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The results of comparative calculations of radar cross section of polydisperse medium with ellipsoidal drops and Pruppacher-Pitter drops are described in paper. The data obtained for dipole scattering, the spherical drop approximation of equivalent volume and rigorous calculation on the base of method of moments for both kinds of drops.
Contour representation is an important application in image compression, template matching, object detection and recognition. However, it is far from meeting the current requirement due to the expensive computational cost and complex noise in the real-world application. In order to make contour representation more practical, we propose a novel approach of abstracting contours of the objects in an...
In this article SEM-images of experimental monocrystal field emitter tips are studied. As a result of digital image processing the point chart of selected sample surface contour is received. It is defined which of three considered surfaces of revolution of the second order (an ellipsoid of rotation, a cavity of a two-sheeted hyperboloid, a rotation paraboloid) in the best way approximates this contour...
Shape from focus (SFF), represents a passive technique in recovering object shapes from scenes. In SFF systems, a single imaging device is used to acquire images followed by the application of Focus Measure (FM) at every point to obtain focus quality, to obtain depth by maximizing the focus curves. Although numerous focus measures have been recently proposed, less attention has been paid to the factors...
The medial axis (or a topological skeleton) is a thinner version of a geometric object The medial axis was first introduced by Blum as a description of shape. Its classical definitions include grass-fire model and maximal disk model The grass-fire model means that an object's boundary is taken as an initial fire front that propagates within the object's interior region. Points where the fire front...
We deal with the performance prediction of the incoherent radar receiver (i.e. squared-law plus integrator) in the presence of independent and possibly non-identically distributed target backscattered echoes. Specifically, we first approximate the lognormal sums with a new lognormal probability density function (pdf). Based on the approximation, we develop an approximate expression of the detection...
Endowing mobile manipulation robots with skills to use objects and tools often involves the programming or training on specific object instances. To apply this knowledge to novel instances from the same class of objects, a robot requires generalization capabilities for control as well as perception. In this paper, we propose an efficient approach to deformable registration of RGB-D images that enables...
In this paper, a target shape reconstruction by using electromagnetic wave in resonance region is proposed. A hybrid level set method and linear sampling method used to reconstruction perfectly electric conducting three dimensional scatterer. The Incident plane wave with frequency 300MHz and uniform directional diversity is exploited to illuminate the corresponding scatterer and the scattered field...
We present verified computational solutions of a one-dimensional nonlinear Poisson equation with Neumann boundary condition. This equation is derived from the Keller-Segel system known as chemotactic model by steady state, and its solution curve possesses a turning point. Using the idea of the shooting method for the boundary value problems, we transform this equation into two integral equations corresponding...
We present in-situ measurements of pulse dynamics along a femtosecond filament. Pulse-splitting has been observed, resulting in self-compression to 5.3 fs, influencing high-order harmonic generation along the filament.
Parametric representation for curves is important in computer-aided geometric design, medical imaging, computer vision, computer graphics, shape matching, and face/object recognition. They are far better alternatives to free form representation, which are plagued with unboundedness and stability problems. This paper deals with the problem of fitting approximating B-spline curves with high compression...
In relay communications, the system performances depend heavily on the statistical distances between the source, relay(s) and destination, since the signal strength decays superlinearly with distance. The capacity analysis of relay systems is non-trivial as the relay node(s) is(are) usually randomly located in the network. In this paper, a stochastic geometric approach is presented to analytically...
We propose a planning method for a gripper grasping daily life objects using quadric surface approximation. This method can decompose the objects to the approximate quadric surfaces. The planner can find regions for contacting fingers quickly so that the gripper grasps the object firmly. The planner evaluates the grasp stability for these postures. The previous evaluation method in surface contact...
We present a novel 3D ear shape matching algorithm. Firstly, we compute the saliency value of every point in 3D ear point cloud using the Gaussian-weighted average of the mean curvature, sort the points in accordance with their saliency value, Then we get the salient key points set using the poisson sampling. Finally, we fit the neighborhood of each salient key point using quadratic principal manifold,...
We propose a facial aging simulator which can synthesize a photo realistic human aged-face image for criminal investigation. Our aging simulator is based on the patch-based facial texture reconstruction with a wrinkle aging pattern model. The advantage of our method is to synthesize an aged-face image with detailed skin texture such as spots and somberness of facial skin, as well as age-related facial...
In this work we present a local comparison approach of deformable 3D models. Two types of deformation are discussed. The first is volume change which is caused by either an increase or a decrease of the body volume. In the second type of deformation, the volume of the model is not altered but the change in shape results from either an articulation or a bending of parts of the object. Our strategy...
There is strong interest in fast, accurate automated examination and detection of pathologies in vocal-fold function. Such systems could assist in detecting abnormalities during screenings, monitor treatment progress, and compare results after therapy or surgical intervention. It has been shown that analysis of the vocal-fold area as a function of time can be beneficial in the detection and diagnosis...
A moving polygonal object takes up large storage space in moving database, which incurs heavy disk I/O cost in querying process. Motivated by TPR-tree and MR-tree, Multiple-Approximation is advanced to be TPMA with Time-Parameterized technology to deal with indexing of moving polygonal objects. New indexing structure for moving polygonal objects based on TPMA, which is termed as MTPR-tree, is presented...
In this paper, an improved method is proposed to detect falls using an uncalibrated camera. The proposed fall detection technique combines human shape analysis and human head detection together to detect falls from normal daily activities. The human shape is represented with an ellipse shape and features extracted from the ellipse are used to detect fall events. The head detection helps to distinguish...
Occlusions are common in real world scenes and are a major obstacle to robust object detection. In this paper, we present a method to coherently reason about occlusions on many types of detectors. Previous approaches primarily enforced local coherency or learned the occlusion structure from data. However, local coherency ignores the occlusion structure in real world scenes and learning from data requires...
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