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Publications

Publications by CRIIS

2011

Internet-based collaborative E-exercisebook system for primary math teaching

Authors
Reis, MJCS; Bacelar, M; Reis, MGAD; Meira, D; Bessa, M; Peres, E; Morais, R; Valente, A; Soares, S; Bulas Cruz, J;

Publication
2011 2nd National Conference on Telecommunications, CONATEL 2011 - Proceedings

Abstract
The academic performance and social competence of a child in school is positively associated with the involvement of their parents. However, the researches about educational learning models often ignore the parents' part. Internet opens a new paradigm: education and communication approach is more complex than ever. Here, we would like to present an Internet based system to support students' homework. We believe that one of the major advantages of our system is time saving, particularly from the teacher's point of view. Also, this system gathers statistical data concerning different groups of students selected by the teacher. From these data on, the teacher can easily see where the students are having problems and decide what to do next. From the student (or parent) point of view, the prompt feedback about the exercises correctness, added to the training with different exercises sets about the same subject, besides the utilization of video, color, sound, etc., that positively reinforce child's senses, are elected as the main advantages. © 2011 IEEE.

2011

A Support Tool for Teaching Grafcet: Engineering Students’ Perceptions

Authors
Lea~o, CP; Soares, FO; Machado, J; de Moura Oliveira, PB; Boaventura Cunha, J;

Publication
Volume 5: Engineering Education and Professional Development

Abstract

2011

ICT in Agro-industrial management Management System for Harvesting Mushrooms

Authors
Canuto, SA; Ramos Moreira Goncalves, RMRM; Mollo Neto, MM; dos Santos Branco, FAD; Cunha, JB;

Publication
SISTEMAS E TECNOLOGIAS DE INFORMACAO, VOL I

Abstract

2011

ICT management in the agro-industry

Authors
Canuto, SA; Goncalves, RMRM; Neto, MM; Dos Santos Branco, FA; Cunha, JB;

Publication
Proceedings of the 6th Iberian Conference on Information Systems and Technologies, CISTI 2011

Abstract
Human pressure is pushing many of our natural resources to their limits in various regions of the world. Optimize their use is an urgent need. The management of agro-industry has been aware of that need, seeking to improve the productivity and reduce waste throughout the production process, as well by increasing the distribution efficiency of their products. Information and Communication Technologies (ICT) can support the control/management of the process inputs and outputs in various activities. This article attempts to describe a complete mushroom production chain. The information system developed by the agro-industry company studied allows to acquire, in real-time, the information about what is being produced (quantity and type of mushroom), which products are to be delivered to the different clients and which should be the planning for the next few days. © 2011 AISTI.

2011

Optimization of the Workpiece Location in a Machining Robotic Cell

Authors
Lopes, AM; Pires, EJS;

Publication
INTERNATIONAL JOURNAL OF ADVANCED ROBOTIC SYSTEMS

Abstract
One important issue in a machining robotic cell is the location of the workpiece with respect to the robot. The feasibility of the task, the quality of the final work and the energy consumption, just to mention a few, are all dependent upon it. This can be formulated as an optimization problem where the objective functions are chosen in order to meet desired performance criteria. Typically, the complexity of the problems and the large number of optimization parameters that, usually, are involved, make the genetic algorithms an appropriate tool in this context. In this paper, two optimization problems are formulated: firstly, the power consumed by the manipulator is considered and the problem is solved using a single-objective genetic algorithm; then the stiffness of the manipulator is also included and the respective optimization problem is solved using a multi-objective genetic algorithm. Simulation results are presented for a parallel manipulator robotic cell.

2011

Complete Dynamic Modeling of a Stewart Platform Using the Generalized Momentum Approach

Authors
Lopes, AM; Pires, EJS;

Publication
NONLINEAR SCIENCE AND COMPLEXITY

Abstract
Dynamic modeling is of great importance regarding computer simulation and advanced control of parallel manipulators. Dynamic modeling of parallel manipulators presents an inherent complexity, mainly due to system closed-loop structure and kinematic constraints. In this paper an approach based on the manipulator generalized momentum is explored and applied to the dynamic modeling of a Stewart platform. The generalized momentum is used to compute the kinetic component of the generalized force acting on each manipulator rigid body. Analytic expressions for the rigid bodies' inertia and Coriolis and centripetal terms matrices are obtained, which can be added, as they are expressed in the same frame. Gravitational part of the generalized force is obtained using the manipulator potential energy.

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