962 resultados para Direct digital detector images


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Purpose: To evaluate and compare the performance of Ripplet Type-1 transform and directional discrete cosine transform (DDCT) and their combinations for improved representation of MRI images while preserving its fine features such as edges along the smooth curves and textures. Methods: In a novel image representation method based on fusion of Ripplet type-1 and conventional/directional DCT transforms, source images were enhanced in terms of visual quality using Ripplet and DDCT and their various combinations. The enhancement achieved was quantified on the basis of peak signal to noise ratio (PSNR), mean square error (MSE), structural content (SC), average difference (AD), maximum difference (MD), normalized cross correlation (NCC), and normalized absolute error (NAE). To determine the attributes of both transforms, these transforms were combined to represent the entire image as well. All the possible combinations were tested to present a complete study of combinations of the transforms and the contrasts were evaluated amongst all the combinations. Results: While using the direct combining method (DDCT) first and then the Ripplet method, a PSNR value of 32.3512 was obtained which is comparatively higher than the PSNR values of the other combinations. This novel designed technique gives PSNR value approximately equal to the PSNR’s of parent techniques. Along with this, it was able to preserve edge information, texture information and various other directional image features. The fusion of DDCT followed by the Ripplet reproduced the best images. Conclusion: The transformation of images using Ripplet followed by DDCT ensures a more efficient method for the representation of images with preservation of its fine details like edges and textures.

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Dissertação (mestrado)—Universidade de Brasília, Faculdade de Economia, Administração e Contabilidade, Programa de Pós-Graduação em Administração, 2016.

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In this work, spoke about the importance of image compression for the industry, it is known that processing and image storage is always a challenge in petrobrás to optimize the storage time and store a maximum number of images and data. We present an interactive system for processing and storing images in the wavelet domain and an interface for digital image processing. The proposal is based on the Peano function and wavelet transform in 1D. The storage system aims to optimize the computational space, both for storage and for transmission of images. Being necessary to the application of the Peano function to linearize the images and the 1D wavelet transform to decompose it. These applications allow you to extract relevant information for the storage of an image with a lower computational cost and with a very small margin of error when comparing the images, original and processed, ie, there is little loss of quality when applying the processing system presented . The results obtained from the information extracted from the images are displayed in a graphical interface. It is through the graphical user interface that the user uses the files to view and analyze the results of the programs directly on the computer screen without the worry of dealing with the source code. The graphical user interface, programs for image processing via Peano Function and Wavelet Transform 1D, were developed in Java language, allowing a direct exchange of information between them and the user

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Direct sampling methods are increasingly being used to solve the inverse medium scattering problem to estimate the shape of the scattering object. A simple direct method using one incident wave and multiple measurements was proposed by Ito, Jin and Zou. In this report, we performed some analytic and numerical studies of the direct sampling method. The method was found to be effective in general. However, there are a few exceptions exposed in the investigation. Analytic solutions in different situations were studied to verify the viability of the method while numerical tests were used to validate the effectiveness of the method.

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Cloud edge mixing plays an important role in the life cycle and development of clouds. Entrainment of subsaturated air affects the cloud at the microscale, altering the number density and size distribution of its droplets. The resulting effect is determined by two timescales: the time required for the mixing event to complete, and the time required for the droplets to adjust to their new environment. If mixing is rapid, evaporation of droplets is uniform and said to be homogeneous in nature. In contrast, slow mixing (compared to the adjustment timescale) results in the droplets adjusting to the transient state of the mixture, producing an inhomogeneous result. Studying this process in real clouds involves the use of airborne optical instruments capable of measuring clouds at the `single particle' level. Single particle resolution allows for direct measurement of the droplet size distribution. This is in contrast to other `bulk' methods (i.e. hot-wire probes, lidar, radar) which measure a higher order moment of the distribution and require assumptions about the distribution shape to compute a size distribution. The sampling strategy of current optical instruments requires them to integrate over a path tens to hundreds of meters to form a single size distribution. This is much larger than typical mixing scales (which can extend down to the order of centimeters), resulting in difficulties resolving mixing signatures. The Holodec is an optical particle instrument that uses digital holography to record discrete, local volumes of droplets. This method allows for statistically significant size distributions to be calculated for centimeter scale volumes, allowing for full resolution at the scales important to the mixing process. The hologram also records the three dimensional position of all particles within the volume, allowing for the spatial structure of the cloud volume to be studied. Both of these features represent a new and unique view into the mixing problem. In this dissertation, holographic data recorded during two different field projects is analyzed to study the mixing structure of cumulus clouds. Using Holodec data, it is shown that mixing at cloud top can produce regions of clear but humid air that can subside down along the edge of the cloud as a narrow shell, or advect down shear as a `humid halo'. This air is then entrained into the cloud at lower levels, producing mixing that appears to be very inhomogeneous. This inhomogeneous-like mixing is shown to be well correlated with regions containing elevated concentrations of large droplets. This is used to argue in favor of the hypothesis that dilution can lead to enhanced droplet growth rates. I also make observations on the microscale spatial structure of observed cloud volumes recorded by the Holodec.

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Current copper based circuit technology is becoming a limiting factor in high speed data transfer applications as processors are improving at a faster rate than are developments to increase on board data transfer. One solution is to utilize optical waveguide technology to overcome these bandwidth and loss restrictions. The use of this technology virtually eliminates the heat and cross-talk loss seen in copper circuitry, while also operating at a higher bandwidth. Transitioning current fabrication techniques from small scale laboratory environments to large scale manufacturing presents significant challenges. Optical-to-electrical connections and out-of-plane coupling are significant hurdles in the advancement of optical interconnects. The main goals of this research are the development of direct write material deposition and patterning tools for the fabrication of waveguide systems on large substrates, and the development of out-of-plane coupler components compatible with standard fiber optic cabling. Combining these elements with standard printed circuit boards allows for the fabrication of fully functional optical-electrical-printed-wiring-boards (OEPWBs). A direct dispense tool was designed, assembled, and characterized for the repeatable dispensing of blanket waveguide layers over a range of thicknesses (25-225 µm), eliminating waste material and affording the ability to utilize large substrates. This tool was used to directly dispense multimode waveguide cores which required no UV definition or development. These cores had circular cross sections and were comparable in optical performance to lithographically fabricated square waveguides. Laser direct writing is a non-contact process that allows for the dynamic UV patterning of waveguide material on large substrates, eliminating the need for high resolution masks. A laser direct write tool was designed, assembled, and characterized for direct write patterning waveguides that were comparable in quality to those produced using standard lithographic practices (0.047 dB/cm loss for laser written waveguides compared to 0.043 dB/cm for lithographic waveguides). Straight waveguides, and waveguide turns were patterned at multimode and single mode sizes, and the process was characterized and documented. Support structures such as angled reflectors and vertical posts were produced, showing the versatility of the laser direct write tool. Commercially available components were implanted into the optical layer for out-of-plane routing of the optical signals. These devices featured spherical lenses on the input and output sides of a total internal reflection (TIR) mirror, as well as alignment pins compatible with standard MT design. Fully functional OEPWBs were fabricated featuring input and output out-of-plane optical signal routing with total optical losses not exceeding 10 dB. These prototypes survived thermal cycling (-40°C to 85°C) and humidity exposure (95±4% humidity), showing minimal degradation in optical performance. Operational failure occurred after environmental aging life testing at 110°C for 216 hours.

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Atmospheric scattering plays a crucial rule in degrading the performance of electro optical imaging systems operating in the visible and infra-red spectral bands, and hence limits the quality of the acquired images, either through reduction of contrast or increase of image blur. The exact nature of light scattering by atmospheric media is highly complex and depends on the types, orientations, sizes and distributions of particles constituting these media, as well as wavelengths, polarization states and directions of the propagating radiation. Here we follow the common approach for solving imaging and propagation problems by treating the propagating light through atmospheric media as composed of two main components: a direct (unscattered), and a scattered component. In this work we developed a detailed model of the effects of absorption and scattering by haze and fog atmospheric aerosols on the optical radiation propagating from the object plane to an imaging system, based on the classical theory of EM scattering. This detailed model is then used to compute the average point spread function (PSF) of an imaging system which properly accounts for the effects of the diffraction, scattering, and the appropriate optical power level of both the direct and the scattered radiation arriving at the pupil of the imaging system. Also, the calculated PSF, properly weighted for the energy contributions of the direct and scattered components is used, in combination with a radiometric model, to estimate the average number of the direct and scattered photons detected at the sensor plane, which are then used to calculate the image spectrum signal to- noise ratio (SNR) in the visible near infra-red (NIR) and mid infra-red (MIR) spectral wavelength bands. Reconstruction of images degraded by atmospheric scattering and measurement noise is then performed, up to the limit imposed by the noise effective cutoff spatial frequency of the image spectrum SNR. Key results of this research are as follows: A mathematical model based on Mie scattering theory for how scattering from aerosols affects the overall point spread function (PSF) of an imaging system was developed, coded in MATLAB, and demonstrated. This model along with radiometric theory was used to predict the limiting resolution of an imaging system as a function of the optics, scattering environment, and measurement noise. Finally, image reconstruction algorithms were developed and demonstrated which mitigate the effects of scattering-induced blurring to within the limits imposed by noise.

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The primary dataset represents the vouchered botanical collections of James Graham and Jose Schunke Vigo in the Department of Ucayali, Peru, from October 1997 until the present. Over 3500 separate collections are included to date, many of which have associated images. We present here primary collections data. Other data on natural history collections for the Department of Ucayali have been compiled, but are not presented at this time. We hope to make this data available as part of a Ucayali Collections dataset, as time and resources permit. It is hoped that this data will will contribute to the exchange of scientific information, and will enhance our knowledge of, and appreciation for, the complex of species, habitats, communities, ecosystems and ecoregions of Amazonia.

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This flyer promotes the event ''Jose Martí: Images of Memory and Mourning", Book Presentation by Emilio Bejel" cosponsored by the Department of Modern Languages at FIU. This event was held at Books & Books in Coral Gables.

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A estética é algo que interfere no bem-estar das pessoas e o sorriso não é excepção, sendo até considerado um factor estético essencial nos dias de hoje, perante uma sociedade cada vez mais exigente relativamente aos padrões de beleza. A área da estética dentária, encontra-se em constantes mudanças devido à evolução da qualidade dos materiais e das técnicas utilizadas, levando a melhorias na reprodução das características naturais dos dentes. O médico dentista tem a responsabilidade de adquirir conhecimento e habilidades profissionais para a elaboração de tratamentos estéticos dentários que satisfaçam as expectativas dos pacientes quanto ao seu sorriso. Actualmente, o médico dentista possui várias opções para planear os tratamentos, entre as quais, o planeamento digital através do Digital Smile Design. O Digital Smile Design (DSD), criado pelo Doutor Christian Coachman, veio responder à procura elevada por tratamentos cada vez mais personalizados por parte dos pacientes. O DSD amplia a visão relativamente aos diagnósticos, melhora a comunicação entre as diferentes especialidades na área da medicina dentária e cria planos previsíveis durante o tratamento dentário. Trata-se de um programma onde são trabalhadas imagens fotográficas do paciente para a elaboração de um tratamento estético que responda as necessidades biológicas, funcionais e emocionais do paciente. Este poderá acompanhar e visualizar todos os passos do tratamento e deste modo, torna-se parte integrante do processo. O paciente expressa a sua opinião e as suas expectativas quanto ao resultado final. Neste trabalho realizou-se uma revisão narrativa da literatura sobre a técnica Digital Smile Design utilizando as palavras-chaves: Digital Smile Design; Visagism; dental planning; meaning of smile; mock-up. Os objetivos deste trabalho foi o de conhecer a técnica Digital Smile Design, os princípios do visagismo e a importância do planeamento nestes contextos. O sucesso de um tratamento está dependente de um correcto planeamento e de uma execução clínica e laboratorial cuidadosa.

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El desarrollo tecnológico y la expansión de las formas de comunicación en Colombia, no solo trajeron consigo grandes beneficios, sino también nuevos retos para el Estado Moderno. Actualmente, la oferta de espacios de difusión de propaganda electoral ha aumentado, mientras persiste un marco legal diseñado para los medios de comunicación del Siglo XX. Por tanto, este trabajo no solo realiza un diagnóstico de los actuales mecanismos de control administrativo sobre la propaganda electoral en Internet, sino también propone unos mecanismos que garanticen los principios de la actividad electoral, siendo esta la primera propuesta en Colombia. Por el poco estudio del tema, su alcance es exploratorio, se basa en un enfoque jurídico-institucional. Se utilizaron métodos cualitativos de recolección de datos (trabajo de archivo y entrevistas) y de análisis (tipologías, comparaciones, exegesis del marco legal), pero también elementos cuantitativos como análisis estadísticos.

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Este proyecto se origina en el interés de analizar las estrategias actuales de promoción de productos farmacéuticos, en el marco del debate sobre el efecto persuasivo o informativo que la publicidad directa tiene sobre los consumidores. El objetivo es determinar el efecto de las estrategias de promoción directa para consumidores (Direct to Consumer Advertising [DTCA]) sobre el comportamiento de compra de pacientes y las prescripciones que formulan los médicos en el mercado de productos bajo receta en Estados Unidos. Para tal fin se propuso realizar una monografía que incluyera una revisión de literatura de carácter argumentativo, consultando información de nivel secundario en bases de datos científicas cuyos contenidos obedecieran a criterios metodológicos determinados por la naturaleza argumentativa del estudio. Adicionalmente, se analizó el debate sobre estos anuncios a la luz de dos estudios realizados a pacientes con cáncer de seno, próstata y colon, liderados por el Pennsylvania Cancer Registry con los productos biofarmacéuticos Avodart® y Flomax®. Finalmente, la investigación se fundamentó en la relación del mercado farmacéutico en Estados Unidos con cada uno de los agentes que interactúan en él; consumidores, médicos prescriptores y empresas farmacéuticas, así como el valor que estos comparten través de dichas interacciones. Se concluye que el comportamiento de compra de los consumidores está determinado por la naturaleza de la patología que padecen y el comportamiento de los profesionales que prescriben a sus pacientes se ve influenciado por los anuncios DTCA.

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A utilização generalizada do computador para a automatização das mais diversas tarefas, tem conduzido ao desenvolvimento de aplicações que possibilitam a realização de actividades que até então poderiam não só ser demoradas, como estar sujeitas a erros inerentes à actividade humana. A investigação desenvolvida no âmbito desta tese, tem como objectivo o desenvolvimento de um software e algoritmos que permitam a avaliação e classificação de queijos produzidos na região de Évora, através do processamento de imagens digitais. No decurso desta investigação, foram desenvolvidos algoritmos e metodologias que permitem a identificação dos olhos e dimensões do queijo, a presença de textura na parte exterior do queijo, assim como características relativas à cor do mesmo, permitindo que com base nestes parâmetros possa ser efectuada uma classificação e avaliação do queijo. A aplicação de software, resultou num produto de simples utilização. As fotografias devem respeitar algumas regras simples, sobre as quais se efectuará o processamento e classificação do queijo. ABSTRACT: The widespread use of computers for the automation of repetitive tasks, has resulted in developing applications that allow a range of activities, that until now could not only be time consuming and also subject to errors inherent to human activity, to be performed without or with little human intervention. The research carried out within this thesis, aims to develop a software application and algorithms that enable the assessment and classification of cheeses produced in the region of Évora, by digital images processing. Throughout this research, algorithms and methodologies have been developed that allow the identification of the cheese eyes, the dimensions of the cheese, the presence of texture on the outside of cheese, as well as an analysis of the color, so that, based on these parameters, a classification and evaluation of the cheese can be conducted. The developed software application, is product simple to use, requiring no special computer knowledge. Requires only the acquisition of the photographs following a simple set of rules, based on which it will do the processing and classification of cheese.

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 Los geógrafos ahora tienen a su disposición la red mundial de INTERNET. Esta res es mucho más que un depósito gigante de datos y programas. Es un cúmulo de experiencias humanas que incluyen texto, artículos, imagen,  video y foros de discusión. Es una nueva forma de procesamiento a la información de formas que antes considerábamos imposibles. El profesional que continúe procesando y obteniendo información de la manera tradicional se estará quedando al margen de nuevo conocimiento disponible a diario en INTERNET. El profesional de hoy no se limita a recopilar información en una biblioteca o librería, sino que accesa directamente sitios de búsqueda que le permitirán encontrar rápidamente los datos que busca. Un ejemplo, son los meteorólogos que tienen en INTERNET su mejor herramienta, ya que pueden recuperar imágenes sobre el clima casi inmediatamente después que son almacenadas desde el satélite, lo cual les permite evaluar y discernir sobre el estado actual del clima (Aberdeen University Compiting Center, 1996). Las imágenes las pueden ver y bajar a su computadora individual para su propio uso. Los profesores en la actualidad brindan al estudiante todo su material almacenándolo en INTERNET. La relación profesor-estudiante ya no es la misma. Al estudiante se le exige encontrar la información en su computadora y asimilarla. El viejo cuaderno no es necesario, las lecciones pueden ser recuperadas para su estudio sin que el profesor tenga que impartirlas, como se hace en la mayoría de las universidades de los Estados Unidos (Ohio State University, 1996). En general, este articulo persigue mostrar a los profesionales de las ciencias geográficas, dónde encontrar la información que buscan t cómo localizar más de lo que imaginan con la red INTERNET.  ABSTRACT Geographers now have at their disposition the world network of INTERNET. This network is much more than just a large deposit of digital data and programs. It is an accumulation of human experiences that include text, articles, images, videos, and discussion bulletin boards. It is a new form of processing and managing information that was previously considered impossible. The professional who continues searching and obtaining information by traditional methods will be left on the fringes of this new wave of digital information and material available daily on INTERNET. Hence, a professional is not limited to compiling information in libraries or bookstores as direct and rapid access of desired research materials is available on the INTERNET. For example, meteorologists have in INTERNET their best tool in that they can acquire meteorologic satellite images, which permit them to evaluate and discern the actual present climatic situation (Aberdeen University Computing Center, 1996). One can see and then down load to one´s personal computer imagines of interest for personal use. Professors can offer to students all their materials for a class through and stores on the INTERNET. The relationship between professor and student is not the same. Students can be asked to access and assimilate the information via individual computers connected to the INTERNTET. Notebooks are becoming obsolete given that all class lectures and materials could be placed on the INTERNET for review without a professor having to give a lecture, as is being done in many universities of the United States (Ohio State University, 1996).This article pursues showing, in general, where professionals in Geographical Sciences can find available information and much more on the INTERNET.

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The objective of this thesis is the investigation of the Mode-I fracture mechanics parameters of quasi-brittle materials to shed light onto the influence of the width and size of the specimen on the fracture response of notched beams. To further the knowledge on the fracture process, 3D digital image correlation (DIC) was employed. A new method is proposed to determine experimentally the critical value of the crack opening, which is then used to determine the size of the fracture process zone (FPZ). In addition, the Mode-I fracture mechanics parameters are compared with the Mode-II interfacial properties of composites materials that feature as matrices the quasi-brittle materials studied in Mode-I conditions. To investigate the Mode II fracture parameters, single-lap direct shear tests are performed. Notched concrete beams with six cross-sections has been tested using a three-point bending (TPB) test set-up (Mode-I fracture mechanics). Two depths and three widths of the beam are considered. In addition to concrete beams, alkali-activated mortar beams (AAMs) that differ by the type and size of the aggregates have been tested using the same TPB set-up. Two dimensions of AAMs are considered. The load-deflection response obtained from DIC is compared with the load-deflection response obtained from the readings of two linear variable displacement transformers (LVDT). Load responses, peak loads, strain profiles along the ligament from DIC, fracture energy and failure modes of TPB tests are discussed. The Mode-II problem is investigated by testing steel reinforced grout (SRG) composites bonded to masonry and concrete elements under single-lap direct shear tests. Two types of anchorage systems are proposed for SRG reinforced masonry and concrete element to study their effectiveness. An indirect method is proposed to find the interfacial properties, compare them with the Mode-I fracture properties of the matrix and to model the effect of the anchorage.