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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.
1

Simulating urban growth for Baltimore-Washington metropolitan area by coupling SLEUTH model and population projection

Zhao, Suwen 18 June 2015 (has links)
This study used two modelling approaches to predict future urban landscape for the Baltimore-Washington metropolitan areas. In the first approach, we implemented traditional SLEUTH urban simulation model by using publicly available and locally-developed land cover and transportation data. Historical land cover data from 1996, 2001, 2006, and 2011 were used to calibrate SLEUTH model and predict urban growth from 2011 to 2070. SLEUTH model achieved 94.9% of overall accuracy for a validation year of 2014. For the second modelling approach, we predicted future county-level population (e.g., 2050) using historical population data and time-series forecasting. We then used future population projection of 2050, aided by strong population-imperviousness statistical relationship (R2, 0.78-0.86), to predict total impervious surface area for each county. These population-predicted total impervious surface areas were compared to SLEUTH model output, at the county-aggregated spatial scale. For most counties, SLEUTH generated substantially higher number of impervious pixels. An annual urban growth rate of 6.24% for SLEUTH model was much higher than the population-based approach (1.33%), suggesting a large discrepancy between these two modelling approaches. The SLEUTH simulation model, although achieved high accuracy for 2014 validation, may have over-predicted urban growth for our study area. For population-predicted impervious surface area, we further developed a lookup table approach to integrate SLEUTH out and generated spatially explicit urban map for 2050. This lookup table approach has high potential to integrate population-predicted and SLEUTH-predicted urban landscape, especially when future population can be predicted with reasonable accuracy. / Master of Science
2

Um modelo geoespacial de uso do solo e demografia. O caso do Município de São Paulo / A geographic model of land use and demography: the case of São Paulo city

Pérez Machado, Reinaldo Paul 10 April 2001 (has links)
Este estudo pretende contribuir para a disseminação e aplicação dos sistemas de informações geográficas e do geoprocessamento, apresentando o desenvolvimento de um modelo de uso do solo e projeção demográfica para a Zona Leste do Município de São Paulo, construído a partir de bases de dados cadastrais imobiliárias e do zoneamento da cidade, e dos setores censitários do IBGE, para aquela região, entre as principais fontes de dados descritivos utilizadas. Apresenta ainda, a base cartográfica digital da cidade de São Paulo, convertida e melhorada, suporte para a criação de mapas temáticos como saída do modelo, forma perceptiva básica para viabilizar as análises espaciais e consumo destas informações geoespaciais pelos usuários interessados, podendo esta metodologia ser reproduzida para outros locus, respeitadas as condições básicas de alimentação do sistema georeferenciado / This study presents the experiment of building an urban geographic information application, containing a fully developed land use and demographic model, using the geographic information system as a tool to gather, convert, link and analyze huge cadastral files from the Municipality of São Paulo, due the real estate aggregation of land use and economic activities, and the Census Tracts, for the East Zone of the city territory. Beyond this, a digital cartographic base was developed and enhanced, to support the descriptive data, in order to generate thematic maps, as outputs, which help the users to understand the reality and forecast the future population distribution, with the sensitive accuracy of the city blocks, minor desegregation of the Census Tracts, they themselves an aggregation of blocks. The main attempt goal was reached by making possible to apply this land use and demographic model to the whole territory, and spreading this created methodology to other similar conditions
3

台灣地區死亡率推估的實證方法之研究與相關年金問題之探討

曾奕翔 Unknown Date (has links)
In Taiwan area, the mortality rates at all ages have decreased since the end of World War II, and the life expectancy of people has increased from 62 in 1950's to 75 in 2000, which is an increase of 21%. The mortality improvement of the elderly (i.e. people ages 65 and over) is especially significant, which effects in the rapid population aging in Taiwan area. For example, the proportion of the elderly has increased from 6.14%in 1990 to 8.52% in 2000. On one hand, the prolonged life span for an individual means a longer period of retirement life and thus a larger retirement fund. On the other hand, a longer life for the government is equivalent to a more thorough social system for the elderly. Therefore, a reliable mortality rates projection is essential to both personal financial and social welfare planning.   In this study, we have two main objectives: First, we explore some frequent used models, such as Lee-Carter, multivariate regression and principal component methods. We use the data between 1950 to 1995 as the pilot data and 1996 to 2000 as the test data to judge which method has the smallest prediction error. In addition, based on computer simulation, we also evaluate the performance of the estimation methods for the Lee-Carter method. The second part (and the other objective) of this study is to explore the effect of mortality improvement on the pure premium of annuity insurance. In particular, we calculate the pure premium of the annuity under the best model acquired from the first part, and compare those under 1989 TSO and other life tables. We found that the pure premiums under current life tables are under estimated, which may cause the insolvency of insurance companies.
4

Um modelo geoespacial de uso do solo e demografia. O caso do Município de São Paulo / A geographic model of land use and demography: the case of São Paulo city

Reinaldo Paul Pérez Machado 10 April 2001 (has links)
Este estudo pretende contribuir para a disseminação e aplicação dos sistemas de informações geográficas e do geoprocessamento, apresentando o desenvolvimento de um modelo de uso do solo e projeção demográfica para a Zona Leste do Município de São Paulo, construído a partir de bases de dados cadastrais imobiliárias e do zoneamento da cidade, e dos setores censitários do IBGE, para aquela região, entre as principais fontes de dados descritivos utilizadas. Apresenta ainda, a base cartográfica digital da cidade de São Paulo, convertida e melhorada, suporte para a criação de mapas temáticos como saída do modelo, forma perceptiva básica para viabilizar as análises espaciais e consumo destas informações geoespaciais pelos usuários interessados, podendo esta metodologia ser reproduzida para outros locus, respeitadas as condições básicas de alimentação do sistema georeferenciado / This study presents the experiment of building an urban geographic information application, containing a fully developed land use and demographic model, using the geographic information system as a tool to gather, convert, link and analyze huge cadastral files from the Municipality of São Paulo, due the real estate aggregation of land use and economic activities, and the Census Tracts, for the East Zone of the city territory. Beyond this, a digital cartographic base was developed and enhanced, to support the descriptive data, in order to generate thematic maps, as outputs, which help the users to understand the reality and forecast the future population distribution, with the sensitive accuracy of the city blocks, minor desegregation of the Census Tracts, they themselves an aggregation of blocks. The main attempt goal was reached by making possible to apply this land use and demographic model to the whole territory, and spreading this created methodology to other similar conditions
5

Population Dynamics and Predictions for the Calcareous Green Algae, Halimeda, on the Coral Reefs of South Florida

Peach, Katherine E. 01 December 2009 (has links)
Halimeda (Chlorophyta, Bryopsidales) (Lamouroux 1812) is a genus of calcareous green algae that has become abundant on coral reefs of the tropics and subtropics. Though they serve biologically and geologically important roles in these ecosystems, their presence may be an indicator of declining environmental conditions. This study focused on a population of Halimeda in the shallow coastal waters of Tavernier, Florida. Three species were encountered: Halimeda discoidea, Halimeda opuntia, and Halimeda incrassata; Halimeda discoidea was the most abundant. The study was conducted in two parts. Part one involved the observation and quantification of the life history characteristics (e.g. fertility rate, growth rate, mortality rate) of the collected specimens in an artificial environment. Population numbers increased throughout the five week study as new individuals were added through vegetative reproduction. Sexual reproduction was not observed. In Part two the life history characteristics of H. discoidea were used in the construction of a size-classified transition matrix model. Sensitivity and elasticity analyses suggested that the population is most sensitive to changes in the survival rate of reproductive juveniles, and least sensitive to the survival of post-reproductive adults. A standard Chi-square test was used to examine the accuracy of the population distribution predicted by the model against the observed distribution during each week of the study. The test results confirmed the validity of the model; however further analysis of the matrix revealed that without the input of sexual recruits the population will go extinct. A random sexual component was then added to the matrix. Environmental stochasticity can have a direct affect on sexual recruitment in Halimeda. Recruitment interval and recruitment success influence the ability of the population to maintain itself. These factors were manipulated in the matrix. With a 25% recruitment interval of 50 recruits the simulated population was able to avoid extinction over a 25 year period. These results implicate that Halimeda populations require both sexual and asexual recruitment. Additionally, the patchy distribution of Halimeda on and near coral reefs of south Florida indicates that the population may actually be a metapopulation. Recommendations for further studies include an investigation of additional sub-populations within the metapopulation. A mortality analysis would also be useful for gaining a better understanding of the population dynamics and sediment contributions of Halimeda in south Florida.
6

小區域生育率與人口推計研究 / Small Population Projections:Modeling and Evaluation

曹郁欣, Eunice Y. Tsao Unknown Date (has links)
由於許多國家死亡率下降快速、壽命延長幅度超乎預期,加上生育率持續低於替代水準,人口老化現象愈發明顯,近年來個人生涯規劃及政府施政,都格外強調退休後經濟生活及老年相關社會資源分配的比重。以臺灣為例,行政院經濟建設委員會 (簡稱經建會) 從1990年代開始,每兩年公布一次未來的人口推估,但過去十年來經建會屢次修正歷年的推估假設,以因應生育率及死亡率變化快速,適時提醒臺灣日益加速的人口老化。正因為人口推估可能受到人口數、社會變遷、資料品質等因素,影響統計分析的可靠性,常用於國家層級的推估方法,往往無法直接套用至縣市及其以下的層級 (即小區域),使得小區域人口推估較為棘手,需要更加謹慎面對。 本文延續王信忠等人 (2012) 的研究,以小區域人口推估為目標,著重在生育率推估研究,結合隨機模型與修勻方法,尋找適合臺灣縣市層級的小區域人口推估方法。本文考量的隨機模型計有區塊拔靴法 (Block Bootstrap) 和 Lee-Carter 模型 (Lee and Carter 1992),以預測未來的生育率和死亡率,並套用年輪組成推計法 (或稱為人口要素合成法;Cohort Component Method) 及修勻 (Graduation) 方法,探討這些方法與人口規模之間的關係,評估用於小區域人口推估之可行性。 本文首先以電腦模擬,探討生育率的推估,討論是否可直接推估總生育率,類似增加樣本數的概念,取代各縣市的年齡別生育率,以取得較為穩定的推估。根據模擬結果,發現人口規模對出生數的推估沒有明顯的關係,只要使用總生育率、再結合區塊拔靴法,就足以提供穩定的推估結果。實證研究方面,以臺灣縣市層級的人口及其年齡結構 (例如:0-14歲、15-64歲、65歲以上) 為驗證對象,發現分析結果也與電腦模擬相似,發現以區塊拔靴法推估臺灣各縣市的總生育率、年齡組死亡率,其推估精確度不因人口規模而打折扣,顯示以區塊拔靴法推估總生育率、年齡組死亡率,可用於推估臺灣小地區的未來人口。 / Due to the rapid mortality reduction, prolonging human longevity is a common phenomenon and longevity risk receives more attention in 21st century. Many developed countries encounter many problems brought up by prolonging life, such as poor community infrastructure and insufficient financial pension funds for the elderly. Population Projection thus becomes essential in government planning in dealing with the population aging. However, rapid changes in mortality and fertility make the projection very tricky. It would be even more difficult to project areas with fewer populations (i.e., small areas) since it takes extra efforts to deal with the larger fluctuations in small population. The objective of the study is to construct a standard operating procedure (SOP) for small population projection. Unlike the previous study, e.g., Wang et al. (2012), we will take both the fertility and mortality into account (but set migration aside for simplicity). First, for the fertility projection, we evaluate if total fertility rates (TFR) are more appropriate than the age-specific fertility rates for small population. Also, we compare two fertility projection methods: Lee-Carter model and block bootstrap, and check which shows better results. Based on the computer simulation, we found that TFR performs better and the block bootstrap method is more sensitive to rapid fertility changes. As for mortality rate projection, we also recommend the standard operating procedure by Wang et al. (2012). However, the smoothing methods have limited impacts on mortality projection and can be ignored. In addition to simulation, we also apply the SOP for projecting the small population to Taiwan counties and it achieves satisfactory results. However, due to the availability of data, our method can only be used for short-term projection (at most 30 years) and these results might not apply to long-term projection. Also, similar to the previous work, the fertility rates have the larger impact on small population projection, although we think that the migration has large impact as well. In this study, only the stochastic projection is considered and we shall consider including expert opinions as the future study.
7

Integral Projection Models and analysis of patch dynamics of the reef building coral Monstastraea annularis

Burgess, Heather Rachel January 2011 (has links)
Over the past 40 years, coral cover has reduced by as much as 80%. At the same time, Coral Reefs are coming under increasing threat from hurricanes, as climate change is expected to increase the intensity of hurricanes. Therefore, it has become increasingly important to understand the effect of hurricanes on a coral population. This Thesis focuses on the reef-building coral Montastraea annularis. This species once dominated Caribbean Coral Reefs, but is fast being replaced by faster growing more opportunistic species. It is important that the underlying dynamics of the decline is understood, if managers stand any chance of reversing this decline. The aim of this Thesis is to investigate the effect of hurricane activity on the dynamics of the reef-building coral Montastraea annularis. To achieve this the Integral Projection Model (IPM) method was adopted and the results compared to those produced using the more traditional method of Population Projection Matrix (PPM) method. The models were fitted using census data from June 1998 to January 2003, which described the area of individual coral patches on a sample of ramets on Glovers Reef, Belize. Glovers Reef is a marine reserve that lies 30km off the coast of Belize and 15km east of the main barrier reef. Three hurricanes struck Glovers Reef during the study: Hurricane Mitch (October 1998), Hurricane Keith (September 2000) and Hurricane Iris (October 2001). The data have been divided by two different methods in order to test two research questions, firstly if the initial trauma following a hurricane affects the long term dynamics of a population and, secondly, if the dynamics exhibited during a hurricane varied with hurricane strength. In this Thesis five main results are shown: 1. All models for all divisions of data are in long term decline. 2. As initial trauma increased, the long term growth rates decreased, conversely the short term extremes increased. 3. Fragmentation is more likely as patch size increased and more likely under stronger hurricanes. 4. Integral Projection Modelling painted a similar picture to Population Projection Matrix models and should be a preferred method of analysis.5. Interaction of the IPMs can be used to model the changing occurrence of hurricanes under climate change. It is shown that with increased intensity, the population could become extinct 6.3 years sooner. This research is the first step in modelling coral patch populations by the IPM method. It suggests possible functional forms and compares the results with the PPM method. Further research is required into the biological functions which drive fragmentation, the method by which large patches divide into groups of smaller patches. The conclusions from this Thesis add to the growing body of knowledge concerning the response of coral species to hurricanes, focusing on the importance of understanding patch dynamics, in order to understand colonial dynamics.
8

Prostorové chování imigrantů: analýza prostorové příbuznosti migračních skupin / Spatial behaviour of immigrants: analysis of spatial relatedness between migration groups

Hasman, Jiří January 2014 (has links)
The entry of immigrants into their incoming country as well as their subsequent spread over the country's territory occurs through processes that have a strong spatial bias. The specific migration groups (here defined as the set of immigrants with the same country of origin) tend to reveal different levels and patterns of their spatial concentrations. The understanding of these similarities and dissimilarities in spatial behaviour is important task from both academic and policy perspective. This thesis has a quantitative character and it is based on the study of "spatial relatedness" of migration groups, which is defined as a rate, how much do given migration groups concentrate into the same regions. The thesis is based on a simple assumption that the spatial relatedness mirrors mutual proximity or similarity between these groups in other respects (e.g. cultural or economical). Plenty of datasets describing spatial distribution of migrants within 32 territorial systems on various scales (from global to local) are analysed. These systems will be analysed separately at first and then a synthesis of these partial results will be done with the aim to discover prevailing pattern of the spatial relatedness of migration groups. The assessments consists of several steps, which include particularly calculation of...
9

Globální trendy ve vývoji úmrtnosti na HIV/AIDS / Global trends in HIV/AIDS mortality

Aubrecht, Vratislav January 2016 (has links)
This thesis is focused on the development of HIV/AIDS mortality in the world starting from the year 1990 and the main goal is estimating the possible future development of the number of inhabitants of the world and defined regions and the influence of HIV/AIDS on the number of inhabitants up to the year 2065. The possible number of HIV/AIDS deaths and people, who were not born because of HIV and AIDS, is computed up to this year. In the theoretical part of the thesis, the most important institutions, which include fight against HIV and AIDS as a part of ther programme, are presented. Natural history of HIV infection and the successes in the research of HIV vaccine are described. In the analytical part, the demographic reproduction of the population of the world and selected regions between years 1950 and 2010 is described, followed by population projection of the world and regions up to year 2065 using the cohort component method. The projection is created in four variants. The first one eliminates the HIV/AIDS mortality. The second one is the constant variant, which conserve the level of HIV/AIDS mortality from the year 2010 up to the year 2065. Last two variants, higher and lower, consider changing levels of HIV/AIDS mortality at time. According to the results of this population projection,...
10

電腦模擬在生育、死亡、遷移及人口推估之應用 / An Application of simulation in projecting fertility, mortality, migration and population

李芯柔, Lee, Hsin Jou Unknown Date (has links)
人口政策的制定需要人口推估作基礎。近年世界各國人口推估逐漸從專家意見推估走向機率推估,常見的機率推估分成三大類,隨機推估、模擬情境、推估誤差三種,本文所使用的人口推估方法為隨機推估法結合生育率之模擬情境方法,在人口變動要素組合法 (Cohort Component Method) 之下輔以電腦模擬的區塊拔靴法 (Block Bootstrap),針對台灣地區與台灣北、中、南、東四地區進行人口推估。另外,本文試圖在隨機模型人口推估中加入遷移人口之考量,以期針對遷移人口在數量與其影響上都能有較深入的了解,比較區塊拔靴法與經建會推估之差異後發現遷移之考量確實會影響人口推估之結果。 / 針對與全區相符的小區域人口推估,本文亦提出可使得推估一致的方法,但其缺點為限制了生育、死亡人口要素之變動性。此推估在總數上與隨機推估方法差異不大,但在人口結構上則有明顯的差別,此差別可能是來自於死亡率在四區間差異造成。 / Population projection is important to policy making, and only with accurate population projection can the government achieve suitable policy planning and improve the welfare of the society. The most popular and well-known population projection method is the Cohort Component method, proposed since 1930’s. The trends of future fertility, mortality and migration are required, in order to apply the cohort component method. Currently in Taiwan, these trends are determined according to experts’ opinions (or scenario projection) and three future scenarios are assumed: high, median and low scenarios. One of the drawbacks in applying experts’ opinions is that the projection results of these three scenarios do not have the meaning in probability. / To modify the expert’ opinions and let the projection results carry the meaning in probability, many demographic researchers have developed stochastic projection methods. The proposed stochastic methods can be categorized into three groups: stochastic forecast, random scenario and ex post methods. In this study, we introduce these stochastic methods and evaluate the possibility of applying the methods in projecting the population in Taiwan. / In this study we use block bootstrap, a computer simulation and stochastic forecast method, to determine the trends of future fertility, mortality and migration in Taiwan, and combine it with the cohort component method for population projection in Taiwan. We compare the projection results with those from the Council for Economic Planning and Development (a scenario projection). We found that the block bootstrap is a possible alternative to the scenario projection in population projection, and the numbers of migration is small but have a non-ignorable influence on the future population. However, we also found that the block bootstrap alone might not be appropriate for population projection in small areas.

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