23,905 research outputs found
High-Level Object Oriented Genetic Programming in Logistic Warehouse Optimization
DisertaÄnĂ prĂĄce je zamÄĹena na optimalizaci prĹŻbÄhu pracovnĂch operacĂ v logistickĂ˝ch skladech a distribuÄnĂch centrech. HlavnĂm cĂlem je optimalizovat procesy plĂĄnovĂĄnĂ, rozvrhovĂĄnĂ a odbavovĂĄnĂ. JelikoĹž jde o problĂŠm patĹĂcĂ do tĹĂdy sloĹžitosti NP-teĹžkĂ˝, je vĂ˝poÄetnÄ velmi nĂĄroÄnĂŠ nalĂŠzt optimĂĄlnĂ ĹeĹĄenĂ. MotivacĂ pro ĹeĹĄenĂ tĂŠto prĂĄce je vyplnÄnĂ pomyslnĂŠ mezery mezi metodami zkoumanĂ˝mi na vÄdeckĂŠ a akademickĂŠ pĹŻdÄ a metodami pouĹžĂvanĂ˝mi v produkÄnĂch komerÄnĂch prostĹedĂch. JĂĄdro optimalizaÄnĂho algoritmu je zaloĹženo na zĂĄkladÄ genetickĂŠho programovĂĄnĂ ĹĂzenĂŠho bezkontextovou gramatikou. HlavnĂm pĹĂnosem tĂŠto prĂĄce je a) navrhnout novĂ˝ optimalizaÄnĂ algoritmus, kterĂ˝ respektuje nĂĄsledujĂcĂ optimalizaÄnĂ podmĂnky: celkovĂ˝ Äas zpracovĂĄnĂ, vyuĹžitĂ zdrojĹŻ, a zahlcenĂ skladovĂ˝ch uliÄek, kterĂŠ mĹŻĹže nastat bÄhem zpracovĂĄnĂ ĂşkolĹŻ, b) analyzovat historickĂĄ data z provozu skladu a vyvinout sadu testovacĂch pĹĂkladĹŻ, kterĂŠ mohou slouĹžit jako referenÄnĂ vĂ˝sledky pro dalĹĄĂ vĂ˝zkum, a dĂĄle c) pokusit se pĹedÄit stanovenĂŠ referenÄnĂ vĂ˝sledky dosaĹženĂŠ kvalifikovanĂ˝m a trĂŠnovanĂ˝m operaÄnĂm manaĹžerem jednoho z nejvÄtĹĄĂch skladĹŻ ve stĹednĂ EvropÄ.This work is focused on the work-flow optimization in logistic warehouses and distribution centers. The main aim is to optimize process planning, scheduling, and dispatching. The problem is quite accented in recent years. The problem is of NP hard class of problems and where is very computationally demanding to find an optimal solution. The main motivation for solving this problem is to fill the gap between the new optimization methods developed by researchers in academic world and the methods used in business world. The core of the optimization algorithm is built on the genetic programming driven by the context-free grammar. The main contribution of the thesis is a) to propose a new optimization algorithm which respects the makespan, the utilization, and the congestions of aisles which may occur, b) to analyze historical operational data from warehouse and to develop the set of benchmarks which could serve as the reference baseline results for further research, and c) to try outperform the baseline results set by the skilled and trained operational manager of the one of the biggest warehouses in the middle Europe.
Evolutionary and demographic correlates of Pleistocene coastline changes in the Sicilian wall lizard Podarcis wagleriana
Aim
Emergence of coastal lowlands during Pleistocene ice ages might have provided conditions for glacial expansions (demographic and spatial), rather than contraction, of coastal populations of temperate species. Here, we tested these predictions in the insular endemic Sicilian wall lizard Podarcis wagleriana.
Location
Sicily and neighbouring islands.
Methods
We sampled 179 individuals from 45 localities across the whole range of P. wagleriana. We investigated demographic and spatial variations through time using Bayesian coalescent models (Bayesian phylogeographic reconstruction, Extended Bayesian Skyline plots, Isolationâwithâmigration models) based on multilocus DNA sequence data. We used species distribution modelling to reconstruct present and past habitat suitability.
Results
We found two main lineages distributed in the east and west portions of the current species range and a third lineage restricted to a small area in the north of Sicily. Multiple lines of evidence from palaeogeographic (shorelines), palaeoclimatic (species distribution models), and multilocus genetic data (demographic and spatial Bayesian reconstructions) indicate that these lineages originated in distinct refugia, located in the northâwestern and southâeastern coastal lowlands, during Middle Pleistocene interglacial phases, and came into secondary contact following demographic and spatial expansions during the last glacial phase.
Main conclusions
This scenario of interglacial contraction and glacial expansion is in sharp contrast with patterns commonly observed in temperate species on the continent but parallels recent findings on other Mediterranean island endemics. Such a reverse expansionâcontraction (EC) dynamic has been likely associated with glacial increases of climatically suitable coastal lowlands, suggesting this might be a general pattern in Mediterranean island species and also in other coastal regions strongly affected by glacial marine regressions during glacial episodes. This study provides explicit predictions and some methodological recommendations for testing the reverse EC model in other region and taxa
Application of Particle Swarm Optimization to Formative E-Assessment in Project Management
The current paper describes the application of Particle Swarm Optimization algorithm to the formative e-assessment problem in project management. The proposed approach resolves the issue of personalization, by taking into account, when selecting the item tests in an e-assessment, the following elements: the ability level of the user, the targeted difficulty of the test and the learning objectives, represented by project management concepts which have to be checked. The e-assessment tool in which the Particle Swarm Optimization algorithm is integrated is also presented. Experimental results and comparison with other algorithms used in item tests selection prove the suitability of the proposed approach to the formative e-assessment domain. The study is presented in the framework of other evolutionary and genetic algorithms applied in e-education.Particle Swarm Optimization, Genetic Algorithms, Evolutionary Algorithms, Formative E-assessment, E-education
Search based software engineering: Trends, techniques and applications
Š ACM, 2012. This is the author's version of the work. It is posted here by permission of ACM for your personal use. Not for redistribution. The definitive version is available from the link below.In the past five years there has been a dramatic increase in work on Search-Based Software Engineering (SBSE), an approach to Software Engineering (SE) in which Search-Based Optimization (SBO) algorithms are used to address problems in SE. SBSE has been applied to problems throughout the SE lifecycle, from requirements and project planning to maintenance and reengineering. The approach is attractive because it offers a suite of adaptive automated and semiautomated solutions in situations typified by large complex problem spaces with multiple competing and conflicting objectives.
This article provides a review and classification of literature on SBSE. The work identifies research trends and relationships between the techniques applied and the applications to which they have been applied and highlights gaps in the literature and avenues for further research.EPSRC and E
Reduction of the size of datasets by using evolutionary feature selection: the case of noise in a modern city
Smart city initiatives have emerged to mitigate the negative effects of a very fast growth of urban areas. Most of the population in our cities are exposed to high levels of noise that generate discomfort and different health problems. These issues may be mitigated by applying different smart cities solutions, some of them require high accurate noise information to provide the best quality of serve possible. In this study, we have designed a machine learning approach based on genetic algorithms to analyze noise data captured in the university campus. This method reduces the amount of data required to classify the noise by addressing a feature selection optimization problem. The experimental results have shown that our approach improved the accuracy in 20% (achieving an accuracy of 87% with a reduction of up to 85% on the original dataset).Universidad de MĂĄlaga. Campus de Excelencia Internacional AndalucĂa Tech.
This research has been partially funded by the Spanish MINECO and FEDER projects TIN2016-81766-REDT (http://cirti.es), and TIN2017-88213-R (http://6city.lcc.uma.es)
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Update of an early warning fault detection method using artificial intelligence techniques
This presentation describes a research investigation to access the feasibility of using an Artificial Intelligence (AI) method to predict and detect faults at an early stage in power systems. An AI based detector has been developed to monitor and predict faults at an early stage on particular sections of power systems. The detector for this early warning fault detection device only requires external measurements taken from the input and output nodes of the power system. The AI detection system is capable of rapidly predicting a malfunction within the system. Artificial Neural Networks (ANNs) are being used as the core of the fault detector. In an earlier paper [11], a computer simulated medium length transmission line has been tested by the detector and the results clearly demonstrate the capability of the detector. Todayâs presentation considers a case study illustrating the suitability of this AI Technique when applied to a distribution transformer. Furthermore, an evolutionary optimisation strategy to train ANNs is also briefly discussed in this presentation, together with a âcrystal ballâ view of future developments in the operation and monitoring of transmission systems in the next millennium
Evolving controllers for simulated car racing
This paper describes the evolution of controllers for racing a simulated radio-controlled car around a track, modelled on a real physical track. Five different controller architectures were compared, based on neural networks, force fields and action sequences. The controllers use either egocentric (first person), Newtonian (third person) or no information about the state of the car (open-loop controller). The only controller that is able to evolve good racing behaviour is based on a neural network acting on egocentric inputs
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