scholarly journals PSYCHOPHYSIOLOGICAL FEATURES OF AIRСRAFT PILOTS DURING VISUAL SEARCH AND DETECTION OF SMALL-SIZE GROUND OBJECTS IN DIFFICULT WEATHER CONDITIONS

2021 ◽  
Vol 13 (4) ◽  
pp. 87-99
Author(s):  
Konstantin Ivanovich Zasyadko ◽  
Sergei Konstantinovich Soldatov ◽  
Aleksei Valerievich Bogomolov ◽  
Aleksandr Pavlovich Vonarshenko ◽  
Mikhail Nikolaevich Yazlyuk
Keyword(s):  
Visual Search ◽  
Emotional Stress ◽  
Weather Conditions ◽  
Subjective Assessment ◽  
Flight Altitude ◽  
Lower Edge ◽  
Recording Equipment ◽  
Activity Increase ◽  
Detection And Identification ◽  
Aircraft Pilots

Background. Visual search and detection of small-size ground objects in difficult weather conditions is a task that provokes psychophysiological stress. The influence of professional pilot activity on the psychophysiological cost of air reconnaissance remains unclear. Materials and methods. The study on the detection and identification of a ground object during landing approach was carried out in winter, during daylight hours: 42 aircraft pilots (average age 30.0 ± 2.8 years, experience from 7 to 14 years) performed 192 research flights. Studies of the subjective assessment of the range to small-size ground objects (SSGO) depending on different visibility conditions and flight altitude were carried out with the participation of 11 aircraft pilots (average age 31.2 ± 1.4 years, experience from 10 to 14 years). The aircraft pilots performed 33 research flights, during which the indicators of neuro-emotional stress were recorded using on-board recording equipment. Results. The search for SSGO in difficult weather conditions (DWC) is accompanied by the increased neuro-emotional stress of the pilot. The pilot's eye estimate of the range to SSGO in conditions of a limited maximum visibility (2.5–4.0 km) for altitudes of 300–400 m is characterized by overestimating the range by an average of 12 %, while good visibility results in underestimating the range. A flight under the clouds with maintaining the distance between the lower edge of the cloud and a flight height of about 50 meters is more favorable for the search for SSGO. With a decrease in this distance to 25 m or less, there is an increase in the physiological cost of such activity (increase in heart rate by 11.6 %; respiration rate by 13.7 %). Conclusion. The psychophysiological features of a pilot that affect the detection and identification of SSGO in DWC mostly depend on the maximum visibility. The coefficients obtained make it possible to adequately estimate the detection and identification range during air reconnaissance in DWC. Pilot’s workload, as well as the level of his/her neuro-emotional stress are determined by the maximum visibility and the distance between the lower edge of the cloud and the specified flight altitude.

Effect of Attention on the Detection and Identification of Masked Spatial Patterns

Perception ◽  
10.1068/p5276 ◽  
2005 ◽  
Vol 34 (3) ◽  
pp. 305-318 ◽  
Author(s):  
Endel Põder
Keyword(s):  
Visual Search ◽  
Spatial Patterns ◽  
Signal Detection Theory ◽  
Detection Task ◽  
Small Target ◽  
Crowding Effect ◽  
Identification Task ◽  
Set Size ◽  
Detection And Identification ◽  
Search Experiment

The effect of attention on the detection and identification of vertically and horizontally oriented Gabor patterns in the condition of simultaneous masking with obliquely oriented Gabors was studied. Attention was manipulated by varying the set size in a visual-search experiment. In the first experiment, small target Gabors were presented on the background of larger masking Gabors. In the detection task, the effect of set size was as predicted by unlimited-capacity signal detection theory. In the orientation identification task, increasing the set size from 1 to 8 resulted in a much larger decline in performance. The results of the additional experiments suggest that attention can reduce the crowding effect of maskers.

Visual Search: Detection, Identification, and Localization

Perception ◽  
1992 ◽  
Vol 21 (6) ◽  
pp. 765-777 ◽  
Author(s):  
Marc Green
Keyword(s):  
Visual Search ◽  
Target Detection ◽  
Detection And Identification ◽  
Display Performance ◽  
The Right ◽  
Detection And Localization

In two studies, observers searched for a single oblique target in a field of vertical distractors. In one experiment, target detection and identification (left versus right tilt) were compared. In another experiment, detection and localization were compared for the left versus the right half of the display. Performance on all three tasks was virtually identical: if a target could be detected, it could also be identified and localized. A review of previous studies generally supports the conclusion that performance on the three tasks is similar. This argues against current search theories, which rest heavily on data showing differences in identification and localization.

Intracranial Recordings Demonstrate Both Cortical and Medial Temporal Lobe Engagement in Visual Search in Humans

2021 ◽  
pp. 1-29
Author(s):  
S. J. Katarina Slama ◽  
Richard Jimenez ◽  
Sujayam Saha ◽  
David King-Stephens ◽  
Kenneth D. Laxer ◽  
...  
Keyword(s):  
Visual Search ◽  
Frontal Cortex ◽  
Temporal Lobe ◽  
Medial Temporal Lobe ◽  
Association Cortex ◽  
Subcortical Structures ◽  
Spatiotemporal Resolution ◽  
Activity Increase ◽  
Anatomical Space ◽  
Intracranial Recordings

Abstract Visual search is a fundamental human behavior, providing a gateway to understanding other sensory domains as well as the role of search in higher-order cognition. Search has been proposed to include two component processes: inefficient search (search) and efficient search (pop-out). According to extant research, these two processes map onto two separable neural systems located in the frontal and parietal association cortices. In this study, we use intracranial recordings from 23 participants to delineate the neural correlates of search and pop-out with an unprecedented combination of spatiotemporal resolution and coverage across cortical and subcortical structures. First, we demonstrate a role for the medial temporal lobe in visual search, on par with engagement in frontal and parietal association cortex. Second, we show a gradient of increasing engagement over anatomical space from dorsal to ventral lateral frontal cortex. Third, we confirm previous intracranial work demonstrating nearly complete overlap in neural engagement across cortical regions in search and pop-out. We further demonstrate pop-out selectivity, manifesting as activity increase in pop-out as compared to search, in a distributed set of sites including frontal cortex. This result is at odds with the view that pop-out is implemented in low-level visual cortex or parietal cortex alone. Finally, we affirm a central role for the right lateral frontal cortex in search.

scholarly journals Efficacy of reduced doses of bentazone assessed by instruments based on measurement of chlorophyll fluorescence

2011 ◽  
Vol 59 (1) ◽  
pp. 137-144
Author(s):  
Vojtěch Kocurek ◽  
Michal Vondra ◽  
Vladimír Smutný
Keyword(s):  
Chlorophyll Fluorescence ◽  
Laboratory Experiments ◽  
Growth Parameters ◽  
Weather Conditions ◽  
Subjective Assessment ◽  
Amaranthus Retroflexus ◽  
Stress Factors ◽  
Fluorescence Measurement ◽  
Different Doses ◽  
Stress Influence

Chlorophyll fluorescence is a type of radiation emitted by plants as unused part of energy absorbed from sunlight. Its intensity depends on many stress factors, nutrition, weather conditions etc. Methods based on chlorophyll fluorescence measurement have potential to be perspective for the assessment of herbicide efficacy, phytotoxicity or stress influence. Two fluorometers (FluorCam and handy FluorPen) were used for measurements in laboratory experiments in 2007–2009. Herbicide Basagran super with active ingredient bentazone (480 g.l−1) was tested using a parameter called ‚Quantum yield of fluorescence‘ (QY) in three different doses: the registered dose 2.0 l.ha−1 (100%) and lower doses 1.5 l.ha−1 (75%) and 1.0 l.ha−1 (50%). Treated experimental plants of redroot pigweed (Amaranthus retroflexus L.) were measured in 0, 1, 2, 3, 6, 9 and 15 days after treatment and the results were compared with subjective assessment (estimation) and growth parameters. The obtained results showed that the effect of bentazone measured by both devices was statistically significantly different from untreated control. We can also detect herbicide effect earlier by QY measurement than by other methods. Different doses showed significant differences 15 days after treatment for dose 2.0 l.ha−1 in comparison with both reduced doses. The subjective assessment showed significant differences in all terms of measurement (1–15 days after application) except of the day of application. Regeneration of plants for which the youngest leaves were not treated by herbicide was observed for all doses. Difference of QY values between used devices was on average 0.119 (higher for FluorCam) but statistically insignificant.

scholarly journals Assessing the quality of digital elevation models obtained from mini unmanned aerial vehicles for overland flow modelling in urban areas

2016 ◽  
Vol 20 (4) ◽  
pp. 1637-1653 ◽  
Author(s):  
João P. Leitão ◽  
Matthew Moy de Vitry ◽  
Andreas Scheidegger ◽  
Jörg Rieckermann
Keyword(s):  
Unmanned Aerial Vehicles ◽  
Urban Areas ◽  
Overland Flow ◽  
Weather Conditions ◽  
Flight Altitude ◽  
Flow Modelling ◽  
Aerial Vehicles ◽  
Digital Elevation ◽  
Flight Parameters

Abstract. Precise and detailed digital elevation models (DEMs) are essential to accurately predict overland flow in urban areas. Unfortunately, traditional sources of DEM, such as airplane light detection and ranging (lidar) DEMs and point and contour maps, remain a bottleneck for detailed and reliable overland flow models, because the resulting DEMs are too coarse to provide DEMs of sufficient detail to inform urban overland flows. Interestingly, technological developments of unmanned aerial vehicles (UAVs) suggest that they have matured enough to be a competitive alternative to satellites or airplanes. However, this has not been tested so far. In this study we therefore evaluated whether DEMs generated from UAV imagery are suitable for urban drainage overland flow modelling. Specifically, 14 UAV flights were conducted to assess the influence of four different flight parameters on the quality of generated DEMs: (i) flight altitude, (ii) image overlapping, (iii) camera pitch, and (iv) weather conditions. In addition, we compared the best-quality UAV DEM to a conventional lidar-based DEM. To evaluate both the quality of the UAV DEMs and the comparison to lidar-based DEMs, we performed regression analysis on several qualitative and quantitative metrics, such as elevation accuracy, quality of object representation (e.g. buildings, walls and trees) in the DEM, which were specifically tailored to assess overland flow modelling performance, using the flight parameters as explanatory variables. Our results suggested that, first, as expected, flight altitude influenced the DEM quality most, where lower flights produce better DEMs; in a similar fashion, overcast weather conditions are preferable, but weather conditions and other factors influence DEM quality much less. Second, we found that for urban overland flow modelling, the UAV DEMs performed competitively in comparison to a traditional lidar-based DEM. An important advantage of using UAVs to generate DEMs in urban areas is their flexibility that enables more frequent, local, and affordable elevation data updates, allowing, for example, to capture different tree foliage conditions.

scholarly journals Intracranial recordings demonstrate medial temporal lobe engagement in visual search in humans

2020 ◽  
Author(s):  
S. J. Katarina Slama ◽  
Richard Jimenez ◽  
Sujayam Saha ◽  
David King-Stephens ◽  
Kenneth D. Laxer ◽  
...  
Keyword(s):  
Visual Search ◽  
Frontal Cortex ◽  
Temporal Lobe ◽  
Medial Temporal Lobe ◽  
Association Cortex ◽  
Subcortical Structures ◽  
Spatiotemporal Resolution ◽  
Activity Increase ◽  
Anatomical Space ◽  
Intracranial Recordings

AbstractVisual search is a fundamental human behavior, which has been proposed to include two component processes: inefficient search (Search) and efficient search (Pop-out). According to extant research, these two processes map onto two separable neural systems located in the frontal and parietal association cortices. In the present study, we use intracranial recordings from 23 participants to delineate the neural correlates of Search and Pop-out with an unprecedented combination of spatiotemporal resolution and coverage across cortical and subcortical structures. First, we demonstrate a role for the medial temporal lobe in visual search, on par with engagement in frontal and parietal association cortex. Second, we show a gradient of increasing engagement over anatomical space from dorsal to ventral lateral frontal cortex. Third, we confirm previous work demonstrating nearly complete overlap in neural engagement across cortical regions in Search and Pop-out. We further demonstrate Pop-out selectivity manifesting as activity increase in Pop-out as compared to Search in a distributed set of sites including frontal cortex. This result is at odds with the view that Pop-out is implemented in low-level visual cortex or parietal cortex alone. Finally, we affirm a central role for the right lateral frontal cortex in Search.

scholarly journals Diversity, dynamics, direction, and magnitude of high-altitude migrating insects in the Sahel

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Jenna Florio ◽  
Laura M. Verú ◽  
Adama Dao ◽  
Alpha S. Yaro ◽  
Moussa Diallo ◽  
...  
Keyword(s):  
Public Health ◽  
Food Security ◽  
Weather Conditions ◽  
Flight Altitude ◽  
Wet Season ◽  
Long Distance ◽  
Diverse Species ◽  
Insect Migration ◽  
Source Populations ◽  
Diversity Dynamics

AbstractLong-distance migration of insects impacts food security, public health, and conservation–issues that are especially significant in Africa. Windborne migration is a key strategy enabling exploitation of ephemeral havens such as the Sahel, however, its knowledge remains sparse. In this first cross-season investigation (3 years) of the aerial fauna over Africa, we sampled insects flying 40–290 m above ground in Mali, using nets mounted on tethered helium-filled balloons. Nearly half a million insects were caught, representing at least 100 families from thirteen orders. Control nets confirmed that the insects were captured at altitude. Thirteen ecologically and phylogenetically diverse species were studied in detail. Migration of all species peaked during the wet season every year across localities, suggesting regular migrations. Species differed in flight altitude, seasonality, and associated weather conditions. All taxa exhibited frequent flights on southerly winds, accounting for the recolonization of the Sahel from southern source populations. “Return” southward movement occurred in most taxa. Estimates of the seasonal number of migrants per species crossing Mali at latitude 14°N were in the trillions, and the nightly distances traversed reached hundreds of kilometers. The magnitude and diversity of windborne insect migration highlight its importance and impacts on Sahelian and neighboring ecosystems.

scholarly journals Assessing the quality of Digital Elevation Models obtained from mini-Unmanned Aerial Vehicles for overland flow modelling in urban areas

2015 ◽  
Vol 12 (6) ◽  
pp. 5629-5670 ◽  
Author(s):  
J. P. Leitão ◽  
M. Moy de Vitry ◽  
A. Scheidegger ◽  
J. Rieckermann
Keyword(s):  
Unmanned Aerial Vehicles ◽  
Urban Areas ◽  
Overland Flow ◽  
Weather Conditions ◽  
Flight Altitude ◽  
Flow Modelling ◽  
Aerial Vehicles ◽  
Digital Elevation ◽  
Flight Parameters

Abstract. Precise and detailed Digital Elevation Models (DEMs) are essential to accurately predict overland flow in urban areas. Unfortunately, traditional sources of DEM remain a bottleneck for detailed and reliable overland flow models, because the resulting DEMs are too coarse to provide DEMs of sufficient detail to inform urban overland flows. Interestingly, technological developments of Unmanned Aerial Vehicles (UAVs) suggest that they have matured enough to be a competitive alternative to satellites or airplanes. However, this has not been tested so far. In this this study we therefore evaluated whether DEMs generated from UAV imagery are suitable for urban drainage overland flow modelling. Specifically, fourteen UAV flights were conducted to assess the influence of four different flight parameters on the quality of generated DEMs: (i) flight altitude, (ii) image overlapping, (iii) camera pitch and (iv) weather conditions. In addition, we compared the best quality UAV DEM to a conventional Light Detection and Ranging (LiDAR)-based DEM. To evaluate both the quality of the UAV DEMs and the comparison to LiDAR-based DEMs, we performed regression analysis on several qualitative and quantitative metrics, such as elevation accuracy, quality of object representation (e.g., buildings, walls and trees) in the DEM, which were specifically tailored to assess overland flow modelling performance, using the flight parameters as explanatory variables. Our results suggested that, first, as expected, flight altitude influenced the DEM quality most, where lower flights produce better DEMs; in a similar fashion, overcast weather conditions are preferable, but weather conditions and other factors influence DEM quality much less. Second, we found that for urban overland flow modelling, the UAV DEMs performed competitively in comparison to a traditional LiDAR-based DEM. An important advantage of using UAVs to generate DEMs in urban areas is their flexibility that enables more frequent, local and affordable elevation data updates, allowing, for example, to capture different tree foliage conditions.

scholarly journals Comparative characteristics of bronchial obstruction formation trigger mechanisms in children with bronchial asthma and recurrent obstructive bronchitis

2016 ◽  
Vol 97 (1) ◽  
pp. 66-69 ◽  
Author(s):  
Z M Gaparkhoeva ◽  
O A Bashkina ◽  
E N Seliverstova
Keyword(s):  
Bronchial Asthma ◽  
Emotional Stress ◽  
Weather Conditions ◽  
Climatic Conditions ◽  
Bronchial Obstruction ◽  
Infectious Agents ◽  
Cross Sectional ◽  
Children With Asthma ◽  
The Impact ◽  
Trigger Mechanisms

Aim. To study the comparative characteristics of the causative significant factors involved in the bronchial obstruction development in children with bronchial asthma and recurrent obstructive bronchitis.Methods. A cross-sectional (transversal) study of 50 children with bronchial asthma, 38 children with recurrent obstructive bronchitis was conducted. The differences and similarities of etiopathogenetic factors of the bronchial obstruction occurrence were revealed. According to medical history, in all patients regardless of the severity and duration of the disease at the time of examination, the impact of the factors, acting as triggers of bronchial asthma, according to patients, such as infectious agents, infectious allergens and aeroallergens, nighttime, climatic conditions deterioration, physical and/or emotional stress, was registered.Results. The main triggers that influence the bronchial obstruction occurrence in children with asthma were infectious factors impact, allergens and aeroallergens, and in patients with recurrent obstructive bronchitis more important in the bronchial obstruction development were infectious agents and weather conditions worsening (high humidity, fog, rain). However, unlike the other factors involved in the bronchial obstruction development in asthma, nighttime, allergens and aeroallergens did not have significant impact on the bronchial obstruction occurrence in children with recurrent obstructive bronchitis. In both groups, physical stress (jogging, gymnastics) and emotional stress (loud laugh, crying) contributed to the bronchial obstruction syndrome development with the corresponding clinical picture, but in the second group of children with recurrent obstructive bronchitis duration of cough lasted 2 times less (1-1,5 h) than in children with bronchial asthma (over 3 hours).Conclusion. Conducted comparative characteristics showed that there is a clear link with the trigger mechanisms of bronchial obstruction occurrence in bronchial asthma and recurrent obstructive bronchitis, and triggers, regardless of the severity and duration of disease, have the same effect on the recurrent obstructive bronchitis outcome.

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