29,341 research outputs found
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Mediated intimacy: Sex advice in media culture
The bold argument of Mediated Intimacy (Barker et al., 2018)1 is that media of various kinds play an increasingly important role in shaping people’s knowledge, desires, practices and expectations about intimate relationships. While arguments rage about the nature and content of sex and relationship education in schools, it is becoming clear that more and more of us – young and old – look not to formal education, or even to our friends, for information about sex, but to the media (Albury, 2016; Attwood et al., 2015). This is not simply a matter of media ‘advice’ in the form of self-help books, magazine problem pages, or online ‘agony’ columns – though these are all proliferating and are discussed at length in the book. It is also about the wider cultural habitat of images, ideas and discourses about intimacy that circulate through and across media: the ‘happy endings’ of romantic comedies; the ‘money shots’ of pornography; the celebrity gossip about who is seeing whom, who is ‘cheating’, and who is looking ‘hot’; the lifestyle TV about ‘embarrassing bodies’ or being ‘undateable’; the newspaper features on how to have a ‘good’ divorce or ‘ten things never to say on a first date’; the new apps that incite us to quantify and rate our sex lives, and so forth. These constitute the ‘taken for granted’ of everyday understandings of intimacy, and they are at the heart of Mediated Intimacy
An invitation to quantum tomography (II)
The quantum state of a light beam can be represented as an infinite
dimensional density matrix or equivalently as a density on the plane called the
Wigner function. We describe quantum tomography as an inverse statistical
problem in which the state is the unknown parameter and the data is given by
results of measurements performed on identical quantum systems. We present
consistency results for Pattern Function Projection Estimators as well as for
Sieve Maximum Likelihood Estimators for both the density matrix of the quantum
state and its Wigner function. Finally we illustrate via simulated data the
performance of the estimators. An EM algorithm is proposed for practical
implementation. There remain many open problems, e.g. rates of convergence,
adaptation, studying other estimators, etc., and a main purpose of the paper is
to bring these to the attention of the statistical community.Comment: An earlier version of this paper with more mathematical background
but less applied statistical content can be found on arXiv as
quant-ph/0303020. An electronic version of the paper with high resolution
figures (postscript instead of bitmaps) is available from the authors. v2:
added cross-validation results, reference
Deterministic entanglement of two neutral atoms via Rydberg blockade
We demonstrate the first deterministic entanglement of two individually
addressed neutral atoms using a Rydberg blockade mediated controlled-NOT gate.
Parity oscillation measurements reveal an entanglement fidelity of
, which is above the entanglement threshold of , without
any correction for atom loss, and after correcting for
background collisional losses. The fidelity results are shown to be in good
agreement with a detailed error model.Comment: 4 figure
NCC Simulation Model: Simulating the operations of the network control center, phase 2
The simulation of the network control center (NCC) is in the second phase of development. This phase seeks to further develop the work performed in phase one. Phase one concentrated on the computer systems and interconnecting network. The focus of phase two will be the implementation of the network message dialogues and the resources controlled by the NCC. These resources are requested, initiated, monitored and analyzed via network messages. In the NCC network messages are presented in the form of packets that are routed across the network. These packets are generated, encoded, decoded and processed by the network host processors that generate and service the message traffic on the network that connects these hosts. As a result, the message traffic is used to characterize the work done by the NCC and the connected network. Phase one of the model development represented the NCC as a network of bi-directional single server queues and message generating sources. The generators represented the external segment processors. The served based queues represented the host processors. The NCC model consists of the internal and external processors which generate message traffic on the network that links these hosts. To fully realize the objective of phase two it is necessary to identify and model the processes in each internal processor. These processes live in the operating system of the internal host computers and handle tasks such as high speed message exchanging, ISN and NFE interface, event monitoring, network monitoring, and message logging. Inter process communication is achieved through the operating system facilities. The overall performance of the host is determined by its ability to service messages generated by both internal and external processors
Technology evaluation of heating, ventilation, and air conditioning for MIUS application
Potential ways of providing heating, ventilation, and air conditioning for a building complex serviced by a modular integrated utility system (MIUS) are examined. Literature surveys were conducted to investigate both conventional and unusual systems to serve this purpose. The advantages and disadvantages of the systems most compatible with MIUS are discussed
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On the Interface Between LENS® Deposited Stainless Steel 304L Repair Geometry and Cast or Machined Components
Laser Engineered Net Shaping™ (LENS®) is being evaluated for use as a metal component
repair/modification process. A component of the evaluation is to better understand the characteristics of
the interface between LENS deposited material and the substrate on which it is deposited. A processing
and metallurgical evaluation was made on LENS processed material fabricated for component
qualification tests. A process parameter evaluation was used to determine optimum build parameters
and these parameters were used in the fabrication of tensile test specimens to study the characteristics of
the interface between LENS deposited material and several types of substrates. Analyses of the
interface included mechanical properties, microstructure, and metallurgical integrity. Test samples
were determined for a variety of geometric configurations associated with interfaces between LENS
deposited material and both wrought base material or previously deposited LENS material. Thirteen
different interface configurations were fabricated for evaluation representing a spectrum of deposition
conditions from complete part build, to hybrid substrate-LENS builds, to repair builds for damaged or
re-designed housings. Good mechanical properties and full density were observed for all configurations.
When tested to failure, fracture occurred by ductile microvoid coalescence. The repair and hybrid
interfaces showed the same metallurgical integrity as, and had properties similar to, monolithic LENS
deposits.Mechanical Engineerin
Analytical and structural studies of acacia polysaccharides
An analytical study of eleven Acacia gums from the subseries Juliflorae
of the series Phyllodineae showed them to be more proteinaceous,
more acidic and more viscous, with higher methoxyl contents and
higher molecular weights but with lower proportions of rhamnose
and arabinose than the majority of Acacia gums studied so far.A structural study of the gum from Acacia auriculiformis involving
hydrolysis, Smith- degradation and methylation studies, revealed a
ß -1, 3 - linked galactose backbone with side chains of ß -1, 6 - linked
galactose. Glucuronic acid was present as end-groups, linked ß-1, 6
to galactose: 4-Ω-methyl glucuronic acid was present as end - groups,
α -1, 4 - linked to galactose. Arabinose was present in short, ß-1, 3-
linked chains, while rhamnose was present as end-group. Proteinaceous
material was attached to the molecule by periodate- resistant linkages.The use of carbon 13-nuclear magnetic resonance spectroscopy for
the study of gum exudates was examined. Spectra were obtained for
the gum from Acacia auriculiformis and its degradation products,
despite their high molecular weight and chemical complexity. The
spectra substantiated the findings of the structural study
Uniform electron gases: III. Low-density gases on three-dimensional spheres
By combining variational Monte Carlo (VMC) and complete-basis-set limit
Hartree-Fock (HF) calculations, we have obtained near-exact correlation
energies for low-density same-spin electrons on a three-dimensional sphere
(3-sphere), i.e.~the surface of a four-dimensional ball. In the VMC
calculations, we compare the efficacies of two types of one-electron basis
functions for these strongly correlated systems, and analyze the energy
convergence with respect to the quality of the Jastrow factor. The HF
calculations employ spherical Gaussian functions (SGFs) which are the
curved-space analogs of cartesian Gaussian functions. At low densities, the
electrons become relatively localized into Wigner crystals, and the natural SGF
centers are found by solving the Thomson problem (i.e. the minimum-energy
arrangement of point charges) on the 3-sphere for various values of . We
have found 11 special values of whose Thomson sites are equivalent. Three
of these are the vertices of four-dimensional Platonic solids --- the
hyper-tetrahedron (), the hyper-octahedron () and the 24-cell
() --- and a fourth is a highly symmetric structure () which has
not previously been reported. By calculating the harmonic frequencies of the
electrons around their equilibrium positions, we also find the first-order
vibrational corrections to the Thomson energy.Comment: 6 pages, 2 figures, accepted for publication in the Journal of
Chemical Physic
Analytic Representation of The Dirac Equation
In this paper we construct an analytical separation (diagonalization) of the
full (minimal coupling) Dirac equation into particle and antiparticle
components. The diagonalization is analytic in that it is achieved without
transforming the wave functions, as is done by the Foldy-Wouthuysen method, and
reveals the nonlocal time behavior of the particle-antiparticle relationship.
We interpret the zitterbewegung and the result that a velocity measurement (of
a Dirac particle) at any instant in time is, as reflections of the fact that
the Dirac equation makes a spatially extended particle appear as a point in the
present by forcing it to oscillate between the past and future at speed c. From
this we infer that, although the form of the Dirac equation serves to make
space and time appear on an equal footing mathematically, it is clear that they
are still not on an equal footing from a physical point of view. On the other
hand, the Foldy-Wouthuysen transformation, which connects the Dirac and square
root operator, is unitary. Reflection on these results suggests that a more
refined notion (than that of unitary equivalence) may be required for physical
systems
Solid-state electronic spin coherence time approaching one second
Solid-state electronic spin systems such as nitrogen-vacancy (NV) color
centers in diamond are promising for applications of quantum information,
sensing, and metrology. However, a key challenge for such solid-state systems
is to realize a spin coherence time that is much longer than the time for
quantum spin manipulation protocols. Here we demonstrate an improvement of more
than two orders of magnitude in the spin coherence time () of NV centers
compared to previous measurements: s at 77 K, which enables
coherent NV spin manipulations before decoherence. We employed
dynamical decoupling pulse sequences to suppress NV spin decoherence due to
magnetic noise, and found that is limited to approximately half of the
longitudinal spin relaxation time () over a wide range of temperatures,
which we attribute to phonon-induced decoherence. Our results apply to
ensembles of NV spins and do not depend on the optimal choice of a specific NV,
which could advance quantum sensing, enable squeezing and many-body
entanglement in solid-state spin ensembles, and open a path to simulating a
wide range of driven, interaction-dominated quantum many-body Hamiltonians
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