An illumination invariant face recognition system for access control using video

Illumination and pose invariance are the most challenging aspects of face recognition. In this paper we describe a fully automatic face recognition system that uses video information to achieve illumination and pose robustness. In the proposed method, highly nonlinear manifolds of face motion are approximated using three Gaussian pose clusters. Pose robustness is achieved by comparing the corresponding pose clusters and probabilistically combining the results to derive a measure of similarity between two manifolds. Illumination is normalized on a per-pose basis. Region-based gamma intensity correction is used to correct for coarse illumination changes, while further refinement is achieved by combining a learnt linear manifold of illumination variation with constraints on face pattern distribution, derived from video. Comparative experimental evaluation is presented and the proposed method is shown to greatly outperform state-of-the-art algorithms. Consistent recognition rates of 94-100% are achieved across dramatic changes in illumination.

Gender differences in emotionality and sociability in children with autism spectrum disorders

Background
Four times as many males are diagnosed with high functioning autism compared to females. A growing body of research that focused on females with autism spectrum disorder (ASD) questions the assumption of gender invariance in ASD. Clinical observations suggest that females with ASD superficially demonstrate better social and emotional skills than males with ASD, which may camouflage other diagnostic features. This may explain the under-diagnosis of females with ASD.

Methods
We hypothesised that females with ASD would display better social skills than males with ASD on a test of friendship and social function. One hundred and one 10- to 16-year-olds (ASD females, n = 25; typically developing (TD) females, n = 25; ASD males, n = 25; TD males, n = 26) were interviewed (using the friendship questionnaire (FQ)) with high scores indicating the child has close, empathetic and supportive relationships. One parent of each child completed the FQ to assess whether there are differences in perception of friendships between parents and children.

Results
It was found that, independent of diagnosis, females demonstrated higher scores on the FQ than males. Further, regardless of gender, children with ASD demonstrated lower scores than TD children. Moreover, the effect of ASD was independent of gender. Interestingly, females with ASD and TD males displayed similar scores on the FQ.

Conclusions
This finding is supported by clinical reports that females with ASD have more developed social skills than males with ASD. Further research is now required to examine the underlying causes for this phenomenon in order to develop gender-appropriate diagnostic criteria and interventions for ASD.

Measurement of stable changes of self-management skills after rehabilitation: a latent state-trait analysis of the Health Education Impact Questionnaire (heiQ™)

To assess stable effects of self-management programs, measurement instruments should primarily capture the attributes of interest, for example, the self-management skills of the measured persons. However, measurements of psychological constructs are always influenced by both aspects of the situation (states) and aspects of the person (traits). This study tests whether the Health Education Impact Questionnaire (heiQ™), an instrument assessing a wide range of proximal outcomes of self-management programs, is primarily influenced by person factors instead of situational factors. Furthermore, measurement invariance over time, changes in traits and predictors of change for each heiQ™ scale were examined.

Measurement of stable changes of self-management skills after rehabilitation: a latent state–trait analysis of the Health Education Impact Questionnaire (heiQ™)

Methods: Subjects were N = 580 patients with rheumatism, asthma, orthopedic conditions or inflammatory bowel disease, who filled out the heiQ™ at the beginning, the end of and 3 months after a disease-specific inpatient rehabilitation program in Germany. Structural equation modeling techniques were used to estimate latent trait-change models and test for measurement invariance in each heiQ™ scale. Coefficients of consistency, occasion specificity and reliability were computed.

Fuzzy measures of pixel cluster compactness

Pixel-scale fine details are often lost during image processing tasks such as image reduction and filtering. Block or region based algorithms typically rely on averaging functions to implement the required operation and traditional function choices struggle to preserve small, spatially cohesive clusters of pixels which may be corrupted by noise. This article proposes the construction of fuzzy measures of cluster compactness to account for the spatial organisation of pixels. We present two construction methods (minimum spannning trees and fuzzy measure decomposition) to generate measures with specific properties: monotonicity with respect to cluster size; invariance with respect to translation, reflection and rotation; and, discrimination between pixel sets of fixed cardinality with different spatial arrangements. We apply these measures within a non-monotonic mode-like averaging function used for image reduction and we show that this new function preserves pixel-scale structures better than existing monotonie averages.

A unified framework for thermal face recognition

The reduction of the cost of infrared (IR) cameras in recent years has made IR imaging a highly viable modality for face recognition in practice. A particularly attractive advantage of IR-based over conventional, visible spectrumbased face recognition stems from its invariance to visible illumination. In this paper we argue that the main limitation of previous work on face recognition using IR lies in its ad hoc approach to treating different nuisance factors which affect appearance, prohibiting a unified approach that is capable of handling concurrent changes in multiple (or indeed all) major extrinsic sources of variability, which is needed in practice. We describe the first approach that attempts to achieve this – the framework we propose achieves outstanding recognition performance in the presence of variable (i) pose, (ii) facial expression, (iii) physiological state, (iv) partial occlusion due to eye-wear, and (v) quasi-occlusion due to facial hair growth.

A Cross-Cultural Evaluation of the Personal Wellbeing Index – School Children in Samples of Australian and Portuguese Adolescents

The practice of comparing nations on subjective wellbeing (SWB) is becoming commonplace, with many countries ranked by economists and social scientists alike according to average levels of SWB based on survey responses. Such large, multi-national population surveys have the potential to generate insights into the causes and correlates of SWB within different cultural groups, as well as inform policy regarding how to improve the wellbeing of citizens. At the heart of these large-scale research endeavors are SWB measures that function equivalently between the various participating cultural groups. For this reason, it is concerning that their remains a paucity of research that supports measurement equivalence for many SWB instruments commonly employed. Thus, it remains unclear whether variations in SWB across cultures reflect true differences, or whether these differences reflect measurement biases (e.g., response bias inherent within a particular cultural group). The aim of this study was to examine the psychometric equivalence of the Personal Wellbeing Index–School Children (PWI-SC) in convenience samples of Australian and Portuguese adolescents using multiple-group confirmatory factor analysis. Participants comprising the Australian sample were 1104 Victorian high-school students aged between 12 and 19 years (M = 14.42, SD = 1.63). Participants comprising the Portuguese sample were 573 high-school students living in Portugal aged between 12 and 18 years (M = 14.32, SD = 1.72). The results demonstrated strict factorial invariance between both versions of the PWI-SC, suggesting that this scale measures the same underlying construct in both samples. Moreover, these findings provide preliminary support for quantitative comparisons between Australian and Portuguese adolescents on the SWB variable as valid.

The effect of recursive detrending on panel unit root tests

This paper analyzes the properties of panel unit root tests based on recursively detrended data. The analysis is conducted while allowing for a (potentially) non-linear trend function, which represents a more general consideration than the current state of affairs with (at most) a linear trend. A new test statistic is proposed whose asymptotic behavior under the unit root null hypothesis, and the simplifying assumptions of a polynomial trend and iid errors are shown to be surprisingly simple. Indeed, the test statistic is not only asymptotically independent of the true trend polynomial, but also is in fact unique in that it is independent also of the degree of the fitted polynomial. However, this invariance property does not carry over to the local alternative, under which it is shown that local power is a decreasing function of the trend degree. But while power does decrease, the rate of shrinking of the local alternative is generally constant in the trend degree, which goes against the common belief that the rate of shrinking should be decreasing in the trend degree. The above results are based on simplifying assumptions. To compensate for this lack of generality, a second, robust, test statistic is proposed, whose validity does not require that the trend function is a polynomial or that the errors are iid.

Internalization as a mediator of the relationship between conformity to masculine norms and body image attitudes and behaviors among young men in Sweden, US, UK, and Australia

We examined whether internalization of sociocultural body ideals mediated the relationship between conformity to masculine norms and drive for muscularity, leanness, and thinness in a sample of males from Sweden, US, UK, and Australia. Over six hundred young men [n=142 (Sweden); n=192 (US); n=141 (UK); n=160 (Australia)] completed an online survey that included assessments of masculine role norms, body image, and internalization of sociocultural body ideals. Path analyses confirmed internalization as a mediator between greater conformity to masculine norms and body image measures (drive for thinness, desire for leanness, and desire for muscularity) across the sample. However, significant cross-country differences in the strength of these mediation effects were found. Mediation effects among US, Australian, and Swedish males were comparable, whereas these effects were weaker in the UK sample. Findings confirmed the importance of internalization of sociocultural body ideals in the tested models.

Characterizing compactness of geometrical clusters using fuzzy measures

Certain tasks in image processing require the preservation of fine image details, while applying a broad operation to the image, such as image reduction, filtering, or smoothing. In such cases, the objects of interest are typically represented by small, spatially cohesive clusters of pixels which are to be preserved or removed, depending on the requirements. When images are corrupted by the noise or contain intensity variations generated by imaging sensors, identification of these clusters within the intensity space is problematic as they are corrupted by outliers. This paper presents a novel approach to accounting for spatial organization of the pixels and to measuring the compactness of pixel clusters based on the construction of fuzzy measures with specific properties: monotonicity with respect to the cluster size; invariance with respect to translation, reflection, and rotation; and discrimination between pixel sets of fixed cardinality with different spatial arrangements. We present construction methods based on Sugeno-type fuzzy measures, minimum spanning trees, and fuzzy measure decomposition. We demonstrate their application to generating fuzzy measures on real and artificial images.

Examining customer evaluations across different self-service technologies

Purpose – This study aims to examine the influence of different self-service technologies (SSTs) on customer satisfaction with and continued usage of SSTs. Specifically, it compares an interactive voice response (IVR) SST and an online SST from the same provider to assess how to manage these parallel SSTs.

Design/methodology/approach – A tracking study was used, beginning with a survey of n = 957 SST users to test a model pertaining to SST satisfaction across IVR and online SSTs. These SST users were then tracked over 12 months. The association between customer satisfaction with and continued usage of the SSTs was examined using behavioural data from the service provider.

Findings – While the overall model was found to be valid across both types of SSTs, perceptions of factors including ease of use, perceived control and reliability differed for IVR and online SSTs. Satisfaction with SSTs is linked with users’ continued use of SSTs, but is not a barrier to users’ adoption of newer SST forms.

Research limitations/implications – Highlighting the rapid developments in this field, a new SST was introduced by the provider to respondents during the 12-month tracking period, thus complicating the results. Further studies could include the customer purpose for using SSTs as a variable.

Practical implications – The findings offer support for organisations offering a suite of SSTs, even if they serve the same purpose. Customers evaluate SST types differently, and even satisfied SST users switch to different SSTs when they become available. Allowing customers to choose the SST that best suits them appears to be good practice.

Originality/value – This study develops a comprehensive model of customer SST satisfaction that is used to undertake a comparison of two different types of SSTs, which has been missing from prior research.