Search results for "Simulation"

Towards sustainable Net Zero Energy Buildings: life cycle energy performances and environmental impacts of a prefabricated building module

The impact of prefabrication in the building sector is currently undergoing significant growth. Although prefabricated buildings cannot in any situation replace conventional buildings, they have some characteristics, such as reduced construction time, higher safety during construction if compared to traditional buildings and modularity, that make them competitive in specific applications, that are undergoing substantial increase importance and market relevance. However, in a context where the transition towards a low-carbon energy system is quickly becoming an important target of scientific efforts and research, prefabricated buildings, as well as any other type of building, will have a key…

To Assess the Validity of the Transfer Function Method: A Neural Model for the Optimal Choice of Conduction Transfer Functions

2010

This paper presents a new mathematical approach applied to the Conduction Transfer Functions (CTFs) of a multilayered wall to predict the reliability of building simula- tions based upon them. Such a procedure can be used to develop a decision support system that identifies the best condition to calculate the best CTFs set. This is a critical point at the core of ASHRAE calculation methodology founded on the Transfer Function Method (TFM). To evaluate the perfor- mance of different CTFs sets, the authors built a large amount of data, subsequently employed to train a Neural Network Classifier (NNC) able to predict the reliability of a simulation without performing it. For this purpose all th…

Large eddy simulation model for wind-driven sea circulation in coastal areas

2013

Abstract. In the present paper a state-of-the-art large eddy simulation model (LES-COAST), suited for the analysis of water circulation and mixing in closed or semi-closed areas, is presented and applied to the study of the hydrodynamic characteristics of the Muggia bay, the industrial harbor of the city of Trieste, Italy. The model solves the non-hydrostatic, unsteady Navier–Stokes equations, under the Boussinesq approximation for temperature and salinity buoyancy effects, using a novel, two-eddy viscosity Smagorinsky model for the closure of the subgrid-scale momentum fluxes. The model employs: a simple and effective technique to take into account wind-stress inhomogeneity related to the …

A demand-based methodology for planning the bus network of a small or medium town.

2010

This work aims at developing a demand-based methodology for designing the bus network of a small or medium town. The proposed modelling tool adopts a multi-agent objective function which evaluates performance in the context of different stakeholders: the surplus of travellers (car and bus users); the bus service provider’s revenues and operation costs. This approach was applied to an existing bus network, serving city of Trapani, which is a medium town in the south of Italy (Sicily), with 100000 inhabitants. The bus-based public transport system attracts only about 5% of commuter trips within Trapani (source: National Institute of Statistics, 2005). This paper reports on an analysis of the …

Asynchronous Runtime Verification of Business Processes: Proof of Concept

2020

Two -methods to generate Bézier surfaces from the boundary

2009

Two methods to generate tensor-product Bezier surface patches from their boundary curves and with tangent conditions along them are presented. The first one is based on the tetraharmonic equation: we show the existence and uniqueness of the solution of @D^4x->=0 with prescribed boundary and adjacent to the boundary control points of a nxn Bezier surface. The second one is based on the nonhomogeneous biharmonic equation @D^2x->=p, where p could be understood as a vectorial load adapted to the C^1-boundary conditions.

Bézier surfaces of minimal area: The Dirichlet approach

2004

The Plateau-Bezier problem consists in finding the Bezier surface with minimal area from among all Bezier surfaces with prescribed border. An approximation to the solution of the Plateau-Bezier problem is obtained by replacing the area functional with the Dirichlet functional. Some comparisons between Dirichlet extremals and Bezier surfaces obtained by the use of masks related with minimal surfaces are studied.

Explicit Bézier control net of a PDE surface

2017

The PDE under study here is a general fourth-order linear elliptic Partial Differential Equation. Having prescribed the boundary control points, we provide the explicit expression of the whole control net of the associated PDE Bézier surface. In other words, we obtain the explicit expressions of the interior control points as linear combinations of free boundary control points. The set of scalar coefficients of these combinations works like a mould for PDE surfaces. Thus, once this mould has been computed for a given degree, real-time manipulation of the resulting surfaces becomes possible by modifying the prescribed information. The work was partially supported by Spanish Ministry of Econo…

Chemical Identification at the Solid–Liquid Interface

2017

Solid-liquid interfaces are decisive for a wide range of natural and technological processes, including fields as diverse as geochemistry and environmental science as well as catalysis and corrosion protection. Dynamic atomic force microscopy nowadays provides unparalleled structural insights into solid-liquid interfaces, including the solvation structure above the surface. In contrast, chemical identification of individual interfacial atoms still remains a considerable challenge. So far, an identification of chemically alike atoms in a surface alloy has only been demonstrated under well-controlled ultrahigh vacuum conditions. In liquids, the recent advent of three-dimensional force mapping…

DEALING WITH RISK IN AGRICULTURE: A CROP LEVEL ANALYSIS AND MANAGEMENT PROPOSAL FOR ITALIAN FARMS

2020

Risk management plays a critical role in agriculture, which is particularly exposed to multiple and heterogeneous risk factors. In addition to the traditional basic risks that generally characterize any business venture, agriculture faces external factors, generally difficult to control and with a strong impact on farm profitability. These are firstly environmental (pests and diseases) and climatic conditions that affect the quantity and quality of agricultural production, but also the structural constraints of the agricultural market, which is characterised by a high degree of supply rigidity, price volatility and inelasticity of demand. This leads to the need to implement risk management …