Search results for "Simulation."
showing 10 items of 4779 documents
Quantifying Excess Deaths Related to Heatwaves under Climate Change Scenarios: A multicountry time series modelling study
2018
Background: Heatwaves are a critical public health problem. There will be an increase in the frequency and severity of heatwaves under changing climate. However, evidence about the impacts of climate change on heatwave-related mortality at a global scale is limited. Methods and findings: We collected historical daily time series of mean temperature and mortality for all causes or nonexternal causes, in periods ranging from January 1, 1984, to December 31, 2015, in 412 communities within 20 countries/regions. We estimated heatwave–mortality associations through a two-stage time series design. Current and future daily mean temperature series were projected under four scenarios of greenhouse g…
Automatic Landing System for Civil Unmanned Aerial System
2013
In spite of a number of potentially valuable civil UAS applications The International Regulations prohibit UAS from operating in the National Air Space. Maybe the primary reasons are safety concerns. In fact their ability to respond to emergent situations involving the loss of contact between the aircraft and the ground station poses a serious problem. Therefore, to an efficient safe insertion of UAS in the Civil Air Transport System one important element is their ability to perform automatic landing afterwards the failure. Moreover, the mathematical model of ground effect is usually neither included in the model of the aircraft during takeoff and landing nor in the design requirements of t…
Extraction of thermal characteristics of surrounding geological layers of a geothermal heat exchanger by 3D numerical simulations
2016
Ground thermal conductivity and borehole thermal resistance are key parameters for the design of closed Ground-Source Heat Pump (GSHP) systems. The standard method to determine these parameters is the Thermal Response Test (TRT). This test analyses the ground thermal response to a constant heat power injection or extraction by measuring inlet and outlet temperatures of the fluid at the top of the borehole heat exchanger. These data are commonly evaluated by models considering the ground being homogeneous and isotropic. This approach estimates an effective ground thermal conductivity representing an average of the thermal conductivity of the different layers crossed by perforation. In order …
Efficiency improvement of a ground coupled heat pump system from energy management
2011
The installed capacity of an air conditioning system is usually higher than the average cooling or heating demand along the year. So, most of the time, the system is working under its actual capacity. In this contribution, we study the way to improve the efficiency of a ground coupled heat pump air conditioning system by adapting its produced thermal energy to the actual thermal demand. For this purpose, an air conditioning system composed by a ground coupled heat pump and a central fan coil linked to an office located in a cooling dominated area was simulated, and a new management strategy aiming to diminish electrical consumption was developed under the basic constraint that comfort requi…
Online mass flow prediction in CFB boilers with explicit detection of sudden concept drift
2010
Fuel feeding and inhomogeneity of fuel typically cause fluctuations in the circulating fluidized bed (CFB) process. If control systems fail to compensate the fluctuations, the whole plant will suffer from dynamics that is reinforced by the closed-loop controls. This phenomenon causes reducing efficiency and the lifetime of process components. In this paper we address the problem of online mass flow prediction, which is a part of control. Particularly, we consider the problem of learning an accurate predictor with explicit detection of abrupt concept drift and noise handling mechanisms. We emphasize the importance of having domain knowledge concerning the considered case and constructing the…
On the classification of observations structured into groups
1988
The paper is concerned with the problem of classifying a specific group into two populations (insect eggs of the same clutch belonging therefore to the same species). Two approaches, one parametric and the other non-parametric, are described. The classical likelihood ratio procedure is derived. An interpretation and a decomposition of the test criteria is given. A misclassification estimate using the Chernoff–Kullback–Kailath region is provided.
Ab initio determination of the electron affinities of DNA and RNA nucleobases
2008
High-level quantum-chemical ab initio coupled-cluster and multiconfigurational perturbation methods have been used to compute the vertical and adiabatic electron affinities of the five canonical DNA and RNA nucleobases: uracil, thymine, cytosine, adenine, and guanine. The present results aim for the accurate determination of the intrinsic electron acceptor properties of the isolated nucleic acid bases as described by their electron affinities, establishing an overall set of theoretical reference values at a level not reported before and helping to rule out less reliable theoretical and experimental data and to calibrate theoretical strategies. Daniel.Roca@uv.es Manuela.Merchan@uv.es Luis.Se…
Umfrage zum Training laparoskopischer Fertigkeiten in Deutschland
2016
Hintergrund: Das Training fur Laparoskopie an Simulationsmoglichkeiten wie Box-, POP- oder Virtual-Reality-Trainern verbessert nachweislich die intraoperativen Leistungen. In Deutschland ist dieses Training nicht verpflichtend in die Facharztweiterbildung integriert, muss jedoch bspw. in zertifizierten Zentren fur minimalinvasive Chirurgie bereitgestellt werden. Simulatoren sind in Deutschland von Weiterbildern und Weiterzubildenden erwunscht, jedoch laut fruheren Umfragen nicht ausreichend verfugbar. Ziel des Projekts war die strukturierte Erfassung der Moglichkeiten fur Laparoskopietraining in Deutschland sowie deren Nutzung und Finanzierung. Methoden: Es wurde eine Onlineumfrage unter Mi…
Virtuelle 3-D-Laparoskopie-Simulation in der chirurgischen Aus- und Weiterbildung – Ergebnisse einer Pilotstudie
2013
Hintergrund: Dem technischen Fortschritt folgend, werden im Operationssaal Module zur 3-dimensionalen Darstellung in der Laparoskopie eingesetzt. Erste Untersuchungen an Box-Trainern haben diskrepante Ergebnisse gezeigt. Fur die Virtual-Reality-Laparoskopie (VRL) fehlen Daten zur 3-dimensionalen Simulation. Material und Methoden: 5 Facharzte fur Chirurgie, 10 chirurgisch tatige Arzte in Weiterbildung und 29 Medizinstudenten fuhrten abstrakte und prozedurale Ubungen am VRL-Simulator im 2-D- und 3-D-Modus durch. Die Reihenfolge der Durchfuhrung (2-D/3-D) wurde randomisiert. Ergebnisse: Fur Arzte und Studenten zeigten sich keine signifikanten Leistungsunterschiede fur Ubungen im 2-D- und 3-D-D…
Optimal selection of touristic packages based on user preferences during sports mega-events
2022
Sport mega-events, such as the Soccer World Cup or Olympic Games, attract many visitors from all over the world. Most of these visitors are also interested in, besides attending the sports events, visiting the host nation and the neighboring countries. In this paper, we focus on the upcoming FIFA World Cup Qatar 2022. As per the schedule of the tournament, a national team can play 7 matches at most. Therefore, a supporter will have six short breaks (of three to five days) between consecutive matches in addition to two longer ones, immediately before and after the tournament, during which they can plan some touris- tic trips. We study the problem faced by a touristic trip provider who wants …