Los mecanismos de defensa dentinopulpar involucran una variedad de sistemas biológicos, en donde ... more Los mecanismos de defensa dentinopulpar involucran una variedad de sistemas biológicos, en donde el sistema inmunológico juega un papel principal. La identificación de células dendríticas (CD) ha generado un sinnúmero de investigaciones para comprender cómo un antígeno puede activar una respuesta inmunológica en la pulpa. El propósito de este estudio fue el realizar la cuantificación y observación de la distribución de CD HLA-DR+ en el tejido pulpar clínicamente sano e inflamado en grado irreversible. Las observaciones inmunohistoquímicas en pulpas clínicamente sanas mostraron una distribución muy marcada en la zona odontoblástica. Por otra parte, las observaciones en pulpas clínicamente inflamadas en grado irreversible mostraron una distribución y número irregular por todo el tejido, sugiriendo su actividad en la pulpa dental.
Hyperspectral images can comprise hundreds of spectral bands, which means that they can represent... more Hyperspectral images can comprise hundreds of spectral bands, which means that they can represent a large volume of data difficult to manage with the available on-board resources. Lossless compression solutions are interesting for reducing the amount of information stored or transmitted while preserving it at the same time. The Hyperspectral Lossless Compressor for space applications (SHyLoC), which is part of the European Space Agency (ESA) IP core’s library, has been demonstrated to meet the requirements of space missions in terms of compression efficiency, low complexity and high throughput. Currently, there is a trend to use Commercial Off-The-Shelf (COTS) on-board electronic devices on small satellites. Moreover, commercial Field-Programmable Gate Arrays (FPGAs) have been used in a number of them. Hence, a reliability analysis is required to ensure the robustness of the applications to Single Event Upsets (SEUs) in the configuration memory. In this work, we present a reliabilit...
Introduction. How to Use This Book. I. DEFINING THE TEAM STRUCTURE. 1. Team Essentials. 2. Clarif... more Introduction. How to Use This Book. I. DEFINING THE TEAM STRUCTURE. 1. Team Essentials. 2. Clarifying Purpose. 3. Leadership. II. DEVELOPING A TEAM PROCESS. 4. Ground Rules. 5. Participation. 6. Decision Making. III. CREATING A TEAM CULTURE. 7. Values. 8. Rituals. 9. Learning. IV. POLITICS AND ADVANCING TEAM RENEWAL. 10. Internal Politics and Implementation. 11. External Politics and Implementation. 12. The Process of Team Renewal. Individual Team Charter. Index.
Communication systems that work in jeopardized environments such as space are affected by soft er... more Communication systems that work in jeopardized environments such as space are affected by soft errors that can cause malfunctions in the behavior of the circuits such as, for example, single event upsets (SEUs) or multiple bit upsets (MBUs). In order to avoid this erroneous functioning, this kind of systems are usually protected using redundant logic such as triple modular redundancy (TMR) or error correction codes (ECCs). After the implementation of the protected modules, the communication modules must be tested to assess the achieved reliability. These tests could be driven into accelerator facilities through ionization processes or they can be performed using fault injection tools based on software simulation such as the SEUs simulation tool (SST), or based on field-programmable gate array (FPGA) emulation like the one described in this work. In this paper, a tutorial for the setup of a fault injection emulation platform based on the Xilinx soft error mitigation (SEM) intellectua...
Electronic circuits in harsh environments, such as space, are affected by soft errors produced by... more Electronic circuits in harsh environments, such as space, are affected by soft errors produced by radiation. A single event functional interrupt (SEFI) can affect the behavior of a memory chip, with one or more rows, columns or even the whole device producing a wrong value when reading a set of stored bits. This problem may affect raw Bayer images stored in satellites and other spacecraft. In this paper, we present a methodology to analyze how different interpolation algorithms behave when they try to reconstruct the affected Bayer images into standard red, green and blue (RGB) images. This methodology can be used to compare and develop new fault-tolerant algorithms. The proposed methodology has been illustrated by studying a subset of interpolation algorithms. The results obtained from this example show that the interpolation algorithms that traditionally offer better results in a normal operation (in the absence of errors) are not always the best when SEFI errors are present in th...
One of the traditional issues in space missions is the reliability of the electronic components o... more One of the traditional issues in space missions is the reliability of the electronic components on board spacecraft. There are numerous techniques to deal with this, from shielding and rad-hard fabrication to ad-hoc fault-tolerant designs. Although many of these solutions have been extensively studied, the recent utilization of FPGAs as the target architecture for many electronic components has opened new possibilities, partly due to the distinct nature of these devices. In this study, we performed fault injection experiments to determine if a RISC-V soft processor implemented in an FPGA could be used as an onboard computer for space applications, and how the specific nature of FPGAs needs to be tackled differently from how ASICs have been traditionally handled. In particular, in this paper, the classic definition of the cross-section is revisited, putting into perspective the importance of the so-called “critical bits” in an FPGA design.
Image processing systems are widely used in space applications, so different radiation-induced ma... more Image processing systems are widely used in space applications, so different radiation-induced malfunctions may occur in the system depending on the device that is implementing the algorithm. SRAM-based FPGAs are commonly used to speed up the image processing algorithm, but then the system could be vulnerable to configuration memory errors caused by single event upsets (SEUs). In those systems, the captured image is streamed pixel by pixel from the camera to the FPGA. Certain local operations such as median or rank filters need to process the image locally instead of pixel by pixel, so some particular pixel caching structures such as line-buffer-based pipelines can be used to accelerate the filtering process. However, an SRAM-based FPGA implementation of these pipelines may have malfunctions due to the mentioned configuration memory errors, so an error mitigation technique is required. In this paper, a novel method to protect line-buffer-based pipelines against SRAM-based FPGA confi...
La autora recoge, en ocho capítulos, seis años de duro trabajo que han dado como resultado una mu... more La autora recoge, en ocho capítulos, seis años de duro trabajo que han dado como resultado una muy interesante obra sobre el modo de vida de las comunidades del II milenio a.C. ubicadas geográficamente en el extremo occidental de nuestro continente europeo. El libro ofrece valiosos enfoques interpretativos muy novedosos que suponen un mayor acercamiento a la realidad histórica.
Los mecanismos de defensa dentinopulpar involucran una variedad de sistemas biológicos, en donde ... more Los mecanismos de defensa dentinopulpar involucran una variedad de sistemas biológicos, en donde el sistema inmunológico juega un papel principal. La identificación de células dendríticas (CD) ha generado un sinnúmero de investigaciones para comprender cómo un antígeno puede activar una respuesta inmunológica en la pulpa. El propósito de este estudio fue el realizar la cuantificación y observación de la distribución de CD HLA-DR+ en el tejido pulpar clínicamente sano e inflamado en grado irreversible. Las observaciones inmunohistoquímicas en pulpas clínicamente sanas mostraron una distribución muy marcada en la zona odontoblástica. Por otra parte, las observaciones en pulpas clínicamente inflamadas en grado irreversible mostraron una distribución y número irregular por todo el tejido, sugiriendo su actividad en la pulpa dental.
Hyperspectral images can comprise hundreds of spectral bands, which means that they can represent... more Hyperspectral images can comprise hundreds of spectral bands, which means that they can represent a large volume of data difficult to manage with the available on-board resources. Lossless compression solutions are interesting for reducing the amount of information stored or transmitted while preserving it at the same time. The Hyperspectral Lossless Compressor for space applications (SHyLoC), which is part of the European Space Agency (ESA) IP core’s library, has been demonstrated to meet the requirements of space missions in terms of compression efficiency, low complexity and high throughput. Currently, there is a trend to use Commercial Off-The-Shelf (COTS) on-board electronic devices on small satellites. Moreover, commercial Field-Programmable Gate Arrays (FPGAs) have been used in a number of them. Hence, a reliability analysis is required to ensure the robustness of the applications to Single Event Upsets (SEUs) in the configuration memory. In this work, we present a reliabilit...
Introduction. How to Use This Book. I. DEFINING THE TEAM STRUCTURE. 1. Team Essentials. 2. Clarif... more Introduction. How to Use This Book. I. DEFINING THE TEAM STRUCTURE. 1. Team Essentials. 2. Clarifying Purpose. 3. Leadership. II. DEVELOPING A TEAM PROCESS. 4. Ground Rules. 5. Participation. 6. Decision Making. III. CREATING A TEAM CULTURE. 7. Values. 8. Rituals. 9. Learning. IV. POLITICS AND ADVANCING TEAM RENEWAL. 10. Internal Politics and Implementation. 11. External Politics and Implementation. 12. The Process of Team Renewal. Individual Team Charter. Index.
Communication systems that work in jeopardized environments such as space are affected by soft er... more Communication systems that work in jeopardized environments such as space are affected by soft errors that can cause malfunctions in the behavior of the circuits such as, for example, single event upsets (SEUs) or multiple bit upsets (MBUs). In order to avoid this erroneous functioning, this kind of systems are usually protected using redundant logic such as triple modular redundancy (TMR) or error correction codes (ECCs). After the implementation of the protected modules, the communication modules must be tested to assess the achieved reliability. These tests could be driven into accelerator facilities through ionization processes or they can be performed using fault injection tools based on software simulation such as the SEUs simulation tool (SST), or based on field-programmable gate array (FPGA) emulation like the one described in this work. In this paper, a tutorial for the setup of a fault injection emulation platform based on the Xilinx soft error mitigation (SEM) intellectua...
Electronic circuits in harsh environments, such as space, are affected by soft errors produced by... more Electronic circuits in harsh environments, such as space, are affected by soft errors produced by radiation. A single event functional interrupt (SEFI) can affect the behavior of a memory chip, with one or more rows, columns or even the whole device producing a wrong value when reading a set of stored bits. This problem may affect raw Bayer images stored in satellites and other spacecraft. In this paper, we present a methodology to analyze how different interpolation algorithms behave when they try to reconstruct the affected Bayer images into standard red, green and blue (RGB) images. This methodology can be used to compare and develop new fault-tolerant algorithms. The proposed methodology has been illustrated by studying a subset of interpolation algorithms. The results obtained from this example show that the interpolation algorithms that traditionally offer better results in a normal operation (in the absence of errors) are not always the best when SEFI errors are present in th...
One of the traditional issues in space missions is the reliability of the electronic components o... more One of the traditional issues in space missions is the reliability of the electronic components on board spacecraft. There are numerous techniques to deal with this, from shielding and rad-hard fabrication to ad-hoc fault-tolerant designs. Although many of these solutions have been extensively studied, the recent utilization of FPGAs as the target architecture for many electronic components has opened new possibilities, partly due to the distinct nature of these devices. In this study, we performed fault injection experiments to determine if a RISC-V soft processor implemented in an FPGA could be used as an onboard computer for space applications, and how the specific nature of FPGAs needs to be tackled differently from how ASICs have been traditionally handled. In particular, in this paper, the classic definition of the cross-section is revisited, putting into perspective the importance of the so-called “critical bits” in an FPGA design.
Image processing systems are widely used in space applications, so different radiation-induced ma... more Image processing systems are widely used in space applications, so different radiation-induced malfunctions may occur in the system depending on the device that is implementing the algorithm. SRAM-based FPGAs are commonly used to speed up the image processing algorithm, but then the system could be vulnerable to configuration memory errors caused by single event upsets (SEUs). In those systems, the captured image is streamed pixel by pixel from the camera to the FPGA. Certain local operations such as median or rank filters need to process the image locally instead of pixel by pixel, so some particular pixel caching structures such as line-buffer-based pipelines can be used to accelerate the filtering process. However, an SRAM-based FPGA implementation of these pipelines may have malfunctions due to the mentioned configuration memory errors, so an error mitigation technique is required. In this paper, a novel method to protect line-buffer-based pipelines against SRAM-based FPGA confi...
La autora recoge, en ocho capítulos, seis años de duro trabajo que han dado como resultado una mu... more La autora recoge, en ocho capítulos, seis años de duro trabajo que han dado como resultado una muy interesante obra sobre el modo de vida de las comunidades del II milenio a.C. ubicadas geográficamente en el extremo occidental de nuestro continente europeo. El libro ofrece valiosos enfoques interpretativos muy novedosos que suponen un mayor acercamiento a la realidad histórica.
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