Une approche heuristique pour l’apprentissage de transformations de modèles complexes à partir d’exemples

L’ingénierie dirigée par les modèles (IDM) est un paradigme d’ingénierie du logiciel bien établi, qui préconise l’utilisation de modèles comme artéfacts de premier ordre dans les activités de développement et de maintenance du logiciel. La manipulation de plusieurs modèles durant le cycle de vie du logiciel motive l’usage de transformations de modèles (TM) afin d’automatiser les opérations de génération et de mise à jour des modèles lorsque cela est possible. L’écriture de transformations de modèles demeure cependant une tâche ardue, qui requiert à la fois beaucoup de connaissances et d’efforts, remettant ainsi en question les avantages apportés par l’IDM. Afin de faire face à cette problématique, de nombreux travaux de recherche se sont intéressés à l’automatisation des TM. L’apprentissage de transformations de modèles par l’exemple (TMPE) constitue, à cet égard, une approche prometteuse. La TMPE a pour objectif d’apprendre des programmes de transformation de modèles à partir d’un ensemble de paires de modèles sources et cibles fournis en guise d’exemples. Dans ce travail, nous proposons un processus d’apprentissage de transformations de modèles par l’exemple. Ce dernier vise à apprendre des transformations de modèles complexes en s’attaquant à trois exigences constatées, à savoir, l’exploration du contexte dans le modèle source, la vérification de valeurs d’attributs sources et la dérivation d’attributs cibles complexes. Nous validons notre approche de manière expérimentale sur 7 cas de transformations de modèles. Trois des sept transformations apprises permettent d’obtenir des modèles cibles parfaits. De plus, une précision et un rappel supérieurs à 90% sont enregistrés au niveau des modèles cibles obtenus par les quatre transformations restantes.

Using Neural Network Classifier Support Vector Machine Regression for the prediction of Melting Point of Drug – like compounds

In our study we use a kernel based classification technique, Support Vector Machine Regression for predicting the Melting Point of Drug – like compounds in terms of Topological Descriptors, Topological Charge Indices, Connectivity Indices and 2D Auto Correlations. The Machine Learning model was designed, trained and tested using a dataset of 100 compounds and it was found that an SVMReg model with RBF Kernel could predict the Melting Point with a mean absolute error 15.5854 and Root Mean Squared Error 19.7576

An Electronic Market-Maker

This paper presents an adaptive learning model for market-making under the reinforcement learning framework. Reinforcement learning is a learning technique in which agents aim to maximize the long-term accumulated rewards. No knowledge of the market environment, such as the order arrival or price process, is assumed. Instead, the agent learns from real-time market experience and develops explicit market-making strategies, achieving multiple objectives including the maximizing of profits and minimization of the bid-ask spread. The simulation results show initial success in bringing learning techniques to building market-making algorithms.

Scitable - Learn Science with Nature Education

Scitable is an open online teaching/learning portal combining high quality educational articles authored by editors at NPG with technology-based community features to fuel a global exchange of scientific insights, teaching practices, and study resources. Scitable currently contains articles in the field of genetics, and is intended for college undergraduate faculty and students. Future plans involve extension of Scitable to other fields within the life sciences, as well as to other audiences. Scitable brings together a library of scientific overviews with a worldwide community of scientists, researchers, teachers and students. Nature Education is a new division of Nature Publishing Group devoted to facilitating high quality, innovative, accessible science education in all countries of the world.

A gestão pedagógica do ensino e aprendizagem on-line : especificidades

A gestão pedagógica do ensino e aprendizagem on-line: especificidades abordam os desafios da Gestão do Projeto Pedagógico que tem as Tecnologias de Informação e Comunicação por base didático-pedagógica. O fenômeno constitui-se na gestão do ensino-aprendizagem de curso lato senso a distância, no uso do computador conectado à internet, e a formação do educador especialista responsável pela coordenação, ensino, avaliação e/ou monitoria a frente do trabalho educativo. Reflete sobre os desafios da práxis pedagógica, subsidiada pela busca questionadora das tecnologias, a fim de responder também à demanda por inclusão sócio-digital. A abordagem metodológica de natureza qualitativa pauta-se na interpretação da realidade, de caráter hermenêutico com o intuito de considerar a experiência vivida pelos sujeitos na educação on-line a partir de uma visão crítica. Questiona o descompasso da educação formal brasileira e os avanços sociais com as incorporações de novas tecnologias de aprendizagens. Estabelece nas análises, a relação entre as teorias que sedimentam os objetivos do curso, as práticas de gestão e as influências ideológicas que marcam esse cenário, no PIGEAD da Universidade Federal Fluminense, Rio de Janeiro Brasil, período de 2010 a 2012. Os resultados desta pesquisa mostram que a interatividade, diferencial que aproxima o indivíduo e o torna parte da comunicação estabelecida na EAD on-line, não ocorre plenamente entre os sujeitos do processo. Além disso, a gestão democrática participativa declarada em seus objetivos de formação se mostra na realidade como prática centralizadora, sinalizando um descompasso entre teoria e prática. Esta pesquisa, entre outros, oferece elementos de avaliação e aprimoramento ao PIGEAD.

Autonomous intelligent cruise control using a novel multiple-controller framework incorporating fuzzy-logic-based switching and tuning

This paper presents a novel intelligent multiple-controller framework incorporating a fuzzy-logic-based switching and tuning supervisor along with a generalised learning model (GLM) for an autonomous cruise control application. The proposed methodology combines the benefits of a conventional proportional-integral-derivative (PID) controller, and a PID structure-based (simultaneous) zero and pole placement controller. The switching decision between the two nonlinear fixed structure controllers is made on the basis of the required performance measure using a fuzzy-logic-based supervisor, operating at the highest level of the system. The supervisor is also employed to adaptively tune the parameters of the multiple controllers in order to achieve the desired closed-loop system performance. The intelligent multiple-controller framework is applied to the autonomous cruise control problem in order to maintain a desired vehicle speed by controlling the throttle plate angle in an electronic throttle control (ETC) system. Sample simulation results using a validated nonlinear vehicle model are used to demonstrate the effectiveness of the multiple-controller with respect to adaptively tracking the desired vehicle speed changes and achieving the desired speed of response, whilst penalising excessive control action. Crown Copyright (C) 2008 Published by Elsevier B.V. All rights reserved.

Acquisition of automatic imitation is sensitive to sensorimotor contingency

The associative sequence learning model proposes that the development of the mirror system depends on the same mechanisms of associative learning that mediate Pavlovian and instrumental conditioning. To test this model, two experiments used the reduction of automatic imitation through incompatible sensorimotor training to assess whether mirror system plasticity is sensitive to contingency (i.e., the extent to which activation of one representation predicts activation of another). In Experiment 1, residual automatic imitation was measured following incompatible training in which the action stimulus was a perfect predictor of the response (contingent) or not at all predictive of the response (noncontingent). A contingency effect was observed: There was less automatic imitation indicative of more learning in the contingent group. Experiment 2 replicated this contingency effect and showed that, as predicted by associative learning theory, it can be abolished by signaling trials in which the response occurs in the absence of an action stimulus. These findings support the view that mirror system development depends on associative learning and indicate that this learning is not purely Hebbian. If this is correct, associative learning theory could be used to explain, predict, and intervene in mirror system development.

Neural and psychological maturation of decision-making in adolescence and young adulthood

We examined the maturation of decision-making from early adolescence to mid-adulthood using fMRI of a variant of the Iowa gambling task. We have previously shown that performance in this task relies on sensitivity to accumulating negative outcomes in ventromedial PFC and dorsolateral PFC. Here, we further formalize outcome evaluation (as driven by prediction errors [PE], using a reinforcement learning model) and examine its development. Task performance improved significantly during adolescence, stabilizing in adulthood. Performance relied on greater impact of negative compared with positive PEs, the relative impact of which matured from adolescence into adulthood. Adolescents also showed increased exploratory behavior, expressed as a propensity to shift responding between options independently of outcome quality, whereas adults showed no systematic shifting patterns. The correlation between PE representation and improved performance strengthened with age for activation in ventral and dorsal PFC, ventral striatum, and temporal and parietal cortices. There was a medial-lateral distinction in the prefrontal substrates of effective PE utilization between adults and adolescents: Increased utilization of negative PEs, a hallmark of successful performance in the task, was associated with increased activation in ventromedial PFC in adults, but decreased activation in ventrolateral PFC and striatum in adolescents. These results suggest that adults and adolescents engage qualitatively distinct neural and psychological processes during decision-making, the development of which is not exclusively dependent on reward-processing maturation.

The joint influence of personal achievement goals and classroom goal structures on achievement-relevant outcomes

The authors provide an analytic framework for studying the joint influence of personal achievement goals and classroom goal structures on achievement-relevant outcomes. This framework encompasses 3 models (the direct effect model, indirect effect model, and interaction effect model), each of which addresses a different aspect of the joint influence of the 2 goal levels. These 3 models were examined together with a sample of 1,578 Japanese junior high and high school students from 47 classrooms. Results provided support for each of the 3 models: Classroom goal structures were not only direct, but also indirect predictors of intrinsic motivation and academic self-concept, and some cross-level interactions between personal achievement goals and classroom goal structures were observed (indicating both goal match and goal mismatch effects). A call is made for more research that takes into consideration achievement goals at both personal and structural levels of representation. (PsycINFO Database Record (c) 2012 APA, all rights reserved)(journal abstract)

Probability distributions or point predictions? Survey forecasts of US output growth and inflation

We consider whether survey respondents’ probability distributions, reported as histograms, provide reliable and coherent point predictions, when viewed through the lens of a Bayesian learning model. We argue that a role remains for eliciting directly-reported point predictions in surveys of professional forecasters.

Pedagogical Methods in Web-Based Language Teaching

This paper presents a research project that is being conducted at Dalarna University in Sweden. The aim is to study the following: 1) The quality of online language education compared with that of campus education, and 2) Advantages and disadvantages of online language education and how the disadvantages might be overcome. The project consists of two parts: pedagogical methods in online language education from the teachers’ point of view and from the students’ point of view. The first part was conducted in 2012 and various characteristics (benefits and difficulties) of online language education were identified. Flexibility and wider opportunities were general benefits, while lack of physical co-presence, difficulty in having lively debates/discussions, and high dropout rates were among the problems. The second part of the project (being conducted in 2014) aims to investigate how students experience online language learning. The goal is to explore alignments and misalignments between teachers’ perspectives and students’ perspectives, and to develop methods to enhance the quality of online education.

Principles of High Quality Documentation for Provenance: A Philosophical Discussion

Computer technology enables the creation of detailed documentation about the processes that create or affect entities (data, objects, etc.). Such documentation of the past can be used to answer various kinds of questions regarding the processes that led to the creation or modification of a particular entity. The answer to such questions is known as an entity's provenance. In this paper, we derive a number of principles for documenting the past, grounded in work from philosophy and history, which allow for provenance questions to be answered within a computational context. These principles lead us to argue that an interaction-based model is particularly suited for representing high quality documentation of the past.

Avaliação do uso de tecnologia de atendimento telefônico automático nos serviços ao consumidor

Com vários propósitos, inclusive o de redução de custos e o de facilitar a obtenção das informações desejadas pelo usuário, muitas empresas prestadoras de serviços ao consumidor adotam em suas CATs (Centrais de Atendimento Telefônico) recursos tecnológicos de automação da interação. Examinando-se sob a ótica dos usuários das CATs, estes poderão ter expectativas sobre o serviço que encontrarão e manifestar preferências com relação aos recursos de interação automática. As CATs, ao utilizarem tecnologias de automação da interação, podem estar ou não satisfazendo as expectativas e as preferências dos usuários. Para a determinação de argumentos que suportem as proposições levantadas durante a revisão bibliográfica sobre o tema, realizou-se uma pesquisa dividida em três partes: a) um focus group com alguns usuários de CATs; b) um estudo de campo com usuários de CATs; c) entrevistas com especialistas (levantamento de experiência). Com a técnica Análise de Preferência, propõe-se um modelo das preferências dos usuários em relação ao atendimento automático em CATs. Esse modelo, em princípio, não é generalizável devido às características do processo de amostragem utilizado nesse estudo exploratório. Determinaram-se três grupos distintos de usuários, de acordo com a similaridade entre suas preferências. Determinaram-se usos da tecnologia de atendimento automático que estão em sintonia com as preferências dos usuários. Finalmente, usando os conceitos do Balanced Scorecard, propõe-se um modelo de avaliação gerencial para o uso da tecnologia de atendimento automatizado nas Centrais de Atendimento Telefônico das empresas prestadoras de serviços ao consumidor.

Uma linguagem de modelagem da interação para auxiliar a comunicação designer-usuário

The development of interactive systems involves several professionals and the integration between them normally uses common artifacts, such as models, that drive the development process. In the model-driven development approach, the interaction model is an artifact that includes the most of the aspects related to what and how the user can do while he/she interacting with the system. Furthermore, the interactive model may be used to identify usability problems at design time. Therefore, the central problematic addressed by this thesis is twofold. In the first place, the interaction modeling, in a perspective that helps the designer to explicit to developer, who will implement the interface, the aspcts related to the interaction process. In the second place, the anticipated identification of usability problems, that aims to reduce the application final costs. To achieve these goals, this work presents (i) the ALaDIM language, that aims to help the designer on the conception, representation and validation of his interactive message models; (ii) the ALaDIM editor, which was built using the EMF (Eclipse Modeling Framework) and its standardized technologies by OMG (Object Management Group); and (iii) the ALaDIM inspection method, which allows the anticipated identification of usability problems using ALaDIM models. ALaDIM language and editor were respectively specified and implemented using the OMG standards and they can be used in MDA (Model Driven Architecture) activities. Beyond that, we evaluated both ALaDIM language and editor using a CDN (Cognitive Dimensions of Notations) analysis. Finally, this work reports an experiment that validated the ALaDIM inspection method

Tele-education on Leprosy: Evaluation of an Educational Strategy

The purpose of this research was to evaluate educational strategies applied to a tele-education leprosy course. The curriculum was for members of the Brazilian Family Health Team and was made available through the São Paulo Telehealth Portal. The course educational strategy was based on a constructivist learning model where interactivity was emphasized. Authors assessed motivational aspects of the course using the WebMAC Professional tool. Forty-eight healthcare professionals answered the evaluation questionnaire. Adequate internal consistency was achieved (Cronbach's alpha = 0.79). More than 95% of queried items received good evaluations. Multidimensional analysis according to motivational groups of questions (STIMULATING, MEANINGFUL, ORGANIZED, EASY-TO-USE) showed high agreement. According to WebMAC's criteria, it was considered an awesome course. The tele-educational strategies implemented for leprosy disclosed high motivational scores.