2,428 research outputs found

    Knowledge representation system for assembly using robots

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    Assembly robots combine the benefits of speed and accuracy with the capability of adaptation to changes in the work environment. However, an impediment to the use of robots is the complexity of the man-machine interface. This interface can be improved by providing a means of using a priori-knowledge and reasoning capabilities for controlling and monitoring the tasks performed by robots. Robots ought to be able to perform complex assembly tasks with the help of only supervisory guidance from human operators. For such supervisory quidance, it is important to express the commands in terms of the effects desired, rather than in terms of the motion the robot must undertake in order to achieve these effects. A suitable knowledge representation can facilitate the conversion of task level descriptions into explicit instructions to the robot. Such a system would use symbolic relationships describing the a priori information about the robot, its environment, and the tasks specified by the operator to generate the commands for the robot

    Quantum information in base n defined by state partitions

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    We define a "nit" as a radix n measure of quantum information which is based on state partitions associated with the outcomes of n-ary observables and which, for n>2, is fundamentally irreducible to a binary coding. Properties of this measure for entangled many-particle states are discussed. k particles specify k nits in such a way that k mutually commuting measurements of observables with n possible outcomes are sufficient to determine the information.Comment: 4 pages, 2 figure

    Different approaches to community detection

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    A precise definition of what constitutes a community in networks has remained elusive. Consequently, network scientists have compared community detection algorithms on benchmark networks with a particular form of community structure and classified them based on the mathematical techniques they employ. However, this comparison can be misleading because apparent similarities in their mathematical machinery can disguise different reasons for why we would want to employ community detection in the first place. Here we provide a focused review of these different motivations that underpin community detection. This problem-driven classification is useful in applied network science, where it is important to select an appropriate algorithm for the given purpose. Moreover, highlighting the different approaches to community detection also delineates the many lines of research and points out open directions and avenues for future research.Comment: 14 pages, 2 figures. Written as a chapter for forthcoming Advances in network clustering and blockmodeling, and based on an extended version of The many facets of community detection in complex networks, Appl. Netw. Sci. 2: 4 (2017) by the same author

    MEASURING CONSUMER PREFERENCES FOR ECOLABELED SEAFOOD: AN INTERNATIONAL COMPARISON

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    An analysis of consumer preferences for seafood labeled with information about environmental production attributes is introduced into the food labeling literature. International seafood ecolabeling programs have proposed to create market-based incentives for fisheries managers to promote sustainable fisheries. We investigate differences in consumer preferences for ecolabeled seafood across the United States and Norway. Using a contingent-choice telephone survey of random households in each nation, a wide range of factors is found to influence consumers' likelihood of purchasing ecolabeled seafood. Consumer preferences differ by price premium, species, consumer group, and certifying agency. The effect of these factors often differs between the United States and Norway, suggesting heterogeneity in international reactions to seafood ecolabels.Consumer/Household Economics,

    Protection of Nonimmune Volunteers against Rubella by Intravenous Administration of Normal Human Gamma Globulin

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    Standard gamma globulin, treated with pepsin and injected intravenously five days after infection, conferred passive protection against rubella on five volunteers. Intravenous injection of gamma globulin is superior to intramuscular injection, because the antibodies enter the bloodstream immediately, and an amount of antibody sufficient for protection can be given. Injection of standard gamma globulin is recommended when gamma globulin hyperimmune to rubella virus is unavailabl

    Towards the H.E.S.S. Galactic Plane Survey Gamma-Ray Source Catalog

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    This thesis deals with the creation of a catalog of Galactic gamma-ray sources using a multiscale detection and morphology characterisation method. The analysis is based on maps of the H.E.S.S. Galactic Plane Survey (HGPS), generated from observations between 2004 and 2013. The emission of the Galactic plane is modelled with a Likelihood-Fit procedure, assuming a Gaussian source morphology. The identified shell-type supernova remnants Vela Junior, HESS J1731-347 and RX J1713.7-3946 are excluded from the analysis. Applying a detection threshold of TS = 30 a total number of 112 source components is obtained. The existence of large, low surface brightness emission underneath known sources is revealed. The origin of this unresolved emission is not known. Furthermore it is observed, that bright extended sources decompose into multiple components, because the morphology assumption does not match the data well enough. First a reference catalog is defined, dealing with these issues by manually classifying and merging source components, using previous H.E.S.S. publications as guidance. A total number of 78 sources in the survey region is found. For all sources the position, extension and ux with uncertainties are determined. The brightness of the sources varies between 0:7% Crab and 80% Crab. The size of the source ranges between σ=0:006° and σ=0:64°. In a second step automatic methods are developed and examined to classify unresolved components by simple cuts in size and significance and to merge components into sources by defining a suitable overlap criterion. The reference catalog can be reproduced except for a few cases, which are discussed in detail

    Study of effect of arbuscular mycorrhiza (Glomus intraradices) fungus on wheat under nickel stress

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    ArticleIn many regions of the world soils are contaminated with heavy metals and therefore restricted in their use. For instance, the absorption of nickel (Ni) in the tissue of plants increase the plant’s metabolism and cause physiological disorders or even death. Arbuscular mycorrhizal fungi are known to enhance the tolerance of host plants to abiotic and biotic stress. Thus, we investigated the potential of the arbuscular m ycorrhizal fungi Glomus intraradices to mitigate deleterious effects of Ni in wheat. The experiment was conducted using four levels of Ni (0, 60, 120 and 180 mg per kg of soil) and two levels of mycorrhizal fungi application (with and without Glomus intrar adices ). Nickel stress significantly decreased seed number per spike, thousand - seed weight, seed yield per plant, concentration of chlorophyll a and b. At the same time, we found increased catalase (CAT) enzyme activity and dityrosine (DT) treatments. Mycorrhizal fungi application attenuated Ni effects, i.e. fungal presence increased seed number per spike, thousand - seed weight, chlorophyll a and b. Furthermore mycorrhizal fungi application reduce CAT enzyme activity and DT. In general, our results sugge st that mycorrhizal fungi application reduces harmful effects of Ni stress in wheat
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