12,387 research outputs found

    The NS five-brane partition sum

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    This note is the written version of a talk which was presented at the Cargese 2002 summer school. It gives a brief introduction to the paper hep-th/0205281, written in collaboration with R. Dijkgraaf and E. Verlinde. In this paper, we calculate the euclidean partition function of the type IIA NS five-brane wrapped on an arbitrary Calabi-Yau space in a double-scaling decoupling limit and in the presence of a flat RR 3-form background field. The result is the product of a theta function, coming from the classical fluxes of the self-dual tensor field, and a factor representing the quantum contributions. The quantum factor turns out to be related to topological B-model string amplitudes, and both factors satisfy a holomorphic anomaly equation. The result can teach us more about little string theories and about instanton corrections to four-dimensional effective quantities.Comment: 5 pages. Contribution to the proceedings of the Cargese 2002 summer schoo

    Late Miocene-Early Pliocene Matemateaonga Formation in eastern Taranaki Peninsula: A new 1:50,000 geological map and stratigraphic framework

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    In recent years the Matemateaonga Formation has become an additional exploration play in Taranaki Basin. Exploration interest has been stimulated by the success of Swift Energy Company in the Rimu/Kauri prospect (38719), located near south Taranaki Coast. At this location, sandstone lithofacies, commonly termed “Manutahi Sandstone” in the lower parts of the Matemateaonga Formation have been intersected by the Kauri-A2 and Kauri-A3 wells at depths of ~1100-1200 m and are yielding commercial quantities of oil. As part of a FRST-funded sedimentary basins research programme, we have geologically mapped in detail Matemateaonga Formation within an 1800 km2 area of the eastern peninsula region (Fig. 1), incorporating license areas 38739, 38718, 38753, 38138, 38139, 38141, 38140, 38716, 38758, 38728 and 38760. Mapping at 1:50,000 scale has revealed an ~1100 m-thick succession of cyclothemic, unconformity bounded shelfal strata of Late Miocene-Early Pliocene (Late Kapitean to Early Opoitian) age (c.5.5-4.7 Ma). This succession formed as a result of the interplay between climatically-driven 6th-order (41 k.y.) eustatic sea-level changes, high rates of basin subsidence and a substantial southerly-derived sediment flux. Individual sequences or groups of sequences are the fundamental mapping entities. The mapping area sits astride the southward-plunging Whangamomona Anticline, which has deformed the Late Neogene succession, producing a regional dip on its western flank of 2 to 4 degrees to the southwest. Northeast-southwest trending normal faults are relatively common and offset Matemateaonga Formation strata with throws of 2-50 m. This improved knowledge of Matemateaonga Formation stratigraphy enhances the understanding of the distribution and geometry of potential reservoir sandstone units and associated mudstone seal units in the region

    Will Liam save us? : an analysis of Apple's zero-waste goals and waste networks associated with the MacBook : a thesis presented in partial fulfilment of the requirements for the degree of Master of Arts in Media Studies at Massey University, Manawatū, New Zealand

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    As popular awareness of global environmental crises rises, the circular economy model is increasingly heralded as a means to address the environmental impact of traditional extractive economies. Technology provider Apple has been among high-profile corporations quick to adopt a circular model, announcing their plans to both end mining and become zero-waste. In this thesis, I analyse Apple’s zero-waste plans using my own notebook as a case study. A discourse analysis of the company’s 2017 Environmental Responsibility Report reveals that the zero-waste approach is (at least in part) a marketing strategy. It works to increase Apple’s power and consumer base. The zero-waste strategy is presented as distinct from their social responsibility, echoing the way that waste is conceptualised within the circular economy. Both Apple’s zero-waste plan and the circular economy rely heavily on technological innovation to offer solutions to waste. Waste is understood as something distinct from, and entirely controllable by, human intention. Individual case studies of my notebooks aluminium casing and hard disk drive demonstrate that vast waste networks of human and nonhuman actors enable Apple to function as they do, and are in fact integral to any economy organised around the pursuit of profit. Within this context, attempts to circumvent the worst harms associated with the extraction, production, consumption, and disposal contexts of ICT equipment will end up reinscribing or reinforcing wasteful practices. Through an auto-ethnographic description of dealing with the notebooks possibly failing battery, I argue that understanding ourselves as separate from waste networks (as zero-waste discourses encourage us to do) similarly forecloses the possibility of disrupting the most negative impacts of waste. Repair tentatively emerges as one way of destabilising the power of large corporations that benefit from capital such as Apple. Ultimately, the case studies presented here raise serious doubts about both Apple’s zero-waste strategy and the circular economy in general

    Eastern Taranaki Basin field guide.

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    Linking the onshore and offshore parts of Eastern Taranaki Basin: Insights to stratigraphic architecture, sedimentary facies, sequence stratigraphy, paleogeography and hydrocarbon exploration from the on land record

    On the partition sum of the NS five-brane

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    We study the Type IIA NS five-brane wrapped on a Calabi-Yau manifold X in a double-scaled decoupling limit. We calculate the euclidean partition function in the presence of a flat RR 3-form field. The classical contribution is given by a sum over fluxes of the self-dual tensor field which reduces to a theta-function. The quantum contributions are computed using a T-dual IIB background where the five-branes are replaced by an ALE singularity. Using the supergravity effective action we find that the loop corrections to the free energy are given by B-model topological string amplitudes. This seems to provide a direct link between the double-scaled little strings on the five-brane worldvolume and topological strings. Both the classical and quantum contributions to the partition function satisfy (conjugate) holomorphic anomaly equations, which explains an observation of Witten relating topological string theory to the quantization of three-form fields.Comment: 35 page

    Neural Networks: Implementations and Applications

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    Artificial neural networks, also called neural networks, have been used successfully in many fields including engineering, science and business. This paper presents the implementation of several neural network simulators and their applications in character recognition and other engineering area

    Using genetic algorithms with grammar encoding to generate neural networks

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    Kitano's approach to neural network design is extended in the sense that not just the neural network structure, but also the values of the weights are coded in the chromosome. Experimental results are presented demonstrating the capability of the technique in the solution of a standard test problem

    Neural Network Applications

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    Artificial neural networks, also called neural networks, have been used successfully in many fields including engineering, science and business. This paper presents the implementation of several neural network simulators and their applications in character recognition and other engineering area
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