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					001 – Poster Electrónica e Telecomunicações

                                    LAFA – Speech Laboratory

                                          Carlos Meneses
                   M2A/ISEL – Grupo de Multimédia e Aprendizagem Automática
                            Instituto Superior de Engenharia de Lisboa
                   Rua Conselheiro Emídio Navarro nº1, 1950-062 Lisboa, Portugal
                                     cmeneses@deetc.isel.ipl.pt
                                         +351.218317224


Abstract

LAFA – Speech Laboratory, is a graphical application developed to analyze speech signals.
Designed with pedagogical objectives in the scope of a speech processing discipline, in order to
help students to initiate in this area, also assists concepts exposition in classroom and help
researchers in the analysis of particular cases of speech signals.
In LAFA, it is possible to analyze a set of speech signals characteristics: voiced detention and
pitch estimation; linear prediction; LSF coefficients estimation; formants estimation; and cepstral
analysis, including MFCC and LPC cepstra. It allows still, even so in a rudimentary way, to
recognize vowels and to synthesize suspended sounds. The input signal can be a file in wav
format or to be acquired directly from a microphone.
Developed in the MATLAB platform, some of the used functions are part of the MATALAB
library (e.g. LPC, cepstra). Others had been developed intentionally for this application (e.g.
LSF, honey-cepstra, pitch), in a modular way, being available and having already been used for
other applications of speech processing, such as coders and recognizers. This modularity allows
the development of new functions and its easy integration.
002 – Oral Telecomunicações III


                         Speaker verification with LSF coefficients

                                 Hugo Cordeiro Carlos Meneses
                  M2A/ISEL – Grupo de Multimédia e Aprendizagem Automática
                           Instituto Superior de Engenharia de Lisboa
                  Rua Conselheiro Emídio Navarro nº1, 1950-062 Lisboa, Portugal
                             {hcordeiro,cmeneses}@deetc.isel.ipl.pt
                                        +351.218317224


Abstract

This article describes experiences with a speaker verification system. These experiences are
intended to awake for possible alternative features in speaker recognition. In this system,
speakers are characterized through LSF coefficients as input to a SVM as classifier, instead of
the traditional MFCC coefficients, achieving comparable results, even without perceptual
information.
Assessment is based on the EER (Equal Error Rate) minimization between the FRR (False
Rejection Ratio) and the FAR (False Acceptance Ratio). 8% EER is achieved testing among 10
speakers, with this value being increased to 20% when tested among 139 speakers. Minimum of
HTER (Half Total Error Rate), defined as the average between the FRR and FAR is also
determined being this values almost the same as the EER values.
Speakers come from the “2002 NIST Speaker Recognition Evaluation Corpora” that becomes a
reference in this area. Of this corpus the recorded cellular component from CDMA and GSM
was tested, in both the cases with different telephones and consequentially with diverse
microphones and headphones.
003 – Oral Telecomunicações IV
004 – Poster Electrónica

                        Controlo por Fase Única de Conversores A/D
                                      de Baixa Tensão

                           A. Galhardo 1, J. Goes 2, B. Vaz 2, N. Paulino 2
                                           1 ISEL – DEEA
                                     Av. Emídio Navarro, nº 1
                                 1949 – 014 Lisboa – PORTUGAL
                                  E-mail: galhardo@deea.isel.ipl.pt
                                     2 DEE/UNINOVA – CRI
                           Campus da Faculdade de Ciências e Tecnologia
                            2825 – 114 Monte da Caparica – PORTUGAL
                                       E-mail: jg@uninova.pt



Abstract
This paper describes the application of a single-phase scheme to low-voltage pipeline ADCs
designed in standard CMOS technologies. After the analysis of the single-phase scheme
behaviour, applied in a S/H circuit, and to validate the theoretical findings, a 10-bit 4 MS/s
pipeline ADC was fully designed and simulated, first with all switches driven by a conventional
six-phase clock generator, and after with the novel single-phase scheme. The simulation results
were compared and it is shown the signal integrity maintenance. The overall performance is
preserved or improved for low values of supply voltage, pointing to the use of simpler low-
voltage circuits, avoiding the complexity as well as the problems normally created by the use of
non-overlapping clock generators.
005 – Poster Electrónica e Telecomunicações

                 Microstrip Planar Array for GPS Pseudolite Applications

                                  D.C.M. Maciel e J.C. da S. Lacava
       Instituto Tecnológico de Aeronáutica (ITA), Laboratório de Antenas e Propagação (LAP)
             Praça Mal. Eduardo Gomes, 50, 12228-900, São José dos Campos, SP – Brasil
                       Telefone: +55 (12) 3947-6811, Fax: +55 (12) 3947-6930

Abstract
This work describes a microstrip planar array for GPS pseudolite applications. The design
specification includes right-hand polarization and operation frequency at L1 (1.575,42 MHz).
Firstly, the radiator element (truncated corner microstrip antenna) is simulated and optimized by
using HFSS™ package and a prototype is manufactured. Theoretical and experimental results for
radiation patterns are presented and very good agreements with the simulations are observed. The
second stage consists of the array geometry determination. It is select as function of prescribed
values for the half-power beamwidth. The feeding network is also implemented using microstrip
technology. Power dividers are employed to guarantee the correct excitation coefficient in each
element input port. Simulations using the IE3D™ package are performed. Results for return loss,
axial ratio and radiation pattern are presented. To validate our assumptions and the design
procedure, a prototype of the array is manufactured. Results for the return loss are presented.
006 – Oral Computadores III
008 – Poster T
009 – Poster Electrónica

                                    Inductive sensor for vehicle guidance

                                João Diogo1, Ricardo Bicho1, Eugénio Furtado2
                                   Instituto Superior de Engenharia de Lisboa
                          R. Conselheiro Emídio Navarro, 1949-014 Lisboa, Portugal
                              Telefone: +351.218.317.180, Fax: +351.218.317.114
                  E-mail: jdiogo@alunos.isel.ipl.pt; rbicho@deetc.isel.ipl.pt; efgf@netcabo.pt


This article presents an inductive sensor directed to vehicle guidance. It’s a work developed in
the Electronics Project class of the Telecommunications and Electronics Engineering Course.
This communication describes the framing, project and implementation of the related sensor.

The motivation for the development of this type of sensor comes from the urge of
complementing other known guidance systems (optic, inductive systems, laser, radio
frequency…). It’s demonstrated the capacity to evaluate the distance between an electric
conductor, who serves as guide, and the vehicle whose route interests to control.
The conductor is powered by an electric signal with one given frequency, which creates an
electromagnetic field due to the passage of electric current. The capture of the field is made by
two coils, symmetrically positioned from the center of the sensor. The generated electromagnetic
field induces a voltage across the coil ends. These voltages depend on the distance between the
sensor and the electrical conductor.
If the sensor moves to one side of the guide wire the voltage in the coil, now closer to the guide
wire, is increased and the voltage in the coil furthest from the guide wire is decreased. By
amplifying the difference in voltage between the two coils is created a steering signal.
Although the idea in the base of this project is not unknown, its concretion resulted of a root
development made by the authors.
The results of the tests have been satisfactory and shown the possibility to use this system in real
applications.
This type of sensor proved to be adjusted to guide platforms if it’s possible the installation of the
conductor on the track.
In future applications it will be possible to overlap the conductor signal with modulated
information that allows the remote control of other vehicle functions.




_________________________________
1
    Electronics Project student
2
    Electronics Project Professor
011 – Poster C


  From the Magic Square to the Optimization of Networks of AGVs and from MIP to an
         Hybrid Algorithm and from this One to the Evolutionary Computation

                          José Barahona da Fonseca (JBFO@Fct.Unl.Pt)
  Departamento de Engenharia Electrotécnica e de Computadores, Faculdade de Ciências e Tecnologia,
                                   Universidade Nova de Lisboa
                            Monte da Caparica, 2829-516 CAPARICA


Abstract

In a previous work we presented an algorithm inspired in the IA and in the minimax optimization
that imitates the human being in the solution of the magic square and we showed that in most
cases its performance was better than the human’s performance and even better than the
performance of the best genetic algorithms to solve the magic square, in terms of number
changes.
In this paper we adapt and transform this algorithm to solve the optimization of an AGVs
network problem, using as a test case 9 workstations in fixed positions, and the optimization
problem is translated in the search of which of the 9! possible manners to distribute 9 operations
by the 9 workstations that minimizes the total production time for a given plan of production.
This gradual process of adaptation and transformation resulted in a evolutionary hybrid
algorithm with high performances, with a little bit of Tabu Search and a little bit of genetic
algorithm. In 1000 successive runs, with the two tabu flags On, it never failed in the search of
one of the 4 optimal solutions and never took more than 3000 iterations and 9!= 362880.
As a final validation test, using random search, in 1000 runs it never reached the optimal solution
at the end of 10000 iterations.
014 – Poster C



            Magic Squares and Rectangles and their Variants as Management Games


                          José Barahona da Fonseca (JBFO@Fct.Unl.Pt)
  Departamento de Engenharia Electrotécnica e de Computadores, Faculdade de Ciências e Tecnologia,
                                   Universidade Nova de Lisboa
                            Monte da Caparica, 2829-516 CAPARICA

Abstract

Although the magic square is a simple problem, it has a very rich combinatory: there are (n2 )!
Manners to fill the nxn matrix with distinct integers between 1 and n2, but there are few solutions
of the magic square. So we used the magic square as a benchmark to compare mathematical
programming, namely mixed integer programming (MIP), to the genetic algorithms (GAs), that
we will show that are much more efficient in the solution of this type of combinatorial explosive
problems.
Then we got the idea to compare the GAs to the human being, and with that purpose we
developed 4 prototypes of games which objectives were, respectively, to get the relaxed magic
square, the generalized relaxed magic square, the magic rectangle and the generalized magic
rectangle with the minimum number of changes between pairs of elements of the referred
matrices.
These games could be adapted to management games, since in management problems we have a
limited budget that must be distributed by the various departments or sections of the enterprise,
lots of constraints and goals which solution also could be formulated in a matrix form similar to
the generalized relaxed magic square or to the generalized magic rectangle.
016 – Oral Computadores IV

                Grid Computing: LIP Participation in the European Projects
                        DATAGRID, CROSSGRID, and EGEE


               Mário David1,Jorge Gomes1, Paulo Barata2, Miguel Gouveia2, Rui Duarte2
               1
                 Laboratório de Instrumentação e Física Experimental de Partículas (LIP)
          2
            Dep. de Ciências e Tecnologias da Universidade Autónoma de Lisboa (DCT/UAL)



Abstract
This paper introduces the Grid Computing concepts needed to understand and use a Grid
infrastructure. "Grid Computing" is a new paradigm in Distributed Computing, where resources
are geographically distributed. A Grid infrastructure joins several research sites creating a
Virtual Organization in order to exploit global scientific research resources. This paper describes
the participation of "Laboratório de Instrumentação e Física Experimental de Partículas" (LIP) in
the European Union projects DataGrid, CrossGrid, and "Enabling Grids for E-SciencE" (EGEE).
The creation of a Portuguese Thematic Network on Grid Computing is also discussed.


Keywords
Grid Computing, Distributed Computing, LIP, EGEE.
017 – Oral Telecomunicações IV

        Circularly Polarized Microstrip Arrays Conformed on Cylindrical Surfaces

                                   Marcos Vinício Thomas Heckler
                                                DLR
                           Oberpfaffenhofen, D-82234 Wessling, Germany
                         Telefone: +498.153.282.398, Fax: +498.153.282.328
                                         J. C. da S. Lacava
                                             ITA - LAP
                        Praça Marechal Eduardo Gomes, 50, 12228-900 Brasil
                         Telefone: +551.239.476.811, Fax: +551.239.476.930


Abstract

Microstrip antennas are very well suited to conformal array applications. Mounted on cylindrical
surfaces, most of the developments emphasize the design of N-element wraparound arrays for
omnidirectional radiation in the cylindrical roll plane. The radiation characteristics for linearly and
circularly polarized (CP) arrays have been studied and reported by several authors. Recently, the
influence of the number of elements on the quality of the circular polarization has been investigated.
Following this subject, the present paper discusses the analysis and the design of CP microstrip
antenna arrays conformed on cylindrical surfaces. To illustrate the potential of the developed
technique, a CP antenna operating at 2.25 GHz was designed using an effective CAD tool (namely
Cylindrical), developed by the Antennas and Propagation Laboratory – LAP/ITA. The radius of the
cylinder was chosen to comply with SONDA IV, a Brazilian sounding rocket. Using this element, two
array topologies were analyzed. The design of the feeding network was performed using a planar
simulator as an approximation because the diameter of the second stage of SONDA IV is larger than
one guided wavelength. To validate our assumptions and the design procedure, two prototypes of
four elements were manufactured, and the tests results for input impedance and radiation pattern
show very good agreement with the simulations.
018 – poster C
019 – Oral Computadores II


       Energy consumption management in microprocessors: increase of autonomy
                         without compromising functionality



                                             Gonçalo Rijo
                     Instituto Superior Técnico – Universidade Técnica de Lisboa
                         DEEC, Av. Rovisco Pais, 1049-001 Lisboa, Portugal
                                    e-mail: goncalorijo@gmail.com
                                            Carlos Almeida
                     Instituto Superior Técnico – Universidade Técnica de Lisboa
               DEEC, AC-Computadores, Av. Rovisco Pais, 1049-001 Lisboa, Portugal
           Telefone: +351-21-8418397 FAX: +351-21-8417499 e-mail: cra@comp.ist.utl.pt
                                              José Rufino
                           Faculdade de Ciências da Universidade de Lisboa
                            Campo Grande, Bloco C5, 1700 Lisboa, Portugal
             Telefone: +351-21-7500254 FAX: +351-21-7500084 e-mail: ruf@di.fc.ul.pt




Abstract
Nowadays, energy consumption is a very important issue in the development of embedded
systems. In this work, a comparison between different approaches of energy saving can be found.
Also, an analysis between consumption and performance is made. The results demonstrate that
significant improvements are obtained in systems with this type of mechanisms.
022 – Poster C
023 – Poster C

 Arquitetura para Transformada de Distância e sua aplicação para o cálculo da Dimensão
                                       Fractal

                           Maximiliam Luppe, Angelo Cesar Colombini
                                   Unifran – Universidade de Franca
                                  Av. Dr. Armando Sales Oliveira, 201
                                   Franca – SP – Brazil – 14404-600
                            maxluppe@unifran.br, accolombini@yahoo.com.br
                                       Valentin Obac Roda
                                   Depto. Eng. Elétrica - EESC – USP
                                   Av. Trabalhador São-carlense, 400
                                  São Carlos – SP– Brasil – 13566-590
                                        valentin@sel.eesc.usp.br




Abstract
Distance Transform is an important tool for digital imaging processing. Using the Distance
Transform it is possible to evaluate the fractal dimension of objects. Fractal dimension is very
important in shape analysis and patter n recognition operations. Few are the hardware
implementation for these operations. In this work we present a parallel implementation based on
the exact dilation for the evaluation of the Distance Transform and Fractal Dimension.
024 – Oral Computadores III
025 – Oral Electrónica III

Técnicas e arquitecturas de comutação totalmente óptica em redes de multiplexagem densa
                               por comprimento de onda

             J. P. Carvalho1, O.Frazão1, R. Romero1, M. B. Marques1,2, H. M. Salgado1,3
            1 INESC  Porto – Instituto de Engenharia de Sistemas e Computadores do Porto
                            (Rua do Campo Alegre 687; 4169 - 007 Porto)
             2 Faculdade de Ciências da Universidade do Porto – Departamento de Física
                            (Rua do Campo Alegre 687; 4169 - 007 Porto)
                     3 Faculdade de Engenharia da Universidade do Porto, DEEC
                             (Rua Dr. Roberto Frias s/n, 4250 - 465 Porto)




Abstract
Optical Switching is a fundamental functionality in the next generation of optical networks in
order to support a sustained growth needed for bandwidth enhancement in modern
communication networks. This communication presents some of the work developed at INESC
Porto in optical switching. Two different techniques that allow tunability of fibre Bragg gratings
(FBG) written in optical fibres are described, as well as its application in switching elements in
dense wavelength division multiplexing (DWDM) networks. At last, some key components in
optical switching networks, such as optical add-drop multiplexers (OADM) and optical cross-
connects (OXC), are presented.
026 – Poster Electrónica

                                 DYE LASER AND APPLICATIONS


                             J. M. A. Frazão(a), F. M.V. Ramos(a) e M. L. Bhatt(b)
                        Centro de Física Molecular da Universidade Técnica de Lisboa
                             I.S.T., Complexo I, Av. Rovisco Pais, 1000 Lisboa
                                            Tel: +351 21 8419210
                                       Fax: +351 21 8464455 / 8464457
                                       Email : frazão@popsrv.ist.utl.pt
         (a)
               Depart. de Engenharia de Electrónica e Telecomunicações e de Computadores , Instituto
                                Superior de Engenharia de Lisboa (I.S.E.L.).
                                 (b)
                                     Reitoria da Universidade Técnica de Lisboa.



Abstract
In this paper the major principles of laser operation are described, among with the analysis of the
main properties of laser radiation, such as the spectral width, beam intensity, and spatial and
temporal resolution. The following types of lasers are described: diode lasers, Nd:YAG laser,
and, in particular, dye lasers (bombed by a Nd:YAG laser). Many applications of laser radiation
will be analysed, especially its use in telecommunications, semiconductors and spectroscopy.
The use of laser radiation on optical communications is referred. A tuneable laser system,
associated with a time of flight mass spectrometer is also described.


Keywords
lasers, dye laser, optical fibre, multi-photo-ionisation.
027 – Poster T

                 Propagation Analysis of GPS Signals in Tropospheric Ducts

                               Gláucia Costa Balvedi e Fernando Walter
              Instituto Tecnológico de Aeronáutica, Departamento de Telecomunicações
                                   São José dos Campos, SP, Brasil
                                 E-mails: balvedi@ita.br, fw2@ita.br

Abstract

The Ray Tracing and Parabolic Equation methods are used to simulate the behavior of low angle
elevation GPS satellite signals in a nonstandard troposphere (tropospheric ducts). The simulation
results using a standard troposphere profile were compared with those using tropospheric ducts
profiles. Preliminary results show that signals were confined in the ducting region. Analyses are
being performed in order to verify under what situations those low angle elevation signals
saturate the GPS receptor.
028 – Poster Electrónica

                            PM Motors with natural redundancy

                         Dora H. Avelar Gonçalves José Carlos Quadrado
                                   ISEL-DEETC ISEL-DEEA
                        R. Conselheiro Emídio Navarro, 1, 1949-014 Lisboa
                       Telephone: +351.218.317.180, Fax: +351.218.317.114

Abstract
This paper describes an electromechanical actuator control system and a method for providing
fault-tolerant operation of its multiphase PM electric motor. Conventionally, the redundancy is
provided at the expense of complex winding and inverter topologies.

The proposed control system uses parallel single phase power modules for energizing each
phase. By taking advantage of the isolated magnetic paths and therefore the independence of
phases, this control system provides “natural” redundancy in the case of phase failures.

The controller can detect a fault and select between non-fault correction and fault-correction
modes. In the fault-correction mode, the currents for the remaining phases are modified in
accordance with preset parameters.


Keywords
Control, Actuator, Simulation
029 – Oral Telecomunicações I
030 – Oral Telecomunicações I

Rádio Móvel
031 – Poster T

                     Repetidor para ambientes interiores em CDMA2000

                               Filipe Feiteira, João Assunção, Nuno Cota,
                            Fernando Fortes, Henrique Silva, Carlos Mendes
                 ffeiteira@deetc.isel.ipl.pt, 19667@alunos.isel.ipl.pt, ncota@deetc.isel.ipl.pt
                 ffortes@deetc.isel.ipl.pt, hjsilva@deetc.isel.ipl.pt, cmendes@deetc.isel.ipl.pt
                                           ISEL-DEETC
                          R. Conselheiro Emídio Navarro, 1, 1949-014 Lisboa


Abstract
This article describes a CDMA2000 indoor repeater for 460MHz band. The prototype is meant to
be connected between two antennas, thus providing amplification in booth directions. At the end
it was tested in field, where it showed a good increase in the indoor signal strength.
034 – Oral Electrónica II

                  Circuits, sensors and actuators for remote train detection

                   Carlos F. Carvalho 1, Carlos R. Martins 2 e Mário S. Nunes 3
               1Instituto Superior de Engenharia de Lisboa, Instituto Politécnico de Lisboa
           Departamento de Engenharia de Electrónica e Telecomunicações e de Computadores
                                    Rua Conselheiro Emídio Navarro, 1
                                       P-1950-062 Lisboa, Portugal
      2Escola Náutica Infante D. Henrique e Instituto de Engenharia de Sistemas e Computadores –
                              Investigação e Desenvolvimento (INESC-ID)
  3Instituto Superior Técnico, Universidade Técnica de Lisboa e Instituto de Engenharia de Sistemas e
                      Computadores – Investigação e Desenvolvimento (INESC-ID)
                                             cfc@isel.ipl.pt



Abstract
In this paper, a remote train detection system is described, characterizing the material part that
makes up the application in the field. There were developed, from scratch, a transmitter and a
receiver circuit, which are intended for the generation and the reception of the system’s sets of
pulses, respectively. Together with these circuits, the adequate transducers were used for each
operation. Together with the transmission circuit, a magnetostrictive transducer was used. By the
use of this transducer, one can excite the rail with the sets of pulses generated by the transmitter.
On what concerns to the receiver, this circuit receives the echo from the rail through the use of a
piezoelectric accelerometer. The circuits that implement the transmission and the reception
modules will be described, as well as the transducers associated to each of them. To finalize,
there is considered the experimental apparatus on what concerns to the transducers mounting in
the physical medium in which the field experiments took place.
035 – Poster C
Telefonar ao Ângelo
036 – Oral Computadores IV
037 – Oral Electrónica III

                       Fully Integrated CMOS Quadrature Oscillators

                                Luís B. Oliveira e Jorge R. Fernandes
                                   Instituto Superior Técnico – IST
               Instituto de Engenharia de Sistemas e Computadores - INESC-ID Lisboa
                               Analog and Mixed-Mode Circuits Group
                                Rua Alves Redol, 9; 1000-029 Lisboa
                Telefone: +351.213.100.349, +351.213.100.327; fax: +351.213.145.843


Abstract
      In this paper we compare quadrature oscillators, which are fundamental blocks in modern
transceivers. We focus on the study of relaxation and LC oscillators, which need to be cross-
coupled to provide quadrature outputs. Moreover, we also study a third type of quadrature
oscillator: the two-integrator oscillator, which has inherited quadrature outputs.
      A detailed study of cross-coupled oscillators is presented in its key aspects: phase noise
and quadrature relationship. We prove that strong coupling is necessary to provide accurate
quadrature outputs. In a cross-coupled relaxation oscillator, coupling reduces the effect of
mismatches to second order effects, and reduces the oscillator phase noise. In a cross-coupled LC
oscillator strong coupling is necessary for accurate quadrature outputs in presence of
mismatches; however it degrades the oscillator phase noise. The two-integrator oscillator is a RC
oscillator with phase noise comparable to that of a relaxation oscillator. The main advantage of
this oscillator is its wideband tuning range, which can be about a decade.
These three types of quadrature oscillators, despite being conceptually different, have some
similarities. The conventional approaches to achieve quadrature outputs are often open loop. In
this work we study closed loop structures, with negative feedback, which provides accurate
quadrature outputs.
038 – Poster T

                          The Radiocommunication Station of NRISEL
                                    A Laboratorial Space

              Henrique Silva, Rodrigo Matias, Carlos Santos, Samuel Ribeiro, João Seixas,
                                      André Matos e Daniel Ferreira
                               Instituto Superior de Engenharia de Lisboa
           Departamento de Engenharia de Electrónica e Telecomunicações e de Computadores
                                           Edifício 5 – Sala 9
                     Rua Conselheiro Emídio Navarro, 1950-062, Lisboa, Portugal
                  telef: 218317209; fax: 218317114; e-mail: hjsilva@deetc.isel.ipl.pt


Abstract
This paper describes the importance of the NRISEL radio-communication station as a laboratorial space
where a wide range of experiments can be produced and the works developed by students can be applied.
To support this defence, three of those student works are summarily presented showing the way how the
station was used and the utility of the works when applied to the station. The three works are from
different areas of knowledge also to show the multidisciplinary and interdisciplinary of this laboratorial
space.
039 – Oral Electrónica IV

      CMOS Integration of Soft-Switching DC-DC Converters: Project Solutions and
                                           Simulations

                            Vitor Costa1,2, Pedro M. Santos2, Beatriz Borges2,
                        1Instituto Superior de Engenharia de Lisboa / DEETC
            2Instituto de Telecomunicações, Av. Rovisco Pais 1, 1049-001 Lisboa, Portugal
              Telephone: +351-218418387, Fax: +351-218418472, e-mail: vsc@isel.ipl.pt



Abstract
This paper presents a first study of resonant converter topologies targeted for CMOS integration.
Similar work has been developed using hard-switching techniques, but the high-speed and
low-voltage applications, nowadays, require high dynamic response, high-efficiency and
minimum footprint. These demands force the switching frequency to increase to several MHz,
leading to higher losses. Maintaining high efficiency at high switching frequency is a major
challenge. Among the Power Electronics DC-DC converters circuit topologies, the soft-
switching topologies are distinguished by their efficiency and low Electromagnetic Interference
(EMI). Thus, the use of soft-switching techniques appears attractive to minimize noise and
switching losses.
  A new method to design very-high frequency (MHz) switching Quasi-Square-Wave converters
with the objective of CMOS implementation is presented.

problems for this soft-switched Quasi-Square-Wave topology, when compared to the discrete
implementation. Two ZVS QSW buck converter was designed using the proposed method, one
for a switching frequency in the range of hundreds of MHz and the other in the range of tens of
MHz. Future work directions are pointed out according to the identified problems.
040 – Poster Electrónica

                Medição das Propriedades Ópticas do Papel e Impressões
042 – Oral Electrónica I

                               Radiation Hardness of a-Si:H Based Particle Detectors

R. Schwarz1,2, A.F. Maçarico2, T. Braz1, C. Casteleiro1, P. Sanguino1,2, M. Niehus1,2 M. Vieira2,
                                  E. Alves3, F. Wünsch4, M. Kunst4 , and H.L. Gomes5

         1
             Instituto Superior Técnico, Departamento de Física, P-1049-001 Lisboa, Portugal
   2
       Instituto Superior de Engenharia de Lisboa, ISEL, DEETC, P-1949-014 Lisbon, Portugal
                     3
                         Instituto Tecnológico Nuclear, ITN, P-2686-953 Sacavém, Portugal
                4
                    Hahn-Meitner-Institut, Solar Energy Division, D-14109 Berlin, Germany
                           5
                               Universidade do Algarve, DEEC, P-8005-139 Faro, Portugal




Abstract

Photoconductivity as a measure of the majority carrier mobility-lifetime product is monitored in
intrinsic amorphous silicon film (a-Si:H) when subjected to a 1.5 MeV He4 beam. In a second
step we looked at the changes of device performance in a 5                 m thick a-Si:H based detector
structure which was subjected to a 1 MeV proton beam that assures a homogeneous damage
profile. We find that the Rose coefficient increases to near unity after strong irradiation
indicating the transition from bi- to monomolecular recombination. The p-i-n device shows
changes that can be related to the properties of the thick intrinsic layer. As a by-product we can
reconstruct the particle beam profile using the analytical fit to the fluence dependence of
photosensitivity.
100 – Poster Electrónica e Telecomunicações

                   Vigilância em Zonas Exteriores com Câmara Fixa
101 – Poster T

                       Fundamental Limits in Small Printed Antennas

                                   Carlos Mendes (1), Custódio Peixeiro (2)
                               (1) Departamento de Engenharia de Electrónica e
                                     Telecomunicações e de Computadores
                                  Instituto Superior de Engenharia de Lisboa
                                        Rua Conselheiro Emídio Navarro
                                           1949-014, Lisboa, Portugal
                                  Tlf: +351 218317209 Fax: +351 218317114
                                        e-mail: cmendes@deetc.isel.ipl.pt
                                       (2) Instituto de Telecomunicações
                                           Instituto Superior Técnico
                                            Avenida Rovisco Pais, 1
                                           1049-001 Lisboa, Portugal
                                  Tlf: +351 218418167 Fax: +351 218418472
                                        e-mail: custodio.peixeiro@lx.it.pt


Abstract
The goal of this communication is the analysis of miniaturized printed antennas used in modern small handheld
terminals of nowadays mobile communication systems. The behaviour of antennas in general is studied, presenting
the fundamental physical limits relating dimension, gain and bandwidth. It is shown that bandwidth, gain and
volume of an antenna are related and that the product gain-bandwidth is proportional to the antenna volume. Some
experimental results of printed antenna prototypes are presented, showing that their performance is still far from the
fundamental limits, suggesting that further optimization may be achievable.
102 – Poster C

                        From Interorganizacional CBPEL Processes to
                                      BPEL Processes


                                         António Teófilo
                                          ISEL-DEETC
                      R. Conselheiro Emídio Navarro, 1, 1949-014 Lisboa
                       Phone: +351.218.317.211, Fax: +351.218.317.114
                                     ateofilo@deetc.isel.ipl.pt

                                          Alberto Silva
                                         IST/INESC-ID
                          Rua Alves Redol, 9, 1000-029 Lisboa, Portugal
                          Phone: +351.21.3100307 Fax: +351.21.3145843
                                     alberto.silva@acm.org


Abstract
The Common Business Process Execution Language (CBPEL) is a XML-based language that
describes interorganizational processes in a global and unique form. This type of descriptions
provide the automatic production of individual organizational processes, and a more error free
edition of the global process, avoiding inconsistencies that could easily arise in the simultaneous
edition of all the participant processes. This work presents the rules to produce individual
processes starting from a single interorganizational process described in CBPEL. The output
language is the Business Process Execution Language (BPEL), because it is the base language of
CBPEL and a language with strong acceptance in the scientific community and the business
world.
103 – Oral Telecomunicações I

                  Lisbon Mobility Simulations for Performance Evaluation
                                    of Mobile Networks

                                    Pedro Vieira1,3, Manuel Vieira1,2
                           1DEETC   / Instituto Superior de Engenharia de Lisboa,
                              Tel. +351 21 8317291, FAX +351 21 8317114
                                  2Câmara Municipal de Lisboa (CML),
                                            Lisboa, PORTUGAL,
                                email: [pvieira, mvieira]@deetc.isel.ipl.pt
                                M. Paula Queluz3, António Rodrigues3
                                     3IT / Instituto Superior Técnico,
                                           Lisboa, PORTUGAL,
                                           Tel. +351 21 8418484
                             email: [paula.queluz, antonio.rodrigues]@lx.it.pt

Abstract
In this paper a novel realistic vehicular mobility model is introduced. It captures the moving-
ingroups, conscious travelling, and introduces the concept of smart travelling while following
drivers’ social behavior extracted from inquiries and experimental traffic measurements. Under
the model, a routing algorithm is considered. The routing algorithm minimizes the distance to a
target on a step by step form, in every street crossing. This is done under a hierarchic street level
structure that optimizes travel speed and quality. The mobility model was simulated for Lisbon
case study and directional statistical results were compared with experimental measurements
from Lisbon Municipality control center. The output shows a good correlation between
simulated and experimental values.


Keywords
Mobility Model, Hierarchic Road Networks, Mobility Patterns, Wireless Communications.
104 – Oral Electrónica III


           A Narrowband, Fully Integrated CMOS 2.4 GHz Low Noise Amplifier

                               Miguel A. Martins e Jorge R. Fernandes
                                  Instituto Superior Técnico – IST /
               Instituto de Engenharia de Sistemas e Computadores - INESC-ID Lisboa
                               Analog and Mixed-Mode Circuits Group
                                Rua Alves Redol, 9; 1000-029 Lisboa
                Telefone: +351.213.100.349, +351.213.100.327; fax: +351.213.145.843


Abstract

Wireless communications brought the faculty of communicating without a physical connection.
However, wireless applications have been up recently limited to several high end applications,
due to the need to use high cost technologies for the highest frequency circuits. To be available
to a large market of wireless applications the technology should be less expensive, thus the use
of low cost technologies becomes very important. The most suitable technology is the
mainstream CMOS which have evolved substantially in the last years. A wireless
communication system always contains an antenna and a front-end block which amplifies and
demodulates the input signal. This amplification is performed by the low noise amplifier, LNA.
This paper describes the design of a narrowband LNA, with an inductively degenerated common
source configuration. The LNA is fully integrated in a digital mainstream 0.35um CMOS
technology, with the inductors designed and modeled with an electromagnetic field solver. The
LNA should simultaneously be impedance matched with the antenna, exhibit gain and good
noise performance, and has been designed to work at 2.4GHz, a band useful for several standards
and ISM applications. The circuit is validated by simulation and a layout has been designed. A
prototype is presently being tested.


Keywords
CMOS, Low Noise Amplifier, Integrated Inductor
105 – Oral Telecomunicações III
106 – Poster Electrónica e Telecomunicações

                              An Architecture for a Data Logger

                   P.Fazenda(1)(2), M.Gomes(1)(2), A.Pinto(1)(2), V.Costa(1)(2)
              (1) Dept. De Eng. De Electrónica e Telecomunicações e de Computadores
                             Instituto Superior de Engenharia de Lisboa
                      Rua Conselheiro Emídio Navarro, N. 1, 1950-062 Lisboa
                             pfazenda@cedet.isel.ipl.pt Tel. 218317281
                                        http://www.isel.ipl.pt
             (2) Centro de Estudos e Desenvolvimento de Electrónica e Telecomunicações
                              Instituto Superior de Engenharia de Lisboa
                       Rua Conselheiro Emídio Navarro, N. 1, 1950-062 Lisboa
                                cedet@cedet.isel.ipl.pt Tel. 218317284
                                     http://www.cedet.isel.ipl.pt



Abstract

Data acquisition is a procedure used in many areas. The purpose of this work is to develop a
datalogger that stores acquired data from one to several sources. For this purpose we present a
solution using the PC architecture. We used a single board computer with a PC/104 interface and
developed an acquisition board for this interface. To fulfil the real time requirements of the
project we used Real Time Linux, running Linux as a low priority task, taking advantage of all
available services and functionalities. To manage the system, a configuration interface is
presented by the main application of the datalogger. This application was programmed using the
Java language. Acquisition cycles are performed within pre-programmed time intervals by a task
that executes in the Real Time Linux space. We programmed this task in C language as a Real
Time Linux module and the main application communicates with this module using first in, first
out type channels. From the user’s point of view, the internal architecture of the system complies
with the existing Standard Commands for Programmable Instrumentation. The data logger’s
configuration is done remotely using a TCP/IP connection. Furthermore, and following the
existing trend for this type of applications, we also developed device managers for the LabVIEW
environment. Finally we give an example by creating a Virtual Instrument in LabView.
107 – Oral Electrónica II

                         Datalogger for low power applications

    J. Casaleiro(1) (2), J. Rocha(1) (2), R. Reis(1) (2), A. Pinto (1) (2), T. Oliveira(1) (2), M.
               Gomes(1) (2), P. Fazenda(1) (2), V. Costa(1) (2), C. Carvalho(1) (2)
                            1 Instituto Superior de Engenharia de Lisboa
       Departamento de Engenharia de Electrónica e Telecomunicações e de Computadores
                     Rua Conselheiro Emídio Navarro, N. 1, 1950-062 Lisboa
                           joao.casaleiro@cedet.isel.ipl.pt Tel.218317238
          2 Centro de Estudos e Desenvolvimento de Electrónica e Telecomunicações
                     Rua Conselheiro Emídio Navarro, N. 1, 1950-062 Lisboa
                               cedet@cedet.isel.ipl.pt Tel.218317284


Abstract

This article describes the architecture of a datalogger to be used in low power applications such
as ocean bottom seismometers. One of the several different modules that compose the system is
the dataloggers main clock source, which is a major issue when we need to synchronize data
obtained from several dataloggers, placed in several different locations and without any
communication means between them. We present experimental results of this oscillator as to its
stability when operating in a selected temperature range. We also present the power consumption
for each module and the autonomy of the overall system
108 – Oral Electrónica IV

         Um Aparato Experimental para Estudo e Desenvolvimento de Circuitos de
               Acondicionamento de Sinal: Uma Experiência Pedagógica

                M. Gomes(1) (2), A. Pinto (1) (2), P. Fazenda(1) (2), J. Casaleiro(1) (2)
                1 Dept. de Eng. de Electrónica e Telecomunicações e de Computadores
                                    Secção de Electrónica Aplicada
                              Instituto Superior de Engenharia de Lisboa
                       Rua Conselheiro Emídio Navarro, N. 1, 1950-062 Lisboa
                      sea@cedet.isel.ipl.pt Tel.218317000 http://www.isel.ipl.pt
              2 Centro de Estudos e Desenvolvimento de Electrónica e Telecomunicações
                              Instituto Superior de Engenharia de Lisboa
                       Rua Conselheiro Emídio Navarro, N. 1, 1950-062 Lisboa
                 contact@cedet.isel.ipl.pt Tel.218317284 http://www.cedet.isel.ipl.pt


Abstract
This paper describes an experimental apparatus developed by the authors and addresses some
aspects regarding the teaching experience resultant from its use in laboratorial lectures. The
apparatus incorporates several sensors and actuators in two small tanks of water, and is intended
for training the development of signal conditioning electronic circuits and simple programming
control algorithms. In the academic context where it has been used, the system may be observed
as a small scale reproduction of an industrial process. This has been a motivating factor for
students. This system’s use intends to promote the ability to recognize the problem(s) to be
solved in an engineering practical application, to correctly state them, and then to solve them. It
is also supposed to encourage an attitude more focused in the problem and not so much on the
individual task, as it is often desired in engineering works.
109 – Poster Electrónica e Telecomunicações



              Transistor parametric analyzer with temperature control

                 F. Campos(1), J. Coelho(1), M. Gomes(1) (2), A. Pinto (1) (2), H. Ramos(1) (2)
                             1 Instituto Superior de Engenharia de Lisboa,
           Departamento de Engenharia de Electrónica e Telecomunicações e de Computadores
                       Rua Conselheiro Emídio Navarro, N. 1, 1950-062 Lisboa
                                     isel@isel.ipl.pt Tel.218317000
              2 Centro de Estudos e Desenvolvimento de Electrónica e Telecomunicações
                       Rua Conselheiro Emídio Navarro, N. 1, 1950-062 Lisboa
                                contact@cedet.isel.ipl.pt Tel.218317284


Abstract
This document describes a static bipolar junction transistor characteristics analyzer, whose
package temperature can be controlled, thus constituting one of the analysis parameters.
The analyzer was developed to demonstrate in laboratorial lessons the temperature dependence
of some static characteristics of the bipolar junction transistors, having therefore, an eminently
pedagogical significance.
110 – Oral Electrónica IV

           Water flow regulator and temperature controller for domestic purpose



                T. Oliveira(1) (2), R. Reis(1) (2), J. Casaleiro(1) (2), P. Fazenda(1) (2),
                 H. Ramos (1) (2), A. Pinto (1) (2), M. Gomes(1) (2), J. Rocha(1) (2)
                             1 Instituto Superior de Engenharia de Lisboa,
                       Rua Conselheiro Emídio Navarro, N. 1, 1950-062 Lisboa
                            tiago.oliveira@cedet.isel.ipl.pt Tel.218317000
                                          http://www.isel.ipl.pt
              2 Centro de Estudos e de Desenvolvimento Electrónica e Telecomunicações
                       Rua Conselheiro Emídio Navarro, N. 1, 1950-062 Lisboa
                                 cedet@cedet.isel.ipl.pt Tel.218317284
                                       http://www.cedet.isel.ipl.pt


Abstract
This paper describes a system that controls the temperature and regulates the water flow for
domestic purposes. The system has a limit of seven independent flow exits, substituting the
traditional mechanical and manual taps.
The architecture of the system is divided in two types of blocks: the user’s interface (IU) and the
control and regulation block (CR). The IU is made up of a display and a keyboard that allows the
user to interact with the system. The CR block is constituted by an electronic circuit that
manages the IU modules and the electromechanical system.
For the temperature control a digital PID controller is used. The flow regulation in each exit is
executed independently.
111 – Oral Telecomunicações IV

                 MAC approaches for QoS Enhancement in Wireless LANs

                             José André Moura and Rui Neto Marinheiro
                                         ADETTI/ISCTE
                      Av. das Forças Armadas, Edifício ISCTE, 1600-082 Lisboa
                        Telefone: +351.217.903.099, Fax: +351.217.903.099

Abstract
Demanding for real-time multimedia applications in wireless access is increasing, and this has
driven recent research in QoS. The upcoming IEEE 802.11e standard will give a firm impulse
towards QoS provisioning in 802.11 wireless LANs. In parallel, during the last years, other
enhanced MAC schemes have also been proposed to improve QoS metrics. Some of these
approaches modify the 802.11e Backoff procedure, either by changing the way the Contention
Window is determined or by changing the way the backoff timer is decreased. Supported by
these previous works, we describe three new approaches. One of them is designated by
Differentiated Exponential Collision Recover – DECR, which uses exponential decrease
functions in the backoff timer, with different exponential decrease rate for each Access Category.
Using simulation results, we conclude that DECR, when compared with other approaches,
improves channel utilization without significantly increasing the collision rate.

Keywords
Medium Access Control (MAC), Backoff, Service differentiation, Wireless               LAN,
IEEE 802.11e, Quality of Service (QoS)
113 – Oral Telecomunicações III

                            MyTv: Personalized Television System

                             João Ferreira, Rui Jesus, Arnaldo Abrantes
                             Instituto Superior de Engenharia de Lisboa
                   jferreira@deetc.isel.ipl.pt rmfj@isel.ipl.pt aja@cedet.isel.ipl.pt

Abstract

The general requirements of a personalized Television System are analysed, in which registered
users receive an alert whenever an interesting program is on. The selection is done in a universe
of all the programs available in a cable TV system.
114 – Oral Electrónica I

                Um novo tipo de transdutor de deslocamento para aplicações
                                   em Engenharia Civil

  Nuno Apolinário1, João Ribas1, David Macário2, Alexandre Costa1, Maria Teresa Restivo1, Fernando
                                                Gomes
   de Almeida1, Joaquim Mendes1, Dinis dos Santos2, António Arede1, Carlos Sousa3 e Aníbal Costa1
                           1 Universidade do Porto, Faculdade de Engenharia
                            Rua Dr. Roberto Frias, 4200-465 Porto, Portugal
                        2 Universidade de Aveiro, Departamento de Electrónica
                              Campus Santiago, 3810-193 Aveiro, Portugal
                      3 Centro de Apoio Tecnológico à Industria Metalomecânica
                            Rua dos Plátanos, 197, 4100-414 Porto, Portugal

Abstract

The strain measurements and monitoring in large structures need a huge number of transducers
and digital recording for large periods of time. The available market solutions are associated to
significant costs. A transducer, based on a differential Hall effect sensor, has been studied and
implemented. The sensor presents high linearity, very small dimensions, and has been integrated
in a transducer housing made of non conducting material, with good thermal stability. The device
high level output signal is symmetric relatively to the transducer’s null position, also possessing
good repeatability and linearity. The development of a CAN network system exhibiting noise
immunity, failure tolerance and low cost allows the integration of those transducers. This system
was also adapted to wireless functionality. The produced prototypes were fully studied
experimentally and calibrated at an official Metrological Laboratory in Oporto (CATIM).
115 – Poster Electrónica



                  A 1 GHz Signal Monolithic CMOS Amplifier with
                                   Digitally Controlled Gain


                      Fernando Azevedo 1,2, Fernando Fortes 1,2, M. João Rosário 2,3
   1 Instituto Superior de Engenharia de Lisboa, Rua Conselheiro Emídio Navarro, 1049-014 Lisboa,
                                                 Portugal
              2 Instituto de Telecomunicações, Av. Rovisco Pais, 1049-001 Lisboa, Portugal
                3 Instituto Superior Técnico, Av. Rovisco Pais, 1049-001 Lisboa, Portugal
            email: fazevedo@deetc.isel.ipl.pt ffortes@deetc.isel.ipl.pt mrosario@alfa.ist.utl.pt




Abstract

 This paper describes the design and simulation of a monolithic amplifier, with digitally controlled gain,
to be used in 900MHz ISM (Industrial, Scientific and Medical) band. The fully integrated circuit was
implemented in a low cost 0.35m CMOS standard process (AMS/C35B4). The simulations were
performed with BSIM3 model and showed that under a 3V power supply voltage and 1GHz RF input, the
gain has a minimum of -36dB and a maximum of 28dB. Under these conditions the maximum total power
supply, including digital circuit, is less than 5mW. The circuit occupies a die area of 500µm x 500µm,
including bond-pads, allowing the complete integration of a transceiver for wireless communications.




Keywords
CMOS RFIC, RF amplifier, wireless communications, front-end.
116 – Poster Electrónica

   A 2.4GHz 1.8V Monolithic CMOS Converter with Integrated Oscillators

                      Fernando Azevedo 1,2, Fernando Fortes 1,2, M. João Rosário 2,3
   1 Instituto Superior de Engenharia de Lisboa, Rua Conselheiro Emídio Navarro, 1049-014 Lisboa,
                                                 Portugal
              2 Instituto de Telecomunicações, Av. Rovisco Pais, 1049-001 Lisboa, Portugal
                3 Instituto Superior Técnico, Av. Rovisco Pais, 1049-001 Lisboa, Portugal
            email: fazevedo@deetc.isel.ipl.pt ffortes@deetc.isel.ipl.pt mrosario@alfa.ist.utl.pt




Abstract

 This paper describes the design and simulation of a monolithic down converter image-rejection mixer,
double conversion, integrated with both oscillators. The fully integrated circuit was implemented in a low
cost 0.35m CMOS standard process (AMS/C35B4). The simulations were performed with BSIM3
model and showed that under a 1.8V power supply voltage and -13dBm RF input, the mixer has 14dB
conversion gain and 50dB image rejection. For fLO1=1.9GHz, fLO2=500MHz and fRF=2.4GHz the total DC
current is 10mA. The total circuit occupies a die area of 500µm x 500µm, including bond-pads, allowing
the complete integration of a transceiver for wireless communications.

 Preliminary experimental results showed a image rejection higher than 35dB and confirm the simulated
conversion gain.



Keywords
CMOS RFIC, mixers,          oscillators,   frequency    conversion,      microwave     mixer,    wireless
communications.
117 – Oral Computadores IV

                              Personal Unified Communications


                             João Pedro Guerreiro da Graça Patriarca
                                   Alberto Rodrigues da Silva
                       CCISEL, Instituto Superior de Engenharia de Lisboa,
                       Rua Conselheiro Emídio Navarro, 1, 1949-014 Lisboa,
                                       jpatri@cc.isel.ipl.pt
                              INESC-ID, Instituto Superior Técnico,
                              Rua Alves Redol, 9, 1000-029 Lisboa,
                                     alberto.silva@acm.org

Abstract
The project PUC, “Personal Communication System for next generation telecommunications
networks”, integrates, in the same platform, a set of personal communication services, namely,
web mail service and instant message service. The supporting application platform is the JBoss, a
J2EE complying product. The services were implemented in order to guarantee the independence
of terminal type access (the access can be made by a Web terminal, voice, WAP or another).
This paper presents the developed work according to mainly an engineering perspective,
focusing the implementation details which had greater relevance, namely the description of the
problems, of the adopted and implemented solutions, discussing the advantages and the
disadvantages of those same solutions and finally proposing alternative solutions.


Keywords
Personal Unified Communications; Personal Information Management; Services Integration;
Open-source; Java; J2EE
118 – Poster T

                 Study of ionosphere effects on the GPS signal propagation

                                Thiago Nunes de Morais e F. Walter
                               Instituto Tecnológico de Aeronáutica
                       Praça Marechal Eduardo Gomes, 50 – CEP 12228-900
                                São José dos Campos – SP – Brasil
                          Telefone: 55 12 39476903, Fax: 55 12 39475879


Abstract

The ionosphere is the major source of error for single frequency GPS receivers. In order to do a
global study of the ionosphere effects on the GPS signal propagation dynamic maps showing the
Vertical Total Electron Content (VTEC) have been made for the period within January, 1999 and
December, 2004. Based on this study the relation between the VTEC variation and the solar
cycle, season, epoch, geomagnetic activity and latitude could be analyzed. An electron density
model based on VTEC values provided in IONEX format have been used in a 3D ray-tracing
program to study ionosphere effects on the GPS signals mainly on the Equatorial Anomaly
region. It has also been made a comparison between IONEX VTEC data and the VTEC
calculated by the IRI (International Reference Ionosphere) model.
119 – Oral Telecomunicações III


                    IDENTIFICATION SYSTEM BASED ON FACES

                 Bruno Calado, Luís Murteira, Pedro Jorge, Arnaldo Abrantes
                         Instituto Superior de Engenharia de Lisboa
                             Rua Conselheiro Emídio Navarro, 1
                                  1950-062 Lisbon, Portugal
                          Phone.: (351) 218317000 Fax: (351) 218317001
                     E-mail: bklad@sapo.pt; murteiraluis@hotmail.com


Abstract
To identify a person from his/her face is a simple task for human beings, but it is a rather
difficult one if we intend to perform it in an automatic way, by using a Vision by Computer
system. The article describes the human faces detection and recognition system. The system
processes static images, video sequences kept in disk or video sequences captured with a Web
Cam. The system makes the recognition, by detecting firstly the location of the faces in the
image. The Face Detection is decomposed into two blocks. The first block involves the face
detection in the image, whereas the second one aims at detecting and locating the eyes position
only in some regions of the image (those considered candidates to faces). After the detection
phase, there comes a Recognition block, where the Principal Component Analysis (PCA) has
been used. In order to evaluate the faces recognition system, suggested in this paper, a FERET
(Face Recognition Technology) database has been used and another database has been created
within the scope of this paper, named ISEL.
121 – Poster Electrónica e Telecomunicações

                                 Hibrid Segmented Swept Sine

                                           Paulo, Joel Preto
                                             ISEL-DEETC
           R. Conselheiro Emídio Navarro, 1, 1949-014 Lisboa, Portugal, jpaulo@deetc.isel.ipl.pt
                           Phone: +351.218.317.180, Fax: +351.218.317.114
                                      Martins, Carlos Rodrigues
                                 Escola Náutica Infante D. Henrique,
                     Paço D’Arcos, Oeiras, 2780, Portugal, carlosmartins@enautica.pt
                           Phone: +351.214.460.010, Fax: +351.214.460.326
                                          Coelho, J. L. Bento
                                  CAPS - Instituto Superior Técnico
                                  Lisboa, Portugal, bcoelho@ist.utl.pt
                           Phone: +351.218.419.393, Fax: +351.218.465.303


Abstract
The Swept Sine is becoming a very popular technique for the measurement of room impulse
responses due to its SNR and immunity against the time–variance of the DUT. For the
measurement of the room impulse response in the presence of high level non-stationary
background noise the mean square of the overall sequence, in time and frequency domains must
be minimized.
This new technique consists in exciting the room with a set of M Swept Sine signal. Instead of
directly applying the averaging technique, a weighting procedure is used in order to improve the
SNR even more. Each captured swept sine frame is divided into N segments with filtering by a
filter bank, which splits the audio spectrum into multiple complementary sub-bands. The energy
within each sub-band is then computed. The weight average technique is applied for each
segment in time and frequency domains. This procedure ensures that the resulting Swept Sine
signal has the highest SNR value.
Several examples are presented where the Hibrid Segmented Swept Sine and classic Swept Sine
are compared and advantages and disadvantages are discussed.
122 – Oral Computadores I

              NDimProA Virtual Machine Architecture for Spatial Reasoning


                                               Jorge Pais
                             Instituto Superior de Engenharia de Lisboa
                                   Instituto de Sistemas e Robótica
                                            Lisboa, Portugal
                                         jpais@deetc.isel.ipl.pt
                                                    e
                                          Carlos Pinto-Ferreira
                                   Instituto deSistemas e Robótica
                                      Instituto Superior Técnico
                                            cpf@isr.ist.utl.pt


Abstract
A pictorial planer named NDimProA (N-Dimensional Projective Architecture) based on the n-
dimensional projective approach for spatial reasoning in n-dimensional spaces is presented. Its
n-dimensional reasoning process is hierarchical, which results in a multi-level architecture that
gave rise to a planer capable of producing pictorial real-time plans. The movement constraints
emerge from physical properties of the spatial entities. Any artificial system that incorporates
this planer as part of its reasoning process is able to interact and adapt in real-time with its
external environment. The n-dimensional projective approach is based on simple geometrical
concepts and its principal features are, the compression of data in representing physical bodies
and the completion and consistency of all projective topological descriptions. This article is
structured as follows. In section 1, we address some problems of spatial reasoning and we
describe the organization of the article. In section 2, the n-dimensional projective architecture is
described. In section 3, we discuss how we solve the movement constraints introduced by spatial
entities that share multiple physical properties. In section 4 some practical problems are
addressed and solved using our system. Finally, in section 5 we summarize our work.



Keywords
Spatial reasoning, automatic reasoning, pictorial reasoning, Euclidean spaces, computing
techniques.
123 – Oral Electrónica II
124 – Poster Electrónica

                 Non-linear optical spontaneous photoluminescence emission
                  enhancement effect in wide gap gallium nitride thin films

                              Manfred Niehus1, Reinhard Schwarz
           SE-DEETC-ISEL, R. Conselheiro Emídio Navarro, 1, 1949-014 Lisboa, Portugal


Abstract

With two interfering pulses from the 4th harmonic of a Nd-YAG laser we burnt a periodic lattice
structure into the surface of GaN thin films. The lattice period of this permanent grating could be
controlled between less than one and several tens of microns. Above the decomposition
threshold, nitrogen evades from the sample surface, and the residual metallic gallium
accumulates in the form of tiny droplets at the surfaces.
The patterned structure shows structural similarities with microcavities. The question arises if the
residual metallic gallium may act as a partially reflecting mirror. To test this hypothesis, we
studied the steady-state and transient photoluminescence through the modulation of light
emerging from the ubiquitous broad “yellow” photoluminescence band. The microlattice shows
up by energy-equidistant spontaneous emission enhancement peaks in the steady-state
photoluminescence spectra. We suggest that the partial reflection due to the residual metallic
gallium leads to the observed enhancement effect.
125 – Oral Electrónica I
126 – Oral Computadores II

        Fully Parameterizable VLSI Architecture for Sub-Pixel Motion Estimation
                      with Low Memory Bandwidth Requirements

                                           Tiago Dias
                                         ISEL - DEETC
                   Rua Conselheiro Emdio Navarro, 1, 1950-007 Lisbon, Portugal
                                    Nuno Roma, Leonel Sousa
                                        IST / INESC-ID
                         Rua Alves Redol, 9, 1000-029 Lisbon, Portugal

Abstract
This paper proposes a new scalable and efficient VLSI type-II architecture for real-time motion
estimation optimized for subpel refinement algorithms. Based on the proposed architecture,
which provides minimum latency, maximum throughput, and full utilization of the hardware
resources, the implementation of a dedicated motion estimation coprocessor is also presented in
this paper. This circuit is characterized by low memory bandwidth requirements, a modular and
highly flexible structure and is capable of estimating motion vectors with half-pixel accuracy
using the bilinear interpolation algorithm. Experimental results for implementations on ASIC and
FPGA devices show that by using the proposed architecture it is possible to estimate motion
vectors up to the 16CIF image format in real-time, with any given sub-pixel accuracy.
127 – Poster Electrónica e Telecomunicações

     MULTIPLE MODEL ADAPTIVE ESTIMATION (MMAE) ALGORITHM: AN
     APPLICATION IN MASS-SPRING-DASHPOT SYSTEM IDENTIFICATION

                                        João C. Martins
                       Escola Superior de Tecnologia e Gestão/INESC-ID
                                 Instituto Politécnico de Beja
                                         Av. Afonso III
                                   7800-050 Beja, Portugal
                              email: Joao.Martins@estig.ipbeja.pt

Abstract
This work addresses the performance of the Multiple-Model Adaptive Estimation (MMAE)
algorithm for different noise scenarios and sensor configurations, when applied to the
identification of a spring-mass-dashpot (MSD) system. The MMAE algorithm will be evaluated
using both the steady-state and the time-varying form of the Kalman filter.
128 – Oral Telecomunicações II

                Estimação do Subespaço de Sinal em Dados Hiperespectrais

                           José M. P. Nascimento and José M. B. Dias
         Instituto Superior de Engenharia de Lisboa and Instituto de Telecomunicações
       edifício DEETC, R. Conselheiro Emídio Navarro, N 1, 1950-062 Lisboa, Portugal
                        Telefone:+351.21.8317282, Fax:+351.21.8317114
                                       E-mail: zen@isel.pt
                  Instituto de Telecomunicações and Instituto Superior Técnico
               Av. Rovisco Pais, Torre Norte, Piso 10, 1049-001 Lisboa, Portugal
                        Telefone: +351.21.8418466, Fax: +351.21.841472
                                     E-mail: bioucas@lx.it.pt

Abstract
Hyperspectral remote sensing exploits the electromagnetic scattering patterns of the different
materials at specific wavelengths. Hyperspectral sensors have been developed to sample the
scattered portion of the electromagnetic spectrum extending from the visible region through the
near-infrared and mid-infrared, in hundreds of narrow contiguous bands.
Each pixel of an hyperspectral image can be considered as a linear mixture of a few endmember
signatures. Therefore, the dimensionality of data is usually much lower than the number of
bands. A key problem in dimensionality reduction in hyperspectral imagery is determining the
number of endmembers of the data set. The estimation of the number of endmembers in a scene
without any prior knowledge is crucial and also critical to the success of hyperspectral image
analysis.
This paper proposes a new mean squared error based approach to determine the signal subspace
in hyperspectral imagery. The method first estimates the noise correlation matrix based on
multiple regression theory, assuming spectral smoothness. To determine the signal subspace
dimension, we identify the subset of eigenvalues that best represents, in the least square sense,
the mean value of data set. The nonnegativity nature of hyperspectral components underlies our
approach: the mean value on any signal subspace eigenvector is always nonzero.
The effectiveness of the proposed method is illustrated using simulated data based on U.S.G.S.
laboratory spectra and using real hyperspectral data collected by the AVIRIS sensor over
Cuprite, Nevada. This set of experiments leads to the conclusion that the method is an useful tool
in hyperspectral data analysis.

Keywords: Subspace Dimensionality, Hyperspectral Data, Linear Mixtures.
129 – Oral Electrónica II

                  Remote data gathering using ZigBee over IEEE 802.15.4

                   David Rua_, Nuno Martins_, Pedro Reis_, João Paulo Sousa
                         {ee99127|ee00186|ee00106|jpsousa}@fe.up.pt
                  Departamento de Engenharia Electrotécnica e de Computadores
                       Faculdade de Engenharia da Universidade do Porto
                       Rua Dr. Roberto Frias, 4200–465 PORTO Portugal
                          Tel +351.22.5081833, Fax +351.22.5081443

Abstract
This paper describes an ongoing development work on sensors' wireless networks using ZigBee
and IEEE 802.15.4. ZigBee is trying to be a standard for the emerging personal area (PAN) and
home area (HAN) networks, connecting all the low data-rate equipment, assuring also reliability
and security as well as low power consumption. IEEE 802.15.4 standard defines the physical and
MAC layers while ZigBee defines the network and application layers.

The prototype is a development board prepared to be a network coordinator (acting as a data
concentrator), working as well as an endpoint node. The gathered data (temperature information)
can be sent to a PC via USB or RS232. As a way to implement several possible applications the
system architecture tried to be flexible, also having the preoccupation to use low power
components. The prototype has a microcontroller with flash ROM, an EEPROM, a RTC, a
graphical LCD, 2.4 Ghz RF, USB and RS232 interfaces, a battery (charged via AC adaptor or
USB), and 3.3 and 5 Volt power buses. Microchip's ZigBee stack was used despite its
underdevelopment state, and a PC's graphical application was created for easy user interface.

Prototype's line-of-sight range is 150 meters and it was measured that the RF card consummates
most of the circuit's power.
130 – Poster C

                           Grid Computing Configuration Profiles

          Rui Duarte1, Miguel Gouveia1, Paulo Barata1, Mário David2, Andrés Castillo-Sanz3
         1
          Dep. de Ciências e Tecnologias da Universidade Autónoma de Lisboa (DCT/UAL)
              2
                Laboratório de Instrumentação e Física Experimental de Partículas (LIP)
                          3
                            Universidade Pontifícia de Salamanca (UPSAM)



Abstract
Quattor is a new Free Software tool suite aimed at the installation, configuration and
management of extremely large computer clusters, containing up to ten thousand nodes, in a
scalable way. This paper presents the various components of the Quattor architecture and its
application to Grid clusters management.

Keywords
Quattor, Free Software, Extremely Large Fabrics, Grid Computing.
131 – Oral Computadores III

                           Team Formation for Urban Fire Combat


                       Paulo Araújo1, Paulo Trigo2, Ana Respício3, Carlos Lopes4
                                1 paraujo@isel.ipl.pt 2 ptrigo@isel.ipl.pt
                                  Instituto Superior Engenharia Lisboa
                          R. Conselheiro Emídio Navarro, 1, 1949-014 Lisboa
                          Telefone: +351.218.317.180, Fax: +351.218.317.114
                                           3 respicio@di.fc.ul.pt
                            Universidade de Lisboa, Faculdade de Ciências
                            FCUL, Dep. Informática, C6, 1749 - 016 Lisboa
                         Telefone: +351.217.500.522, Fax: +351. 217.500.084
                                      4 carloslopes@portugalmail.pt
                                    Universidade Católica Portuguesa
                   Universidade Católica Portuguesa Palma de Cima, 1649-023 Lisboa
                         Telefone: +351. 217.214.066, Fax: +351. 217.215.188

Abstract
This paper presents an approach to dimension a fire brigade team to combat an urban fire
within a simulation environment. The simulation was carried through in the
RoboCupRescue environment which combines, in the same geographic space (e.g. a city),
the evolution of a catastrophe (e.g. an urban fire) and the performance of the means
(humans) that aim to mitigate the effect of the catastrophe. Our approach determines the
minimum number of fire brigade team elements required to extinguish a specific fire. A
process of knowledge exploration was used, on a training set, to construct a decision tree,
using the ID3 classification algorithm. The training set was built after different situations
of fire simulation using the geographic space (map) of the Japanese city of Kobe. The rules
generated by the classification algorithm are analyzed and conclusions are taken regarding
the factors that influence the criterion of fire brigade team formation.


Keywords
Artificial Intelligence, Team Formation in Multi-Agent Systems, Simulation Environments.
132 – Poster C


                           Information Retrieval Statistical Methods
                       João Ferreira Alberto Rodrigues da Silva José Delgado
                           ISEL INESC-ID, IST Instituto Superior Técnico
            jferreira@deetc.isel.ipl.pt alberto.silva@acm.org Jose.Delgado@tagus.ist.utl.pt



Abstract

A statistical approach to the problem of information retrieval methods is presented, establishing
relations between the different algorithms and creates a unified vision from the different models
based in statistical methods. A common representation is proposed avoiding the use of so many
different representations. The requirements for a flexible index are identified and represent raw
material for all retrieval models based on the documents’ statistical properties.
133 – Poster C

                     Combination of methods on Information Retrieval

                        João Ferreira Alberto Rodrigues da Silva José Delgado
                            ISEL INESC-ID, IST Instituto Superior Técnico
             jferreira@deetc.isel.ipl.pt alberto.silva@acm.org Jose.Delgado@tagus.ist.utl.pt

Abstract

Different information retrieval systems’ combination possibilities are investigated targeting the
systems’ performance maximization. It brings a new perspective to the investigation of retrieval
systems aiming to reach the better strategy by proposing a combination method based on three
models: Textual, connections and classification.
136 – Poster Electrónica


                     Wireless sensors using Zigbee over IEEE 802.15.4


                       Hugo Malafaya_, Luís Tomás_, João Paulo Sousa
                           {ee00099|ee00043|jpsousa}@fe.up.pt
                Departamento de Engenharia Electrotécnica e de Computadores
                     Faculdade de Engenharia da Universidade do Porto
                     Rua Dr. Roberto Frias, 4200–465 PORTO Portugal
                        Tel +351.22.5081833, Fax +351.22.5081443


Abstract
Personal area networks (PAN) and home area networks (HAN) are two emerging fields of
application for low data-rate and low-power communications. Both issues are addressed by the
recent ZigBee specification (for the network and application layers) and the IEEE02.15.4
standard (for the physical and MAC layers). This paper describes the ongoing development of a
ZigBee endpoint node. The main goals of the proposed system architecture are the flexibility
required to act as a development board and the low-power required to act as a ZigBee endpoint
node. The main characteristics of the prototype are: 2.4GHz RF interface, microcontroller with
flash ROM, combined temperature and relative humidity sensor, luminosity sensor, four digital
input and outputs and two analog inputs. A smart battery system allows a wider set of
information about power consumption. Microchip's ZigBee stack was used and a suitable
application was created for user interface, sensor reading and signal conditioning. The
prototype's line-of-sight range is 150 meters and has very low power consumption (a few mW),
with the RF card consuming most of the power. The paper also presents and discusses the most
relevant aspects of the ZigBee technology and the remaining, already established, alternatives
and suggests possible enhancements to be implemented in a near future to improve and expand
the capabilities of the system.
137 – Oral Computadores I

                    Third Generation of Information Retrieval Systems
                              João Ferreira Rui Jesus Arnaldo Abrantes
                                          Instituto Superior de
                                         Engenharia de Lisboa
                                          Instituto Superior de
                                         Engenharia de Lisboa
                                          Instituto Superior de
                                         Engenharia de Lisboa
                    jferreira@deetc.isel.ipl.pt rmfj@isel.ipl.pt aja@cedet.isel.ipl.pt


Abstract
A group of ideas necessary for information retrieval systems’ development is discussed and
supported with the aim of improving the systems’ performance. Topics such as personalization,
profile, help interface, use of classification systems and context of retrieval are analysed and
discussed in an approach that allows the integration of its potential on a unified way.
138 – Oral Computadores I


                   Modelling Language for Information Retrieval Systems

                         João Ferreira Alberto Rodrigues da Silva José Delgado
                             ISEL INESC-ID, IST Instituto Superior Técnico
             jferreira@deetc.isel.ipl.pt alberto.silva@acm.org Jose.Delgado@tagus.ist.utl.pt


Abstract

The problem of lack of standardization of concepts, formulas and parameters in the information
retrieval area is analysed, introducing a dedicated language based on the UML extension
mechanisms. This language is the base for the construction of information retrieval abstract
models. These models operate as libraries that can be integrated in an infrastructure allowing the
construction of retrieval systems on a simplified, modular and uniform way.
200 – Oral Telecomunicações I

                                     UMTS Traffic Estimation
                                   Hugo Silva, António Serrador
                                 Instituto Superior de Engenharia de Lisboa
           Departamento de Engenharia de Electrónica e Telecomunicações e de Computadores
                     Rua Conselheiro Emídio Navarro, 1949-014 Lisboa, Portugal
                                {hsilva, aserrador}@deetc.isel.ipl.pt
                                        Tele: +351 218317226

Abstract

This paper presents a set of traffic source models for UMTS traffic estimation. In order to
estimate UMTS traffic, the city of Lisbon was used as reference scenario, where a set of twelve
appropriated services were selected and three user profiles, were identified. All these data are
crossed with Lisbon operational environments (classified by a local operator). After this process,
it is possible to estimate the traffic density for UMTS, which is weighted by: user profile,
service, operational environment and the total traffic volume. Being the total traffic volume, a
very useful result, that allows the estimation of base stations localisation. Additionally in this
work, the impact of services and network general parameters into the UMTS network capacity is
analysed. Based on these work, one can for example, estimate that for Lisbon (2006), 325 base
stations are required to cover the UMTS traffic.
202 – Poster Electrónica

                 Oscilador LC Monolítico Comandado por Tensão a 2,4GHz

                            Vítor Fialho, Ricardo Barreto, Fernando Fortes
                                            ISEL-DEETC
                         R. Conselheiro Emídio Navarro, 1, 1949-014 Lisboa
                         Telefone: +351.218.317.180, Fax: +351.218.317.114
                     {vfialho,ffortes}@deetc.isel.ipl.pt ; 24849@alunos.isel.ipl.pt


Abstract

This communication has the purpose to divulge the project of a monolithic VCO at 2.4GHz to
integrate a Phase Lock Loop (PLL). The oscillator is based on a crossed differential pairs (active
circuit). The VCO is feed with a tension of 2.8V. The command tension is 1.6V and 1.8V,
producing a variation of frequency between 2.4GHz and 2.75GHz.
203 – Oral Computadores II

                          Design Methodology of Reconfigurable SoC
                           Platforms based on a NoC Architecture

                                         Mário P. Véstias
                                          ISEL-DEETC
                                     mvestias@deetc.isel.ipl.pt

Abstract
The constant increase of gate capacity and performance of reconfigurable hardware chips made it
possible to implement systems-on-chip (SoC) able to tackle the demanding requirements of
many embedded systems. Moreover, the flexibility of these systems enables a reconfigurable
platform-based design methodology with IP reuse reducing the time-to-market while improving
the system performance.

In this paper, we propose an approach to the design space exploration of a reconfigurable SoC
platform based on a network on chip (NoC) architecture for the execution of dataflow dominated
embedded systems. Our strategy focuses on the exploration of architectural parameters of a
generic SoC platform.

Our approach has been used to design a JPEG application with a throughput of 640 Mbps. The
results are very promising since we where capable of easily integrate several IP cores in a single
reconfigurable chip and obtain high quality solutions.

We also conclude that the well-structured design of the SoC platform and the acceptable
computation times of the co-synthesis tool allow the rapid development of architectures for
specific applications.

Future research includes developing a more flexible SoC with different network-on-chip
parameters.
204 – Oral Telecomunicações IV

      The monIT Project: Electromagnetic Radiation Exposure Assessment in Mobile
                                  Communications


               Carla Oliveira1, Daniel Sebastião1, Gonçalo Carpinteiro1, Luís M. Correia1,
                           Carlos F. Fernandes1, Afonso Serralha2, Nuno Marques2
     1Instituto de Telecomunicações / Instituto Superior Técnico, Universidade Técnica de Lisboa,
                                Av. Rovisco Pais 1, 1049-001 Lisboa, Portugal
          {carla.oliveira, daniel.sebastiao, goncalo.carpinteiro, luis.correia, carlos.fernandes} @lx.it.pt
                2Magnete Lda., Pr. Dr. Nuno Pinheiro Torres, 1500–246 Lisboa, Portugal
                                  {afonso_serralha, nuno_marques}@yahoo.com


Abstract

The monIT Project provides public information on population exposure to electromagnetic
fields (EMFs) from mobile communication systems in Portugal. The monitoring system is based
on a network of autonomous remote probing stations, and also on an extensive EMFs sounding
program, both carried out in public areas across the country. Measured results are automatically
uploaded to a website for public dissemination (www.lx.it.pt/monit), which includes also other
relevant information about EMFs for the general public. This paper describes the project
structure, the automatic monitoring system, the project activities, and finally it presents a brief
analysis of the measured results.
Results from the 311 measurements carried out within the EMFs sounding program show that
radiation levels in all the analysed sites are below safety levels, with 62 % of the measured points
being at least 32 times below the EMF radiation strictest threshold. Another interesting result is
that the distribution of all measured points is almost independent from the distance to the
antennas, meaning that for each distance there are higher and lower field values. This way, one
can conclude that in real urban environments the distance to the antenna is almost irrelevant to
evaluate the risks of exposure to the radiation.
205 – Oral Electrónica IV

              Evaluation in Real Time of the Autonomy of Lead-Acid Batteries

                      F. L. Grilo1, O.P. Dias1, I.M.Teixeira2, J.P. Teixeira2
           1Escola Superior de Tecnologia de Setúbal/IPS, CESET, INESC, Portugal.
        2 Instituto Superior Técnico, Universidade Técnica de Lisboa, INESC, Portugal.



Abstract
This paper describes the development of an electronic system for monitoring the autonomy of
lead-acid batteries, in real time. The monitoring system implements an algorithm that models the
dynamic behaviour of the charge and discharge of the batteries.


The monitoring system implements an algorithm that models the dynamic behaviour during the
charge and discharge of the batteries, allowing, in real time, the continuous evaluation of the
available electrical energy, which, in this text, is named autonomy.


For the development of the system they were identified the most important parameters than
affect the autonomy of the batteries, namely, the current, the tension, the temperature and the
historical of the batteries concerned with the way as they are used in the charge and discharge
regimes.


Extensive tests were made on the system for different charge and discharge profiles, which
demonstrated the correct operation and efficiency of the monitoring system, as well as the
precision of the proposed model of batteries; typically with a margin of error less than 6% in the
calculation of the autonomy of the batteries.


Keywords
battery, autonomy of batteries, monitoring system, charge of batteries, discharge of batteries.
206 – Oral Computadores I

           Information management system: economic dispatch in a carbon market


            V.M.F. Mendes(1), J.P.S. Catalão(2), S.J.P.S. Mariano(3) e L.A.F.M. Ferreira(4)
                                        ISEL(1)-UBI(2, 3)-IST(4)
                         ISEL, Instituto Superior de Engenharia de Lisboa
                       R. Conselheiro Emídio Navarro, 1, 1950-062 Lisboa
                       Telefone: +351.218.317.038, Fax: +351.218.317.009
                                 UBI, Universidade da Beira Interior
                              R. Fonte do Lameiro, 6201-001 Covilhã
                                   IST, Instituto Superior Técnico
                                 Av. Rovisco Pais, 1049-001 Lisboa


Abstract

This paper merges economic with environmental policy issues regarding thermal units economic
dispatch in electric energy power systems.
On the one hand, within the energy market, power systems operation has move on from a
minimum-cost policy in state-owned monopolistic companies to a profit-based policy under
energy market conditions. On the other hand, as a consequence of growing environmental
concern, an unprecedented change points to a scenario where it is necessary to take into account
the emission pollution due to those thermal units.
Consequently, operation of thermal power systems needs to be not only considered within the
energy market, but also within the carbon market. Since minimizing the fuel cost, best solution
for the energy market, and the level of emission, best solution for the carbon market, are
conflicting objectives, an approach based on multiobjective optimisation is proposed in this
paper to obtain compromised solutions. In the aim of achieving rationality decisions, an
operation that may although lead to a higher operation cost, can represent an advantage in terms
of emissions.
This paper is a contribution in order to access those rationality decisions regarding thermal units
economic dispatch in electric energy power systems.
207 – Poster T

                                 Virtual Toll Gate System

                                Laurindo Berenguer, António Serrador

                             Instituto Superior de Engenharia de Lisboa
                                  Rua Conselheiro Emídio Navarro
                                      1949-014 Lisboa, Portugal
                                        Telefone: +351 218317226
                       laurindober@yahoo.com.br, aserrador@deetc.isel.ipl.pt


Abstract

The mobile communications systems are, nowadays, very common in the users everyday life.
Applications based on satellite positioning systems are experiencing a strong growth among
navigation systems applied to the motor car industry. This paper presents a new Virtual Toll Gate
System, which avoids the need of physical infrastructure construction of the toll gate. The
Virtual Toll Gate System is composed of a device that is installed in the mobile vehicles, that
communicates with the Toll Gate Management Centre. The toll gates are substituted by
geographic coordinates, and compared with the ones provided by the Global Positioning System.
Integrated with services offered by the Global System for Mobile Communications, this system
promotes the interoperability of billing systems on Toll Gate Systems at European level. A
prototype was developed to test the algorithms of the Virtual Toll Gate System; it was also built
an application that handles payment messages received from remote devices for a later delivery
to a Toll Gate Management Centre. The messages are sent using GSM services, passing trough
the Internet or by a Short Message Service.


Keywords
GSM/GPRS, SMS, GPS, OBU, TGMC, Toll Gate.
208 – Oral Computadores IV

                   Distributed feature interactions resolution in Internet

                                    Fernando Miguel Carvalho
           ISEL, Dept. de Engenharia Electrónica e Telecomunicações e de Computadores
                        R. Conselheiro Emídio Navarro, 1, 1949-014 Lisboa
                                     mcarvalho@cc.isel.ipl.pt

                                        Rui Gustavo Crespo
                        IST, Dept. of Electrical Engineering and Computers
                           Av. Rovisco Pais, 1049-001 Lisboa, Portugal
                                    R.G.Crespo@comp.ist.utl.pt


Abstract
Internet applications, such as Email, VoIP and WWW, have been enhanced with many features.
However, the introduction and modification of features may result in undesired behaviors, and
this effect is known as feature interaction-FI.
We propose a solution where each Internet application is served by an adviser, which has the FI
resolution role. Besides, the resolution must follow the Internet constraints and should be
distributed. In case of failure of one of the Internet nodes, the resolution must not be
compromised.
Finally we propose an adviser implementation based on deontic logics and Java technology. The
solution was customized and tested to James Email application (Java Apache Mail Enterprise
Server) of Apache Software Foundation (ASF), and the results satisfies the main requirements,
not compromising the application performance.


Key words
Feature interactions, Adviser, deontic formulas, object-oriented, Java, JAMES.
209 – Poster Electrónica

                       Misturador Monolítico a 2.4GHz em Tecnologia
                          CMOS 0.35µm usando Célula de Gilbert

                           Ricardo Barreto, Vítor Fialho, Fernando Fortes
                                           ISEL-DEETC
                         Rua Conselheiro Emídio Navarro, 1949-014 Lisboa
                                   Telefone: +351 218 317 228
                   rjbarreto@alunos.isel.ipl.pt; {vfialho, ffortes}@deetc.isel.ipl.pt


Abstract

This communication aims to present a 2.4 GHz double-balanced mixer, in 0.35µm CMOS using
the Gilbert cell.
The presented mixer was made to operate as a phase detector in a Phase Locked Loop (PLL).
The circuit uses MOS transistors and was initially designed as mixer of two signals to analyze
spurious, the behaviour as mixer and the isolation between pairs of ports, verifying the operation
as balanced circuit. Next was tested as phase detector, presenting an output signal, proportional
to the phase difference between the two input signals.
In design and simulation of the circuit performance, CADENCE Design Tools were used, and
the Austria Micro Systems design-kit, using its 0.35µm (C35B4) CMOS standard technology
with 4 metal and 2 poly layers.
210 – Poster T

                              An Indoor Propagation Model

                            Rui Lopes, Paulo Freixo, António Serrador
                            Instituto Superior de Engenharia de Lisboa
         Departamento de Engenharia de Electrónica e Telecomunicações e de Computadores
                 Rua Conselheiro Emídio Navarro No.1, 1950-062 Lisboa, Portugal.
                                       Telef: +351 218317226
            rui_wimax_lopes@yahoo.com, pfreixo@influe.pt, aserrador@deetc.isel.ipl.pt


Abstract
WLANs are nowadays at the top of the mass market networks technologies. They are essentially
implemented in indoor environments, where the traditional planning tools are not yet focused.
Although the concerning to improve the radio planning quality, the existing propagation models
can still be sharpened for better outcomes, mainly in large buildings. A new propagation model
is proposed and evaluated with measurements at 2.4GHz and also a 3D planning tool is
presented, with the ability to execute coverage and capacity analysis on indoor multi-floors
environments. This new propagation model adapts itself to multiple indoor scenarios following
the performed measurements.




Keywords
WLAN, Indoor Propagation Models, 2.4GHz Measurements, Planning.
211 – Poster T


                 Performance Analysis of Transactions over Bluetooth

                       José Albino, António Serrador
                Instituto Superior de Engenharia de Lisboa
    Departamento de Engenharia de Electrónica e de Telecomunicações e
                               Computadores
    Grupo de Investigação em Electrónica de Sistemas e Telecomunicações
     Rua Conselheiro Emídio Navarro No.1, 1950-062 Lisboa, Portugal.
                      {jalbino, aserrador}@deetc.isel.ipl.pt
                           Telef: +351 21 8317226

Abstract
In this paper the Bluetooth standard is analyzed and used in applications with different
characteristics than the standard initially foresee. The transmission of 128 bytes is the object in
study, the setup time of this transaction as to be made as quickly as possible since the mobile
terminals will have high mobility speed. The performance of this technology is analyzed using
several connections that are created on different layers of the bluetooth stack, using different
versions of the standard. In this work, it is demonstrated that the transaction setup time required
to transmit 128 bytes, occur inside of a maximum window of 5s,, independently of the bluetooth
version that is analysed. To reduce the transaction setup time is needed to change the default
values recommended in the standard, thus improving the time needed to research the devices and
establish new connections. Therefore, is possible to reduce the standard time necessary to
establish connections, allowing the establishment of fast transactions allowing high terminal
mobility.


Keywords
Bluetooth, Mobility, Transactions Setup
301 – Poster T

                      GNSS: A Tool For Teaching Telecommunications

                                          F. Walter
           Instituto Tecnológico de Aeronáutica, Departamento de Telecomunicações
                              Praça Marechal Eduardo Gomes, 50
                          12228-900 São José dos Campos, SP, Brasil
            Telefone: +55 12 3947 5962, Fax: +55 12 3947-5879, E-mail: fw2@ita.br



Abstract
This paper reports recent development programs and activities in the GNSS Laboratory at the
Instituto Tecnológico de Aeronáutica (ITA). Since the early 1990’s, personnel at the ITA have
been working in the integration and evaluation of GPS sensors and related technology. Following
directives from ICAO, ITA developed a systematic training program that uses GNSS as a
curricular option for Telecommunications engineering courses. The objective is to generate
human resources capable of overcoming the technological challenges and changes imposed to
the aeronautical fields in the imminent presence of three main GNSS systems. Experimental
project results and trends of this methodology are presented.




Keywords
Global navigation; GNSS; Education; Telecommunication; Satellite Communication.
302 – Oral Telecomunicações II

                             CBIR system with Relevance Feedback

                        Rui M. Jesus1, Arnaldo J. Abrantes1, Jorge S. Marques2
                           1M2A - Instituto Superior de Engenharia de Lisboa
                  Rua Conselheiro Emídio Navarro, nº 1, 1940-014 Lisboa, Portugal
                  Telefone: 218317227, rjesus@deetc.isel.ipl.pt, aja@deetc.isel.ipl.pt
                        2 ISR/IST, Av. Rovisco Pais 1049-001 Lisboa, Portugal


Abstract

Content Based Image Retrieval (CBIR) systems aim to find sets of relevant images in image
databases. This is a difficult task since it is not possible to manually annotate large databases of
images by describing their content in terms of keywords. Automatic systems rely on low level
image features (e.g., color, texture coefficients). Unfortunately, such systems have a poor
performance since low level features are unable to capture semantic concepts e.g., flowers or
persons. This problem is known as semantic gap. Relevance Feedback has been used to
overcome this difficulty and to improve the performance of CBIR algorithms. This paper
presents a relevance feedback method based on the regularized least squares classifier, and a
technique to select feedback information in order to increase the learning rate. Experimental
results are presented in the paper to illustrate the performance of the proposed relevance
feedback.
305 – Oral Electrónica III


                              Local Oscillator for UHF Repeaters

      Nelson Santos, Sérgio Oliveira, Luís Mendes, Rafael Caldeirinha e Bárbara Coelho
               
                 Escola Superior de Tecnologia e Gestão – Instituto Politécnico de Leiria
              Morro do Lena – Alto do Vieiro, Apartado 4163,2411-901 Leiria, Portugal
           Telefone: +351 244 820 300, Fax: +351 244 820 310, http://www.estg.ipleiria.pt
                           
                             Instituto de Telecomunicações, http://www.it.pt


Abstract
This paper describes the project, implementation and experimental results of a local oscillator for
UHF frequency band. The chosen architecture, responsible for high precision and stability of the
local oscillator, uses a direct digital synthesizer and a phase-locked loop synthesizer. The local
oscillator presents a tune range from 450MHz to 900MHz, an output signal power of 0.5dBm, a
typical phase noise of -91dBc/Hz@10kHz, a harmonic suppression better than 23dBc and a
spurious rejection higher than 60dBc. The output signal frequency is tuned with coarse steps of
1MHz or with a high precision step of 1Hz, both digitally controlled. The primary application of
this oscillator will be in repeater equipments of signals with analog modulation. This paper also
presents some experimental results of a newer version of this oscillator, that will be integrated in
commercial repeaters for digital bandpass signals, such as orthogonal frequency division
multiplexing signals.
307 – Oral Telecomunicações II
400 – Oral Computadores III

                    MAMIS – A Multi-Agent Medical Information System

                    José Manuel Fonseca André Damas Mora Ana Celeste Marques
                          jmf@uninova.pt atm@uninova.pt acm@uninova.pt
                   UNINOVA - Instituto de Desenvolvimento de Novas Tecnologias
                      Campus da FCT/UNL – Monte de Caparica – PORTUGAL

Abstract
Information technology has expanded enormously in the last decades affecting almost any field
of activity. Healthcare industry couldn’t be out of this technical revolution. However, despite the
huge potential demonstrated by informatics for the improvement of the healthcare industry,
changes are going slowly. The implantation of the Electronic Health Record of a patient creates
in the near future the possibility of collecting a complete bioprofile of a patient that conveniently
analyzed can improve significantly the healthcare services, reducing cost and improving
efficiency and safety of the patients. In this paper, after identifying the main requirements for a
modern Medical Information System, we present MAMIS – a Multi-Agent Medical Information
System. This system, inherently distributed, was designed with the goal of proving a solution for
patient information search on a community of autonomous healthcare units and provide
ubiquitous information access to physicians and healthcare professionals in a variety of
situations.
402 - Oral Computadores II

                   VITRAL: A Text Mode Windows Manager for RTEMS

                                        Manuel Coutinho
                  Instituto Superior Técnico - Universidade Técnica de Lisboa,
                       DEEC, Av. Rovisco Pais, 1049-001 Lisboa, Portugal,
                                  e-mail: mabeco@comp.ist.utl.pt
                                            José Rufino
                         Faculdade de Ciàencias da Universidade de Lisboa,
                      Campo Grande - Bloco C8, 1749-016 Lisboa, Portugal.
                          Tel: +351-21-7500254 - Fax: +351-21-7500084
                                       e-mail: ruf@di.fc.ul.pt
                                          Carlos Almeida
                   Instituto Superior Técnico - Universidade Técnica de Lisboa,
               DEEC, AC-Computadores, Av. Rovisco Pais, 1049-001 Lisboa, Portugal
                       Telefone: +351-21-8418397 FAX: +351-21-8417499
                                    e-mail: cra@comp.ist.utl.pt


Abstract
Most embedded control applications consist of several different tasks that need to be executed in
a concurrent fashion and usually have real-time requirements. In some cases, these applications
need to interact with the real-world, performing input/output operations through a set of devices
such as sensors and actuators, but they may also need to interact with human users. This
interaction, if not bounded, may jeopardize the system timeliness. Due to the basic requirements
of these applications (concurrent tasks, real-time, input/output event handling), multitasking real-
time kernels are a fundamental component to support their development. One example of such a
real-time kernel is RTEMS, the Real-Time Executive for Multiprocessor Systems, which is a
well-known, real-time multitasking kernel, with a modular architecture, offering interesting
characteristics to support the development of real-time embedded control applications. The
standard RTEMS
visual interface lacks clarity and quality of data presentation to the user.
The VITRAL (Portuguese word for Stained Glass Window) driver is a simple yet reliable
multiple text windows manager. It is compatible with standard input/output calls (stdio library)
where each window can read from the keyboard and write to the output. To prevent event
overload, VITRAL provides a protective mechanism to limit the rate of processed keyboard
interruptions

Keywords
Text mode windows manager, Real-time kernels, RTEMS, Timeliness properties
500 – Poster T

                            Cellular Optimisation in UMTS-FDD

                      Luís Caetano, Mário Marques e António Serrador
                                        ISEL-DEETC
                     R. Conselheiro Emídio Navarro, 1, 1949-014 Lisboa
                     Telefone: +351 21 8317226, Fax: +351 21 8317114
     luis.caetano@netcabo.pt ; mario.rosado.marques@sapo.pt ; aserrador@deetc.isel.ipl.pt


Abstract

The process of planning and optimisation of an UMTS network is a complex task. In this paper
some quasi optimal solutions for UMTS-FDD optimisation are presented. The system
optimisation is accomplished using Artificial Intelligence algorithms that implement a
heuristically guided optimisation. For such, an UMTS-FDD network simulator was implemented
and a cost function calculated for each simulation. This function evaluates the performance of
the system and is used as an input to the optimisation algorithm and its decisions. The
optimisation parameters are: the number of base stations, the antennas height and its tilt angles.
The simulation tool allows several graphical and statistical analyses of the optimisation
procedure and the best simulation performed. All solutions can be recorded as scenery
optimisation results for future reference. Finally the main conclusion is that the capacity of an
UMTS network is strongly conditioned by the generated level of interference and the set of
supported services.


Keywords
UMTS-FDD, Artificial Intelligence, Simulated Annealing, Tabu Search
501 – Oral Telecomunicações II
502 – Oral Electrónica I

				
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