Assessment of IT Infrastructures: A Model Driven Approach

Several approaches to evaluate IT infrastructure architectures have been proposed, mainly by supplier and consulting firms. However, they do not have a unified approach of these architectures where all stakeholders can cement the decision-making process, thus facilitating comparability as well as the verification of best practices adoption. The main goal of this dissertation is the proposal of a model-based approach to mitigate this problem. A metamodel named SDM (System Definition Model) and expressed with the UML (Unified Modeling Language) is used to represent structural and operational knowledge on the infrastructures. This metamodel is automatically instantiated through the capture of infrastructures configurations of existing distributed architectures, using a proprietary tool and a transformation tool that was built in the scope of this dissertation. The quantitative evaluation is performed using the M2DM (Meta-Model Driven Measurement) approach that uses OCL (Object Constraint Language) to formulate the required metrics. This proposal is expected to increase the understandability of IT infrastructures by all stakeholders (IT architects, application developers, testers, operators and maintenance teams) as well as to allow expressing their strategies of management and evolution. To illustrate the use of the proposed approach, we assess the complexity of some real cases in the diachronic and synchronic perspective

A Pattern-Based Approach to Scaffold the IT Infrastructure Design Process

Context. The design of Information Technology (IT) infrastructures is a challenging task since it implies proficiency in several areas that are rarely mastered by a single person, thus raising communication problems among those in charge of conceiving, deploying, operating and maintaining/managing them. Most IT infrastructure designs are based on proprietary models, known as blueprints or product-oriented architectures, defined by vendors to facilitate the configuration of a particular solution, based upon their services and products portfolio. Existing blueprints can be facilitators in the design of solutions for a particular vendor or technology. However, since organizations may have infrastructure components from multiple vendors, the use of blueprints aligned with commercial product(s) may cause integration problems among these components and can lead to vendor lock-in. Additionally, these blueprints have a short lifecycle, due to their association with product version(s) or a specific technology, which hampers their usage as a tool for the reuse of IT infrastructure knowledge. Objectives. The objectives of this dissertation are (i) to mitigate the inability to reuse knowledge in terms of best practices in the design of IT infrastructures and, (ii) to simplify the usage of this knowledge, making the IT infrastructure designs simpler, quicker and better documented, while facilitating the integration of components from different vendors and minimizing the communication problems between teams. Method. We conducted an online survey and performed a systematic literature review to support the state of the art and to provide evidence that this research was relevant and had not been conducted before. A model-driven approach was also used for the formalization and empirical validation of well-formedness rules to enhance the overall process of designing IT infrastructures. To simplify and support the design process, a modeling tool, including its abstract and concrete syntaxes was also extended to include the main contributions of this dissertation. Results. We obtained 123 responses to the online survey. Their majority were from people with more than 15 years experience with IT infrastructures. The respondents confirmed our claims regarding the lack of formality and documentation problems on knowledge transfer and only 19% considered that their current practices to represent IT Infrastructures are efficient. A language for modeling IT Infrastructures including an abstract and concrete syntax is proposed to address the problem of informality in their design. A catalog of IT Infrastructure patterns is also proposed to allow expressing best practices in their design. The modeling tool was also evaluated and according to 84% of the respondents, this approach decreases the effort associated with IT infrastructure design and 89% considered that the use of a repository with infrastructure patterns, will help to improve the overall quality of IT infrastructures representations. A controlled experiment was also performed to assess the effectiveness of both the proposed language and the pattern-based IT infrastructure design process supported by the tool. Conclusion. With this work, we contribute to improve the current state of the art in the design of IT infrastructures replacing the ad-hoc methods with more formal ones to address the problems of ambiguity, traceability and documentation, among others, that characterize most of IT infrastructure representations. Categories and Subject Descriptors:C.0 [Computer Systems Organization]: System architecture; D.2.10 [Software Engineering]: Design-Methodologies; D.2.11 [Software Engineering]: Software Architectures-Patterns

Strain sensors based on knocked down carbon nanotubes and bucky papers thin films

Recently, carbon nanotubes (CNTs) thin films have been widely applied in sensing applications due to their piezoresistive response. Furthermore, CNT anisotropic electric properties, due to its alignment, can provide useful information regarding strain direction. We present a comparative study between knocked down vertically aligned CNT based sensor, reported in our previous work [1], and CNT bucky papers (BP) based sensors. For this purpose, commercial multi-wall carbon nanotubes (MWCNTs) were dispersed in two different solvents, dimethylformamide (DMF) and ethanol, vacuum filtrated and dried. From these freestanding BP thin films, 10x10 mm squares were cut off and transferred to polyimide (PI) films. The relative electric resistance response and sensitivity of the strained samples was measured and compared with the knocked down CNT/PI based sensor. Moreover, the morphology of the samples was characterized by scanning electron microscopy (SEM). The results showed a high sensitivity to strain, however knocked down CNT/PI based sensor presented better mechanical performance and an anisotropic behaviour that can be used to infer strain direction.FCT, Programa MIT Portugal, projeto "IAMAT (Introduction of Advanced Materials Technologies into New Product Development for the Mobility Industries

The effect of training programs for the treatment of Sarcopenia in elderly people: a systematic review.

Objetivo: O objetivo deste trabalho foi analisar o efeito da intervenção de programas de exercícios na massa muscular como tratamento de indivíduos idosos com sarcopenia. Método: Revisão sistemática de ensaios clínicos comparando idosos sarcopenicos em grupo submetido a um programa de exercício (grupo intervenção) em relação à um grupo de controle. Os Critérios de seleção para esta revisão são: ensaios clínicos (tipo de estudo); indivíduos idosos, com idade igual ou superior a 60 anos, sedentários com sarcopenia (tipo de participante); programa de exercícios que tivessem, no mínimo, 04 semanas de duração e 8 sessões de treino; a intensidade média das sessões (mínimo) deveria ser de moderada à alta (igual ou maior a 60% da capacidade máxima) (Tipo de intervenção); e variação percentual da massa muscular (Tipo de desfecho). A estratégia de busca se desenvolveu nos bancos de dados virtuais como Medline, Pubmed; Bireme; Lilacs, PEDro; Science Direct; e a Biblioteca Cochrane. As buscas ocorreram no período de 2012 à 2013, sem considerar limite de tempo de publicação dos artigos incluídos. Os descritores/termos de pesquisa utilizados foram exercise, sarcopenia e clinical trial. Não houve restrições de linguagem ou ano de publicação. Resultados: Foram identificadas 1.580 referências. Após a primeira etapa da revisão, 92 estudos foram considerados elegíveis para inclusão e selecionados para a análise do texto integral. Ao final, 23 estudos foram incluídos para a revisão. Os resultados indicaram um aumento de massa muscular em vinte e dois (22) grupos de intervenção com programas de exercícios físicos. Conclusões: Os resultados da análise sugerem uma associação positiva do efeito de programas de exercício sobre a massa muscular de idosos e redução da sarcopenia.Objective: The objective of this study was to analyze the effect of exercise program intervention on muscle mass as treatment of elderly individuals with sarcopeniaMethod: Systematic review of clinical trials comparing elderly sarcopenics in a group undergoing an exercise program (intervention group) in relation to a control group. The selection criteria for this review were: clinical trials (type of study); Elderly individuals, aged 60 years or older, sedentary with sarcopenia (type of participant); Program of exercises that had at least 04 weeks of duration and 8 sessions of training; The mean intensity of the sessions (minimum) should be moderate to high (equal to or greater than 60% of maximum capacity) (Type of intervention) and percentage variation of muscle mass (Type of outcome). The search strategy was developed in virtual databases such as Medline, Pubmed; Bireme; Lilacs, PEDro; Science Direct and the Cochrane Library. The searches occurred in the period from 2012 to 2013, without considering the time limit for publication of the articles included. The descriptors/search terms used were exercise; Sarcopenia and clinical trial. There were no language restrictions or year of publication.Results: 1,580 references were identified. After the first stage of the review, 92 studies were considered eligible for inclusion and selected for full text analysis. At the end, 23 studies were included for review. The results indicated an increase in muscle mass in twenty-two (22) intervention groups with exercise programs.Conclusion: The results suggest a positive association of exercise programs effect on muscle mass and reduction of sarcopenia

Assessment of the quality of brain regions and neuroimaging metrics as biomarkers of Alzheimer’s disease

Alzheimer Disease (AD) is characterized by progressive cognitive decline and dementia. Earlier diagnosis and classification of different stages of the disease are currently the main challenges and can be assessed by neuroimaging. With this work we aim to evaluate the quality of brain regions and neuroimaging metrics as biomarkers of AD. Multimodal Imaging Brain Connectivity Analysis (MIBCA) toolbox functionalities were used to study AD by T1weighted, Diffusion Tensor Imaging and 18FAV45 PET, with data obtained from the AD Neuroimaging Initiative database, specifically 12 healthy controls (CTRL) and 33 patients with early mild cognitive impairment (EMCI), late MCI (LMCI) and AD (11 patients/group). The metrics evaluated were gray-matter volume (GMV), cortical thickness (CThk), mean diffusivity (MD), fractional anisotropy (FA), fiber count (FiberConn), node degree (Deg), cluster coefficient (ClusC) and relative standard-uptake-values (rSUV). Receiver Operating Characteristic (ROC) curves were used to evaluate and compare the diagnostic accuracy of the most significant metrics and brain regions and expressed as area under the curve (AUC). Comparisons were performed between groups. The RH-Accumbens/Deg demonstrated the highest AUC when differentiating between CTRLEMCI (82%), whether rSUV presented it in several brain regions when distinguishing CTRL-LMCI (99%). Regarding CTRL-AD, highest AUC were found with LH-STG/FiberConn and RH-FP/FiberConn (~100%). A larger number of neuroimaging metrics related with cortical atrophy with AUC>70% was found in CTRL-AD in both hemispheres, while in earlier stages, cortical metrics showed in more confined areas of the temporal region and mainly in LH, indicating an increasing of the spread of cortical atrophy that is characteristic of disease progression. In CTRL-EMCI several brain regions and neuroimaging metrics presented AUC>70% with a worst result in later stages suggesting these indicators as biomarkers for an earlier stage of MCI, although further research is necessary

Adequação da densidade de plantas à época de semeadura em milho irrigado

This work aimed to determine the most suitable plant density for early and late sowing dates of irrigated maize in Brazilian regions with long growing season. Two experiments were carried out in Eldorado do Sul, southern Brazil. The first trial was set on 08/22/2006 (early sowing). It tested the hybrids D 2B587 and NB 4214 at four plant densities (55, 73, 91 and 110 thousand pl ha-1). The second experiment was set on 12/07/2007 (late sowing). It evaluated the hybrids D 2B587 and AS 1565 at the plant densities of 45, 60, 75 and 90 thousand pl ha-1. Both experiments were irrigated. At the early sowing, grain yield increased with the increment in plant density up to values ranging from 9.4 and 11 pl m-2, depending on the hybrid. When maize was sown in August, grain yield was greater than 15 t ha-1 at the higher plant densities. At the late sowing date, the highest kernel yields ranged from 10 to 11 t ha-1 and were obtained using plant populations of 9 pl m-2. The potential grain yield of irrigated maize in southern Brazil is reached using high plant densities, regardless of sowing date.O objetivo deste trabalho foi determinar a densidade mais adequada nas semeaduras precoce e tardia de milho irrigado, em regiões com longa estação estival de crescimento. Foram conduzidos dois experimentos em Eldorado do Sul, RS. O primeiro foi implantado em 22/08/2006 (semeadura precoce). Nele foram testados os híbridos D 2B587 e NB 4214, em quatro densidades (55, 73, 91 e 110 mil pl ha-1). O segundo foi instalado em 07/12/2007 (semeadura tardia) e testou os híbridos D 2B587 e AS 1565, em quatro densidades (45, 60, 75, e 90 mil pl ha-1). Na semeadura precoce, o rendimento de grãos aumentou com o incremento na densidade até valores compreendidos entre 9,4 e 11 pl m-2, dependendo do híbrido. Quando o milho foi semeado em agosto, seu rendimento superou a 15 t ha-1 nas densidades mais altas. Na semeadura tardia, as maiores produtividades oscilaram entre 10 e 11 t ha-1 e foram obtidas na densidade de 9 pl m-2. O potencial de rendimento do milho irrigado é atingido com o uso de densidades elevadas, independentemente da época de semeadura