@conference {8570384, title = {A Robustness Study of Metaheuristics to the Optimal Design of RF Integrated Inductors}, booktitle = {2018 15th International Multi-Conference on Systems, Signals Devices (SSD)}, year = {2018}, note = {

DOI: 10.1109/SSD.2018.8570384

}, month = {March}, pages = {1459-1464}, abstract = {

In this paper, three metaheuristics are investigated to optimize RF Integrated Inductors; namely Differential Evolution (DE) from the field of evolutionary computation, Gravitational Search Algorithm (GSA) based on the law of gravity and mass interactions and Particle Swarm Optimization (PSO) inspired by swarm behaviors in nature. A particular interest is given to the optimization of RF Integrated Inductors. Performances in terms of optimum quality and computing time of the metaheuristics are checked via three test functions and one application that consist of optimizing performances of characterize integrated inductors based on the double$π$-model.

}, keywords = {Convergence, Differential Evolution, Gravitational Search Algoritm, inductors, Mathematical model, Metaheuristics, optimization, Particle swarm optimization, Radio frequency, RF integrated inductors, robustness}, issn = {2474-0446}, doi = {10.1109/SSD.2018.8570384}, url = {https://doi.org/10.1109/SSD.2018.8570384}, author = {H. Marouani and Sallem, A. and M. Chaoui and P Pereira and N. Masmoudi} } @conference {12887, title = {Sustainable Heritage Management Towards Mass Tourism Impact: the HERIT-DATA project}, booktitle = {9th International Conference on Intelligent Systems IS{\textquoteright}18}, year = {2018}, note = {

DOI:

}, month = {25-27 Sep.}, publisher = {IEEE}, organization = {IEEE}, address = {Madeira - PT}, abstract = {

Although tourism is a major engine of economic growth, it also creates a burden hard to manage, and has a great impact on the conservation of the heritage. The HERIT-DATA project aims to reduce the impact of human activities, related to tourism, on cultural heritage, with a special focus on two kind of cultural destinations that can benefit from and be affected by mass tourism: Old towns and places of specific cultural heritage or archaeological interest for visitors, including UNESCO World Heritage Sites. In that framework, HERIT-DATA plans to develop of a sustainable and responsible tourism management towards cultural heritage in MED regions, in particular by taking advantage of technology and innovation in management tools (Smart Cities), as well as other policy and social measures.

}, url = {https://doi.org/}, author = {Pedro Pereira and Martins, Jo{\~a}o} } @conference {10.1007/978-3-319-75789-6_7, title = {An Application to Improve Smart Heritage City Experience}, booktitle = {Advances in Digital Cultural Heritage}, year = {2018}, note = {

DOI: 10.1007/978-3-319-75789-6_7

Print ISBN
978-3-319-75788-9
Online ISBN
978-3-319-75789-6

}, pages = {89{\textendash}103}, publisher = {Springer International Publishing}, organization = {Springer International Publishing}, address = {Cham}, abstract = {

Nowadays technologies relate to so many aspects in our daily life that makes society eager for more and more ways of using it. To keep up with this new technological world, all economic sectors, from industry to services, are trying to adapt their products into this new reality. Presently, cultural heritage is already a field where the application of technology allows a static site to be converted into an intelligent environment, with detailed information about a specific monument or historical place, becoming more interesting, not only for local habitants, but also for tourists. This paper describes an application that allows tourists, managers and historical sites{\textquoteright} habitants to experience a completely new way of discovering those places, offering a visit with detailed real-time information taking into account their personal interests. Tourists will have at their disposal a full set of optimized routes, combining their interests with their visiting time.

}, isbn = {978-3-319-75789-6}, url = {https://doi.org/10.1007/978-3-319-75789-6_7}, author = {Mar, Adriana and Monteiro, Fernando and Pedro Pereira and Martins, Jo{\~a}o}, editor = {Ioannides, Marinos and Martins, Jo{\~a}o and {\.Z}arni{\'c}, Roko and Lim, Veranika} } @conference {10.1007/978-3-030-01762-0_36, title = {Smart Tourism Routes Based on Real Time Data and Evolutionary Algorithms}, booktitle = {Digital Heritage. Progress in Cultural Heritage: Documentation, Preservation, and Protection}, year = {2018}, note = {

DOI: 10.1007/978-3-030-01762-0_36

Print ISBN
978-3-030-01761-3
Online ISBN
978-3-030-01762-0

}, pages = {417{\textendash}426}, publisher = {Springer International Publishing}, organization = {Springer International Publishing}, address = {Cham}, abstract = {

Tourism is an industry that has been growing rapidly in the last few years and it is expected that it will continue to grow. Due to the evolution of technology, mobile applications are being increasingly used in all kinds of industries, being one of them tourism. Presently there are already a few mobile applications used to increase the experience of the user when visiting a place, but these mobile applications lack some important features. This paper describes the development of a mobile application with integrated routing algorithms used to increase the experience of the tourists when visiting the city of Avila, Spain. The tourist will have at their disposal real time information about all the monuments available for visit, a full set of predefined circuits with different visit times and degrees of difficulty and also the possibility to create an optimized or personalized circuit combining the user preferences such as visiting time and number of monuments to visit.

}, isbn = {978-3-030-01762-0}, url = {https://doi.org/10.1007/978-3-030-01762-0_36}, author = {Amorim, M{\'a}rio and Mar, Adriana and Monteiro, Fernando and Sylaiou, Stella and Pedro Pereira and Martins, Jo{\~a}o}, editor = {Ioannides, Marinos and Fink, Eleanor and Brumana, Raffaella and Patias, Petros and Doulamis, Anastasios and Martins, Jo{\~a}o and Wallace, Manolis} } @conference {8292123, title = {Automatic sensitivity analysis tool for analog active filter}, booktitle = {2017 24th IEEE International Conference on Electronics, Circuits and Systems (ICECS)}, year = {2017}, note = {

DOI: 10.1109/ICECS.2017.8292123

}, month = {Dec}, pages = {124-127}, abstract = {

In this paper we deal with analog active filter design using discrete components taking into consideration tolerance effects. Sensitivity analysis is performed to determine the most influential components in the considered circuit, thus relative higher precision is offered to those parameters. Further, an in-loop optimization technique is considered, thus actual IC models are handled. An application example is presented. HSpice simulation results, supported by Monte Carlo analysis, are given to highlight efficiency of the proposed selection technique.

}, keywords = {Active filters, Algorithm design and analysis, Analog active filter, Extrapolation, Monte Carlo methods, optimization, Particle swarm optimization, Richardson extrapolation, Sensitivity analysis, Simulation}, doi = {10.1109/ICECS.2017.8292123}, url = {https://doi.org/10.1109/ICECS.2017.8292123}, author = {Sallem, A. and P Pereira and Fakhfakh, M.} } @conference {7935638, title = {Smart-meter in power quality}, booktitle = {2017 International Young Engineers Forum (YEF-ECE)}, year = {2017}, note = {

DOI: 10.1109/YEF-ECE.2017.7935638

}, month = {5 May}, pages = {42-46}, abstract = {

In this paper, an innovative approach for monitoring home electric power quality indicators is presented. Using an electric power analysis device (for this work purpose it will be a smart-meter) and a personal computer it is proved that it is possible to monitor and register electric power quality anomalies, such as long interruptions, voltage dips/swells and frequency oscillations. Through an application developed in Java, a user can view real-time electric parameters, check for electric power quality anomalies and assess load diagram of previous days. Experimental results regarding the application performance are also presented with the respective conclusions.

}, keywords = {Databases, Harmonic analysis, monitoring, Power quality, Standards, Voltage fluctuations}, doi = {10.1109/YEF-ECE.2017.7935638}, url = {https://doi.org/10.1109/YEF-ECE.2017.7935638}, author = {N. R. Ramos and P Pereira and J. F. Martins} } @book {11600, title = {Focus on Swarm Intelligence Research and Applications}, year = {2017}, note = {

Bachir Benhala (University of Moulay Ismail, Faculty of Sciences, Meknes - Morocco), Pedro Pereira (FCT NOVA, Portugal), and Amin Sallem (LETI-ENIS, University of Sfax, Tunisia) (Eds.)

ISBN-13
978-1-53612-452-1
ISBN-10
1536124524

}, publisher = {Nova Science Publishers}, organization = {Nova Science Publishers}, abstract = {

Swarm intelligence techniques are among the most talented and successful approaches that gained a lot of popularity over the past two decades. They are inspired by animal behavior (such as ants, termites and bees) and insect conduct (by swarm, herd, flock and shoal phenomena) in order to develop these techniques in terms of mimicking their problem/solution abilities. These techniques provide good approximate solutions in a reasonable time for solving hard and complex problems in many engineering fields. This book is intended for researchers, engineers and graduate students with interests in swarm intelligence algorithms and their applications. It discusses and describes the various swarm intelligence techniques as useful tools for solving practical problems, such as urban traffic optimization, electrical engineering problems and the design of integrated analog circuits.

}, url = {https://novapublishers.com/shop/focus-on-swarm-intelligence-research-and-applications/} } @proceedings {proceedings1070695, title = {Interoperability: A Data Conversion Framework to Support Energy Simulation}, journal = {Sustainable Places 2017}, volume = {1}, number = {7}, year = {2017}, note = {

DOI: 10.3390/proceedings1070695

}, abstract = {

In this paper an interoperability solution is proposed, aiming to go from (building) construction models to energy simulation. Moreover, the energy simulation results will feed the KPI{\textquoteright}s analysis of a designed building. The proposed solution will be used to translate different data formats allowing the communication between different systems in an automated environment. The solution presented in this paper exploits the concept of Plug{\textquoteright}n{\textquoteright}Interoperate (PnI), that is supported by the principle of self-configuration as to automate, as much as possible, the configuration and participation of systems into a shared interoperability environment. In order to validate this approach two different scenarios were taken into account, translating from a CAD (Computer- Aided Design) model data format to an energy simulation data format.

}, issn = {2504-3900}, doi = {10.3390/proceedings1070695}, url = {https://doi.org/10.3390/proceedings1070695}, author = {Paiva, Lu{\'\i}s and Pedro Pereira and Almeida, Bruno and Mal{\'o}, Pedro and Hyv{\"a}rinen, Juha and Klobut, Krzysztof and Dimitriou, Vanda and Tarek Hassan} } @inbook {11601, title = {Sensitivity Analysis in the Optimization of Analog Active Filters by Applying the Richardson Extrapolation}, booktitle = {Focus on Swarm Intelligence Research and Applications}, year = {2017}, note = {

ISBN-13
978-1-53612-452-1
ISBN-10
1536124524

}, pages = {247-275}, publisher = {Nova Science Publishers}, organization = {Nova Science Publishers}, abstract = {

The key step of the analog active filter design is the optimal selection of component values due to manufactured series (E12, E24, E48, E96 and E192). In this paper, four simulation-based metaheuristics are applied to optimize four active filters using commercials available ICs as building blocks. The emphasis of this work is applying Richardson extrapolation-based sensitivity analysis in the optimization process of analog active filters. Indeed, Richardson extrapolation technique facilitates the calculation of the partial derivatives for the sensitivity using the simulation-based evaluation, without an explicit mathematical expression. Viability and benefits of the sensitivity analysis are highlighted. Monte Carlo analysis is performed in order to investigate robustness of the proposed sensitivity analysis of the active filters in case of component value variations due to specified tolerances of manufactured series.

}, url = {https://www.novapublishers.com/catalog/product_info.php?products_id=62945}, author = {Amin Sallem and Pedro Pereira}, editor = {Benhala, Bachir and Pedro Pereira and Amin Sallem} } @proceedings {11131, title = {Technical challenges and approaches to transfer building information models to building energy}, journal = {Proceedings of ECPPM 2016}, year = {2016}, note = {

DOI:10.1201/9781315386904-54

Print ISBN: 978-1-138-03280-4

eBook ISBN: 978-1-315-38689-8

}, month = {2016/08/15}, pages = {355-362}, publisher = {CRC Press}, abstract = {

The complex data exchange between architectural design and building energy simulation constitutes the main challenge in the use of energy performance analyses in the early design stage. The enhancement of BIM model data with additional specific energy-related information and the subsequent mapping to the input of an energy analysis or simulation tool is yet an open issue. This paper examines three approaches for the data transfer from 3D CAD applications to building performance simulations using BIM as central data repository and points out their current and envisaged use in practice. The first approach addresses design scenarios. It focuses on the supporting tools needed to achieve interoperability given a 74 wide-spread commercial BIM model (Autodesk Revit) and a dedicated pre-processing tool (DesignBuilder) for EnergyPlus. The second approach is similar but addresses retrofitting scenarios. In both workflows gbXML is used as the transformation format. In the third approach a standard BIM model, IFC is used as basis for the transfer process for any relevant lifecycle phase.

}, isbn = {978-1-138-03280-4}, url = {http://www.crcnetbase.com/doi/abs/10.1201/9781315386904-54}, author = {Noack, F and Katranuschkov, P and Scherer, R and Dimitriou, V and Firth, SK and Hassan, TM and Ramos, N and P Pereira and Mal{\'o}, P and Fernando, T}, editor = {Christodoulou, Symeon E. and Scherer, Raimar} } @article {Kchaou2016220, title = {Sensitivity aware NSGA-II based Pareto front generation for the optimal sizing of analog circuits}, journal = {Integration, the \{VLSI\} Journal}, volume = {55}, year = {2016}, note = {

DOI: 10.1016/j.vlsi.2016.07.001

}, pages = {220 - 226}, abstract = {

Abstract This paper deals with multiobjective analog circuit optimization taking into consideration performance sensitivity vis-a-vis parameters{\textquoteright} variations. It mainly considers improving computation time of the inloop optimization approaches by including sensitivity considerations in the Pareto front generation process, not as a constraint, but by involving it within the used metaheuristic evolution process. Different approaches are proposed and compared. NSGA-II metaheuristic is considered. The proposed sensitivity aware approaches are showcased via two analog circuits, namely, a second generation \{CMOS\} current conveyor and a \{CMOS\} voltage follower. We show that the proposed ideas considerably alleviate the long computation time of the process and improve the quality of the generated front, as well.

}, keywords = {Richardson extrapolation technique}, issn = {0167-9260}, doi = {http://dx.doi.org/10.1016/j.vlsi.2016.07.001}, url = {https://doi.org/10.1016/j.vlsi.2016.07.001}, author = {O. Bellaaj Kchaou and A. Garbaya and Kotti, M. and P Pereira and Fakhfakh, M. and M. Helena Fino} } @conference {7301696, title = {Multi-objective sensitivity-based optimization of analog circuits exploiting NSGA-II front ranking}, booktitle = {Synthesis, Modeling, Analysis and Simulation Methods and Applications to Circuit Design (SMACD), 2015 International Conference on}, year = {2015}, note = {

DOI: 10.1109/SMACD.2015.7301696

}, month = {Sept}, pages = {1-4}, address = {Istanbul, Turkey}, abstract = {

This work deals with the multi-objective optimization of analog circuits by generating the Pareto front where elements are low sensitive to parameters{\textquoteright} variations. NSGA-II is used for obtaining the non-dominated solutions. Richardson extrapolation technique is used for the in-loop optimization approach for computing partial derivatives and, thus, the solutions{\textquoteright} sensitivity. NSGA-II Pareto fronts{\textquoteright} intrinsic ranking is exploited for the generation of the new {\textquoteleft}low-sensitive{\textquoteright} Pareto front. The case of the optimal sizing of a CMOS voltage follower is considered to exemplify the proposed approach.

}, keywords = {analog circuits, Extrapolation, optimization, Sensitivity analysis, sociology, Statistics}, doi = {10.1109/SMACD.2015.7301696}, url = {http://dx.doi.org/10.1109/SMACD.2015.7301696}, author = {Omaya Bellaaj Kchaou and Amin Sallem and Pedro Pereira and Mourad Fakhfakh and Maria Helena Fino} } @conference {7266356, title = {Android-based m-learning remote system for mobile power quality assessment in large buildings with renewable energies}, booktitle = {Power Engineering, Energy and Electrical Drives (POWERENG), 2015 IEEE 5th International Conference on}, year = {2015}, note = {

DOI: 10.1109/PowerEng.2015.7266356
Print ISBN
978-1-4673-7203-9

}, month = {May}, pages = {431-434}, address = {Riga, Latvia}, abstract = {

Power Quality is a generic term focusing on several issues, going from reliability to the quality of service provided by the energy supplier. It addresses limiting aspects such as harmonic distortion, flicker, sags, swells and transients... It is important for the students to understand the differences between the large amounts of events that fit into poor power quality category. Moreover it is important for them to analyze real time non-laboratory events. To provide this experience to the students this paper presents a remote m-learning experimental system where several types of poor power quality events can be tested. The developed system is based on a power quality analysis distributed network and can be remotely accessed from a remote computer or smart phones.

}, keywords = {Android (operating system), Android-based m-learning remote system, Buildings, computer aided instruction, Data acquisition, Databases, distributed network, educational courses, energy supplier, Europe, flicker, harmonic distortion, large buildings, Mobile communication, mobile handsets, mobile learning, mobile power quality assessment, monitoring, poor power quality category, poor power quality events, power engineering education, Power quality, power quality analysis, power supply quality, power system harmonics, power system reliability, quality of service, real time nonlaboratory events, remote computer, remote m-learning experimental system, renewable energies, renewable energy sources, smart phones}, doi = {10.1109/PowerEng.2015.7266356}, url = {http://dx.doi.org/10.1109/PowerEng.2015.7266356}, author = {Cardoso, T. and P Pereira and Fernaao Pires, V. and J. F. Martins} } @conference {7231124, title = {Study of an axial flux disc motor with superconductor rotor}, booktitle = {Compatibility and Power Electronics (CPE), 2015 9th International Conference on}, year = {2015}, note = {

DOI: 10.1109/CPE.2015.7231124

}, month = {June}, pages = {488-493}, address = {Costa de Caparica, Portugal }, abstract = {

The integration of high temperature superconductors (HTS) in electrical machines potentially allows reduction in devices dimensions or performance improvement for the same active volume, when compared with their conventional ones. The use of polycrystalline HTS samples allows big bulk samples. An axial disc motor with HTS material or conventional aluminium in the rotor and conventional armature has been designed and developed. This paper describes simulations and laboratory experiments performed at liquid nitrogen temperature (77 K) in order to analyze the motor{\textquoteright}s behaviour and its electromechanical characteristics and to define an electric equivalent circuit that allows describing its operation. In order to evaluate the superconducting quality of the bulks and flux pinning phenomena, Hall probe mapping system was performed in order to define the field profiles at 77 K for different polar configurations. The analysis of the obtained results allows confirm the flux pinning phenomena, being the entire rotor magnetized and conclude that the motor with the HTS rotor behaves as a conventional hysteresis motor even though with a different nature, while the motor with aluminium rotor behaves as a conventional induction motor. In asynchronous regime, the HTS motor exhibits a constant torque, higher than the conventional aluminium one. For both cases, the developed torque is proportional to the poles pairs.

}, keywords = {aluminium rotor, axial flux disc motor, axial flux disc motor experiments, electric equivalent circuit, electric machines, electrical machines, electromechanical characteristics, equivalent circuits, flux pinning, Hall probe mapping system, high temperature superconductors, high-temperature superconductors, HTS, HTS rotor, induction motors, Magnetic flux, rotors, Superconducting magnets, superconducting quality, superconductor rotor, Synchronous motors, Torque, YBCO}, doi = {10.1109/CPE.2015.7231124}, url = {http://dx.doi.org/10.1109/CPE.2015.7231124}, author = {Inacio, D. and Murta Pina, J. and P Pereira and Pronto, A. and Ventim Neves, M. and A Alvarez} } @article {6939640, title = {Validation and Application of Sand Pile Modeling of Multiseeded HTS Bulk Superconductors}, journal = {Applied Superconductivity, IEEE Transactions on}, volume = {25}, number = {3}, year = {2015}, note = {

DOI: 10.1109/TASC.2014.2366073

Online ISSN: 1051-8223

}, month = {June}, pages = {1-5}, abstract = {

Sand pile and Bean models have already been applied to describe single grain HTS bulks. An extension to that approach was used to model multiseed bulks, needed for several practical applications as electric motors or flywheels with superconducting bearings. The use of genetic algorithms was then proposed to determine intra- and intergrain current densities, and application to two and three seeds samples using trapped flux experimental measurements was exemplified. However, this model assumed some simplifications, as equal properties in grain boundaries between neighboring grains. In this paper an extension to this methodology is proposed and evaluated by analyzing measurements performed in plans at different distances from surfaces of samples with three seeds. Discussion of its influence on a practical application is also explored.

}, keywords = {Bean model, Bean models, current density, Density measurement, flux pinning, genetic algorithms, grain boundaries, high-temperature superconductors, intergrain current density, intraintergrain current density, Materials, multiseeded HTS bulk superconductors, multiseeded superconductors, sand pile model, sand pile modeling, sandpile models, Superconducting magnets, trapped flux, trapped flux experimental measurements}, issn = {1051-8223}, doi = {10.1109/TASC.2014.2366073}, url = {http://dx.doi.org/10.1109/TASC.2014.2366073}, author = {Murta-Pina, J. and P Pereira and Ceballos, J.M. and A Alvarez and Amaro, N. and Pronto, A. and Silva, J. and Arsenio, P.} } @conference {7392748, title = {A new teaching tool to enhance power quality assessment}, booktitle = {Industrial Electronics Society, IECON 2015 - 41st Annual Conference of the IEEE}, year = {2015}, note = {

DOI: 10.1109/IECON.2015.7392748

}, month = {9-12 Nov.}, pages = {004158-004162}, publisher = {IEEE-IES}, organization = {IEEE-IES}, address = {Yokohama, Japan}, abstract = {

The study and assessment of Power Quality issues is nowadays a very important subject, particularly regarding Cyber-physical and Industrial Agents based systems, which are extremely sensitive to Power Quality disturbances. Giving students or engineers practical experience in this field requires a large investment from teaching institutions. This paper presents a laboratory device that emulates Power Quality disturbances in order to provide the required experimental expertize in the subject. It addresses limiting aspects such as harmonic distortion, flicker, sags, swells and transients. The developed system presents a good opportunity for technicians, even without deep knowledge on the field of power quality, to learn basic principles and be able to identify Power Quality events. Since the system is based on real data, represents a valuable approach giving trainees practical knowledge on the field.

}, keywords = {fault event generator, power inverter, Power quality}, doi = {10.1109/IECON.2015.7392748}, url = {http://dx.doi.org/10.1109/IECON.2015.7392748}, author = {J. F. Martins and P Pereira and A. J. Pires and V. F. Pires} } @inbook {7771, title = {Optimization-Based Design of RF-VCOs with Tapered Inductors}, booktitle = {Performance Optimization Techniques in Analog, Mixed-Signal, and Radio-Frequency Circuit Design}, year = {2015}, note = {

DOI: 10.4018/978-1-4666-6627-6.ch006

}, month = {2015}, pages = {134 - 157}, publisher = {IGI Global}, organization = {IGI Global}, address = {Hershey, PA, USA}, abstract = {

Voltage-Controlled Oscillators (VCOs) are widely used in wireless transceivers. Due to the stringent specifications regarding phase-noise, LC-VCOs are usually adopted. The need for maximizing phase-noise as well as minimizing the power consumption makes imperious the adoption of optimization-based design methodologies. For the optimization of the LC-VCO characteristics, special attention must be paid to the integrated inductor design, since its quality factor may have a strong influence in the LC-VCO phase-noise. Furthermore, designers must ensure that the higher limit of VCO operating frequency is sufficiently below the inductor resonant frequency. In this chapter, a study on the influence of the quality factor of the inductors on the LC-VCO overall behavior is presented. Then, optimization of integrated inductors by exploring the inductor geometric layout is presented. Finally, results obtained for the design of an LC-VCO in 130nm Technology using a previously optimized inductor are presented.

}, isbn = {9781466666276}, url = {http://services.igi-global.com/resolvedoi/resolve.aspx?doi=10.4018/978-1-4666-6627-6.ch006}, author = {Pedro Pereira and F{\'a}bio Passos and M. Helena Fino}, editor = {Mourad Fakhfakh and Esteban Tlelo-Cuautle and Maria Helena Fino} } @article {Sallem2015, title = {A hybrid approach for the sensitivity analysis of integrated inductors}, journal = {Integration, the \{VLSI\} Journal}, year = {2015}, note = {

DOI: 10.1016/j.vlsi.2015.04.006

}, pages = {1-6}, abstract = {

Abstract This paper proposes a hybrid methodology for the evaluation of integrated inductors sensitivity against technological/geometrical parameters variation. The obtained results are used in an optimization-based design environment for integrated inductors, as a way of guaranteeing that obtained solutions are robust against parameter variation. For the inductor characterization, a lumped element model is used, where each element value is evaluated through physics based equations. The sensitivity of the inductor characterization to parameter variations is evaluated at two levels. At the physical level, the sensitivity of the model element values to technological/geometrical parameters variations is computed through an equation-based strategy. Then, the sensitivity of the inductor characterization to the model parameter variations is obtained through a simulation-based approach, where the Richardson extrapolation technique is used for the calculation of the partial derivatives. Several examples considering the evaluation of sensitivity of both inductance and quality factor of two inductors in \{UMC130\} technology are presented. Obtained results are compared against Monte-Carlo simulations.

}, keywords = {Inductor π-model and double π-model}, issn = {0167-9260}, doi = {http://dx.doi.org/10.1016/j.vlsi.2015.04.006}, url = {http://www.sciencedirect.com/science/article/pii/S016792601500053X}, author = {Sallem, A. and P Pereira and M. Helena Fino and Fakhfakh, M.} } @conference {6603, title = {Power quality and long life education}, booktitle = {Industrial Electronics (ISIE), 2014 IEEE 23rd International Symposium on}, year = {2014}, note = {

DOI: 10.1109/ISIE.2014.6864963

}, month = {2014/06}, pages = {2224 - 2228}, address = {Istanbul - Turkey}, abstract = {

This paper presents a remote laboratory linked with mobile devices for real data analysis on the field of power quality. A global system was developed from the power quality analyzer into the human machine interface devoted to the m-learning system. This m-learning system is intended to be used in a long life learning perspective. The developed remote laboratory is a good opportunity for people, even without deep knowledge on the field, to learn power quality principles in an applied way. Since the system is based on real data, is a good approach to give trainees practical knowledge on the field.

}, keywords = {data analysis;educational technology;laboratory techniques;man-machine systems;mobile handsets;power supply quality;data analysis;human machine interface;long life education;m-learning system;mobile devices;power quality analyzer;remote laboratory;Data ac}, url = {http://dx.doi.org/10.1109/ISIE.2014.6864963}, author = {Cardoso, T. and P Pereira and Fernao Pires, V. and J. F. Martins} } @article {5104, title = {Optimal LC-VCO design through evolutionary algorithms}, journal = {Analog Integrated Circuits and Signal Processing}, volume = {78}, year = {2014}, note = {

DOI: 10.1007/s10470-013-0212-x
Print ISSN
0925-1030
Online ISSN
1573-1979

}, pages = {99-109}, publisher = {Springer US}, abstract = {

The need for implementing low cost, fully integrated RF wireless transceivers has motivated the widespread use CMOS technology. However, in the particular case for voltage-controlled oscillators (VCO) where ever more stringent specifications in terms of phase-noise must be attained, the design of the on-chip LC tank is a challenging task, where fully advantage of the actual technologies characteristics must be pushed to nearly its limits. To overcome phase-noise limitations arising from the low quality factor of integrated inductors, optimization design methodologies are usually used. In this paper a model-based optimization approach is proposed. In this work the characterization of the oscillator behaviour is guaranteed by a set of analytical models describing each circuit element performance. A set of working examples for UMC130 technology, aiming the minimization of both VCO phase noise and power consumption, is addressed. The results presented, illustrate the potential of a GA optimization procedure design methodology yielding accurate and timely efficient oscillator designs. The validity of the results is checked against HSPICE/RF simulations.

}, keywords = {Design methodology, Discrete-variable optimization, Evolutionary algorithms, LC-VCO}, issn = {0925-1030}, doi = {10.1007/s10470-013-0212-x}, url = {http://dx.doi.org/10.1007/s10470-013-0212-x}, author = {P Pereira and Helena Fino, M. and Ventim-Neves, M.} } @article {3687, title = {Sand Pile Modeling of Multiseeded HTS Bulk Superconductors: Current Densities Identification by Genetic Algorithms}, journal = {IEEE Transactions on Applied Superconductivity}, volume = {23}, year = {2013}, note = {

DOI:10.1109/TASC.2012.2234187

}, month = {June}, pages = {8000804 - 8000804}, abstract = {

The sand pile model, in conjunction with Bean model, is often applied to describe single grain bulk superconductors. However, in several applications such as electric motors, multiseeded bulks are needed, due to the need to increase sample dimensions. In this paper, an extension of the sand pile model is presented in order to manage this type of materials. Multiseeded HTS bulk superconductors, produced, e.g., by the top-seeded melt growth process, are characterized by intra- and intergrain currents, and these are reflected in the model. However, identifying these currents from flux density measurements is not straightforward, when considering more than one grain. In fact, the number of currents increases with the number of grains, and these have to be identified from the measured field surface. A method to identify these currents based on genetic algorithms is validated with artificial data and then used in real measurements.

}, keywords = {Bean model;critical current density (superconductivity);flux pinning;genetic algorithms;high-temperature superconductors;sandpile models;Bean model;artificial data;current density identification;electric motors;flux density measurements;genetic algorithms}, url = {http://dx.doi.org/10.1109/TASC.2012.2234187 }, author = {J M Pina and P Pereira and Valadas, D. and Ceballos, J.M. and A Alvarez} } @conference {4322, title = {Metaheuristic algorithms comparison for the LC - Voltage controlled oscillators optimal design}, booktitle = {5th International Conference on Modeling, Simulation and Applied Optimization (ICMSAO)}, year = {2013}, note = {

DOI:10.1109/ICMSAO.2013.6552658
Print ISBN
978-1-4673-5812-5

}, month = {28-30 April 2013}, pages = {1 - 6}, address = {Hammamet, Tunisia}, abstract = {

The goal of this paper is to present a comparison among three known metaheuristics: Genetic Algorithm (GA), Particle Swarm Optimization (PSO) and Simulated Annealing (SA). For the comparison, the design of an LC - Voltage Controlled Oscillator (LC-VCO) is considered, where the minimization of both VCO phase noise and power consumption is envisaged. The objective of this comparison is to find the algorithm yielding the best solution. The validity of the solution obtained with each metaheuristic algorithm is checked against HSPICE/RF simulation results. Robustness checks for each algorithm are presented at the end of this paper.

}, keywords = {Genetic Algorithms;LC-VCO;Metaheuristics;Particle Swarm Optimization;Simulated Annealing}, url = {http://dx.doi.org/10.1109/ICMSAO.2013.6552658}, author = {P Pereira and Kotti, M. and Fino, H. and Fakhfakh, M.} } @inbook {3792, title = {LC-VCO Design Challenges in the Nano-Era}, booktitle = {Analog/RF and Mixed-Signal Circuit Systematic Design}, series = {Lecture Notes in Electrical Engineering}, volume = {233}, year = {2013}, note = {

DOI:10.1007/978-3-642-36329-0_16
Print ISBN
978-3-642-36328-3
Online ISBN
978-3-642-36329-0
Series ISSN
1876-1100

}, pages = {363-379}, publisher = {Springer Berlin Heidelberg}, organization = {Springer Berlin Heidelberg}, abstract = {

The progressive scaling of CMOS technology towards nanometre sizes has made the implementation of highly integrated systems for the wireless communication systems possible. Additionally, higher speed, lower power consumption and area reduction has been reached. Due to the high-density integration needs, as well as to low cost fabrication, RF applications, such as the LC-voltage controlled oscillator (LC-VCO), are usually implemented in CMOS technology. The complexity of designing LC-VCOs has lead to the development of several design methodologies. This chapter introduces an optimization based methodology for the design of LC-VCOs, where its efficiency is granted by the use of analytical models to characterize the active and passive elements{\textquoteright} behaviour.

}, isbn = {978-3-642-36328-3}, doi = {10.1007/978-3-642-36329-0_16}, url = {http://dx.doi.org/10.1007/978-3-642-36329-0_16}, author = {Pedro Pereira and Fino, Helena and Mourad Fakhfakh and Coito, Fernando and Ventim-Neves, M{\'a}rio}, editor = {Mourad Fakhfakh and Esteban Tlelo-Cuautle and Castro-Lopez, Rafael} } @conference {3793, title = {A Multi-objective Simulation Based Tool: Application to the Design of High Performance LC-VCOs}, booktitle = {Technological Innovation for the Internet of Things}, series = {IFIP Advances in Information and Communication Technology}, volume = {394}, year = {2013}, note = {

DOI:10.1007/978-3-642-37291-9_49
Print ISBN
978-3-642-37290-2
Online ISBN
978-3-642-37291-9

}, pages = {459-468}, publisher = {Springer Berlin Heidelberg}, organization = {Springer Berlin Heidelberg}, address = {Portugal}, abstract = {

The continuing size reduction of electronic devices imposes design challenges to optimize the performances of modern electronic systems, such as: wireless services, telecom and mobile computing. Fortunately, those design challenges can be overcome thanks to the development of Electronic Design Automation (EDA) tools. In the analog, mixed signal and radio-frequency (AMS/RF) domains, circuit optimization tools have demonstrated their usefulness in addressing design problems taking into account downscaling technological aspects. Recent advances in EDA have shown that the simulation-based sizing technique is a very interesting solution to the {\textquoteleft}complex{\textquoteright} modelling task in the circuit design optimization problem. In this paper we propose a multi-objective simulation-based optimization tool. A CMOS LC-VCO circuit is presented to show the viability of this tool. The tool is used to generate the Pareto front linking two conflicting objectives, namely the VCO Phase Noise and Power Consumption. The accuracy of the results is checked against HSPICE/RF simulations.

}, keywords = {Inductor 2-π model, LC-VCO, Metaheuristic, Multi-Objective Optimization, Pareto Front, Simulation-based optimization}, isbn = {978-3-642-37290-2}, doi = {10.1007/978-3-642-37291-9_49}, url = {http://dx.doi.org/10.1007/978-3-642-37291-9_49}, author = {Amin Sallem and Pedro Pereira and Mourad Fakhfakh and Fino, Helena}, editor = {Camarinha-Matos, LuisM. and Tomic, Slavisa and Gra{\c c}a, Paula} } @conference {3794, title = {Using Variable Width RF Integrated Inductors for Quality Factor Optimization}, booktitle = {Technological Innovation for the Internet of Things}, series = {IFIP Advances in Information and Communication Technology}, volume = {394}, year = {2013}, note = {

DOI:10.1007/978-3-642-37291-9_67
Print ISBN
978-3-642-37290-2
Online ISBN
978-3-642-37291-9

}, pages = {619-627}, publisher = {Springer Berlin Heidelberg}, organization = {Springer Berlin Heidelberg}, abstract = {

The advancement of CMOS technology led to the integration of more complex functions. In the particular of wireless transceivers, integrated LC tanks are becoming popular both for VCOs and integrated filters [1]. For RF applications the main challenge is still the design of integrated inductors with the maximum quality factor. For that purpose, tapered, i.e., variable width inductors have been proposed in the literature. In this paper, analytical expressions for the determination the pi-model parameters, for the characterization of variable width integrated inductors are proposed. The expressions rely exclusively on geometrical and technological parameters, thus granting the rapid adaptation of the model to different technologies. The results obtained with the model are compared against simulation with ASITIC, showing errors below 10\%. The model is then integrated into an optimization procedure where inductors with a quality factor improvement in the order of 20-30\% are obtained, when compared with fixed width inductors.

}, keywords = {Inductor layout optimization, integrated RF inductor, variable metal width}, isbn = {978-3-642-37290-2}, doi = {10.1007/978-3-642-37291-9_67}, url = {http://dx.doi.org/10.1007/978-3-642-37291-9_67}, author = {Almeida, Pedro and Pedro Pereira and Fino, Helena}, editor = {Camarinha-Matos, LuisM. and Tomic, Slavisa and Gra{\c c}a, Paula} } @inbook {1780, title = {Variability-Aware Optimization of RF Integrated Inductors in Nanometer-Scale Technologies}, booktitle = {Integrated Circuits for Analog Signal Processing}, year = {2013}, note = {

DOI:10.1007/978-1-4614-1383-7_12
ISBN 978-1-4614-1382-0

}, pages = {271-287}, publisher = {Springer-Verlag}, organization = {Springer-Verlag}, address = {New York}, abstract = {

Progressive scaling of CMOS technology towards nanoscale regime enables the design of highly integrated systems for the wireless communications market. As technology continues to scale, the variability in process parameters may cause significant deviations in device behaviour. The complexity of designing spiral inductors has lead to the development of multi-objective optimization based design methodologies yielding the generation of Pareto-optimal surfaces. However, the variability of the process parameters is usually ignored, yielding the selection of ideally optimal solutions in detriment of quasi-optimal solutions that may prove to be better, should the robustness against process parameter variation be accounted for. We propose the generation of an extended Pareto front containing both optima and quasi-optima solutions. Finally information on the robustness to process parameter variations, is used for electing the best design solutions.The evaluation of the extended set of sub-optima solutions requires methods capable to find the set of local optima, since solutions that are close to each other in the performance index space may be very distant in the design parameter space.

}, url = {http://dx.doi.org/10.1007/978-1-4614-1383-7_12}, author = {Coito, Fernando and Fino, Helena and Pedro Pereira}, editor = {Esteban Tlelo-Cuautle} } @conference {6226193, title = {RF Varactor Design Based on Evolutionary Algorithms}, booktitle = {Mixed Design of Integrated Circuits and Systems (MIXDES), 2012 Proceedings of the 19th International Conference}, year = {2012}, note = {

Print ISBN
978-1-4577-2092-5

}, month = {may}, pages = {277 -282}, address = {Warsaw, Poland}, abstract = {

This paper introduces an optimization methodology for the design of RF varactors. The characterization of the varactor behaviour is supported by a set of equations based on technological parameters, granting the accuracy of the results, as well as the adaptability of the model to any technology. The varactor design is achieved through the implementation of a Genetic Algorithms (GA) optimization methodology, which is able to deal with continuous and/or discrete variables, making possible to suit both technological and layout constraints. A set of working examples for UMC130 technology are addressed. The results presented, spotlight the potential of varactor analytical model, combined with a GA optimization procedure, when integrated in optimization design tools. The accuracy of the results is checked against HSPICE simulator.

}, url = {http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=\&arnumber=6226193}, author = {Pedro Pereira and Fino, Helena and Ventim-Neves, M.} } @conference {6249830, title = {Towards to a Web Service alert software system for standard electrical protective devices}, booktitle = {Intelligent Engineering Systems (INES), 2012 IEEE 16th International Conference on}, year = {2012}, note = {

doi: 10.1109/INES.2012.6249830

}, month = {june}, pages = {197 -201}, address = {Lisbon, Portugal}, abstract = {

Electrical Protective Devices are key elements in the electrical network. Their purpose is to perform fault detection in electric power systems, by analysing power system voltages and currents. In order to achieve a more centralized control, protective devices can be connected using Web Services through a Service-Oriented Architecture (SOA) approach. This work targets planning and specification of a mapping between Abstract Communication Service Interface (ACSI) Reporting and Device Profile for Web Services (DPWS) Eventing to achieve a better protective electrical devices control, obtaining an event based alert software system, replacing conventional polling-based systems.

}, doi = {10.1109/INES.2012.6249830}, url = {http://dx.doi.org/10.1109/INES.2012.6249830}, author = {Delgado-Gomes, Vasco and Oliveira-Lima, Jose A. and Martins, Joao F. and Lima, Celson and Pedro Pereira} } @inbook {novapublishers23737, title = {A Technology-Aware Optimization of RF Integrated Inductors}, booktitle = {Analog Circuits: Applications, Design and Performance}, year = {2012}, month = {February}, pages = {213-234}, publisher = {Nova Science Publishers, Inc.}, organization = {Nova Science Publishers, Inc.}, abstract = {

This Chapter presents the optimal design of radio-frequency integrated spiral inductors. The basic idea is to generate an analytical model to characterize integrated inductors based on the double {\ensuremathπ}-model, and offer to the designer an approach to determine the inductor layout parameters. Particle Swarm Optimization technique is used to generate optimal values of parameters of the developed models. Viability of the proposed models is highlighted via comparison with ASITIC simulation results.

}, url = {https://www.novapublishers.com/catalog/product_info.php?products_id=23737}, author = {Pedro Pereira and Amin Sallem and Mourad Fakhfakh and Maria H. Fino and Coito, Fernando}, editor = {Esteban Tlelo-Cuautle} } @conference {2827, title = {LC-VCO design methodology based on evolutionary algorithms}, booktitle = {Synthesis, Modeling, Analysis and Simulation Methods and Applications to Circuit Design (SMACD), 2012 International Conference on}, year = {2012}, note = {

DOI:10.1109/SMACD.2012.6339449

}, month = {2012/sept.}, pages = {189 - 192}, address = {Seville - Spain}, abstract = {

In his paper the design of LC-VCOs is addressed. Due to the high-density integration needs as well as to low cost fabrication, RF applications are usually implemented in CMOS technology. However, this technology development brought up several issues such as the degradation of on-chip LC tank quality factor, yielding VCO{\textquoteright}s phase noise limitation. To overcome phase-noise limitations, optimization design methodologies are usually used. Since electromagnetic simulations are timely expensive, model based approaches are needed. In this work the characterization of the oscillator behaviour is guaranteed by a set of analytical models describing each circuit element performance. A set of working examples for UMC130 technology, aiming the VCO phase noise and power consumption optimization, is addressed. The results presented, spotlight the potential of the proposed design methodology, combined with a GA optimization procedure, for an accurate and timely efficient oscillator design. The accuracy of the results is checked against HSPICE/RF simulator.

}, url = {http://dx.doi.org/10.1109/SMACD.2012.6339449}, author = {Pedro Pereira and Fino, Helena and Ventim-Neves, M.} } @article {Pina20121248, title = {Modelling and Simulation of Inductive Fault Current Limiters}, journal = {Physics Procedia}, volume = {36}, year = {2012}, note = {

SUPERCONDUCTIVITY CENTENNIAL Conference 2011
DOI: 10.1016/j.phpro.2012.06.284

}, pages = {1248 - 1253}, abstract = {

Inductive superconducting fault current limiters have already demonstrated their technical viability in electrical networks. Its architecture and robustness make them potentially adequate for distribution networks, and this type of devices is considered as an enabling technology for the advent of embedded generation with renewable energy sources. In order to promote the growth and maturity of these superconducting technologies, fast design tools must be developed, allowing simulating devices with different materials in grids with diverse characteristics. This work presents advances in the development of such tool, which, at present stage, is an effective alternative to software simulations by finite elements methods, reducing dramatically computation time. The algorithms are now compared with experimental results from a laboratory scale prototype, showing the need to refine them.

}, keywords = {Magnetic Shielding Limiters}, issn = {1875-3892}, doi = {10.1016/j.phpro.2012.06.284}, url = {http://dx.doi.org/10.1016/j.phpro.2012.06.284}, author = {Jo{\~a}o Murta Pina and Pedro Pereira and Anabela Pronto and Pedro Ars{\'e}nio and Tiago Silva} } @conference {springerlink:10.1007/978-3-642-28255-3_50, title = {Optimization-Based Design of Nano-CMOS LC-VCOs}, booktitle = {Doctoral Conference on Computing, Electrical and Industrial Systems, DoCEIS 2012}, series = {IFIP Advances in Information and Communication Technology}, volume = {372}, year = {2012}, note = {

DOI:10.1007/978-3-642-28255-3_50

}, pages = {453-464}, publisher = {Springer Boston}, organization = {Springer Boston}, address = {Costa de Caparica - Portugal}, abstract = {

This paper introduces a variability-aware methodology for the design of LC-VCOs in Nano-CMOS technologies. The complexity of the design as well as the necessity for having an environment offering the possibility for exploring design trade-offs has led to the development of design methodologies based multi-objective optimization procedures yielding the generation of Pareto-optimal surfaces. The efficiency of the process is granted by using analytical models for both passive and active devices. Although physics-based analytical expressions have been proposed for the evaluation of the lumped elements, the variability of the process parameters is usually ignored due to the difficulty to formalize it into an optimization performance index. The usually adopted methodology of considering only optimum solutions for the Pareto surface, may lead to pruning quasi-optimal solutions that may prove to be better, should their sensitivity to process parameter variation be accounted for. In this work we propose starting by generating an extended Pareto surface where both optimum and quasi-optimum solutions are considered. Finally information on the sensitivity to process parameter variations, is used for electing the best design solution.

}, isbn = {978-3-642-28254-6}, url = {http://dx.doi.org/10.1007/978-3-642-28255-3_50}, author = {Pedro Pereira and Fino, Helena and Coito, Fernando and Ventim-Neves, M.}, editor = {Camarinha-Matos, Luis and Shahamatnia, Ehsan and Nunes, Gon{\c c}alo} } @conference {springerlink:10.1007/978-3-642-28255-3_52, title = {PSO-Based Design of RF Integrated Inductor}, booktitle = {Doctoral Conference on Computing, Electrical and Industrial Systems, DoCEIS 2012}, series = {IFIP Advances in Information and Communication Technology}, volume = {372}, year = {2012}, note = {

DOI:10.1007/978-3-642-28255-3_52

}, pages = {475-482}, publisher = {Springer Boston}, organization = {Springer Boston}, address = {Costa de Caparica - Portugal}, abstract = {

This paper addresses an optimization-based approach for the design of RF integrated inductors. The methodology presented deals with the complexity of the design problem by formulating it as a multi-objective optimization. The multi-modal nature of the underlying functions combined with the need to be able to explore design trade-offs leads to the use of niching methods. This allows exploring not only the best trade-off solutions lying on the Pareto-optimum surface but also the quasi-optimum solutions that would be otherwise discarded. In this paper we take advantage of the niching properties of lbest PSO algorithm using ring topology to devise a simple optimizer able to find the local-optima. For the efficiency of the process analytical models are used for the passive/active devices. In spite the use of physics-based analytical expressions for the evaluation of the lumped elements, the variability of the process parameters is ignored in the optimization stage due to the significant computational burden it involves. Thus in the final stage both the Pareto-optimum solutions and the quasi-optimum solutions are evaluated with respect to the sensitivity to process parameter variations.

}, isbn = {978-3-642-28254-6}, url = {http://dx.doi.org/10.1007/978-3-642-28255-3_52}, author = {Pedro Pereira and Coito, Fernando and Fino, Helena}, editor = {Camarinha-Matos, Luis and Shahamatnia, Ehsan and Nunes, Gon{\c c}alo} } @article {5677621, title = {Research and Development of Alternative Concepts in HTS Machines}, journal = {Applied Superconductivity, IEEE Transactions on}, volume = {21}, number = {3}, year = {2011}, note = {n/a}, month = {june}, pages = {1141 -1145}, abstract = {

High temperature superconducting (HTS) machines are recognized to offer several advantageous features when comparing to conventional ones. Amongst these, highlights the decrease in weight and volume of the machines, due to increased current density in conductors or the absence of iron slots{\textquoteright} teeth; or the decrease in AC losses and consequent higher efficiency of the machines, even accounting for cryogenics. These concepts have been already demonstrated and some machines have even achieved commercial stage. In this paper, several alternative approaches are applied to electrical motors employing HTS materials. The first one is an all superconducting linear motor, where copper conductors and permanent magnets are replaced by Bi-2223 windings and trapped flux magnets, taking advantage of stable levitation due to flux pinning, higher current densities and higher excitation field. The second is an induction disk motor with Bi-2223 armature, where iron, ironless and hybrid approaches are compared. Finally, an innovative command strategy, consisting of an electronically variable pole pairs{\textquoteright} number approach, is applied to a superconducting hysteresis disk motor. All these concepts are being investigated and simulation and experimental results are presented.

}, keywords = {Bi-2223 armature, Bi-2223 windings, copper conductors, cryogenics, current density, electrical motors, flux pinning, high temperature superconducting machines, high-temperature superconductors, HTS machines, HTS materials, induction disk motor, induction motors, linear motors, permanent magnets, superconducting hysteresis disk motor, superconducting linear motor, superconducting machines, trapped flux magnets}, issn = {1051-8223}, doi = {10.1109/TASC.2010.2094594}, author = {J M Pina and Inacio, D. and Luis, G. and Ceballos, J.M. and P Pereira and J. Martins and Ventim-Neves, M. and A Alvarez and A L Rodrigues} } @article {springerlink:10.1007/s10470-011-9682-x, title = {RF integrated inductor modeling and its application to optimization-based design}, journal = {Analog Integrated Circuits and Signal Processing}, volume = {73}, year = {2011}, note = {

DOI:10.1007/s10470-011-9682-x

}, pages = {47-55}, publisher = {Springer Netherlands}, abstract = {

In this paper an optimization-based approach for the design of RF integrated inductors is addressed. For the characterisation of the inductor behaviour the double pi-model is used. The use of this model is twofold. On one hand it enables the generation of the inductor characterisation in a few seconds. On the other hand its integration into the optimization procedure is straightforward. For the evaluation of the model element values analytical expressions based on technology parameters as well as on the device geometric characteristics are used. The use of a technology-based methodology for the evaluation of the model parameters grants the adaptability of the model to any technology. The inductor analytical characterization is integrated into an optimization-based tool for the automatic design of RF integrated inductors. This tool uses a modified genetic algorithm (MGA) optimization procedure, which has proved its validation in previous work. Due to the design parameter constraints nature as well as the topology constraints, discrete variables optimization techniques are used. The accuracy of the results is checked against a non-commercial software.

}, issn = {0925-1030}, url = {http://dx.doi.org/10.1007/s10470-011-9682-x}, author = {P Pereira and Helena Fino, M. and Coito, F. and Ventim-Neves, M.} } @conference {springerlink:10.1007/978-3-642-19170-1_49, title = {Sustainable Housing Techno-Economic Feasibility Application}, booktitle = {Doctoral Conference on Computing, Electrical and Industrial Systems, DoCEIS 2011}, series = {IFIP Advances in Information and Communication Technology}, volume = {349}, year = {2011}, note = {

DOI:10.1007/978-3-642-19170-1_49

}, pages = {445-454}, publisher = {Springer Boston}, organization = {Springer Boston}, address = {Costa de Caparica - Portugal}, abstract = {

The high prices currently achieved in the acquisition of non-renewable energy for electricity production and the low levels of energy efficiency in the housing sector are the national situation, which leads the Portuguese government to encourage the acquisition, the installation and the use of technologies which exploit indigenous and renewable energy. This study presents an application that was developed in order to help the citizen in his decision to invest in renewable technologies in their homes. The application is able to elaborate an economic analysis based on the selected type of renewable technology, providing the user with the knowledge of benefits and the annual costs involved in the system that he selected. This tool aims at facilitating the interaction of any user with such technologies and it can be used as a helpful tool to support the decision of investment in such systems.

}, isbn = {978-3-642-19169-5}, url = {http://dx.doi.org/10.1007/978-3-642-19170-1_49}, author = {Francisco, Ricardo and Pedro Pereira and Martins, Jo{\~a}o}, editor = {Camarinha-Matos, Luis} } @conference {springerlink:10.1007/978-3-642-19170-1_53, title = {Weather Monitoring System for Renewable Energy Power Production Correlation}, booktitle = {Doctoral Conference on Computing, Electrical and Industrial Systems, DoCEIS 2011}, series = {IFIP Advances in Information and Communication Technology}, volume = {349}, year = {2011}, note = {

DOI:10.1007/978-3-642-19170-1_53

}, pages = {481-490}, publisher = {Springer Boston}, organization = {Springer Boston}, address = {Costa de Caparica - Portugal}, abstract = {

This work describes the development of a system designed for renewable power generation integration. It continuously acquires wind, solar and temperature data, which is automatically correlated with energy parameters, obtained from renewable energy systems. The developed system was installed in an urban building equipped with photovoltaic cells and wind renewable generation. To validate the developed application, it was analyzed data of a wind generator and a set of photovoltaic panels, installed near to the weather station. The developed application allows, in addition to the acquisition of weather and energy data, their continuous monitoring and correlation through a graphical user interface, providing a friendly interactivity with the user.

}, isbn = {978-3-642-19169-5}, url = {http://dx.doi.org/10.1007/978-3-642-19170-1_53}, author = {Afonso, Marcos and Pedro Pereira and Martins, Jo{\~a}o}, editor = {Camarinha-Matos, Luis} } @conference {5672295, title = {Automatic generation of RF integrated inductors analytical characterization}, booktitle = {Symbolic and Numerical Methods, Modeling and Applications to Circuit Design (SM2ACD), 2010 XIth International Workshop on}, year = {2010}, note = {n/a}, month = {oct.}, pages = {1-4}, abstract = {

This paper addresses the automatic generation of RF integrated inductors model. In this work the double p-model is used as a way of characterizing the inductor behaviour over a frequency range beyond the self-resonant value. For the evaluation of the model element values analytical expressions based on technology parameters as well as on the device geometric characteristics are used. The use of a technology-based methodology for the evaluation of the model parameters grants the adaptability of the models generated to any technology. The inductor analytical characterization is integrated into an optimization-based tool for the automatic design of RF integrated inductors. This tool uses a Genetic Algorithm (GA) optimization procedure, where user defined constraints on the design parameters are taken into account. Due to the design constraints nature and topology constraints, discrete variables optimization techniques are used.

}, keywords = {automatic design, automatic generation, design constraints, device geometric characteristics, discrete variables optimization, double pi-model, genetic algorithm, genetic algorithms, inductors, integrated circuit design, integrated circuit modelling, radiofrequency integrated circuits, RF integrated inductors, self-resonant value, topology constraints}, doi = {10.1109/SM2ACD.2010.5672295}, url = {http://dx.doi.org/10.1109/SM2ACD.2010.5672295}, author = {P Pereira and Fino, M.H. and Ventim-Neves, M.} } @proceedings {camarinha2010emerging, title = {Emerging Trends in Technological Innovation: First IFIP WG 5.5/SOCOLNET Doctoral Conference on Computing, Electrical and Industrial Systems, DoCEIS 2010, Costa de Caparica, Portugal, February 22}, journal = {Doctoral Conference on Computing, Electrical and Industrial Systems, DoCEIS 2010}, volume = {314}, year = {2010}, note = {

Camarinha-Matos, Luis M.; Pereira, Pedro; Ribeiro, Luis (Eds.)

}, publisher = {Springer-Verlag New York Inc}, address = {Costa de Caparica - Portugal}, url = {http://dx.doi.org/10.1007/978-3-642-11628-5}, editor = {Camarinha-Matos, L.M. and P Pereira and Ribeiro, L.} } @conference {springerlink:10.1007/978-3-642-11628-5_46, title = {Energy Consumption Monitoring System for Large Complexes}, booktitle = {Doctoral Conference on Computing, Electrical and Industrial Systems, DoCEIS 2010}, series = {IFIP Advances in Information and Communication Technology}, volume = {314}, year = {2010}, note = {

DOI:10.1007/978-3-642-11628-5_46

}, pages = {419-426}, publisher = {Springer Boston}, organization = {Springer Boston}, address = {Costa de Caparica - Portugal}, abstract = {

This paper describes the development of an open source system for monitoring and data acquisition of several energy analyzers. The developed system is based on a computer with Internet/Intranet connection by means of RS485 using Modbus RTU as communication protocol. The monitoring/metering system was developed for large building complexes and was validated in the Faculdade de Ci{\^e}ncias e Tecnologia University campus. The system considers two distinct applications. The first one allows the user to verify, in real time, the energy consumption of any department in the complex, produce load diagrams, tables and print, email or save all available data. The second application keeps records of active/reactive energy consumption in order to verify the existence of some anomalous situation, and also monthly charge energy consumption to each corresponding department.

}, isbn = {978-3-642-11627-8}, url = {http://dx.doi.org/10.1007/978-3-642-11628-5_46}, author = {Jorge, Andr{\'e} and Guerreiro, Jo{\~a}o and Pedro Pereira and Martins, Jo{\~a}o and Gomes, Lu{\'\i}s}, editor = {Camarinha-Matos, Luis and Pedro Pereira and Ribeiro, Luis} } @conference {springerlink:10.1007/978-3-642-11628-5_57, title = {GADISI {\textendash} Genetic Algorithms Applied to the Automatic Design of Integrated Spiral Inductors}, booktitle = {Doctoral Conference on Computing, Electrical and Industrial Systems, DoCEIS 2010}, series = {IFIP Advances in Information and Communication Technology}, volume = {314}, year = {2010}, note = {

DOI:10.1007/978-3-642-11628-5_57

}, pages = {515-522}, publisher = {Springer Boston}, organization = {Springer Boston}, address = {Costa de Caparica - Portugal}, abstract = {

This work introduces a tool for the optimization of CMOS integrated spiral inductors. The main objective of this tool is to offer designers a first approach for the determination of the inductor layout parameters. The core of the tool is a Genetic Algorithm (GA) optimization procedure where technology constraints on the inductor layout parameters are considered. Further constraints regarding inductor design heuristics are also accounted for. Since the layout parameters are inherently discrete due to technology and topology constraints, discrete variable optimization techniques are used. The Matlab GA toolbox is used and the modifications on the GA functions, yielding technology feasible solutions is presented. For the sake of efficiency and simplicity the pi-model is used for characterizing the inductor. The validity of the design results obtained with the tool, is checked against circuit simulation with ASITIC.

}, doi = {10.1007/978-3-642-11628-5_57}, url = {http://dx.doi.org/10.1007/978-3-642-11628-5_57}, author = {Pedro Pereira and Fino, M. and Coito, Fernando and Ventim-Neves, M{\'a}rio}, editor = {Camarinha-Matos, Luis and Pedro Pereira and Ribeiro, Luis} } @conference {Pereira2009, title = {ADISI- An efficient tool for the automatic design of integrated spiral inductors}, booktitle = {Proc. 16th IEEE Int. Conf. Electronics, Circuits, and Systems ICECS 2009}, year = {2009}, note = {n/a}, pages = {799{\textendash}802}, abstract = {

This paper introduces a tool for the optimization of CMOS integrated spiral inductors. Its aim is to offer designers a first approach on designing inductors without the need for fabrication. The core of the tool is an optimization procedure where technology constraints on the inductor layout parameters are considered by applying user-defined discretization on the design variables. User-defined constraints between layout parameters may also be accounted for, as a way of taking into account design heuristics. For those cases where the device area is a major concern area minimization may be considered. On the other hand, if a major design goal is the inductor quality factor the tool may yield the layout parameters which maximize the quality factor. The trade-off between quality factor and device area is evaluated through the generation of a graphical representation of quality factor versus output diameter for a given inductance. For the sake of simplicity the pi-model has been used for characterising the inductor. The application was developed in Matlab and the optimization toolbox is used. The validity of the design results obtained is checked against circuit simulation with ASITIC.

}, doi = {10.1109/ICECS.2009.5410776}, url = {http://dx.doi.org/10.1109/ICECS.2009.5410776}, author = {P Pereira and Fino, H. and Coito, F. and Ventim-Neves, M.} } @conference {Pereira2009a, title = {Using discrete-variable optimization for CMOS spiral inductor design}, booktitle = {Proc. Int Microelectronics (ICM) Conf}, year = {2009}, note = {n/a}, pages = {324{\textendash}327}, abstract = {

In this paper a discrete-variable optimization methodology for the automatic design of CMOS integrated spiral inductors is introduced. The use of discrete variable optimization procedure offers the designer the possibility for exploring the design space exclusively in those points available for the technology under use. Further user-defined constraints between layout parameters may also be incorporated as a way of taking into account design heuristics. A comparison between using discrete-variable optimization and a continuous optimization procedure followed by a discretization of the results is presented, where the benefits of the proposed methodology are presented. An application using the proposed methodology was developed in Matlab and the optimization toolbox is used. For the sake of simplicity the pi-model has been used for characterizing the inductor. The validity of the design results is checked against circuit simulation with ASITIC.

}, doi = {10.1109/ICM.2009.5418617}, url = {http://dx.doi.org/10.1109/ICM.2009.5418617}, author = {P Pereira and Fino, M.H. and Coito, F. V.} } @conference {OA1696, title = {CMOS Delay and Power Estimation for Deep Submicrometer Technologies Using EKV Model}, booktitle = {10th International Workshop on Symbolic and Numerical Methods, Modeling and Applications to Circuit Design (SM2ACD 2008)}, year = {2008}, note = {n/a}, pages = {253{\textendash}257}, abstract = {

This paper presents an analytical model for CMOS delay and power estimation in deep sub micrometer technologies. In this paper the EKV transistor model is considered as a way of granting the accuracy of results in the characterization of deep submicron CMOS circuits. The analytical model proposed is valid for a ramp input signal, and takes into account all the operation regions of the transistor as well the influence of the gate-to-drain capacitance. For estimating the power consumption, a simple numerical integration process is applied to the current wave. An application example considering the use of the model for the evaluation of the delay and power consumption associated to a CMOS inverter is considered. The validity of the results obtained with the proposed model for a 1.2V TSMCN65 CMOS inverter is checked against those obtained through Hspice simulation.

}, url = {http://oa.uninova.pt/1696/}, author = {P Pereira and Maria H. Fino} } @article {1742-6596-97-1-012219, title = {Power electronics performance in cryogenic environment: evaluation for use in HTS power devices}, journal = {Journal of Physics: Conference Series}, volume = {97}, number = {1}, year = {2008}, note = {n/a}, pages = {012219}, abstract = {

Power electronics (PE) plays a major role in electrical devices and systems, namely in electromechanical drives, in motor and generator controllers, and in power grids, including high-voltage DC (HVDC) power transmission. PE is also used in devices for the protection against grid disturbances, like voltage sags or power breakdowns. To cope with these disturbances, back-up energy storage devices are used, like uninterruptible power supplies (UPS) and flywheels. Some of these devices may use superconductivity. Commercial PE semiconductor devices (power diodes, power MOSFETs, IGBTs, power Darlington transistors and others) are rarely (or never) experimented for cryogenic temperatures, even when designed for military applications. This means that its integration with HTS power devices is usually done in the hot environment, raising several implementation restrictions. These reasons led to the natural desire of characterising PE under extreme conditions, e. g. at liquid nitrogen temperatures, for use in HTS devices. Some researchers expect that cryogenic temperatures may increase power electronics{\textquoteright} performance when compared with room-temperature operation, namely reducing conduction losses and switching time. Also the overall system efficiency may increase due to improved properties of semiconductor materials at low temperatures, reduced losses, and removal of dissipation elements. In this work, steady state operation of commercial PE semiconductors and devices were investigated at liquid nitrogen and room temperatures. Performances in cryogenic and room temperatures are compared. Results help to decide which environment is to be used for different power HTS applications.

}, url = {http://stacks.iop.org/1742-6596/97/i=1/a=012219}, author = {P Pereira and S Valtchev and J. Pina and A Gon{\c c}alves and M Ventim Neves and A L Rodrigues} } @article {1742-6596-97-1-012220, title = {A test rig for thrust force measurements of an all HTS linear synchronous motor}, journal = {Journal of Physics: Conference Series}, volume = {97}, number = {1}, year = {2008}, note = {n/a}, pages = {012220}, abstract = {

This paper presents the design of a test rig for an all HTS linear synchronous motor. Although this motor showed to have several unattractive characteristics, its design raised a number of problems which must be considered in future HTS machines design. HTS electromagnetic properties led to the development of new paradigms in electrical machines and power systems, as e. g. in some cases iron removal and consequent assembly of lighter devices. This is due to superconductor{\textquoteright}s ability to carry high currents with minimum losses and consequent generation in the surrounding air of flux densities much higher than the allowed by ferromagnetic saturation. However, severe restrictions in HTS power devices design that goes further beyond cryogenic considerations must be accounted in. This is usually the case when BSCCO tapes are used as conductors. Its bending limitations and the presence of flux components perpendicular to tape surface, due to the absence of iron, have to be considered for it may turn some possible applications not so attractive or even practically unfeasible. An all HTS linear synchronous motor built by BSCCO tapes as armature conductors and two trapped-flux YBCO bulks in the mover was constructed and thrust force measurements are starting to be performed. Although the device presents severe restrictions due to the exposed and other reasons, it allowed systematising its design. A pulsed-field magnetiser to generate opposite fluxes for both YBCO bulks is also detailed. Thrust force numerical predictions were already derived and presented.

}, url = {http://stacks.iop.org/1742-6596/97/i=1/a=012220}, author = {J. Pina and P Pereira and S Valtchev and A Gon{\c c}alves and M Ventim Neves and A Alvarez and L Rodrigues} } @conference {OA1019, title = {Delay Propagation of a CMOS Inverter Using the Nexp Transistor Model}, booktitle = {XXII Conference on Design of Circuits and Integrated Systems}, year = {2007}, note = {n/a}, month = {November}, pages = {12{\textendash}16}, abstract = {

This paper presents an analytical model for the delay propagation of a CMOS Invert circuit. In this paper the Nexp transistor model is considered as a way of granting the accuracy of results in the characterization of submicron CMOS circuits. The analytical model proposed is valid for a ramp input, and takes into account all the operation regions of the transistor and take into account the influence of the gate-to-drain capacitance. An application example considering the use of the model for the evaluation of the delay associated to the CMOS inverter is considered. The validity of the results obtained with analytical model of a 1.8V SMIC018 CMOS inverter is checked against Hspice simulation of the circuit.

}, url = {http://oa.uninova.pt/1019/}, author = {Pedro Pereira and Maria H. Fino} } @conference {Pereira2005, title = {VCOSYM -an application for the automatic design of ring VCOS}, booktitle = {Proc. 12th IEEE Int. Conf. Electronics, Circuits and Systems ICECS 2005}, year = {2005}, note = {n/a}, pages = {1{\textendash}4}, abstract = {

This paper presents an application for the automatic design of ring VCOs. In this application a VCO model based on the Npower transistor model is considered as a away of granting the accuracy of results for submicron technologies. In order to easily integrate any VCO previously designed into a PLL automatic design tool, a corresponding linear model of the VCO is automatically generated, yielding a simple and precise characterization for higher level system design. The design of a 150 MHz VCO using a seven stage ring topology is presented. The validity of the design obtained is checked against Hspice simulation of the circuit.

}, doi = {10.1109/ICECS.2005.4633504}, url = {http://dx.doi.org/10.1109/ICECS.2005.4633504}, author = {P Pereira and Fino, H.} }