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Modelos para relacionar variáveis de solos e área basal de espécies florestais em uma área de vegetação natural / Models to relate variable soil and basal area of forest species in an area of natural vegerationGrego, Simone 08 October 2014 (has links)
O padrão espacial de ocorrência de atributos de espécies florestais, tal como a área basal das árvores, pode fornecer informações para o entendimento da estrutura da comunidade vegetal. Uma vez que fatores ambientais podem influenciar tanto o padrão espacial de ocorrência quanto os atributos das espécies em florestas nativas. Desse modo, investigar a relação entre as características ambientais e o padrão espacial de espécies florestais pode ajudar a entender a dinâmica das florestas. Especificamente, neste trabalho, o objetivo é avaliar métodos estatísticos que permitam identificar quais atributos do solo são capazes de explicar a variação da área basal de cada espécie de árvore. A área basal foi considerada como variável resposta e como covariáveis, um grande número de atributos físicos e químicos do solo, medidos em uma malha de localizações cobrindo a área de estudo. Foram revisados e utilizados os métodos de regressão linear múltipla com método de seleção stepwise, modelos aditivos generalizados e árvores de regressão. Em uma segunda fase das análises, adicionou-se um efeito espacial aos modelos, com o intuito de verificar se havia ainda padrões na variabilidade, não capturados pelos modelos. Com isso, foram considerados os modelos autoregressivo simultâneo, condicional autoregressivo e geoestatístico. Dado o grande número de atributos do solo, as análises foram também conduzidas utilizando-se as covariáveis originais, fatores identificados em uma análise fatorial prévia dos atributos de solo. A seleção de modelos com melhor ajuste foi utilizada para identificar os atributos de solo relevantes, bem como a presença e melhor descrição de padrões espaciais. A área de estudo foi a Estação Ecológica de Assis, da Unidade de Conservação do Estado de São Paulo em parcelas permanentes, dentro do projeto \"Diversidade, Dinâmica e Conservação em Florestas do Estado de São Paulo: 40 ha de parcelas permanentes\", do programa Biota da FAPESP. As análises reportadas aqui se referem à área basal das espécies Copaifera langsdorffii, Vochysia tucanorum e Xylopia aromatica. Com os atributos de solo reduzidos e consistentemente associados à área basal, a declividade, altitude, saturação por alumínio e potássio mostraram-se relevantes para duas das espécies. Resultados obtidos mostraram a presença de um padrão na variabilidade, mesmo levando-se em consideração os efeitos das covariáveis, ou seja, os atributos do solo explicam parcialmente a variabilidade da área basal, mas existe um padrão que ocorre no espaço que não é capturado por essas covariáveis. / The spatial pattern of occurrenceis of forest species and their attributes, such as the basal area of trees, can provide information for understanding the structure of the vegetable community. Considering the environmental factors can influence the spatial pattern of occurrences of species in native forests and related attributes, describing relationship between environmental characteristics and spatial pattern of forest species can be associated with the dynamics of forests. The objective of the present study is to assess different statistical methods used to identify which soil attributes are associated with the basal area of each tree selected species. The basal area was considered as the response variable and the covariates are given by a large number of physical and chemical attributes of the soil, measured at a grid of locations covering the study area. The methods considered are the multiple linear regression with stepwise model selection, generalized additive models and regression trees. Spatial effects were added to the models, in order to ascertain whether there is residual spatial patterns not captured by the covariates. Thus, simultaneous autoregressive model, autoregressive conditional and geostatistical were considered. Considering the large number of soil attributes, analysis were were conducted both ways, using the original covariates, and using factors identified in a preliminar factor analysis of the soil attributes. Model selection was used to identify the relevant attributes of soil as well as the presence and better description of spatial patterns. The study area was the Ecological Station of Assis, the Conservation Unit of the State of São Paulo in permanent plots within the \"Diversity Dynamics and Conservation Forests in the State of São Paulo: 40 ha of permanent plots\" project, under the research project FAPESP biota. The analyzes reported here refer to the basal area of the species Copaifera langsdorffii, Vochysia tucanorum and Xylopia aromatica. Results differ among the considered methods reinforcing the reccomendation of considering differing modeling strategies. Covariates consistently associated with basal area are slope, altitude and aluminum saturation, potassium, relevant to at least two of the species. Results obtained showed the presence of patterns in residual variability, even taking into account the effects of covariates. The soil characteristics only partially explain the variability of the basal area and there are spatial patterns not captured by these covariates.
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Self-ligating vs. conventional ligating orthodontic bracket systems (smile aesthetics perspective) : data from randomised clinical trialsAlarabi, Abdulghani Mustafa S. January 2018 (has links)
<b>Introduction</b>: Today one of the primary goals of any kind of dental treatment is the achievement of balanced smile aesthetics, as patients increasingly attend dental clinics to improve their appearance. The main aim of the present study was to assess and compare the smile aesthetics created by the use of two orthodontic bracket systems (self-ligating vs. conventional ligating) as a part of analysing secondary outcomes of two randomised clinical trials comparing between these two systems. <b>Methodology</b>: The assessment of smile aesthetics was done by analysing and scoring post-orthodontic treatment 125 frontal smile photographs subjectively and objectively. The subjective evaluation was performed by 20 dental professionals and 20 laypeople, while the objective assessment was done by one principal examiner using a group of smile aesthetics parameters. <b>Statistical analysis</b>: Multiple regression statistical analyses were performed to test the association between subjective and objective assessment of smile aesthetics in order to find the significant smile aesthetics predictors and assess the effect of the bracket type (self-ligating vs conventional) on the resulting smile aesthetics. <b>Results</b>: The finding from this research shows that the bracket type was not an important smile aesthetics factor in all the statistical models, although there are other important smile aesthetics factors as there was a significant correlation between the subjective and objective assessment of smile aesthetics parameters (Pearson’s correlation coefficients “r” > 0.50). <b>Conclusion</b>: There is insufficient evidence to reject the null hypotheses of no significant difference in the smile aesthetics created by the two orthodontic bracket systems. An Orthodontic Smile Aesthetics Rating (OSAR) tool has been developed.
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台灣省各地區普查資料之統計分析莊靖芬 Unknown Date (has links)
本研究的目的為研究台灣省在1990年之15-17歲的在學率,在找出可能影響因素並蒐集好相關的資料後,我們將蒐集到的資料分成兩個部份,一個部份用來建造模型,而另一個部份則用來測試所建立出來的模型。主要的過程是:先利用簡單迴歸模型了解各個可能的因素對於15-17歲的在學率的影響程度,經過許多分析及了解後再對這些變數採取可能的變數轉換(variable transformations),而後再利用三種常用的統計迴歸方法﹝包含有逐步迴歸(stepwise regression)方法、前進選擇(forward selection)方法以及後退消除(backward elimination)方法﹞去發展出一個適當的複迴歸模型(multiple regression model)。對於這個模型,以實際的台灣在學情況來看,我們看不出它有任何的不合理;同時也利用圖形及檢定去驗證模型的假設,其次還做有關迴歸參數的推論(inferences about regression parameters)。再其次,我們運用變異數分析的結果(analysis of variance results)以及新觀察值的預測情形(predictions of new observations)來評估模型的預測能力。最後並利用所得到的最適當的模型,對如何提昇15-17歲青少年的在學率給予適當的建議。 / The objective of this research is to study what factors may affect the schooling rates of 15-17 years old in Taiwan province in 1990. After finding out some possible factors and collecting those data regarding those factors, we separate the data (by stratified random sampling) into two sets. One set is used to construct the model, and the other set shall be used to test the model. The main process to build a regression model is as follows. First, we shall use simple linear regression models to help us to see if each factor may have relation with the schooling rates. With the analysis of residuals and so on, we then make appropriate transformations on each of these factors. Finally, we use three common statistical regression techniques (including stepwise regression, forward selection, and backward elimination methods) to develop a suitable multiple regression model. It seems that, by our understanding of schooling rates in Taiwan, this model is not unreasonable. In addition, we verify the assumptions of the model by graphical methods and statistical tests. We also do the inferences about regression parameters. Furthermore, ye use the results of the analysis of variance and predictions of new observations to evaluate the prediction ability of the model. Finally, we use the most appropriate multiple regression model to give some suggestions to improve (or keep) the schooling rates of 15-17 years old.
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不同管教方式之父母比較行為對子女能力影響之研究 / The impact of parental comparison from different parenting styles on children's general ability王正婷 Unknown Date (has links)
本研究以TEPS資料庫第二、三波追蹤樣本為資料來源,使用多元迴歸分析中的OLS(ordinal least squares)最小平方法,分析不同管教方式之父母比較行為如何影響子女之綜合能力。刪除作答不全的缺失值後,共計取得有效樣本為2,595人。
研究結果顯示:父母管教方式若以雙向度作為分類,以高反應(74.6%)與高要求(69.2%)者居多,綜合兩大面向後,有52.40%的父母採取開明權威型的管教方式,有22.20%的父母為專制權威型,有16.90%的父母為寬鬆放任型,有8.50%的父母是忽視冷漠型。此外,父母最常把子女與其同班同學(45.5%)進行比較,其次依序為鄰居小孩、同事或朋友小孩(42.0%)、同年齡的親戚(37.0%)、兄弟姊妹(26.9%),父母最少拿自己小時候(18.8%)與子女相比。
經由多元迴歸分析之後得知,無論是開明權威、專制權威、寬鬆放任或忽視冷漠型的父母,凡拿子女與其「同班同學」比較者,子女的綜合能力越高,達到統計顯著水準;但是當父母持專制權威的管教方式時,無論有無加入控制變項(子女性別、父母教育程度和家庭月收入),有與「同班同學」和「父母小時候」比較者,其綜合能力顯著越高,但與「同年齡親戚」比較者,其綜合能力顯著越低。 / The research was to explore the effects of parenting style, parental comparison, and the interaction of them on children’s general ability. Data were collected from Taiwan Education Panel Survey (TEPS), the core panel in the second and the third wave. Total number of the students from high school reduced to 2,595 people after listwise deletion. We explored the effects by using ordinal least squares in the multiple regression analysis.
The results showed that there were 74.6% high-respective parents, and 69.2% high-demanding ones. Mixed with the two dimensions, demanding and responsive, there were 52.40% authoritative parents, 22.20% authoritarian ones, 16.90% indulgent ones, and 8.50% neglectful ones. Besides, parents compared their children with their classmates (45.5%), neighbors (42.0%), cousins (37.0%), siblings (26.9%), and parents’ childhood (18.8%).
After regression, the results showed in the following ways. First, no matter what the parenting style was, children who were compared with classmates had significantly higher ability. Whether adding the control variables like children’ gender, parents’ education level and family monthly income or not, when parents were authoritarian, children compared with classmates and parents’ childhood had significantly higher ability. Meanwhile, if they were compared with cousins, then they had significantly lower ability.
Keywords: Taiwan Education Panel Survey (TEPS), multiple regression analysis, parenting style, social comparison, general ability
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The Role of Linguistic Context in the Acquisition of the Pluperfect : Polish Learners of Swedish as a Foreign LanguageZielonka, Bronisława January 2005 (has links)
<p>This work consists of two parts: the theoretical and the experimental. In the theoretical part, some general and some language specific theories of tense, aspect and aktionsart are presented, and the temporal systems of Swedish and Polish are compared. </p><p>The theoretical part is not a mere review of the literature on the subject. The comparison of the descriptions of aspect and aktionsart by Slavic researchers with the universal theory of Smith (1991) and (1977) and with description of aktionsart in Swedish in Teleman et al. (1999) has allowed me for some important observations as to the nature of the long-lasting dispute about the differences between aspect and aktionsart.</p><p>The experimental part is a cross-sectional study on the role of the linguistic context on the acquisition of the pluperfect by Polish learners Swedish as a foreign language. The informants are university students studying Swedish as a foreign language. The language samples were collected by means of two types of tests: gap-filling and translation from Polish. </p><p>Twelve linguistic factors, each divided into two subgroups, were hypothesised to have affected the correct use of the pluperfect. All those hypotheses as to which of the subgroups may inhibit and which may facilitate the correct use of the pluperfect are grounded in linguistic theories, i.e. presented in the form of linguistically-based discussions as to what kind of effect, facilitative or inhibiting, each of the linguistic factors may have had, and why. </p><p>The effect of those factors upon the correct use of the pluperfect has been tested by means of a step-wise multiple regression which measured the simultaneous effect of each factor upon the correct use of the pluperfect. This method has confirmed the facilitative effect of the following six linguistic factors: intrasentential indication of topic time (subordinate clause), unbounded verb indicating topic time, agentive meaning of the target verb, specifying subordinate clause, statal pluperfect and location of the time of action of pluperfect clause outside the temporal frame of narrative plot.</p>
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The Role of Linguistic Context in the Acquisition of the Pluperfect : Polish Learners of Swedish as a Foreign LanguageZielonka, Bronisława January 2005 (has links)
This work consists of two parts: the theoretical and the experimental. In the theoretical part, some general and some language specific theories of tense, aspect and aktionsart are presented, and the temporal systems of Swedish and Polish are compared. The theoretical part is not a mere review of the literature on the subject. The comparison of the descriptions of aspect and aktionsart by Slavic researchers with the universal theory of Smith (1991) and (1977) and with description of aktionsart in Swedish in Teleman et al. (1999) has allowed me for some important observations as to the nature of the long-lasting dispute about the differences between aspect and aktionsart. The experimental part is a cross-sectional study on the role of the linguistic context on the acquisition of the pluperfect by Polish learners Swedish as a foreign language. The informants are university students studying Swedish as a foreign language. The language samples were collected by means of two types of tests: gap-filling and translation from Polish. Twelve linguistic factors, each divided into two subgroups, were hypothesised to have affected the correct use of the pluperfect. All those hypotheses as to which of the subgroups may inhibit and which may facilitate the correct use of the pluperfect are grounded in linguistic theories, i.e. presented in the form of linguistically-based discussions as to what kind of effect, facilitative or inhibiting, each of the linguistic factors may have had, and why. The effect of those factors upon the correct use of the pluperfect has been tested by means of a step-wise multiple regression which measured the simultaneous effect of each factor upon the correct use of the pluperfect. This method has confirmed the facilitative effect of the following six linguistic factors: intrasentential indication of topic time (subordinate clause), unbounded verb indicating topic time, agentive meaning of the target verb, specifying subordinate clause, statal pluperfect and location of the time of action of pluperfect clause outside the temporal frame of narrative plot.
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Family resources as predictors of positive family-to-work spilloverKempton-Doane, Gina Leah 04 April 2008
The purpose of this study was to predict the family resources that influence positive family-to-work spillover for women who are engaged in parent, partner, and paid employee roles. While much research examines the construct of work-family conflict, little examines the positive benefits for women participating in multiple roles. A conceptual framework for the study was obtained from Voydanoffs (2002) work applying ecological systems theory to the work-family interface. Several factors were hypothesized to predict positive family-to-work spillover for multiple role women, including: spousal support; perceived fairness in the division of housework and childcare; relative share of childcare and housework; and paid assistance with housework.<p>Data for this study was collected in a survey designed for a larger assessment of work, family, gender, and health in the Saskatoon area. The current study utilized data collected from women who met the following criteria: 1) spoke fluent English; 2) fell between the ages of 25 - 54 years; 3) were employed full-time or part-time; and 4) were the parent of at least one child under the age of 20 years. The dependent variable was a measure of positive family-to-work spillover. Independent variables included: spousal support; perceived fairness of the division of childcare; perceived fairness of the division of housework; relative of share of housework for respondents compared to ones partner; and paid assistance with housework. Control variables included income, presence of preschool children, number of children, educational attainment, and hours of paid employment. A sequential multiple regression was performed to predict positive family-to-work spillover from the independent variables. The final regression model predicting positive family-to-work spillover included three independent variables: 1) spousal support; 2) the perception of division of childcare as unfair to ones partner; and 3) relative share of housework for the respondent. Implications and limitations of these findings are discussed.
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Family resources as predictors of positive family-to-work spilloverKempton-Doane, Gina Leah 04 April 2008 (has links)
The purpose of this study was to predict the family resources that influence positive family-to-work spillover for women who are engaged in parent, partner, and paid employee roles. While much research examines the construct of work-family conflict, little examines the positive benefits for women participating in multiple roles. A conceptual framework for the study was obtained from Voydanoffs (2002) work applying ecological systems theory to the work-family interface. Several factors were hypothesized to predict positive family-to-work spillover for multiple role women, including: spousal support; perceived fairness in the division of housework and childcare; relative share of childcare and housework; and paid assistance with housework.<p>Data for this study was collected in a survey designed for a larger assessment of work, family, gender, and health in the Saskatoon area. The current study utilized data collected from women who met the following criteria: 1) spoke fluent English; 2) fell between the ages of 25 - 54 years; 3) were employed full-time or part-time; and 4) were the parent of at least one child under the age of 20 years. The dependent variable was a measure of positive family-to-work spillover. Independent variables included: spousal support; perceived fairness of the division of childcare; perceived fairness of the division of housework; relative of share of housework for respondents compared to ones partner; and paid assistance with housework. Control variables included income, presence of preschool children, number of children, educational attainment, and hours of paid employment. A sequential multiple regression was performed to predict positive family-to-work spillover from the independent variables. The final regression model predicting positive family-to-work spillover included three independent variables: 1) spousal support; 2) the perception of division of childcare as unfair to ones partner; and 3) relative share of housework for the respondent. Implications and limitations of these findings are discussed.
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Werkstoff-, Geometrie- und Reihenfolgeeinflüsse auf die Lebensdauer unter BetriebslastenMüller, Matthias 29 March 2003 (has links) (PDF)
Ausgangspunkt für die angestellten Untersuchungen bildet das Wissen um die unbefriedigende Treffsicherheit in der Lebensdauerabschätzung bei Belastungen mit ausgeprägten Mittelwertänderungen. Die Grundlage zur Weiterentwicklung theoretischer Lebensdauervorhersagemodelle auf Basis von Nenn- und örtlichen Beanspruchungen wurde mit experimentellen Untersuchungen an Werkstoff- und gekerbten Proben geschaffen, sowohl für einfache als auch gezielt abgeleitete, realitätsnahe komplexe Belastungs-Zeit-Abläufe. Es stehen zwei, ihrem zeitlich abhängigen Materialverhalten nach unterschiedliche Werkstoffe im Mittelpunkt der Betrachtungen. Ziel war es, die grundsätzliche zeitabhängige Reaktion der Werkstoffe auf die Belastung zu erkennen und diese Erkenntnisse mittels integra-len Parametern für die Verbesserung der Treffsicherheit der Lebensdauerabschätzung zu nutzen. Die Abschätzung der experimentell ermittelten Lebensdauern mit dem Nennspannungskonzept, die statistische Auswertung der Schädigungssummen und die Untersuchung der Korrelation von Schädigungssumme und zunächst frei wählbaren Parametern mittels multipler Regressionsanalyse führt zur Festlegung auf drei die Geometrie, den Werkstoff und die Belastung beschreibende Parameter. Bei beiden Werkstoffen wird durch Verwendung einer sogenannten korrigierten mit der Regressionsgleichung bestimmten Schädigungssumme eine Erhöhung der Treffsicherheit der Lebensdauervorhersage nachgewiesen. Den gesammelten Erfahrungen und Erkenntnissen entsprechend werden Empfehlungen zur Anwendung der behandelten Lebensdauerabschätzungsverfahren auf der Grundlage örtlicher Beanspruchungen gegeben. Mit den Versuchen innerhalb der Arbeit wurde eine experimentelle Basis geschaffen, die eine Weiterentwicklung von Ansätzen zur Berücksichtigung des transienten Materialverhaltens in Konzepten auf der Basis örtlicher Beanspruchungen ermöglicht.
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外商在中國投資區位選擇的決定因素:長三角與珠三角的比較陳銘宏 Unknown Date (has links)
目前,中國大陸最熱門的兩大經濟區域為長江三角洲與珠江三角洲,此兩地吸引眾多外商至當地投資。究竟此兩區域具有何區位優勢能吸引眾多外資,以及此兩地區的優勢有何差異,成為本論文重心所在。本論文主要探討三個主題:
一﹑這兩區域自改革開放以來,區位優勢的消長如何,才造成今日長江三角洲吸引外商投資金額超越珠江三角洲。
二﹑這兩區域有何區位優勢,才能吸引眾多外商至當地投資。
三﹑這兩區域與中國大陸整體平均水準的區位優勢作比較,究竟這兩區域相較於中國大陸整體平均水準具有何優勢,使外商特別關注此兩大地區。
以上問題運用中國統計年鑑的數據資料,以複回歸模型分析各地區的外商投資數據,以得出各項主題的結果。 / Yangtze River Delta and Pearl River Delta are both the most famous economic areas in Mainland China nowadays, attracting many foreign capitals to invest. The purpose of this thesis is to investigate what are the advantages in these two areas that attract foreign direct investment, and what are the differences between them. Three subjects are discussed in the present study. First, how did the location advantages rise and fall between Yangtze River Delta and Pearl River Delta, thus now there are more foreign investment enterprises located in Yangtze River Delta than in Pearl River Delta since the beginning of China’s ‘Open Door’ Policy. Second, what are the location advantages in these two areas that attract so many foreign investment enterprises to locate in these two areas. Third, what are the unique location advantages in these two areas compared with the average level of Mainland China, so that many foreign investment enterprises pay especially high attention to this two areas. Data of Statistical Yearbook of China are used in the present study, and multiple regression model is adopted to analyze the data in order to obtain the results.
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