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As a result of computational and experimental study the regularities of wear of the grinding wheel working surfaces in the process of double disk grinding of bearing rings ends have been established. Adequacy of mathematical and computer models has been confirmed by a satisfactory agreement of computer simulation results and experimental data. The established regularities have laid the basis for a...
This paper presents an algorithm for triangular mesh generation from unorganized points based on 3D Delaunay tetrahedralization and mesh-growing method. This algorithm requires the point density to meet the well-sampled condition in smooth regions and dense sampling in sections of a great curvature and two close opposite surfaces. The principle of the algorithm is as follows. It begins with 3D Delaunay...
Nowadays, ear shape study is one of the most significant trends in the biometric research. In this study, we present a novel surface fiducial point's detection that is computed from the differential surface geometry. The fiducial points are intrinsic, local, and relative invariants, i.e., they are preserved under similarity, affine, and nonlinear transformations that are piecewise affine. In our experiment,...
Processing surfaces with data coming from an automatic acquisition technique always generates the problem of unorganized 3D point sets or presence of geometric deficiencies (i.e. in some regions of the surface, the obtained data points are sparse or without containing any points). It leads to what we call "holes", and a mandatory surface reconstruction process. Applying the process to the...
This paper presents an approach to derive a novel 3D signature based on the micro-geometry of paper surfaces so as to uniquely characterise and classify different paper substrates. This procedure is extremely important to confront different conducts of tampering valuable documents. We use a 4-light source photometric stereo (PS) method to recover dense 3D geometry of paper surfaces captured using...
When processing 3D point cloud data, features must be extracted from a small set of points, usually called keypoints. This is done to avoid the computational complexity required to extract features from all points in a point cloud. There are many keypoint detectors and this suggests the need of a comparative evaluation. When the keypoint detectors are applied to 3D objects, the aim is to detect a...
We present a new unsupervised technique to segment 3D Lidar points in outdoor environments. The main idea of this work is to identify artificial objects according to the existence of extruded shapes. Many artificial objects are composed of extruded shapes such as cylinders, planes, cubes, and lines. Therefore, we detect these arbitrarily extruded shapes on the basis of an indicator for repetitive...
The aim of this paper is the demonstration of a novel parameter called localization factor for the detection and monitoring of tin surface oxidation through atomic force microscope (AFM) imaging. A previously polished and oxide free tin surface was oxidized in a controlled environment and the resulting surface topography was evaluated numerically with AFM. Results indicate that the obtained localization...
Ophthalmometers are very important for clinical ophthalmology and usually used to measure the radius of curvature, direction of principal meridian and keratometric dioptre of the human cornea. In order to realize the calibration and quality evaluation of ophthalmometers, standard devices based on reflection principle are developed. It consists of both radius and axial standard device. The radius standard...
3D model is normally designed by 3D-CAD software or animation software, but a 3D direct drawing method is still a developing research. In a previous study, we suggest a 3D direct drawing method for polygonal/curved surface model using Microsoft Kinect. In this study, some subjects performe the gesture expressing a solid, analyzed the gesture trajectory. And we construct the creating solid algorithm...
Gecko's superb climbing ability to move unhamperedly across dirty, wet and rough surfaces stems from the non-wetting characteristics of gecko toes. Self-cleaning is crucial for dry adhesive to be reusable and practical, yet till now low-cost self-cleaning artificial dry adhesives are rarely reported and difficult to fabricate. Herein we proposed a novel low-cost superlyophobic dry adhesive film based...
We fabricated 〈100〉, 〈110〉, 〈111〉, and 〈112〉 p-channel gate-all-around Si nanowire (SiNW) MOSFETs, cross sections of which are rectangles with various widths, and investigated the hole mobility of the SiNW MOSFETs using the double Lm method. Measured hole mobilities of SiNW MOSFETs were about 80–140 cm2/Vs at surface carrier density of 1 × 1013 cm−2. The dependences of the hole mobility on orientations...
This article deals with the calculation of curvature of free-surfaces for the use in processes of machining. The calculation is realized in Matlab environment. Objects with free-surfaces are mainly used in machine engineering, design, automotive and aerospace industry etc. The manufacturing of such surfaces are realized on multi-axes machining centres, where the tool path controlling is crucial process...
This paper presents a method to transfer functional grasps among objects of the same category through contact warping and local replanning. The method transfers implicit knowledge that enables an action on a class of objects for which no explicit grasp or task information has been given in advance. Contact points on the source object are warped based on global and local shape similarities to the target...
In this paper we present an algorithm to determine the location of contact points to obtain force closure grasps on tree dimensional objects. The shape of the object is assumed to be given by a triangle mesh - a format widely used in CAD software. Our algorithm can handle an arbitrary number of contact points and does nor require any prior information about their initial locations. Through an iterative...
In recent years, QR codes have found a wide range of applications in business and industry. Moreover, their popularity and function are still growing (fast). Therefore, the processing of the images of QR codes is an important task. In this paper, we try to solve a problem encountered in QR decoding when the QR code is printed near the binding edge inside a book or on the surface of a cylindrical container...
This paper presents a new image analysis approach based on the Hough Transform, for the characterisation of natural objects of approximately circular shape in real situations. To accomplish this purpose, an innovative interpretation and filtering methodology of the three dimensional Hough Transform (HT) accumulation space for circles was conceived and implemented, which proved to be crucial when dealing...
This paper presents the results of an ongoing research on the survey of vaulted structures of important Italian monumental buildings belonging to UNESCO World Heritage Sites (Ravenna, Rome and Florence). The three case studies deal with various problems of documentation and representation of vaults and domes from different points of view: the first example is concerned with the conversion of apparent...
Most of molecular interactions often occur in feature regions of molecular surfaces such as convex regions, cavities or pockets. In this paper we propose a method to identify these feature regions by expanding the molecular surface to its surrounding spherical surface, that is, a 1-1 mapping is established between them. According to the expansion distance, feature regions can be determined to be concave...
In this paper, we propose a novel method to reconstruct Chinese ancient architecture from incomplete point cloud obtained from multi-view reconstruction approach. The proposed method utilizes both global symmetry and partial symmetry to complete the missing part in the original point cloud. First global symmetry is extracted automatically and a matching cost function based on the images associated...
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