Image, video and 3D data registration: medical, satellite and video processing applications with quality metrics

Data registration refers to a series of techniques for matching or bringing similar objects or datasets together into alignment. These techniques enjoy widespread use in a diverse variety of applications, such as video coding, tracking, object and face detection and recognition, surveillance and satellite imaging, medical image analysis and structure from motion. Registration methods are as numerous as their manifold uses, from pixel level and block or feature based methods to Fourier domain methods. This book is focused on providing algorithms and image and video techniques for registration and quality performance metrics. The authors provide various assessment metrics for measuring registration quality alongside analyses of registration techniques, introducing and explaining both familiar and state–of–the–art registration methodologies used in a variety of targeted applications.

Elements of a methodology to assess the alignment of core-values in collaborative networks

Collaborative networks are typically formed by heterogeneous and autonomous entities, and thus it is natural that each member has its own set of core-values. Since these values somehow drive the behaviour of the involved entities, the ability to quickly identify partners with compatible or common core-values represents an important element for the success of collaborative networks. However, tools to assess or measure the level of alignment of core-values are lacking. Since the concept of 'alignment' in this context is still ill-defined and shows a multifaceted nature, three perspectives are discussed. The first one uses a causal maps approach in order to capture, structure, and represent the influence relationships among core-values. This representation provides the basis to measure the alignment in terms of the structural similarity and influence among value systems. The second perspective considers the compatibility and incompatibility among core-values in order to define the alignment level. Under this perspective we propose a fuzzy inference system to estimate the alignment level, since this approach allows dealing with variables that are vaguely defined, and whose inter-relationships are difficult to define. Another advantage provided by this method is the possibility to incorporate expert human judgment in the definition of the alignment level. The last perspective uses a belief Bayesian network method, and was selected in order to assess the alignment level based on members' past behaviour. An example of application is presented where the details of each method are discussed.

Crianças com défices no controlo motor: contributo para a elaboração do core set da Classificação Internacional de Funcionalidade, Incapacidade e Saúde (CIF)

A CIF é um sistema de classificação adotado pela OMS, que serve de referência universal para descrever, avaliar e medir saúde e incapacidade, a nível individual e ao nível da população. Contudo, apesar do interesse internacional gerado em torno da CIF, esta é considerada uma classificação complexa e extensa, fato que despoletou a criação de core sets – listas de itens da CIF especificamente selecionados pela sua relevância na descrição e qualificação de uma determinada condição de saúde – como resposta a esta problemática. Até à data, foram desenvolvidos core sets para várias patologias comuns. Contudo, apesar do controlo motor ser uma área de investigação muito reconhecida nos últimos 20 anos, ainda não possui um core set próprio. Assim, o objetivo deste estudo é contribuir para o desenvolvimento de um core set, com base na CIF-CJ, dirigido para uma descrição abrangente das competências inerentes a crianças, dos 6 aos 18 anos de idade, com défices no controlo motor. Deste modo, recorreu-se a uma revisão da literatura sobre a temática em estudo, de modo a reunir informação para a construção de uma proposta a core set, posteriormente sujeita ao escrutínio de peritos, através do recurso ao método de Delphi. Após várias rondas, foi alcançado um consenso acerca da lista final de códigos CIF que constituem o core set final.

Padrão de ativação de músculos do core abdominal e tilt pélvico no teste de extensão da anca, em indivíduos com e sem dor lombo- pélvica

Introdução: Os padrões de movimento podem sofrer alterações por atraso no timing de ativação e/ou modificações na sequência de recrutamento muscular, predispondo o indivíduo a disfunções, nomeadamente a dor lombo-pélvica. Objetivo: Investigar o timing e o padrão de ativação de músculos do core abdominal, durante o movimento de extensão da anca, do membro dominante, em indivíduos com e sem dor lombo- pélvica crónica inespecífica. Pretende-se, também, pesquisar a existência do padrão de ativação considerado “normal“ e verificar a relação entre o padrão de ativação e o tilt pélvico, em ambos os indivíduos. Métodos: Estudo transversal, com 64 estudantes universitários, divididos em dois grupos: 31 sem e 33 com dor lombo-pélvica. Através de eletromiografia de superfície foi recolhida a atividade muscular dos Eretores da Espinha ipsilateral e contralateral, Glúteo Máximo e Bicípite Femoral ipsilaterais. Foi analisado o timing de ativação muscular e as respetivas ordens de ativação. Adicionalmente foi medido o tilt pélvico. Resultados: O grupo com dor lombo-pélvica apresentou um atraso significativo no timing de ativação dos músculos Glúteo Máximo ipsilateral (t=-3,171;p=0,002) e Bicípite Femoral ipsilateral (t=-2,092;p=0,041), em comparação com o grupo sem dor. Verificou-se uma associação significativa entre as 5 ordens de ativação mais frequentes e a presença de dor lombo-pélvica (xf2=11,54;p=0,015). A ordem de ativação "normal" – Glúteo Máximo ipsilateral>Bicípite Femoral ipsilateral>Eretor da Espinha contralateral>Eretor da Espinha ipsilateral – não foi utilizada. Verificou-se que o Bicípite Femoral ipsilateral foi maioritariamente o primeiro a ativar-se e o Glúteo Máximo ipsilateral o último em ambos os grupos. Verificou-se um tilt pélvico significativamente superior nos indivíduos que ativam primeiro o Bicípite Femoral ipsilateral nos grupos com (U=51;p=0,001) e sem dor (U=41p=0,001). Conclusão: Os indivíduos com dor lombo-pélvica apresentaram um atraso no timing de ativação dos músculos do core abdominal. Os resultados parecem refutar a ordem de ativação "normal" que tem sido proposta. Não foi possível apoiar nem contestar a teoria de que um atraso na ativação do Glúteo Máximo está associado com dor lombo-pélvica.

Simulation of the magnetic induction vector of a magnetic core to be used in FFC NMR relaxometry

This paper is a contribution for the assessment and comparison of magnet properties based on magnetic field characteristics particularly concerning the magnetic induction uniformity in the air gaps. For this aim, a solver was developed and implemented to determine the magnetic field of a magnetic core to be used in Fast Field Cycling (FFC) Nuclear Magnetic Resonance (NMR) relaxometry. The electromagnetic field computation is based on a 2D finite-element method (FEM) using both the scalar and the vector potential formulation. Results for the magnetic field lines and the magnetic induction vector in the air gap are presented. The target magnetic induction is 0.2 T, which is a typical requirement of the FFC NMR technique, which can be achieved with a magnetic core based on permanent magnets or coils. In addition, this application requires high magnetic induction uniformity. To achieve this goal, a solution including superconducting pieces is analyzed. Results are compared with a different FEM program.

Many-core approach to 2D-DCT calculation using an FPGA

Trabalho Final de Mestrado para obtenção do grau de Mestre em Engenharia de Electrónica e Telecomunicações

Corrugated horn antenna for a CosmoGal satellite with reduced dimensions

This paper presents the design methodology for the creation of corrugated horn antennas for the CosmoGal satellite. The mission will collect the radiation of the cosmic microwave background, by a radiometer in three different radio astronomy frequency bands (10.6-10.7GHz; 15.35-15.4GHz; 23.6-24GHz). It is discussed the design of several types of horns, simulated with the CST software. The best result points to a choked Gaussian corrugated horn antenna, with directivity of 23 dBi, side lobes 35 dB below and cross polarization better than -45 dB. Plus, with the advantage of having a small dimension, with a total length of only 7.43λ © 2014 IEEE.

Algorithm-oriented design of efficient many-core architectures applied to dense matrix multiplication

Recent integrated circuit technologies have opened the possibility to design parallel architectures with hundreds of cores on a single chip. The design space of these parallel architectures is huge with many architectural options. Exploring the design space gets even more difficult if, beyond performance and area, we also consider extra metrics like performance and area efficiency, where the designer tries to design the architecture with the best performance per chip area and the best sustainable performance. In this paper we present an algorithm-oriented approach to design a many-core architecture. Instead of doing the design space exploration of the many core architecture based on the experimental execution results of a particular benchmark of algorithms, our approach is to make a formal analysis of the algorithms considering the main architectural aspects and to determine how each particular architectural aspect is related to the performance of the architecture when running an algorithm or set of algorithms. The architectural aspects considered include the number of cores, the local memory available in each core, the communication bandwidth between the many-core architecture and the external memory and the memory hierarchy. To exemplify the approach we did a theoretical analysis of a dense matrix multiplication algorithm and determined an equation that relates the number of execution cycles with the architectural parameters. Based on this equation a many-core architecture has been designed. The results obtained indicate that a 100 mm(2) integrated circuit design of the proposed architecture, using a 65 nm technology, is able to achieve 464 GFLOPs (double precision floating-point) for a memory bandwidth of 16 GB/s. This corresponds to a performance efficiency of 71 %. Considering a 45 nm technology, a 100 mm(2) chip attains 833 GFLOPs which corresponds to 84 % of peak performance These figures are better than those obtained by previous many-core architectures, except for the area efficiency which is limited by the lower memory bandwidth considered. The results achieved are also better than those of previous state-of-the-art many-cores architectures designed specifically to achieve high performance for matrix multiplication.

A many-core co-processor for embedded parallel computing on FPGA

Single processor architectures are unable to provide the required performance of high performance embedded systems. Parallel processing based on general-purpose processors can achieve these performances with a considerable increase of required resources. However, in many cases, simplified optimized parallel cores can be used instead of general-purpose processors achieving better performance at lower resource utilization. In this paper, we propose a configurable many-core architecture to serve as a co-processor for high-performance embedded computing on Field-Programmable Gate Arrays. The architecture consists of an array of configurable simple cores with support for floating-point operations interconnected with a configurable interconnection network. For each core it is possible to configure the size of the internal memory, the supported operations and number of interfacing ports. The architecture was tested in a ZYNQ-7020 FPGA in the execution of several parallel algorithms. The results show that the proposed many-core architecture achieves better performance than that achieved with a parallel generalpurpose processor and that up to 32 floating-point cores can be implemented in a ZYNQ-7020 SoC FPGA.

Sparse matrix multiplication on a reconfigurable many-core architecture

Sparse matrix-vector multiplication (SMVM) is a fundamental operation in many scientific and engineering applications. In many cases sparse matrices have thousands of rows and columns where most of the entries are zero, while non-zero data is spread over the matrix. This sparsity of data locality reduces the effectiveness of data cache in general-purpose processors quite reducing their performance efficiency when compared to what is achieved with dense matrix multiplication. In this paper, we propose a parallel processing solution for SMVM in a many-core architecture. The architecture is tested with known benchmarks using a ZYNQ-7020 FPGA. The architecture is scalable in the number of core elements and limited only by the available memory bandwidth. It achieves performance efficiencies up to almost 70% and better performances than previous FPGA designs.

A framework for memory contention analysis in multi-core platforms

The last decade has witnessed a major shift towards the deployment of embedded applications on multi-core platforms. However, real-time applications have not been able to fully benefit from this transition, as the computational gains offered by multi-cores are often offset by performance degradation due to shared resources, such as main memory. To efficiently use multi-core platforms for real-time systems, it is hence essential to tightly bound the interference when accessing shared resources. Although there has been much recent work in this area, a remaining key problem is to address the diversity of memory arbiters in the analysis to make it applicable to a wide range of systems. This work handles diverse arbiters by proposing a general framework to compute the maximum interference caused by the shared memory bus and its impact on the execution time of the tasks running on the cores, considering different bus arbiters. Our novel approach clearly demarcates the arbiter-dependent and independent stages in the analysis of these upper bounds. The arbiter-dependent phase takes the arbiter and the task memory-traffic pattern as inputs and produces a model of the availability of the bus to a given task. Then, based on the availability of the bus, the arbiter-independent phase determines the worst-case request-release scenario that maximizes the interference experienced by the tasks due to the contention for the bus. We show that the framework addresses the diversity problem by applying it to a memory bus shared by a fixed-priority arbiter, a time-division multiplexing (TDM) arbiter, and an unspecified work-conserving arbiter using applications from the MediaBench test suite. We also experimentally evaluate the quality of the analysis by comparison with a state-of-the-art TDM analysis approach and consistently showing a considerable reduction in maximum interference.

Hard real-time multiprocessor scheduling resilient to core failures

Presented at 21st IEEE International Conference on Embedded and Real-Time Computing Systems and Applications (RTCSA 2015). 19 to 21, Aug, 2015, pp 122-131. Hong Kong, China.

Parallel Software framework for time-critical many-core systems

The recent technological advancements and market trends are causing an interesting phenomenon towards the convergence of High-Performance Computing (HPC) and Embedded Computing (EC) domains. On one side, new kinds of HPC applications are being required by markets needing huge amounts of information to be processed within a bounded amount of time. On the other side, EC systems are increasingly concerned with providing higher performance in real-time, challenging the performance capabilities of current architectures. The advent of next-generation many-core embedded platforms has the chance of intercepting this converging need for predictable high-performance, allowing HPC and EC applications to be executed on efficient and powerful heterogeneous architectures integrating general-purpose processors with many-core computing fabrics. To this end, it is of paramount importance to develop new techniques for exploiting the massively parallel computation capabilities of such platforms in a predictable way. P-SOCRATES will tackle this important challenge by merging leading research groups from the HPC and EC communities. The time-criticality and parallelisation challenges common to both areas will be addressed by proposing an integrated framework for executing workload-intensive applications with real-time requirements on top of next-generation commercial-off-the-shelf (COTS) platforms based on many-core accelerated architectures. The project will investigate new HPC techniques that fulfil real-time requirements. The main sources of indeterminism will be identified, proposing efficient mapping and scheduling algorithms, along with the associated timing and schedulability analysis, to guarantee the real-time and performance requirements of the applications.

Influência de um programa de treino da musculatura do core em jogadoras ado-lescentes de voleibol

Introdução: Apesar de na reabilitação e nas atividades da vida diária já se perceber que o treino do core tem bastantes benefícios, no desporto ainda não há provas conclusivas deste mesmo benefício e de como o treino do core deve ser elaborado. Objectivo(s): Avaliar a eficácia de um programa de intervenção sobre a musculatura do core em jogadoras de voleibol Métodos: O presente estudo quasi experimental longitudinal teve uma amostra final de 56 indivíduos – grupo controlo (GC) (n= 27), e grupo experimental (GE) (n=29). Avaliou-se os testes de endurance, e respectivos rácios, descritos por McGill. Ambos os grupos foram avaliados antes (Momento 0) e após (Momento 1) a aplicação de um programa de intervenção. Resultados: Na análise entre os 2 grupos, tanto no Momento 0 como no Momento 1, não se registou diferenças estatisticamente significativas, nem nas médias de tempo dos testes de McGill nem nos rácios. Já na análise intragrupo, o GC não apresentou resultados estatisti-camente significativos, nem nas médias de tempo dos testes do McGill nem nos rácios, enquanto o GE apenas apresentou valores estatisticamente significativos nas médias de tempo da prancha lateral direita (p = 0,04) e prancha lateral esquerda (p = 0,03). Conclusão: Atletas jovens e do sexo feminino, apresentaram um fraco de-sempenho da musculatura extensora do tronco que as torna mais passíveis de contrair lesões lumbopélvicas. Será necessário implementar um programa de intervenção, diferente do aplicado neste estudo, e com maior ênfase na musculatura extensora para equilibrar os rácios propostos por McGill, e assim, diminuir o risco de lesão.

Dominant and Recessive RYR1 Mutations in Adults with Core Lesions and Mild Muscle Symptoms

INTRODUCTION: Ryanodine receptor gene (RYR1) mutations have been associated with central core disease (CCD), multiminicore/minicore/multicore disease (MmD), and susceptibility to malignant hyperthermia (MH). METHODS: Patients with muscle symptoms in adulthood, who had features compatible with CCD/MmD, underwent clinical, histological, and genetic (RYR1 and SEPN1 genes) evaluations. Published cases of CCD and MmD with adult onset were also reviewed. RESULTS: Eight patients fulfilled the criteria for further analysis. Five RYR1 mutations, 4 of them unreported, were detected in 3 patients. Compound heterozygosity was proven in 1 case. CONCLUSIONS: To our knowledge, this is the only report of adult onset associated with recessive RYR1 mutations and central core/multiminicores on muscle biopsy. Although adult patients with CCD, MmD, and minimally symptomatic MH with abnormal muscle biopsy findings usually have a mild clinical course, differential diagnosis and carrier screening is crucial for prevention of potentially life-threatening reactions to general anesthesia.