Topographic matching of distal radius and proximal fibula articular surface for distal radius osteoarticular reconstruction

2015 ◽  
Vol 41 (6) ◽  
pp. 657-663 ◽  
Author(s):  
H. Zhang ◽  
S. Chen ◽  
Z. Wang ◽  
Y. Guo ◽  
B. Liu ◽  
...  
Keyword(s):  
Distal Radius ◽  
Articular Surface ◽  
Three Dimensional ◽  
Three Dimensional Model ◽  
Optimal Position ◽  
Fibula Graft ◽  
Proximal Fibula ◽  
Articular Surfaces ◽  
Computed Tomography Scanning

During osteoarticular reconstruction of the distal radius with the proximal fibula, congruity between the two articular surfaces is an important factor in determining the quality of the outcome. In this study, a three-dimensional model and a coordinate transformation algorithm were developed on computed tomography scanning. Articular surface matching was performed and parameters for the optimal position were determined quantitatively. The mean radii of best-fit spheres of the articular surfaces of the distal radius and proximal fibula were compared quantitatively. The radial inclination and volar tilt following reconstruction by an ipsilateral fibula graft, rather than the contralateral, best resembles the values of the native distal radius. Additionally, the ipsilateral fibula graft reconstructed a larger proportion of the distal radius articular surface than did the contralateral. The ipsilateral proximal fibula graft provides a better match for the reconstruction of the distal radius articular surface than the contralateral, and the optimal position for graft placement is quantitatively determined.

Intra-articular distal radius fractures in elderly patients: a randomized prospective study of casting versus volar plating

2017 ◽  
Vol 43 (2) ◽  
pp. 142-147 ◽  
Author(s):  
Daniel Martinez-Mendez ◽  
Alejandro Lizaur-Utrilla ◽  
Joaquin de-Juan-Herrero
Keyword(s):  
Conservative Treatment ◽  
Elderly Patients ◽  
Distal Radius ◽  
Articular Surface ◽  
Distal Radius Fractures ◽  
Volar Plating ◽  
Radius Fractures ◽  
Level Of Evidence ◽  
Loss Of Reduction

We compared outcomes in elderly patients with intra-articular distal radius fractures treated by closed reduction and plaster immobilization or open reduction and internal fixation with a volar plate. Ninety-seven patients older than 60 years were randomly allocated to conservative (47 patients) or surgical (50 patients) treatment. Over a 2-year period, we assessed patient-rated wrist evaluation score, DASH (disability arm, shoulder and hand) questionnaire, pain, wrist range of motion, grip strength, and radiological parameters. The functional outcomes and quality of life were significantly better after volar plating fixation compared with conservative treatment. We found that restoration of the articular surface, radial inclination, and ulnar variance affected the outcomes, but the articular step-off did not. Twenty-five per cent of the patients with conservative treatment had secondary loss of reduction. We conclude that surgical plating leads to better outcomes than conservative treatment for elderly patients with intra-articular distal radius fractures. Level of evidence: I

scholarly journals IMPROVING UAV TELEMETRY POSITIONING FOR DIRECT PHOTOGRAMMETRY

2021 ◽  
Vol XLIII-B2-2021 ◽  
pp. 61-68
Author(s):  
L. Rossi ◽  
F. Ioli ◽  
E. Capizzi ◽  
L. Pinto ◽  
M. Reguzzoni
Keyword(s):  
Low Cost ◽  
Three Dimensional ◽  
Control Points ◽  
Three Dimensional Model ◽  
Commercial Software ◽  
Ground Control Points ◽  
Lower Accuracy ◽  
Least Squares Adjustment ◽  
Gnss Receivers

Abstract. A fundamental step of UAV photogrammetric processes is to collect Ground Control Points (GCPs) by means of geodetic-quality GNSS receivers or total stations, thus obtaining an absolutely oriented model with a centimetric accuracy. This procedure is usually time-consuming, expensive and potentially dangerous for operators who sometimes need to reach inaccessible areas. UAVs equipped with low-cost GNSS/IMU sensors can provide information about position and attitude of the images. This telemetry information is not enough for a photogrammetric restitution with a centimetric accuracy, but it can be usefully exploited when a lower accuracy is required. The algorithm proposed in this paper aims at improving the quality of this information, in order to introduce it into a direct-photogrammetric process, without collecting GCPs. In particular, the estimation of an optimal trajectory is obtained by combining the camera positions derived from UAV telemetry and from the relative orientation of the acquired images, by means of a least squares adjustment. Then, the resulting trajectory is used as a direct observation of the camera positions into a commercial software, thus replacing the information of GCPs. The algorithm has been tested on different datasets, comparing the classical photogrammetric solution (with GCPs) with the proposed one. These case-studies showed that using the improved trajectory as input to the commercial software (without GCPs) the reconstruction of the three-dimensional model can be improved with respect to the solution computed by using the UAV raw telemetry only.

scholarly journals Application of stakeholder theory to corporate environmental disclosures

2009 ◽  
Vol 7 (1) ◽  
pp. 394-410 ◽  
Author(s):  
Pamela Kent ◽  
Christopher Chan
Keyword(s):  
Social Responsibility ◽  
Stakeholder Theory ◽  
Mission Statement ◽  
Three Dimensional ◽  
Annual Reports ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Environmental Disclosures ◽  
Significant Support

Ullmann’s (1985) three-dimensional model of social responsibility disclosure is tested to determine whether it can be operationalized to help explain the quantity and quality of environmental disclosures in Australian annual reports. The stakeholder power dimension of Ullmann’s framework is significant in explaining environmental disclosures while content of the mission statement and existence or otherwise of environmental or social responsibility committees also find strong statistically significant support in the results. Ullmanns’ stakeholder theory has previously been applied to explain social disclosures in general (Roberts, 1992) and is an important theory because it introduces a measure of strategy. The current paper demonstrates how this theory can be applied to a specific social disclosure using variables that are idiosyncratically applicable to the types of disclosures.

Image processing algorithms in the assessment of grain damage degree

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Wojciech Maliga ◽  
Włodzimierz Dudziński ◽  
Magdalena Łabowska ◽  
Jerzy Detyna ◽  
Marcin Łopusiewicz ◽  
...  
Keyword(s):  
Image Processing ◽  
Cross Sections ◽  
Three Dimensional ◽  
Sample Volume ◽  
Three Dimensional Model ◽  
Time Intervals ◽  
Damage Degree ◽  
Grain Damage ◽  
Analyse Sample

Abstract Objectives The paper presents preliminary results on the assessment of algorithms used in image processing of the grain damage degree. The purpose of the work is developing a tool allowing to analyse sample cross-sections of rye germs. Methods The analysis of the grain cross-sections was carried out on the basis of a series their photos taken at equal time intervals at a set depth. The cross-sections will be used to create additional virtual cross-sections allowing to analyse the whole sample volume. The ultimate plan is to generate two cross-sections perpendicular to each other. Based on volumetric data read from the sample section, a three-dimensional model of an object will be generated. Results The analysis of model surface will allowed us to detect possible grain damage. The developed method of preparing the research material and the proprietary application allowed for the identification of internal defects in the biological material (cereal grains). Conclusions The presented methodology may be used in the agri-food industry in the future. However, much research remains to be done. These works should primarily aim at significantly reducing the time-consuming nature of individual stages, as well as improving the quality of the reconstructed image.

Numerical Investigation of Curing Process in Reaction Injection Molding of Rubber for Quality Improvements

2011 ◽  
Vol 462-463 ◽  
pp. 1206-1211 ◽  
Author(s):  
Seyyed Mohammad Javadi ◽  
Mohammad Moghiman ◽  
Mohammad Reza Erfanian ◽  
Naseh Hosseini
Keyword(s):  
Three Dimensional ◽  
Measured Data ◽  
Production Costs ◽  
Curing Process ◽  
Quality Improvements ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Final Temperature ◽  
Reaction Injection Molding

A large number of rubber products are formed into their final shape by vulcanization. In particular, curing process of rubber is the final step in manufacturing many rubber products and determines both the quality of the resulting product as well as production costs. This paper is devoted to the simulation of rubber curing process in a three-dimensional model. The effects of final temperature of mold are investigated on curing process and quality of final product. The results were compared with the experimentally measured data, which confirmed the accuracy and applicability of the method.

scholarly journals A flash-based thermal simulation of scanning paths in LPBF additive manufacturing

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Kamel Ettaieb ◽  
Sylvain Lavernhe ◽  
Christophe Tournier
Keyword(s):  
High Performance ◽  
Laser Scanning ◽  
Thermal Field ◽  
Computational Cost ◽  
Three Dimensional ◽  
Three Dimensional Model ◽  
Content Type ◽  
Proposed Model ◽  
Scanning Path

Purpose This paper aims to propose an analytical thermal three-dimensional model that allows an efficient evaluation of the thermal effect of the laser-scanning path. During manufacturing by laser powder bed fusion (LPBF), the laser-scanning path influences the thermo-mechanical behavior of parts. Therefore, it is necessary to validate the path generation considering the thermal behavior induced by this process to improve the quality of parts. Design/methodology/approach The proposed model, based on the effect of successive thermal flashes along the scanning path, is calibrated and validated by comparison with thermal results obtained by FEM software and experimental measurements. A numerical investigation is performed to compare different scanning path strategies on the Ti6Al4V material with different stimulation parameters. Findings The simulation results confirm the effectiveness of the approach to simulate the thermal field to validate the scanning strategy. It suggests a change in the scale of simulation thanks to high-performance computing resources. Originality/value The flash-based approach is designed to ensure the quality of the simulated thermal field while minimizing the computational cost.

Influence of Ageing on Surface Quality of Machined Nanostructures

2013 ◽  
Vol 662 ◽  
pp. 108-112
Author(s):  
Xing Lei Hu ◽  
Ya Zhou Sun ◽  
Ying Chun Liang ◽  
Jia Xuan Chen
Keyword(s):  
Surface Quality ◽  
Three Dimensional ◽  
Defect Structures ◽  
Three Dimensional Model ◽  
Machined Surface ◽  
Ageing Processes ◽  
Fault Structures ◽  
Mc Simulation ◽  
Atomic Stress

A three-dimensional model of Monte Carlo (MC) simulation is proposed to study the effects of ageing on the surface quality of machined nanostructures. The model includes the utilization of the Morse potential function to simulate the interatomic force between the atoms in workpieces. The results show that the ageing processes have important influence on the surface morphology and internal structure of machined workpiece. Most of the disordered point defects and one large stacking fault structures in machined workpiece disappear after ageing, but still some defect structures remain. In addition, distribution of atomic potential and atomic stress in the workpiece become regular in the aging process, and the atoms of the defect structures have much higher potential energy and stress. Finally, surface roughness of machined workpiece definitely increases after ageing. To analyze the morphology of machined surface after ageing is very practical and meaningful.

Numerical Simulation on Drawing Deep of Cylindrical Pieces Based on Dynaform

2014 ◽  
Vol 684 ◽  
pp. 252-258 ◽  
Author(s):  
Jun Hong Wang ◽  
Xu Dong Bao ◽  
Hai Mei Feng ◽  
Chang Du
Keyword(s):  
Numerical Simulation ◽  
Three Dimensional ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Forming Process ◽  
Minimum Thickness ◽  
Optimum Parameters ◽  
Design And Manufacture ◽  
The Impact

Abstract: The design and manufacture of mold often rely on the experience of the designers, which led to the fact that the mold needs to be repeatedly debugged and corrected. Numerical simulation technology enables the simulation of the forming process of sheet metal and prediction of defects in design, thus to improve labor efficiency, save time and reduce costs. In this paper, the software Dynaform is used as a platform and a three-dimensional model is built to numerical simulate and analyze the drawing deep of a typical thin-walled cylindrical piece.Orthogonal experimentis adopted to analyze the impact of BHF, punching speed and punch-die gap on forming quality of the drawing pieces. With minimum thickness and wrinkling as indicators, the impact of various factors is analyzed and a set of optimum parameters is found out that is, BHF is 20kN, punching speed is 2000mm / s and punch-die gap is 0.9mm.

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