Anomaly detection in moving-camera videos with sparse and low-rank matrix decompositions

This work presents two methods based on sparse decompositions that can detect anomalies in video sequences obtained from moving cameras. The first method starts by computing the union of subspaces (UoS) that best represents all the frames from a reference (anomaly-free) video as a low-rank projection plus a sparse residue. Then it performs a low-rank representation of the target (possibly anomalous) video by taking advantage of both the UoS and the sparse residue computed from the reference video. The anomalies are extracted after post-processing this video with these residual data. Such algorithm provides good detection results while at the same time obviating the need for previous video synchronization. However, this technique looses its detection efficiency when target and reference videos presents more severe misalignments. This may happen due to small uncontrolled camera moviment and shaking during the acquisition phase, which is often common in realworld situations. To extend its applicability, a second contribution is proposed in order to cope with these possible pose misalignments. This is done by modeling the target-reference pose discrepancy as geometric transformations acting on the domain of frames of the target video. A complete matrix decomposition algorithm is presented in order to perform a sparse representation of the target video as a sparse combination of the reference video plus a sparse residue, while taking into account the transformation acting on it. Our method is then verified and compared against state-of-the-art techniques using a challenging video dataset, that comprises recordings presenting the described misalignments. Under the evaluation metrics used, the second proposed method exhibits an improvement of at least 16% over the first proposed one, and 22% over the next best rated method.Apresentamos dois métodos baseados em decomposições esparsas que podem detectar anomalias em sequências de vídeo obtidas por câmeras em movimento. O primeiro método estima a união de subespaços (UdS) que melhor representa todos os quadros de um vídeo de referência (livre de anomalias) como uma projeção de baixo-posto mais um resíduo esparso. Em seguida, é realizada uma representação de baixo-posto do vídeo alvo (possivelmente anômalo) aproveitando a UdS e o resíduo esparso calculado a partir do vídeo de referência. As anomalias são extraídas após o pós-processamento destas informações residuais. Esse algoritmo fornece bons resultados de detecção, além de eliminar a necessidade de uma sincronização prévia dos vídeos. No entanto, essa técnica perde eficiência quando os vídeos de referência e alvo apresentam desalinhamentos mais graves entre si. Isso pode ocorrer devido a pequenos movimentos descontrolados da câmera e tremores durante a fase de aquisição. Para estender sua aplicabilidade, uma segunda contribuição é proposta a fim de lidar com esse possível desalinhamento. Isso é feito modelando a discrepância de pose de câmera entre os vídeos de referência e alvo com transformações geométricas agindo no domínio dos quadros do vídeo alvo. Um algoritmo completo de decomposição de matrizes é apresentado para realizar uma representação esparsa do vídeo alvo como uma combinação esparsa do vídeo de referência, levando em consideração as transformações que atuam sobre seus quadros. Nosso método é então verificado e comparado com técnicas de última geração com auxílio de vídeos de uma base desafiadora, apresentando os desalinhamentos em questão. Sob as métricas de avaliação usadas, o segundo método proposto exibe uma melhoria de pelo menos 16% em relação ao primeiro, e 22% sobre o método melhor avaliado logo em seguida

The Murine Accessory Olfactory Bulb as a Model Chemosensory System: Experimental and Computational Analysis of Chemosensory Representations

A common challenge across sensory processing modalities is forming meaningful associations between the neural responses and the outside world. These neural representations of the world must then be integrated across different sensory systems contributing to each individuals perceptual experience. While there has been considerable study of sensory representations in the visual system of humans and multiple model organisms, other sensory domains, including olfaction, are less well understood. In this thesis, I set out to better understand the sensory representations of the mouse accessory olfactory system (AOS), a part of the olfactory system. The mouse AOS, our model chemosensory system, comprises peripheral vomeronasal sensory neurons (VSNs), the accessory olfactory bulb (AOB), and downstream effectors. Our work describes the neural representations of multiple sensory inputs in the AOS, specifically the representations of odorants in high dimensional chemical sensory space in the AOB, and how these representations are shaped by interactions within the circuit. Given the complex nature of olfactory chemosensory representations, the features of our model system may give new perspectives on the neural representation of the outside world. In a neural representation of olfactory information, both the interactions between each receptor and odor compounds as well as the circuit mediated interactions could potentially affect the neural representations of the outside world. The initial neural response comprises component interactions between each receptor and the odor; chemical signals must interact with physical receptors. However, chemosensory processing, such as olfaction, requires interpreting a large variety of potentially overlapping chemical cues from the environment with only a finite number of receptor types. This means that each chemical cue does not necessarily activate only one receptor type or region of the circuit, but rather the cue is likely to be represented by multiple receptor and odor component interactions. Also, the component parts of odors may be processed differently when presented in isolation versus in a more complex mixture, thus allowing the response to a particular odor to vary with chemical context. Moreover, once these component representations exist, interactions within the neural circuit may further shape these responses. For example, one might expect component parts of a complex odor to specifically inhibit other component parts. In the case of the accessory olfactory system this inhibition could be at the receptor level or at the level of the sensory representation in the accessory olfactory bulb (AOB). In Chapter 3, I describe the overall organization of chemosensory representations in the accessory olfactory bulb (AOB), which is found to be a modular map in which the primary associations of functional sensory responses are spatially organized relative to one another. I find these primary associations are condensations of the first order sensory neuron axon terminals, which form population response pooling structures called glomeruli. In these glomeruli, similar response types from those sensory neurons expressing one of the approximately 300 receptor types in the vomeronasal organ (VNO) co-converge. One purpose of converging inputs of neurons expressing the same receptor is likely to minimize noise, and I demonstrate that pooling of like receptor responses into glomeruli does increase neural signal relative to noise. However, I also observed a modular organization among and between glomeruli in which certain types or patterns of chemosensory responses are always spatially adjacent to one another, while others are much farther apart than would be expected by chance. I found this spatial modularity for both ethological stimuli (urine collected from conspecifics with widely divergent physiological endocrine status) and individual sulfated steroids. In Chapter 4, I explore the consequences of changing sensory context, specifically the presentation of multiple compounds, and the role that inhibition plays in the neural representation of the sensory stimuli. First, I tested whether the circuit responds differently to demands to represent a single odor than to demands to represent multiple odors by using odors that activate glomeruli both inside and outside of modules. I found that responses to mixtures rapidly diverge from the responses of individual component parts. Moreover, there was an effect of inhibition in modulating the response to preferred stimuli in all glomeruli. However, initial analysis of one type of pregnanolone responsive glomeruli demonstrated that the divergent response to mixtures in this type of glomerulus was not mediated by inhibition at the glomerular level, but was rather attributable to bottom-up effects from the interactions of multiple ligands with chemosensory receptors in the VNO. Nonetheless, I also demonstrated that in the AOB, the axon terminals of the same sensory neurons (glomeruli) are organized into modules that allow for feedback inhibition. Significant ionotropic glutamate receptor signal modulation was observed within modules, demonstrating that there are inhibition mediated effects in the representation of complex mixtures when glomeruli are co-locally arranged. Specifically, at both the level of the VSNs and also in AOB glomeruli, the response to allopregnanolone sulfate is inhibited by co-presentation with estradiol sulfate. This both significantly increases the relative representation of estradiol sulfate and shifts representation of allopregnanolone primarily within modules. These types of context dependent interactions depend on the spatial organization described in Chapter 3 as well as mixture context, and have the potential to optimize the representation of some chemical cues in a context specific manner

Research Reports: 1984 NASA/ASEE Summer Faculty Fellowship Program

A NASA/ASEE Summer Faulty Fellowship Program was conducted at the Marshall Space Flight Center (MSFC). The basic objectives of the programs are: (1) to further the professional knowledge of qualified engineering and science faculty members; (2) to stimulate an exchange of ideas between participants and NASA; (3) to enrich and refresh the research and teaching activities of the participants' institutions; and (4) to contribute to the research objectives of the NASA Centers. The Faculty Fellows spent ten weeks at MSFC engaged in a research project compatible with their interests and background and worked in collaboration with a NASA/MSFC colleague. This document is a compilation of Fellows' reports on their research during the summer of 1984. Topics covered include: (1) data base management; (2) computational fluid dynamics; (3) space debris; (4) X-ray gratings; (5) atomic oxygen exposure; (6) protective coatings for SSME; (7) cryogenics; (8) thermal analysis measurements; (9) solar wind modelling; and (10) binary systems

The development of the novel electrode materials for electrochemical energy storage applications

In this thesis, a series of perovskite oxides and spinal oxides were chosen for the study in supercapacitors. Hierarchically porous bio-carbon microspheres were used as an exceedingly active and stable ORR electrocatalysts. To investigate the performance and the energy storage mechanism of the synthesized materials, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) and other characterization methods were use

SYNTHESIS, CHARACTERIZATION, AND KINETIC EVALUATION OF PLANAR AND SUPPORTED HETEROGENEOUS CATALYSTS

An integrated approach for biomass upgrading to fuels requires catalyst synthesis, characterization, and kinetic evaluation. The work was divided in three areas, 1-preparation and characterization of model catalysts containing metal oxide overcoats and metal nanoparticles synthesized by atomic layer deposition (ALD), a gas-phase material deposition technique, 2-the study of structure sensitivity for formic acid decomposition on planar Pt catalysts, and 3-characterization of bimetallic Pt-M (M = Re, Mo) catalysts using surface sensitive techniques and theory

Microgravity Materials Science Conference: Research Sumaries

No abstract availabl

The Apertif Surveys:The First Six Months

Apertif is a new phased-array feed for the Westerbork Synthesis Radio Telescope (WSRT), greatly increasing its field of view and turning it into a natural survey instrument. In July 2019, the Apertif legacy surveys commenced; these are a time-domain survey and a two-tiered imaging survey, with a shallow and medium-deep component. The time-domain survey searches for new (millisecond) pulsars and fast radio bursts (FRBs). The imaging surveys provide neutral hydrogen (HI), radio continuum and polarization data products. With a bandwidth of 300 MHz, Apertif can detect HI out to a redshift of 0.26. The key science goals to be accomplished by Apertif include localization of FRBs (including real-time public alerts), the role of environment and interaction on galaxy properties and gas removal, finding the smallest galaxies, connecting cold gas to AGN, understanding the faint radio population, and studying magnetic fields in galaxies. After a proprietary period, survey data products will be publicly available through the Apertif Long Term Archive (ALTA, https://alta.astron.nl). I will review the progress of the surveys and present the first results from the Apertif surveys, including highlighting the currently available public data

SPICA:revealing the hearts of galaxies and forming planetary systems : approach and US contributions

How did the diversity of galaxies we see in the modern Universe come to be? When and where did stars within them forge the heavy elements that give rise to the complex chemistry of life? How do planetary systems, the Universe's home for life, emerge from interstellar material? Answering these questions requires techniques that penetrate dust to reveal the detailed contents and processes in obscured regions. The ESA-JAXA Space Infrared Telescope for Cosmology and Astrophysics (SPICA) mission is designed for this, with a focus on sensitive spectroscopy in the 12 to 230 micron range. SPICA offers massive sensitivity improvements with its 2.5-meter primary mirror actively cooled to below 8 K. SPICA one of 3 candidates for the ESA's Cosmic Visions M5 mission, and JAXA has is committed to their portion of the collaboration. ESA will provide the silicon-carbide telescope, science instrument assembly, satellite integration and testing, and the spacecraft bus. JAXA will provide the passive and active cooling system (supporting the