Técnicas de computação natural para segmentação de imagens médicas

Image segmentation is one of the image processing problems that deserves special attention from the scientific community. This work studies unsupervised methods to clustering and pattern recognition applicable to medical image segmentation. Natural Computing based methods have shown very attractive in such tasks and are studied here as a way to verify it's applicability in medical image segmentation. This work treats to implement the following methods: GKA (Genetic K-means Algorithm), GFCMA (Genetic FCM Algorithm), PSOKA (PSO and K-means based Clustering Algorithm) and PSOFCM (PSO and FCM based Clustering Algorithm). Besides, as a way to evaluate the results given by the algorithms, clustering validity indexes are used as quantitative measure. Visual and qualitative evaluations are realized also, mainly using data given by the BrainWeb brain simulator as ground truth

Estudo do efeito de substratos metamateriais em parâmetros de antenas de microfita

Microstrip antennas are subject matter in several research fields due to its numerous advantages. The discovery, at 1999, of a new class of materials called metamaterials - usually composed of metallic elements immersed in a dielectric medium, have attracted the attention of the scientific community, due to its electromagnetic properties, especially the ability to use in planar structures, such as microstrip, without interfering with their traditional geometry. The aim of this paper is to analyze the effects of one and bidimensional metamaterial substrates in microstrip antennas, with different configurations of resonance rings, SRR, in the dielectric layer. Fractal geometry is applied to these rings, in seeking to verify a multiband behavior and to reduce the resonance frequency of the antennas. The results are then given by commercial software Ansoft HFSS, used for precise analysis of the electromagnetic behavior of antennas by Finite Element Method (FEM). To reach it, this essay will first perform a literature study on fractal geometry and its generative process. This paper also presents an analysis of microstrip antennas, with emphasis on addressing different types of substrates as part of its electric and magnetic anisotropic behavior. It s performed too an approach on metamaterials and their unique properties

Aplicação e análise de metodologia de deterioração ambiental em micro-bacia do seridó potiguar

In the contemporary world to the deterioration of semi-arid areas of the planet has been the focus of media attention and the scientific community. Brazil has a semiarid, considered the most problematic of the world, either by pressure from physical factors, whether as a result of misguided public policies, has over time been suffering from the consequences of a deterioration that expands over the years. Methodologies, that amidst the problems of semi-arid, come against the deteriorating local, have a good chance to be reapplied in other contexts around the world. This research, based on methodological model for analyzing environmental deterioration, introduced and examined the applicability of the methodology in the semi-arid region of Rio Grande do Norte - Brazil. Although the results provide guidelines for the introduction of underground dams, the application of the methodology was ineffective, given the high rates of forest cover that gave low values for the physical diagnosis conservationist

Análise do modelo troposférico empregado na geração de uma estação de referência virtual utilizando o posicionamento por ponto preciso

In the past few years the interest is accomplishing a high accuracy positioning increasing. One of the methods that has been applied by the scientific community is the network based on positioning. By using multiple reference station data, it is possible to obtain centimetric positioning in a larger coverage area, in addition to gain in reliability, availability and integrity of the service. Besides, using this concept, it is possible to model the atmospheric effects (troposphere refraction and ionosphere effect). Another important question concerning this topic is related to the transmission of the network corrections to the users. There are some possibilities for this fact and an efficient one is the Virtual Reference Station (VRS) concept. In the VRS concept, a reference station is generated near to the rover receiver (user). This provides a short baseline and the user has the possibility of using a single frequency receiver to accomplish the relative positioning. In order to test this kind of positioning method, a software has been developed at São Paulo State University. In this paper, the methodology applied to generate the VRS data is described and the VRS quality is analyzed by using the Precise Point Positioning (PPP) method.

RINEX_HO: second- and third-order ionospheric corrections for RINEX observation files

When GNSS receivers capable of collecting dual-frequency data are available, it is possible to eliminate the first-order ionospheric effect in the data processing through the ionosphere-free linear combination. However, the second- and third-order ionospheric effects still remain. The first-, second- and third-order ionospheric effects are directly proportional to the total electron content (TEC), although the second- and third-order effects are influenced, respectively, by the geomagnetic field and the maximum electron density. In recent years, the international scientific community has given more attention to these kinds of effects and some works have shown that for high precision GNSS positioning these effects have to be taken into consideration. We present a software tool called RINEX_HO that was developed to correct GPS observables for second- and third-order ionosphere effects. RINEX_HO requires as input a RINEX observation file, then computes the second- and third-order ionospheric effects, and applies the corrections to the original GPS observables, creating a corrected RINEX file. The mathematical models implemented to compute these effects are presented, as well as the transformations involving the earth's magnetic field. The use of TEC from global ionospheric maps and TEC calculated from raw pseudorange measurements or pseudoranges smoothed by phase is also investigated.

Study of the carbon dioxide chemical fixation-activation by guanidines

Fixation of CO2 is one of the most important priorities of the scientific community dedicated to reduce global warming. In this work, we propose new methods for the fixation of CO2 using the guanidine bases tetramethylguanidine (TMG) and 1,3,4,6,7,8-hexahydro-2H-pyrimido[1,2-a]-pyrimidine (TBD). In order to understand the reactions occurring during the CO2 fixation and release processes, we employed several experimental methods, including solution and solid-state NMR, FTIR, and coupled TGA-FTIR. Quantum mechanical NMR calculations were also carried out. Based on the results obtained, we concluded that CO2 fixation with both TMG and TBD guanidines is a kinetically reversible process, and the corresponding fixation products have proved to be useful as transcarboxylating compounds. Afterward, CO2 thermal releasing from this fixation product with TBD was found to be an interesting process for CO2 capture and isolation purposes. (C) 2008 Elsevier Ltd. All rights reserved.

A escrita do texto acadêmico na graduação: modos de utilização de conceitos teóricos de uma área de conhecimento

In this study we have developed a discussion about academic text production in the undergraduate course of Literature and Languages. Specifically, we are going to analyze the monographic text writing in order to verify the meaning effects created from the ways of showing other s discourses that constitute a written production. As a means to do that, we are going to answer the following question: How does a young researcher make use of a theory in order to be part of a particular scientific community? We aim to: 1) analyze the linguistic resources, like quotations and signs of cohesion that demonstrate the other s voice presence in academic writing; 2) observe the meaning effects produced through the ways that the one who writes shows the other s voice in the written text. Firstly, we have selected 23 (twentythree) monographs produced in the last five years by students from a Literature and Languages undergraduate course in a determined public university. However, in this study, we have analyzed just 02 (two) different monographic texts. To develop such an investigation, we have inquired Kuhn s concept of science, which shows the existence of different meanings of science production in the course of the centuries. It allows us to define academic writing as science production that develops and contributes to knowledge production. With the purpose of restricting the meaning of writing conception, we have relied on Coracini, who assumes that all writing production is the registration of the self, in other words, writing comes from the subject s intervention, it is to say that only an imposition of the self guarantees the subject as author of what he writes. We have as theoretical basis the following concepts: 1-) Authier-Revus s enunciative heterogeneity, that allowed us to analyze the written marks of the other in the monographic writing; 2-) Pêcheux s reformulation-paraphrase and Orlandi s polysemy and paraphrase, concepts that present notions of productivity and creativity as ways of meaning production, and allows us to observe how the process of language production in academic writing is established; 3-) Rossi-Landi s concept of exchange-value and use-value, which consider language as a linguistic work, allowing us to verify the differences between use and social functionality in a determined theory; and 4-) Possenti s notion of authorship indicia, with which we have identified attitudes that make the one who writes author of his own text. We have verified that writing characterized for repetition and reproduction may develop a meaning effect that constructs the idea that writing production promotes an author, a concept or a theory. We have also realized that a written text that restricts itself to reproduce other authors discourses and does not articulate a theory with data analysis or with work methodology, when evaluated is approved and legitimates itself as scientific production. That demonstrates the existence of academic productions that do not develop any functionality of the employed theory. The text works as a means to promote its theoretical concepts, and theory. It is to say that the theoretical foundantion, which usually is a way to argue and sustain scientific production, does not have any function. Thus, we consider that the way someone shows the other s discourse in academic writing may work as a way to underline what the other asserts to the detriment of the researcher s words. This fact allows us to comprehend that a way of writing may evidence a meaning effect of the author s, theory s or theoretical concepts promotion

Medidas e análise estatística em sinais bioelétricos sobre pontos de acupuntura

In the 20th century, the acupuncture has spread on occident as a complementary practice of heath care. This fact has motivated the international scientific community to invest in research that seek to understand why acupuncture works. In this work we compare statistically volt age fluctuation of bioelectric signals caught on the skin at an acupuncture point (IG 4) another nearby on acupuncture point. The acquisition of these signals was performed utilizing an electronic interface with a computer, which was based on an instrumentation amplifier designed with adequate specifications to this end. On the collected signals from a sample of 30 volunteers we have calculated major statistics and submitted them to pairing t-test with significance leveI a = O, 05. We have estimated to bioelectric signals the following parameters: standard deviation, asymmetry and curtose. Moreover, we have calculated the self-correlation function matched by on exponential curve we have observed that the signal decays more rapidly from a non-acupoint then from an acupoint. This fact is an indicative of the existence of information in the acupoint

Propriedades magnéticas quase-estáticas de filmes ferromagnéticos amorfos de FeCuNbSiB

Today, one of the topics that attracts interest of the scientific community is the understanding of magnetic properties of magnetic systems with reduced dimensions, in particular, ferromagnetic thin films. In this case, the comprehension and control of these properties, as well as the development of routes to obtain them, are crucial issues in many aspects of current and future technologies for storage and transmission of information in the electro-electronic industry. There are several materials that exhibit soft magnetic properties, and we highlight the amorphous alloys and that ones obtained by partial crystallization, so-called nanocrystalline materials. The production of these alloys as magnetic ribbons is very common in scientific and technological area, but there are just a few works related to the production of these alloys as thin films. In this work, we studied the quasi-static magnetic properties of ferromagnetic thin films based on FeCuNbSiB in a wide range of thicknesses, from 20 to 500 nm, produced by sputtering. In particular, after the structural characterization performed via X-ray diffraction, the magnetic properties of the sets of samples were investigated using experimental magnetization curve, obtained using a vibrating sample magnetometer, as well as through theoretical curves obtained by theoretical modeling and numerical computation. The modeling process is based on the Stoner Wohlfarth model applied to three dimensions, and adds some energy terms, using as reference experimental results of magnetization. In this case, from the comparison between theoretical and experimental results and the analysis of the constant anisotropy behavior as a function of film thickness, we aim to obtain further information on the magnetization process of the samples, to identify routes for the production of thin films and develop a theoretical to films to use it, in the future, in the obtainment of the theoretical curves of some magnetic measurements, such as magnetoimpedance and magnetoresistance

Uma breve biografia de Stephen Gray (1666-1736)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

O princípio da precaução e a saúde no trabalho

O princípio da precaução (PP) é uma diretriz em saúde que vem ganhando relevo nos últimos 20 anos. Seu propósito é orientar medidas nas situações em que o conhecimento científico está ainda incompleto, denotando a incerteza. As condições de economia de mercado estimulam o uso de produtos e processos inovadores, dependentes do desenvolvimento científico e das novas descobertas em curso. Suas implicações para a saúde nem sempre estão inteiramente avaliadas, expondo a população trabalhadora às incertezas. O exame da literatura mostra que o uso do PP, embora sob consenso dos órgãos reguladores em diferentes países, ainda é objeto de intenso debate na comunidade científica. em coerência com os propósitos básicos, a proteção do meio ambiente conta com milhares de citações do seu emprego, em contraste com as poucas recomendações de uso para as exposições ocupacionais. Entre estas, o PP vem sendo entendido como pouco adequado ao âmbito dos especialistas e mais indicado à proteção de populações vulneráveis. Investigações históricas mostram que a noção de precaução foi quase sempre usada em sentido inverso, fazendo-se uso da dúvida para conter as possíveis melhorias de proteção no trabalho. Conclui-se que o uso do PP depende do pressuposto da incerteza científica, caracterizada pela noção de risco, em detrimento do determinismo da causa, condição ainda não superada nas relações de trabalho.

Publicação e avaliação de periódicos científicos: paradoxos da classificação Qualis em Psicologia

Recently, Brazilian scientific production has increased greatly, due to demands for productivity from scientific agencies. However, this high increases requires a more qualified production, since it s essential that publications are relevant and original. In the psychological field, the assessment scientific journals of the CAPES/ANPEPP Commission had a strong effect on the scientific community and raised questions about the chosen evaluation method. Considering this impact, the aim of this research is a meta-analysis on the assessment of Psychological journals by CAPES to update the Qualis database. For this research, Psychology scientific editors (38 questionnaires were applied by e-mail) were consulted, also 5 librarians who work with scientific journals assessment (semi-structured interviews) and 8 members who acted as referees in the CAPES/ANPEPP Commission (open questions were sent by e-mail). The results are shown through 3 analysis: general evaluation of the Qualis process (including the Assessment Committee constitution), evaluation criteria used in the process and the effect of the evaluation on the scientific community (changes on the editing scene included). Some important points emerged: disagreement among different actors about the suitability of this evaluation model; the recognition of the improvement of scientific journals, mainly toward normalization and diffusion; the verification that the model does not point the quality of the journal, i.e., the content of the scientific articles published in the journal; the disagreement with the criteria used, seemed necessary and useful but needed to be discussed and cleared between the scientific community. Despite these points, the scientific journals evaluation still is the main method to assure quality for Psychology publications

Estimativa das máximas pistas de vento no reservatório da barragem de Ilha Solteira, Estado de São Paulo

Most methods employed to estimate the height of waves generated by the wind require the surface length over which the wind blows. The choice of method depends on the nature of the water body, being applicable to ocean areas or interior water bodies, such as bays, lakes and reservoirs. One of the usual solutions has been the direct usage of the method validated in ocean waters for interior waters, therefore, not taking into consideration the effect of the restriction imposed by the shores. Nevertheless, the excessive quantity of operations of the method applied to interior water bodies (where the shore is a restraint condition) may not assure a satisfactory precision degree, unless an accurate enough graphic base of the shore with the addition of the operator's subjectivity is used. Thus, this scientific community brings this discussion to light, proposing a classic solution based on the application of the adequate method to interior waters (Saville et al., 1954) via automatized processing. Therefore, a program in AutoLISP, a computational language, has been developed. The application of the program has determined the maximum wind fetches in Ilha Solteira, state of São Paulo, reservoir as being between 9.5 and 12.5 km, in contrast with a previous study which has predicted far longer fetches (factor of three).

Tomada de decisão de Psicólogos em avaliação Psicologica

Psychological assessment is a procedure that is inserted in all areas of a psychologist s professional field of work. When starting any psychological intervention, it is necessary to carry an analysis of how individual operate in order to identify and define their demands to adequately meet them. It is important to study this practice because the choice of instruments, techniques and procedures to be employed influences the efficiency and effectiveness of the work and the image of the profession towards society in general, also impacting the scientific community. This study aimed to identify, in the subjects, the percentage of professionals in psychology who make use of the Psychological Assessment in the Northeastern region of Brazil; another objectives were to analyze the profile of these professionals in terms of gender, time after graduation, additional training in PA, the state of the country where he/she works; to check how psychologists do their planning when using PA as well as to identify which differences can be observed in terms of time from graduation and additional training in the process of planning the assessment different extents. The instrument used was an online questionnaire and the sample was by adhesion to the application. The attendance was of 159 professionals and most of them were females with a specialist degree. It was found that the majority of the professionals perform the planning of the PA, establishing a method and choosing the most appropriate strategies to be used. It was also verified that most of the subjects fulfill the steps of the whole process, and when planning the techniques of data collection, integrating database from different sources, reporting the results and returning the information, the professional demonstrates his/her goals to understand their demands and accomplish the decision making and/or proposed intervention for individuals assessed. It was found that the undergraduate degree may not have produced a more complete effect in the professional qualification and therefore, of the quality of the actions in PA, and that there is a need for training and continuing education

Síntese e Caracterização de Titanatos de Cobalto e Níquel, dopados com Praseodímio, obtidos a partir da decomposição de Nitrilotriacetatos

In recent years, studies about the physicochemical properties of mixed oxides, call attention of the scientific community, properties like as piezoelectricity, photoluminescence, or applications as catalysts, arise in these compounds, when their chemical compositions are modified, in this context some routes are employed in the synthesis of these materials, among which can be cited these methods: ceramic, combustion, co-precipitation, Pechini or polymeric precursor method, hydrothermal, sol-gel; these routes are divided into traditional routes or chemical routes. In this work were synthesized oxides with variable composition, from the thermal decomposition of titanium, cobalt, nickel and praseodymium nitrilotriacetates. The nitrilotriacetates were characterized by IR Spectroscopy (FTIR), Thermogravimetric (TG/ DTG) and Differential Scanning Calorimetry (DSC), while oxides have been characterized by X-ray diffraction (XRD), Spectrofluorimetry and IR Spectroscopy (FTIR). From FTIR data, it was demonstrated that the displacement of the band corresponding to the carboxylate group (νCOOH) at 1712 cm-1, present in nitrilotriacetic acid (H3NTA), for 1680-1545 cm-1, these stretches are characteristics of coordinated nitrilotriacetates, By thermal analysis (TG/DTG /DSC), it was suggested, that in an oxidizing atmosphere (air) oxides are obtained at lower temperatures than in an inert atmosphere N2(g). By results from X-ray Diffraction (XRD), it was determinated that the oxides are crystalline and the predominant phases obtained are summarized titanate phases rutile and ilmenite. By fluorimetry was observed that the intensity of emission bands are directly proportional to the concentration of ions Ni2+, Co2+ and Pr3+, and IR spectroscopy (FTIR) from oxides, demonstrated the disappearance of characteristic bands by nitrilotriacetates, determining the complete decomposition of the nitrilotriacetates in oxides