Detection of Relative Motion

Perception ◽  
1996 ◽  
Vol 25 (1_suppl) ◽  
pp. 71-71
Author(s):  
M A Hogervorst ◽  
A M L Kappers ◽  
J J Koenderink ◽  
J Bongaerts
Keyword(s):  
Reference Frame ◽  
Relative Motion ◽  
Detection System ◽  
Temporal Frequency ◽  
Critical Time ◽  
Critical Distance ◽  
Viewing Distance ◽  
Scale Invariant ◽  
Motion Direction ◽  
Threshold Amplitude

We measured human sensitivity to the relative motion of blobs moving in the peripheral visual field. The stimuli consisted of one or two blobs (Gaussian luminance profiles) oscillating relative to an (invisible) reference frame which rotated with constant angular velocity about a fixation point. We determined thresholds for detecting the oscillation of different configurations of one or two blobs as a function of velocity, eccentricity (viewing distance), and temporal frequency. By determining thresholds as a function of frequency the temporal characteristics of the detection system could be revealed. Thresholds are higher for oscillations in the motion direction of the reference frame than perpendicular to it. No influence has been found of the position of the blobs in the frame of reference. The thresholds are scale-invariant. For low frequencies (<2 Hz) the threshold amplitude of the velocity modulation is constant whereas for high frequencies (>2 Hz) the threshold amplitude of the position modulation is constant. This behaviour can be well described by a model which detects the oscillations whenever, within a critical time (of about 200 ms for two blobs), the relative displacement is larger than a critical distance. The critical distance shows the same dependence on velocity as the span in the bilocal detector model of Koenderink et al (1985 Journal of the Optical Society of America A2 252 – 259).

scholarly journals Image Detection System Using Image Processing

2021 ◽  
Vol 9 (VI) ◽  
pp. 5356-5362
Author(s):  
Mohini Gawande
Keyword(s):  
Image Processing ◽  
Computer Vision ◽  
Detection System ◽  
Estimation Method ◽  
Scale Invariant ◽  
Matrix Estimation ◽  
Speeded Up Robust Features ◽  
Invariant Features ◽  
Marketing Analysis ◽  
New Strategies

The increasing popularity of Social Networks makes change the way people interact. These interactions produce a huge amount of data and it opens the door to new strategies and marketing analysis. According to Instagram and Tumblr, an average of 80 and 59 million photos respectively are published every day, and those pictures contain several implicit or explicit brand logos. Image recognition is one of the most important fields of image processing and computer vision. The CNNs are a very effective class of neural networks that is highly effective at the task of image classifying, object detection and other computer vision problems.in recent years, several scale- invariant features have been proposed in literature, this paper analyzes the usage of Speeded Up Robust Features (SURF) as local descriptors, and as we will see, they are not only scale-invariant features, but they also offer the advantage of being computed very efficiently. Furthermore, a fundamental matrix estimation method based on the RANSAC is applied.

scholarly journals OBSERVER INVARIANCE OF THE COLLAPSE POSTULATE OF QUANTUM MECHANICS

2012 ◽  
Vol 27 (01n03) ◽  
pp. 1345013 ◽  
Author(s):  
MILTON A. DA SILVA ◽  
ROBERTO M. SERRA ◽  
LUCAS C. CÉLERI
Keyword(s):  
Wave Function ◽  
Quantum Mechanics ◽  
Reference Frame ◽  
Relative Motion ◽  
Information Transfer ◽  
Measurement Process ◽  
Quantum Mechanical ◽  
Wave Function Collapse ◽  
Amount Of Information ◽  
Effective Efficiency

We analyze the wave function collapse as seen by two distinct observers (with identical detectors) in relative motion. Imposing that the measurement process demands information transfer from the system to the detectors, we note that although different observers will acquire different amount of information from their measurements due to correlations between spin and momentum variables, all of them will agree about the orthogonality of the outcomes, as defined by their own reference frame. So, in this sense, such a quantum mechanical postulate is observer invariant, however the effective efficiency of the measurement process differs for each observer.

scholarly journals The “twin paradox”: the role of acceleration

2019 ◽  
Vol 97 (10) ◽  
pp. 1049-1063
Author(s):  
J. Gamboa ◽  
F. Mendez ◽  
M.B. Paranjape ◽  
Benoit Sirois
Keyword(s):  
Reference Frame ◽  
Relative Motion ◽  
Complete Resolution ◽  
Proper Time ◽  
The Other ◽  
Twin Paradox ◽  
Age Difference ◽  
Inertial Reference Frame

The “twin paradox” corresponds to the situation where two twins begin at rest in an inertial reference frame, one of them takes a journey, normally very fast and to a distant place, and then returns to the twin at rest. The “twin paradox” evokes the idea that each twin would say that it should be the other who is younger because of their relative motion. A complete resolution of the paradox corresponds to the calculation of the elapsed proper time of each twin, by each twin, and the subsequent observation that they actually get the same answer, that the travelling twin is indeedthe younger twin. Acceleration has a role to play; indeed, if one tries to calculate the age difference from the point of the view of the travelling twin, then the role of the acceleration is crucial and cannot be dismissed. In this tutorial, we show in complete and pedagogical detail, how to do the necessary calculations according to each twin using simple transformations of coordinates.

Rotordynamic Analysis Using the Complex Transfer Matrix

2012 ◽  
Author(s):  
Philip Varney ◽  
Itzhak Green
Keyword(s):  
Reference Frame ◽  
Transfer Matrix ◽  
Reference Frames ◽  
Detection System ◽  
Numerical Technique ◽  
External Support ◽  
Starting Point ◽  
Rotating Reference Frame ◽  
Rotating Reference Frames ◽  
Lumped Masses

The transfer matrix method is an expedient numerical technique for determining the dynamic behavior of a rotordynamic system (e.g., whirl frequencies, steady-state response to forcing). The typical 8 × 8 transfer matrix suffers from several deficiencies. First, for a system incorporating damping, the method generates a characteristic polynomial of degree 8N for a model of N lumped masses (degree 4N for an undamped model). The high degree of the polynomial results in lengthy computation times and decreased accuracy. Second, as discussed herein, the 8 × 8 formulation fails to distinguish between forward and backward whirl. These deficiencies are overcome by a novel complex-valued state variable redefinition resulting in a 4×4 transfer matrix including external support stiffness and damping. The complex transfer matrix is then modified to account for analysis within a rotating reference frame. Analysis in a rotating reference frame is a judicious means to determine unique system fault characteristics, which serve as a starting point for the development of an on-line fault detection system. Insights into using the complex transfer matrix in a rotating reference frame are discussed. Analytical results in both inertial and rotating reference frames for an overhung rotor model are provided.

scholarly journals The effective reference frame in perceptual judgments of motion direction

2015 ◽  
Vol 107 ◽  
pp. 101-112 ◽  
Author(s):  
Mehmet N. Agaoglu ◽  
Michael H. Herzog ◽  
Haluk Öğmen
Keyword(s):  
Reference Frame ◽  
Motion Direction ◽  
Perceptual Judgments

scholarly journals Content-independent orientation detection with histogram of optimized local binary pattern

2021 ◽  
Author(s):  
Nan Dong
Keyword(s):  
Local Binary Pattern ◽  
Detection System ◽  
Human Face ◽  
Scale Invariant ◽  
New Approach ◽  
Impressive Result ◽  
The Face ◽  
Orientation Detection ◽  
Image Orientation ◽  
Future Work

This thesis is primarily concerned with the introduction of a new approach to the general problem of automatic image orientation detection. Inspired by the local binary pattern (LBP), a luminance, rotation and scale invariant and content-independent algorithm is proposed, namely: Histogram of Optimized Local Binary Pattern (HOOPLBP). Whilst the proposed approach is essentially generic, the core application considered in this study is human face orientation detection. To detect the face orientation, a general face model is trained using the HOOPLBP feature. The experiment show a very impressive result. Integrating this result with other face related techniques will facilitate some applications. To this end, this thesis propose a hybrid face detection system. Specifically, the new system aims to detect both upright and tilted human face in digital images. In the scheme, several face related algorithms are integrated to achieve difference tasks in different stages. In addition, two modified systems are used in this thesis to detect faces in both grayscale images and color images. The HOOPLBP is a new and robust method in automatic image orientation detection. It can be improved by other techniques and also can be used in many other fields. The future work is also included in the thesis.

scholarly journals The Reference Frame for Encoding and Retention of Motion-Direction Information Depends on Stimulus Set-size

2017 ◽  
Vol 17 (10) ◽  
pp. 436
Author(s):  
Haluk Ogmen ◽  
Duong Huynh ◽  
Srimant Tripathy ◽  
Harold Bedell
Keyword(s):  
Reference Frame ◽  
Motion Direction ◽  
Set Size ◽  
Stimulus Set ◽  
Direction Information

scholarly journals Cooperative Exploration by Multi-Robots without Global Localization

10.5772/5682 ◽  
2007 ◽  
Vol 4 (3) ◽  
pp. 36 ◽  
Author(s):  
Shi Chao-xia ◽  
Hong Bing-rong ◽  
Wang Yan-qing
Keyword(s):  
Reference Frame ◽  
Mobile Robotics ◽  
Fundamental Problem ◽  
Global Localization ◽  
Scale Invariant ◽  
Topological Map ◽  
Invariant Features ◽  
Unknown Environments ◽  
Efficient Exploration ◽  
Cooperative Exploration

Efficient exploration of unknown environments is a fundamental problem in mobile robotics. We propose a novel topological map whose nodes are represented with the range finder's free beams together with the visual scale-invariant features. The topological map enables teams of robots to efficiently explore environments from different, unknown locations without knowing their initial poses, relative poses and global poses in a certain world reference frame. The experiments of map merging and coordinated exploration demonstrate the proposed map is not only easy for merging, but also convenient for robust and efficient explorations in unknown environments.

Design of Icing Prober Configuration for Horizontal Axis Wind Turbine

2012 ◽  
Vol 608-609 ◽  
pp. 658-661
Author(s):  
Xian Yi ◽  
Kun Chen ◽  
Kai Chun Wang ◽  
Hong Lin Ma
Keyword(s):  
Wind Turbine ◽  
Real Time ◽  
Reference Frame ◽  
Detection System ◽  
Horizontal Axis ◽  
Future Research ◽  
Ice Accretion ◽  
Horizontal Axis Wind Turbine ◽  
Ice Detection ◽  
Multiple Reference

A design approach of ice detection system for wind turbine is presented in this paper. Basic steps for design are proposed. Numerical arithmetic used for design configuration and shape of the icing prober is given. The arithmetic is composed of the Multiple Reference Frame (MRF) method to calculate flowfield of air, a Lagrangian method to compute droplet trajectories and a technique for fast computing ice accretion. Icing prober configuration for a 1.5 MW horizontal axis wind turbine is then obtained with the approach. The state of wind turbine icing can be reflected by the prober in real time. All these achievements build a good base for future research.

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