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Publications

Publications by CRIIS

2017

A new brain emotional learning Simulink (R) toolbox for control systems design

Authors
Coelho, JP; Pinho, TM; Boaventura Cunha, J; de Oliveira, JB;

Publication
IFAC PAPERSONLINE

Abstract
The brain emotional learning (BEL) control paradigm has been gathering increased interest by the control systems design community. However, the lack of a consistent mathematical formulation and computer based tools are factors that have prevented its more widespread use. In this article both features are tackled by providing a coherent mathematical framework for both the continuous and discrete-time formulations and by presenting a SIMULINK (R) computational tool that can be easily used for fast prototyping BEL based control systems.

2017

An experimental analysis of the Trombe wall temperature fluctuations for high range climate conditions: Influence of ventilation openings and shading devices

Authors
Sa, AB; Boaventura Cunha, J; Lanzinha, JC; Paiva, A;

Publication
ENERGY AND BUILDINGS

Abstract
Despite the studies already developed about Trombe walls, more research work is needed to contribute to the knowledge about their behaviour and optimize it according to the specific characteristics of each climatic region. The ventilation openings and the shading device operation decisively influence the temperatures fluctuation along the system and that impact should be discussed. In this context, a test cell with a classical Trombe wall was submitted to real climatic conditions in a Portuguese city. The effect of ventilation openings and shading devices in the temperatures fluctuation was analysed. The temperatures in the air layer and along the massive wall presented a similar oscillation pattern and exceeded 60 degrees C without ventilation and shading devices. For this configuration, temperature values at the top of the air layer were always higher than those obtained at the base and a differential of 19 degrees C was achieved. The temperature fluctuation across the massive wall was not proportional to its thickness due to its heat storage capacity. When the ventilation system was closed and the shading device was not activated, the temperature inside the test cell exceeded the outside temperature value in 9 degrees C, showing the system ability to store and release heat.

2017

Experimental and analytical approach on the Trombe wall thermal performance parameters characterization

Authors
Briga Sa, A; Boaventura Cunha, J; Lanzinha, JC; Paiva, A;

Publication
ENERGY AND BUILDINGS

Abstract
An analytical and experimental analysis on the Trombe wall thermal performance was carried out for different conditions of ventilation openings and occlusion device operation. Experimental results allowed to determine temperature fluctuation, heat flux, heat delay and air velocity at the ventilation openings. A calculation methodology was applied to estimate the heat gains and losses through the system using experimental data. Ventilation openings and occlusion device effect was immediately visible in the temperature fluctuation and, consequentelly, in the heat gains and losses. Experimental.results showed that, when there was no occlusion device, massive wall external surface temperature values exceeded 60 degrees C and, when it was placed, reduced to 30 degrees C or less. Heat took almost 3 times more to achieve the interior of the test cell when the ventilation openings were closed. Air velocity increased following a diagonally pattern from the bottom to the top of the ventilation opening and its values varied between 0.10 m/s and 0.40 m/s, leading to air flow values between 0.002 m(3)/s and 0.008 m(3)/s. The calculation methodology application allowed to determine the total gains through the system for a continuous period. The impact of the system operation on the different thermal performance parameters was observed.

2017

A cost-effective instrumented walkway for measuring ground reaction forces in rats to assess gait pattern

Authors
Silva, N; Sousa, JJ; Peres, E; Sousa, A; Ruiz Armenteros, AM; Varejao, A; Morais, R;

Publication
MEASUREMENT

Abstract
Animal experiments have gained importance in human diseases studies, namely neurological diseases and its biomechanical and physiological aspects. As a model of human disease, the rat offers many advantages over other organisms. For the biomechanical aspects of locomotion these studies are based on the analysis of animals' kinetic parameters, accessed through a locomotion measurement system. However, these systems are not yet thoroughly developed, are still scarce and are also very expensive when developed for studies using small rodents. In this paper, a system capable of measuring contact forces of small rodents is presented. The platform hardware is based on a 5 x 3 matrix of ultra-sensitive force sensors that produce a set of signals acquired in a LabVIEW (TM) environment, used for data acquisition and processing. The post processing steps include the removal of null data, curve normalization related to the rat's weight and expressed as percentage of passage, resulting in a gait pattern. The proposed cost-effective system has achieved excellent results regarding the locomotion profile of healthy animals.

2017

Very high resolution aerial data to support multi-temporal precision agriculture information management

Authors
Padua, L; Adao, T; Hruska, J; Sousa, JJ; Peres, E; Morais, R; Sousa, A;

Publication
CENTERIS 2017 - INTERNATIONAL CONFERENCE ON ENTERPRISE INFORMATION SYSTEMS / PROJMAN 2017 - INTERNATIONAL CONFERENCE ON PROJECT MANAGEMENT / HCIST 2017 - INTERNATIONAL CONFERENCE ON HEALTH AND SOCIAL CARE INFORMATION SYSTEMS AND TECHNOLOGIES, CENTERI

Abstract
The usage of small-sized unmanned aerial systems (UAS) has increased in the last years, in many different areas, being agriculture and forestry those who benefit the most from this relatively new remote sensing platform. Leaf area index, canopy and plant volume are among the parameters that can be determined using the very high resolution aerial data obtained by sensors coupled in unmanned aerial vehicles (UAV). This remote sensing technology affords the possibility of monitoring the vegetative development, identifying different types of issues, enabling the application of the most appropriated treatments in the affected areas. In this paper, a methodology allowing to perform multi-temporal UAS-based data analysis obtained by different sensors is proposed. A case study in vineyards and chestnuts is used to prove the benefits of continuous crop monitoring in its management and productivity of agroforestry parcels/activities. (C) 2017 The Authors. Published by Elsevier B.V.

2017

Nash equilibrium for Proactive Anti-jamming in IEEE 802.15.4e (Emerging wireless sensor actuator technologies for 14.0)

Authors
Homay, A; de Sousa, M; Almeida, L;

Publication
2017 IEEE 15TH INTERNATIONAL CONFERENCE ON INDUSTRIAL INFORMATICS (INDIN)

Abstract
An emerging trend in industry 4.0 is to use wireless communication infrastructure and mesh networks in applications requiring high reliability and safety. Although not a typical industrial production process, railway vehicular networks are also an industrial application which come with stringent reliability and safety requirements. Current research is focusing on using vehicular networks as an enabling technology to actively control the separation between two consecutive vehicles, enforcing a safe distance which is nevertheless much shorter than currently used to maintain vehicle separation. In this respect, we analyze a hopping strategy for Time-Slotted Channel-Hopping (TSCH), which was introduced in the IEEE 802.15.4e amendment with a view of improving the reliability of IEEE 802.15.4 networks. We define a probability framework to estimate the chance of successful hopping assuming two previously merged vehicles, and we design a zero-sum game and propose a payoff function to always place communicating nodes in a Nash equilibrium by choosing whether to hop or not, and therefore maximizing the communication throughput by mitigating jamming signals.

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