121 research outputs found

    Perceptual Organization

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    Perceiving the world of real objects seems so easy that it is difficult to grasp just how complicated it is. Not only do we need to construct the objects quickly, the objects keep changing even though we think of them as having a consistent, independent existence (Feldman, 2003). Yet, we usually get it right, there are few failures. We can perceive a tree in a blinding snowstorm, a deer bounding across a tree line, dodge a snowball, catch a baseball, detect the crack of a branch breaking in a strong windstorm amidst the rustling of trees, predict the sounds of a dripping faucet, or track a street musician strolling down the road

    Development of dynamic model and control techniques for microelectromechanical gyroscopes

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    In this thesis we investigate the effects of stiffness, damping and temperature on the performance of a MEMS vibratory gyroscope. The stiffness and damping parameters are chosen because they can be appropriately designed to synchronize the drive and sense mode resonance to enhance the sensitivity and stability of MEMS gyroscope. Our results show that increasing the drive axis stiffness from its tuned value by 50%, reduces the sense mode magnitude by ~27% and augments the resonance frequency by ~21%. The stiffness and damping are mildly sensitive to typical variations in operating temperature. The stiffness decreases by 0.30%, while the damping increases by 3.81% from their initial values, when the temperature is raised from -40 to 60C. Doubling the drive mode damping from its tuned value reduces the oscillation magnitude by 10%, but ~0.20% change in the resonance frequency. The predicted effects of stiffness, damping and temperature can be utilized to design a gyroscope for the desired operating condition

    Music Listening as Therapy

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    Music is a universal phenomenon and is a real, physical thing. It is processed in neural circuits that overlap with language circuits, and it exerts cognitive, emotional, and physiological effects on humans. Many of those effects are therapeutic, such as reduced symptoms of physical and mental ailments. Music is the result of the elements rhythm, melody, harmony, timbre, dynamics, and form. Rhythm is the focus of pop music, and melody is the focus of classical music. The mind perceives and organizes music in learned, consistent ways in order to generate predictions and extract meaning. There are perceptual laws and information processing limitations to this process. Predictions are based in schematic and veridical approaches, which give rise to expectations. Frustrated expectations result in an effective response. Music only has meaning unto itself and the music listener ascribes any extra-musical meaning. This includes any emotional meaning. The unfolding of a song is much like how Gestalt Therapy theory conceptualizes human experience. Mindfulness offers a clear definition of how one can frame and approach experience to support health and well-being. MinMuList (said “min-mew-list”) is an evidenced-based workshop that offers a concise discussion and straightforward methods for implementation of these aspects of music and psychology

    Treatise on Hearing: The Temporal Auditory Imaging Theory Inspired by Optics and Communication

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    A new theory of mammalian hearing is presented, which accounts for the auditory image in the midbrain (inferior colliculus) of objects in the acoustical environment of the listener. It is shown that the ear is a temporal imaging system that comprises three transformations of the envelope functions: cochlear group-delay dispersion, cochlear time lensing, and neural group-delay dispersion. These elements are analogous to the optical transformations in vision of diffraction between the object and the eye, spatial lensing by the lens, and second diffraction between the lens and the retina. Unlike the eye, it is established that the human auditory system is naturally defocused, so that coherent stimuli do not react to the defocus, whereas completely incoherent stimuli are impacted by it and may be blurred by design. It is argued that the auditory system can use this differential focusing to enhance or degrade the images of real-world acoustical objects that are partially coherent. The theory is founded on coherence and temporal imaging theories that were adopted from optics. In addition to the imaging transformations, the corresponding inverse-domain modulation transfer functions are derived and interpreted with consideration to the nonuniform neural sampling operation of the auditory nerve. These ideas are used to rigorously initiate the concepts of sharpness and blur in auditory imaging, auditory aberrations, and auditory depth of field. In parallel, ideas from communication theory are used to show that the organ of Corti functions as a multichannel phase-locked loop (PLL) that constitutes the point of entry for auditory phase locking and hence conserves the signal coherence. It provides an anchor for a dual coherent and noncoherent auditory detection in the auditory brain that culminates in auditory accommodation. Implications on hearing impairments are discussed as well.Comment: 603 pages, 131 figures, 13 tables, 1570 reference

    ESCOM 2017 Proceedings

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    Embracing a Diverse Student Population within an Urban Science Classroom Through the Use of Inquiry-Based and Culturally Relevant Pedagogy: A Multipedagogical Approach in Narrowing the Science Achievement Gap

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    Inequalities have always existed between individuals of varying race, ethnicity, gender, and socioeconomic status. How to overcome such injustices is always a highly debated topic. One way these inequalities between individuals of various demographic groups have shown themselves in a tangible way, is through the modern day recognizable achievement gaps that exist between urban and nonurban student populations in the realm of science education. Improving science learning outcomes for all students while attempting to narrow the science achievement gaps have become a theme in recent science education reforms brought about through the National Research Council (1996, 2000) and the release of the Next Generation Science Standards (NGSS, 2013). The demographic student population within modern urban science classrooms have seen both rapid changes and an increase in diversity. Traditional ways of teaching science are no longer successful in reaching the current diverse student groups as can be seen in the noticeable science achievement gaps. Ineffective pedagogy and a lack of understanding for new diverse student populations have led to an increase in research and studies examining alternative methods for teaching science. Keeping these realities at the forefront of intent, this project and unit plan were designed with an attempt at teaching science in a way that is both meaningful and relevant to diverse student populations found within current urban science classrooms. A multipedagogical approach through the use of Inquiry-Based and Culturally Relevant Pedagogy was chosen per recommendation of current literature and research on how to successfully teach science within an urban setting

    An Enactivist Model of Improvisational Dance

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    An Enactivist Model of Improvisational Danc

    Health condition monitoring of civil structures using time varying autoregressive models

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    In recent years, there have been an increasing interest in long-term monitoring of civil structures, as the research community has been alarmed by some tragic events and collapses of bridges and buildings that pointed out the vulnerability of some existing structures and the uncertainties in their analysis for monitoring and maintenance purposes. SHM is the measurement of the operating and loading environment; as well as the critical responses of a structure to track and evaluate the symptoms of incidents, anomalies, damage and/or deterioration which may affect operation, serviceability, safety and reliability. Although many damage detection techniques were applied to scaled models or specimen tests in controlled laboratory environments, the performance of these techniques in real operational environments is still questionable and needs to be validated. Often damage sensitive features employed in these damage detection techniques are also sensitive to changes of environmental and operation conditions of the structure. The objective of this study is to propose a new Time Varying Autoregressive (TVAR) modeling technique for SHM of large-scale structures like bridges and buildings. TVAR model, a method by virtue of its nature is applicable for modeling data whose spectral content varies with time. The research is conducted to critically understand the effective performance of the structures under various loads and health conditions, and detect their operational anomalies using the proposed data-driven technique. In this research, an attempt is made to alleviate the use of system identification method where TVAR modeling is conducted directly on the data. The proposed method does not depend on the complicated algorithms and free of any other user-defined parameters. In pursuance of applying the proposed data-driven technique, the data collected on site are essentially paramount. Data inherently used are mainly obtained from experiments, as well as the data acquired from the Harbin Institute of Technology in fulfillment of a full-scale validation. The proposed TVAR technique detects not only the occurrence of structural damage, but also the location of damage. Whereas the TVAR developed captures the changes in the time domain, for comparison, Stochastic Subspace System Identification (SSI) method is applied to the experimental data. The method is used because it is an important tool that captures the frequency changes, as the SSI tracks the changes in the frequency domain. Using both experimental and full-scale studies, it is shown that the proposed TVAR technique and the comparable SSI method applied, can therefore be considered as a useful tool for SHM

    Biophysical modeling of a cochlear implant system: progress on closed-loop design using a novel patient-specific evaluation platform

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    The modern cochlear implant is one of the most successful neural stimulation devices, which partially mimics the workings of the auditory periphery. In the last few decades it has created a paradigm shift in hearing restoration of the deaf population, which has led to more than 324,000 cochlear implant users today. Despite its great success there is great disparity in patient outcomes without clear understanding of the aetiology of this variance in implant performance. Furthermore speech recognition in adverse conditions or music appreciation is still not attainable with today's commercial technology. This motivates the research for the next generation of cochlear implants that takes advantage of recent developments in electronics, neuroscience, nanotechnology, micro-mechanics, polymer chemistry and molecular biology to deliver high fidelity sound. The main difficulties in determining the root of the problem in the cases where the cochlear implant does not perform well are two fold: first there is not a clear paradigm on how the electrical stimulation is perceived as sound by the brain, and second there is limited understanding on the plasticity effects, or learning, of the brain in response to electrical stimulation. These significant knowledge limitations impede the design of novel cochlear implant technologies, as the technical specifications that can lead to better performing implants remain undefined. The motivation of the work presented in this thesis is to compare and contrast the cochlear implant neural stimulation with the operation of the physiological healthy auditory periphery up to the level of the auditory nerve. As such design of novel cochlear implant systems can become feasible by gaining insight on the question `how well does a specific cochlear implant system approximate the healthy auditory periphery?' circumventing the necessity of complete understanding of the brain's comprehension of patterned electrical stimulation delivered from a generic cochlear implant device. A computational model, termed Digital Cochlea Stimulation and Evaluation Tool (‘DiCoStET’) has been developed to provide an objective estimate of cochlear implant performance based on neuronal activation measures, such as vector strength and average activation. A patient-specific cochlea 3D geometry is generated using a model derived by a single anatomical measurement from a patient, using non-invasive high resolution computed tomography (HRCT), and anatomically invariant human metrics and relations. Human measurements of the neuron route within the inner ear enable an innervation pattern to be modelled which joins the space from the organ of Corti to the spiral ganglion subsequently descending into the auditory nerve bundle. An electrode is inserted in the cochlea at a depth that is determined by the user of the tool. The geometric relation between the stimulation sites on the electrode and the spiral ganglion are used to estimate an activating function that will be unique for the specific patient's cochlear shape and electrode placement. This `transfer function', so to speak, between electrode and spiral ganglion serves as a `digital patient' for validating novel cochlear implant systems. The novel computational tool is intended for use by bioengineers, surgeons, audiologists and neuroscientists alike. In addition to ‘DiCoStET’ a second computational model is presented in this thesis aiming at enhancing the understanding of the physiological mechanisms of hearing, specifically the workings of the auditory synapse. The purpose of this model is to provide insight on the sound encoding mechanisms of the synapse. A hypothetical mechanism is suggested in the release of neurotransmitter vesicles that permits the auditory synapse to encode temporal patterns of sound separately from sound intensity. DiCoStET was used to examine the performance of two different types of filters used for spectral analysis in the cochlear implant system, the Gammatone type filter and the Butterworth type filter. The model outputs suggest that the Gammatone type filter performs better than the Butterworth type filter. Furthermore two stimulation strategies, the Continuous Interleaved Stimulation (CIS) and Asynchronous Interleaved Stimulation (AIS) have been compared. The estimated neuronal stimulation spatiotemporal patterns for each strategy suggest that the overall stimulation pattern is not greatly affected by the temporal sequence change. However the finer detail of neuronal activation is different between the two strategies, and when compared to healthy neuronal activation patterns the conjecture is made that the sequential stimulation of CIS hinders the transmission of sound fine structure information to the brain. The effect of the two models developed is the feasibility of collaborative work emanating from various disciplines; especially electrical engineering, auditory physiology and neuroscience for the development of novel cochlear implant systems. This is achieved by using the concept of a `digital patient' whose artificial neuronal activation is compared to a healthy scenario in a computationally efficient manner to allow practical simulation times.Open Acces
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