Scene Analysis Using Scale Invariant Feature Extraction and Probabilistic Modeling

Conventional pattern recognition systems have two components: feature analysis and pattern classification. For any object in an image, features could be considered as the major characteristic of the object either for object recognition or object tracking purpose. Features extracted from a training image, can be used to identify the object when attempting to locate the object in a test image containing many other objects. To perform reliable scene analysis, it is important that the features extracted from the training image are detectable even under changes in image scale, noise and illumination. Scale invariant feature has wide applications such as image classification, object recognition and object tracking in the image processing area. In this thesis, color feature and SIFT (scale invariant feature transform) are considered to be scale invariant feature. The classification, recognition and tracking result were evaluated with novel evaluation criterion and compared with some existing methods. I also studied different types of scale invariant feature for the purpose of solving scene analysis problems. I propose probabilistic models as the foundation of analysis scene scenario of images. In order to differential the content of image, I develop novel algorithms for the adaptive combination for multiple features extracted from images. I demonstrate the performance of the developed algorithm on several scene analysis tasks, including object tracking, video stabilization, medical video segmentation and scene classification

Open motion control architecture for humanoid robots

This Ph.D. thesis contributes to the development of control architecture for robots. It provides a complex study of a control systems design and makes a proposal for generalized open motion control architecture for humanoid robots. Generally speaking, the development of humanoid robots is a very complex engineering and scientific task that requires new approaches in mechanical design, electronics, software engineering and control. First of all, taking into account all these considerations, this thesis tries to answer the question of why we need the development of such robots. Further, it provides a study of the evolution of humanoid robots, as well as an analysis of modern trends. A complex study of motion, that for humanoid robots, means first of all the biped locomotion is addressed. Requirements for the design of open motion control architecture are posed. This work stresses the motion control algorithms for humanoid robots. The implementation of only servo control for some types of robots (especially for walking systems) is not sufficient. Even having stable motion pattern and well tuned joint control, a humanoid robot can fall down while walking. Therefore, these robots need the implementation of another, upper control loop which will provide the stabilization of their motion. This Ph.D. thesis proposes the study of a joint motion control problem and a new solution to walking stability problem for humanoids. A new original walking stabilization controller based on decoupled double inverted pendulum dynamical model is developed. This Ph.D. thesis proposes novel motion control software and hardware architecture for humanoid robots. The main advantage of this architecture is that it was designed by an open systems approach allowing the development of high-quality humanoid robotics platforms that are technologically up-to-date. The Rh-1 prototype of the humanoid robot was constructed and used as a test platform for implementing the concepts described in this Ph.D. thesis. Also, the implementation of walking stabilization control algorithms was made with OpenHRP platform and HRP-2 humanoid robot. The simulations and walking experiments showed favourable results not only in forward walking but also in turning and backwards walking gaits. It proved the applicability and reliability of designed open motion control architecture for humanoid robots. Finally, it should be noted that this Ph.D. thesis considers the motion control system of a humanoid robot as a whole, stresses the entire concept-design-implementation chain and develops basic guidelines for the design of open motion control architecture that can be easily implemented in other biped platforms

Acoustic Measurement of Snow

Instrumentation commonly used to measure snowpack stratigraphy, snow density, Snow Water Equivalent (SWE), temperature and liquid water content is usually invasive and requires disruption of the snowpack. Most measurement techniques modify the snow medium and more than one sample cannot be taken at the same location. This does not permit continuous monitoring of these parameters using a single measurement instrument. An acoustic wave sent into the snowpack was used to measure snow. To provide the theory required to make acoustic measurements, the Biot-Stoll model of sound wave propagation in porous media was modified using a mixture theory so that it was applicable to a multiphase porous medium. The combined model is called the Unified Thermoacoustic Model (UTAM) for snow. An acoustic measurement device, the System for the Acoustic Sensing of Snow (SAS2), was designed to send sound waves into snow and to receive the reflected sound waves using a loudspeaker and a microphone array. A stationary version of the SAS2 was deployed on a met station and a portable version of the SAS2 was placed on a roving ski-based platform. The systems were deployed at field sites in the Canadian Rocky Mountains, Alberta. The results showed that the SAS2 was able to measure snow density, temperature, and liquid water content and serve as a replacement technology for snowtube and snowpit measurements. Snow density was estimated more accurately by the SAS2 than from commonly-used snow tube techniques

Simulation verification techniques study. Subsystem simulation validation techniques

Techniques for validation of software modules which simulate spacecraft onboard systems are discussed. An overview of the simulation software hierarchy for a shuttle mission simulator is provided. A set of guidelines for the identification of subsystem/module performance parameters and critical performance parameters are presented. Various sources of reference data to serve as standards of performance for simulation validation are identified. Environment, crew station, vehicle configuration, and vehicle dynamics simulation software are briefly discussed from the point of view of their interfaces with subsystem simulation modules. A detailed presentation of results in the area of vehicle subsystems simulation modules is included. A list of references, conclusions and recommendations are also given

Psychologically informed vestibular rehabilitation for persistent dizziness

Vertigo or dizziness is not a disease, but rather a leading symptom of various underlying conditions. These include disorders of the vestibular system, which is responsible for our sense of balance and motion. Many people with vestibular system disorders experience persistent dizziness that can be particularly hard to treat. Vestibular rehabilitation therapy (VRT) is an established physiotherapy-based treatment for people with vestibular dysfunction, which tries to reduce dizziness and improve postural and gaze stability. However, the benefits are not universal and do not always correlate with physiological findings. Poor response to VRT may be because there are concomitant psychosocial factors contributing to the chronicity of the symptoms which are not addressed during VRT. Previous studies have shown a correlation between dizziness and anxiety and depression. Studies of cognitive-behavioural therapy (CBT) for persistent dizziness have to date focused on reducing generalised anxiety to determine if this in turn relieves the dizziness symptoms. This appears to have limited or only short-term success. This may be because although anxiety and depression likely play a role in exacerbating symptoms, mood is only one factor in this multifactorial condition. Understanding a broader range of psychosocial factors specific to vestibular disorders may be needed to provide more tailored and targeted CBT. Combining this with VRT would provide an integrated approach to treating both physiological and psychological features of the disorder. The central question of this thesis was to see whether we could design and evaluate the feasibility of an empirically derived theory-based ‘CBT informed’ vestibular rehabilitation intervention for people with persistent dizziness. The project followed the Medical Research Council framework for developing and evaluating complex interventions. A systematic review of 89 studies using meta-analysis and narrative synthesis identified potentially modifiable psychosocial factors from existing research related to dizziness handicap and symptom severity. A longitudinal survey (n =185 pre diagnosis) was conducted to test the relationship between relevant psychological variables, clinical tests of vestibular deficits and dizziness handicap and subjective symptoms. The cross-sectional results showed that the psychological factors which included distress, negative illness perceptions, and unhelpful cognitive-behavioural responses to symptoms explained >50% of the variance in self-reported handicap and around 30% of the variance in symptom severity. Following diagnosis (n=135) an all-or-nothing erratic pattern of behaviour and experiencing symptoms for a longer time predicted higher dizziness handicap, although baseline ‘handicap’ was the strongest predictor. The results of the review and the survey, together with patient-public representation, informed the development of an integrated manual-based programme of ‘CBT informed’ vestibular rehabilitation, called INVEST, combining cognitive behavioural therapy and physical rehabilitation. A parallel group randomised controlled pilot-feasibility trial was then conducted, with 40 participants with persistent dizziness who were randomly assigned to receive 6 sessions of INVEST (n=20) or current ‘gold standard’ VRT (n=20). Participants were individually randomised using a minimisation procedure with allocation concealment. Both interventions were delivered by specialist physiotherapists. Primary feasibility and self-report outcomes were collected at baseline and 4 months post randomisation. A nested qualitative study was also conducted post-intervention to explore the acceptability of the intervention and identify any areas in need of improvement. This study demonstrated excellent acceptability and feasibility. The study met all the a-priori criteria to progress to a full-scale efficacy trial, including 80% of eligible patients participating (pre-defined criteria >70%), 15% therapy and 2.5% trial drop-out rates (criteria <20%), comparable acceptability ratings to current gold standard VRT, and 80% adherence to sessions (criteria >60%). Fifty-nine percent of patients screened met the selection criteria and the enrolment rate was 80%. According to the qualitative data and exploratory treatment effect sizes, the intervention appeared to be both acceptable and potentially beneficial. This thesis improves our understanding of chronic vestibular symptoms. It provides invaluable information to inform a larger scale trial of an intervention that could potentially improve the quality of life of sufferers, above and beyond standard physiotherapy care. By delivering the intervention as part of physiotherapy, this in turn will improve the access to psychological therapies and use of available resources; reduce the need for patients to see more than one healthcare professional and allow clinicians to respond to patient preference. Improving the outcome of rehabilitation may have additional beneficial social and economic implications as the patient is able to better manage their condition. Given the high prevalence of persistent dizziness in audio-vestibular, neuro-otology, and VRT clinics there is a sufficient need, and number of patients, to run a fully powered RCT