Contextual CMA-ES

Many stochastic search algorithms are designed to optimize a fixed objective function to learn a task, i.e., if the objective function changes slightly, for example, due to a change in the situation or context of the task, relearning is required to adapt to the new context. For instance, if we want to learn a kicking movement for a soccer robot, we have to relearn the movement for different ball locations. Such relearning is undesired as it is highly inefficient and many applications require a fast adaptation to a new context/situation. Therefore, we investigate contextual stochastic search algorithms that can learn multiple, similar tasks simultaneously. Current contextual stochastic search methods are based on policy search algorithms and suffer from premature convergence and the need for parameter tuning. In this paper, we extend the well known CMA-ES algorithm to the contextual setting and illustrate its performance on several contextual tasks. Our new algorithm, called contextual CMAES, leverages from contextual learning while it preserves all the features of standard CMA-ES such as stability, avoidance of premature convergence, step size control and a minimal amount of parameter tuning

An exploration of the psychosocial effects that school-age children with Child Absence Epilepsy (CAE) experience when their condition is misdiagnosed as Attention-Deficit/Hyperactivity Disorder (ADHD)

In today's society, the misdiagnosis of school-age children with the neurological condition Child Absence Epilepsy (CAE) as having Attention-Deficit/Hyperactivity Disorder (ADHD) has a low profile. This may be because of the lack of popular awareness of CAE. The increasing social salience towards the neuropsychological condition of ADHD places these children at risk of experiencing high psychosocial effects. Many symptoms of CAE are also associated with ADHD. However if the condition is misdiagnosed as ADHD, the child with CAE is often mistreated, both medically and socially until the correct diagnosis is made. There is little research available on the psychosocial effects of the misdiagnosis of epilepsy as ADHD, and none available relating to CAE. This research study uses case study methodology to focus on how children with CAE are psychosocially affected at the time of the misdiagnosis of ADHD and subsequently. It also explores the experiences of their parents. An in-depth interview method was adopted to gather the personal recollections of these effects directly from the ten participants in this study. The participants were found with the assistance of Epilepsy Australia and constituted one adolescent from five different families who had experienced the sequence of events and effects under investigation, and a parent (guardian) who cared for these children during this period. The findings of this research indicate that as a result of labelling, these children were misjudged in their communities, leaving strong psychosocial effects on each of the child participants who had previously been misdiagnosed with ADHD. These effects include low self-esteem, insecurity and fear experienced most often in the company of peers. As a result, when reaching adulthood, most of these participants chose to isolate themselves from social contact whenever possible. The findings offer a basis for further research in the area

Effects of alkaline and acid solutions on glass/epoxy composites

Composite structures can be exposed to a range of corrosive environments during their in-service life, which causes degradation in terms of material properties. The effect of alkaline and acid solutions on the GRP mechanical properties can be found in open literature, but the studies presented are not sufficient to establish a full knowledge of this subject. In this paper the flexural properties and the impact strength of a glass fibre/epoxy composite after immersion in hydrochloric acid (HCl) and sodium hydroxide (NaOH) were analysed. Independently of the solution, the flexural strength and the flexural modulus decrease with the exposure time. However, alkaline solution promotes higher decrease of the flexural properties than the acid solution. The same tendency was observed for impact strength

Influence of superposition length on mechanical resistance of single-lap adhesive joints

The present work studies the mechanical behaviour of single-lap joints of PP reinforced with glass fibres. Failure loads were obtained experimentally for different superposition lengths (15, 30, 45 and 60 mm). A 2D numerical analysis was developed using the finite element method, and assuming a plane strain state, an orthotropic behaviour for the laminates and an elastic-plastic behaviour for the adhesive. It was found that the positions where [sigma]yy and [tau]xy stresses have their maximum values, which are near the extremities of the joint and close to the interface adhesive/adherends, move inside the joint with load increasing. An equivalent stress was defined from [sigma]yy and [tau]xy and was obtained for the failure loads obtained experimentally. This quantity varies 9.7% with superposition length, which can be considered reasonable therefore can be used as a damage criterion for single-lap joints.http://www.sciencedirect.com/science/article/B6TWP-4D10M0S-1/1/2688e3bfdf6948a62719955d74a9d64

Effect of saline environment on mechanical properties of adhesive joints

Literature reports very few works about the effect of corrosive environments on the mechanical properties of adhesive joints. Therefore, the present study intends to contribute for a better understanding of the effect of saline solution on the mechanical properties of single-lap adhesive joints. The specimens were manufactured using Docol 1000 high strength steel plates with 1 mm of thickness and Araldite® 420 A/B epoxy adhesive. The static shear strength of the joints was influenced by the exposure time in saline solutions only up to 120 h, and remained, after this period, nearly constant. In terms of fatigue strength, for 105 cycles, a decrease about 25% and 39% occurred in specimens immersed during 120 h in deionised water and saline solution, respectively, comparatively to the control samples

Influence of multi-impacts on GFRP composites laminates

The behaviour of Glass Fibre Reinforced Composites (GFRPs) under single and multi-impact events of the same total energy was analysed. Experimental tests were performed considering circular simple supported plates impacted on its centre. The analyses of the results issuing from load–time, load–displacement and energy–time curves have shown that the sole impact of 3 J is more detrimental for the plate, relative to the other cases of cumulative damage (1 J + 2 J and 1 J + 1 J + 1 J). A fine-tune analysis of damage evolution between subsequent impacts using a numerical procedure including a cohesive mixed-mode damage model was also performed. This analysis permits to verify the evolution of the projected delaminated area as well as the fracture process zone in the vicinity of delaminations. It was verified that a negligible evolution of damage occurs in the case of three consecutive impacts of the same energy. Additionally, it was concluded that the cumulative damage in the case of (1 J + 2 J) is inferior to the one propitiated by the sole impact of maximum energy (3 J)

Fault systems of Upper Triassic outcrops in Coimbra region

Poster apresentado ao VIII Congresso Nacional de Geologia, em Braga (9-16 de Julho 2010)A partir da análise estrutural dos sistemas de falhas em afloramentos do Triásico Superior localizados na região de Coimbra, na Bacia Lusitânica, foi possível definir famílias e sub-famílias de falhas. Este trabalho permitiu reconhecer que os acidentes tectónicos extensionais que afectaram os depósitos do Triásico nesta região, durante toda a evolução do contexto tectónico do Mesozóico foram sistematicamente reactivados nos regimes compressivos do final do Mesozóico e Cenozóico.From the structural analysis of the fault system in the Upper Triassic outcrops, located in the Coimbra region of the Lusitanian Basin, it was possible to define fault families and subfamilies. This recognizing that the extensional tectonic strutures that affected the Triassic deposits from this region, were systematically reactivated during the Late Mesozoic and Cenozoic compressive regimes

Irrigação suplementar em cafeeiros do sul de Minas.

As regiões Sul e Oeste de Minas Gerais possuem, historicamente, condições climáticas ideais ao cultivo do café arábica, com temperatura média anual na faixa de 19 a 21ºC e precipitações de 1400 a 1500 mm anuais, bem distribuídas na primavera, verão e outono. Apesar disto, estas regiões estão sujeitas a períodos prolongados de estiagens em épocas críticas de demanda de água pela cultura. Este trabalho foi realizado com o objetivo de avaliar diversas doses de irrigação suplementar por gotejamento, em períodos críticos de deficiência hídrica no Sul de Minas. As produtividades da cultivar Acaiá IAC 474/19 foram avaliadas sob irrigação suplementar por gotejamento, em lavouras plantadas em 2004 no espaçamento 3,50 x 0,70m. A produção do cafeeiro é influenciada pela irrigação, e para as condições da Fazenda Experimental de Varginha uma irrigação adequada no período crítico propicia ganhos de até 30% na média de cinco safras. Na lavoura irrigada com o tratamento padrão o efeito de bienalidade na produção é menor quando comparada a de sequeiro

Chondroitin sulfate and glucosamine in the cartilage and subchondral bone repair of dogs - Histological findings

Chondroitin and glucosamine sulfate nutraceuticals are commonly used in the management of degenerative articular disease in veterinary routine. However, there are controversies on the contribution of these substances to articular cartilage. The purpose of this study was to evaluate the efficiency of a chondroitin and glucosamine sulfate-based veterinary nutraceutical on the repair of an induced osteochondral defect in a dog femoral condyle, by macroscopic, histological and histomorphometric analyses. The nutraceutical was orally administered the day following injury induction, every 24 hours (treated group, TG, n=24), compared with animals that did not receive the product (control group, CG, n=24). Six animals per group were anaesthetized for sample collection at 15, 30, 60 and 90 days after surgery. At 15 days, defects were macroscopically filled with red-pinkish tissue. After 30 days, whitish color tissue was observed, both in TG and CG animals, with firmer consistency to touch at 60 and 90 postoperative days. Histological analysis demonstrated that, in both groups, there was initial blood clot formation, which was subsequently substituted by a fibrin net, with capillary proliferation from the adjacent bone marrow and infiltration of mesenchymal cells in clot periphery. As cellular differentiation developed, repair tissue presented a fibrocartilage aspect most of the time, and new subchondral bone formation occurred in the deepest area corresponding to the defect. Histomorphometry suggested that the nutraceutical did not favor the articular cartilage repair process. It was concluded that nutraceutical did not significantly influence chondrocytes proliferation or hyaline architecture restoration.Os nutracêuticos compostos de sulfato de condroitina e glucosamina são comumente utilizados no manejo da doença articular degenerativa na rotina veterinária. Entretanto, existem controvérsias sobre a contribuição dessas substâncias à cartilagem articular. O objetivo deste trabalho foi avaliar a eficácia de um nutracêutico veterinário à base de sulfato de condroitina e glucosamina na reparação de defeitos osteocondrais induzidos no côndilo femoral de cães, através de análises macroscópica, histológica e histomorfométrica. O nutracêutico foi administrado no dia seguinte à indução da lesão, pela via oral, a cada 24 horas (grupo tratado - GT, 24 animais), sendo comparado a animais que não receberam o produto (grupo controle - GC, de igual número de animais). Aos 15, 30, 60 e 90 dias após a cirurgia, seis animais por grupo foram anestesiados para ser realizada a coleta das amostras. Aos 15 dias, os defeitos eram macroscopicamente preenchidos por tecido de coloração rósea a avermelhada. Já a partir dos 30 dias, observou-se preenchimento por tecido de coloração esbranquiçada, tanto nos animais do GT quanto nos do GC, com consistência mais firme ao toque digital aos 60 e 90 dias de pós-operatório. A análise histológica revelou que, em ambos os grupos, houve inicialmente formação de coágulo sanguíneo que, posteriormente, foi substituído por uma rede de fibrina, com proliferação de capilares a partir da medula óssea adjacente e infiltração de células mesenquimais na periferia do coágulo. À medida que se processou a diferenciação celular, o tecido de reparação se apresentou na maioria das vezes com aspecto de fibrocartilagem e, na região mais profunda da área correspondente ao defeito, ocorreu formação de osso novo subcondral. A histomorfometria sugeriu que o nutracêutico não favoreceu o processo de reparação da cartilagem articular. Concluiu-se que o nutracêutico não influenciou consideravelmente na proliferação de condrócitos nem na restauração da arquitetura hialina