53 resultados para Distribuições
em Universidade Federal do Rio Grande do Norte(UFRN)
Resumo:
DUTRA, Ricardo Peixoto Suassuna ; SILVA, Jaquelígia Brito da ; MORAES, Márcio Luiz Varela Nogueira de ; NASCIMENTO, R. M. ; GOMES, Uilame Umbelino ; PASKOCIMAS, Carlos Alberto . Avaliação da potencialidade de argilas do Rio Grande do Norte. Cerâmica Industrial, v. 13, p. 47-50, 2008.
Resumo:
This study aimed to measure the perception of maturity project management of state boards of Rio Grande do Norte by the perception of its managers. Argues that project management has been highlighted as a critical factor for the success of any organization, because the projects are directly related to the set of activities that result in organizational innovation as products, services and processes and the improvement of project management is directly aligned with the main pillars of the New Public Management. Methodologically, this is a quantitative research of a descriptive nature in which 161 forms were applied with coordinators and subcoordinators of state departments of Rio Grande do Norte, culminating in a sampling error of less than 6% to 95% confidence according to the procedures finite sampling. The process of tabulation and analysis was done using the package Statistical Package for Social Sciences - SPSS 18.0 and worked with techniques such as mean, standard deviation, frequency distributions, cluster analysis and factor analysis. The results indicate that the levels of maturity in project management in state departments of Rio Grande do Norte is below the national average and that behavioral skills are the main problem for improving management in these departments. It was possible to detect the existence of two groups of different perceptions about the management of projects, indicating, according to the managers, there are islands of excellence in project management in some sectors of the state departments. It was also observed that there are eight factors that affect maturity in project management: Planning and Control , Development of Management Skills , Project Management Environment , Acceptance of the Subject Project Management , Stimulus to Performance , Project Evaluation and Learning , Project Management Office and Visibility of Project Managers . It concludes that the project management in state departments of Rio Grande do Norte has no satisfactory levels of maturity in project management, affecting the levels of efficiency and effectiveness of the state apparatus, which shows that some of the assumptions that guide the New Public Management are not getting the levels of excellence nailed by this management model
Resumo:
Na unfolding method of linear intercept distributions and secction área distribution was implemented for structures with spherical grains. Although the unfolding routine depends on the grain shape, structures with spheroidal grains can also be treated by this routine. Grains of non-spheroidal shape can be treated only as approximation. A software was developed with two parts. The first part calculates the probability matrix. The second part uses this matrix and minimizes the chi-square. The results are presented with any number of size classes as required. The probability matrix was determined by means of the linear intercept and section area distributions created by computer simulation. Using curve fittings the probability matrix for spheres of any sizes could be determined. Two kinds of tests were carried out to prove the efficiency of the Technique. The theoretical tests represent ideal cases. The software was able to exactly find the proposed grain size distribution. In the second test, a structure was simulated in computer and images of its slices were used to produce the corresponding linear intercept the section area distributions. These distributions were then unfolded. This test simulates better reality. The results show deviations from the real size distribution. This deviations are caused by statistic fluctuation. The unfolding of the linear intercept distribution works perfectly, but the unfolding of section area distribution does not work due to a failure in the chi-square minimization. The minimization method uses a matrix inversion routine. The matrix generated by this procedure cannot be inverted. Other minimization method must be used
Resumo:
In this work we developed a computer simulation program for physics porous structures based on programming language C + + using a Geforce 9600 GT with the PhysX chip, originally developed for video games. With this tool, the ability of physical interaction between simulated objects is enlarged, allowing to simulate a porous structure, for example, reservoir rocks and structures with high density. The initial procedure for developing the simulation is the construction of porous cubic structure consisting of spheres with a single size and with varying sizes. In addition, structures can also be simulated with various volume fractions. The results presented are divided into two parts: first, the ball shall be deemed as solid grains, ie the matrix phase represents the porosity, the second, the spheres are considered as pores. In this case the matrix phase represents the solid phase. The simulations in both cases are the same, but the simulated structures are intrinsically different. To validate the results presented by the program, simulations were performed by varying the amount of grain, the grain size distribution and void fraction in the structure. All results showed statistically reliable and consistent with those presented in the literature. The mean values and distributions of stereological parameters measured, such as intercept linear section of perimeter area, sectional area and mean free path are in agreement with the results obtained in the literature for the structures simulated. The results may help the understanding of real structures.
Resumo:
This work focuses on the creation and applications of a dynamic simulation software in order to study the hard metal structure (WC-Co). The technological ground used to increase the GPU hardware capacity was Geforce 9600 GT along with the PhysX chip created to make games more realistic. The software simulates the three-dimensional carbide structure to the shape of a cubic box where tungsten carbide (WC) are modeled as triangular prisms and truncated triangular prisms. The program was proven effective regarding checking testes, ranging from calculations of parameter measures such as the capacity to increase the number of particles simulated dynamically. It was possible to make an investigation of both the mean parameters and distributions stereological parameters used to characterize the carbide structure through cutting plans. Grounded on the cutting plans concerning the analyzed structures, we have investigated the linear intercepts, the intercepts to the area, and the perimeter section of the intercepted grains as well as the binder phase to the structure by calculating the mean value and distribution of the free path. As literature shows almost consensually that the distribution of the linear intercepts is lognormal, this suggests that the grain distribution is also lognormal. Thus, a routine was developed regarding the program which made possible a more detailed research on this issue. We have observed that it is possible, under certain values for the parameters which define the shape and size of the Prismatic grain to find out the distribution to the linear intercepts that approach the lognormal shape. Regarding a number of developed simulations, we have observed that the distribution curves of the linear and area intercepts as well as the perimeter section are consistent with studies on static computer simulation to these parameters.
Resumo:
Deep bed filtration occurs in several industrial and environmental processes like water filtration and soil contamination. In petroleum industry, deep bed filtration occurs near to injection wells during water injection, causing injectivity reduction. It also takes place during well drilling, sand production control, produced water disposal in aquifers, etc. The particle capture in porous media can be caused by different physical mechanisms (size exclusion, electrical forces, bridging, gravity, etc). A statistical model for filtration in porous media is proposed and analytical solutions for suspended and retained particles are derived. The model, which incorporates particle retention probability, is compared with the classical deep bed filtration model allowing a physical interpretation of the filtration coefficients. Comparison of the obtained analytical solutions for the proposed model with the classical model solutions allows concluding that the larger the particle capture probability, the larger the discrepancy between the proposed and the classical models
Resumo:
Modeling transport of particulate suspensions in porous media is essential for understanding various processes of industrial and scientific interest. During these processes, particles are retained due to mechanisms like size exclusion (straining), adsorption, sedimentation and diffusion. In this thesis, a mathematical model is proposed and analytical solutions are obtained. The obtained analytic solutions for the proposed model, which takes pore and particle size distributions into account, were applied to predict the particle retention, pore blocking and permeability reduction during dead-end microfiltration in membranes. Various scenarios, considering different particle and pore size distributions were studied. The obtained results showed that pore blocking and permeability reduction are highly influenced by the initial pore and particle size distributions. This feature was observed even when different initial pore and particle size distributions with the same average pore size and injected particle size were considered. Finally, a mathematical model for predicting equivalent permeability in porous media during particle retention (and pore blocking) is proposed and the obtained solutions were applied to study permeability decline in different scenarios
Resumo:
The epilepsy is one of the neurological disorders more common in the pediatric period, and which interferes significantly in the psycho and social life of children and teenagers. The objective of this study was analyzing the practice of sedentary practices, physicals, traditional infant fun and games of children and teenagers with and without epilepsy. The study was prospective, transversal descriptive, done with 60 children and teenagers with epilepsy (Epileptic Group - EG) patients from Pediatric Neurology Clinic of the Centre Integrated Health Lineu Araújo and 60 children and teenagers without epilepsy (Control Group - CG) students from municipal public school, both of the two groups paired with the same age (age group 7 to 14 years) of both the genders (female = 25/41,6% and male = 35/58,3%) of the Teresina city Piauí. It was done two pattern questionnaires, one applied to children and teenagers of the EG and CG to identify the sedentary activities, physical and traditional infant games and other to the parents/responsible of the EG about the clinical and demographic information. The results permitted the elaboration of two manuscripts: a) the first one titled The Practice of Sedentary and Physical Activities of Children and Teenagers with Epilepsy which showed significant difference in the sedentary activities of playing with car toy (p=0,021) to the EG and reading to the CG (p=0,001); in the physical activities the school physical education (p=0,001) and riding a bike (p=0,014) to the CG; b) the second one The Practice of Infant Games and Fun the children and teenagers with and without Epilepsy in this one the playing with marble presented significant difference (p=0,016) to the CG, despite the girls of the two groups don t do this activity. Observing the distribution of frequencies, it was verified that in the play catch-up and hide-and-seek and burn the EG plays more than the CG both in female and male gender. The girls of the EG play less skip, 60 while the boys of the two groups don t play. Elastic jump the girls of the two groups play in a same frequency and the boys don t participate of this fun. The seizures were found to occur during: soccer (23,3%); hide-and-seek (6,6%) and running (3,3%). In the sedentary activities, seizures were reported to occur: resting and watching TV (18,3%), sleeping (36,0%); sitting (13,3%) and lying down (11,7%). Our results showed that the epileptic group and the controls group engage in the same activities, although the epileptic group participates less than the controls. Although the EG had presented a bigger percentage of generalized attacks, they don t occur during the practice of formal physical activities. The research was developed by a multidisciplinary team, and this contributed a lot to the realization of this study
Resumo:
Family farming has been considered as the new axis of rural development in the country, the focus of several public policies, especially the National Program for Strengthening Family Agriculture - PRONAF and Food Purchase Program - PAA. PRONAF was created with the aim of providing credit to farmers, while the PAA to support family farmers through the purchase of its production. In this context, the objective of this study is to analyze the correspondence of these two public policies for family farming, in the Territories of Citizenship of the state of Rio Grande do Norte, between the years 2008 to 2010. In the methodology, the analysis was performed by comparing the distributions of the two programs in the territories of citizenship status. There were also statistical tests of differences in proportions, and Spearman correlations, and estimated a logit regression model, in order to measure the probability of a farmer participating in the PAA is associated with one of the modes of PRONAF. The data used were obtained from the National and Supply - CONAB at the Institute of Technical Assistance and Rural Extension - EMATER, and the Ministry of Agrarian Development - MDA. Among the key findings was noted that policies were associated with a direct, but low in the districts of the Territories of Citizenship. And that, in the years 2008 and 2009, only in the territories of Mato Grande, Alto Oeste and Seridó, the actions of PAA and PRONAF had direct and significant correlations. It was found that in most of the territories, policies are performed randomly, ie that both have no correlation to each other. The estimates of the logit model showed that the chance of a family farmer, the PAA participant, receive credits PRONAF A, is higher in the territory of Mato Grande, and would have a chance to fall in PRONAF B in all areas surveyed. Moreover, farmers in the territories of the Assu-Mossoró, Sertão of Apodi, Seridó and Alto Oeste, participating in the PAA would be more likely to receive credits PRONAF C, reflecting thus the family farm more consolidated these territories
Resumo:
The pregnancy as a process in woman's life requires several biological, psychological, relational and socio-cultural changes for the preparation for motherhood. By modifying its capacity and, at the expense of these factors, it is observed that the physical, social and emotional problems experienced by women during pregnancy can affect their quality of life, especially related to health. It had as objectives of this research verifying the quality of life of women in the context of the Family Health Strategy in a municipality in Paraíba, in order to characterize the sociodemographic aspects, lifestyle habits, and obstetric care of pregnant women and to characterize the fields of quality of life of pregnant women according to the WHOQOL-bref. This is a descriptive exploratory study with cross-sectional and quantitative approach. The population consisted of 120 pregnant women in primary care in the municipality of Sousa-PB. Data collection occurred over a period of two months by the own master's degree student and two nursing students in applying a standard form about sociodemographic characteristics, and obstetric care and the WHOQOL-bref instrument. The data collected were organized into an electronic database of the Microsoft Excel application, coded, tabulated and presented in tables, charts and figures with their respective percentage distributions. Of the surveyed, the predominant were age group of 20 to 25 years, Catholic religion, with a steady partner, low education, no employment, wage income of 01 minimum wage. As for the data and obstetric care, almost all had never aborted and reported to the care received as excellent. The most frequent complaints were back pain and in lower abdomen. Regarding quality of life according to the WHOQOL-bref, dissatisfactions that predominated in the areas were in the physical pain and discomfort, sleep, rest, energy and fatigue. In the psychological domain, body image and appearance, memory, concentration and negative feelings. In the field of social relationships, sexual activity and the environment domain, the greatest dissatisfaction with facets scored: financial resources, leisure opportunities and transport. It is concluded that the quality of life of the users interviewed were deemed unsatisfactory for these facets, indicating that assistance to this target audience should be done comprehensively and holistically, in order to accommodate the affected facets to improve the quality of life pregnant women attended in primary care
Resumo:
The Urinary Tract Infection (UTI) in pregnancy is important as a consequence of the high incidence during the gestation. It is the third most common clinical complication in pregnancy affecting 10-12% of women whether prevalence is increasing in the first trimester of pregnancy, it may also contribute to maternal and infant mortality. Due the relevance for the results of obstetric and neonatal complications from UTI, these complications must be prevented, because it can lead to health hazards to pregnant women and newborns, producing a direct effect on morbidity and perinatal mortality. On this basis, it was defined as objectives of this research the identification of the profile of nurses from the Family Health Strategy (FHS) in the East and West Health Districts from the city of Natal / RN before the women with UTI and to verify the nurse performance during prenatal consultations. This is an exploratory study with a quantitative approach using a sample of 40 nurses active workers during this survey, it was approved by the Research Ethics Committee of the Universidade Federal do Rio Grande do Norte Protocol n0 232/10 P-CEP/UFRN and opinion n0 080/2011. The tool for data collection was a structured interview. The data collected were organized into an electronic database application Microsoft ® Excel 2007, exported and analyzed using the Statistical Package for Social Sciences (SPSS) version 17.0, and coded, tabulated and presented through tables and charts into their respective percentage distributions, using the descriptive and inferential statistical analysis, chi-square test and significance level of 5% (distribution in relative and absolute frequencies) in the independent variables. Therefore, it was observed from these results that the longer action of nurses in the FHS from the East and Weast health districts of the city of Natal/RN contributed to the development of a greater number of activities to control the incidence of UTI in women who are attended in the prenatal care service, proven by significance in statistics
Resumo:
This work consists in the development of a theoretical and numerical analysis for frequency selective surfaces (FSS) structures with conducting patch elements, such as rectangular patches, thin dipoles and cross dipoles, on anisotropic dielectric substrates. The analysis is developed for millimeter wave band applications. The analytical formulation is developed in the spectral domain, by using a rigorous technique known as equivalent transmission line method, or immitance approach. The numerical analysis is completed through the use of the Galerkin's technique in the Fourier transform domain, using entire-domain basis functions. In the last decades, several sophisticated analytical techniques have been developed for FSS structure applications. Within these applications, it can be emphasized the use of FSS structures on reflecting antennas and bandpass radomes. In the analysis, the scattered fields of the FSS geometry are related to the surface induced currents on the conducting patches. After the formulation of the scattering problem, the numerical solution is obtained by using the moment method. The choice of the basis functions plays a very important role in the numerical efficiency of the numerical method, once they should provide a very good approximation to the real current distributions on the FSS analyzed structure. Thereafter, the dyadic Green's function components are obtained in order to evaluate the basis functions unknown coefficients. To accomplish that, the Galerkin's numerical technique is used. Completing the formulation, the incident fields are determined through the incident potential, and as a consequence the FSS transmission and reflection characteristics are determined, as function of the resonant frequency and structural parameters. The main objective of this work was to analyze FSS structures with conducting patch elements, such as thin dipoles, cross dipoles and rectangular patches, on anisotropic dielectric substrates, for high frequency applications. Therefore, numerical results for the FSS structure main characteristics were obtained in the millimeter wave bando Some of these FSS characteristics are the resonant
Resumo:
Bayesian networks are powerful tools as they represent probability distributions as graphs. They work with uncertainties of real systems. Since last decade there is a special interest in learning network structures from data. However learning the best network structure is a NP-Hard problem, so many heuristics algorithms to generate network structures from data were created. Many of these algorithms use score metrics to generate the network model. This thesis compare three of most used score metrics. The K-2 algorithm and two pattern benchmarks, ASIA and ALARM, were used to carry out the comparison. Results show that score metrics with hyperparameters that strength the tendency to select simpler network structures are better than score metrics with weaker tendency to select simpler network structures for both metrics (Heckerman-Geiger and modified MDL). Heckerman-Geiger Bayesian score metric works better than MDL with large datasets and MDL works better than Heckerman-Geiger with small datasets. The modified MDL gives similar results to Heckerman-Geiger for large datasets and close results to MDL for small datasets with stronger tendency to select simpler network structures
Resumo:
Dois dos principais objetivos no estudo da aerodinâmica de veículos é a segurança e o desempenho. Esses objetivos podem ser alcançados através do desenvolvimento de dispositivos que modifiquem o escoamento de ar ao redor do veículo e também através de alterações da forma das superfícies externas. O perfil mais baixo da frente do veículo, por exemplo, tem grande influência sobre o coeficiente de penetração aerodinâmica (Cx) e posteriormente sobre grande parte da distribuição de pressão ao longo da superfície do veículo. O objetivo deste trabalho foi de analisar o comportamento aerodinâmico que incide sobre 2 (dois) tipos de carrocerias de veículos, baseado em experimentação em túnel aerodinâmico, visando determinar a eficiência aerodinâmica de cada uma delas. Foram comparados dois modelos de veículos, sendo um deles com configuração familiar, muito comum nas grandes cidades e outro modelo com configuração esportiva mais voltado para o desempenho, ambos com escala 1:18. Para a realização do experimento foi construído um túnel aerodinâmico do tipo soprador com circuito aberto, onde foram analisadas as distribuições de pressão nas superfícies inferiores e superiores da carroceria dos modelos e o deslocamento da camada-limite. Tomando-se por base toda a teórica deste trabalho, com relação à aerodinâmica de carroceria, considerou-se nesta dissertação que essa filosofia de pesquisa é capaz de gerar reflexos positivos, que podem tornar os veículos cada vez mais eficientes e influenciar positivamente nos níveis de segurança e desempenho
Resumo:
The great importance in selecting the profile of an aircraft wing concerns the fact that its relevance in the performance thereof; influencing this displacement costs (fuel consumption, flight level, for example), the conditions of flight safety (response in critical condition) of the plane. The aim of this study was to examine the aerodynamic parameters that affect some types of wing profile, based on wind tunnel testing, to determine the aerodynamic efficiency of each one of them. We compared three types of planforms, chosen from considerations about the characteristics of the aircraft model. One of them has a common setup, and very common in laboratory classes to be a sort of standard aerodynamic, it is a symmetrical profile. The second profile shows a conFiguration of the concave-convex type, the third is also a concave-convex profile, but with different implementation of the second, and finally, the fourth airfoil profile has a plano-convex. Thus, three different categories are covered in profile, showing the main points of relevance to their employment. To perform the experiment used a wind tunnel-type open circuit, where we analyzed the pressure distribution across the surface of each profile. Possession of the drag polar of each wing profile can be, from the theoretical basis of this work, the aerodynamic characteristics relate to the expected performance of the experimental aircraft, thus creating a selection model with guaranteed performance aerodynamics. It is believed that the philosophy used in this dissertation research validates the results, resulting in an experimental alternative for reliable implementation of aerodynamic testing in models of planforms