1,338 research outputs found
Towards an Information Theoretic Framework for Evolutionary Learning
The vital essence of evolutionary learning consists of information flows between the environment and the entities differentially surviving and reproducing therein. Gain or loss of information in individuals and populations due to evolutionary steps should be considered in evolutionary algorithm theory and practice. Information theory has rarely been applied to evolutionary computation - a lacuna that this dissertation addresses, with an emphasis on objectively and explicitly evaluating the ensemble models implicit in evolutionary learning. Information theoretic functionals can provide objective, justifiable, general, computable, commensurate measures of fitness and diversity.
We identify information transmission channels implicit in evolutionary learning. We define information distance metrics and indices for ensembles. We extend Price\u27s Theorem to non-random mating, give it an effective fitness interpretation and decompose it to show the key factors influencing heritability and evolvability. We argue that heritability and evolvability of our information theoretic indicators are high. We illustrate use of our indices for reproductive and survival selection. We develop algorithms to estimate information theoretic quantities on mixed continuous and discrete data via the empirical copula and information dimension. We extend statistical resampling. We present experimental and real world application results: chaotic time series prediction; parity; complex continuous functions; industrial process control; and small sample social science data. We formalize conjectures regarding evolutionary learning and information geometry
A Field Guide to Genetic Programming
xiv, 233 p. : il. ; 23 cm.Libro ElectrĂłnicoA Field Guide to Genetic Programming (ISBN 978-1-4092-0073-4) is an introduction to genetic programming (GP). GP is a systematic, domain-independent method for getting computers to solve problems automatically starting from a high-level statement of what needs to be done. Using ideas from natural evolution, GP starts from an ooze of random computer programs, and progressively refines them through processes of mutation and sexual recombination, until solutions emerge. All this without the user having to know or specify the form or structure of solutions in advance. GP has generated a plethora of human-competitive results and applications, including novel scientific discoveries and patentable inventions. The authorsIntroduction --
Representation, initialisation and operators in Tree-based GP --
Getting ready to run genetic programming --
Example genetic programming run --
Alternative initialisations and operators in Tree-based GP --
Modular, grammatical and developmental Tree-based GP --
Linear and graph genetic programming --
Probalistic genetic programming --
Multi-objective genetic programming --
Fast and distributed genetic programming --
GP theory and its applications --
Applications --
Troubleshooting GP --
Conclusions.Contents
xi
1 Introduction
1.1 Genetic Programming in a Nutshell
1.2 Getting Started
1.3 Prerequisites
1.4 Overview of this Field Guide I
Basics
2 Representation, Initialisation and GP
2.1 Representation
2.2 Initialising the Population
2.3 Selection
2.4 Recombination and Mutation Operators in Tree-based
3 Getting Ready to Run Genetic Programming 19
3.1 Step 1: Terminal Set 19
3.2 Step 2: Function Set 20
3.2.1 Closure 21
3.2.2 Sufficiency 23
3.2.3 Evolving Structures other than Programs 23
3.3 Step 3: Fitness Function 24
3.4 Step 4: GP Parameters 26
3.5 Step 5: Termination and solution designation 27
4 Example Genetic Programming Run
4.1 Preparatory Steps 29
4.2 Step-by-Step Sample Run 31
4.2.1 Initialisation 31
4.2.2 Fitness Evaluation Selection, Crossover and Mutation Termination and Solution Designation Advanced Genetic Programming
5 Alternative Initialisations and Operators in
5.1 Constructing the Initial Population
5.1.1 Uniform Initialisation
5.1.2 Initialisation may Affect Bloat
5.1.3 Seeding
5.2 GP Mutation
5.2.1 Is Mutation Necessary?
5.2.2 Mutation Cookbook
5.3 GP Crossover
5.4 Other Techniques 32
5.5 Tree-based GP 39
6 Modular, Grammatical and Developmental Tree-based GP 47
6.1 Evolving Modular and Hierarchical Structures 47
6.1.1 Automatically Defined Functions 48
6.1.2 Program Architecture and Architecture-Altering 50
6.2 Constraining Structures 51
6.2.1 Enforcing Particular Structures 52
6.2.2 Strongly Typed GP 52
6.2.3 Grammar-based Constraints 53
6.2.4 Constraints and Bias 55
6.3 Developmental Genetic Programming 57
6.4 Strongly Typed Autoconstructive GP with PushGP 59
7 Linear and Graph Genetic Programming 61
7.1 Linear Genetic Programming 61
7.1.1 Motivations 61
7.1.2 Linear GP Representations 62
7.1.3 Linear GP Operators 64
7.2 Graph-Based Genetic Programming 65
7.2.1 Parallel Distributed GP (PDGP) 65
7.2.2 PADO 67
7.2.3 Cartesian GP 67
7.2.4 Evolving Parallel Programs using Indirect Encodings 68
8 Probabilistic Genetic Programming
8.1 Estimation of Distribution Algorithms 69
8.2 Pure EDA GP 71
8.3 Mixing Grammars and Probabilities 74
9 Multi-objective Genetic Programming 75
9.1 Combining Multiple Objectives into a Scalar Fitness Function 75
9.2 Keeping the Objectives Separate 76
9.2.1 Multi-objective Bloat and Complexity Control 77
9.2.2 Other Objectives 78
9.2.3 Non-Pareto Criteria 80
9.3 Multiple Objectives via Dynamic and Staged Fitness Functions 80
9.4 Multi-objective Optimisation via Operator Bias 81
10 Fast and Distributed Genetic Programming 83
10.1 Reducing Fitness Evaluations/Increasing their Effectiveness 83
10.2 Reducing Cost of Fitness with Caches 86
10.3 Parallel and Distributed GP are Not Equivalent 88
10.4 Running GP on Parallel Hardware 89
10.4.1 Masterâslave GP 89
10.4.2 GP Running on GPUs 90
10.4.3 GP on FPGAs 92
10.4.4 Sub-machine-code GP 93
10.5 Geographically Distributed GP 93
11 GP Theory and its Applications 97
11.1 Mathematical Models 98
11.2 Search Spaces 99
11.3 Bloat 101
11.3.1 Bloat in Theory 101
11.3.2 Bloat Control in Practice 104
III
Practical Genetic Programming
12 Applications
12.1 Where GP has Done Well
12.2 Curve Fitting, Data Modelling and Symbolic Regression
12.3 Human Competitive Results â the Humies
12.4 Image and Signal Processing
12.5 Financial Trading, Time Series, and Economic Modelling
12.6 Industrial Process Control
12.7 Medicine, Biology and Bioinformatics
12.8 GP to Create Searchers and Solvers â Hyper-heuristics xiii
12.9 Entertainment and Computer Games 127
12.10The Arts 127
12.11Compression 128
13 Troubleshooting GP
13.1 Is there a Bug in the Code?
13.2 Can you Trust your Results?
13.3 There are No Silver Bullets
13.4 Small Changes can have Big Effects
13.5 Big Changes can have No Effect
13.6 Study your Populations
13.7 Encourage Diversity
13.8 Embrace Approximation
13.9 Control Bloat
13.10 Checkpoint Results
13.11 Report Well
13.12 Convince your Customers
14 Conclusions
Tricks of the Trade
A Resources
A.1 Key Books
A.2 Key Journals
A.3 Key International Meetings
A.4 GP Implementations
A.5 On-Line Resources 145
B TinyGP 151
B.1 Overview of TinyGP 151
B.2 Input Data Files for TinyGP 153
B.3 Source Code 154
B.4 Compiling and Running TinyGP 162
Bibliography 167
Inde
Error management in ATLAS TDAQ : an intelligent systems approach
This thesis is concerned with the use of intelligent system techniques (IST) within
a large distributed software system, specifically the ATLAS TDAQ system which
has been developed and is currently in use at the European Laboratory for Particle
Physics(CERN). The overall aim is to investigate and evaluate a range of ITS
techniques in order to improve the error management system (EMS) currently used
within the TDAQ system via error detection and classification. The thesis work
will provide a reference for future research and development of such methods in the
TDAQ system.
The thesis begins by describing the TDAQ system and the existing EMS, with a
focus on the underlying expert system approach, in order to identify areas where
improvements can be made using IST techniques. It then discusses measures of
evaluating error detection and classification techniques and the factors specific to
the TDAQ system.
Error conditions are then simulated in a controlled manner using an experimental
setup and datasets were gathered from two different sources. Analysis and processing
of the datasets using statistical and ITS techniques shows that clusters exists in
the data corresponding to the different simulated errors.
Different ITS techniques are applied to the gathered datasets in order to realise an
error detection model. These techniques include Artificial Neural Networks (ANNs),
Support Vector Machines (SVMs) and Cartesian Genetic Programming (CGP) and
a comparison of the respective advantages and disadvantages is made.
The principle conclusions from this work are that IST can be successfully used to
detect errors in the ATLAS TDAQ system and thus can provide a tool to improve
the overall error management system. It is of particular importance that the IST can
be used without having a detailed knowledge of the system, as the ATLAS TDAQ
is too complex for a single person to have complete understanding of. The results
of this research will benefit researchers developing and evaluating IST techniques in
similar large scale distributed systems
MILCS: A mutual information learning classifier system
This paper introduces a new variety of learning classifier system (LCS), called MILCS, which utilizes mutual information as fitness feedback. Unlike most LCSs, MILCS is specifically designed for supervised learning. MILCS's design draws on an analogy to the structural learning approach of cascade correlation networks. We present preliminary results, and contrast them to results from XCS. We discuss the explanatory power of the resulting rule sets, and introduce a new technique for visualizing explanatory power. Final comments include future directions for this research, including investigations in neural networks and other systems. Copyright 2007 ACM
Neural networks in multiphase reactors data mining: feature selection, prior knowledge, and model design
Les rĂ©seaux de neurones artificiels (RNA) suscitent toujours un vif intĂ©rĂȘt dans la plupart des domaines dâingĂ©nierie non seulement pour leur attirante « capacitĂ© dâapprentissage » mais aussi pour leur flexibilitĂ© et leur bonne performance, par rapport aux approches classiques. Les RNA sont capables «dâapproximer» des relations complexes et non linĂ©aires entre un vecteur de variables dâentrĂ©es x et une sortie y. Dans le contexte des rĂ©acteurs multiphasiques le potentiel des RNA est Ă©levĂ© car la modĂ©lisation via la rĂ©solution des Ă©quations dâĂ©coulement est presque impossible pour les systĂšmes gaz-liquide-solide. Lâutilisation des RNA dans les approches de rĂ©gression et de classification rencontre cependant certaines difficultĂ©s. Un premier problĂšme, gĂ©nĂ©ral Ă tous les types de modĂ©lisation empirique, est celui de la sĂ©lection des variables explicatives qui consiste Ă dĂ©cider quel sous-ensemble xs â x des variables indĂ©pendantes doit ĂȘtre retenu pour former les entrĂ©es du modĂšle. Les autres difficultĂ©s Ă surmonter, plus spĂ©cifiques aux RNA, sont : le sur-apprentissage, lâambiguĂŻtĂ© dans lâidentification de lâarchitecture et des paramĂštres des RNA et le manque de comprĂ©hension phĂ©nomĂ©nologique du modĂšle rĂ©sultant. Ce travail se concentre principalement sur trois problĂ©matiques dans lâutilisation des RNA: i) la sĂ©lection des variables, ii) lâutilisation de la connaissance apriori, et iii) le design du modĂšle. La sĂ©lection des variables, dans le contexte de la rĂ©gression avec des groupes adimensionnels, a Ă©tĂ© menĂ©e avec les algorithmes gĂ©nĂ©tiques. Dans le contexte de la classification, cette sĂ©lection a Ă©tĂ© faite avec des mĂ©thodes sĂ©quentielles. Les types de connaissance a priori que nous avons insĂ©rĂ©s dans le processus de construction des RNA sont : i) la monotonie et la concavitĂ© pour la rĂ©gression, ii) la connectivitĂ© des classes et des coĂ»ts non Ă©gaux associĂ©s aux diffĂ©rentes erreurs, pour la classification. Les mĂ©thodologies dĂ©veloppĂ©es dans ce travail ont permis de construire plusieurs modĂšles neuronaux fiables pour les prĂ©dictions de la rĂ©tention liquide et de la perte de charge dans les colonnes garnies Ă contre-courant ainsi que pour la prĂ©diction des rĂ©gimes dâĂ©coulement dans les colonnes garnies Ă co-courant.Artificial neural networks (ANN) have recently gained enormous popularity in many engineering fields, not only for their appealing âlearning ability, â but also for their versatility and superior performance with respect to classical approaches. Without supposing a particular equational form, ANNs mimic complex nonlinear relationships that might exist between an input feature vector x and a dependent (output) variable y. In the context of multiphase reactors the potential of neural networks is high as the modeling by resolution of first principle equations to forecast sought key hydrodynamics and transfer characteristics is intractable. The general-purpose applicability of neural networks in regression and classification, however, poses some subsidiary difficulties that can make their use inappropriate for certain modeling problems. Some of these problems are general to any empirical modeling technique, including the feature selection step, in which one has to decide which subset xs â x should constitute the inputs (regressors) of the model. Other weaknesses specific to the neural networks are overfitting, model design ambiguity (architecture and parameters identification), and the lack of interpretability of resulting models. This work addresses three issues in the application of neural networks: i) feature selection ii) prior knowledge matching within the models (to answer to some extent the overfitting and interpretability issues), and iii) the model design. Feature selection was conducted with genetic algorithms (yet another companion from artificial intelligence area), which allowed identification of good combinations of dimensionless inputs to use in regression ANNs, or with sequential methods in a classification context. The type of a priori knowledge we wanted the resulting ANN models to match was the monotonicity and/or concavity in regression or class connectivity and different misclassification costs in classification. Even the purpose of the study was rather methodological; some resulting ANN models might be considered contributions per se. These models-- direct proofs for the underlying methodologies-- are useful for predicting liquid hold-up and pressure drop in counter-current packed beds and flow regime type in trickle beds
Dynamic multi-objective optimisation using deep reinforcement learning::benchmark, algorithm and an application to identify vulnerable zones based on water quality
Dynamic multi-objective optimisation problem (DMOP) has brought a great challenge to the reinforcement learning (RL) research area due to its dynamic nature such as objective functions, constraints and problem parameters that may change over time. This study aims to identify the lacking in the existing benchmarks for multi-objective optimisation for the dynamic environment in the RL settings. Hence, a dynamic multi-objective testbed has been created which is a modified version of the conventional deep-sea treasure (DST) hunt testbed. This modified testbed fulfils the changing aspects of the dynamic environment in terms of the characteristics where the changes occur based on time. To the authorsâ knowledge, this is the first dynamic multi-objective testbed for RL research, especially for deep reinforcement learning. In addition to that, a generic algorithm is proposed to solve the multi-objective optimisation problem in a dynamic constrained environment that maintains equilibrium by mapping different objectives simultaneously to provide the most compromised solution that closed to the true Pareto front (PF). As a proof of concept, the developed algorithm has been implemented to build an expert system for a real-world scenario using Markov decision process to identify the vulnerable zones based on water quality resilience in SĂŁo Paulo, Brazil. The outcome of the implementation reveals that the proposed parity-Q deep Q network (PQDQN) algorithm is an efficient way to optimise the decision in a dynamic environment. Moreover, the result shows PQDQN algorithm performs better compared to the other state-of-the-art solutions both in the simulated and the real-world scenario
Quantum-circuit design for efficient simulations of many-body quantum dynamics
We construct an efficient autonomous quantum-circuit design algorithm for
creating efficient quantum circuits to simulate Hamiltonian many-body quantum
dynamics for arbitrary input states. The resultant quantum circuits have
optimal space complexity and employ a sequence of gates that is close to
optimal with respect to time complexity. We also devise an algorithm that
exploits commutativity to optimize the circuits for parallel execution. As
examples, we show how our autonomous algorithm constructs circuits for
simulating the dynamics of Kitaev's honeycomb model and the
Bardeen-Cooper-Schrieffer model of superconductivity. Furthermore we provide
numerical evidence that the rigorously proven upper bounds for the simulation
error here and in previous work may sometimes overestimate the error by orders
of magnitude compared to the best achievable performance for some
physics-inspired simulations.Comment: 20 Pages, 6 figure
A factor augmented vector autoregressive model and a stacked de-noising auto-encoders forecast combination to predict the price of oil
The following dissertation aims to show the benefits of a forecast combination between an
econometric and a deep learning approach. On one side, a Factor Augmented Vector Autoregressive
Model (FAVAR) with naming variables identification following Stock and Watson (2016)1; on the
other side, a Stacked De-noising Auto-Encoder with Bagging (SDAE-B) following Zhao, Li and Yu
(2017)2 are implemented. From January 2010 to September 2018 Two-hundred-eighty-one monthly
series are used to predict the price of the West Texas Intermediate (WTI). The model performance is
analysed by Root Mean Squared Error (RMSE), Mean Absolute Percentage Error (MAPE) and
Directional Accuracy (DA). The combination benefits from both SDAE-Bâs high accuracy and
FAVARâs interpretation features through impulse response functions (IRFs) and forecast error
variance decomposition (FEVD)
A generalised feedforward neural network architecture and its applications to classification and regression
Shunting inhibition is a powerful computational mechanism that plays an important role in sensory neural information processing systems. It has been extensively used to model some important visual and cognitive functions. It equips neurons with a gain control mechanism that allows them to operate as adaptive non-linear filters. Shunting Inhibitory Artificial Neural Networks (SIANNs) are biologically inspired networks where the basic synaptic computations are based on shunting inhibition. SIANNs were designed to solve difficult machine learning problems by exploiting the inherent non-linearity mediated by shunting inhibition. The aim was to develop powerful, trainable networks, with non-linear decision surfaces, for classification and non-linear regression tasks. This work enhances and extends the original SIANN architecture to a more general form called the Generalised Feedforward Neural Network (GFNN) architecture, which contains as subsets both SIANN and the conventional Multilayer Perceptron (MLP) architectures. The original SIANN structure has the number of shunting neurons in the hidden layers equal to the number of inputs, due to the neuron model that is used having a single direct excitatory input. This was found to be too restrictive, often resulting in inadequately small or inordinately large network structures
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