291 research outputs found

    Models to Reduce the Complexity of Simulating a Quantum Computer

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    Recently Quantum Computation has generated a lot of interest due to the discovery of a quantum algorithm which can factor large numbers in polynomial time. The usefulness of a quantum com puter is limited by the effect of errors. Simulation is a useful tool for determining the feasibility of quantum computers in the presence of errors. The size of a quantum computer that can be simulat ed is small because faithfully modeling a quantum computer requires an exponential amount of storage and number of operations. In this paper we define simulation models to study the feasibility of quantum computers. The most detailed of these models is based directly on a proposed imple mentation. We also define less detailed models which are exponentially less complex but still pro duce accurate results. Finally we show that the two different types of errors, decoherence and inaccuracies, are uncorrelated. This decreases the number of simulations which must be per formed.Comment: 25 page

    Characterization of the alternative respiratory pathway in soybean

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    The alternative respiratory pathway may be important in the energy economy of higher plants. The objective of this study was to characterize the alternative pathway in soybean and to gain a better understanding of the importance of this respiratory pathway to soybean productivity;Capacity for the alternative pathway was assessed in leaf and root tissue of male-sterile and fertile soybean plants and in leaf, embryonic axis and epicotyl tissue, as well as isolated mitochondria, of pea (Pisum sativum L.) by measurement of oxygen uptake in the presence and absence of KCN and salicylhydroxamic acid (SHAM). Male-sterile and fertile soybean tissues showed similar responses to the inhibitors and both possessed a capacity for alternative respiration. Tissues and isolated mitochondria from \u27Progress No. 9\u27 pea, contrary to published information, possessed alternative respiratory pathway capacity similar to that of \u27Alaska\u27 pea;The effects of the respiratory inhibitors, KCN and SHAM, on dark CO[subscript]2 evolution in soybean leaves were examined to test the hypothesis that KCN stimulation of O[subscript]2 uptake in this tissue is due to decontrol of glycolysis, caused by a diversion of electrons into the alternative pathway. Both KCN and SHAM, when used individually, caused a 30% increase in CO[subscript]2 evolution. When both inhibitors were present together, the resulting rate was approximately equal to the control. Due to the unexpected stimulatory effect of SHAM on CO[subscript]2 evolution, conclusions about the cause of KCN stimulation of O[subscript]2 uptake in this tissue could not be drawn;In soybean axis tissue and cotyledons 3 to 9 days of age, increasing amount of alternative oxidase, as determined by immunoblots probed with alternative oxidase antibodies, corresponded with the increasing alternative pathway capacity of isolated mitochondria from these tissues. In older cotyledons, however, little or no change in amount of alternative oxidase occurred even though there were substantial changes in capacity. This suggests that, whereas alternative oxidase content is likely to be important in determining the capacity of the alternative pathway in axis tissue and young cotyledons, other factors regulate the capacity in older cotyledons

    Konzeption und Implementation des Aufbaus eines Suchmaschinenindexes fĂŒr Solr im bibliothekarischen Kontext

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    Diese Arbeit befasst sich mit der Struktur und dem Betrieb von VuFind, das eine bibliographische Suchmaschine darstellt. VuFind wird als Open-Source-Projekt entwickelt und mittlerweile von mehreren hundert Bibliotheken weltweit genutzt. Außerdem wird SolrMarc, ein Teilprojekt von VuFind, analysiert und ĂŒberarbeitet, wodurch die Effizienz dieses Programmes erhöht wird

    An efficient quantum circuit analyser on qubits and qudits

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    This paper presents a highly efficient decomposition scheme and its associated Mathematica notebook for the analysis of complicated quantum circuits comprised of single/multiple qubit and qudit quantum gates. In particular, this scheme reduces the evaluation of multiple unitary gate operations with many conditionals to just two matrix additions, regardless of the number of conditionals or gate dimensions. This improves significantly the capability of a quantum circuit analyser implemented in a classical computer. This is also the first efficient quantum circuit analyser to include qudit quantum logic gates

    Using Safety Margins for a German Seismic PRA

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    The German regulatory guide demands the performance of a probabilistic risk assessment (PRA) including external events. In 2005, a new methodology guideline (Methodenband) based on the current state of science and technology was released to provide the analyst with a set of suitable tools and methodologies for the analysis of all PRA events. In the case of earthquake, a multilevel verification procedure is suggested. The verification procedure which has to be used depends on the seismic risk at the site of the plant. For sites in areas with low seismic activity no analysis or only a reduced analysis is proposed. This paper describes the evaluation of safety margins of buildings, structures, components and systems for plants at sites with high seismic risk, corresponding to the German methodology guideline. The seismic PRA results in an estimation of core damage frequencies caused by earthquakes. Additionally, the described approach can also be adapted for the usage in a reduced analysis for sites with lower earthquake risks. Westinghouse has wide experience in performing seismic PRA for both BWR as well as PWR plants. Westinghouse uses the documented set of seismic design analyses dating from construction phase and from later updates, if done, as a basis for a seismic PRA, which means that usually no costly new structural mechanics calculations have to be performed

    Zentrales Pionierensemble Görlitz (ZPE), Kinder- und Jugendensemble Görlitz - Medaillen zur Auszeichnung und Anerkennung - Souvenirs; Jugendblasorchester Görlitz - Anstecker/Abzeichen: Jugendblasorchester Görlitz - Anstecker/Abzeichen

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    Ziel dieser Ausarbeitung ist eine fĂŒr den Sammler erstellte Zusammenfassung zu diesem sehr eng begrenzten Sammelgebiet. Die Auflistung der erschienenen Medaillen sowie KlĂ€rung geschichtlicher und kultureller ZusammenhĂ€nge zu den Geschehnissen soll dem interessierten Leser einen Einblick geben, wie und in welcher Weise in den Schulen in Görlitz Kinder und Jugendliche an musische KĂŒnste herangefĂŒhrt worden sind. Damit war dann oft eine ansprechende und sinnvolle Freizeitgestaltung verbunden. [... aus dem Vorwort

    Effect of Phytosanitary Irradiation on the Quality of Two Varieties of Pummelos (\u3cem\u3eCitrus maxima\u3c/em\u3e (Burm.) Merr.)

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    Phytosanitary treatments prevent the introduction of pests such as fruit flies into pest free zones, and are often required for international trade. Irradiation is increasingly being considered as an alternative to cold and chemical phytosanitary treatments, such as methyl bromide. In this study, the effect of low dose gamma irradiation on the post-harvest quality of two varieties of pummelos (Citrus maxima (Burm.) Merr.), an emerging crop of interest in the US was evaluated. Two varieties of pummelos grown in California were irradiated at the phytosanitary target dose of 150 Gy and a higher dose of 1000 Gy to exaggerate and hence confirm the effects of treatment. The fruit was stored at 12 °C for 3 weeks and at 20 °C for the 4th week to reflect three weeks of sea shipment at the ideal temperature for storage of pummelos and an additional week of retail under ambient conditions. Neither irradiation nor storage affected juice content, organic acids, sugars, peel or pulp color and consumer sensory preference, although numerous volatiles increased in concentration as a result of irradiation treatment. Irradiation caused an immediate reduction in whole fruit and pulp firmness in ‘Chandler’ but not ‘Sarawak’ pummelos at both 150 Gy and 1000 Gy. The quality of irradiated pummelos stored at refrigerated temperature for 3 weeks was similar to untreated pummelos, however, physical handling and exposure to higher temperature resulted in increased peel pitting of irradiated fruit compared to non-treated fruit. The results suggest that irradiation could serve as a potential phytosanitary treatment for Chandler and Sarawak pummelos, provided that the fruit is subjected to minimal handling and not temperature abused

    Managing Postharvest Storage Issues in ‘Shiranui’ Mandarin

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    ‘Shiranui’ is a mandarin (Citrus reticulata var. austera) that is highly treasured for its unique and delicious flavor, and obtains premium prices in the marketplace. Although flavorful, ‘Shiranui’ tends to develop off-flavor during storage. In this study we examined the use of different storage wax (SW) and pack wax (PW) combinations to determine whether flavor in ‘Shiranui’ can be improved after storage by adjusting wax coating protocols. In the initial test, either SW or no wax was applied after harvest, and each was followed by an application of SW or one of two types of PW after 1 day, 3 weeks, or 7 weeks of storage and then held 1 week at either 7 or 20 °C. Results indicate that the initial wax was not an important factor but the use of SW instead of either type of PW as the final coating led to greater internal oxygen levels in the fruit and less off-flavor formation. The lessening of off-flavor by SW was significant only after 20 °C of storage, when off-flavor was greatest. Greater weight loss accompanied the use of SW as the final coating. In a second test, SW with greater solids concentrations (5%, 10%, and 15%) were evaluated to attempt to reduce weight loss, but this led to greater development of off-flavor and loss in acceptability than observed when using SW with 1% solids in test 1. ‘Shiranui’ is prone to developing off-flavor in storage, but this may be mitigated, at least in part, by using SW as the final wax rather than PW
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