Contribuciones a la estimación de la pose de la cámara en aplicaciones industriales de realidad aumentada

Augmented Reality (AR) aims to complement the visual perception of the user environment superimposing virtual elements. The main challenge of this technology is to combine the virtual and real world in a precise and natural way. To carry out this goal, estimating the user position and orientation in both worlds at all times is a crucial task. Currently, there are numerous techniques and algorithms developed for camera pose estimation. However, the use of synthetic square markers has become the fastest, most robust and simplest solution in these cases. In this scope, a big number of marker detection systems have been developed. Nevertheless, most of them presents some limitations, (1) their unattractive and non-customizable visual appearance prevent their use in industrial products and (2) the detection rate is drastically reduced in presence of noise, blurring and occlusions. In this doctoral dissertation the above-mentioned limitations are addressed. In first place, a comparison has been made between the different marker detection systems currently available in the literature, emphasizing the limitations of each. Secondly, a novel approach to design, detect and track customized markers capable of easily adapting to the visual limitations of commercial products has been developed. In third place, a method that combines the detection of black and white square markers with keypoints and contours has been implemented to estimate the camera position in AR applications. The main motivation of this work is to offer a versatile alternative (based on contours and keypoints) in cases where, due to noise, blurring or occlusions, it is not possible to identify markers in the images. Finally, a method for reconstruction and semantic segmentation of 3D objects using square markers in photogrammetry processes has been presented.La Realidad Aumentada (AR) tiene como objetivo complementar la percepción visual del entorno circunstante al usuario mediante la superposición de elementos virtuales. El principal reto de dicha tecnología se basa en fusionar, de forma precisa y natural, el mundo virtual con el mundo real. Para llevar a cabo dicha tarea, es de vital importancia conocer en todo momento tanto la posición, así como la orientación del usuario en ambos mundos. Actualmente, existen un gran número de técnicas de estimación de pose. No obstante, el uso de marcadores sintéticos cuadrados se ha convertido en la solución más rápida, robusta y sencilla utilizada en estos casos. En este ámbito de estudio, existen un gran número de sistemas de detección de marcadores ampliamente extendidos. Sin embargo, su uso presenta ciertas limitaciones, (1) su aspecto visual, poco atractivo y nada customizable impiden su uso en ciertos productos industriales en donde la personalización comercial es un aspecto crucial y (2) la tasa de detección se ve duramente decrementada ante la presencia de ruido, desenfoques y oclusiones Esta tesis doctoral se ocupa de las limitaciones anteriormente mencionadas. En primer lugar, se ha realizado una comparativa entre los diferentes sistemas de detección de marcadores actualmente en uso, enfatizando las limitaciones de cada uno. En segundo lugar, se ha desarrollado un novedoso enfoque para diseñar, detectar y trackear marcadores personalizados capaces de adaptarse fácilmente a las limitaciones visuales de productos comerciales. En tercer lugar, se ha implementado un método que combina la detección de marcadores cuadrados blancos y negros con keypoints y contornos, para estimar de la posición de la cámara en aplicaciones AR. La principal motivación de este trabajo se basa en ofrecer una alternativa versátil (basada en contornos y keypoints) en aquellos casos donde, por motivos de ruido, desenfoques u oclusiones no sea posible identificar marcadores en las imágenes. Por último, se ha desarrollado un método de reconstrucción y segmentación semántica de objetos 3D utilizando marcadores cuadrados en procesos de fotogrametría

The Prediction and Mitigation of Road Traffic Congestion Based on Machine Learning

Traffic congestion is a major issue for all developed countries. In most urbanised areas space is a scarce commodity. Therefore, better management of the existing roads to increase or maintain their capacity level is the only viable solution. Research in the last two decades has focused on Intelligent Transport Systems (ITS) development. Predicting traffic flow in real time can be used to prevent or alleviate future congestion. The key to an effective proactive method is a model that produces timely and accurate predictions. However, despite extensive research in this area, a reliable method is still not available. Therefore, in this thesis, we developed an accurate online road traffic flow prediction model, with a particular focus on heterogeneous traffic flow, for urbanised road networks. The contributions of this work include: Firstly, we conducted a comprehensive literature review and benchmark evaluation of existing machine learning models using a real dataset obtained from Transport for Greater Manchester. We investigated their prediction accuracy, time horizon sensitivity, and input feature settings (different classes of vehicles), to understand how they can affect their prediction accuracy. The experimental results show that the artificial neural network was the most successful at predicting short-term road traffic flow. Additionally, it was found that different classes of vehicles can improve prediction accuracy. Secondly, we examined three recurrent neural networks (a standard recurrent, a long short-term memory, and a gated recurrent unit). We compared their accuracy, training time, and sensitivity to architectural change using a new performance metric we developed to standardise the accuracy and training time into a comparable score (STATS). The experimental results show that the gated recurrent unit performed the best and was most stable against architectural changes. Conversely, the long short-term memory was the least stable model. Thirdly, we investigated different magnitudes of temporal patterns in the dataset, both short and long-term, to understand how contextual temporal data can improve prediction accuracy. We also developed a novel online dynamic temporal context neural network framework. The framework dynamically determines how useful a temporal data segment is for prediction, and weights it accordingly for use in the regression model. The experimental results show that short and long-term temporal patterns improved prediction accuracy. In addition, the proposed online dynamical framework improved prediction results by 10.8% when compared with a deep gated recurrent model. Finally, we investigated the dynamic nature of road traffic flow’s input features by examining their spatial and temporal relationships. We also developed a novel dynamic exogenous feature filter mechanism. The feature filter mechanism uses ’local windows’ to filter input features in real-time to improve prediction accuracy. The results show that a global correlation was insufficient to describe the complex and dynamic relationships between the input features. The local correlations (local windows) were able to identify additional geospatial and temporal relationships. Furthermore, the proposed feature filter mechanism was compared to a state-of-the-art method, a dynamic rolling window feature filter model. The experimental results showed that the proposed model was the most accurate, with an RMSE of 10.06%, closely followed by the dynamic rolling window feature filter model, with an RMSE of 10.98%. However, the proposed model was computationally much lighter than the rolling windows model

The Visegrad Group countries and the Western Balkans states : pre-accesion experiences and proposals for Macedonia

Rozszerzenie Unii Europejskiej jest uwarunkowane różnymi czynnikami. Nie bez znaczenia jest wpływ sytuacji międzynarodowej, politycznej i gospodarczej. Akcesji państw Grupy Wyszehradzkiej do Unii sprzyjała sytuacja międzynarodowa. Szybka decyzja o "otwarciu bram" UE umożliwiła sprawne przeprowadzenie procesu negocjacyjnego w wyniku którego nowe państwa dołączyła do Unii w 2004 i 2007 roku. Odbywało się to w okresie rozwoju gospodarczego i generalnej prosperity Europy. Okresu tego nie wykorzystały państwa bałkańskie, dotknięte konfliktami o charakterze etnicznym, nierzadko także ambicjonalnym. Jedynie Chorwacja w 2013 r. zdołała, jak dotąd, dołączyć do organizacji. Pozostałe państwa zostały w tyle. Ich opóźnienie jest spowodowane nie zawsze niespełnianiem kryteriów członkostwa ale wynika też z problemów o charakterze politycznym ze swoimi sąsiadami. Spór grecko-macedoński o nazwę państwa dowodzi tego najdobitniej. Obecnie sytuacja nie sprzyja rozszerzeniu Unii. Zarówno pod względem gospodarczym (przedłużający się kryzys w strefie euro) jak i politycznym (przejawy postaw eurosceptycznych w kilku państwach unijnych) sytuacja jest nieporównywalna z tą sprzed kilkunastu lat. Społeczeństwa krajów unijnych wydają się też zmęczone rozszerzeniami pierwszego dziesięciolecia obecnego wieku. W przypadku Macedonii, biorąc pod uwagę jej położenie geopolityczne, trudno wskazać jakąkolwiek alternatywę dla przystąpienia do tejże organizacji. Brak jednak odpowiedzi na pytanie kiedy do tego dojdzie. Tak jak w przypadku Europy Środkowej, co jej wyraźnie widoczne 10 lat po rozszerzeniu, tak w przypadku Bałkanów rozszerzenie powinno przynieść sukces.The enlargement of the European Union is subject to various factors that affect this process. Not without significance is the impact of the international, political and economic situation. The international situation favoured the accession of the Visegrad Group. A prompt decision to „open the gates” of the EU enabled a smooth introduction of the negotiation process in result of which new countries joined the EU in 2004 and 2007. It was taking place in the period of economic growth and general prosperity of Europe. This period has not been made use of by the Balkan countries affected by ethnic conflicts often dictated by ambition. Only Croatia in 2013 succeeded, so far, in joining the organization. Other countries have been left behind. The delay is due not always to non-compliance with the criteria for membership but also results from political problems with the neighbours. Greek- Macedonian dispute about the name of the country shows that problem most emphatically. Today, the situation does not favour the enlargement of the UE. Both economically (the prolonged crisis in the euro zone) and politically (eurosceptic attitudes in several EU countries) the situation is incomparable with that of several years ago. Moreover, the societies of the EU countries seem to be tired with the enlargements of the first decade of this century

How the Qaddafi regime was driven into nuclear disarmament

How can we drive atomic renegades – states that run illegal nuclear weapons programs – into disarmament with the help of negotiations? This question, which puts the design of negotiation strategies at the focus of attention, has puzzled foreign policy makers for decades. It has, thus far, lost nothing of its relevance. But despite its importance, bargaining dynamics with atomic renegade states – so-called Nuclear Reversal Negotiations (NRN) – were largely omitted in International Relations (IR) literature. A systematic and theoretically grounded analysis on NRN is still missing.[...

Building green : investment opportunities in sustainable construction materials

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Civil and Environmental Engineering; and, Thesis (M.B.A.)--Massachusetts Institute of Technology, Sloan School of Management, 1998.Includes bibliographical references (leaves 111-114).by Maia A. Hansen.M.B.A.S.M

MS FT-2-2 7 Orthogonal polynomials and quadrature: Theory, computation, and applications

Quadrature rules find many applications in science and engineering. Their analysis is a classical area of applied mathematics and continues to attract considerable attention. This seminar brings together speakers with expertise in a large variety of quadrature rules. It is the aim of the seminar to provide an overview of recent developments in the analysis of quadrature rules. The computation of error estimates and novel applications also are described

Generalized averaged Gaussian quadrature and applications

A simple numerical method for constructing the optimal generalized averaged Gaussian quadrature formulas will be presented. These formulas exist in many cases in which real positive GaussKronrod formulas do not exist, and can be used as an adequate alternative in order to estimate the error of a Gaussian rule. We also investigate the conditions under which the optimal averaged Gaussian quadrature formulas and their truncated variants are internal

Understanding and applying the concept of sustainable development to transportation planning and decision-making in the U.S.

Thesis (Ph. D.)--Massachusetts Institute of Technology, Engineering Systems Division, Technology, Management, and Policy Program, 2006.Includes bibliographical references.This research demonstrates that sustainable development is a multidimensional concept that should be approached in a transdisciplinary manner. Its objective has been to synthesize and integrate disparate and currently unconnected lines of thought that have not yet been applied in a systematic way to promote sustainable development and sustainable transportation. The primary contribution of this research is the theoretical development of a decision-support framework that identifies the tools and approaches that decision-makers could/should use to create policies and programs that transition society towards sustainability. These tools and approaches are either articulated or developed by the author throughout the dissertation. Specific ideas explored include a Rawlsian/utilitarian decision-making philosophy; a hybrid trade-off/positional analysis framework that is presented as an alternative to benefit-cost analysis; ecological vs. environmental economics; participatory backcasting; and ways to stimulate disrupting and/or radical technological innovation. To identify gaps that exist between theory and practice, the approach embodied in the proposed sustainable transportation decision-support framework is compared with current metropolitan transportation planning and decision-making processes in the U.S. The framework is then used to consider how the U.S. federal government might move the nation's transportation system towards sustainability.by Ralph P. Hall.Ph.D

Science and Beyond: Cosmology, Consciousness and Technology in the Indic Traditions (NIAS Special Publications No.SP2-2004)

The announcement of the Symposium whose proceedings you now hold in your hands said: Modern science, mathematics and technology have during the last three centuries, transformed our understanding of life, nature and the universe, and provided mankind with unprecedented power to control its environment - for good or ill. This extraordinary development, built on older scientific and technological traditions in both East and West, has been so spectacularly successful that it has raised a fundamental question: Is there anything beyond Science?. For, even as scientific knowledge is increasingly translated into power over the physical world, the very practitioners of the science have often been drawn on a quest beyond it - and that quest has often led the seeker to philosophy, religion, spirituality, humanism and other similar paths to an integrative view of life and the universe. If there is something beyond science, what is it - for each of us, and for mankind as a whole