12 research outputs found

    Efficient Model-Based 3D Tracking of Deformable Objects

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    Efficient incremental image alignment is a topic of renewed interest in the computer vision community because of its applications in model fitting and model-based object tracking. Successful compositional procedures for aligning 2D and 3D models under weak-perspective imaging conditions have already been proposed. Here we present a mixed compositional and additive algorithm which is applicable to the full projective camera case

    A graphical model based solution to the facial feature point tracking problem

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    In this paper a facial feature point tracker that is motivated by applications such as human-computer interfaces and facial expression analysis systems is proposed. The proposed tracker is based on a graphical model framework. The facial features are tracked through video streams by incorporating statistical relations in time as well as spatial relations between feature points. By exploiting the spatial relationships between feature points, the proposed method provides robustness in real-world conditions such as arbitrary head movements and occlusions. A Gabor feature-based occlusion detector is developed and used to handle occlusions. The performance of the proposed tracker has been evaluated on real video data under various conditions including occluded facial gestures and head movements. It is also compared to two popular methods, one based on Kalman filtering exploiting temporal relations, and the other based on active appearance models (AAM). Improvements provided by the proposed approach are demonstrated through both visual displays and quantitative analysis

    Optimum design and machining parameters of a permanent magnet brushless DC linear motor as a CNC feed drive

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    A new heuristic has been developed to determine optimal operating parameters applied to a permanent magnet brushless DC linear motor (PMBDCLM) as a CNC feed drive. An FEA model has been developed utilizing an -electromagnetic postprocessor to provide performance output of a PMBDCLM and DC servomotor. Based on the developed FEA models, velocity results have been utilized to provide feedrate levels for design of experiments (DOE). DOE has been conducted to provide force, tolerance, and surface finish data necessary for the performance comparison of a DC servo motor/ballscrew equipped CNC vertical milling machine and a PMBDCLM equipped CNC vertical milling machine. Based on the DOE, a knowledge base has been developed using force, tolerance, and surface finish data. Relationships between force, and spindle speed and feedrate with tolerance and surface finish indices were determined. A heuristic has been developed which represents a guide of applying a set of decisions through the knowledge base to provide a set of operating parameters that will meet user specified tolerance and surface finish requirements for given surfaces. Application of the developed heuristic to a milled part is illustrated. A PMBDCLM CNC retrofit for a conventional ballscrew feed drive system has also been developed to improve machine performance and cost

    View-based models for visual tracking and recognition

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    Ph.DDOCTOR OF PHILOSOPH

    Condensing a priori data for recognition based augmented reality

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    My research proposes novel methods to reduce the cardinality of a priori data used in recognition based augmented reality, whilst retaining distinctive and persistent features in the sets. This research will help reduce latency and increase accuracy in recognition based pose estimation systems, thus improving the user experience for augmented reality applications

    Non-invasive measurement of load capacity of trabecular bones with defects

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    Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 1997.Includes bibliographical references.by Gregory D. Cabe.M.S

    Technology 2002: the Third National Technology Transfer Conference and Exposition, Volume 1

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    The proceedings from the conference are presented. The topics covered include the following: computer technology, advanced manufacturing, materials science, biotechnology, and electronics

    Muscle activation mapping of skeletal hand motion: an evolutionary approach.

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    Creating controlled dynamic character animation consists of mathe- matical modelling of muscles and solving the activation dynamics that form the key to coordination. But biomechanical simulation and control is com- putationally expensive involving complex di erential equations and is not suitable for real-time platforms like games. Performing such computations at every time-step reduces frame rate. Modern games use generic soft- ware packages called physics engines to perform a wide variety of in-game physical e ects. The physics engines are optimized for gaming platforms. Therefore, a physics engine compatible model of anatomical muscles and an alternative control architecture is essential to create biomechanical charac- ters in games. This thesis presents a system that generates muscle activations from captured motion by borrowing principles from biomechanics and neural con- trol. A generic physics engine compliant muscle model primitive is also de- veloped. The muscle model primitive forms the motion actuator and is an integral part of the physical model used in the simulation. This thesis investigates a stochastic solution to create a controller that mimics the neural control system employed in the human body. The control system uses evolutionary neural networks that evolve its weights using genetic algorithms. Examples and guidance often act as templates in muscle training during all stages of human life. Similarly, the neural con- troller attempts to learn muscle coordination through input motion samples. The thesis also explores the objective functions developed that aids in the genetic evolution of the neural network. Character interaction with the game world is still a pre-animated behaviour in most current games. Physically-based procedural hand ani- mation is a step towards autonomous interaction of game characters with the game world. The neural controller and the muscle primitive developed are used to animate a dynamic model of a human hand within a real-time physics engine environment

    Sixth NASTRAN (R) Users' Colloquium

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    Papers are presented on NASTRAN programming, and substructuring methods, as well as on fluids and thermal applications. Specific applications and capabilities of NASTRAN were also delineated along with general auxiliary programs
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