2,580 research outputs found

    The Emergence of Cooperative Playing Routines: Optimality and Learning

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    We investigate the emergence of (optimal and suboptimal) behavioural routines in the context of a cooperative game. In particular we construct a search model of the gradient descent type for the optimization of 'static' and 'dynamic' playing routines. That optimality study sets the basis for the analysis of the dynamics and modelling of routine learning. In the last part of the paper we propose a learning heuristics for the development of routinized behaviour on the basis of a simple network model of the subject player

    Behavior of Holstein milking cows exposed to different environmental conditioning systems

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    Objectives: The aim of the study was to evaluate the behavior of dairy cows in summer in relation to the environmental conditioning system (fans with or without misting). Materials and Methods: Twenty Holstein lactating cows were allotted in free-stall pens, divided in two groups: VN ? with fans plus misting; V ? only with fans. The behavior was estimated as time standing and eating, ruminating and idling activities. Data were registered during 4 days by scan method, from 0600h to 1800h, with 30 minutes intervals. Results: Air temperature and relative humidity were registered and indicated a heat stress situation, with maximum temperatures of 32oC and 87% of relative humidity. We observed high values of in standing posture and eating activity on 11h30, 1630h and 1700h hours of VN animals (P <0.05). High frequency for ruminating and idling activities were found at 1700h and 1630h, respectively, for the V animals (P <0.05). Conclusions: The use of fans as the only resource of thermal comfort in these experimental conditions was inefficient when compared to the combination of fans and misting, which give a better thermal comfort condition, allowing cows to feed for long periods, even during the hottest hours of the day, indicating less heat stress

    The data cyclotron query processing scheme

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    Distributed database systems exploit static workload characteristics to steer data fragmentation and data allocation schemes. However, the grand challenge of distributed query processing is to come up with a self-organizing architecture, which exploits all resources to manage the hot data set, minimize query response time, and maximize throughput without global co-ordination. In this paper, we introduce the Data Cyclotron architecture which addresses the challenges using turbulent data movement through a storage ring built from distributed main memory capitalizing modern remote-DMA facilities. Queries assigned to individual nodes interact with the Data Cyclotron by picking up data fragments continuously flowing around, i.e., the hot set. Each data fragment carries a level of interest (LOI) metric, which represents the cumulative query interest as the fragment passes around the ring multiple times. A fragment with a LOI below a given threshold, inversely proportional to the ring load, is pulled o

    Diversity Of Medium-sized And Large Mammals From Atlantic Forest Remnants In Southern Minas Gerais State, Brazil

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    Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Studies on mammal diversity provide the essential groundwork for the development of conservation methods and practices. The region of the Poços de Caldas Plateau is lacks such studies, which may be a problem for future conservation actions. Here, we analyze the richness of medium-sized and large mammals from Atlantic Forest remnants on the Poços de Caldas Plateau, Minas Gerais state. Diurnal censuses of direct observations and mammal signs were conducted, and we documented 20 species of mammals belonging to eight orders. Three species of primates, one carnivore, one cingulate, one lagomorpha, three rodents, one artiodactyla, and two marsupials were found. The largest forest remnant that presented the greatest richness is currently a conservation unit. Forest remnants are important for the consolidation of management strategies and have fundamental role for the conservation of mammal diversity in the south of Minas Gerais state. © 2016 Check List and Authors.125CNPq, Conselho Nacional de Desenvolvimento Científico e TecnológicoConselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

    Hydrothermal Surface-Wave Instability and the Kuramoto-Sivashinsky Equation

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    We consider a system formed by an infinite viscous liquid layer with a constant horizontal temperature gradient, and a basic nonlinear bulk velocity profile. In the limit of long-wavelength and large nondimensional surface tension, we show that hydrothermal surface-wave instabilities may give rise to disturbances governed by the Kuramoto-Sivashinsky equation. A possible connection to hot-wire experiments is also discussed.Comment: 11 pages, RevTex, no figure

    Peak Performance – Remote Memory Revisited

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    Many database systems share a need for large amounts of fast storage. However, economies of scale limit the utility of extending a single machine with an arbitrary amount of memory. The recent broad availability of the zero-copy data transfer protocol RDMA over low-latency and high throughput network connections such as InfiniBand prompts us to revisit the long-proposed usage of memory provided by remote machines. In this paper, we present a solution to make use of remote memory without manipulation of the operating system, and investigate the impact on database performance

    Exploiting the Power of Relational Databases for Efficient Stream Processing

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    Stream applications gained significant popularity over the last years that lead to the development of specialized stream engines. These systems are designed from scratch with a different philosophy than nowadays database engines in order to cope with the stream applications requirements. However, this means that they lack the power and sophisticated techniques of a full fledged database system that exploits techniques and algorithms accumulated over many years of database research. In this paper, we take the opposite route and design a stream engine directly on top of a database kernel. Incoming tuples are directly stored upon arrival in a new kind of system tables, called baskets. A continuous query can then be evaluated over its relevant baskets as a typical one-time query exploiting the power of the relational engine. Once a tuple has been seen by all relevant queries/operators, it is dropped from its basket. A basket can be the input to a single or multiple similar query plans. Furthermore, a query plan can be split into multiple parts each one with its own input/output baskets allowing for flexible load sharing query scheduling. Contrary to traditional stream engines, that process one tuple at a time, this model allows batch processing of tuples, e.g., query a basket only after xx tuples arrive or after a time threshold has passed. Furthermore, we are not restricted to process tuples in the order they arrive. Instead, we can selectively pick tuples from a basket based on the query requirements exploiting a novel query component, the basket expressions. We investigate the opportunities and challenges that arise with such a direction and we show that it carries significant advantages. We propose a complete architecture, the DataCell, which we implemented on top of an open-source column-oriented DBMS. A detailed analysis and experimental evaluation of the core algorithms using both micro benchmarks and the standard Linear Road benchmark demonstrate the potential of this new approach

    Physicochemical and microbial analysis of feces from horses fed diets containing citrus pulp.

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    This study aimed to evaluate the e ect of diets containing increasing levels of citrus pulp on the physic-chemical and microbiological characteristics of horses feces. Five mares, at an average age of 3.5 years old and body weight of 492 ± 44.5 kg were arranged in a 5 x 5 Latin Square. The experimental diet consisted of 60% coast-cross hay and 40 % of concentrate with increasing levels of citrus pulp (0, 7, 14, 21, and 28 %). To determine the fecal pH, samples were collected directly from the oor, immediately after defecation, in the rst feces the day at 07:00 a.m., and color and fecal consistency were evaluated. For microbiological analysis, an aliquot was reserved in plastic bags, frozen, and sent to the microbiological laboratory for further analysis. Lactic acid bacteria were counted for Lactobacillus spp. and Streptococcus spp. from fecal samples under anaerobic conditions. The diet produced di erences (P0.05) on pH and on the number of Lactobacillus spp. and Streptococcus spp. The inclusion of up to 28% citrus pulp concentrates for horses did not promote change in the physio-chemical characteristics and on the population of lactic acid-producing bacteria in feces

    Physiological and behavioral responses of Holstein cows housed under cooling system

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    Este estudo teve como objetivo avaliar a influência de recursos de climatização, ventilação e nebulização, sobre a fisiologia e o comportamento de vacas Holandesas alojadas em free-stall, durante o verão do sudeste brasileiro. Foram utilizadas 20 vacas Holandesas submetidas a dois tratamentos com e sem climatização. Os parâmetros ambientais registrados foram temperatura de bulbo seco, umidade relativa do ar e temperatura de globo negro. As variáveis fisiológicas avaliadas foram temperatura retal e frequência respiratória. As variáveis comportamentais registradas foram postura e suas atividades dentro da instalação. Para análise estatística utilizou-se a metodologia de quadrados mínimos por meio do procedimento PROC MIXED e PROC GLM. Apesar das diferenças estatísticas obtidas para as variáveis fisiológicas, as mesmas não foram biologicamente efetivas e indicaram que os animais se encontravam em conforto térmico. Os animais que dispunham de ventilação e nebulização alimentaram-se mesmo nas horas mais quentes do dia. A climatização é uma estratégia que permite maior conforto térmico aos animais e por consequência pode aperfeiçoar a produção leiteira através do aumento no consumo alimentar
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