Search results for " Models"

How to formulate an accident prediction model for urban intersections.

2009

Several safety prediction models and methods have been developed to eliminate the relationship between the expected accident frequency and various urban intersection geometry and operational attributes. It is generally accepted that accident rates tend to be higher at intersections than on through sections of a road. This is particularly frequent in urban area where roads are characterized by intersections in close succession; moreover, the safe and effective operations of the urban road system can be significantly affected by safety conditions at intersections. In this paper models and methods designed to understand and to predict the accident process at urban intersections are reviewed. I…

ROAD project: Robotics for assisted diving

2014

The activities associated to underwater diving are of great importance in many areas. In the second half of the last century, diving technologies have greatly progressed, but diving is still characterized by significant risks, especially for professional divers who works at high depth, and limited practicability. The use of robotic systems and automatic procedures would allow, as in other situations where safety is of concern (for example, in case of hazardous works or in relation to hostile environments), a reliable monitoring and assessment of the physiological conditions of human operators during their activities. Moving from currently available technologies in underwater robotics, the R…

Robust Adaptive Modulation and Coding (AMC) selection in LTE systems using reinforcement learning

2014

Adaptive Modulation and Coding (AMC) in LTE networks is commonly employed to improve system throughput by ensuring more reliable transmissions. Most of existing AMC methods select the modulation and coding scheme (MCS) using pre-computed mappings between MCS indexes and channel quality indicator (CQI) feedbacks that are periodically sent by the receivers. However, the effectiveness of this approach heavily depends on the assumed channel model. In addition CQI feedback delays may cause throughput losses. In this paper we design a new AMC scheme that exploits a reinforcement learning algorithm to adjust at run-time the MCS selection rules based on the knowledge of the effect of previous AMC d…

Learners’ opinion on their English pronunciation formation

2018

Globalisoituvassa maailmassamme on entistä tavallisempaa kohdata ihmisiä vieraista maista ja kommunikoida heidän kanssaan vieraalla kielellä. Koska englanti on tällä hetkellä läntisen maailman lingua franca, on se usein tällaisissa kohtaamisissa käytetty kieli. Ääntämisen oppimisella on suuri rooli näissä vieraskielisissä kohtaamisessa, koska ensivaikutelmaan vaikuttaa ulkoisten tekijöiden lisäksi myös ihmisen tapa ja taito puhua. Tässä tutkimuksessa lukion toisen vuoden opiskelijat kertovat itse, mitkä asiat luokkahuoneissa tai niiden ulkopuolella ovat auttaneet heitä englannin kielen ääntämisen oppimisessa. Tutkimuksen tavoitteena on saada selville, mitkä asiat ovat tärkeimpiä ääntämisen …

Les pratiques pédagogiques des enseignants du secondaire: l'éclairage des comparaisons internationales

2017

International audience; L'objectif de cet article est de comparer, à l'appui des données de l'enquête internationale TALIS, les pratiques pédagogiques des enseignants du second degré de plusieurs systèmes éducatifs (France, Royaume-Uni, Corée du Sud et Finlande) et de proposer des modèles d'analyse de la structure de ces pratiques. Nous montrons qu'il existe une hétérogénéité des pratiques pédagogiques et que les différentes composantes des pratiques entretiennent entre elles des liens statistiquement forts, susceptibles de varier d'un système à l'autre.

Exact quantum dynamics of interacting spin systems subjected to controllable time dependent magnetic fields

2020

Environmental Quality and Entrepreneurial Activity in Rural Tourism in Italy

2012

We estimate the relation between environmental quality and services in rural tourism in Italy. We use the average number of firms per region in 2003-07 to indicate entrepreneurial activity. We suggest that heterogeneity among administrative regions can be tied to environmental quality. Incorporated farms in rural tourism are relatively more common in regions with better environmental quality, and command higher average price from better quality in hospitality. Only 7% of entrepreneurial activity can be attributable to environmental quality. We conclude that rural tourism activity in Italy is not genuinely tied to environmental quality.

Modelling the metabolic shift of polyphosphate-accumulating organisms

2014

Enhanced biological phosphorus removal (EBPR) is one of the most important methods of phosphorus removal in municipal wastewater treatment plants, having been described by different modelling approaches. In this process, the PAOs (polyphosphate accumulating organisms) and GAOs (glycogen accumulating organisms) compete for volatile fatty acids uptake under anaerobic conditions. Recent studies have revealed that the metabolic pathways used by PAOs in order to obtain the energy and the reducing power needed for polyhydroxyalkanoates synthesis could change depending on the amount of polyphosphate stored in the cells. The model presented in this paper extends beyond previously developed metaboli…

Influence of the Height of Municipal Solid Waste Landfill on the Formation of Perched Leachate Zones

2015

Waste settlement as well as consolidation phenomena, which occur inside a landfill for municipal solid waste (MSW), can cause a decrease in waste permeability. This can lead to a reduction in conveyance of the leachate drainage system. It is therefore possible that a so-called perched leachate zone will form. Such a zone is constituted by an area in the body of the landfill where the leachate is temporarily trapped and is unable to infiltrate downward. This phenomenon is influenced by many factors, which include rain infiltration rate, waste moisture and composition, landfill height, and so on. The main aim of the paper is to elucidate the role played by landfill height in the formation of …

Implications of terrain resolution on modeling rainfall-triggered landslides using a TIN- based model

2021

Abstract This study employs a distributed eco-hydrological-landslide model, the tRIBS-VEGGIE-Landslide, to evaluate the influence of terrain resolution on the hydro-geomorphological processes involved in slope stability analysis. The model implements a Triangulated Irregular Network (TIN) to describe the topography starting from a grid-DEM. Five grid-DEM resolutions of the case study basin, i.e., 10, 20, 30 and 70 m, are used to derive the corresponding TINs. The results show that using irregular meshes reduces the loss of accuracy with coarser resolutions in the derived slope distribution in comparison to slope distributions estimated from the original grid-based DEM. From a hydrological p…