62 research outputs found
Room geometry inference using sources and receivers on a uniform linear array
State-of-the-art room geometry inference algorithms estimate the shape of a room by analyzing peaks in room impulse responses. These algorithms typically require the position of the source wrt the receiver array; this position is often estimated with sound source localization, which is susceptible to high errors under common sampling frequencies. This paper proposes a new approach, namely using an array with a known geometry and consisting of both sources and receivers. When these transducers constitute a uniform linear array, new challenges and opportunities arise for performing room geometry inference. We propose solutions designed to address these challenges, but also designed to leverage the opportunities for better results
Rigorous data-driven computation of spectral properties of Koopman operators for dynamical systems
Koopman operators are infinite-dimensional operators that globally linearize
nonlinear dynamical systems, making their spectral information useful for
understanding dynamics. However, Koopman operators can have continuous spectra
and infinite-dimensional invariant subspaces, making computing their spectral
information a considerable challenge. This paper describes data-driven
algorithms with rigorous convergence guarantees for computing spectral
information of Koopman operators from trajectory data. We introduce residual
dynamic mode decomposition (ResDMD), which provides the first scheme for
computing the spectra and pseudospectra of general Koopman operators from
snapshot data without spectral pollution. Using the resolvent operator and
ResDMD, we also compute smoothed approximations of spectral measures associated
with measure-preserving dynamical systems. We prove explicit convergence
theorems for our algorithms, which can achieve high-order convergence even for
chaotic systems, when computing the density of the continuous spectrum and the
discrete spectrum. We demonstrate our algorithms on the tent map, Gauss
iterated map, nonlinear pendulum, double pendulum, Lorenz system, and an
-dimensional extended Lorenz system. Finally, we provide kernelized
variants of our algorithms for dynamical systems with a high-dimensional
state-space. This allows us to compute the spectral measure associated with the
dynamics of a protein molecule that has a 20,046-dimensional state-space, and
compute nonlinear Koopman modes with error bounds for turbulent flow past
aerofoils with Reynolds number that has a 295,122-dimensional
state-space
Computer-aided detection and diagnosis of breast cancer in 2D and 3D medical imaging through multifractal analysis
This Thesis describes the research work performed in the scope of a doctoral research program
and presents its conclusions and contributions. The research activities were carried on in the
industry with Siemens S.A. Healthcare Sector, in integration with a research team.
Siemens S.A. Healthcare Sector is one of the world biggest suppliers of products, services and
complete solutions in the medical sector. The company offers a wide selection of diagnostic
and therapeutic equipment and information systems. Siemens products for medical imaging and
in vivo diagnostics include: ultrasound, computer tomography, mammography, digital breast tomosynthesis,
magnetic resonance, equipment to angiography and coronary angiography, nuclear
imaging, and many others.
Siemens has a vast experience in Healthcare and at the beginning of this project it was strategically
interested in solutions to improve the detection of Breast Cancer, to increase its competitiveness
in the sector.
The company owns several patents related with self-similarity analysis, which formed the background
of this Thesis. Furthermore, Siemens intended to explore commercially the computer-
aided automatic detection and diagnosis eld for portfolio integration. Therefore, with the
high knowledge acquired by University of Beira Interior in this area together with this Thesis,
will allow Siemens to apply the most recent scienti c progress in the detection of the breast
cancer, and it is foreseeable that together we can develop a new technology with high potential.
The project resulted in the submission of two invention disclosures for evaluation in Siemens
A.G., two articles published in peer-reviewed journals indexed in ISI Science Citation Index,
two other articles submitted in peer-reviewed journals, and several international conference
papers. This work on computer-aided-diagnosis in breast led to innovative software and novel
processes of research and development, for which the project received the Siemens Innovation
Award in 2012.
It was very rewarding to carry on such technological and innovative project in a socially sensitive
area as Breast Cancer.No cancro da mama a deteção precoce e o diagnóstico correto são de extrema importância na
prescrição terapêutica e caz e e ciente, que potencie o aumento da taxa de sobrevivência à
doença. A teoria multifractal foi inicialmente introduzida no contexto da análise de sinal e a
sua utilidade foi demonstrada na descrição de comportamentos siológicos de bio-sinais e até
na deteção e predição de patologias. Nesta Tese, três métodos multifractais foram estendidos
para imagens bi-dimensionais (2D) e comparados na deteção de microcalci cações em mamogramas.
Um destes métodos foi também adaptado para a classi cação de massas da mama, em
cortes transversais 2D obtidos por ressonância magnética (RM) de mama, em grupos de massas
provavelmente benignas e com suspeição de malignidade. Um novo método de análise multifractal
usando a lacunaridade tri-dimensional (3D) foi proposto para classi cação de massas da
mama em imagens volumétricas 3D de RM de mama. A análise multifractal revelou diferenças
na complexidade subjacente às localizações das microcalci cações em relação aos tecidos normais,
permitindo uma boa exatidão da sua deteção em mamogramas. Adicionalmente, foram
extraídas por análise multifractal características dos tecidos que permitiram identi car os casos
tipicamente recomendados para biópsia em imagens 2D de RM de mama. A análise multifractal
3D foi e caz na classi cação de lesões mamárias benignas e malignas em imagens 3D de RM de
mama. Este método foi mais exato para esta classi cação do que o método 2D ou o método
padrão de análise de contraste cinético tumoral. Em conclusão, a análise multifractal fornece
informação útil para deteção auxiliada por computador em mamogra a e diagnóstico auxiliado
por computador em imagens 2D e 3D de RM de mama, tendo o potencial de complementar a
interpretação dos radiologistas
Sense and Respond
Over the past century, the manufacturing industry has undergone a number of paradigm shifts: from the Ford assembly line (1900s) and its focus on efficiency to the Toyota production system (1960s) and its focus on effectiveness and JIDOKA; from flexible manufacturing (1980s) to reconfigurable manufacturing (1990s) (both following the trend of mass customization); and from agent-based manufacturing (2000s) to cloud manufacturing (2010s) (both deploying the value stream complexity into the material and information flow, respectively). The next natural evolutionary step is to provide value by creating industrial cyber-physical assets with human-like intelligence. This will only be possible by further integrating strategic smart sensor technology into the manufacturing cyber-physical value creating processes in which industrial equipment is monitored and controlled for analyzing compression, temperature, moisture, vibrations, and performance. For instance, in the new wave of the ‘Industrial Internet of Things’ (IIoT), smart sensors will enable the development of new applications by interconnecting software, machines, and humans throughout the manufacturing process, thus enabling suppliers and manufacturers to rapidly respond to changing standards. This reprint of “Sense and Respond” aims to cover recent developments in the field of industrial applications, especially smart sensor technologies that increase the productivity, quality, reliability, and safety of industrial cyber-physical value-creating processes
Audio for Virtual, Augmented and Mixed Realities: Proceedings of ICSA 2019 ; 5th International Conference on Spatial Audio ; September 26th to 28th, 2019, Ilmenau, Germany
The ICSA 2019 focuses on a multidisciplinary bringing together of developers, scientists, users, and content creators of and for spatial audio systems and services. A special focus is on audio for so-called virtual, augmented, and mixed realities.
The fields of ICSA 2019 are: - Development and scientific investigation of technical systems and services for spatial audio recording, processing and reproduction / - Creation of content for reproduction via spatial audio systems and services / - Use and application of spatial audio systems and content presentation services / - Media impact of content and spatial audio systems and services from the point of view of media science. The ICSA 2019 is organized by VDT and TU Ilmenau with support of Fraunhofer Institute for Digital Media Technology IDMT
The Long-Baseline Neutrino Experiment: Exploring Fundamental Symmetries of the Universe
The preponderance of matter over antimatter in the early Universe, the
dynamics of the supernova bursts that produced the heavy elements necessary for
life and whether protons eventually decay --- these mysteries at the forefront
of particle physics and astrophysics are key to understanding the early
evolution of our Universe, its current state and its eventual fate. The
Long-Baseline Neutrino Experiment (LBNE) represents an extensively developed
plan for a world-class experiment dedicated to addressing these questions. LBNE
is conceived around three central components: (1) a new, high-intensity
neutrino source generated from a megawatt-class proton accelerator at Fermi
National Accelerator Laboratory, (2) a near neutrino detector just downstream
of the source, and (3) a massive liquid argon time-projection chamber deployed
as a far detector deep underground at the Sanford Underground Research
Facility. This facility, located at the site of the former Homestake Mine in
Lead, South Dakota, is approximately 1,300 km from the neutrino source at
Fermilab -- a distance (baseline) that delivers optimal sensitivity to neutrino
charge-parity symmetry violation and mass ordering effects. This ambitious yet
cost-effective design incorporates scalability and flexibility and can
accommodate a variety of upgrades and contributions. With its exceptional
combination of experimental configuration, technical capabilities, and
potential for transformative discoveries, LBNE promises to be a vital facility
for the field of particle physics worldwide, providing physicists from around
the globe with opportunities to collaborate in a twenty to thirty year program
of exciting science. In this document we provide a comprehensive overview of
LBNE's scientific objectives, its place in the landscape of neutrino physics
worldwide, the technologies it will incorporate and the capabilities it will
possess.Comment: Major update of previous version. This is the reference document for
LBNE science program and current status. Chapters 1, 3, and 9 provide a
comprehensive overview of LBNE's scientific objectives, its place in the
landscape of neutrino physics worldwide, the technologies it will incorporate
and the capabilities it will possess. 288 pages, 116 figure
Selected Topics in Gravity, Field Theory and Quantum Mechanics
Quantum field theory has achieved some extraordinary successes over the past sixty years; however, it retains a set of challenging problems. It is not yet able to describe gravity in a mathematically consistent manner. CP violation remains unexplained. Grand unified theories have been eliminated by experiment, and a viable unification model has yet to replace them. Even the highly successful quantum chromodynamics, despite significant computational achievements, struggles to provide theoretical insight into the low-energy regime of quark physics, where the nature and structure of hadrons are determined. The only proposal for resolving the fine-tuning problem, low-energy supersymmetry, has been eliminated by results from the LHC. Since mathematics is the true and proper language for quantitative physical models, we expect new mathematical constructions to provide insight into physical phenomena and fresh approaches for building physical theories
Natural Selection and Natural Processes: a philosophical examination of the processes of evolution
This thesis concerns evolution and how it is explained. The ambition here is to identify clearly the many aspects of evolution, and to evaluate past and present explanations of evolution for their coherence and validity. Historically natural selection has been taken to be the central and main explanans, with other explanations playing lesser roles. Here it will be argued that the sheer complexity and diversity within nature cannot be accounted for by any single explanatory mechanism and that a plurality of explanatory mechanisms is required. Loading natural selection with the main weight of explanation is an overburden which, far from strengthening its explanatory powers, actually renders it vacuous. A critical historical and philosophical examination of the concept of natural selection reveals that it has never received a formal scientific definition that commands universal respect. This has created a problem of demarcation between that which natural selection can legitimately be said to explain and that which it cannot. In fact, the ontology of natural selection is equivocal, giving rise to the many controversies that have plagued evolutionary biology. The disambiguation of the concept of natural selection is the principle aim of this thesis and guidelines on how this should be accomplished are provided. However, should these reforming guidelines fail to achieve a consensus then a more radical alternative is proposed. It is recommended that the selective terminology is replaced with the less anomalous and demanding principle of ‘meeting the conditions of existence’. Moreover, talk of the evolution and origins by means of natural selection is to be replaced by talk of evolution and origins by means of natural processes. Finally, drawing from a ‘Structuralist’ alternative, it will be demonstrated that biological evolution should not be divorced from general or cosmological evolution. Rather, elucidation should be drawn more deeply from the fields of physics, chemistry, mathematics and topology, without the use of selection-tinted spectacles
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