A fast coding algorithm based on variance and irregular region

2012 ◽  
Author(s):  
Fajin Gao ◽  
Guangfen Wei
Keyword(s):  
Irregular Region

An Effective Image Matching Algorithm Based on Rotation Independence

2013 ◽  
Vol 347-350 ◽  
pp. 3685-3690
Author(s):  
Xian Ying Huang ◽  
Wei Wei Chen
Keyword(s):  
Image Matching ◽  
Irregular Shape ◽  
Matching Accuracy ◽  
Similarity Comparison ◽  
Matching Algorithm ◽  
Irregular Shapes ◽  
Irregular Region ◽  
Histogram Intersection ◽  
Intersection Method ◽  
Traditional Image

Traditional image matching algorithms has poor accuracy in image comparing, such as histogram intersection method. A new image matching algorithm based on the similarity comparison of irregular shape is presented in this paper, which divides the image into a number of irregular regions according to different colors, and extracts the boundary points of the irregular region to compose an irregular shape. The direction and distance is used to comparing the two irregular shapes if the rotation of the image is not considered, otherwise circular list is used to ignore the image rotation. It can be used widely. If two irregular shapes are similar, the two images are considered similar. Experiment proves that this method can effectively improve the image matching accuracy.

Surface waves in structures with locally irregular boundaries

1980 ◽  
Vol 70 (3) ◽  
pp. 791-808
Author(s):  
Anne Suteau ◽  
Louis Martel
Keyword(s):  
Surface Waves ◽  
Body Wave ◽  
Complex Structure ◽  
Additional Term ◽  
The Body ◽  
Body Waves ◽  
First Order ◽  
Irregular Region ◽  
Regular Medium ◽  
General Method

abstract The transmitted field due to surface waves incident on a local irregularity of a plane-layered medium has been studied. A perturbation method to the first order and the Born approximation can be used if the variations in the thickness of the layers are sufficiently smooth and the wavelengths are long when compared to the size of the irregularities. The spectrum of the perturbed part of the displacement field at the surface is a sum over the surface-wave modes for the regular medium, with an additional term involving the scattered body waves. Numerical computations have been performed for structures composed of a layer overlying a half-space. The contribution of the various modes to the transmitted Love or Rayleigh fields has been studied for several structures. A general method has been obtained to analyze the effect of a complex structure as the superposition of the fields due to simpler ones. When the layer thickness is kept unchanged, the incident mode is not perturbed to the first order. Synthetic seismograms, computed at stations sufficiently close to the irregular region, show how the perturbation of the signal depends on distance. A comparison has been made for Love waves with a finite element method. Both methods give very similar results when the stations are not too close to the irregularities so that the body-wave contribution is negligible. The local phase velocity shows departures from the curves for a regular model.

Control architecture of autonomous underwater vehicle for coverage mission in irregular region

2021 ◽  
Vol 236 ◽  
pp. 109407
Author(s):  
Guanzhong Chen ◽  
Yue Shen ◽  
Nanzhu Qu ◽  
Dianrui Wang ◽  
Bo He
Keyword(s):  
Autonomous Underwater Vehicle ◽  
Underwater Vehicle ◽  
Control Architecture ◽  
Irregular Region

Structural studies of reelin N-terminal region provides insights into a unique structural arrangement and functional multimerization

2020 ◽  
Author(s):  
Masamichi Nagae ◽  
Kei Suzuki ◽  
Norihisa Yasui ◽  
Terukazu Nogi ◽  
Takao Kohno ◽  
...  
Keyword(s):  
Domain Architecture ◽  
Terminal Region ◽  
Adult Brain ◽  
Structural Studies ◽  
Irregular Domain ◽  
Inhibitory Antibody ◽  
Brain Functions ◽  
Irregular Region ◽  
Self Association ◽  
Embryonic Brain Development

Abstract The large, secreted glycoprotein reelin regulates embryonic brain development as well as adult brain functions. Although reelin binds to its receptors via its central part, the N-terminal region directs multimer formation and is critical for efficient signal transduction. In fact, the inhibitory antibody CR-50 interacts with the N-terminal region and prevents higher-order multimerization and signaling. Reelin is a multidomain protein in which the central part is composed of eight characteristic repeats, named reelin repeats, each of which is further divided by insertion of an EGF module into two subrepeats. In contrast, the N-terminal region shows unique “irregular” domain architecture since it comprises three consecutive subrepeats without the intervening EGF module. Here we determined the crystal structure of the murine reelin fragment named RX-R1 including the irregular region and the first reelin repeat at 2.0 Å resolution. The overall structure of RX-R1 has a branched Y-shaped form. Interestingly, two incomplete subrepeats cooperatively form one entire subrepeat structure, though an additional subrepeat is inserted between them. We further reveal that Arg335 of RX-R1 is crucial for binding CR-50. A possible self-association mechanism via the N-terminal region is proposed based on our results.

Configuration of Random Transducer Array in Irregular Region Based on Delaunay Triangulation

2010 ◽  
Vol 29-32 ◽  
pp. 1085-1090
Author(s):  
Shi Lin Wu ◽  
Qi Zhang ◽  
Zhi Ping Huang
Keyword(s):  
Delaunay Triangulation ◽  
Linear Array ◽  
Minimum Variance ◽  
Uniform Linear Array ◽  
Transducer Array ◽  
Irregular Region ◽  
Random Array ◽  
Minimum Variance Distortionless Response ◽  
Uniform Plane ◽  
Better Than

To realize the configuration of a cymbal transducer array in an irregular region, Delaunay triangulation is adopted to mesh the irregular region and the vertices of the Delaunay triangular mesh are regarded as the positions of the array elements. In this way, a random array of cymbal transducers is formed. Minimum Variance Distortionless Response (MVDR) beamformer is used to optimize the beam of the random array, and the directivity simulation is carried out in MATLAB. The results show that the directivity of the random array within the irregular region is better than that of the uniform linear array and that of the uniform plane array configured in the same region.

Application of the method of integral equations based on the Lorentz lemma for calculation of matching transitions between rectangular waveguides with offset axes

Antennas ◽  
2021 ◽  
Author(s):  
S. M. Garanin ◽  
I. N. Danilov ◽  
A. V. Kashin ◽  
A. Yu. Sedakov
Keyword(s):  
Electromagnetic Wave ◽  
Integral Equations ◽  
Longitudinal Section ◽  
Fundamental Wave ◽  
Transmission Characteristics ◽  
Method Of Integral Equations ◽  
Waveguide Transition ◽  
Irregular Region ◽  
Analytical Algorithm ◽  
Rectangular Waveguides

This work presents a brief description of the method of integral equations. Integral equations are obtained on the basis of the integral form of Lorentz's lemma using a non-standard physical approach. This method allows one to calculate the characteristics of various three-dimensional irregularities of the waveguide path. As an example of such irregularity, the considered transition between straight shielded waveguides with offset axes and with different transverse sizes. The main attention is paid to the description of the developed numerical-analytical algorithm for calculating the transmission characteristics of the matching transition. A procedure for obtaining an approximate record of the field components on the surface of an irregular region is presented, which makes it possible to take into account the curvature of the wave surface of an electromagnetic wave propagating in the guiding structure. In this case, the profile of the longitudinal section of the guiding structure can be described by any analytical functions. The concept of a 4W-fold comparison waveguide is introduced. In addition, this paper presents the results of calculating the frequency dependences of the transmission characteristics of the fundamental wave of waveguide transition at displacements of the axis of the second waveguide relative to the axis of the first waveguide by different values. The indicated transmission characteristics are found for single-mode and multimode modes of operation of the waveguide transition. In order to verify the results obtained, they have been compared with the results obtained using a modern licensed computer-aided design tool CST Microwave Studio. To demonstrate the possibility of solving the problem of “functional” optimization using the developed algorithm, the results of calculating the transmission characteristics of a waveguide transition between rectangular waveguides with cosine functions describing the profile of the longitudinal section of an irregular region have been presented. In order to indirectly substantiate the equivalence of the initial integral equations underlying the constructed algorithm and the problem of diffraction of an electromagnetic wave in a waveguide transition, a test problem of calculating the transmission characteristics of a stepped transition of two rectangular regular waveguides with different sizes has been solved. The calculation results have been compared with the results obtained on the basis of the electrodynamic substantiated method of half-inversion of the operator of the original boundary value problem. In addition to all the above, in order to assess the validity of the proposed method and the numerical-analytical algorithm built on its basis, a study of the convergence of the calculated results against the approximation number has been made.

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