Literatura académica sobre el tema "Dynamic visual signal"
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Artículos de revistas sobre el tema "Dynamic visual signal"
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Hirata, Yutaka. "Neural signal processing for dynamic visual stabilization". Brain & Neural Networks 11, n.º 4 (2004): 176–92. http://dx.doi.org/10.3902/jnns.11.176.
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Nittrouer, Susan y Joanna H. Lowenstein. "Beyond Recognition: Visual Contributions to Verbal Working Memory". Journal of Speech, Language, and Hearing Research 65, n.º 1 (12 de enero de 2022): 253–73. http://dx.doi.org/10.1044/2021_jslhr-21-00177.
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Purpose: It is well recognized that adding the visual to the acoustic speech signal improves recognition when the acoustic signal is degraded, but how that visual signal affects postrecognition processes is not so well understood. This study was designed to further elucidate the relationships among auditory and visual codes in working memory, a postrecognition process. Design: In a main experiment, 80 young adults with normal hearing were tested using an immediate serial recall paradigm. Three types of signals were presented (unprocessed speech, vocoded speech, and environmental sounds) in three conditions (audio-only, audio–video with dynamic visual signals, and audio–picture with static visual signals). Three dependent measures were analyzed: (a) magnitude of the recency effect, (b) overall recall accuracy, and (c) response times, to assess cognitive effort. In a follow-up experiment, 30 young adults with normal hearing were tested largely using the same procedures, but with a slight change in order of stimulus presentation. Results: The main experiment produced three major findings: (a) unprocessed speech evoked a recency effect of consistent magnitude across conditions; vocoded speech evoked a recency effect of similar magnitude to unprocessed speech only with dynamic visual (lipread) signals; environmental sounds never showed a recency effect. (b) Dynamic and static visual signals enhanced overall recall accuracy to a similar extent, and this enhancement was greater for vocoded speech and environmental sounds than for unprocessed speech. (c) All visual signals reduced cognitive load, except for dynamic visual signals with environmental sounds. The follow-up experiment revealed that dynamic visual (lipread) signals exerted their effect on the vocoded stimuli by enhancing phonological quality. Conclusions: Acoustic and visual signals can combine to enhance working memory operations, but the source of these effects differs for phonological and nonphonological signals. Nonetheless, visual information can support better postrecognition processes for patients with hearing loss.
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Lajoie, Guillaume y Lai-Sang Young. "Dynamic Signal Tracking in a Simple V1 Spiking Model". Neural Computation 28, n.º 9 (septiembre de 2016): 1985–2010. http://dx.doi.org/10.1162/neco_a_00868.
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This work is part of an effort to understand the neural basis for our visual system’s ability, or failure, to accurately track moving visual signals. We consider here a ring model of spiking neurons, intended as a simplified computational model of a single hypercolumn of the primary visual cortex of primates. Signals that consist of edges with time-varying orientations localized in space are considered. Our model is calibrated to produce spontaneous and driven firing rates roughly consistent with experiments, and our two main findings, for which we offer dynamical explanation on the level of neuronal interactions, are the following. First, we have documented consistent transient overshoots in signal perception following signal switches due to emergent interactions of the E- and I-populations. Second, for continuously moving signals, we have found that accuracy is considerably lower at reversals of orientation than when continuing in the same direction (as when the signal is a rotating bar). To measure performance, we use two metrics, called fidelity and reliability, to compare signals reconstructed by the system to the ones presented and assess trial-to-trial variability. We propose that the same population mechanisms responsible for orientation selectivity also impose constraints on dynamic signal tracking that manifest in perception failures consistent with psychophysical observations.
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Cezário, Rodrigo Roucourt, Vinicius Marques Lopez, Stanislav Gorb y Rhainer Guillermo-Ferreira. "Dynamic iridescent signals of male copperwing damselflies coupled with wing-clapping displays: the perspective of different receivers". Biological Journal of the Linnean Society 134, n.º 1 (2 de junio de 2021): 229–39. http://dx.doi.org/10.1093/biolinnean/blab068.
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Abstract Dynamic signals are a widespread phenomenon in several taxa, usually associated with intraspecific communication. In contrast, dynamic iridescent signals are detectable only at specific angles of illumination; hence, the animal can hide the signal to avoid detection when necessary. This structural coloration is mostly dependent on the illumination, the contrast against the background and the vision of the receiver. Complex behavioural displays can be coupled with structural coloration to create dynamic visual signals that enhance these functions. Here, we address whether iridescence of the males of a damselfly that inhabits dark rainforests, Chalcopteryx scintillans, can be considered a dynamic visual signal. We analyse whether coloration is perceived by conspecifics, while reducing detectability to eavesdroppers against three types of backgrounds. Our results suggest that the visual background affects the detectability of male hindwings by different receivers, mostly predators and prey. We discuss whether these results and the angle dependence of colour could indicate a mechanism to avoid unwanted intraspecific interactions or even to lure both predators and prey. We conclude that the main functions of the dynamic iridescent signal are to communicate with conspecifics while hindering the signal for prey, adding evidence of the multifunctionality of structural coloration coupled with behavioural displays in animals.
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Pomante, A., L. P. J. Selen y W. P. Medendorp. "Perception of the dynamic visual vertical during sinusoidal linear motion". Journal of Neurophysiology 118, n.º 4 (1 de octubre de 2017): 2499–506. http://dx.doi.org/10.1152/jn.00439.2017.
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The vestibular system provides information for spatial orientation. However, this information is ambiguous: because the otoliths sense the gravitoinertial force, they cannot distinguish gravitational and inertial components. As a consequence, prolonged linear acceleration of the head can be interpreted as tilt, referred to as the somatogravic effect. Previous modeling work suggests that the brain disambiguates the otolith signal according to the rules of Bayesian inference, combining noisy canal cues with the a priori assumption that prolonged linear accelerations are unlikely. Within this modeling framework the noise of the vestibular signals affects the dynamic characteristics of the tilt percept during linear whole-body motion. To test this prediction, we devised a novel paradigm to psychometrically characterize the dynamic visual vertical—as a proxy for the tilt percept—during passive sinusoidal linear motion along the interaural axis (0.33 Hz motion frequency, 1.75 m/s2peak acceleration, 80 cm displacement). While subjects ( n=10) kept fixation on a central body-fixed light, a line was briefly flashed (5 ms) at different phases of the motion, the orientation of which had to be judged relative to gravity. Consistent with the model’s prediction, subjects showed a phase-dependent modulation of the dynamic visual vertical, with a subject-specific phase shift with respect to the imposed acceleration signal. The magnitude of this modulation was smaller than predicted, suggesting a contribution of nonvestibular signals to the dynamic visual vertical. Despite their dampening effect, our findings may point to a link between the noise components in the vestibular system and the characteristics of dynamic visual vertical.NEW & NOTEWORTHY A fundamental question in neuroscience is how the brain processes vestibular signals to infer the orientation of the body and objects in space. We show that, under sinusoidal linear motion, systematic error patterns appear in the disambiguation of linear acceleration and spatial orientation. We discuss the dynamics of these illusory percepts in terms of a dynamic Bayesian model that combines uncertainty in the vestibular signals with priors based on the natural statistics of head motion.
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Gielen, CCAM y JAM van Gisbergen. "The Visual Guidance of Saccades and Fast Aiming Movements". Physiology 5, n.º 2 (1 de abril de 1990): 58–63. http://dx.doi.org/10.1152/physiologyonline.1990.5.2.58.
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Sensory signals are used to create an internal representation of the environment. There is good evidence that the same internal representation of target position in space is shared by different motor systems. A central problem is how the command signal is transformed from a spatial code at the sensory side into a dynamic activation signal appropriately matched to the properties of the effector system.
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J. B. Meyers, S. E. Prussia y C. J. Karwoski. "Signal Detection Theory for Optimizing Dynamic Visual Inspection Performance". Applied Engineering in Agriculture 6, n.º 4 (1990): 412–17. http://dx.doi.org/10.13031/2013.26406.
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López, María T., Antonio Fernández-Caballero, Miguel A. Fernández, José Mira y Ana E. Delgado. "Visual surveillance by dynamic visual attention method". Pattern Recognition 39, n.º 11 (noviembre de 2006): 2194–211. http://dx.doi.org/10.1016/j.patcog.2006.04.018.
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Ligon, Russell A. y Kevin J. McGraw. "Social costs enforce honesty of a dynamic signal of motivation". Proceedings of the Royal Society B: Biological Sciences 283, n.º 1841 (26 de octubre de 2016): 20161873. http://dx.doi.org/10.1098/rspb.2016.1873.
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Understanding the processes that promote signal reliability may provide important insights into the evolution of diverse signalling strategies among species. The signals that animals use to communicate must comprise mechanisms that prohibit or punish dishonesty, and social costs of dishonesty have been demonstrated for several fixed morphological signals (e.g. colour badges of birds and wasps). The costs maintaining the honesty of dynamic signals, which are more flexible and potentially cheatable, are unknown. Using an experimental manipulation of the dynamic visual signals used by male veiled chameleons ( Chamaeleo calyptratus ) during aggressive interactions, we tested the idea that the honesty of rapid colour change signals is maintained by social costs. Our results reveal that social costs are an important mechanism maintaining the honesty of these dynamic colour signals—‘dishonest’ chameleons whose experimentally manipulated coloration was incongruent with their contest behaviour received more physical aggression than ‘honest’ individuals. This is the first demonstration, to the best our knowledge, that the honesty of a dynamic signal of motivation—physiological colour change—can be maintained by the social costliness of dishonesty. Behavioural responses of signal receivers, irrespective of any specific detection mechanisms, therefore prevent chameleon cheaters from prospering.
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Soundirarajan, Mirra, Mohammad Hossein Babini, Sue Sim, Visvamba Nathan y Hamidreza Namazi. "Decoding of the Relationship between Brain and Facial Muscle Activities in Response to Dynamic Visual Stimuli". Fluctuation and Noise Letters 19, n.º 04 (23 de junio de 2020): 2050041. http://dx.doi.org/10.1142/s0219477520500418.
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In this research, for the first time, we analyze the relationship between facial muscles and brain activities when human receives different dynamic visual stimuli. We present different moving visual stimuli to the subjects and accordingly analyze the complex structure of electromyography (EMG) signal versus the complex structure of electroencephalography (EEG) signal using fractal theory. Based on the obtained results from analysis, presenting the stimulus with greater complexity causes greater change in the complexity of EMG and EEG signals. Statistical analysis also supported the results of analysis and showed that visual stimulus with greater complexity has greater effect on the complexity of EEG and EMG signals. Therefore, we showed the relationship between facial muscles and brain activities in this paper. The method of analysis in this research can be further employed to investigate the relationship between other human organs’ activities and brain activity.
Tesis sobre el tema "Dynamic visual signal"
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Júnior, Alcebíades Dal Col. "Visual analytics via graph signal processing". Universidade de São Paulo, 2018. http://www.teses.usp.br/teses/disponiveis/55/55134/tde-22102018-112358/.
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The classical wavelet transform has been widely used in image and signal processing, where a signal is decomposed into a combination of basis signals. By analyzing the individual contribution of the basis signals, one can infer properties of the original signal. This dissertation presents an overview of the extension of the classical signal processing theory to graph domains. Specifically, we review the graph Fourier transform and graph wavelet transforms both of which based on the spectral graph theory, and explore their properties through illustrative examples. The main features of the spectral graph wavelet transforms are presented using synthetic and real-world data. Furthermore, we introduce in this dissertation a novel method for visual analysis of dynamic networks, which relies on the graph wavelet theory. Dynamic networks naturally appear in a multitude of applications from different domains. Analyzing and exploring dynamic networks in order to understand and detect patterns and phenomena is challenging, fostering the development of new methodologies, particularly in the field of visual analytics. Our method enables the automatic analysis of a signal defined on the nodes of a network, making viable the detection of network properties. Specifically, we use a fast approximation of the graph wavelet transform to derive a set of wavelet coefficients, which are then used to identify activity patterns on large networks, including their temporal recurrence. The wavelet coefficients naturally encode spatial and temporal variations of the signal, leading to an efficient and meaningful representation. This method allows for the exploration of the structural evolution of the network and their patterns over time. The effectiveness of our approach is demonstrated using different scenarios and comparisons involving real dynamic networks.A transformada wavelet clássica tem sido amplamente usada no processamento de imagens e sinais, onde um sinal é decomposto em uma combinação de sinais de base. Analisando a contribuição individual dos sinais de base, pode-se inferir propriedades do sinal original. Esta tese apresenta uma visão geral da extensão da teoria clássica de processamento de sinais para grafos. Especificamente, revisamos a transformada de Fourier em grafo e as transformadas wavelet em grafo ambas fundamentadas na teoria espectral de grafos, e exploramos suas propriedades através de exemplos ilustrativos. As principais características das transformadas wavelet espectrais em grafo são apresentadas usando dados sintéticos e reais. Além disso, introduzimos nesta tese um método inovador para análise visual de redes dinâmicas, que utiliza a teoria de wavelets em grafo. Redes dinâmicas aparecem naturalmente em uma infinidade de aplicações de diferentes domínios. Analisar e explorar redes dinâmicas a fim de entender e detectar padrões e fenômenos é desafiador, fomentando o desenvolvimento de novas metodologias, particularmente no campo de análise visual. Nosso método permite a análise automática de um sinal definido nos vértices de uma rede, tornando possível a detecção de propriedades da rede. Especificamente, usamos uma aproximação da transformada wavelet em grafo para obter um conjunto de coeficientes wavelet, que são então usados para identificar padrões de atividade em redes de grande porte, incluindo a sua recorrência temporal. Os coeficientes wavelet naturalmente codificam variações espaciais e temporais do sinal, criando uma representação eficiente e com significado expressivo. Esse método permite explorar a evolução estrutural da rede e seus padrões ao longo do tempo. A eficácia da nossa abordagem é demonstrada usando diferentes cenários e comparações envolvendo redes dinâmicas reais.
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How, Martin John y martin how@anu edu au. "The fiddler crab claw-waving display: an analysis of the structure and function of a movement-based visual signal". The Australian National University. Research School of Biological Sciences, 2004. http://thesis.anu.edu.au./public/adt-ANU20081001.111333.
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Communication is an essential component of animal social systems and a diverse suite of signals can be found in the natural environment. An area of animal communication that, for technical reasons, we know very little about is the field of movement-based or dynamic visual signals. In this thesis, I make use of recent advances in measurement and analysis techniques, including digital video and image motion processing tools, to improve our understanding of how movement-based signals are adjusted according to signalling context. I measured and characterised the flamboyant claw-waving displays of male fiddler crabs (Genus Uca) and made use of their transparent lifestyle to record the behavioural contexts in which these signals are produced.¶
The claw-waving displays of seven Australian species of fiddler crab are compared and contrasted to show that these signals are species-specific, but also vary within and between individuals. I show that the species Uca perplexa produces different types of signal in different behavioural contexts, a lateral wave for courtship, and a vertical wave during short-range agonistic and courtship interactions. The structure of the lateral courtship waves of Uca perplexa vary according to the distance of signal receivers, the first time this kind of relationship has been shown in a dynamic visual signal. Finally, I describe and analyse the signalling and orientation behaviour of U. elegans during courtship herding, an unusual mating system that uses the claw-waving display in a novel way.¶
The adjustments made by fiddler crabs to their displays during changes in behavioural contexts suggest that the fine-scale context-sensitivity of animal signals may be far more widespread in communication than hitherto recognised.
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Huang, Jian. "Dynamic Image Precompensation for Improving Visual Performance of Computer Users with Ocular Aberrations". FIU Digital Commons, 2013. http://digitalcommons.fiu.edu/etd/902.
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With the progress of computer technology, computers are expected to be more intelligent in the interaction with humans, presenting information according to the user's psychological and physiological characteristics. However, computer users with visual problems may encounter difficulties on the perception of icons, menus, and other graphical information displayed on the screen, limiting the efficiency of their interaction with computers.
In this dissertation, a personalized and dynamic image precompensation method was developed to improve the visual performance of the computer users with ocular aberrations. The precompensation was applied on the graphical targets before presenting them on the screen, aiming to counteract the visual blurring caused by the ocular aberration of the user's eye. A complete and systematic modeling approach to describe the retinal image formation of the computer user was presented, taking advantage of modeling tools, such as Zernike polynomials, wavefront aberration, Point Spread Function and Modulation Transfer Function. The ocular aberration of the computer user was originally measured by a wavefront aberrometer, as a reference for the precompensation model. The dynamic precompensation was generated based on the resized aberration, with the real-time pupil diameter monitored. The potential visual benefit of the dynamic precompensation method was explored through software simulation, with the aberration data from a real human subject.
An "artificial eye'' experiment was conducted by simulating the human eye with a high-definition camera, providing objective evaluation to the image quality after precompensation. In addition, an empirical evaluation with 20 human participants was also designed and implemented, involving image recognition tests performed under a more realistic viewing environment of computer use. The statistical analysis results of the empirical experiment confirmed the effectiveness of the dynamic precompensation method, by showing significant improvement on the recognition accuracy. The merit and necessity of the dynamic precompensation were also substantiated by comparing it with the static precompensation. The visual benefit of the dynamic precompensation was further confirmed by the subjective assessments collected from the evaluation participants.
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Varatharajah, Alexander. "EEG signal dynamics in unrestricted natural visual search". Thesis, University of Leicester, 2017. http://hdl.handle.net/2381/39777.
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EEG signal dynamics in unrestricted natural visual search: By Alexander Varatharajah. Visual search is a skill that if not mastered, would leave you considerably unfit for Darwin’s idea of survival. Prior knowledge of the cognitive processes involved in visual search stemmed from modelling and behavioural studies collecting subjects’ reaction times, their eye movements, or EEG target signatures under fixed-gaze. To further understand these concepts, progression has to be made with the collection of data. Recent co-registration of EEG and Eye-Tracking has further enhanced this understanding by allowing brain responses to be seen in the form of fixation-Related Potentials (fRPs). To date, only a handful of studies have investigated brain correlates of visual search paradigms involving eye-movements. In this research, subjects search for targets in natural images, resembling the children’s game; “Where’s Waldo?” Results show early and late target detection effects. Also presented is a novel full trial analysis, that has allowed investigation into local and global fRPs driving characteristics, which were related to classical concepts of expectancy and surprise. Additionally, potential pitfalls from commonly used techniques are highlighted.
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Rawashdeh, Samir Ahmed. "VISUAL ATTITUDE PROPAGATION FOR SMALL SATELLITES". UKnowledge, 2013. http://uknowledge.uky.edu/ece_etds/30.
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As electronics become smaller and more capable, it has become possible to conduct meaningful and sophisticated satellite missions in a small form factor. However, the capability of small satellites and the range of possible applications are limited by the capabilities of several technologies, including attitude determination and control systems. This dissertation evaluates the use of image-based visual attitude propagation as a compliment or alternative to other attitude determination technologies that are suitable for miniature satellites. The concept lies in using miniature cameras to track image features across frames and extracting the underlying rotation.
The problem of visual attitude propagation as a small satellite attitude determination system is addressed from several aspects: related work, algorithm design, hardware and performance evaluation, possible applications, and on-orbit experimentation. These areas of consideration reflect the organization of this dissertation.
A “stellar gyroscope” is developed, which is a visual star-based attitude propagator that uses relative motion of stars in an imager’s field of view to infer the attitude changes. The device generates spacecraft relative attitude estimates in three degrees of freedom. Algorithms to perform the star detection, correspondence, and attitude propagation are presented. The Random Sample Consensus (RANSAC) approach is applied to the correspondence problem to successfully pair stars across frames while mitigating false-positive and false-negative star detections. This approach provides tolerance to the noise levels expected in using miniature optics and no baffling, and the noise caused by radiation dose on orbit. The hardware design and algorithms are validated using test images of the night sky. The application of the stellar gyroscope as part of a CubeSat attitude determination and control system is described. The stellar gyroscope is used to augment a MEMS gyroscope attitude propagation algorithm to minimize drift in the absence of an absolute attitude sensor.
The stellar gyroscope is a technology demonstration experiment on KySat-2, a 1-Unit CubeSat being developed in Kentucky that is in line to launch with the NASA ELaNa CubeSat Launch Initiative. It has also been adopted by industry as a sensor for CubeSat Attitude Determination and Control Systems (ADCS).
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Yavuz, Esin. "Source separation analysis of visual cortical dynamics revealed by voltage sensitive dye imaging". Phd thesis, Université Pierre et Marie Curie - Paris VI, 2012. http://tel.archives-ouvertes.fr/tel-00836931.
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Ce travail consiste en une analyse statistique de la séparation des sources des enregistrements d'imagerie VSD afin de 1) séparer le signal neuronal des artefacts, et 2) d'étudier la dynamique des motifs spatio-temporels de l'activité créés par les populations neuronales qui partagent des statistiques communes. À cette fin, nous avons effectué des enregistrements en imagerie VSD des zones 17 et 18 du cortex du chat anesthésié et paralysé, en réponse à des réseaux sinusoïdaux de luminance en mouvement et en plein champ. Nous avons développé une méthode d'analyse pour l'imagerie VSD qui sépare la réponse neuronale des artefacts, et extrait les motifs de l'activité qui sont fonctionnellement liés à des populations différentiables. Notre méthode de débruitage permet d'effectuer des analyses sur des essais unitaires, par exemple pour étudier la variabilité intrinsèque de chaque réponse de la population neuronale enregistrée pour une même stimulation. En outre, nous avons pu séparer des populations de neurones qui montrent différents profils de réponse à l'orientation et/ou à la direction des stimuli à l'aide de la PCA et de l'ICA. La compression et la projection de l'activité de V1 sur trois axes de composantes principales nous a permis d'étudier la dynamique des états corticaux et de démontrer la séparabilité des trajectoires d'état en fonction de l'orientation. Nos résultats indiquent que le codage neuronal de la préférence à l'orientation au niveau de la population plutôt que des canaux individuels est plus efficace. Nous espérons à l'avenir fournir un cadre de mesure pour la quantification et l'interprétation des réponses à des stimuli plus naturels
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How, Martin John. "The fiddler crab claw-waving display: an analysis of the structure and function of a movement-based visual signal". Phd thesis, 2007. http://hdl.handle.net/1885/49333.
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Communication is an essential component of animal social systems and a diverse suite of signals can be found in the natural environment. An area of animal communication that, for technical reasons, we know very little about is the field of ‘movement-based’ or ‘dynamic’ visual signals. In this thesis, I make use of recent advances in measurement and analysis techniques, including digital video and image motion processing tools, to improve our understanding of how movement-based signals are adjusted according to signalling context. I measured and characterised the flamboyant claw-waving displays of male fiddler crabs (Genus Uca) and made use of their transparent lifestyle to record the behavioural contexts in which these signals are produced.
The claw-waving displays of seven Australian species of fiddler crab are compared and contrasted to show that these signals are species-specific, but also vary within and between individuals. I show that the species Uca perplexa produces different types of signal in different behavioural contexts, a lateral wave for courtship, and a vertical wave during short-range agonistic and courtship interactions. The structure of the lateral courtship waves of Uca perplexa vary according to the distance of signal receivers, the first time this kind of relationship has been shown in a dynamic visual signal. Finally, I describe and analyse the signalling and orientation behaviour of U. elegans during courtship herding, an unusual mating system that uses the claw-waving display in a novel way.¶
The adjustments made by fiddler crabs to their displays during changes in behavioural contexts suggest that the fine-scale context-sensitivity of animal signals may be far more widespread in communication than hitherto recognised.
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Karakaya, Mahmut. "Collaborative Solutions to Visual Sensor Networks". 2011. http://trace.tennessee.edu/utk_graddiss/1087.
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Visual sensor networks (VSNs) merge computer vision, image processing and wireless sensor network disciplines to solve problems in multi-camera applications in large surveillance areas. Although potentially powerful, VSNs also present unique challenges that could hinder their practical deployment because of the unique camera features including the extremely higher data rate, the directional sensing characteristics, and the existence of visual occlusions.
In this dissertation, we first present a collaborative approach for target localization in VSNs. Traditionally; the problem is solved by localizing targets at the intersections of the back-projected 2D cones of each target. However, the existence of visual occlusions among targets would generate many false alarms. Instead of resolving the uncertainty about target existence at the intersections, we identify and study the non-occupied areas in 2D cones and generate the so-called certainty map of targets non-existence. We also propose distributed integration of local certainty maps by following a dynamic itinerary where the entire map is progressively clarified.
The accuracy of target localization is affected by the existence of faulty nodes in VSNs. Therefore, we present the design of a fault-tolerant localization algorithm that would not only accurately localize targets but also detect the faults in camera orientations, tolerate these errors and further correct them before they cascade. Based on the locations of detected targets in the fault-tolerated final certainty map, we construct a generative image model that estimates the camera orientations, detect inaccuracies and correct them.
In order to ensure the required visual coverage to accurately localize targets or tolerate the faulty nodes, we need to calculate the coverage before deploying sensors. Therefore, we derive the closed-form solution for the coverage estimation based on the "certainty-based detection" model that takes directional sensing of cameras and existence of visual occlusions into account.
The effectiveness of the proposed collaborative and fault-tolerant target localization algorithms in localization accuracy as well as fault detection and correction performance has been validated through the results obtained from both simulation and real experiments. In addition, conducted simulation shows extreme consistency with results from theoretical closed-form solution for visual coverage estimation, especially when considering the boundary effect.
Libros sobre el tema "Dynamic visual signal"
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Stokes, Mark y John Duncan. Dynamic Brain States for Preparatory Attention and Working Memory. Editado por Anna C. (Kia) Nobre y Sabine Kastner. Oxford University Press, 2014. http://dx.doi.org/10.1093/oxfordhb/9780199675111.013.032.
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This chapter considers how dynamic brain states continuously fine-tune processing to accommodate changes in behavioural context and task goals. First, the authors review the extant literature suggesting that content-specific patterns of preparatory activity bias competitive processing in visual cortex to favour behaviourally relevant input. Next, they consider how higher-level brain areas might provide a top-down attentional signal for modulating baseline visual activity. Extensive evidence suggests that working memory representations in prefrontal cortex are especially important for generating and maintaining biases in preparatory visual activity via modulatory feedback. Although it is often proposed that such working memory representations are maintained via persistent prefrontal activity, the authors review more recent evidence that rapid short-term synaptic plasticity provides a common substrate for maintaining the content of past experience and the rules for guiding future goal-directed processing.
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O’Hanlon, James C., Thomas E. White y Kate D. L. Umbers. Visual communication. Oxford University Press, 2018. http://dx.doi.org/10.1093/oso/9780198797500.003.0011.
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The diverse ecological niches that insects occupy have led to the immense variation we observe in the structure of their compound eyes and the visual signals that insects can produce. The modular structure of the compound eye, through which insects receive visual information, is a highly adaptable structure capable of impressive feats of image resolution, colour perception, and motion detection, in a range of varying light environments. Additionally, the insect exoskeleton, through which insects produce visual signals and cues, is a dynamic canvas producing a diversity of shapes, textures, pigments, and structural colours. This chapter attempts to present the diversity resultant from millennia of selective pressure in a variety of contexts, including conspecific assessment, prey capture, and predator avoidance.
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Babo-Rebelo, Mariana y Catherine Tallon-Baudry. Interoceptive signals, brain dynamics, and subjectivity. Oxford University Press, 2018. http://dx.doi.org/10.1093/oso/9780198811930.003.0003.
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The self has long been hypothesized to be rooted in the neural monitoring of bodily signals. We propose here to focus on visceral inputs, which present some key characteristics. Inputs from the heart or the gastrointestinal tract are continuously produced, and can reach multiple cortical targets. In addition, cardiac inputs elicit a neural response at each heartbeat that can be recorded non-invasively in humans, even in the absence of measurable changes in bodily state. We review the recent experimental evidence that neural responses to heartbeats are related to the self, in situations where the self is explicit or reflective (bodily awareness, thinking about oneself) but also when the self is implicit (the self as the agent, the self experiencing a visual input). These results are compatible with our proposal that the integration of visceral signals generates a subject-centered reference frame underlying different facets of the self.
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Huffaker, Ray, Marco Bittelli y Rodolfo Rosa. Data Preprocessing. Oxford University Press, 2018. http://dx.doi.org/10.1093/oso/9780198782933.003.0006.
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Successful reconstruction of a shadow attractor provides preliminary empirical evidence that a signal isolated from observed time series data may be generated by deterministic dynamics. However, because we cannot reasonably expect signal processing to purge the signal of all noise in practice, and because noisy linear behavior can be visually indistinguishable from nonlinear behavior, the possibility remains that noticeable regularity detected in a shadow attractor may be fortuitously reconstructed from data generated by a linear-stochastic process. This chapter investigates how we can test this null hypothesis using surrogate data testing. The combination of a noticeably regular shadow attractor, along with strong statistical rejection of fortuitous regularity, increases the probability that observed data are generated by deterministic real-world dynamics.
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Bucy, Erik P. y Patrick Stewart. The Personalization of Campaigns: Nonverbal Cues in Presidential Debates. Oxford University Press, 2018. http://dx.doi.org/10.1093/acrefore/9780190228637.013.52.
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Nonverbal cues are important elements of persuasive communication whose influence in political debates are receiving renewed attention. Recent advances in political debate research have been driven by biologically grounded explanations of behavior that draw on evolutionary theory and view televised debates as contests for social dominance. The application of biobehavioral coding to televised presidential debates opens new vistas for investigating this time-honored campaign tradition by introducing a systematic and readily replicated analytical framework for documenting the unspoken signals that are a continuous feature of competitive candidate encounters. As research utilizing biobehavioral measures of presidential debates and other political communication progresses, studies are becoming increasingly characterized by the use of multiple methodologies and merging of disparate data into combined systems of coding that support predictive modeling.Key elements of nonverbal persuasion include candidate appearance, communication style and behavior, as well as gender dynamics that regulate candidate interactions. Together, the use of facial expressions, voice tone, and bodily gestures form uniquely identifiable display repertoires that candidates perform within televised debate settings. Also at play are social and political norms that govern candidate encounters. From an evaluative standpoint, the visual equivalent of a verbal gaffe is the commission of a nonverbal expectancy violation, which draws viewer attention and interferes with information intake. Through second screens, viewers are able to register their reactions to candidate behavior in real time, and merging biobehavioral and social media approaches to debate effects is showing how such activity can be used as an outcome measure to assess the efficacy of candidate nonverbal communication during televised presidential debates.Methodological approaches employed to investigate nonverbal cues in presidential debates have expanded well beyond the time-honored technique of content analysis to include lab experiments, focus groups, continuous response measurement, eye tracking, vocalic analysis, biobehavioral coding, and use of the Facial Action Coding System to document the muscle movements that comprise leader expressions. Given the tradeoffs and myriad considerations involved in analyzing nonverbal cues, critical issues in measurement and methodology must be addressed when conducting research in this evolving area. With automated coding of nonverbal behavior just around the corner, future research should be designed to take advantage of the growing number of methodological advances in this rapidly evolving area of political communication research.
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Sandler, Daniela. Counterpreservation. Cornell University Press, 2017. http://dx.doi.org/10.7591/cornell/9781501703164.001.0001.
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In Berlin, decrepit structures do not always denote urban blight. Decayed buildings are incorporated into everyday life as residences, exhibition spaces, shops, offices, and as leisure space. As nodes of public dialogue, they serve as platforms for dissenting views about the future and past of Berlin. This book introduces the concept of counter-preservation as a way to understand this intentional appropriation of decrepitude. The embrace of decay is a sign of Berlin's iconoclastic rebelliousness, but it has also been incorporated into the mainstream economy of tourism and development as part of the city's countercultural cachet. It presents the possibilities and shortcomings of counter-preservation as a dynamic force in Berlin and as a potential concept for other cities. Counter-preservation is part of Berlin's fabric: in the city's famed Hausprojekte (living projects) such as the Køpi, Tuntenhaus, and KA 86; in cultural centers such as the Haus Schwarzenberg, the Schokoladen, and the legendary, now defunct Tacheles; in memorials and museums; and even in commerce and residences. The appropriation of ruins is a way of carving out affordable spaces for housing, work, and cultural activities. It is also a visual statement against gentrification, and a complex representation of history, with the marks of different periods—the nineteenth century, World War II, postwar division, unification—on display for all to see. Counter-preservation exemplifies an everyday urbanism in which citizens shape private and public spaces with their own hands, but it also influences more formal designs, such as the Topography of Terror, the Berlin Wall Memorial, and Daniel Libeskind's unbuilt redevelopment proposal for a site peppered with ruins of Nazi barracks. By featuring these examples, the book questions conventional notions of architectural authorship and points toward the value of participatory environments.
Capítulos de libros sobre el tema "Dynamic visual signal"
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Narwaria, Manish, Matthieu Perreira Da Silva y Patrick Le Callet. "High Dynamic Range Visual Quality of Experience Measurement: Challenges and Perspectives". En Visual Signal Quality Assessment, 129–55. Cham: Springer International Publishing, 2014. http://dx.doi.org/10.1007/978-3-319-10368-6_5.
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Yamada, T., K. Ukai y S. Ishikawa. "Error signal detection and dynamics of accommodation". En Accommodation and Vergence Mechanisms in the Visual System, 213–23. Basel: Birkhäuser Basel, 2000. http://dx.doi.org/10.1007/978-3-0348-7586-8_19.
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Cannas, Barbara, Sara Carcangiu, Alessandra Fanni, Ivan Lupelli, Fulvio Militello, Augusto Montisci, Fabio Pisano, Giuliana Sias y Nick Walkden. "Convolutional Neural Networks for the Identification of Filaments from Fast Visual Imaging Cameras in Tokamak Reactors". En Neural Advances in Processing Nonlinear Dynamic Signals, 167–77. Cham: Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-319-95098-3_15.
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Niebur, Ernst y Christof Koch. "Models for the Neuronal Implementation of Selective Visual Attention Based on the Temporal Structure of Neural Signals". En Oscillatory Event-Related Brain Dynamics, 295–309. Boston, MA: Springer US, 1994. http://dx.doi.org/10.1007/978-1-4899-1307-4_21.
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Oswald, Julie N., Christine Erbe, William L. Gannon, Shyam Madhusudhana y Jeanette A. Thomas. "Detection and Classification Methods for Animal Sounds". En Exploring Animal Behavior Through Sound: Volume 1, 269–317. Cham: Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-030-97540-1_8.
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AbstractClassification of the acoustic repertoires of animals into sound types is a useful tool for taxonomic studies, behavioral studies, and for documenting the occurrence of animals. Classification of acoustic repertoires enables the identification of species, age, gender, and individual identity, correlations between sound types and behavior, the identification of changes in vocal behavior over time or in response to anthropogenic noise, comparisons between the repertoires of populations living in different geographic regions and environments, and the development of software tools for automated signal processing. Techniques for classification have evolved over time as technical capabilities have expanded. Initially, researchers applied qualitative methods, such as listening and visually discerning sounds in spectrograms. Advances in computer technology and the development of software for the automatic detection and classification of sounds have allowed bioacousticians to quickly find sounds in recordings, thus significantly reducing analysis time and enabling the analysis of larger datasets. In this chapter, we present software algorithms for automated signal detection (based on energy, Teager–Kaiser energy, spectral entropy, matched filtering, and spectrogram cross-correlation) as well as for signal classification (e.g., parametric clustering, principal component analysis, discriminant function analysis, classification trees, artificial neural networks, random forests, Gaussian mixture models, support vector machines, dynamic time-warping, and hidden Markov models). Methods for evaluating the performance of automated tools are presented (i.e., receiver operating characteristics and precision-recall) and challenges with classifying animal sounds are discussed.
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Brandstetter, Andrea, Najoua Bolakhrif, Christian Schiffer, Timo Dickscheid, Hartmut Mohlberg y Katrin Amunts. "Deep Learning-Supported Cytoarchitectonic Mapping of the Human Lateral Geniculate Body in the BigBrain". En Lecture Notes in Computer Science, 22–32. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-82427-3_2.
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AbstractThe human lateral geniculate body (LGB) with its six sickle shaped layers (lam) represents the principal thalamic relay nucleus for the visual system. Cytoarchitectonic analysis serves as the groundtruth for multimodal approaches and studies exploring its function. This technique, however, requires experienced knowledge about human neuroanatomy and is costly in terms of time. Here we mapped the six layers of the LGB manually in serial, histological sections of the BigBrain, a high-resolution model of the human brain, whereby their extent was manually labeled in every 30th section in both hemispheres. These maps were then used to train a deep learning algorithm in order to predict the borders on sections in-between these sections. These delineations needed to be performed in 1 µm scans of the tissue sections, for which no exact cross-section alignment is available. Due to the size and number of analyzed sections, this requires to employ high-performance computing. Based on the serial section delineations, high-resolution 3D reconstruction was performed at 20 µm isotropic resolution of the BigBrain model. The 3D reconstruction shows the shape of the human LGB and its sublayers for the first time at cellular precision. It represents a use case to study other complex structures, to visualize their shape and relationship to neighboring structures. Finally, our results could provide reference data of the LGB for modeling and simulation to investigate the dynamics of signal transduction in the visual system.
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Maharaj, Gyanpriya, Godfrey Bourne y Abdullah Ansari. "A Review of Floral Color Signals and Their Heliconiid Butterfly Receivers". En Arthropods [Working Title]. IntechOpen, 2021. http://dx.doi.org/10.5772/intechopen.98666.
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Signals vary in type and function. However, regardless of the signal, effective transmission and receiver detection are needed to exist for communication. This chapter focuses on a review of visual color signals used by plants to attract pollinators. Signal detection work has intensely focused on epigamic signals; therefore, this review adds to the body of knowledge on nonsexual signal communication. In this review, we investigate visual signals as it relates to pollinators. We focus specifically on visual color signals used by Angiosperms flowers, both static and dynamic, and look at their Heliconiid pollinators as these butterflies provide a perfect organism for studies on floral signal use and pollinators’ behavior. We noted that many of these butterflies have three specifically distinct rhodopsins used to identify food and oviposition sites and some have more due to selective pressures of conspecific and mate identification as such they have served as the focal organisms of numerous genetic and ecological studies as they use color signaling in all aspects of their lives. This review further shows that although their color preferences related to feeding, ovipositing, and mate selection have been demonstrated in countless studies, there are gaps in invertebrate literature, as research on the relationships among signal use, evolution, dynamic signals, effects of signals changes on decision making and thus behavior have not been carried out to a large extent.
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Shiell, Derek J., Louis H. Terry, Petar S. Aleksic y Aggelos K. Katsaggelos. "Audio-Visual and Visual-Only Speech and Speaker Recognition". En Visual Speech Recognition, 1–38. IGI Global, 2009. http://dx.doi.org/10.4018/978-1-60566-186-5.ch001.
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The information imbedded in the visual dynamics of speech has the potential to improve the performance of speech and speaker recognition systems. The information carried in the visual speech signal compliments the information in the acoustic speech signal, which is particularly beneficial in adverse acoustic environments. Non-invasive methods using low-cost sensors can be used to obtain acoustic and visual biometric signals, such as a person’s voice and lip movement, with little user cooperation. These types of unobtrusive biometric systems are warranted to promote widespread adoption of biometric technology in today’s society. In this chapter, the authors describe the main components and theory of audio-visual and visual-only speech and speaker recognition systems. Audio-visual corpora are described and a number of speech and speaker recognition systems are reviewed. Finally, various open issues about the system design and implementation, and present future research and development directions in this area are discussed.
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Plastino, A. y M. T. Martin. "Generalized Information Measures and the Analysis of Brain Electrical Signals". En Nonextensive Entropy. Oxford University Press, 2004. http://dx.doi.org/10.1093/oso/9780195159769.003.0020.
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The traditional way of analyzing brain electrical activity, on the basis of electroencephalogram (EEG) records, relies mainly on visual inspection and years of training. Although it is quite useful, of course, one has to acknowledge its subjective nature that hardly allows for a systematic protocol. In order to overcome this undesirable feature, a quantitative EEG analysis has been developed over the years that introduces objective measures. These reflect not only characteristics of the brain activity itself, but also clues concerning the underlying associated neural dynamics. The processing of information by the brain is reflected in dynamical changes of the electrical activity in (i) time, (ii) frequency, and (iii) space. Therefore, the concomitant studies require methods capable of describing the qualitative variation of the signal in both time and frequency. In the present work we introduce new information tools based on the wavelet transform for the assessment of EEG data. In particular, different complexity measures are utilized…. The traditional electroencephalogram (EEG) tracing is now interpreted in much the same way as it was 50 years ago. More channels are used now and much more is known about clinical implication of the waves, but the basic EEG display and quantification of it are quite similar to those of its predecessors. The clinical interpretation of EEG records is made by a complex process of visual pattern recognition and the association with external and evident characteristics of clinical symptomatology. Analysis of EEG signals always involves the queries of quantification, i.e., the ability to state objective data in numerical and/or graphic form that simplify the analysis of long EEG time series. Without such measures, EEG appraisal remains subjective and can hardly lead to logical systematization [36]. Spectral decomposition of the EEG by computing the Fourier transform has been used since the very early days of electroencephalography. The rhythmic nature of many EEG activities lends itself naturally to this analysis. Fourier transform allows separation of various rhythms and estimation of their frequencies independently of each other, a difficult task to perform visually if several rhythmic activities occur simultaneously. Spectral analysis can also quantify the amount of activity in a frequency band.
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Afef, Ouelhazi, Rudy Lussiez y Molotchnikoff Stephane. "Cortical Plasticity under Ketamine: From Synapse to Map". En Sensory Nervous System - Computational Neuroimaging Investigations of Topographical Organization in Human Sensory Cortex [Working Title]. IntechOpen, 2022. http://dx.doi.org/10.5772/intechopen.104787.
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Sensory systems need to process signals in a highly dynamic way to efficiently respond to variations in the animal’s environment. For instance, several studies showed that the visual system is subject to neuroplasticity since the neurons’ firing changes according to stimulus properties. This dynamic information processing might be supported by a network reorganization. Since antidepressants influence neurotransmission, they can be used to explore synaptic plasticity sustaining cortical map reorganization. To this goal, we investigated in the primary visual cortex (V1 of mouse and cat), the impact of ketamine on neuroplasticity through changes in neuronal orientation selectivity and the functional connectivity between V1 cells, using cross correlation analyses. We found that ketamine affects cortical orientation selectivity and alters the functional connectivity within an assembly. These data clearly highlight the role of the antidepressant drugs in inducing or modeling short-term plasticity in V1 which suggests that cortical processing is optimized and adapted to the properties of the stimulus.
Actas de conferencias sobre el tema "Dynamic visual signal"
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Feng, Tian y Charith Abhayaratne. "Visual Saliency Guided High Dynamic Range Image Compression". En 2018 26th European Signal Processing Conference (EUSIPCO). IEEE, 2018. http://dx.doi.org/10.23919/eusipco.2018.8553456.
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Rice, Iain y David Lowe. "Topographic visual analytics of multibeam dynamic SONAR data". En 2014 Sensor Signal Processing for Defence (SSPD). IEEE, 2014. http://dx.doi.org/10.1109/sspd.2014.6943326.
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Lv, Guoyun, Shuixian Hu, Yangyu Fan y Min Qi. "Visual emotion recognition based on dynamic models". En 2013 IEEE International Conference on Signal Processing, Communications and Computing. IEEE, 2013. http://dx.doi.org/10.1109/icspcc.2013.6664137.
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Yagi, Nobuyuki, Ryoichi Yajima, Kazumasa Enami, Kazuo Fukui, Nobuyuki Sasaki, Kouji Hoshino, Kazuhiro Harukawa y Masaru Kogure. "Real-Time Video Signal Processing System For Dynamic Images". En 1989 Symposium on Visual Communications, Image Processing, and Intelligent Robotics Systems, editado por William A. Pearlman. SPIE, 1989. http://dx.doi.org/10.1117/12.970096.
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Sagel, Alexander y Hao Shen. "Dynamic Variational Autoencoders for Visual Process Modeling". En ICASSP 2020 - 2020 IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP). IEEE, 2020. http://dx.doi.org/10.1109/icassp40776.2020.9053660.
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Dal Col, Alcebiades y Luis Gustavo Nonato. "Visual Analytics via Graph Signal Processing". En XXXII Conference on Graphics, Patterns and Images. Sociedade Brasileira de Computação - SBC, 2019. http://dx.doi.org/10.5753/sibgrapi.est.2019.8295.
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This dissertation presents an overview of the extension of the classical signal processing theory to graph domains. Furthermore, we introduce in this dissertation a novel method for visual analysis of dynamic networks, which relies on the graph wavelet theory. Our method enables the automatic analysis of a signal defined on the nodes of a network. We use a fast approximation of the graph wavelet transform to derive a set of wavelet coefficients, which are then used to identify activity patterns on large networks, including their temporal recurrence. The wavelet coefficients naturally encode spatial and temporal variations of the signal, leading to an efficient and meaningful representation. This method allows for the exploration of the structural evolution of the network and their patterns over time. The effectiveness of our approach is demonstrated using different scenarios and comparisons involving real dynamic networks.
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Siracusa, Michael R. y John W. Fisher. "Dynamic Dependency Tests for Audio-Visual Speaker Association". En 2007 IEEE International Conference on Acoustics, Speech, and Signal Processing. IEEE, 2007. http://dx.doi.org/10.1109/icassp.2007.366271.
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Chen, Duan-Yu, Hsiao-Rong Tyan, Sheng-Wen Shih y Hong-Yuan Mark Liao. "Dynamic Visual Saliency Modeling for Video Semantics". En 2008 Fourth International Conference on Intelligent Information Hiding and Multimedia Signal Processing (IIH-MSP). IEEE, 2008. http://dx.doi.org/10.1109/iih-msp.2008.306.
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Marcheret, Etienne, Vit Libal y Gerasimos Potamianos. "Dynamic Stream Weight Modeling for Audio-Visual Speech Recognition". En 2007 IEEE International Conference on Acoustics, Speech, and Signal Processing. IEEE, 2007. http://dx.doi.org/10.1109/icassp.2007.367227.
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Zhao, Jinlong, Zhiyu Xiang, Lei Liu y Zhike Zhang. "DMVO: A Multi-motion Visual Odometry for Dynamic Environments". En 2021 13th International Conference on Wireless Communications and Signal Processing (WCSP). IEEE, 2021. http://dx.doi.org/10.1109/wcsp52459.2021.9613336.
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