Applying Q-Methodology to Investigate People’ Preferences for Multivariate Stimuli

This article serves as a step-by-step guide of a new application of Q-methodology to investigate people’s preferences for multivariate stimuli. Q-methodology has been widely applied in fields such as sociology, education and political sciences but, despite its numerous advantages, it has not yet gained much attention from experimental psychologists. This may be due to the fact that psychologists examining preferences, often adopt stimuli resulting from a combination of characteristics from multiple variables, and in repeated measure designs. At present, Q methodology has not been adapted to accommodate. We therefore developed a novel analysis procedure allowing Q-methodology to handle these conditions. We propose a protocol requiring five analyses of a decision process to estimate: (1) the preference of stimuli, (2) the dominance of variables, (3) the individual differences, (4) the interaction between individual differences and preference, and (5) the interaction between individual differences and dominance. The guide comes with a script developed in R (R Core Team, 2020) to run the five analyses; furthermore, we provide a case study with a detailed description of the procedure and corresponding results. This guide is particularly beneficial to conduct and analyze experiments in any research on people’s preferences, such as experimental aesthetics, prototype testing, visual perception (e.g., judgments of similarity/dissimilarity to a model), etc

Nonverbal communication in selfies posted on Instagram: Another look at the effect of gender on vertical camera angle

Background Selfies are a novel social phenomenon that is gradually beginning to receive attention within the cognitive sciences. Several studies have documented biases that may be related to nonverbal communicative intentions. For instance, in selfies posted on the dating platform Tinder males but not females prefer camera views from below (Sedgewick, Flath & Elias, 2017). We re-examined this study to assess whether this bias is confined to dating selection contexts and to compare variability between individuals and between genders. Methods Three raters evaluated vertical camera position in 2000 selfies– 1000 by males and 1000 by females—posted in Instagram. Results We found that the choices of camera angle do seem to vary depending on the context under which the selfies were uploaded. On Tinder, females appear more likely to choose neutral, frontal presentations than they do on Instagram, whereas males on Tinder appear more likely to opt for camera angles from below than on Instagram. Conclusions This result confirms that the composition of selfies is constrained by factors affecting nonverbal communicative intentions

Low-complexity bound on irregular LDPC belief-propagation decoding thresholds using a Gaussian approximation

Since irregular low-density parity-check (LDPC) codes are known to perform better than regular ones, and to exhibit, like them, the so-called \u2018threshold phenomenon\u2019, this Letter investigates a low-complexity upper bound on belief-propagation decoding thresholds for this class of codes on memoryless binary input additive white Gaussian noise channels, with sum-product decoding. A simplified analysis of the belief-propagation decoding algorithm is used, i.e. consider a Gaussian approximation for message densities under density evolution, and a simple algorithmic method, defined recently, to estimate the decoding thresholds for regular and irregular LDPC codes

Effect of pretreatment with immune serum on murine sarcoma virus (Moloney) tumour induction and growth.

Regressor serum from MSV-M-infected mice markedly reduced MSV-M oncogenesis when administered i.p. (0-1 ml/mouse) as much as 30 days before i.m. MSV-M infection in adult BALB/c mice. The regressor serum activity appeared to be directly dependent on the amount of IgG, as shown by: (1) inactivity of sera which have low virus-neutralizing antibody content; (2) high effectiveness only of the IgG serum fraction; (3) inactivity of regressor serum incubated with anti-mouse gamma-globulin serum. The regressor serum activity was specific and could not be ascribed to interferon or interferon-inducing factors, antigen-antibody complexes or free antigen. The activity was not suppressed by sublethal irradiation (380 rad) of recipient mice. These results suggest that the activity of regressor serum administered before MSV-M infection is mediated through sensitization of host cells which are not radiosensitive

A new accurate approximation of the Gaussian Q-function with relative error less than 1 thousandth in a significant domain

The approximations of the Gaussian Q-function found in the literature have been often developed with the goal of obtaining high estimation accuracies in deriving the error probability for digital modulation schemes. Unfortunately, the obtained mathematical expressions are often too complex, even difficultly tractable. A new approximation for the Gaussian Q-function is presented in the form of the standard normal density multiplied by a rational function. The rational function is simply a linear combination of the first 5 integer negative powers of the same term, linear in x, using only 4 decimal constants. In this paper we make some considerations about the significant interval where to consider the Q-function in telecommunication theory. The relative error in absolute value of the given approximation is less than 0.06% in the considered significant interval

Performance Study of a Class of Irregular Near Capacity Achieving LDPC Codes

This paper investigates the performance of a class of irregular low-density parity-check (LDPC) codes through a recently published low complexity upper bound on their beliefpropagation decoding thresholds. Moreover, their performance analysis is carried out through a recently published algorithmic method, presented in Babich et al. 2017 paper. In particular, the class considered is characterized by variable node degree distributions λ(x) of minimum degree i1 > 2: being, in this case, λ0(0) = λ2 = 0, this is useful to design LDPC codes presenting a linear minimum distance growth with the block length with probability 1, as shown in Di et al.'s 2006 paper. These codes unfortunately cannot reach capacity under iterative decoding, since the achievement of capacity requires λ2 ≠ 0. However, in this latter case, the block error probability might converge to a constant, as shown in the aforementioned paper

Simultaneous color contrast

The Encyclopedia of Color Science and Technology provides an authoritative single source for understanding and applying the concepts of color to all fields of science and technology, including artistic and historical aspects of color. Many topics are discussed in this timely reference, including an introduction to the science of color, and entries on the physics, chemistry and perception of color. Color is described as it relates to optical phenomena of color and continues on through colorants and materials used to modulate color and also to human vision of color. The measurement of color is provided as is colorimetry, color spaces, color difference metrics, color appearance models, color order systems and cognitive color. Other topics discussed include industrial color, color imaging, capturing color, displaying color and printing color. Descriptions of color encodings, color management, processing color and applications relating to color synthesis for computer graphics are included in this work. The Encyclopedia also delves into color as it applies to other domains such as art and design – ie – color design, color harmony, color palettes, color and accessibility, researching color deficiency, and color and data visualization. There is also information on color in art conservation, color and architecture, color and educations, color and culture, and an overview of the history of color and comments on the future of color. This unique work will extend the influence of color to a much wider audience than has been possible to date

Remote sensing for optimal estimation of water temperature dynamics in shallow tidal environments

Given the increasing anthropogenic pressures on lagoons, estuaries, and lakes and considering the highly dynamic behavior of these systems, methods for the continuous and spatially distributed retrieval of water quality are becoming vital for their correct monitoring and management. Water temperature is certainly one of the most important drivers that influence the overall state of coastal systems. Traditionally, lake, estuarine, and lagoon temperatures are observed through point measurements carried out during field campaigns or through a network of sensors. However, sporadic measuring campaigns or probe networks rarely attain a density sufficient for process understanding, model development/validation, or integrated assessment. Here, we develop and apply an integrated approach for water temperature monitoring in a shallow lagoon which incorporates satellite and in-situ data into a mathematical model. Specifically, we use remote sensing information to constrain large-scale patterns of water temperature and high-frequency in situ observations to provide proper time constraints. A coupled hydrodynamic circulation-heat transport model is then used to propagate the state of the system forward in time between subsequent remote sensing observations. Exploiting the satellite data high spatial resolution and the in situ measurements high temporal resolution, the model may act a physical interpolator filling the gap intrinsically characterizing the two monitoring techniques