105,822 research outputs found
Evaluation of closed cubic failure criterion for graphite/epoxy laminates
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
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
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
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 and with query time
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 and query time . When the objects and
query are fat, we obtain query time using storage
Optimal Deterministic Polynomial-Time Data Exchange for Omniscience
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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