815 research outputs found

    On Real-Time Synthetic Primate Vision

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    The primate vision system exhibits numerous capabilities. Some important basic visual competencies include: 1) a consistent representation of visual space across eye movements; 2) egocentric spatial perception; 3) coordinated stereo fixation upon and pursuit of dynamic objects; and 4) attentional gaze deployment. We present a synthetic vision system that incorporates these competencies.We hypothesize that similarities between the underlying synthetic system model and that of the primate vision system elicit accordingly similar gaze behaviors. Psychophysical trials were conducted to record human gaze behavior when free-viewing a reproducible, dynamic, 3D scene. Identical trials were conducted with the synthetic system. A statistical comparison of synthetic and human gaze behavior has shown that the two are remarkably similar

    Modelling Word Associations with Word Embeddings for a Guesser Agent in the Taboo City Challenge Competition

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    In the Taboo City Challenge, artificial agents should guess the names of cities from simple textual hints and are evaluated with games played by humans. Thus, playing the games successfully requires mimicking associations that humans have with geographical locations. In this paper, an architecture is proposed that calculates the associative similarity between a city and a hint from a semantic vector space. The semantic vector space is created using the Skip-gram hierarchical softmax model, from a tailored corpus about travel destinations. We investigate the effect of varying training parameters and introduce a targeted corpus annotation method that significantly improves performance. The results on a dataset of 149 games indicate that the proposed architecture can guess the target city with up to 22.45% accuracy — a substantial improvement over the 4.11% accuracy achieved by the baseline architecture

    Compensatory behaviour of visually impaired cyclists in everyday settings

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    This study investigated whether visually impaired cyclists, compared to cyclists without visual limitations, take other, potentially safer routes to destinations in their own living environment and whether they ride at a lower speed. In total, 19 matched pairs of a visually impaired cyclist and a normally sighted peer from the same neighbourhood recorded their everyday bicycle rides, using GPS action cameras. In addition, they completed an 'assigned ride', a ride for which only a starting and an ending point were provided by the researcher. A risk-assessment procedure showed that the route taken by visually impaired cyclists during this assigned ride was not less risky than the route taken by the normally sighted cyclists. Analysis of the everyday rides showed that, on average, cyclists with a visual impairment more frequently (i.e. for longer periods) cycled at a speed below 10 km/h compared to cyclists without visual impairment. Also, the visually impaired participants' cruising speed was 1.4 km/h lower than that of their normally sighted counterparts. In conclusion, no evidence was found that visually impaired cyclists compensate strategically by taking different, potentially safer routes than normally sighted cyclists when riding in their own environment. They may (unconsciously) compensate tactically for their visual function limitations by riding at a lower speed when necessary. Mobility trainers in vision rehabilitation as well as road designers could apply these findings to optimise the cycling mobility of visually impaired people

    Diagnose, indicate, and treat severe mental illness (DITSMI) as appropriate care:A three-year follow-up study in long-term residential psychiatric patients on the effects of re-diagnosis on medication prescription, patient functioning, and hospital bed utilization

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    BACKGROUND: While polypharmacy is common in long-term residential psychiatric patients, prescription combinations may, from an evidence-based perspective, be irrational. Potentially, many psychiatric patients are treated on the basis of a poor diagnosis. We therefore evaluated the DITSMI model (i.e., Diagnose, Indicate, and Treat Severe Mental Illness), an intervention that involves diagnosis (or re-diagnosis) and appropriate treatment for severely mentally ill long-term residential psychiatric patients. Our main objective was to determine whether DITSMI affected changes over time regarding diagnoses, pharmacological treatment, psychosocial functioning, and bed utilization. METHODS: DITSMI was implemented in a consecutive patient sample of 94 long-term residential psychiatric patients during a longitudinal cohort study without a control group. The cohort was followed for three calendar years. Data were extracted from electronic medical charts. As well as diagnoses, medication use and current mental status, we assessed psychosocial functioning using the Health of the Nations Outcome Scale (HoNOS). Bed utilization was assessed according to length of stay (LOS). Change was analyzed by comparing proportions of these data and testing them with chi-square calculations. We compared the numbers of diagnoses and medication changes, the proportions of HoNOS scores below cut-off, and the proportions of LOS before and after provision of the protocol. RESULTS: Implementation of the DITSMI model was followed by different diagnoses in 49% of patients, different medication in 67%, some improvement in psychosocial functioning, and a 40% decrease in bed utilization. CONCLUSIONS: Our results suggest that DITSMI can be recommended as an appropriate care for all long-term residential psychiatric patients

    How visually impaired cyclists ride regular and pedal electric bicycles

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    The present study investigates whether visually impaired cyclists compensate for their vision limitations by maintaining a lower speed or a larger distance to the kerb than normally sighted cyclists when riding a regular bicycle or pedal electric bicycle (pedelec). A normally sighted control group (n = 10), a peripheral visual field loss group (n = 9), and a low visual acuity group (n = 12) rode a fixed route (7.5 km) in the Netherlands on a regular bicycle and on a pedelec. Speed and lateral position were measured when participants cycled a (I) one-way cycle path, (II) two-way cycle path, (III) residential area, and (IV) shared space zone. With regard to both the regular bicycle and the pedelec, no significant speed or lateral position differences were found between the three groups. In conclusion, for some people with severe and permanent visual impairments, and under certain circumstances, regular bicycle and pedelec riding may be possible without noticeable speed reduction or adapted lane position to compensate for their functional impairment. The present findings may further optimise the cycling advice provided by mobility trainers of vision rehabilitation centres and the independent mobility of visually impaired people

    Ontwikkeling van enkele mosselbanken in de Nederlandse Waddenzee; situatie 2010

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    In dit project wordt de lange termijnontwikkeling van mosselbanken, en de factoren die het al dan niet overleven van mosselbanken bepalen, onderzocht. Hiervoor worden door IMARES enkele individuele mosselbanken in detail bestudeerd. Drie mosselbanken worden sinds 1997 gevolgd, één sinds 1998, twee sinds 2002, één sinds 2003 en zeven mosselbanken worden sinds 2006 gevolgd. In deze rapportage wordt de ontwikkeling van deze veertien mosselbanken tot en met 2010 beschreven. De meeste mosselbanken uit het project bestaan inmiddels uit mosselen van meerdere jaarklassen. Uit de gegevens die gedurende de jaren zijn verzameld blijkt dat naarmate een mosselbank ouder wordt het percentage levende mosselen langzaam afneemt tot ongeveer 40%. De rest van het oppervlak van de mosselbank bestaat dan uit lege mosselschelpen, ingevangen schelpen van andere soorten, slakken, andere schelpdieren, pokken en macro-algen. De afname in levende mosselen op een mosselbank wordt voornamelijk veroorzaakt door stormen en predatie. Lokale, matige mosselbroedvallen op individuele mosselbanken kunnen de afnemende mosselpopulatie op de korte termijn in stand houden, maar af en toe optredende goede broedvallen zijn nodig voor lange termijnoverleving van een mosselbank. De laatste jaren zijn veel van de onderzochte mosselbanken bedekt geraakt met Japanse oesters. Toch zijn er tussen de oesters nog veel mosselen te vinden en kan gesproken worden van gemengde mosselbanken. De oesters in de mosselbanken lijken in sommige gevallen voor extra stevigheid te zorgen, hoewel er ook delen met oesters verdwijnen tijdens winterstormen
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