nutrient intake between smokers and non-smokers. Logistic regression however revealed there was a positive association between smoking and inadequacies of vitamin C (OR = 2.91, 95% CI, 1.17-5.25), iron (OR = 3.16, 95% CI, 1.27-5.90), and zinc (OR = 2.78, 95% CI, 1.12-4.94). A high percentage of women (>60%), regardless of smoking status, did not meet the dietary recommendations for fiber, vitamin D, E and potassium. Conclusions: This study provides evidence of inadequate dietary intake among Inuvialuit of childbearing age regardless of smoking behavior.

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Background: Evidence-based medication and lifestyle modification are important for secondary prevention of cardiovascular disease but are underutilized. Mobile health strategies could address this gap but existing evidence is mixed. Therefore, we piloted a pre-post study to assess the impact of patient-directed text messages as a means of improving medication adherence and modifying major health risk behaviors among coronary heart disease (CHD) patients in Hainan, China.

Methods: 92 CVD patients were surveyed between June and August 2015 (before the intervention) and then between October and December 2015 (after 12 week intervention) about (a) medication use (b) smoking status,(c) fruit and vegetable consumption, and (d) physical activity uptake. Acceptability of text-messaging intervention was assessed at follow-up. Descriptive statistics, along with paired comparisons between the pre and post outcomes were conducted using both parametric (t-test) and non-parametric (Wilcoxon signed rank test) methods.

Results: The number of respondents at follow-up was 82 (89% retention rate). Significant improvements were observed for medication adherence (P<0.001) and for the number of cigarettes smoked per day (P=.022). However there was no change in the number of smokers who quitted smoking at follow-up. There were insignificant changes for physical activity (P=0.91) and fruit and vegetable consumption.

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This study aims at exploring the potential impact of forest protection intervention on rural households’ private fuel tree planting in Chiro district of eastern Ethiopia. The study results revealed a robust and significant positive impact of the intervention on farmers’ decisions to produce private household energy by growing fuel trees on their farm. As participation in private fuel tree planting is not random, the study confronts a methodological issue in investigating the causal effect of forest protection intervention on rural farm households’ private fuel tree planting through non-parametric propensity score matching (PSM) method. The protection intervention on average has increased fuel tree planting by 503 (580.6%) compared to open access areas and indirectly contributed to slowing down the loss of biodiversity in the area. Land cover/use is a dynamic phenomenon that changes with time and space due to anthropogenic pressure and development. Forest cover and land use changes in Chiro District, Ethiopia over a period of 40 years was studied using remotely sensed data. Multi temporal satellite data of Landsat was used to map and monitor forest cover and land use changes occurred during three point of time of 1972,1986 and 2012. A pixel base supervised image classification was used to map land use land cover classes for maps of both time set. The result of change detection analysis revealed that the area has shown a remarkable land cover/land use changes in general and forest cover change in particular. Specifically, the dense forest cover land declined from 235 ha in 1972 to 51 ha in 1986. However, government interventions in forest protection in 1989 have slowed down the drastic change of dense forest cover loss around the protected area through reclaiming 1,300 hectares of deforested land through reforestation program up to 2012.

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We present an extensive photometric catalog for 548 CALIFA galaxies observed as of the summer of 2015. CALIFA is currently lacking photometry matching the scale and diversity of its spectroscopy; this work is intended to meet all photometric needs for CALIFA galaxies while also identifying best photometric practices for upcoming integral field spectroscopy surveys such as SAMI and MaNGA. This catalog comprises gri surface brightness profiles derived from Sloan Digital Sky Survey (SDSS) imaging, a variety of non-parametric quantities extracted from these pro files, and parametric models fitted to the i-band pro files (1D) and original galaxy images (2D). To compliment our photometric analysis, we contrast the relative performance of our 1D and 2D modelling approaches. The ability of each measurement to characterize the global properties of galaxies is quantitatively assessed, in the context of constructing the tightest scaling relations. Where possible, we compare our photometry with existing photometrically or spectroscopically obtained measurements from the literature. Close agreement is found with Walcher et al. (2014), the current source of basic photometry and classifications of CALIFA galaxies, while comparisons with spectroscopically derived quantities reveals the effect of CALIFA's limited field of view compared to broadband imaging surveys such as the SDSS. The colour-magnitude diagram, star formation main sequence, and Tully-Fisher relation of CALIFA galaxies are studied, to give a small example of the investigations possible with this rich catalog. We conclude with a discussion of points of concern for ongoing integral field spectroscopy surveys and directions for future expansion and exploitation of this work.

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Identifying 20th-century periodic coastal surge variation is strategic for the 21st-century coastal surge estimates, as surge periodicities may amplify/reduce future MSL enhanced surge forecasts. Extreme coastal surge data from Belfast Harbour (UK) tide gauges are available for 1901–2010 and provide the potential for decadal-plus periodic coastal surge analysis. Annual extreme surge-elevation distributions (sampled every 10-min) are analysed using PCA and cluster analysis to decompose variation within- and between-years to assess similarity of years in terms of Surge Climate Types, and to establish significance of any transitions in Type occurrence over time using non-parametric Markov analysis. Annual extreme surge variation is shown to be periodically organised across the 20th century. Extreme surge magnitude and distribution show a number of significant cyclonic induced multi-annual (2, 3, 5 & 6 years) cycles, as well as dominant multi-decadal (15–25 years) cycles of variation superimposed on an 80 year fluctuation in atmospheric–oceanic variation across the North Atlantic (relative to NAO/AMO interaction). The top 30 extreme surge events show some relationship with NAO per se, given that 80% are associated with westerly dominant atmospheric flows (+ NAO), but there are 20% of the events associated with blocking air massess (− NAO). Although 20% of the top 30 ranked positive surges occurred within the last twenty years, there is no unequivocal evidence of recent acceleration in extreme surge magnitude related to other than the scale of natural periodic variation.

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Ce projet illustre cinq études, mettant l'emphase sur le développement d'une nouvelle approche diagnostique cardiovasculaire afin d'évaluer le niveau d’oxygène contenu dans le myocarde ainsi que sa fonction microvasculaire. En combinant une séquence de résonance magnétique cardiovasculaire (RMC) pouvant détecter le niveau d’oxygène (OS), des manœuvres respiratoires ainsi que des analyses de gaz artériels peuvent être utilisés comme procédure non invasive destinée à induire une réponse vasoactive afin d’évaluer la réserve d'oxygénation, une mesure clé de la fonction vasculaire. Le nombre de tests diagnostiques cardiaques prescrits ainsi que les interventions, sont en pleine expansion. L'imagerie et tests non invasifs sont souvent effectués avant l’utilisation de procédures invasives. L'imagerie cardiaque permet d’évaluer la présence ou absence de sténoses coronaires, un important facteur économique dans notre système de soins de santé. Les techniques d'imagerie non invasives fournissent de l’information précise afin d’identifier la présence et l’emplacement du déficit de perfusion chez les patients présentant des symptômes d'ischémie myocardique. Néanmoins, plusieurs techniques actuelles requièrent la nécessité de radiation, d’agents de contraste ou traceurs, sans oublier des protocoles de stress pharmacologiques ou physiques. L’imagerie RMC peut identifier une sténose coronaire significative sans radiation. De nouvelles tendances d’utilisation de RMC visent à développer des techniques diagnostiques qui ne requièrent aucun facteur de stress pharmacologiques ou d’agents de contraste. L'objectif principal de ce projet était de développer et tester une nouvelle technique diagnostique afin d’évaluer la fonction vasculaire coronarienne en utilisant l' OS-RMC, en combinaison avec des manœuvres respiratoires comme stimulus vasoactif. Ensuite, les objectifs, secondaires étaient d’utilisés l’OS-RMC pour évaluer l'oxygénation du myocarde et la réponse coronaire en présence de gaz artériels altérés. Suite aux manœuvres respiratoires la réponse vasculaire a été validée chez un modèle animal pour ensuite être utilisé chez deux volontaires sains et finalement dans une population de patients atteints de maladies cardiovasculaires. Chez le modèle animal, les manœuvres respiratoires ont pu induire un changement significatif, mesuré intrusivement par débit sanguin coronaire. Il a été démontré qu’en présence d'une sténose coronarienne hémodynamiquement significative, l’OS-RMC pouvait détecter un déficit en oxygène du myocarde. Chez l’homme sain, l'application de cette technique en comparaison avec l'adénosine (l’agent standard) pour induire une vasodilatation coronarienne et les manœuvres respiratoires ont pu induire une réponse plus significative en oxygénation dans un myocarde sain. Finalement, nous avons utilisé les manœuvres respiratoires parmi un groupe de patients atteint de maladies coronariennes. Leurs myocardes étant altérées par une sténose coronaire, en conséquence modifiant ainsi leur réponse en oxygénation. Par la suite nous avons évalué les effets des gaz artériels sanguins sur l'oxygénation du myocarde. Ils démontrent que la réponse coronarienne est atténuée au cours de l’hyperoxie, suite à un stimuli d’apnée. Ce phénomène provoque une réduction globale du débit sanguin coronaire et un déficit d'oxygénation dans le modèle animal ayant une sténose lorsqu’un supplément en oxygène est donné. En conclusion, ce travail a permis d'améliorer notre compréhension des nouvelles techniques diagnostiques en imagerie cardiovasculaire. Par ailleurs, nous avons démontré que la combinaison de manœuvres respiratoires et l’imagerie OS-RMC peut fournir une méthode non-invasive et rentable pour évaluer la fonction vasculaire coronarienne régionale et globale.

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In an environment of constant change, technological developments, market competition and more informed consumers, the search for a lasting relationship through the conquest of loyalty has become the objective of companies. However, several authors suggest that this loyalty can be affected by negative comments available on the internet. Therefore, this dissertation has as objective to examine if the complaints are available on the internet impact the loyalty to a brand of mobile phone. The research used as the basis the Expanded NCSB model suggest by Johnson et al. (2001), studying five prominent drives of loyalty: image/brand reputation, affective commitment, calculative commitment, perceived value and trust, beyond the satisfaction construct as moderator variable. The research method adopted was the experimental design which included 285 undergraduate students, with the trial which included 285 undergraduate students, with the field study of the mobile industry, specifically, the brands of cell phones. The research approach was quantitative and methods were descriptive statistics, factor analysis, cluster analysis, linear regression and non-parametric test of Wilcoxon for data analysis. Of the 16 hypothesis stemmed from the research model proposed, 12 were confirmed. The results showed that the complaint available on the internet, here represented by the available on the site Reclame Aqui, may impact consumer perceptions about brand loyalty, as well as its antecedents, being that these complaints can affect all the consumers, regardless of historical satisfaction with the brand. It also noted the positive relationship between the independent variables trust, image/brand reputation, perceived value, affective commitment and calculative commitment and the dependent variable - loyalty, even when considering the data obtained after exposure to the complaint. However, no unanimous conclusion that the relationship between these variables was strongest in the group with satisfactory experience. At the first moment of the research, the trust was the most important variable for the formation of loyalty. However, after exposure to treatment, the image/brand reputation, was more relevant. Contributions of the study, limitations and recommendations for future researches are approached in the present investigation

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Les méthodes classiques d’analyse de survie notamment la méthode non paramétrique de Kaplan et Meier (1958) supposent l’indépendance entre les variables d’intérêt et de censure. Mais, cette hypothèse d’indépendance n’étant pas toujours soutenable, plusieurs auteurs ont élaboré des méthodes pour prendre en compte la dépendance. La plupart de ces méthodes émettent des hypothèses sur cette dépendance. Dans ce mémoire, nous avons proposé une méthode d’estimation de la dépendance en présence de censure dépendante qui utilise le copula-graphic estimator pour les copules archimédiennes (Rivest etWells, 2001) et suppose la connaissance de la distribution de la variable de censure. Nous avons ensuite étudié la consistance de cet estimateur à travers des simulations avant de l’appliquer sur un jeu de données réelles.

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The goal of the study was to investigate differences in how two groups of students activated mathematical competencies in the mathematical kangaroo (MK). The two groups, group 1 and 2, were identified from a sample of 264 students (grade 7, age 13) through high achievement (top 20 %) in only one of the tests: the MK or a curriculum bounded test (CT). Analysis of mathematical competencies showed that the high achievers in the MK, activated the problem solving competency to a greater extent than the high achievers in the CT, when doing the MK. The results indicate the importance of using non-traditional tests in the assessment process of students to be able to find students that might possess good mathematical competencies although they do not show it on curriculum bounded tests.

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This thesis aims to investigate vibrational characteristics of magnetic resonance elastography (MRE) of the brain. MRE is a promising, non-invasive methodology for the mapping of shear stiffness of the brain. A mechanical actuator shakes the brain and generates shear waves, which are then imaged with a special MRI sequence sensitive to sub-millimeter displacements. This research focuses on exploring the profile of vibrations utilized in brain elastography from the standpoint of ultimately investigating nonlinear behavior of the tissue. The first objective seeks to demonstrate the effects of encoding off-frequency vibrations using standard MRE methodologies. Vibrations of this nature can arise from nonlinearities in the system and contaminate the results of the measurement. The second objective is to probe nonlinearity in the dynamic brain system using MRE. A non-parametric decomposition technique, novel to the MRE field, is introduced and investigated.

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The National School Feeding Programme (PNAE) is a public policy in Brazil for over 60 years and represents one of the most important programs of feeding and nutrition in the world. The role of family farming as a source of employment in rural areas, food provider and for ensuring much of the Brazil’s food security is constantly present at the government's and social movement’s agendas. Law 11.947 of 2009 marked its integration in the food supply for the National School Feeding Programme. Article 14 of aforementioned law highlights that a minimum of 30% (thirty percent) of the funds transferred by the National Development Fund Education (FNDE) to the Programme must be used for the purchase of food directly from family farmers or their organizations. The national school feeding policy under the responsibility of the FNDE and is subjected to agencies of internal control, such as the General Controllership of the Union (CGU), of external control, such as the Audit Courts of the Union and the of the states, and to the social control of the school feeding councils. Those funds are transferred to the implementing agencies, which are the education offices of the states, municipalities and of the Federal District. These entities must annually present their accountings to the School Feeding Councils, which analyze them and then issue a conclusive report to the FNDE, approving with or without reservations, or rejecting them. In this sense, this research aims to propose parameters that should contribute to the improvement of the social control over purchases from family farming for the National School Feeding Programme. The study was conducted by non parametric sampling alongside the managers of the implementing entities, school feeding councils and Family Farming Organizations all across Brazil, from the databases provided by FNDE and by the National Union of Cooperatives of Family Agriculture and Solidarity Economy (Unicafes). The study points out that the legal framework of PNAE seeks to ensure the participation of family farming in the food supply for the Programme, despite allowing the executing agencies to justify the non-compliance of the minimum required in a number of ways. The survey also signalizes that the school feeding councils follow the implementation of the Programme very shyly, and points out that there is room to expand and enhance the participation of these councils and organizations of family farming in the execution of PNAE. Its effectiveness requires a constant and effective process of training of the agents involved in the Programme.