14,830 research outputs found
Automated Semantic Content Extraction from Images
In this study, an automatic semantic segmentation and object recognition methodology is implemented which bridges the semantic gap between low level features of image content and high level conceptual meaning. Semantically understanding an image is essential in modeling autonomous robots, targeting customers in marketing or reverse engineering of building information modeling in the construction industry. To achieve an understanding of a room from a single image we proposed a new object recognition framework which has four major components: segmentation, scene detection, conceptual cueing and object recognition. The new segmentation methodology developed in this research extends Felzenswalb\u27s cost function to include new surface index and depth features as well as color, texture and normal features to overcome issues of occlusion and shadowing commonly found in images. Adding depth allows capturing new features for object recognition stage to achieve high accuracy compared to the current state of the art. The goal was to develop an approach to capture and label perceptually important regions which often reflect global representation and understanding of the image. We developed a system by using contextual and common sense information for improving object recognition and scene detection, and fused the information from scene and objects to reduce the level of uncertainty. This study in addition to improving segmentation, scene detection and object recognition, can be used in applications that require physical parsing of the image into objects, surfaces and their relations. The applications include robotics, social networking, intelligence and anti-terrorism efforts, criminal investigations and security, marketing, and building information modeling in the construction industry. In this dissertation a structural framework (ontology) is developed that generates text descriptions based on understanding of objects, structures and the attributes of an image
Mutual Composite Fermion and composite Boson approaches to balanced and imbalanced bilayer quantum Hall system: an electronic analogy of the Helium 4 system
We use both Mutual Composite Fermion (MCF) and Composite Boson (CB) approach
to study balanced and im-balanced Bi-Layer Quantum Hall systems (BLQH) and make
critical comparisons between the two approaches. We find the CB approach is
superior to the MCF approach in studying ground states with different kinds of
broken symmetries. In the phase representation of the CB theory, we first study
the Excitonic superfluid state (ESF). The theory puts spin and charge degree
freedoms in the same footing, explicitly bring out the spin-charge connection
and classify all the possible excitations in a systematic way. Then in the dual
density representation of the CB theory, we study possible intermediate phases
as the distance increases. We propose there are two critical distances and three phases as the distance increases. When ,
the system is in the ESF state which breaks the internal symmetry,
when , the system is in an Pseudo-spin density wave
(PSDW) state which breaks the translational symmetry, there is a first order
transition at driven by the collapsing of magneto-roton minimum at a
finite wavevector in the pseudo-spin channel. When , the
system becomes two weakly coupled Composite Fermion Fermi Liquid
(FL) state. There is also a first order transition at . We
construct a quantum Ginzburg Landau action to describe the transition from ESF
to PSDW which break the two completely different symmetries. By using the QGL
action, we explicitly show that the PSDW takes a square lattice and analyze in
detail the properties of the PSDW at zero and finite temperature.Comment: 29 PRB pages, 18 figures, 2 tables, REVTEX
Quantum QED Flux Tubes in 2+1 and 3+1 Dimensions
We compute energies and energy densities of static electromagnetic flux tubes
in three and four spacetime dimensions. Our calculation uses scattering data
from the potential induced by the flux tube and imposes standard perturbative
renormalization conditions. The calculation is exact to one-loop order, with no
additional approximation adopted. We embed the flux tube in a configuration
with zero total flux so that we can fully apply standard results from
scattering theory. We find that upon choosing the same on-shell renormalization
conditions, the functional dependence of the energy and energy density on the
parameters of the flux tube is very similar for three and four spacetime
dimensions. We compare our exact results to those obtained from the derivative
and perturbation expansion approximations, and find good agreement for
appropriate parameters of the flux tube. This remedies some puzzles in the
prior literature.Comment: 49 pages, 13 figures, minor changes in wording, accepted for
publication in Nucl. Phys.
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An Examination of Three-dimensional Geometry in High School Curricula in the US and China
Geometry is an essential branch in mathematics that helps students learn to grasp their environment and leverage that grasp into abstract understanding and reasoning. There has been an observable decrease in geometrical content in secondary education curricula, and particularly a “puzzling scarcity” in three-dimensional geometry, which has led to a decline in students’ geometrical abilities, spatial thinking and deductive reasoning abilities. This study addresses this issue by scrutinizing the enacted curriculum standards and the most influential textbooks related to three-dimensional geometry in two prominent countries, the US and China, both of which embrace the interplay of both conventional and innovative practices. This qualitative study used both content analysis and cross-cultural comparison methods to inquire about and to understand the current situation of three-dimensional geometry in high school. I focused on probing the communication types, objects, concepts, and spatial thinking abilities related to three-dimensional geometry in the standards and texts. To understand spatial abilities, I synthesized a spatial thinking abilities framework with six attributes and used this framework to exam the affordance of these abilities in the texts and requirements in the standards.
The result and analysis reveal the details of each text and standards individually and offer an examination of the alignment between the standards and texts. The comparison of the two countries’ different approaches also sharpens the understanding of the issue. I also worked to unveil students’ multiple ways of making sense of geometry concepts by two geometry learning models, Piaget’s model and van Hiele’s model, as well as spatial thinking abilities
Framework development for providing accessibility to qualitative spatial calculi
Dissertation submitted in partial fulfillment of the requirements for the Degree of Master of Science in Geospatial Technologies.Qualitative spatial reasoning deals with knowledge about an infinite spatial domain using a finite set of qualitative relations without using numerical computation. Qualitative knowledge is relative knowledge where we obtain the knowledge on the basis of comparison of features with in the object domain rather then using some external scales. Reasoning is an intellectual facility by which, conclusions are drawn from premises and is present in our everyday interaction with the geographical world. The kind of reasoning that human being relies on is based on commonsense knowledge in everyday situations. During the last decades a multitude of formal calculi over spatial relations have been proposed by focusing on different aspects of space like topology, orientation and distance.
Qualitative spatial reasoning engines like SparQ and GQR represents space and reasoning about the space based on qualitative spatial relations and bring qualitative reasoning closer to the geographic applications. Their relations and certain operations defined in qualitative calculi use to infer new knowledge on different aspects of space.
Today GIS does not support common-sense reasoning due to limitation for how to formalize spatial inferences. It is important to focus on common sense geographic reasoning, reasoning as it is performed by human. Human perceive and represents geographic information qualitatively, the integration of reasoner with spatial application enables GIS users to represent and extract geographic information qualitatively using human understandable query language.
In this thesis, I designed and developed common API framework using platform independent software like XML and JAVA that used to integrate qualitative spatial reasoning engines (SparQ) with GIS application. SparQ is set of modules that structured to provides different reasoning services. SparQ supports command line instructions and it has a specific syntax as set of commands. The developed API provides interface between GIS application and reasoning engine. It establishes connection with reasoner over TCP/IP, takes XML format queries as input from GIS application and converts into SparQ module specific syntax. Similarly it extracts given result, converts it into defined XML format and passes it to GIS application over the same TCP/IP connection.
The most challenging part of thesis was SparQ syntax analysis for inputs and their outputs. Each module in Sparq takes module specific query syntax and generates results in multiple syntaxes like; error, simple result and result with comments. Reasoner supports both binary and ternary calculi. The input query syntax for binary-calculi is different for ternary-calculi in the terms of constraint-networks. Based on analysis I, identified commonalities between input query syntaxes for both binary and ternary calculi and designed XML structures for them. Similarly I generalized SparQ results into five major categories and designed XML structures. For ternary-calculi, I considered constraint-reasoning module and their specific operations and designed XML structure for both of their inputs and outputs
Tomograms of Spinning Black Holes
The classical internal structure of spinning black holes is vastly different
from that of static black holes. We consider spinning BTZ black holes, and
probe their interior from the gauge theory. Utilizing the simplicity of the
geometry and reverse engineering from the geodesics, we propose a thermal
correlator construction which can be interpreted as arising from two entangled
CFTs. By analytic continuation of these correlators, we can probe the Cauchy
horizon. Correlators that capture the Cauchy horizon in our work have a
structure closely related to those that capture the singularity in a
non-rotating BTZ. As expected, the regions beyond the Cauchy horizon are not
probed in this picture, protecting cosmic censorship.Comment: 41 pages, 7 figure
(2+1)-Dimensional Quantum Gravity as the Continuum Limit of Causal Dynamical Triangulations
We perform a non-perturbative sum over geometries in a (2+1)-dimensional
quantum gravity model given in terms of Causal Dynamical Triangulations.
Inspired by the concept of triangulations of product type introduced
previously, we impose an additional notion of order on the discrete, causal
geometries. This simplifies the combinatorial problem of counting geometries
just enough to enable us to calculate the transfer matrix between boundary
states labelled by the area of the spatial universe, as well as the
corresponding quantum Hamiltonian of the continuum theory. This is the first
time in dimension larger than two that a Hamiltonian has been derived from such
a model by mainly analytical means, and opens the way for a better
understanding of scaling and renormalization issues.Comment: 38 pages, 13 figure
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