Search results for "Non-parametric"

The analysis of convergence in ecological indicators: An application to the Mediterranean fisheries

2017

9 pages, 4 figures, 3 tables

Health Insurance Reforms and Health Policies in Rural China

2016

Since the early 2000s, the Chinese government has undertaken a series of reforms in the health sector. Among these, the three most important have been concerned with medical insurance, hospital administration, and pharmaceutical policies. The aims of these reforms were to extend health insurance coverage, to increase the activities and the efficiency of the health establishments, and to improve patient care. This article focuses on two components of these reforms: the development of health insurance in rural areas and the policy on essential medicines in conjunction with hospital reforms. Our longstanding co-operation with a research team from Weifang University and with the Weifang Health …

Optical remote sensing and the retrieval of terrestrial vegetation bio-geophysical properties – A review

2015

Abstract: Forthcoming superspectral satellite missions dedicated to land monitoring, as well as planned imaging spectrometers, will unleash an unprecedented data stream. The processing requirements for such large data streams involve processing techniques enabling the spatio-temporally explicit quantification of vegetation properties. Typically retrieval must be accurate, robust and fast. Hence, there is a strict requirement to identify next-generation bio-geophysical variable retrieval algorithms which can be molded into an operational processing chain. This paper offers a review of state-of-the-art retrieval methods for quantitative terrestrial bio-geophysical variable extraction using op…

Experimental Sentinel-2 LAI estimation using parametric, non-parametric and physical retrieval methods – A comparison

2015

Abstract Given the forthcoming availability of Sentinel-2 (S2) images, this paper provides a systematic comparison of retrieval accuracy and processing speed of a multitude of parametric, non-parametric and physically-based retrieval methods using simulated S2 data. An experimental field dataset (SPARC), collected at the agricultural site of Barrax (Spain), was used to evaluate different retrieval methods on their ability to estimate leaf area index (LAI). With regard to parametric methods, all possible band combinations for several two-band and three-band index formulations and a linear regression fitting function have been evaluated. From a set of over ten thousand indices evaluated, the …

A non-parametric Scale-based Corner Detector

2008

This paper introduces a new Harris-affine corner detector algorithm, that does not need parameters to locate corners in images, given an observation scale. Standard detectors require to fine tune the values of parameters which strictly depend on the particular input image. A quantitative comparison between our implementation and a standard Harris-affine implementation provides good results, showing that the proposed methodology is robust and accurate. The benchmark consists of public images used in literature for feature detection.

A non-parametric segmentation methodology for oral videocapillaroscopic images

2014

We aim to describe a new non-parametric methodology to support the clinician during the diagnostic process of oral videocapillaroscopy to evaluate peripheral microcirculation. Our methodology, mainly based on wavelet analysis and mathematical morphology to preprocess the images, segments them by minimizing the within-class luminosity variance of both capillaries and background. Experiments were carried out on a set of real microphotographs to validate this approach versus handmade segmentations provided by physicians. By using a leave-one-patient-out approach, we pointed out that our methodology is robust, according to precision-recall criteria (average precision and recall are equal to 0.9…

P-spline quantile regression: a new algorithm for smoothing parameter selection

Assessing covariate imbalance in meta-analysis studies.

2010

The main goal of meta-analysis is to combine data across studies or data sets to obtain summary estimates. In this paper, the novelty is to propose a statistical tool to assess a possible covariate imbalance in baseline variables to investigate similarity of trials. We conducted the detection of the covariate imbalance, first, through some graphical comparison of the empirical cumulative distribution functions or ECDFs, which are built by putting together arms or trials according to some risk factor, and second, through some non-parametric tests such as the Kolmogorov–Smirnov and the Anderson–Darling tests. To overcome the huge presence of ties, we conducted the statistical tests on perturbe…

Extrapolation of the Species Accumulation Curve for Incomplete Species Samplings: A New Nonparametric Approach to Estimate the Degree of Sample Compl…

2015

9 pages; International audience; Incomplete species samplings are deemed to remain the common practice in those groups of animals, such as small or micro- invertebrates, with numerous species that often are more or less difficult to detect in the field. Thus, extrapolating the Species Accumulation Curve as far as possible beyond the actual sample size may thus serve as a useful (although imperfect) surrogate to the desired, but practically inaccessible, complete samplings. In this context, several kinds of theoretical or empirical models for the Species Accumulation Curve and also a lot of estimators of the asymptotic limit of the Curve (i.e. total species richness) have been proposed. The …

Levels of cognitive congruence between managers and team members’ perceptions of cooperation at work

2019

Much of the research on the psychological dynamics of performance teams suffers from the following limitations: consideration of only one theoretical framework and analysis of just one perspective (e.g., manager&ndash