Artificial Chemistry and Replicator Theory of Coevolution of Genes and Memes

2007 ◽  
Vol 72 (2) ◽  
pp. 223-251 ◽  
Author(s):  
Vladimír Kvasnička ◽  
Jiří Pospíchal
Keyword(s):  
Computer Simulations ◽  
Present Model ◽  
Gene Interaction ◽  
Darwinian Evolution ◽  
M Gene ◽  
Artificial Chemistry ◽  
Different Types

A simple replication theory of coevolution of genes and memes is proposed. A population composed of pairs of genes and memes, the so-called m-genes, is postulated as a subject of Darwinian evolution. Three different types of operations over m-genes are introduced: Replication (an m-gene is replicated with mutations onto an offspring m-gene), interaction (a memetic transfer from a donor to an acceptor), and extinction (an m-gene is eliminated). Computer simulations of the present model allow to identify different mechanisms of gene and meme coevolution.

Theory of Cooperative Coevolution of Genes and Memes

2011 ◽  
pp. 33-45
Author(s):  
Vladimir Kvasnicka ◽  
Jiri Pospichal
Keyword(s):  
Computer Simulations ◽  
Present Model ◽  
Gene Interaction ◽  
Darwinian Evolution ◽  
M Gene ◽  
Cooperative Coevolution ◽  
Different Types

This chapter proposes a simple replicator theory of the coevolution of genes and memes. The presented coevolutionary theory assumes that units of information acquired from parents by imitation (memes) are not independent of genes, but are obligatorily bounded with genes as composites, which are subjects of Darwinian evolution. A population composed of couples of genes and memes, the so-called m-genes, is postulated as a subject of Darwinian evolution. Three different types of operations over m-genes are introduced: replication (an m-gene is replicated with mutations onto an offspring m-gene), interaction (a memetic transfer from a donor to an acceptor), and extinction (an m-gene is eliminated). Computer simulations of the present model allow us to identify different mechanisms of gene and meme coevolutions.

Artificial Chemistry and Molecular Darwinian Evolution in silico

2003 ◽  
Vol 68 (1) ◽  
pp. 139-177 ◽  
Author(s):  
Vladimír Kvasnička ◽  
Jiří Pospíchal
Keyword(s):  
Graph Theory ◽  
Molecular Level ◽  
Stable State ◽  
Chemical Reactor ◽  
Darwinian Evolution ◽  
Simplified Model ◽  
Asymptotically Stable ◽  
Artificial Chemistry ◽  
Neutral Mutations ◽  
Binary Strings

A simplified model of Darwinian evolution at the molecular level is studied by applying the methods of artificial chemistry. A chemical reactor (chemostat) contains molecules that are represented by binary strings, the strings being capable of replication with a probability proportional to their fitness. Moreover, the process of replication is not fully precise, sporadic mutations may produce new offspring strings, which are slightly different from their parent templates. The dynamics of such an autoreplicating system is described by Eigen's differential equations. These equations have a unique asymptotically stable state, which corresponds to those strings that have the highest rate constants (fitness). Fitness of binary string is calculated as a graph-theory similarity between a folding (phenotype) of respective string and the so-called required folding. The presented method offers a detailed view of mechanisms of the molecular Darwinian evolution, in particular of the meaning and importance of neutral mutations.

Investigation of the tyre characteristics under non-steady-state conditions on the basis of road tests

2016 ◽  
Vol 231 (1) ◽  
pp. 3-15 ◽  
Author(s):  
Hubert Sar ◽  
Andrzej Reński ◽  
Janusz Pokorski
Keyword(s):  
Steady State ◽  
Computer Simulations ◽  
Dynamic Characteristics ◽  
Slip Angle ◽  
Real Motion ◽  
Side Force ◽  
The Real ◽  
Different Types ◽  
Non Linear ◽  
The Difference

This paper presents a method of identifying the dynamic characteristics of tyres for non-steady-state conditions on the basis of road measurements on a vehicle. The side force acting on the tyre is presented as a function of not only the slip angle but also the slip angle derivative (i.e. the velocity of the change in the slip angle). Hence, the influence of the manoeuvre dynamics on the tyre characteristics and the difference between the characteristics obtained for steady-state conditions and the characteristics for non-steady-state conditions are shown. Also the results of computer simulations prepared for different types of tyre characteristics are presented in this paper. It is evident from the presented graphs that applying dynamic non-linear tyre characteristics for computer simulations instead of steady-state characteristics enables us to describe the real motion of a vehicle better.

scholarly journals Steady streaming of a viscoelastic fluid within a periodically rotating sphere

2014 ◽  
Vol 761 ◽  
pp. 329-347 ◽  
Author(s):  
Rodolfo Repetto ◽  
Jennifer H. Siggers ◽  
Julia Meskauskas
Keyword(s):  
Viscoelastic Fluid ◽  
Present Model ◽  
Transport Processes ◽  
Rigid Sphere ◽  
Steady Streaming ◽  
Circulation Cell ◽  
Different Types ◽  
Parameter Values ◽  
Streaming Flow ◽  
Axis Passing

AbstractMotivated by understanding mass transport processes occurring in the vitreous chamber of the eye, we consider the steady streaming component of the flow generated in a viscoelastic fluid contained within a hollow, rigid sphere performing small-amplitude, periodic, torsional oscillations about an axis passing through its centre. The problem is solved semi-analytically, assuming that the amplitude of the oscillations is small. The paper extends the work by Repetto et al. (J. Fluid Mech., vol. 608, 2008, pp. 71–80), in which the case of a purely viscous fluid was analysed. However, in reality, in young and healthy subjects, the vitreous humour has complex rheological properties, and so here we model it as a viscoelastic fluid. A similar problem was studied by Nikolakis (Eine Theorie für stationäre Drifterscheinungen viskoelastischer Flüssigkeiten, 1992, VDI). In the present model, the steady streaming flow is governed by four dimensionless parameters. We show that, when we account for the viscoelasticity of the fluid, there is a considerably more complex set of possible flow regimes than was found in the purely viscous case, and the flows can be classified into five qualitatively different types. Whereas there was only one circulation cell in each hemisphere in the viscous case, accounting for viscoelasticity it is possible have either one, two or three circulation cells, with different senses of rotation, depending on the parameter values.

ON THE CORRELATION BETWEEN FRACTAL DIMENSION AND ROBUSTNESS OF COMPLEX NETWORKS

Fractals ◽  
2019 ◽  
Vol 27 (04) ◽  
pp. 1950067 ◽  
Author(s):  
YIPENG WU ◽  
ZHILONG CHEN ◽  
KUI YAO ◽  
XUDONG ZHAO ◽  
YICUN CHEN
Keyword(s):  
Fractal Dimension ◽  
Complex Networks ◽  
Urban Infrastructure ◽  
Gene Interaction ◽  
Strongly Correlated ◽  
Gene Interaction Networks ◽  
Important Index ◽  
Filling Ability ◽  
Different Types ◽  
The Relationship

In recent years, because complex networks can be used to model real-world complex systems, such as the Internet, urban infrastructure networks, and gene interaction networks, such research has been widely applied in engineering, social sciences, and life sciences and has caused widespread concern. Fractal dimension, as a concept concerning the filling ability and complexity of an object space, has great significance for the study of the robustness of complex networks. This paper studies the relationship between fractal dimension and the robustness of different types of complex networks from the perspective of network structure and network scale. We find that fractal dimension is strongly correlated with robustness under certain conditions and can be used as an important index to evaluate the robustness of complex networks.

scholarly journals Automatic Identification of Communication Signals Using Zero-Crossing Based Techniques

2019 ◽  
Vol 3 (2) ◽  
pp. 25-30
Author(s):  
Emanuel S. H. Qas Marrogy
Keyword(s):  
Computer Simulations ◽  
Automatic Identification ◽  
Zero Crossing ◽  
Communication Signals ◽  
Communication Signal ◽  
Different Types ◽  
Modulation Type ◽  
New Algorithms

The identification of different types of modulation for any intercepted communication signal out of the vast hierarchy of possible modulation types is a key fundamental before advising a suitable type of demodulator, where this process is usually a manual option. This technique is extremely important for the purposes of communication intelligence. In this paper, a proposed methodology is suggested, validated, and tested (through computer simulations) for the automatic identification of the modulation type (analog and digital) of the intercepted communication signals. The methodology is based on the zero-based representation of signals and utilization of new algorithms for such identification.

Optical stimulator for vision-based sensors

2014 ◽  
Vol 3 (2) ◽  
Author(s):  
Dirk Roessler ◽  
David A.K. Pedersen ◽  
Mathias Benn ◽  
John L. Jørgensen
Keyword(s):  
Computer Simulations ◽  
High Precision ◽  
Test Bench ◽  
Efficient Tool ◽  
Ground Testing ◽  
Planetary Rovers ◽  
Long Term Stability ◽  
Camera Systems ◽  
Different Types

AbstractWe have developed an optical stimulator system for vision-based sensors. The stimulator is an efficient tool for stimulating a camera during on-ground testing with scenes representative of spacecraft flights. Such scenes include starry sky, planetary objects, and other spacecraft. The optical stimulator is used as a test bench to simulate high-precision navigation by different types of camera systems that are used onboard spacecraft, planetary rovers, and for spacecraft rendezvous and proximity maneuvers. Careful hardware design and preoperational calibration of the stimulator result in high precision and long-term stability. The system can be continuously used over several days. By facilitating a full camera including optics in the loop, the stimulator enables the more realistic simulation of flight maneuvers based on navigation cameras than pure computer simulations or camera stimulations without the involvement of the actual optics.

scholarly journals Molecular Characterization of tet(M) Genes in Lactobacillus Isolates from Different Types of Fermented Dry Sausage

2003 ◽  
Vol 69 (2) ◽  
pp. 1270-1275 ◽  
Author(s):  
Dirk Gevers ◽  
Morten Danielsen ◽  
Geert Huys ◽  
Jean Swings
Keyword(s):  
Lactic Acid ◽  
Tetracycline Resistance ◽  
Molecular Study ◽  
Enzyme Analysis ◽  
Resistant Bacteria ◽  
Restriction Enzyme Analysis ◽  
Bacterial Isolates ◽  
M Gene ◽  
Different Types ◽  
Dry Sausage

ABSTRACT The likelihood that products prepared from raw meat and milk may act as vehicles for antibiotic-resistant bacteria is currently of great concern in food safety issues. In this study, a collection of 94 tetracycline-resistant (Tcr) lactic acid bacteria recovered from nine different fermented dry sausage types were subjected to a polyphasic molecular study with the aim of characterizing the host organisms and the tet genes, conferring tetracycline resistance, that they carry. With the (GTG)5-PCR DNA fingerprinting technique, the Tcr lactic acid bacterial isolates were identified as Lactobacillus plantarum, L. sakei subsp. carnosus, L. sakei subsp. sakei, L. curvatus, and L. alimentarius and typed to the intraspecies level. For a selection of 24 Tcr lactic acid bacterial isolates displaying unique (GTG)5-PCR fingerprints, tet genes were determined by means of PCR, and only tet(M) was detected. Restriction enzyme analysis with AccI and ScaI revealed two different tet(M) allele types. This grouping was confirmed by partial sequencing of the tet(M) open reading frame, which indicated that the two allele types displayed high sequence similarities (>99.6%) with tet(M) genes previously reported in Staphylococcus aureus MRSA 101 and in Neisseria meningitidis, respectively. Southern hybridization with plasmid profiles revealed that the isolates contained tet(M)-carrying plasmids. In addition to the tet(M) gene, one isolate also contained an erm(B) gene on a different plasmid from the one encoding the tetracycline resistance. Furthermore, it was also shown by PCR that the tet(M) genes were not located on transposons of the Tn916/Tn1545 family. To our knowledge, this is the first detailed molecular study demonstrating that taxonomically and genotypically diverse Lactobacillus strains from different types of fermented meat products can be a host for plasmid-borne tet genes.

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