4,115 research outputs found

    Visual attention during brand choice: an eye-fixation analysis.

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    Measures derived from eye-movement data reveal that during brand choice consumers adapt to time pressure by accelerating information, by filtering information and by changing their information acquisation strategy. In addition, consumers with high task motivation filter brand information less and pictorial information more. Consumers under time pressure filter textual ingredients information more, and pictoral information less. The results of multi-level logistic regression analysis reveal that the chosen brand is involved in significantly more intra-brand and inter-brand saccades than non-chosen brands, independent of time pressure and task motivation conditions. Implications for the theory of consumer attention and for pretesting of packaging ans shelf lay-outs are offered.

    Non-parametric linear time-invariant system identification by discrete wavelet transforms

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    We describe the use of the discrete wavelet transform (DWT) for non-parametric linear time-invariant system identification. Identification is achieved by using a test excitation to the system under test (SUT) that also acts as the analyzing function for the DWT of the SUT's output, so as to recover the impulse response. The method uses as excitation any signal that gives an orthogonal inner product in the DWT at some step size (that cannot be 1). We favor wavelet scaling coefficients as excitations, with a step size of 2. However, the system impulse or frequency response can then only be estimated at half the available number of points of the sampled output sequence, introducing a multirate problem that means we have to 'oversample' the SUT output. The method has several advantages over existing techniques, e.g., it uses a simple, easy to generate excitation, and avoids the singularity problems and the (unbounded) accumulation of round-off errors that can occur with standard techniques. In extensive simulations, identification of a variety of finite and infinite impulse response systems is shown to be considerably better than with conventional system identification methods.Department of Computin

    The influence of advertisement familiarity and originality on visual attention and brand memory.

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    Based on Mandler's theory of schema organization and previous visual attention research, we formulate and test hypotheses about the impact of ad familiarity and ad originality on attention and memory for print advertisements. To that end, one hundred and nineteen consumers browsed through two consumer magazines containing 68 print advertisements. Attention to the ads and their brand, picture and text components was assessed through infrared eye tracking. Trained judges rated the ads independently for familiarity and originality. In support of the hypotheses we find a sharp attention decline with ad familiarity, which is largely due to a reduction in attention to text. Originality of ad execution serves as a buffer against the negative influence of ad familiarity on attention, but only for the brand and picture components. The reduction of attention to the text is even larger for original than for unoriginal ads. Moreover, over and above their indirect influence through visual attention patterns, ad familiarity, ad originality and their interaction had a direct influence on brand memory.Advertising;

    Preference in the harried eye of the beholder: the effect of time pressure and task motivation.

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    We report a study in which eye tracking data were gathered to examine the impact of time-pressure and task motivation on the flow of visual attention during choice processing from a naturalistic stimulus-based product display. We find patterns of adaptation of visual attention to time pressure in terms of acceleration, filtration, and strategy shift that have not been reported previously. In addition we find, regardless of condition, strong correlation's between visual attention to the brands in the choice set and preference for the brands. Results are discussed in terms of strategic and non-strategic information acquisition during stimulus-based choice, and implications for attention theory are offered.

    Measurement Method for Evaluating the Probability Distribution of the Quality Factor of Mode-Stirred Reverberation Chambers

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    An original experimental method for determining the empirical probability distribution function (PDF) of the quality factor (Q) of a mode-stirred reverberation chamber is presented. Spectral averaging of S-parameters across a relatively narrow frequency interval at a single pair of locations for the transmitting and receiving antennas is applied to estimate the stored and dissipated energy in the cavity, avoiding the need for spatial scanning to obtain spatial volume or surface averages. The effective number of simultaneously excited cavity modes per stir state, M, can be estimated by fitting the empirical distribution to the parametrized theoretical distribution. The measured results support a previously developed theoretical model for the PDF of Q and show that spectral averaging over a bandwidth as small as a few hundred kHz is sufficient to obtain accurate results.Comment: submitted for publicatio

    Increasing external effects negate local efforts to control ozone air pollution: a case study of Hong Kong and implications for other Chinese cities.

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    It is challenging to reduce ground-level ozone (O3) pollution at a given locale, due in part to the contributions of both local and distant sources. We present direct evidence that the increasing regional effects have negated local control efforts for O3 pollution in Hong Kong over the past decade, by analyzing the daily maximum 8 h average O3 and Ox (=O3+NO2) concentrations observed during the high O3 season (September-November) at Air Quality Monitoring Stations. The locally produced Ox showed a statistically significant decreasing trend over 2002-2013 in Hong Kong. Analysis by an observation-based model confirms this decline in in situ Ox production, which is attributable to a reduction in aromatic hydrocarbons. However, the regional background Ox transported into Hong Kong has increased more significantly during the same period, reflecting contributions from southern/eastern China. The combined result is a rise in O3 and a nondecrease in Ox. This study highlights the urgent need for close cross-boundary cooperation to mitigate the O3 problem in Hong Kong. China's air pollution control policy applies primarily to its large cities, with little attention to developing areas elsewhere. The experience of Hong Kong suggests that this control policy does not effectively address secondary pollution, and that a coordinated multiregional program is required

    Inhibition of the multidrug resistance P-glycoprotein: Time for a change of strategy?

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    P-glycoprotein (P-gp) is a key player in the multidrug-resistant phenotype in cancer. The protein confers resistance by mediating the ATP-dependent efflux of an astonishing array of anticancer drugs. Its broad specificity has been the subject of numerous attempts to inhibit the protein and restore the efficacy of anticancer drugs. The general strategy has been to develop compounds that either compete with anticancer drugs for transport or act as direct inhibitors of P-gp. Despite considerable in vitro success, there are no compounds currently available to "block" P-gp-mediated resistance in the clinic. The failure may be attributed to toxicity, adverse drug interaction, and numerous pharmacokinetic issues. This review provides a description of several alternative approaches to overcome the activity of P-gp in drug-resistant cells. These include 1) drugs that specifically target resistant cells, 2) novel nanotechnologies to provide high-dose, targeted delivery of anticancer drugs, 3) compounds that interfere with nongenomic transfer of resistance, and 4) approaches to reduce the expression of P-gp within tumors. Such approaches have been developed through the pursuit of greater understanding of resistance mediators such as P-gp, and they show considerable potential for further application. Copyright Ā© 2014 by The American Society for Pharmacology and Experimental Therapeutics
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