Artificial Development of Neural-Symbolic Networks

Total Page:16

File Type:pdf, Size:1020Kb

Artificial Development of Neural-Symbolic Networks University of Exeter Department of Computer Science Artificial Development of Neural-Symbolic Networks Joseph Paul Townsend March 2014 Supervised by Dr. Ed Keedwell and Dr. Antony Galton Submitted by Joseph Paul Townsend, to the University of Exeter as a thesis for the degree of Doctor of Philosophy in Computer Science , March 2014. This thesis is available for Library use on the understanding that it is copyright material and that no quotation from the thesis may be published without proper acknowledgement. I certify that all material in this thesis which is not my own work has been identi- fied and that no material has previously been submitted and approved for the award of a degree by this or any other University. (signature) ................................................................................................. 1 Abstract Artificial neural networks (ANNs) and logic programs have both been suggested as means of modelling human cognition. While ANNs are adaptable and relatively noise resis- tant, the information they represent is distributed across various neurons and is therefore difficult to interpret. On the contrary, symbolic systems such as logic programs are in- terpretable but less adaptable. Human cognition is performed in a network of biological neurons and yet is capable of representing symbols, and therefore an ideal model would combine the strengths of the two approaches. This is the goal of Neural-Symbolic In- tegration [4, 16, 21, 40], in which ANNs are used to produce interpretable, adaptable representations of logic programs and other symbolic models. One neural-symbolic model of reasoning is SHRUTI [89, 95], argued to exhibit biological plausibility in that it captures some aspects of real biological processes. SHRUTI's original developers also suggest that further biological plausibility can be ascribed to the fact that SHRUTI networks can be represented by a model of genetic development [96, 120]. The aims of this thesis are to support the claims of SHRUTI's developers by producing the first such genetic representation for SHRUTI networks and to explore biological plausibility further by investigating the evolvability of the proposed SHRUTI genome. The SHRUTI genome is developed and evolved using principles from Generative and De- velopmental Systems and Artificial Development [13, 105], in which genomes use indirect encoding to provide a set of instructions for the gradual development of the phenotype just as DNA does for biological organisms. This thesis presents genomes that develop SHRUTI representations of logical relations and episodic facts so that they are able to correctly answer questions on the knowledge they represent. The evolvability of the SHRUTI genomes is limited in that an evolutionary search was able to discover genomes for simple relational structures that did not include conjunction, but could not discover structures that enabled conjunctive relations or episodic facts to be learned. Experiments were performed to understand the SHRUTI fitness landscape and demonstrated that this landscape is unsuitable for navigation using an evolutionary search. Complex SHRUTI structures require that necessary substructures must be discovered in unison and not individually in order to yield a positive change in objective fitness that informs the evolutionary search of their discovery. The requirement for multiple substructures to be in place before fitness can be improved is probably owed to the localist representation of concepts and relations in SHRUTI. Therefore this thesis concludes by making a case for switching to more distributed repre- sentations as a possible means of improving evolvability in the future. 2 Acknowledgements I would like to thank my supervisors Dr. Ed Keedwell and Dr. Antony Galton for all the help they have provided throughout my research and for encouraging me to share my work with the wider research community through various publications. Furthermore, I would like to thank them for taking an interest in my research in the first place and for their willingness to supervise it. I would also like to thank my parents, Derek William and Margaret Townsend, and my brother Martyn Townsend, for supporting, advising and encouraging every single decision I have made to date regarding my education, work and life in general. Finally, I would like to acknowledge my friends James Gould, David Singeisen, Marjorie Gehrhardt and Rachel Warren. Over the past few years we have shared the joys and hardships of academia together and supported each other in doing so. I would like to thank these people for their support, particularly for encouraging me to keep going. I would like to encourage them to do the same and wish them all the best in their future work, be it in academia or elsewhere. 3 Contents List of tables 7 List of figures 9 Publications 14 Definitions 15 1 Introduction 18 1.1 Aims . 24 1.2 Claims . 24 1.3 Contributions . 24 1.4 Thesis overview . 25 2 Background 27 2.1 Biological preliminaries . 27 2.1.1 The biological neuron . 27 2.1.2 Neural learning mechanisms . 28 2.1.3 Representation of reasoning in the brain . 28 2.1.4 Localist and distributed representation . 29 2.1.5 Temporal coding . 31 2.1.6 Genetic development . 31 2.1.7 Biological plausibility . 32 2.2 Psychological preliminaries . 33 2.3 Neural-symbolic integration . 34 2.3.1 Logic programs . 35 2.3.2 Artificial neural networks . 37 2.3.3 General relational structure . 38 2.3.4 Connectionist models . 38 2.3.5 SHRUTI . 43 2.3.6 Distributed representations . 52 2.3.7 Summary of neural-symbolic reasoning . 57 2.4 Evolutionary algorithms . 58 2.5 Generative and developmental systems . 60 2.5.1 Grammatical encodings . 61 2.5.2 Cellular development models . 64 2.5.3 GDS and objective fitness . 66 2.6 Evolution of neural-symbolic networks . 68 4 Contents 3 Evolution with Hebbian learning 69 3.1 Hebbian learning . 70 3.1.1 Logic programs without negation . 72 3.1.2 Logic programs with negation . 74 3.2 SHRUTI genome . 78 3.2.1 Learning and development cycle . 78 3.2.2 Genome structure . 79 3.2.3 Testing the genome model . 82 3.2.4 Discussion . 88 3.3 Method for evolving SHRUTI genomes . 90 3.3.1 Parameters . 91 3.3.2 Variation . 91 3.3.3 Training and test data . 93 3.3.4 Evaluating error . 94 3.3.5 Alternative objectives . 94 3.3.6 Sampling evolved genomes . 96 3.4 Evolution of networks . 97 3.4.1 Selection of objectives . 97 3.4.2 Performance on training data . 101 3.4.3 Performance on test data . 109 3.5 Larger Predicates . 114 3.6 Discussion . 116 4 Evolution with recruitment learning 119 4.1 Recruitment learning . 120 4.2 Genome model . 121 4.3 Mediator structures . 126 4.3.1 Learning mediator structures . 127 4.3.2 Developing mediator structures . 130 4.3.3 Testing development . 134 4.3.4 Method for evolving mediator structures . 136 4.3.5 Results of evolving mediator structures . 140 4.3.6 Fitness landscape . 146 4.4 Fact structures . 154 4.4.1 Learning fact structures . 154 4.4.2 Developing fact structures . 156 4.4.3 Testing development . 160 4.4.4 Evolving fact structures . 161 4.4.5 Fitness landscape . 165 4.5 Discussion . 172 5 Distributed SHRUTI Networks 175 5.1 Generalising the problem to all localist models . 177 5.2 Distributed neural-symbolic reasoning systems . 179 5.3 Distributed SHRUTI: preliminary results . 180 5 Contents 5.3.1 Distributed relational structure . 180 5.3.2 Error and ambiguity . 182 5.3.3 Probability of θ-overlap: method . 184 5.3.4 Probability of θ-overlap: results . 185 5.3.5 Organising distributed representations . 188 5.3.6 Other nodes . 189 5.3.7 Other SHRUTI structures . 190 5.3.8 Evolvability . 190 5.4 Visuospatial and linguistic systems . 191 5.5 Summary . 191 6 Conclusions 194 6.1 Overview of findings . 195 6.2 Contributions . 197 6.3 Future work . 198 6.3.1 Distributed SHRUTI model . 199 6.3.2 Localist SHRUTI model . 200 6.3.3 Biological plausibility . 201 6.3.4 The goals of neural-symbolic integration . 201 Appendices 204 A Question sets and event sequences 205 A.1 NoNeg data sets . 206 A.1.1 NoNeg1 . 206 A.1.2 NoNeg2 . 206 A.1.3 NoNeg3 . 207 A.1.4 NoNeg4 . 207 A.1.5 NoNeg5 . ..
Recommended publications
  • A Novel Generative Encoding for Evolving Modular, Regular and Scalable Networks
    A Novel Generative Encoding for Evolving Modular, Regular and Scalable Networks Marcin Suchorzewski Jeff Clune Artificial Intelligence Laboratory Creative Machines Laboratory West Pomeranian University of Technology Cornell University [email protected] [email protected] ABSTRACT 1. INTRODUCTION In this paper we introduce the Developmental Symbolic En- Networks designed by humans and evolution have certain coding (DSE), a new generative encoding for evolving net- properties that are thought to enhance both their perfor- works (e.g. neural or boolean). DSE combines elements of mance and adaptability, such as modularity, regularity, hier- two powerful generative encodings, Cellular Encoding and archy, scalability, and being scale-free [12, 11, 1]. In this pa- HyperNEAT, in order to evolve networks that are modular, per we introduce a new generative representation called the regular, scale-free, and scalable. Generating networks with Developmental Symbolic Encoding that evolves networks these properties is important because they can enhance per- that possess these properties. We first review the mean- formance and evolvability. We test DSE’s ability to gener- ing of these terms before discussing them with respect to ate scale-free and modular networks by explicitly rewarding previous evolutionary algorithms. these properties and seeing whether evolution can produce Modularity is the encapsulation of function within mostly networks that possess them. We compare the networks DSE independently operating units, where the internal workings evolves to those of HyperNEAT. The results show that both of the module tend to only affect the rest of the structure encodings can produce scale-free networks, although DSE through the module’s inputs and outputs [12, 11].
    [Show full text]
  • Artificial Biochemical Networks : Evolving Dynamical Systems to Control Dynamical Systems
    This is a repository copy of Artificial Biochemical Networks : Evolving Dynamical Systems to Control Dynamical Systems. White Rose Research Online URL for this paper: https://eprints.whiterose.ac.uk/75277/ Version: Accepted Version Article: Lones, Michael Adam, Fuente, Luis Alberto, Turner, Alexander Phillip et al. (4 more authors) (2014) Artificial Biochemical Networks : Evolving Dynamical Systems to Control Dynamical Systems. IEEE Transactions on Evolutionary Computation. 6423886. pp. 145- 166. ISSN 1089-778X https://doi.org/10.1109/tevc.2013.2243732 Reuse Items deposited in White Rose Research Online are protected by copyright, with all rights reserved unless indicated otherwise. They may be downloaded and/or printed for private study, or other acts as permitted by national copyright laws. The publisher or other rights holders may allow further reproduction and re-use of the full text version. This is indicated by the licence information on the White Rose Research Online record for the item. Takedown If you consider content in White Rose Research Online to be in breach of UK law, please notify us by emailing [email protected] including the URL of the record and the reason for the withdrawal request. [email protected] https://eprints.whiterose.ac.uk/ IEEE TRANSACTIONS ON EVOLUTIONARY COMPUTATION, PREPRINT, ACCEPTED FOR PUBLICATION DECEMBER 2012 1 Artificial Biochemical Networks: Evolving Dynamical Systems to Control Dynamical Systems Michael A. Lones, Senior Member, IEEE, Luis A. Fuente, Alexander P. Turner, Leo S. D. Caves, Susan Stepney, Stephen L. Smith, Member, IEEE, and Andy M. Tyrrell, Senior Member, IEEE Abstract—Biological organisms exist within environments in different evolutionary algorithms have been used to design which complex, non-linear dynamics are ubiquitous.
    [Show full text]
  • Artificial Intelligence Vs (General) Artificial Intelligence 3
    ISSN 0798 1015 HOME Revista ESPACIOS ÍNDICES / Index A LOS AUTORES / To the ! ! AUTORS ! Vol. 40 (Number 4) Year 2019. Page 3 ¿Will machines ever rule the world? ¿Las máquinas dominarán el mundo? PEDROZA, Mauricio 1; VILLAMIZAR, Gustavo 2; MENDEZ, James 3 Received: 11/08/2018 • Approved: 16/12/2018 • Published 04/02/2019 Contents 1. Introduction 2. (Narrow) Artificial Intelligence vs (General) Artificial Intelligence 3. Machines designed as tools of man 4. Machines thought as similar to man 5. Conclusions Acknowledgments Bibliographic references ABSTRACT: RESUMEN: From ancient automatons, to the latest technologies Desde los antiguos autómatas hasta las últimas of robotics and supercomputing, the continued tecnologías de la robótica, el continuo progreso de la progress of mankind has led man to even question his humanidad ha llevado al hombre a cuestionar incluso future status as a dominant species. “Will machines su estatus futuro como especie dominante. "¿Alguna ever rule the world?” or more precisely: Do we want vez dominarán las máquinas el mundo?" O más machines to rule the world? Theoretical and precisamente: ¿Queremos que las máquinas dominen technological challenges involved in this choice will be el mundo? Los retos teóricos y tecnológicos que se considered both under the conservative approach of plantean en esta elección serán considerados tanto "machines designed as tools of man" and in the bajo el enfoque conservador de "máquinas que sirven scenario of "machines thought as similar to man". al hombre" como en el escenario de "máquinas Keywords: Artificial Intelligence, Cognitive Machines, equiparables al hombre" Narrow Artificial Intelligence Strong Artificial Palabras clave: Inteligencia Artificial, Máquinas Intelligence, Artificial General Intelligence.
    [Show full text]
  • Artificial Intelligence and Broadband Divide
    Artificial Intelligence and Broadband Divide State of ict Connectivity in Asia and the Pacific 2017 The Economic and Social Commission for Asia and the Pacific (ESCAP) serves as the United Nations’ regional hub promoting cooperation among countries to achieve inclusive and sustainable development. The largest regional intergovernmental platform with 53 Member States and 9 associate members, ESCAP has emerged as a strong regional think-tank offering countries sound analytical products that shed insight into the evolving economic, social and environmental dynamics of the region. The Commission’s strategic focus is to deliver on the 2030 Agenda for Sustainable Development, which it does by reinforcing and deepening regional cooperation and integration to advance connectivity, financial cooperation and market integration. ESCAP’s research and analysis coupled with its policy advisory services, capacity building and technical assistance to governments aims to support countries’ sustainable and inclusive development ambitions. The shaded areas of the map indicate ESCAP members and associate members. Information and statistics presented in this publication include only those member and associate member States located in the Asia-Pacific region. Disclaimer: This report of the Information and Communications Technology and Disaster Risk Reduction Division provides policy-relevant analysis on regional trends and challenges in support of the development of the Asia-Pacific Information Superhighway and inclusive development. The views expressed herein are those of the authors, and do not necessarily reflect the views of the United Nations. This report has been issued without formal editing, and the designations employed and material presented do not imply the expression of any opinion whatsoever on the part of the Secretariat of the United Nations concerning the legal status of any country, territory, city or area, or of its authorities, or concerning the delimitation of its frontiers or boundaries.
    [Show full text]
  • Building Processes Optimization : Toward an Artificial Ontogeny Based Approach
    Building processes optimization : Toward an artificial ontogeny based approach Alexandre Devert Directed by Marc Schoenauer and Nicolas Bred`eche Submitted in total fulfilment of the requirements of the degree of Doctor of Philosophy June 21, 2009 Ecole Doctorale d’Informatique Universit´eParis-Sud 11 Contents 1 Introduction to Evolutionary Design 5 1.1 Anevolutionaryalgorithmsprimer . 7 1.1.1 Description .......................... 8 1.1.2 Lamarckian and Baldwinian evolutions . 9 1.1.3 Onthe designof anevolutionaryalgorithm . 10 1.2 Simulationandevaluation . 11 1.2.1 Designofanevaluationfunction . 13 1.2.2 Theusageofsimulation . 14 1.3 Representations for Evolutionary Design . .. 15 1.3.1 Blockstacks.......................... 15 1.3.2 Explicit and implicit representations . 18 1.3.3 Modularity .......................... 19 1.3.4 Treestructures .. .. .. .. .. .. .. .. .. .. 21 1.3.5 Grammarsandrewritingsystems . 23 1.3.6 Theevolvabilityissue . 26 1.3.7 Cellularrepresentations . 26 1.4 Preview ................................ 29 2 AguidedtourofEvolutionaryDesign 31 2.1 Explicitrepresentations . 31 2.1.1 Blockstacks.......................... 31 2.1.2 Legostructures.. .. .. .. .. .. .. .. .. .. 32 2.1.3 Antennae ........................... 33 2.1.4 Shapes............................. 34 2.1.5 Robots............................. 35 2.1.6 Tensegritystructures. 36 2.1.7 TopologicalOptimumDesign . 37 2.1.8 Opticalfibersdesign . 38 2.1.9 Bladeshapedesignforwindturbines. 39 2.2 Implicitrepresentations . 40 2.2.1 KarlSims’creatures . 40 2.2.2 Hornby’sL-systems . 41 2.2.3 EnvironmentawareL-systems. 44 2.3 Cellularrepresentations . 45 2.3.1 Virtualcreatures . 46 2.3.2 Skyscraperframes . 47 2.3.3 Trussstructures . .. .. .. .. .. .. .. .. .. 48 2.3.4 Environmentawareness . 50 2.4 Conclusion .............................. 51 1 CONTENTS 3 An Evolutionary algorithm for blueprints 55 3.1 TheBlindBuilderrepresentation . 55 3.1.1 Variationoperators. 57 3.2 Designofsimple3dobjects .
    [Show full text]
  • Evolving Gene Expression to Reconfigure Analogue Devices
    EVOLVING GENE EXPRESSION TO RECONFIGURE ANALOGUE DEVICES Kester Dean Clegg Thesis submitted in partial fulfilment of the requirements for the degree of Doctor of Philosophy. Department of Computer Science May, 2008 Abstract Repeated, morphological functionality, from limbs to leaves, is widespread in nature. Pattern formation in early embryo development has shed light on how and why the same genes are expressed in different locations or at different times. Practitioners working in evolutionary computation have long regarded nature’s reuse of modular functionality with admiration. But repeating na- ture’s trick has proven difficult. To date, no one has managed to evolve the design for a car, a house or a plane. Or indeed anything where the number of interdependent parts exposed to random mutation is large. It seems that while we can use evolutionary algorithms for search-based optimisation with great success, we cannot use them to tackle large, complex designs where functional reuse is essential. This thesis argues that the modular functionality provided by gene reuse could play an important part in evolutionary computation being able to scale, and that by expressing subsets of genes in specific contexts, successive stages of phenotype configuration can be controlled by evolutionary search. We present a conceptual model of context-specific gene expression and show how a ge- nome representation can hold many genes, only a few of which need be ex- pressed in a solution. As genes are expressed in different contexts, their func- tional role in a solution changes. By allowing gene expression to discover phe- notype solutions, evolutionary search can guide itself across multiple search domains.
    [Show full text]
  • Melomics: a Case-Study of AI in Spain Research Groups in the Spanish Computer Sci - Ences
    Column Worldwide AI Australia Spain n Traditionally focused on good old-fashioned Carlos Sánchez Quintana, Francisco Moreno Arcas, David Albar - AI and robotics, the Spanish AI community holds a vigorous computational intelligence racín Molina, Jose David Fernández Rodríguez, Francisco J. Vico substrate. Neuromorphic, evolutionary, or fuzzylike systems have been developed by many Melomics: A Case-Study of AI in Spain research groups in the Spanish computer sci - ences. It is no surprise, then, that these nature- grounded efforts start to emerge, enriching the In Spain there are 74 universities, many of which have computer sci - AI catalogue of research projects and publica - ence departments that host AI-related research groups. AEPIA, the tions and, eventually, leading to new directions Spanish society for AI research, was founded in 1983 and has been of basic or applied research. In this article, we vigorously promoting the advancement of AI since then. Along with review the contribution of Melomics in compu - several other societies and communities of interest, it promotes var - tational creativity. ious periodic conferences and workshops. The Artificial Intelligence Research Institute (IIIA) of the Spanish National Research Council constitutes one of the flagships of local AI research. Ramón López de Mántaras, IIIA’s renowned director, was one of the pioneers of AI in Spain, and he also was the recipient of the prestigious AAAI Engle - more Award in 2011. Other researchers that have reached an out - standing position, and lead important research groups in Spain, include Antonio Bahamonde (University of Oviedo), Federico Barber (Polytechnic University of Madrid), Vicent Botti (Polytechnic Uni - versity of Valencia), and Amparo Vila (University of Granada).
    [Show full text]
  • A Review of Morphogenetic Engineering (Running Title: a Review of Morphogenetic Engineering)
    A Review of Morphogenetic Engineering (Running title: A Review of Morphogenetic Engineering) Ren´eDoursat*1, Hiroki Sayama2, and Olivier Michel3 1School of Biomedical Engineering, Drexel University 3141 Chestnut Street, Philadelphia, PA 19104, US ([email protected]) *corresp. author 2Department of Bioengineering, Binghamton University SUNY PO Box 6000, Binghamton, NY 13902, US ([email protected]) 3Facult´edes Sciences et Technologie, Universit´ede Cr´eteil 61, ave du G´en´eral de Gaulle, 94010 Cr´eteilCedex, France ([email protected]) Abstract Generally, phenomena of spontaneous pattern formation are random and repetitive, whereas elaborate devices are the deterministic product of human design. Yet, biological organisms and collective insect constructions are exceptional examples of complex systems that are both ar- chitectured and self-organized. Can we understand their precise self-formation capabilities and integrate them with technological planning? Can physical systems be endowed with informa- tion, or informational systems be embedded in physics, to create autonomous morphologies and functions? To answer these questions, we have launched in 2009, and developed through a series of workshops and a collective book, a new field of research called Morphogenetic Engi- neering. It is the first initiative of its kind to rally and promote models and implementations of complex self-architecturing systems. Particular emphasis is set on the programmability and com- putational abilities of self-organization, properties that are often underappreciated in complex systems science|while, conversely, the benefits of self-organization are often underappreciated in engineering methodologies1. Keywords: agent-based modeling, artificial life, collective construction, complex systems, evo- lutionary development, generative grammars, morphogenesis, self-organization, swarm robotics, systems engineering.
    [Show full text]
  • Hello, World: Artificial Intelligence and Its Use in the Public Sector
    Hello, World: Artificial intelligence and its use in the public sector Jamie Berryhill Kévin Kok Heang Rob Clogher Keegan McBride November 2019 | http://oe.cd/helloworld OECD Working Papers on Public Governance No. 36 Cover images are the European Parliament and the dome of Germany’s Reichstag building processed through Deep Learning algorithms to match the style of Van Gogh paintings. tw Hello, World: Artificial Intelligence and its Use in the Public Sector Authors: Jamie Berryhill, Kévin Kok Heang, Rob Clogher, Keegan McBride PUBE 2 This document and any map included herein are without prejudice to the status of or sovereignty over any territory, to the delimitation of international frontiers and boundaries and to the name of any territory, city or area. 1. Note by Tukey: The information in this document with reference to ‘Cyprus’ relates to the southern part of the island. There is no single authority representing both Turkish and Greek Cypriot people on the island. Turkey recognises the Turkish Republic of Northern Cyprus (TRNC). Until a lasting and equitable solution is found within the context of the United Nations, Turkey shall preserve its position concerning the ‘Cyprus issue’. 2. Note by all the European Union Member States of the OECD and the European Commission: The Republic of Cyprus is recognised by all members of the United Nations with the exception of Turkey. The information in this document relates to the area under the effective control of the Government of the Republic of Cyprus. HELLO, WORLD: ARTIFICIAL INTELLIGENCE AND ITS USE IN THE PUBLIC SECTOR © OECD 2019 3 Foreword Artificial Intelligence (AI) is an area of research and technology application that can have a significant impact on public policies and services in many ways.
    [Show full text]
  • Phenotypic, Developmental and Computational Resources: Scaling in Artificial Development
    Phenotypic, Developmental and Computational Resources: Scaling in Artificial Development Gunnar Tufte Norwegian University of Science and Technology Department of Computer and Information Science Sem Selandsvei 7-9 7491 Trondheim Norway [email protected] ABSTRACT Algorithms (EAs) is the aspect of scalability. In the work Developmental systems have inherent properties favourable of Kitano [20] the scaling issue was addressed by searching for scaling. The possibility to generate very large scale for an effective encoding in order to generate more complex structures combined with gene regulation opens for systems network structures. The urge towards evolution of complex where the genome size do not reflect the size and complexity network structures was motivated by a need to handle scal- of the phenotype. Despite the presence of scalability in na- ing of the complexity of solvable problems. ture there is limited knowledge of what makes a developmen- The proposed solution was a developmental system i.e. an tal mapping scalable. As such, there is few artificial system indirect mapping. In contrast, in a direct mapping approach that show true scaling. Scaling for any system, biological there is a single phenotype, defined by the genotype. This or artificial, is a question of resources. Toward an under- implies that each element in the phenotype is represented ex- standing of the challenges of scalability the issue of scaling plicitly in the genotype. As such, introducing mechanisms, is investigated in an aspect of resources within the develop- inspired by development, into evolutionary computation was mental model itself. The resources are decompositioned into motivated by a need to overcome limitations in such direct domains that can be scaled separately each may influence on mapping approaches, e.g.
    [Show full text]
  • Artificial Development
    ARTIFICIAL DEVELOPMENT Simon Harding and Wolfgang Banzhaf1 1 Department of Computer Science, Memorial University Abstract There is growing interest in the use of analogies of biological development for problem solving in computer science. Nature is extremely intricate when com- pared to human designs, and incorporates features such as the ability to scale, adapt and self-repair that could be usefully incorporated into human-designed artifacts. In this chapter, we discuss how the metaphor of biological develop- ment can be used in artificial systems and highlight some of the challenges of this emerging field. Keywords: Developmental systems, genetic algorithms, pattern formation 1. Introduction Organic processes can serve as inspiration for computational systems. The design and functionality of organic systems is both a challenge and an exis- tence proof of achievements of Nature posed to the human designer. In this context it has turned out that the level of complexity commanded in the design of natural systems is still unparalleled. To put the scalability of biological sys- tems into perspective: Microsoft’s latest version of Windows has 106 lines of code, some Linux distributions have 107 lines of computer code, but there are 1014 cells in the human body each much more complex than a line of code. Such complexity would be out of reach of human designers, who even struggle to keep the simplest designs and manufacturing processes defect-free. With the increasing complexity of both hardware and software, there is need is growing for new design techniques that allow us to work with such complexity. Evolutionary algorithms that mimic Darwinian evolution have provided part of the answer to this problem.
    [Show full text]
  • A Review of Morphogenetic Engineering
    Nat Comput DOI 10.1007/s11047-013-9398-1 A review of morphogenetic engineering Rene´ Doursat • Hiroki Sayama • Olivier Michel Ó Springer Science+Business Media Dordrecht 2013 Abstract Generally, phenomena of spontaneous pattern (Chapter 1, in Doursat R et al. (eds.) Morphogenetic engi- formation are random and repetitive, whereas elaborate neering: toward programmable complex systems. Under- devices are the deterministic product of human design. Yet, standing complex systems. Springer, 2012a).] biological organisms and collective insect constructions are exceptional examples of complex systems (CS) that are both Keywords Agent-based modeling Á Artificial life Á architectured and self-organized. Can we understand their Collective construction Á Complex systems Á precise self-formation capabilities and integrate them with Evolutionary development Á Generative grammars Á technological planning? Can physical systems be endowed Morphogenesis Á Self-organization Á Swarm robotics Á with information, or informational systems be embedded in Systems engineering physics, to create autonomous morphologies and functions? To answer these questions, we have launched in 2009, and developed through a series of workshops and a collective book, 1 Introduction a new field of research called morphogenetic engineering. It is the first initiative of its kind to rally and promote models and Classical engineered products (mechanical, electrical, implementations of complex self-architecturing systems. computer, civil) are generally made of a number of unique, Particular emphasis is set on the programmability and heterogeneous components assembled in very precise and computational abilities of self-organization, properties that possibly complicated ways. They are expected to work as are often underappreciated in CS science—while, con- deterministically and predictably as possible following the versely, the benefits of self-organization are often underap- specifications given by their designers (Fig.
    [Show full text]