Salvatore Coco, Antonino Laudani, Giuseppe Pollicino, Giuseppe Pulcini, Francesco Riganti Fulginei and Alessandro Salvini
The purpose of this paper is to present the application of a novel hybrid algorithm, called MeTEO (Metric‐Topological‐Evolutionary‐Optimization), based on the combination of three…
Abstract
Purpose
The purpose of this paper is to present the application of a novel hybrid algorithm, called MeTEO (Metric‐Topological‐Evolutionary‐Optimization), based on the combination of three heuristics inspired by artificial life to the solution of optimization problems of a real electronic vacuum device.
Design/methodology/approach
The Particle Swarm Optimization (PSO), the Flock‐of‐Starlings Optimization (FSO) and the Bacterial Chemotaxis Algorithm (BCA) were adapted to implement a novel meta‐heuristic MeTEO the FSO has been powerfully employed for exploring the whole space of solutions, whereas the PSO is used to explore local regions where FSO had found solutions, and BCA to refine the solutions found by PSO, thanks its better performances in local search.
Findings
The optimization of the focusing magnetic field of a Travelling Wave Tubes (TWT) collector is presented in order to show the effectiveness of MeTEO, in combination with COLLGUN FE simulator and equivalent source representation. The optimization of the focusing magnetic structure is obtained by using a maximum of 100 steps for each heuristic.
Practical implications
The paper describes the development of a novel efficient parallel method for the solution of electromagnetic device optimization problems.
Originality/value
The paper shows the capabilities of a novel combination of optimization methods inspired by “artificial life” which allows us to achieve effective solutions of multimodal optimization problems, typical of the electromagnetic device optimization, with an acceptable computational cost, thanks also to its natural parallel implementation.
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Salvatore Coco, Antonino Laudani, Giuseppe Pulcini, Francesco Riganti Fulginei and Alessandro Salvini
This paper aims the application of a novel hybrid algorithm, called MeTEO, based on the combination of three heuristics inspired by artificial life to the optimization of…
Abstract
Purpose
This paper aims the application of a novel hybrid algorithm, called MeTEO, based on the combination of three heuristics inspired by artificial life to the optimization of electrodes voltages of multistage depressed collector.
Design/methodology/approach
The flock-of-starlings optimization (FSO), the particle swarm optimization (PSO) and the bacterial chemotaxis algorithm (BCA) were adapted to implement a hybrid and parallel algorithm: the FSO has been powerfully employed for exploring the whole space of solutions, whereas the PSO+BCA has been used to refine the FSO-found solutions, exploiting their better performances in local search.
Findings
The optimization of the voltage of the electrodes of multistage depressed collector are efficiently handled with a moderate computational effort.
Practical implication
The development of an efficient method for the solution of a complicated electromagnetic optimization problem, exploiting the different characteristic of different approaches based on evolutionary computation algorithm.
Originality/value
The paper shows that the combination of stochastic methods having different exploration properties with appositely developed FE electromagnetic simulator allows us to produce effective solutions of multimodal electromagnetic optimization problems, with an acceptable computational cost.
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Salvatore Coco and Antonino Laudani
This paper aims to present a new iterative procedure for the 3D representation of focusing magnetic fields in TWTs generated by PPMs, by using equivalent sources and optimisation…
Abstract
Purpose
This paper aims to present a new iterative procedure for the 3D representation of focusing magnetic fields in TWTs generated by PPMs, by using equivalent sources and optimisation algorithms.
Design/methodology/approach
In the integrated optimisation strategy general models for magnetic sources are employed and local and global inverse problems are iteratively solved for the minimization of the representation error.
Findings
The results obtained show that the target accuracy is reached with a low computational effort, employing a minimum number of equivalent sources.
Practical implications
The procedure is robust and converges for all the examined magnetic field configurations.
Originality/value
Different from other approaches, the procedure presented here can be directly applied to a variety of different models for magnetic sources.
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Antonino Laudani, Salvatore Coco and Francesco Riganti Fulginei
The paper aims to illustrate the two kinds of analysis approach for which finite element method (FEM) can be successfully employed: the Poisson-Nernst-Planck (PNP) model and the…
Abstract
Purpose
The paper aims to illustrate the two kinds of analysis approach for which finite element method (FEM) can be successfully employed: the Poisson-Nernst-Planck (PNP) model and the Langevin-Lorentz-Poisson (LLP) one.
Design/methodology/approach
The approach of this work is to try making a survey of the use of the FEM in the modelling of charge transport/ion flow across membrane channels, in particular for the PNP analysis and for a particle based model such as LLP model.
Findings
In this paper, the two kinds of analysis approach for which FEM can be successfully employed, the PNP model and the LLP one, have been shown. In both cases the FEM is extremely useful to carry out these analysis and the simulation results obtained are in good agreement with experimental results.
Originality/value
The value of this paper is to demonstrate the FEM is extremely useful to carry out analysis and results which are in good agreement with experimental ones.
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Salvatore Coco, Antonino Laudani and Giuseppe Pollicino
The paper's aim is to focus on the utilization of the GRID distributed computing environment in order to reduce simulation time for parameter studies of travelling wave tube (TWT…
Abstract
Purpose
The paper's aim is to focus on the utilization of the GRID distributed computing environment in order to reduce simulation time for parameter studies of travelling wave tube (TWT) electron guns and helix slow‐wave structures.
Design/methodology/approach
Two TWT finite‐element analysis modules were adapted to be run on the GRID, for this purpose scripts were written to submit a collection of independent jobs (the parameter study) to the GRID and collect the results.
Findings
A 25‐job electron gun parameter study runs on the GRID in 30‐40 min instead of 7 h locally. A 16‐job slow‐wave structure parameter study runs in 1 h on the GRID instead of 8 h locally. Turnaround time on the GRID was limited by priority levels presently set by GRID management for the various jobs submitted.
Practical implications
The procedures guarantee a remarkable reduction of the computing time.
Originality/value
For heavy‐computational cost tasks such as the above finite element electromagnetic calculations, the effective use of a heterogeneous, distributed, computing platform (the GRID computing platform) is very advantageous. The paper shows the development of new generation collaborative tools.
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Salvatore Coco, Antonino Laudani, Francesco Riganti Fulginei and Alessandro Salvini
This paper aims the application of a novel synergy between a neural network (NN) and the finite element method (FEM) in the solution of electromagnetic problem involving…
Abstract
Purpose
This paper aims the application of a novel synergy between a neural network (NN) and the finite element method (FEM) in the solution of electromagnetic problem involving hysteretic material in unbounded domain.
Design/methodology/approach
The hysteretic nature of the material is taken into account by an original NN able to perform the modelling of any kind of quasi-static loop (saturated and non-saturated, symmetric or asymmetric). An appositely developed iterative FEM procedure is presented for the solution of this kind of problems in unbounded domains.
Findings
By starting from a small set of measured loops, the NN manages the values of the magnetic field, H, and the flux density, B, as inputs while the differential permeability is the output. In particular, the proposed NN is capable to perform the modelling of saturated and non-saturated, symmetric or asymmetric hysteresis loops.
Practical implications
The development of an efficient method for the solution of a complicated electromagnetic problem in unbounded domain by using an iterative approach and NNs, which can be implemented also in existing FEM code.
Originality/value
The paper shows that the combination of FEM, iterative procedure and NNs allows us to produce effective solutions of electromagnetic problems in unbounded domains involving also nonlinear hysteretic magnetic materials with an acceptable computational cost.
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Salvatore Coco, Antonino Laudani, Francesco Riganti Fulginei and Alessandro Salvini
The purpose of this paper is to apply a hybrid algorithm based on the combination of two heuristics inspired by artificial life to the solution of optimization problems.
Abstract
Purpose
The purpose of this paper is to apply a hybrid algorithm based on the combination of two heuristics inspired by artificial life to the solution of optimization problems.
Design/methodology/approach
The flock‐of‐starlings optimization (FSO) and the bacterial chemotaxis algorithm (BCA) were adapted to implement a hybrid and parallel algorithm: the FSO has been powerfully employed for exploring the whole space of solutions, whereas the BCA has been used to refine the FSO‐found solutions, thanks to its better performances in local search.
Findings
A good solution of the 8‐th parameters version of the TEAM problem 22 is obtained by using a maximum 200 FSO steps combined with 20 BCA steps. Tests on an analytical function are presented in order to compare FSO, PSO and FSO+BCA algorithms.
Practical implications
The development of an efficient method for the solution of optimization problems, exploiting the different characteristic of the two heuristic approaches.
Originality/value
The paper shows the combination and the interaction of stochastic methods having different exploration properties, which allows new algorithms able to produce effective solutions of multimodal optimization problems, with an acceptable computational cost, to be defined.
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Janine Pierce and Benjamin Pierce
The themes of love, commitment and honour are explored within the context of the American Mafia. In most capitalist-focussed conventional organizations managers acquire assets and…
Abstract
The themes of love, commitment and honour are explored within the context of the American Mafia. In most capitalist-focussed conventional organizations managers acquire assets and income through exchanges, through wages, direct operations and build cultures and cultural norms (Friedman, 1970). The authors argue the Mafia organization has similarities and differences to conventional organizations, differences being in how money is acquired and in ethical behaviours which could be described as counter to what is the expectation of conventional organizations. Parallel to the Christian Ten Commandments, baptism and initiation rituals existing within the Mafia are drawn that provide insights into Mafia values that guide behaviours. Honour as a key Mafia value is argued in this article as being a misnomer, being more reflective of dishonourable values of revenge, fear and punishment. Love and commitment within Mafia families1 including roles of women are examined. It appears that love for family appears secondary to primary commitment to the Mafia Family. This paper contributes to literature on the Mafia in highlighting how ‘love’ and virtues are relative terms from which unethical acts can be justified within Mafia codes of behaviours. Also highlighted is that organizations valuing vice can survive and sustain if shrouded in secrecy rather than transparency. In the Mafia organization as in conventional organizations, codes of behaviours and commitment central to all money-making organizations are a key to survival.
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Gives introductory remarks about chapter 1 of this group of 31 papers, from ISEF 1999 Proceedings, in the methodologies for field analysis, in the electromagnetic community…
Abstract
Gives introductory remarks about chapter 1 of this group of 31 papers, from ISEF 1999 Proceedings, in the methodologies for field analysis, in the electromagnetic community. Observes that computer package implementation theory contributes to clarification. Discusses the areas covered by some of the papers ‐ such as artificial intelligence using fuzzy logic. Includes applications such as permanent magnets and looks at eddy current problems. States the finite element method is currently the most popular method used for field computation. Closes by pointing out the amalgam of topics.
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Moawiya A. Haddad, Sharaf S. Omar and Salvatore Parisi
The purpose of this study comes from the need of defining improved durability values and the realization of a good traceability management for selected vegan cheeses has suggested…
Abstract
Purpose
The purpose of this study comes from the need of defining improved durability values and the realization of a good traceability management for selected vegan cheeses has suggested the comparison between a processed cheese and its analogous version without animal-origin raw materials. The durability should be studied at a well-defined temperature, probably agreed among the food producer and the food processor. In addition, the traceability system should consider many components and related suppliers.
Design/methodology/approach
A supply chain risk assessment analysis has been carried out with relation to two different products: an analogue cheese and a vegan cheese-like preparation. Raw materials and ingredients have been evaluated (production method and origin; geographical identification), with the aim of identifying simplified food.
Findings
An assessment of food supply networks has been carried out. In the first situation (analogue cheeses), the ingredient “cheeses” shows an important complexity: five suppliers with a related six-interconnection hub. On the other side, vegan cheeses are obtained from 11 ingredients (a challenging hub); four of them may be produced from 2–5 components of different origin (five total hubs). Tested processed cheeses are represented by means of a linear food supply network with two hubs (cheeses and “arrival” show degrees 6 and 9, respectively). Networks concerning vegan cheeses include five different hubs: four complex raw materials (degree: 2, 3, 4 and 5) and the “arrival” step (degree: 12).
Originality/value
The information load of vegan cheeses (two hubs, degrees >> average degree) appears high if compared with processed cheeses (two hubs), although the complexity of networks appears similar. Vegan cheeses may seem technologically simpler than processed cheeses and be sometimes questioned because of important traceability issues. Adequate traceability countermeasures in terms of preventive monitoring actions should be recommended when speaking of vegan cheeses. Anyway, a centralized manager would be always required.