Search results for "Extension"
showing 10 items of 534 documents
Empirical definition of social types in the analysis of inequality of opportunity: a latent classes approach
2014
The empirical analysis of inequality of opportunity centres on disparities between social types, defined by the exposure to circumstances beyond individual control. Despite this, its main theoretical foundation—the Roemer model—does not indicate how to carry out, in practice, the required partition of the population into such types. This paper operationalises this definition of social types using a latent classes approach. Our specification is embedded in a probabilistic extension of the canonical Roemer model, which assumes that the relevant population consists of a finite number of latent types, from which each individual can be treated as a random draw. This makes possible the use of the…
Didactic proposal to change misconceptions about the contribution of the fusion of the ice to the rise in sea level
2020
En la actualidad existen muchos estudios acerca del conocimiento teórico de la población sobre el cambio climático. Los resultados de estos estudios muestran la existencia de confusiones e ideas alternativas respecto a determinados fenómenos y conceptos básicos de gran importancia, las cuales constituyen un serio obstáculo para el aprendizaje en educación ambiental. En este trabajo se analiza una de esas ideas, relacionada con el impacto directo que tiene la fusión del hielo flotante en el aumento del nivel del mar. Concretamente, se muestra una primera aproximación respecto a su extensión y fortaleza entre alumnado de secundaria y profesorado en formación, detallando a su vez una estrategi…
Misinterpretation caused by 3D effects on 2D Electrical Resistivity Tomography: tests on simple models
2018
Summary The aim of this work is to evaluate the effects of 2D inversion of electrical resistivity data when in presence on 3D structures by testing synthetic and experimental models. Several numerical simulations have been calculated for different resistivity models and 2D datasets were extracted to study and quantify the effects of 2D inversion on 3D structures. Results have been compared with field texts carried out in quarrying sites. The main tests here presented simulates prism-shaped cavities with a square vertical section of 1 × 1 size and a variable lateral extension d, from 1 to infinity (this latter being a 2D tunnel model). Inversion of predicted data show that 2D tomography does…
The extended CC2 model ECC2
2013
We present a size-extensive extension to the CC2 model that avoids the complications with quasi-degeneracies that are present in the CC2 model and related perturbation theory-based approaches. The formulation also provides a consistent model for treating different parts of a molecular system at different levels of electron correlation. Such a subsystem approach leads to large reductions in the computational requirements without compromising the accuracy. In this initial study, we focus on static molecular properties. © 2013 Copyright Taylor and Francis Group, LLC.
A comprehensive experimental study of the rheological behaviour of HDPE.
1986
Extensional properties of four high density polyethylenes with different molecular weights and molecular weight distributions are presented. The samples have already been well characterized in shear and non-isothermal extensional flow. The data were collected at 180 °C for elongational rates between 3 · 10−1 and 10−4s−1. Some qualitative and quantitative generalizations of the results are given.
Increasing the Capacity of Existing Bridges by Using Unbonded Prestressing Technology: A Case Study
2014
External posttensioning or unbonded prestressing was found to be a powerful tool for retrofitting and for increasing the life extension of existing structures. Since the 1950s, this technique of reinforcement was applied with success to bridge structures in many countries, and was found to provide an efficient and economic solution for a wide range of bridge types and conditions. Unbonded prestressing is defined as a system in which the post-tensioning tendons or bars are located outside the concrete cross-section and the prestressing forces are transmitted to the girder through the end anchorages, deviators, or saddles. In response to the demand for a faster and more efficient transportati…
Physical Properties of Latvian Hemp Fibres
2015
Each year more and more people focus on healthy, ecological and environmental-friendly living. Environmentally friendly lifestyle doesn’t mean that we are using only natural products, but attention is pointed to the manufacturing and production process also. The rapid development of recycled and biodegradable products causes expanding usage of hemp fibers both in household and technical textiles. The analysis of hemp cultivation and usage trends in the world and Europe shows that hemp cultivation and processing in Latvia has good perspectives. Product quality is influenced by raw materials. In this case it is hemp fiber descriptive characteristics. Hemp fibers are natural fibers and their p…
Validation Specimen for Contour Method Extension to Multiple Residual Stress Components
2007
A new theoretical development of the contour method [1], that allow the user to measure the three normal residual stress components on cross sections of a generic mechanical part, is presented. To validate such a theoretical development, a residual stress test specimen was properly designed, fabricated and then tested with different experimental techniques.
A cooperative lifetime extension MAC protocol in duty cycle enabled wireless sensor networks
2011
To reduce energy consumption in wireless sensor networks, the concept of duty cycle is used in many MAC protocols. Although these protocols provide efficient energy-conservation solutions, they cannot resolve the energy hole problem in a multi-hop network, where a few nodes near the sink must relay the packets from the rest of the network, and consequently exhaust their batteries earlier. The previously proposed REACT forwarding protocol triggers the cooperation of several nodes to extend transmission range and hop over the highly burdened node, thereby allowing it to save its energy and extend the lifetime of the network. However, the previous work lacked a MAC protocol with a duty cycle. …
Energy Harvesting-Aware Backoff Algorithms for Distributed Device-to-Device Communication
2016
Due to limited energy capacity in mobile devices, energy harvesting is regarded as a promising technology for lifetime extension in device-to-device (D2D) communication. However, medium access control (MAC) protocols designed for D2D communication intrinsically do not consider the existence of harvested energy. In this paper we study four backoff (BO) algorithms, among which one algorithm is proposed to enhance the BO selection based on energy harvesting rate and residual energy of devices. Simulations are performed in order to assess how the proposed algorithm can extend the lifetime of a D2D communication network as well as to provide fair channel access opportunities among devices.