325 research outputs found
Aerospace Ground Equipment\u27s Impact on Aircraft Availability and Deployment
The first purpose of this thesis was to study the effects of four factors on aircraft availability: the aerospace ground equipment (AGE) design configuration, the mean time between failure (MTBF) of AGE, the mean time to repair (MTTR) AGE, and the travel time to transport the AGE around the flightline. A simulation developed by Carrico (1996) that has its foundation based on the Logistics Composite Model (LCOM) was used. ANOVA results indicated that the present estimates of these factors are too broad for trade studies that include an estimate of aircraft availability to begin. The time it takes AGE to travel from one place to another around the flightline strongly affected aircraft availability. It is recommended that further AGE field observation and data collection be accomplished before the merits of one AGE cart technology is compared to another. The second purpose of this thesis was to collect as much information on the deployability and affordability of AGE as possible. Although much of the information collected was a few years old, the results suggest that new technologies improve the deployment footprint and the combined acquisition and deployment costs. Background information about support equipment and AGE is included in the study
Supervised learning with quantum enhanced feature spaces
Machine learning and quantum computing are two technologies each with the
potential for altering how computation is performed to address previously
untenable problems. Kernel methods for machine learning are ubiquitous for
pattern recognition, with support vector machines (SVMs) being the most
well-known method for classification problems. However, there are limitations
to the successful solution to such problems when the feature space becomes
large, and the kernel functions become computationally expensive to estimate. A
core element to computational speed-ups afforded by quantum algorithms is the
exploitation of an exponentially large quantum state space through controllable
entanglement and interference. Here, we propose and experimentally implement
two novel methods on a superconducting processor. Both methods represent the
feature space of a classification problem by a quantum state, taking advantage
of the large dimensionality of quantum Hilbert space to obtain an enhanced
solution. One method, the quantum variational classifier builds on [1,2] and
operates through using a variational quantum circuit to classify a training set
in direct analogy to conventional SVMs. In the second, a quantum kernel
estimator, we estimate the kernel function and optimize the classifier
directly. The two methods present a new class of tools for exploring the
applications of noisy intermediate scale quantum computers [3] to machine
learning.Comment: Fixed typos, added figures and discussion about quantum error
mitigatio
Qudits of composite dimension, mutually unbiased bases and projective ring geometry
The Pauli operators attached to a composite qudit in dimension may
be mapped to the vectors of the symplectic module
( the modular ring). As a result, perpendicular vectors
correspond to commuting operators, a free cyclic submodule to a maximal
commuting set, and disjoint such sets to mutually unbiased bases. For
dimensions , and 18, the fine structure and the incidence
between maximal commuting sets is found to reproduce the projective line over
the rings , , ,
and ,
respectively.Comment: 10 pages (Fast Track communication). Journal of Physics A
Mathematical and Theoretical (2008) accepte
Hormonal contraception use during relationship formation and sexual desire during pregnancy
Women who are regularly cycling exhibit different partner preferences than those who use hormonal contraception. Preliminary evidence appears to suggest that during pregnancy women’s partner preferences also diverge from those prevalent while regularly cycling. This is consistent with the general assertion that women’s mate preferences are impacted by hormonal variation. During pregnancy, women’s preferences are thought to closely resemble those displayed by women who are using hormonal contraception. Here, based on this literature, we compared levels of sexual desire among pregnant women who met their partner while using hormonal contraception and pregnant women who met their partner while regularly cycling. We predicted that women who met their partner while using hormonal contraception would experience higher levels of in-pair sexual desire during pregnancy since these women will have partner preferences that more closely match those prevalent at the time of their partner choice. Our results provided support for the idea that previous contraceptive use/non-use may impact subsequent sexual desire for the partner during pregnancy. Pregnant women who met their partner while using hormonal contraception (N=37) were shown to have higher levels of in-pair sexual desire than those who met while regularly cycling (N=47). In contrast, levels of extra-pair desire were not related to previous use/non-use of hormonal contraception. These findings were robust when controlling for a number of relevant individual difference variables known to impact sexual desire. Our results contribute to our understanding of factors affecting relationship functioning during pregnancy
Oral contraception and romantic relationships - from the lab to the real world
We review recent evidence that suggests that oral contraceptives may influence the dynamics of sexual relationships and the human pair-bond. Hormonal birth control likely has positive effects on cementing the pair-bond by decoupling sex from conception. However, changes in women's evolved mate preferences associated with initiation or discontinuation of hormonal contraception may alter attraction to her partner, with potentially negative consequences for sexual satisfaction. We describe the evidence for such changes produced by laboratory studies, including prospective experimental designs, and how the consequences of such changes are being explored beyond the laboratory. In view of the growing prevalence of modern hormonal contraceptive methods across the globe, further study of such effects is urgently required
The impact of artificial fragrances on the assessment of mate quality cues in body odor
We investigated the impact of artificial fragrances on the accurate detection of biologically relevant information in human body odor. To do this, we examined cross-sensory consistency (across faces and odors) in the perception of masculinity and femininity in men and women, and how consistency is influenced by the use of artificial fragrance. Independent sets of same and opposite-sex participants rated odor samples (with and without a fragrance, N = 239 raters), and photographs (N = 130) of 20 men and 20 women. In female, but not male raters, judgments of masculinity/femininity of non-fragranced odor and faces were correlated. However, the correlation between female ratings of male facial and odor masculinity was not evident when assessing a body odor and fragrance blend. Further analysis also indicated that differences in ratings of male odor masculinity between men with very masculine or high and low levels of facial masculinity were removed by the addition of fragrance. This effect was absent in ratings of female odors by both female and male raters, suggesting sex-specificity in the effects of fragrance on odor perception. The widespread use of artificial fragrance in many modern populations raises questions about how this cultural practice influences ability to detect and utilize mate-choice relevant cues. Our findings suggest that women may be more sensitive to these cues, and therefore also to disruption of this information through fragrance use. We discuss our results using the framework of culture-gene coevolution
The Projective Line Over the Finite Quotient Ring GF(2)[]/ and Quantum Entanglement I. Theoretical Background
The paper deals with the projective line over the finite factor ring
GF(2)[]/. The line is endowed with 18
points, spanning the neighbourhoods of three pairwise distant points. As
is not a local ring, the neighbour (or parallel) relation is
not an equivalence relation so that the sets of neighbour points to two distant
points overlap. There are nine neighbour points to any point of the line,
forming three disjoint families under the reduction modulo either of two
maximal ideals of the ring. Two of the families contain four points each and
they swap their roles when switching from one ideal to the other; the points of
the one family merge with (the image of) the point in question, while the
points of the other family go in pairs into the remaining two points of the
associated ordinary projective line of order two. The single point of the
remaining family is sent to the reference point under both the mappings and its
existence stems from a non-trivial character of the Jacobson radical, , of the ring. The factor ring is isomorphic to GF(2)
GF(2). The projective line over features nine
points, each of them being surrounded by four neighbour and the same number of
distant points, and any two distant points share two neighbours. These
remarkable ring geometries are surmised to be of relevance for modelling
entangled qubit states, to be discussed in detail in Part II of the paper.Comment: 8 pages, 2 figure
Greater precision, not parsimony, is the key to testing the peri-ovulation spandrel hypothesis: a response to comments on Havlíček et al. 2015
We welcome the wide range of comments provoked by the introduction of our alternative theoretical perspective on the peri-ovulation paradigm (Havlíček etal. 2015)—some positive and some very critical—and here we address briefly some of the key objection
The spandrels of Santa Barbara? A new perspective on the peri-ovulation paradigm
Numerous recent studies document peri-ovulatory increases in women’s physical attractiveness and in their preferences for certain male traits, which appear to be linked to cyclical fluctuation in levels of ovarian hormones. Changes in physical traits are subtle, leading to the widespread conclusion that cues of ovulation are adaptively concealed. It has been argued that concealment enables women to pursue a mixed-mating strategy characterized by pair-bonding with opportunistic extrapair copulation with high-quality mates when conception is possible. Men’s preferences for peri-ovulatory cues and women’s cyclical preference shifts are thus also argued to reflect distinct psychological adaptations. Here, we re-interpret the evidence for each of these putative adaptations and argue that cyclic changes need not result from incomplete concealment of ovulatory status. We also emphasize that ovarian hormone levels underpin between-individual differences in both women’s attractiveness and their mate preferences, which influence the sexes’ mate-choice decisions. We contrast the salience and efficiency of these within- and between-individual effects, and suggest that, although both effects have the potential to influence mating behavior, the between-individual effects are stronger and more robust. This introduces the possibility that both men’s increased attraction towards peri-ovulatory women and women’s cyclical shifts in preference for certain male traits may not constitute adaptations per se, but are, instead, inevitable by-products, or “perceptual spandrels,” of putative adaptations related to between-individual differences in reproductive potential. Our framework parsimoniously explains several observable phenomena and potentially could transform the way evolutionary researchers interpret changes in behavior associated with the menstrual cycle. 
The Clumping Transition in Niche Competition: a Robust Critical Phenomenon
We show analytically and numerically that the appearance of lumps and gaps in
the distribution of n competing species along a niche axis is a robust
phenomenon whenever the finiteness of the niche space is taken into account. In
this case depending if the niche width of the species is above or
below a threshold , which for large n coincides with 2/n, there are
two different regimes. For the lumpy pattern emerges
directly from the dominant eigenvector of the competition matrix because its
corresponding eigenvalue becomes negative. For the lumpy
pattern disappears. Furthermore, this clumping transition exhibits critical
slowing down as is approached from above. We also find that the number
of lumps of species vs. displays a stair-step structure. The positions
of these steps are distributed according to a power-law. It is thus
straightforward to predict the number of groups that can be packed along a
niche axis and it coincides with field measurements for a wide range of the
model parameters.Comment: 16 pages, 7 figures;
http://iopscience.iop.org/1742-5468/2010/05/P0500
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