997 resultados para photorealistic image synthesis


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In recent years a large number of studies have examined body image concerns, and early symptoms of eating disturbance among children. However, to date there has been no synthesis or evaluation of these studies. The purpose of the present article is to review and evaluate the research that has examined body image concerns, and eating attitudes and behaviors among children 6 to 11 years of age. The instruments used to assess body image concerns and eating disturbance in children closely resemble those used with adolescents and adults. Overall, the psychometric data for these instruments are very good and there is sufficient evidence indicating that they can be used reliably and validly. In addition, similar variables to those studied in adolescent and adult samples have been found to be associated with children's body image concerns and early eating disturbance. These include gender, age, body mass index, race, sociocultural pressures, and self-concept. Our understanding of the development of body image concerns and eating disturbance in children is limited, however, by the fact that most of the research in this field has been based on cross-sectional data, and the studies have focused almost exclusively on weight-loss cognitions and behaviors.

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An increasing number of researchers have examined body image concerns, disordered eating, and other behaviors associated with increasing muscle size among men from different cultural groups. However, to date there has been no synthesis or evaluation of these studies. In this paper we specifically review studies which have included a comparison between males from different cultural groups with White males on body image concerns or other related behaviors. The groups include Blacks, Hispanic Americans, Asians, Native Americans, Pacific Islanders, and men from Middle Eastern countries. Overall, evidence suggests that males from a range of cultural groups engage in more extreme body change strategies and binge eating than Whites. On the other hand, there is no consistent pattern which summarizes the nature of body image concerns across the different cultures. Mediating and/or moderating variables are proposed to account for the inconsistent findings. These include body build, levels of acculturation, socio-economic status, media exposure, and internalization of the muscular and lean body ideal.

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Existing texture synthesis-from-example strategies for polygon meshes typically make use of three components: a multi-resolution mesh hierarchy that allows the overall nature of the pattern to be reproduced before filling in detail; a matching strategy that extends the synthesized texture using the best fit from a texture sample; and a transfer mechanism that copies the selected portion of the texture sample to the target surface. We introduce novel alternatives for each of these components. Use of p2-subdivision surfaces provides the mesh hierarchy and allows fine control over the surface complexity. Adaptive subdivision is used to create an even vertex distribution over the surface. Use of the graph defined by a surface region for matching, rather than a regular texture neighbourhood, provides for flexible control over the scale of the texture and allows simultaneous matching against multiple levels of an image pyramid created from the texture sample. We use graph cuts for texture transfer, adapting this scheme to the context of surface synthesis. The resulting surface textures are realistic, tolerant of local mesh detail and are comparable to results produced by texture neighbourhood sampling approaches.

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"Monumental Vision” is a nuanced summary of Nietzschean nihilism and the Eternal Return as rite of passage for free subjects and as condensed image of speculative intelligence proper. Utilizing Gerhard Richter’s “Sheet 692” from Atlas, a series of photographs of the mountains and lake at Sils Maria, Switzerland, as summary judgment of the limit imposed by this condition on all systems of representation, this form of vision discloses the chiasmus embedded in consciousness itself. In constantly revisiting Sils, the very location where Nietzsche “suffered” the vision of the Eternal Return, Richter has engaged repeatedly this origin for what has come into his work via Nietzsche – that is, an elective veil that refuses all compromises with transcendence until such is merged with immanence.

As situated amidst modernist “ideology as intellection”, and subsequent nascent forms of anti-modernism, the Eternal Return as image also signals the return of the Kantian “aesthetic-teleological” synthesis in non-discursive or purely visual agency. As an elective form of aesthetic vision, and as image of time insofar as it registers an overwhelming externality (Other) that nominally swallows and empowers the subject at once, this excoriating sense of universal praxis underwrites artistic and architectural production of the highest order, renegotiating concepts of the paradigmatic.

Utilizing Georg Simmel’s late work on Rembrandt (1916) and his encounter with Schopenhauer and Nietzsche (1907), the essay suggests that by the 1920s the avant-garde premises of modernism had already come under attack by an ahistorical and synoptic vision here denoted “monumental vision,” which also contains the imprint of eschatological time (invoking a schism present in rationality as such). The two readings of this image perpetrated by Karl Löwith in Nietzsche’s Philosophy of the Eternal Recurrence of the Same (Nietzsches Philosophie der ewigen Wiederkehr des Gleichen, 1935), or the cosmological and the ethical, while considered irreconcilable by Löwith, have since the 1960s been recalibrated through the figure of the event to pose possible scenarios out of the stalemate of the confrontation between Self and Other (ipseity and alterity) buried within this image as limit. In this manner, the image of the Eternal Return stands at the boundary between two forms of time (or two worlds) and signals the irreducible confrontation present in speculative thought and the necessity of closure through an aesthetic vision that produces a unitary field for all creative acts.

Notably, Nietzsche’s startling vision from Zarathustra suggests that the limit imposed by the Eternal Return is also a mask for an austere condition within subjectivity closely resembling the conundrum of Fichte’s I facing I, or thought turned toward thought itself (absolute subjectivity as cipher for Being). In Alenka Zupančič’s reading, in The Shortest Shadow: Nietzsche’s Philosophy of the Two (2003), the Eternal Return effectively contains a secret formal function that grinds all “error” to dust – a highly suggestive interpretation that also neutralizes the schism introduced by Löwith between the cosmological and the ethical.

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Composite images are synthesized from existing photographs by artists who make concept art, e.g., storyboards for movies or architectural planning. Current techniques allow an artist to fabricate such an image by digitally splicing parts of stock photographs. While these images serve mainly to “quickly”convey how a scene should look, their production is laborious. We propose a technique that allows a person to design a new photograph with substantially less effort. This paper presents a method that generates a composite image when a user types in nouns, such as “boat”and “sand.”The artist can optionally design an intended image by specifying other constraints. Our algorithm formulates the constraints as queries to search an automatically annotated image database. The desired photograph, not a collage, is then synthesized using graph-cut optimization, optionally allowing for further user interaction to edit or choose among alternative generated photos. An implementation of our approach, shown in the associated video, demonstrates our contributions of (1) a method for creating specific images with minimal human effort, and (2) a combined algorithm for automatically building an image library with semantic annotations from any photo collection.

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This communication describes, for the first time, the growth of SnO2 nanoribbons by a controlled carbothermal reduction process. An analysis of the transmission electron microscopy image revealed that these nanoribbons have a well-defined shape, with a typical width in the range of 70-300 nm. In general, the nanostructured ribbons were more than 100 mum in length. The results reported here support the hypothesis that this ribbon-like nanostructured material grows by a vapor-solid process. This study introduces two hypotheses to explain the SnO2 nanoribbon growth process.

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Nanosized and highly reactive magnesium mobate (MgNb2O6) powders were successfully synthesized by a new wet-chemical method by means of the dissolution of Nb2O5 center dot 5H(2)O and in a solution of oxalic acid followed by the addition of stoichiometric amounts of magnesium carbonate. The Nb-Mg-oxalic acid solution was evaporated resulting in a dry and amorphous powder that was calcined in the temperature range from 200 to 900 degrees C for 2 h. The crystallization process from the amorphous state to the crystalline MgNb2O6 was followed by thermal analysis. The calcined powders characterized by FT-Raman spectroscopy, X-ray diffraction (XRD) and their morphology examined by high resolution scanning electron microscopy (HR-SEM). Pure MgNb2O6, free from the second phases and obtained at 800 degrees C was confirmed by a combined analysis using XRD and FT-Raman. The average diameter of the particles was calculated from the HR-SEM image as 70 urn approximately. This technique allows a better mixing of the constituent elements and thus a better reactivity of the mixture to obtain pre-reaction products with high purity at lower temperatures and reducing cost. It can offer a great advantage in the PMN-PT formation with respect to the solid-state synthesis. (c) 2006 Elsevier Ltd and Techna Group S.r.l. All rights reserved.

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In this work we propose a new image inpainting technique that combines texture synthesis, anisotropic diffusion, transport equation and a new sampling mechanism designed to alleviate the computational burden of the inpainting process. Given an image to be inpainted, anisotropic diffusion is initially applied to generate a cartoon image. A block-based inpainting approach is then applied so that to combine the cartoon image and a measure based on transport equation that dictates the priority on which pixels are filled. A sampling region is then defined dynamically so as to hold the propagation of the edges towards image structures while avoiding unnecessary searches during the completion process. Finally, a cartoon-based metric is computed to measure likeness between target and candidate blocks. Experimental results and comparisons against existing techniques attest the good performance and flexibility of our technique when dealing with real and synthetic images. © 2013 Elsevier B.V. All rights reserved.

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Four liquid crystals (LC) 3,7a-bis(4-alkyloxyphenyl)-7,7a-dihydro-6H-isoxazolo[2,3-d][1,2,4]oxadiazol-6-yl)acetic acid (7a-d) were synthesised and the mesomorphic behaviour reported. The LCs were characterised as 2: 1 bisadducts, which were obtained from a double [3+2] 1,3-dipolar cycloaddition. In the first step, the cycloaddition of 4-alkyloxyphenylnitrile oxide (4a-d) and vinylacetic acid (5) gave the initial unobserved 1:1 cycloadducts 2-[3-(4-alkyloxyphenyl)-4,5-dihydroisoxazol-5-yl]acetic acid (6a-d). In the second step, the addition of a second equivalent of 4 to 6 yielded the 2: 1 bisadducts 7a-d without any traces of 6. All compounds 7a-d were unstable during the transition from the mesophase to the isotropic state upon first heating as evidenced by the large peaks in the differential scanning calorimetry traces. Due to the chemical instability of the compounds upon heating, the transition temperature related to the smectic C to smectic A transitions was acquired by means of an image processing method. X-Ray diffraction experiments were also used to analyse the liquid-crystalline phases. A theoretical calculation was performed using density functional theory (DFT) methods at the PBE1PBE/6-311+G(2d,p) level (with solvent effect) in order to get information about the energetic profile of the 2: 1 cycloaddition. DFT studies revealed that the cycloaddition process is controlled by the HOMO(dipolarophile) - LUMO(1,3-dipole), and that the double [3+2] 1,3-dipolar cycloaddition reaction is quite possible.

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Nowadays, it is clear that the target of creating a sustainable future for the next generations requires to re-think the industrial application of chemistry. It is also evident that more sustainable chemical processes may be economically convenient, in comparison with the conventional ones, because fewer by-products means lower costs for raw materials, for separation and for disposal treatments; but also it implies an increase of productivity and, as a consequence, smaller reactors can be used. In addition, an indirect gain could derive from the better public image of the company, marketing sustainable products or processes. In this context, oxidation reactions play a major role, being the tool for the production of huge quantities of chemical intermediates and specialties. Potentially, the impact of these productions on the environment could have been much worse than it is, if a continuous efforts hadn’t been spent to improve the technologies employed. Substantial technological innovations have driven the development of new catalytic systems, the improvement of reactions and process technologies, contributing to move the chemical industry in the direction of a more sustainable and ecological approach. The roadmap for the application of these concepts includes new synthetic strategies, alternative reactants, catalysts heterogenisation and innovative reactor configurations and process design. Actually, in order to implement all these ideas into real projects, the development of more efficient reactions is one primary target. Yield, selectivity and space-time yield are the right metrics for evaluating the reaction efficiency. In the case of catalytic selective oxidation, the control of selectivity has always been the principal issue, because the formation of total oxidation products (carbon oxides) is thermodynamically more favoured than the formation of the desired, partially oxidized compound. As a matter of fact, only in few oxidation reactions a total, or close to total, conversion is achieved, and usually the selectivity is limited by the formation of by-products or co-products, that often implies unfavourable process economics; moreover, sometimes the cost of the oxidant further penalizes the process. During my PhD work, I have investigated four reactions that are emblematic of the new approaches used in the chemical industry. In the Part A of my thesis, a new process aimed at a more sustainable production of menadione (vitamin K3) is described. The “greener” approach includes the use of hydrogen peroxide in place of chromate (from a stoichiometric oxidation to a catalytic oxidation), also avoiding the production of dangerous waste. Moreover, I have studied the possibility of using an heterogeneous catalytic system, able to efficiently activate hydrogen peroxide. Indeed, the overall process would be carried out in two different steps: the first is the methylation of 1-naphthol with methanol to yield 2-methyl-1-naphthol, the second one is the oxidation of the latter compound to menadione. The catalyst for this latter step, the reaction object of my investigation, consists of Nb2O5-SiO2 prepared with the sol-gel technique. The catalytic tests were first carried out under conditions that simulate the in-situ generation of hydrogen peroxide, that means using a low concentration of the oxidant. Then, experiments were carried out using higher hydrogen peroxide concentration. The study of the reaction mechanism was fundamental to get indications about the best operative conditions, and improve the selectivity to menadione. In the Part B, I explored the direct oxidation of benzene to phenol with hydrogen peroxide. The industrial process for phenol is the oxidation of cumene with oxygen, that also co-produces acetone. This can be considered a case of how economics could drive the sustainability issue; in fact, the new process allowing to obtain directly phenol, besides avoiding the co-production of acetone (a burden for phenol, because the market requirements for the two products are quite different), might be economically convenient with respect to the conventional process, if a high selectivity to phenol were obtained. Titanium silicalite-1 (TS-1) is the catalyst chosen for this reaction. Comparing the reactivity results obtained with some TS-1 samples having different chemical-physical properties, and analyzing in detail the effect of the more important reaction parameters, we could formulate some hypothesis concerning the reaction network and mechanism. Part C of my thesis deals with the hydroxylation of phenol to hydroquinone and catechol. This reaction is already industrially applied but, for economical reason, an improvement of the selectivity to the para di-hydroxilated compound and a decrease of the selectivity to the ortho isomer would be desirable. Also in this case, the catalyst used was the TS-1. The aim of my research was to find out a method to control the selectivity ratio between the two isomers, and finally to make the industrial process more flexible, in order to adapt the process performance in function of fluctuations of the market requirements. The reaction was carried out in both a batch stirred reactor and in a re-circulating fixed-bed reactor. In the first system, the effect of various reaction parameters on catalytic behaviour was investigated: type of solvent or co-solvent, and particle size. With the second reactor type, I investigated the possibility to use a continuous system, and the catalyst shaped in extrudates (instead of powder), in order to avoid the catalyst filtration step. Finally, part D deals with the study of a new process for the valorisation of glycerol, by means of transformation into valuable chemicals. This molecule is nowadays produced in big amount, being a co-product in biodiesel synthesis; therefore, it is considered a raw material from renewable resources (a bio-platform molecule). Initially, we tested the oxidation of glycerol in the liquid-phase, with hydrogen peroxide and TS-1. However, results achieved were not satisfactory. Then we investigated the gas-phase transformation of glycerol into acrylic acid, with the intermediate formation of acrolein; the latter can be obtained by dehydration of glycerol, and then can be oxidized into acrylic acid. Actually, the oxidation step from acrolein to acrylic acid is already optimized at an industrial level; therefore, we decided to investigate in depth the first step of the process. I studied the reactivity of heterogeneous acid catalysts based on sulphated zirconia. Tests were carried out both in aerobic and anaerobic conditions, in order to investigate the effect of oxygen on the catalyst deactivation rate (one main problem usually met in glycerol dehydration). Finally, I studied the reactivity of bifunctional systems, made of Keggin-type polyoxometalates, either alone or supported over sulphated zirconia, in this way combining the acid functionality (necessary for the dehydrative step) with the redox one (necessary for the oxidative step). In conclusion, during my PhD work I investigated reactions that apply the “green chemistry” rules and strategies; in particular, I studied new greener approaches for the synthesis of chemicals (Part A and Part B), the optimisation of reaction parameters to make the oxidation process more flexible (Part C), and the use of a bioplatform molecule for the synthesis of a chemical intermediate (Part D).

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Stilbenoid dendrimers with stilbene in the periphery and stilbene in periphery as well as core were synthesized by convergent approach except 2nd generation dendrimer with stilbene in the periphery as well as in core (D-5). All dendrimers were characterized by standard techniques such as 1H NMR, 13C NMR, MS and IR spectroscopy. The MALDI-TOF technique proved to be very helpful in the identification of the 2nd generation dendrimer (D-5) with a mass of 3231 a.m.u. The dendrimers were designed in such a way that an intramolecular photochemical CC bond formation was favored. As two stilbene units of the same molecule were close enough so they preferred an intramolecular cyclic process except for zero generation dendrimers. Apart from the cycloaddition, some E/Z isomerization and oligomer formation was also observed on irradiation. These processes were observed by 1H NMR and MALDI-TOF MS. The photochemical behavior was also studied by UV absorption spectroscopy. Irradiating by monochromatic light led to an initial E/Z isomerization and by prolonged irradiation, an irreversible cyclic structure was formed. The choice of the wavelength of incident light is very important as irradiation at 320 nm leads to a reversible E/Z isomerization and a non-reversible cyclobutane formation, but irradiation at 340 nm favors the one-way process E Z. The [2+2] cycloaddition of molecule Tm2De was also studied by irradiating thin films on a quartz surface. An AFM image was taken before irradiation, after 3 sec irradiation and after long irradiation (1 hour). AFM studies show that a short irradiation leads to a cyclic structure as formation of hills of about 20-30 nm on the surface. A prolonged irradiation leads to a CC cross linking which can be monitored on AFM images as disappearance of hills. The roughness goes back to an almost smooth surface. These results prove a very complex material transport, which accompanies the reaction in the surface region.

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Surgical navigation systems visualize the positions and orientations of surgical instruments and implants as graphical overlays onto a medical image of the operated anatomy on a computer monitor. The orthopaedic surgical navigation systems could be categorized according to the image modalities that are used for the visualization of surgical action. In the so-called CT-based systems or 'surgeon-defined anatomy' based systems, where a 3D volume or surface representation of the operated anatomy could be constructed from the preoperatively acquired tomographic data or through intraoperatively digitized anatomy landmarks, a photorealistic rendering of the surgical action has been identified to greatly improve usability of these navigation systems. However, this may not hold true when the virtual representation of surgical instruments and implants is superimposed onto 2D projection images in a fluoroscopy-based navigation system due to the so-called image occlusion problem. Image occlusion occurs when the field of view of the fluoroscopic image is occupied by the virtual representation of surgical implants or instruments. In these situations, the surgeon may miss part of the image details, even if transparency and/or wire-frame rendering is used. In this paper, we propose to use non-photorealistic rendering to overcome this difficulty. Laboratory testing results on foamed plastic bones during various computer-assisted fluoroscopybased surgical procedures including total hip arthroplasty and long bone fracture reduction and osteosynthesis are shown.

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El presente artículo busca identificar y analizar algunas de los principales tratamientos poéticos y artísticos del binomio paz / riqueza en una perspectiva diacrónica y comparativa, intentando aislar las más frecuentes imágenes, metáforas y epítetos relacionados con ese tema. El estudio de los pasajes elegidos deja claro cómo ambos, poetas y artistas plásticos, conocían y manipulaban con su arte un mismo patrimonio bastante antiguo

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El presente artículo busca identificar y analizar algunas de los principales tratamientos poéticos y artísticos del binomio paz / riqueza en una perspectiva diacrónica y comparativa, intentando aislar las más frecuentes imágenes, metáforas y epítetos relacionados con ese tema. El estudio de los pasajes elegidos deja claro cómo ambos, poetas y artistas plásticos, conocían y manipulaban con su arte un mismo patrimonio bastante antiguo

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El presente artículo busca identificar y analizar algunas de los principales tratamientos poéticos y artísticos del binomio paz / riqueza en una perspectiva diacrónica y comparativa, intentando aislar las más frecuentes imágenes, metáforas y epítetos relacionados con ese tema. El estudio de los pasajes elegidos deja claro cómo ambos, poetas y artistas plásticos, conocían y manipulaban con su arte un mismo patrimonio bastante antiguo