895 resultados para Hyperspectral imagery
Resumo:
A method for reconstructing 3D rational B-spline surfaces from multiple views is proposed. The method takes advantage of the projective invariance properties of rational B-splines. Given feature correspondences in multiple views, the 3D surface is reconstructed via a four step framework. First, corresponding features in each view are given an initial surface parameter value (s; t), and a 2D B-spline is fitted in each view. After this initialization, an iterative minimization procedure alternates between updating the 2D B-spline control points and re-estimating each feature's (s; t). Next, a non-linear minimization method is used to upgrade the 2D B-splines to 2D rational B-splines, and obtain a better fit. Finally, a factorization method is used to reconstruct the 3D B-spline surface given 2D B-splines in each view. This surface recovery method can be applied in both the perspective and orthographic case. The orthographic case allows the use of additional constraints in the recovery. Experiments with real and synthetic imagery demonstrate the efficacy of the approach for the orthographic case.
Resumo:
A method for reconstruction of 3D rational B-spline surfaces from multiple views is proposed. Given corresponding features in multiple views, though not necessarily visible in all views, the surface is reconstructed. First 2D B-spline patches are fitted to each view. The 3D B-splines and projection matricies can then be extracted from the 2D B-splines using factorization methods. The surface fit is then further refined via an iterative procedure. Finally, a hierarchal fitting scheme is proposed to allow modeling of complex surfaces by means of knot insertion. Experiments with real imagery demonstrate the efficacy of the approach.
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A method for deformable shape detection and recognition is described. Deformable shape templates are used to partition the image into a globally consistent interpretation, determined in part by the minimum description length principle. Statistical shape models enforce the prior probabilities on global, parametric deformations for each object class. Once trained, the system autonomously segments deformed shapes from the background, while not merging them with adjacent objects or shadows. The formulation can be used to group image regions based on any image homogeneity predicate; e.g., texture, color, or motion. The recovered shape models can be used directly in object recognition. Experiments with color imagery are reported.
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A specialized formulation of Azarbayejani and Pentland's framework for recursive recovery of motion, structure and focal length from feature correspondences tracked through an image sequence is presented. The specialized formulation addresses the case where all tracked points lie on a plane. This planarity constraint reduces the dimension of the original state vector, and consequently the number of feature points needed to estimate the state. Experiments with synthetic data and real imagery illustrate the system performance. The experiments confirm that the specialized formulation provides improved accuracy, stability to observation noise, and rate of convergence in estimation for the case where the tracked points lie on a plane.
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The concept of attention has been used in many senses, often without clarifying how or why attention works as it does. Attention, like consciousness, is often described in a disembodied way. The present article summarizes neural models and supportive data and how attention is linked to processes of learning, expectation, competition, and consciousness. A key them is that attention modulates cortical self-organization and stability. Perceptual and cognitive neocortex is organized into six main cell layers, with characteristic sub-lamina. Attention is part of unified design of bottom-up, horizontal, and top-down interactions among indentified cells in laminar cortical circuits. Neural models clarify how attention may be allocated during processes of visual perception, learning and search; auditory streaming and speech perception; movement target selection during sensory-motor control; mental imagery and fantasy; and hallucination during mental disorders, among other processes.
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Classifying novel terrain or objects front sparse, complex data may require the resolution of conflicting information from sensors working at different times, locations, and scales, and from sources with different goals and situations. Information fusion methods can help resolve inconsistencies, as when evidence variously suggests that an object's class is car, truck, or airplane. The methods described here consider a complementary problem, supposing that information from sensors and experts is reliable though inconsistent, as when evidence suggests that an object's class is car, vehicle, and man-made. Underlying relationships among objects are assumed to be unknown to the automated system or the human user. The ARTMAP information fusion system used distributed code representations that exploit the neural network's capacity for one-to-many learning in order to produce self-organizing expert systems that discover hierarchical knowledge structures. The system infers multi-level relationships among groups of output classes, without any supervised labeling of these relationships.
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An improved Boundary Contour System (BCS) and Feature Contour System (FCS) neural network model of preattentive vision is applied to large images containing range data gathered by a synthetic aperture radar (SAR) sensor. The goal of processing is to make structures such as motor vehicles, roads, or buildings more salient and more interpretable to human observers than they are in the original imagery. Early processing by shunting center-surround networks compresses signal dynamic range and performs local contrast enhancement. Subsequent processing by filters sensitive to oriented contrast, including short-range competition and long-range cooperation, segments the image into regions. The segmentation is performed by three "copies" of the BCS and FCS, of small, medium, and large scales, wherein the "short-range" and "long-range" interactions within each scale occur over smaller or larger distances, corresponding to the size of the early filters of each scale. A diffusive filling-in operation within the segmented regions at each scale produces coherent surface representations. The combination of BCS and FCS helps to locate and enhance structure over regions of many pixels, without the resulting blur characteristic of approaches based on low spatial frequency filtering alone.
Resumo:
An improved Boundary Contour System (BCS) and Feature Contour System (FCS) neural network model of preattentive vision is applied to two large images containing range data gathered by a synthetic aperture radar (SAR) sensor. The goal of processing is to make structures such as motor vehicles, roads, or buildings more salient and more interpretable to human observers than they are in the original imagery. Early processing by shunting center-surround networks compresses signal dynamic range and performs local contrast enhancement. Subsequent processing by filters sensitive to oriented contrast, including short-range competition and long-range cooperation, segments the image into regions. Finally, a diffusive filling-in operation within the segmented regions produces coherent visible structures. The combination of BCS and FCS helps to locate and enhance structure over regions of many pixels, without the resulting blur characteristic of approaches based on low spatial frequency filtering alone.
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This thesis discusses Irish Modernist poetry written between 1905 and 1970, specifically the poetry of Joseph Campbell (1879-1944), Thomas MacGreevy (1893-1967), Denis Devlin (1908-1959) and Brian Coffey (1905-1995). All four poets have been largely neglected in criticism until a growth of interest encouraged by Michael Smith and Trevor Joyce’s New Writers’ Press during the 1970s. J.C.C. Mays, Stan Smith, Susan Schreibman, Terence Brown, Patricia Coughlan and Alex Davis published subsequent critical support during the ‘80s and ‘90s. My research aims to highlight poetry previously omitted from the canon of Irish literature, those with connections to British or continental European literary movements as well as poetry by women writers and writers from the North. Part of this exploration of Irish Poetic Modernisms involves an investigation of intersections between poetic modernisms and Irish war poetry and of depictions of Irish masculinity in the poetry of Devlin and Coffey. My discussion of Campbell’s poetry focuses on links between the early regional modernism of his poetry and later Irish modernist poetry, including his participation in the Ulster Literary Theatre, with the Literary Revival community in Dublin and his association with the proto-Imagist movement in London. My examination of connections between Irish war poetry and Irish modernism allows me to discuss the writing of several underrecognized Irish poets who are contemporaries and near contemporaries of the main subjects of my thesis. Thomas MacGreevy’s poetry is the most clear case study of the links between Irish modernist poetry and poetry about Ireland’s participation in the Great War. MacGreevy’s writing reveals his multiple allegiances: he both elegizes and challenges the increasing cultural inhibitions of Free State Ireland. Denis Devlin’s poetic portrayals of Ireland reveal his rejection both of the Literary Revival’s fascination with Celticism and of Dublin’s literary community while upholding tradition poetic gender roles. My research explores representations of masculinity and Irish politics, including heroic masculine imagery, in the long poems of Devlin and Coffey. My discussion of Brian Coffey considers the importance of the figure of the “poet as maker” to his writing and his relationship with Ireland during his long writing career. I also consider his role as the editor and executor of Devlin’s literary estate and the impact that had on both the latter’s posthumous reputation and Coffey’s later writing.
Resumo:
The aim of this study was to develop a methodology, based on satellite remote sensing, to estimate the vegetation Start of Season (SOS) across the whole island of Ireland on an annual basis. This growing body of research is known as Land Surface Phenology (LSP) monitoring. The SOS was estimated for each year from a 7-year time series of 10-day composited, 1.2 km reduced resolution MERIS Global Vegetation Index (MGVI) data from 2003 to 2009, using the time series analysis software, TIMESAT. The selection of a 10-day composite period was guided by in-situ observations of leaf unfolding and cloud cover at representative point locations on the island. The MGVI time series was smoothed and the SOS metric extracted at a point corresponding to 20% of the seasonal MGVI amplitude. The SOS metric was extracted on a per pixel basis and gridded for national scale coverage. There were consistent spatial patterns in the SOS grids which were replicated on an annual basis and were qualitatively linked to variation in landcover. Analysis revealed that three statistically separable groups of CORINE Land Cover (CLC) classes could be derived from differences in the SOS, namely agricultural and forest land cover types, peat bogs, and natural and semi-natural vegetation types. These groups demonstrated that managed vegetation, e.g. pastures has a significantly earlier SOS than in unmanaged vegetation e.g. natural grasslands. There was also interannual spatio-temporal variability in the SOS. Such variability was highlighted in a series of anomaly grids showing variation from the 7-year mean SOS. An initial climate analysis indicated that an anomalously cold winter and spring in 2005/2006, linked to a negative North Atlantic Oscillation index value, delayed the 2006 SOS countrywide, while in other years the SOS anomalies showed more complex variation. A correlation study using air temperature as a climate variable revealed the spatial complexity of the air temperature-SOS relationship across the Republic of Ireland as the timing of maximum correlation varied from November to April depending on location. The SOS was found to occur earlier due to warmer winters in the Southeast while it was later with warmer winters in the Northwest. The inverse pattern emerged in the spatial patterns of the spring correlates. This contrasting pattern would appear to be linked to vegetation management as arable cropping is typically practiced in the southeast while there is mixed agriculture and mostly pastures to the west. Therefore, land use as well as air temperature appears to be an important determinant of national scale patterns in the SOS. The TIMESAT tool formed a crucial component of the estimation of SOS across the country in all seven years as it minimised the negative impact of noise and data dropouts in the MGVI time series by applying a smoothing algorithm. The extracted SOS metric was sensitive to temporal and spatial variation in land surface vegetation seasonality while the spatial patterns in the gridded SOS estimates aligned with those in landcover type. The methodology can be extended for a longer time series of FAPAR as MERIS will be replaced by the ESA Sentinel mission in 2013, while the availability of full resolution (300m) MERIS FAPAR and equivalent sensor products holds the possibility of monitoring finer scale seasonality variation. This study has shown the utility of the SOS metric as an indicator of spatiotemporal variability in vegetation phenology, as well as a correlate of other environmental variables such as air temperature. However, the satellite-based method is not seen as a replacement of ground-based observations, but rather as a complementary approach to studying vegetation phenology at the national scale. In future, the method can be extended to extract other metrics of the seasonal cycle in order to gain a more comprehensive view of seasonal vegetation development.
Resumo:
An Impressionistic piece. Dance of the Waves uses and expansive structure (A, A2, B, A2, Solos, D, C2, D). The piece is an atmospheric soundscape which evokes imagery of the ocean.
Resumo:
The problem was to determine whether a method of aural and visual vocal training that included a program of portable electronic piano keyboard experience would be more effective in teaching sight-singing skills to novice high school chorus students than a method that included only aural and visual vocal training. A sub-problem was to determine whether novice chorus students enjoyed playing electronic keyboards in chorus as a reinforcement experience in sight-singing training. Students were randomly assigned to two treatment groups, tested with the Musical Aptitude Profile, Tonal Imagery, part A, and then trained separately. The experimental group sang repetitions of melodic patterns and utilized techniques associated with the Kodály Method while simultaneously playing keyboard. The comparison group received a similar treatment without using keyboards. The students were pre- and post-tested in sight-singing using the Vocal Sight-Reading Inventory. Results of the Analysis of Covariance using MAP scores as the covariate revealed no significant difference (p<.05) between post-test scores of the two groups. Improvement was noted in 96% of students from pre-test to post-test regardless of grouping. The repeated measures ANOVA revealed a significant relationship (p<.006) between aptitude group and post-test score. High aptitude students in both groups were found to benefit more from the training than low aptitude students. High aptitude keyboard group students achieved an average gain score that was 8.67 points higher than the comparison group. Of the total experimental group, 92% enjoyed playing keyboards in chorus. It is recommended that future research be undertaken to study the use of keyboards with advanced high school choruses and with uncertain singers in the high school chorus. Research is also needed to develop graded, valid, and reliable sight-singing tests for use in high school chorus. Techniques of the Kodály Method should be further investigated for use in high school sight-singing training.
Resumo:
Long term, high quality estimates of burned area are needed for improving both prognostic and diagnostic fire emissions models and for assessing feedbacks between fire and the climate system. We developed global, monthly burned area estimates aggregated to 0.5° spatial resolution for the time period July 1996 through mid-2009 using four satellite data sets. From 2001ĝ€ "2009, our primary data source was 500-m burned area maps produced using Moderate Resolution Imaging Spectroradiometer (MODIS) surface reflectance imagery; more than 90% of the global area burned during this time period was mapped in this fashion. During times when the 500-m MODIS data were not available, we used a combination of local regression and regional regression trees developed over periods when burned area and Terra MODIS active fire data were available to indirectly estimate burned area. Cross-calibration with fire observations from the Tropical Rainfall Measuring Mission (TRMM) Visible and Infrared Scanner (VIRS) and the Along-Track Scanning Radiometer (ATSR) allowed the data set to be extended prior to the MODIS era. With our data set we estimated that the global annual area burned for the years 1997ĝ€ "2008 varied between 330 and 431 Mha, with the maximum occurring in 1998. We compared our data set to the recent GFED2, L3JRC, GLOBCARBON, and MODIS MCD45A1 global burned area products and found substantial differences in many regions. Lastly, we assessed the interannual variability and long-term trends in global burned area over the past 13 years. This burned area time series serves as the basis for the third version of the Global Fire Emissions Database (GFED3) estimates of trace gas and aerosol emissions.
Resumo:
The Fantasy form offered a composer the freedom to create a work without concerns for fitting into the current stylistic and traditional structures. The flowering of the form seems to be concentrated from 1820-1920 since the composer started to use it as a way to convey a personal idea or to portray a special spirit. This dissertation is comprised of three recitals with fantasies in different genres and styles. Through performing these diverse fantasies, I have been inspired to connect with the imagery and spirit of the compositions in order to capture the unique sentiments of each piece. Also, in order to keep the audience absorbed in the music that is without structure, I have focused on expanding my technical abilities to vary color, sonority, and phrasing. Program one (April 26,2004) includes Fantasie, Op. 17 and Piano Concerto, Op. 54 (assisted by Ya-Hsin Wu) by R. Schumann. Program two (December 10, 2004) includes Three Fantastic Dances, Op. 5 by D. Shostakovitch, Fantasy "Sonataecossaise ", Op. 28 by F. Mendelssohn, Sonata No.2 "Sonata-Fantasy", Op. 19 by A. Scriabin and Fantasie for Piano and Violin, D 934 by F. Schubert with violinist, TaoChang Yu. The last program (November 1, 2005) includes Fantasia baetica by E. de Falla, Morceaux de Fantaisie, Op. 3 by S. Rachrnaninoff, Fantaisie, Op. 49, Impromptu No. 4 '%h.ntasy-hpromptu", Op. 66 and Polonaise-Fantaisie, Op. 61 by F. Chopin.
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This dissertation addresses the growing need to entice people to attend a classical solo vocal recital by incorporating thematic programming, multi-media presentations, collaborations and innovative marketing. It comprises four programs that use the above tactics, creating live performances of classical vocal music that appeal to the attention deficient 21st-century audience. Each program focuses on repertoire appropriate for the male alto voice and includes elements of spoken word, visual imagery and for movement through collaborations with actors, singers, dancers, designers and visual artists. Program one (March 1, 2004), La Voix Humaine: The Life of an Englishwoman in Music, Poetry, & Art, outlines the life of a fictitious Englishwoman through a self-composed narration, spoken by an actress, a Power Point presentation of visual art by 20th-century English artists and musical commentary provided by the collaboration of a vocalist and a pianist. Program two (October 15, 2004), La Voix Thfrmatique: Anima - Music that Moves, is a program of pieces ranging from the 14th- to the 20th-centuries of which half are choreographed by members of the University of Maryland Dance Department. Program three is a lecture recital entitled L 'Haute Voix: Identifying the High Male Voice and Appropriate Repertoire which is presented in collaboration with three singers, a pianist, a harpsichordist and a cellist. Program four, La Voix Dramatique: Opera Roles for the Countertenor Voice, comprises performances of George Frederic Handel's Giulio Cesare in Egitto (1724) in collaboration with the Maryland Opera Studio and the Clarice Smith Performing Arts Center (Leon Major, director; Kenneth Merrill, conductor). There are two performances each of the title role, Cesare (April 15 & 17, 2005), and his nemesis, Tolomeo (April 21 & 23,2005). All programs are documented in a digital audio format available on compact disc and are accompanied by program notes also available in digital format. Programs two and four are also documented in digital video format available on digital video disc.