Search results for "parametric"

Bone status in adolescents with type 1 diabetes

2010

Aims The aim of the study was to investigate the potential negative impact of type 1 diabetes on bone status of adolescents. Bone status in adolescents with type 1 diabetes was assessed by means of quantitative ultrasound (QUS) and the influence of metabolic control and other diseaserelated and growth variables was analysed. Methods Group I consisted of 99 pubertal (Tanner ≥2) adolescents (49 female), aged 14.3±2.5 years, diabetes duration 4.6±2.3 years. Controls (group II) were 297 children, matched by sex and age, from a healthy population. The influence of glycated haemoglobin (current: HbA1cD; last year’s mean: HbA1cY; whole duration mean: HbA1cT), diabetes duration, percentage of life …

Five-year results following treatment of intrabony defects with enamel matrix proteins and guided tissue regeneration

2004

Treatment with enamel matrix proteins (EMD) or guided tissue regeneration (GTR) has been shown to enhance periodontal regeneration. However, until now there are limited data on the long-term results following these treatment modalities.The aim of the present clinical study was to present the 5-year results following treatment of intrabony defects with EMD, GTR, combination of EMD and GTR, and open flap debridement (OFD).Forty-two patients, each of whom displayed one intrabony defect of a probing depth of at least 6 mm, were randomly treated with one of the four treatment modalities. The following parameters were evaluated prior to surgery, at 1 year and at 5 years after: plaque index, gingi…

Statistical Learning Algorithms to Forecast the Equity Risk Premium in the European Union

2018

With the explosion of “Big Data”, the application of statistical learning models has become popular in multiple scientific areas as well as in marketing, finance or other business disciplines. Nonetheless, there is not yet an abundant literature that covers the application of these learning algorithms to forecast the equity risk premium. In this paper we investigate whether Classification and Regression Trees (CART) algorithms and several ensemble methods, such as bagging, random forests and boosting, improve traditional parametric models to forecast the equity risk premium. In particular, we work with European Monetary Union data for a period that spans from the EMU foundation at the begin…

Driven Bose-Hubbard Model with a Parametrically Modulated Harmonic Trap

2016

We investigate a one-dimensional Bose–Hubbard model in a parametrically driven global harmonic trap. The delicate interplay of both the local interaction of the atoms in the lattice and the driving of the global trap allows us to control the dynamical stability of the trapped quantum many-body state. The impact of the atomic interaction on the dynamical stability of the driven quantum many-body state is revealed in the regime of weak interaction by analyzing a discretized Gross–Pitaevskii equation within a Gaussian variational ansatz, yielding a Mathieu equation for the condensate width. The parametric resonance condition is shown to be modified by the atom interaction strength. In particul…

Measuring High-Order Interactions in Rhythmic Processes Through Multivariate Spectral Information Decomposition

2021

Many complex systems in physics, biology and engineering are modeled as dynamical networks and described using multivariate time series analysis. Recent developments have shown that the emergent dynamics of a network system are significantly affected by interactions involving multiple network nodes which cannot be described using pairwise links. While these higher-order interactions can be probed using information-theoretic measures, a rigorous framework to describe them in the frequency domain is still lacking. This work presents an approach for the spectral decomposition of multivariate information measures, capable of identifying higher-order synergistic and redundant interactions betwee…

A Geometric Algorithm for Ray/Bézier Surfaces Intersection Using Quasi-Interpolating Control Net

2008

In this paper, we present a new geometric algorithm to compute the intersection between a ray and a rectangular Bezier patch. The novelty of our approach resides in the use of bounds of the difference between a Bezier patch and its quasi-interpolating control net. The quasi-interpolating polygon of a Bezier surface of arbitrary degree approximates the limit surface within a precision that is function of the second order difference of the control points, which allows for very simple projections and 2D intersection tests to determine sub-patches containing a potential intersection. Our algorithm is simple, because it only determines a 2D parametric interval containing the solution, and effici…

Searching for the right timing of surgical delay: angiogenesis, vascular endothelial growth factor and perfusion changes in a skin-flap model.

2009

Summary Background The angiogenic potential of vascular endothelial growth factor (VEGF) and its oxygen pressure-dependent regulation suggest a strong connection between this growth factor and the ‘delay phenomenon'. In this study we focused on the chronological changes in VEGF concentration and flap perfusion in order to optimise the duration of surgical delay. Methods The VEGF concentration in skin and underlying muscle was measured in oversized, random-pattern flaps on 38 male Sprague-Dawley rats after 3, 5 or 7 days of surgical delay. Additionally, flaps were raised 5 or 7 days past preconditioning. The effect on flap perfusion was measured using indocyanine green fluoroscopy and the si…

CFD parametric analysis and experimental results on a hydraulic actuator

2014

Stronger proprioceptive BOLD-responses in the somatosensory cortices reflect worse sensorimotor function in adolescents with and without cerebral pal…

2020

Graphical abstract

Stochastic sensitivity of bull and bear states

2021

We study the price dynamics generated by a stochastic version of a Day–Huang type asset market model with heterogenous, interacting market participants. To facilitate the analysis, we introduce a methodology that allows us to assess the consequences of changes in uncertainty on the dynamics of an asset price process close to stable equilibria. In particular, we focus on noise-induced transitions between bull and bear states of the market under additive as well as parametric noise. Our results are obtained by combining the stochastic sensitivity function (SSF) approach, a mixture of analytical and numerical techniques, due to Mil’shtein and Ryashko (1995) with concepts and techniques from th…