Antonio Esteves | Universidade do Minho (original) (raw)

Papers by Antonio Esteves

Ciência & Tecnologia dos Materiais, 2017

The main objective of the present work is to profound the applicability of a synchronous parallel... more The main objective of the present work is to profound the applicability of a synchronous parallel kinetic Monte Carlo (spkMC) algorithm for simulating the nucleation of Al 3 Sc precipitates. Parallel processes communication is implemented through Message Passing Interface (MPI). Consequently, the capability of extending time and length scales of atomistic kinetic Monte Carlo (kMC) will be attested. Lastly, we present the results obtained from simulations of nucleation of Al 3 Sc precipitates, which include a comparative view between sequential and parallel algorithms.

Proceedings of the 15th International Conference on Web Information Systems and Technologies, 2019

This paper describes the process of optimizing the latency of Python-based Web applications. The ... more This paper describes the process of optimizing the latency of Python-based Web applications. The case study used to validate the optimizations is an article sharing system, which was developed in Django. Memcached, Celery and Varnish enabled the implementation of additional performance optimizations. The latency of operations was measured, before and after the application of the optimization techniques. The optimization of the application was performed at various levels, including the transfer of content across the network and the back-end services. HTTP caching, data compression and minification techniques, as well as static content replication using Content Delivery Networks, were used. Partial update of the application's pages on the frontend and asynchronous processing techniques were applied. The database utilization was optimized by creating indexes and by taking advantage of a NoSQL solution. Memory caching strategies, with distinct granularities, were implemented to store templates and application objects. Furthermore, asynchronous task queues were used to perform some costly operations. All of the aforementioned techniques favorably contributed to the Web application's latency decrease. Since Django operates on the back-end, and optimizations must be implemented at various levels, it was necessary to use other tools.

Esta tese propõe uma metodologia de partição automática, que é parte integrante duma metodologia ... more Esta tese propõe uma metodologia de partição automática, que é parte integrante duma metodologia mais abrangente orientada para o desenvolvimento de sistemas embebidos predominantemente de fluxo de dados. É formulado o problema de partição, tarefa que ...

DORII middleware was already successfully tested with several instruments, in order to integrate ... more DORII middleware was already successfully tested with several instruments, in order to integrate instruments into the Grid, to perform a remote control and monitoring, and to apply the resulting data into Grid jobs or in dissemination. In the present case, the middleware was tested with a particular instrument-a WSN-and with realistic parameters, to simulate an effective and user friendly way, as it is required by CP applications. It was implemented an Instrument Element and several Instrument Managers (IMs), which virtualize the WSN. It was also developed a Custom Java interface (CJI) to connect the IMs with sensors, performing the translation of the commands/data exchanged between IMs and sensors. Since it was intended to have a long duration-offline monitoring, additional modules were implemented to manage this issue, saving the data in a database. A Sensor Observation Service (SOS), following OGC standards, was implemented. The users access the database through the SOS.

The CROSS-Fire project focus on developing a grid-based framework for wild fire management using ... more The CROSS-Fire project focus on developing a grid-based framework for wild fire management using FireStation (FS) as a standalone application that simulates the fire spread over complex topography. The overall software development is made of several components: client applications, which request geo-referenced data and fire spread simulation, Spatial Data Infrastructures (SDI), which provide geo-referenced data, and the GRID, which gives support to the computational and data storage requirements. Herein we present the central Web Processing System (WPS) layer developed to support the interaction between all components of the architecture. This OGC-WS compatible layer provides the mechanism to access the Grid facilities for processing and data management and including all the algorithms, calculations, or models that operate on spatially referenced data, also mediating communication with the FS console. We also describe the work that has been done to provide FS with dynamic fuel maps, by using an OGC-WCS suite of services and satellite data. This task complements the previous integration of dynamic data from meteorological stations using OGC-SWE services.

Deliverable Dissemination Level PU Public PP Restricted to other programme participants (includin... more Deliverable Dissemination Level PU Public PP Restricted to other programme participants (including the Commission Services) RE Restricted to a group specified by the consortium (including the Commission Services) X CO Confidential, only for members of the consortium (including the Commission Services)

: The main purpose of this article is to present how Petri Nets (PNs) have been used for hardware... more : The main purpose of this article is to present how Petri Nets (PNs) have been used for hardware design at our research laboratory. We describe the use of PN models to specify synchronous parallel controllers and how PN specifications can be extended to include the behavioural description of the data path, by using object-oriented concepts. Some hierarchical mechanisms which deal with the specification of complex digital systems are highlighted. It is described a design flow that includes, among others, the automatic generation of VHDL code to synthesize the control unit of the system. The use of PNs as part of a multiple-view model within an object-oriented methodology for hardware/software codesign is debated. The EDgAR-2 platform is considered as the reconfigurable target architecture for implementing the systems and its main characteristics are shown. Keywords: Petri Nets, Hardware Design, Reconfigurable Architecture, HW/SW Co-Design An Evolutionary Approach to the Use of Petr...

Hardware Design and Petri Nets, 2000

A two-step hardware/software partition methodology was developed. It departs from an initial part... more A two-step hardware/software partition methodology was developed. It departs from an initial partition solution based on the cluster growth algorithm and iteratively leads the designer to an improved solution, using the tabu search algorithm. A PCI-based reconfigurable ...

This paper describes a Sensor Observation Service (SOS) client developed to integrate dynamic geo... more This paper describes a Sensor Observation Service (SOS) client developed to integrate dynamic geospatial data from meteorological sensors, on a grid-based risk management decision support system. The present work is part of the CROSS-Fire project, which uses forest fires as the main case study and the FireStation application to simulate fire spread. The meteorological data is accessed through the SOS standard from Open Geospatial Consortium (OGC), using the Observations and Measurements (O&M) standard encoding format. Since the SOS standard was not designed to directly access sensors, we developed an interface application to load the SOS database with observations from a Vantis Weather Station (WS). To integrate the SOS meteorological data into the FireStation, the developed SOS client was embedded on a Web Processing Service (WPS) algorithm. This algorithm was designed to be functional and fully compliant with SOS, SensorML, and O&M standards from OGC. With minor modifications to the developed SOS database interface, the SOS client works with any WS. This client supports spatial and temporal filters, including the integration of dynamic data from satellites into FireStation, as described.

Este trabalho apresenta um conjunto de ferramentas desenvolvidas para auxiliar a distribuição das... more Este trabalho apresenta um conjunto de ferramentas desenvolvidas para auxiliar a distribuição das classes de uma aplicação Java pelos recursos de uma arquitec-tura heterogénea, baseada em microprocessadores gené-ricos e dispositivos de lógica reconfigurável. Para poder ...

The CROSS-Fire project aims to develop a grid-based risk management decision support system for t... more The CROSS-Fire project aims to develop a grid-based risk management decision support system for the Civil Protection (CP) authorities, using forest fires as the main case study and FireStation as a standalone CAD application to simulate the fire spread over complex topography. CROSS-Fire approach is based in an architecture that includes: information models, encodings, and metadata that represent the scientific knowledge associated to FireStation execution models and standards to enable the discovery and access of Web services, data repository, sensor networks and data processing facilities. To achieve the desired integration of information and services we use: i) EGEE to provide raw technological capability provision, including data management and storage, access to meta-data data bases and high-performance computing and ii) a Geospatial Information Infrastructure based on OCG-WS and SWE Web services to provide the access and management of remote geospatial data and virtualized sensor networks. This article, stresses the relevance of standards adoption of OGC-WS by describing the work that is been done to provide G-FireStation with: i) a standard-based SDI layer, based on Geoserver to exploit/enable geospatial services for data access/processing and ii) a 52N's implementation of a OGC-SWE compatible layer, to address sensors CP data sources, such as meteorological stations data and satellite images and iii) the development of G-FireStation graphical user interface to access the platform facilities. The core of the CROSS-Fire Platform is a WPS 52North OGC standard layer divided into three interoperable components, respectively, the CROSS-Fire Business Logic, the Grid Services and Geospatial Services. WPS serves as an interface to a wide range of distributed computing resources provides the mechanism to access the grid facilities for processing and data management and including all the algorithms, calculation, or model that operates on spatially referenced data, also mediating all the communication with the portal and other GUI clients. The G-FireStation user interface that is currently under development is an open-source desktop with GIS and CAD capabilities that exploits an SDI client complying with OGC-WS and EU INSPIRE directives. It provides facilities to locate and access the spatial data infrastructure and to visualise the fire propagation, based on the native facilities of gvSig, it was also extended to support a OGC WPS client that mediate all the interactions with the core WPS service layer.

pop.cp.di.uminho.pt

Integrating Sensors into the Grid-3 / 41 CYCLOPS consortium 2 Integrating Sensors into the Grid i... more Integrating Sensors into the Grid-3 / 41 CYCLOPS consortium 2 Integrating Sensors into the Grid in order to Feed Civil Protection Applications 2.1 Introduction to Wireless Sensor Networks Wireless networks are being used in such different areas as the military, tourism, education, stock control, discovery of ecological disasters, and medical emergencies, among others. In

A metodologia de co-projecto está vocacionada para o desenvolvimento de sistemas de média e grand... more A metodologia de co-projecto está vocacionada para o desenvolvimento de sistemas de média e grande complexidade. A prototipagem rápida de sistemas digitais é um complemento da simulação, indispensável em certos sistemas de grande complexidade. Esta comunicação apresenta a plataforma EDgAR que permite obter rapidamente protótipos de sistemas digitais de elevada complexidade, recorrendo a componentes lógicos reprogramáveis (MACHs e FPGAs) ea uma arquitectura paralela baseada em ...

Ciência & Tecnologia dos Materiais, 2017

The main objective of the present work is to profound the applicability of a synchronous parallel... more The main objective of the present work is to profound the applicability of a synchronous parallel kinetic Monte Carlo (spkMC) algorithm for simulating the nucleation of Al 3 Sc precipitates. Parallel processes communication is implemented through Message Passing Interface (MPI). Consequently, the capability of extending time and length scales of atomistic kinetic Monte Carlo (kMC) will be attested. Lastly, we present the results obtained from simulations of nucleation of Al 3 Sc precipitates, which include a comparative view between sequential and parallel algorithms.

Proceedings of the 15th International Conference on Web Information Systems and Technologies, 2019

This paper describes the process of optimizing the latency of Python-based Web applications. The ... more This paper describes the process of optimizing the latency of Python-based Web applications. The case study used to validate the optimizations is an article sharing system, which was developed in Django. Memcached, Celery and Varnish enabled the implementation of additional performance optimizations. The latency of operations was measured, before and after the application of the optimization techniques. The optimization of the application was performed at various levels, including the transfer of content across the network and the back-end services. HTTP caching, data compression and minification techniques, as well as static content replication using Content Delivery Networks, were used. Partial update of the application's pages on the frontend and asynchronous processing techniques were applied. The database utilization was optimized by creating indexes and by taking advantage of a NoSQL solution. Memory caching strategies, with distinct granularities, were implemented to store templates and application objects. Furthermore, asynchronous task queues were used to perform some costly operations. All of the aforementioned techniques favorably contributed to the Web application's latency decrease. Since Django operates on the back-end, and optimizations must be implemented at various levels, it was necessary to use other tools.

Esta tese propõe uma metodologia de partição automática, que é parte integrante duma metodologia ... more Esta tese propõe uma metodologia de partição automática, que é parte integrante duma metodologia mais abrangente orientada para o desenvolvimento de sistemas embebidos predominantemente de fluxo de dados. É formulado o problema de partição, tarefa que ...

DORII middleware was already successfully tested with several instruments, in order to integrate ... more DORII middleware was already successfully tested with several instruments, in order to integrate instruments into the Grid, to perform a remote control and monitoring, and to apply the resulting data into Grid jobs or in dissemination. In the present case, the middleware was tested with a particular instrument-a WSN-and with realistic parameters, to simulate an effective and user friendly way, as it is required by CP applications. It was implemented an Instrument Element and several Instrument Managers (IMs), which virtualize the WSN. It was also developed a Custom Java interface (CJI) to connect the IMs with sensors, performing the translation of the commands/data exchanged between IMs and sensors. Since it was intended to have a long duration-offline monitoring, additional modules were implemented to manage this issue, saving the data in a database. A Sensor Observation Service (SOS), following OGC standards, was implemented. The users access the database through the SOS.

The CROSS-Fire project focus on developing a grid-based framework for wild fire management using ... more The CROSS-Fire project focus on developing a grid-based framework for wild fire management using FireStation (FS) as a standalone application that simulates the fire spread over complex topography. The overall software development is made of several components: client applications, which request geo-referenced data and fire spread simulation, Spatial Data Infrastructures (SDI), which provide geo-referenced data, and the GRID, which gives support to the computational and data storage requirements. Herein we present the central Web Processing System (WPS) layer developed to support the interaction between all components of the architecture. This OGC-WS compatible layer provides the mechanism to access the Grid facilities for processing and data management and including all the algorithms, calculations, or models that operate on spatially referenced data, also mediating communication with the FS console. We also describe the work that has been done to provide FS with dynamic fuel maps, by using an OGC-WCS suite of services and satellite data. This task complements the previous integration of dynamic data from meteorological stations using OGC-SWE services.

Deliverable Dissemination Level PU Public PP Restricted to other programme participants (includin... more Deliverable Dissemination Level PU Public PP Restricted to other programme participants (including the Commission Services) RE Restricted to a group specified by the consortium (including the Commission Services) X CO Confidential, only for members of the consortium (including the Commission Services)

: The main purpose of this article is to present how Petri Nets (PNs) have been used for hardware... more : The main purpose of this article is to present how Petri Nets (PNs) have been used for hardware design at our research laboratory. We describe the use of PN models to specify synchronous parallel controllers and how PN specifications can be extended to include the behavioural description of the data path, by using object-oriented concepts. Some hierarchical mechanisms which deal with the specification of complex digital systems are highlighted. It is described a design flow that includes, among others, the automatic generation of VHDL code to synthesize the control unit of the system. The use of PNs as part of a multiple-view model within an object-oriented methodology for hardware/software codesign is debated. The EDgAR-2 platform is considered as the reconfigurable target architecture for implementing the systems and its main characteristics are shown. Keywords: Petri Nets, Hardware Design, Reconfigurable Architecture, HW/SW Co-Design An Evolutionary Approach to the Use of Petr...

Hardware Design and Petri Nets, 2000

A two-step hardware/software partition methodology was developed. It departs from an initial part... more A two-step hardware/software partition methodology was developed. It departs from an initial partition solution based on the cluster growth algorithm and iteratively leads the designer to an improved solution, using the tabu search algorithm. A PCI-based reconfigurable ...

This paper describes a Sensor Observation Service (SOS) client developed to integrate dynamic geo... more This paper describes a Sensor Observation Service (SOS) client developed to integrate dynamic geospatial data from meteorological sensors, on a grid-based risk management decision support system. The present work is part of the CROSS-Fire project, which uses forest fires as the main case study and the FireStation application to simulate fire spread. The meteorological data is accessed through the SOS standard from Open Geospatial Consortium (OGC), using the Observations and Measurements (O&M) standard encoding format. Since the SOS standard was not designed to directly access sensors, we developed an interface application to load the SOS database with observations from a Vantis Weather Station (WS). To integrate the SOS meteorological data into the FireStation, the developed SOS client was embedded on a Web Processing Service (WPS) algorithm. This algorithm was designed to be functional and fully compliant with SOS, SensorML, and O&M standards from OGC. With minor modifications to the developed SOS database interface, the SOS client works with any WS. This client supports spatial and temporal filters, including the integration of dynamic data from satellites into FireStation, as described.

Este trabalho apresenta um conjunto de ferramentas desenvolvidas para auxiliar a distribuição das... more Este trabalho apresenta um conjunto de ferramentas desenvolvidas para auxiliar a distribuição das classes de uma aplicação Java pelos recursos de uma arquitec-tura heterogénea, baseada em microprocessadores gené-ricos e dispositivos de lógica reconfigurável. Para poder ...

The CROSS-Fire project aims to develop a grid-based risk management decision support system for t... more The CROSS-Fire project aims to develop a grid-based risk management decision support system for the Civil Protection (CP) authorities, using forest fires as the main case study and FireStation as a standalone CAD application to simulate the fire spread over complex topography. CROSS-Fire approach is based in an architecture that includes: information models, encodings, and metadata that represent the scientific knowledge associated to FireStation execution models and standards to enable the discovery and access of Web services, data repository, sensor networks and data processing facilities. To achieve the desired integration of information and services we use: i) EGEE to provide raw technological capability provision, including data management and storage, access to meta-data data bases and high-performance computing and ii) a Geospatial Information Infrastructure based on OCG-WS and SWE Web services to provide the access and management of remote geospatial data and virtualized sensor networks. This article, stresses the relevance of standards adoption of OGC-WS by describing the work that is been done to provide G-FireStation with: i) a standard-based SDI layer, based on Geoserver to exploit/enable geospatial services for data access/processing and ii) a 52N's implementation of a OGC-SWE compatible layer, to address sensors CP data sources, such as meteorological stations data and satellite images and iii) the development of G-FireStation graphical user interface to access the platform facilities. The core of the CROSS-Fire Platform is a WPS 52North OGC standard layer divided into three interoperable components, respectively, the CROSS-Fire Business Logic, the Grid Services and Geospatial Services. WPS serves as an interface to a wide range of distributed computing resources provides the mechanism to access the grid facilities for processing and data management and including all the algorithms, calculation, or model that operates on spatially referenced data, also mediating all the communication with the portal and other GUI clients. The G-FireStation user interface that is currently under development is an open-source desktop with GIS and CAD capabilities that exploits an SDI client complying with OGC-WS and EU INSPIRE directives. It provides facilities to locate and access the spatial data infrastructure and to visualise the fire propagation, based on the native facilities of gvSig, it was also extended to support a OGC WPS client that mediate all the interactions with the core WPS service layer.

pop.cp.di.uminho.pt

Integrating Sensors into the Grid-3 / 41 CYCLOPS consortium 2 Integrating Sensors into the Grid i... more Integrating Sensors into the Grid-3 / 41 CYCLOPS consortium 2 Integrating Sensors into the Grid in order to Feed Civil Protection Applications 2.1 Introduction to Wireless Sensor Networks Wireless networks are being used in such different areas as the military, tourism, education, stock control, discovery of ecological disasters, and medical emergencies, among others. In

A metodologia de co-projecto está vocacionada para o desenvolvimento de sistemas de média e grand... more A metodologia de co-projecto está vocacionada para o desenvolvimento de sistemas de média e grande complexidade. A prototipagem rápida de sistemas digitais é um complemento da simulação, indispensável em certos sistemas de grande complexidade. Esta comunicação apresenta a plataforma EDgAR que permite obter rapidamente protótipos de sistemas digitais de elevada complexidade, recorrendo a componentes lógicos reprogramáveis (MACHs e FPGAs) ea uma arquitectura paralela baseada em ...