Computer recognition of unconstrained handwritten numerals

Four independently, developed expert algorithms for recognizing unconstrained handwritten numerals are presented. All have high recognition rates. Different experimental approaches for incorporating these recognition methods into a more powerful system are also presented. The resulting multiple-expert system proves that the consensus of these methods tends to compensate for individual weaknesses, while preserving individual strengths. It is shown that it is possible to reduce the substitution rate to a desired level while maintaining a fairly high recognition rate in the classification of totally unconstrained handwritten ZIP code numerals. If reliability is of the utmost importance, substitutions can be avoided completely (reliability=100%) while retaining a recognition rate above 90%. Results are compared with those for some of the most effective numeral recognition systems found in the literature     

Higher order impedance and absorbing boundary conditions

Traditionally, generalized impedance boundary conditions (GIBCs) have been used to model dielectrics and coated surfaces, and absorbing boundary conditions (ABCs) have been used to simulate nonreflecting surfaces. The two types have the same mathematical form and, in most instances, a higher order condition involving higher order field derivatives has a better accuracy. We demonstrate that there is a close connection between the two and this enables us to use a systematic method which is available for generating GIBCs of any desired order to derive new two- and three-dimensional ABCs. The method is applicable to curvilinear/doubly-curved surfaces and examples are given. Finally, curves are presented that quantify the accuracy of two-dimensional ABCs up to the fourth order, and show how higher order ABCs can improve the efficiency of large scale partial differential equation (PDE) solutions     

Solution of a difference equation in diffraction theory

A simple technique is described for solving a class of second-order functional difference equations that occur in diffraction problems involving edges and corners     

A canine ex vivo shunt for isotopic hemocompatibility evaluation of a NHLBI DTB primary reference material and of a IUPAC reference material

Factors determining the thrombogenic response to particular artificial surfaces were investigated ex vivo in a canine shunt model. Methods using radioisotopic tracers made it possible to dynamically monitor the deposition of labelled blood cells and proteins on a NHLBI.DTB primary reference material polydimethylsiloxane (PRM.PDMS) and on a IUPAC reference material polyvinyl chloride (IUPAC.PVC). On the one hand, leukocyte affinity tau s(leu) (number of deposited leukocytes mm-2s-1) was not significantly different between IUPAC.PVC (tau s(leu) = 1.2-2.5) and PRM.PDMS (tau s(leu) = 1.5-3.4) and the fibrinogen adsorption rate varied from 33 to 48.10(-5) micrograms mm-2s-1 for both these materials. On the other hand, platelet affinity tau s(plat) (number of deposited platelets mm-2s-1) was significantly different (p < 0.05) for IUPAC.PVC and PRM.PDMS (tau s(plat)PVC = 683 +/- 200 > tau s(plat)PDMS = 327 +/- 80). Scanning electron micrographs of adherent platelets, red cells and leukocytes after blood contact ex vivo were performed after each experiment. This preliminary work contributes not only to quantify the adsorption of different radiotracers, but also to evaluate the superficial distribution of the labelled biological species on the inner surface of the tested biomaterials.     

Eating quality of meat from European × Chinese crossbred pigs

Meat from half-Chinese crossbred pigs was compared with meat from purebred European pigs for chemical composition and eating quality. In a first experiment, purebred Pietrain pigs were compared to Pietrain × Chinese (Meishan or Jia Xin ) pigs for sensory qualities as assessed by a taste panel. In a second experiment, purebred Large Whites were compared to Large White × Meishan pigs for chemical composition and eating quality as assessed by both taste panel and consumer testing. The lipid and collagen content in the meat were higher in the Large White × Chinese crossbred pigs than in the purebred Large White pigs. In both experiments, meat from half-Chinese cross bred pigs was judged more tender, more juicy and more tasty than meat from purebred European pigs by the taste panel as well as by consumers. However, the latter judged that the overall acceptability of the meat from half-Chinese pigs was not better, probably due to the excessive amount of visible fat.     

Quantification of phenolic contents and antioxidant capacity of Atlantic sea cucumber, Cucumaria frondosa

The antioxidant activity (oxygen radical absorbance capacity, ORAC) and total phenols and flavonoids were determined in extracts from digestive tract, gonads, muscles and respiratory apparatus of sea cucumber, Cucumaria frondosa. Total phenols content varied from 22.5 to 236.0 mg of gallic acid equivalents/100 g dw, and flavonoids from 2.9 to 59.8 mg of rutin equivalents/100 g. ORAC values ranged from 140 to 800 μmol of Trolox equivalents/g dw. Among all extracts, best antioxidant potencies were observed in ethyl acetate extracts from digestive tract, and in acetonitrile-rich fractions obtained from mixed extracts using acetonitrile/TFA (trifluoroacetic acid) acidified water on muscles, gonads and respiratory apparatus. The weakest potencies were observed with water extracts from digestive tract and respiratory apparatus, and with water-rich fractions obtained from mixed extraction of gonads and muscles. A significant correlation was observed between ORAC values and total phenol content in extracts and fractions of gonads and muscles, but ORAC and phenols were not correlated in digestive tract and respiratory apparatus extracts. ORAC values were significantly correlated (p < 0.05) with total flavonoids in all extracts. Successive eluates obtained from solid-phase extraction of water-rich fractions using C₁₈ cartridge showed ORAC values (105–500 μmol of TE/g) reaching up to 2.3 times the potency of their parent fractions. Flavonoids are suggested to be mainly responsible for observed activities. Our results provide a first quantitative evaluation of C. frondosa tissues as useful sources of antioxidants for human consumption.     

Une méthode heuristique de dimensionnement de réseaux téléinformatiques

Since the implementation of the first computer networks, a great attention has been given to their topological design, because of the financial aspects of their dimensioning and operating. The high number of possible topological configurations, the discrete character of the link capacity options available in the marketplace, the non- linearity of the cost functions associated with the network topologies, constitute the main factors which make complex this design problem. As a result, only heuristic methods can lead with a reasonable computing effort, to good feasible solutions, but not necessarily optimal. This paper proposes a heuristic method for generating in an economical manner network topologies which satisfy some reliability and quality of service constraints. The implementation of the method has been submitted to a sequence of tests which confirm its robustness and its efficiency according to the quality of solutions provided.     

Multi-Modal Locomotion Robotic Platform Using Leg-Track-Wheel Articulations

Other than from its sensing and processing capabilities, a mobile robotic platform can be limited in its use by its ability to move in the environment. Legs, tracks and wheels are all efficient means of ground locomotion that are most suitable in different situations. Legs allow to climb over obstacles and change the height of the robot, modifying its viewpoint of the world. Tracks are efficient on uneven terrains or on soft surfaces (snow, mud, etc.), while wheels are optimal on flat surfaces. Our objective is to work on a new concept capable of combining different locomotion mechanisms to increase the locomotion capabilities of the robotic platform. The design we came up with, called AZIMUT, is symmetrical and is made of four independent leg-track-wheel articulations. It can move with its articulations up, down or straight, allowing the robot to deal with three-dimensional environments. AZIMUT is also capable of moving sideways without changing its orientation, making it omnidirectional. By putting sensors on these articulations, the robot can also actively perceive its environment by changing the orientation of its articulations. Designing a robot with such capabilities requires addressing difficult design compromises, with measurable impacts seen only after integrating all of the components together. Modularity at the structural, hardware and embedded software levels, all considered concurrently in an iterative design process, reveals to be key in the design of sophisticated mobile robotic platforms.This research is supported financially by the Canada Research Chair (CRC) program, the Natural Sciences and Engineering Research Council of Canada (NSERC), the Canadian Foundation for Innovation (CFI) and the Faculty of Engineering of the Université de Sherbrooke. Patent pending.François Michaud is the Canada Research Chairholder in Autonomous Mobile Robots and Intelligent Systems, and an Associate Professor at the Department of Electrical Engineering and Computer Engineering of the Université de Sherbrooke. He is the principal investigator of LABORIUS, a research laboratory working on applying AI methodologies in the design of intelligent autonomous systems that can assist humans in everyday lives. His research interests are architectural methodologies for intelligent decision making, autonomous mobile robotics, social robotics, robot learning and intelligent systems. He received his bachelors degree, Masters degree and Ph.D. degree in Electrical Engineering from the Université de Sherbrooke. He is a member of IEEE, AAAI and OIQ (Ordre des ingénieurs du Québec).Dominic Létourneau has a Bachelor degree in Computer Engineering and a Masters degree in Electrical Engineering from the Université de Sherbrooke. Since 2001, he is a research engineer at the LABORIUS Mobile Robotics and Intelligent Systems Laboratory. His research interests cover combination of systems and intelligent capabilities to increase the usability of autonomous mobile robots in the real world. His expertise lies in artificial vision, mobile robotics, robot programming and integrated design. He is a member of OIQ (Ordre des ingénieurs du Québec).Martin Arsenault has a Bachelor degree in Mechanical Engineering and from the Université de Sherbrooke. For AZIMUT, he developed the Direction subsystem.Yann Bergeron is a Mechanical Junior Engineer working in a consulting engineering firm, Groupe HBA. His field of activity is most oriented in industrial projects and construction. He received his bachelors degree in Mechanical Engineering from the University de Sherbrooke. For AZIMUT, he worked on the Track-Wheel subsystem. He is a member of OIQ (Ordre des ingénieurs du Québec) and JECQ (Jeunes entrepreneurs du Centre-du-Québec).Richard Cadrin has a Bachelor degree in Mechanical Engineering from the Université de Sherbrooke. For AZIMUT, he worked on the Propulstion subsystem.Frédéric Gagnon has a Bachelor degree in Mechanical Engineering and from the Université de Sherbrooke. For AZIMUT, he designed the chassis and worked on the integration of the articulations, the bodywork and the hardware. He is currently a research engineer at LABORIUS, working on AZIMUTs second prototype and other robotic projects. He also contributes in a mobile robotic.Marc-Antoine Legault has a Bachelor degree in Mechanical Engineering from the Université de Sherbrooke, and is currently pursuing a Masters degree at LABORIUS on serial-elastic actuators. He worked on AZIMUTs Propulsion subsystem. He also works on the design of other mobile robotic platforms. He is a member of OIQ (Ordre des ingénieurs du Québec).Mathieu Millette has a Bachelor degree in Mechanical Engineering from the Université de Sherbrooke. For AZIMUT, he developed the Tensor subsystem and he designed and integrated the battery support inside the chassis. He is now working as a junior mechanical engineer in process and technical development in a third sector mill.Jean-François Paré graduated in Mechanical Engineering from the Université de Sherbrooke. He is also trained as a professional coach from R.I.C.K. (Réseau International de Coaching Kokopelli). He launched is own business in individual coaching, team coaching, team building and coaching workshops. For businesses and individuals, he assists people in reaching their well-being and efficiency and to manifest their leadership.Marie-Christine Tremblay has obtained a Bachelor degree in Mechanical Engineering from the Université de Sherbrooke. As a part of the AZIMUTõs team, she contributed the Track-Wheel subsystem and developed a new track with high adherence and wear resistance to climb stairs. She is working in the Engineering Department at Hydra-Fab Industriel, a company conceiving electro-hydraulic systems for high speed trains.Pierre Lepage has a Computer Engineering degree from the Université de Sherbrooke. For AZIMUT, he designed the user interface to control the robot and the propulsion system. He is currently a research engineer at LABORIUS, working on AZIMUTs second prototype and other robotic projects. He is involved in research projects on coordinated behavior of a group of mobile robots. He is also actively involved in a mobile robotic startup.Yan Morin has an Electrical Engineering degree from the Université de Sherbrooke. For AZIMUT, he designed the electrical interface to control the motors of the robot. He is currently a research engineer at LABORIUS, working on AZIMUTs second prototype and other robotic projects. He is also actively involved in a mobile robotic startup.Jonathan Bisson has a Bachelor degree in Computer Engineering and a Masters degree in Electrical Engineering from the Université de Sherbrooke. His contribution to AZIMUT was on the modular distributed computing architecture. His expertise lies in electronics, motor control, embedded systems and ultrasonic transducers.Serge Caron is technician in computer systems at the Department of Electrical Engineering and Computer Engineering of the Universit de Sherbrooke. His interests are in designing mobile robotic platforms, from four-legged to wheeled robots. He is also a writer for hobbyist robotic journals.     

Major attenuation of food reward with performance-sparing doses of pimozide in the rat.

48 male Sprague-Dawley rats were trained to leverpress for food or saccharin reward, and then tested 4 successive times under conditions of normal reward, nonreward, or pretreatment with the dopamine receptor blocker, pimozide. Normally rewarded Ss progressively slowed responding within sessions (became satiated) with food reward but not with saccharin reward. Nonrewarded Ss and pimozide-treated Ss responded vigorously at the beginning of sessions, but slowed within sessions and showed reduced willingness to respond across sessions. Normal responding in the 1st session and in the early phases of later sessions rules out significant motor impairment. Pimozide appears to attenuate selectively the rewarding quality of food for hungry rats. (French summary) (21 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)