scholarly journals A functional skeleton transfer

2021 ◽  
Vol 4 (3) ◽  
pp. 1-15
Author(s):  
Pietro Musoni ◽  
Riccardo Marin ◽  
Simone Melzi ◽  
Umberto Castellani
Keyword(s):  
Large Set ◽  
Limited Information ◽  
Intrinsic Geometry ◽  
3D Data ◽  
Dense Point ◽  
Different Shapes ◽  
Point To Point ◽  
New Applications ◽  
Significant Effort ◽  
Do So

The animation community has spent significant effort trying to ease rigging procedures. This is necessitated because the increasing availability of 3D data makes manual rigging infeasible. However, object animations involve understanding elaborate geometry and dynamics, and such knowledge is hard to infuse even with modern data-driven techniques. Automatic rigging methods do not provide adequate control and cannot generalize in the presence of unseen artifacts. As an alternative, one can design a system for one shape and then transfer it to other objects. In previous work, this has been implemented by solving the dense point-to-point correspondence problem. Such an approach requires a significant amount of supervision, often placing hundreds of landmarks by hand. This paper proposes a functional approach for skeleton transfer that uses limited information and does not require a complete match between the geometries. To do so, we suggest a novel representation for the skeleton properties, namely the functional regressor, which is compact and invariant to different discretizations and poses. We consider our functional regressor a new operator to adopt in intrinsic geometry pipelines for encoding the pose information, paving the way for several new applications. We numerically stress our method on a large set of different shapes and object classes, providing qualitative and numerical evaluations of precision and computational efficiency. Finally, we show a preliminar transfer of the complete rigging scheme, introducing a promising direction for future explorations.

Structural phenomena in the growth of carbon nanotubes

1993 ◽  
Vol 51 ◽  
pp. 750-751
Author(s):  
Jun Jiao
Keyword(s):  
Carbon Nanotubes ◽  
Growth Mechanism ◽  
Carbonaceous Material ◽  
Cluster Growth ◽  
Structural Elements ◽  
Rich Variety ◽  
Different Shapes ◽  
Point To Point

HREM studies of the carbonaceous material deposited on the cathode of a Huffman-Krätschmer arc reactor have shown a rich variety of multiple-walled nano-clusters of different shapes and forms. The preparation of the samples, as well as the variety of cluster shapes, including triangular, rhombohedral and pentagonal projections, are described elsewhere.The close registry imposed on the nanotubes, focuses attention on the cluster growth mechanism. The strict parallelism in the graphitic separation of the tube walls is maintained through changes of form and size, often leading to 180° turns, and accommodating neighboring clusters and defects. Iijima et. al. have proposed a growth scheme in terms of pentagonal and heptagonal defects and their combinations in a hexagonal graphitic matrix, the first bending the surface inward, and the second outward. We report here HREM observations that support Iijima’s suggestions, and add some new features that refine the interpretation of the growth mechanism. The structural elements of our observations are briefly summarized in the following four micrographs, taken in a Hitachi H-8100 TEM operating at an accelerating voltage of 200 kV and with a point-to-point resolution of 0.20 nm.

scholarly journals Towards footwear manufacturing 4.0: shoe sole robotic grasping in assembling operations

2021 ◽  
Author(s):  
Guillermo Oliver ◽  
Pablo Gil ◽  
Jose F. Gomez ◽  
Fernando Torres
Keyword(s):  
Industry 4.0 ◽  
Laser Scanner ◽  
Point Clouds ◽  
Average Score ◽  
Low Density ◽  
Contour Extraction ◽  
Shoe Industry ◽  
Simulated Environment ◽  
Dense Point ◽  
Different Shapes

AbstractIn this paper, we present a robotic workcell for task automation in footwear manufacturing such as sole digitization, glue dispensing, and sole manipulation from different places within the factory plant. We aim to make progress towards shoe industry 4.0. To achieve it, we have implemented a novel sole grasping method, compatible with soles of different shapes, sizes, and materials, by exploiting the particular characteristics of these objects. Our proposal is able to work well with low density point clouds from a single RGBD camera and also with dense point clouds obtained from a laser scanner digitizer. The method computes antipodal grasping points from visual data in both cases and it does not require a previous recognition of sole. It relies on sole contour extraction using concave hulls and measuring the curvature on contour areas. Our method was tested both in a simulated environment and in real conditions of manufacturing at INESCOP facilities, processing 20 soles with different sizes and characteristics. Grasps were performed in two different configurations, obtaining an average score of 97.5% of successful real grasps for soles without heel made with materials of low or medium flexibility. In both cases, the grasping method was tested without carrying out tactile control throughout the task.

scholarly journals THE EFFECT OF TEMPERATURE AND OF LYSIN CONCENTRATION ON THE ACCELERATION OF HEMOLYSIS

1941 ◽  
Vol 25 (2) ◽  
pp. 247-261
Author(s):  
Eric Ponder
Keyword(s):  
Cell Surface ◽  
Quantitative Description ◽  
Negative Temperature ◽  
Effect Of Temperature ◽  
Membrane Component ◽  
Temperature Coefficients ◽  
Rate Of Escape ◽  
Point To Point ◽  
Special Case ◽  
Do So

The acceleration of saponin hemolysis by benzene, indol, and nonyl alcohol has been investigated as a function of temperature, and it has been found that these accelerators have negative temperature coefficients. This points to their being concentrated at the cell surface, and to the surface being the seat of their accelerating action. It is shown that the accelerating power of indol (used as a typical accelerator) is constant so long as the lysin in the system is capable of producing lysis per se, but that the acceleration falls off when only sublytic concentrations are present. The relations are expressed in a series of equations, and explained in terms of the reactions among the accelerator, the lysin, and the membrane component, which breaks down in spots, rather than uniformly, when lysis occurs. The argument involves a consideration of the idea that a monolayer of lysin at the cell surface is necessary for hemolysis, of Abramson's hypothesis of "key spots" on the surface, of the rate of escape of hemoglobin from the hemolyzing cell, and of the results of electrophoretic and impedance measurements. The existing theory of the kinetics is extended by introducing the idea of a variation in resistance from point to point in the cell membrane; in this form it describes the situation so far as is at present known, and shows that the results of the various methods of investigation are consistent with each other. The only idea discussed which seems to have little foundation is that lysis is determined by the formation of a monolayer of lysin at the cell surface; when this occurs, it must do so only as a special case. Finally, a semi-quantitative description of the frequency distribution of the resistances in the membrane is derived from existing data. The variation in resistance which it is necessary to assume is quite small, as might be expected in the case of a membrane with a regular ultra-structure.

scholarly journals Shape Correspondence Analysis for Biomolecules Based on Volumetric Eigenfunctions

2015 ◽  
Vol 3 (1) ◽  
Author(s):  
Tao Liao ◽  
Hao-Chih Lee ◽  
Ge Yang ◽  
Yongjie Jessica Zhang
Keyword(s):  
Correspondence Analysis ◽  
Flexible Structures ◽  
Spectral Shape ◽  
The Other ◽  
Shape Deformation ◽  
Second Step ◽  
Analysis Method ◽  
Shape Correspondence ◽  
Dense Point ◽  
Different Shapes

AbstractThe functionality of biomolecules depends on their flexible structures, which can be characterized by their surface shapes. Tracking the deformation and comparing biomolecular shapes are essential in understanding their mechanisms. In this paper, a new spectral shape correspondence analysis method is introduced for biomolecules based on volumetric eigenfunctions. The eigenfunctions are computed from the joint graph of two given shapes, avoiding the sign flipping and confusion in the order of modes. An initial correspondence is built based on the distribution of a shape diameter, which matches similar surface features in different shapes and guides the eigenfunction computation. A two-step scheme is developed to determine the final correspondence. The first step utilizes volumetric eigenfunctions to correct the assignment of boundary nodes that disobeys the main structures. The second step minimizes the distortion induced by deforming one shape to the other. As a result, a dense point correspondence is constructed between the two given shapes, based on which we approximate and predict the shape deformation, as well as quantitatively measure the detailed shape differences.

Building a Standard 3D Face Database Based on Planar Templates

2011 ◽  
Vol 48-49 ◽  
pp. 280-283
Author(s):  
Xin Xin Li ◽  
Xun Gong
Keyword(s):  
3D Models ◽  
Face Database ◽  
Matching Method ◽  
Matching Accuracy ◽  
Point Matching ◽  
Dense Point ◽  
The Mean ◽  
Point To Point ◽  
3D Face Database ◽  
2D Space

This paper presents a new point matching method to solve the dense point-to-point alignment of scanned 3D faces. Texture maps of 3D models are generated at first by unwrapping 3D faces to 2D space. Then, we build planar templates based on the mean shape computed by a group of annotated texture map. 34 landmarks on the unwrapped texture images are located by AAM and the final correspondence is built according to the templates. Comparing to the traditional algorithms, the presented point matching method can achieve good matching accuracy and stability.

scholarly journals Household Production in an Egalitarian Society

Social Forces ◽  
2018 ◽  
Vol 97 (3) ◽  
pp. 1127-1154
Author(s):  
Yuko Onozaka ◽  
Kamran Hafzi
Keyword(s):  
Low Income ◽  
Large Set ◽  
Economic Rationality ◽  
Representative Survey ◽  
Gender Expectations ◽  
Income Differences ◽  
Egalitarian Society ◽  
And Gender ◽  
Gender Neutrality ◽  
Do So

Abstract Norwegian national policies strongly incentivize double-earner households and gender equality, but various gender gaps persist both at work and at home. In these seemingly contradictory situations, what are the mechanisms under which Norwegian households allocate their market and domestic labor? Drawing on both a large set of administrative data and a representative survey, this question is examined from two perspectives. First, we focus on the micro-economic processes and investigate if Norwegian households act according to economic rationality or if they still follow the gender norm “A man should earn more than his wife.” Second, we focus on how Norway’s contextual factors may influence the household experiences when a wife has better market productivity. We find that a wife with better market productivity, who is thereby facing the risk of outearning her husband, works more hours and earns more than her husband, while doing less chores—behavior consistent with economic rationality. Further analyses show that women’s “higher” relative market productivity is mainly a consequence of having low-income husbands, and “higher” and “lower” market productivity women are surprisingly similar in other sociodemographic aspects. Norwegian redistribution policies, through progressive taxation and benefit transfers, seem to mitigate the income differences and promote gender neutrality in a sense that if couples wish to pursue an untraditional division, by preference or by necessity, they seem to be able to do so without being held back by the traditional gender expectations or being very poor.

scholarly journals Evaluation of forest fire models on a large observation database

2014 ◽  
Vol 2 (5) ◽  
pp. 3219-3249 ◽  
Author(s):  
J.-B. Filippi ◽  
V. Mallet ◽  
B. Nader
Keyword(s):  
Large Set ◽  
Limited Information ◽  
Propagation Models ◽  
Ignition Point ◽  
Fire Propagation ◽  
Simulation Performance ◽  
Velocity Models ◽  
Wide Range ◽  
Complex Models

Abstract. This paper presents the evaluation of several fire propagation models using a large set of observed fires. The observation base is composed of 80 Mediterranean fire cases of different sizes, which come with the limited information available in an operational context (burned surface and approximative ignition point). Simulations for all cases are carried out with 4 different front velocity models. The results are compared with several error scoring methods applied to each of the 320 simulations. All tasks are performed in a fully automated manner, with simulations ran as first guesses with no tuning for any of the models or cases. This approach leads a wide range of simulation performance, including some of the bad simulation results to be expected in an operational context. Regardless the quality of the input data, it is found that the models can be ranked based on their performance and that the most complex models outperform the more empirical ones. Data and source code used for this paper are freely available to the community.

scholarly journals Polylidar3D-Fast Polygon Extraction from 3D Data

Sensors ◽  
2020 ◽  
Vol 20 (17) ◽  
pp. 4819
Author(s):  
Jeremy Castagno ◽  
Ella Atkins
Keyword(s):  
Point Clouds ◽  
Autonomous Driving ◽  
Convex Polygons ◽  
Flat Surfaces ◽  
Plane Normal ◽  
3D Point Clouds ◽  
3D Data ◽  
Dense Point ◽  
Real World Datasets ◽  
Low Dimensional

Flat surfaces captured by 3D point clouds are often used for localization, mapping, and modeling. Dense point cloud processing has high computation and memory costs making low-dimensional representations of flat surfaces such as polygons desirable. We present Polylidar3D, a non-convex polygon extraction algorithm which takes as input unorganized 3D point clouds (e.g., LiDAR data), organized point clouds (e.g., range images), or user-provided meshes. Non-convex polygons represent flat surfaces in an environment with interior cutouts representing obstacles or holes. The Polylidar3D front-end transforms input data into a half-edge triangular mesh. This representation provides a common level of abstraction for subsequent back-end processing. The Polylidar3D back-end is composed of four core algorithms: mesh smoothing, dominant plane normal estimation, planar segment extraction, and finally polygon extraction. Polylidar3D is shown to be quite fast, making use of CPU multi-threading and GPU acceleration when available. We demonstrate Polylidar3D’s versatility and speed with real-world datasets including aerial LiDAR point clouds for rooftop mapping, autonomous driving LiDAR point clouds for road surface detection, and RGBD cameras for indoor floor/wall detection. We also evaluate Polylidar3D on a challenging planar segmentation benchmark dataset. Results consistently show excellent speed and accuracy.

Mobile Processes and Mobile Channels

2007 ◽  
pp. 576-580
Author(s):  
K. Chalmers
Keyword(s):  
Interest Groups ◽  
Mobile Device ◽  
The Internet ◽  
Internet Technologies ◽  
Mobile Processes ◽  
Mobile Channels ◽  
Point To Point ◽  
New Applications ◽  
Different Characteristics ◽  
Primary Medium

Since the late 1990s there has been an explosion of new Internet technologies, making the Internet a primary medium for academic, business, and focus interest groups. As a result, new applications are constantly emerging and evolving. Couple this with the concept of mobility, something that is all around us today, and it can be seen that new applications require vastly different characteristics to those envisioned by the original Internet architects. For example, point-to-point IP traffic was designed to allow stationary parties to communicate, but when one of these parties becomes mobile with a wirelessly enabled mobile device, the original models become more difficult to implement.

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