105,820 research outputs found

    Evaluation of closed cubic failure criterion for graphite/epoxy laminates

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    An analytical method has been developed to ensure closure of the cubic form of the tensor polynomial strength criterion. The intrinsic complexity of the cubic function is such that special conditions must be met to close the failure surface in three-dimensional stress space. These requirements are derived in terms of non-intersecting conditions for asymptotes and an asymptotic plane. To demonstrate the validity of this approach, closed failure surfaces were derived for two graphite/epoxy material systems (3M SP288-T300 and IM7 8551-7). The agreement of test data with this model clearly shows that it is possible to use a higher order cubic failure theory with confidence

    Subsystem Complexity and Measurements in Holography

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    We investigate the impact of measuring one subsystem on the holographic complexity of another. While a naive expectation might suggest a reduction in complexity due to the collapse of the state to a trivial product state during quantum measurements, our findings reveal a counterintuitive result: in numerous scenarios, measurements on one subsystem can amplify the complexity of another. We first present a counting argument elucidating this complexity transition in random states. Then, employing the subregion "complexity=volume" (CV) proposal, we identify a complexity phase transition induced by projection measurements in various holographic CFT setups, including CFT vacuum states, thermofield double states, and the joint system of a black hole coupled to a bath. According to the AdS/BCFT correspondence, the post-measurement dual geometry involves an end-of-the-world brane created by the projection measurement. The complexity phase transition corresponds to the transition of the entanglement wedge to the one connected to the brane. In the context of the thermofield double setup, complete projection on one side can transform the other side into a boundary state black hole with higher complexity or a pure AdS with lower complexity. In the joint system of a black hole coupled to a nongraviting bath, where (a part of) the radiation is measured, the BCFT features two boundaries: one for the black hole and the other for the measurement. We construct the bulk dual involving intersecting or non-intersecting branes, and investigate the complexity transition induced by the projection measurement. Notably, for a subsystem that contains the black hole brane, its RT surface may undergo a transition, giving rise to a complexity jump.Comment: 44 pages, 32 figure

    Drawing the line: drawing and construction strategies for simple and complex figures in Williams Syndrome and typical development

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    In the typical population, a series of drawing strategies have been outlined, which progressively emerge during childhood. Individuals with Williams syndrome (WS), a rare genetic disorder, produce drawings that lack cohesion, yet drawing strategies in this group have hitherto not been investigated. In this study, WS and typically developing (TD) groups drew and constructed (from pre-drawn lines and shapes) a series of intersecting and embedded figures. Participants with WS made use of the same strategies as the TD group for simple intersecting figures, though were less likely to use a typical strategy for more complex figures that contained many spatial relations. When replicating embedded shapes, the WS group used typical drawing strategies less frequently than the TD group, despite attempting to initiate a strategy that is observed in TD children. Results suggested that individuals with WS show a particular difficulty with replicating figures that include multiple spatial relations. The impact of figure complexity and task demands on performance are discussed

    Finding Pairwise Intersections Inside a Query Range

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    We study the following problem: preprocess a set O of objects into a data structure that allows us to efficiently report all pairs of objects from O that intersect inside an axis-aligned query range Q. We present data structures of size O(n(polylogn))O(n({\rm polylog} n)) and with query time O((k+1)(polylogn))O((k+1)({\rm polylog} n)) time, where k is the number of reported pairs, for two classes of objects in the plane: axis-aligned rectangles and objects with small union complexity. For the 3-dimensional case where the objects and the query range are axis-aligned boxes in R^3, we present a data structures of size O(nn(polylogn))O(n\sqrt{n}({\rm polylog} n)) and query time O((n+k)(polylogn))O((\sqrt{n}+k)({\rm polylog} n)). When the objects and query are fat, we obtain O((k+1)(polylogn))O((k+1)({\rm polylog} n)) query time using O(n(polylogn))O(n({\rm polylog} n)) storage

    Optimal Deterministic Polynomial-Time Data Exchange for Omniscience

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    We study the problem of constructing a deterministic polynomial time algorithm that achieves omniscience, in a rate-optimal manner, among a set of users that are interested in a common file but each has only partial knowledge about it as side-information. Assuming that the collective information among all the users is sufficient to allow the reconstruction of the entire file, the goal is to minimize the (possibly weighted) amount of bits that these users need to exchange over a noiseless public channel in order for all of them to learn the entire file. Using established connections to the multi-terminal secrecy problem, our algorithm also implies a polynomial-time method for constructing a maximum size secret shared key in the presence of an eavesdropper. We consider the following types of side-information settings: (i) side information in the form of uncoded fragments/packets of the file, where the users' side-information consists of subsets of the file; (ii) side information in the form of linearly correlated packets, where the users have access to linear combinations of the file packets; and (iii) the general setting where the the users' side-information has an arbitrary (i.i.d.) correlation structure. Building on results from combinatorial optimization, we provide a polynomial-time algorithm (in the number of users) that, first finds the optimal rate allocations among these users, then determines an explicit transmission scheme (i.e., a description of which user should transmit what information) for cases (i) and (ii)
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