Search results for "parametric"
showing 10 items of 980 documents
Novel Distance Estimation Methods Using 'Stochastic Learning on the Line' Strategies
2018
In this paper, we consider the problem of Distance Estimation (DE) when the inputs are the $x$ and $y$ coordinates (or equivalently, the latitudinal and longitudinal positions) of the points under consideration. The aim of the problem is to yield an accurate value for the real (road) distance between the points specified by the latter coordinates. 1 This problem has, typically, been tackled by utilizing parametric functions called the “Distance Estimation Functions” (DEFs). The parameters are learned from the training data (i.e., the true road distances) between a subset of the points under consideration. We propose to use Learning Automata (LA)-based strategies to solve the problem. In par…
Using Genetic Algorithms for Optimizing the PPC in the Highway Horizontal Alignment Design.
2016
Various studies have emphasized the interesting advantages related to the use of new transition curves for improving the geometric design of highway horizontal alignments. In a previous paper, one of the writers proposed a polynomial curve, called a polynomial parametric curve (PPC), proving its efficiency in solving several design problems characterized by a very complex geometry (egg-shaped transition, transition between reversing circular curves, semidirect and inner-loop connections, and so on). The PPC also showed considerable advantages from a dynamic perspective, as evidenced by the analysis of the main dynamic variables related to motion (as well as rate of change of radial accelera…
Crop nitrogen monitoring: Recent progress and principal developments in the context of imaging spectroscopy missions
2020
Abstract Nitrogen (N) is considered as one of the most important plant macronutrients and proper management of N therefore is a pre-requisite for modern agriculture. Continuous satellite-based monitoring of this key plant trait would help to understand individual crop N use efficiency and thus would enable site-specific N management. Since hyperspectral imaging sensors could provide detailed measurements of spectral signatures corresponding to the optical activity of chemical constituents, they have a theoretical advantage over multi-spectral sensing for the detection of crop N. The current study aims to provide a state-of-the-art overview of crop N retrieval methods from hyperspectral data…
Accurate estimation of retinal vessel width using bagged decision trees and an extended multiresolution Hermite model.
2012
We present an algorithm estimating the width of retinal vessels in fundus camera images. The algorithm uses a novel parametric surface model of the cross-sectional intensities of vessels, and ensembles of bagged decision trees to estimate the local width from the parameters of the best-fit surface. We report comparative tests with REVIEW, currently the public database of reference for retinal width estimation, containing 16 images with 193 annotated vessel segments and 5066 profile points annotated manually by three independent experts. Comparative tests are reported also with our own set of 378 vessel widths selected sparsely in 38 images from the Tayside Scotland diabetic retinopathy scre…
A combined treatment regimen for chronic desquamative gingivitis in patients with oral lichen planus
2007
Background: Chronic desquamative gingivitis (DG) is a condition characterized by erythema, ulceration, and desquamation of the free and attached gingiva, usually expression of a district-systemic disease, such as oral lichen planus (OLP). Methods: A combined protocol of oral hygiene and topic corticosteroid therapy was applied in 30 patients with DG associated with OLP. Plaque index (PI) and bleeding on probing (BoP) were evaluated at baseline and after 3 months. Results: PI scoring was significantly lower after treatment in anterior, posterior, and all sites (P < 0.0001) as well as in vestibular and lingual ones (P < 0.0001 and P = 0.0001, respectively). BoP measures were found to be reduc…
Biocompatibility of various collagen membranes in cultures of human PDL fibroblasts and human osteoblast-like cells
2004
The aim of the present study was to evaluate the biocompatibility of differently cross-linked collagen membranes in cultures of human PDL fibroblasts and human osteoblast-like cells. Four collagen membranes [BioGide (BG), BioMend (BM), Ossix (OS) and TutoDent (TD)] were tested. Cells plated on culture dishes (CD) served as positive controls. Six specimens of each membrane were incubated with (1) human PDL fibroblasts [2 x 10(4) cells] (n=24), and (2) human osteoblast-like cells (SaOs-2) [2 x 10(4) cells] (n=24) under standardized conditions. After 7 days, adherent cells were stained with hematoxylin and counted using a reflected light microscope and the cell density per square millimeter wa…
Effect of contact lenses on ocular biometric measurements based on swept-source optical coherence tomography
2019
ABSTRACT Purpose: To determine the reliability of swept- source optical coherence tomography in cases in which soft contact lenses cannot be removed when acquiring biometric measurements. Methods: Eight subjects were included and only one eye per participant was analyzed. Each eye was measured six times by swept-source optical coherence tomography with the IOLMaster 700 instrument (Carl Zeiss Meditec, Jena, Germany). Axial length, central corneal thickness, anterior chamber depth, lens thickness, and keratometric measurements were evaluated for the naked eye and while wearing soft contact lenses of three different powers (-1.5, -3.0, and +2.0 D). Results: There were statistically significan…
Alterations in Lipid and Carbohydrate Metabolism in Patients with Classic Congenital Adrenal Hyperplasia due to 21-Hydroxylase Deficiency
2009
<i>Background:</i> Classic 21-hydroxylase deficiency (21HD) presents some traits of the metabolic syndrome. <i>Aim:</i> To characterize discrete alterations of lipid and carbohydrate metabolism in children and young adults with classic 21HD, which could predict early atherogenesis. <i>Patients and Methods:</i> Twenty-seven Caucasian patients with classic 21HD (4–31 years); 27 sex-, age- and BMI-matched controls. Clinical parameters, hormonal status and genotype were assessed in all patients. Lipid parameters, including relative (%) and absolute (mg/dl) small-dense low-density lipoproteins subfractions (sd-LDL) were measured in patients and controls. Oral …
Ethnic differences in serum lipoproteins and their determinants in South African women.
2010
The objective of the study was to characterize ethnic differences in lipid levels and low-density lipoprotein (LDL) particle size and subclasses in black and white South African women and to explore the associations with insulin sensitivity (S(I)), body composition, and lifestyle factors. Fasting serum lipids and LDL size and subclasses, body composition (dual-energy x-ray absorptiometry), and S(I) (frequently sampled intravenous glucose tolerance test) were measured in normal-weight (body mass index25 kg/m(2)) black (n = 15) and white (n = 15), and obese (body mass index30 kg/m(2)) black (n = 13) and white (n = 13) women. Normal-weight and obese black women had lower triglycerides (0.59 +/…
Curasan PRP kit vs. PCCS PRP system
2002
An important reason to improve methods of isolating platelet-rich plasma (PRP) is the potential use of autologous thrombocyte growth factors. In addition to discontinuous cell separation, two methods for extracting PRP that can be performed directly by the surgeon are now available. This study compared the suitability of these two methods for the preparation of PRP. Whole blood was drawn from 47 healthy donors (18 men, 29 women) aged 20-59 years (mean 29.9, SD 7.7). For each donor, PRP was separated by the PCCS method (PCCS Kit, 3i Implant Innovations, Palm Beach Gardens, FL, USA) and by the Curasan method (analogous to the PRP kit, Curasan, Kleinostheim, Germany). Thrombocyte counts differ…