Search results for "VAI"
showing 10 items of 5155 documents
Starpzvaigžņu putekļu virsmas un mantijas ķīmisko procesu makroskopiskā Montekarlo modelēšana
2018
No starpzvaigžņu vides novērojumiem konstatēts, ka ap starpzvaigžņu putekļa kodolu aukstos apstākļos (T~10 K) aug ledus apvalciņš no apkārtējās vides gāzes vielām, kuras piesalst pie šī putekļa. Ledus apvalciņu var ķīmiski diferencēt virsmā un mantijā. Šī ledus apvalka virsma un mantija ļauj veidoties sarežģītām molekulām starpzvaigžņu vidē. Tagad nāk daudz spektroskopisku datu par to kā šie putekļi palīdz veidoties sarežģītām un pat organiskām molekulām, ir nepieciešams izveidot modeļus, kas saskaņā ar šiem datiem spēs modelēt starpzvaigžņu vides reakciju kinētiku un palīdzēs izskaidrot kompleksu molekulu rašanos starpzvaigžņu vidē. Ņemot vērā to, ka puteklis sastāv no maza skaita molekulu…
Social–ecological connections across land, water, and sea demand a reprioritization of environmental management
2022
International audience; Despite many sectors of society striving for sustainability in environmental management, humans often fail to identify and act on the connections and processes responsible for social-ecological tipping points. Part of the problem is the fracturing of environmental management and social-ecological research into ecosystem domains (land, freshwater, and sea), each with different scales and resolution of data acquisition and distinct management approaches. We present a perspective on the social-ecological connections across ecosystem domains that emphasize the need for management reprioritization to effectively connect these domains. We identify critical nexus points rel…
Estimating energy balance fluxes above a boreal forest from radiometric temperature observations
2009
Abstract The great areal extent of boreal forests confers these ecosystems potential to impact on the global surface-atmosphere energy exchange. A modelling approach, based on a simplified two-source energy balance model, was proposed to estimate energy balance fluxes above boreal forests using thermal infrared measurements. Half-hourly data from the Solar-Induced Fluorescence Experiment, carried out in a Finnish boreal forest, was used to evaluate the performance of the model. Energy balance closure, determined by linear regression, found all fluxes to underestimate available energy by 9% (r2 = 0.94). Significance in the energy balance of the heat storage in the air and in the soil terms w…
Voices behind and beyond the label : the master narrative of ADHD (de)constructed by diagnosed children and their parents
2016
Artikkeliväitöskirja. Sisältää yhteenveto-osan ja neljä artikkelia. Article dissertation. Contains an introduction part and four articles. The dominant understanding of attention deficit hyperactivity disorder (ADHD) is that of diagnosed children “suffering” from neurodevelopmental condition owing to which they are prone to develop adverse life trajectories. This master narrative of ADHD and psychomedical and normative discourses it adheres to and employs have been integrated into the daily activities of homes and schools. This compilation dissertation study employs a social constructionist discourse framework and is located in the intersection of the disciplines of disability studies and s…
Both attention and prediction are necessary for adaptive neuronal tuning in sensory processing
2014
International audience; The brain as a proactive system processes sensory information under the top-down influence of attention and prediction. However, the relation between attention and prediction remains undetermined given the conflation of these two mechanisms in the literature. To evaluate whether attention and prediction are dependent of each other, and if so, how these two top-down mechanisms may interact in sensory processing, we orthogonally manipulated attention and prediction in a target detection task. Participants were instructed to pay attention to one of two interleaved stimulus streams of predictable/unpredictable tone frequency. We found that attention and prediction intera…
Prior Precision Modulates the Minimization of Auditory Prediction Error
2019
International audience; The predictive coding model of perception proposes that successful representation of the perceptual world depends upon canceling out the discrepancy between prediction and sensory input (i.e., prediction error). Recent studies further suggest a distinction to be made between prediction error triggered by non-predicted stimuli of different prior precision (i.e., inverse variance). However, it is not fully understood how prediction error with different precision levels is minimized in the predictive process. Here, we conducted a magnetoencephalography (MEG) experiment which orthogonally manipulated prime-probe relation (for contextual precision) and stimulus repetition…
On the Difference Between Necessary and Unnecessary Glances Away From the Forward Roadway : An Occlusion Study on the Motorway
2019
Objective The present study strove to distinguish traffic-related glances away from the forward roadway from non-traffic-related glances while assessing the minimum amount of visual information intake necessary for safe driving in particular scenarios. Background Published gaze-based distraction detection algorithms and guidelines for distraction prevention essentially measure the time spent looking away from the forward roadway, without incorporating situation-based attentional requirements. Incorporating situation-based attentional requirements would entail an approach that not only considers the time spent looking elsewhere but also checks whether all necessary information has been sampl…
Multitasking in Driving as Optimal Adaptation Under Uncertainty
2021
Objective The objective was to better understand how people adapt multitasking behavior when circumstances in driving change and how safe versus unsafe behaviors emerge. Background Multitasking strategies in driving adapt to changes in the task environment, but the cognitive mechanisms of this adaptation are not well known. Missing is a unifying account to explain the joint contribution of task constraints, goals, cognitive capabilities, and beliefs about the driving environment. Method We model the driver’s decision to deploy visual attention as a stochastic sequential decision-making problem and propose hierarchical reinforcement learning as a computationally tractable solution to it. The…
Mitigating the Climate Change Impacts of Aviation through Behavioural Change
2020
Aviation plays a crucial role for economic development and social welfare, but at the same time it also significantly contributes to climate change. Therefore, if the industry wants to follow the same growth path as it has in the past, it will need to mitigate its environmental impacts more seriously or it may otherwise face regulatory restrictions. The current literature has discussed five mitigation strategies. These are technological changes, market-based changes, operational changes, regulatory changes and behavioural changes. While several authors have regarded behavioural changes as the measure with the greatest mitigation potential, it is also the measure that has received far less a…