scholarly journals The evolution of patterning during movement in a large-scale citizen science game

2021 ◽  
Vol 288 (1942) ◽  
pp. 20202823
Author(s):  
Anna E. Hughes ◽  
David Griffiths ◽  
Jolyon Troscianko ◽  
Laura A. Kelley
Keyword(s):  
Citizen Science ◽  
Optimal Strategy ◽  
Large Scale ◽  
Programming Approach ◽  
Moving Target ◽  
High Contrast ◽  
Low Contrast ◽  
Geometric Patterns ◽  
Motion Energy ◽  
Motion Dazzle

The motion dazzle hypothesis posits that high contrast geometric patterns can cause difficulties in tracking a moving target and has been argued to explain the patterning of animals such as zebras. Research to date has only tested a small number of patterns, offering equivocal support for the hypothesis. Here, we take a genetic programming approach to allow patterns to evolve based on their fitness (time taken to capture) and thus find the optimal strategy for providing protection when moving. Our ‘Dazzle Bug’ citizen science game tested over 1.5 million targets in a touch screen game at a popular visitor attraction. Surprisingly, we found that targets lost pattern elements during evolution and became closely background matching. Modelling results suggested that targets with lower motion energy were harder to catch. Our results indicate that low contrast, featureless targets offer the greatest protection against capture when in motion, challenging the motion dazzle hypothesis.

scholarly journals No evidence for motion dazzle in an evolutionary citizen science game

2019 ◽  
Author(s):  
Anna E. Hughes ◽  
David Griffiths ◽  
Jolyon Troscianko ◽  
Laura A. Kelley
Keyword(s):  
Genetic Programming ◽  
Citizen Science ◽  
Optimal Strategy ◽  
Programming Approach ◽  
Moving Target ◽  
High Contrast ◽  
Low Contrast ◽  
Geometric Patterns ◽  
Motion Energy ◽  
Motion Dazzle

AbstractThe motion dazzle hypothesis posits that high contrast geometric patterns can cause difficulties in tracking a moving target, and has been argued to explain the patterning of animals such as zebras. Research to date has only tested a small number of patterns, offering equivocal support for the hypothesis. Here, we take a genetic programming approach to allow patterns to evolve based on their fitness (time taken to capture) and thus find the optimal strategy for providing protection when moving. Our ‘Dazzle Bug’ citizen science game tested over 1.5 million targets in a touch screen game at a popular visitor attraction. Surprisingly, we found that targets lost pattern elements during evolution and became closely background matching. Modelling results suggested that targets with lower motion energy were harder to catch. Our results indicate that low contrast, featureless targets offer the greatest protection against capture when in motion, challenging the motion dazzle hypothesis.

scholarly journals Motion dazzle: a locust's eye view

2013 ◽  
Vol 9 (6) ◽  
pp. 20130811 ◽  
Author(s):  
Roger D. Santer
Keyword(s):  
World War I ◽  
Lower Half ◽  
Movement Detector ◽  
High Contrast ◽  
World War ◽  
Limited Evidence ◽  
Low Contrast ◽  
Motion Camouflage ◽  
Contralateral Movement ◽  
Motion Dazzle

Motion dazzle describes high-contrast patterns (e.g. zigzags on snakes and dazzle paint on World War I ships) that do not conceal an object, but inhibit an observer's perception of its motion. However, there is limited evidence for this phenomenon. Locusts have a pair of descending contralateral movement detector (DCMD) neurons which respond to predator-like looming objects and trigger escape responses. Within the network providing input to a DCMD, separate channels are excited when moving edges cause areas of the visual field to brighten or darken, respectively, and these stimuli interact antagonistically. When a looming square has an upper half and lower half that are both darker than background, it elicits a stronger DCMD response than the upper half does alone. However, when a looming square has a darker-than-background upper half and a brighter-than-background lower half, it elicits a weaker DCMD response than its upper half does alone. This effect allows high-contrast patterns to weaken and delay DCMD response parameters implicated in escape decisions, and is analogous to motion dazzle. However, the motion dazzle effect does not provide the best means of motion camouflage, because uniform bright squares, or low-contrast squares, elicit weaker DCMD responses than high-contrast, half dark, half bright squares.

scholarly journals Planar photonic chips with tailored angular transmission for high-contrast-imaging devices

2021 ◽  
Author(s):  
Yan Kuai ◽  
Junxue Chen ◽  
Gang Zou ◽  
Joseph Lakowicz ◽  
Douguo Zhang
Keyword(s):  
Large Scale ◽  
Biological Species ◽  
High Contrast ◽  
Contrast Imaging ◽  
Imaging Device ◽  
Low Contrast ◽  
High Contrast Imaging ◽  
Brightfield Microscopy ◽  
Photonic Band ◽  
Microscopy Images

Abstract A limitation of standard brightfield microscopy is its low contrast images, especially for thin specimens of weak absorption, and biological species with refractive indices very close in value to that of their surroundings. Here, we demonstrate, using a planar photonic chip with tailored angular transmission as the sample substrate, a standard brightfield microscopy can provide both darkfield and total internal reflection (TIR) microscopy images with one experimental configuration. The image contrast is enhanced without altering the specimens and the microscope configurations. This planar chip consists of several multilayer sections with designed photonic band gaps and a central region with dielectric nanoparticles, which does not require top-down nanofabrication and can be fabricated in a large scale. The photonic chip eliminates the need for a bulky condenser or special objective to realize darkfield or TIR illumination. Thus, it can work as a miniaturized high-contrast-imaging device for the developments of versatile and compact microscopes.

Resistance Monitor and Control for Vacuum Evaporation of Metals and Carbon

1976 ◽  
Vol 34 ◽  
pp. 572-573
Author(s):  
Russell L. Steere ◽  
Eric F. Erbe ◽  
J. Michael Moseley
Keyword(s):  
Electronic Device ◽  
Point Sources ◽  
High Contrast ◽  
Variable Resistor ◽  
Quality Of Results ◽  
Low Contrast ◽  
Evaporation Source ◽  
And Control ◽  
At Will

We have designed and built an electronic device which compares the resistance of a defined area of vacuum evaporated material with a variable resistor. When the two resistances are matched, the device automatically disconnects the primary side of the substrate transformer and stops further evaporation.This approach to controlled evaporation in conjunction with the modified guns and evaporation source permits reliably reproducible multiple Pt shadow films from a single Pt wrapped carbon point source. The reproducibility from consecutive C point sources is also reliable. Furthermore, the device we have developed permits us to select a predetermined resistance so that low contrast high-resolution shadows, heavy high contrast shadows, or any grade in between can be selected at will. The reproducibility and quality of results are demonstrated in Figures 1-4 which represent evaporations at various settings of the variable resistor.

scholarly journals Analyzing indoor mycobiomes through a large‐scale citizen science study in Norway

2021 ◽  
Author(s):  
Pedro M. Martin‐Sanchez ◽  
Eva‐Lena F. Estensmo ◽  
Luis N. Morgado ◽  
Sundy Maurice ◽  
Ingeborg B. Engh ◽  
...  
Keyword(s):  
Citizen Science ◽  
Large Scale ◽  
Science Study

scholarly journals Minimum Detectable Change of Visual Acuity Measurements Using ETDRS Charts (Early Treatment Diabetic Retinopathy Study)

2021 ◽  
Vol 18 (15) ◽  
pp. 7876
Author(s):  
María Carmen Sánchez-González ◽  
Raquel García-Oliver ◽  
José-María Sánchez-González ◽  
María-José Bautista-Llamas ◽  
José-Jesús Jiménez-Rejano ◽  
...  
Keyword(s):  
Visual Acuity ◽  
Diabetic Retinopathy ◽  
Early Treatment ◽  
High Reliability ◽  
Minimal Detectable Change ◽  
High Contrast ◽  
Detectable Change ◽  
Low Contrast ◽  
Minimum Detectable Change ◽  
The Mean

In our work, we determined the value of visual acuity (VA) with ETDRS charts (Early Treatment Diabetic Retinopathy Study). The purpose of the study was to determine the measurement reliabilities, calculating the correlation coefficient interclass (ICC), the value of the error associated with the measure (SEM), and the minimal detectable change (MDC). Forty healthy subjects took part. The mean age was 23.5 ± 3.1 (19 to 26) years. Visual acuities were measured with ETDRS charts (96% ETDRS chart nº 2140) and (10% SLOAN Contrast Eye Test chart nº 2153). The measurements were made (at 4 m) under four conditions: Firstly, photopic conditions with high contrast (HC) and low contrast (LC) and after 15 min of visual rest, mesopic conditions with high and low contrast. Under photopic conditions and high contrast, the ICC = 0.866 and decreased to 0.580 when the luminosity and contrast decreased. The % MDC in the four conditions was always less than 10%. It was minor under photopic conditions and HC (5.83) and maximum in mesopic conditions and LC (9.70). Our results conclude a high reliability of the ETDRS test, which is higher in photopic and high contrast conditions and lower when the luminosity and contrast decreases.

Pattern Writing by Implantation in a Large-Scale PSII System With Planar Inductively Coupled Plasma Source

2000 ◽  
Vol 624 ◽  
Author(s):  
Lingling Wu ◽  
Hongjun Gao ◽  
Dennis M. Manos
Keyword(s):  
Inductively Coupled Plasma ◽  
Large Scale ◽  
Lateral Diffusion ◽  
Plasma Source ◽  
Direct Writing ◽  
Large Area ◽  
Depth Profiles ◽  
Geometric Patterns ◽  
Planar Coil ◽  
Rf Antenna

ABSTRACTA large-scale plasma source immersion ion implantation (PSII) system with planar coil RFI plasma source has been used to study an inkless, deposition-free, mask-based surface conversion patterning as an alternative to direct writing techniques on large-area substrates by implantation. The apparatus has a 0.61 m ID and 0.51 m tall chamber, with a base pressure in the 10−8 Torr range, making it one of the largest PSII presently available. The system uses a 0.43 m ID planar rf antenna to produce dense plasma capable of large-area, uniform materials treatment. Metallic and semiconductor samples have been implanted through masks to produce small geometric patterns of interest for device manufacturing. Si gratings were also implanted to study application to smaller features. Samples are characterized by AES, TEM and variable-angle spectroscopic ellipsometry. Composition depth profiles obtained by AES and VASE are compared. Measured lateral and depth profiles are compared to the mask features to assess lateral diffusion, pattern transfer fidelity, and wall-effects. The paper also presents the results of MAGIC calculations of the flux and angle of ion trajectories through the boundary layer predicting the magnitude of flux as a function of 3-D location on objects in the expanding sheath

scholarly journals Adaptive Integration in the Visual Cortex by Depressing Recurrent Cortical Circuits

2008 ◽  
Vol 20 (7) ◽  
pp. 1847-1872 ◽  
Author(s):  
Mark C. W. van Rossum ◽  
Matthijs A. A. van der Meer ◽  
Dengke Xiao ◽  
Mike W. Oram
Keyword(s):  
Visual Cortex ◽  
Physiological Data ◽  
High Contrast ◽  
Cortical Circuits ◽  
Response Latencies ◽  
Low Contrast ◽  
Visual Areas ◽  
Higher Visual Areas ◽  
Recurrent Connections

Neurons in the visual cortex receive a large amount of input from recurrent connections, yet the functional role of these connections remains unclear. Here we explore networks with strong recurrence in a computational model and show that short-term depression of the synapses in the recurrent loops implements an adaptive filter. This allows the visual system to respond reliably to deteriorated stimuli yet quickly to high-quality stimuli. For low-contrast stimuli, the model predicts long response latencies, whereas latencies are short for high-contrast stimuli. This is consistent with physiological data showing that in higher visual areas, latencies can increase more than 100 ms at low contrast compared to high contrast. Moreover, when presented with briefly flashed stimuli, the model predicts stereotypical responses that outlast the stimulus, again consistent with physiological findings. The adaptive properties of the model suggest that the abundant recurrent connections found in visual cortex serve to adapt the network's time constant in accordance with the stimulus and normalizes neuronal signals such that processing is as fast as possible while maintaining reliability.

Research on Moving Target Monitoring Collaborative Simulation Technology Based on Multi-Channel

2010 ◽  
Vol 20-23 ◽  
pp. 700-705
Author(s):  
Tian Yuan ◽  
Shang Guan Wei ◽  
Zhi Zhong Lu
Keyword(s):  
Large Scale ◽  
Target Space ◽  
Laboratory Simulation ◽  
Moving Target ◽  
Simulation Technology ◽  
Collaborative Simulation ◽  
Mobile Target ◽  
Target Monitoring ◽  
Six Degree Of Freedom ◽  
High Degree

Multi-channel Virtual reality simulation technology is a kind of simulation technology, which support the grand scene and high degree of immersion, has better visualization effect. In this paper, a moving target monitoring collaboratory simulation technology based on multi-channel is studied. Firstly, study the mathematical modeling foundation of Multi-Channel technology systematically, based on the mobile target spatial model and co-simulation technology, select the appropriate applications of multi-channel technology, building laboratory simulation platform and achieved a space-based six-degree of freedom simulation of multi-channel moving target monitoring simulation. The experiment has proved that in multi-channel target monitoring co-simulation technology used in this paper has strong practicality, combine with a moving target-space model and co-simulation technology, the advantages of objective observation to solve the requirements like large-scale, realism, immersion requirements, etc.

scholarly journals The epistemic culture in an online citizen science project: Programs, antiprograms and epistemic subjects

2018 ◽  
Vol 48 (4) ◽  
pp. 564-588 ◽  
Author(s):  
Dick Kasperowski ◽  
Thomas Hillman
Keyword(s):  
Citizen Science ◽  
Distributed Cognition ◽  
Large Scale ◽  
Science Project ◽  
Large Sets ◽  
The Galaxy ◽  
Epistemic Culture ◽  
Classification Of Images ◽  
Citizen Science Project

In the past decade, some areas of science have begun turning to masses of online volunteers through open calls for generating and classifying very large sets of data. The purpose of this study is to investigate the epistemic culture of a large-scale online citizen science project, the Galaxy Zoo, that turns to volunteers for the classification of images of galaxies. For this task, we chose to apply the concepts of programs and antiprograms to examine the ‘essential tensions’ that arise in relation to the mobilizing values of a citizen science project and the epistemic subjects and cultures that are enacted by its volunteers. Our premise is that these tensions reveal central features of the epistemic subjects and distributed cognition of epistemic cultures in these large-scale citizen science projects.

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