Search results for " Optimization"
showing 10 items of 2367 documents
Computational stability of an initially radial solution of a growth/dissolution problem in a nonradial implementation
1991
We consider a free boundary problem modelling the growth/dissolution of a crystal. The aim is to investigate the following question: Does the solution to the crystal growth problem posed in two dimensions with radially symmetric initial and boundary condition evolve as a radially symmetric solution?
An improved smoothed particle electromagnetics method in 3D time domain simulations
2011
In this paper, an enhanced variant of the meshless smoothed particle electromagnetics (SPEM) method is performed in order to solve PDEs in time domain describing 3D transient electromagnetic phenomena. The method appears to be very efficient in approximating spatial derivatives in the numerical treatment of Maxwell's curl equations. In many cases, very often, accuracy degradation, due to a lack of particle consistency, severely limits the usefulness of this approach. A numerical corrective strategy, which allows to restore the SPEM consistency, without any modification of the smoothing kernel function and its derivatives, is presented. The method allows to restore the same order of consiste…
Multiphysics Optimization for Water-Cooled Breeding Blanket Design Enhancement
2021
The commercial feasibility of the first fusion power plant generation adopting D-T plasma is strongly dependent upon the self-sustainability in terms of tritium fueling. Within such a kind of reactor, the component selected to house the tritium breeding reactions is the breeding blanket, which is further assigned to heat power removal and radiation shielding functions. As a consequence of both its role and position, the breeding blanket is heavily exposed to both surface and volumetric heat loads and, hence, its design requires a typical multiphysics approach, from the neutronics to the thermo-mechanics. During last years, a great deal of effort has been put in the optimization of the breed…
Damage identification by a modified Ant Colony Optimization for not well spaced frequency systems
2011
Recently, it has been shown , that a damage detection strategy based on a proper functional calculated on the analytical signal of the structural dynamical response, consents to identify very low damage level. In this regard, they stressed the efficiency of Hilbert Transform to obtain the analytical response representation that shows more sensitivity for predicting damage with respect to the simple signal response. Then, a damage identification procedure based on the minimization of the difference between theoretical and measured data was proposed with satisfactory results. Unfortunately, this procedure, since the need of use of band pass filter around the natural frequency of the system, f…
Data-driven decision support to reduce "driving-under the influence of alcohol" offenses
2018
Extracting valuable knowledge from data to support decision making is a widely practiced trend. Data-driven decision support (DDDS) provides insight for decision makers by exploring and extracting underlying patterns within a dataset. This thesis covers the process of DDDS in reducing driving under the influence of alcohol (DUI) offenses by introducing proposed prison sentences. In this thesis, DDDS is applied to a DUI dataset by analyzing patterns in the dataset and by introducing proposed prison sentences for offenders to reduce the number of DUI cases. Background theories in data mining, machine learning, optimization and decision science that are related to the thesis project are also c…
Quasi-Newton approach to nonnegative image restorations
2000
Abstract Image restoration, or deblurring, is the process of attempting to correct for degradation in a recorded image. Typically the blurring system is assumed to be linear and spatially invariant, and fast Fourier transform (FFT) based schemes result in efficient computational image restoration methods. However, real images have properties that cannot always be handled by linear methods. In particular, an image consists of positive light intensities, and thus a nonnegativity constraint should be enforced. This constraint and other ways of incorporating a priori information have been suggested in various applications, and can lead to substantial improvements in the reconstructions. Neverth…
A multi-scenario Decision Support System for real-time operation of over-year multi-reservoir system 2. DSS simulation
2019
A companion paper (Arena et al, 2019) has introduced the architecture of the DSS and has described its governing equations. In a real-time, dynamic decision-making context, it is a tool to support decisions at the current time step concerning water allocations to municipal demand centres and irrigation districts as well as additional intakes from costly water sources in a water resources system featuring reservoirs with over-year behaviour. The DSS is designed as a linearized MIP (mixed integer programming) optimization model and as such, it includes an objective function and constraints on 1) mass balances at system’s nodes, 2) systems’ topology, 3) component’s capacity, 4) spills, as well…
Survey of methods to visualize alternatives in multiple criteria decision making problems
2012
When solving decision problems where multiple conflicting criteria are to be considered simultaneously, decision makers must compare several different alternatives and select the most preferred one. The task of comparing multidimensional vectors is very demanding for the decision maker without any support. Different graphical visualization tools can be used to support and help the decision maker in understanding similarities and differences between the alternatives and graphical illustration is a very important part of decision support systems that are used in solving multiple criteria decision making problems. The visualization task is by no means trivial because, on the one hand, the grap…
Business Constraints Integration in a Search Engine Optimization Fuzzy Decision Support System
2017
The Internet has dramatically changed the way companies can reach their clients. Henceforth, to develop their business online, companies have to drive qualified traffic to their website. For this, their website must be visible in the first pages of search engine results. Search Engine Optimization (SEO) permits the improvement of the position of a website on the search engines results pages. However, the practice of SEO is complex, and results are uncertain, because search engines do not communicate much about their ranking methods. Moreover, this activity takes time, and requires the implementation of modifications that can alter the visual appearance of the webpages. This paper proposes a…
Integrated Computer-Aided Innovation: The PROSIT approach
2009
Abstract The paper presents a methodology aimed at the improvement of the product development cycle through the integration of Computer-Aided Innovation (CAI) with Optimization and PLM systems. The interoperability of these tools is obtained through the adoption of Optimization systems as a bridging element between CAI and PLM systems. This methodology was developed within the PROSIT project ( http://www.kaemart.it/prosit ). The paper describes the main issues related to the integration of these complementary instruments and the solutions proposed by the authors. More specifically, the main idea of the PROSIT project to link CAI and Optimization systems is the adoption of the latter tools n…