9,745 research outputs found

    Social differences in women's use of personal care products: A study of magazine advertisements, 1950 - 1994

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    This study examined advertising for women's personal care products from 1950 through 1994 in widely read, long-lived magazines whose audience have different demographic profiles: Ladies' Home Journal, Mademoiselle, and Essence

    Statistical Geometry in Quantum Mechanics

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    A statistical model M is a family of probability distributions, characterised by a set of continuous parameters known as the parameter space. This possesses natural geometrical properties induced by the embedding of the family of probability distributions into the Hilbert space H. By consideration of the square-root density function we can regard M as a submanifold of the unit sphere in H. Therefore, H embodies the `state space' of the probability distributions, and the geometry of M can be described in terms of the embedding of in H. The geometry in question is characterised by a natural Riemannian metric (the Fisher-Rao metric), thus allowing us to formulate the principles of classical statistical inference in a natural geometric setting. In particular, we focus attention on the variance lower bounds for statistical estimation, and establish generalisations of the classical Cramer-Rao and Bhattacharyya inequalities. The statistical model M is then specialised to the case of a submanifold of the state space of a quantum mechanical system. This is pursued by introducing a compatible complex structure on the underlying real Hilbert space, which allows the operations of ordinary quantum mechanics to be reinterpreted in the language of real Hilbert space geometry. The application of generalised variance bounds in the case of quantum statistical estimation leads to a set of higher order corrections to the Heisenberg uncertainty relations for canonically conjugate observables.Comment: 32 pages, LaTex file, Extended version to include quantum measurement theor

    Geometric Phase and Modulo Relations for Probability Amplitudes as Functions on Complex Parameter Spaces

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    We investigate general differential relations connecting the respective behavior s of the phase and modulo of probability amplitudes of the form \amp{\psi_f}{\psi}, where âˆŁÏˆf⟩\ket{\psi_f} is a fixed state in Hilbert space and âˆŁÏˆâŸ©\ket{\psi} is a section of a holomorphic line bundle over some complex parameter space. Amplitude functions on such bundles, while not strictly holomorphic, nevertheless satisfy generalized Cauchy-Riemann conditions involving the U(1) Berry-Simon connection on the parameter space. These conditions entail invertible relations between the gradients of the phase and modulo, therefore allowing for the reconstruction of the phase from the modulo (or vice-versa) and other conditions on the behavior of either polar component of the amplitude. As a special case, we consider amplitude functions valued on the space of pure states, the ray space R=CPn{\cal R} = {\mathbb C}P^n, where transition probabilities have a geometric interpretation in terms of geodesic distances as measured with the Fubini-Study metric. In conjunction with the generalized Cauchy-Riemann conditions, this geodesic interpretation leads to additional relations, in particular a novel connection between the modulus of the amplitude and the phase gradient, somewhat reminiscent of the WKB formula. Finally, a connection with geometric phases is established.Comment: 11 pages, 1 figure, revtex

    The Silver State and the Black Book

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    Sequence reproduction, single trial learning, and mimicry based on a mammalian-like distributed code for time

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    Animals learn tasks requiring a sequence of actions over time. Waiting a given time before taking an action is a simple example. Mimicry is a complex example, e.g. in humans, humming a brief tune you have just heard. Re-experiencing a sensory pattern mentally must involve reproducing a sequence of neural activities over time. In mammals, neurons in prefrontal cortex have time-dependent firing rates that vary smoothly and slowly in a stereotyped fashion. We show through modeling that a Many are Equal computation can use such slowly-varying activities to identify each timepoint in a sequence by the population pattern of activity at the timepoint. The MAE operation implemented here is facilitated by a common inhibitory conductivity due to a theta rhythm. Sequences of analog values of discrete events, exemplified by a brief tune having notes of different durations and intensities, can be learned in a single trial through STDP. An action sequence can be played back sped up, slowed down, or reversed by modulating the system that generates the slowly changing stereotyped activities. Synaptic adaptation and cellular post-hyperpolarization rebound contribute to robustness. An ability to mimic a sequence only seconds after observing it requires the STDP to be effective within seconds.Comment: 18 page

    Sport Fans and Online Data Collection: Challenges and Ethics

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    The growth of online communities and social networking has provided opportunities to investigate sport fans from a wide range of perspectives. Motivations to consume online media and engage in interactive web functions are areas providing new and innovative research opportunities. There are several ethical considerations when conducting research in an online environment. This article discusses four major ethical values of honesty, responsibility, justice, and beneficence and how each relates to online data collection. Specifically, these four values will guide the discussion focused on issues of intrusion, interaction, and invitation in online communication contexts. Researchers and administrators must consider fans and other stakeholders’ core moral and ethical values in the data collection process

    Hidden variable interpretation of spontaneous localization theory

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    The spontaneous localization theory of Ghirardi, Rimini, and Weber (GRW) is a theory in which wavepacket reduction is treated as a genuine physical process. Here it is shown that the mathematical formalism of GRW can be given an interpretation in terms of an evolving distribution of particles on configuration space similar to Bohmian mechanics (BM). The GRW wavefunction acts as a pilot wave for the set of particles. In addition, a continuous stream of noisy information concerning the precise whereabouts of the particles must be specified. Nonlinear filtering techniques are used to determine the dynamics of the distribution of particles conditional on this noisy information and consistency with the GRW wavefunction dynamics is demonstrated. Viewing this development as a hybrid BM-GRW theory, it is argued that, besides helping to clarify the relationship between the GRW theory and BM, its merits make it worth considering in its own right.Comment: 13 page

    Gameday Food and Beverage: The Perspective of College Football Fans

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    This study examines sport spectators’ food and beverage experience through the lens of service quality, targets of quality, and standards of quality in sport-based services. Both qualitative and quantitative data were collected from 1,495 adults attending at least one American college football game. Thematic analysis produced five themes of price, variety, quality, service, and amenities while comparison analysis found several demographic differences. Findings reveal food and beverage to be critical in overall experience at sporting events. The overwhelming majority of comments were negative and findings provide feedback as to how important this aspect of the game experience is

    James Robert Lotz (1929–2015)

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