Daniele Peri

Italian National Research Council | CNR · Institute for Applied Mathematics "Mauro Picone" IAC

In this paper, a multidisciplinary design optimization algorithm, the Normal Boundary Intersection (NBI) method, is applied to the design of some devices of a sailing yacht. The full Pareto front is identified for two different design problems, and the optimal configurations are compared with standard devices. The great efficiency of the optimizati...

The appearance of AC72 foiling catamarans in the scenario of sailing yacht competitions in 2013 raised attention to this ship design concept, although not brand new in the yacht design history. The drastic drag reduction connected with the elevation of the ship hull outside the water is obtained by the use of a foil, or a system of foils, acting as...

We propose a hybrid approach based on meta-modelling techniques and machine-learning algorithms to determine the best car configuration for each circuit. By a specific interpolation model, we obtain an accurate estimation of the car’s speed as a function of the front wing configuration and the bend curvature. Some high-fidelity fluid dynamic simula...

Usually, clinicians assess the correct hemodynamic behavior and fetal well-being during the gestational age thanks to their professional expertise, with the support of some indices defined for Doppler fetal waveforms. Although this approach has demonstrated to be satisfactory in the most of the cases, it can be largely improved with the aid of more...

Numerical optimization of complex systems benefits from the technological development of computing platforms in the last twenty years. Unfortunately, this is still not enough, and a large computational time is still necessary when mathematical models that include richer (and therefore more realistic) physical models are adopted. In this paper we sh...

The present work is motivated by the development of a mathematical model mimicking the mechanisms observed in lab-on-chip experiments, made to reproduce on microfluidic chips the in vivo reality. Here we consider the Cancer-on-Chip experiment where tumor cells are treated with chemotherapy drug and secrete chemical signals in the environment attrac...

Targeted drug delivery systems represent a promising strategy to treat localised disease with minimum impact on the surrounding tissue. In particular, polymeric nanocontainers have attracted major interest because of their structural and morphological advantages and the variety of polymers that can be used, allowing the synthesis of materials capab...

In this survey we consider mathematical models and methods recently developed to control crowd dynamics, with particular emphasis on egressing pedestrians. We focus on two control strategies: the first one consists in using special agents, called leaders, to steer the crowd towards the desired direction. Leaders can be either hidden in the crowd or...

In this paper, some methodologies aimed at the identification of the Pareto front of a multi-objective optimization problem are presented and applied. Three different approaches are presented: local sampling, Pareto front resampling and Normal Boundary Intersection (NBI). A first approximation of the Pareto front is obtained by a regular sampling o...

In this survey we consider mathematical models and methods recently developed to control crowd dynamics, with particular emphasis on egressing pedestrians. We focus on two control strategies: The first one consists in using special agents, called leaders, to steer the crowd towards the desired direction. Leaders can be either hidden in the crowd or...

Drug delivery systems represent a promising strategy to treat cancer and to overcome the side effects of chemotherapy. In particular, polymeric nanocontainers have attracted major interest because of their structural and morphological advantages and the variety of polymers that can be used, allowing the synthesis of materials capable of responding...

Particle Swarm Optimization is an evolutionary optimization algorithm, largely studied during the years: analysis of convergence, determination of the optimal coefficients, hybridization of the original algorithm and also the determination of the best relationship structure between the swarm elements (topology) have been investigated largely. Unfor...

Background and objective: The paper focuses on the numerical strategies to optimize a plasmid DNA delivery protocol, which combines hyaluronidase and electroporation. Methods: A well-defined continuum mechanics model of muscle porosity and advanced numerical optimization strategies have been used, to propose a substantial improvement of a pre-ex...

In the wide scenario of the optimization techniques, a large number of algorithms are inspired by natural processes, in many different ways. One of the latest is the Imperialist Competitive Algorithm (ICA) Atashpaz-Gargari and Lucas (2007), judged by their authors as very efficient and competitive with other popular optimization algorithms. However...

The definition of an innovative therapeutic protocol requires the fine tuning of all the involved operations in order to maximize the efficiency. In some cases, the price of the experiments, or their duration, represents a great obstacle and the full potential of the protocol risks to be reduced or even hidden by a non-optimal application. The impl...

In this paper, we deal with a size-variable group of pedestrians moving in a unknown confined environment and searching for an exit. Pedestrian dynamics are simulated by means of a recently introduced microscopic (agent-based) model, characterized by an exploration phase and an egress phase. First, we study the model to reveal the role of its main...

In this paper, we deal with a group variable in size of pedestrians moving in a unknown confined environment and searching for an exit. Pedestrian dynamics are simulated by means of a recently introduced microscopic (agent-based) model, characterized by an exploration phase and an egress phase. First, we study the model to reveal the role of its ma...

Among the different techniques for interpolation/approximation of sparse data, Spline interpolation represents one of the most popular alternatives. It is largely used for one-dimensional and two-dimensional problems, but the use in case of multi-dimensional datasets, where the space dimension is larger than 2, is not common. The necessity of a top...

BELL is the software adopted for the hull shape deformation in the paper ”Optimal ship hull via optimal parameterisation” ( DOI 10.1080/09377255.2016.1255297). Code is contained in the file bell.f, input file is bell.inp.

Robust Design Optimization (RDO) represents a really interesting opportunity when the specifications of the design are careful and accurate: the possibility to optimize an industrial object for the real usage situation, improving the overall performances while reducing the risk of occurrence of off-design con- ditions, strictly depends on the avail...

Numerical optimisation of a ship hull requires, like every shape design optimisation problem, the definition of a parametric expression of the object to be deformed. In this phase, some decisions are taken regarding the shape variability and the portion of the hull to be modified: the parameterisation of the hull is problem-dependent, with implicat...

This paper presents a comparative study between a large number of different existing sequential quadrature schemes suitable for Robust Design Optimization (RDO), with the inclusion of two partly original approaches. Efficiency of the different integration strategies is evaluated in terms of accuracy and computational effort: main goal of this paper...

In this paper we are concerned with the simulation of crowds in built environments, where obstacles play a role in the dynamics and in the interactions among pedestrians. First of all, we review the state-of-the-art of the techniques for handling obstacles in numerical simulations. Then, we introduce a new modelling technique which guarantees both...

The hybrid use of exact and heuristic derivative-free methods for global unconstrained optimization problems is presented. Many real-world problems are modeled by computationally expensive functions, such as problems in simulation-based design of complex engineering systems. Objective-function values are often provided by systems of partial differe...

Application of interpolation/approximation techniques (metamodels, for brevity) is commonly adopted in numerical optimization, typically to reduce the overall execution time of the optimization process. A limited number of trial solution are computed, covering the design variable space: those trial points are then used for the determination of an e...

In this paper, multi-disciplinary optimization techniques are applied to sail design. Two different mathematical models, providing the solution of the fluid-dynamic and the structural problems governing the behaviour of a complete sailplan, are coupled in a fluid-structure interaction (FSI) scheme, in order to determine the real flying shape of the...

Purpose – The purpose of this paper is to propose a modification of the original PSO algorithm in order to avoid the evaluation of the objective function outside the feasible set, improving the parallel performances of the algorithm in the view of its application on parallel architectures. Design/methodology/approach – Classical PSO iteration is r...

A proposal for particles’ initialization in PSO is presented and discussed, with focus on costly global unconstrained optimization problems. The standard PSO iteration is reformulated such that the trajectories of the particles are studied in an extended space, combining particles’ position and speed. To the aim of exploring effectively and efficie...

A guideline for an effective and efficient use of a deterministic variant of the Particle Swarm Optimization (PSO) algorithm is presented and discussed, assuming limited computational resources. PSO was introduced in Kennedy and Eberhart (1995) and successfully applied in many fields of engineering optimization for its ease of use. Its performance...

We consider the solution of bound constrained optimization problems, where we assume that the evaluation of the objective function is costly, its derivatives are unavailable and the use of exact derivative-free algorithms may imply a too large computational burden. There is plenty of real applications, e.g. several design optimization problems [1,2...

We consider the solution of bound constrained optimization problems, where we assume that the evaluation of the objective function is costly, its derivatives are unavailable and the use of exact derivative-free algorithms may imply a too large computational burden. There is plenty of real applications, e.g. several design optimization problems [1,2...

Purpose The purpose of this paper is the introduction of a globally convergent algorithm into a framework for global derivative‐free optimization, such as particle swarm optimization (PSO) for which a full proof of convergence is currently missing. Design/methodology/approach The substitution of the classical PSO iteration by the Newton method is...

The present work focuses on the application of simulation-based design for the resistance optimization of waterjet propelled Delft catamaran, using integrated computational and experimental fluid dynamics. A variable physics/variable fidelity approach was implemented wherein the objective function was evaluated using both low fidelity potential flo...

The paper presents a formulation for multidisciplinary design optimization of vessels, subject to uncertain operating conditions. The formulation couples the multidisciplinary design analysis with the Bayesian approach to decision problems affected by uncertainty. In the present context, the design specifications are no longer given in terms of a s...

Particle Swarm Optimization (PSO) is having a growing space in the optimization community, mainly due to its appreciable qualities of fast initial progress, reduced computational cost and parallel structure, suitable for High Performance Computation (HPC) platforms. Original formulation includes some random coecients, so that a statistical analysis...

The paper presents an application of ship design optimisation subject to epistemic uncertainty. Generally, uncertainty that results from intrinsic variability (e.g. stochastic environmental or operating conditions) is termed aleatoric. Conversely, uncertainty is described as epistemic when it results from a lack of knowledge about a quantity whose...

This paper focuses on the solution of difficult multidisciplinary optimisation formulations arising in ship design. The latter schemes are by nature the result of the interaction among several optimisation problems. Each optimisation problem summarises the issues related to a specific aspect (discipline) of the formulation, and it may be hardly sol...

The paper presents an approach for the deformation of complex geometries by means of Free Form Deformation (FFD). Usually, FFD is dealing with rectangular boxes including the objects to be deformed. Here an intermediate space mapping is adopted in order to include objects inside arbitrarily shaped boxes. The example of the optimisation of a propell...

Numerical optimization of the initial design of a fast catamaran (high-speed sealift research model B, HSSL-B) has been carried out through a simulation-based design (SBD) framework, based on an advanced free-surface unsteady Reynolds-averaged Navier-Stokes (URANS) solver and a potential flow solver, and global optimization (GO) algorithms. The pot...

The wakes of high-speed passenger-only ferries that operated through Rich Passage, on the Seattle-Bremerton ferry route, caused beach erosion and damage to habitat. A task was initiated to design a low-wake high-speed vessel using multi-fidelity CFD based design optimization by using low-fidelity potential flow solvers for initial global design opt...

This paper details the CFD validation studies carried out as a prerequisite for multi-fidelity CFD-based design optimization of high-speed passenger-only ferries aimed at reducing far-field wake energy that causes beach erosion. A potential flow program (WARP) and a URANS program (CFDSHIP) were validated using full-scale measurements of resistance,...

A strategy for solving optimisation problems with an unknown number of design variables is presented. The number of the design variables and their values are defined implicitly by adopting a special rearrangement of the data structure which does not require direct definition of the number of design variables and their values. The optimal number of...

The paper presents an application of ship design optimisation subject to epistemic uncertainty. Generally, uncertainty that results from intrinsic variability (e.g. stochastic environmental or operating conditions) is termed aleatoric. Conversely, uncertainty is described as epistemic when it results from a lack of knowledge about a quantity whose...

The present work focuses on the application of Simulation Based Design (SBD) for the resistance optimization of two waterjet propelled high-speed ships, namely, the Joint High Speed Sea-lift (JHSS) which is a monohull, and the Delft Catamaran (DC) at Fr=0.34 and 0.5, respectively. Design optimization has been performed for both the parent hull form...

The paper presents an approach for the robust optimization of a bulk carrier conceptual design, subject to uncertain operating and environmental conditions. The uncertainties involved in the optimization process are addressed and a general formulation for robust design is given. Specifically, the uncertainties involved in the decision making proces...

The paper presents a two-stage approach for ship design optimisation under uncertainties related to stochastic parameters that cannot be controlled by the designer. The designer decision is partitioned into two sets: the first contains variables that have to be decided before the onset of any uncertain condition, while the second involves variables...

The paper presents a formulation for robust optimization of aerial and marine vehicles design. The general framework is that of optimal design under uncertainty, also referred as Robust Design Optimization (RDO). Specifically, statistical decision theory concepts are used to formulate the design decision problem under uncertain operating conditions...

We focus on the solution of a class of unconstrained optimization problems, where the eval- uation of the objective function is possibly costly and the use of exact algorithms may require a too large computational burden. Several real applications, included in the latter class, claim for optimization methods where the derivatives of the objective f...

The use of computational methods in design engineering is growing rapidly at all stages of the design process, with the final goal of a substantial reduction of the cost and time for the development of a design. Simulations and optimization algorithms can be combined together into what is known as Simulation-Based Design (SBD) techniques. Using the...

The aim of this paper is to solve optimal design problems for industrial applications when the objective function value requires the evaluation of expensive simulation codes and its first derivatives are not available. In order to achieve this goal we propose two new algorithms that draw inspiration from two existing approaches: a filled function b...

The use of computational methods in design engineering is growing rapidly at all stages of the design process, with the final goal of a substantial reduction of the cost and time for the development of a design. Simulations and optimization algorithms can be combined together into what is known as Simulation-Based Design (SBD) techniques. Using the...

"Il Moro di Venezia" was the challenger for the XXVIII edition of the America’s Cup in San Diego, 1992, and it has become the first non-English European challenger in the history of the cup. Due to the change in class rules at that time, a great effort was spent in the research of the more favorable design in terms of displacement and sail area: to...

ABSTRACT

Some gradient numerical optimization methods for ship hydrodynamic design are discussed. These gradients are obtained by approximating their elements by finite differences. A relatively recent approach computing the sensitivity derivatives is the use of automatic differentiation tools by using this software, if the CFD solver is properly coded, der...

"II Moro di Venezia" was the challenger for the XXVIII edition of the America's Cup in San Diego, 1992, and it has become the first non-English European challenger in the history of the cup. Due to the change in class rules at that time, a great effort was spent in the research of the more favorable design in terms of displacement and sail area: to...

While Multidisciplinay Design Optimization (MDO) literature focuses mainly on the development of different formulations, through the manipulation of design variables, less attention is generally devoted to the combination of specific MDO formulations with existing nonlinear optimization algorithms. In this paper, the focus is on the application of...

The main objective of this article is to describe the development of two advanced multiobjective optimization methods based on derivative-free techniques and complex computational fluid dynamics (CFD) analysis. Alternatives for the geometry and mesh manipulation techniques are also described. Emphasis is on advanced strategies for the use of comput...

We consider the use of global optimization techniques for the minimization of a nonconvex function, arising from a Multidisciplinary Design Optimization problem of a ship. In ship design different disciplines must be often coupled, encompassing hydrodynamic and structural problems. This scenario requires the use of specific multidisciplinary formul...

The purpose of this paper is to show how the improvement of the hydrodynamics performance of a ship can be obtained by solving a shape optimization problem using the particle swarm optimization (PSO) technique. PSO has been recently introduced to solve global optimization problems and belongs to the class of evolutionary algorithms. In this paper,...

The fundamental elements and strategies needed to build and apply SBD are discussed, with attention to some critical issues, such as global optimization algorithms, grid deforming techniques, parallel architectures and large number of design variables. In the attempt to include also tools more familiar to the vast majority of ship designers, a new...

A definite trend in computational applied mechanics is the development of integrated procedures for design optimization based on large-scale numerical simulations (Simulation-Based Design, SBD). In the present paper the fundamental elements of a SBD environment for shape optimization are presented and analyzed. The focus is on complex engineering o...

In this paper we consider the Particle Swarm Optimization (PSO) algorithm [1], [2], in the class of Evolutionary Algorithms, for the solution of global optimization problems. We analyze a couple of issues aiming at improving both the effectiveness and the efficiency of PSO. In particular, first we recognize that in accordance with the results in [3...

For the major part of real-life application, the formulation of an optimisation problem involves a lot of different objective functions, often coming from different disciplines or areas. In this context, the optimisation represents a meeting point for many specialists, each one focused his proper requirements, that is, criteria constraints and obje...

In this paper the multiobjective optimization of a cruise ship is presented. The hull shape is optimized in order to reduce the hydrodynamic resistance and to improve the seakeeping performance. Geometrical and functional constrains are defined to prevent unreliable geometries, and to respect some of the peculiar requirements for this kind of ship,...

This work is concerned with the study and the evaluation of formulations for Multidisciplinary Design Optimization (MDO) problems. The latter topic includes very difficult computational aspects, naturally arising from the simultaneous solution of several related optimization problems. In particular, in the naval applications deep interaction among...

Ship design is addressed as a multidisciplinary optimisation problem. Two criteria are considered, namely the total drag of the ship and its behaviour in waves, characterising the range and the operability of the ship. The necessary analysis is carried out via numerical codes based on potential flow models. The problem is solved as a nonlinear mult...

This work presents a simulation-based design environment for the solution of optimum ship design problems based on a global optimization (GO) algorithm that prevents the optimizer from being trapped into local minima. The procedure, illustrated in the framework of multiobjective optimization problems, makes use of high-fidelity, CPU-time-expensive...

The geometry and bare hull resistance of the IACC systematic series “Il Moro di Venezia” are presented and analyzed. In the first part, the geometry of the model is described; then a number of comparisons is made, following the logic of development of the series. The parent model resistance is compared with that of models for which a single paramet...