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Dive into the research topics where Shadia Elgazzar is active.

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Featured researches published by Shadia Elgazzar.


international conference on robotics and automation | 1985

Efficient kinematic transformations for the PUMA 560 robot

Shadia Elgazzar

Efficient solutions for the kinematic positions, velocities, and accelerations for the six-degree-of-freedom PUMA 560 robot are presented. The kinematic problem is defined as the transformation from the Cartesian space to the joint space and vice versa. The solution method is based on a method that fully exploits the special geometry of the robot in the derivation of the solution. Special attention is given to the arm configuration in both directions of the transformation.


IEEE Transactions on Instrumentation and Measurement | 1994

Active infrared sensors for mobile robots

Larry Korba; Shadia Elgazzar; Timothy Welch

Sensors based on the ultrasonic, pulse-echo technique for measuring range have been the mainstay for robotic collision avoidance systems. Although these sensors have been successfully applied to both indoor and outdoor mobile robotic applications, certain disadvantages of these systems prompted our investigation of inexpensive sensors that use light to determine the range or presence of targets. A number of commercially available, light-based sensors are analyzed for application in a mobile robotic space application. The objective of the analysis is to develop a cost-effective, light-based ranging sensor for a collision avoidance system for an experimental Mars Rover. This paper presents some results from our investigation. >


IEEE Transactions on Instrumentation and Measurement | 1998

Active range sensing for indoor environment modeling

Shadia Elgazzar; Ramiro Liscano; François Blais; Andrew Miles

This paper investigates modeling indoor environments using a low-cost, compact, active-range camera, known as BIRIS, mounted onto a pan and tilt motor unit. The BIRIS sensor, developed at the National Research Council of Canada, is a rugged small camera with no moving parts. The objectives of this paper are to describe and demonstrate the viability of the use of a low-cost range sensor in the domain of indoor environment modeling; to present the results of processing three-dimensional (3-D) data to build a virtual environment for navigation and visualization; and, to analyze and outline the advantages and limitations encountered when scanning large indoor environments.


instrumentation and measurement technology conference | 1993

Active infrared sensors for robotics

Larry Korba; Shadia Elgazzar; T. Welch

The authors investigate cost-effective sensors that are based on light sensing techniques. A number of light-based sensors were analyzed for use in a mobile robotic application. The objective of the analysis was to develop a cost-effective light-based ranging sensor that may be used as an alternative to sonar. Commercial optoelectronic sensors priced under


instrumentation and measurement technology conference | 1997

3D data acquisition for indoor environment modeling using a compact active range sensor

Shadia Elgazzar; Ramiro Liscano; Francois Blais; A. Miles

500 and several different camera auto-focus systems were examined to determine their suitability for the application. A description of the tests used in the assessments followed by a description of each sensor are included.<<ETX>>


ICCBSS'05 Proceedings of the 4th international conference on COTS-Based Software Systems | 2005

COTS acquisition: getting a good contract

Shadia Elgazzar; Anatol W. Kark; Erik Putrycz; Mark R. Vigder

This paper investigates modeling indoor environments using a low-cost compact active range camera, known as BIRIS, mounted onto a pan and tilt motor unit. The BIRIS sensor, developed at the National Research Council of Canada, is a rugged small camera with no moving parts. The contributions of this paper are mainly in three areas: it demonstrates the viability of the use of a low-cost range sensor in the domain of indoor environment modeling; it presents the of processing 3-D data to build a virtual environment for navigation and visualization; and, it analyses and outlines the advantages and and limitations encountered when scanning large indoor environments.


Optics for Productivity in Manufacturing | 1994

Robust position estimation of a mobile vehicle

Vania Conan; Pierre Boulanger; Shadia Elgazzar

Organizations that are acquiring a COTS based system must adapt many of their acquisition process activities that are traditionally used for acquiring non-COTS based systems. Much of this adaptation becomes quite difficult within government environments where the process is often constrained by government rules and regulations. This paper provides an experience report on COTS based acquisition for a government agency during the early stages of the process. The impact on requirements engineering and the steps for developing the Request For Proposal (RFP) and evaluating the proposals are outlined. The parties involved in the acquisition process are identified, and their relationship within a project governance structure are discussed. The final discussion provides some guidance as to how the early stages of the acquisition process should be adapted to minimize risk through the project.


Canadian Electrical Engineering Journal | 1984

Feedback controller for PFM systems with quadratic performance index

Shadia Elgazzar; Steve Onyshko

The ability to estimate the position of a mobile vehicle is a key task for navigation over large distances in complex indoor environments such as nuclear power plants. Schematics of the plants are available, but they are incomplete, as real settings contain many objects, such as pipes, cables or furniture, that mask part of the model. The position estimation method described in this paper matches 3-D data with a simple schematic of a plant. It is basically independent of odometry information and viewpoint, robust to noisy data and spurious points and largely insensitive to occlusions. The method is based on a hypothesis/verification paradigm and its complexity is polynomial; it runs in (Omicron) (m4n4), where m represents the number of model patches and n the number of scene patches. Heuristics are presented to speed up the algorithm. Results on real 3-D data show good behavior even when the scene is very occluded.


systems man and cybernetics | 1998

Bayesian attributed hypergraphs: a unified representation of Bayesian networks and hypergraphs for perceptual grouping

Ramiro Liscano; Andrew Wong; Shadia Elgazzar

The problem of finding the optimal control sequences for pulse frequency modulated (PFM) systems with quadratic performance indices and fixed final time is considered. A method for the implementation of the on-line controller and the modulator, using the modified maximum principles (MMP), is presented and illustrated by an example.


Canadian Electrical Engineering Journal | 1981

Display enhancement for seismic interpretation

Shadia Elgazzar

This article introduces a representation known as Bayesian attributed hypergraphs (BAHGs) that are based on the integration of Bayesian networks and attributed hypergraphs. BAHGs are an augmentation to attributed hypergraphs that allow for the management of uncertainty, using Bayesian theory, and can reason about formations from the sensory data using simple graph operators. They allow for the creation of multiple instantiations of Bayesian networks while maintaining single instantiation of nodes that represent the same event. This unification of uncertainty management and attributed hypergraphs removes the need of maintaining and synchronizing between a representation for managing uncertainty and another to manage declarative knowledge. A formalism for the construction of a BAHG for image understanding is presented based on the decomposition by parts methodology and the use of geometric constraints among feature sets. An example is presented that performs perceptual grouping among fragmented 3-D surfaces in an attempt to group the surfaces into corners and continuous surfaces.

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Larry Korba

National Research Council

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A. Miles

National Research Council

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Anatol W. Kark

National Research Council

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Andrew Wong

National Research Council

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Erik Putrycz

National Research Council

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Francois Blais

National Research Council

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Mark R. Vigder

National Research Council

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Vania Conan

National Research Council

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