Dissertations / Theses on the topic 'Hybrid fitness'

Clustering is the art of locating patterns in large data sets. It is an active research area that provides value to scientific as well as business applications. There are some challenges that face practical clustering including: identifying clusters of arbitrary shapes, sensitivity to the order of input, dynamic determination of the number of clusters, outlier handling, high dependency on user-defined parameters, processing speed of massive data sets, and the potential to fall into sub-optimal solutions. Many studies that were conducted in the realm of clustering have addressed some of these challenges. This study proposes a new approach, called parallel hybrid clustering using genetic programming and multi-objective fitness with density (PYRAMID), that tackles several of these challenges from a different perspective. PYRAMID employs genetic programming to represent arbitrary cluster shapes and circumvent falling in local optima. It accommodates large data sets and avoids dependency on the order of input by quantizing the data space, i.e., the space on which the data set resides, thus abstracting it into hyper-rectangular cells and creating genetic programming individuals as concatenations of these cells. Thus the cells become the subject of clustering, rather than the data points themselves. PYRAMID also utilizes a density-based multi-objective fitness function to handle outliers. It gathers statistics in a pre-processing step and uses them so not to rely on user-defined parameters. Finally, PYRAMID employs data parallelism in a master-slave model in an attempt to cure the inherent slow performance of evolutionary algorithms and provide speedup. A master processor distributes the clustering data evenly onto multiple slave processors. The slave processors conduct the clustering on their local data sets and report their clustering results back to the master, which consolidates them by merging the partial results into a final clustering solution. This last step also involves determining the number of clusters dynamically and labeling them accordingly. Experiments have demonstrated that, using these features, PYRAMID offers an advantage over some of the existing approaches by tackling the clustering challenges from a different angle.

Population structure, gene flow and dispersal are some of the most commonly estimated population parameters in population genetics, evolutionary biology and conservation genetics. The primary aim of thesis is to test the precision and accuracy of genetic estimates of population structure, gene flow and dispersal. The controlled replicated Drosophila melanogaster experiments of known effective population size (Ne = 14.3) and dispersal rate (m = 0.0025 - 0.04) all adhered to Wright??s demographic island model. Three statistical approaches were empirically tested: 1) the conversion of population structure to gene flow using FST, RST, SHUA and PhiST ; 2) the private alleles method to estimate gene flow; 3) a Bayesian assignment method to estimate dispersal (BAYESASS 1.2). Even in the best-case scenario, almost all current methods except SHUA significantly underestimate population structure, and consequently overestimate gene flow and dispersal when applied to real populations. It was crucial to ensure that the manipulated rate of gene flow was correctly defined. This led to three supporting investigations of hybrid performance, inversion polymorphisms and effective population size. The hybrid performance investigation demonstrated that the manipulated rate of gene flow had not been unexpectedly inflated by hybrid vigour or reduced by breakdown. These experiments also demonstrated that close inbreeding is not a necessary precondition for hybrid vigour or breakdown, which is important for conservation strategies involving induced dispersal. The investigation of inversion polymorphisms ensured that the manipulated rate of gene flow was not affected by selection on inverted regions. The effective population size investigation used a temporal estimation method to confirm that the Ne was accurately predicted by an N:Ne ratio of 0.286. Additionally this experiment showed that the single-sample estimation methods implemented by ONeSAMP or LDNE resulted in downwardly biased estimates of Ne in structured populations. In conclusion these results call into question the confidence that biologists may have in some of the most widely used molecular tools in conservation biology.

This study deals with the trend of male bodybuilding in Korea and investigates the motivations and aesthetic ideals of Korean male bodybuilders. The author of the study uses the few hitherto academic research works on the subject and tries to give an overview of the history of Korean bodybuilding. Besides, the author has conducted a digital survey in order to collect answers from Korean male bodybuilders about their motivations, aesthetic ideals, etc. The aesthetic ideals of the bodybuilders are then compared to the male aesthetic ideals of modern Korean society and also discussed in relation to the somatic beliefs of NeoConfucianism. The findings are thereafter analyzed in context of two theses of the cultural consequences of globalization, namely homogenization and hybridization. The study concludes that Korean bodybuilders are more concerned with the arduous process of sculpting their physiques rather than the look of them themselves. Although the research material on Korean bodybuilding is scarce and the responses to the conducted survey are small in terms of both numbers and scale, it may be suggested that Korean bodybuilding appears to be an instance of the hybridization thesis. Lastly, the study emphasizes the need for more extensive research on the subject in question.
Denna studie behandlar ämnet koreansk bodybuilding för män och undersöker dels vad som motiverar koreanska kroppsbyggare att utöva sin sport, dels vad deras estetiska ideal är. Studiens författare använder sig av den begränsade befintliga forskningen inom ämnet och försöker även ge en överblick över koreansk bodybuildings historia. Författaren har dessutom utfört en digital undersökning för att samla in svar från koreanska kroppsbyggare om deras drivkrafter, estetiska ideal, etc. Dessa ideal jämförs sedan med det moderna koreanska samhällets motsvarigheter och diskuteras även utifrån de somatiska föreställningarna inom neokonfucianismen. Studiens forskningsresultat analyseras sedan utifrån två teorier om globaliseringens kulturella konsekvenser, närmare bestämt homogenisering respektive hybridisering. Trots det knappa forskningsmaterialet kring koreansk bodybuilding är studiens slutsats att koreanska kroppsbyggare är mer måna om den mödosamma processen i att bygga sina kroppar, snarare än hur dessa ser ut i sig själva. Studien suggererar också att koreansk bodybuilding verkar vara ett exempel på hybridiseringsteorin. Slutligen betonar studien behovet av mer utförlig forskning kring ämnet i fråga.

Master thesis is focused on optimization of cogeneration system for purpose of rating optimization methods and evaluating properties of these methods. For each method there is description together with block schemes. First part of thesis is devoted to description of methods and their comparison. Second part consists of development of hybrid algorithm, which is used to optimize cogeneration systém model. Each algorithm compared is together with hybrid algorithms included in annexes.

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Made available in DSpace on 2016-06-28T16:05:18Z (GMT). No. of bitstreams: 1 David Augusto Silva.pdf: 1453777 bytes, checksum: 4516b869e7e749b770a803eb7e91a084 (MD5) Previous issue date: 2011-07-01
The techniques for Time Series Analysis and Forecasting have great presence on the literature over the years. The computational resources combined with statistical techniques are improving the predictive results, and these results have been become increasingly accurate. Computational methods base on Artificial Neural Networks (ANN) and Evolutionary Computing (EC) are presenting a new approach to solve the Time Series Analysis and Forecasting problem. These computational methods are contained in the branch of Artificial Intelligence (AI), and they are biologically inspired, where the ANN models are based on the neural structure of intelligent organism, and the EC uses the concept of nature selection of Charles Darwin. Both methods acquire experience from prior knowledge and example of the given problem. In particular, for the Time Series Forecasting Problem, the objective is to find the predictive model with highest forecast perfomance, where the performance measure are statistical errors. However, there is no universal criterion to identify the best performance measure. Since the ANNs are the predictive models, the EC will constantly evaluate the forecast performance of the ANNs, using a fitness functions to guide the predictive model for an optimal solution. The Data Envelopment Analysis (DEA) was employed to predictive determine the best combination of variables based on the relative efficiency of the best models. Therefore, this work to study the optimization Fitness Function process with Data Envelopment Analysis applied the Intelligence Hybrid System for time series forecasting problem. The data analyzed are composed by financial data series, agribusiness and natural phenomena. The C language program was employed for implementation of the hybrid intelligent system and the R Environment version 2.12 for analysis of DEA models. In general, the perspective of using DEA procedure to evaluate the fitness functions were satisfactory and serves as an additional resource in the branch of time series forecasting. Researchers need to compute the results under different perspectives, whether in the matter of the computational cost of implementing a particular function or which function was more efficient in the aspect of assessing which combinations are unwanted saving time and resources.
As técnicas de análise e previsão de séries temporais alcançaram uma posição de distinção na literatura ao longo dos anos. A utilização de recursos computacionais, combinada com técnicas estatísticas, apresenta resultados mais precisos quando comparados com os recursos separadamente. Em particular, técnicas que usam Redes Neurais Artificiais (RNA) e Computação Evolutiva (CE), apresenta uma posição de destaque na resolução de problemas de previsão na análise de séries temporais. Estas técnicas de Inteligência Artificial (AI) são inspiradas biologicamente, no qual o modelo de RNA é baseado na estrutura neural de organismos inteligentes, que adquirem conhecimento através da experiência. Para o problema de previsão em séries temporais, um fator importante para o maior desempenho na previsão é encontrar um método preditivo com a melhor acurácia possível, tanto quanto possível, no qual o desempenho do método pode ser analisado através de erros de previsão. Entretanto, não existe um critério universal para identificar qual a melhor medida de desempenho a ser utilizada para a caracterização da previsão. Uma vez que as RNAs são os modelos de previsão, a CE constantemente avaliará o desempenho de previsão das RNAs, usando uma função de fitness para guiar o modelo preditivo para uma solução ótima. Desejando verificar quais critérios seriam mais eficientes no momento de escolher o melhor modelo preditivo, a Análise Envoltória de Dados (DEA) é aplicada para fornecer a melhor combinação de variáveis visando a otimização do modelo. Portanto, nesta dissertação, foi estudado o processo de otimização de Funções de Fitness através do uso da Análise Envoltória de Dados utilizando-se de técnicas hibridas de Inteligência Artificial aplicadas a área de previsão de séries temporais. O banco de dados utilizado foi obtido de séries históricas econômico- financeiras, fenômenos naturais e agronegócios obtidos em diferentes órgãos específicos de cada área. Quanto à parte operacional, utilizou-se a linguagem de programação C para implementação do sistema híbrido inteligente e o ambiente R versão 2.12 para a análise dos modelos DEA. Em geral, a perspectiva do uso da DEA para avaliar as Funções de Fitness foi satisfatório e serve como recurso adicional na área de previsão de séries temporais. Cabe ao pesquisador, avaliar os resultados sob diferentes óticas, quer seja sob a questão do custo computacional de implementar uma determinada Função que foi mais eficiente ou sob o aspecto de avaliar quais combinações não são desejadas poupando tempo e recursos.

The typical intermediate morphology of hybrids may result in their failure to utilize the same niches as their parents. However, the fitness consequences of the potentially intermediate life-history traits of hybrids have been given less scientific attention. In this study I aimed to investigate how life-history divergence in parental species affects the relative fitness of nestling hybrids resulting from crosses between collared (Ficedula albicollis) and pied flycatchers (F. hypoleuca). Previous studies showed that collared flycatcher nestlings beg more intensively and grow faster under good conditions, but are less robust against the seasonal decline in food availability compared to pied flycatcher nestlings. This life-history divergence between the species allows regional coexistence. To investigate whether the life-history divergence in flycatchers influences the relative fitness of nestling hybrids, I cross-fostered hybrid nestlings in aviaries into the nests of conspecific pairs and compared their performance. I found that the hybrids displayed intermediate growth rates between collared and pied flycatchers across the season. There might therefore be environmental conditions when hybrids perform better than purebred offspring with respect to growth and survival.

Syfte: Denna studie ämnar beskriva och analysera organisationsformer och ledarskap inom svensk golfverksamhet. Svensk golf är speciell eftersom den både finns i ideell form inom Riksidrottsförbundets ramar, i kombination med ett aktiebolag och som rent kommersiell verksamhet. Svensk idrottsverksamhet lägger högt fokus på samhällsvärde, samtidigt som organisationer behöver hantera en komplex ekonomisk verksamhet. Oavsett verksamhetsform kan friktion uppstå och organisationer med multipla institutionella logiker behöver hantera de krav som skapas.   Metod: Studien utfördes genom intervjuer med nio klubbchefer inom tre olika organisationsformer. Klubbchefer valdes för att de antogs ha insyn i verksamheten. Urvalet var strategiskt för att få så stor bredd som möjligt beträffande verksamhetsform, geografi, ålder och kön. Analysen genomfördes tematiskt och utgår ifrån analysprocessen ”Big Q” (Braun, Clarke & Weate, 2016) för att studera intervjupersonernas livsvärld i den svenska idrottskontexten.   Analys: Med hjälp av ny-institutionell organisationsteori diskuteras utmaningar och strategier för de olika organisationerna och för klubbcheferna som leder dem. Ett organisationsschema över golfverksamhet i Sverige presenteras för att ge en beskrivning av den kontext studien analyserar. Här beskrivs klubbchefen som ”spindeln i nätet” vilket representerar den övergripande arbetsroll hen besitter, oavsett organisationsform. Vidare presenteras en tillämpbar praktisk modell för att sammanställa och jämföra organisationsformerna.   Slutsats: De konkurrerande logikerna visar sig kunna hanteras väl inom golfen i Sverige. Verksamheterna i denna studie arbetar med ett integrerat ledningsorgan som tar hänsyn till både den samhällsfrämjande logiken och den finansiella logiken. Klubbchefen är den hybrida individen som håller samman organisationen. En återkommande utmaning är dock hög arbetsbelastning på klubbchef på grund av bristfälliga resurser, både ekonomiska möjligheter och stöd från ideellt arbetande inom organisationen. Golfaren som medlem eller kund är en central fråga för framtiden.
Purpose: This study means to describe and analyze organizational forms and management in Swedish golf organizations. Swedish golf stands out because it governs in associations within the Swedish Sport Confederations framework, in combination with an incorporated company and as a commercialized business. Swedish sports prioritize societal value and simultaneously needs to manage a complex financial business. Regardless organizational form can tension arise and organizations with multiple institutional logics needs to manage the challenges created.   Method: The study conducted interviews with nine general managers in three different organizational forms. General managers were chosen because they assumed to have insight in the organization. The sample was made strategically to get a wide population regarding organizational form, location, age, and gender. The analyze process performed thematically was inspired by the strategy “Big Q” (Braun, Clarke & Weate, 2016) to study the interviewees workday in the Swedish sport context.   Analysis: With aid from new institutionalized theory discusses challenges and strategies for the differentialized organizations and for the general manager who leads them. A club structure is presented to describe the Swedish context. The general manager describes as “the spider in the web” which represents the comprehensive work role possessed, regardless organizational form. The study also presents a practical model is to summarize and compare the organizational forms.   Conclusion: The competing logics is shown to be handled well in Swedish golf organizations. The organizations in this study govern through an integrated management which considers both social value logic and the financial logic. The general manager is the hybrid individual which holds the organization together. A recurrent challenge is a high workload on the general manager created by inadequate resources, both economic resources and lack of support from voluntary workforce. The golfer as a member or a customer is a central question for the future.

Studies were conducted in 1996 through 1999 to: (1) evaluate the responses of one imidazolinone (IMI)-susceptible (S) and four -resistant (R1, R2, R3, and R4) smooth pigweed populations to various acetolactate synthase (ALS)-inhibiting herbicides, (2) determine the mechanism of resistance, and (3) evaluate the relative growth and competitiveness of each population. Field studies were conducted in 1996 near Marion, MD, in a field with a history of repeated imazaquin use. Smooth pigweed control with IMI herbicides was < 8 percent, but control with sulfonylurea (SU) herbicides ranged from 73 to 99 percent. Follow-up greenhouse studies were used to confirm IMI resistance in the Marion, MD smooth pigweed population (R4) as well as three others (R1, R2, and R3). R populations were 730- to 1350-fold more tolerant to imazethapyr than the S population. Based on resistance ratios, all R populations displayed low-level cross-resistance to chlorimuron and negative cross-resistance to thifensulfuron, pyrithiobac, and cloransulam-methyl with R2 being the most sensitive of the R populations to pyrithiobac and cloransulam-methyl. Absorption, translocation, and metabolism of ¹⁴C-cloransulam-methyl in S and R2 populations were generally similar. Three metabolites of cloransulam-methyl with ratio of front (Rf) values approximately 0.83, 0.65, and 0.45 were isolated. The metabolite with a 0.83 Rf value increased over time as the parent molecule decreased indicating that it plays a major role in cloransulam-methyl metabolism in smooth pigweed. The other metabolites did not change significantly over time and never represented more than 5 percent of the extracted radioactivity. The identity of these metabolites has not been determined. Using enzyme assays, it was determined that IMI resistance in R populations was due to an altered ALS that was no longer susceptible to inhibition by these herbicides. ALS from S, R1, and R2 populations responded similarly to chlorimuron and thifensulfuron, but reductions in enzyme activity by chlorimuron and thifensulfuron were significantly greater for R3 ALS than for S, R1 or R2 ALS. ALS from R2 and R3 was significantly more sensitive to inhibition by pyrithiobac compared to S ALS. Based on resistance ratios, R2 and R3 ALS were also more sensitive to inhibition by cloransulam-methyl than S ALS. Negative cross-resistance to thifensulfuron, pyrithiobac, and cloransulam-methyl in some R populations at the whole-plant level can be explained by increased sensitivity at the enzyme level. Under noncompetitive conditions in the greenhouse, S produced 17, 23, 25, and 44 percent more biomass than R1, R2, R3, and R4 populations, respectively. S plants were also taller than R plants 17 and 21 d after planting (DAP) and displayed a faster initial rate of leaf area increase compared to all R populations. The net assimilation rate of S was significantly higher than R2 and R3 populations 24 DAP. R3 and R4 populations had significantly less chlorophyll per g of plant tissue compared to S; therefore, reduced growth in some R populations compared to S may be linked to chlorosis that generally appears early in seedling development. Biomass production in the field under competitive conditions was similar for all populations using both monoculture and mixed populations. For this reason, the differences in growth observed in the greenhouse in the S population may not confer a competitive advantage over R populations in the field.
Ph. D.

Introgression of genes from crops into ruderal populations is a multi-step process requiring sympatry, synchronous flowering, chromosomal compatibility, successful pollination and development of the zygote, germination, establishment and reproduction of hybrid progeny. The goal of this thesis was to generate data on as many steps in this process as possible and integrate them into a predictive statistical model to estimate the likelihood of successful introgression under a range of scenarios. Rape (Brassica napus) and wild turnip (B. rapa var. oleifera) were used as a model system. A homozygous dominant mutation in the rape genome conferring herbicide resistance provided a convenient marker for the study of introgression. Potential differences between wild turnip populations from a wide range of geographic locations in New Zealand were examined. Hand pollination established the genetic compatibility of rape and wild turnip and a high potential for gene introgression from rape to wild turnip. Interspecific hybrids were easily generated using wild turnip as the maternal plant, with some minor differences between wild turnip populations. The frequency of successful hybridisation between the two species was higher on the lower raceme. However, the upper raceme produced more dormant interspecific hybrid seed. Field trials, designed to imitate rare rape crop escapes into the ruderal environment, examined the ability of rare rape plants to pollinate wild turnip plants over four summers. At a ratio of 1 rape plant for every 400 wild turnip plants, the incidence of interspecific hybridisation was consistently low (<0.1 to 2.1 % of total seed on wild turnip plants). There was a significant year effect with the first season producing significantly more seed and a greater frequency of interspecific hybrid progeny than the other years. The frequency of interspecific hybrid progeny increases when the ratio of rape: wild turnip plant numbers increases. The relative importance of anemophily and entomophily in the production of interspecific hybrids was examined. Wild turnip plants produced twice as many seeds with bee pollination relative to wind pollination. However, the frequency of interspecific hybrids under wind pollination was nearly twice that for bee pollination. Light reflectance patterns under UV light revealed a marked difference between wild turnip and rape flowers compared to near identical appearance under visible light. The data indicates that bees are able to distinguish between rape and wild turnip flowers and exhibit floral constancy when foraging among populations with these two species. Hybrid survival in the seed bank, germination and seedling establishment in the field are important components of fitness. Seed banks established in the soil after the field trials described above germinated in subsequent spring seasons. The predominantly brassica weed populations were screened for herbicide resistance and the numbers of interspecific hybrids germinating compared to the original frequency in the field trial results. Frequency of interspecific hybrids was reduced in the populations compared to the original seed deposit. Seed with a known frequency of interspecific hybrid seed was sown in a separate trial, and the frequency of interspecific hybrids compared at 0, 4, 6, and 8 weeks after sowing. Poor germination resulted limited competition between seedlings, however the frequency of interspecific hybrids declined over time indicating low plant fitness. There were no significant population effects on any parameters tested. Interspecific hybrids grown in a glasshouse were backcrossed to the parental species and selfed within the plant and within populations. Pollen from the interspecific hybrids was found to have markedly reduced fertility. Interspecific hybrid plants had low female fertility, with the majority (88%) of the pollinated flowers aborting the siliques. Of the remaining siliques, most (98%) had only one to three seeds per silique. Inheritance of the herbicide resistance gene was regular in backcrosses but highly skewed following self pollination with an excess of herbicide-sensitive progeny. Production of a stochastic predictive model integrated the information acquired over the practical work phase of this thesis and utilised the capabilities of @risk, a new application of a risk analysis tool. The three outputs examined were the number of flowering plants resulting from backcrosses to rape and wild turnip and self pollination of the interspecific hybrid progeny. Five scenarios were modelled and all demonstrated the high likelihood of introgression failure in this system. In all scenarios, >75% of simulations resulted in no interspecific hybrid progeny surviving to flowering in the third generation. In all scenarios, and for all three outputs, the seed set on the interspecific hybrids of the second generation was the major factor that limited the number interspecific hybrid progeny surviving to flowering in the third generation.

Polymorphisme d'insertion de 4 elements mobiles (mdg-1, copia, i, p) etudie par hybridation in situ de sondes d'adn biotinylees sur les chromosomes geants de larves de 17 lignees consanguines de d. Melanogaster sur plusieurs generations

This thesis evaluates the Children’s Fitness Tax Credit and similar credits to determine whether they are suitable to increase physical activity levels in Canada. It begins by reviewing the literature on physical activity to establish that increasing physical activity is a worthy public policy goal. It then reviews the literature on tax expenditures and health behaviour interventions to provide information in order to evaluate the credits. The credits are then described and their stated purpose is discussed. This description establishes how quickly the credits expanded from one small credit to many. One of the credits, the Active Families Benefit, requires a new concept to evaluate it as it is not simply a tax measure or a spending measure. The term hybrid tax measure is introduced to explore this credit. An evaluation of the credits considering their effectiveness, efficiency and equity in determining their suitability to increase physical activity is performed and the conclusion is made that they are unlikely to be effective and that the inequity of the credits is problematic, particularly in light of this ineffectiveness finding. It is recommended that the credits be repealed and no new credits be created, but as repeal is unlikely, alternative recommendations are also provided.