scholarly journals A Novel Two-Stage Illumination Estimation Framework for Expression Recognition

2014 ◽  
Vol 2014 ◽  
pp. 1-12 ◽  
Author(s):  
Zheng Zhang ◽  
Guozhi Song ◽  
Jigang Wu
Keyword(s):  
Three Dimensional ◽  
Facial Appearance ◽  
Expression Recognition ◽  
Two Stage ◽  
Illumination Estimation ◽  
3D Face ◽  
Critical Issues ◽  
Negative Effect ◽  
Small Test ◽  
Test Sets

One of the critical issues for facial expression recognition is to eliminate the negative effect caused by variant poses and illuminations. In this paper a two-stage illumination estimation framework is proposed based on three-dimensional representative face and clustering, which can estimate illumination directions under a series of poses. First, 256 training 3D face models are adaptively categorized into a certain amount of facial structure types byk-means clustering to group people with similar facial appearance into clusters. Then the representative face of each cluster is generated to represent the facial appearance type of that cluster. Our training set is obtained by rotating all representative faces to a certain pose, illuminating them with a series of different illumination conditions, and then projecting them into two-dimensional images. Finally the saltire-over-cross feature is selected to train a group of SVM classifiers and satisfactory performance is achieved when estimating a number of test sets including images generated from 64 3D face models kept for testing, CAS-PEAL face database, CMU PIE database, and a small test set created by ourselves. Compared with other related works, our method is subject independent and has less computational complexityO(C×N)without 3D facial reconstruction.

scholarly journals Three-Dimensional Evaluation of Soft Tissue Malar Modifications after Zygomatic Valgization Osteotomy via Geometrical Descriptors

2021 ◽  
Vol 11 (3) ◽  
pp. 205
Author(s):  
Elena Carlotta Olivetti ◽  
Federica Marcolin ◽  
Sandro Moos ◽  
Alberto Ferrando ◽  
Enrico Vezzetti ◽  
...  
Keyword(s):  
Soft Tissue ◽  
Facial Expression Recognition ◽  
Three Dimensional ◽  
Ground Truth ◽  
Surface Shape ◽  
Facial Appearance ◽  
Expression Recognition ◽  
Shape Modification ◽  
Angular Measure ◽  
The Face

Patients with severe facial deformities present serious dysfunctionalities along with an unsatisfactory aesthetic facial appearance. Several methods have been proposed to specifically plan the interventions on the patient’s needs, but none of these seem to achieve a sufficient level of accuracy in predicting the resulting facial appearance. In this context, a deep knowledge of what occurs in the face after bony movements in specific surgeries would give the possibility to develop more reliable systems. This study aims to propose a novel 3D approach for the evaluation of soft tissue zygomatic modifications after zygomatic osteotomy; geometrical descriptors usually involved in face analysis tasks, i.e., face recognition and facial expression recognition, are here applied to soft tissue malar region to detect changes in surface shape. As ground truth for zygomatic changes, a zygomatic openness angular measure is adopted. The results show a high sensibility of geometrical descriptors in detecting shape modification of the facial surface, outperforming the results obtained from the angular evaluation.

scholarly journals Do 3D Face Images Capture Cues of Strength, Weight, and Height Better than 2D Face Images do?

2021 ◽  
Vol 7 (3) ◽  
pp. 209-219
Author(s):  
Iris J Holzleitner ◽  
Alex L Jones ◽  
Kieran J O’Shea ◽  
Rachel Cassar ◽  
Vanessa Fasolt ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Physical Characteristics ◽  
Two Dimensional ◽  
3D Images ◽  
3D Face ◽  
Face Images ◽  
Similar Accuracy ◽  
2D And 3D ◽  
2D Images ◽  
Better Than

Abstract Objectives A large literature exists investigating the extent to which physical characteristics (e.g., strength, weight, and height) can be accurately assessed from face images. While most of these studies have employed two-dimensional (2D) face images as stimuli, some recent studies have used three-dimensional (3D) face images because they may contain cues not visible in 2D face images. As equipment required for 3D face images is considerably more expensive than that required for 2D face images, we here investigated how perceptual ratings of physical characteristics from 2D and 3D face images compare. Methods We tested whether 3D face images capture cues of strength, weight, and height better than 2D face images do by directly comparing the accuracy of strength, weight, and height ratings of 182 2D and 3D face images taken simultaneously. Strength, height and weight were rated by 66, 59 and 52 raters respectively, who viewed both 2D and 3D images. Results In line with previous studies, we found that weight and height can be judged somewhat accurately from faces; contrary to previous research, we found that people were relatively inaccurate at assessing strength. We found no evidence that physical characteristics could be judged more accurately from 3D than 2D images. Conclusion Our results suggest physical characteristics are perceived with similar accuracy from 2D and 3D face images. They also suggest that the substantial costs associated with collecting 3D face scans may not be justified for research on the accuracy of facial judgments of physical characteristics.

Ownership Structure and Dividend Policy in Listed Industrial and Consumer Goods Firms in Nigeria: Heckman’s Two-Stage Approach

2021 ◽  
Vol 3 (3) ◽  
pp. 288-308
Keyword(s):  
Ownership Structure ◽  
Consumer Goods ◽  
Dividend Policy ◽  
Stock Exchange ◽  
Institutional Ownership ◽  
Foreign Ownership ◽  
Two Stage ◽  
Second Stage ◽  
Negative Effect ◽  
Block Holders

The decision on the magnitude of dividend has been identified to be highly related to the decisions to pay or not to pay dividends in formulating dividend policy. However, literature seems to be homogeneous and focused on examining the effect of ownership structure on dividend level or probability of paying dividends. Therefore, the paper examines the effect of ownership structure on dividend policy using Heckman’s two-stage technique. Utilizing 304 firm-year observations from industrial and consumer goods firms listed in the Nigerian Stock Exchange for the period within 2009-2019, the result shows that in the first stage, only foreign ownership has a negative significant effect on the probability of paying dividends. However, after accounting for a possible correlation between the probability of paying dividends and dividend pay-out, the result on the second stage exhibits a significant negative effect with block-holders and foreign ownerships on dividend policy while institutional ownership reveals a positive significant effect. The overall results show that the lower the foreign ownership the higher the possibility of paying dividends. Also, higher dividend pay-out is associated with the lower level of block-holders and foreign ownerships coupled with higher institutional ownership in listed industrial and consumer goods firms in Nigeria.

Time-Averaged Heat Transfer and Pressure Measurements and Comparison With Prediction for a Two-Stage Turbine

1994 ◽  
Vol 116 (1) ◽  
pp. 14-22 ◽  
Author(s):  
M. G. Dunn ◽  
J. Kim ◽  
K. C. Civinskas ◽  
R. J. Boyle
Keyword(s):  
Surface Pressure ◽  
Space Shuttle ◽  
Three Dimensional ◽  
Stanton Number ◽  
Navier Stokes ◽  
Pressure Measurements ◽  
Two Stage ◽  
Pressure Transducers ◽  
Pressure Distributions ◽  
Main Engine

Time-averaged Stanton number and surface-pressure distributions are reported for the first-stage vane row and the first-stage blade row of the Rocketdyne Space Shuttle Main Engine two-stage fuel-side turbine. These measurements were made at 10, 50, and 90 percent span on both the pressure and suction surfaces of the component. Stanton-number distributions are also reported for the second-stage vane at 50 percent span. A shock tube is used as a short-duration source of heated and pressurized air to which the turbine is subjected. Platinum thin-film gages are used to obtain the heat-flux measurements and miniature silicone-diaphragm pressure transducers are used to obtain the surface pressure measurements. The first-stage vane Stanton number distributions are compared with predictions obtained using a quasi-three dimensional Navier–Stokes solution and a version of STAN5. This same N–S technique was also used to obtain predictions for the first blade and the second vane.

scholarly journals An Application of Integrated 3D Technologies for Replicas in Cultural Heritage

2019 ◽  
Vol 8 (6) ◽  
pp. 285 ◽  
Author(s):  
Balletti ◽  
Ballarin
Keyword(s):  
3D Printing ◽  
Cultural Heritage ◽  
Laser Scanning ◽  
Low Cost ◽  
Three Dimensional ◽  
Digital Data ◽  
Survey Analysis ◽  
Critical Issues ◽  
Data Acquisition And Processing ◽  
Short Time

In recent decades, 3D acquisition by laser scanning or digital photogrammetry has become one of the standard methods of documenting cultural heritage, because it permits one to analyze the shape, geometry, and location of any artefact without necessarily coming into contact with it. The recording of three-dimensional metrical data of an asset allows one to preserve and monitor, but also to understand and explain the history and cultural heritage shared. In essence, it constitutes a digital archive of the state of an artefact, which can be used for various purposes, be remodeled, or kept safely stored. With the introduction of 3D printing, digital data can once again take on material form and become physical objects from the corresponding mathematical models in a relatively short time and often at low cost. This possibility has led to a different consideration of the concept of virtual data, no longer necessarily linked to simple visual fruition. The importance of creating high-resolution physical copies has been reassessed in light of different types of events that increasingly threaten the protection of cultural heritage. The aim of this research is to analyze the critical issues in the production process of the replicas, focusing on potential problems in data acquisition and processing and on the accuracy of the resulting 3D printing. The metric precision of the printed model with 3D technology are fundamental for everything concerning geomatics and must be related to the same characteristics of the digital model obtained through the survey analysis.

scholarly journals Two-Stage Discrete Mechanical Modelin Three-Dimensional Space for Garment Simulation

2019 ◽  
Vol 19 (1) ◽  
pp. 26-35 ◽  
Author(s):  
Xuan Luo ◽  
Gaoming Jiang ◽  
Honglian Cong
Keyword(s):  
Mechanical Model ◽  
Dimensional Space ◽  
Three Dimensional ◽  
Mathematical Expression ◽  
Two Stage ◽  
Second Stage ◽  
Simulation Speed ◽  
Optimal Value ◽  
Variable Distance ◽  
Stage Process

Abstract This paper focuses on the better performance between the garment simulation result and the simulation speed. For simplicity and clarity, a notation “PART” is defined to indicate the areas between the garment and the human body satisfying some constraints. The discrete mechanical model can be achieved by the two-stage process. In the first stage, the garment can be divided into several PARTs constrained by the distance. In the second stage, the mechanical model of each PART is formulated with a mathematical expression. Thus, the mechanical model of the garment can be obtained. Through changing the constrained distance, the simulation result and the simulation speed can be observed. From the variable distance, a desired value can be chosen for an optimal value. The results of simulations and experiments demonstrate that the better performance can be achieved at a higher speed by saving runtime with the acceptable simulation results and the efficiency of the proposed scheme can be verified as well.

scholarly journals The Dynamics of Suspended Solid Particles in a Two Stage Gas Turbine

1986 ◽  
Author(s):  
W. Tabakoff ◽  
A. Hamed
Keyword(s):  
Flow Field ◽  
Gas Turbine ◽  
Turbine Blades ◽  
Three Dimensional ◽  
Suspended Solid ◽  
Solid Particles ◽  
Two Stage ◽  
Particle Momentum ◽  
Performance Deterioration ◽  
And Performance

Gas turbine engines operating in dusty environments are exposed to erosion and performance deterioration. In order to provide the basis for calculating the erosion and performance deterioration of turbines using pulverized coal, an investigation is undertaken to determine the three dimensional particle trajectories in a two stage turbine. The solution takes into account the influence of the variation in the three dimensional flow field. The change in particle momentum due to their collision with the turbine blades and casings is modeled using empirical equations derived from experimental Laser Doppler Velocimetry (LDV) measurements. The results show the three dimensional trajectory characteristics of the solid particles relative to the turbine blades. The results also show that the particle distribution in the flow field are determined by particle-blade impacts. The results obtained from this study indicate the turbine blade locations which are subjected to more blade impacts and hence more erosion damage.

Computation of Viscous Flow Around Propeller-Body Configurations: Series 60 CB = 0.6 Ship Model

1994 ◽  
Vol 38 (02) ◽  
pp. 137-157 ◽  
Author(s):  
F. Stern ◽  
H. T. Kim ◽  
D. H. Zhang ◽  
Y. Toda ◽  
J. Kerwin ◽  
...  
Keyword(s):  
Viscous Flow ◽  
Turbulence Modeling ◽  
Critical Evaluation ◽  
Three Dimensional ◽  
Inviscid Flow ◽  
Ship Model ◽  
Flow Method ◽  
Critical Issues ◽  
Three Dimensional Configuration ◽  
Extensive Experimental Data

Validation of a viscous-flow method for predicting propeller-hull interaction is provided through detailed comparisons with recent extensive experimental data for the practical three-dimensional configuration of the Series 60 CB = 0.6 ship model. Modifications are made to the k-e turbulence model for the present geometry and application. Agreement is demonstrated between the calculations and global and some detailed aspects of the data; however, very detailed resolution of the flow is lacking. This supports the previous conclusion for propeller-shaft configurations and axisymmetric bodies that the present procedures can accurately simulate the steady part of the combined propeller-hull flow field, although turbulence modeling and detailed numerical treatments are critical issues. The present application enables a more critical evaluation through further discussion of these and other relevant issues, such as the use of radial-and angular-varying body-force distributions, the relative importance of turbulence modeling and grid density on the resolution of the harmonics of the propeller inflow, and three-dimensional propeller-hull interaction, including the differences for the nominal and effective inflows and for the resulting steady and unsteady propeller performance. Also, comparisons are made with an inviscid-flow method. Lastly, some concluding remarks are made concerning the limitations of the method, requirements and prognosis for improvements, and application to the design of wake-adapted propellers.

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