Effects of gender differences on the subjective perceived intensity of steering wheel rotational vibration based on a multivariate regression model

This is the post-print version of the Article. The official published version can be accessed from the link below - Copyright @ 2009 ElsevierThe aims of this study were to determine equal sensation curves for hand-arm steering wheel rotational vibration and to investigate the effect of gender on the subjective perceived intensity of steering wheel hand-arm vibration. Psychophysical response tests of 40 participants (20 mates and 20 females) were performed using a steering wheel rotational vibration simulator using the category-ratio Borg CR10 scale procedure for direct estimation of perceived intensity. The test stimuli were sinusoidal vibrations at 22 third octave band centre frequencies in the range from 3 to 400 Hz, with acceleration amplitudes in the range from 0.04 to 27 m/s(2) r.m.s. Multivariate regression procedures were applied to the experimentally acquired data in order to establish a regression model expressing the Borg CR10 perceived intensity values as a function of the two independent parameters of the frequency and amplitude of vibration. The equal sensation curves suggested a non-linear dependency of the subjective perceived intensity on both frequency and amplitude. Females were found to provide higher Borg CR10 perceived intensity values than males (p < 0.05), particularly at the higher intensity levels above approximately 1.0 m/s(2) r.m.s and at the higher frequencies above approximately 20 Hz.Relevance to industry: For the manufacturers of steering systems and of other automobile components this study provides vibration perception curves and identifies the possible importance of gender towards the perception of vibration which arrives at the steering wheel. (C) 2009 Elsevier B.V. All rights reserved

Effect of fuel content on the human perception of engine idle irregularity

This thesis describes a digital signal processing analysis of diesel engine idle vibration in automobiles, and an analysis of the human subjective response to the idle vibration which occurs at the steering wheel. In order to quantify the variations in the diesel idle vibration that can be introduced by the engine technology, the vehicle, and the fuel type, a set of acceleration time histories were measured at the engine block and at the steering wheel for two automobiles equipped with 4-cylinder engines which had different injection systems and which operated under different fuel conditions. A combination of time domain, frequency domain and time-frequency wavelet-based analysis were used. Both the continuous wavelet transform and the discrete orthogonal wavelet transform were applied to the steering wheel acceleration time histories in order to analyse the statistical variation in terms of both instantaneous variations, and the cycle-to-cycle variations which occur across complete thermodynamic engine cycles. The combination of orthogonal wavelet transform and time-varying auto-covariance analysis, performed across a complete engine thermodynamic cycle, was identified as the most sensitive method for describing the statistical variation in diesel idle vibration. The second-order engine harmonic H2 was found to account for most of the vibrational energy at the steering wheel when at idle. Amplitude modulation of the second-order engine harmonic H2 by the half-order engine harmonic H112 has been identified as the main characteristic of the steering wheel signature of automobiles at idle. The steering wheel idle vibration produced by different engines and different fuel conditions have therefore been described in terms of the amplitude modulation depth "mil that characterises the idle waveform. Four psychophysical response tests, determined by the combination of two test protocols and two semantic descriptors, were performed. A model of the growth in the human subjective response to diesel idle vibration has been proposed in which the response scale is a function of the modulation depth parameter "mil. The model is defined over two regions of modulation depth. For values of "m" less than 0.2, humans have been found to be unable to distinguish variations in idle modulation. For values of "m" greater than 0.2, the human response grows as a power function with respect to modulation depth. Based on the current findings, suggestions for future research are also provided

Understanding meaningfulness in AI-infused artefacts

Creating meaningful artefacts translates into creating meaningful experiences for the consumers going beyond the artefact’s functional features to reach people intrinsic motivation and their symbolic values. This process would require acquiring an understanding of how people come to understand in their own terms and for their own reasons the meaning attached to the designed artefacts. Despite the advances on the market of AI-infused products, the sophistication of modern tech-nologies of these designed artefacts and the complexity of modern social behaviors would make simplistic to continue to consider the user experience (UX) mostly characterized by the performance of its users or in terms of interaction quality. Relatively little empirical work has instead focused on understanding why designed artefacts are seen as salient choice criteria, that is, understanding the reason why do consumers perceive AI-infused artefacts to be personally relevant for their needs. The understanding of the concept of meaningful-ness discussed in this chapter suggests that the consideration of target values and meanings is important as a strategy towards defining the relational role of AI-infused artefacts in the lives of their owners for which artefacts are not simply functional tools, but are also relational mediators which shape the long term aims, objectives and behaviors of an individual or of a group. The research presented in this chapter aims to set the basic considerations regarding the term “meaning” used by commercially active designers and introduces the concept of “meaningfication” for the purpose of designing AI-infused artefacts based on new meanings

Meaning of artefacts

Previous research has suggested three primary categories of meaning which designers should consider during their design processes, i.e. function, ritual and myth, which cover a spectrum from the purely instrumental to the purely symbolic. The research hypothesis of the current study was that the previously identified three primary categories of meaning would be commonly encountered in practice, and that statistically significant differences would occur between designers and consumers. A semi-structured questionnaire was deployed with ten designers and with ten consumers using a set of twenty photographs of designed artefacts. The results suggested that all three categories of meaning could occur individually or could be co-present to some degree. The results further suggested that statistically significant differences occurred between the group of designers and the group of consumers in the indicated category of meaning and in the adjectives used to describe the artefacts. The findings suggest that some meaning divergences may be occurring between designers and consumers, and would appear to highlight the need for carefully executed ethnographic and user testing activities.</jats:p

Meaning of artefacts: interpretations can differ between designers and consumers

Previous research has suggested three primary categories of meaning which designers should consider during their design processes, i.e. function, ritual and myth, which cover a spectrum from the purely instrumental to the purely symbolic. The research hypothesis of the current study was that the previously identified three primary categories of meaning would be commonly encountered in practice, and that statistically significant differences would occur between designers and consumers. A semi-structured questionnaire was deployed with ten designers and with ten consumers using a set of twenty photographs of designed artefacts. The results suggested that all three categories of meaning could occur individually or could be co-present to some degree. The results further suggested that statistically significant differences occurred between the group of designers and the group of consumers in the indicated category of meaning and in the adjectives used to describe the artefacts. The findings suggest that some meaning divergences may be occurring between designers and consumers, and would appear to highlight the need for carefully executed ethnographic and user testing activities

Emotional Engagement in Mobile Multi-Tasking Activities: A Human Factors Review

Mobile devices are ever increasingly being used in multi-tasking situations, although the design for these multi-tasking scenarios has taken a backwards with the rapid uptake of the touchscreen. The neglected dimension of tactility is becoming very important for mobile device designers. The investigation explores how tactility within mobile devices can be used to enhance multi-tasking. An exploration of the potential for tactility within mobile devices looked at how tactile interfaces can be used to communicate information. The ideas covered were then summarized in a design project of an electronic purse

Behaviours

In a world that is ageing fast technology can really make a difference to keep people independent, healthy and socially connected. While the physical and sensorial signs of ageing have to some extent been considered in the design of technology for older people, much work is still needed to understand the impact of cognitive and emotional changes in the adoption, deferral or rejection of technology devices. Understanding the behavioural strategies of older people when dealing with technology-based products can help designers as well as marketers to reconsider product attributes and market communication, respectively. A set of smart computational materials suggests novel application opportunities for the design of more immediate and intuitive technology products