13,445 research outputs found
A NOTE ON COMONOTONICITY AND POSITIVITY OF THE CONTROL COMPONENTS OF DECOUPLED QUADRATIC FBSDE
In this small note we are concerned with the solution of Forward-Backward
Stochastic Differential Equations (FBSDE) with drivers that grow quadratically
in the control component (quadratic growth FBSDE or qgFBSDE). The main theorem
is a comparison result that allows comparing componentwise the signs of the
control processes of two different qgFBSDE. As a byproduct one obtains
conditions that allow establishing the positivity of the control process.Comment: accepted for publicatio
Searching, navigating, and recommending movies through emotions: A scoping review
Movies offer viewers a broad range of emotional experiences, providing entertainment, and meaning. Following the PRISMA-ScR guidelines, we reviewed the literature on digital systems designed to help users search and browse movie libraries and offer recommendations based on emotional content. Our search yielded 83 eligible documents (published between 2000 and 2021). We identified 22 case studies, 34 empirical studies, 26 proof of concept, and one theoretical paper. User transactions (e.g., ratings, tags) were the preferred source of information. The documents examined approached emotions from both categorical (n=35) and dimensional (n=18) perspectives, and nine documents offer a combination of both approaches. Although there are several authors mentioned, the references used are frequently dated, and 12 documents do not mention the author or the model used. We identified 61 words related to emotion or affect. Documents presented on average 1.36 positive terms and 2.64 negative terms. Sentiment analysis () is frequently used for emotion identification, followed by subjective evaluations (n= 15), movie low-level audio and visual features (n = 11), and face recognition technologies (n = 8). We discuss limitations and offer a brief review of current emotion models and research.info:eu-repo/semantics/publishedVersio
Regularized covariance estimation for weighted maximum likelihood policy search methods
Many episode-based (or direct) policy search algorithms, maintain a multivariate Gaussian distribution as search distribution over the parameter space of some objective function. One class of algorithms, such as episodic REPS, PoWER or PI2 uses, a weighted maximum likelihood estimate (WMLE) to update the mean and covariance matrix of this distribution in each iteration. However, due to high dimensionality of covariance matrices and limited number of samples, the WMLE is an unreliable estimator. The use of WMLE leads to over-fitted covariance estimates, and, hence the variance/entropy of the search distribution decreases too quickly, which may cause premature convergence. In order to alleviate this problem, the estimated covariance matrix can be regularized in different ways, for example by using a convex combination of the diagonal covariance estimate and the sample covariance estimate. In this paper, we propose a new covariance matrix regularization technique for policy search methods that uses the convex combination of the sample covariance matrix and the old covariance matrix used in last iteration. The combination weighting is determined by specifying the desired entropy of the new search distribution. With this mechanism, the entropy of the search distribution can be gradually decreased without damage from the maximum likelihood estimate
Dinâmica de espécies do gênero Manilkara após a exploração madeireira no município de Moju, estado do Pará.
Dinâmica de espécies da família Lecythidaceae, após a exploração florestal, no município de Moju-PA.
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
Dinâmica de espécimes da família Sapotaceae após a colheita de madeiras na Floresta Nacional do Tapajós, PA.
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
Powering process intensification in an oscillatory flow meso-reactor
info:eu-repo/semantics/publishedVersio
Influência de aléias de leguminosas arbóreas na infestação de bicho-mineiro em cafeeiro.
O bicho-mineiro, Leucoptera coffeella (Guérin - Mèneville, 1842) (Lepidoptera: Lyonetiidae), é talvez a principal praga do cafeeiro (Coffea spp.) na atualidade, principalmente nas regiões de temperaturas mais elevadas e de maior déficit hídrico. Vários estudos indicam que a abundância e diversidade de insetos dentro de um campo podem estar intimamente relacionadas com a natureza da vegetação circundante. Considerando o exposto, foi objetivo deste trabalho observar o efeito de espécies de leguminosas arbóreas utilizadas como quebra-ventos (aléias) sobre os aspectos fitossanitários do cafeeiro. As leguminosas utilizadas foram: o Guandu (Cajanus cajan Millsp.), Bracatinga (Mimosa scabrella Benth.), Leucena (Leucaena leucocephala (Lam.) De Wit) e Acácia (Acacia mangium Willd.), plantadas perpendiculares ao sentido dos ventos predominantes. Os resultados parciais, obtidos em 2003, 2004, 2005 e 2006, mostram que a menor porcentagem de folhas com minas intactas foi observada nos cafeeiros sob Leucena e Guandu e também a menor porcentagem de minas predadas. Os cafeeiros sob Leucena e Guandu apresentaram nível de controle (NC) para o bicho-mineiro (30% de folhas minadas sem sinais de predação) no final de agosto enquanto que aqueles sob Acácia e Bracatinga foram semelhantes à testemunha e apresentaram NC bem mais cedo, no mês de junho
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