4,672 research outputs found
Records and occupation time statistics for area-preserving maps
No full textA relevant problem in dynamics is to characterize how deterministic systems
may exhibit features typically associated to stochastic processes. A widely
studied example is the study of (normal or anomalous) transport properties for
deterministic systems on a non-compact phase space. We consider here two
examples of area-preserving maps: the Chirikov-Taylor standard map and the
Casati-Prosen triangle map, and we investigate transport properties, records'
statistics and occupation time statistics. While the standard map, when a
chaotic sea is present, always reproduces results expected for simple random
walks, the triangle map -- whose analysis still displays many elusive points --
behaves in a wildly different way, some of the features being compatible with a
transient (non conservative) nature of the dynamics.Comment: 8 pages and 7 figure
Junior Barrera, Roberto M Cesar-Jr, Joo E. Ferreira, Marco D. Gubitoso
No full textThis paper describes a datamining environment for knowledge discovery in bioinformatics applications. The system has a generic kernel that implements the mining functions to be applied to input primary databases, with a warehouse architecture, of biomedical information. Both supervised and unsupervised classification can be implemented within the kernel and applied to data extracted from the primary database, with the results being suitably stored in a complex object database for knowledge discovery. The kernel also includes a specific high-performance library that allows designing and applying the mining functions in parallel machines. Experimental results obtained by the application of the kernel functions are reported
Satisfação do consumidor em relação ao supermercado como local de compra: um estudo no Hippo Supermercados Ltda.
No full textDissertação (mestrado) - Universidade Federal de Santa Catarina, Centro Sócio-EconômicoEsta dissertação avalia a satisfação do consumidor em relação ao supermercado como local de compra, em função de atributos salientes e por variáveis de segmentação demográfica selecionadas e por variáveis de segmentação demográfica, relacionadas ao nível de satisfação do consumidor. Tratar-se de uma pesquisa qualitativa e quantitativa inserida no estudo do comportamento do consumidor sob a visão do Marketing, que utilizou como objeto de pesquisa a empresa Hippo Supermercados Ltda. da cidade de Florianópolis - SC, Brasil. Os objetivos específicos da pesquisa são: investigar atributos salientes de supermercado como local de compra; descrever o perfil do consumidor, por variáveis de segmentação demográfica selecionadas; pesquisar hábitos de mídia do consumidor e avaliar a satisfação do consumidor para com o supermercado como local de compra, em função de seus atributos e por variáveis de segmentação demográfica selecionadas. Dentre as conclusões pode-se destacar que consumidores em questão estão extremamente satisfeitos com aos atributos Preço/Promoção, Variedade de Produtos/Marcas, Eficiência nos Caixas, Atendimento, Localização e Qualidade dos Produtos. Descobriu-se ainda que o atributo atendimento é o ponto forte mais expressivo e de grande contribuição para a satisfação dos consumidores estudado
Seasonal Feeding Behavior and Forage Selection by Goats in Cleared and Thinned Deciduous Woodlands in Northeast Brazil
No full textThe seasonal feeding behavior, forage preferences and body weight responses of goats were studied under three densities of woodland (called caatinga), and under three stocking rates. The experiment was located in the semi-arid tropics of northeastern Brazil at 3 42\u27 South latitude, and 40 21\u27 West longitude at an elevation of 75 meters. Mean annual precipitation of the area is 832 mm.
Removing the shrubs and trees increased yields of herbaceous only on partially-cleared sites. Goats gained body weight (kg BW/ha) during the wet season, with the cleared treatment showing the best body weight response per unit of land. However during the dry season, animals lost weight probably due the low quality and quantity of available forage.
The botanical composition of goats\u27 diets showed them to be mixed feeders, consuming grasses, forbs and browse in various combinations depending on the season and the array of forage species available. During the dry season standing hay from herbaceous species and regrowth of some woody evergreen species were the principal forages. Animals maintained body weight on this forage. However, leaf litter was an important component of goats\u27 diets during the dry season, but was inadequate for weight maintenance.
Goats in all treatments spent the least time grazing during the wet season and the most time during the beginning of the dry season. They spent the most time lying ruminating during the dry season and the least time during the wet season. Forage quality was probably a limiting factor to effective animal response during the dry season.
Goats exhibited dislike for rain and wet conditions. They grazed freely when the temperatures were high (35 to 39 C). However, periods of high temperature corresponded to periods of low relative humidity, perhaps moderating the discomfort factor of combined high temperatures and high humidity
Paralacydoniidae
No full textFamily Paralacydoniidae Species: Paralacydonia paradoxa Fauvel 1913 References: Amaral & Rossi-Wongtschowski (2004) Environment: Continental slope Depth: 280 m Coordinates: 27 °0' 52.8 "S / 46 ° 40 ' 12.6 "WPublished as part of Pagliosa, Paulo Roberto, Doria, João Gabriel, Alves, Giorgia Freitas, Almeida, Tito Cesar Marques De, Lorenzi, Luciano, Netto, Sergio Antonio & Lana, Paulo Da Cunha, 2012, Polychaetes from Santa Catarina State (southern Brazil): checklist and remarks on species distribution, pp. 1-49 in Zootaxa 3486 on page 34, DOI: 10.5281/zenodo.21366
Sabellidae
No full textFamily: Sabellidae Species: Potamilla reniformis (Müller 1778) References: Rullier & Amoureux (1979) Environment: Inner continental shelf Depth: 18 m Coordinates: 27 ° 15 'S / 48 ° 29 'WPublished as part of Pagliosa, Paulo Roberto, Doria, João Gabriel, Alves, Giorgia Freitas, Almeida, Tito Cesar Marques De, Lorenzi, Luciano, Netto, Sergio Antonio & Lana, Paulo Da Cunha, 2012, Polychaetes from Santa Catarina State (southern Brazil): checklist and remarks on species distribution, pp. 1-49 in Zootaxa 3486 on page 40, DOI: 10.5281/zenodo.21366
Agile testing practices in software quality: State of the art review
No full textIn this paper you can find a review of articles related to agile testing practices in software quality, looking
for theoretical information and real cases applied to testing inside a modern context, comparing them with
the standard procedures taking into account their advantages and relevant features. As final result, we
determine that agile practices in software quality have wide acceptance and many companies have chosen
their use for all their benefits and impact on development software processes in several real applications,
not necessarily IT governance ones, since other kind of technical applications have shown excellent results
on testing.Gil Arrieta, Cesar Javier-909723be-2777-4527-a571-c7f983f515ab-0Díaz Martínez, Jorge Luis-0000-0001-9555-0424-600Orozco Bohórquez, Mario-0000-0003-4435-0320-600De La Hoz Manotas, Alexis Kevin-8c2e7635-6db0-49a2-bb3b-b7131e3bad0f-0De La Hoz Correa, Eduardo Miguel-f50d0e8b-2e3b-4e05-816a-bcd89cf4b021-0Morales Ortega, Roberto Cesar-ec775181-8c64-4b76-a4ac-1444380e3d0b-
Synthesis of enantiomerically pure glycidol via a fully enantioselective lipase-catalyzed resolution
No full textThe efficient enzymatic synthesis of enantiopure 2,3-epoxypropanol (glycidol) has been achieved. The racemic glycidyl
butyrate was successfully resolved by enzymatic hydrolysis using a strategy that combines different immobilization protocols and
different experimental reaction conditions. A new enzyme (25 kDa lipase)—which is a lipase-like enzyme purified from the pancreatic
porcine lipase (PPL) extract—immobilized on DEAE–Sepharose was selected as the optimal biocatalyst. The optimal results were
obtained at pH 7, 25 °C and 10% dioxane using this biocatalyst and a very high enantioselectivity for the enzyme was displayed,
obtaining both (R)-(-)-glycidyl butyrate and (R)-(+)-glycidol with enantiomeric excesses >99% (E >100). The hydrolysis of (R)-(-)-glycidyl butyrate produced pure (S)-(-)-glycidol
Synchronization properties, malleability of synchronization, and nonstationary states ein neural networks
No full textOrientador: Prof. Dr. Sergio Roberto LopesTese (doutorado) - Universidade Federal do Paraná, Setor de Ciências Exatas, Programa de Pós-Graduação em Física. Defesa : Curitiba, 04/03/2021Inclui referências: p.132-145Resumo: A pesar dos grandes avancos, os mecanismos de funcionam ento por trás dos interessantes fenôm enos observados no cerebro ain d a carecem de u m a te o ria fu n d am en tal que de u m a descricao m a te m a tic a e explique os fenom enos neurais e a N eurociencia com o um todo. Investigacoes recentes forneceram inform açoes sobre as prop riedad es individuais dos neuronios, seus padroes de ativ id ad e e ate m esm o como eles estao conectados. No en tan to , os m ecanism os p o r trá s do com p o rtam en to coletivo dos sistem as neurais ainda nao sao entendidos. P o r o u tro lado, e im p o rta n te en fatizar que os avanços recentes nas analises ex perim entais, com binados com esforços interdisciplinares, p ro d u zira m ideias interessantes que abrem grandes cam inhos p ara os práxim os anos de pesquisa. E sta tese e desenvolvida considerando este am biente frutífero, onde o uso de m odelagem m atem atica, ideias físicas e análise com putacional abrem oportunidades p ara avancos im portantes para um a m elhor com preensão das questoes da neurociencia. Nesse sentido, o com portam ento coletivo dos sistem as n eurais assum e g ran d e im p o rtan cia, onde se observam fenom enos interessantes, como oscilacoes, sincronizacao e m etaestabilid ad e, que estao relacionados ta n to a características saudíveis quanto nao saudíveis do cerebro. P ortanto, a anílise desse tip o de fenom eno te m grande im p o rtân cia do p o n to de v ista d a física e da neurociencia. D esta forma, os objetivos desta tese sao descritos em três linhas principais de pesquisa: (i) a relaçao entre os padroes de atividade neural individuais e a sincronizacao da rede; (ii) a resposta dos sistem as neurais devido a pequenas m udanças nos estímulos de externos; (iii) o papel da topologia da rede nas propriedades de sincronização e interm itència observada em sistem as neurais. P a ra investigar essas questães, os sistem as neurais sao m odelados p o r redes com plexas, onde cad a no rep resen ta um neuronio e as arestas rep resen tam as sinapses. A lem disso, sao considerados diferentes m odelos neurais e a rq u ite tu ra s de conexao, onde o sistem a e resolvido p or meio de simulacoes num ericas e, a seguir, o nível de sincronizacao e suas prop riedad es sao estu dado s com base nos dados sim ulados. P o r fim, os resu ltado s aqui obtidos indicam características im p o rtan tes do co m po rtam ento coletivo de sistem as neurais, onde se en co n tram estados com diferentes prop riedad es de sincronizacão e padrães espaco-tem porais. A lem disso, um a relacão en tre a variabilidade neural individual e a sincronizaçcaão íe encontrada: quanto m enor a variabilidade da atividade neural individual, m aior o nível de sincronização considerando sinapses fracas. Alem disso, um equilíbrio entre conexães nao-locais e locais leva a rede neural a representar um a alta m aleabilidade de sincronizacao devido a pequenas m udancas nos estím ulos externos. Por outro lado, o processo de transicao p ara a sincronizacao pode representar a interm itència d a sincronizacao, onde estad os nao estacionarios p o d em ser observados e a topologia desem p en ha u m p ap el im p o rtan te. P o rta n to , os resu ltad o s aqui descritos con tribu em p a ra um a m elhor com preensao do com portam ento coletivo em sistem as neurais e abrem questoes e possibilidades im po rtan tes p a ra fu tu ras aplicaçoes.Abstract: T D espite great advances, the functioning m echanisms behind the interesting phenom ena observed in th e b rain still lacking a fu n d am en tal theory, w hich gives a m ath em a tic al description, su p p o rts and explains th e n eu ral p hen om ena and neuroscience as a whole. Recent investigations have provided inform ation about th e individual properties of neurons, their p attern s of activity, and even how they are connected. Yet, the m echanisms behind the collective behavior of neural system s still lacking. Otherwise, it is im p ortan t to em phasize th a t recent advances in experim ental analyses, combined w ith interdisciplinary efforts have p rod uced in terestin g ideas th a t open large avenues for th e n ex t years of research. T his thesis is developed considering th is fruitful environm ent, w here th e use of m ath em atical m odeling, physics ideas, and co m p u tatio n al analysis open o p p o rtu n itie s for im p o rta n t advances tow ard a b e tte r understanding of neuroscience issues. In this sense, th e collective behavior of neural system s is im p o rtan t, where interesting phenom ena are observed, such as oscillations, synchronization, an d m etastability, which are related to b o th healthy and unhealthy characteristics in th e brain. Therefore, the analysis of this kind of phenom enon has huge im portance from the point-of-view of bo th, physics and neuroscience. Then, the goals of this thesis are described in three m ain research lines: (i) th e relationship between individual neural activity p a tte rn s an d th e netw ork synchronization; (ii) th e response of neural system s due to small changes in the input stim uli; (iii) the role of network topology in th e synchronization properties and interm itten cy observed in neural system s. In order to investigate th ese questions, n eu ral system s are m odeled by com plex netw orks, w here each node represents a neuron, and th e edges represent th e synapses. Moreover, different n eural m odels and connection architectu res are used, w here th e problem is solved using num erical sim ulations, and, then, the level of synchronization and its properties are studied based on th e sim ulated data. At last, th e results obtained here indicate im po rtant features of th e collective behavior of neu ral system s, w here states w ith different synchronization p ro p erties and sp atio tem p o ral p a tte rn s are found. F urtherm ore, a relatio nship betw een in dividual n eu ral v ariability an d synchronization is found: th e lower th e v ariability of individual neural activity th e higher the level of synchronization for weak synapses. Also, a balance between nonlocal and local connections leads the neural network to depict a high m alleability of synchronization due to tiny changes in the external stimuli. Besides this, in th e process of transitio n to synchronization, synchronization interm ittency can be observed, w here n o n statio n ary sta te s can be observed and th e topology plays an im p o rta n t role. Therefore, th e results here contribute to a b e tte r understanding of th e collective behavior in neural system s and open im p o rtan t issues and possibilities for fu rth er application
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