With the growing need for STEM workers in the job market, schools tend to look for extra-curricul... more With the growing need for STEM workers in the job market, schools tend to look for extra-curricular activities that promote this type of skills. With activities like The Inventors or Happy Code, schools encourage kids to have a mindset more open towards technology. Despite these efforts, the tools available to teach programming to primary school students are still lacking. Available solutions can be too difficult to understand, overly expensive for school budgets or may require IT infrastructure that is lacking from the majority of public schools. As a result, this paper aims to create a concept that can convey the fundamentals of programming/Logical Thinking in an accessible and fun way, without using a computer. For this purpose we use a micro-controller, Micro: Bit, and a physical, puzzle-like representation of a programming framework, called MakeCode.
This paper addresses the use of events within discrete-event systems modeling formalisms, present... more This paper addresses the use of events within discrete-event systems modeling formalisms, presenting the concept of event life time when enclosed in the detection of a specific behavior defined by sequences of events. This concept defines the time interval during which a macro-event is valid (a macro-event is an event computed as the result of a pre-defined sequence of events). Two types of life times are defined: Absolute and Relative. Absolute life time is associated with the maximum time between the occurrence of the first and last event in the sequence. The relative life time is associated with each elementary event from the sequence and is defined by minimum and maximum values among which the next event in the sequence must occur. If the next event does not occur during the defined time, the event expires. Finally the use of these concepts is discussed presenting some specific cases of use.
ABSTRACT In this paper, a set of event types for human-system interaction modeling is presented, ... more ABSTRACT In this paper, a set of event types for human-system interaction modeling is presented, and its usage with IOPT nets (Input-Output Place-Transition Petri nets) models is illustrated. Currently, a non-autonomous event based on the computation of the change with respect to a specific threshold of input signals values on two consecutive execution steps is defined for IOPT models. Other types of events are proposed, allowing the definition of an event not only based on a threshold in the signal value, but also as a change on the variation of the signal. The concept of delayed events considers two values in different time steps (other than consecutive steps). This concept can be applied to previous types of events. The concept of composed events is also introduced, in order to create events dependent on two or more events on the same signal, at the same time step as well as at different time steps. Finally, an example is used to illustrate the concepts presented.
ABSTRACT A model-based development flow based on IOPT Petri nets models and its insertion in a di... more ABSTRACT A model-based development flow based on IOPT Petri nets models and its insertion in a digital system design course is presented. The IOPT-Tools framework is used to support a cloud enabled design automation flow, including specification of system's behavior, state space based verification, and automatic code generation (C and VHDL) leading to implementation deployment into reconfigurable computing platforms. Teaching flow method is presented, supported by reconfigurable platforms (FPGA based boards and Arduino devices) giving adequate flexibility for exercising different implementation strategies and allowing laboratory prototyping during classes. The proposed approach was fully validated during a course on Digital Systems Design offered to Electric and Computer Engineering MSc course, and student's assessment on usage of cloud based development IOPT-Tools framework is analyzed.
In this paper, an ultrasonic anemometer based in the time of flight is presented. The wind speed ... more In this paper, an ultrasonic anemometer based in the time of flight is presented. The wind speed and direction is obtained using four ultrasonic transducers in an orthogonal configuration. Two transducers are used in each orthogonal direction as transmitter and receiver of a short sequence of pulses and the time of flight is recorded in both ways. The system is based on a low-cost Arduino-Nano board and the overall system was tested in a wind tunnel, where accuracy and linearity were analyzed. The developed anemometer is intended to be used in a scale model sailboat to support its autonomous navigation.
The paper presents a novel design methodology of cyber-physical systems supported by computer aid... more The paper presents a novel design methodology of cyber-physical systems supported by computer aided tools. In particular, IOPT and Hippo tools are involved in the design and analysis techniques of the system. The proposed idea combines the main advantages of both tools by offering the complex design path of the control part of the cyber-physical system, including specification, analysis and verification, decomposition, and modelling stages. Additionally, the designer is able to choose the most suitable representation of the system (graphical or formal). The presented concepts are illustrated by a case-study example.
Ferreira, Ricardo and Gomes, Luís and Costa, Anikó (2010) Interligação intrae inter-circuito de c... more Ferreira, Ricardo and Gomes, Luís and Costa, Anikó (2010) Interligação intrae inter-circuito de componentes especificados com Redes de Petri. [Paper]. In: REC'2010 – VI Jornadas sobre Sistemas Reconfiguráveis, 4-5 Fevereiro 2010, IEETA, Universidade de Aveiro, Aveiro, Portugal. ... Full text not available from this repository. ... OA.uninova.pt is powered by EPrints 3 which is developed by the School of Electronics and Computer Science at the University of Southampton. More information and software credits.
Advances in intelligent systems and computing, 2014
This work presents some new ways to analyze a signal that allows the modeling of human-system int... more This work presents some new ways to analyze a signal that allows the modeling of human-system interactions. In addition to the possibility of creating conditions associated with the current value of the signal, the work focuses mainly on the definition of events and on their use within Input-Output Place-Transition (IOPT) nets models. Currently, non-autonomous events can be defined in two different ways, namely as a threshold detection of a signal, or variation of the first derivative of the signal. Here, this concept is generalized, allowing the analysis of events in higher derivatives of the signal. On the other hand, a new set of types of events are defined for each derivative of the signal, improving existing UP and DOWN events. Finally, an example is used to illustrate discussed concepts.
This paper presents a controller architecture targeted for autonomous sailing of a small yacht, h... more This paper presents a controller architecture targeted for autonomous sailing of a small yacht, having in mind its control within a regatta contest. The controller architecture considers a three layer hierarchical decomposition, where the bottom layer takes care of the low level control of the sail and the rudder, based on the usage of a fuzzy controller, while the middle one selects the adequate navigation strategy (avoiding no-go zone), and the top layer is responsible for the definition of the regatta sequence of intermediate and final goals. A model-based development strategy is used, relying as much as possible on automatic code generation from models. Initial electronic instrumentation support comes from a compass, a GPS and a wind vane, but current developments include addition of an anemometer (providing wind speed and direction), as well as the introduction of virtual sensors obtained from computation of sensor data (as velocity obtained from GPS). A framework allowing the emulation of the different electronic instrumentation components support a complete offline validation of the controller, in a laboratory environment.
With the growing need for STEM workers in the job market, schools tend to look for extra-curricul... more With the growing need for STEM workers in the job market, schools tend to look for extra-curricular activities that promote this type of skills. With activities like The Inventors or Happy Code, schools encourage kids to have a mindset more open towards technology. Despite these efforts, the tools available to teach programming to primary school students are still lacking. Available solutions can be too difficult to understand, overly expensive for school budgets or may require IT infrastructure that is lacking from the majority of public schools. As a result, this paper aims to create a concept that can convey the fundamentals of programming/Logical Thinking in an accessible and fun way, without using a computer. For this purpose we use a micro-controller, Micro: Bit, and a physical, puzzle-like representation of a programming framework, called MakeCode.
This paper addresses the use of events within discrete-event systems modeling formalisms, present... more This paper addresses the use of events within discrete-event systems modeling formalisms, presenting the concept of event life time when enclosed in the detection of a specific behavior defined by sequences of events. This concept defines the time interval during which a macro-event is valid (a macro-event is an event computed as the result of a pre-defined sequence of events). Two types of life times are defined: Absolute and Relative. Absolute life time is associated with the maximum time between the occurrence of the first and last event in the sequence. The relative life time is associated with each elementary event from the sequence and is defined by minimum and maximum values among which the next event in the sequence must occur. If the next event does not occur during the defined time, the event expires. Finally the use of these concepts is discussed presenting some specific cases of use.
ABSTRACT In this paper, a set of event types for human-system interaction modeling is presented, ... more ABSTRACT In this paper, a set of event types for human-system interaction modeling is presented, and its usage with IOPT nets (Input-Output Place-Transition Petri nets) models is illustrated. Currently, a non-autonomous event based on the computation of the change with respect to a specific threshold of input signals values on two consecutive execution steps is defined for IOPT models. Other types of events are proposed, allowing the definition of an event not only based on a threshold in the signal value, but also as a change on the variation of the signal. The concept of delayed events considers two values in different time steps (other than consecutive steps). This concept can be applied to previous types of events. The concept of composed events is also introduced, in order to create events dependent on two or more events on the same signal, at the same time step as well as at different time steps. Finally, an example is used to illustrate the concepts presented.
ABSTRACT A model-based development flow based on IOPT Petri nets models and its insertion in a di... more ABSTRACT A model-based development flow based on IOPT Petri nets models and its insertion in a digital system design course is presented. The IOPT-Tools framework is used to support a cloud enabled design automation flow, including specification of system's behavior, state space based verification, and automatic code generation (C and VHDL) leading to implementation deployment into reconfigurable computing platforms. Teaching flow method is presented, supported by reconfigurable platforms (FPGA based boards and Arduino devices) giving adequate flexibility for exercising different implementation strategies and allowing laboratory prototyping during classes. The proposed approach was fully validated during a course on Digital Systems Design offered to Electric and Computer Engineering MSc course, and student's assessment on usage of cloud based development IOPT-Tools framework is analyzed.
In this paper, an ultrasonic anemometer based in the time of flight is presented. The wind speed ... more In this paper, an ultrasonic anemometer based in the time of flight is presented. The wind speed and direction is obtained using four ultrasonic transducers in an orthogonal configuration. Two transducers are used in each orthogonal direction as transmitter and receiver of a short sequence of pulses and the time of flight is recorded in both ways. The system is based on a low-cost Arduino-Nano board and the overall system was tested in a wind tunnel, where accuracy and linearity were analyzed. The developed anemometer is intended to be used in a scale model sailboat to support its autonomous navigation.
The paper presents a novel design methodology of cyber-physical systems supported by computer aid... more The paper presents a novel design methodology of cyber-physical systems supported by computer aided tools. In particular, IOPT and Hippo tools are involved in the design and analysis techniques of the system. The proposed idea combines the main advantages of both tools by offering the complex design path of the control part of the cyber-physical system, including specification, analysis and verification, decomposition, and modelling stages. Additionally, the designer is able to choose the most suitable representation of the system (graphical or formal). The presented concepts are illustrated by a case-study example.
Ferreira, Ricardo and Gomes, Luís and Costa, Anikó (2010) Interligação intrae inter-circuito de c... more Ferreira, Ricardo and Gomes, Luís and Costa, Anikó (2010) Interligação intrae inter-circuito de componentes especificados com Redes de Petri. [Paper]. In: REC'2010 – VI Jornadas sobre Sistemas Reconfiguráveis, 4-5 Fevereiro 2010, IEETA, Universidade de Aveiro, Aveiro, Portugal. ... Full text not available from this repository. ... OA.uninova.pt is powered by EPrints 3 which is developed by the School of Electronics and Computer Science at the University of Southampton. More information and software credits.
Advances in intelligent systems and computing, 2014
This work presents some new ways to analyze a signal that allows the modeling of human-system int... more This work presents some new ways to analyze a signal that allows the modeling of human-system interactions. In addition to the possibility of creating conditions associated with the current value of the signal, the work focuses mainly on the definition of events and on their use within Input-Output Place-Transition (IOPT) nets models. Currently, non-autonomous events can be defined in two different ways, namely as a threshold detection of a signal, or variation of the first derivative of the signal. Here, this concept is generalized, allowing the analysis of events in higher derivatives of the signal. On the other hand, a new set of types of events are defined for each derivative of the signal, improving existing UP and DOWN events. Finally, an example is used to illustrate discussed concepts.
This paper presents a controller architecture targeted for autonomous sailing of a small yacht, h... more This paper presents a controller architecture targeted for autonomous sailing of a small yacht, having in mind its control within a regatta contest. The controller architecture considers a three layer hierarchical decomposition, where the bottom layer takes care of the low level control of the sail and the rudder, based on the usage of a fuzzy controller, while the middle one selects the adequate navigation strategy (avoiding no-go zone), and the top layer is responsible for the definition of the regatta sequence of intermediate and final goals. A model-based development strategy is used, relying as much as possible on automatic code generation from models. Initial electronic instrumentation support comes from a compass, a GPS and a wind vane, but current developments include addition of an anemometer (providing wind speed and direction), as well as the introduction of virtual sensors obtained from computation of sensor data (as velocity obtained from GPS). A framework allowing the emulation of the different electronic instrumentation components support a complete offline validation of the controller, in a laboratory environment.
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Papers by Aniko Costa