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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
71

Sensitivity of the EQ-5D-5L for fatigue, memory and concentration problems, and dyspnea, and their added value in patients after COVID-19 with persistent long-term symptoms : - An application of multiple linear regression and LASSO

Wadsten, Carl January 2023 (has links)
This thesis examined the sensitivity of the EQ-5D-5L instrument in measuring health-related quality of life (HRQoL) among patients with persistent symptoms following COVID-19, including fatigue, memory and concentration problems, and dyspnea. Additionally, it was analyzed whether adding these symptoms to the EQ-5D-5L improved the explained variance for HRQoL. Patients from Uppsala University Hospital, Sweden, answered a survey that included questions on five dimensions of health represented by the EQ-5D-5L and an additional question on general health score called EQ-VAS. Multiple linear regression, Spearman’s rank correlation coefficient, and Least Absolute Shrinkage and Selection Operator (LASSO) were used to examine the sensitivity of the EQ-5D-5L. For the explanatory analysis, the Adjusted 𝑅2 was used to evaluate explanatory power with and without the presence of the symptoms. The results showed that the EQ-5D-5L dimensions explained a moderate proportion of the variance for fatigue and memory/concentration problems and a weak proportion for dyspnea. The explanatory analysis provided findings that fatigue significantly improved the explained variance of EQ-VAS by 5.5%, adding memory/concentration problems only improved it marginally, and adding dyspnea was non-significant. Additionally, strong to moderate correlations between fatigue and memory/concentration problems were found with multiple dimensions of the EQ-5D-5L. These findings suggest that the EQ-5D-5L instrument may be a valuable tool in assessing HRQoL in patients with persistent COVID-19 symptoms and that adding fatigue to the EQ-5D-5L could be beneficial for improving explanatory power to HRQoL in patients suffering from infectious disease. / COMBAT post-covid
72

Trångboddhet i OECD : En jämförande tvärsnittsstudie om trångboddhet

Nykvist, Lucas January 2017 (has links)
Denna uppsats försöker besvara frågan: Vad förklarar skillnader i trångboddhet mellan OECD:s medlemsländer? Detta görs genom tvärsnittsstudie där jag analyserar vilken effekt faktorerna Hyresreglering, Reglering av byggbranschen, Demografiska förändringar, Styrande regeringsparti och Välstånd har på Trångboddheten. Tjugonio av OECD:s medlemsländer har tagits med i analysen. Med hjälp av en multipel linjär regression baserat på observationsdata från variablerna presenteras resultaten. Slutsatserna är att Reglering av byggbranschen och Välstånd har störst effekt på Trångboddheten. / This paper attempts to answer the research question: What explains the differences in housing density between the members of the OECD? This is done by a cross-sectional study in which I analyze the impact of rent regulation, regulation of the construction industry, demographic changes, executive government party and wealth has on the dependent variable housing density. Twenty-nine of the OECD members have been included in the analysis. The paper is using a multiple linear regression to analyze the results. The conclusions are that the regulation of the construction industry and wealth has the greatest effect on housing density.
73

An exploratory analysis of convoy protection using agent-based simulation

Hakola, Matthew B. 06 1900 (has links)
Approved for public release, distribution is unlimited / Recent insurgent tactics during Operation Iraqi Freedom (OIF) have demonstrated that coalition logistical convoys are vulnerable targets. This thesis examines the tactics, techniques and procedures (TTPs) used in convoy operations in an attempt to identify the critical factors that lead to mission success. A ground convoy operation scenario is created in the agentbased model (ABM) Map Aware Non-uniform Automata (MANA). The scenario models a generic logistical convoy consisting of security vehicles, logistical vehicles, an unmanned aerial vehicle (UAV) and an enemy ambushing force. The convoy travels along a main supply route (MSR) where it is ambushed by a small insurgent force. We use military experience, judgment and exploratory simulation runs to identify 11 critical factors within the created scenario. The data farming process and Latin Hypercube (LHC) experimental design technique are used to thoroughly examine the 11 factors. Using the 11 factors 516 design points are created and data farmed over to produce 25,800 observations. Additive multiple linear regression is used to fit a model to the 25,800 observations. From the created scenario it is concluded that: convoy mission success may be determined by only a few factors; the actions of logistical vehicles are more critical than those of security vehicles; UAVs provide a statistically significant advantage; and ABMs coupled with LHCs and data farming are valuable tools for understanding complex problems. / Captain, United States Marine Corps
74

Einführung in die Ökonometrie

Huschens, Stefan 30 March 2017 (has links) (PDF)
Die Kapitel 1 bis 6 im ersten Teil dieses Skriptes beruhen auf einer Vorlesung Ökonometrie I, die zuletzt im WS 2001/02 gehalten wurde, die Kapitel 7 bis 16 beruhen auf einer Vorlesung Ökonometrie II, die zuletzt im SS 2006 gehalten wurde. Das achte Kapitel enthält eine komprimierte Zusammenfassung der Ergebnisse aus dem Teil Ökonometrie I.
75

Modélisation statistique de l’érosion de cavitation d’une turbine hydraulique selon les paramètres d’opération

Bodson-Clermont, Paule-Marjolaine 03 1900 (has links)
Dans une turbine hydraulique, la rotation des aubes dans l’eau crée une zone de basse pression, amenant l’eau à passer de l’état liquide à l’état gazeux. Ce phénomène de changement de phase est appelé cavitation et est similaire à l’ébullition. Lorsque les cavités de vapeur formées implosent près des parois, il en résulte une érosion sévère des matériaux, accélérant de façon importante la dégradation de la turbine. Un système de détection de l’érosion de cavitation à l’aide de mesures vibratoires, employable sur les turbines en opération, a donc été installé sur quatre groupes turbine-alternateur d’une centrale et permet d’estimer précisément le taux d’érosion en kg/ 10 000 h. Le présent projet vise à répondre à deux objectifs principaux. Premièrement, étudier le comportement de la cavitation sur un groupe turbine-alternateur cible et construire un modèle statistique, dans le but de prédire la variable cavitation en fonction des variables opératoires (tels l’ouverture de vannage, le débit, les niveaux amont et aval, etc.). Deuxièmement, élaborer une méthodologie permettant la reproductibilité de l’étude à d’autres sites. Une étude rétrospective sera effectuée et on se concentrera sur les données disponibles depuis la mise à jour du système en 2010. Des résultats préliminaires ont mis en évidence l’hétérogénéité du comportement de cavitation ainsi que des changements entre la relation entre la cavitation et diverses variables opératoires. Nous nous proposons de développer un modèle probabiliste adapté, en utilisant notamment le regroupement hiérarchique et des modèles de régression linéaire multiple. / Cavitation erosion which results from repeated collapse of transient vapor cavities on solid surfaces is a constant problematic in hydraulic turbine runners and continues to enforce costly repair and loss of revenues. A vibratory detection system of cavitation erosion was installed 10 years ago for continuous monitoring of 4 hydropower units. A new hardware version of the system was developed and installed in 2010. This new system configuration is more reliable and allows more accurate evaluation of the cavitation erosion of the runners in kg/10 000 h. The first objective of this study is to investigate cavitation behavior upon one generating unit and to build a statistical model which will allow prediction of instant cavitation related to operating variables, such as gate opening, water flow, headwater level, tailwater levels, etc. The second objective is to develop a methodology for the reproducibility of the studies to other sites. A retrospective study will be conducted and we will mainly focus on data available since the system update in 2010. The preliminary analysis enhanced the complexity of the phenomenon. Indeed, changes in the relationship between cavitation and various operating variables were observed and could be due to a seasonal behavior or different operating conditions. Using hierarchical clustering and regression models, we formalize this heterogeneity by developing a model which includes operating variables such as active power, tailwater level and gate opening.
76

"Jag vill spara etiskt, men vad har jag för alternativ?" : En kvantitativ studie av etiska restriktioners påverkan på svenska fonders prestation

Atterby, Alfred, Ekström Hagevall, Adam, Wikström, Carl January 2019 (has links)
During the last few decades, the Swedish population has shown an increased interest in investment fund savings, and more than 60% of Swedish citizens are saving through funds today. In addition to this, awareness on climate change and related risks has increased, which has contributed to a greater focus on corporate sustainability among Swedish companies. As a result of these trends, there has been an increase in fund companies that are basing their investments on certain ethical restrictions, in order for private investors to save ethically. The purpose of this study was to examine how ethical restrictions affect the financial performance of Swedish funds with regards to risk-adjusted return. Previous studies have focused on comparing ethical and traditional funds, but this study chose not to make any difference between the two types of funds. The study's relevance is based on how it can make private investors aware of which ethical restrictions that have a negative impact on the risk-adjusted return, and how much each restriction decreases the return. A total of 101 Swedish funds were analyzed. Information about each fund's performance measures were retrieved from Morningstar, and is based on three years development. Information about each fund's ethical restrictions were retrieved from Hållbarhetsprofilen and their information pamphlets. With data about the performance measures Sharpe ratio, Alpha, and Treynor ratio, three statistical models were defined and analyzed with multiple linear regression analysis. Each model's reliability was assessed with residual analysis; the models were adjusted and improved if necessary. Hypotheses were evaluated with significance testing to answer the research questions. The results indicate that exclusion of tobacco and gambling companies affect the risk-adjusted return of Swedish funds negatively, while exclusion of alcohol companies affect the risk-adjusted return positively. This implies that private investors should save their money in Swedish funds that exclude alcohol companies in order to avoid lower risk-adjusted return. / Fondsparandet i Sverige har under de senaste decennierna ökat kraftigt och idag sparar över 60% av befolkningen i fonder. Utöver detta har bland annat miljömedvetenheten hos befolkningen ökat, vilket har bidragit till ett ökat engagemang i hållbarhetsfrågor hos företag. I kölvattnet av dessa trender har allt fler svenska fondbolag valt att införa etiska restriktioner på deras investeringar, så att fondsparare på ett enkelt sätt ska kunna investera hållbart. Syftet med denna studie var att undersöka hur etiska restriktioner påverkar svenska fonders prestation med avseende på riskjusterad avkastning. Där tidigare forskning har fokuserat på att jämföra etiska och traditionella fonder, valde denna studie istället att inte göra någon skillnad mellan de två fondtyperna. Studiens relevans baseras på hur studiens slutsatser kan hjälpa småsparare att bli medvetna om vilka etiska restriktioner som hämmar avkastningen och vad varje restriktion kostar investerare i potentiellt förlorad avkastning. Totalt har 101 svenska fonder undersökts. Information som gäller fondernas prestationsmått har hämtats från Morningstar, och baseras på tre års utveckling. Information om fondernas etiska restriktioner har hämtats från Hållbarhetsprofilen och fondernas informationsbroschyrer. Med insamlad data om prestationsmåtten Sharpekvoten, Alfa, och Treynorkvoten, har tre modeller definierats som sedan analyserats med multipel linjär regressionsanalys. Modellernas tillförlitlighet har sedan utvärderats med residualanalys; modellerna förbättrades om det fanns belägg för det. Utifrån signifikanstest har hypoteser utvärderats för att besvara studiens frågeställningar. Studiens resultat pekar på att exkludering av företag inom tobak- och spelbranschen påverkar svenska fonders riskjusterade avkastning negativt, medan exkludering av företag inom alkoholbranschen påverkar den positivt. Detta betyder alltså att småsparare bör investera i svenska fonder som väljer bort företag inom alkoholbranschen för att undvika låg avkastning.
77

L'usage du vélo en libre-service : impact de l'environnement socio-économique des stations sur la génération de la demande : application sur la Métropole de Lyon / The usage of bike sharing : impact of built environment of the stations on the generation of demand : the case of the metropolis of Lyon

Tran, Tien Dung 20 December 2016 (has links)
Dans un contexte de mobilité durable, le vélo en libre-service (VLS) représente un élément important dans les politiques de mobilité urbaine pour favoriser les modes doux dans le centre urbain. Son développement rapide dans le monde nécessite des recherches pour mieux comprendre le succès de ce mode de déplacement. Notre contribution à travers cette recherche est d’analyser les éléments socio-économiques importants ainsi que les caractéristiques du système VLS qui influent son usage pour construire des modèles de prédiction de la demande en VLS. Partant de l’hypothèse que les éléments socio-économiques autour des stations de VLS constituent des facteurs qualitativement et quantitativement explicatifs pour l’usage du VLS, notre démarche de recherche repose d’abord sur une analyse statistique, temporelle et spatiale des éléments explicatifs du système VLS pour ensuite les quantifier. Ces éléments sont utilisés pour modéliser la génération de la demande journalière en VLS par la méthode de régression linéaire multiple. Les modèles estimant les flux entrants et sortants journaliers en VLS ont été développés. Ils sont basés sur l’environnement socio-économique autour des stations et des variables d’offre de VLS. Ces modèles sont utiles pour comprendre le fonctionnement du système VLS, l’améliorer et estimer la demande des nouvelles stations dans une perspective d’élargissement d’un système VLS existant. Les modèles développés peuvent être également utilisés pour la localisation et le dimensionnement des stations d’un nouveau système VLS. La démarche de détermination, de quantification des variables explicatives et de modélisation forment un cadre de travail pour modéliser la demande d’autres modes de déplacement partagés. / In a context of sustainable transport, the bike sharing is an important factor in the policies to promote soft modes of transport in the urban center. Its rapid development in the world requires a need to deepen the usage of this mode of travel. Our contribution through this research is to analyze the important built-environment factors and the characteristics of bike sharing system that influence the use of bike sharing in order to build predictive models of demand for bike sharing. Assuming that socio-economic elements around the bike sharing stations are qualitatively and quantitatively explanatory for the use of bike sharing, our approach are based primarily on statistical analysis of temporal and spatial elements explaining bike sharing usage in order to determine and quantify the important built-environment variables. These variables are then used to model the generation of the daily demand of bike sharing using multiple linear regression method. The models estimating inflows and outflows of bike sharing using socioeconomic variables determined in a buffer area of each station are built. These models are useful for estimating the demand for new stations in an enlargement perspective of an existing bike sharing system or location and sizing of a new bike sharing system. The similar process of determination, quantification of the explanatory variables and modelling can be used to form a framework to predict the demand of other vehicle sharing systems.
78

Estatística espacial e sensoriamento remoto para a predição volumétrica em florestas de Eucalyptus spp. / Spatial Statistics and Remote Sensing applied to estimating volume in Eucalyptus spp. forests

Gasparoto, Esthevan Augusto Goes 12 February 2016 (has links)
O inventário florestal é uma das principais ferramentas na gestão dos recursos florestais, uma vez que as informações geradas por ele são utilizadas ao longo de toda a cadeia produtiva do setor. Desta forma, erros nas estimativas volumétricas dos inventários florestais devem ser controlados. Inúmeras informações podem ser obtidas a partir de imagens orbitais ou aerotransportadas, uma vez que podem cobrir facilmente toda a área de interesse, e estão comumente disponíveis em empresas florestais ou ao usuário final. A utilização de preditores derivados das imagens pode trazer benefícios para as estimativas do inventário florestal. Desta forma, a aplicação de técnicas de regressão linear múltipla (RLM) ganhou espaço no setor devido a sua facilidade de aplicação. Porém, a RLM não leva em consideração a dependência espacial entre as unidades amostrais, sendo que a geoestatística pode ser utilizada para predizer a distribuição espacial do estoque de madeira (VTCC) para uma dada região. A modelagem geoestatística mais simples como a krigagem ordinária (KO), por considerar apenas a dependência espacial entre os pontos não amostrados, pode apresentar erros de predição nestes locais. Tais erros podem ser reduzidos com a aplicação de técnicas mais robustas como a Krigagem com Deriva Externa (KDE), pois esta agrega as informações obtidas das imagens com a distribuição espacial do volume. Buscando-se avaliar as vantagens da integração do Sensoriamento Remoto (SR) ao inventário florestal foram testados 4 tipos diferentes de imagens; as oriundas dos satélites LANDSAT8, RAPIDEYE e GEOEYE, e as provenientes de aeronaves (Imagens Aerotransportadas). Avaliou-se também diferentes tipos de estimativas para a predição volumétrica sendo estas RLM, KDE e KO. A melhor estimativa serviu de variável auxiliar para o estimador de regressão (ER), sendo os resultados comparados com a abordagem tradicional da amostragem aleatória simples (AAS). Os resultados demonstraram por meio da validação cruzada que as estimativas da KDE foram mais eficientes que as estimativas da KO e da RLM. Os melhores preditores (variáveis auxiliares) foram aqueles derivados do satélite LANDSAT8 e do satélite RAPIDEYE. Obteve-se como produto das estimativas de KDE e RLM mapas capazes de detectar áreas com mortalidade ou anomalias em meio a formação florestal. A utilização de uma estimativa de KDE utilizando imagens LANDSAT8 como medida auxiliar para o ER permitiu reduzir o erro amostral da AAS de 3,87% para 2,34%. Da maneira tradicional, tal redução de erro apenas seria possível com um aumento de mais 99 unidades amostrais. / Forest Inventory (FI) is one of the main tools for managing forest resources, once the information derived from FI is used along the sector production chain. When estimating volume, errors resulting from FI are common, therefore these errors must be controlled. Once orbital or airborne imaging data are easily acquired for an entire area, and are commonly available in forest companies or for the end user, much information can be obtained from these products. The use of predictor derived from images can be of significant benefits to forest inventory estimates. For that reason, the application of linear multiple regression (LMR) techniques have taken place in the forest sector, due to the facilities of its application. However, the LMR technique does not take the spatial dependence among sample units in consideration, the geostatistics utilized to predict the spatial distribution of the wood stock (VTCC) for a specific region. Simpler geostatistical modeling as the ordinary kriging (OK), just takes in consideration the spatial dependence among non-sampled points, because of that, prediction errors can be found. Such errors can be reduced when techniques that are more robust are applied, such as the kriging with external drift (KED) approach. This technique aggregates the information obtained from the images with the spatial distribution of the volume. In order to evaluate the advantages of Remote Sensing and Forest Inventory integration, we considered 4 different types of images, from the satellites LANSAT 8, RAPIDEYE, GEOEYE and from airborne images. When predicting volume, three different approaches were evaluated: LMR, EDK, OK. The best model among those evaluated, served as auxiliary variable for the regression estimator (RE). The result were then compared to the traditional approach, simple random sampling (SRS).This approach showed, through a cross-validation, that the KDE estimates were more efficiently than the OK and the LMR. The best predictor model (auxiliary variables) were derived from LADNSAT 8 and RAPIDEYE satellites. There is a significant advantage to using the KDE and LMR approaches, as it allows for a spatial representation of areas with mortality or anomalies, in a forest environment. The combination of KDE approach and LANDSAT 8 images as an auxiliary method for the RE, abled the decrease of the sampling error of SRS from 3.87% to 2.34%.The traditional approaches to conduct plantation inventories would allow for this error reduction, only if there were an increase of 99 more sampling units.
79

Fatores relacionados à ocorrência de Leishmaniose Tegumentar Americana no Vale do Ribeira / Factors related to the occurrence American cutaneous leishmaniasis in the Ribeira Valley

Silva, Alessandra Ferreira da 18 December 2008 (has links)
Este trabalho é um estudo ecológico descritivo sobre a leishmaniose tegumentar americana (LTA) na região do Vale do Ribeira paulista (composto por 23 municípios), que teve como objetivo correlacionar a incidência da doença com fatores determinantes ambientais e sociais. O trabalho se refere ao período de 1998 a 2006 o qual foi divido em três triênios, o primeiro de 1998 a 2000, o segundo de 2001 a 2003 e o terceiro de 2004 a 2006. Os coeficientes de incidência da LTA foram calculados para estes períodos (Coefmtr1, Coefmtr2 e Coefmtr3) segundo Szklo. Essa divisão de triênios se deu de acordo com as características gráficas dos coeficientes de incidência da LTA no período, que demonstraram haver num primeiro período uma fase endêmica da doença, no segundo período (2001 a 2003) a análise mostra picos de incidência que caracteriza um período epidêmico acentuado. No terceiro período alguns municípios mostram picos de incidência de proporções menores que os observados no período anterior, contudo ainda característicos de fase epidêmica. Os coeficientes de incidência são as variáveis dependentes dos três modelos de regressão realizados. As variáveis independentes foram obtidas de fontes de dados secundários e são de natureza sócio-demográfica, relacionadas as condições climáticas, de natureza político-geográficas e físico-biológicas. Essas variáveis foram separadas em qualitativas e quantitativas e analisadas respectivamente por testes não paramétricos de Mann Whitney e Spearman e selecionou-se para o processo de modelagem múltipla, as variáveis com p<0,20. Houve a necessidade de três modelos diferentes para verificar se os fatores determinantes que levaram as séries a se comportar de maneira diferenciada, seriam os mesmos ou não. O que se percebe é que há uma mudança no padrão do primeiro para os dois outros períodos. O trabalho aponta para fatores sócio-demográficos como determinantes na incidência de LTA, bem como a presença do vetor / This work is an ecological descriptive study on the American cutaneous leishmaniasis (ACL) in the Ribeira Valley region of Sao Paulo (composed of 23 municipalities), which aimed to correlate the incidence of the disease with environmental and social factors. The paper refers to the period 1998 to 2006 which was divided into three years, the first from 1998 to 2000, the second from 2001 to 2003 and the third from 2004 to 2006. The rates of incidence of ACL were calculated for these periods (Coefmtr1, Coefmtr2 and Coefmtr3) Szklo seconds. This division was made in accordance with the graphics characteristics of the coefficients of incidence of ACL in the period, which has shown a period in a first stage of the disease endemic in the second period (2001 to 2003) the peak incidence analysis shows that characterizes a epidemic period strong. In the second period some municipalities show peaks of incidence of proportions lower than those observed in the previous period, yet still features the epidemic stage. The rates of incidence are dependent variables of the three regression models performed. The independent variables were obtained from sources in secondary databases, and are: in nature and socio-demographic, related climatic conditions, a political-geographical and physical and biological. These variables were separated in quality and quantity respectively and analyzed by non-parametric tests for Spearman and Mann Whitney and selected for the process of regress multiple model, the variables with p <0.20. There was a need for three different models to see if the determining factors that led to the series to behave in a different way, would be the same or not. What we understand is that there is a change in the pattern of the first to the other two periods. The study points to socio-demographic factors as determinants in the incidence of ACL and the presence of vector
80

Emprego de estatística multivariada no estudo quimiossistemática da família Asteraceae e da sua tribo Heliantheae / Use of Multivariate Statistics in the Chemosystematics of Asteraceae family and its Heliantheae tribe

Fokoue, Harold Hilarion 18 March 2010 (has links)
Este trabalho análise as ocorrências de 12 classes de substâncias (monoterpenos, sesquiterpenos, lactonas sesquiterpênicas, diterpenos, triterpenos, cumarinas, flavonóides, poliacetilenos, benzofuranos, benzopiranos, acetofenonas e fenilpropanóides) na família Asteraceae e na sua tribo Heliantheae. Pretende-se demonstrar a existência de correlações na produção de metabólitos secundários em níveis taxonômicos baixos (tribos, subtribos e gêneros). Utilizou-se um banco de dados com cerca de 36.000 ocorrências das principais substâncias isoladas em plantas da família. O estudo do equilíbrio químico na produção de metabólitos secundários foi feito utilizando-se Regressão Linear Múltipla. As afinidades entre os grupos com base na sua Química foram pesquisadas por vários métodos tais como: Análise de componentes principais, Análise de Cluster e Análises cladísticas. Observou-se também o grau de oxidação médio de vários metabólitos e sua utilidade como ferramenta em análises quimiotaxonômicas. Foi possível mostrar a existência de um equilíbrio na produção das 12 classes de metabólitos em níveis das tribos e subtribos. Mas, no nível dos gêneros um equilíbrio moderado foi encontrado. Também foi possível mostrar a existência de um equilíbrio oxidativo em vários níveis (tribos, subtribos). No nível dos gêneros nenhum equilíbrio foi encontrado utilizando-se o parâmetro passo oxidativo. Foi possível agrupar algumas das subfamílias de Asteraceae segundo Bremer e subtribos da tribo Heliantheae segundo Stuessy usando Análises de componentes principais e Análise de Cluster / This work analyse the occurrence of 12 classes of substances (monoterpenes, sesquiterpenes, sesquiterpene lactones, diterpenes, triterpenes, coumarins, flavonoids, polyacetylenes, Benzofurans, benzopyrans, acetophenones and phenylpropanoids) in the Asteraceae family and its Heliantheae tribe. This study intends to demonstrate the existence of correlations in the production of secondary metabolites in lower taxonomic levels (tribes, subtribes and genera). We used a database of about 36,000 occurrences of the main substances isolated from the plant family. The study of chemical equilibrium in the production of secondary metabolites was done using Multiple Linear Regression. The affinities between the groups based on their chemistry were investigated by various methods such as principal component analysis, Cluster and cladistic analysis. There was also the average degree of oxidation of various metabolites and their usefulness as a tool in chemotaxonomic analysis. It was possible to show the existence of a balance in the production of 12 classes of metabolites in the levels of the tribes and subtribes. But the level of the genus balance was found moderate. It was also possible to show the existence of an oxidative equilibrium in various levels (tribes, subtribes). The level of genus balance was not found using the parameter oxidation step. We could group some of the subfamilies of Asteraceae according to Bremer and the subtribes of Heliantheae according to Stuessy using the principal component analysis and Cluster Analysis

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