971 resultados para object modeling from images


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The passage of an electric current through graphite or few-layer graphene can result in a striking structural transformation, but there is disagreement about the precise nature of this process. Some workers have interpreted the phenomenon in terms of the sublimation and edge reconstruction of essentially flat graphitic structures. An alternative explanation is that the transformation actually involves a change from a flat to a three-dimensional structure. Here we describe detailed studies of carbon produced by the passage of a current through graphite which provide strong evidence that the transformed carbon is indeed three-dimensional. The evidence comes primarily from images obtained in the scanning transmission electron microscope using the technique of high-angle annular dark-field imaging, and from a detailed analysis of electron energy loss spectra. We discuss the possible mechanism of the transformation, and consider potential applications of “three-dimensional bilayer graphene”.

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Observers generally fail to recover three-dimensional shape accurately from binocular disparity. Typically, depth is overestimated at near distances and underestimated at far distances [Johnston, E. B. (1991). Systematic distortions of shape from stereopsis. Vision Research, 31, 1351–1360]. A simple prediction from this is that disparity-defined objects should appear to expand in depth when moving towards the observer, and compress in depth when moving away. However, additional information is provided when an object moves from which 3D Euclidean shape can be recovered, be this through the addition of structure from motion information [Richards, W. (1985). Structure from stereo and motion. Journal of the Optical Society of America A, 2, 343–349], or the use of non-generic strategies [Todd, J. T., & Norman, J. F. (2003). The visual perception of 3-D shape from multiple cues: Are observers capable of perceiving metric structure? Perception and Psychophysics, 65, 31–47]. Here, we investigated shape constancy for objects moving in depth. We found that to be perceived as constant in shape, objects needed to contract in depth when moving toward the observer, and expand in depth when moving away, countering the effects of incorrect distance scaling (Johnston, 1991). This is a striking example of the failure of shape con- stancy, but one that is predicted if observers neither accurately estimate object distance in order to recover Euclidean shape, nor are able to base their responses on a simpler processing strategy.

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This paper presents an automatic method to detect and classify weathered aggregates by assessing changes of colors and textures. The method allows the extraction of aggregate features from images and the automatic classification of them based on surface characteristics. The concept of entropy is used to extract features from digital images. An analysis of the use of this concept is presented and two classification approaches, based on neural networks architectures, are proposed. The classification performance of the proposed approaches is compared to the results obtained by other algorithms (commonly considered for classification purposes). The obtained results confirm that the presented method strongly supports the detection of weathered aggregates.

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Vegetation growing on railway trackbeds and embankments present potential problems. The presence of vegetation threatens the safety of personnel inspecting the railway infrastructure. In addition vegetation growth clogs the ballast and results in inadequate track drainage which in turn could lead to the collapse of the railway embankment. Assessing vegetation within the realm of railway maintenance is mainly carried out manually by making visual inspections along the track. This is done either on-site or by watching videos recorded by maintenance vehicles mainly operated by the national railway administrative body. A need for the automated detection and characterisation of vegetation on railways (a subset of vegetation control/management) has been identified in collaboration with local railway maintenance subcontractors and Trafikverket, the Swedish Transport Administration (STA). The latter is responsible for long-term planning of the transport system for all types of traffic, as well as for the building, operation and maintenance of public roads and railways. The purpose of this research project was to investigate how vegetation can be measured and quantified by human raters and how machine vision can automate the same process. Data were acquired at railway trackbeds and embankments during field measurement experiments. All field data (such as images) in this thesis work was acquired on operational, lightly trafficked railway tracks, mostly trafficked by goods trains. Data were also generated by letting (human) raters conduct visual estimates of plant cover and/or count the number of plants, either on-site or in-house by making visual estimates of the images acquired from the field experiments. Later, the degree of reliability of(human) raters’ visual estimates were investigated and compared against machine vision algorithms. The overall results of the investigations involving human raters showed inconsistency in their estimates, and are therefore unreliable. As a result of the exploration of machine vision, computational methods and algorithms enabling automatic detection and characterisation of vegetation along railways were developed. The results achieved in the current work have shown that the use of image data for detecting vegetation is indeed possible and that such results could form the base for decisions regarding vegetation control. The performance of the machine vision algorithm which quantifies the vegetation cover was able to process 98% of the im-age data. Investigations of classifying plants from images were conducted in in order to recognise the specie. The classification rate accuracy was 95%.Objective measurements such as the ones proposed in thesis offers easy access to the measurements to all the involved parties and makes the subcontracting process easier i.e., both the subcontractors and the national railway administration are given the same reference framework concerning vegetation before signing a contract, which can then be crosschecked post maintenance.A very important issue which comes with an increasing ability to recognise species is the maintenance of biological diversity. Biological diversity along the trackbeds and embankments can be mapped, and maintained, through better and robust monitoring procedures. Continuously monitoring the state of vegetation along railways is highly recommended in order to identify a need for maintenance actions, and in addition to keep track of biodiversity. The computational methods or algorithms developed form the foundation of an automatic inspection system capable of objectively supporting manual inspections, or replacing manual inspections.

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Due to the huge growth of the World Wide Web, medical images are now available in large numbers in online repositories, and there exists the need to retrieval the images through automatically extracting visual information of the medical images, which is commonly known as content-based image retrieval (CBIR). Since each feature extracted from images just characterizes certain aspect of image content, multiple features are necessarily employed to improve the retrieval performance. Meanwhile, experiments demonstrate that a special feature is not equally important for different image queries. Most of existed feature fusion methods for image retrieval only utilize query independent feature fusion or rely on explicit user weighting. In this paper, we present a novel query dependent feature fusion method for medical image retrieval based on one class support vector machine. Having considered that a special feature is not equally important for different image queries, the proposed query dependent feature fusion method can learn different feature fusion models for different image queries only based on multiply image samples provided by the user, and the learned feature fusion models can reflect the different importances of a special feature for different image queries. The experimental results on the IRMA medical image collection demonstrate that the proposed method can improve the retrieval performance effectively and can outperform existed feature fusion methods for image retrieval.

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With the development of the internet, medical images are now available in large numbers in online repositories, and there exists the need to retrieval the medical images in the content-based ways through automatically extracting visual information of the medical images. Since a single feature extracted from images just characterizes certain aspect of image content, multiple features are necessarily employed to improve the retrieval performance. Furthermore, a special feature is not equally important for different image queries since a special feature has different importance in reflecting the content of different images. However, most existed feature fusion methods for image retrieval only utilize query independent feature fusion or rely on explicit user weighting. In this paper, based on multiply query samples provided by the user, we present a novel query dependent feature fusion method for medical image retrieval based on one class support vector machine. The proposed query dependent feature fusion method for medical image retrieval can learn different feature fusion models for different image queries, and the learned feature fusion models can reflect the different importance of a special feature for different image queries. The experimental results on the IRMA medical image collection demonstrate that the proposed method can improve the retrieval performance effectively and can outperform existed feature fusion methods for image retrieval.

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The New Wilderness is a practice-led, multidisciplinary arts project first piloted by artists, writers, teachers and academics from Geelong, Deakin University and Courthouse ARTS Centre in 2013. In a series of workshops run by artists, and working to specific themes, the project provided a platform for participants to explore and respond creatively to change in the community; it culminated in a large-scale installation at Courthouse ARTS Centre’s main gallery. Our paper positions the project as a able to cut across convention, empowering young artists to respond to ‘big questions’ of relevance to the changing material, spatial and social relations within their communities. In questioning and seeking to transform communities into sustainable media, economic, environmental and social ecologies, this emergent model begins with a localised focus, which is designed to travel across time and place, and pedagogical frameworks. The paper positions Geelong as a community under radical transformation in its economic foundations and demographics. As artists and academics living and working in the region we see it as an experimental ground for investigations into a series of provocations that mirror the shape of the paper we intend to give. The provocations, as outlined in the workshops, might also be envisaged as new relations to:ObjectFrom consumable to unusable to play. In revisiting the first iteration of The New wilderness in 2013 we discuss the ‘superfictional’ (Hill, 2000) enquiry that participants were asked to engage with. Its premise described Geelong as an abandoned, post-apocalyptic site. Participants were asked to imagine themselves as a group of future explorers and excavate objects from the city’s old tip. In unearthing their choices and re-presenting the objects in the gallery the participant was prompted to analyse site, situation, object and process as phenomena for ‘being’ or ‘telling stories’, providing insights into wider realms of cultural experience (Ellis, Adams and Bochner, 2010). Parallel to this ‘autoethnographic’ reflection our paper uses the philosopher Giorgio Agamben’s analysis of consumer and material culture. He traces the subject’s relation to objects from use-value, to exchange-value and in the era of extreme capitalism, to pure exhibition-value. He searches for ways that the objects produced in our material culture can be ‘profaned’ (Agamben, 2007). Space – From the material to the spatial to the situation. We are interested in how objects and the practices they elicit can be ‘profaned’ by their situation (Agamben, 2007; Wark, 2103). To profane, according to Agamben, is to open up the possibility that the object loses its exhibition-value to ‘a special form of negligence’ (Agamben). He uses the example of the child’s ability to insinuate any object into a new logic of play (Agamben). Like the objects excavated for The New Wilderness they could be from a variety of spheres – business, household, industry, health etc… The child, like the artist, reconstitutes, reorders and assembles new relations between things. In reflecting on the first New Wilderness project the paper correlates the creative response of the participant (student, child, artist) with the occupier. The Occupy Movement, which took up residence in many of the world’s cities’ financial districts in 2011, used a number of strategies commensurate with both Agamben’s notion of profanation and McKenzie Wark’s reading of the Situationist International’s use of détournement - as a strategy that releases objects and subjects back into the field of play (Wark, 2013). The field was taken by the occupy movement to be the space in which they occupied – capitalism, its logic and its practices, were, for a short time, redundant in the occupied field. The New Wilderness conceptualises the city as a localised field, from which its discarded objects can be ‘profaned’ or, repurposed, to reflect on shared histories, responsibilities, pedagogies and future action. Subject: self/other– As much as we propose New Wilderness to be a pedagogical initiative we see it as personal, critical and political. In the themed workshops, designed to elicit personal responses to the object and the site, which culminated in a multi-disciplinary installation, performance and/or text based work, participants were encouraged to think critically, and importantly, collectively. Through the four workshops run in the first iteration of the project participants were asked to re-consider their material value-systems, much as the occupy movement was trying to do, and like the occupiers, participants were empowered to be agents of change. Our paper reflects on the practical outcomes and the conceptual, political and pedagogical strategies embedded in The New Wilderness project. The paper affords us the additional opportunity to imagine a life for it in other geographical, socio-economic and educational situations. Merinda Kelly and Cameron Bishop, 2013Bio: Merinda Kelly is a sculptor and installation artist, educator and PhD student at Deakin University. Her research interests include Visual Culture, Practice Led Research, the Ontology of Art, and Autoethnography. Her most recent work includes the Pop Archaeology' and the Globo-Touro Projects.Bio: Dr Cameron Bishop is an artist and academic working in Visual Arts at Deakin University. He exhibits regularly and has written a number of journal articles and book chapters. His research has focused on the philosophical and postcolonial dimensions of space and subjectivity and more recently has evolved into an active interest in strategic interventions into space and practice.

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This research covers the topic of social housing and its relation to thermal comfort, so applied to an architectural and urban intervention in land situated in central urban area of Macaíba/RN, Brazil. Reflecting on the role of design and use of alternative building materials in the search for better performance is one of its main goals. The hypothesis is that by changing design parameters and choice of materials, it is possible to achieve better thermal performance results. Thus, we performed computer simulations of thermal performance and natural ventilation using computational fluid dynamics or CFD (Computational Fluid Dynamics). The presentation of the thermal simulation followed the methodology proposed in the dissertation Negreiros (2010), which aims to find the percentage of the amount of hours of comfort obtained throughout the year, while data analysis was made of natural ventilation from images generated by the images extracted from the CFD. From model building designed, was fitted an analytical framework that results in a comparison between three different proposals for dwellings housing model, which is evaluated the question of the thermal performance of buildings, and also deals with the spatial variables design, construction materials and costs. It is concluded that the final report confirmed the general hypotheses set at the start of the study, it was possible to quantify the results and identify the importance of design and construction materials are equivalent, and that, if combined, lead to gains in thermal performance potential.

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As Sociology becomes a mandatory subject in the curricular componentof Brazilian high schools, we find anopportune moment to proposals and changes in the subject and in teaching, in a general aspect. It s noticed the great importance of the role that the create imagination plays in individual s formation (BACHELARD), and it s also seen that Brazilian education system has marginalized imagination to the detriment of a unifocused scientism that sterilizes creativity, playfulness and poetry in its educational process. Nevertheless, a way of thinking redefinitions to the educational horizons of Sociology as a subject and education is upheld. An educational practice that reconnects the prosaic and the poetic, using images/songs as paths/strategies of the teaching-learning process. As for that, the school structure was used where the tutor work was done to undertake experiences that made the use of songs as strategy to facilitate/stimulate the learning of the subject Sociology in high school. From thoughts and results of this experience, plus the bibliographic studies, analysis were made. The goal of this essay is to make use and stimulate the creation of poetic images from the teaching point of view, specially the Sociology subject in high school, rethinking and searching more efficient and playful ways of approaching and building educational methods from images; stimulating the development of the Thinking Reform and the Anthropoetics of the human gender (MORIN); acknowledging that imagination is an indispensable part of our integral formation

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In this paper a methodology for automatic extraction of road segments from images with different resolutions (low, middle and high resolution) is presented. It is based on a generalized concept of lines in digital images, by which lines can be described by the centerlines of two parallel edges. In the specific case of low resolution images, where roads are manifested as entities of 1 or 2 pixels wide, the proposed methodology combines an automatic image enhancement operation with the following strategies: automatic selection of the hysteresis thresholds and the Gaussian scale factor; line length thresholding; and polygonization. In medium and high resolution images roads manifest as narrow and elongated ribbons and, consequently, the extraction goal becomes the road centerlines. In this case, it is not necessary to apply the previous enhancement step used to enhance roads in low resolution images. The results obtained in the experimental evaluation satisfied all criteria established for the efficient extraction of road segments from different resolution images, providing satisfactory results in a completely automatic way.

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Land cover mappings represent important tools for the regional planning. However, the current mappings are related to very specific purposes and, consequently, they are limited in their capacity to define the wide variety of existing types of land cover. In that context, this paper aims at developing a wide and including hierarchical classification system for land cover mapping in regional scale, which should contribute for a future standardization of classes. Besides, it is intended to test that system for a study case that contemplates the use of a classification method based on fuzzy approach, which has shown to be more appropriate than conventional approaches. Therefore, it was proposed a hierarchical classification system with three detailing levels and a study case was defined with the specification of the test area and of the classification project. Then, the georreferencing of a TM/Landsat-5 image that comprises the test area was carried out. Later, it was applied a fuzzy classification approach in the TM/Landsat-5 image, starting from images of probability for the mapped classes and an uncertainty image were generated. Finally, it was produced a conventional output that represents the thematic mapping of the test area.

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Porosity in starch consolidation casting technique is rightly related to original size and morphology of starch granules, leaving a pore structure after burning out. This work reports the results for the addition of different native potato and corn starch proportions in suspension,; with TiO(2) (rutile) powder. Gelling temperature have been defined after observation under light microscopy using a heating stage. Analysis of porous network and isolated pores have been clone from images of samples surfaces obtained by depth from focus reconstruction, revealing a qualitative correlation of pores characteristics and starches additions in suspensions, suggesting that the presence of isolated or interconnected pores can be handled by starches selection to control the amylopectin and amylose contents in slurries. Also, the analysis of porous fraction distribution shows no consistent pattern through specimens' volume according to starches in mixtures.

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Remote sensing is one technology of extreme importance, allowing capture of data from the Earth's surface that are used with various purposes, including, environmental monitoring, tracking usage of natural resources, geological prospecting and monitoring of disasters. One of the main applications of remote sensing is the generation of thematic maps and subsequent survey of areas from images generated by orbital or sub-orbital sensors. Pattern classification methods are used in the implementation of computational routines to automate this activity. Artificial neural networks present themselves as viable alternatives to traditional statistical classifiers, mainly for applications whose data show high dimensionality as those from hyperspectral sensors. This work main goal is to develop a classiffier based on neural networks radial basis function and Growing Neural Gas, which presents some advantages over using individual neural networks. The main idea is to use Growing Neural Gas's incremental characteristics to determine the radial basis function network's quantity and choice of centers in order to obtain a highly effective classiffier. To demonstrate the performance of the classiffier three studies case are presented along with the results.

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Mobile robots need autonomy to fulfill their tasks. Such autonomy is related whith their capacity to explorer and to recognize their navigation environments. In this context, the present work considers techniques for the classification and extraction of features from images, using artificial neural networks. This images are used in the mapping and localization system of LACE (Automation and Evolutive Computing Laboratory) mobile robot. In this direction, the robot uses a sensorial system composed by ultrasound sensors and a catadioptric vision system equipped with a camera and a conical mirror. The mapping system is composed of three modules; two of them will be presented in this paper: the classifier and the characterizer modules. Results of these modules simulations are presented in this paper.

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Neste artigo construímos um entrelaçamento teórico-filosófico que tem como objetivo discutir a relação entre Modelagem Matemática e realidade do mundo cibernético. em particular, essa abrangência da realidade é evidenciada como um possível vetor de virtualização, isto é, como um aspecto que pode influenciar o modo como a problemática que envolve uma determinada situação ou entidade é compreendida. Para tanto, fazemos uma associação entre Modelagem Matemática e as transformações que envolvem os modos de ser denotados por real, possível, atual e virtual, tendo como base ilustrativa as quatro causas aristotélicas. Complementando essa associação, assumimos uma concepção de problema que permite uma consolidação entre as relações estabelecidas e, também, uma concepção de realidade que entende o mundo cibernético como uma de suas dimensões. Por fim, apresentamos um exemplo de Modelagem Matemática ocorrido em sala de aula, que visa caracterizar a realidade do mundo cibernético como um vetor de virtualização.