Cultural influences on perception of disability and disabled people: A comparison of opinions from students in the United Kingdom (UK) Pakistan (PAK) about a generic wheelchair using a semantic differential scale

Assistive Technology (AT) product use occurs within a socio-cultural setting. The growth internationally in the AT product market suggests that designers need to be aware of the influences that diverse cultures may have on the societal perception of an AT product through its semantic attributes. The study aimed to evaluate the visual interaction with an AT product by young adults from Pakistan, a collectivist society, and the United Kingdom (UK), an individualist society. A paper-based questionnaire survey was carried out with 281 first-year undergraduate students from the UK and Pakistan to evaluate their perception towards the visual representation of a generic conventional wheelchair image. A semantics differential (SD) scale method was used involving a seven-point bipolar SD scale incorporating sixteen pairs of adjectives defining functional, meaning, and usability attributes of the product. The mean (M) and standard deviation (sd) values were obtained for each pair of adjectives and compared between both groups by employing appropriate parametric tests. The results show that having a diverse cultural background did not appear to have overtly influenced the meanings ascribed to the generic manual wheelchair, which was unexpected. The University ‘Internationalist’ environment may have influenced the results. Some minor but critical differences were found for some pairs of adjectives (bulky-compact, heavy-light), having p-value less than 0.05 (p<0.05) that related to previous experience of wheelchairs and/or their use. Further studies are planned to investigate and validate outcomes with other student and non-student groups

Visual Memory of Fragmented Scenes - Role of Detail and Extrapolation

Každý den jsme vystaveni velkému množství vizuálních podnětů (scén). Není však stále jasné, jak dobře jsou tyto scény v paměti uloženy a pamatovány a jaká je role detailu vzhledem k paměti celého obrazu. Konkrétně, do jaké míry jsou pamatovány detaily a do jaké míry extrapolujeme z neviděného obsahu z prezentovaných částí. K prozkoumání této otázky jsme využili fragmentovaných scén (rozčleněných na 4x4 dílků), které se skládaly ze tří různých kategorií (vnitřní, vnější-přírodní a vnější-umělé) s různým počtem prezentovaných dílků (3, 5 a 8). Zajímá nás, jestli je nějaký vztah mezi počtem prezentovaných dílků a schopností rozpoznat, které dílky byly prezentované a které ne (přestože byly ze stejné fotografie). V analýze jsme se soustředili na charakteristiky SDT (signal detection theory), především na citlivost paměti (d') a bias. Byly provedeny dva experimenty a u obou byly zjištěny největší hodnoty správnosti v odpovědích u 3 zobrazených dílků (Exp.1: d'(n3) = 0,67; Exp.2: d'(n3) = 0,66), u kterých převažovala tendence biasu k záporným odpovědím (Exp.1: c(n3) = 0,27; Exp.2: c(n3) = 0,16). U počtu 5 a 8 dílků se správnost odpovědí snížila (Exp.1: d'(n5) = 0,35; d'(n8) = 0,34; Exp.2: d'(n5) = 0,39; d'(n8) = 0,41) a zároveň se bias přiklonil ke kladným odpovědím (Exp.1: c(n5) = -0,11, c(n8) = -0,34;...Every day we are exposed to huge amounts of visual stimuli (scenes). However, i tis not yet clear how accurately these scenes are stored and remembered, and what is the role of detail relative to the memory for the whole image. More specifically, to what extent the details are remembered and to what extent we extrapolate the unseen content from the presented details. We used fragmented scenes (broken to 4x4 grids) to investigate this question. Fragmented scenes were composed of three different theme categories (indoor, natural, man-made), each with different number of presented patches (3, 5 and 8). Our main research question is, whether there is any relationship between the number of presented patches and the ability to recognize which patches were presented and which were not (but still patches from the same photograph). In analysis we focus on Signal Detection Theory characteristics, mainly memory sensitivity (d') and bias. We run two experiments and in both the highest scores for (d') were for 3 patches (Exp.1: d'(n3) = 0,67; Exp.2: d'(n3) = 0,66) with bias towards negative answers (Exp.1: c(n3) = 0,27; Exp.2: c(n3) = 0,16). For 5 and 8 patches the (d') was lower (Exp.1: d'(n5) = 0,35; d'(n8) = 0,34; Exp.2: d'(n5) = 0,39; d'(n8) = 0,41) and in the same time bias was towards positive answers...Katedra psychologieDepartment of PsychologyFaculty of ArtsFilozofická fakult

Subset selection using nonlinear optimization

A common problem in computer science is how to represent a large dataset in a smaller more compact form. This thesis describes a generalized framework for selecting canonical subsets of data points that are highly representative of the original larger dataset. The contributions of the work are formulation of the subset selection problem as an optimization problem, an analysis of the complexity of the problem, the development of approximation algorithms to compute canonical subsets, and a demonstration of the utility of the algorithms in several problem domains.Ph.D., Computer Science -- Drexel University, 200