Search results for "Homogeneous"

2020

To validly assess teachers’ pedagogical content knowledge (PCK), performance-based tasks with open-response formats are required. Automated scoring is considered an appropriate ap-proach to reduce the resource-intensity of human scoring and to achieve more consistent scor-ing results than human raters. The focus is on the comparability of human and automated scor-ing of PCK for economics teachers. The answers of (prospective) teachers (N=852) to six open-response tasks from a standardized and validated test were scored by two trained human raters and the engine "Educational SCoRIng TOolkit" (ESCRITO). The average agreement between human and computer ratings, κw = .66, suggests a convergent …

Prevalence os sending, receiving and forwarding sexts among youths: A three-level meta-analysis.

2020

Alttes ajuts: Conselleria d'Educació, Investigació, Cultura i Esport DOGV No. 7943, ACIF, 837 2017 By systematic review with a three-level, mixed-effects meta-analysis, this paper examines the prevalence of sexting experiences among youths aimed at analyzing conceptual and methodological moderators that might explain its heterogeneity. A search was conducted of five bibliographic databases and grey literature up until February 2020. The risk of bias in primary studies was assessed. A total of seventy-nine articles met the set inclusion criteria. Mean prevalences for sending, receiving and forwarding sexts were.14 (95% CI:.12,.17),.31 (95% CI:.26,.36) and.07 (95% CI:.05,.09), respectively, e…

Traffic Flow Variables Estimation: An Automated Procedure Based on Moving Observer Method. Potential Application for Autonomous Vehicles

2019

Abstract The estimation of traffic flow variables (flow, space mean speed and density) plays a fundamental role in highways planning and designing, as well as in traffic control strategies. Moving Observer Method (MOM) allows traffic surveys in a road, or in a road network. This paper proposes a novel automated procedure, called MOM-AP based on Moving Observer Method and Digital Image Processing (DIP) Technique able to automatically detect (without human observers) and calculate flow q, space mean speed vs and density k in case of stationary and homogeneous traffic conditions. In order to evaluate how reliable is the MOM-AP, an experiment has been carried out in a segment of one two-lane si…

Adaptive Large Neighborhood Search with a Constant-Time Feasibility Test for the Dial-a-Ride Problem

2019

In the dial-a-ride problem, user-specified transport requests from origin to destination points have to be served by a fleet of homogeneous vehicles. The problem variant we consider aims at finding a set of minimum-cost routes satisfying constraints on vehicle capacity, time windows, maximum route duration, and maximum user ride times. We propose an adaptive large neighborhood search (ALNS) for its solution. The key novelty of the approach is an exact amortized constant-time algorithm for evaluating the feasibility of request insertions in the repair steps of the ALNS. In addition, we use two optional improvement techniques: a local-search-based intraroute improvement of routes of promisin…

1,2,3-Triazole in Heterocyclic Compounds, Endowed with Biological Activity, through 1,3-Dipolar Cycloadditions

2014

1,3-Dipolar cycloaddition reactions can be considered a powerful synthetic tool in the building of heterocyclic rings, with applications in different fields. In this review we focus on the synthesis of biologically active compounds possessing the 1,2,3-triazole core through 1,3-dipolar cycloaddition reactions. The 1,2,3-triazole skeleton can be present as a single disubstituted ring, as a linker between two molecules, or embedded in a polyheterocycle. The cycloaddition reactions are usually catalysed by copper or ruthenium. Domino reactions can be achieved through dipolarophile anion formation, generally followed by cyclisation. The variety of attainable heterocyclic structures gives an ill…

A coarse to fine 3D acquisition system

2015

International audience; The 3D chain (acquisition-processing-compression) is , most of the time , sequenced into several steps. Such approaches result into an one-dense acquisition of 3D points. In large scope of applications , the first processing step consists in simplifying the data. In this paper , we propose a coarse to fine acquisition system which permits to obtain simplified data directly from the acquisition. By calculating some complementary information from 2D images , such as 3D normals , multiple homogeneous regions will be segmented and affected to a given primitive class. Contrary to other studies , the whole process is not based on a mesh. The obtained model is simplified di…

Faultlines and subgroups: A meta-review and measurement guide

2014

Research on faultlines—hypothetical dividing lines splitting a team into homogeneous subgroups based on team members’ attributes—has produced several meta-analyses, reviews, and algorithms for faultline and subgroup detection. To help navigate this complexity, we summarize the current theories underlying faultline and subgroup research. We also compare the two most recent algorithms for computational faultline/subgroup detection, offer a guideline for choosing adequate algorithms, and recommend measure combinations for future research. We further review empirical faultlines and subgroup research and show that different contextual factors exhibit a strong influence on the effects of faultlin…

A controlled clinical study of periodontal health in anticoagulated patients : assessment of bleeding on probing

2017

Background According to the Spanish Society of Cardiology, 700,000 patients receive oral anticoagulants, and in these cases bleeding on probing (BOP) could be altered. However, no studies have analyzed the periodontal status of these patients and the effects anticoagulants may have upon BOP. A study was made of the possible relationship between plaque index, probing depth, INR (International Normalized Ratio) and acenocoumarol dose versus the clinical signs of BOP in a sample of anticoagulated patients. Likewise, an analysis was made of oral hygiene habits and attitude towards bleeding in these patients. Material and Methods A controlled observational clinical study was made in La Ribera Ho…

Über die homogene und heterogene acetylierung von polyformaldehyd. 28. Mitteilung über polyoxymethylene1

1966

Die Acetylierung der Endgruppen eines hochmoleckularen Polyoxymethylendiols mit Essigsaureanhydrid wurde bei 200°C in Substanz sowie bei 135°C in Losung und in Suspension untersucht. Die Umsetzung ist in homogenem Medium innerhalb kurzer Zeit praktisch vollstandig; bei 200°C erfolgt jedoch ohne Zusatz eines (tertiaren) Amins eine besonders starke Verminderung der Molekulargewichte und ein Verlust an Polymerem durch Bildung flussiger Oligo-oxymethylendiacetate. Eine fast quantitative Acetylierung ohne Molekulargewichtsverminderung ist durch Umsetzung bei 135°C in Losung unter Zusatz eines tertiaren Amins moglich. Die Veresterungsgeschwindigkeit bei 135°C ist in heterogenem Medium wesentlich …

Electromyographic study of activity of the masseter and anterior temporalis muscles in patients with temporomandibular joint (TMJ) dysfuction : compa…

2010

Objectives: A comparison was made between the electromyographic patterns specific to patient with temporomandibular disorders and that of normal healthy patients. Study design: Electromyographic tests were carried out during rest and function of the masseter muscles and anterior temporalis muscles in a homogeneous group consisting of 95 patients for whom such pathology and its different degree of severity had been previously studied by means of a Helkimo Test. The electromyographic exploration results were compared to those of a control group consisting of 31 healthy subjects. Results: There were significant differences among patients with a different degree of clinical dysfunction, as well…