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Spatial Reasoning for 3D Shape Understanding
No full textIn this thesis, we studied deep learning based approaches to estimate different 3D properties
of an object. As a result, we proposed methods that make use of either a single image or a
single point cloud to reason about an object’s geometry.
We started from a very recent problem, 3D shape reconstruction from a single-view RGB
image. We observed that some of the existing methods work for synthetic images only and
they fail when they are executed for real images (with background). While other approaches
can extract 3D shapes from real images, however, their estimations are not smooth, sharp
and complete. By considering the background as a major limitation of the existing methods,
we proposed two solutions. The first solution (baseline solution) enables the execution of the
synthetic methods for the real dataset. The solution is based on two modules; a segmenter and
a reconstruction. The segmenter module takes a real image, segments the object of interest,
and pastes the segmented object in the center of the white image. The processed image
(which seems similar to the synthetic image) is passed to the reconstructor that estimates the
object’s 3D shape. We found that the solution has increased the performance of the existing
synthetic approaches for real images.
Since the baseline solution is based on a segmenter module, it can not be considered an
optimal solution. It is due to the fact that the reconstruction accuracy is totally dependent on
the output of the segmenter – if the object is not segmented accurately, the reconstructor will
not reconstruct the accurate 3D shape. To solve this problem, we present a second solution
that removes the requirement of the segmenter module. Instead of segmenting the object
from the image, it separates the features of the object of interest by filtering the features of
the background. The object’s features are later used to reconstruct the object’s 3D shape. The
reconstructed shapes are compared with those of the State-Of-The-Art (SOTA) approaches.
It is found that the proposed approach outperforms them by estimating comparatively more
accurate, smooth, sharp and complete 3D shapes.
The proposed two object reconstruction solutions produce 3D shapes always in the canonical
pose. However, for many applications such as object grasping manipulators, pose information
is required. Considering that the object pose can be estimated using the keypoints, we
conducted research to estimate such keypoints from images in a supervised way and from
point clouds in a self-supervised setting.
Our first keypoints estimation approach takes a single-view RGB image as input, extracts
pixel-wise features and uses them to estimate keypoints in 3D space. The designed network
is trained in a fully supervised way using the ground truth human-annotated keypoints.
Moreover, the approach also estimates a confidence score for every keypoint representing
its validity. Based on the confidence scores, the network separates valid keypoints from
the estimated N keypoints based on the object’s geometry. The valid keypoints are used
to estimate the relative pose between different views of an object. It is found that the
angular distance error of the proposed approach is comparatively lower than that of the SOTA
approaches.
The first presented keypoints estimation approach uses only RGB images to estimate 3D
keypoints without using any 3D/depth information as input. Thus in some cases, the keypoints
are not accurately predicted. Therefore as a second approach, we present a teacher-student
architecture to estimate the keypoints from a single-view RGB image. The network is trained
in two steps: first, the teacher module is trained to extract 3D features from point clouds, and
second, the teacher module teaches the student module to produce 3D features from RGB
images that are similar to those achieved from point clouds. During inference, the network
only uses only the student module and extracts 2D and 3D features directly from an RGB
image to estimate keypoints in 3D space. The keypoints are compared with those of the
existing approaches, including the previously proposed keypoints estimation approach. The
results show that the keypoints estimated by the proposed approach are more accurate for
computing relative pose between different views of an object.
It can be observed that the above two keypoints estimation solutions are fully supervised
and require a huge dataset with ground truth human-annotated keypoints. This limits the
reusability of the approaches since very limited datasets contain accurate keypoint annotations.
Therefore, as a third approach, we present an approach that estimates keypoints in a self-
supervised without using any ground truth information. Although estimating keypoints
similar to human-annotated ones without supervision is a challenging task, the proposed
approach estimates the keypoints that best characterize the object’s shape. We achieved this
by utilizing a combination of loss components that forces the estimated keypoints towards
the object’s surface and prevents them from moving away from the object. The approach is
tested for rotated, noisy and decimated point clouds, and it is found that it outperforms the
SOTA un-/self-supervised approaches.
Apart from the contributions and comparisons with the competitor approaches, the thesis
also presents limitations, possible extensions and real-world applications of the proposed
approaches
Supplemental Material - Serotonin syndrome and cannabis: A case report
No full textSupplemental Material for Serotonin syndrome and cannabis: A case report by Zohaib Nadeem, Chaston Wu, Sophie Burke and Stephen Parker in Australasian Psychiatry</p
IMPACT OF INTEREST RATE, EXCHANGE RATE AND INFLATION ON STOCK RETURNS OF KSE 100 INDEX 1. BACKGROUND OF THE STUDY
No full textABSTRACT This research covers the impact of interest rate, exchange rate and inflation on stock returns of KSE 100 index. All the three macro variables which is taken under consideration are considered very important for the economy of any country and any change among these variables effect the economy in various ways and the regulatory authority take steps in order to make changes in their policies which can affect the economy in a positive way. Zohaib Khan, et.,al., Int. J. Eco. Res., 2012v3i5, 142-155 ISSN: 2229 IJER | Sep -Oct 2012 Available [email protected] 143 Objective of the Study The objective of the study is to investigate impact of interest rate, exchange rate and inflation on stock returns of KSE 100. Hypothesis A) Interest rate is negatively related to stock returns. B) Inflation is negatively related to stock returns. C) Exchange rate is negatively related to stock returns. Methodology In this study we are investigating th
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Electrochemical and photocatalytic oxidation of organic pollutants from waste water using efficient nano-catalytic coatings prepared by electrodeposition
No full textWastewater from the textile industry is considered to be one of the most pollutant effluents due to its toxic organic colourants content being strongly resistant to oxidation. When these substances are directly discharged into rivers and sea they persist for long periods causing environmental and aesthetic problems together with high health risks to living organisms. The main goal of this research is to study the oxidation of different textile dyes and organic pollutants, in particular reactive black-5 (RB-5) and methylene blue (MB) dyes using different nano catalytic coatings. A 3D flexible titanium felt electrode was anodized for growing TiO2 nanotubes and further decorated with PbO2 subsequently employed for anodic electrochemical and photochemical treatment of wastewater containing RB-5 dye. Similarly, reticulated vitreous carbon (RVC)surfaces were decorated with a layer of PbO2 and titanate nanosheets by anodic electrophoretic deposition, with subsequent structural and morphological characterization using FESEM and Raman spectroscopy. The TiNS/PbO2/RVC electrode has titanium anatase phase which was obtained by annealing at 450°C for 60 min in air. The structure revealed a well-specified, microporous structure with hydrophilic properties along the length and thickness of the RVC struts. Electrochemical and photocatalytic behaviour of the composite assisted the decolourisation of organic RB-5 dye in aqueous solution; on one hand • OH radicals were electrochemically produced via TiNS/PbO2/RVC anode composite coating and the photocatalytic decolourisation use the synergetic photocatalytic activity associated with the holes and free electron acceptors generated during UV irradiation experiments. Another objective of this thesis is the synthesis of efficient nanotubular titanates (TiNTs) coatings over the surface of the RVC substrate to make the organic oxidation more efficient. Titanate nanotubes (TiNTs) were deposited over the surface of a 100 pores per inch (ppi) RVC by anodic electrophoresis. The photocatalytic characteristics of the coating were enhanced by annealing at 450 °C for 60 min in air. A preliminary evaluation of novel TiNT/RVC coatings demonstrated to be useful for the photocatalytic colour removal of MB dye. In addition, a zinc metal plate was electrochemically anodised to produce ZnO nanowires. The selected operational conditions together a subsequent dip-coating process of the anodised ZnO surface in a TiO2 containing solution, produced a core-shell coating. A further electrochemical deposition of PbO2 over the core-shell produced a hybrid core (ZnO-TiO2)-shell (PbO2) coatings. The electrochemical and photocatalytic behaviour of the coatings were analysed by employing them to remove RB-5 dye (1 × 10-5 mol dm-3 ). The nano-coatings are low cost option for the oxidation of textile dyes and improved removal of RB-5 and MB dyes at a removal efficiency of ≈99 %
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Circuit synthesizable guaranteed passive modeling for multiport structures
No full textIn this paper we present a highly efficient algorithm to automatically generate circuit synthesizable dynamical models for passive multiport structures. The algorithm is based on a natural convex relaxation of the original nonconvex problem of modeling multiport devices from frequency response data, subject to global passivity constraints. The algorithm identifies a collection of first and second order passive networks interconnected in either series or parallel fashion. Passive models for several multiport structures, including Wilkinson type combiners, power and ground distribution grids and coupled on-chip inductors are provided to corroborate the theoretical development and show efficacy of the implemented algorithm. To demonstrate the practical usage of our algorithm, the identified models are also interfaced with commercial simulators and used to perform time domain simulations while being connected to highly nonlinear power amplifiers.United States. Defense Advanced Research Projects AgencySemiconductor Research Corporation. Center for Circuits and Systems SolutionsFocus Center Research Program. Focus Center for Circuit & System Solutions. Semiconductor Research Corporation. Interconnect Focus Cente
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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