The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
Assembly process complexity in the production of manufactured products has received considerable attention in recent years. With the growing trend towards cyber-physical systems and the fourth industrial revolution, assembly research efforts must aim to develop efficient production systems incorporating robotic arms and flexible fixtures. The aim of the research was to investigate end effector and...
This study explores the non-parametric estimation of a shape boundary from noisy points in 2D when the sensor characteristics are known. As the underlying shape information is not known, the offered algorithm estimates points on the shape boundary by using the statistics of the subsets of point cloud data. The novel approach proposed in this paper is able to find corner points in a local geometry...
In this paper we present a novel approach for depth map enhancement from an RGB-D video sequence. The basic idea is to exploit the photometric information in the color sequence. Instead of making any assumption about surface albedo or controlled object motion and lighting, we use the lighting variations introduced by casual object movement. We are effectively calculating photometric stereo from a...
3D face reconstruction is a fundamental Computer Vision problem of extraordinary difficulty. Current systems often assume the availability of multiple facial images (sometimes from the same subject) as input, and must address a number of methodological challenges such as establishing dense correspondences across large facial poses, expressions, and non-uniform illumination. In general these methods...
Morphing is a technique that smoothly transforms a shape onto another. In this paper, we present a method for morphing of two dynamic meshes: mesh sequences representing the keyframes of animated shapes over time. The pipeline of the proposed method comprises two main stages: template-based cross-parameterization and dynamic mesh interpolation. In the cross-parameterization stage, we use a variation...
Traditional approaches for learning 3D object categories use either synthetic data or manual supervision. In this paper, we propose a method which does not require manual annotations and is instead cued by observing objects from a moving vantage point. Our system builds on two innovations: a Siamese viewpoint factorization network that robustly aligns different videos together without explicitly comparing...
The recent boom in the field of virtual and augmented reality has dramatically increased the prevalence of spherical video. Given the enormous amount of data consumed by spherical video, it is critical to achieve efficient compression for storage and transmission. Prevalent approaches simply project (via different geometries) the spherical video onto planes for processing with traditional 2D video...
This paper studies the influence of three volute geometries of a single-stage centrifugal compressor, using the same vaned diffuser and impeller, the only differences are given by the volute geometry: cross section area and volute tongue. The objective of this research is to determine which of parameters has a major impact on the compressor and how much are the operating range and overall performance...
This paper provides an tractable analysis of the downlink spectral efficiency of multi-cell multi-user distributed antenna systems (DASs) using stochastic geometry with maximal ratio transmission (MRT) and zero-forcing (ZF) beamforming. Firstly, based on the properties of Gamma variable, the distributions of signal and interference power can be obtained. Then by modeling remote antenna units (RAUs)...
We present an approach to learning features that represent the local geometry around a point in an unstructured point cloud. Such features play a central role in geometric registration, which supports diverse applications in robotics and 3D vision. Current state-of-the-art local features for unstructured point clouds have been manually crafted and none combines the desirable properties of precision,...
We propose a data-driven method for recovering missing parts of 3D shapes. Our method is based on a new deep learning architecture consisting of two sub-networks: a global structure inference network and a local geometry refinement network. The global structure inference network incorporates a long short-term memorized context fusion module (LSTM-CF) that infers the global structure of the shape based...
We present a method to jointly refine the geometry and semantic segmentation of 3D surface meshes. Our method alternates between updating the shape and the semantic labels. In the geometry refinement step, the mesh is deformed with variational energy minimization, such that it simultaneously maximizes photo-consistency and the compatibility of the semantic segmentations across a set of calibrated...
How much does a single image reveal about the environment it was taken in? In this paper, we investigate how much of that information can be retrieved from a foreground object, combined with the background (i.e. the visible part of the environment). Assuming it is not perfectly diffuse, the foreground object acts as a complexly shaped andfar-from-perfect mirror An additional challenge is that its...
Two types of information exist in a stereo pair: correlation (matching) and decorrelation (half-occlusion). Vision science has shown that both types of information are used in the visual cortex, and that people can perceive depth even when correlation cues are absent or very weak, a capability that remains absent from most computational stereo systems. As a step toward stereo algorithms that are more...
In this paper, we study the problem of facial expression recognition using a novel space-time geometric representation. We describe the temporal evolution of facial landmarks as parametrized trajectories on the Riemannian manifold of positive semidefinite matrices of fixed-rank. Our representation has the advantage to bring naturally a second desirable quantity when comparing shapes – the spatial...
Analyzing data representing multifarious trajectories is central to the many fields in Science and Engineering; for example, trajectories representing a tennis serve, a gymnast’s parallel bar routine, progression/remission of disease and so on. We present a novel geometric algorithm for performing statistical analysis of trajectories with distinct number of samples representing longitudinal (or temporal)...
This paper presents the characterization of integrated micromachined waveguide absorbers in the frequency band of 220 to 325 GHz. Tapered absorber wedges were cut out of four different commercially available semi-rigid absorber materials and inserted in a backshorted micromachined waveguide cavity for characterization. The absorption properties of these materials are only specified at 10 GHz, and...
Today, driver assistance systems and autonomous vehicles are actively developed and verified in real-world test scenarios. These real-world tests are neither cheap nor sufficient to ensure a reasonably low enough risk of failure. In order to enable efficient and methodical system tests, we propose the use of Virtual Testbeds (VTBs) as a software environment in which "Digital Twins" of real...
Due to their enhanced properties with respect to conventional piezoelectric ceramics, 1–3 piezocomposite materials are predominant in high performance transducer applications. The determination of their effective electroelastic modulus has been the subject of numerous investigations. Simple modeling of the thickness mode is well documented in literature, however precise simple modeling of the full...
In the paper, the Wind Driven Optimization WDO algorithm is applied to the optimal shape design of a class of switched reluctance motors. The goal of the optimization is to identify a class of geometries which maximize the torque and simultaneously minimize the iron losses of the motor. Because of the twofold design criterion, the multi-objective version of the wind driven algorithm M-WDO is used...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.