Dissertations / Theses on the topic 'Importance'

There arise two problems when the expectation of some function with respect to a nonuniform multivariate distribution has to be computed by (quasi-) Monte Carlo integration: the integrand can have singularities when the domain of the distribution is unbounded and it can be very expensive or even impossible to sample points from a general multivariate distribution. We show that importance sampling is a simple method to overcome both problems. (author's abstract)
Series: Preprint Series / Department of Applied Statistics and Data Processing

This thesis is mainly concerned with how equality is related to social and individual wellbeing. It is widely believed that inequalities are both necessary and beneficial for society. This has been repudiated by recent studies claiming the opposite. This thesis will first elaborate on the concept of equality before investigating the relation between inequalities and different components of wellbeing with the use of a literature review. It finds that several adverse effects are correlated with inequalities and that competition might be an explanation for- as well as an amplifier of the adverse effects. Based on these findings, the thesis presents some guidelines for incorporating equality within a set of policy-areas. It concludes that the main points of importance are to avoid connecting the ability and merit of a person to the value of that person as well as to achieve material equality: both these working as a foundation for a subjective feeling of equality in value.

To compute the expectation of a function with respect to a multivariate distribution naive Monte Carlo is often not feasible. In such cases importance sampling leads to better estimates than the rejection method. A new importance sampling distribution, the product of one-dimensional table mountain distributions with exponential tails, turns out to be flexible and useful for Bayesian integration problems. To obtain a heavy-tailed importance sampling distribution a new radius transform for the above distribution is suggested. Together with a linear transform the new importance sampling distributions lead to simple and fast integration algorithms with reliable error bounds. (author's abstract)
Series: Preprint Series / Department of Applied Statistics and Data Processing

The genus Arcobacter, belongs to the family Campylobacteraceae, along with. Some species, are considered emerging pathogens and have been associated with gastrointestinal diseases and bacteraemia in humans and with diarrhoea, mastitis and abortions in animals. Diarrhoea, is the most common clinical presentation in humans. However, still are not fully defined the routes of transmission, the virulence factors present in pathogenic strains have not been determined and the isolation and identification methods are still deficient. All of these factors contribute to a possible underestimation of the sanitary importance of this genus. In this thesis it has been demonstrated the existence of five new species of this genus. In their differentiation, new tools have been used, such as the Matrix Assisted Laser Desorption Ionization Time of Flight (MALDI TOF) Multilocus Phylogenetic Analysis (MLPA) with concatenated 5 genes (rpoB, gyrB, hsp60, gyrA and atpA). Furthermore, the performance of 5 molecular identification methods was compared and none of them was useful for all the strains studied. In this regard, the updating of 16S rRNARFLP method for the identification of all species proved very useful. Moreover, in this thesis was a great diversity of species of this genus in samples of shellfish and sewage. Both matrices have epidemiological importance; however, they have been poorly studied. It was also demonstrated that the use in parallel of direct culturing and post enrichment, as well as the incubation under aerobic and microaerophilic, enhances the recovery and diversity of arcobacters. Regarding the virulence of Arcobacter spp., most of them proved to be potential enteropathogens for man, as they showed the presence of virulence factors and were able to adhere and invade human intestinal cells (Caco-2). Finally, it was demonstrated that Arcobacter may be confused with Campylobacter sp., generating an underestimation of their sanitary importance.
El género Arcobacter incluye especies consideradas patógenos emergentes, ya que se han asociado con patologías gastrointestinales y bacteriemia en humanos y con diarrea, mastitis y abortos en animales. Sin embargo, aún no se ha definido completamente las rutas de transmisión, los factores de virulencia presentes en cepas patogénicas no se han determinado y los métodos de aislamiento e identificación aún son deficientes. Todo esto genera una subestimación de la importancia sanitaria de Arcobacter. En esta tesis doctoral se demostró la existencia de 5 nuevas especies de este género. Para su diferenciación se utilizó herramientas nuevas, tales como el Matrix Assisted Laser desorption Ionization Time of Flight (MALDI TOF) y un Multilocus Phylogenetic Analysis (MLPA) con 5 genes concatenados (rpoB, gyrB, hsp60, atpA y gyrA). Considerando el número de especies incluidas actualmente en el género (n=17), se evaluó si 5 de los métodos moleculares de identificación son todavía útiles para la identificación de las especies para las que se habían definido o si se generan confusiones, demostrrando que todos ellos generan algún error que osciló entre el 16,8% y 67,4% de las cepas estudiadas. En este sentido, la ampliación del método 16S rRNA-RFLP para poder identificar todas las especies resultó ser de gran utilidad. Por otra parte, en esta tesis se observó una gran diversidad de especies de este género en muestras de mariscos y aguas residuales. Ambas matrices han sido poco estudiados a pesar de su importancia epidemiológica. Más aún, se demostró que el uso en paralelo del cultivo por siembra directa y post enriquecimiento, además de incubación en aerobiosis y microaerofilia, favorece la recuperación de una mayor diversidad. Por otra parte, también se demostró que la mayoría de las especies de este género, en especial algunas cepas A. butzleri, A. cryaerophilus, A. skirrowii, A. trophiarum y A. defluvii, son potenciales enteropatógenos para el hombre, ya que presentaron factores de virulencia y fueron capaces de adherir e invadir células intestinales humanas (Caco-2). Por último, se demostró que Arcobacter puede ser confundido con Campylobacter sp., lo que puede contribuir aún más a subestimar su importancia sanitaria.

The medicinal effects of betaines have only recently been studied, and this thesis furthers this field. Chapter 2 describes the process of developing a betaine assay in order to assay the betaine content of foods. The final methods are described in section 2.5. Using those methods, foods commonly found the New Zealand diet were assayed and a database of betaine contents in foods can be found in chapter 3. Foods that were high in particular betaines have been studied further, to get an indication of the variation between food samples that is present. This study found that there are only three betaines present in the diet at leyels high enough to have potential metabolic effects: glycine betaine, trigonelline and proline betaine. The database has been used to estimate the average daily intake of glycine betaine, trigonelline and proline betaine at 150-200, 20 and 15 mg/day respectively. A diet was also designed to maximize glycine betaine intake, resulting in an intake of 620 mg/day. Chapters 4 and 5 describe experiments on the effect of dietary betaines on different medical problems. Chapter 4 shows that there is a increase in plasma homocysteine concentrations associated with the consumption of coffee, which is consistent with the hypothesis that trigonelline in coffee interacts with homocysteine homoeostasis. Trigonelline has some antimicrobial properties in certain conditions, and the question of trigonelline in the diet being a potential to be utilized in the treatment or prevention of urinary tract infections (UTI) is addressed in Chapter 5. Due to a number of factors (discussed in section 5.5), the antimicrobial properties of trigonelline have no effect in human urine, and trigonelline is unable to be used to treat or prevent UTI.

Approved for public release; distribution is unlimited.
Balochistan, the southwestern province of Pakistan, is taking on increased importance in regional affairs. With the discovery of vast fields of natural gas, along with other valuable minerals, the region is experiencing increased interest from foreign investors and developers. Along with this, the terrain of Balochistan makes it a prime location for the development of roads, railroads and pipelines to connect the Middle East, Central Asia and South Asia. To augment this development, the construction of a deep-water port at Gwadar has the potential of bringing globalization to the region in an exponential manner. In the face of this development and growth are the Baloch whose continued insurgencies have created an unstable environment. Although deterring large-scale growth, interest in the region continues to grow, and with it, the threat of international politics and agendas colliding in a violent manner as Balochistan grows. As such, the strategic importance of Balochistan lies in its potential to either take the forefront in development in South Asia, or be the epicenter of the next large-scale multinational conflict.

Stochastic programming models are large-scale optimization problems that are used to facilitate decision-making under uncertainty. Optimization algorithms for such problems need to evaluate the exptected future costs of current decisions, often referred to as the recourse function. In practice, this calculation is computationally difficult as it requires the evaluation of a multidimensional integral whose integrand is an optimization problem. In turn, the recourse function has to be estimated using techniques such as scenario trees or Monte Carlo methods, both of which require numerous function evaluations to produce accurate results for large-scale problems with multiple periods and high-dimensional uncertainty. In this thesis, we introduce an Importance Sampling framework for stochastic programming that can produce accurate estimates of the recourse function using a small number of samples. Previous approaches for importance sampling in stochastic programming were limited to problems where the uncertainty was modelled using discrete random variables, and the recourse function was additively separable in the uncertain dimensions. Our framework avoids these restrictions by pairing Markov Chain Monte Carlo methods with Kernel Density Estimation algorithms to build a non-parametric Importance Sampling distribution, which can then be used to produce a low-variance estimate of the recourse function. We demonstrate the increased accuracy and efficiency of our approach using variants of well-known multistage stochastic programming problems. Our numerical results show that our framework produces more accurate estimates of the optimal value of stochastic programming models, especially for problems with moderate-to-high variance distributions or rare-event distributions. For example, in some applications, we found that if the random variables are drawn from a rare-event distribution, our proposed algorithm can achieve four times reduction in the mean square error and variance given by other existing methods (e.g.: SDDP with Crude Monte Carlo or SDDP with Quasi Monte Carlo method) for the same number of samples. Or when the random variables are drawn from the high variance distribution, our proposed algorithm can reduce the variance averagely by two times compared to the results obtained by other methods for approximately the same level of mean square error and a fixed number of samples. We use our proposed algorithm to solve a capacity expansion planning problem in the electric power industry. The model includes the unit commitment problem and maintenance scheduling. It allows the investors to make optimal decisions on the capacity and the type of generators to build in order to minimize the capital cost and operating cost over a long period of time. Our model computes the optimal schedule for each of the generators while meeting the demand and respecting the engineering constraints of each generator. We use an aggregation method to group generators of similar features, in order to reduce the problem size. The numerical experiment shows that by clustering the generators of the same technology with similar size together and apply the SDDP algorithm with our proposed sampling framework on this simplified formulation, we are able to solve the problem using only one fourth the amount of time to solve the original problem by conventional algorithms. The speed-up is achieved without a significant reduction in the quality of the solution.

Most studies of subsidiary knowledge flows involve technological knowledge seeking, and exclude currently less important subsidiaries in the multinational corporation (MNC). Yet those subsidiaries are often located in developing markets with high economic growth and expansion opportunities for MNCs. Less is known about knowledge flows between less important subsidiaries, or about operational knowledge seeking. This study proposes a definition for subsidiary importance, compares more and less important subsidiaries, and examines technological and operational knowledge seeking. Findings suggest headquarters remain the dominant source for technological knowledge for both high and low importance subsidiaries but operational knowledge seeking is more varied.
Mini Dissertation (MBA)--University of Pretoria, 2017.
vn2017
Gordon Institute of Business Science (GIBS)
MBA
Unrestricted

The purpose of the study is to analyze the role of tech-pack for the development of a sustainable supply chain management. The purpose is addressed by analyzing if tech-pack contains standard sustainable requirements and acts as an enabling factor to integrate sustainability in current textile and fashion supply chain. The nature of the research is qualitative and case study has been conducted to collect data through telephonic interviews. A Textile apparel buying agency from Pakistan was selected as a case study and data has been collected from company employees and managers from knitwear apparel manufacturers (suppliers) to ensure the relevance and validity of the research. The results and the data analysis have been presented in various dimensions to understand the current practices in the textile supply chain management and future recommendations for designers, product developers and managers from the supply chain management. Findings show that in the current practices of supply chain management, tech-pack is not communicating the sustainable requirements efficiently and there is a need to standardize the sustainable requisites for product development. For progression in sustainable supply chain management, designers and product developers are required to adopt the Higg index as a standard source of information to standardize the sustainable requirement for each stage of the supply chain.

In this thesis I present a strong and universally compelling case for the importance of Heidegger’s question, namely, the question of the meaning of being. I show how the being-question has been obscured and forgotten over the past two millennia of western philosophy. I attempt to raise this question again, and elucidate why it is an important one to examine, not only for philosophy as a discipline, but for any human endeavor. My aim is to reach those of you who would normally not come across, or might even dismiss, Heidegger’s work. I hope the arguments I make will convince you, hard though it may be, that reawakening ourselves to the question of being is a task that we must undertake.

Variable importance measures for random forests have been receiving increased attention as a means of variable selection in many classification tasks in bioinformatics and related scientific fields, for instance to select a subset of genetic markers relevant for the prediction of a certain disease. We show that random forest variable importance measures are a sensible means for variable selection in many applications, but are not reliable in situations where potential predictor variables vary in their scale level or their number of categories. This is particularly important in genomics and computational biology, where predictors often include variables of different types. Simulation studies are presented illustrating that, when random forest variable importance measures are used with data of varying types, the results are misleading because suboptimal predictor variables may be artificially preferred in variable selection. The two mechanisms underlying this deficiency are biased variable selection in the individual classification trees used to build the random forest on one hand, and effects induced by bootstrap sampling with replacement on the other hand. We propose to employ an alternative implementation of random forests, that provides unbiased variable selection in the individual classification trees. When this method is applied using subsampling without replacement, the resulting variable importance measures can be used reliably for variable selection even in situations where the potential predictor variables vary in their scale level or their number of categories. The usage of both random forest algorithms and their variable importance measures in the R system for statistical computing is illustrated and documented thoroughly in an application re-analysing data from a study on RNA editing. Therefore the suggested method can be applied straightforwardly by scientists in bioinformatics research. (author's abstract)
Series: Research Report Series / Department of Statistics and Mathematics

The aim of this thesis is to try to establish a relationship between Heidegger&rsquo
s thought on authenticity and art, and to show the role of art in authentic being of Dasein. Dasein&rsquo
s being authentic depends on Dasein&rsquo
s revealing of itself as itself. In this respect art plays an important role in revealing Dasein as itself. Thus, the relation between art and authenticity can be based on alethia which is the revealing of being as itself. At the same time art plays an important role in authenticating Dasein by its world-disclosing feature as it allows Dasein&rsquo
s own world to reveal itself in its own way.

This thesis consists of four papers. In the first paper, Monte Carlo simulation for tail probabilities of heavy-tailed random walks is considered. Importance sampling algorithms are constructed by using mixtures of the original distribution with some other state-dependent distributions. Sufficient conditions under which the relative error of such algorithms is bounded are found, and the bound is calculated. A new mixture algorithm based on scaling of the original distribution is presented and compared to existing algorithms. In the second paper, Monte Carlo simulation of quantiles is treated. It is shown that by using importance sampling algorithms developed for tail probability estimation, efficient quantile estimators can be obtained. A functional limit of the quantile process under the importance sampling measure is found, and the variance of the limit process is calculated for regularly varying distributions. The procedure is also applied to the calculation of expected shortfall. The algorithms are illustrated numerically for a heavy-tailed random walk. In the third paper, large deviation probabilities for a sum of dependent random variables are derived. The dependence stems from a few underlying random variables, so-called factors. Each summand is composed of two parts: an idiosyncratic part and a part given by the factors. Conditions under which both factors and idiosyncratic components contribute to the large deviation behavior are found, and the resulting approximation is evaluated in a simple example. In the fourth paper, the asymptotic eigenvalue distribution of the exponentially weighted moving average covariance estimator is studied. Equations for the asymptotic spectral density and the boundaries of its support are found using the Marchenko-Pastur theorem.
QC 20100811

The highly competitive environment in which businesses operate today requires a skilful workforce in every organisation in order to remain a successful player in the competitive game of the industry. One of the main problems which occur in the workplace is the lack of training. A large number of employees can appear dissatisfied (Heinemann and Greenberger, 2002) due to being assigned responsibilities without-having the right knowledge and skills in that area. Training is an essential process which should be cautiously designed and implemented within all firms. The overall aim of this dissertation is to assess the importance of training- in work field.For many years now human capital has been regarded as vital for the efficient functioning of an organisation because of its contribution in improving productivity, business performance and economic growth (Schultz, 1961). Therefore it is important to invest in human resources through training (Lucas, 1988) in order to improve the competitive position of the firm, and because of the enhanced quality, innovation, continual increased productivity and in turn improved profitability that can be achieved through this (Taylor and Davies, 2004).Throughout this research the training system in Hilton Hotel will be examined and appropriate recommendations for a more effective training system will be given where appropriate. The overall aim of this study is to assess the importance of training in hospitality industry.

Thesis (Ph. D.)--Ohio State University, 2005.
Title from first page of PDF file. Document formatted into pages; contains xiv, 126 p.; also includes graphics. Includes bibliographical references (p. 119-126). Available online via OhioLINK's ETD Center

This research is concentrated mainly on Cambodian Small and Medium Enterprises (SMEs). SMEs are said to playa vital role in economic development and income growth in Cambodia, as they have been the primary source of job creation, not only in urban areas but also in rural areas. However, there are still considerable controversies over whether SMEs are more efficient than large enterprises (LEs) in contributing to economic development in Cambodia. The purpose of this study is to investigate the importance of SMEs in development taking Cambodia as a case study. Three hypotheses are investigated to reveal SMEs' advantages relative to LEs: (1) SMEs are more labour-intensive than LEs and S"MEs provide more jobs for women than LEs; (2) SMEs are as productive as LEs or even more productive than LEs; and (3) srvms are more equitable in distributing the income they generate than LEs. Most of the previous researchers have provided empirical evidences to support the three hypotheses. In this study, however, srvms were found to possess many undesirable characteristics, including the uneconomic use of capital, the inequitable distribution of the income they generate, the low productivity of SMEs, especially in provincial areas, and employing less female labour. Thus, Cambodia experiences the low efficiency of SMEs' performance. This is due to the government's ability to implement an enabling environment for business remaining weak. In particular, the legal framework for supporting SME activity remains weak, infrastructure and communication in rural areas are poor, and labour productivity is relatively low. Therefore, in order to improve SMEs in Cambodia, the government has to improve the efficiency of SMEs, implementation an action plan of the market-oriented framework for SME development, reduce the cost of doing business and related to bureaucratic red tape, improve the access to finance for SMEs, and improve market access for SMEs.

Thesis (M.A.)--Central Connecticut State University, 2002.
Thesis advisor: Matthew Warshauer. " ... in partial fulfillment of the requirements for the degree of Master of Arts in History." Includes bibliographical references (leaves 109). Also available via the World Wide Web.

In my work in a diocesan marriage tribunal I have observed that many couples who are planning their weddings are influenced greatly by the superficial focus of our culture. In fact, there is statistical and sociological evidence that culture is highly influential in much Catholic wedding planning. Presented in this paper is evidence of how little Catholics know about the sacramental nature of marriage and how their married life affects themselves and others around them. This paper presents a theological reflection on the sacrament of marriage; an analysis of how the Rite of Marriage is usually perceived and carried out; a study of how the attitude of brides and grooms at the time of their wedding effects their life thereafter and, by association, the greater family and community; and it offers an explanation of how instructing couples on the theology behind the Rite of Marriage as prima theologia can better prepare them to live their marriage sacramentally. The pre-marital classes in the Diocese of Orange are currently comprised of mostly practical information on how to live successfully as a married couple, but they neglect to also consider the most important issue for them as Catholics: how to live out a sacramental marriage. It is proposed in this document that a diocesan-wide premarital handbook be designed and employed which provides greater emphasis on the ecclesial aspect of marriage as well as the practical advice of seasoned mentors.

In recent years, the attention of lawyers and Law students in the legal skills has greatly increased.In this round table, the rapporteurs deliberate about their possible limits, regulation and enforcement, and give a vision about the future of the practice of Law.
En los últimos años, se ha incrementado notablemente el interés de abogados y estudiantes de Derecho por las destrezas legales.En esta mesa, los ponentes reflexionan sobre sus límites, regulación y aplicación, y dan una visión del futuro del ejercicio del Derecho.

It is well known that for highly skewed distributions the standard method of using the t statistic for the confidence interval of the mean does not give robust results. This is an important problem for importance sampling (IS) as its final distribution is often skewed due to a heavy tailed weight distribution. In this paper, we first explain Hall's transformation and its variants to correct the confidence interval of the mean and then evaluate the performance of these methods for two numerical examples from finance which have closed-form solutions. Finally, we assess the performance of these methods for credit risk examples. Our numerical results suggest that Hall's transformation or one of its variants can be safely used in correcting the two-sided confidence intervals of financial simulations.(author's abstract)
Series: Research Report Series / Department of Statistics and Mathematics

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Secretaría Nacional de Educación Superior, Ciencia y Tecnología
Os quintais estão presentes na sociedade humana desde a sua origem e estão distribuídos mundialmente. Estes espaços de terra estão localizados perto das casas, e o trabalho feminino neles é fundamental. Uma característica principal deles é que mantêm altos índices de agrobiodiversidade, fornecendo constante e ampla variedade de produtos, como alimentos, remédios, madeira ou forragem, principalmente para o autoconsumo das famílias e também para a geração de renda adicional. Além disso, a diversidade dos quintais contribui para a conservação de espécies ameaçadas e variedades tradicionais, preservando práticas agrícolas tradicionais, confirmando sua importância sócio-ecológica. Apesar de serem de grande importância, os quintais nem sempre recebem a devida atenção e, para serem valorizados, é necessário entender sua contribuição para os agricultores familiares e para o meio ambiente. Esta pesquisa teve como objetivo avaliar a importância ambiental, econômica e sócio-cultural de quintais rurais, sendo realizada em duas partes: a primeira consistiu em visitar quatro quintais na Zona da Mata para estimar sua agrobiodiversidade através da identificação das espécies e famílias e, consequentemente, calcular os índices de biodiversidade alfa (Índice de Riqueza) e biodiversidade beta (índice de Whittaker, coeficiente de Jaccard (CJ) e coeficiente de Sorensen (CS)). Finalmente, foi realizado escaneamento de uma das propriedades com equipamento laser scanner terrestre, que permitiu medir (média de três leituras) as alturas de árvores e arbustos selecionados ao acaso e, assim, observar a distribuição e a estrutura vertical do quintal. A segunda parte consistiu na análise de dados secundários contendo os valores da produção gerada em 30 propriedades na Zona da Mata de Minas Gerais, utilizando a metodologia denominada "Caderneta Agroecológica", na qual as mulheres compilam os dados da produção dos quintais, seu destino (autoconsumo, venda, doação e troca) e sua transformação em valores monetários, de acordo com os preços nos mercados locais de cada produto. Os resultados demonstraram que os quintais visitados variaram em tamanho, de 1990 metros quadrados para 8830 metros quadrados, com uma idade entre cinco e 20 anos. Através do trabalho participativo foi conhecido que os quintais são espaços onde as decisões são tomadas e as atividades são lideradas pelas mulheres, mas com a cooperação dos outros membros das famílias. Em nenhum dos quintais foram utilizados agrotóxicos ou fertilizantes químicos, limitando o uso de calcário como um corretivo do pH do solo em apenas uma propriedade. O solo foi adubado com esterco animal, resíduos de colheitas e resíduos orgânicos caseiros, e o controle de ervas foi feito com capina e roçado, contribuindo com a cobertura do solo. Encontraram-se 246 espécies de plantas distribuídas em 81 famílias, e seis espécies animais distribuídos em igual número de famílias. A maioria das espécies de plantas é utilizada como alimento (147 espécies), seguido de remédio (69), espécies ornamentais (56), forragem (quatro espécies) e outros usos (13 espécies). As espécies animais são utilizadas como alimento (quatro espécies) e companhia (duas espécies). A biodiversidade alfa mostrou uma elevada diversidade em cada quintal; no entanto, biodiversidade beta indicou que não há semelhança entre as quatro propriedades. O laser scanner permitiu calcular a altura das plantas selecionadas, observando coeficiente de variação máximo nas leituras de 6,24% que a maioria dos indivíduos mais altos está no pomar, e os indivíduos de médio e baixo porte estão localizados ao redor da casa. Finalmente, a Caderneta Agroecológica permitiu registrar a produção dos quintais e seu destino, assim como seu valor monetário estimado. A produção dos quintais foi diversificada (com 140 produtos registrados pelas mulheres), permanente ao longo dos 12 meses do ano, mas variável em cada mês. Monetariamente, representou uma porcentagem média equivalente a 29% do salário mínimo no Brasil.
Home gardens exist throughout the world and have been present since the beginning of human society. They are located near houses and are fundamentally dependent on female labor. One of their main characteristics is that they maintain high rates of agro-biodiversity and provide a constant and wide variety of products for the consumption of the families and for the generation of additional income: these products include food, medicine, wood, and forage. From a socio- ecological perspective the diversity of home gardens contributes to the conservation of endangered species, traditional varieties, and traditional farming practices. Despite being of great importance, these home gardens or yards do not always receive proper attention; and in order to value them accurately, it will be necessary to understand the contribution they make both to family farmers and to the environment. The aim of this study, divided into two parts, was to understand the environmental, economic, and socio-cultural importance of rural home gardens. The first part consisted in the analysis of secondary information containing production values generated on 30 farms located in the Zona da Mata of Minas Gerais. The methodology used is called “Agro-ecological Booklet,” in which women collect the production data from the yards, their destination (consumption, sale, donation, and exchange) and their conversion into monetary values based on the prices of the local markets for each product. The second part consisted in actually visiting four home gardens in the Zona da Mata to estimate their agro- biodiversity through the identification and the uses of the species and families; and consequently to calculate the indexes of alfa-biodiversity (Index of Richness) and beta- biodiversity (Whittaker Index, Coefficient of Jaccard (CJ) and Coefficient of Sorensen (CS)). Finally, a scanning of one of the properties was performed using terrestrial laser scanner equipment that measured (average of three measurements) the height of random trees and shrubs in order to observe both the distribution and the vertical structure of the home garden. The results showed that the Agro-ecological Booklet methodology was able to record the production of the home gardens and their location, as well as an estimate of their monetary value. The production of home gardens was diverse (140 products were recorded by the women), permanent throughout the year but variable every month. Monetarily, they represented an average percentage equivalent to 29% of the minimum wage in Brazil. The visited home gardens varied in area from 1,990 square meters to 8,830 square meters, with an age range between five and twenty years. With the participatory work it was known that the home gardens are spaces where the activities and decisions are led and made by women, albeit with the co- operation of the other members of the family. Neither pesticides nor chemical fertilizers were used in any of the home gardens, thus limiting the use of agricultural lime as a soil amendment to just one single property. The soil was fertilized with animal manure, crop residues, and organic garbage from the houses; and the control of spontaneous weeds was done by mowing and weeding, contributing with the coverage of the soil. It was found that 246 plant species were distributed in 81 families, and six animal species were distributed in an equal number of families. Most plant species are used for food (147 species), followed by medicinal (69 species), ornamental (56 species), fodder (four species), and others (13 species). The animal species are used for food (four species) and companionship (two species). Alfa-biodiversity showed a high diversity in each home garden; however, beta-biodiversity indicated that there is no similarity between the four properties. Finally, the laser scanner allowed calculating the height of the selected plants, obtaining a maximum coefficient of variation of 6,24%, with the observation that the majority of the highest individuals are in the orchard while the individuals of medium and smaller height are located around the house.

The goal of this project will be to design a phonemic awareness handbook which will be discussed at a kindergarten staff in-service. The information in the handbook will explain the concept of phonemic awareness and its importance to successful reading acquistion. The handbook will also provide some phonemic awareness assessment inventories as well as some activities.

Thesis (Ph.D.)--Boston University PLEASE NOTE: Boston University Libraries did not receive an Authorization To Manage form for this thesis or dissertation. It is therefore not openly accessible, though it may be available by request. If you are the author or principal advisor of this work and would like to request open access for it, please contact us at open-help@bu.edu. Thank you.
Monte Carlo simulation, while flexible and widely applicable, has a relatively slow rate of convergence and significant effort has been devoted to improving its efficiency. In this thesis, we focus on the efficient simulation technique of Importance Sampling (IS) in simulation settings where the objective is to improve computational efficiency when solving several instances of an estimation problem and not a single instance only. In the setting of parametric estimation where instances of the estimation problem differ in some model or decision parameters, we consider using the optimal sampling measure at a nominal parameter as the sampling measure at neighboring parameters and analyze the variance of the resulting importance sampling estimator. We show that the resulting estimator can be very effective in estimations in the vicinity of the nominal parameter. We describe an approach to implement this scheme using an approach called the DataBase Monte Carlo (DBMC). Generalizations of DBMC to Importance Sampling and combining Importance Sampling with Stratification are introduced. Next we consider the application of Importance Sampling to a problem in computational finance, namely, portfolio risk evaluation. We use a linear approximation to the portfolio loss, as a function of the underlying risk factors, to obtain a good importance sampling density. We derive the optimal direction for shifting the means of the underlying risk factor. We apply this approach to estimate the probability of large portfolio losses in both one-level and nested simulation settings. In the one-level simulation, it is assumed that the approximation to the loss function is available. In the context of nested simulation, we consider an initial learning phase to "learn" the approximation function using "a regression-like" approach. In cases where the linear approximation is inadequate, we propose an approach that combines Importance Sampling with Stratificiation by subdividing the sampling space into strata and then applying Importance Sampling in each subdivision.

This research explored the existence and importance of interaction in online courses as perceived by online learners and instructors. The study was based on data from online students and instructors in the fall 2002 semester at Mid-Atlantic Community College(1). Two web-based surveys were used to collect data. Eighty-eight of 267 online students completed the survey, for a response rate of 33%. The study was based on constructivist theory which suggested that students learn by actively participating in the learning process through interaction with the instructor, other students, and course materials. This interaction was measured by different online interaction modalities and a five-step interactivity model developed by Salmon. This model suggested that the intensity of interactivity involves five steps: access and motivation, online socialization, information exchange, knowledge construction, and development. In addition, student characteristics (age and gender) and pedagogical variables (online experience and learning preferences) were included. Findings of the survey revealed that students perceived a moderate to high level of availability in a majority of the interactivity modalities. The highest interaction was reported between students and instructor through email communication and feedback on students? work by instructors. In addition, student ratings of the availability of different interaction modalities in online instruction were correlated with their perceptions of the importance of these modalities. Students reported satisfaction with the level of interactivity in their online courses. In contrast, responses to Salmon?s model revealed a high level of unavailability of the various interactivity criteria. The result of instructor survey, based on 13 responses, revealed that online instructors perceive interaction with students through email communication and providing feedback on their work were important. They did not perceive many of the interactivity criteria introduced by this research to be important. Therefore, they reported these criteria as unavailable in their online courses. This study is important because the extent of systematic research on availability and importance of online interaction is limited. (1)- To preserve the anonymity of respondents, this name is a pseudonym.
Ph. D.

Background Random forests are becoming increasingly popular in many scientific fields because they can cope with "small n large p" problems, complex interactions and even highly correlated predictor variables. Their variable importance measures have recently been suggested as screening tools for, e.g., gene expression studies. However, these variable importance measures show a bias towards correlated predictor variables. Results We identify two mechanisms responsible for this finding: (i) A preference for the selection of correlated predictors in the tree building process and (ii) an additional advantage for correlated predictor variables induced by the unconditional permutation scheme that is employed in the computation of the variable importance measure. Based on these considerations we develop a new, conditional permutation scheme for the computation of the variable importance measure. Conclusion The resulting conditional variable importance reflects the true impact of each predictor variable more reliably than the original marginal approach. (authors' abstract)