NFS Fountain : sistema de ficheiros distribuído com códigos Fountain

Mestrado em Engenharia de Computadores e TelemáticaActualmente, mais do que nunca, o processamento e armazenamento de informação ´e um requisito essencial em qualquer sociedade. Com o crescimento da procura de armazenamento de informação em formato digital, aumentam os riscos da sua perda. Isto deve-se à falta de fiabilidade dos sistemas de armazenamento actuais. Uma possível solução para este problema, passa pelo armazenamento de backups da informação em viários sistemas de armazenamento. No entanto, esta solução não é de todo a melhor devido à necessidade de replicar totalmente a informação em cada sistema. Com a introdução dos códigos Fountain), surge um novo método para transmissão de informação sem erros. Estes códigos permitem a recuperação da informação original, através de um subconjunto quaisquer de blocos codificados. Imagine-se que a informação ´e codificada e distribuída por vários sistemas de armazenamento. Mesmo que alguns sistemas avariem, existe um boa probabilidade de recuperar a informação original. O trabalho desta dissertação reflecte a construção de um sistema de armazenamento distribuído com tolerância a falhas de informação. A informação ´e armazenada em formato codificado com redundˆancia, atrav´es de uma implementação do código Fountain. É avaliado do uso deste tipo de códigos, comprovando-se que a construção de sistemas com integração de códigos Fountain pode ser uma boa solução para aplicar em sistemas de armazenamento num futuro próximo. ABSTRACT: Nowadays, more than ever, the processing and storage of data is a critical requirement in any society. With the growth in demand of digital data storage, the risk of data loss is increased. This happens due the lack of reliability of the current storage systems. A possible solution to this problem, is the storage of multiple backups of the data in multiple storage systems. However, that is not a good solution because the data must be fully replicated in each system. With the introduction of rateless codes for erasure channels (Fountain codes), arises a new method to transmit data without errors. These codes allow the recovery of the original data through any subset of encoded blocks of data. Imagine that the data is encoded and distributed across multiple storage systems. Even if some systems fails, it would still be possible to recover the original data with great probability. The work in this dissertation reflects on the development of a distributed storage system with data failure tolerance. The data is stored in encoded format with redundancy, through a Fountain code. It is avaliated the use of this type of codes, proving that the development of systems with Fountain codes can be a good solution to be applied on future storage systems

A novel olfactory receptor gene family in teleost fish:phylogenomics, cellular localization and comparison with other olfactory receptor gene families

While for two of four mammalian olfactory receptor families, all of them G protein-coupled receptors, ortholog teleost families have been identified and well-characterized (OR and V2R), two other families (V1R and TAAR) lack to date a systematic study in non-mammalian vertebrates. By data mining I identified a total of six V1R-like genes in five teleost species plus four orthologs in one jawless and one cartilaginous fish species each. In the phylogenetic analysis these ora genes (olfactory receptor, class A-related) form a single clade with three subclades, one of them including the entire mammalian V1R superfamily. The Ora family originates early in the vertebrate lineage, before the separation of the jawless from jawed fish. A similar search was performed also for taar genes in genomes of five teleosts, two basal fish and seven higher vertebrates. Taar genes segregate into three classes and their family size ranges from 18 to 112 genes in teleosts (pufferfish and zebrafish, respectively), while mammalian families contain at most 19 genes (opossum). The TAAR family originated in the common ancestor of bony and cartilaginous fishes, after its divergence from jawless fish. In these and other properties the ora and taar gene families turn out to be at opposite poles of the spectrum of olfactory receptor families. All the six teleost Ora family members are evolutionarily much older than the speciation events in the teleost lineage, while most extant teleost taar genes have emerged late in evolution, well after the split between basal teleosts (zebrafish) and neoteleostei (stickleback, medaka, pufferfish). Taar genes are largely arranged according to phylogenetic proximity in two big clusters (both syntenic to the single sarcopterygian gene cluster), whereas the ora genes are organized as singletons or symmetrical gene pairs. TAAR genes are mostly monoexonic, whereas two ora genes exhibit a highly conserved multi-exonic structure. Furthermore, the ora genes are under strong negative selection (minute dN/dS values), whereas the teleost taar genes display a relaxed pattern of global negative selection and an unprecedented degree of local positive selection. Taken together, the ora gene repertoire is highly conserved across teleosts, in striking contrast to the frequent species-specific expansions observed in mammalian V1Rs. The inverse is observed for the taar gene repertoire, which is rather conserved across mammalian species, but exhibits frequent and large species-specific expansions in teleosts. Thus, the transition from teleosts to tetrapods may parallel a transition in function as well as regulation of both the ora/V1R and TAAR gene families. Consistent with a function as olfactory receptors all zebrafish ora and all analyzed taar genes (except taar1) were expressed in sparse subsets of olfactory receptor neurons. The olfactory epithelium contains three subtypes of olfactory receptor neurons, ciliated, microvillous and crypt cells, the latter so far without known receptors, but with both cilia and microvilli. I found the ora genes to be expressed in the crypt cells, thereby deorphanizing this third type of OSN. Furthermore, the ora genes follow the monogenic rule of expression previously reported for members of other olfactory receptor gene families. Ora genes co-express both Gαi and Gαo, supporting the hypothesis that crypt cells might possess two distinct olfactory signaling pathways, one via their cilia and the other via microvilli

Autonomous environmental protection drone

During the summer, forest fires are the main reason for deforestation and the damage caused to homes and property in different communities around the world. The use of Unmanned Aerial Vehicles (UAVs, and also known as drones) applications has increased in recent years, making them an excellent solution for difficult tasks such as wildlife conservation and forest fire prevention. A forest fire detection system can be an answer to these tasks. Using a visual camera and a Convolutional Neural Network (CNN) for image processing with an UAV can result in an efficient fire detection system. However, in order to be able to have a fully autonomous system, without human intervention, for 24-hour fire observation and detection in a given geographical area, it requires a platform and automatic recharging procedures. This dissertation combines the use of technologies such as CNNs, Real Time Kinematics (RTK) and Wireless Power Transfer (WPT) with an on-board computer and software, resulting in a fully automated system to make forest surveillance more efficient and, in doing so, reallocating human resources to other locations where they are most needed.Durante o verão, os incêndios florestais constituem a principal razão do desflorestamento e dos danos causados às casas e aos bens das diferentes comunidades de todo o mundo. A utilização de veículos aéreos não tripulados (VANTs), em inglês denominados por Unmanned Aerial Vehicles (UAVs) ou Drones, aumentou nos últimos anos, tornando-os uma excelente solução para tarefas difíceis como a conservação da vida selvagem e prevenção de incêndios florestais. Um sistema de deteção de incêndio florestal pode ser uma resposta para essas tarefas. Com a utilização de uma câmara visual e uma Rede Neuronal Convolucional (RNC) para processamento de imagem com um UAV pode resultar num eficiente sistema de deteção de incêndio. No entanto, para que seja possível ter um sistema completamente autónomo, sem intervenção humana, para observação e deteção de incêndios durante 24 horas, numa dada área geográfica, requer uma plataforma e procedimentos de recarga automática. Esta dissertação reúne o uso de tecnologias como RNCs, posicionamento cinemático em tempo real (RTK) e transferência de energia sem fios (WPT) com um computador e software de bordo, resultando num sistema totalmente automatizado para tornar a vigilância florestal mais eficiente e, ao fazê-lo, realocando recursos humanos para outros locais, onde estes são mais necessários

FPGA in image processing supported by IOPT-Flow

Image processing is widely used in the most diverse industries. One of the tools widely used to perform image processing is the OpenCV library. Although the implementation of image processing algorithms can be made in software, it is also possible to implement image processing algorithms in hardware. In some cases, the execution time can be smaller than the execution time achieved in software. This work main goal is to evaluate the use of VHDL, DS-Pnets, and IOPT-Flow to develop image processing systems in hardware, in FPGA-based platforms. To enable it, a validation platform was developed. A set of image processing algorithms were specified, during this work, in VHDL and/or in DS-Pnets. These were validated using the IOPT-Flow validation tool and/or the Xilinx ISE Simulator. The automatic VHDL code generator from IOPT-Flow framework was used to translate DS-Pnet models into the implementation code. The FPGA-based implementations were compared with software implementations, supported by the OpenCV library. The created DS-Pnet models were added into a folder of the IOPT-Flow editor, to create an image processing library. It was possible to conclude that the DS-Pnets and their associated tools, IOPT-Flow tools, support the development of image processing systems. These tools, which simplify the development of image processing systems, are available online at http://gres.uninova.pt/iopt-flow/

The influence of the Sound scattering layers on the vertical behaviour of two mesopelagic sharks

As apex predators, large sharks sustain the structure and function of marine communities. However, due to the ever-increasing fishing pressure and their slow life-history traits, shark populations have drastically declined in the last decades. Thus, improved knowledge on shark movements is crucial to implement effective management actions to prevent biodiversity loss and the disruption of marine ecosystems. Vertical patterns of apex predators have regularly been associated with foraging behaviours, yet the direct connection with prey’s vertical distribution and availability is often missing. In the open ocean, large aggregations of zooplanktonic and micronektonic organisms produce two unique acoustical signatures known as sound scattering layers (SSLs), believed to be an essential food source for oceanic predators. The present study uses pop-up satellite archival transmitters data of 22 blue (Prionace glauca) and 17 shortfin mako sharks (Isurus oxyrinchus), tracked within the North Atlantic Ocean, to assess the SSLs influence on these species’ diel vertical migrations (DVM) and foraging patterns. The sharks’ vertical patterns followed the SSLs diel migrations, commonly exhibiting surface-oriented behaviour when daytime micronekton concentrations at the shallow scattering layer (SSL) were higher compared to the upper deep scattering layer (DSL). Also, both species seemed to use the SSLs as foraging grounds, yet, while the mako shark appeared to target non-migrant or semi-migrant prey at the DSL, the blue shark generally favoured higher micronekton concentrations. Nevertheless, temperature and oxygen levels limited the extent of the vertical movements and impact the time spent at depth, sometimes preventing the animals from reaching the DSL. Thus, considering the ongoing expansion of the oxygen minimum zones, some predators might lose access to highly energetic prey and subsequently decrease their fitness. The SSLs showed to affect the sharks’ vertical range and time spent at epipelagic waters, revealing a potential use to detect regions with increased fishing risk

Of form and feeling: correlating urban form and feelings of insecurity in Porto, Portugal

Environmental criminology is built on the principle that criminal behaviour is conditioned by the (built) environment it occurs in, and that the introduction/removal of design and built features may reduce insecurity and criminal occurrences. Hence, local-based strategies have proven that "place matters" in crime-prevention, and have established the need for interdisciplinary research where urban morphology plays a central role, due to the influence of different spatial elements in feelings and behaviours. Although environmental criminology exists since the 1970s, it has recently been the object of new interest due to the increased success of strategies related to the criminology of places. This paper pretends to contribute to this debate by making an early exploration of how different components of place (built environment) and safety (perceptions of insecurity) correlate, using the city of Porto as case study. Based on a population survey carried out in 2020, feelings of unsafety towards places and their environmental features were determined, and compared with morphological variables at local level, derived from official data sources. A sample of about 500 respondents was analysed, and the results were compared spatially. It is expected that the resulting research contributes to draw locallybased prevention strategies based on the articulation between urban morphological elements, planning policies and the different realms of prevention

The Viseu and Lamego clergy : clerical wills and social ties

From the documentation collated under the auspices of the Fasti Ecclesiae Portugaliae project, we selected as the object of this paper the as yet unpublished series of wills of the Viseu and Lamego Sees, penned between the years 1147 and 1325.We focusfocused on the analysis of the final wills inscribed in the testaments of the bishops, dignitaries, canons and other clergy of these two cathedrals, with a particular interest in the bequests through which these clergymen reveal some type of connection to their family group or to other social groups or networks. By means of these data, we study whether the entrance of these clergymen into the Church of Viseu and Lamego implied a breaking off from kinship ties, replacing them with new bonds of confidence and dependence established within the clergy or whether, on the contrary, these men simultaneously continued with distinct levels and modes of relationship, whether within or beyond the Church. Should this latter position be confirmed, we seek to identify the various relational networks and evaluate the influence they exerted on the clergymen’s social life, through the importance that, as testators, they ascribed to these relationships at the moment of preparing for death and dividing up their worldly possessions.Fundação para a Ciência e a Tecnologi