Search results for " optimization."

Distributed Consensus in Networks of Dynamic Agents

2006

Stationary and distributed consensus protocols for a network of n dynamic agents under local information is considered. Consensus must be reached on a group decision value returned by a function of the agents' initial state values. As a main contribution we show that the agents can reach consensus if the value of such a function computed over the agents' state trajectories is time invariant. We use this basic result to introduce a protocol design rule allowing consensus on a quite general set of values. Such a set includes, e.g., any generalized mean of order p of the agents' initial states. We demonstrate that the asymptotical consensus is reached via a Lyapunov approach. Finally we perfor…

2017

Abstract. We present a Monte Carlo genetic algorithm (MCGA) for efficient, automated, and unbiased global optimization of model input parameters by simultaneous fitting to multiple experimental data sets. The algorithm was developed to address the inverse modelling problems associated with fitting large sets of model input parameters encountered in state-of-the-art kinetic models for heterogeneous and multiphase atmospheric chemistry. The MCGA approach utilizes a sequence of optimization methods to find and characterize the solution of an optimization problem. It addresses an issue inherent to complex models whose extensive input parameter sets may not be uniquely determined from limited in…

Robust H-Infinity Filter Design for Uncertain Linear Systems Over Network with Network-Induced Delays and Output Quantization

2009

This paper investigates a convex optimization approach to the problem of robust H-Infinity filtering for uncertain linear systems connected over a common digital communication network. We consider the case where quantizers are static and the parameter uncertainties are norm bounded. Firstly, we propose a new model to investigate the effect of both the output quantization levels and the network conditions. Secondly, by introducing a descriptor technique, using Lyapunov-Krasovskii functional and a suitable change of variables, new required sufficient conditions are established in terms of delay-dependent linear matrix inequalities (LMIs) for the existence of the desired network-based quantize…

Operator splitting methods for American option pricing

2004

Abstract We propose operator splitting methods for solving the linear complementarity problems arising from the pricing of American options. The space discretization of the underlying Black-Scholes Scholes equation is done using a central finite-difference scheme. The time discretization as well as the operator splittings are based on the Crank-Nicolson method and the two-step backward differentiation formula. Numerical experiments show that the operator splitting methodology is much more efficient than the projected SOR, while the accuracy of both methods are similar.

The Network Balance Realized by Routing Organization System

2011

In the presented paper, we propose to exploit routing organization for the purpose of managing network resources. According to our assumptions, we have the same quantity of materials, objects, tokens, tools etc. at our disposal in every node of the network. During network operation we must distribute resources between these nodes. It should be carried out as instantaneously and as economically as possible. Multi-Agent Systems are also used to deal with this kind of tasks and the centralised algorithms presented in this paper are to be used to measure the efficiency of the distributed MAS solution. From the logistical point of view, we have a sequence of stages with different states of token…

Sizing and shape optimization material use in 10 bar trusses

2021

Truss optimization has the goal of achieving savings in costs and material while maintaining structural characteristics. In this research a 10 bar truss was structurally optimized in Rhino 6 using genetic algorithm optimization method. Results from previous research where sizing optimization was limited to using only three different cross-sections were compared to a sizing and shape optimization model which uses only those three cross-sections. Significant savings in mass have been found when using this approach. An analysis was conducted of the necessary bill of materials for these solutions. This research indicates practical effects which optimization can achieve in truss design.

Multi-Resource Management for Multi-Tier Space Information Networks: A Cooperative Game

2019

With the drastic increase of space information network (SIN) traffic and the diversity of network traffic types, the optimal allocation of the scarce network resources is of great significance for optimizing the SIN system capability. In this paper, we propose a multi-resource management method for multi-tier SIN using the cooperative Nash bargaining solution. Since the original problem is a non-convex problem, we firstly make logarithmic transition, and then find a tightest lower bound function to convert the initial problem into a convex one. In order to carry out the optimal bandwidth and power allocation in SIN, we construct a joint bandwidth and power allocation (JBPA) algorithm. Simul…

Dynamic Gaussian Graphical Models for Modelling Genomic Networks

2014

After sequencing the entire DNA for various organisms, the challenge has become understanding the functional interrelatedness of the genome. Only by understanding the pathways for various complex diseases can we begin to make sense of any type of treatment. Unfortunately, decyphering the genomic network structure is an enormous task. Even with a small number of genes the number of possible networks is very large. This problem becomes even more difficult, when we consider dynamical networks. We consider the problem of estimating a sparse dynamic Gaussian graphical model with \(L_1\) penalized maximum likelihood of structured precision matrix. The structure can consist of specific time dynami…

Batteries for Aerospace: A Brief Review

2018

This paper presents a brief overview on batteries for aerospace application. In particular, More Electric Aircraft (MEA) and All Electric Aircraft (AEA) concepts are introduced at first, together with their main advantages and drawbacks. Subsequently, opportunities and issues related to the employment of batteries on aircrafts are presented and briefly discussed. Reference is then made to aircraft power system architectures and battery technologies, as well as on the state-of-the-art of battery management systems, state-of-charge and state-of-health estimations, and thermal management.

Life Cycle Assessment for Supporting Eco-Design: The Case Study of Sodium–Nickel Chloride Cells

2021

The European Union is moving towards a sustainable, decarbonized, and circular economy. It has identified seven key value chains in which to intervene, with the battery and vehicle value chain being one of them. Thus, actions and strategies for the sustainability of batteries need to be developed. Since Life Cycle Assessment (LCA) is a strategic tool for evaluating environmental sustainability, this paper investigates its application to two configurations of a sodium–nickel chloride cell (planar and tubular), focusing on the active material and the anode, with the purpose of identifying the configuration characterized by the lowest environmental impacts. The results, based on a “from cradle…