Polytechnic Institute of Guarda

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Mateus J.P.,Polytechnic Institute of Guarda | Silva C.M.,University of Beira Interior
Nonlinear Analysis: Real World Applications | Year: 2017

For a family of periodic SEIRS models with general incidence, we prove the existence of at least one endemic periodic orbit when some condition related to R0 holds. Additionally, we prove the existence of a unique disease-free periodic orbit, that is globally asymptotically stable when R0<1. In particular, our main result generalizes the one in Zhang et al. (2012). We also discuss some examples where our results apply and show that, in some particular situations, we have a sharp threshold between existence and non existence of an endemic periodic orbit. © 2016 Elsevier Ltd


Martins N.,Ensiguarda | Carreto C.,Polytechnic Institute of Guarda
Iberian Conference on Information Systems and Technologies, CISTI | Year: 2017

In outdoor activities, such as managing paths in all-terrain vehicles, mountain biking, hiking or tourist itineraries, it is common to resort to the navigation by using a guide containing the description of the path that should be followed. A roadbook is usually printed on paper, but with current advances in mobile computing and mobile devices, it has become very interesting and useful to have a digital roadbook for smartphones and tablets, in order to facilitate the preparation of notes upon recognition of the route, as well as to assist the user when they apply these same notes when navigating. © 2017 AISTI.


de Sousa Gabriel V.M.,Polytechnic Institute of Guarda | Rodeiro-Pazos D.,University of Santiago de Compostela
Corporate Social Responsibility and Environmental Management | Year: 2017

The degree of connection and integration between stock market indices is crucial to identifying the potential benefits associated with international diversification. However, there have been no findings on relationships between sustainability indices. The present study analyses the existence of equilibrium between short- and long-term environmentally sustainable investments through Johansen cointegration tests and based on a model of asymmetric multivariate conditional heteroscedasticity. We selected indices for five segments of environmental investment (alternative energy, clean technology, green building, sustainable water, and pollution prevention) and applied a time period of roughly nine years. The obtained results show that over the long term, the indices' behaviour is autonomous, creating opportunities to diversify investment. Over the short term, environmental segments exhibit similar behaviour, approaching behaviours described by conventional indices. © 2017 John Wiley & Sons, Ltd and ERP Environment.


Marques G.,Polytechnic Institute of Guarda | Pitarma R.,Polytechnic Institute of Guarda
Iberian Conference on Information Systems and Technologies, CISTI | Year: 2017

The time that people spend inside buildings is very significant, so the environmental quality of these spaces is recognized as an important risk factor for human health. The Internet of Things (IoT) represents a technological revolution in the ascendant that is already present in several types of equipment. Thus, combining the need to monitor environmental parameters with a view to improving occupational health, with the Internet of Things paradigm, an automatic system has been developed that allows the monitoring and control of environmental conditions in indoor spaces through the Internet. The system allows you to collect moisture, temperature and luminosity data that are stored in a structured database. Access to monitoring data is accomplished through three applications - a Web portal, an Android application, and a Desktop application. Real-time monitoring allows detection and correction of unfavorable occupational health and energy efficiency situations by controlling external devices. © 2017 AISTI.


Marques G.,Polytechnic Institute of Guarda | Pitarma R.,Polytechnic Institute of Guarda
Iberian Conference on Information Systems and Technologies, CISTI | Year: 2017

The Internet of Things (loT) is a concept created to define the technological revolution of the devices used in day-today connected to the global Internet network. It is a technological revolution on the rise that is already present in various types of equipment. Thereby associating the need for monitoring of energy consumption to the paradigm of the Internet of Things, we intend to design and build an automatic system that allows monitoring and control of power outlets connected to the Internet via Wi-Fi called 'iPlug'. This system is a smart plug that fits a generic socket and provides information of power consumption (s) device (s) connected to it by calculating the current and the line voltage, this information is placed in a database. The iPlug also lets you know whether the outlet is on or off, change your status, and access to consumer data through two applications, a web portal and an application for iOS. © 2017 AISTI.


Marques G.,Polytechnic Institute of Guarda | Pitarma R.,Polytechnic Institute of Guarda
Advances in Intelligent Systems and Computing | Year: 2017

Indoor air quality parameters are extremely important to create a productive and healthy indoor environment however in many cases the air quality parameters are very different from those defined as healthy values. Considering that we spend about 90% of our lives indoors, it is extremely important to monitor the indoor air quality in real time to detect problems in the quality of air and plan interventions in the building, or in the ventilation systems in order to improve air quality. This paper aims to present a solution for indoor air quality monitoring based in Internet of Things Architecture (IoT). This solution is composed by a hardware prototype for ambient data collection and a web and smartphone compatibility for data consulting. This system, denominated by iAQ Wi-Fi, is based on open-source technologies. It is a totality Wi-Fi system, with several advantages compared to existing systems, such as its modularity, scalability, low cost and easy installation. This system performs real-time data collection that is stored in a ThingSpeak platform. The system has smartphone compatibility which allow easier access to data in real time. In this application, the user can check the latest data collected by the system and access to the history of the air quality parameters in graphical representation. iAQ Wi-Fi uses a open-source Arduino UNO as processing unit, a ESP8266 for Wi-Fi 2.4 GHZ as communication unit and incorporates an temperature and humidity sensor, a CO2 sensor, a dust sensor and a digital light sensor as sensing unit. © Springer International Publishing AG 2017.


Marques G.,Polytechnic Institute of Guarda | Pitarma R.,Polytechnic Institute of Guarda
Advances in Intelligent Systems and Computing | Year: 2017

The National Action Plan for Energy Efficiency sets targets for the years 2016 to 2020 in which energy efficiency is a European priority covering all Member States. Energy efficiency has been increasing its importance over the years National and international laws have been introduced to reinforce that concept. The Internet of Things (IoT) is a concept created to define the technological revolution of the devices used in day-to-day connected to the global Internet network. Thereby associating the need for monitoring of energy consumption to the paradigm of the Internet of Things, we intend to design and build an automatic system that allows monitoring and control of electrical devices connected to the Internet via Wi-Fi denominated by iPlug. This system is a smart plug that fits a generic socket and provides information of power consumption (s) device (s) connected to it by calculating the current and the line voltage, this information is stored in a database. The iPlug also lets you know whether the outlet is on or off, change your status, and access to consumption data through two applications, a Web portal and an application for iOS. © Springer International Publishing AG 2017.


Lobao J.A.,Polytechnic Institute of Guarda | Devezas T.,University of Beira Interior | Catalao J.P.S.,University of Beira Interior | Catalao J.P.S.,University of Lisbon
Energy | Year: 2014

Increasing energy needs are accompanied by environmental responsibilities, since nowadays electricity companies operate in a competitive and sustainable energy framework. In this context, any proposal for action on energy efficiency becomes important for consumers to minimize operational costs. In electrical installations, electricity consumption can be decreased by reducing losses in the cables, associated with the overall efficiency of the equipment, allowing a better use of the installed power. The losses must be analysed in conjunction with all loads that contribute to the currents in the sections of an electrical installation. When replacing equipment in output distribution boxes with more efficient ones, the current in those sections is reduced in association with the decrease in power losses. This decrease, often forgotten, is taken into account in this work for the economic analysis of efficiency and sustainable electrical equipment. This paper presents a new software application that compares and chooses the best investment in the acquisition of electrical equipment. Simulation results obtained with the new software application are provided and are then validated with experimental results from a real electrical installation. © 2013 Elsevier Ltd.


Gaspar P.D.,University of Beira Interior | Carrilho Goncalves L.C.,University of Beira Interior | Pitarma R.A.,Polytechnic Institute of Guarda
Applied Thermal Engineering | Year: 2011

The vertical open refrigerated display cabinets suffer alterations of their thermal performance and energy efficiency due to variations of ambient air conditions. The air curtain provides an aerothermodynamics insulation effect that can be evaluated by the thermal entrainment factor calculation as an engineering approximation or by the calculus of all sensible and latent thermal loads. This study presents the variation of heat transfer rate and thermal entrainment factor obtained through experimental tests carried out for different ambient air conditions, varying air temperature, relative humidity, velocity and its direction relatively to the display cabinet frontal opening. The thermal entrainment factor are analysed and compared with the total sensible and latent heats results for the experimental tests. From an engineering point of view, it is concluded that thermal entrainment factor cannot be used indiscriminately, although its use is suitable to design better cabinet under the same climate class condition. © 2010 Elsevier Ltd. All rights reserved.


Amado L.,Polytechnic Institute of Guarda | Albuquerque A.,University of Beira Interior | Espirito Santo A.,University of Beira Interior
Ecological Engineering | Year: 2012

This research work evaluates the impact of stormwater infiltration on the removal of organics, solids, nitrogen and phosphorus in a LECA-based horizontal subsurface flow constructed wetland. Stormwater runoff for the period between January 2008 and June 2010 (30 months) was estimated for the drainage basin of the Vila Fernando wastewater treatment plant (constructed wetland system) and it was observed proportionality between the increase in surface runoff and the infiltration flow rate that reached the plant. The average stormwater infiltration rate that reached the plant was 67.4m 3d -1 (77% of the influent flow rate into the plant). The 30 month monitoring campaign set up at one of the reed beds showed that stormwater infiltration led to a high variation of the hydraulic loading rate (HLR) throughout the bed, which affected its performance in the removal of organic matter, suspended solids and nitrogen. For a HLR below 20cmd -1 the removal efficiencies for BOD 5, COD and TSS doubled. The removal of nitrogen was too low and was associated with the weak development of nitrifying biofilm and the poor growth of reeds. However, it was observed a good relationship between the applied and removed loads for most of the parameters, which seems to indicate that the organic, solid, nitrogen and phosphorus loading rates influenced the respective removal rates. The use of a bed material with high specific surface area, such as LECA, can only improve the treatment capacity of horizontal subsurface flow systems if the organic and solid loading rates, as well as the HLR, can be effectively controlled. © 2011 Elsevier B.V.

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