Algorithmic skeleton framework for the orchestration of GPU computations

Dissertação para obtenção do Grau de Mestre em Engenharia InformáticaThe Graphics Processing Unit (GPU) is gaining popularity as a co-processor to the Central Processing Unit (CPU), due to its ability to surpass the latter’s performance in certain application fields. Nonetheless, harnessing the GPU’s capabilities is a non-trivial exercise that requires good knowledge of parallel programming. Thus, providing ways to extract such computational power has become an emerging research topic. In this context, there have been several proposals in the field of GPGPU (Generalpurpose Computation on Graphics Processing Unit) development. However, most of these still offer a low-level abstraction of the GPU computing model, forcing the developer to adapt application computations in accordance with the SPMD model, as well as to orchestrate the low-level details of the execution. On the other hand, the higher-level approaches have limitations that prevent the full exploitation of GPUs when the purpose goes beyond the simple offloading of a kernel. To this extent, our proposal builds on the recent trend of applying the notion of algorithmic patterns (skeletons) to GPU computing. We propose Marrow, a high-level algorithmic skeleton framework that expands the set of skeletons currently available in this field. Marrow’s skeletons orchestrate the execution of OpenCL computations and introduce optimizations that overlap communication and computation, thus conjoining programming simplicity with performance gains in many application scenarios. Additionally, these skeletons can be combined (nested) to create more complex applications. We evaluated the proposed constructs by confronting them against the comparable skeleton libraries for GPGPU, as well as against hand-tuned OpenCL programs. The results are favourable, indicating that Marrow’s skeletons are both flexible and efficient in the context of GPU computing.FCT-MCTES - financing the equipmen

protocol for a scoping review

Background: Patient safety is a fundamental principle of health care but is one of the biggest challenges currently faced and a serious public health problem, since the occurrence of adverse events is probably one of the main causes of morbidity and mortality worldwide. The vulnerability of the paediatric population, combined with the potentially dangerous context of intensive care, makes Paediatric Intensive Care Units services of particular complexity in matters of safety, where there is a greater likelihood of incidents with serious consequences. It is agreed that research on the topic of PS should start with the measuring of different types of harm that exist in the contexts, to identify high-risk areas and define priorities. For this, it is necessary to resort to a multiplicity of valid, reliable and specific measurement instruments and to learn their advantages and limitations. The objective of this review will be to identify and map in scientific literature the instruments for measuring incidents related to patient safety applicable in the context of paediatric intensive care. Methods: This review will cover studies and documents that refer to all measurement instruments used in the field of patient safety in a context of paediatric intensive care. Quantitative, qualitative, or mixed nature published studies, as well as grey literature, produced in the last 5 years and relevant to the topic will be included, in Portuguese, English or Spanish languages. The sources of information include several databases (such as MEDLINE, CINAHL, Cochrane Library, JBI Databases) and sources relevant to grey literature. Two reviewers will independently screen all citations, full-text articles and abstract data. The extracted data, after being organised in the extraction table, will be mapped in a descriptive and logical way, taking into account the defined review questions. Discussion: The mapping of the tools in these protocols will allow to summarise the most widely used instruments, to know their specificities and to guide researchers to use the most appropriate measurement tools for their context, specifically, in paediatric intensive care. Systematic review registration: Open Science Framework (osf.io/b5m7j).publishersversionpublishe

Eficacia de las consultas realizadas por enfermeros en pacientes con artritis reumatoide : revisión sistemática

Enquadramento: Tradicionalmente, as pessoas com artrite reumatóide são monitorizadas apenas em consultas médicas. No entanto, vários estudos sugerem que este seguimento pode ser realizado também por enfermeiros, de forma protocolada. Objetivos: Determinar a eficácia das consultas de enfermagem no controlo da atividade da doença e de outros outcomes reportados em comparação com as consultas realizadas apenas por reumatologistas, em pessoas com artrite reumatóide. Método de Revisão: Seguiu-se a metodologia da Cochrane. Incluíram-se estudos em adultos com artrite reumatoide. Dois revisores independentes realizaram a avaliação crítica, extração e síntese dos dados. Apresentação e interpretação dos resultados: Os 7 estu- dos incluídos reportaram melhores resultados das consultas de enfermagem em termos de dor, capacidade funcional, qualidade de vida, autoeficácia, ou satisfação global. Destes estudos, 4 integraram a meta-análise que revelou não existir diferença estatisticamente significativa no controlo da atividade da doença entre enfermeiros e reumatologistas. Conclusão: As consultas de enfermagem são eficazes no controlo da atividade de doença, na redução do impacto sentido e na satisfação em pessoas com artrite reumatóide.Abstract Background: Traditionally, patients with rheumatoid arthritis are only monitored in medical consultations. However, several studies suggest that, with protocols, this follow-up can also be performed by nurses. Objectives: To determine the effectiveness of nursing consultations in controlling disease activity and other patient-reported outcomes compared to rheumatology consultations only, in patients with rheumatoid arthritis. Review Method: The Cochranemethodology was followed. Studies that had been conducted with adults with rheumatoid arthritis were included. Critical appraisal, data extraction, and data synthesis were performed by 2 independent reviewers. Presentation and interpretation of results: The 7 studies included reported better outcomes of nursing consultations in terms of pain, physical function, quality of life, self-efficacy, or overall satisfaction. Of these, 4 studies were included in the meta-analysis, which revealed no statistically significant differences in the control of disease activity between nursing and rheumatology consultations. Conclusion: Nursing consultations are effective in controlling disease activity, reducing disease impact, and improving satisfaction in people with rheumatoid arthritis.Resumen Marco contextual: Normalmente a las personas con artritis reumatoide solo se las monitoriza en consultas médicas. Sin embargo, varios estudios sugieren que este seguimiento lo pueden realizar también los enfermeros, de forma protocolaria. Objetivos: Determinar la eficacia de las consultas de enfermería para controlar la actividad de la enfermedad y de otros resultados en comparación con las consultas realizadas solo por reumatólogos en pacientes con artritis reumatoide. Método de revisión: Se siguió la metodología de Cochrane. Se incluyeron estudios en adultos con artritis reumatoide. Dos revisores independientes realizaron una evaluación crítica, extracción y síntesis de los datos. Presentación e interpretación de los resultados: Los 7estudios incluidos registraron mejores resultados de las consultas de enfermería en relación al dolor, la capacidad funcional, la calidad de vida, la autoeficacia o la satisfacción global. De estos estudios, 4 formaron parte del metanálisis en el que se observó que no existía diferencia estadísticamente significativa en el control de la actividad de la enfermedad entre enfermeros y reumatólogos. Conclusión: Las consultas de enfermería son eficaces en el control de la actividad de la enfermedad, en la reducción del impacto sentido y en la satisfacción de los pacientes con artritis reumatoide.info:eu-repo/semantics/publishedVersio

Estudo da relação entre a espessura do ligamento cruzado anterior, os dados antropométricos e as medidas anatômicas do joelho

ResumoObjetivoObter as medidas da espessura do ligamento cruzado anterior (LCA) em seu terço médio em exames de ressonância magnética e avaliar se existe associação entre a variação da espessura do ligamento com a altura e a idade dos pacientes, bem como com as variações das medidas anatômicas do joelho.MétodosForam avaliados os exames de ressonância magnética de 48 joelhos, aferidas as medidas do tamanho anteroposterior dos côndilos femorais, distância interepicondilar, distância intercondilar e as espessuras anteroposterior e mediolateral do LCA e avaliamos se existe relação estatística entre a espessura do LCA e a idade ou a altura dos pacientes e as demais medidas avaliadas.ResultadosA média da espessura no terço médio do LCA foi de 4,5mm no plano sagital e 4,3mm no plano frontal. A espessura anteroposterior do LCA no seu terço médio tem relação positiva com o tamanho do côndilo lateral. A espessura mediolateral do LCA no seu terço médio tem relação positiva com o tamanho do côndilo lateral e com a distância intercondilar no plano axial. Não encontramos relação entre a espessura do LCA e a idade ou a altura dos pacientes.ConclusãoA espessura do LCA apresenta uma associação positiva com o tamanho do côndilo femoral lateral e a distância intercondilar.AbstractObjectivesTo ascertain thickness measurements on the anterior cruciate ligament (ACL) in its middle third on magnetic resonance imaging (MRI) scans and to assess whether there is any association between variations in ligament thickness and patients’ heights and ages, along with variations in the anatomical measurements on the knee.MethodsMRI scans on 48 knees were evaluated. The anteroposterior size of the femoral condyles, interepicondylar distance, intercondylar distance and anteroposterior and mediolateral thicknesses of the ACL were measured. It was assessed whether there was any statistical relationship between ACL thickness and the patients’ age, height or other measurements evaluated.ResultsThe mean thickness of the middle third of the ACL was 4.5mm in the sagittal plane and 4.3mm in the frontal plane. The anteroposterior thickness of the ACL in its middle third had a positive relationship with the size of the lateral condyle. The mediolateral thickness of the ACL in its middle third had a positive relationship with the size of the lateral condyle and with the intercondylar distance in the axial plane. There was no relationship between the thickness of the ACL and the patients’ age or height.ConclusionThe thickness of the ACL presented positive associations with the size of the lateral femoral condyle and the intercondylar distance

Measurement of the differential cross-section of B+B^{+} meson production in pp collisions at s\sqrt{s} = 7 TeV at ATLAS

The production cross-section of B+ mesons is measured as a function of transverse momentum pT and rapidity y in proton--proton collisions at center-of-mass energy sqrt(s) = 7 TeV, using 2.4 fb-1 of data recorded with the ATLAS detector at the Large Hadron Collider. The differential production cross-sections, determined in the range 9<pT<120 GeV and y<2.25, are compared to next-to-leading-order theoretical predictions.Peer Reviewe

Dynamics of isolated-photon plus jet production in pp collisions at (s)=7\sqrt(s)=7 TeV with the ATLAS detector

The dynamics of isolated-photon plus jet production in pp collisions at a centre-of-mass energy of 7 TeV has been studied with the ATLAS detector at the LHC using an integrated luminosity of 37 pb^-^1. Measurements of isolated-photon plus jet bin-averaged cross sections are presented as functions of photon transverse energy, jet transverse momentum and jet rapidity. In addition, the bin-averaged cross sections as functions of the difference between the azimuthal angles of the photon and the jet, the photon-jet invariant mass and the scattering angle in the photon-jet centre-of-mass frame have been measured. Next-to-leading-order QCD calculations are compared to the measurements and provide a good description of the data, except for the case of the azimuthal opening angle.Peer Reviewe

Measurements of Higgs boson production and couplings in diboson final states with the ATLAS detector at the LHC

Measurements are presented of production properties and couplings of the recently discovered Higgs boson using the decays into boson pairs, $H\rightarrow\gamma\gamma$, $H\rightarrow ZZ^{*}\rightarrow 4 \ell$ and $H\rightarrow W W \rightarrow \ell\nu\ell\nu$. The results are based on the complete pp collision data sample recorded by the ATLAS experiment at the CERN Large Hadron Collider at centre-of-mass energies of 7 TeV and 8 TeV, corresponding to an integrated luminosity of about 25 fb$^{-1}$. Evidence for Higgs boson production through vector-boson fusion is reported. Results of combined fits probing Higgs boson couplings to fermions and bosons, as well as anomalous contributions to loop-induced production and decay modes, are presented. All measurements are consistent with expectations for the Standard Model Higgs boson.Peer Reviewe

Observation of an Excited Bc±B_c^\pm Meson State with the ATLAS Detector

A search for excited states of the Bc± meson is performed using 4.9  fb-1 of 7 TeV and 19.2  fb-1 of 8 TeV pp collision data collected by the ATLAS experiment at the LHC. A new state is observed through its hadronic transition to the ground state, with the latter detected in the decay Bc±→J/ψπ±. The state appears in the m(Bc±π+π-)-m(Bc±)-2m(π±) mass difference distribution with a significance of 5.2 standard deviations. The mass of the observed state is 6842±4±5  MeV, where the first error is statistical and the second is systematic. The mass and decay of this state are consistent with expectations for the second S-wave state of the Bc± meson, Bc±(2S).Peer Reviewe

A measurement of the ratio of the production cross sections for WW and ZZ bosons in association with jets with the ATLAS detector

The ratio of the production cross sections for $W$ and $Z$ bosons in association with jets has been measured in proton–proton collisions at $\sqrt{s}=7\,\mathrm {TeV}$ with the ATLAS experiment at the Large Hadron Collider. The measurement is based on the entire 2011 dataset, corresponding to an integrated luminosity of $4.6\,\mathrm {fb}^{-1}$ . Inclusive and differential cross-section ratios for massive vector bosons decaying to electrons and muons are measured in association with jets with transverse momentum $p_\mathrm {T} >30\,\mathrm {GeV}$ and jet rapidity $|y| < 4.4$ . The measurements are compared to next-to-leading-order perturbative QCD calculations and to predictions from different Monte Carlo generators implementing leading-order matrix elements supplemented by parton showers.Peer Reviewe

Measurement of the muon reconstruction performance of the ATLAS detector using 2011 and 2012 LHC proton–proton collision data

This paper presents the performance of the ATLAS muon reconstruction during the LHC run with $pp$ collisions at $\sqrt{s}=7$ –8 TeV in 2011–2012, focusing mainly on data collected in 2012. Measurements of the reconstruction efficiency and of the momentum scale and resolution, based on large reference samples of ${J/\psi \rightarrow \mu \mu }$ , $Z \rightarrow \mu \mu$ and ${\Upsilon \rightarrow \mu \mu }$ decays, are presented and compared to Monte Carlo simulations. Corrections to the simulation, to be used in physics analysis, are provided. Over most of the covered phase space (muon $|\eta |<2.7$ and $5 \lesssim p_{\mathrm{T}}\lesssim 100$  GeV) the efficiency is above $99\,\%$ and is measured with per-mille precision. The momentum resolution ranges from $1.7\,\%$ at central rapidity and for transverse momentum $p_{\mathrm{T}}\simeq 10$  GeV, to $4\,\%$ at large rapidity and $p_{\mathrm{T}}\simeq 100$  GeV. The momentum scale is known with an uncertainty of $0.05\,\%$ to $0.2\,\%$ depending on rapidity. A method for the recovery of final state radiation from the muons is also presented.Peer Reviewe