217 research outputs found
METHODOLOGY FOR AUTOMOTIVE AIR-CONDITIONING CONTROL OPTIMIZATION USING ARTIFICIAL NEURAL NETWORKS
The transient nature of automotive air conditioning systems control is generally achieved through proportional–integral–derivative controllers (PID’s) parameters tunning. Due to the vast database available from decades of automotive manufacturers design and expertise, Artificial Neural Networks (ANN) might be able to identify underlying patterns to predict and properly tune the air-conditioning PID control systems under different thermal requirements. Recently, advances in computational capability have enabled compact embarked systems to rapidly solve complex, multi-variable sets of equations, thus allowing for ANN to promptly calculate tunning parameters and act upon PID controllers. As any new application, technical literature is still scarce. On this research, a coupled PID and 6-layers perceptron ANN system was devised, programmed and used to simulate how an air-conditioning system performance can be optimized through proportional–integral–derivative controllers tuning. This proposed setup response was then compared to a conventional heuristic PID tunning method (Ziegler Nichols) to demonstrate how ANN’s can more rapidly stabilize the system output
Variabilidade genética de acessos de Brachiaria humidicola utilizando a técnica de RAPD.
Com o objetivo de avaliar a variabilidade genética em Brachiaria humidicola, 58 acessos que constituem o banco de germoplasma da Embrapa Gado de Corte tiveram seus DNAs extraÃdos e amplificados utilizando 10 primers de RAPD. Após a análise dos perfis eletroforéticos em gel de agarose 1,5%, uma matriz de similaridade foi gerada utilizando-se o coeficiente de Jaccard e os acessos foram agrupados pelos métodos UPGMA e de Tocher
Penalized likelihood and multi-objective spatial scans for the detection and inference of irregular clusters
Background: Irregularly shaped spatial clusters are difficult to delineate. A cluster found by an algorithm often spreads through large portions of the map, impacting its geographical meaning. Penalized likelihood methods for Kulldorff's spatial scan statistics have been used to control the excessive freedom of the shape of clusters. Penalty functions based on cluster geometry and non-connectivity have been proposed recently. Another approach involves the use of a multi-objective algorithm to maximize two objectives: the spatial scan statistics and the geometric penalty function. Results & Discussion: We present a novel scan statistic algorithm employing a function based on the graph topology to penalize the presence of under-populated disconnection nodes in candidate clusters, the disconnection nodes cohesion function. A disconnection node is defined as a region within a cluster, such that its removal disconnects the cluster. By applying this function, the most geographically meaningful clusters are sifted through the immense set of possible irregularly shaped candidate cluster solutions. To evaluate the statistical significance of solutions for multi-objective scans, a statistical approach based on the concept of attainment function is used. In this paper we compared different penalized likelihoods employing the geometric and non-connectivity regularity functions and the novel disconnection nodes cohesion function. We also build multi-objective scans using those three functions and compare them with the previous penalized likelihood scans. An application is presented using comprehensive state-wide data for Chagas' disease in puerperal women in Minas Gerais state, Brazil. Conclusions: We show that, compared to the other single-objective algorithms, multi-objective scans present better performance, regarding power, sensitivity and positive predicted value. The multi-objective non-connectivity scan is faster and better suited for the detection of moderately irregularly shaped clusters. The multi-objective cohesion scan is most effective for the detection of highly irregularly shaped clusters
Current status of ticks and tick-host relationship in domestic and wild animals from Pantanal wetlands in the state of Mato Grosso do Sul, Brazil.
This is a commented list of tick?s species collected on various wild and domestic animals, including the reports on scientifi c literature for the studied region. Most of animals were small or medium mammals. Carnivores were the main taxa group examined. Although, the pampas deer (Ozotocerus bezoarticus) and giant anteater (Mymercophaga tridactyla) also has a good representation on study. Among domestic animals, dogs, horses and cattle were examined. Summing up, 18 tick species were listed for the region. Sixteen were hard ticks (Ixodidae) and two soft ticks (Argasidae). Amblyomma sculptum was the most common and abundant hard tick. Ornithodoros rostratus (Argasidae) was very abundant, being the more important Argasidae tick on the study region. The following species were colleted or reported on scientifi c literature: Argas miniatus Koch, 1844; Ornithodoros rostratus Aragão, 1911; Dermacentor nitens Newmann, 1897; Rhipicephalus (Boophilus) microplus Canestrini, 1887; Amblyomma tigrinum Koch, 1844; A.dissimile Koch, 1844; A. ovale Koch, 1844; A. pauvum Aragão, 1908; A. sculptum Berlese, 1888; A. calcaratum Neumann, 1899; A. coelebs Neumann, 1899; A. dubittatum Newmann, 1899; A. scalpturatum Newmann, 1906; A. naponense Packard, 1869; A. nodosum Newmann, 1899; A. pseudoconcolor Aragão, 1908; A. rotundatum Koch, 1844; A. triste Koch, 1844.TÃtulo em português: Estado atual dos carrapatos em relação a seus animais-hospedeiros domésticos e selvagens do Pantanal no Estado do Mato Grosso do Sul, Brasil
Direct Imaging of Graphene Edges: Atomic Structure and Electronic Scattering
We report an atomically-resolved scanning tunneling microscopy (STM)
investigation of the edges of graphene grains synthesized on Cu foils by
chemical vapor deposition (CVD). Most of the edges are macroscopically parallel
to the zigzag directions of graphene lattice. These edges have microscopic
roughness that is found to also follow zigzag directions at atomic scale,
displaying many ~120 degree turns. A prominent standing wave pattern with
periodicity ~3a/4 (a being the graphene lattice constant) is observed near a
rare-occurring armchair-oriented edge. Observed features of this wave pattern
are consistent with the electronic intervalley backscattering predicted to
occur at armchair edges but not at zigzag edges
Diversidade genética em germoplasma internacional de pinhão-manso.
O pinhão-manso (Jatropha curcas L.) é uma oleaginosa em potencial, que tem despertado ointeresse de produtores, governos e instituições de pesquisa, visando aodesenvolvimento de tecnologia que possibilite sua utilização como cultura agroenergética
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