Search results for "Core"

2016

Abstract. Various geoscientific applications require a fast prediction of fracture permeability for an optimal workflow. Hence, the objective of the current study is to introduce and validate a practical method to characterize and approximate single flow in fractures under different stress conditions by using a core-flooding apparatus, in situ X-ray computed tomography (CT) scans and a finite-volume method solving the Navier–Stokes–Brinkman equations. The permeability of the fractured sandstone sample was measured stepwise during a loading–unloading cycle (0.7 to 22.1 MPa and back) to validate the numerical results. Simultaneously, the pressurized core sample was imaged with a medical X-ray…

Adaptive SDN-based architecture using QoE metrics in live video streaming on Cloud Mobile Media

2017

The increasing adoption of smart phones, the increased access to mobile broadband networks and the availability of public cloud infrastructures are aligning to the next generation of truly ubiquitous multimedia services, known as Cloud Mobile Media (CMM) services. Nevertheless, due to an inherit higher and variable end to end delay mainly as a result of the virtualization process, new challenges appear in particular for live video streaming applications in order to keep a good Quality of Experience of the delivered video. Thus, to keep client's satisfaction at good levels in terms of Mean Opinion Score (MOS), we propose an adaptive Software Defined Networking (SDN)-based architecture runnin…

5G Functional Architecture and Signaling Enhancements to Support Path Management for eV2X

2019

Enhanced vehicle-to-everything (eV2X) communication is one of the most challenging use cases that the fifth generation (5G) of cellular mobile communications must address. In particular, eV2X includes some 5G vehicular applications targeting fully autonomous driving which require ultra-high reliability. The usual approach to providing vehicular communication based on single-connectivity transmission, for instance, through the direct link between vehicles (PC5 interface), often fails at guaranteeing the required reliability. To solve such a problem, in this paper, we consider a scheme where the radio path followed by eV2X messages can be proactively and dynamically configured to either trans…

Genetic and psychosocial stressors have independent effects on the level of subclinical psychosis: findings from the multinational EU-GEI study.

2022

the Spanish Ministry of Science and Innovation. Instituto de Salud Carlos III (SAM16PE07CP1, PI16/02012, PI19/024), co-financed by ERDF Funds from the European Commission, ‘A way of making Europe’, CIBERSAM. Madrid Regional Government (B2017/BMD-3740 AGES-CM-2), European Union Structural Funds. European Union Seventh Framework Program under grant agreements FP7-4-HEALTH-2009-2.2.1-2-241909 (Project EU-GEI) and FP7-HEALTH-2013-2.2.1-2-603196 (Project PSYSCAN); and European Union H2020 Program under the Innovative Medicines Initiative 2 Joint Undertaking (grant agreement No 115916, Project PRISM, and grant agreement No 777394, Project AIMS-2-TRIALS) (...)

Statistical validation of simulation models of observable systems

2003

In this paper, for validating computer simulation models of real, observable systems, an uniformly most powerful invariant (UMPI) test is developed from the generalized maximum likelihood ratio (GMLR). This test can be considered as a result of a new approach to solving the Behrens‐Fisher problem when covariance matrices of two multivariate normal populations (compared with respect to their means) are different and unknown. The test is based on invariant statistic whose distribution, under the null hypothesis, does not depend on the unknown (nuisance) parameters. The sample size and threshold of the UMPI test are determined from minimization of the weighted sum of the model builder's risk a…

BICKEL–ROSENBLATT TEST FOR WEAKLY DEPENDENT DATA

2012

The aim of this paper is to analyze the Bickel–Rosenblatt test for simple hypothesis in case of weakly dependent data. Although the test has nice theoretical properties, it is not clear how to implement it in practice. Choosing different band-width sequences first we analyze percentage rejections of the test statistic under H0 by some empirical simulation analysis. This can serve as an approximate rule for choosing the bandwidth in case of simple hypothesis for practical implementation of the test. In the recent paper [12] a version of Neyman goodness-of-fit test was established for weakly dependent data in the case of simple hypotheses. In this paper we also aim to compare and discuss the …

Vibration effect on ball score test in international vs. national level table tennis

2018

In table tennis, motor skills are crucial for discriminating player level. However, there is a dearth of studies exploring the impact of a vibrational stimulus on performance. Thirty-four male players (age 25 +/- 2 years ; body mass index, BMI 23.4 +/- 1.2 kg.m(-2)) participated in the study. Seventeen played at international level (IL), while the remaining 17 played at national level (NL). The participants underwent a ball-handling test, the ball score, before (PRE) and after (POST) a vibrational stimulus. Intra-class correlation (ICC) for the ball score result showed good reliability (ICC 0.87 for IL and 0.80 for NL). Repeated measures ANOVA showed differences between groups for ball scor…

Survival Prediction in Intrahepatic Cholangiocarcinoma: A Proof of Concept Study Using Artificial Intelligence for Risk Assessment

2021

Several scoring systems have been devised to objectively predict survival for patients with intrahepatic cholangiocellular carcinoma (ICC) and support treatment stratification, but they have failed external validation. The aim of the present study was to improve prognostication using an artificial intelligence-based approach. We retrospectively identified 417 patients with ICC who were referred to our tertiary care center between 1997 and 2018. Of these, 293 met the inclusion criteria. Established risk factors served as input nodes for an artificial neural network (ANN). We compared the performance of the trained model to the most widely used conventional scoring system, the Fudan score. Pr…

What Drove Past Teleconnections?

2003

Ice core records from Greenland and Antarctica and sediment records from the world9s oceans have shown that over the past 100,000 years, climate has varied substantially across the globe. In his Perspective, Sirocko asks what drove these--sometimes very rapid--climate oscillations. He highlights the report of Burns et al., whose monsoon record from the Indian Ocean shows strong similarities with ice core records from Greenland. Sirocko argues that the large areas of homogeneous sea surface temperature in the cold circum-Antarctic current and in the warm-water masses of the low latitudes must have played an important role in linking climate forcing between distant parts of the world. The muc…

La geografía escolar: deseos institucionales y vivencias de aula

2018

School geography embodies the attempt of political and academic institutions of systematizing geographical content knowledge: to transform geography in a learning object for the population. The purpose of this article is to highlight the existing differences and similarities in the analysis of school geography. On the one hand, we refer to the curricular framework and to the education system. On the other hand, we deal with the inherent problems of geography teaching in childhood, primary and secondary education. In these contexts, geography contents aim to convey the description of the environment to students that tend to distrust canonical academic discourse, as they consider it to be bey…