309 research outputs found
Shipping Configuration Optimization with Topology-Based Guided Local Search for Irregular Shaped Shipments
Manufacturer that uses containers to ship products always works to optimize the space inside the containers. Container loading problems (CLP) are widely encountered in forms of raw material flow and handling, product shipments, warehouse management, facility floor planning, as well as strip-packing nesting problems.Investigations and research conducted two decades ago were logistic orientated, on the basis of the empirical approaches
Development of an augmented reality guided computer assisted orthopaedic surgery system
Previously held under moratorium from 1st December 2016 until 1st December 2021.This body of work documents the developed of a proof of concept augmented reality
guided computer assisted orthopaedic surgery system – ARgCAOS.
After initial investigation a visible-spectrum single camera tool-mounted tracking
system based upon fiducial planar markers was implemented. The use of
visible-spectrum cameras, as opposed to the infra-red cameras typically used by
surgical tracking systems, allowed the captured image to be streamed to a display in
an intelligible fashion. The tracking information defined the location of physical
objects relative to the camera. Therefore, this information allowed virtual models to
be overlaid onto the camera image. This produced a convincing augmented
experience, whereby the virtual objects appeared to be within the physical world,
moving with both the camera and markers as expected of physical objects.
Analysis of the first generation system identified both accuracy and graphical
inadequacies, prompting the development of a second generation system. This too
was based upon a tool-mounted fiducial marker system, and improved performance
to near-millimetre probing accuracy. A resection system was incorporated into the
system, and utilising the tracking information controlled resection was performed,
producing sub-millimetre accuracies.
Several complications resulted from the tool-mounted approach. Therefore, a third
generation system was developed. This final generation deployed a stereoscopic
visible-spectrum camera system affixed to a head-mounted display worn by the user.
The system allowed the augmentation of the natural view of the user, providing
convincing and immersive three dimensional augmented guidance, with probing and
resection accuracies of 0.55±0.04 and 0.34±0.04 mm, respectively.This body of work documents the developed of a proof of concept augmented reality
guided computer assisted orthopaedic surgery system – ARgCAOS.
After initial investigation a visible-spectrum single camera tool-mounted tracking
system based upon fiducial planar markers was implemented. The use of
visible-spectrum cameras, as opposed to the infra-red cameras typically used by
surgical tracking systems, allowed the captured image to be streamed to a display in
an intelligible fashion. The tracking information defined the location of physical
objects relative to the camera. Therefore, this information allowed virtual models to
be overlaid onto the camera image. This produced a convincing augmented
experience, whereby the virtual objects appeared to be within the physical world,
moving with both the camera and markers as expected of physical objects.
Analysis of the first generation system identified both accuracy and graphical
inadequacies, prompting the development of a second generation system. This too
was based upon a tool-mounted fiducial marker system, and improved performance
to near-millimetre probing accuracy. A resection system was incorporated into the
system, and utilising the tracking information controlled resection was performed,
producing sub-millimetre accuracies.
Several complications resulted from the tool-mounted approach. Therefore, a third
generation system was developed. This final generation deployed a stereoscopic
visible-spectrum camera system affixed to a head-mounted display worn by the user.
The system allowed the augmentation of the natural view of the user, providing
convincing and immersive three dimensional augmented guidance, with probing and
resection accuracies of 0.55±0.04 and 0.34±0.04 mm, respectively
Efficient Human Activity Recognition in Large Image and Video Databases
Vision-based human action recognition has attracted considerable interest in recent research for its applications to video surveillance, content-based search, healthcare, and interactive games. Most existing research deals with building informative feature descriptors, designing efficient and robust algorithms, proposing versatile and challenging datasets, and fusing multiple modalities. Often, these approaches build on certain conventions such as the use of motion cues to determine video descriptors, application of off-the-shelf classifiers, and single-factor classification of videos. In this thesis, we deal with important but overlooked issues such as efficiency, simplicity, and scalability of human activity recognition in different application scenarios: controlled video environment (e.g.~indoor surveillance), unconstrained videos (e.g.~YouTube), depth or skeletal data (e.g.~captured by Kinect), and person images (e.g.~Flicker). In particular, we are interested in answering questions like (a) is it possible to efficiently recognize human actions in controlled videos without temporal cues? (b) given that the large-scale unconstrained video data are often of high dimension low sample size (HDLSS) nature, how to efficiently recognize human actions in such data? (c) considering the rich 3D motion information available from depth or motion capture sensors, is it possible to recognize both the actions and the actors using only the motion dynamics of underlying activities? and (d) can motion information from monocular videos be used for automatically determining saliency regions for recognizing actions in still images
Advances in Data-Driven Analysis and Synthesis of 3D Indoor Scenes
This report surveys advances in deep learning-based modeling techniques that
address four different 3D indoor scene analysis tasks, as well as synthesis of
3D indoor scenes. We describe different kinds of representations for indoor
scenes, various indoor scene datasets available for research in the
aforementioned areas, and discuss notable works employing machine learning
models for such scene modeling tasks based on these representations.
Specifically, we focus on the analysis and synthesis of 3D indoor scenes. With
respect to analysis, we focus on four basic scene understanding tasks -- 3D
object detection, 3D scene segmentation, 3D scene reconstruction and 3D scene
similarity. And for synthesis, we mainly discuss neural scene synthesis works,
though also highlighting model-driven methods that allow for human-centric,
progressive scene synthesis. We identify the challenges involved in modeling
scenes for these tasks and the kind of machinery that needs to be developed to
adapt to the data representation, and the task setting in general. For each of
these tasks, we provide a comprehensive summary of the state-of-the-art works
across different axes such as the choice of data representation, backbone,
evaluation metric, input, output, etc., providing an organized review of the
literature. Towards the end, we discuss some interesting research directions
that have the potential to make a direct impact on the way users interact and
engage with these virtual scene models, making them an integral part of the
metaverse.Comment: Published in Computer Graphics Forum, Aug 202
Advancement in robot programming with specific reference to graphical methods
This research study is concerned with the derivation of advanced robot
programming methods. The methods include the use of proprietary
simulation modelling and design software tools for the off-line
programming of industrial robots. The study has involved the generation
of integration software to facilitate the co-operative operation of these
software tools.
The three major researcli'themes7of "ease of usage", calibration and the
integration of product design data have been followed to advance robot
programming. The "ease of usage" is concerned with enhancements in the
man-machine interface for robo t simulation systems in terms of computer
assisted solid modelling and computer assisted task generation.
Robot simulation models represent an idealised situation, and any off-line
robot programs generated from'them may contain'discrepancies which could
seriously effect thq programs' performance; Calibration techniques have
therefore been investigated as 'a method of overcoming discrepancies
between the simulation model and the real world.
At the present time, most computer aided design systems operate as
isolated islands of computer technology, whereas their product databases
should be used to support decision making processes and ultimately
facilitate the generation of machine programs. Thus the integration of
product design data has been studied as an important step towards truly
computer integrated manufacturing.
The functionality of the three areas of study have been generalised and
form the basis for recommended enhancements to future robot programming
systems
Intraoperative Planning and Execution of Arbitrary Orthopedic Interventions Using Handheld Robotics and Augmented Reality
The focus of this work is a generic, intraoperative and image-free planning and execution application for arbitrary orthopedic interventions using a novel handheld robotic device and optical see-through glasses (AR). This medical CAD application enables the surgeon to intraoperatively plan the intervention directly on the patient’s bone. The glasses and all the other instruments are accurately calibrated using new techniques. Several interventions show the effectiveness of this approach
Robust and affordable localization and mapping for 3D reconstruction. Application to architecture and construction
La localización y mapeado simultáneo a partir de una sola cámara en movimiento se conoce como Monocular
SLAM. En esta tesis se aborda este problema con cámaras de bajo coste cuyo principal reto consiste en ser
robustos al ruido, blurring y otros artefactos que afectan a la imagen. La aproximación al problema es discreta,
utilizando solo puntos de la imagen significativos para localizar la cámara y mapear el entorno. La principal
contribución es una simplificación del grafo de poses que permite mejorar la precisión en las escenas más
habituales, evaluada de forma exhaustiva en 4 datasets. Los resultados del mapeado permiten obtener una
reconstrucción 3D de la escena que puede ser utilizada en arquitectura y construcción para Modelar la Información
del Edificio (BIM). En la segunda parte de la tesis proponemos incorporar dicha información en un sistema de
visualización avanzada usando WebGL que ayude a simplificar la implantación de la metodología BIM.Departamento de Informática (Arquitectura y Tecnología de Computadores, Ciencias de la Computación e Inteligencia Artificial, Lenguajes y Sistemas Informáticos)Doctorado en Informátic
The benefits of an additional practice in descriptive geomerty course: non obligatory workshop at the Faculty of Civil Engineering in Belgrade
At the Faculty of Civil Engineering in Belgrade, in the Descriptive geometry (DG) course,
non-obligatory workshops named “facultative task” are held for the three generations of freshman
students with the aim to give students the opportunity to get higher final grade on the exam. The
content of this workshop was a creative task, performed by a group of three students, offering free
choice of a topic, i.e. the geometric structure associated with some real or imagery
architectural/art-work object.
After the workshops a questionnaire (composed by the professors at the course) is given to the
students, in order to get their response on teaching/learning materials for the DG course and the
workshop. During the workshop students performed one of the common tests for testing spatial
abilities, named “paper folding".
Based on the results of the questionnairethe investigation of the linkages between:students’
final achievements and spatial abilities, as well as students’ expectations of their performance on
the exam, and how the students’ capacity to correctly estimate their grades were associated with
expected and final grades, is provided. The goal was to give an evidence that a creative work,
performed by a small group of students and self-assessment of their performances are a good way
of helping students to maintain motivation and to accomplish their achievement.
The final conclusion is addressed to the benefits of additional workshops employment in the
course, which confirmhigherfinal scores-grades, achievement of creative results (facultative tasks)
and confirmation of DG knowledge adaption
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