Tesis: "Natural and Artificial Selection"

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Ramey, Holly Rene. "Mapping natural and artificial selection events in animal genomes". Thesis, University of Missouri - Columbia, 2016. http://pqdtopen.proquest.com/#viewpdf?dispub=10182613.

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Raj, Towfique. "Molecular signatures of natural and artificial selection in mammalian genomes". Thesis, University of Cambridge, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.609021.

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Zeng, Zhao-Bang. "Theoretical studies on genetic limits to natural and artificial selection with mutation". Thesis, University of Edinburgh, 1986. http://hdl.handle.net/1842/13251.

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Channon, Alastair. "Evolutionary emergence : the struggle for existence in artificial biota". Thesis, University of Southampton, 2001. https://eprints.soton.ac.uk/256270/.

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Pichler, Peter-Paul. "Natural selection, adaptive evolution and diversity in computational ecosystems". Thesis, University of Hertfordshire, 2009. http://hdl.handle.net/2299/4006.

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The central goal of this thesis is to provide additional criteria towards implementing open-ended evolution in an artificial system. Methods inspired by biological evolution are frequently applied to generate autonomous agents too complex to design by hand. Despite substantial progress in the area of evolutionary computation, additional efforts are needed to identify a coherent set of requirements for a system capable of exhibiting open-ended evolutionary dynamics. The thesis provides an extensive discussion of existing models and of the major considerations for designing a computational model of evolution by natural selection. Thus, the work in this thesis constitutes a further step towards determining the requirements for such a system and introduces a concrete implementation of an artificial evolution system to evaluate the developed suggestions. The proposed system improves upon existing models with respect to easy interpretability of agent behaviour, high structural freedom, and a low-level sensor and effector model to allow numerous long-term evolutionary gradients. In a series of experiments, the evolutionary dynamics of the system are examined against the set objectives and, where appropriate, compared with existing systems. Typical agent behaviours are introduced to convey a general overview of the system dynamics. These behaviours are related to properties of the respective agent populations and their evolved morphologies. It is shown that an intuitive classification of observed behaviours coincides with a more formal classification based on morphology. The evolutionary dynamics of the system are evaluated and shown to be unbounded according to the classification provided by Bedau and Packard’s measures of evolutionary activity. Further, it is analysed how observed behavioural complexity relates to the complexity of the agent-side mechanisms subserving these behaviours. It is shown that for the concrete definition of complexity applied, the average complexity continually increases for extended periods of evolutionary time. In combination, these two findings show how the observed behaviours are the result of an ongoing and lasting adaptive evolutionary process as opposed to being artifacts of the seeding process. Finally, the effect of variation in the system on the diversity of evolved behaviour is investigated. It is shown that coupling individual survival and reproductive success can restrict the available evolutionary trajectories in more than the trivial sense of removing another dimension, and conversely, decoupling individual survival from reproductive success can increase the number of evolutionary trajectories. The effect of different reproductive mechanisms is contrasted with that of variation in environmental conditions. The diversity of evolved strategies turns out to be sensitive to the reproductive mechanism while being remarkably robust to the variation of environmental conditions. These findings emphasize the importance of being explicit about the abstractions and assumptions underlying an artificial evolution system, particularly if the system is intended to model aspects of biological evolution.

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EKSTAM, LJUSEGREN LOVE y MIKAEL FLORÉN. "Basic simulation of natural selection : A study of the evolution of artificial life in varied environments". Thesis, KTH, Skolan för datavetenskap och kommunikation (CSC), 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-146345.

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In this project one way of simulating natural selection and its most basic principles was examined. In order to show how simple and effective evolutionary systems really can be, a number of simulated lifeforms struggled for survival and evolved over generations. With this project we wanted both to showcase simple evolutionary principles for educational purposes and to highlight the potential of self improving al- gorithms. This has been done by posing two questions. Can this type of simple simulation suffice to produce stable popu- lation and gene pools, given time? And if so, can it evolve to different stable solutions given different problems, in this case environments, to tackle? The test setup was very simple; a set of simulated organisms were placed in different environ- ments, with the ability to produce offspring with random mutations. The results of the simulation show that the pop- ulation stabilizes in both numbers and gene configurations over time. It also shows that different environmental con- ditions lead to different gene configurations. From this we can conclude that a basic test environment such as the one described in this project can be used for producing both dif- ferent and stable species that are far better suited to survive than early generations.
I det här projektet undersöktes ett sätt att simulera natur- ligt urval med sina mest grundläggande principer. För att visa hur simpla och kraftfulla evolutionära system kan va- ra, kämpade ett antal simulerade livsformer för överlevnad och utvecklades över generationer. Med detta projekt ville vi både påvisa hur enkla evolutionära system kan vara för ut- bildningsändamål, och visa potentialen hos självförbättrande algoritmer. Detta gjordes genom att ställa två frågor. Kan ett enkelt system, så som det som beskrivs i denna rapport, räcka för att producera stabila populationer och genpooler, givet tid? Och om så är fallet, kan de utvecklas till olika stabila lösningar givet olika problem, i detta fall olika mil- jöer, att ta itu med? Testmiljön var väldigt enkel; ett antal simulerade livsformer, med förmågan att producera avkom- ma med slumpmässiga mutationer, placerades i olika miljöer. Resultaten från simulationen visar att vi efter en tid får po- pulationer som är stabila i både genuppsättning och antal. De visar också att olika miljöer leder till olika genuppsätt- ningar. Från detta kan vi dra slutsatsen att ett så simpelt test som detta, kan användas för att producera både olika och stabila arter som är bättre anpassade för att överleva än tidiga generationer.

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Campbell, Lesley G. "Rapid evolution in a crop-weed complex (Raphanus spp.)". The Ohio State University, 2007. http://rave.ohiolink.edu/etdc/view?acc_num=osu1166549627.

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Biegelmeyer, Patrícia. "Resistência genética à infestação natural e artificial por Rhipicephalus (Boophilus) microplus em bovinos das raças Hereford e Braford". Universidade Federal de Pelotas, 2012. http://repositorio.ufpel.edu.br/handle/ri/2601.

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The overall aim of this study was to analyze different perspectives of Rhipicephalus (Boophilus) microplus genetic resistance. Therefore, the present study was divided into three manuscripts. Firstly, a literature review was conducted to present some aspects of tick resistance, like results of previous studies of bovine resistance, environmental effects on this triat, and some findings in molecular biology that will help to identify resistant animals. The second trial was conducted to estimate genetic parameters for tick resistance measured by two assessment methods in Hereford and Braford cattle, and genetic correlations between tick resistance and growth of animals. The animals belonging to the Delta G Connection genetic improvement consortium, were raised on nature and artificial pastures in Southern Brazil, and the age at the evaluation period was about 18 months. Data were analyzed from 6,462 bovines naturally exposed to ticks. The number of ticks was counted at inner hind legs region (IHL) of 3,413 animals between 2001 and 2008, and was recorded up to three consecutive counts at one side of body (LAT) in 3,049 bovines between 2009 and 2010, a total of 7,813 records. In addition, the database contained data of 109,566 birth weights (BW), 112,815 records of weight gain from birth to weaning (ADG) and 54,843 data of weight gain from weaning to yearling (PWG). For the analyses, tick count data was transformed using a logarithmic function. Heritability estimates obtained by bivariate analysis were IHL = 0.152 ± 0.043 and LAT = 0.235 ± 0.063 and genetic correlation between both methods was 0.575 ± 0.220. Single-trait analysis of LAT indicated a repeatability of 0.312 ± 0.014. Genetics association analysis between IHL and LAT and the development characteristics evaluated indicated significant associations between IHL and BW (0.220 ± 0.102), and favorable negative correlations between LAT and ADG (-0.211 ± 0.099) and LAT and PWG (-0.650 ± 0.125) (P<0.05). The objective of third trial was to analyze the bovine genetic resistance effect on tick biological traits. The engorged female ticks analyzed were collected from 40 Braford heifers classified as genetically resistant (R) or susceptible (S), according to the breeding values for tick count, calculated based on a database with 9,036 records of Hereford and Braford bovines. After classification, the selected heifers were moved to an experimental area in Embrapa Pecuária Sul, located in the city of Bagé, in the Brazilian state of Rio Grande do Sul, and subjected to four artificial infestations, 14 days apart each one. Weights of engorged female ticks and of female ticks after oviposition did not differ between resistant and susceptible heifers. Female ticks engorged in genetically susceptible heifers showed higher capacity of posture (R = 0.097 ± 0.021g and S = 0.109 ± 0.030g) and higher values of reproductive efficiency index (R = 47.23 ± 5.85% and S = 53.27 ± 3.74%) The overall aim of this study was to analyze different perspectives of Rhipicephalus (Boophilus) microplus genetic resistance. Therefore, the present study was divided into three manuscripts. Firstly, a literature review was conducted to present some aspects of tick resistance, like results of previous studies of bovine resistance, environmental effects on this triat, and some findings in molecular biology that will help to identify resistant animals. The second trial was conducted to estimate genetic parameters for tick resistance measured by two assessment methods in Hereford and Braford cattle, and genetic correlations between tick resistance and growth of animals. The animals belonging to the Delta G Connection genetic improvement consortium, were raised on nature and artificial pastures in Southern Brazil, and the age at the evaluation period was about 18 months. Data were analyzed from 6,462 bovines naturally exposed to ticks. The number of ticks was counted at inner hind legs region (IHL) of 3,413 animals between 2001 and 2008, and was recorded up to three consecutive counts at one side of body (LAT) in 3,049 bovines between 2009 and 2010, a total of 7,813 records. In addition, the database contained data of 109,566 birth weights (BW), 112,815 records of weight gain from birth to weaning (ADG) and 54,843 data of weight gain from weaning to yearling (PWG). For the analyses, tick count data was transformed using a logarithmic function. Heritability estimates obtained by bivariate analysis were IHL = 0.152 ± 0.043 and LAT = 0.235 ± 0.063 and genetic correlation between both methods was 0.575 ± 0.220. Single-trait analysis of LAT indicated a repeatability of 0.312 ± 0.014. Genetics association analysis between IHL and LAT and the development characteristics evaluated indicated significant associations between IHL and BW (0.220 ± 0.102), and favorable negative correlations between LAT and ADG (-0.211 ± 0.099) and LAT and PWG (-0.650 ± 0.125) (P<0.05). The objective of third trial was to analyze the bovine genetic resistance effect on tick biological traits. The engorged female ticks analyzed were collected from 40 Braford heifers classified as genetically resistant (R) or susceptible (S), according to the breeding values for tick count, calculated based on a database with 9,036 records of Hereford and Braford bovines. After classification, the selected heifers were moved to an experimental area in Embrapa Pecuária Sul, located in the city of Bagé, in the Brazilian state of Rio Grande do Sul, and subjected to four artificial infestations, 14 days apart each one. Weights of engorged female ticks and of female ticks after oviposition did not differ between resistant and susceptible heifers. Female ticks engorged in genetically susceptible heifers showed higher capacity of posture (R = 0.097 ± 0.021g and S = 0.109 ± 0.030g) and higher values of reproductive efficiency index (R = 47.23 ± 5.85% and S = 53.27 ± 3.74%)
O objetivo geral do presente estudo foi abordar diferentes perspectivas sobre a resistência genética de bovinos ao carrapato Rhipicephalus (Boophilus) microplus. Para tanto, foi dividido em três trabalhos. Primeiramente, foi realizado um estudo de revisão que abrangeu alguns aspectos relacionados à resistência, como resultados de trabalhos que avaliaram a resistência de bovinos, fatores ambientais capazes de afetar os fenótipos de resistência e algumas descobertas na área da biologia molecular que poderão ser úteis no processo de identificação de animais geneticamente resistentes. O segundo trabalho objetivou estimar parâmetros genéticos para a resistência mensurada por dois métodos de avaliação em bovinos Hereford e Braford, e as correlações genéticas entre a resistência e características de crescimento dos animais. Os bovinos que participaram das avaliações foram provenientes de rebanhos controlados pelo programa de melhoramento da Conexão Delta G, localizados no estado do Rio Grande do Sul e criados a campo sobre pastagens naturais e artificiais. Foram avaliados dados de 6.462 bovinos com idade média de 18 meses, naturalmente infestados, sendo as contagens realizadas na região do entrepernas (ENT) em 3.413 animais entre 2001 e 2008, e 7.813 registros de contagens na lateral do corpo (LAT) de 3.049 bovinos realizadas entre 2009 e 2011. Foram utilizados também 109.566 dados de peso ao nascimento (PN), 112.815 registros de ganho de peso do nascimento à desmama (GPD) e 55.843 dados de ganho da desmama ao sobreano (GDS). Para as análises, os dados de contagens sofreram transformação logarítmica. As estimativas de herdabilidade dos métodos de avaliação obtidas por análise bicaracterística foram ENT = 0,152 ± 0,043 e LAT = 0,235 ± 0,063, e a correlação genética entre ambos foi de 0,575 ± 0,220. A análise unicaráter da LAT apontou uma repetibilidade de 0,312 ± 0,014. As associações genéticas entre a ENT e a LAT e as características de desenvolvimento avaliadas apontaram associações significativas entre ENT e PN (0,220 ± 0,102), e favoráveis correlações negativas e entre LAT e GPD (-0,211 ± 0,099) e LAT e GDS (-0,650 ± 0,125) (P<0,05). O terceiro trabalho objetivou analisar o efeito da resistência dos bovinos sobre características biológicas dos carrapatos. As teleóginas analisadas foram coletadas em 40 novilhas Braford classificadas como geneticamente resistentes (R) ou suscetíveis (S), de acordo com os valores genéticos obtidos para a característica de contagem de carrapatos, calculados com base em um banco de dados com registros de 9.036 animais das raças Hereford e Braford. Após a classificação, as novilhas selecionadas foram encaminhadas à Embrapa Pecuária Sul (Bagé, RS), onde foram submetidas a quatro infestações artificiais, com intervalos de 14 dias. Os pesos médios iniciais das teleóginas e os pesos das quenóginas não diferiram entre os grupos de novilhas resistentes e suscetíveis. Fêmeas ingurgitadas em novilhas geneticamente suscetíveis apresentaram maior capacidade de postura (R = 0,097 ± 0,021g e S = 0,109 ± 0,030g) e maiores índices de eficiência reprodutiva (R = 47,23 ± 5,85% e S = 53,27 ± 3,74%) e nutricional (R = 54,33 ± 4,36% e S = 65,62 ± 8,84%) que teleóginas ingurgitadas em novilhas resistentes.

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Svedin, Johan. "Effekten av Modighet och risken för Artificiell selektion när bubblor används för att guida smolt förbi vattenkraftverk". Thesis, Umeå universitet, Institutionen för ekologi, miljö och geovetenskap, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-173390.

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Fragmentation of rivers due to the rapid expansion of hydropower plants is one of the major factors responsible for the decline in the Atlantic salmon (Salmo salar L.) in the Baltic Sea. Current methods to aid downstream migrating salmon smolt still struggle with effectively stopping the smolt from going through the hydropower turbines, by guiding them towards the available salmon ladders. A promising guiding method is using a barrier of bubbles which may serve as a non-intrusive alternative to conventional guiding structures. This study evaluated the risk of artificial selection caused using bubble barriers and compared the results with an earlier study. The three hypotheses tested were: i) the salmon display a scototaxis behaviour related to their boldness, ii) temperature, and size of arena affect the scototaxis of the salmon, and iii) the salmons reaction to a bubble barrier is correlated to their boldness. The hypotheses were tested in a controlled laboratory setting by conducting three scototaxis tests and an experiment with several bubble barriers, where the reaction of salmon to bubbles could be assessed. There was significant positive correlation (r = 0,62 & p = 0,012) between the boldness of an individual and the time it took to swim through the bubbles. Even though a significant difference in scototaxis as a result of lowered temperature were discovered, the difference was too small to have a noticeable effect on the overall results. A bubble barrier may therefore put artificial selection pressure on the salmon population.

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Sharma, Manmohan Dev. "Sexual selection in Drosophila simulans". Thesis, University of Exeter, 2010. http://hdl.handle.net/10036/3003.

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Over the last 100 years sexual selection has advanced into a vast field of theoretical and empirical research. While Darwin’s idea of female preference being an integral mechanism of sexual selection is no longer debated, our understanding of female preference is still very limited. For example, we know little about the genetic variation in female preference, and the costs of preference over and above the costs of mating with particular male phenotypes. Additionally, while costs of mate choice are well documented, the benefits of mate choice and their implications are still debated. For example, controversy exists over the inevitability of good gene benefits and their capability to promote adaptive sexual selection. Furthermore, the adaptiveness of sexual selection itself is debated. Our understanding of the traits involved in mate choice is also far from complete. Here I investigated aspects of sexual selection in Drosophila simulans, employing a range of behavioural approaches along with artificial selection and environmental manipulations. The findings presented here indicate that female preference can evolve when directly selected on, and that preference itself is not particularly costly. There was also no conclusive evidence for the good genes benefits of mate choice in D. simulans. These benefits are considered crucial in promoting the adaptiveness of sexual selection, and although we found sexual selection to be adaptive under some test conditions it was not adaptive in other conditions. Our investigations into traits involved in mate choice established sex-specific genetic variation in cuticular hydrocarbons and the genetic architecture of this trait was found to sex-specific evolution of cuticular hydrocarbons under natural and sexual selection. Additionally, we found that a secondary sexual character, the sex combs was positively allometric – just like most signalling and weapon traits, and there was no association between trait fluctuating asymmetry and trait size. These findings collectively indicate that sexual selection in D. simulans is consistent with classical models of this process.

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Fetter, Karl Christian. "Natural Selection For Disease Resistance In Hybrid Poplars Targets Stomatal Patterning Traits And Regulatory Genes". ScholarWorks @ UVM, 2019. https://scholarworks.uvm.edu/graddis/1162.

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The evolution of disease resistance in plants occurs within a framework of interacting phenotypes, balancing natural selection for life-history traits along a continuum of fast-growing and poorly defended, or slow-growing and well-defended lifestyles. Plant populations connected by gene flow are physiologically limited to evolving along a single axis of the spectrum of the growth-defense trade-off, and strong local selection can purge phenotypic variance from a population or species, making it difficult to detect variation linked to the trade-off. Hybridization between two species that have evolved different growth-defense trade-off optima can reveal trade-offs hidden in either species by introducing phenotypic and genetic variance. Here, I investigated the phenotypic and genetic basis for variation of disease resistance in a set of naturally formed hybrid poplars. The focal species of this dissertation were the balsam poplar (Populus balsamifera), black balsam poplar (P. trichocarpa), narrowleaf cottonwood (P. angustifolia), and eastern cottonwood (P. deltoides). Vegetative cuttings of samples were collected from natural populations and clonally replicated in a common garden. Ecophysiology and stomata traits, and the severity of poplar leaf rust disease (Melampsora medusae) were collected. To overcome the methodological bottleneck of manually phenotyping stomata density for thousands of cuticle micrographs, I developed a publicly available tool to automatically identify and count stomata. To identify stomata, a deep con- volutional neural network was trained on over 4,000 cuticle images of over 700 plant species. The neural network had an accuracy of 94.2% when applied to new cuticle images and phenotyped hundreds of micrographs in a matter of minutes. To understand how disease severity, stomata, and ecophysiology traits changed as a result of hybridization, statistical models were fit that included the expected proportion of the genome from either parental species in a hybrid. These models in- dicated that the ratio of stomata on the upper surface of the leaf to the total number of stomata was strongly linked to disease, was highly heritable, and wass sensitive to hybridization. I further investigated the genomic basis of stomata-linked disease variation by performing an association genetic analysis that explicitly incorporated admixture. Positive selection in genes involved in guard cell regulation, immune sys- tem negative regulation, detoxification, lipid biosynthesis, and cell wall homeostasis were identified. Together, my dissertation incorporated advances in image-based phenotyping with evolutionary theory, directed at understanding how disease frequency changes when hybridization alters the genomes of a population.

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12

Okawa, Marina Sayuri. ""Estudo do tamanho dos dentes naturais superiores e dentes artificiais de diferentes marcas comerciais"". Universidade de São Paulo, 2005. http://www.teses.usp.br/teses/disponiveis/23/23137/tde-12112005-094121/.

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Neste estudo analisou-se o tamanho de dentes naturais superiores de 119 indivíduos com idade entre 20 e 30 anos. Mediu-se a largura e a altura de todos os dentes superiores em modelos de gesso, com auxílio de um paquímetro digital. Aferiu-se também o tamanho de dentes artificiais de três marcas comerciais. Essa análise permitiu a identificação do que freqüentemente ocorre na dentição natural. Concluiu-se que: aproximadamente 48% dos incisivos centrais superiores naturais possuem a largura maior que 9,0mm. Em contrapartida, somente 14,28% dos incisivos centrais superiores artificiais analisados possuíam essa dimensão. Aproximadamente 64% dos indivíduos da pesquisa possuíam o dente 14 com largura maior que 7,0mm. Nas cartelas de dentes artificiais aferidas, encontrou-se apenas um modelo com dimensão mesiodistal superior a 7,0mm. Cerca de 74% dos primeiros molares superiores naturais possuíam altura menor que 7,0mm. Somente um modelo artificial possui altura menor que 7,0mm. A adequação das dimensões dos dentes artificiais facilitaria a montagem dos dentes e traria a estética almejada ao portador de reabilitações protéticas.
In this study, the size of natural maxillary teeth of 119 individuals between 20 and 30 years old were analyzed. The width and the height of all of the upper teeth on the casts were measured with a digital caliper. The size of the artificial teeth of three commercial marks was also checked. That analysis allowed the identification of what frequently occurs in the natural dentition. The conclusion was that: approximately 48% of the width of natural maxillary central incisor was greater than 9,0mm. However, only 14,28% of the artificial central upper incisor analyzed had that dimension. Approximately 64% of the population in the research had tooth 14 with width larger than 7,0mm. In the moulds of the teeth available, was found only a model with mesiodistal dimension over 7,0mm. Around 74% of the height of natural maxillary first molars was smaller than 7,0mm. Only an artificial model had height smaller than 7,0mm. The adaptation of the dimensions by artificial teeth would facilitate the assembly of the teeth and would bring the esthetics desired for to the user of the prosthetic replacements.

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Dahl, Jonas. "Feature Selection for Sentiment Analysis of Swedish News Article Titles". Thesis, KTH, Skolan för elektroteknik och datavetenskap (EECS), 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-233534.

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The aim of this study was to elaborate the possibilities of sentiment analyzing Swedish news article titles using machine learning approaches and find how the text is best represented in such conditions. Sentiment analysis has traditionally been conducted by part-of-speech tagging and counting word polarities, which performs well for large domains and in absence of large sets of training data. For narrower domains and previously labeled data, supervised learning can be used. The work of this thesis tested the performance of a convolutional neural network and a Support Vector Machine on different sets of data. The data sets were constructed to represent various language features. This included for example a simple unigram bag-of-words model storing word counts, a bigram bag-of-words model to include the ordering of words and an integer vector summary of the title. The study concluded that each of the tested feature sets gave information about the sentiment to various extents. The neural network approach with all feature sets combined performed better than the two annotators of the study. Despite the limited data set, overfitting did not seem to be a problem when using the features together.
Målet med detta arbete var att undersöka möjligheten till sentimentanalys av svenska nyhetsrubriker med hjälp av maskininlärning och förstå hur dessa rubriker bäst representeras. Sentimentanalys har traditionellt använt ordklassmärkning och räknande av ordpolariteter, som fungerar bra för stora domäner där avsaknaden av större uppmärkt träningsdata är stor. För mindre domäner och tidigare uppmärkt data kan övervakat lärande användas. Inom ramen för detta arbete undersöktes ett artificiellt neuronnät med faltning och en stödvektormaskin på olika datamängder. Datamängderna formades för att representera olika språkegenskaper. Detta inkluderade bland annat en enkel ordräkningsmodell, en bigramräkningsmodell och en heltalssummering av generella egenskaper för rubriken. I studien dras slutsatsen att varje datamängd innebar att ny information kunde tillföras i olika stor utsträckning. Det artificiella neuronnätet med alla datamängder tillsammans presterade bättre än de två personer som märkte upp data till denna studie. Trots en begränsad datamängd inträffade verkade inte modellerna övertränas.

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Cruz, Rossana Moreno Santa. "An?lise e otimiza??o de superf?cies seletivas de Frequ?ncia utilizando redes neurais artificiais e algoritmos de otimiza??o natural". Universidade Federal do Rio Grande do Norte, 2009. http://repositorio.ufrn.br:8080/jspui/handle/123456789/15134.

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The bidimensional periodic structures called frequency selective surfaces have been well investigated because of their filtering properties. Similar to the filters that work at the traditional radiofrequency band, such structures can behave as band-stop or pass-band filters, depending on the elements of the array (patch or aperture, respectively) and can be used for a variety of applications, such as: radomes, dichroic reflectors, waveguide filters, artificial magnetic conductors, microwave absorbers etc. To provide high-performance filtering properties at microwave bands, electromagnetic engineers have investigated various types of periodic structures: reconfigurable frequency selective screens, multilayered selective filters, as well as periodic arrays printed on anisotropic dielectric substrates and composed by fractal elements. In general, there is no closed form solution directly from a given desired frequency response to a corresponding device; thus, the analysis of its scattering characteristics requires the application of rigorous full-wave techniques. Besides that, due to the computational complexity of using a full-wave simulator to evaluate the frequency selective surface scattering variables, many electromagnetic engineers still use trial-and-error process until to achieve a given design criterion. As this procedure is very laborious and human dependent, optimization techniques are required to design practical periodic structures with desired filter specifications. Some authors have been employed neural networks and natural optimization algorithms, such as the genetic algorithms and the particle swarm optimization for the frequency selective surface design and optimization. This work has as objective the accomplishment of a rigorous study about the electromagnetic behavior of the periodic structures, enabling the design of efficient devices applied to microwave band. For this, artificial neural networks are used together with natural optimization techniques, allowing the accurate and efficient investigation of various types of frequency selective surfaces, in a simple and fast manner, becoming a powerful tool for the design and optimization of such structures
As estruturas planares peri?dicas bidimensionais, conhecidas como Superf?cies Seletivas de Frequ?ncia, t?m sido bastante estudadas por causa da propriedade de filtragem de frequ?ncia que apresentam. Similares aos filtros que operam na faixa tradicional de radiofrequ?ncia, tais estruturas podem apresentar caracter?sticas espectrais de filtros rejeitafaixa ou passa-faixa, dependendo do tipo de elemento do arranjo (patch ou abertura, respectivamente) e podem ser utilizadas em uma variedade de aplica??es, tais como radomes, refletores dicr?icos, filtros de micro-ondas, condutores magn?ticos artificiais, absorvedores etc. Para melhorar o desempenho de tais dispositivos eletromagn?ticos e investigar suas propriedades, muitos estudiosos t?m analisado v?rios tipos de estruturas peri?dicas: superf?cies seletivas de frequ?ncia reconfigur?veis, filtros de m?ltiplas camadas seletivas, al?m de arranjos peri?dicos impressos sobre substratos diel?tricos anisotr?picos e que utilizam geometrias fractais na sua forma??o. Em geral, n?o existe uma solu??o anal?tica diretamente extra?da a partir da resposta em frequ?ncia de um dispositivo; desta forma, a an?lise de suas caracter?sticas espectrais requer a aplica??o de t?cnicas de onda completa rigorosas, como o m?todo da equa??o integral, por exemplo. Al?m disso, devido ? complexidade computacional exigida para a implementa??o destes m?todos, muitos estudiosos ainda utilizam a investiga??o por tentativa e erro, para alcan?ar crit?rios satisfat?rios ao projeto dos dispositivos. Como este procedimento ? muito trabalhoso e dependente do homem, faz-se necess?rio o emprego de t?cnicas de otimiza??o que acelerem a obten??o de estruturas peri?dicas com especifica??es de filtragem desejadas. Alguns autores t?m utilizado redes neurais artificiais e algoritmos de otimiza??o natural, como os algoritmos gen?ticos e a otimiza??o por enxame de part?culas no projeto e otimiza??o das superf?cies seletivas de frequ?ncia. Este trabalho tem como objetivo realizar um estudo mais aprofundado sobre o comportamento eletromagn?tico das estruturas peri?dicas seletivas de frequ?ncia, possibilitando a obten??o de dispositivos eficientes e aplic?veis na faixa de micro-ondas. P ra isto, redes neurais artificiais s?o utilizadas em conjunto com t?cnicas de otimiza??o baseadas na natureza, permitindo a investiga??o precisa e eficiente de v?rios tipos de superf?cies seletivas de frequ?ncia, de forma simples e r?pida, tornando-se, portanto, uma poderosa ferramenta de projeto e otimiza??o de tais estruturas

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15

Vick, Jeffrey A. "Natural Selection". VCU Scholars Compass, 2006. http://scholarscompass.vcu.edu/etd/1254.

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My thesis work is about imagination. I use the collaborative efforts of the viewer's mind and my sculptures, or specimens, to make associations of real life animals. I feel this engages the viewer and in turn invites them to inspect the work on closer level. This is my ultimate goal in the work, to take hold of the viewer's curiosity and have them examine the work on a closer level.

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16

Bruno, Odemir Martinez. "Paralelismo em visão natural e artificial". Universidade de São Paulo, 2000. http://www.teses.usp.br/teses/disponiveis/76/76132/tde-26052014-161557/.

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Nesta tese são abordados, de maneira integrada, aspectos de paralelismo em visão natural e artificial, com discussões críticas das diversas áreas relacionadas. O paralelismo é discutido no sistema visual dos primatas, assim como suas principais contribuições e motivações incentivando a incorporação de paralelismo em sistemas de visão artificial. Um dos objetivos principais é fornecer as bases de paralelismo para o desenvolvimento do projeto Cyvis-1, uma proposta do Grupo de Pesquisa em Visão Cibernética (IFSC-USP) para visão versátil, com forte motivação biológica e baseada no córtex visual dos primatas. Para tanto, foi introduzida e implementada a proposta CVMP (Cybernetic Vision Message Passage), um conjunto de ferramentas para o desenvolvimento de aplicações paralelas em visão, tanto para sistemas distribuídos como para máquinas multiprocessadores. Baseada em programação orientada a objetos, interação homem-máquina, engenharia de software e programação visual, a proposta prima pelo desenvolvimento de forma simples e amigável. O CVMP é testado, avaliado e validado quanto a aspectos de funcionalidade e utilização, através da implementação paralela de diversos algoritmos de visão computacional e de processamento de imagens (operadores locais, transformada de Hough e transformada de Fourier, entre outros) os quais, além de ilustrar a utilização da ferramenta, são discutidos em termos de arquitetura e balanceamento de carga. São apresentadas três aplicações reais de sistemas paralelos de visão computacional, implementadas através do CVMP, demonstrando a eficiência da ferramenta, na implementação paralela, na utilização e cooperação de trabalho. Duas destas aplicações (integração de atributos visuais no projeto Cyvis-1 e um modelo de complexidade com base na percepção humana), foram desenvolvidas em conjunto com outros pesquisadores do Grupo de Pesquisa em Visão Cibernética. A terceira aplicação apresenta uma proposta do autor para um sistema automático de reconhecimento de plantas arbóreas (Botânica)
This thesis addresses, in an integrated way, the concept and usage of parallelism in natural and artificial vision. It starts by revising the primate visual system, and discussing how its principles and solutions can be extended to computational systems. One of the main objectives is to supply the parallelism backbone for the development of the Cyvis-1 System, which is a proposal of the Cybernetic Vision Research Group (IFSC-USP) for versatile vision, presenting a strong biological motivation, especially regarding the primate visual cortex. In order to achieve these objectives, the CVMP - Cybernetic Vision Message Passage - had to be developed, representing a set of simple and friendly parallel tools for computer vision applications in distributed and parallel (multiprocessor) systems, which is based on object oriented programming, human-machine interaction, software engineering and visual programming. The CVMP is tested, evaluated and validated with respect to functionality and utilization through the parallel implementation of several algorithms in computer vision and image processing (local operators, Hough transform, Fourier transform, etc.) which, in addition to illustrating the tools, are also discussed as far as their architecture and load balancing is concerned. Three applications of parallel computer vision systems to real situations are presented and implemented by using CVMP, corroborating the effectiveness of the tools in the parallel implementation, usage, and researcher integration. Two such applications (visual attributes integration in Cyvis-1 and a human complexity model) have been developed in collaboration with other researchers at the Cybernetic Vision Research Group. The third application presents the author\'s proposal for an automated system for arboreal plants recognition (Botany)

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17

Mirzakulova, Ekaterina Viktorovna. "Natural and Artificial Flavin-Based Catalysis". Bowling Green State University / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=bgsu1371415783.

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18

Freeland, Stephen J. "Natural selection and the genetic code". Thesis, University of Cambridge, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.313922.

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19

Aliyev, Elshan. "Development Of Expert System For Artificial Lift Selection". Master's thesis, METU, 2013. http://etd.lib.metu.edu.tr/upload/12615578/index.pdf.

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During the reservoir production life reservoir pressure will decline. Also after water breakthrough the fluid column weight will increase as hydrostatic pressure will increase because of increased water and oil mixture density. In this case, reservoir pressure may not be enough to lift up the fluid from bottom to the surface. These reasons decrease or even may cause to stop flowing of fluids from the well. Some techniques must be applied to prevent the production decline. Artificial lift techniques are applied to add energy to the produced fluids. It increases production rate by reducing down-hole pressure and so that by increasing the drawdown. Artificial lift techniques increase production either by pumping the produced fluid from the bottom to the surface or reduce bottom-hole pressure by reducing the fluid column weight as a result of decreased fluid mixture density. Artificial lift is used worldwide in approximately 85% of the wells, thus its impact in overall efficiency and profitability of production operations cannot be overemphasized. The most important problem is how to select optimum artificial lift techniques by taking into consideration the reservoir, well, environmental conditions. Selection of poor technique could cause decrease in efficiency and low profitability. As a result, it will lead to high operating expenses. Several techniques have been developed for selection of optimum artificial lift techniques. Expert Systems (ES) is the most suitable technique used in these selection techniques. Because the use and availability of required parameters is easy. Also in this selection method most of the artificial lift techniques are analyzed rather than other selection techniques. Expert Systems program mainly consist of three modules: (1) Expert Module, (2) Design Module, and (3) Economic Module. By entering required data to the system, program automatically suggests the feasible artificial lift techniques those might be used referring to given data. In this thesis work the artificial lift selection criteria and Expert Systems available in the literature have been studied. A Microsoft Windows based program has been developed to predict suitability of artificial lift methods for a given set of wells and produced fluid parameters. For the selected artificial lift method (i.e. sucker rod pump, ESP, gas lift, hydraulic pump, PCP) the program is able to perform basic calculations for the given data. Different case studies have been performed by running the program with actual data from fields. Well data of Venezuela, Azerbaijan and Iranian oil fields has been used in case studies. The results have been compared with previous studies those have been done on these fields with other selection techniques and current artificial lift techniques are being applied in selected wells. The obtained program results have been overlap with current real field application and previous studies.

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20

Duttala, Satish. "Virtual material processing artificial intelligence based process selection". Ohio : Ohio University, 2002. http://www.ohiolink.edu/etd/view.cgi?ohiou1174590077.

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21

Lindblom, Jessica. "Social Situatedness of Natural and Artificial Intelligence". Thesis, University of Skövde, Department of Computer Science, 2001. http://urn.kb.se/resolve?urn=urn:nbn:se:his:diva-626.

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The situated approach in cognitive science and artificial intelligence (AI) has argued since the mid-1980s that intelligent behaviour emerges as a result of a close coupling between agent and environment. Lately, many researchers have emphasized that in addition to the physical environment, the social environment must not be neglected. In this thesis we will focus on the nature of social situatedness, and the aim of this dissertation is to investigate its role and relevance for natural and artificial intelligence.

This thesis brings together work from separate areas, presenting different perspectives on the role and mechanisms social situatedness. More specifically, we will analyse Vygotsky's cognitive development theory, studies of primate (and avian) intelligence, and last, but not least, work in contemporary socially situated AI. These, at a first glance, quite different fields have a lot in common since they particularly stress the importance of social embeddedness for the development of individual intelligence.

Combining these separate perspectives, we analyse the remaining differences between natural and artificial social situatedness. Our conclusion is that contemporary socially artificial intelligence research, although heavily inspired by empirical findings in human infants, tends to lack the developmental dimension of situatedness. Further we discuss some implications for research in cognitive science and AI.

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22

Young, Rupert. "Visual control in natural and artificial systems". Thesis, University of Surrey, 2000. http://epubs.surrey.ac.uk/843083/.

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The desire to produce artificial vision systems which behave in an intelligent, humanlike way or which can autonomously and automatically perform tasks currently only performed by humans has been a goal of Artificial Intelligence research for many decades. Until recently much of the research concentrated on extracting visual representations of objects from single, static scenes. The last decade has seen an increase in interest concerning mobile robotics for navigation, planning and autonomous control as well as for the interpretation of events in real, dynamic scenes. Presented in this thesis is research on artificial vision systems from two different, but both necessary, standpoints. One concerns low-level vision-based behaviour of object tracking based upon a naturalistic theory of perception and behaviour within living systems. The other takes a more application and engineering based approach and its goal is to address high-level scene interpretation and control of processing resources. Numerous experiments are presented to demonstrate the various issues. The two main experiments, corresponding to the two research streams, are a system which is able to fixate complex multi-coloured objects and a fully integrated vision system for predicting and following, with a mobile sensor, events in a dynamic scene.

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23

Gillespie, Duncan O. S. "Natural selection on female reproduction in humans". Thesis, University of Sheffield, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.556741.

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Nearly all animals show senescent deterioration in physical condition with increasing age but the social and ecological context of how senescence is maintained by natural selection in wild populations remains unclear. I investigated human female reproductive ageing in a multi-generational dataset of pre-industrial Finns, which reconstructed family-lines from dates of birth, marriage and death and also contained information on family economicstatus. Family-building often required many births because not all offspring survived to reproduce themselves, however, high numbers of breeding offspring in landless economicstatus families limited total grand-offspring number (Chapter 1). The likelihood a female was married and thus had an opportunity to reproduce peaked at ages 30-40 years before declining due to female death or widowhood and low re-marriage probabilities for older widows with dependent offspring (Chapter 2). High birth order offspring had lower survival and reproductive success than their elder siblings, especially in landowning families where land inheritance favoured firstborns (Chapter 3). Female reproductive capability improved after the first birth but declined after many previous births, resulting in reduced infant survival and providing evidence for reproductive senescence (Chapter 4). These findings indicate that senescence could be maintained by two processes: declines in the exposure of genetic variation to natural selection at the oldest fertile ages; and because maternal reproductive investment in earlier born offspring has a greater effect on their reproductive success due to the advantage of earlier born offspring in sibling competition. There was also evidence that total lifetime reproduction could be limited by family resource availability. This illustrates how both ecological and social factors can constrain reproductive success while simultaneously maintaining senescence in the female life history.

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24

Exton, Samantha Jane. "Natural selection in fossil and recent molluscs". Thesis, University of Liverpool, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.366482.

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25

Hu, Min. "Positive natural selection in the human genome". Thesis, University of Cambridge, 2013. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.607687.

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26

Bentley, Michael. "The dynamical systems theory of natural selection". Thesis, University of Oxford, 2016. https://ora.ox.ac.uk/objects/uuid:ff01467a-c1ac-4852-a4b8-9055e9dcb1b0.

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Darwin's (1859) theory of evolution by natural selection accounts for the adaptations of organisms, but, as Fisher (1930) famously said, 'natural selection is not evolution.' Evolutionary theory has two major components: i) natural selection, which involves the underlying dynamics of populations; and ii) adaptive evolutionary change, which involves the optimisation of phenotypes for fitness maximisation. Many of the traditional theoretical frameworks in evolutionary theory have focussed on studying optimisation processes that generate biological adaptations. In recent years, however, a number of evolutionary theorists have turned to using frameworks such as the 'replicator dynamics' or 'eco-evolutionary dynamics', to explore the dynamics of natural selection. There has, however, been little attempt to explore how these dynamical systems frameworks relate to more traditional frameworks in evolutionary theory or how they incorporate the principles that embody the process of evolution by natural selection, namely, phenotypic variation, differential reproductive success, and heritability. In this thesis, I use these principles to provide the formal foundations of a general framework - a mathematical synthesis - in which the future state of an evolutionary system can be predicted from its present state; what I will call a 'dynamical systems theory of natural selection.' Given the state of an existing biological system, and a set of assumptions about how individuals within the system interact, the job of the dynamical systems theory of natural selection is no less than to predict the future in its entirety.

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27

Thivierge, Jean-Philippe. "Knowledge selection, mapping and transfer in artificial neural networks". Thesis, McGill University, 2005. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=111824.

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Knowledge-based Cascade-correlation is a neural network algorithm that combines inductive learning and knowledge transfer (Shultz & Rivest, 2001). In the present thesis, this algorithm is tested on several real-world and artificial problems, and extended in several ways. The first extension consists in the incorporation of the Knowledge-based Artificial Neural Network (KBANN; Shavlik, 1994) technique for generating rule-based (RBCC) networks. The second extension consists of the adaptation of the Optimal Brain Damage (OBD; LeCun, Denker, & Solla, 1990) pruning technique to remove superfluous connection weights. Finally, the third extension consists in a new objective function based on information theory for controlling the distribution of knowledge attributed to subnetworks. A simulation of lexical ambiguity resolution is proposed. In this study, the use of RBCC networks is motivated from a cognitive and neurophysiological perspective.

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28

Habermann, Mateus. "Band selection in hyperspectral images using artificial neural networks". Thesis, Compiègne, 2018. http://www.theses.fr/2018COMP2434/document.

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Les images hyperspectrales (HSI) fournissent des informations spectrales détaillées sur les objets analysés. Étant donné que différents matériaux ont des signatures spectrales distinctes, les objets ayant des couleurs et des formes similaires peuvent être distingués dans le domaine spectral. Toutefois, l’énorme quantité de données peut poser des problèmes en termes de stockage et de transmission des données. De plus, la haute dimensionnalité des images hyperspectrales peut entraîner un surajustement du classificateur en cas de données d'apprentissage insuffisantes. Une façon de résoudre de tels problèmes consiste à effectuer une sélection de bande (BS), car elle réduit la taille du jeu de données tout en conservant des informations utiles et originales. Dans cette thèse, nous proposons trois méthodes de sélection de bande différentes. La première est supervisée, conçu pour utiliser seulement 20% des données disponibles. Pour chaque classe du jeu de données, une classification binaire un contre tous utilisant un réseau de neurones est effectuée et les bandes liées aux poids le plus grand et le plus petit sont sélectionnées. Au cours de ce processus, les bandes les plus corrélées avec les bandes déjà sélectionnées sont rejetées. Par conséquent, la méthode proposée peut être considérée comme une approche de sélection de bande orientée par des classes. La deuxième méthode que nous proposons est une version non supervisée du premier framework. Au lieu d'utiliser les informations de classe, l'algorithme K-Means est utilisé pour effectuer une classification binaire successive de l'ensemble de données. Pour chaque paire de grappes, un réseau de neurones à une seule couche est utilisé pour rechercher l'hyperplan de séparation, puis la sélection des bandes est effectuée comme décrit précédemment. Pour la troisième méthode de BS proposée, nous tirons parti de la nature non supervisée des auto-encodeurs. Pendant la phase d'apprentissage, le vecteur d'entrée est soumis au bruit de masquage. Certaines positions de ce vecteur sont basculées de manière aléatoire sur zéro et l'erreur de reconstruction est calculée sur la base du vecteur d'entrée non corrompu. Plus l'erreur est importante, plus les fonctionnalités masquées sont importantes. Ainsi, à la fin, il est possible d'avoir un classement des bandes spectrales de l'ensemble de données
Hyperspectral images (HSIs) are capable of providing a detailed spectral information about scenes or objects under analysis. It is possible thanks to both numerous and contiguous bands contained in such images. Given that di_erent materials have distinct spectral signatures, objects that have similar colors and shape can be distinguished in the spectral domain that goes beyond the visual range. However, in a pattern recognition system, the huge amount of data contained in HSIs may pose problems in terms of data storage and transmission. Also, the high dimensionality of hyperspectral images can cause the overfitting of the classifer in case of insufficient training data. One way to solve such problems is to perform band selection(BS) in HSIs, because it decreases the size of the dataset while keeping both useful and original information. In this thesis, we propose three different band selection frameworks. The first one is a supervised one, and it is designed to use only 20% of the available training data. For each class in the dataset, a binary one-versus-all classification using a single-layer neural network is performed, and the bands linked to the largest and smallest coefficients of the resulting hyperplane are selected. During this process, the most correlated bands with the bands already selected are automatically discarded, following a procedure also proposed in this thesis. Consequently, the proposed method may be seen as a classoriented band selection approach, allowing a BS criterion that meets the needs of each class. The second method we propose is an unsupervised version of the first framework. Instead of using the class information, the K-Means algorithm is used to perform successive binary clustering of the dataset. For each pair of clusters, a single-layer neural network is used to find the separating hyperplane, then the selection of bands is done as previously described. For the third proposed BS framework, we take advantage of the unsupervised nature of autoencoders. During the training phase, the input vector is subjected to masking Noise - some positions of this vector are randomly flipped to zero and the reconstruction error is calculated based on the uncorrupted input vector. The bigger the error, the more important the masked features are. Thus, at the end, it is possible to have a ranking of the spectral bands of the dataset

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29

SILVA, Adenilton José da. "Artificial neural network architecture selection in a quantum computer". UNIVERSIDADE FEDERAL DE PERNAMBUCO, 2015. https://repositorio.ufpe.br/handle/123456789/15011.

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Miniaturisation of computers components is taking us from classical to quantum physics domain. Further reduction in computer components size eventually will lead to the development of computer systems whose components will be on such a small scale that quantum physics intrinsic properties must be taken into account. The expression quantum computation and a first formal model of a quantum computer were first employed in the eighties. With the discovery of a quantum algorithm for factoring exponentially faster than any known classical algorithm in 1997, quantum computing began to attract industry investments for the development of a quantum computer and the design of novel quantum algorithms. For instance, the development of learning algorithms for neural networks. Some artificial neural networks models can simulate an universal Turing machine, and together with learning capabilities have numerous applications in real life problems. One limitation of artificial neural networks is the lack of an efficient algorithm to determine its optimal architecture. The main objective of this work is to verify whether we can obtain some advantage with the use of quantum computation techniques in a neural network learning and architecture selection procedure. We propose a quantum neural network, named quantum perceptron over a field (QPF). QPF is a direct generalisation of a classical perceptron which addresses some drawbacks found in previous models for quantum perceptrons. We also present a learning algorithm named Superposition based Architecture Learning algorithm (SAL) that optimises the neural network weights and architectures. SAL searches for the best architecture in a finite set of neural network architectures and neural networks parameters in linear time over the number of examples in the training set. SAL is the first quantum learning algorithm to determine neural network architectures in linear time. This speedup is obtained by the use of quantum parallelism and a non linear quantum operator.
A miniaturização dos componentes dos computadores está nos levando dos domínios da física clássica aos domínios da física quântica. Futuras reduções nos componentes dos computadores eventualmente levará ao desenvolvimento de computadores cujos componentes estarão em uma escala em que efeitos intrínsecos da física quântica deverão ser considerados. O termo computação quântica e um primeiro modelo formal de computação quântica foram definidos na década de 80. Com a descoberta no ano de 1997 de um algoritmo quântico para fatoração exponencialmente mais rápido do que qualquer algoritmo clássico conhecido a computação quântica passou a atrair investimentos de diversas empresas para a construção de um computador quântico e para o desenvolvimento de algoritmos quânticos. Por exemplo, o desenvolvimento de algoritmos de aprendizado para redes neurais. Alguns modelos de Redes Neurais Artificiais podem ser utilizados para simular uma máquina de Turing universal. Devido a sua capacidade de aprendizado, existem aplicações de redes neurais artificiais nas mais diversas áreas do conhecimento. Uma das limitações das redes neurais artificiais é a inexistência de um algoritmo com custo polinomial para determinar a melhor arquitetura de uma rede neural. Este trabalho tem como objetivo principal verificar se é possível obter alguma vantagem no uso da computação quântica no processo de seleção de arquiteturas de uma rede neural. Um modelo de rede neural quântica denominado perceptron quântico sobre um corpo foi proposto. O perceptron quântico sobre um corpo é uma generalização direta de um perceptron clássico que resolve algumas das limitações em modelos de redes neurais quânticas previamente propostos. Um algoritmo de aprendizado denominado algoritmo de aprendizado de arquitetura baseado no princípio da superposição que otimiza pesos e arquitetura de uma rede neural simultaneamente é apresentado. O algoritmo proposto possui custo linear e determina a melhor arquitetura em um conjunto finito de arquiteturas e os parâmetros da rede neural. O algoritmo de aprendizado proposto é o primeiro algoritmo quântico para determinar a arquitetura de uma rede neural com custo linear. O custo linear é obtido pelo uso do paralelismo quântico e de um operador quântico não linear.

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30

Pires, André Rama. "A evidência do natural". Master's thesis, Universidade de Lisboa. Faculdade de Arquitetura, 2016. http://hdl.handle.net/10400.5/12661.

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31

Woolfson, Adrian. "Natural and artificial forms of human CD1 genes". Thesis, University of Cambridge, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.282946.

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32

Koroidov, Sergey. "Water splitting in natural and artificial photosynthetic systems". Doctoral thesis, Umeå universitet, Kemiska institutionen, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-86363.

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Photosynthesis is the unique biological process that converts carbon dioxide into organic compounds, for example sugars, using the energy of sunlight. Thereby solar energy is converted into chemical energy. Nearly all life depends on this reaction, either directly, or indirectly as the ultimate source of their food. Oxygenic photosynthesis occurs in plants, algae and cyanobacteria. This process created the present level of oxygen in the atmosphere, which allowed the formation of higher life, since respiration allows extracting up to 15-times more energy from organic matter than anaerobic fermentation. Oxygenic photosynthesis uses as substrate for the ubiquitous water. The light-induced oxidation of water to molecular oxygen (O2), catalyzed by the Mn4CaO5 cluster associated with the photosystem II (PS II) complex, is thus one of the most important and wide spread chemical processes occurring in the biosphere. Understanding the mechanism of water-oxidation by the Mn4CaO5 cluster is one of today’s great challenges in science. It is believed that one can extract basic principles of catalyst design from the natural system that than can be applied to artificial systems. Such systems can be used in the future for the generation of fuel from sunlight. In this thesis the light-induced production of molecular oxygen and carbon dioxide (CO2) by PSII was observed by membrane-inlet mass spectrometry. By analyzing this observation is shown that CO2 not only is the substrate in photosynthesis for the production of sugars, but that it also regulates the efficiency of the initial steps of the electron transport chain of oxygenic photosynthesis by acting, in form of HCO3-, as acceptor for protons produced during water-splitting. This finding concludes the 50-years old search for the function of CO2/HCO3− in photosynthetic water oxidation. For understanding the mechanism of water oxidation it is crucial to resolve the structures of all oxidation states, including transient once, of the Mn4CaO5 cluster. With this application in mind a new illumination setup was developed and characterized that allowed to bring the Mn4CaO5 cluster of PSII microcrystals into known oxidation states while they flow through a narrow capillary. The optimized illumination conditions were employed at the X-ray free electron laser at the Linac Coherent Light Source (LCLS) to obtain simultaneous x-ray diffraction (XRD) and x-ray emission spectroscopy (XES) at room temperature. This two methods probe the overall protein structure and the electronic structure of the Mn4CaO5 cluster, respectively. Data are presented from both the dark state (S1) and the first illuminated state (S2) of PS II. This approach opens new directions for studying structural changes during the catalytic cycle of the Mn4CaO5 cluster, and for resolving the mechanism of O-O bond formation. In two other projects the mechanism of molecular oxygen formation by artificial water oxidation catalysts containing inexpensive and abundant elements were studied. Oxygen evolution catalyzed by calcium manganese and manganese only oxides was studied in 18O-enriched water. It was concluded that molecular oxygen is formed by entirely different pathways depending on what chemical oxidant was used. Only strong non-oxygen donating oxidants were found to support ‘true’ water-oxidation. For cobalt oxides a study was designed to understand the mechanistic details of how the O-O bond forms. The data demonstrate that O-O bond formation occurs by direct coupling between two terminal water-derived ligands. Moreover, by detailed theoretical modelling of the data the number of cobalt atoms per catalytic site was derived.

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33

Vasconcelos, Margarida Perloiro Morgadinho Pablo. "Densidade urbana entre o natural e o artificial". Master's thesis, Universidade de Lisboa, Faculdade de Arquitetura, 2017. http://hdl.handle.net/10400.5/14436.

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34

Svedin, Nina. "Natural and Sexual Selection in a Natural Hybrid Zone of Ficedula Flycatchers". Doctoral thesis, Uppsala : Acta Universitatis Upsaliensis, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-7372.

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35

Huisman, Jisca. "Gene Flow and Natural Selection in Atlantic Salmon". Doctoral thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for biologi, 2012. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-16991.

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36

Reardon, James T. "Natural selection and evolutionary ecology in Anolis oculatus". Thesis, Bangor University, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.297668.

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37

Beckley, Colin. "Natural selection and natural processes : a philosophical examination of the processes of evolution". Thesis, Oxford Brookes University, 2012. https://radar.brookes.ac.uk/radar/items/76e8697b-c2b8-4d91-8790-08b637fcbc79/1/.

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This thesis concerns evolution and how it is explained. The ambition here is to identify clearly the many aspects of evolution, and to evaluate past and present explanations of evolution for their coherence and validity. Historically natural selection has been taken to be the central and main explanans, with other explanations playing lesser roles. Here it will be argued that the sheer complexity and diversity within nature cannot be accounted for by any single explanatory mechanism and that a plurality of explanatory mechanisms is required. Loading natural selection with the main weight of explanation is an overburden which, far from strengthening its explanatory powers, actually renders it vacuous. A critical historical and philosophical examination of the concept of natural selection reveals that it has never received a formal scientific definition that commands universal respect. This has created a problem of demarcation between that which natural selection can legitimately be said to explain and that which it cannot. In fact, the ontology of natural selection is equivocal, giving rise to the many controversies that have plagued evolutionary biology. The disambiguation of the concept of natural selection is the principle aim of this thesis and guidelines on how this should be accomplished are provided. However, should these reforming guidelines fail to achieve a consensus then a more radical alternative is proposed. It is recommended that the selective terminology is replaced with the less anomalous and demanding principle of ‘meeting the conditions of existence’. Moreover, talk of the evolution and origins by means of natural selection is to be replaced by talk of evolution and origins by means of natural processes. Finally, drawing from a ‘Structuralist’ alternative, it will be demonstrated that biological evolution should not be divorced from general or cosmological evolution. Rather, elucidation should be drawn more deeply from the fields of physics, chemistry, mathematics and topology, without the use of selection-tinted spectacles.

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38

Säberg, Mikael. "Sustainability of Artificial Turf Fields : Comparative life cycle assessment of artificial and natural turf fields". Thesis, Linköpings universitet, Industriell miljöteknik, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-177901.

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Soccer accounts for a third of the Swedish sports movement with 3 503 fields of both natural and artificial turf. The European Union will make a decision in 2021 on how to handle the issue of rubber performance infill. This infill can be found in artificial turf fields and are used for performance properties. The problem with this infill is the microplastics that spreads into the nature which is considered as toxic. Because of this the EU have decided to either ban or provide mandatory rules to reduce the spread of rubber performance infill. The north and the majority of Sweden’s climate is not adapted for play of soccer on natural turf according to FIFA, and EU want to ban or provide mandatory rules for artificial turfs. This action from the EU can perturb the entire Swedish sports movement since soccer accounts for a third of that movement. This study was therefore created to show if artificial turf fields are as bad for the environment as rumours has said compared with the natural turfs. To investigate this, a life cycle assessment (LCA) was performed regarding the global warming potential (GWP) and embodied water consumption for three different field types: an artificial turf field with recycled SBR, an artificial turf field with cork and a natural turf field. The result visualised that a natural turf field had the highest embodied water consumption and the highest impact on the GWP of a ten-year life cycle while the artificial turf field with recycled SBR had the least embodied water consumption and the least impact on the GWP. The findings of this LCA were that Sweden for the moment is dependent on artificial turf and the rubber performance infill, since the material properties are the best adapted to their climate. Therefore, a ban would be a risk for the Swedish sports movement. It was also revealed that natural turf fields in Sweden consumes at least 50 % municipal drinking water when irrigate. The high GWP impact came from the production of fertilisers (NPK). This report has shown how artificial turf and natural turf can work together in an industrial symbiosis by making the artificial turf field constructed to collect rainwater and use that water to irrigate the natural turf with.

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39

Li, Shanghao. "Theoretical Insight into Mechanisms of Natural and Artificial Metalloproteases". Scholarly Repository, 2011. http://scholarlyrepository.miami.edu/oa_theses/265.

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In this study, theoretical and computational approaches have been utilized to investigate the mechanisms of natural and artificial metalloproteases. The active sites of most natural metalloproteases contain a tetrahedral zinc center, coordinated by three amino acid residues combinated from His(N), Cys(S), Glu(O), and Asp(O) with a water molecule as the fourth ligand. However, the roles played by the ligands environment in the catalytic functions of enzyme are not clear. In this study, the effects of different ligand combinations (NS2, N2S, N2O, N3, S3, NO2 and NSO) in the mechanism were investigated energy barriers were compared. The machanism and energetics of the substrate bound artificial metalloproteases Ni(II)cyclen (cyclen: 1,4,7,10-tetraazacyclododecane) and Cd(II)cyclen have been investigated. In addition, the mechanism of hydrolysis of Phe-Phe peptide bond catalyzed by another artificial metalloprotease [Pd(H2O)4]2+ has also been studied.

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40

Arican, Zafer. "Vision-based Robot Localization Using Artificial And Natural Landmarks". Master's thesis, METU, 2004. http://etd.lib.metu.edu.tr/upload/12605333/index.pdf.

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In mobile robot applications, it is an important issue for a robot to know where it is. Accurate localization becomes crucial for navigation and map building applications because both route to follow and positions of the objects to be inserted into the map highly depend on the position of the robot in the environment. For localization, the robot uses the measurements that it takes by various devices such as laser rangefinders, sonars, odometry devices and vision. Generally these devices give the distances of the objects in the environment to the robot and proceesing these distance information, the robot finds its location in the environment. In this thesis, two vision-based robot localization algorithms are implemented. The first algorithm uses artificial landmarks as the objects around the robot and by measuring the positions of these landmarks with respect to the camera system, the robot locates itself in the environment. Locations of these landmarks are known. The second algorithm instead of using artificial landmarks, estimates its location by measuring the positions of the objects that naturally exist in the environment. These objects are treated as natural landmarks and locations of these landmarks are not known initially. A three-wheeled robot base on which a stereo camera system is mounted is used as the mobile robot unit. Processing and control tasks of the system is performed by a stationary PC. Experiments are performed on this robot system. The stereo camera system is the measurement device for this robot.

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41

Rosolem, Rafael. "Land Surface Processes In Natural and Artificial Tropical Ecosystems". Diss., The University of Arizona, 2010. http://hdl.handle.net/10150/194510.

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Land Surface Parameterization (LSP) schemes have evolved from simple tipping-bucket models to fully interactive models, including parameterizations which account for exchanges of momentum, energy, mass, and biogeochemistry. As the demand for greater realism has increased, so has the complexity of LSPs which now includes some parameters that may not be universally relevant to all regions of the globe. The performance of LSP schemes depends on the magnitude of structural, data-related (input and output), and parameter uncertainties in the model. Parameter estimation uncertainty can be reduced by calibrating LSPs against measurements available at field sites. Given the multiple outputs of the models, multi-objective optimization approaches are performed. Some of the parameter values used in LSPs have originally obtained from laboratory studies which analyzed plant behavior under a range of conditions in enclosed chambers. The research described in this dissertation takes advantage of currently available data from several eddy covariance flux towers located mainly in the Brazilian Amazon basin to estimate parameter values of a widely-used LSP scheme, version 3 of the Simple Biosphere model (SiB3). Background climatological data was used to assess the representativeness of the data collection period that might have affected model calibration. Variance-based sensitivity analysis was then used to investigate potential structural deficiencies in SiB3 and to reduce the dimensionality of the subsequent optimization by identifying those model parameters that merit calibration. Finally, some structural and conceptual aspects of SiB3 were tested inside Biosphere 2 Tropical Rain Forest biome (B2-TRF) under meteorological conditions that resemble those predicted in future climate scenarios for the Amazon basin.

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42

Cameron, Craig G. "Natural and artificial fluorescence on 3-dimensional bioorganic nanostructures". Diss., Georgia Institute of Technology, 2014. http://hdl.handle.net/1853/53451.

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A challenge exists for understanding the origin of color for structurally colored, 3-dimensional bioorganic nanostructures, such as the scales of butterflies, beetles, and moths. Complex, hierarchical structures found within such scales create the overall scale appearance. The controlled alteration of color through material deposition and the addition of new optical functionalities to such structures are other areas of scientific interest. This dissertation addresses these challenges with a first-of-its-kind, systematic isolation (deconstruction) of scale component nanostructures, followed by evaluation of optical property/structure correlations. The additive deposition (constructive alteration) of emissive materials to structurally-colored templates complements this deconstructive approach towards understanding the origin of color in butterfly scales. Discoveries made through this work may help advance the bioinspired design of synthetic optical structures and subsequent color control through the addition of multilayered, emissive optical components.

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43

Sichula, Vincent A. "Flavins and Their Analogues as Natural and Artificial Catalysts". Bowling Green State University / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=bgsu1294288149.

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44

Smith, Terrance J. "Foot and Ankle Injuries: Artificial Turf vs. Natural grass". Wittenberg University Honors Theses / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=wuhonors1470240556.

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45

Oliveira, Inês Mouco de. "Entre o natural e o artificial, uma topografia urbana". Master's thesis, Universidade de Lisboa. Faculdade de Arquitetura, 2016. http://hdl.handle.net/10400.5/13556.

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46

McCrae, Richard. "The Impact of Cost on Feature Selection for Classifiers". Thesis, Nova Southeastern University, 2018. http://pqdtopen.proquest.com/#viewpdf?dispub=13423087.

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Supervised machine learning models are increasingly being used for medical diagnosis. The diagnostic problem is formulated as a binary classification task in which trained classifiers make predictions based on a set of input features. In diagnosis, these features are typically procedures or tests with associated costs. The cost of applying a trained classifier for diagnosis may be estimated as the total cost of obtaining values for the features that serve as inputs for the classifier. Obtaining classifiers based on a low cost set of input features with acceptable classification accuracy is of interest to practitioners and researchers. What makes this problem even more challenging is that costs associated with features vary with patients and service providers and change over time.

This dissertation aims to address this problem by proposing a method for obtaining low cost classifiers that meet specified accuracy requirements under dynamically changing costs. Given a set of relevant input features and accuracy requirements, the goal is to identify all qualifying classifiers based on subsets of the feature set. Then, for any arbitrary costs associated with the features, the cost of the classifiers may be computed and candidate classifiers selected based on cost-accuracy tradeoff. Since the number of relevant input features k tends to be large for typical diagnosis problems, training and testing classifiers based on all 2^k – 1 possible non-empty subsets of features is computationally prohibitive. Under the reasonable assumption that the accuracy of a classifier is no lower than that of any classifier based on a subset of its input features, this dissertation aims to develop an efficient method to identify all qualifying classifiers.

This study used two types of classifiers—artificial neural networks and classification trees—that have proved promising for numerous problems as documented in the literature. The approach was to measure the accuracy obtained with the classifiers when all features were used. Then, reduced thresholds of accuracy were arbitrarily established which were satisfied with subsets of the complete feature set. Threshold values for three measures—true positive rates, true negative rates, and overall classification accuracy were considered for the classifiers. Two cost functions were used for the features; one used unit costs and the other random costs. Additional manipulation of costs was also performed.

The order in which features were removed was found to have a material impact on the effort required (removing the most important features first was most efficient, removing the least important features first was least efficient). The accuracy and cost measures were combined to produce a Pareto-Optimal Frontier. There were consistently few elements on this Frontier. At most 15 subsets were on the Frontier even when there were hundreds of thousands of acceptable feature sets. Most of the computational time is taken for training and testing the models. Given costs, models in the Pareto-Optimal Frontier can be efficiently identified and the models may be presented to decision makers. Both the Neural Networks and the Decision Trees performed in a comparable fashion suggesting that any classifier could be employed.

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47

Shi, Arthur Q. X. "Structural Damage Assessment Using Artificial Neural Networks and Artificial Immune Systems". DigitalCommons@CalPoly, 2015. https://digitalcommons.calpoly.edu/theses/1499.

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Structural health monitoring (SHM) systems have been technologically advancing over the past few years. Improvements in fabrication and microelectronics allow the development of highly sophisticated sensor arrays, capable of detecting and transmitting an unprecedented amount of data. As the complexity of the hardware increases, research has been performed in developing the means to best utilize and effectively process the data. Algorithms from other computational fields are being introduced for the first time into SHM systems. Among them, the artificial neural network (ANN) and artificial immune systems (AIS) show great potential. In this thesis, features are extracted out of the acceleration data with the use of discrete wavelet transforms (DWT)s first. The DWT coefficients are used to calculate energy ratios, which are then classified using a neural network and an AIS algorithm known as negative selection (NS). The effectiveness of both methods are validated using simulated acceleration data of a four story structure exhibiting various damage states via computer simulation.

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48

Al-Enezi, Jamal. "Artificial immune systems based committee machine for classification application". Thesis, Brunel University, 2012. http://bura.brunel.ac.uk/handle/2438/6826.

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A new adaptive learning Artificial Immune System (AIS) based committee machine is developed in this thesis. The new proposed approach efficiently tackles the general problem of clustering high-dimensional data. In addition, it helps on deriving useful decision and results related to other application domains such classification and prediction. Artificial Immune System (AIS) is a branch of computational intelligence field inspired by the biological immune system, and has gained increasing interest among researchers in the development of immune-based models and techniques to solve diverse complex computational or engineering problems. This work presents some applications of AIS techniques to health problems, and a thorough survey of existing AIS models and algorithms. The main focus of this research is devoted to building an ensemble model integrating different AIS techniques (i.e. Artificial Immune Networks, Clonal Selection, and Negative Selection) for classification applications to achieve better classification results. A new AIS-based ensemble architecture with adaptive learning features is proposed by integrating different learning and adaptation techniques to overcome individual limitations and to achieve synergetic effects through the combination of these techniques. Various techniques related to the design and enhancements of the new adaptive learning architecture are studied, including a neuro-fuzzy based detector and an optimizer using particle swarm optimization method to achieve enhanced classification performance. An evaluation study was conducted to show the performance of the new proposed adaptive learning ensemble and to compare it to alternative combining techniques. Several experiments are presented using different medical datasets for the classification problem and findings and outcomes are discussed. The new adaptive learning architecture improves the accuracy of the ensemble. Moreover, there is an improvement over the existing aggregation techniques. The outcomes, assumptions and limitations of the proposed methods with its implications for further research in this area draw this research to its conclusion.

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49

Huas, Hugo y Titouan Jérome. "Artificial Spider Web : Selection of Polymeric Materials for Special Effects Applications". Thesis, KTH, Materialvetenskap, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-298418.

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Artificial spider webs are a challenge for the special eﬀects companies. The natural spider webs are displaying incredible mechanical properties combined with a low density and a high stickiness making them hard to reproduce. Throughout this project the aim is to produce artificial spider webs using a specific manufacturing method, pouring a mix of polymer and Naphtha oil into water to form the webs. This method was used in previous cinematic applications giving outstanding results for the artificial spider webs. Unfortunately, due to the loss of it, the specific parameters, tools and raw materials have to be found. A material selection is given leading to a specific choice of thermoplastic polymers. The selected material are then tested manually so they can be listed depending on the results obtained. Finally, the most promising material seems to be TPU, thermoplastic polyurethane; thanks to its excellent mechanical properties and good visual aspect.
Konstgjord spindelväv är en utmaning för specialeﬀektföretag. De naturliga spindelnäten visar otroliga mekaniska egenskaper i kombination med låg densitet och hög klibbighet vilket gör dem svåra att reproducera. Under hela detta projekt är målet att producera konstgjord spindelväv med hjälp av en specifik tillverkningsmetod, hälla en blandning av polymer och naftaolja i vatten för att bilda näten. Denna metod användes i tidigare filmiska applikationer och gav enastående resultat för de konstgjorda spindelnäten. Tyvärr, på grund av förlusten av det, måste de specifika parametrarna, verktygen och råvarorna hittas. Ett materialval ges vilket leder till ett specifikt val av termoplastiska polymerer. Det valda materialet testas sedan manuellt så att de kan listas beroende på de erhållna resultaten. Slutligen verkar det mest lovande materialet vara TPU, termoplastisk polyuretan; på grund av dess utmärkta mekaniska egenskaper och bra visuella aspekt.

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50

Andrews, Tessa Marie. "Natural selection in the field and in the classroom". Diss., Montana State University, 2012. http://etd.lib.montana.edu/etd/2012/andrews/AndrewsT0512.pdf.

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This dissertation examined natural selection in westslope cutthroat trout (Oncorhynchus clarkii lewisi) and undergraduate learning in the subject area natural selection. Translocation-moving individuals to a new habitat to establish, re-establish or supplement a population-is a crucial management strategy for cutthroat trout. One of the major questions managers face in a translocation is which population(s) should contribute individuals? Unfortunately, we often know little about the differences among potential contributing population. The goal of the first half of this dissertation was to look for differences in performance among individuals from five populations of westslope cutthroat trout. I assessed survival, growth, and condition (Chapter 2) and dispersal (Chapter 3) following the translocation of embryos from these five populations to six introduction sites in Cherry Creek. No differences existed among these populations in relative survival, growth, or condition at age 1 or 2. In contrast, statistically significant differences existed in dispersal distance among these populations. These differences were consistent across some, but not all, introduction locations. As our knowledge of evolutionary biology has continued to grow, so too has our knowledge of how students learn evolution. Students taught using active learning strategies can learn substantially more about complex scientific concepts than students taught using primarily lectures. The goal of the second half of this dissertation was to further examine how students learn natural selection and how instructors facilitate that learning. I conducted a national survey of the relationship between an instructor's use of active learning strategies and how much students learned about natural selection (Chapter 4). I used a random sample of instructors from the largest and most prestigious universities in the country so that my results could be inferred to this large population of instructors. The degree to which instructors used active learning was NOT associated with student learning in this population of typical biology instructors. However, I found that a discussion of contemporary human evolution that used active learning strategies could effectively facilitate student learning of natural selection (Chapter 5). 'Co-authored by Bradley B. Shepard, Andrea R. Litt, Carter G. Kruse, Lee M. Nelson, Patrick Clancey, Alexandar V. Zale, Mark L Taper, Steven T. Kalinowski, Mary J. Leonard, and Clinton A. Colgrove.'

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