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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.
31

Embryo cryopreservation and transfer to rederive a paternal rabbit line after 18 generations. Evaluation of growth and reproductive traits

Juárez Moreno, Jorge Daniel 01 September 2022 (has links)
Tesis por compendio / [ES] Para evaluar los efectos del proceso de selección en una línea paterna de conejos, se compararon los rasgos de crecimiento y rendimiento reproductivo de la descendencia actual (generación R36) en similar ambiente con una población control rederivada de embriones de una generación anterior (R18). Para reducir/evitar el efecto del proceso de criopreservación sobre los rasgos fenotípicos se rederivaron embriones de la generación actual (R36) y obtener una 3ra población (R37V). Capítulo 1, se compara la R37V y la descendencia de la R36 nacida por inseminación artificial (R37). Hubo diferencias en rasgos de crecimiento postnatal en las 3 generaciones evaluadas, pero no en el crecimiento fetal, componentes del tamaño de la camada y rasgos reproductivos. Así, los procesos de criopreservación y transferencia de embriones causan cambios en rasgos de crecimiento de poblaciones reconstituidas que influyen en las siguientes generaciones, sin producir cambios en los reproductivos. En los siguientes capítulos, para reducir/evitar los efectos del proceso de rederivación, la deriva genética y factores ambientales sobre los rasgos fenotípicos, se usó sólo poblaciones rederivadas para comparar los rendimientos reproductivos y de crecimiento. Capítulo 2, al ser los machos usados para producir dosis seminales en centros de inseminación y granjas, se evaluó si el programa de selección modificaba los rasgos seminales, el proteoma del plasma seminal y de espermatozoides, y la fertilidad del semen al usarla en inseminación artificial. Se analizó el proteoma del plasma seminal y espermatozoides de machos maduros de c/grupo y se prepararon dosis seminales para inseminación. Sólo el porcentaje de espermatozoides anormales mostró diferencias, presentando los R21 menos espermatozoides anormales que los R39. El análisis discriminante (DA-PLS) mostró efecto de la generación para el proteoma plasmático y espermático. En plasma seminal, se reportaron 64 proteínas diferencialmente expresadas y 56 sobreexpresadas en R39 (87,5%). Del proteoma de espermatozoides 132 diferencialmente abundantes y 89 sobreexpresadas en R39 (67,4%). A pesar de las diferencias en importantes proteínas relacionadas con la capacitación, la motilidad, la inmunoprotección de espermatozoides y la fecundación, no hubo diferencias en fertilidad y prolificidad con las dosis seminales para inseminación. Capítulo 3, se analizó el efecto de la selección por ganancia media diaria de peso (GMD) post-destete después de 37 generaciones. Tras 2 generaciones post rederivación (R21 vs. R39), todos los caracteres evaluados mostraron progreso resultado de la selección, y no afecta a los parámetros estimados de la curva de crecimiento de Gompertz. Los resultados demuestran que el programa de selección mejoró la GMD sin variar el peso corporal adulto, pero tras 37 generaciones de selección, este carácter parece agotado. Capítulo 4, comparamos los parámetros reproductivos de conejas entre las poblaciones rederivadas y control. Los rasgos de desarrollo prenatal y los componentes del tamaño de camada se midieron en la 2da generación post rederivación (R20 y R38). Así la selección por GMD no tiene efectos adversos sobre los componentes del tamaño de la camada, y el área del saco fetal al día 12 de gestación, área de la placenta fetal y la longitud cráneo-rabadilla del feto al 19 de gestación fueron mayores en R38. Resultados muestran que la selección por GMD no afecta negativamente el rendimiento reproductivo. Conclusión, el estudio demuestra que los efectos de la criopreservación sobre los rasgos de crecimiento persisten dos generaciones post rederivación. Además, la línea muestra signos de agotamiento del progreso genético quizás por el bajo rendimiento reproductivo y elevada mortalidad postnatal. La selección por GMD influyó en cambios del crecimiento fetal y del proteoma del eyaculado, sin afectar al rendimiento reproductivo de hembras ni la fertilidad y prolificidad de las dosis seminales de machos. / [CA] Per avaluar els efectes del procés de selección en una línia paterna de conills, es van comparar els trets de creixement i el rendiment reproductiu de la descendència de la generació actual (R36) sota el mateix entorn amb una població control derivada dels embrions emmagatzemats d'una generació anterior (R18). Per reduir/evitar l'efecte del procés de criopreservació embrions de la generació actual (R36) es van criopreservar i transferir (rederivar) per obtenir una 3a població (R37V). Capítol 1, es compara la generació R37V i la descendència de la 36a generació nascuda per inseminació artificial (R37). Hi ha diferències en els trets de creixement postnatal a les tres generacions avaluades. Tot i que el creixement fetal, els components de la mida de la ventrada i els trets reproductius no van mostrar diferències. La rederivació provoquen canvis en els trets de creixement de les poblacions reconstituïdes que influeixen en les generacions següents, sense canvis en els trets reproductius. En els capítols següents, per reduir/evitar els efectes del procés de rederivació, la deriva genètica i els factors ambientals sobre els trets fenotípics, es van utilitzar les poblacions rederivades per comparar els rendiments reproductius i de creixement. Capítol 2, ja que els mascles s'utilitzaven per produir dosis de semen en centres d'inseminació i granges, es va estudiar si un programa de selecció per guany mitja de pes diari pot canviar els trets seminals, el proteoma del plasma i dels espermatozoides i la fertilitat del semen en la inseminació artificial. Només el percentatge d'espermatozoides anormals mostra diferències significatives, R21 presentant menys espermatozoides anormals que R39. L'anàlisi discriminant (DA-PLS) mostra efecte de la generació al proteoma del plasma i dels espermatozoides. En plasma seminal, 64 proteïnes es van expressar de manera diferent, 56 sobre-expressades en R39 (87,5%). El proteoma de l'esperma 132 proteïnes diferencialment abundants, 89 sobre-expressades en R39 (67,4%). Tot i observar diferències en proteïnes importants relacionades amb la capacitat, la motilitat o la immunoprotecció dels espermatozoides i la fecundació, La fertilitat i la prolificitat es van detectar quan es van utilitzar dosis seminals comercials per a la inseminació. Capítol 3, vam avaluar l'efecte d'una selecció a llarg termini per a l'augment de pes mitjà diari (ADG). Després de dues generacions d'ambdues poblacions rederivades (R21 vs. R39), tots els trets avaluats mostra algun progrés. Aquesta resposta no sembla afectar els paràmetres estimats de la corba de creixement de Gompertz. Resultats demostra que el programa de selecció havia millorat l'ADG sense variacions en pes corporal adult, però després de 37 generacions de selecció, aquest tret sembla esgotat. Capítol 4, compara els trets reproductius entre poblacions femenins entre ambdues poblacions (rederivades i control). El desenvolupament fetal i els components de la mida de la ventrada es mesura els trets a la segona generació després de la rederivació (R20 i R38). Resultats suggereix que la selecció per ADG no té cap efecte advers sobre els components de la mida de la ventrada i la zona del sac fetal el dia 12 de gestació i la zona de la placenta fetal i la longitud de la corona-gropa del fetus el dia 19 de gestació eren més grans a la R38. La selecció per ADG no afecta negativament els components de la mida de la ventrada, el creixement fetal i el rendiment reproductiu. Nostre estudi proporciona més proves dels efectes de la criopreservació sobre els trets de creixement que persisteixen dues generacions després de la rederivació. La línia va mostrar signes d'esgotament del progrés genètic per baix rendiment reproductiu i l'alta mortalitat postnatal. La selecció per ADG va influir en els canvis en el creixement fetal i en el proteoma ejaculat, però no va afectar el rendiment reproductiu de les femelles ni la fertilitat i la prolificitat de les dosis seminals dels mascles. / [EN] To evaluate the effects of the selection process in a paternal line of rabbits, growth traits and reproductive performance from the offspring of the current generation (R36) were compared under the same environment with a control population rederived from embryos stored of a previous generation (R18). To reduce or avoid the effect of the cryopreservation process on phenotypic traits embryos of current generation (R36) were cryopreserved and transferred to obtain a third population (R37V). In chapter 1, R37V generation and offspring of 36th generation born by artificial insemination (generation R37) were compared. Differences in postnatal growth traits were observed in the three generations assessed. Although foetal growth, litter size components and reproductive traits did not show significant differences. In conclusion, cryopreservation and embryo transfer processes cause changes in growth traits of reconstituted populations that influence the following generations, without changes in reproductive traits. In the following chapters, to reduce or avoid the effects of the rederivation process, genetic drift and environmental factors on phenotypic traits, only the rederived populations were used to compare reproductive and growth performances. In chapter 2, considering that males were used to produce semen doses at insemination centres and farms, we studied whether a programme of selection by daily gain changed the seminal traits, plasma and sperm proteome and the fertility of semen when used in artificial insemination. Seminal plasma and sperm proteome from mature males of each group were analysed and semen doses were used to inseminate females. Only the percentage of abnormal sperm showed significant differences, R21 presented fewer abnormal sperm than R39. The discriminant analysis (DA-PLS) showed an effect of the generation for plasma and sperm proteome. In seminal plasma, 64 proteins were differentially expressed, 56 were overexpressed in R39 (87.5%). Sperm proteome reported 132 differentially abundant proteins, 89 were overexpressed in R39 (67.4%). Despite differences in important proteins related to capacitation, sperm motility or immunoprotection and to the fertilization process, no differences in fertility and prolificacy were detected when commercial seminal doses were used for insemination. In chapter 3, we evaluated the effect of a long-term selection for post-weaning average daily weight gain (ADG) over 37 generations. After two generations of both rederived populations (R21 vs. R39 generations), all evaluated traits showed some progress as a result of the selection. This response does not seem to affect the estimated Gompertz growth curve parameters. Results demonstrated that the selection programme had improved ADG without variations in adult body weight but, after 37 generations of selection, this trait seems exhausted. In chapter 4, we compared female reproductive traits between both rabbit populations (rederived and control). Foetal growth and litter size traits were measured in the second generation after rederivation (R20 and R38 generations). Our study suggests that selection for growth rate has no adverse effect on litter size components and the foetal sac area at day 12 of gestation, and foetal placenta area and crown-rump length of the foetus at day 19 of gestation were higher in the R38 generation. These results show that selection for growth rate does not adversely affect on reproductive performance. In conclusion, our study provides further evidence of the effects of cryopreservation on growth traits persisting two generations after rederivation. Moreover, the paternal line showed signs of genetic progress exhaustion due to low reproductive performance and high postnatal mortality. Selection by daily weight gain influenced changes in foetal growth and ejaculate proteome, but did not affect the reproductive performance of females or the fertility of seminal doses of males. / This research was supported by AGL2017-85162-C2-1-R research project funded by Ministerio de Economía, Industria y Competitividad (MICINN, Spain). Funding for open access charge: CRUE- Universitat Politècnica de València. / Juárez Moreno, JD. (2022). Embryo cryopreservation and transfer to rederive a paternal rabbit line after 18 generations. Evaluation of growth and reproductive traits [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/185071 / Compendio
32

Curvas de crescimento de frangos caipiras submetidos a diferentes níveis de lisina digestível

Cunha Filho, Octavio Gomes da 10 February 2014 (has links)
The goal of the present work was to analyze the Gompertz functions in order to describe the growth of hillbilly broilers Color Plume (CPK) subjected to different levels of digestible lysine. On the experiment were used 432 chickens from one day old, was divided into three stages: initial, growth and finale respectively corresponding to the ages from 1 to 21, from 22 to 77 days of age and from 78 to 84 days of age. During the initial phase, the birds were reared on shavings beds with access to water, food and a heating source until after 21 days of age, the birds had access to paddocks. After 21 days of age, the birds which were in terms of the medium weight were distributed randomly in four treatments of 27 birds, with four replicates each one and 10 birds per replication (5 males and 5 females) were chipped with microchip brand Animall TAG and dimensions 12x2 mm. Treatments were represented by different lysine levels (0.850, 0.970, 1.090; 1.210%) on the experimental diet. The diets used were based on corn and bran soybean, and were formulated to meet the nutritional requirements at each stage of creation, as suggested by Rostagno et al. (2011), except lysine. Diets and birds were weighed weekly to determine the performance (weight gain, feed intake and feed conversion). Gompertz curves adjusted showed good correlation coefficients above 90%, and good values of Durbin Watson test accurately, estimating the average weight gain, and the consumption ration of mixed batch of free range broiler chickens. After the tests comparison between Gompertz parameters of the model for each level of lysine was determined that: the only parameter that varied was A, since B = 0.0329 and C = 45.819 parameters presented not significant differences. At the level of digestible lysine 0.850%, A = 4870.3, 0.970% A = 4894.9, 4784.3 A = 1.09%, 1.21% A = 4740. Among them, the parameter A in 0.970% level, differed from the others, ie, showing a higher body weight at maturity. Based the performance results, it is recommended for free range broiler CPK chickens of both sexes, to use a level of digestible lysine up to 0.970% on the period 22-77 days of age. After comparison tests between the Gompertz parameters of the model for each lysine level was determined for female that: the only parameter that varied was A, since B = 0.0356 and C = 45.54 parameters presented not significant differences. In males it has been concluded that only a single equation may represent the growth in four levels of lysine. The lysine levels did not influence (P> 0.05) carcass variables, except the yield of abdominal fat, than for females improved quadratically up to the level of 1.064%, for males there was a quadratic effect. / O presente trabalho objetivou-se utilizar o modelo não linear de Gompertz para descrever o crescimento de frangos caipira da linhagem Colorcpk Plumé (CPK), de ambos os sexos e entre os sexos, submetidos a diferentes níveis de lisina digestível. Foram utilizados 432 frangos com um dia de idade, o experimento foi dividido em três fases: inicial, crescimento e final correspondendo respectivamente às idades de 1 a 21, 22 a 77 e 78 a 84 dias de idade. Na fase inicial as aves foram criadas sobre cama de maravalha com acesso a água, ração e fonte de aquecimento e uma única dieta. Aos 21 dias de idade, as aves em função do peso médio foram distribuídas num delineamento inteiramente casualizado, em quatro tratamentos com quatro repetições de 27 aves por unidade experimental, e dentre elas, 10 aves de cada repetição (5 machos e 5 fêmeas) foram chipadas com microchips da marca Animall TAG e dimensões de 12x2 mm. Os tratamentos foram representados pelos diferentes níveis de lisina digestível (0,850; 0,970; 1,090; 1,210%) na dieta experimental na fase de crescimento. As dietas foram à base de milho e farelo de soja e formuladas para atender as exigências nutricionais em cada fase de criação, conforme sugerido de Rostagno et al. (2011), exceto lisina digestível. As rações e as aves foram pesadas semanalmente para determinação do desempenho (ganho de peso, consumo de ração e conversão alimentar), as aves chipadas também eram pesadas individualmente a cada 7 dias. Aos 84 dias de idade as aves chipadas foram abatidas, totalizando 160 aves. As características de carcaça avaliadas foram calculadas em relação ao peso corporal após jejum. As curvas de Gompertz ajustadas apresentaram bons coeficientes de determinação, acima de 90%, e bons valores do teste de Durbin Watson, estimando com boa acurácia o peso médio, ganho de peso e consumo de ração dos frangos caipira. Após os testes de comparação entre os parâmetros do modelo de Gompertz para cada nível de lisina para o lote misto, determinou-se que somente o parâmetro A deveria variar, pois os parâmetros B=0,0329 e C=45,819 não apresentaram diferenças significativas. No nível de lisina digestível 0,850% A=4870,3; 0,970% A=4894,9; 1,09% A=4784,3; 1,21% A=4740; dentre eles o parâmetro A no nível 0,970% diferiu dos demais, ou seja, maior peso corporal a maturidade. Com base nos resultados de desempenho, recomenda-se, para aves caipiras da linhagem CPK de ambos os sexos o nível de lisina digestível na ração de 0,970% no período de 22 a 77 dias de idade. Após os testes de comparação entre os parâmetros do modelo de Gompertz para cada nível de lisina, determinou-se para fêmeas que somente o parâmetro A deveria variar, pois os parâmetros B=0,0356 e C=42,54 não apresentaram diferenças significativas. Para os machos concluiu-se que apenas uma única equação pode representar o crescimento nos quatro níveis de lisina digestível. Os níveis de lisina digestível não influenciaram (P>0,05) as variáveis de carcaça, exceto o rendimento de gordura abdominal, que para as fêmeas melhorou de forma quadrática até o nível estimado de 1,064%.
33

Stokastisk modellering och prognosticering inom livförsäkring : En dödlighetsundersökning på Länsförsäkringar Livs bestånd / Stochastic modeling and prognostication in life insurance : A mortality survey on Länsförsäkringar Liv

Andersson, Henrik, Bakke Cato, Robin January 2023 (has links)
Studier av livslängder och dödssannolikheter är avgörande för livförsäkring. Betalningar gällande livförsäkringar är helt beroende av om en individ lever eller ej, eller befinner sig i olika hälsotillstånd. För att kunna prissätta premier korrekt och avsätta reserver är det därför av stort intresse att modellera livslängden på ett så korrekt sätt som möjligt. Försäkringsbranschen använder idag historiskt beprövade och välfungerande modeller som går så långt bak i tiden som 200 år. Det finns modeller ännu längre bak i tiden, men de modeller som används idag är främst Gompertz (1826), Makeham (1860) och Lee-Carter (1992). Även om dessa modeller presterar bra är det alltid nödvändigt att undersöka om det kan finnas alternativa modeller som modellerar dödligheten bättre. I detta examensarbete tillämpas affina korträntemodeller för modellering av dödlighetsintensiteten som ligger till grund för flertalet intressanta aktuariella storheter. Då dessa modeller introducerar stokastisk dödlighet kan osäkerheten och beroendet över tid därmed beskrivas. De korträntemodeller som undersöks i arbetet och som är vanligt förekommande inom den finansiella teorin; är Ornstein-Uhlenbeck, Feller och Hull-White. Dessa modeller jämförs sedan mot varandra vad gäller modellerad dödlighetsintensitet samt förväntad återstående livslängd och ettårig dödssannolikhet. En aspekt av stokastisk dödlighetsmodellering som ej återfinns i befintlig litteratur men som undersöks i detta examensarbete är modellering av dödlighet över tid då detta är en av de mest väsentliga aspekterna inom det livförsäkringsmatematiska arbetet. Till sist i valideringssyfte utvärderas samtliga korträntemodeller genom back-testing. Den andra huvudsakliga delen av arbetet består i att generera resultat för samma storheter som ovan baserat på DUS-metoden för att på så sätt jämföra en kommersiell metod mot en mer teoretisk mindre beprövad sådan. Resultaten visar på en stor potential hos flera av korträntemodellerna kontra DUS både vad gäller modellering över åldrar och kalenderår. Däremot är inte resultaten helt felfria för enstaka kalenderår där stora spikar uppstår på grund av parametermässig felanpassning. Modelleringen av korträntemodellerna över tid var över förväntan då modellerna inte är konstruerade för att fånga avtagande trender. Detta är något som kan betraktas som en stor flexibilitet hos korträntemodellerna då de står sig väl mot Lee-Cartermodellen som används i DUS, både vad gäller ålders- och tidsmodellering av dödlighet. / Studies of life expectancy and death probabilities are crucial for life insurance. Payments for life insurance are completely dependent on whether an individual is alive or not, or is in various health conditions. In order to be able to price premiums correctly and set aside reserves, it is therefore of great importance to model life expectancy in the most accurate way possible. The insurance industry today uses historically proven well-functioning models that go as far back in time as 200 years. There are models even further back in time, but the models used today are mainly Gompertz (1826), Makeham (1860) and Lee-Carter (1992). Although these models perform well, it is always necessary to investigate whether there may be alternative models that model mortality better. In this thesis, affine short-term interest rate models are applied for modeling the force of mortality that forms the basis for most interesting actuarial variables. As these models introduce stochastic mortality, the uncertainty and dependence over time can thus be described. The three short-term interest rate models examined in this project, which are common in financial theory; are Ornstein-Uhlenbeck, Feller and Hull-White. These models are then compared against each other in terms of the modeled force of mortality as well as the expected remaining life expectancy and the one-year probability of death. One aspect of stochastic mortality modeling that is not found in the existing literature but which is examined in this thesis is the modeling of mortality over time as this is one of the most important aspects in the life insurance mathematical industry. Finally, for validation purposes, all short-term interest rate models are evaluated using back-testing. The second main part of the work consists of generating results for the same quantities as above based on the DUS method in order to compare a commercial method with more theoretical and less approved ones. The results show a great potential in several of the short-term interest rate models versus DUS both in terms of modeling over ages and calendar years. However, the results are not completely impeccable for individual calendar years where large spikes occur due to inaccurate parameter calibration. The satisfactory modeling of the short-term interest rate models over time was above the expectations as the models are not designed to capture decreasing trends. This is something that can be considered a great flexibility of the short-term interest rate models as they are more or less as accurate as the Lee-Carter model used in DUS, both in terms of age and time modeling of mortality.
34

Explorative Scenarios for Future Lithium Supplies and Demand / Utforskande prognoser för tillgång och efterfrågan av litium i framtiden

Rahman, Aksel January 2023 (has links)
Because of its specific qualities, lithium is a key element for making lithium-ion batteries, which is of great relevance since the battery sector is the fastest growing user of lithium to date and with the transition towards a fully electrified transportation sector due to the current climate agenda and an even bigger increase in demand for lithium is anticipated for the coming decades. The two main sources for lithium to date are mines and brines, with brine water composing around 87 % of the world’s lithium reserves in terms of contained lithium. Salars, dominantly large salt flats in South America, provide the type of brine water that has a high concentration of lithium. These salars occur primarily in Argentina, Bolivia and Chile (the ABC-triangle), where solid lithium-compounds occur dominantly as evaporate minerals such as lithium carbonates. Lithium from salars is recovered with natural evaporation and salar-derived lithium-salts generally have a higher purity than lithium derived from pegmatite mining. However, the process of lithium extraction from salars much slower than mining lithium from pegmatite, although large amounts of energy are required and large amounts of waste rock material is produced in the process. Lithium also occurs in geothermal waters and in seawater, but at far lower concentrations then in pegmatites or salar brines, which thus requires large processing efforts to be economically attractive.The purpose of this study is to provide a modern update based on the lithium production data in metric tons from recent years and interpolate the lithium production for the remaining part of the century. Then I will assess the difference between the projections from the study by Vikström et al. 2014, that were previously used to estimate possible future production rates annually, and current production and availability estimates. To achieve this, the present study will compare the different sources of lithium all over the world, mainly hard rock and brine, with a focus on the geological aspects and the EU from a financial aspect. This thesis thus aims to assess future production trends based on most recent data on geological availability, which will be retrieved from The United States Geological Survey, and earlier forecasts with the purpose to investigate if and how previous forecasts will need to change in respect to various resource availability. The production data ranging from 1900 to 2010 from the previous study by Vikström et al., on which the previous forecast production is based on, is updated with data from 2011 to 2019. With the addition of the more recent data, a similar forecast projection will be made using the same mathematical models (logistic, Gompertz and Richards).
35

臺灣地區的人口推估研究 / The study of population projection: a case study in Taiwan area

黃意萍 Unknown Date (has links)
台灣地區的人口隨著生育率及死亡率的雙重下降而呈現快速老化,其中生育率的降低影響尤為顯著。民國50年時,台灣平均每位婦女生育5.58個小孩,到了民國70年卻只生育1.67個小孩,去年(民國90年)生育率更創歷年新低,只有1.4。死亡率的下降可由平均壽命的延長看出,民國75年時男性為70.97歲,女性為75.88歲;到了民國90年,男性延長到72.75歲,女性延長到78.49歲。由於生育率的變化幅度高於死亡率,對人口結構的影響較大,因此本文分成兩個部份,主要在研究台灣地區15至49歲婦女生育率的變化趨勢,再將研究結果用於台灣地區未來人口總數及其結構的預測。   本研究第一部分是生育率的研究,引進Gamma函數、Gompertz函數、Lee-Carter法三種模型及單一年齡組個別估計法,以民國40年至84年(西元1951年至1995年)的資料為基礎,民國85年至89年(西元1996年至2000年)資料為檢測樣本,比較模型的優劣,尋求較適合台灣地區生育率的模型,再以最合適的模型預測民國91年至140年(西元2002年至2051年)的生育率。第二部分是人口推估,採用人口變動要素合成方法(Cohort Component Projection Method)推估台灣地區未來50年的人口總數及其結構,其中生育率採用上述最適合台灣地區的模型、死亡率則引進國外知名的Lee-Carter法及SOA法(Society of Actuaries),探討人口結構,並與人力規劃處的結果比較之。 / Both the fertility rate and mortality rate have been experiencing dramatic decreases in recent years. As a result, the population aging has become one of the major concerns in Taiwan area, and the proportion of the elderly (age 65 and over) increases promptly from 2.6% in 1965 to 8.8% in 2001. The decrease of fertility rate is especially significant. For example, the total fertility rate was 5.58 in 1961, and then decreases dramatically to 1.67 in 1981 (1.4 in 2001), a reduction of almost 70% within 20 years.   The goal of this paper is to study the population aging in Taiwan area, in particular, the fertility pattern. The first part of this paper is to explore the fertility models and decide which model is the most suitable based on age-fertility fertility rates in Taiwan. The models considered are Gamma function, Gompertz function, Lee-Carter method and individual group estimation. We use the data from 1951 to 1995 as pilot data and 1996 to 2000 as test data to judge which model fit well. The second part of this study is to project the Taiwan population for the next 50 years, i.e. 2002-2051. The projection method used is Cohort Component Projection method, assuming the population in Taiwan area is closed. We also compare our projection result to that by Council for Economic Planning and Development, the Executive Yuan of the Republic of China.

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