Search results for "Computer Science Application"

Approximation Properties of the Modified Stancu Operators

2017

ABSTRACTIn this article we construct a sequence of Stancu-type operators that are based on a function τ. This function is any function on [0,1] continuously differentiable ∞ times, such that τ(0) =...

Silhouette encoding and synthesis using elliptic Fourier descriptors, and applications to videoconferencing

2004

Abstract This paper investigates the use of elliptic Fourier descriptors as a shape descriptor for encoding the silhouette of a person. Shape descriptors are here used for predicting the shape of silhouettes in missing frames within a sequence. This prediction scheme is applied to the case of generating in-between images in a low frame rate videoconferencing system, where the reconstructed silhouette is used as a binary mask for reducing the computational time for the frame reconstruction.

Quantifying the complexity of short-term heart period variability through K nearest neighbor local linear prediction

2008

The complexity of short-term heart period (HP) variability was quantified exploiting the paradigm that associates the degree of unpredictability of a time series to its dynamical complexity. Complexity was assessed through k-nearest neighbor local linear prediction. A proper selection of the parameter k allowed us to perform either linear or nonlinear prediction, and the comparison of the two approaches to infer the presence of nonlinear dynamics. The method was validated on simulations reproducing linear and nonlinear time series with varying levels of predictability. It was then applied to HP variability series measured from healthy subjects during head-up tilt test, showing that short-te…

A correction method for dynamic analysis of linear continuous systems

2005

A method to improve the dynamic response analysis of continuous classically damped linear system is proposed. As in fact usually, following a classical approach, a reduced number of eigenfunctions are accounted for and the response is evaluated by integrating the uncoupled differential equations of motion in modal space, neglecting the contribution of high frequency modes (truncation procedure). Here, starting from the given system, it is proposed to set up two differential equations governing the motion of two new continuous systems: the first one contains only the first m non-zero eigenvalues of the given system and the second one contains the remainder non-zero infinity - m eigenvalues. …

Experimental approach for testing the uncoupling between cardiovascular variability series

2002

In cardiovascular variability analysis, the significance of the coupling between two series is commonly assessed by defining a zero level on the magnitude-squared coherence (MSC). Although the use of the conventional value of 0.5 does not consider the dependence of MSC estimates on the analysis parameters, a theoretical threshold Tt is available only for the weighted covariance (WC) estimator. In this study, an experimental threshold for zero coherence Te was derived by a statistical test from the sampling distribution of MSC estimated on completely uncoupled time series. MSC was estimated by the WC method (Parzen window, spectral bandwidth B = 0.015, 0.02, 0.025, 0.03 Hz) and by the parame…

On estimating contemporaneous quarterly regional GDP

2007

Subnational regional jurisdictions rarely have at their disposal a reasonable array of timely statistics to monitor their economic condition. In light of this, we develop a procedure that simultaneously estimates a quarterly time series for all regions of a country based upon quarterly national and annual regional data. While other such techniques exist, we suggest a temporal error structure that eliminates possible spurious jumps. Using our approach, regional analysts should now be able to distribute national growth among regions as soon as quarterly national figures are released. In a Spanish application, we detail some practicalities of the process and show that our proposal produces bet…

Corrigendum to “Predicting service request in support centers based on nonlinear dynamics, ARMA modeling and neural networks” [Expert Systems with Ap…

2013

Value, supplier dependence and long‐term orientation

2011

PurposeIn organizational markets, many companies tend to reduce the number of providers to focus on establishing relationships with few of them. The purpose of this paper is to analyze the influence of relationship value and dependence of supplier on long‐term orientation and customer loyalty in the setting of relationships between travel agencies and their main providers.Design/methodology/approachA partial least square regression is performed to test a proposed model that links several relational variables with outcomes in terms of customer loyalty.FindingsResults provide support for the positive indirect influence of relationship value on long‐term orientation, while customer dependence …

Online or offline – Does it matter?: A study of in-service teachers' perceptions of learning outcomes in Norway

2020

Policymakers and scholars are scaling up online professional development programmes for teachers. We studied how in-service teachers in Norway perceived their learning outcomes for professional development programmes conducted either as campus-based or online courses. Based on survey data, we found teachers studying online and in campus-based settings have relatively similar perceptions of the learning outcomes. This changes when indicators of collaboration and support from teachers are controlled for, suggesting that these factors are more strongly related to learning outcomes for those in campus-based studies than those in online studies. Our findings contribute new insights on how percei…

Logistics service quality: a new way to loyalty

2008

PurposeNow‐a‐days, logistics research focuses on the ability of logistics to deliver a quality service and generate greater satisfaction with the delivered service. Therefore, the aim of this work is to analyze the quality, satisfaction, and loyalty sequence in the logistic service delivery context, with the purpose of considering the role of information and communication technologies (ICT) in this chain of effects.Design/methodology/approachAfter reviewing the different approaches given by the literature, SEM analysis is used to contrast the hypotheses for the analyzed constructs in the presence of high/low ICT level. A questionnaire based on personal survey was conducted among manufacture…