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Evomorph: Morphological Modularization in A.I. for Machine Vision Inspired by Embryology
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It is suggested that a system of chemical substances, called morphogens, reacting together and diffusing through a tissue, is adequate to account for the main phenomena of morphogenesis. Such a system, although it may originally be quite homogeneous, may later develop a pattern or structure due to an instability of the homogeneous equilibrium, which is triggered off by random disturbances. Such reaction-diffusion systems are considered in some detail in the case of an isolated ring of cells, a mathematically convenient, though biologically unusual system. The investigation is chiefly concerned with the onset of instability. It is found that there are six essentially different forms which this may take. In the most interesting form stationary waves appear on the ring. It is suggested that this might account, for instance, for the tentacle patterns on Hydra and for whorled leaves. A system of reactions and diffusion on a sphere is also considered. Such a system appears to account for gastrulation. Another reaction system in two dimensions gives rise to patterns reminiscent of dappling. It is also suggested that stationary waves in two dimensions could account for the phenomena of phyllotaxis. The purpose of this paper is to discuss a possible mechanism by which the genes of a zygote may determine the anatomical structure of the resulting organism. The theory does not make any new hypotheses; it merely suggests that certain well-known physical laws are sufficient to account for many of the facts. The full understanding of the paper requires a good knowledge of mathematics, some biology, and some elementary chemistry. Since readers cannot be expected to be experts in all of these subjects, a number of elementary facts are explained, which can be found in text-books, but whose omission would make the paper difficult reading.
A Genetic Programming (GP) method uses multiple runs, data decomposition stages, to evolve a hierarchical set of vehicle detectors for the automated inspection of infrared line scan imagery that has been obtained by a low flying aircraft. The performance on the scheme using two different sets of GP terminals (all are rotationally invariant statistics of pixel data) is compared on 10 images. The discrete Fourier transform set is found to be marginally superior to the simpler statistics set that includes an edge detector. An analysis of detector formulae provides insight on vehicle detection principles. In addition, a promising family of algorithms that take advantage of the GP method’s ability to prescribe an advantageous solution architecture is developed as a post-processor. These algorithms selectively reduce false alarms by exploring context, and determine the amount of contextual information that is required for this task.
The automatic detection of ships in low-resolution synthetic aperture radar (SAR) imagery is investigated in this article. The detector design objectives are to maximise detection accuracy across multiple images, to minimise the computational effort during image processing, and to minimise the effort during the design stage. The results of an extensive numerical study show that a novel approach, using genetic programming (GP), successfully evolves detectors which satisfy the earlier objectives. Each detector represents an algebraic formula and thus the principles of detection can be discovered and reused. This is a major advantage over artificial intelligence techniques which use more complicated representations, e.g. neural networks.
In tree-based genetic programming (GP), the most frequent subtrees on later generations are likely to constitute useful partial
solutions. This paper investigates the effect of encapsulating such subtrees by representing them as atoms in the terminal
set, so that the subtree evaluations can be exploited as terminal data. The encapsulation scheme is compared against a second
scheme which depends on random subtree selection. Empirical results show that both schemes improve upon standard GP.
The paper addresses an important and difficult problem of object recognition in poorly constrained environments and with objects
having large variability. This research uses genetic programming (GP) to develop automatic object detectors. The task is to
detect vehicles in infrared line scan (IRLS) images gathered by low flying aircraft. This is a difficult task due to the diversity
of vehicles and the environments in which they can occur, and because images vary with numerous factors including fly-over,
temporal and weather characteristics. A novel multi-stage approach is presented which addresses automatic feature detection,
automatic object segregation, rotation invariance and generalisation across diverse objects whilst discriminating from a myriad
of potential non-objects. The approach does not require imagery to be pre-processed.
Most current models for morphogenesis of repeated patterns, such as vertebrate somites, cannot explain the observed degree of constancy for the number of somites in individuals of a given species. This precision requires a mechanism whereby the lengths of someites (i.e. number of cells per somite) must adjust to the overall size of individual embryos, and one which co-ordinates numbers of somites with position in the whole pattern of body parts.
A qualitative model is presented that does admit the observed precision. It is also compatible with experimental observations such as the sequential formation of somites from anterior to posterior in a regular time sequence, the timing of cellular change during development generally, and the increasing evidence for widespread existence of cellular biorhythms. The model involves an interacting “clock” and “wavefront”. The clock is is asmooth cellular oscillator, for which cells throughout the embryo are assumed to be phase-linked. The wavefront is a front of rapid cell change moving slowly down the long axis of the embryo; cells enter a phase of rapid alteration in locomotory and/or adhesive properties at successively later times according to anterior-posterior body position. In the model, the smooth intracellular oscillator itself interacts with the possibility of the rapid primary change or its transmission within cells, thereby gating rhythmically the slow progress of the wavefront. Cells thus enter their rapid change of properties in a succession of separate populations, creating the pattern.
It is argued that the elements, a smooth oscillator, a slow wavefront and a rapid cellular change, have biological plausibility. The consequences of combining them were suggested by catastrophe theory. We stress the necessary relation between the present model and the more general concept of positional information (Wolpert, 1969, 1971). Prospective and ongoing experiments stimulated by the model are discussed, and emphasis is placed on how such conceptions of morphogenesis can help reval homology between organisms having developments that are very different to a surface inspection.
It is suggested that a system of chemical substances, called morphogens, reacting together and diffusing through a tissue,
is adequate to account for the main phenomena of morphogenesis. Such a system, although it may originally be quite homogeneous,
may later develop a pattern or structure due to an instability of the homogeneous equilibrium, which is triggered off by random
disturbances. Such reaction-diffusion systems are considered in some detail in the case of an isolated ring of cells, a mathematically
convenient, though biologically unusual system. The investigation is chiefly concerned with the onset of instability. It is
found that there are six essentially different forms which this may take. In the most interesting form stationary waves appear
on the ring. It is suggested that this might account, for instance, for the tentacle patterns onHydra and for whorled leaves. A system of reactions and diffusion on a sphere is also considered. Such a system appears to account
for gastrulation. Another reaction system in two dimensions gives rise to patterns reminiscent of dappling. It is also suggested
that stationary waves in two dimensions could account for the phenomena of phyllotaxis.
The purpose of this paper is to discuss a possible mechanism by which the genes of a zygote may determine the anatomical structure
of the resulting organism. The theory does not make any new hypotheses; it merely suggests that certain well-known physical
laws are sufficient to account for many of the facts. The full understanding of the paper requires a good knowledge of mathematics,
some biology, and some elementary chemistry. Since readers cannot be expected to be experts in all of these subjects, a number
of elementary facts are explained, which can be found in text-books, but whose omission would make the paper difficult reading.
Evolution of Vehicle Detectors for Infrared Linescan Imagery
- S C Roberts
- D Howard
- Riccardo Poli
- Hans-Michael Voigt
- Stefano Cagnoni
- Dave Come
- George D Smith
- Terence C Fogarty
Private Communiations
- trosko
Innovating with Automatic Programming
- howard
Subtree encapsulation versus ADFs in GP for parity problems
- S C Roberts
- D Howard
- J R Koza
- Lee Spector
- Erik D Goodman
- Annie Wu
- W B Langdon
- Hans-Michael Voigt
- Mitsuo Gen
- Sandip Sen
- Marco Dorigo
- Shahram Pezeshk
- Max H Garzon
- Edmund Burke
Subtree encapsulation versus ADFs in GP for parity problems
- S C Roberts
- D Howard
- J R Koza
Subtree encapsulation versus ADFs in GP for parity problems
- roberts