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Self-Inspection Based Reproduction in Cellular Automata.
Abstract
In this work we analyze different existing cellular automata capable of reproducing, and conclude that reproduction in those models is attained as a fixed point of the more general operation of construction, instead of being founded as a higher level specialized mechanism. Thus reproduction becomes a very unstable property and this fact is an obstacle in the aim of studying it together with other Alife characteristics, mainly because of destructive interactions. We propose a cellular reproduction model based on self-inspection as an attempt to overcome at least partially these drawbacks. We argue that our model attains a better founded an more robust reproduction scheme, and briefly explore the possibilities of using it to model the emergence of reproducing structures, to study the interplay between autonomy and reproduction, and to use it as a basis for evolutionary experimental scenarios.
... Using sensors and self-knowledge, the system investigates its own internal state [32] or compares the actual state with the intended one [38]. ...
... -Hinchey and Sterritt [50] intends to create selfware and write about self-situation/self-situatedness and selfdestruction. -Ibanez et al [38] refers to self-recognition. -Goldberg [37] explains self-deception. ...
This article reviews the existing work in self-healing and self-repairing technologies, including work in software engineering, materials, mechanics, electronics, MEMS, self-reconfigurable robotics, and others. It suggests a terminology and taxonomy for self-healing and self-repair, and discusses the various related types of other self-* properties. The mechanisms and methods leading to self-healing are reviewed, and common elements across disciplines are identified.
... After that, Langton' loop attracts much attention and various attempts have been done, such as deleting the external sheath (Tempesti, 1995) or the inner sheath (Byl, 1989), producing unsheathed loops with less states (Reggia et al., 1993), and considering self-replication on asynchronous cellular automata (Nehaniv, 2002). Likewise, Ibáñez et al. (1995) introduced the ability of self-inspection, which allows the genome to dynamically construct concomitantly with its interpretation. Making full of the self-inspection ability, Morita and Imai (1996b) proposed a shape-encoding mechanism that depends on genetic codes from the loops' phenotypical pattern to self-replication. ...
Numerous varieties of life forms have filled the earth throughout evolution. Evolution consists of two processes: self-replication and interaction with the physical environment and other living things around it. Initiated by von Neumann et al. studies on self-replication in cellular automata have attracted much attention, which aim to explore the logical mechanism underlying the replication of living things. In nature, competition is a common and spontaneous resource to drive self-replications, whereas most cellular-automaton-based models merely focus on some self-protection mechanisms that may deprive the rights of other artificial life (loops) to live. Especially, Huang et al. designed a self-adaptive, self-replicating model using a greedy selection mechanism, which can increase the ability of loops to survive through an occasionally abandoning part of their own structural information, for the sake of adapting to the restricted environment. Though this passive adaptation can improve diversity, it is always limited by the loop’s original structure and is unable to evolve or mutate new genes in a way that is consistent with the adaptive evolution of natural life. Furthermore, it is essential to implement more complex self-adaptive evolutionary mechanisms not at the cost of increasing the complexity of cellular automata. To this end, this article proposes new self-adaptive mechanisms, which can change the information of structural genes and actively adapt to the environment when the arm of a self-replicating loop encounters obstacles, thereby increasing the chance of replication. Meanwhile, our mechanisms can also actively add a proper orientation to the current construction arm for the sake of breaking through the deadlock situation. Our new mechanisms enable active self-adaptations in comparison with the passive mechanism in the work of Huang et al. which is achieved by including a few rules without increasing the number of cell states as compared to the latter. Experiments demonstrate that this active self-adaptability can bring more diversity than the previous mechanism, whereby it may facilitate the emergence of various levels in self-replicating structures.
... While less general than the universal constructor (obviously, the machine can only build an exact copy of itself), this approach is more versatile than Langton's loop, as structures of (almost) any size and shape can replicate. In practice, however, the best-known example of self-inspection is that of a self-replicating loop [14]. Also, while traditionally there has been a very loose connection between the kind of cellular automata used to study selfreplication and actual circuit design, some researchers have been trying to close this gap by studying automata that more closely approach some particular features of digital circuits. ...
This article presents the implementation of a self-replication algorithm in a Field Programmable Gate Array (FPGA). Whereas previous research on self-replication has been mostly limited to theoretical examples and small problem sizes, this work shows how the Tom Thumb self-replication algorithm can be extended to take into account realistic FPGA architectures and representative processor-scale digital logic circuits. To achieve this objective, the algorithm was implemented within the POEtic tissue, a programmable logic device for bio-inspired systems, and a dedicated processor, based on the MOVE paradigm, was developed. Starting from a single processor, the self-replication process can be used to generate an arbitrarily large array of identical processors that then differentiate to realize a given application. In this article, this process is demon-strated through a four-processor system that implements a simple counter. The ultimate goal of this research is to demonstrate how a bio-inspired approach can exploit self-replication to tackle the complexity and high fault rates of next-generation electronic devices.
... In our approach, we will redefine the molecules of the Embryonics project in a form similar to the cells of the Cell Matrix circuit (a LUT and two types of input/output connections) in order to realize a cellular division mechanism based on self-inspection [2] in Embryonics systems. Moreover, we will present the design of a finite state machine (FSM), which is placed in each molecule: during the configuration phase, this FSM will control the hardware configuration and the communication protocol of the molecule. ...
This article describes a novel approach to the implementation on an electronic substrate of a process analogous to the cellular
division of biological organisms. Cellular division is one of the two processes that allow the multicellular organization
of complex living beings, and is therefore a key mechanism for the implementation of bio-inspired features such as development
(growth) and self-repair (cicatrization). In particular, we shall describe the architecture and operation of a new kind of
programmable logic device capable of realizing, in silicon, a cellular division process.
... Following von Neumann's work of the late 1940s and early 1950s, research on CA-based self-replicators split into a number of major trends. Among these, the majority are efforts to implement regulated behavior (universal construc- tion[8, 9, 20, 38, 40], self-replication[5, 12, 14, 18, 22, 34], self-inspection[11] , func- tionality[7, 19, 37] ) manually introduced to satisfy pre-defined goals of the designer . Such goal-oriented design is important for resolving theoretical problems (bounds and limitations on self-replicating structures) and for direct application (computation, problem-solving, nanotechnology), yet does little to address the fundamental issue that shaped von Neumann's original theory. ...
This paper reviews the history of embedded, evolvable self- replicating structures implemented as cellular automata systems. We relate recent advances in this field to the concept of the evolutionary growth of complexity, a term introduced by McMullin to describe the central idea contained in von Neumann's self-reproducing automata the- ory. We show that conditions for such growth are in principle satisfied by universal constructors, yet that in practice much simpler replicators may satisfy scaled-down — yet equally relevant — versions thereof. Examples of such evolvable self-replicators are described and discussed, and future challenges identified.
... [4] ...
This volume contains the papers sent to the workshop Tilings and cellular automata to be held in Auckland as a satellite workshop of DLT’04.
... The self-replication process that we have implemented as a first test is based on the self-inspection concept [Ibañez et al. 1995] where, in order to replicate itself, a system has to generate its description by examining its own structure. This description is then used to create an identical copy of the original system [Laing 1977]. ...
The multicellular structure of biological organisms and the interpretation in each of their cells of a chemical program (the DNA string or genome) is the source of inspiration for the Embryonics (embryonic electronics) project, whose final objective is the design of highly robust integrated circuits, endowed with properties usually associated with the living world: self-repair and self-replication. In this article, we provide an overview of our latest research in the domain of the self-replication of processing elements within a programmable logic substrate, a key prerequisite for achieving system-level fault tolerance in our bio-inspired approach.
... The self-replication process that we have implemented is based on the selfinspection concept [17], where, in order to replicate itself, a system has to generate its description by examining its own structure. This description is then used to create an identical copy of the original system [18]. ...
This article describes an implementation of a basic multiprocessor system that exhibits replication and differentiation abilities on the POEtic tissue, a programmable hardware designed for bio-inspired applications. As for a living organism, whose existence starts with only one cell that first divides, our system begins with only one totipotent processor, able to implement any of the cells required by the final organism, which can also fully replicate itself, using the functionalities of the POEtic substrate. Then, analogously to the cells in a developing organism, our just replicated totipotent processors differentiate in order to execute their specific part of the complete organism functionality. In particular, we will present a working realization using MOVE processors whose instructions define the flow of data rather than the operations to be executed. It starts with one basic MOVE processor that first replicates itself three times; the four resulting processors then differentiate and connect together to implement a multi-processor modulus-60 counter.
... As explained before, and unlike the standard Tom Thumb Algorithm, our TTA-UC system does not possess a running genome that keeps unchanged the initial configuration of the organism. In fact, our replication system works by selfinspection [6]: the organism generates the bits configuration that permits to copy its current state (and not the initial one). ...
This article describes the addition to the von Neumann cellular automaton of the Tom Thumb Algorithm, a mechanism developed for the self-replication of multi-processor systems. Except for the cell construction process, every functionality of the original CA has been preserved in our new system. Moreover, the Tom Thumb Algorithm now allows the replication of any structure within the von Neumann environment, whatever its number of cells may be.
... However, if the machine can encode its shape into a description by checking its body dynamically, there is no need to keep the entire description. In fact, there proposed a few models that performs self-reproduction in such a manner 9,11,20,21]. Ib añes et al. 9] showed a 16-state model in which sheathed loops can reproduce by using a self-inspection method. ...
A reversible cellular automaton (RCA) is a "backward deterministic " CA in which every configuration of the cellular space has at most one predecessor. Such reversible systems have a close connection to physical reversibility, and have been known to play an important role in the problem of inevitable power dissipation in computing systems. In this paper, we investigate problems of logical universality and selfreproducing ability in two-dimensional reversible cellular spaces. These problems will become much more important when one tries to construct nano-scaled functional objects based on microscopic physical law. Here, we first discuss how logical universality can be obtained under the reversibility constraint, and show our previous models of 16-state universal reversible CA. Next we explain how self-reproduction is possible in a reversible CA. 1
An implementation of Self-Reproducing Loops (SRL) on Asynchronous Cellular Automata (ACA) is proposed in this paper. The transition rules in this ACA are called Aggregate Neighborhood Rules, in which the output domain of the rules are the same as input. In the proposed SRL, the head of the loop can move backward and forward because of asynchronous nature in ACA, thus making it possible to avoid collisions of loop heads.
Definition of the SubjectMachine self-replication, besides inspiring numerous fictional books and movies, has long been considered a powerful paradigm to allow artifacts, for example, to survive in hostile environments (such as other planets) or to operate more efficiently by creating populations of machines working together to achieve a given task. Where the self-replication of computing machines is concerned, other motivations can also come into play, related to concepts such as fault tolerance and self-organization.Cellular automata have traditionally been the framework of choice for the study of self-replicating computing machines, ever since they were used by John von Neumann, who pioneered the field in the 1950s. In this context, self-replication is seen as the process whereby a configuration in the cellular space is capable of creating a copy of itself in a di ...
This paper proposes self-reproducing loops (SRLs) implemented on a self-timed cellular automaton (STCA), a type of asynchronous cellular automaton (ACA). Self-reproduction of a wide variety of shapes of SRLs is made possible by employing the so-called shape-encoding mechanism, which self-inspects a loop and generates construction signals accordingly. Due to the model’s asynchronous mode of timing, a dynamic interplay between SRLs occurs, in which SRLs compete for space to place their offspring. Deadlock situations caused by the collisions are reliably arbitrated utilizing only local interactions of SRLs.
This article presents a survey of some of the main research on the development of self-replicating loops. The defining feature of these cellular automata is their ability to create identical copies of themselves by constantly executing a set of instructions dynamically stored within their structure. Interest in these structures has grown in recent years as a possible solution to tackle some of the issues relative to the introduction of next-generation molecular-scale electronics.
Of interest to the theory of machines that construct is ontogeny, by which process of development the constructor is transformed from immature to mature form. Whereas we have already shown that self-replicating machines generally are able to bootstrap themselves through the construction of sub-machines (such as organs that rewind a tape, or replicate a tape, or initiate the behavior of a construct), in this paper we present in abstract a constructor that bootstraps its ability to construct, through the construction of sub-constructors. This is to say, we present a constructor that learns how to construct, and does so by constructing; our constructor is in truth a proto-constructor. Here, learning occurs by the addition of new machine configuration; each learned lesson is correlated with specific additions to machine configuration.
We have designed self-reproducing cellular automata based on two- and three-dimensional self-inspection, and emphasized the importance of simulating the intercellular transitions during the design phase. In particular, to understand the behavior in three dimensions, viewing the video image is essential. In this paper, we present videos generated by a simulation tool we built and demonstrate the operation according to the designs of previously designed self-reproducing cellular automata. © 2003 Wiley Periodicals, Inc. Electron Comm Jpn Pt 3, 87(3): 58–66, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjc.10083
In this paper, we investigate and discuss the problem of how the abilities of computing and self-reproduction can be realized
in a “reversible” environment, especially in reversible cellular automata (RCA). An RCA is a “backward deterministic” CA in
which every configuration of the cellular space has at most one predecessor. Such systems have a close connection to physical
reversibility, and have been known to play an important role in the problem of inevitable power dissipation in computing systems.
This problem will become much more important when one tries to construct nano-scaled functional objects based on microscopic
physical law. We first discuss how computation-universality can be obtained under the reversibility constraint, and show our
models of one- and two-dimensional universal RCAs. Next, we explain a self-reproducing model on a two-dimensional RCA and
its mechanism. Our new attempt to create a three-dimensional self-reproducing RCA is also stated.
Since von Neumann's seminal work around 1950, computer scientists and others have studied the algorithms needed to support self-replicating systems. Much of this work has focused on abstract logical machines (automata) embedded in two-dimensional cellular spaces. This research has been motivated by the desire to understand the basic information-processing principles underlying self-replica-tion, the potential long term applications of programmable self-replicating machines, and the possibility of gaining insight into biological replication and the origins of life. Here we briefly summarize the historical development of work on artificial self-replicating structures in cellular spaces, and then describe some recent advances in this area. Past research is viewed as taking three main directions: early complex universal computer-constructors modeled after Turing machines, qualitatively simpler self-replicating loops, and efforts to view self- replication as an emergent phenomenon. We discuss our own recent studies showing that self-replicating structures can emerge from non-replicating compo-nents and that genetic algorithms can be applied to automatically program simple but arbitrary structures to replicate. We also describe recent work in which self-replicating structures are successfully programmed to do useful problem solving as they replicate. We conclude by identifying some implications and important research directions for the future.
Self-reproducing, cellular automata-based systems developed to date broadly fall under two categories; the first consists of machines which are capable of performing elaborate tasks, yet are too complex to simulate, while the second consists of extremely simple machines which can be entirely implemented, yet lack any additional functionality aside from self-reproduction. In this paper we present a self-reproducing system which is completely realizable, while capable of executing any desired program, thereby exhibiting universal computation. Our starting point is a simple self-reproducing loop structure onto which we “attach” an executable program (Turing machine) along with its data. The three parts of our system (loop, program, data) are all reproduced, after which the program is run on the given data. The system reported in this paper has been simulated in its entirety; thus, we attain a viable, self-reproducing machine with programmable capabilities.
After a survey of some typical realizations of self-replicating machines, this paper presents the self-replication based on
construction and the self-replication based on inspection of an interactive loop, chosen as an easily understandable example.
The construction-based replication process is achieved by translation and transcription of the configuration information of
the loop in the processing unit of a data and signals cellular automaton (DSCA). The inspection-based replication process
is realized by duplication and translation of the same configuration information in the processing unit of the DSCA.
An experimental method is developed to evaluate the possibility of spontaneous emergence of self-reproducing patterns from
a quasi-random configuration. In order to achieve viability to the emerging patterns and to their components a robust transition
table is designed. Genetic reproduction is compared with self-inspection based reproduction in order to conclude that the
latter is better adapted to achieve the specified goal.
After a survey of some realizations of self-replicating machines, this paper presents the construction based self-replication
of 3D structures. This self-replication process is achieved by translation and transcription of a configuration information
in a three-dimensional data and signals cellular automaton (DSCA). The specifications and the design of the basic three-dimensional
cell of the automaton results in a new and straightforward methodology for the self-replication of 3D computing machines of
any dimensions.
This paper is devoted to the study of systems of entities that are capable of generating other entities of the same kind and, possibly, self-reproducing. The main technical issue addressed is to quantify the requirements that such entities must meet to be able to produce a progeny that is not degenerative, i.e., that has the same reproductive capability as the progenitor. A novel theory that allows an explicit quantification of these requirements is presented. The notion of generation rank of an entity is introduced, and it is proved that the generation process, in most cases, is degenerative in that it strictly and irreversibly decreases the generation rank from parent to descendent. It is also proved that there exists a threshold of rank such that this degeneracy can be avoided if and only if the entity has a generation rank that meets that threshold – this is the von Neumann rank threshold. On the basis of this threshold, an information threshold is derived, which quantifies the minimum amount of information that must be provided to specify an entity such that its descendents are not degenerative. Furthermore, a complexity threshold is obtained, which quantifies the minimum length of the description of that entity in a given language. As an application, self-assembly for a 2 Degrees of Freedom planar robot is considered, and simulation results are presented. A robot arm capable of picking up and placing the components of another arm, in the presence of errors, is considered to have successfully reproduced if these are placed within an allowable tolerance. The example shows that, due to the kinematics of the robot, errors can grow from one generation to the next, until the reproduction process fails eventually. However, error correction (via error sensing and feedback control) can then be used to prevent such degeneracy. The von Neumann generation rank and information thresholds are computed for this example, and are consistent with the simulation results in predicting degeneracy in the case without error correction, and predicting successful self-reproduction in the case with error correction.
The study of self-replicating structures or machines has been taking place now for almost half a century. My goal in this article is to present an overview of research carried out in the domain of self-replication over the past 50 years, starting from von Neumann's work in the late 1940s and continuing to the most recent research efforts. I shall concentrate on computational models, that is, ones that have been studied from a computer science point of view, be it theoretical or experimental. The systems are divided into four major classes, according to the model on which they are based: cellular automata, computer programs, strings (or strands), or an altogether different approach. With the advent of new materials, such as synthetic molecules and nanomachines, it is quite possible that we shall see this somewhat theoretical domain of study producing practical, real-world applications.
We propose a self-replicating machine that is embedded in a two-dimensional asynchronous cellular automaton with von Neumann neighborhood. The machine dynamically encodes its shape into description signals, and despite the randomness of cell updating, it is able to successfully construct copies of itself according to the description signals. Self-replication on asynchronously updated cellular automata may find application in nanocomputers, where reconfigurability is an essential property, since it allows avoidance of defective parts and simplifies programming of such computers.
. Von Neumann's architecture for self-reproducing, evolvable machines is described. From this starting point, a number of issues relating to self-reproduction and evolution are discussed. A summary is given of various arguments which have been put forward regarding the superiority of genetic reproduction over self-inspection methods. It is argued that programs in artificial life platforms such as Tierra reproduce genetically rather than by self-inspection (as has previously been claimed). However, the distinction is blurred because significant parts of the reproduction process in Tierran programs are implicitly encoded in the Tierran operating system. The desirable features of a structure suitable for acting as a seed for an open-ended evolutionary process are discussed. It is found that the properties of such a structure are somewhat different to those of programs in Tierra-like platforms. These analyses suggest ways in which the evolvability of individuals in artificial ...
Complexity is defined in the context of biological systems which contain their own genetic descriptions. This definition is justified on the grounds that without self-description complex organizations tend to deteriorate in function and do not evolve when challenged by environmental interactions. This leads to the problem of what constitutes a description in terms of physical structures, and what are the simplest conditions for writing, reading and executing descriptions. To explain the relation of systems and descriptions of systems, we introduce the distinction between dynamic, or continuous, rate-dependent events and linguistic, or discrete, rate-independent events. The stability and evolutionary potential of self-describing, complex systems depend on the complementary relation between these two modes, and this relation is inextricably dependent on the epistemological problem of measurement,
Biological experience and intuition suggest that self-replication is an inherently complex phenomenon, and early cellular automata models support that conception. More recently, simpler computational models of self-directed replication called sheathed loops have been developed. It is shown here that "unsheathing" these structures and altering certain assumptions about the symmetry of their components leads to a family of nontrivial self-replicating structures, some substantially smaller and simpler than those previously reported. The dependence of replication time and transition function complexity on initial structure size, cell state symmetry, and neighborhood are examined. These results support the view that self-replication is not an inherently complex phenomenon but rather an emergent property arising from local interactions in systems that can be much simpler than is generally believed.
Self-reproduction in cellular automata is discussed with reference to Langton's criteria as to what constitutes genuine self-reproduction. It is found that it is possible to construct self-reproducing structures that are substantially less complex than that presented by Langton.
Using the simple observation that programs are identical to data, programs alter data, and thus programs alter programs, the authors have constructed a self-programming system based on a parallel von Neumann architecture. This system has the same fundamental property as living systems have: the ability to evolve new properties. They demonstrate how this constructive dynamical system is able to develop complex cooperative structures with adaptive responses to external perturbations. The experiments with this system are discussed with special emphasis on the relation between information theoretical measures (entropy and mutual information functions) and on the emergence of complex functional properties. Decay and scaling of long-range correlations are studied by calculation of mutual information functions. 10 refs., 9 figs., 2 tabs.
The von Neumann cellular automaton model is described and designs within this model are presented for objects that behave like tape and constructing units. An algorithm is developed for embedding in the cellular structure any automat on which effectively manipulates the tape and constructing units. The algorithm is based on a very simple language in which the behavior of such machines can be described. Finally, universality of construction and computation as well as automaton self-reproduction are disdussed relative to the von Neumann model. (Author)
Following the fixpoint theory of Scott, the semantics of computer programs are defined in terms of the least fixpoints of recursive programs. This allows not only the justification of all existing verification techniques, but also their extension to the handling, in a uniform manner of various properties of computer programs, including correctness, termination, and equivalence.
Central concerns of the book are related theories of recursively enumerable sets, of degree of un-solvability and turing degrees in particular. A second group of topics has to do with generalizations of recursion theory. The third topics group mentioned is subrecursive computability and subrecursive hierarchies
There is a strategy by which an automaton can examine itself to obtain a complete description of its own constituent structure. This strategy is here employed to show that machine self-reproduction by means of self-inspection is possible. Since the parent automaton structure serves as the sole model for the structure of offspring, the result shows that there is a logically consistent strategy of self-reproduction in which any acquired structural characteristics of parent could perforce be transmitted to the offspring. Peer Reviewed http://deepblue.lib.umich.edu/bitstream/2027.42/22905/1/0000469.pdf
Artificial Darwinism: the very idea! In Autopoiesis and Perception, Technical Report bmcm9401 of the School of Electronic Engineering at the Ollscoil Chathair
- B Mcmullin