An efficient algorithm for planning collision-free translational motion of a convex polygonal object in 2-dimensional space amidst polygonal obstacles

1985 ◽  
Author(s):  
K. Kedem ◽  
M. Sharir
Keyword(s):  
Efficient Algorithm ◽  
Dimensional Space ◽  
Translational Motion

An Efficient Algorithm for Traffic Sign Detection

2006 ◽  
Vol 10 (3) ◽  
pp. 409-418 ◽  
Author(s):  
Aryuanto Soetedjo ◽  
◽  
Koichi Yamada ◽  
Keyword(s):  
Objective Function ◽  
Efficient Algorithm ◽  
Template Matching ◽  
Dimensional Space ◽  
Random Search ◽  
Computation Time ◽  
False Alarms ◽  
Detection Accuracy ◽  
Traffic Sign ◽  
Traffic Signs

We propose an efficient algorithm for detecting traffic signs in images.Geometric fragmentationdetects circular red traffic signs in an image by finding and combining the left and right fragments of elliptical objects to increase the accuracy of detection and cope with occlusion. The search for fragments resembles a genetic algorithm (GA) in that it uses the termsindividual,population,crossover, andobjective functionused in the GA. It is different in that it conducts a concurrent random search in a small two-dimensional space devised heuristically. The objective function for evaluating individuals is devised to increase detection accuracy and reduce computation time. The algorithm was tested for detecting circular red traffic signs both from artificial sign images and real scene images. Experimental results demonstrated that the proposed algorithm has higher detection, fewer false alarms, and lower computation cost than GA-based ellipse detection. Compared to conventional template matching, the proposed algorithm performs better in detection and execution time and does not require a large number of carefully prepared templates.

N-dimensional Numerical Integration over a Delta Function

1991 ◽  
Vol 02 (01) ◽  
pp. 331-336 ◽  
Author(s):  
T.J. DRYE ◽  
J.W. TUCKER
Keyword(s):  
Numerical Integration ◽  
Efficient Algorithm ◽  
Dimensional Space ◽  
Delta Function

We present a method of numerical integration over N-dimensional space of integrals containing a delta function constraint. The method outlined below extends the method of Kaprzyk and Mijnarends and describes an efficient algorithm for N-dimensional tessellation.

An Efficient Algorithm for Shortest Path in Three Dimensions With Polyhedral Obstacles

1989 ◽  
Vol 111 (3) ◽  
pp. 433-436 ◽  
Author(s):  
J. Khouri ◽  
K. A. Stelson
Keyword(s):  
Shortest Path ◽  
Efficient Algorithm ◽  
Dimensional Space ◽  
Three Dimensional ◽  
Three Dimensions ◽  
Minimum Length ◽  
Precise Location ◽  
Computer Storage ◽  
Polyhedral Obstacles ◽  
Three Dimensional Space

An algorithm to find the shortest path between two specified points in three-dimensional space in the presence of polyhedral obstacles is described. The proposed method iterates for the precise location of the minimum length path on a given sequence of edges on the obstacles. The iteration procedure requires solving a tri-diagonal matrix at each step. Both the computer storage and the number of computations are proportional to n, the number of edges in the sequence. The algorithm is stable and converges for the general case of any set of lines, intersecting, parallel or skew.

scholarly journals Integrated Trajectory Planning and Sloshing Suppression for Three-Dimensional Motion of Liquid Container Transfer Robot Arm

2015 ◽  
Vol 2015 ◽  
pp. 1-15 ◽  
Author(s):  
Wisnu Aribowo ◽  
Takahito Yamashita ◽  
Kazuhiko Terashima
Keyword(s):  
Trajectory Planning ◽  
Dimensional Space ◽  
Translational Motion ◽  
Three Dimensional ◽  
Joint Space ◽  
Robot Arm ◽  
Task Space ◽  
Robot Wrist ◽  
Point To Point ◽  
Sloshing Suppression

For liquid transfer system in three-dimensional space, the use of multijoint robot arm provides much flexibility. To realize quick point-to-point motion with minimal sloshing in such system, we propose an integrated framework of trajectory planning and sloshing suppression. The robot motion is decomposed into translational motion of the robot wrist and rotational motion of the robot hand to ensure the upright orientation of the liquid container. The trajectory planning for the translational motion is based on cubic spline optimization with free via points that produces smooth trajectory in joint space while it still allows obstacle avoidance in task space. Input shaping technique is applied in the task space to suppress the motion induced sloshing, which is modeled as spherical pendulum with moving support. It has been found through simulations and experiments that the proposed approach is effective in generating quick motion with low amount of sloshing.

The motion of a lunar orbiter

1966 ◽  
Vol 25 ◽  
pp. 373
Author(s):  
Y. Kozai
Keyword(s):  
Degrees Of Freedom ◽  
Dimensional Space ◽  
Artificial Satellite ◽  
Equations Of Motion ◽  
Triaxial Ellipsoid ◽  
The Moon ◽  
Secular Motion ◽  
The Earth ◽  
Close Satellite ◽  
The Mean

The motion of an artificial satellite around the Moon is much more complicated than that around the Earth, since the shape of the Moon is a triaxial ellipsoid and the effect of the Earth on the motion is very important even for a very close satellite.The differential equations of motion of the satellite are written in canonical form of three degrees of freedom with time depending Hamiltonian. By eliminating short-periodic terms depending on the mean longitude of the satellite and by assuming that the Earth is moving on the lunar equator, however, the equations are reduced to those of two degrees of freedom with an energy integral.Since the mean motion of the Earth around the Moon is more rapid than the secular motion of the argument of pericentre of the satellite by a factor of one order, the terms depending on the longitude of the Earth can be eliminated, and the degree of freedom is reduced to one.Then the motion can be discussed by drawing equi-energy curves in two-dimensional space. According to these figures satellites with high inclination have large possibilities of falling down to the lunar surface even if the initial eccentricities are very small.The principal properties of the motion are not changed even if plausible values ofJ3andJ4of the Moon are included.This paper has been published in Publ. astr. Soc.Japan15, 301, 1963.

Three Dimensional structure and organization of diploid chromosomes by optical section microscopy

1987 ◽  
Vol 45 ◽  
pp. 633-635
Author(s):  
David A. Agard ◽  
Yasushi Hiraoka ◽  
John W. Sedat
Keyword(s):  
Dimensional Space ◽  
Three Dimensional ◽  
Developmental State ◽  
Mitotic Cell ◽  
Biological Properties ◽  
Dimensional Structure ◽  
Specific Gene ◽  
Three Dimensional Structure ◽  
Complementary Techniques ◽  
Dynamic Structures

In an effort to understand the complex relationship between structure and biological function within the nucleus, we have embarked on a program to examine the three-dimensional structure and organization of Drosophila melanogaster embryonic chromosomes. Our overall goal is to determine how DNA and proteins are organized into complex and highly dynamic structures (chromosomes) and how these chromosomes are arranged in three dimensional space within the cell nucleus. Futher, we hope to be able to correlate structual data with such fundamental biological properties as stage in the mitotic cell cycle, developmental state and transcription at specific gene loci.Towards this end, we have been developing methodologies for the three-dimensional analysis of non-crystalline biological specimens using optical and electron microscopy. We feel that the combination of these two complementary techniques allows an unprecedented look at the structural organization of cellular components ranging in size from 100A to 100 microns.

Computational Micrograph Registration with Sieve Processes

1996 ◽  
Vol 54 ◽  
pp. 440-441
Author(s):  
P.J. Phillips ◽  
J. Huang ◽  
S. M. Dunn
Keyword(s):  
Planar Graph ◽  
Efficient Algorithm ◽  
Spatial Organization ◽  
Spatial Arrangement ◽  
Stereo Image ◽  
Image Model ◽  
Geometric Invariants ◽  
Point Set

In this paper we present an efficient algorithm for automatically finding the correspondence between pairs of stereo micrographs, the key step in forming a stereo image. The computation burden in this problem is solving for the optimal mapping and transformation between the two micrographs. In this paper, we present a sieve algorithm for efficiently estimating the transformation and correspondence.In a sieve algorithm, a sequence of stages gradually reduce the number of transformations and correspondences that need to be examined, i.e., the analogy of sieving through the set of mappings with gradually finer meshes until the answer is found. The set of sieves is derived from an image model, here a planar graph that encodes the spatial organization of the features. In the sieve algorithm, the graph represents the spatial arrangement of objects in the image. The algorithm for finding the correspondence restricts its attention to the graph, with the correspondence being found by a combination of graph matchings, point set matching and geometric invariants.

Diffraction contrast of dislocations in icosahedral quasicrystals

1990 ◽  
Vol 48 (4) ◽  
pp. 454-455
Author(s):  
K. Urban ◽  
Z. Zhang ◽  
M. Wollgarten ◽  
D. Gratias
Keyword(s):  
Dimensional Space ◽  
Three Dimensional ◽  
Complete Characterization ◽  
Extinction Condition ◽  
Burgers Vector ◽  
Diffraction Contrast ◽  
Lattice Geometry ◽  
Reference Space ◽  
Icosahedral Quasicrystals ◽  
The One

Recently dislocations have been observed by electron microscopy in the icosahedral quasicrystalline (IQ) phase of Al65Cu20Fe15. These dislocations exhibit diffraction contrast similar to that known for dislocations in conventional crystals. The contrast becomes extinct for certain diffraction vectors g. In the following the basis of electron diffraction contrast of dislocations in the IQ phase is described. Taking account of the six-dimensional nature of the Burgers vector a “strong” and a “weak” extinction condition are found.Dislocations in quasicrystals canot be described on the basis of simple shear or insertion of a lattice plane only. In order to achieve a complete characterization of these dislocations it is advantageous to make use of the one to one correspondence of the lattice geometry in our three-dimensional space (R3) and that in the six-dimensional reference space (R6) where full periodicity is recovered . Therefore the contrast extinction condition has to be written as gpbp + gobo = 0 (1). The diffraction vector g and the Burgers vector b decompose into two vectors gp, bp and go, bo in, respectively, the physical and the orthogonal three-dimensional sub-spaces of R6.

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