Search results for "contour"
showing 10 items of 99 documents
Measuring Inaccessible Residual Stresses Using Multiple Methods and Superposition
2010
The traditional contour method maps a single component of residual stress by cutting a body carefully in two and measuring the contour of the cut surface. The cut also exposes previously inaccessible regions of the body to residual stress measurement using a variety of other techniques, but the stresses have been changed by the relaxation after cutting. In this paper, it is shown that superposition of stresses measured post-cutting with results from the contour method analysis can determine the original (pre-cut) residual stresses. The general superposition theory using Bueckner’s principle is developed and limitations are discussed. The procedure is experimentally demonstrated by determini…
Sparse Image Representation by Directionlets
2010
Despite the success of the standard wavelet transform (WT) in image processing in recent years, the efficiency and sparsity of its representation are limited by the spatial symmetry and separability of its basis functions built in the horizontal and vertical directions. One-dimensional discontinuities in images (edges or contours), which are important elements in visual perception, intersect too many wavelet basis functions and lead to a non-sparse representation. To capture efficiently these elongated structures characterized by geometrical regularity along different directions (not only the horizontal and vertical), a more complex multidirectional (M-DIR) and asymmetric transform is requi…
KNOWN RESIDUAL STRESS SPECIMENS USING OPPOSED INDENTATION
2009
In order to test new theories for residual stress measurement or to test the effects of residual stress on fatigue, fracture, and stress corrosion cracking, a known stress test specimen was designed and then fabricated, modeled, and experimentally validated. To provide a unique biaxial stress state, a 60 mm diameter 10 mm thick disk of 316L stainless steel was plastically compressed through the thickness with an opposing 15 mm diameter hard steel indenters in the center of the disk. For validation, the stresses in the specimen were first mapped using time-of-flight neutron diffraction and Rietveld full pattern analysis. Next, the hoop stresses were mapped on a cross section of two disks usi…
Mechatronic Contouring System for Unconventional Sheet Metal Forming Processes
2006
This paperwork was developed in order to present the work concerning the use of mechatronic approach in the study of motion control systems for metal forming processes. The paper presents the use of low cost motion control systems, based upon induction motors, as driving systems in unconventional sheet metal forming processes. The main goal of this work was to implement a 2D contouring system for driving the active plate. The model of the system, simulations and some experimental work will be presented.
Researches Regarding Optimizing the Accuracy of CNC Laser Cutting Machines
2015
The experimental researches presented in this paper are aimed to improve the manufacturing accuracy of a contouring machine together with an approach to eliminate the errors which lead to a less precise part after machining.In order to eliminate the errors, the machine's feed drives were tuned leading to a more precise part. In order to validate the proposed approach, the accuracy of the machine was tested before and after the tuning process.
Nutrient mitigation under the impact of climate and land-use changes: A hydro-economic approach to participatory catchment management
2020
Abstract Excessive nutrient loadings into rivers are a well-known ecological problem. Implemented mitigation measures should ideally be cost-effective, but perfectly ranking alternative nutrient mitigation measures according to cost-effectiveness is a difficult methodological challenge. Furthermore, a particularly practical challenge is that cost-effective measures are not necessarily favoured by local stakeholders, and this may impede their successful implementation in practice. The objective of this study was to evaluate the cost-effectiveness of mitigation measures using a methodology that includes a participatory process and social learning to ensure their successful implementation. By …
DEVELOPMENT AND IMPLEMENTATION OF MACHINE LEARNING METHODS FOR THE IIF IMAGES ANALYSIS
2021
Fat Transplantion: Different Clinical Applications to Achieve Symmetry in Face and Body Contouring
2008
Introduction: Fat autograft was first described in 1893 by Neuber for cosmetic and congenital defects. Nowadays its use is becoming widespread for soft tissue augmentation to improve simmetry and contour in all areas of the face and body. The authors present their experience with face and body contouring by fat autograft in post-oncological, post-traumatic and cosmetic settings. Materials and Methods: Between 2005 and 2008 31 patients underwent fat autografting in the plastic surgery unit of the university of palermo. There were 10 cases of breast asimmetry after reduction mammaplasty, breast augmentation and breast recostruction; 3 cases of post-traumatic and 1 congenital deformities in th…
Diffuse soil gas emissions of gaseous elemental mercury (GEM) from hydrothermal-volcanic systems: An innovative approach by using the static closed-c…
2016
This study was aimed to test a new methodological approach to carry out measurements of gaseous elemental mercury (GEM) diffusively emitted from soils in hydrothermal-volcanic environments. This method was based on the use of a static closed-chamber (SCC) in combination with a Lumex® RA-915M analyzer that provides GEM measurements in a wide range of concentrations (from 2 to 50,000 ng m-3). Gas samples were collected at fixed time intervals from the SCC positioned on the ground (time-series samples). The Lumex® inlet port was equipped with a three-way Teflon valve allowing the free entrance of air through a carbon trap, in order to: (i) prevent disturbance to the Lumex® operative flow rate …
On the function of cell systems in area 18. Part I
1981
In addition to the asymmetry of the spatial coupling and of the specific temporal combination of excitation and inhibition, the non-linearity is very pronounced in area 18. Taking the sequence of a linear operation and a stationary nonlinear characteristic as a model, the experimental findings can be systematized and a cell classification specified which departs from the customary ones. The hypercomplex cell system probably originates in recurrent inhibition and leads to differentiation of the patterns along their contour line. Problems of cell classification and of the type of parallelism in the visual cortex are discussed.