147 research outputs found
Impact of Strain on Drain Current and Threshold Voltage of Nanoscale Double Gate Tunnel Field Effect Transistor: Theoretical Investigation and Analysis
Tunnel field effect transistor (TFET) devices are attractive as they show
good scalability and have very low leakage current. However they suffer from
low on-current and high threshold voltage. In order to employ the TFET for
circuit applications, these problems need to be tackled. In this paper, a novel
lateral strained double-gate TFET (SDGTFET) is presented. Using device
simulation, we show that the SDGTFET has a higher on-current, low leakage, low
threshold voltage, excellent subthreshold slope, and good short channel effects
and also meets important ITRS guidelines.Comment: http://web.iitd.ac.in/~mamidal
Face or building superiority in peripheral vision reversed by task requirements
Peripheral vision has been the topic of few studies compared with central vision.
Nevertheless, given that visual information covers all the visual field and that
relevant information can originate from highly eccentric positions, the
understanding of peripheral vision abilities for object perception seems
essential. The poorer resolution of peripheral vision would first suggest that
objects requiring large-scale feature integration such as buildings would be
better processed than objects requiring finer analysis such as faces.
Nevertheless, task requirements also determine the information (coarse or fine)
necessary for a given object to be processed. We therefore investigated how task
and eccentricity modulate object processing in peripheral vision. Three
experiments were carried out requiring finer or coarser information processing
of faces and buildings presented in central and peripheral vision. Our results
showed that buildings were better judged as identical or familiar in periphery
whilst faces were better categorised. We conclude that this superiority for a
given stimulus in peripheral vision results (a) from the available information,
which depends on the decrease of resolution with eccentricity, and (b) from the
useful information, which depends on both the task and the semantic
category
Observation of 1D Behavior in Si Nanowires: Toward High-Performance TFETs
This article provides experimental evidence of one-dimensional behavior of silicon (Si) nanowires (NWs) at low-temperature through both transfer (Id−VG) and capaci- tance−voltage characteristics. For the first time, operation of Si NWs in the quantum capacitance limit (QCL) is experimentally demonstrated and quantitatively analyzed. This is of relevance since working in the QCL may allow, e.g., tunneling field-effect transistors (TFETs) to achieve higher on-state currents (Ion) and larger on-/off-state current ratios (Ion/Ioff), thus addressing one of the most severe limitations of TFETs. Comparison of the experimental data with simulations finds excellent agreement using a simple capacitor model
Impaired working speed and executive functions as frontal lobe dysfunctions in young first-degree relatives of schizophrenic patients
The aim of the investigation was to detect neuropsychological markers, such as sustained and selective attention and executive functions, which contribute to the vulnerability to schizophrenia especially in young persons. Performance was assessed in 32 siblings and children of schizophrenic patients and 32 matched controls using Wisconsin Card Sorting Test, Colour-Word-Interference-Test, Trail Making Test, and d2-Concentration-Test. The first-degree relatives showed certain impairments on all four tests, in particular, slower times on all time-limited tests. These results suggest the need for more time when completing neuropsychological tasks involving selected and focused attention, as well as cognitive flexibility, as a possible indicator of genetic vulnerability to schizophrenia
Eye tracking – The overlooked method to measure cognition in neurodegeneration?
Eye tracking (ET) studies are becoming increasingly popular due to rapid methodological and technological advances as well as the development of cost efficient and portable eye trackers. Although historically ET has been mostly employed in psychophysics or developmental cognition studies, there is also promising scope to use ET for movement disorders and measuring cognitive processes in neurodegeneration. Particularly, ET can be a powerful tool for cognitive and neuropsychological assessments of patients with pathologies affecting motor and verbal abilities, as tasks can be adapted without requiring motor (except eye movements) or verbal responses. In this review, we will examine the existing evidence of ET methods in neurodegenerative conditions and its potential clinical impact for cognitive assessment. We highlight that current evidence for ET is mostly focused on diagnostics of cognitive impairments in neurodegenerative disorders, where it is debatable whether it has any more sensitivity or specificity than existing cognitive assessments. By contrast, there is currently a lack of ET studies in more advanced disease stages, when patients’ motor and verbal functions can be significantly affected, and standard cognitive assessments are challenging or often not possible. We conclude that ET is a promising method not only for cognitive diagnostics but more importantly, for potential cognitive disease tracking in progressive neurodegenerative conditions
Influence of Physical and Semantic Information in a Categorization Task of Fragmented Forms
Two experiments were carried out to investigate the influence of structural and semantic information in the categorisation of visual forms. In experiment 1 the stimuli were pairs of 'well structured' or 'poorly structured' fragmented forms differing in structural properties including convexity, collinearity, and closure of the elements, and in their 'name-ability'. The influence of structural and semantic information was tested by means of a task involving the presentation to both visual hemifields separately of stimuli having within-category physical similarity. For well structured forms, subjects were asked to judge if two sequentially presented forms belonged to the same semantic category. For poorly structured forms, subjects were required to decide if two stimuli belonged to the same previously learnt category of forms. For the two types of stimuli, one category was composed of physically similar items, and the other was composed of physically dissimilar items. The results show a marked advantage for the category composed of physically similar forms when the stimuli are well structured but no differences between the two categories when the stimuli are poorly structured. This suggests a facilitation in the computation of global shape information for forms having collinear and closed elements. The only effect of semantic information was a tendency towards a right visual field advantage for same-category pairs of well structured forms. The pattern of results for well structured fragmented forms (experiment 1) and forms in which fragments had been joined in order to complete the contour (experiment 2) were similar, suggesting that structured incomplete forms can be processed in the same way as forms having a continuous contour. Hypotheses about the organisational processes of forms are proposed in the discussion
Influence of physical and semantic information in a categorisation task of fragmented forms.
International audienceTwo experiments were carried out to investigate the influence of structural and semantic information in the categorisation of visual forms. In experiment 1 the stimuli were pairs of 'well structured' or 'poorly structured' fragmented forms differing in structural properties including convexity, collinearity, and closure of the elements, and in their 'nameability'. The influence of structural and semantic information was tested by means of a task involving the presentation to both visual hemifields separately of stimuli having within-category physical similarity. For well structured forms, subjects were asked to judge if two sequentially presented forms belonged to the same semantic category. For poorly structured forms, subjects were required to decide if two stimuli belonged to the same previously learnt category of forms. For the two types of stimuli, one category was composed of physically similar items, and the other was composed of physically dissimilar items. The results show a marked advantage for the category composed of physically similar forms when the stimuli are well structured but no differences between the two categories when the stimuli are poorly structured. This suggests a facilitation in the computation of global shape information for forms having collinear and closed elements. The only effect of semantic information was a tendency towards a right visual field advantage for same-category pairs of well structured forms. The pattern of results for well structured fragmented forms (experiment 1) and forms in which fragments had been joined in order to complete the contour (experiment 2) were similar, suggesting that structured incomplete forms can be processed in the same way as forms having a continuous contour. Hypotheses about the organisational processes of forms are proposed in the discussion
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