A new model to imitate the foraging behavior of Physarum polycephalum on a nutrient-poor substrate

Researches on Physarum polycephalum show that methods inspired by the primitive unicellular organism can construct an efficient network and solve some complex problems in graph theory. Current models simulating the intelligent behavior of Physarum are mainly based on Hagen-Poiseuille Law and Kirchhoff Law, reaction-diffusion, Cellular Automaton and multi-agent approach. In this paper, based on an assumption that the plasmodium of Physarum forages for food along the gradient of chemo-attractants on a nutrient-poor substrate, a new model is proposed to imitate its intelligent foraging behavior. The key point of the model is that the growth of Physarum is determined by the simple particle concentration field relating the distance to food source and the shape of food source on a nutrient-poor substrate. To verify this model, numerical experiments are conducted according to Adamatzky[U+05F3]s experiment. Results in spanning tree construction by this model are almost the same as those of Physarum and Oregonator model. The proposed model can also imitate Physarum to avoid repellents. Furthermore, the Euclidean Spanning tree built by this model is similar to its corresponding Minimal Euclidean Spanning tree.

Detection of dynamic background due to swaying movements from motion features

Dynamically changing background (dynamic background) still presents a great challenge to many motion-based video surveillance systems. In the context of event detection, it is a major source of false alarms. There is a strong need from the security industry either to detect and suppress these false alarms, or dampen the effects of background changes, so as to increase the sensitivity to meaningful events of interest. In this paper, we restrict our focus to one of the most common causes of dynamic background changes: 1) that of swaying tree branches and 2) their shadows under windy conditions. Considering the ultimate goal in a video analytics pipeline, we formulate a new dynamic background detection problem as a signal processing alternative to the previously described but unreliable computer vision-based approaches. Within this new framework, we directly reduce the number of false alarms by testing if the detected events are due to characteristic background motions. In addition, we introduce a new data set suitable for the evaluation of dynamic background detection. It consists of real-world events detected by a commercial surveillance system from two static surveillance cameras. The research question we address is whether dynamic background can be detected reliably and efficiently using simple motion features and in the presence of similar but meaningful events, such as loitering. Inspired by the tree aerodynamics theory, we propose a novel method named local variation persistence (LVP), that captures the key characteristics of swaying motions. The method is posed as a convex optimization problem, whose variable is the local variation. We derive a computationally efficient algorithm for solving the optimization problem, the solution of which is then used to form a powerful detection statistic. On our newly collected data set, we demonstrate that the proposed LVP achieves excellent detection results and outperforms the best alternative adapted from existing art in the dynamic background literature.

A taxonomy and mapping of computer-based critiquing tools

Critics have emerged in recent times as a specific tool feature to support users in computer-mediated tasks. These computer-supported critics provide proactive guidelines or suggestions for improvement to designs, code, and other digital artifacts. The concept of a critic has been adopted in various domains, including medical, programming, software engineering, design sketching, and others. Critics have been shown to be an effective mechanism for providing feedback to users. We propose a new critic taxonomy based on extensive review of the critic literature. The groups and elements of our critic taxonomy are presented and explained collectively with examples, including the mapping of 13 existing critic tools, predominantly for software engineering and programming education tasks to the taxonomy. We believe this critic taxonomy will assist others in identifying, categorizing, developing, and deploying computer-supported critics in a range of domains.<br />

Intelligent line segment perception with cortex-like mechanisms

This paper proposes a novel general framework for line segment perception, which is motivated by a biological visual cortex, and requires no parameter tuning. In this framework, we design a model to approximate receptive fields of simple cells. More importantly, the structure of biological orientation columns is imitated by organizing artificial complex and hypercomplex cells with the same orientation into independent arrays. Besides, an interaction mechanism is implemented by a set of self-organization rules. Enlightened by the visual topological theory, the outputs of these artificial cells are integrated to generate line segments that can describe nonlocal structural information of images. Each line segment is evaluated quantitatively by its significance. The computation complexity is also analyzed. The proposed method is tested and compared to state-of-the-art algorithms on real images with complex scenes and strong noises. The experiments demonstrate that our method outperforms the existing methods in the balance between conciseness and completeness.

Terapia ocupacional em ação interdisciplinar: jogos educativo-nutricionais na prevenção da obesidade infantil

The inter-subjectivity is the answer in the search for the solution of complex problems, which concerns interfaces of knowledge, respecting their borders. This paradigm is essential in the author's work. So, the search on screen is based on this perspective, by using inter-subject groups of work conduced by professionals of Computer Science, Social Communication, Architecture and Urbanism, Pedagogy, Psicopegagogy, Nutritional Science, Endocrinology, Occupational Therapy and Nursing, it was also part of this group an 8 year old child, daughter of one of the professional who took part of the group. This thesis aims to present the course of investigation developed, analyzing the action of inter-subject Occupational Therapy and Nutrition on the promotion of learning nutritional concepts through educative-nutritional games in order to prevent child's obesity in an educative context. The research was analytic, interventionist and almost experimental. It took place in a public school in Fortaleza, Ceará, Brazil, between August and December 2004. It was selected a sample non-probabilistic, by convenience, of 200 children, born from 1994 to 1996. It was selected almost nonprobabilistically, by convenience, 200 children born between 1994 and 1996. To analyze the results it was used a triangulation, associated by quantitative and qualitative approaches. The basis collect happened through games specially manufactured to these research- video-games, board games, memory games, puzzles, scramble, searching words and iterative basics. There were semi-structured interviews, direct and structured observations and focus in-groups. It was noticed the efficiency of educativenutritional games in the learning process, which lead to a changing of attitude towards the eating choices. These games gave similar results in relation to the compared variations preferences, experience and attitudes, theses attitudes were observed through the game; and the categories to compare the possibility of learning by playing, the fantasy in the learning process, learning concepts of nutritional education and the need of help in the learning process (mediation). It was proved that educativenutritional games could be used to teach nutritional concepts, in an inter-subjective action of Occupational Therapy and Nutrition in schools. The simultaneous application of these games lead to the optimization of child s learning process. It should be emphasized the need of studies about the adaptation of tools used in a child s Nutritional Education, with the help of inter-subjective action. Because just one subject, in a fractionated way can give an answer to complex problems and help to a change of the reality with effectiveness and resolution

A representação social de disciplinas didático-pedagógicas no contexto da formação inicial docente: um entremear de saberes

We seek, through this study, to analyze about social representation that the students of licentiate degree course of the Federal Institute of Education, Science and Technology of Rio Grande do Norte - IFRN - have about didactic-pedagogical subjects. We utilize the Social Representations Theory (MOSCOVICI, 2009; 2012; JODELET, 2001) as a theoretical and methodological contribution and as aim, we identify this social representation and understand how it is influenced by the formation of these undergraduates. So we developed the research under the seven undergraduate classroom courses offered by IFRN, namely: Biology, Spanish, Physics, Geography, Computer Science, Mathematics and Chemistry, covering units located both in the capital and in the countryside. While methodological approach we used the Procedure of Multiple Classification (PMC) - (ROAZZI, 1995), whose realization requires a set of words achieved through of Free Technique of Words Association - FTWA - (ABRIC, 1998). For this realization we have a total of one hundred twenty (120) participants, with thirty (30) in FTWA and other stage in the realization of free classification and directed that correspond to the MPR. Achieved the empirical data, we use the analysis of content (BARDIN, 2011; FRANCO, 2007) and multidimensional (ROAZZI, 1995) for the course of his interpretation. Finally, we identify the social representation of didactic and pedagogical subjects centered around the idea that it is through these subjects that can achieve the profile of "good professional" as one who gathers knowledge and attributes required for the full development of teaching involving capabilities it and characteristics that mark the sense of professionalism. Furthermore, we found that the anchoring social representation on the understanding that these disciplines "teach the teacher to be" in the image and its objectification of the "good teacher", ie, one that reaches through the training process and experiences, qualities that make it unique and able to carry full professional. Still see that the actions of the teacher trainer affects the way students perceive, assume and engage in the study of teaching and pedagogical subjects and it reflects significantly the social representation then created

Improving accuracy and speed of optimum-path forest classifier using combination of disjoint training subsets

The Optimum-Path Forest (OPF) classifier is a recent and promising method for pattern recognition, with a fast training algorithm and good accuracy results. Therefore, the investigation of a combining method for this kind of classifier can be important for many applications. In this paper we report a fast method to combine OPF-based classifiers trained with disjoint training subsets. Given a fixed number of subsets, the algorithm chooses random samples, without replacement, from the original training set. Each subset accuracy is improved by a learning procedure. The final decision is given by majority vote. Experiments with simulated and real data sets showed that the proposed combining method is more efficient and effective than naive approach provided some conditions. It was also showed that OPF training step runs faster for a series of small subsets than for the whole training set. The combining scheme was also designed to support parallel or distributed processing, speeding up the procedure even more. © 2011 Springer-Verlag.

A proposed neural control for the trajectory tracking of a nonholonomic mobile robot with disturbances

In this paper, a trajectory tracking control problem for a nonholonomic mobile robot by the integration of a kinematic neural controller (KNC) and a torque neural controller (TNC) is proposed, where both the kinematic and dynamic models contains disturbances. The KNC is a variable structure controller (VSC) based on the sliding mode control theory (SMC), and applied to compensate the kinematic disturbances. The TNC is a inertia-based controller constituted of a dynamic neural controller (DNC) and a robust neural compensator (RNC), and applied to compensate the mobile robot dynamics, and bounded unknown disturbances. Stability analysis with basis on Lyapunov method and simulations results are provided to show the effectiveness of the proposed approach. © 2012 Springer-Verlag.

Teoria da ressonância adaptativa através da linguagem Java para detecção e classificação de e-mails indesejados

Pós-graduação em Engenharia Elétrica - FEIS

Ensaio sobre o fluxo de Ricci e os buracos negros: fundamentação e estudo computacional

Pós-graduação em Ciência da Computação - IBILCE

Role playing game eletrônico: uma tecnologia lúdica para aprender e ensinar matemática

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Estabilidade global e bifurcação de Hopf em um modelo de HIV baseado em sistemas do tipo Lotka-Volterra

Pós-graduação em Matematica Aplicada e Computacional - FCT

Previsão de carga multinodal usando a rede neural ART-ARTMAP fuzzy

Pós-graduação em Engenharia Elétrica - FEIS

Mediação midiática e teoria histórico-cultural: aproximações pedagógicas

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

A aprendizagem de algoritmos: uma experiência no curso de Tecnologia em Informática do CEFET- PA

Esta pesquisa trata de uma experiência vivida com os alunos do curso de Tecnologia em Análise e Desenvolvimento de Sistemas do Centro Federal de Educação Tecnológica do Pará - CEFET sobre o aprendizado de algoritmos e programação. O presente estudo justifica-se pela relevância em se discutir a prática do profissional da área de informática que atua na educação profissional superior com o ensino de algoritmos. Embora haja concepções acerca dos obstáculos relacionados ao tema, há a necessidade de se investigar as dificuldades e fatores que contribuem com a aprendizagem de algoritmos e consequentemente de programação. Assim este trabalho se propõe a responder a seguinte questão? É possível melhorar o processo ensino-aprendizagem de algoritmos através da pedagogia de projetos? Com base nas observações levantadas, propomos e colocamos em prática um modelo de ensino baseado nesta pedagogia, com o objetivo de potencializar a compreensão de algoritmos. A metodologia adotada utilizou a pesquisa-ação no sentido de investigação colaborativa de observação na ação. Os fundamentos teóricos basearam-se na teoria de aprendizagem significativa de David Ausubel, nas propostas facilitadoras dessa aprendizagem por Postman e Weingartner, Marco Antônio Moreira e no Construcionismo de Papert. De um modo geral foram constatadas boas impressões com desenvolvimento do projeto especialmente por termos observado nos alunos maior motivação com a atividade de programação percebida pela autonomia e reflexão nas etapas de desenvolvimento do projeto.