Algoritmos genéticos aplicados a um comitê de LS-SVM em problemas de classificação

The pattern classification is one of the machine learning subareas that has the most outstanding. Among the various approaches to solve pattern classification problems, the Support Vector Machines (SVM) receive great emphasis, due to its ease of use and good generalization performance. The Least Squares formulation of SVM (LS-SVM) finds the solution by solving a set of linear equations instead of quadratic programming implemented in SVM. The LS-SVMs provide some free parameters that have to be correctly chosen to achieve satisfactory results in a given task. Despite the LS-SVMs having high performance, lots of tools have been developed to improve them, mainly the development of new classifying methods and the employment of ensembles, in other words, a combination of several classifiers. In this work, our proposal is to use an ensemble and a Genetic Algorithm (GA), search algorithm based on the evolution of species, to enhance the LSSVM classification. In the construction of this ensemble, we use a random selection of attributes of the original problem, which it splits the original problem into smaller ones where each classifier will act. So, we apply a genetic algorithm to find effective values of the LS-SVM parameters and also to find a weight vector, measuring the importance of each machine in the final classification. Finally, the final classification is obtained by a linear combination of the decision values of the LS-SVMs with the weight vector. We used several classification problems, taken as benchmarks to evaluate the performance of the algorithm and compared the results with other classifiers

Medição da densidade óssea através de ondas eletromagnéticas e classificação por MVS

This work holds the purpose of presenting an auxiliary way of bone density measurement through the attenuation of electromagnetic waves. In order to do so, an arrangement of two microstrip antennas with rectangular configuration has been used, operating in a frequency of 2,49 GHz, and fed by a microstrip line on a substrate of fiberglass with permissiveness of 4.4 and height of 0,9 cm. Simulations were done with silica, bone meal, silica and gypsum blocks samples to prove the variation on the attenuation level of different combinations. Because of their good reproduction of the human beings anomaly aspects, samples of bovine bone were used. They were subjected to weighing, measurement and microwave radiation. The samples had their masses altered after mischaracterization and the process was repeated. The obtained data were inserted in a neural network and its training was proceeded with the best results gathered by correct classification on 100% of the samples. It comes to the conclusion that through only one non-ionizing wave in the 2,49 GHz zone it is possible to evaluate the attenuation level in the bone tissue, and that with the appliance of neural network fed with obtained characteristics in the experiment it is possible to classify a sample as having low or high bone density

Arquiteturas eficientes para sensoriamento espectral e classificação automática de modulações usando características cicloestacionárias

The increasing demand for high performance wireless communication systems has shown the inefficiency of the current model of fixed allocation of the radio spectrum. In this context, cognitive radio appears as a more efficient alternative, by providing opportunistic spectrum access, with the maximum bandwidth possible. To ensure these requirements, it is necessary that the transmitter identify opportunities for transmission and the receiver recognizes the parameters defined for the communication signal. The techniques that use cyclostationary analysis can be applied to problems in either spectrum sensing and modulation classification, even in low signal-to-noise ratio (SNR) environments. However, despite the robustness, one of the main disadvantages of cyclostationarity is the high computational cost for calculating its functions. This work proposes efficient architectures for obtaining cyclostationary features to be employed in either spectrum sensing and automatic modulation classification (AMC). In the context of spectrum sensing, a parallelized algorithm for extracting cyclostationary features of communication signals is presented. The performance of this features extractor parallelization is evaluated by speedup and parallel eficiency metrics. The architecture for spectrum sensing is analyzed for several configuration of false alarm probability, SNR levels and observation time for BPSK and QPSK modulations. In the context of AMC, the reduced alpha-profile is proposed as as a cyclostationary signature calculated for a reduced cyclic frequencies set. This signature is validated by a modulation classification architecture based on pattern matching. The architecture for AMC is investigated for correct classification rates of AM, BPSK, QPSK, MSK and FSK modulations, considering several scenarios of observation length and SNR levels. The numerical results of performance obtained in this work show the eficiency of the proposed architectures

Sistema inteligente para detecção de manchas de óleo na superfície marinha através de imagens de SAR

Oil spill on the sea, accidental or not, generates enormous negative consequences for the affected area. The damages are ambient and economic, mainly with the proximity of these spots of preservation areas and/or coastal zones. The development of automatic techniques for identification of oil spots on the sea surface, captured through Radar images, assist in a complete monitoring of the oceans and seas. However spots of different origins can be visualized in this type of imaging, which is a very difficult task. The system proposed in this work, based on techniques of digital image processing and artificial neural network, has the objective to identify the analyzed spot and to discern between oil and other generating phenomena of spot. Tests in functional blocks that compose the proposed system allow the implementation of different algorithms, as well as its detailed and prompt analysis. The algorithms of digital image processing (speckle filtering and gradient), as well as classifier algorithms (Multilayer Perceptron, Radial Basis Function, Support Vector Machine and Committe Machine) are presented and commented.The final performance of the system, with different kind of classifiers, is presented by ROC curve. The true positive rates are considered agreed with the literature about oil slick detection through SAR images presents

Compressão Seletiva de Imagens Coloridas com Detecção Automática de Regiões de Interesse

There has been an increasing tendency on the use of selective image compression, since several applications make use of digital images and the loss of information in certain regions is not allowed in some cases. However, there are applications in which these images are captured and stored automatically making it impossible to the user to select the regions of interest to be compressed in a lossless manner. A possible solution for this matter would be the automatic selection of these regions, a very difficult problem to solve in general cases. Nevertheless, it is possible to use intelligent techniques to detect these regions in specific cases. This work proposes a selective color image compression method in which regions of interest, previously chosen, are compressed in a lossless manner. This method uses the wavelet transform to decorrelate the pixels of the image, competitive neural network to make a vectorial quantization, mathematical morphology, and Huffman adaptive coding. There are two options for automatic detection in addition to the manual one: a method of texture segmentation, in which the highest frequency texture is selected to be the region of interest, and a new face detection method where the region of the face will be lossless compressed. The results show that both can be successfully used with the compression method, giving the map of the region of interest as an input

Imagens da morte: um estudo do gênero policial-fantástico em Poe, Wilde e Christie

The mirror has always been related to different symbols, usually connected to self-knowledge and truth. This is due to the fact that this object shows whoever looks oneself in it an image as close to reality as it is possible. On the other hand, the mirror is also associated to mysticism and to the supernatural for it can magically duplicate one who looks into it. This ambiguous characteristic turns the mirror into an element that is fantastic in itself and places it in the central position of our discussion. Therefore, in this study, we analyze the texts In a Glass Darkly, by Agatha Christie, The Oval Portrait, by Edgar Allan Poe, and The Picture of Dorian Gray, by Oscar Wilde, giving special attention to the study of the images and artificial representations of men: the mirror, as an ephemeral representation; and the portrait, as an attempt to eternize an ephemeral image. We also discuss themes such as jealousy, the double, and death in the several forms in which it appears in the texts: suicides, homicides, attempted murders, death in life (mourning, separation, and developmental phases) all of which are, somehow, related to the specular representations. The narrative resource of using a mirror to introduce the supernatural event, along with the theme of death in all the narratives we have studied, and the difficulty to place these texts within the pre-established genres led us to categorize them as being part of a hybrid genre that presents characteristics both of the fantastic and of the detective story which we have named fantastic-detective story

Helena de Machado de Assis; Imagens literárias e a retórica da morte da nação inconclusa

Helena is the romance of perishable and discontinuous title character denominator of a dialectic that does not consume and build the narrative by sequential fragmentation combined with episodic frame. The novel is a lightning stroke to the romantic literary project. Therefore, this study aims to find "objective" elements of the novel that would constitute a conception of literary nation proposed by Machado de Assis, as in classical writing, where women are engaged as a metaphor for the nation by a non-cultural heroism, as the example of the Greek myth of Helena, where the feminine represents a mythical image of the nation. The paper's theoretical conception of the history of Walter Benjamin, that is, that is constructed as an allegorical appeal, the conclusions about the disciplinary society of nineteenth century of Michel Foucault, the construction of the nation as a subtle game to remember and forget of Wander Miranda and the rhetoric of death and loss reflected in the speeches of the cultural heritage of José Reginaldo Santos Gonçalves, which allow you to analyze the work permeated by subjectivity and existential conflicts by Machado, who has it arranged in dialectic with the avant-garde literary romanticism and realism. In this relationship with the Greek myth of Helen, explained that characters with the nickname of Helena in Machado's work are not uncommon. As in classical Helena, Machado s Helena uses three rhetorical are the cause of the seizure of the nation. In this game of remembering and forgetting, in the daily plebiscite, Machado draw ideal images that forged our mythical past and commitment to the future. The suffering love of Helena is suffering from failure of the nation which would have led the author to the use of allegorical language, seeking a balance in the chaos generated by the opposition between cruelty and pity widespread view in an area where only left the character's confession guilt for the death. It is a simulacrum of unfinished nation, the space for the game of remembering and forgetting, while the rhetoric of negotiation of our Brazilianness

Imagens mí(s)ticas do gato

La valeur évocative, magique ou my(s)thique attribuée à la relation homme/animal peut être observée dans la culture depuis les époques lointaines. Dans la symbologie animale on trouve une immense charge sémantique justifiant les croyances les plus anciennes que les êtres humains ont déjà eues. Les animaux sont à la base du symbolisme mythique et ils se constituent en tant qu une source pour la riche production artistique englobant une grande variété iconographique et des textes de nature diverse. Ayant comme référence de la symbologie animal l image my(s)thique du chat, on observe la façon par laquelle le langage poétique contemple les profils mythiquesymboliques qui ont un rapport avec ce langage, tout en mettant en relief ceux qui ont des rapports aux relations entre le monde humain et le félin. À partir de l antologie tématique Assinar a pele ; des concepts théoriques ; et des abordages mitocritiques, nous cherchons à analyser les façons par lesquelles les différentes images mythiques associées au chat ont été explorées par la poésie. La définition d une typologie englobant des catégories telles : chat domestique, chat de rue, chat femme, chat nocturne, chat démoniaque et chat divin, parmi d autres, soutient la reconnaissance d identités possibles entre ces poèmes et signale la répétition d un répertoire symbolique divers en soi, mais, cohérent avec la présence du chat dans la société humaine à travers les temps

O mundo criado pelas imagens: paisagens e espaços coloniais na obra do holandês Frans Post

The aims of this dissertation is to study formation of the Dutch view seeing the colonial scenery in screens by Frans Post, as well as, to perceive a colonial world constitution through landscape paintings by him with his natural and human representation. The artist was the first to portray South American views, after he landed in Pernambuco with retinue of Dutch governor of colony, John Maurice, Prince of Nassau-Siegen. Post, by his 24 years old, was designated to represent for Dutch people their colony. The text reflects on visual construction of natural and human aspects in landscapes by Dutchman and how that aspects were included in colonizer imaginary about the strange world of America. European (Dutch) look about their conquered possessions in the New World was charged with exoticism and imagination. In order to understand that view, it`s paramount to study imaginary pictures reared by Frans Post, on his return to the Netherlands, and notions of landscape and exotic, wild and unspoiled nature which the Dutch people had when they thought about the Dutch colony in America. Our principal (visual) sources of research are six paintings: Vista da Sé de Olinda (1662), Vista das ruínas de Olinda (undated), Engenho (undated), Engenho (1660), Vista da cidade Maurícia e do Recife (1653), e Paisagem com rio e tamanduá (1649), all these canvases were painted when Frans Post returned to Europe. We seek to work through a methodology that focuses on investigation of primary visual and textual material, because these textual and pictorial representations reflect the 17th-century colonial view of colonial history themes of the - here called - Dutch America

As chaves para o mundo do quinto império: as imagens de mundo na história do futuro do padre Antonio Vieira

Iconic historical figure, Antônio Vieira (1608-1697) is regarded as an essential character to the Luso-Brazilian history. Between 1646 and 1667, the priest began writing the History of the Future, the first volume of the celebrated "Clavis Prophetarum , political and theological unity that would leverage the process of spread of Christianity across the globe, recognizing Portugal as forefront and center of all millenarian movement. Them, Jesuit represented the "World" in two metaphors: "theater" and "body" responsible for viewing spaces of abstract Christian truth. Starting from the hermeneutical assumptions of analysis, we investigated the historical relations present in the construction of such representations, by which establish the dialogue between politics, theology and seventeenth-century rhetoric. Therefore, the following study supports the hypothesis that beyond a mere stylistic expressions, spatial metaphors of "World" were formulated by Antonio Vieira as a resource that could sharpen the minds of his readers, engaging words into action, become alive and effective use of rhetoric

Medo de dentista em cena: uma análise de produções cinematográficas

The fear related to dental procedures can be acquired through disturbing experiences and/or negative cultural influences related in experiences of previous generations. Such influences may be present in diverse forms of cultural expression: in the cinema, plastic arts, music, literature, and diverse vehicles of printed and visual media. This research aimed investigates the images of fear related to the dental service and dentist in motion pictures. The study has qualitative approach, which used the documentary analysis of movies. The data collection was accomplished through research in the Internet by means of the Google tool (http://www.google.com.br), using the describing words filme and dentista . A total of 44 films were found. Of these, after selective criterion for films with scenes showing interaction between dentist and patient in the execution of clinical procedure, only 24 films were enclosed. Then, these were registered in data base created for this research. After second selective criterion of inclusion (scenes with suggestion of dental anxiety), 15 films remained. As regards cinematographic gender, the films with scenes showing "dental anxiety" varied between comedy (8), horror (3), drama (2), thriller (1) and childish (1). Of these films, scenes with images of situations that suggest fear of the dentist and his job were selected and described. The images were categorized by the identification of negative characteristics that incite "dental anxiety". Then, the classification of the categories was proceeded detaching the most recurrent characteristics in the scenes: situation of fear in the waiting-room; pain; instrument coarse/rudimentary; coarseness of the dentist; torture; and low qualification technique. The waiting-room was observed as a place of great tension, due to the noises coming from the dental attendance. The pain related to the Dentistry was the predominant subject in the majority of films (14), associated to others negative characteristics. The rudimentary aspects of procedures and instruments, and the coarse attitudes of the professional could be observed too. The dentist was characterized as confused, sadist, violent, insensitive, incompetent person and disturbed. Such results suggest that, despite the technological advances of the profession, the image of the dentist and his job is still transmitted in a negative way aspect and reinforces the dental anxiety

Estudo comportamental, hormonal e histopatológico de animais com perda de peso progressina (SEP) e da variável peso associada a uma nova classificação ontogenética em Callithrix jacchus

The use of non-human primates in scientific research has contributed significantly to the biomedical area and, in the case of Callithrix jacchus, has provided important evidence on physiological mechanisms that help explain its biology, making the species a valuable experimental model in different pathologies. However, raising non-human primates in captivity for long periods of time is accompanied by behavioral disorders and chronic diseases, as well as progressive weight loss in most of the animals. The Primatology Center of the Universidade Federal do Rio Grande do Norte (UFRN) has housed a colony of C. jacchus for nearly 30 years and during this period these animals have been weighed systematically to detect possible alterations in their clinical conditions. This procedure has generated a volume of data on the weight of animals at different age ranges. These data are of great importance in the study of this variable from different perspectives. Accordingly, this paper presents three studies using weight data collected over 15 years (1985-2000) as a way of verifying the health status and development of the animals. The first study produced the first article, which describes the histopathological findings of animals with probable diagnosis of permanent wasting marmoset syndrome (WMS). All the animals were carriers of trematode parasites (Platynosomum spp) and had obstruction in the hepatobiliary system; it is suggested that this agent is one of the etiological factors of the syndrome. In the second article, the analysis focused on comparing environmental profile and cortisol levels between the animals with normal weight curve evolution and those with WMS. We observed a marked decrease in locomotion, increased use of lower cage extracts and hypocortisolemia. The latter is likely associated to an adaptation of the mechanisms that make up the hypothalamus-hypophysis-adrenal axis, as observed in other mammals under conditions of chronic malnutrition. Finally, in the third study, the animals with weight alterations were excluded from the sample and, using computational tools (K-means and SOM) in a non-supervised way, we suggest found new ontogenetic development classes for C. jacchus. These were redimensioned from five to eight classes: infant I, infant II, infant III, juvenile I, juvenile II, sub-adult, young adult and elderly adult, in order to provide a more suitable classification for more detailed studies that require better control over the animal development

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

Ferramentas quimiométricas aplicadas a classificação de amostras de leite em pó e quantificação de proteínas

In this work we used chemometric tools to classify and quantify the protein content in samples of milk powder. We applied the NIR diffuse reflectance spectroscopy combined with multivariate techniques. First, we carried out an exploratory method of samples by principal component analysis (PCA), then the classification of independent modeling of class analogy (SIMCA). Thus it became possible to classify the samples that were grouped by similarities in their composition. Finally, the techniques of partial least squares regression (PLS) and principal components regression (PCR) allowed the quantification of protein content in samples of milk powder, compared with the Kjeldahl reference method. A total of 53 samples of milk powder sold in the metropolitan areas of Natal, Salvador and Rio de Janeiro were acquired for analysis, in which after pre-treatment data, there were four models, which were employed for classification and quantification of samples. The methods employed after being assessed and validated showed good performance, good accuracy and reliability of the results, showing that the NIR technique can be a non invasive technique, since it produces no waste and saves time in analyzing the samples

Sistema de agentes poligínicos para esteganálise de imagens digitais

In this work, we propose a multi agent system for digital image steganalysis, based on the poliginic bees model. Such approach aims to solve the problem of automatic steganalysis for digital media, with a case study on digital images. The system architecture was designed not only to detect if a file is suspicious of covering a hidden message, as well to extract the hidden message or information regarding it. Several experiments were performed whose results confirm a substantial enhancement (from 67% to 82% success rate) by using the multi-agent approach, fact not observed in traditional systems. An ongoing application using the technique is the detection of anomalies in digital data produced by sensors that capture brain emissions in little animals. The detection of such anomalies can be used to prove theories and evidences of imagery completion during sleep provided by the brain in visual cortex areas