scholarly journals ĮVAIRAUS SIMETRIJOS LAIPSNIO DAUGIAKAMPIŲ SIMETRIJOS APTIKIMO YPATUMAI

Psichologija ◽  
2005 ◽  
Vol 31 ◽  
pp. 101-112 ◽  
Author(s):  
Ona Gurčinienė ◽  
Alvydas Šoliūnas
Keyword(s):  
Mirror Symmetry ◽  
Small Deviation ◽  
Psychophysical Experiment ◽  
Detection Accuracy ◽  
Detection Time ◽  
Practice Session ◽  
Perfect Symmetry ◽  
The Subject ◽  
Symmetry Perception ◽  
White Colour

Nors veidrodinė arba atspindžio simetrija, kaip svarbi regimųjų vaizdų formos savybė, įvairiapusiškai tiriama, iki šiol neaiškūs jos suvokimo mechanizmai, todėl reikia tolesnių teorinių ir empirinių tyrimų. Dauguma simetrijos suvokimo tyrimų atlikta su specifiniais taškiniais stimulais, reikalaujančiais detalios, taškas po taško analizės. Mūsų manymu, trūksta tyrimų su paprastais plokštuminiais daugiakampiais, kurių simetrija būtų aptinkama globaliai ir greitai. Šis tyrimas atliktas su daugiakampiais, sudarytais 3×3 kvadratų matricos pagrindu, užimančiais 5 kvadratų plotą, pateikiamais trumpai (vidutiniškai 80 ms) galinio maskavimo sąlygomis. Figūros buvo arba idealiai simetrinės arba nesimetrinės, didelio, vidutinio ir mažo simetrijos laipsnio, orientuotos vertikaliai arba horizontaliai. Tiriamasis turėjo atsakyti, nuspausdamas atitinkamą klavišą, ar figūra simetrinė (idealiai simetrinėms), ar nesimetrinė (kad ir koks būtų simetrijos laipsnis). Rezultatai patvirtino vertikalios orientacijos pranašumą horizontalios atžvilgiu. Tiriamieji pagal kokybinius simetrijos ir asimetrijos aptikimo skirtumus suskirstyti į dvi grupes. Didesnė dalis tiriamųjų tiksliau ir greičiau aptinka asimetriją negu simetriją, tiksliau aptinka nedidelius nukrypimus nuo simetrijos, šių tiriamųjų trumpesnis bendras aptikimo laikas, o mažėjant nesimetrinių figūrų simetrijos laipsniui, simetrijos aptikimo laikas trumpėja. Mažesnė dalis tiriamųjų tiksliau ir greičiau aptinka simetriją negu asimetriją, neskiria didžiausio simetrijos laipsnio nesimetrinių figūrų nuo simetrinių, jų ilgesnis bendras aptikimo laikas, beveik nepriklausantis nuo nesimetrinių figūrų simetrijos laipsnio. Vyrai greičiau negu moterys aptinka tiek simetriją, tiek asimetriją. PECULARITIES OF SYMMETRY DETECTION IN POLYGONS WITH DIFFERENT DEGREE OF SYMMETRYOna Gurčinienė, Alvydas Šoliūnas SummaryThough the mirror symmetry is investigated broadly the mechanisms of symmetry perception are not yet known. Most studies of symmetry perception are performed with dot patterns. This paper is devoted to extend the experimental data with different type of stimuli and procedures. The psychophysical experiment was conducted to determine the symmetry and asymmetry detection time and accuracy in the perfectly symmetrical and asymmetrical figures with different degree of symmetry. The figures (plane polygons) were constructed on a base of 3x3 square matrix and covered 5 squares area. The ratio of coincident with noncoincident elements of figures on both sides of axis of symmetry had three different values and indicated the degree of symmetry of asymmetrical figures. The symmetrical and asymmetrical figures were oriented vertically or horizontally and were of white colour on a black background. The exposition duration of figures was defined during the practice session individually for each subject so, that detection accuracy would be approximately 60–90% (it varied from 17 to 300 ms for different subjects). After the figure presentation the white masking square was presented for 500 ms covering the figure. The subject was asked to answer as fast as possible whether the figure was symmetrical or asymmetrical by pressing an appropriate key on a keyboard. Altogether 480 figures were presentated during the experiment that lasted about 40 minutes.The experimental results confirmed the advantage of vertical symmetry over the horizontal, that is the vertically symmetrical figures were detected more accurately and faster than horizontally symmetrical ones. Averaged results of all subjects indicated that the detection accuracy of asymmetry increased and the detection time decreased as the degree of symmetry of asymmetrical figures decreased. Depending on qualitative differences in the symmetry and asymmetry detection the subjects were divided into two groups. Majority of subjects detected asymmetry more accurately and faster than symmetry, and theirs detection time of asymmetry decreased as a degree of symmetry decreased. They detected the small deviation from perfect symmetry more accurately and theirs averaged detection time was shorter than it was for other subjects, which detected symmetry more accurately and faster than asymmetry. Last-mentioned subjects did not discriminate the asymmetrical figures with highest degree of symmetry from symmetrical ones, and the detection time of asymmetry almost did not depend on the degree of symmetry of asymmetrical figures. Detection time of symmetry and asymmetry was shorter for male than female subjects. The implications of individual differences in symmetry and asymmetry detection are discussed.

scholarly journals Symmetry perception with spiking neural networks

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jonathan K. George ◽  
Cesare Soci ◽  
Mario Miscuglio ◽  
Volker J. Sorger
Keyword(s):  
Neural Networks ◽  
Mirror Symmetry ◽  
Satellite Image ◽  
Image Data ◽  
Coincidence Detection ◽  
Spiking Neural Networks ◽  
Feed Forward Neural Network ◽  
Neuromorphic Computing ◽  
Symmetry Perception ◽  
High Level

AbstractMirror symmetry is an abundant feature in both nature and technology. Its successful detection is critical for perception procedures based on visual stimuli and requires organizational processes. Neuromorphic computing, utilizing brain-mimicked networks, could be a technology-solution providing such perceptual organization functionality, and furthermore has made tremendous advances in computing efficiency by applying a spiking model of information. Spiking models inherently maximize efficiency in noisy environments by placing the energy of the signal in a minimal time. However, many neuromorphic computing models ignore time delay between nodes, choosing instead to approximate connections between neurons as instantaneous weighting. With this assumption, many complex time interactions of spiking neurons are lost. Here, we show that the coincidence detection property of a spiking-based feed-forward neural network enables mirror symmetry. Testing this algorithm exemplary on geospatial satellite image data sets reveals how symmetry density enables automated recognition of man-made structures over vegetation. We further demonstrate that the addition of noise improves feature detectability of an image through coincidence point generation. The ability to obtain mirror symmetry from spiking neural networks can be a powerful tool for applications in image-based rendering, computer graphics, robotics, photo interpretation, image retrieval, video analysis and annotation, multi-media and may help accelerating the brain-machine interconnection. More importantly it enables a technology pathway in bridging the gap between the low-level incoming sensor stimuli and high-level interpretation of these inputs as recognized objects and scenes in the world.

scholarly journals Effects of Element Type and Spatial Grouping on Symmetry Detection

Perception ◽  
1993 ◽  
Vol 22 (5) ◽  
pp. 565-587 ◽  
Author(s):  
Paul J Locher ◽  
Johan Wagemans
Keyword(s):  
Mirror Symmetry ◽  
Symmetry Axis ◽  
Detection Accuracy ◽  
Axis Orientation ◽  
Primal Sketch ◽  
Affect Detection ◽  
Spatial Grouping ◽  
Element Type ◽  
Random Patterns ◽  
Advance Knowledge

The influence of local and global attributes of symmetric patterns on the perceptual salience of symmetry was investigated. After tachistoscopic viewing, subjects discriminated between symmetric and either random patterns (experiment 1) or their perturbed counterparts (experiment 2) created by replacing one third of the mirror element-pairs of symmetric stimuli with ‘random’ elements. In general, it was found that perceptibility of symmetry, measured by response time and detection accuracy, was not influenced in a consistent way by type of pattern element (dots or line segments oriented vertically, horizontally, obliquely, or in all three orientations about the symmetry axis). Nor did axis orientation (vertical, horizontal, oblique), advance knowledge of axis orientation, practice effects, or subject sophistication differentially affect detection. A highly salient global percept of symmetry emerged, on the other hand, when elements were clustered together within a pattern, or grouped in symmetric pairs along a single symmetry axis or two orthogonal axes. Results suggest that mirror symmetry is detected preattentively, presumably by some kind of integral code which emerges from the interaction between display elements and the way they are organized spatially. It is proposed that symmetry is coded and signalled by the same spatial grouping processes as those responsible for construction of the full primal sketch.

scholarly journals An Enhanced Multimedia Video Surveillance Security Using Wavelet Encryption Framework

2020 ◽  
Author(s):  
Velliangiri S
Keyword(s):  
Wavelet Transform ◽  
False Positive Rate ◽  
Digital Data ◽  
Detection Accuracy ◽  
Detection Time ◽  
Arbitrary Permutation ◽  
Secret Keys ◽  
Positive Rate ◽  
Cae System ◽  
Distortion Rate

Multimedia digital data include medical record and financial documents, which are not guaranteed with security. The concerns for security of multimedia digital data is been a widespread issue in the field of cybernetics. With increasing malwares in video payloads, the proposed study aims to reduce the embedding of malwares using Pseudo Arbitrary Permutation based Cellular Automata Encryption (PAP-CAE) System in video payloads. This method reduces the malware attacks and distortion rate by permuting the secret keys with Pseudo arbitrary permutation. Before the application of PAP-CAE, 2D wavelet transform is applied on the multimedia files that compresses the complex files into different scales and position to be transmitted via a network with reduced size. Simultaneously, it performs the process of decryption and decompression to retrieve the original files. The proposed method is evaluated against existing methods to test its efficacy in terms of detection accuracy, detection time of malwares and false positive rate. The result shows that the proposed method is effective against the detection of malwares in multimedia video files.

Target Detection, Rifle Marksmanship, and Mood during Three Hours of Simulated Sentry Duty

1989 ◽  
Vol 33 (20) ◽  
pp. 1414-1418 ◽  
Author(s):  
Richard F. Johnson ◽  
Donna J. McMenemy
Keyword(s):  
Target Detection ◽  
Rating Scale ◽  
Test Session ◽  
Profile Of Mood States ◽  
Detection Time ◽  
Target Speed ◽  
The Subject ◽  
Time Required ◽  
Duty Time ◽  
Over Time

The purpose of this study was to evaluate the effects of sentry duty time on the soldier's speed of detection of visually presented targets, his ability to hit targets (rifle marksmanship), and his mood. Prior to the test day, each of eight subjects was given five days of training on the Weaponeer Rifle Marksmanship Simulator and was familiarized with the targets to be presented during testing. The test session lasted three hours, during which time the subject assumed a standing foxhole position and monitored the target scene of the Weaponeer. The Weaponeer M16A1 modified rifle lay next to the subject at chest height. When a pop-up target appeared, the subject pressed a telegraph key, lifted the rifle, aimed, and fired at the target. Speed of target detection was measured in terms of the time required by the subject to press the telegraph key in response to the presentation of the target. Marksmanship was measured in terms of number of targets hit. Target detection time and rifle marksmanship were averaged every 30 minutes. At the end of the test session, the subject completed the Profile of Mood States rating scale. The results showed that target detection time deteriorated with time on sentry duty; impairments were not evident within the first hour but were clearly evident by 1.5 hours. Marksmanship remained constant over time; soldiers were just as accurate in hitting the targets at the end of the 3 hours of sentry duty as they were at the beginning. Whereas the soldier's predominant mood during baseline practice sessions was one of vigor, during sentry duty the predominant mood was one of fatigue. The results of this study suggest that sentry duty performance may be optimized if it is limited to one hour or less.

Impaired and superior mirror symmetry perception in autism

Autism ◽  
2012 ◽  
Vol 17 (1) ◽  
pp. 117-118 ◽  
Author(s):  
Christine M. Falter
Keyword(s):  
Mirror Symmetry ◽  
Symmetry Perception

scholarly journals WHAT'S IN A NAME?

2004 ◽  
Vol 15 (03) ◽  
pp. 371-379 ◽  
Author(s):  
LUCIANO DA FONTOURA COSTA
Keyword(s):  
Complex Network ◽  
English Language ◽  
Power Laws ◽  
Psychophysical Experiment ◽  
The Hierarchical Structure ◽  
The Subject ◽  
Attraction Basins ◽  
Strange Loops ◽  
The Brain

Among the several findings deriving from the application of complex network formalism to the investigation of natural phenomena, the fact that linguistic constructions follow power laws presents special interest for its potential implications for psychology and brain science. By corresponding to one of the most essentially human manifestations, such language-related properties suggest that similar dynamics may also be inherent to the brain areas related to language and associative memory, and perhaps even consciousness. The present work reports a preliminary experimental investigation aimed at characterizing and modeling the flow of sequentially induced associations between words from the English language in terms of complex networks. The data is produced through a psychophysical experiment where a word is presented to the subject, who is requested to associate another word. Complex network and graph theory formalism and measurements are applied in order to characterize the experimental data. Several interesting results are identified, including the characterization of attraction basins, association asymmetries, context biasing, as well as a possible power-law underlying word associations, which could be explained by the appearance of strange loops along the hierarchical structure underlying word categories.

Introduction

2017 ◽  
Author(s):  
Dusa McDuff ◽  
Dietmar Salamon
Keyword(s):  
Mirror Symmetry ◽  
Complex Geometry ◽  
Equations Of Motion ◽  
Classical Mechanics ◽  
Hamiltonian Formalism ◽  
Theoretical Physics ◽  
Lagrange Equations ◽  
Low Dimensional Topology ◽  
The Subject ◽  
Low Dimensional

Symplectic topology has a long history. It has its roots in classical mechanics and geometric optics and in its modern guise has many connections to other fields of mathematics and theoretical physics ranging from dynamical systems, low-dimensional topology, algebraic and complex geometry, representation theory, and homological algebra, to classical and quantum mechanics, string theory, and mirror symmetry. One of the origins of the subject is the study of the equations of motion arising from the Euler–Lagrange equations of a one-dimensional variational problem. The Hamiltonian formalism arising from a Legendre transformation leads to the notion of a ...

The effect of vision on tactile TOJ during arm crossing

2012 ◽  
Vol 25 (0) ◽  
pp. 35
Author(s):  
Makoto Wada ◽  
Kenji Kansaku
Keyword(s):  
Significant Role ◽  
Temporal Order ◽  
Temporal Order Judgment ◽  
Psychophysical Experiment ◽  
Eyes Closed ◽  
Tactile Stimuli ◽  
Eyes Open ◽  
The Subject ◽  
Opening And Closing ◽  
Tactile Temporal Order Judgment

When people cross their arms, subjective rank ordering of successive unseen tactile stimuli delivered to both arms is affected (often being reversed) (Shore et al., 2002; Yamamoto and Kitazawa, 2001). It is also known that vision plays a significant role in modulating perceived limb position (Graziano et al., 2000). In this study, we examined the effect of vision; i.e., eyes opening and closing on tactile temporal order judgment (TOJ) with their arms crossed or uncrossed. In a psychophysical experiment, participants (, 13 males, 27.3 ± 1.8 y.o.) were required to judge temporal order of two tactile stimuli that were delivered to their both ring fingers with four conditions: uncrossed arms with eyes closed, crossed arms with eyes closed, uncrossed arms with eyes open and crossed arms with eyes open. To evaluate judgment probabilities of the participants, degree of reversals of their judgment was calculated as the sum of differences between correct response rates of the arms crossed condition and those of the arms uncrossed condition. In arms uncrossed conditions, judgment probabilities of the participants were not significantly different between eyes closed and open conditions. In contrast, reversal of the judgment with eyes closed was significantly larger than that with eyes open in arms crossed conditions (). The results suggest that vision play a significant role in tactile order judgment when the subject arms crossed.

scholarly journals Temporal dynamics of mirror-symmetry perception

2018 ◽  
Vol 18 (5) ◽  
pp. 10 ◽  
Author(s):  
Rebecca J. Sharman ◽  
Sebastian Gregersen ◽  
Elena Gheorghiu
Keyword(s):  
Mirror Symmetry ◽  
Temporal Dynamics ◽  
Symmetry Perception

A Collaborative Reputation-Based Vector Space Model for Email Spam Filtering

2018 ◽  
Vol 15 (2) ◽  
pp. 474-479 ◽  
Author(s):  
P. Mano Paul ◽  
R. Ravi
Keyword(s):  
Vector Space ◽  
False Negative ◽  
False Negative Rate ◽  
Vector Space Model ◽  
Spam Detection ◽  
Detection Accuracy ◽  
Detection Time ◽  
Good Efficiency ◽  
Space Model ◽  
Email Spam

In this paper, we propose a novel Collaborative Reputation-based Vector Space Model (CRVSM) for detection of spam email. CRVSM uses a vector space model for representing the feature vectors in multidimensional vector space in order to detect the spam emails in large space. We cluster the emails into five clusters so as to reduce the email spam detection time. To reduce the number of false positives and false negatives, we calculate maximum similarity measure with maximum and minimum threshold range. Moreover we use a reputation evaluation function which determines the reporter's trust level in validating an email as spam or non-spam. The CRVSM approach achieves good efficiency while obtaining good reputation result in Email spam detection. The performance of CRVSM model has been evaluated using metrics such as false positive rate, false negative rate, detection accuracy and detection time. The performance results clearly show that CRVSM accurately detects the incoming emails as spam or non-spam with less FPR and FNR values thereby achieving a high efficiency with short detection time and outperforms the existing detection protocols.

Sign in / Sign up

Export Citation Format

Share Document