DEPTH PERCEPTION IN DRIVING SIMULATORS : Observer-produced motion parallax, how it affects car drivers’ position and perceived presence

Driving simulators of today are lacking the full third visual dimension. This makes comparing driving simulators with driving in real life problematic. Thus it is important to improve the simulators' validity. The present study investigated whether the depth cue observer-produced motion parallax (Obs-PMP) affects drivers’ performance and perception of presence. Twenty-two participants (11 males and 11 females) drove in a driving simulator with and without Obs-PMP. An experiment with two scenarios was conducted, in which one scenario took place in an urban environment and one in a rural environment. Distance estimation, judgments of speed and perceived virtual presence was investigated. An effect of Obs-PMP on lateral positioning of the car just before an overtaking and of scenario on head movement was found. This suggests that Obs-PMP affects driver’s performance in driving simulators and motivates further research on the area, e.g. comparing simulators with real life scenarios.Körsimulatorer idag saknar en tredje visuell dimension. Detta gör att jämförelser av körsimulatorer med körning i verkliga livet blir problematiskt. Därför är det viktigt att förbättra simulatorernas validitet. Denna studie undersökte huruvida införandet av observatör-producerat rörelse parallax (Obs-PMP) påverkar förarnas prestationer och perception av viruell närvaro. Tjugotvå deltagare (11 män och 11 kvinnor) körde i en körsimulator med och utan Obs-PMP. Ett experiment med två scenarier genomfördes, ett scenario ägde rum i en urban miljö och ett annat på en landsväg. Avstånds- och hastighetsuppfattning samt upplevd virtuell närvaro undersöktes. En effekt av obs-PMP på lateral placering av bilen precis innan en omkörning samt av scenario på huvudrörelser hittades. Detta tyder på att obs-PMP påverkar förarens prestationsförmåga i körsimulatorer och motiverar ytterligare utredning och forskning för att bland annat jämföra simulatorer med verkliga scenarier

Tid för att Planera : Att stödja vardagsplanering hos ungdomar med intellektuell funktionsnedsättning

Children and adolescents with intellectual disability (ID) have difficulties in executive functioning and when coping with everyday planning tasks. However, the literature cannot explain whether individuals with ID perform according to their developmental level or not. The studies in this thesis investigated if life experience could be a contributing factor to the diversity seen in the literature. Planning performance can be improved by either using external or internal support. Assistive technology for cognition (ATC) is an example of external support. This thesis investigated how the ATC is being used in an everyday planning situation which has not been investigated before. Furthermore, this thesis explored whether the internal supports of cognitive abilities and life experience correlate with planning ability in adolescents with ID, and if planning ability can be trained using a cognitive training program for everyday planning. Results showed that ATC supported cognitive functions, but that the children did not formulate the plans themselves. Furthermore, the results support the difference model of ID since planning correlated with different cognitive measures and life experience in adolescents with ID compared to children with a typical development. Adolescents with ID got better at the planning tasks in the training program, however, no transfer effects to untrained planning tasks were found. To conclude, the planning was supported by external and internal support. However, ATC needs to be designed and prescribed in a way that increases independence. Practitioners should actively support in training planning and should be cautious when introducing cognitive interventions if the transfer gap is too large.  Barn och ungdomar med intellektuell funktionsnedsättning (IF) har svårt med sina exekutiva funktioner och dagliga planeringsuppgifter. Litteraturen kan dock inte förklara om individer med IF presterar enligt deras utvecklingsnivå eller inte. Studierna i denna avhandling undersökte om livserfarenhet kan vara en bidragande faktor till varför denna skillnad ses i litteraturen. Planeringsförmågan kan förbättras genom att använda externt eller internt stöd. Hjälpteknik för kognition (HM-K) är ett exempel på externt stöd. Denna avhandling undersökte hur HM-K används i en vardaglig planeringssituation vilket inte har undersökts tidigare. Vidare undersökte denna avhandling om de interna stöden för kognitiva förmågor och livserfarenhet korrelerar med planeringsförmåga hos ungdomar med IF, och om planeringsförmåga kan förbättras med hjälp av ett kognitivt träningsprogram för vardagsplanering. Resultaten visade att HM-K stödde kognitiva funktioner, men att barnen inte formulerade planerna själva. Vidare stöder resultaten skillnadsmodellen för IF eftersom planering korrelerade med olika kognitiva mått och livserfarenhet hos ungdomar med IF jämfört med barn med en typisk utveckling. Ungdomar med IF blev bättre på planeringsuppgifterna i träningsprogrammet, men inga överföringseffekter till otränade planeringsuppgifter hittades. Avslutningsvis så stöds planeringen av externa och interna stöd. HM-K måste dock utformas och förskrivas på ett sätt som ökar självständighet. Praktiker bör aktivt stödja träning av planering och bör vara försiktiga när de inför kognitiva insatser om överföringsgapet är för stort

Executive functions and Planning in everyday life : Assistive Technologies for Cognition and their lack of support for children with Attention Deficit / Hyperactive Disorder

The evaluation of how Assistive Technologies for Cognition (ATC) serve their purpose in providing support for children with Attention Deficit/Hyperactive Disorder (AD/HD) is limited and it is not clear how to best support the cognitive functions in order to help the individual increase task performance in everyday life. This thesis sought to scrutinise how families with at least one child diagnosed with AD/HD incorporate ATCs in their daily life in order to cope with appurtenant difficulties. An online survey, answered by 92 caregivers for children with AD/HD, attended to the cognitive abilities in need of support, the usage of ATCs, and how ATCs supported the executive functions in everyday planning. The results reveal that children encounter difficulty in dealing with cognitive ability, executive functioning and causal inference when it comes to planning in everyday life situations, which relates to lower levels of independence. Executive functioning and causal inference is negatively correlated to number of symptoms of AD/HD. The ATC is not satisfactorily supporting the cognitive functions, which results in another person by default being the one who sets up the ATC, and the child merely follows the instruction. The results has been processed into a table containing concepts which is suggested to be considered both when developing, as well as evaluating, ATCs for children with AD/HD.

DEPTH PERCEPTION IN DRIVING SIMULATORS : Observer-produced motion parallax, how it affects car drivers’ position and perceived presence

Driving simulators of today are lacking the full third visual dimension. This makes comparing driving simulators with driving in real life problematic. Thus it is important to improve the simulators' validity. The present study investigated whether the depth cue observer-produced motion parallax (Obs-PMP) affects drivers’ performance and perception of presence. Twenty-two participants (11 males and 11 females) drove in a driving simulator with and without Obs-PMP. An experiment with two scenarios was conducted, in which one scenario took place in an urban environment and one in a rural environment. Distance estimation, judgments of speed and perceived virtual presence was investigated. An effect of Obs-PMP on lateral positioning of the car just before an overtaking and of scenario on head movement was found. This suggests that Obs-PMP affects driver’s performance in driving simulators and motivates further research on the area, e.g. comparing simulators with real life scenarios.Körsimulatorer idag saknar en tredje visuell dimension. Detta gör att jämförelser av körsimulatorer med körning i verkliga livet blir problematiskt. Därför är det viktigt att förbättra simulatorernas validitet. Denna studie undersökte huruvida införandet av observatör-producerat rörelse parallax (Obs-PMP) påverkar förarnas prestationer och perception av viruell närvaro. Tjugotvå deltagare (11 män och 11 kvinnor) körde i en körsimulator med och utan Obs-PMP. Ett experiment med två scenarier genomfördes, ett scenario ägde rum i en urban miljö och ett annat på en landsväg. Avstånds- och hastighetsuppfattning samt upplevd virtuell närvaro undersöktes. En effekt av obs-PMP på lateral placering av bilen precis innan en omkörning samt av scenario på huvudrörelser hittades. Detta tyder på att obs-PMP påverkar förarens prestationsförmåga i körsimulatorer och motiverar ytterligare utredning och forskning för att bland annat jämföra simulatorer med verkliga scenarier

Interactions between polymeric dispersants and colloidal ceramic surfaces

Increased use of environmentally acceptable chemicals and reduced energy consumption are two foreseeable demands within the ceramics industry. This will require the replacement of organic solvents and lowering of sintering temperatures. To meet these demands, new dispersants will be needed for colloidal processing of highly sinterable ceramic nanopowders. When selecting new dispersants, it is essential to understand the relations between molecular structures and adsorption properties of present dispersants. A deeper understanding of the properties of adsorbed layers, such as viscoelasticity, is also necessary to design dispersants for improved fluid properties and consolidation behavior of highly concentrated systems. The present work has been devoted to increasing the knowledge in this area. Interactions between polymeric dispersants and ceramic surfaces have been studied with a combination of surface characterization techniques (quartz crystal microbalance with dissipation (QCM-D), atomic force microscopy (AFM) and zeta potential) and rheological evaluations. More specifically, the efficiency of polyelectrolyte type dispersants represented by a poly(acrylic acid) and a lignosulphonate were compared to that of graft copolymers with nonionic chains of different molecular weights. A novel approach of this research work has been to use hydrophilic block and graft copolymers in aqueous systems and in mixtures of water and alcohols. The water content of adsorbed dispersant layers was determined by combining mass adsorption data from QCM-D measurements with mass optimization by viscosity measurements of alumina suspensions. Water was found to constitute up to 90% of the total adsorbed layer of a comb copolymer with long polyoxyethylene chains. Viscoelastic modeling also showed that these layers were viscous and thick, about 6 nm. It was also found that plastic behavior of wet consolidated bodies was obtained when a block copolymer with shorter polyoxyethylene chains was used, probably due to a lubrication effect from bound water. In contrast to this, both polyelectrolytes adsorbed in thin, highly rigid layers with relatively low water content, about 30%. Brittle behavior of wet bodies stabilized by poly(acrylic acid) indicated lack of lubrication effect with the polyelectrolyte dispersant. AFM showed that both polyelectrolytes gave efficient electrostatic stabilization, while the long comb copolymer provided steric stabilization. Moderate additions (25%) of isopropanol to water systems were shown to improve long-term stability of ceramic dispersions with slightly soluble species. This was demonstrated for an alumina suspension with magnesia added as a grain growth inhibitor

Executive functions and Planning in everyday life : Assistive Technologies for Cognition and their lack of support for children with Attention Deficit / Hyperactive Disorder

The evaluation of how Assistive Technologies for Cognition (ATC) serve their purpose in providing support for children with Attention Deficit/Hyperactive Disorder (AD/HD) is limited and it is not clear how to best support the cognitive functions in order to help the individual increase task performance in everyday life. This thesis sought to scrutinise how families with at least one child diagnosed with AD/HD incorporate ATCs in their daily life in order to cope with appurtenant difficulties. An online survey, answered by 92 caregivers for children with AD/HD, attended to the cognitive abilities in need of support, the usage of ATCs, and how ATCs supported the executive functions in everyday planning. The results reveal that children encounter difficulty in dealing with cognitive ability, executive functioning and causal inference when it comes to planning in everyday life situations, which relates to lower levels of independence. Executive functioning and causal inference is negatively correlated to number of symptoms of AD/HD. The ATC is not satisfactorily supporting the cognitive functions, which results in another person by default being the one who sets up the ATC, and the child merely follows the instruction. The results has been processed into a table containing concepts which is suggested to be considered both when developing, as well as evaluating, ATCs for children with AD/HD.