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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
321

Utilização dos produtos obtidos por sensoriamento remoto na caracterização da qualidade do ar na Região Metropolitana de São Paulo / Use of remote sensing derived products in the air quality characterization over the Metropolitan Area of São Paulo.

Natali, Luciene 28 July 2008 (has links)
O objetivo desse trabalho foi estudar a relação entre profundidade óptica de aerossóis (AOD), obtida por sensoriamento remoto, e a concentração de material particulado (MP10 e MP2,5) medida próximo à superfície sobre a Região Metropolitana de São Paulo (RMSP). A profundidade óptica foi derivada a partir de medidas de radiâncias fornecidas pelos sensores MODIS. Estes sensores estão posicionados a bordo dos satélites EOS-TERRA e EOS-AQUA, operados pela NASA. As concentrações de MP10 e MP2,5 foram obtidas nas estações da rede operacional da CETESB. Foram feitos alguns estudos de caso considerando diferentes situações atmosféricas, aos quais se aplicou a metodologia proposta por Castanho (2005) que busca reduzir as incertezas na determinação da profundidade óptica derivada do MODIS e identificar qual o modelo de aerossol é mais adequado para aplicação em estudos de qualidade do ar. Os valores de AOD calculados para as diferentes situações foram comparados com aqueles obtidos pela AERONET e com as concentrações anteriormente citadas, buscando uma validação dos mesmos. Valores médios de AOD foram calculados para áreas de 10 km x 10 km ao redor das estações de monitoramento do MP. Testes foram realizados para verificar os efeitos de sazonalidade, da quantidade de água na coluna atmosférica, da resposta da AOD por faixas de concentração de MP10, da geometria do sensor, da presença de nuvens e da presença de aerossol acima da Camada de Mistura (CM). Os resultados foram apresentados por estações com o objetivo de se visualizar diferentes condições sobre a região estudada. Alguns dos fatores relevantes observados durante a comparação entre a concentração de MP10 e a AOD foram: a influência do período do ano e da quantidade de água na coluna atmosférica. A geometria do sensor foi fator determinante para melhora das correlações, quando limitado o ângulo de espalhamento em 140°. Situações em que há ausência de nuvens, identificadas através de imagens do MODIS no visível, também apresentaram melhores resultados. Outro fator de extrema importância foi a estrutura vertical da CM. Através de medidas obtidas de um LIDAR foi verificado que a presença de aerossóis acima da CM, a qual é determinada principalmente pelas condições atmosféricas, é determinante para as correlações entre AOD e o MP. / The main purpose of this work was to study the relationship between the Aerosol Optical Depth (AOD), obtained by remote sensing, and the particulate material concentration (PM10 and PM2.5), near to the surface over the Metropolitan Area of Sao Paulo (MASP). The Aerosol Optical Depth was retrieved based on reflectance measurements provided by MODIS sensors. These sensors are carried aboard EOS-TERRA and EOS-AQUA satellites, which are operated by NASA. The PM10 and PM2.5 concentrations were obtained in the CETESB operational network. Case studies were performed, considering several atmospheric conditions, applying the methodology proposed by CASTANHO (2005), designed both to reduce the uncertainty in the determination of the MODIS derived Optical Depth and to identify which aerosol model is more appropriated for air quality studies. Some derived results were compared with AERONET data and with the previously mentioned concentrations as a cross-check test. Mean AOD values were calculated using 10 km x 10 km area ground around PM monitoring stations. Tests were performed to estimate the effects of seasonality, atmospheric column water content, AOD response to PM10 concentration, sensor geometry, clouds and aerosol concentration above the Mixing Layer (ML). To stress the different conditions of the studied region, the results were presented considering each station. Some of the relevant observed factors in the PM10 concentration and AOD comparison were the year period influence and the atmospheric column water content. The sensor geometry was an important factor to the improvement of the obtained correlations when the scattering angle was bounded to 140°. Cloudless situations, identified by MODIS true color images, also improved the results. Another important factor was the Mixing Layer vertical structure. Using LIDAR measurements it was verified that the presence of aerosols above the ML, which is determined mainly by atmospheric conditions, is crucial for the correlations between AOD and PM.
322

ESTIMATION OF DEPTH FROM DEFOCUS BLUR IN VIRTUAL ENVIRONMENTS COMPARING GRAPH CUTS AND CONVOLUTIONAL NEURAL NETWORK

Prodipto Chowdhury (5931032) 17 January 2019 (has links)
Depth estimation is one of the most important problems in computer vision. It has attracted a lot of attention because it has applications in many areas, such as robotics, VR and AR, self-driving cars etc. Using the defocus blur of a camera lens is one of the methods of depth estimation. In this thesis, we have researched this technique in virtual environments. Virtual datasets have been created for this purpose. In this research, we have applied graph cuts and convolutional neural network (DfD-net) to estimate depth from defocus blur using a natural (Middlebury) and a virtual (Maya) dataset. Graph Cuts showed similar performance for both natural and virtual datasets in terms of NMAE and NRMSE. However, with regard to SSIM, the performance of graph cuts is 4% better for Middlebury compared to Maya. We have trained the DfD-net using the natural and the virtual dataset and then combining both datasets. The network trained by the virtual dataset performed best for both datasets. The performance of graph-cuts and DfD-net have been compared. Graph-Cuts performance is 7% better than DfD-Net in terms of SSIM for Middlebury images. For Maya images, DfD-Net outperforms Graph-Cuts by 2%. With regard to NRMSE, Graph-Cuts and DfD-net shows similar performance for Maya images. For Middlebury images, Graph-cuts is 1.8% better. The algorithms show no difference in performance in terms of NMAE. The time DfD-net takes to generate depth maps compared to graph cuts is 500 times less for Maya images and 200 times less for Middlebury images.
323

Motion and shape from apparent flow.

January 2013 (has links)
捕捉攝像機運動和重建攝像機成像場景深度圖的測定是在計算機視覺和機器任務包括可視化控制和自主導航是非常重要。在執行上述任務時,一個攝像機(或攝像機群組)通常安裝在機器的執行端部。攝像機和執行端部之間的手眼校準在視覺控制的正常操作中是不可缺少的。同樣,在對於需要使用多個攝像機的情况下,它們的相對幾何關係也是對各種計算機視覺應用來說也是非常重要。 / 攝像機和場景的相對運動通常產生出optical flow。問題的困難主要在於,在直接觀察視頻中的optical flow通常不是完全由運動誘導出的optical flow,而只是它的一部分。這個部分就是空間圖像等光線輪廓的正交。這部分的流場被稱為normal flow。本論文提出直接利用normal flow,而不是由normal flow引申出的optical flow,去解決以下的問題:尋找攝像機運動,場景深度圖和手眼校準。這種方法有許多顯著的貢獻,它不需引申流場,進而不要求平滑的成像場景。跟optical flow相反,normal flow不需要複雜的優化處理程序去解決流場不連續性的問題,這種技術一般是需要用大量的計算量。這也打破了傳統攝像機運動與場景深度之間的問題,在沒有預先知道不連續位置的情況下也可找出攝像機的運動。這篇論提出了幾個直接方法運用在三種不同類型的視覺系統,分別是單個攝像機,雙攝像機和多個攝像機,去找出攝像機的運動。 / 本論文首先提通過Apparent Flow 正深度 (AFPD) 約束去利用所有觀察到的normal flow去找出單個攝像機的運動參數。AFPD約束是利用一個優化問題來估計運動參數。一個反复由粗到細雙重約束的投票框架能使AFPD約束尋找出運動參數。 / 由於有限的視頻採樣率,normal flow在提取方向比其幅度部分更準確。本論文提出了兩個約束條件:一個是Apparent Flow方向(AFD)的約束,另外一個是Apparent Flow 幅度(AFM)的約束去尋找運動參數。第一個約束本身是作為一個線性不等式系統去約束運動方向的參數,第二個是利用所有圖像位置的旋轉幅度的統一性去進一步限制運動參數。一個兩階段從粗到細的約束框架能使AFD及AFM約束尋找出運動參數。 / 然而,如果沒有optical flow,normal flow是唯一的原始資料,它通常遭受到有限影像分辨率和有限視頻採樣率的問題而產生出錯誤。本文探討了這個問題的補救措施,方法是把一些攝像機併在一起,形成一個近似球形的攝像機,以增加成像系統的視野。有了一個加寬視野,normal flow的數量可更大,這可以用來抵銷normal flow在每個成像點的提取錯誤。更重要的是,攝像頭的平移和旋轉運動方向可以透過Apparent Flow分離 (AFS) 約束 及 延伸Apparent Flow分離 (EAFS) 約束來獨立估算。 / 除了使用單攝像機或球面成像系統之外,立體視覺成像系統提供了其它的視覺線索去尋找攝像機在沒有被任意縮放大小的平移運動和深度圖。傳統的立體視覺方法是確定在兩個輸入圖像特徵的對應。然而,對應的建立是非常困難。本文探討了兩個直接方法來恢復完整的攝像機運動,而沒有需要利用一對影像明確的點至點對應。第一種方法是利用AFD和AFM約束伸延到立體視覺系統,並提供了一個穩定的幾何方法來確定平移運動的幅度。第二個方法需要利用有一個較大的重疊視場,以提供一個不需反覆計算的closed-form算法。一旦確定了運動參數,深度圖可以沒有任何困難地重建。從normal flow產生的深度圖一般是以稀疏的形式存在。我們可以通過擴張深度圖,然後利用它作為在常見的TV-L₁框架的初始估計。其結果不僅有一個更好的重建性能,也產生出更快的運算時間。 / 手眼校準通常是基於像圖特徵對應。本文提出一個替代方法,是從動態攝像系統產生的normal flow來做自我校準。為了使這個方法有更強防備噪音的能力,策略是使用normal flow的流場方向去尋找手眼幾何的方向部份。偏離點及部分的手眼幾何可利用normal flow固有的流場屬性去尋找。最後完整的手眼幾何可使用穩定法來變得更可靠。手眼校準還可以被用來確定多個攝像機的相對幾何關係,而不需要求它們有重疊的視場。 / Determination of general camera motion and reconstructing depth map from a captured video of the imaged scene relative to a camera is important for computer vision and various robotics tasks including visual control and autonomous navigation. A camera (or a cluster of cameras) is usually mounted on the end-effector of a robot arm when performing the above tasks. The determination of the relative geometry between the camera frame and the end-effector frame which is commonly referred as hand-eye calibration is essential to proper operation in visual control. Similarly, determining the relative geometry of multiple cameras is also important to various applications requiring the use of multi-camera rig. / The relative motion between an observer and the imaged scene generally induces apparent flow in the video. The difficulty of the problem lies mainly in that the flow pattern directly observable in the video is generally not the full flow field induced by the motion, but only partial information of it, which is orthogonal to the iso-brightness contour of the spatial image intensity profile. The partial flow field is known as the normal flow field. This thesis addresses several important problems in computer vision: determination of camera motion, recovery of depth map, and performing hand-eye calibration from the apparent flow (normal flow) pattern itself in the video data directly but not from the full flow interpolated from the apparent flow. This approach has a number of significant contributions. It does not require interpolating the flow field and in turn does not demand the imaged scene to be smooth. In contrast to optical flow, no sophisticated optimization procedures that account for handling flow discontinuities are required, and such techniques are generally computational expensive. It also breaks the classical chicken-and-egg problem between scene depth and camera motion. No prior knowledge about the locations of the discontinuities is required for motion determination. In this thesis, several direct methods are proposed to determine camera motion using three different types of imaging systems, namely monocular camera, stereo camera, and multi-camera rig. / This thesis begins with the Apparent Flow Positive Depth (AFPD) constraint to determine the motion parameters using all observable normal flows from a monocular camera. The constraint presents itself as an optimization problem to estimate the motion parameters. An iterative process in a constrained dual coarse-to-fine voting framework on the motion parameter space is used to exploit the constraint. / Due to the finite video sampling rate, the extracted normal flow field is generally more accurate in direction component than its magnitude part. This thesis proposes two constraints: one related to the direction component of the normal flow field - the Apparent Flow Direction (AFD) constraint, and the other to the magnitude component of the field - the Apparent Flow Magnitude (AFM) constraint, to determine motion. The first constraint presents itself as a system of linear inequalities to bind the direction of motion parameters; the second one uses the globality of rotational magnitude to all image positions to constrain the motion parameters further. A two-stage iterative process in a coarse-to-fine framework on the motion parameter space is used to exploit the two constraints. / Yet without the need of the interpolation step, normal flow is only raw information extracted locally that generally suffers from flow extraction error arisen from finiteness of the image resolution and video sampling rate. This thesis explores a remedy to the problem, which is to increase the visual field of the imaging system by fixating a number of cameras together to form an approximate spherical eye. With a substantially widened visual field, the normal flow data points would be in a much greater number, which can be used to combat the local flow extraction error at each image point. More importantly, the directions of translation and rotation components in general motion can be separately estimated with the use of the novel Apparent Flow Separation (AFS) and Extended Apparent Flow Separation (EAFS) constraints. / Instead of using a monocular camera or a spherical imaging system, stereo vision contributes another visual clue to determine magnitude of translation and depth map without the problem of arbitrarily scaling of the magnitude. The conventional approach in stereo vision is to determine feature correspondences across the two input images. However, the correspondence establishment is often difficult. This thesis explores two direct methods to recover the complete camera motion from the stereo system without the explicit point-to-point correspondences matching. The first method extends the AFD and AFM constraints to stereo camera, and provides a robust geometrical method to determine translation magnitude. The second method which requires the stereo image pair to have a large overlapped field of view provides a closed-form solution, requiring no iterative computation. Once the motion parameters are here, depth map can be reconstructed without any difficulty. The depth map resulted from normal flows is generally sparse in nature. We can interpolate the depth map and then utilizing it as an initial estimate in a conventional TV-L₁ framework. The result is not only a better reconstruction performance, but also a faster computation time. / Calibration of hand-eye geometry is usually based on feature correspondences. This thesis presents an alternative method that uses normal flows generated from an active camera system to perform self-calibration. In order to make the method more robust to noise, the strategy is to use the direction component of the flow field which is more noise-immune to recover the direction part of the hand-eye geometry first. Outliers are then detected using some intrinsic properties of the flow field together with the partially recovered hand-eye geometry. The final solution is refined using a robust method. The method can also be used to determine the relative geometry of multiple cameras without demanding overlap in their visual fields. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Hui, Tak Wai. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2013. / Includes bibliographical references (leaves 159-165). / Abstracts in English and Chinese. / Acknowledgements --- p.i / Abstract --- p.ii / Lists of Figures --- p.xiii / Lists of Tables --- p.xix / Chapter Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Background --- p.1 / Chapter 1.2 --- Motivation --- p.4 / Chapter 1.3 --- Research Objectives --- p.6 / Chapter 1.4 --- Thesis Outline --- p.7 / Chapter Chapter 2 --- Literature Review --- p.10 / Chapter 2.1 --- Introduction --- p.10 / Chapter 2.2 --- Recovery of Optical Flows --- p.10 / Chapter 2.3 --- Egomotion Estimation Based on Optical Flow Field --- p.14 / Chapter 2.3.1 --- Bilinear Constraint --- p.14 / Chapter 2.3.2 --- Subspace Method --- p.15 / Chapter 2.3.3 --- Partial Search Method --- p.16 / Chapter 2.3.4 --- Fixation --- p.17 / Chapter 2.3.5 --- Region Alignment --- p.17 / Chapter 2.3.6 --- Linearity and Divergence Properties of Optical Flows --- p.18 / Chapter 2.3.7 --- Constraint Lines and Collinear Points --- p.18 / Chapter 2.3.8 --- Multi-Camera Rig --- p.19 / Chapter 2.3.9 --- Discussion --- p.21 / Chapter 2.4 --- Determining Egomotion Using Direct Methods --- p.22 / Chapter 2.4.1 --- Introduction --- p.22 / Chapter 2.4.2 --- Classical Methods --- p.23 / Chapter 2.4.3 --- Pattern Matching --- p.24 / Chapter 2.4.4 --- Search Subspace Method --- p.25 / Chapter 2.4.5 --- Histogram-Based Method --- p.26 / Chapter 2.4.6 --- Multi-Camera Rig --- p.26 / Chapter 2.4.7 --- Discussion --- p.27 / Chapter 2.5 --- Determining Egomotion Using Feature Correspondences --- p.28 / Chapter 2.6 --- Hand-Eye Calibration --- p.30 / Chapter 2.7 --- Summary --- p.31 / Chapter Chapter 3 --- Determining Motion from Monocular Camera Using Merely the Positive Depth Constraint --- p.32 / Chapter 3.1 --- Introduction --- p.32 / Chapter 3.2 --- Related Works --- p.33 / Chapter 3.3 --- Background --- p.34 / Chapter 3.3 --- Apparent Flow Positive Depth (AFPD) Constraint --- p.39 / Chapter 3.4 --- Numerical Solution to AFPD Constraint --- p.40 / Chapter 3.5 --- Constrained Coarse-to-Fine Searching --- p.40 / Chapter 3.6 --- Experimental Results --- p.43 / Chapter 3.7 --- Conclusion --- p.47 / Chapter Chapter 4 --- Determining Motion from Monocular Camera Using Direction and Magnitude of Normal Flows Separately --- p.48 / Chapter 4.1 --- Introduction --- p.48 / Chapter 4.2 --- Related Works --- p.50 / Chapter 4.3 --- Apparent Flow Direction (AFD) Constraint --- p.51 / Chapter 4.3.1 --- The Special Case: Pure Translation --- p.51 / Chapter 4.3.1.1 --- Locus of Translation Using Full Flow as a Constraint --- p.51 / Chapter 4.3.1.2 --- Locus of Translation Using Normal Flow as a Constraint --- p.53 / Chapter 4.3.2 --- The Special Case: Pure Rotation --- p.54 / Chapter 4.3.2.1 --- Locus of Rotation Using Full Flow as a Constraint --- p.54 / Chapter 4.3.2.2 --- Locus of Rotation Using Normal Flow as a Constraint --- p.54 / Chapter 4.3.3 --- Solving the System of Linear Inequalities for the Two Special Cases --- p.55 / Chapter 4.3.5 --- Ambiguities of AFD Constraint --- p.59 / Chapter 4.4 --- Apparent Flow Magnitude (AFM) Constraint --- p.60 / Chapter 4.5 --- Putting the Two Constraints Together --- p.63 / Chapter 4.6 --- Experimental Results --- p.65 / Chapter 4.6.1 --- Simulation --- p.65 / Chapter 4.6.2 --- Video Data --- p.67 / Chapter 4.6.2.1 --- Pure Translation --- p.67 / Chapter 4.6.2.2 --- General Motion --- p.68 / Chapter 4.7 --- Conclusion --- p.72 / Chapter Chapter 5 --- Determining Motion from Multi-Cameras with Non-Overlapping Visual Fields --- p.73 / Chapter 5.1 --- Introduction --- p.73 / Chapter 5.2 --- Related Works --- p.75 / Chapter 5.3 --- Background --- p.76 / Chapter 5.3.1 --- Image Sphere --- p.77 / Chapter 5.3.2 --- Planar Case --- p.78 / Chapter 5.3.3 --- Projective Transformation --- p.79 / Chapter 5.4 --- Constraint from Normal Flows --- p.80 / Chapter 5.5 --- Approximation of Spherical Eye by Multiple Cameras --- p.81 / Chapter 5.6 --- Recovery of Motion Parameters --- p.83 / Chapter 5.6.1 --- Classification of a Pair of Normal Flows --- p.84 / Chapter 5.6.2 --- Classification of a Triplet of Normal Flows --- p.86 / Chapter 5.6.3 --- Apparent Flow Separation (AFS) Constraint --- p.87 / Chapter 5.6.3.1 --- Constraint to Direction of Translation --- p.87 / Chapter 5.6.3.2 --- Constraint to Direction of Rotation --- p.88 / Chapter 5.6.3.3 --- Remarks about the AFS Constraint --- p.88 / Chapter 5.6.4 --- Extension of Apparent Flow Separation Constraint (EAFS) --- p.89 / Chapter 5.6.4.1 --- Constraint to Direction of Translation --- p.90 / Chapter 5.6.4.2 --- Constraint to Direction of Rotation --- p.92 / Chapter 5.6.5 --- Solution to the AFS and EAFS Constraints --- p.94 / Chapter 5.6.6 --- Apparent Flow Magnitude (AFM) Constraint --- p.96 / Chapter 5.7 --- Experimental Results --- p.98 / Chapter 5.7.1 --- Simulation --- p.98 / Chapter 5.7.2 --- Real Video --- p.103 / Chapter 5.7.2.1 --- Using Feature Correspondences --- p.108 / Chapter 5.7.2.2 --- Using Optical Flows --- p.108 / Chapter 5.7.2.3 --- Using Direct Methods --- p.109 / Chapter 5.8 --- Conclusion --- p.111 / Chapter Chapter 6 --- Motion and Shape from Binocular Camera System: An Extension of AFD and AFM Constraints --- p.112 / Chapter 6.1 --- Introduction --- p.112 / Chapter 6.2 --- Related Works --- p.112 / Chapter 6.3 --- Recovery of Camera Motion Using Search Subspaces --- p.113 / Chapter 6.4 --- Correspondence-Free Stereo Vision --- p.114 / Chapter 6.4.1 --- Determination of Full Translation Using Two 3D Lines --- p.114 / Chapter 6.4.2 --- Determination of Full Translation Using All Normal Flows --- p.115 / Chapter 6.4.3 --- Determination of Full Translation Using a Geometrical Method --- p.117 / Chapter 6.5 --- Experimental Results --- p.119 / Chapter 6.5.1 --- Synthetic Image Data --- p.119 / Chapter 6.5.2 --- Real Scene --- p.120 / Chapter 6.6 --- Conclusion --- p.122 / Chapter Chapter 7 --- Motion and Shape from Binocular Camera System: A Closed-Form Solution for Motion Determination --- p.123 / Chapter 7.1 --- Introduction --- p.123 / Chapter 7.2 --- Related Works --- p.124 / Chapter 7.3 --- Background --- p.125 / Chapter 7.4 --- Recovery of Camera Motion Using a Linear Method --- p.126 / Chapter 7.4.1 --- Region-Correspondence Stereo Vision --- p.126 / Chapter 7.3.2 --- Combined with Epipolar Constraints --- p.127 / Chapter 7.4 --- Refinement of Scene Depth --- p.131 / Chapter 7.4.1 --- Using Spatial and Temporal Constraints --- p.131 / Chapter 7.4.2 --- Using Stereo Image Pairs --- p.134 / Chapter 7.5 --- Experiments --- p.136 / Chapter 7.5.1 --- Synthetic Data --- p.136 / Chapter 7.5.2 --- Real Image Sequences --- p.137 / Chapter 7.6 --- Conclusion --- p.143 / Chapter Chapter 8 --- Hand-Eye Calibration Using Normal Flows --- p.144 / Chapter 8.1 --- Introduction --- p.144 / Chapter 8.2 --- Related Works --- p.144 / Chapter 8.3 --- Problem Formulation --- p.145 / Chapter 8.3 --- Model-Based Brightness Constraint --- p.146 / Chapter 8.4 --- Hand-Eye Calibration --- p.147 / Chapter 8.4.1 --- Determining the Rotation Matrix R --- p.148 / Chapter 8.4.2 --- Determining the Direction of Position Vector T --- p.149 / Chapter 8.4.3 --- Determining the Complete Position Vector T --- p.150 / Chapter 8.4.4 --- Extrinsic Calibration of a Multi-Camera Rig --- p.151 / Chapter 8.5 --- Experimental Results --- p.151 / Chapter 8.5.1 --- Synthetic Data --- p.151 / Chapter 8.5.2 --- Real Image Data --- p.152 / Chapter 8.6 --- Conclusion --- p.153 / Chapter Chapter 9 --- Conclusion and Future Work --- p.154 / Related Publications --- p.158 / Bibliography --- p.159 / Appendix --- p.166 / Chapter A --- Apparent Flow Direction Constraint --- p.166 / Chapter B --- Ambiguity of AFD Constraint --- p.168 / Chapter C --- Relationship between the Angle Subtended by any two Flow Vectors in Image Plane and the Associated Flow Vectors in Image Sphere --- p.169
324

Distribuição longitudinal e produtividade do milho em função da velocidade de deslocamento e da profundidade de deposição da semente

Mello, Adilson José Rocha [UNESP] 06 January 2011 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:31:03Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-01-06Bitstream added on 2014-06-13T20:21:43Z : No. of bitstreams: 1 mello_ajr_dr_jabo.pdf: 1408395 bytes, checksum: 68cfa6cc41152d189a4a79ca6a70aed8 (MD5) / Realizar a semeadura em maior profundidade para se proporcionar melhores condições à germinação e emergência pode ser decisivo em momentos de condições climáticas adversas. Conduziu-se o presente trabalho na área experimental do Laboratório de Máquinas e Mecanização Agrícola da UNESP/Jaboticabal com o objetivo de avaliar a demanda energética do conjunto trator-semeadora-adubadora nas velocidades de 4,5; 6,0 e 7,5 km h-1, mensurar a posição relativa entre adubo e sementes, quantificar a distribuição longitudinal de plantas logo após a semeadura e na colheita em função de quatro velocidades de semeadura, incluindo uma semeadura manual, com duas profundidades de deposição da semente. Os valores de falhas, na colheita, foram semelhantes para as três velocidades tratorizadas (4,5; 6,0 e 7,5 km h- 1), 31% em média, e maiores que a semeadura manual, que foi de 4%. Não houve efeito das profundidades de semeadura para produtividade de grãos. No entanto, observou-se o maior valor de produtividade para a semeadura manual. A capacidade de campo operacional foi 70% maior, de 1,19 para 2,02 ha h-1, para a maior velocidade. A potência foi de 28,42 kW para 7,5 km h-1, na profundidade de 0,05 m que não diferiu da potência requerida aos 0,10 m. / To sow in greater depth to provide better conditions for germination and emergence can be decisive in times of adverse weather conditions. We conducted this study in the Laboratório de Máquinas e Mecanização Agrícola da UNESP/Jaboticabal in order to assess the energy demand of the tractor-seeder-fertilizer at speeds of 4.5, 6.0 and 7.5 km h-1, measuring the relative position between fertilizer and seeds, measure the longitudinal distribution of plants immediately after planting and at harvest due to four seeding rates, including a manual seeding, with two depths of deposition of the seed. The fault values at harvest were similar for the three tractor-implement speeds (4.5, 6.0 and 7.5 km h-1), 31% on average and higher than manual sowing, which was 4%. There was no effect of sowing depths for grain yield. However, we observed the highest value of productivity for manual seeding. The field operational capacity was 70% higher, from 1.19 ha to 2.02 h-1 for the highest speed. The power was 28.42 kW to 7.5 km h-1 at a depth of 0.05 m did not differ from that required power to 0.10 m.
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Aspectos da biologia da Digitaria insularis resistente ao herbicida glyphosate / Aspects of the biology of Digitaria insularis resistant to glyphosate

Camila Schorr Reinert 06 December 2013 (has links)
A utilização frequente de glyphosate em sistemas de produção envolvendo as culturas de soja e milho, resistentes ao glyphosate, tem selecionado populações resistentes de plantas daninhas a este herbicida, sendo comum no Brasil a ocorrência de populações resistentes de capim amargoso (Digitaria insularis). Para manejo racional destas populações, há necessidade de medidas alternativas envolvendo herbicidas e práticas culturais, as quais somente podem ser empregadas adequadamente com o conhecimento da biologia da planta daninha, porém atualmente pouco se sabe sobre a biologia do capim amargoso. Portanto, este trabalho teve como objetivo obter informações básicas da biologia das populações de capim-amargoso suscetíveis e resistentes ao herbicida glyphosate. Para isso, foram conduzidos três ensaios no Departamento de produção Vegetal da ESALQ/USP, em Piracicaba - SP, durante o ano de 2012. Para isso foram coletadas sementes do biótipo resistente no município de Matão, São Paulo, e as sementes do biótipo suscetível no município de Piracicaba, São Paulo. A determinação do fator de resistência entre estes biótipos ao glyphosate foi determinas a partir da elaboração de curvas de dose-resposta no estádio de desenvolvimento de 3 a 4 perfilhos do capim amargoso. Em seguida, foram conduzidos experimentos para avaliar a germinação e quantificação de massa seca produzida sob efeito de diferentes volumes da cobertura do solo com resíduos de milheto. Também foram desenvolvidos ensaios para avaliar a longevidade das sementes dos biótipos resistentes e suscetíveis, conduzidas em diferentes profundidades no solo. Através do modelo de curva dose-resposta foi possível quantificar o fator de resistência (GR50) a partir do programa estatístico R obtendo o valor de 16,66, comparando-se o biótipo resistente ao suscetível. O aumento da quantidade de palha de milheto sobre as sementes proporciona diminuição do peso de matéria seca de plântulas de Digitaria insularis, tanto resistente como suscetível ao glyphosate, sendo percebida de forma mais acentuada nos tratamentos 4,0 e 8,0 ton ha-1. O biótipo resistente apresenta número de plântulas significativamente maior que o biótipo suscetível, independentemente da quantidade de palha. Não é possível concluir que as sementes dos biótipos resistentes possuem maior longevidade que as sementes dos biótipos suscetíveis, sendo que a presença de luz é indiferente para a sua germinação. / The frequent use of glyphosate in production systems that involve the crops soybean and corn, resistant to glyphosate, have selected weed populations resistant to this herbicide, being very common in Brazil the occurrence of resistant populations of bitter grass (Digitaria insularis). For the rational management of these populations, there is a need of alternative measures, that involve herbicides and cultural practices, which can be applied only with the knowledge of the weed biology, however little is known about the bitter grass biology. Therefore, this study aimed to obtain basic information of the biology of populations of bitter grass susceptible and resistant to the herbicide glyphosate. For that, three assays were conducted in the Department of Crop Science at ESALQ / USP, in Piracicaba - SP, during the year 2012. For that, it was collected seeds of the resistant biotype in Matão, São Paulo and seeds of the susceptible population in Piracicaba, São Paulo. The determination of the resistance factor for glyphosate between the biotypes was performed using dose-response curves at stage 3-4 tillers of bitter grass. Following, it was evaluated the germination and quantification of dry matter produced under the effect of different amounts of coverage with millet straw. It was also developed trials to see longevity of the resistant and susceptible biotypes, conducted at different soil depths. With the model of dose-response curve, it was possible to quantify the resistance factor (GR50) from the R statistical program by obtaining the value of 16.66, compared to the susceptible biotype resistant. The increased amount of millet straw on seed caused reduction in dry weight of seedlings of Digitaria insularis, for both biotypes, being more evident in treatments of 4.0 and 8.0 ton ha-1. The resistant biotype showed significantly higher number of seedlings than susceptible population, regardless of the amount of straw. It is not possible to conclude that the seeds of resistant biotypes have greater longevity than the seeds of the susceptible biotype, and the presence of light is indifferent to its germination.
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Priming de sementes de espécies brasileiras visando ao uso potencial para programas de reflorestamento / Brazilian species of seed priming aimed at potential use for reforestation programs

Francisco Ortolan Santos 27 August 2015 (has links)
Mudas ou sementes podem ser utilizadas em projetos de restauração, sendo que, o uso da semente por meio da semeadura direta tem vantagem em função da redução do custo, pois não há gastos para a formação inicial da muda, por proporcionar a reconstituição do banco de sementes do solo e possibilitar a formação de uma comunidade heterogênea. Portanto, nessa pesquisa foram avaliadas as sementes de quatro espécies de recobrimento, Apeiba tibourbou, Heliocarpus popayanensis, Senna alata e Senna multijuga, para a utilização na semeadura direta, associada aos estudos da aplicação das técnicas do priming e da interferência da profundidade de semeadura na emergência da plântula. O estudo dos métodos de priming incluiu a hidratação das sementes em água (imersão e entre papel) e em soluções -0,1 MPa e -0,6MPa de PEG 6000 (entre papel), sendo que parte das sementes foi avaliada ainda úmida quanto à germinação, parte foi seca até graus de umidade semelhantes aos obtidos antes da realização do priming e parte foi seca e armazenada para ser semeada após 45 dias. A determinação da qualidade das sementes foi baseada nos resultados dos testes de germinação e de emergência da plântula e foram calculados os totais, em porcentagem, o índice de velocidade de germinação (IVG) e o tempo médio de germinação (TMG). Para o estudo da profundidade de semeadura foi avaliada a distribuição superficial das sementes 0 (superficial) e 0,5 cm, 1,0 cm e 2,0 cm e determinados a emergência da plântula, o IVEP e o TMEP. O estudo da absorção de água das sementes indicou que os teores de água, na fase II da germinação, são 48 a 55% para as sementes de A. tibourbou e 55 a 60% para as de S. alata e de S. multijuga. Em função dos resultados dessa pesquisa, o priming não beneficia a germinação das sementes de A. tibourbou e de H. popayanensis. A utilização da solução -0,1 MPa de PEG 6000 reduz o tempo de germinação das sementes de S. alata, quando avaliadas úmidas. Esse mesmo método é eficiente para o priming das sementes de S. multijuga, avaliadas após a secagem. As sementes de S. alata e S. multijuga são recomendadas para semeadura direta em projetos de restauração ecológica, desde que, seja superada a dormência dessas sementes. A profundidade ideal de semeadura é 1 a 2 cm para as sementes de A. tibourbou, de 0,5 cm para as de H. popayanensis, de 1 cm para as de S. alata e de 1 a 2 cm para as sementes de S. multijuga. / Seedlings or seeds can be used in reforestation projects and the use of seed through direct sowing has the advantage because there is no cost for the initial formation of the seedlings and additionally it provides enriching soil seed bank and the possibility of a heterogeneous community formation. Then, in this research were evaluated the seeds of four pioneer species, Apeiba tibourbou, Heliocarpus popayanensis, Senna alata and Senna multijuga, for direct sowing associated with the priming techniques and the study of the interference of sowing depth in the emergence of seedling. The study of priming methods included seed hydration (water immersion and between paper water moistened) and the use of PEG 6000 solutions (- 0,6MPa and -0.1MPa between paper). For evaluations, these seeds were sown still wet and after dry; furthermore, the dry seeds were stored for evaluation after 45 days. The determination of the seed quality was based on the results of seed germination and seedling emergence. In the study of seed sowing the seeds were sowing on surface and in 0.5 cm, 1.0 cm and 2.0 cm depth, and these results were based on seedling emergence. This research results indicated the possibility of using S. alata and S. multijuga seeds for direct sowing. There are benefits of using seed priming for S. alata and S. multijuga seeds. Appropriate sowing depth for these seeds are 0.5 cm, 1.0 cm or 2.0 cm; seed surface sowing is not recommended.
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AvaliaÃÃo em Profundidade da PolÃtica de AssistÃncia Estudantil do Instituto Federal do PiauÃ. / Depth Assessment of the Student Assistance Policy of the Federal Institute of PiauÃ.

Clefra Vieira Guedelho 14 July 2017 (has links)
UFC / Esta pesquisa trata da avaliaÃÃo da PolÃtica de AssistÃncia Estudantil (POLAE) do Instituto Federal do PiauÃ, enquanto regulamentaÃÃo institucional do Programa Nacional de AssistÃncia Estudantil (PNAES), sob a perspectiva da avaliaÃÃo em profundidade. Avalia a forma como as definiÃÃes do PNAES sÃo consubstanciadas na POLAE, considerando as concepÃÃes que norteiam a ambos, em articulaÃÃo aos contextos de formulaÃÃo nacional e local, situadas tanto pelo aspecto normativo quanto pelas percepÃÃes dos sujeitos envolvidos na implementaÃÃo. O objetivo à avaliar as concepÃÃes de assistÃncia estudantil que norteiam a implementaÃÃo do PNAES no Instituto Federal do Piauà e as implicaÃÃes desse processo, na visÃo de estudantes, professores e tÃcnicos-administrativos. A abordagem à qualitativa e os procedimentos adotados sÃo: revisÃo bibliogrÃfica, anÃlise documental e entrevistas. Discute-se sobre o contexto econÃmico, polÃtico e social propiciador da regulamentaÃÃo do PNAES, articulando tal discussÃo à anÃlise do conteÃdo do Programa, ou seja, a base conceitual que lhe confere sustentaÃÃo teÃrico-ideolÃgica. O PNAES nasce a partir do processo de expansÃo do ensino superior e profissional em nÃvel federal, com o foco na equidade social entre os estudantes de graduaÃÃo, atravÃs da focalizaÃÃo naqueles suscetÃveis à evasÃo e retenÃÃo, perspectivas associadas ao ideÃrio novo desenvolvimentista emergente nos anos 2000. No Ãmbito local, o Programa foi regulamentado a partir do protagonismo de um grupo, sendo incorporadas as definiÃÃes das diretrizes nacionais, com adaptaÃÃes visando atender as demandas institucionais. Prevalece na fala dos sujeitos a concepÃÃo de assistÃncia estudantil como auxÃlio financeiro aos estudantes, devido à condiÃÃo socioeconÃmica de vulnerabilidade. Constatou-se que as implicaÃÃes da implementaÃÃo da POLAE se referem ao objetivo de prevenir a evasÃo e retenÃÃo, tanto pela incipiente efetividade das aÃÃes, quanto devido aos fatores que fogem ao seu alcance, sobretudo devido à canalizaÃÃo de tal intento para o plano individual, em que os prÃprios estudantes sÃo responsabilizados por tais resultados.
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Estimação e análise automática de parâmetros de postura ergonômica usando sensor de profundidade / Estimation and automatic analysis of ergonomic posture parameters using depth sensor

QUINTANILHA, Darlan Bruno Pontes 19 February 2013 (has links)
Submitted by Rosivalda Pereira (mrs.pereira@ufma.br) on 2017-08-17T17:55:05Z No. of bitstreams: 1 DarlanQuintanilha.pdf: 3786941 bytes, checksum: 02e764c0fb1f5831eefb5fb0b92e32de (MD5) / Made available in DSpace on 2017-08-17T17:55:05Z (GMT). No. of bitstreams: 1 DarlanQuintanilha.pdf: 3786941 bytes, checksum: 02e764c0fb1f5831eefb5fb0b92e32de (MD5) Previous issue date: 2013-02-19 / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPQ) / During a workday, a person can take many positions and require muscle strain that can cause work-related musculoskeletal diseases (MSDs). In this situation, the joints will become worn over a long period of time, causing fatigue, injuries, or in severe cases, can lead to permanent deformation. In this sense, postural analysis is essential to evaluate the activity of a person in a work environment, however the traditional monitoring methods are manual, which can be exhausting, tedious and inefficient. An automated approach using sensors depth, by contrast, can provide valuable information about the behavior related to the activity of the person. In this sense, this work presents a methodology for the purpose of assisting the professional use of the ergonomic assessment methods posture: the 3DSSPP (Three Dimensional Static Strength Prediction Program) and RULA (Rapid Upper Limb Assessment) using a depth sensor to extract information for accurate setting of posture. The estimation and analysis of posture parameters based on two valuation methods chosen presented good results, the RULA method showed an accuracy of 71.67%. / Durante uma jornada de trabalho, uma pessoa pode assumir inúmeras posturas e demandar esforços musculares que podem causar distúrbios osteomusculares relacionados ao trabalho (DORT). Nesta situação, as articulações ficarão desgastadas por um longo período de tempo, causando fadiga, lesões ou, em casos graves, levará deformação permanente. Nesse sentido, a análise postural é essencial para avaliar a atividade de uma pessoa em um ambiente de trabalho, no entanto os métodos tradicionais de monitoramento são manuais, podendo ser exaustivos, entediantes e ineficientes. Uma abordagem automatizada utilizando sensores de profundidade, por outro lado, pode fornecer informações valiosas sobre o comportamento relacionado à atividade da pessoa. Nesse sentido, este trabalho apresenta uma metodologia com objetivo de auxiliar o profissional de ergonomia na utilização de métodos de avaliação de postura: o 3DSSPP (Three Dimensional Static Strength Prediction Programme) e o RULA (Rapid Upper Limb Assessment), utilizando um sensor de profundidade para extração de informações precisas para definição de parâmetros de postura. A estimação e análise de parâmetros de postura baseados nos dois métodos de avaliação escolhidos apresentaram bons resultados, o método RULA apresentou uma acurácia de 71,67%.
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Narrativa tridimensional: uma investigação sobre a linguagem 3D estereoscópica / Three-dimensional narrative. An analysis of stereocopic 3D language

Luzzi, Grace Maria Martins da Silva 25 April 2014 (has links)
A partir da investigação de elementos que remontam o passado de técnicas de ilusão e imersão na arte da representação da imagem, bem como teorias que condicionam a existência de uma linguagem audiovisual própria, este trabalho tem o objetivo de analisar e identificar a existência de uma linguagem própria pertinente à estereoscopia. A pesquisa toma como ponto de análise estereoscópica o filme Coraline [2009] de Henry Selick, uma animação stop motion, concebida e lançada nos cinemas 3D estereoscópicos / Through an investigation of the history of techniques of illusion and immersion in popular art and entertainment, as well as theories that determine the existence of a distinct visual language, this work aims to analyse and identify the existence of a unique narrative language exclusive to 3-D stereoscopic film-making. The research takes as its point of stereoscopic analysis the stop-motion animation movie Coraline (2009, Henry Selick) designed and launched in cinemas using the stereoscopic technique.
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The bilingual mind...simultaneous and sequential processing and spelling ability in monolingual English and bilingual Afrikaans-English children

De Sousa, Diana Soares 14 February 2007 (has links)
Student Number : 0006815V - MA research report - School of Human and Community Development - Faculty of Humanities / In South Africa, the majority of children are bilingual and little research exists on the cognitive processes bilingual children use to spell. This has far-reaching and challenging implications for cognitive models of spelling. Specifically, bilingualism exhibits a pervasive influence on children’s literacy development (Bialystok, 2002). The majority of research on children’s spelling has been conducted internationally with monolingual English children. From international literature, cognitive processing (simultaneous processing and sequential processing) has been identified as an important area for consideration in the spelling acquisition process of English children (Kaufman & Kaufman, 1983b). Simultaneous processing is important for whole word spelling, whilst sequential processing is important for decoding letter sound correspondences. Cross-linguistic research demonstrates a bias towards one or the other spelling strategy may be tied to the depth of a language’s orthography, possibly due to the different demands the language orthography places on how children learn to spell (Frost et al., 1987; Wimmer & Hummer, 1990, 1994; Goswami et al., 1998). The present study examined the relationship between simultaneous and sequential processing and spelling in Grade 3 monolingual English-speaking children and bilingual Afrikaans-English speaking children at one point in time. Thirty bilingual Afrikaans-English children (Afrikaans first language, English second language) and were learning to spell in Afrikaans and in English simultaneously, and thirty monolingual (English first language) learning to spell in English. Simultaneous and sequential processing subtests of the Kaufman Assessment Battery (K-ABC) were administered to the monolingual and to the bilingual children. Monolingual Englishspeaking children received the English word and non-word spelling tests, while the bilingual Afrikaans-English children were asked to spell English and Afrikaans words and non-words (Klein, 1993). The results suggest that lexical (logographic or simultaneous) and non-lexical (alphabetic or sequential) routes are available in English and Afrikaans, but orthography did exert an influence on cognitive processing strategies. Sequential processing demonstrates a higher relationship than simultaneous processing with spelling in English and Afrikaans, although sequential processing contributes more to spelling in a shallow orthography, because the reliable relationship between spelling supports easier and faster computation than in an opaque orthography. Additionally, the results demonstrate that in the bilingual Afrikaans-English children spelling in a second language (L2) rely on spelling skills in a first language (L1), even when the same teaching strategies are used for spelling instruction. Orthography as a tool of academic literacy instruction, influences whether the transfer of spelling skills has a positive or negative influence on spelling in English as a second language in bilingual Afrikaans-English children with a transparent L1. A dual-route model that incorporates the influence of orthographic depth is supported (Seymour, Bunce & Evans, 1992). The present research study concludes that (1) simultaneous processing and sequential processing influence and predict the production of spelling in L1 and L2 in both English and Afrikaans alphabetic orthographies that differ in orthographic transparency, (2) orthographic demands of learning to spell in different orthographies varies and influences cognitive processing resources and decoding skills, which may provide an indication of a cumulative or challenging development of L2 spelling skills particularly when the L1 is transparent. The present research has implications for assessment, traditional spelling models and teaching bilingual children learning to spell in a second language, which is orthographically opaque relative to their transparent mother tongue.

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