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91
Special Purpose Parallel Computing
 Lectures on Parallel Computation
, 1993
"... A vast amount of work has been done in recent years on the design, analysis, implementation and verification of special purpose parallel computing systems. This paper presents a survey of various aspects of this work. A long, but by no means complete, bibliography is given. 1. Introduction Turing ..."
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Cited by 77 (5 self)
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A vast amount of work has been done in recent years on the design, analysis, implementation and verification of special purpose parallel computing systems. This paper presents a survey of various aspects of this work. A long, but by no means complete, bibliography is given. 1. Introduction Turing [365] demonstrated that, in principle, a single general purpose sequential machine could be designed which would be capable of efficiently performing any computation which could be performed by a special purpose sequential machine. The importance of this universality result for subsequent practical developments in computing cannot be overstated. It showed that, for a given computational problem, the additional efficiency advantages which could be gained by designing a special purpose sequential machine for that problem would not be great. Around 1944, von Neumann produced a proposal [66, 389] for a general purpose storedprogram sequential computer which captured the fundamental principles of...
A brief history of cellular automata
, 2000
"... Cellular automata are simple models of computation which exhibit fascinatingly complex behavior. They have captured the attention of several generations of researchers, leading to an extensive body of work. Here we trace a history of cellular automata from their beginnings with von Neumann to the pr ..."
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Cited by 46 (2 self)
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Cellular automata are simple models of computation which exhibit fascinatingly complex behavior. They have captured the attention of several generations of researchers, leading to an extensive body of work. Here we trace a history of cellular automata from their beginnings with von Neumann to the present day. The emphasis is mainly on topics closer to computer science and mathematics rather than physics, biology or other applications. The work should be of interest to both new entrants into the field as well as researchers working on particular aspects of cellular automata.
Computation in cellular automata: A selected review
 Nonstandard Computation
, 1996
"... Cellular automata (CAs) are decentralized spatially extended systems consisting of large numbers of simple identical components with local connectivity. Such systems have the potential to perform complex computations with a high degree of efficiency and robustness, as well as to model the behavior o ..."
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Cited by 36 (2 self)
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Cellular automata (CAs) are decentralized spatially extended systems consisting of large numbers of simple identical components with local connectivity. Such systems have the potential to perform complex computations with a high degree of efficiency and robustness, as well as to model the behavior of complex systems in nature. For these reasons CAs and related architectures have
Artificial Chemistries  A Review
, 2000
"... This article reviews the growing body of scientific work in Artificial Chemistry. First, common motivations and fundamental concepts are introduced. Second, current research activities are discussed along three application dimensions: modelling, information processing and optimization. Finally, comm ..."
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Cited by 34 (4 self)
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This article reviews the growing body of scientific work in Artificial Chemistry. First, common motivations and fundamental concepts are introduced. Second, current research activities are discussed along three application dimensions: modelling, information processing and optimization. Finally, common phenomena among the different systems are summarized. It is argued here that Artificial Chemistries are "the right stuff" for the study of prebiotic and biochemical evolution, and they provide a productive framework for questions regarding the origin and evolution of organizations in general. Furthermore, Artificial Chemistries have a broad application range to practical problems as shown in this review.
Emergence of selfreplicating structures in a cellular automata space
 Physica D
, 1997
"... Past cellular automata models of selfreplication have always been initialized with an original copy of the structure that will replicate, and have been based on a transition function that only works for a single, specific structure. This article demonstrates for the first time that it is possible t ..."
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Cited by 30 (5 self)
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Past cellular automata models of selfreplication have always been initialized with an original copy of the structure that will replicate, and have been based on a transition function that only works for a single, specific structure. This article demonstrates for the first time that it is possible to create cellular automata models in which a selfreplicating structure emerges from an initial state having a random density and distribution of individual components. These emergent selfreplicating structures employ a fairly general rule set that can support the replication of structures of different sizes and their growth from smaller to larger ones. This rule set also allows "random " interactions of selfreplicating structures with each other and with other structures within the cellular automata space. Systematic simulations show that emergence and growth of replicants occurs often and is essentially independent of the cellular space size, initial random pattern of components, and initial density of components, over a broad range of these parameters. The number of replicants and the total number of components they incorporate generally approach quasistable values with time.
A New SelfReproducing Cellular Automaton Capable of Construction and Computation
 in ECAL95: Proceedings of the Third European Conference on Artificial
, 1995
"... We present a new selfreproducing cellular automaton capable of construction and computation beyond selfreproduction. Our automaton makes use of some of the concepts developed by Langton for his selfreproducing automaton, but provides the added advantage of being able to perform independent constr ..."
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Cited by 30 (7 self)
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We present a new selfreproducing cellular automaton capable of construction and computation beyond selfreproduction. Our automaton makes use of some of the concepts developed by Langton for his selfreproducing automaton, but provides the added advantage of being able to perform independent constructional and computational tasks alongside selfreproduction. Our automaton is capable, like Langton's automaton and with comparable complexity, of simple selfreplication, but it also provides (at the cost, naturally, of increased complexity) the option of attaching to the automaton an executable program which will be duplicated and executed in each of the copies of the automaton. After describing in some detail the selfreproduction mechanism of our automaton, we provide a nontrivial example of its constructional capabilities. 1 Introduction The history of selfreproducing cellular automata basically begins with John von Neumann's research in the field of complex selfreproducing machi...
An Implementation of von Neumann's SelfReproducing Machine
 Artificial Life
, 1996
"... This article describes in detail an implementation of John von Neumann's selfreproducing machine. Selfreproduction is achieved as a special case of construction by a universal constructor. The theoretical proof of the existence of such machines was given by John von Neumann in the early 1950s ..."
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Cited by 29 (0 self)
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This article describes in detail an implementation of John von Neumann's selfreproducing machine. Selfreproduction is achieved as a special case of construction by a universal constructor. The theoretical proof of the existence of such machines was given by John von Neumann in the early 1950s [6], but was first implemented in 1994, by the author in collaboration with R. Nobili. Our implementation relies on an extension of the statetransition rule of von Neumann's original cellular automaton. This extension was introduced to simplify the design of the constructor. The main operations in our constructor can be mapped into operations of von Neumann's machine. 1 Introduction Von Neumann [6] introduced constructive universality in cellular automata to study the implementability of selfreproducing machines and to extend the concept of computational universality, introduced by A. Turing [5]. A computing machine is said to be computationally universal if it is capable of simu...
A New Structurally Dissolvable SelfReproducing Loop Evolving in a Simple Cellular Automata Space
 Artificial Life
"... We constructed a simple evolutionary system, "evoloop," on a deterministic ninestate fiveneighbor cellular automata (CA) space by improving the structurally dissolvable selfreproducing loop we had previously contrived [14] after Langton's selfreproducing loop [7]. The principal role of this ..."
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Cited by 27 (9 self)
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We constructed a simple evolutionary system, "evoloop," on a deterministic ninestate fiveneighbor cellular automata (CA) space by improving the structurally dissolvable selfreproducing loop we had previously contrived [14] after Langton's selfreproducing loop [7]. The principal role of this improvement is to enhance the adaptability (a degree of the variety of situations in which structures in the CA space can operate regularly) of the selfreproductive mechanism of loops. The experiment with evoloop met with the intriguing result that, though no mechanism was explicitly provided to promote evolution, the loops varied through direct interaction of their phenotypes, smaller individuals were naturally selected thanks to their quicker selfreproductive ability, and the whole population gradually evolved toward the smallest ones. This result gives a unique example of evolution of selfreplicators where genotypical variation is caused by precedent phenotypical variation. Such interrelation of genotype and phenotype would be one of the important factors driving the evolutionary process of primitive life forms that might have actually occurred in ancient times.
An Evolutionary Autonomous Agents Approach to Image Feature Extraction
 IEEE Transactions on Evolutionary Computation
, 1997
"... This paper presents a new approach to image feature extraction which utilizes evolutionary autonomous agents. Image features are often mathematically defined in terms of the graylevel intensity at image pixels. The optimality of image feature extraction is to find all the feature pixels from the im ..."
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Cited by 27 (12 self)
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This paper presents a new approach to image feature extraction which utilizes evolutionary autonomous agents. Image features are often mathematically defined in terms of the graylevel intensity at image pixels. The optimality of image feature extraction is to find all the feature pixels from the image. In the proposed approach, the autonomous agents, being distributed computational entities, operate directly in the twodimensional lattice of a digital image, and exhibit a number of reactive behaviors. In order to effectively locate the feature pixels, individual agents sense the local stimuli from their image environment by means of evaluating the graylevel intensity of locally connected pixels, and accordingly activate their behaviors. The behavioral repository of the agents consists of: (1) featuremarking at local pixels and selfreproduction of offspring agents in the neighboring regions if the local stimuli are found to satisfy feature conditions, (2) diffusion to adjacent image ...
Coevolving NonUniform Cellular Automata to Perform Computations
, 1996
"... A major impediment of cellular automata (CA) stems from the difficulty of utilizing their complex behavior to perform useful computations. Recent studies by [ Packard, 1988, Mitchell et al., 1994b ] have shown that CAs can be evolved to perform a computational task. In this paper nonuniform CAs are ..."
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Cited by 25 (5 self)
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A major impediment of cellular automata (CA) stems from the difficulty of utilizing their complex behavior to perform useful computations. Recent studies by [ Packard, 1988, Mitchell et al., 1994b ] have shown that CAs can be evolved to perform a computational task. In this paper nonuniform CAs are studied, where each cell may contain a different rule, in contrast to the original, uniform model. We describe experiments in which nonuniform CAs are evolved to perform the computational task using a local, coevolutionary algorithm. For radius r = 3 we attain peak performance values of 0:92 comparable to those obtained for uniform CAs (0:93 \Gamma 0:95). This is notable considering the huge search spaces involved, much larger than the uniform case. Smaller radius CAs (previously unstudied in this context) attain performance values of 0:93 \Gamma 0:94. For r = 1 this is considerably higher than the maximal possible uniform CA performance of 0:83, suggesting that nonuniformity reduces con...