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W artykule przedstawiono algorytmy koewolucyjne, heurystyczną metodę rozwiązywania złożonych obliczeniowo problemów opartą na zasadzie korelacji oraz darwinowskiej teorii ewolucji. Opisano zalety algorytmu, możliwe zastosowania, sposób działania oraz niektóre z dotychczasowych implementacji. Następnie wybrano trzy wielomodalne lub nieciągłe funkcje testowe: Rosenbrocka, Styblinskiego-Tanga oraz Schaffer’a. Dokonano dekompozycji problemu wyznaczenia minimum globalnego funkcji i przeprowadzono optymalizację wykorzystując kooperacyjny algorytm koewolucyjny. Uzyskane wyniki pozwoliły na ocenę jakości działania algorytmu. Przeprowadzone testy i ich rezultaty są wstępem do szerszych badań nad algorytmami koewolucyjnymi.
In this paper a brief study of coevolutionary algorithm is presented. The coevolutionary algorithm (CA) is an evolutionary algorithm (or collection of evolutionary algorithms) in which the fitness of an individual depends on the relationship between that individual and other individuals. CA can be divided into two fundamental sub-types. In cooperative algorithms, individuals are rewarded when they work well with other individuals and punished when they perform poorly. In competitive algorithms, however, individuals are rewarded at the expense of those with which they interact. The principle of operation of CA is quite similar to traditional evolutionary algorithm. The main deference lies in a fact that CA operate on multi-populations and evaluate individual based on its collaboration with individuals (collaborators) from other populations. Applying CA requires decomposition of the problem into components and assigning each component to a population. This article presents an optimization of discontinuous and multimodal functions using cooperative coevolutionry algorithm. The modified testing functions: Rosenbrocka, Styblinskiego-Tanga and Schaffer’a are decomposed and minimize using coevolutionary algorithm. Obtained results allow to evaluate the quality of the algorithm and will be used for further research on the topic.
Content available Niektóre osobliwości ewolucji endopasożytów
Evolution of parasite - host systems should be treated as a specific kind of co-evolution. Although its course is in accordance with the general rules of organic world evolution, it has some peculiarities. One of them is retardation or acceleration of endoparasites' phylogenesis, as compared with the hosts' one. The second one is different speed of phylogenetic changes of endoparasites belonging to the same systematic group. These changes can be significantly limited, as well. Phylogenetic changes of euglenids - intestine parasites of Copepoda - are considerably limited, even in comparison with the scale of changes of such species which begin their parasitic life by infecting Copepoda eggs.
We apply Coevolutionary Temporal Difference Learning (CTDL) to learn small-board Go strategies represented as weighted piece counters. CTDL is a randomized learning technique which interweaves two search processes that operate in the intra-game and inter-game mode. Intra-game learning is driven by gradient-descent Temporal Difference Learning (TDL), a reinforcement learning method that updates the board evaluation function according to differences observed between its values for consecutively visited game states. For the inter-game learning component, we provide a coevolutionary algorithm that maintains a sample of strategies and uses the outcomes of games played between them to iteratively modify the probability distribution, according to which new strategies are generated and added to the sample. We analyze CTDL's sensitivity to all important parameters, including the trace decay constant that controls the lookahead horizon of TDL, and the relative intensity of intra-game and inter-game learning. We also investigate how the presence of memory (an archive) affects the search performance, and find out that the archived approach is superior to other techniques considered here and produces strategies that outperform a handcrafted weighted piece counter strategy and simple liberty-based heuristics. This encouraging result can be potentially generalized not only to other strategy representations used for small-board Go, but also to various games and a broader class of problems, because CTDL is generic and does not rely on any problem-specific knowledge.
The evolutionary interests of any two individuals are rarely, if ever, identical. This must be true, simply because they do not share the same allels for all loci. Where alleles at a locus differ, there will be competition among them. Because males and tmales, by definition, produce gametes of different size (anizogamy), they typically maximize their reproductive success in more or less different ways. Whenever selection favors different values for a phenotypic trait in males than in females, there is potential for intragenomic (intralocus) sexual conflict. Intragenomic conflict will ppear in all those cases where the direction of selection at a given allele depends upon in which sex it resides (i.e., whenever there is a sex-genotype interaction for fitness). Sexual selection guided by male-female conflicts of interest can result in resolvable evolutionary chases that tend to be unending. It has been reported that in many insects mating involve high costs to females (increased predation risk and energetic expenditure) but few, if any, balancing direct benefits. Sperm-displacement rates are high, and males thus gain from rematings. Mating frequencies are high; males mate multiply for reasons of convenience. In many species, inclouding waterstriders (Heteroptera: Gerridae) males are considered to have won’ the evolutionary conflict over the mating decision in the sense that they have made acceptance of superfluous matings ‘the best of a bad job’ for females, by evolving behavioral and morfological traits that make it costly for females to reject males attempting copulations. Females, however, have apparently evolved a variety of counteradaptations to make males harassmnet, to gain control over mating.
Alpine accentors (Prunella collaris) and dunnocks (P. modularis) are closely related species of Prunellidae, which often breed in polygynandrous groups and have specific types of mating behaviour. The alpine accentor lives at high altitudes, in an extreme alpine environment; the dunnock is widely dispersed from lowland to tree line in the mountains. Both species are hosts of the related species of wing lice Philoptersus emiliae and Ph. modularis, respectively. Behavioural differences between these two host species may have resulted in different breeding and seasonal adaptations by their parasites. The main goal of this paper was to test this hypothesis. Sixty five alpine accentors Prunella collaris (Scopoli, 1769) and eighty four dunnocks Prunella modularis (Linnaeus, 1758) were examined for Ischnocera lice in the West Carpathians, Slovakia from 1988 to 2001, and from 2007 to 2010, respectively. Birds were found to be infested with two species of Ischnoceran lice: the parasite species are not competing as they each have their own host Philopterus emiliae Balát, 1955 /P. collaris and Philopterus modularis (Denny, 1842) /P. modularis. Significant differences in abundance and prevalence existed between these two species of lice. High number of Ph. modularis nymphs in the comparison to Ph. emiliae nymphs reflects the different ecological, behavioural and phylogenetic trajectories of their host bird species. This work is the first to assess the louse breeding strategies on two closely related bird species in the high mountain environment.
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