An Analysis of Eye Scanpath Entropy in a Progressively Forming Virtual Environment

A sign of presence in virtual environments is that people respond to situations and events as if they were real, where response may be considered at many different levels, ranging from unconscious physiological responses through to overt behavior,emotions, and thoughts. In this paper we consider two responses that gave different indications of the onset of presence in a gradually forming environment. Two aspects of the response of people to an immersive virtual environment were recorded: their eye scanpath, and their skin conductance response (SCR). The scenario was formed over a period of 2 min, by introducing an increasing number of its polygons in random order in a head-tracked head-mounted display. For one group of experimental participants (n 8) the environment formed into one in which they found themselves standing on top of a 3 m high column. For a second group of participants (n 6) the environment was otherwise the same except that the column was only 1 cm high, so that they would be standing at normal ground level. For a third group of participants (n 14) the polygons never formed into a meaningful environment. The participants who stood on top of the tall column exhibited a significant decrease in entropy of the eye scanpath and an increase in the number of SCR by 99 s into the scenario, at a time when only 65% of the polygons had been displayed. The ground level participants exhibited a similar decrease in scanpath entropy, but not the increase in SCR. The random scenario grouping did not exhibit this decrease in eye scanpath entropy. A drop in scanpath entropy indicates that the environment had cohered into a meaningful perception. An increase in the rate of SCR indicates the perception of an aversive stimulus. These results suggest that on these two dimensions (scanpath entropy and rate of SCR) participants were responding realistically to the scenario shown in the virtual environment. In addition, the response occurred well before the entire scenario had been displayed, suggesting that once a set of minimal cues exists within a scenario,it is enough to form a meaningful perception. Moreover, at the level of the sympathetic nervous system, the participants who were standing on top of the column exhibited arousal as if their experience might be real. This is an important practical aspect of the concept of presence.

Nou web de la Biblioteca Virtual: anàlisi del nou web de la Biblioteca de la UOC

Informe de l'anàlisi realitzat sobre el nou web de la Biblioteca Virtual de la UOC, mitjançant el mètode de test amb usuaris, per tal d'avaluar el grau d'usabilitat de la nova eina. L'anàlisi s'emmarca en el procés de disseny centrat en l'usuari que s'ha utilitzat per al seu disseny.

Nou web de la Biblioteca Virtual: test amb usuaris, desembre 2013

Informe de l'anàlisi realitzat sobre el nou web de la Biblioteca Virtual de la UOC, per tal d'avaluar el grau d'usabilitat de la nova eina. És el segon test amb usuaris que es realitza del nou web i s'han analitzat els següents aspectes: l'accés a la col·lecció digital, les cinc funcionalitats més utilitzades del web i les cinc funcionalitats menys visibles del web.

The Impact of a Character Posture Model on the Communication of Affect in an Immersive Virtual Environment

This paper presents the quantitative and qualitative findings from an experiment designed to evaluate a developing model of affective postures for full-body virtual characters in immersive virtual environments (IVEs). Forty-nine participants were each requested to explore a virtual environment by asking two virtual characters for instructions. The participants used a CAVE-like system to explore the environment. Participant responses and their impression of the virtual characters were evaluated through a wide variety of both quantitative and qualitative methods. Combining a controlled experimental approach with various data-collection methods provided a number of advantages such as providing a reason to the quantitative results. The quantitative results indicate that posture plays an important role in the communication of affect by virtual characters. The qualitative findings indicated that participants attribute a variety of psychological states to the behavioral cues displayed by virtual characters. In addition, participants tended to interpret the social context portrayed by the virtual characters in a holistic manner. This suggests that one aspect of the virtual scene colors the perception of the whole social context portrayed by the virtual characters. We conclude by discussing the importance of designing holistically congruent virtual characters especially in immersive settings.

Diphenyl urea derivatives as inhibitors of transketolase: a structure-based virtual screening.

Transketolase is an enzyme involved in a critical step of the non-oxidative branch of the pentose phosphate pathway whose inhibition could lead to new anticancer drugs. Here, we report new human transketolase inhibitors, based on the phenyl urea scaffold, found by applying structure-based virtual screening. These inhibitors are designed to cover a hot spot in the dimerization interface of the homodimer of the enzyme, providing for the first time compounds with a suggested novel binding mode not based on mimicking the thiamine pyrophosphate cofactor.

Joustava hitsausautomaatio piensarjatuotannossa

Kustannuspaineet, tuotteiden laatuvaatimukset ja lisääntyvässä määrin myös ammattitaitoisen työvoiman pula lisäävät robotisoinnin käyttötarvetta hitsauksessa. Tämä työ on tehty edellä mainituista lähtökohdista ja käsittelee robottihitsausjärjestelmän suunnitteluprojektia, joustavaa hitsausautomaatiota ja robotiikan soveltamista. Näkökohtana on Savonia-ammattikorkeakoulun sekä Pohjois-Savon alueen yritysten tutkimus-, kehitys- ja koulutustoiminnan tarpeet. Joustavuus on hitsausjärjestelmän päätavoite, jolla pyritään vastaamaan asiakasohjautuvan yksittäis- ja piensarjatuotannon haasteisiin. Ratkaisua yksittäis- ja piensarjatuotteiden kokonaistaloudelliseen hitsaukseen on haettu hitsausrobotin rinnalle lisätyllä apurobotilla, jonka päätehtävä on kappaleenkäsittely, mutta sitä voidaan käyttää myös mm. robotisoituun leikkauksen ja särmäykseen. Tavallisuudesta poikkeavaa järjestelmäratkaisua on perusteltu sillä, että ohjaus- ja ohjelmointitekniikan sekä kehittyneen anturoinnin myötä on robottien käytettävyys parantunut ja aiempaa haasteellisempien robottijärjestelmien toteuttaminen on tullut näin mahdolliseksi. Lisäksi virtuaalimallinnus, simulointi ja etäohjelmointi ovat työkaluja, joita voidaan käyttää mm. tuotannon laadun ja tehokkuuden parantamiseen. Työssä esitetty robottiaseman suunnittelu alkaa järjestelmän määrittelystä, vaatimuslistan laadinnasta sekä visioinnista ja päättyy kolmen järjestelmävaihtoehdon vertailuun. Esitetyillä järjestelmävaihtoehdoilla on haettu mahdollisuutta yhdistää yleensä erillisinä toteutettuja työvaiheita yhteiseen soluun. Tuotannon joustavuus on ollut tuotantokapasiteettia tärkeämpi laitteistokokoonpanon valintaperuste.

8Ruedas, botiga virtual

L'aplicació 8Ruedas és una botiga virtual desenvolupada amb llenguatge Java en la tecnologia J2EE. El projecte està estructurat dins el framework Struts2, que segueix un patró MVC (Model-Vista-Controlador) amb metodologia orientada a objectes.

Virtual hand illusion induced by visuomotor correlations

Our body schema gives the subjective impression of being highly stable. However, a number of easily-evoked illusions illustrate its remarkable malleability. In the rubber-hand illusion, illusory ownership of a rubber-hand is evoked by synchronous visual and tactile stimulation on a visible rubber arm and on the hidden real arm. Ownership is concurrent with a proprioceptive illusion of displacement of the arm position towards the fake arm. We have previously shown that this illusion of ownership plus the proprioceptive displacement also occurs towards a virtual 3D projection of an arm when the appropriate synchronous visuotactile stimulation is provided. Our objective here was to explore whether these illusions (ownership and proprioceptive displacement) can be induced by only synchronous visuomotor stimulation, in the absence of tactile stimulation.

Drumming in immersive virtual reality: the body shapes the way we play

It has been shown that it is possible to generate perceptual illusions of ownership in immersive virtual reality (IVR) over a virtual body seen from first person perspective, in other words over a body that visually substitutes the person's real body. This can occur even when the virtual body is quite different in appearance from the person's real body. However, investigation of the psychological, behavioral and attitudinal consequences of such body transformations remains an interesting problem with much to be discovered. Thirty six Caucasian people participated in a between-groups experiment where they played a West-African Djembe hand drum while immersed in IVR and with a virtual body that substituted their own. The virtual hand drum was registered with a physical drum. They were alongside a virtual character that played a drum in a supporting, accompanying role. In a baseline condition participants were represented only by plainly shaded white hands, so that they were able merely to play. In the experimental condition they were represented either by a casually dressed dark-skinned virtual body (Casual Dark-Skinned - CD) or by a formal suited light-skinned body (Formal Light-Skinned - FL). Although participants of both groups experienced a strong body ownership illusion towards the virtual body, only those with the CD representation showed significant increases in their movement patterns for drumming compared to the baseline condition and compared with those embodied in the FL body. Moreover, the stronger the illusion of body ownership in the CD condition, the greater this behavioral change. A path analysis showed that the observed behavioral changes were a function of the strength of the illusion of body ownership towards the virtual body and its perceived appropriateness for the drumming task. These results demonstrate that full body ownership illusions can lead to substantial behavioral and possibly cognitive changes depending on the appearance of the virtual body. This could be important for many applications such as learning, education, training, psychotherapy and rehabilitation using IVR.