Search results for "A* algorithm"
showing 10 items of 2538 documents
INVESTIGATIONS ON INFILTRATION METHODS FOR AN IMPROVED SOIL HYDRAULIC CHARACTERIZATION
2020
Some New Symbolic Algorithms for the Computation of Generalized Asymptotes
2022
We present symbolic algorithms for computing the g-asymptotes, or generalized asymptotes, of a plane algebraic curve, C, implicitly or parametrically defined. The g-asymptotes generalize the classical concept of asymptotes of a plane algebraic curve. Both notions have been previously studied for analyzing the geometry and topology of a curve at infinity points, as well as to detect the symmetries that can occur in coordinates far from the origin. Thus, based on this research, and in order to solve practical problems in the fields of science and engineering, we present the pseudocodes and implementations of algorithms based on the Puiseux series expansion to construct the g-asymptotes of a p…
A branch and bound algorithm for the matrix bandwidth minimization
2008
In this article, we first review previous exact approaches as well as theoretical contributions for the problem of reducing the bandwidth of a matrix. This problem consists of finding a permutation of the rows and columns of a given matrix which keeps the non-zero elements in a band that is as close as possible to the main diagonal. This NP-complete problem can also be formulated as a labeling of vertices on a graph, where edges are the non-zero elements of the corresponding symmetrical matrix. We propose a new branch and bound algorithm and new expressions for known lower bounds for this problem. Empirical results with a collection of previously reported instances indicate that the propose…
An ant colony optimization-based fuzzy predictive control approach for nonlinear processes
2015
In this paper, a new approach for designing an adaptive fuzzy model predictive control (AFMPC) based on the ant colony optimization (ACO) is proposed. On-line adaptive fuzzy identification is introduced to identify the system parameters. These parameters are used to calculate the objective function based on a predictive approach and structure of RST control. Then the optimization problem is solved based on an ACO algorithm, used at the optimization process in AFMPC to determine optimal controller parameters of RST control. The utility of the proposed controller is demonstrated by applying it to two nonlinear processes, where the proposed approach provides better performances compared with p…
Some Experiments in Supervised Pattern Recognition with Incomplete Training Samples
2002
This paper presents some ideas about automatic procedures to implement a system with the capability of detecting patterns arising from classes not represented in the training sample. The procedure aims at incorporating automatically to the training sample the necessary information about the new class for correctly recognizing patterns from this class in future classification tasks. The Nearest Neighbor rule is employed as the central classifier and several techniques are added to cope with the peril of incorporating noisy data to the training sample. Experimental results with real data confirm the benefits of the proposed procedure.
Multiple UAV cooperative path planning via neuro-dynamic programming
2004
In this paper, a team of n unmanned air-vehicles (UAVs) in cooperative path planning is given the task of reaching the assigned target while i) avoiding threat zones ii) synchronizing minimum time arrivals on the target, and iii) ensuring arrivals coming from different directions. We highlight three main contributions. First we develop a novel hybrid model and suit it to the problem at hand. Second, we design consensus protocols for the management of information. Third, we synthesize local predictive controllers through a distributed, scalable and suboptimal neuro-dynamic programming (NDP) algorithm.
Distributed Coverage of Ego Networks in F2F Online Social Networks
2016
Although most online social networks rely on a centralized infrastructure, several proposals of Distributed Online Social Networks (DOSNs) have been recently presented. Since in DOSNs user profiles are stored on the peers of the users belonging to the network, one of the main challenges comes from guaranteeing the profile availability when the owner of the data is not online. In this paper, we propose a DOSN based on a friend-to-friend P2P overlay where the user's data is stored only on friend peers. Our approach is based on the ego-network concept, which models the social network from the local point of view of a single user. We propose a distributed algorithm which is based on the notion …
Selection From Bibliographic Resources of an Analytical Method for Cosmetic Products
2018
Abstract This chapter is focussed on a general strategy to select an appropriate method from the scientific literature to solve an analytical problem in cosmetic analysis using useful and flexible web tools. A short introduction on the use of ScienceDirect (Elsevier), Scopus (Elsevier), SciFinder Scholar (American Chemical Society), Web of Science (Thomson Reuters) and the freely available Google Scholar is given. The main analytical features to be considered in the selection of the method, such as limit of detection, limit of quantification, linearity, precision (repeatability, intermediate precision and reproducibility), selectivity, robustness and accuracy, are briefly described. Additio…
Context-sensitive text mining with fitness leveling Genetic Algorithm
2015
Contextual processing is a great challenge for information retrieval study - the most approved techniques include scanning content of HTML web pages, user supported metadata analysis, automatic inference grounded on knowledge base, or content-oriented digital documents analysis. We propose a meta-heuristic by making use of Genetic Algorithms for Contextual Search (GACS) built on genetic programming (GP) and custom fitness leveling function to optimize contextual queries in exact search that represents unstructured phrases generated by the user. Our findings show that the queries built with GACS can significantly optimize the retrieval process.
Improving Efficacy of PubMed Clinical Queries for Retrieving Scientifically Strong Studies on Treatment
2006
The authors evaluated the retrieval power of PubMed "Clinical Queries," narrow search string, about therapy in comparison with a modified search string to avoid possible retrieval bias. PubMed search strategy was compared to a slightly modified string that included the Britannic English term "randomised." The authors tested the two strings joined onto each of four terms concerning topics of broad interest: hypertension, hepatitis, diabetes, and heart failure. In particular, precision was computed for not-indexed citations. The added word "randomised" improved total citation retrieval in any case. Total retrieval gain for not-indexed citations ranged from 11.1% to 21.4%. A significant number…