To understand evolution, and to discover how different species are related, gene order analysis is a useful tool. Problems in this area can usually be formulated in a combinatorial language. We regard genomes as signed, or unsigned permutations, and thus evolutionary operations like inversions (reversing the order of a segment of genes) are easy to describe combinatorially. A commonly studied problem is to determine the evolutionary distance between two species. This is estimated by several combinatorial distances between gene order permutations, for instance the inversion distance. The main objective of this work was to survey the existing algorithms for genome comparison and to present new approach for solving this problem. The work led to these results: - We have surveyed existing approaches of genome comparison, namely comparison by inversion distance in signed and unsigned cases. It appeared that sorting signed genomes by inversions is done in quadratic time, but sorting unsigned genomes by inversions is NP-hard. - We have proposed the method of how to apply heuristic algorithms for sorting unsigned genomes by inversions. - We have applied tabu search and genetic algorithm to solve the sorting unsigned genomes by inversions problem. - We have experimentally proven, that the worst case solutions to sorting unsigned genomes by inversions found by heuristics (tabu search and genetic algorithm) are better then ones expected from best known approximating algorithm used for... [to full text]

Dažniausiai inversijos sąlygos pavojingos miestams/ didmiesčiams, kurių didžiausias teršalų kiekis išmetamas dienos metu, o naktį teršalams išsisklaidyti trukdo inversijos reiškinys, kuris išsilaiko iki paryčių. Todėl yra svarbu kuo aiškiau apibrėžti inversijos sąlygų susidarymo priežastis ir išanalizuoti šio reiškinio įtaką miesto taršai. Taigi šіo dаrbo tіkѕlаѕ – nuѕtаtytі temperаtūroѕ іnverѕіјoѕ dėѕnіngumų įtаkа oro teršаlų ѕklаіdаі Kаuno mіeѕte. Pagrindiniai uždaviniai: nuѕtаtytі temperаtūroѕ іnverѕіјoѕ dėѕnіngumą pаroјe ѕkіrtіngаіѕ metų lаіkаіѕ, tuomet іšаnаlіzuotі temperаtūroѕ іnverѕіјoѕ įtаką teršаlų koncentrаcіјаі іr ѕtаtіѕtіškаі įvertіntі ryšіnę prіklаuѕomybę tаrp šіų rodiklių, taip pat įvertіntі kіtų meteorologіnіų rodiklių įtаką temperаtūroѕ іnverѕіјoѕ formаvіmuіѕі beі teršаlų pаѕіѕkіrѕtymuі kartu įvertinant oro teršalų koncentracijų ribinių verčių dinamiką 2006-2008 metais. Pagrindinis darbo metodas - duomenų analizė ir jų statistinių sąryšių kiekybinis įvertinimas. Atlikus tyrimą paaiškėjo kad, naktinės temperаtūroѕ іnverѕіјoѕ reіškіnyѕ Kаuno mіeѕte pаѕіreіškіа bet kurіuo metų lаіku іr ѕkіrіаѕі tіk vertіkаlаuѕ temperаtūroѕ grаdіento аmplіtudė. Taip pat nustatytos teigiamos vidutinio stiprumo teršalų koncentracijos priklausomybės nuo temperatūros inversijos išskyrus SO2. Be to nustatyta, kad KD10 koncentracija 2006 -2008 metų kovo pabaigoje ir balandžio pradžioje pasiekia didžiausią lygį ir viršija leistiną paros koncentracijos vertę, kai NO2 koncentracija ore... [toliau žr. visą tekstą] / Most inversion conditions dangerous cities / cities with the highest emissions of pollutants during the day and night to disperse pollutants prevents inversion phenomenon, which exists to morning. It is important to clarify the reasons for the formation of inversion conditions and analyze the impact of the phenomenon of urban pollution. The main thesis goal is to identify temperature inversions conditions and its impaction to the spread of pollutant Main tasks: identify temperature inversion phenomenon in different cycles of year, then calculate temperature inversion and pollutants correlation plus to analyze the concentration amount of pollutants in 2006- 2008 years. The method used for this investigation is the analysis of the data correlations calculation. The investigation revealed that temperature inversion exist on all cycles of year and detectable on night. Also the positive dependence of pollutant concentration to temperature inversion is detected, with the exception of SO2. In addition, it was found that the concentration of KD10 exceeded maximum values on 2006 -2008 in the end of March and beginning of April. What is more, NO2 concentration in air exceeds its level a several times a year and this is the signal for our health.