scholarly journals Methods of long-term and short-term adaptation for biometric image of keystroke dynamics

2021 ◽  
Vol 7 (3D) ◽  
pp. 450-457
Author(s):  
Dmitry V. Pashchenko ◽  
Dmitry A. Trokoz ◽  
Alexey I. Martyshkin ◽  
Elena A. Balzannikova
Keyword(s):  
Working Capacity ◽  
Keystroke Dynamics ◽  
Short Term ◽  
User Identification ◽  
New Device ◽  
Short Term Adaptation ◽  
Long Time

This article discusses one of the main problems of user identification by keyboard handwriting - short-term changes in the keystroke dynamics of users in connection with its psychophysical state, as well as changes over a long time associated with the formation of keystroke dynamics by a new user or when switching to a new device. A method for determining the phase of working capacity by the time characteristics of the keystroke dynamics is proposed.

scholarly journals Mechanisms of short-term and long-term adaptation

2020 ◽  
pp. 77-86
Author(s):  
Н.Б. Панкова
Keyword(s):  
Gene Expression ◽  
Epigenetic Regulation ◽  
Adaptive Response ◽  
Educational Environment ◽  
Stress Factors ◽  
Short Term ◽  
Functional Reserve ◽  
Short Term Adaptation ◽  
Expression Program

В лекции рассмотрены общие представления об адаптации, основанные на классических работах Г. Селье, Ф.З. Меерсона, Н.А. Агаджаняна, а также особенности адаптивного ответа развивающегося организма. Рассмотрены механизмы срочной адаптации как мобилизации функциональных резервов организма. В качестве одного из механизмов долговременной адаптации представлена эпигенетическая регуляция, которая позволяет выбрать и реализовать программу экспрессии генов - в соответствии с этапом онтогенетического развития, или средовым окружением. В качестве ещё одного механизма долговременной адаптации рассмотрено воздействие на генетический материал. Приведены примеры формирования адаптивного ответа организма на физико-химические и климатогеографические стрессорные факторы. Отдельно проанализированы механизмы адаптивного ответа организма детей на факторы образовательной среды. The lecture addresses general ideas about adaptation based on classic studies by H. Selye, F.Z. Meerson, and N.A. Agadzhanyan and features of the adaptive response in a developing body. Mobilization of the functional reserve is considered as a mechanism of short-term adaptation. Epigenetic regulation is presented as one of mechanisms for long-term adaptation, which allows selecting and implementing a gene expression program consistent with the stage of ontogenetic development or the environment. Another mechanism of long-term adaptation is influence on the genome. The lecture provides examples of adaptation to physicochemical and climatic geographical stress factors. Mechanisms of the adaptive response to factors of the educational environment in children are analyzed separately.

Simulation of Hydrogen Distribution due to In-Vessel Severe Accident in WWER-1000 NPP Containment: A Comparison of CONTAIN and MELCOR Codes Results

2018 ◽  
Author(s):  
Omid Noorikalkhoran ◽  
Massimiliano Gei
Keyword(s):  
Severe Accident ◽  
Second Step ◽  
Hydrogen Distribution ◽  
Short Term ◽  
Long Time ◽  
Design Basis Accident ◽  
Safety Features ◽  
Design Pressure ◽  
Good Agreement

During a severe accident or Beyond Design Basis Accident (BDBA), the reaction of water with zirconium alloy as fuel clad, radiolysis of water, molten corium-concrete interaction (MCCI) and post-accident corrosion can generate a source of hydrogen. In the present work, hydrogen distribution due to in-vessel reaction (between zircaloy and steam) has been simulated inside a WWER-1000 reactor containment. In the first step, the thermal hydraulic parameters of containment have been simulated for a DECL (Double Ended Cold Leg) accident (DBA phase) in both short and long time and the effects of spray as Engineering Safety Features (ESFs) on mitigating the parameters have been studied. In the second step, it has been assumed that the accident developed into an in-vessel core melting accident. While in pre-phase of core melting (severe accident phase), hydrogen will be produced as a result of zircaloy and steam reaction (BDBA phase), the hydrogen distribution has been simulated for 23 cells inside the reactor containment by using CONTAIN 2.0 (Best estimate code) and MELCOR 1.8.6 codes. Finally, the results have been compared to FSAR results. As it can be seen from the comparisons, both CONTAIN and MELCOR codes can predict the results in good agreement with FSAR (ANGAR code) results. CONTAIN shows peak pressure around 0.36 MPa in short-term and this amount is about 0.38 and 0.4 MPa for MELCOR and ANGAR (FSAR) results respectively. All these values are under design pressure that is around 0.46 MPa. Cell 20 has the maximum mole fraction of hydrogen in long-term about 9.5% while the maximum amount of hydrogen takes place in cell 22. The differences between the results of codes are because of different equations, Models, Numerical methods and assumptions that have been considered by the codes. The simulated Hydrogen Distribution Map (HDM) can be used for upgrading the location of HCAV systems and Hydrogen Mitigator features (like the recombiners and ignitors) inside the containment to reduce the risk of hydrogen explosion.

Disability pensions in severely disturbed in-patient adolescents

1998 ◽  
Vol 172 (2) ◽  
pp. 159-163 ◽  
Author(s):  
M. Pelkonen ◽  
M. Marttunen ◽  
E. Pulkkinen ◽  
P. Laippala ◽  
J. Lönnqvist ◽  
...  
Keyword(s):  
Psychosocial Functioning ◽  
Disability Pension ◽  
Psychiatric Care ◽  
Critical Time ◽  
Working Capacity ◽  
Short Term ◽  
Related Factors ◽  
Long Term Prognosis

BackgroundKnowledge of working capacity from adolescence until adulthood among severely disturbed in-patients is scarce.MethodIn a follow-up study of 61 adolescent in-patients, we studied associations between being on a disability pension 20 years after hospitalisation, and the patients' psychopathology and treatment-related factors during the hospitalisation and seven-year follow-up.ResultsOf the former in-patients. 27% had not been on a disability pension, 20% had short-term pension periods, and 53% were pensioned. Subjects whose overall psychosocial functioning had improved and who had not utilised in-patient services until the seven-year follow-up, had a better prognosis in terms of working capacity Half of the subjects who had not been on pension during the follow-up had received a diagnosis of conduct disorder at discharge, and half of those pensioned had a psychotic disorder.ConclusionsThe patients' level of psychosocial functioning and capability to work in young adulthood were associated with long-term prognosis in terms of working capacity Adolescence seems to be the critical time for intensive psychiatric care combined with vocational rehabilitation programmes.

A Canonical Microfunction for Learning Perceptual Invariances

Perception ◽  
1996 ◽  
Vol 25 (2) ◽  
pp. 207-220 ◽  
Author(s):  
James V Stone
Keyword(s):  
Model Neuron ◽  
Learning Rule ◽  
Image Sequences ◽  
Weight Changes ◽  
Short Term ◽  
Stereo Disparity ◽  
Random Dot Stereograms ◽  
Long Time ◽  
Generic Strategy

An unsupervised method is presented which permits a set of model neurons, or a microcircuit, to learn low-level vision tasks, such as the extraction of surface depth. Each microcircuit implements a simple, generic strategy which is based on a key assumption: perceptually salient visual invariances, such as surface depth, vary smoothly over time. In the process of learning to extract smoothly varying invariances, each microcircuit maximises a microfunction. This is achieved by means of a learning rule which maximises the long-term variance of the state of a model neuron and simultaneously minimises its short-term variance. The learning rule involves a linear combination of anti-Hebbian and Hebbian weight changes, over short and long time scales, respectively. The method is demonstrated on a hyperacuity task: estimating subpixel stereo disparity from a temporal sequence of random-dot stereograms. After learning, the microcircuit generalises, without additional learning, to previously unseen image sequences. It is proposed that the approach adopted here may be used to define a canonical microfunction, which can be used to learn many perceptually salient invariances.

scholarly journals fMRI of the rod scotoma elucidates cortical rod pathways and implications for lesion measurements

2015 ◽  
Vol 112 (16) ◽  
pp. 5201-5206 ◽  
Author(s):  
Brian Barton ◽  
Alyssa A. Brewer
Keyword(s):  
Blood Oxygen Level Dependent ◽  
Cortical Reorganization ◽  
Blood Oxygen Level ◽  
Short Term ◽  
Traumatic Lesion ◽  
Electrophysiological Studies ◽  
Short Term Adaptation ◽  
Early Visual Cortex ◽  
Dependent Signal

Are silencing, ectopic shifts, and receptive field (RF) scaling in cortical scotoma projection zones (SPZs) the result of long-term reorganization (plasticity) or short-term adaptation? Electrophysiological studies of SPZs after retinal lesions in animal models remain controversial, because they are unable to conclusively answer this question because of limitations of the methodology. Here, we used functional MRI (fMRI) visual field mapping through population RF (pRF) modeling with moving bar stimuli under photopic and scotopic conditions to measure the effects of the rod scotoma in human early visual cortex. As a naturally occurring central scotoma, it has a large cortical representation, is free of traumatic lesion complications, is completely reversible, and has not reorganized under normal conditions (but can as seen in rod monochromats). We found that the pRFs overlapping the SPZ in V1, V2, V3, hV4, and VO-1 generally (i) reduced their blood oxygen level-dependent signal coherence and (ii) shifted their pRFs more eccentric but (iii) scaled their pRF sizes in variable ways. Thus, silencing, ectopic shifts, and pRF scaling in SPZs are not unique identifiers of cortical reorganization; rather, they can be the expected result of short-term adaptation. However, are there differences between rod and cone signals in V1, V2, V3, hV4, and VO-1? We did not find differences for all five maps in more peripheral eccentricities outside of rod scotoma influence in coherence, eccentricity representation, or pRF size. Thus, rod and cone signals seem to be processed similarly in cortex.

scholarly journals Genomics of long- and short- term adaptation in maize and teosinte

2018 ◽  
Author(s):  
Anne Lorant ◽  
Jeffrey Ross-Ibarra ◽  
Maud Tenaillon
Keyword(s):  
Natural Variation ◽  
Genetic Basis ◽  
Wild Relatives ◽  
Short Term ◽  
Short Term Adaptation ◽  
Maize Domestication ◽  
Cultivated Populations ◽  
Genetic Bases

Maize is an excellent model for the study of plant adaptation. Indeed, post domestication maize quickly adapted to a host of new environments across the globe. And work over the last decade has begun to highlight the role of the wild relatives of maize – the teosintes Zea mays ssp. parviglumis and ssp. mexicana – as excellent models for dissecting long-term local adaptation. Although human-driven selection associated with maize domestication has been extensively studied, the genetic bases of natural variation is still poorly understood. Here we review studies on the genetic basis of adaptation and plasticity in maize and its wild relatives. We highlight a range of different processes that contribute to adaptation and discuss evidence from natural, cultivated, and experimental populations. From an applied perspective, understanding the genetic bases of adaptation and the contribution of plasticity will provide us with new tools to both better understand and mitigate the effect of climate changes on natural and cultivated populations.

scholarly journals Brief stimuli cast a long-term trace in visual cortex

2021 ◽  
Author(s):  
Matthias Fritsche ◽  
Samuel G. Solomon ◽  
Floris P. de Lange
Keyword(s):  
Visual Cortex ◽  
Sensory Processing ◽  
Time Lags ◽  
Short Term ◽  
Statistical Representation ◽  
Specific Memory ◽  
Short Term Adaptation ◽  
Early Visual Cortex ◽  
Long Timescales

AbstractSensory processing and perception are strongly influenced by recent stimulus history – a phenomenon termed adaptation. While perception can be influenced even by brief stimuli presented dozens of seconds ago, neural adaptation to brief stimuli has not been observed beyond time lags of a few hundred milliseconds. Here, using an openly available dataset from the Allen Brain Observatory, we show that neurons in the early visual cortex of the mouse exhibit remarkably long timescales of adaptation in response to brief visual stimuli, persisting over dozens of seconds, despite the presentation of several intervening stimuli. Long-term adaptation was selectively expressed in cortical, but not in thalamic neurons, which only showed short-term adaptation. Visual cortex thus maintains concurrent stimulus-specific memory traces of past input that enable the visual system to build up a statistical representation of the world over multiple timescales, to efficiently represent information in a changing environment.

scholarly journals Efficacy of complex medical rehabilitation of employees of special squads with the autonomic dysfunction of the cardiovascular system

2019 ◽  
Vol 18 (2) ◽  
pp. 96-102
Author(s):  
Victor A. Godilo-Godlevsky ◽  
Andrey V. Ganishev ◽  
Alexei А. Voropaev
Keyword(s):  
Cardiovascular System ◽  
Autonomic Dysfunction ◽  
Medical Rehabilitation ◽  
Working Capacity ◽  
Short Term ◽  
Physical Methods ◽  
Performance Recovery ◽  
Component C ◽  
Professional Longevity

Relevance. Vegetative dysfunctions of the cardiovascular system are an actual pathology among the employees of the special agent, while vegetative disorders are not severe. In diagnostics, simple physical methods for estimating are effective, the results of which correlate with the data of instrumental survey. Aticle is devoted to the question of comparing the effectiveness of various schemes of medical rehabilitation of employees of the special agent having manifestations of autonomic dysfunction of the cardiovascular system at the stationary stage. The methods of traditional rehabilitation with the use of physical methods and methods, including complex effects of physical, psychotherapeutic and medicinal methods were compared. It is shown that the complex rehabilitation of the special component. In provides the best performance recovery in the short term and ensures the preservation of good indicators of tolerability of professional factors in the long term. Purpose. Study the effectiveness of various schemes of medical rehabilitation of employees of the special agent having manifestations of autonomic dysfunction of the cardiovascular system Material and methods. Study was conducted in a group of 60 employees who underwent medical rehabilitation and examination of temporary disability at the centers for medical rehabilitation of the Ministry of internal Affairs of Russia after performing special tasks in 20122013. Results. It is shown that complex rehabilitation of a special component C in C provides the best indicators of recovery of working capacity at the short-term stage and ensures the preservation of good indicators of tolerability of professional factors in the long-term period. Conclusions. The results obtained show significant advantages of conducting comprehensive medical rehabilitation of employees after performing special tasks, both immediately after their implementation, and in achieving stable remission in the long term, ensuring the retention of qualified and experienced employees and prolonging professional longevity.

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