Sökning: "stochastic growth rate"

Visar resultat 6 - 10 av 37 avhandlingar innehållade orden stochastic growth rate.

  1. 6. Biomarkers of ionising radiation relevant to carcinogenesis : Dose, dose rate and LET dependency of the responses

    Författare :Milagrosa López Riego; Andrzej Wojcik; Lovisa Lundholm; Alexandros G. Georgakilas; Stockholms universitet; []
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Ionising radiation; low dose; low dose rate; linear energy transfer LET ; mixed beams; dose and dose rate effectiveness factor DDREF ; cancer; DNA damage response; biomarkers; molekylär biovetenskap; Molecular Bioscience;

    Sammanfattning : A better understanding of the relationship between ionising radiation (IR) dose, dose rate and radiation quality, and the risk of stochastic effects would improve risk extrapolation from atomic bomb survivors’ data. Owing to insufficient statistical power of epidemiological studies to detect excess incidence of cancer following low doses of IR delivered at low dose rates (LDLDR), as typically encountered in most common human exposure scenarios, radiobiological experiments are fundamental to describe the biological effectiveness of LDLDR and to define the underlying molecular mechanisms. LÄS MER

  3. 7. Pollinators, Enemies, Drought, and the Evolution of Reproductive Traits in Primula farinosa

    Författare :Per Toräng; Jon Ågren; Johan Ehrlén; Rebecca Irwin; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Ecology; Alternative reproductive strategies; climate change; facilitation; floral display; flowering phenology; frequency-dependent selection; genetic diversity; life-history strategies; local adaptation; pollination; predation; Primula farinosa; reproductive effort; soil disturbance; stochastic growth rate; Ekologi;

    Sammanfattning : In this thesis, I combined comparative and experimental approaches to examine selection on reproductive traits and population differentiation in the insect-pollinated, self-incompatible, perennial herb Primula farinosa. More specifically, I (1) determined whether the effects of floral display and interactions with pollinators and seed predators, and plant reproductive success were frequency-dependent and affected by surrounding vegetation context, (2) examined the consequences of intermittent drought years on population dynamics using numerical simulations based on demographic data collected over seven years, (3) analyzed among-population differentiation in flowering phenology and reproductive allocation, and its relationship to soil-depth at the site of origin. LÄS MER

  4. 8. Asymptotic Methods for Pricing European Option in a Market Model With Two Stochastic Volatilities

    Författare :Betuel Canhanga; Sergei Sivestrov; Anatoliy Malyarenko; Ying Ni; Milica Rancic; Raimondo Manca; Mälardalens högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Asymptotic Expansion; European Options; Stochastic Volatilities; Mathematics Applied Mathematics; matematik tillämpad matematik;

    Sammanfattning : Modern financial engineering is a part of applied mathematics that studies market models. Each model is characterized by several parameters. Some of them are familiar to a wide audience, for example, the price of a risky security, or the risk free interest rate. Other parameters are less known, for example, the volatility of the security. LÄS MER

  5. 9. Stochastic epidemic models in heterogeneous communities

    Författare :David Lindenstrand; Tom Britton; Åke Svensson; Denis Mollison; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Mathematical Statistics; matematisk statistik;

    Sammanfattning : The aim of Paper I is to explain where randomness should be taken into account when modelling epidemic spread, i.e. when a stochastic model is preferable to a deterministic counterpart. LÄS MER

  7. 10. Time Varying Parameters in Exchange Rate Models

    Författare :Richard Henricsson; Nationalekonomiska institutionen; []
    Nyckelord :SAMHÄLLSVETENSKAP; SOCIAL SCIENCES; economic systems; economic theory; econometrics; Economics; stochastich volatility.; purchasing power parity; GARCH; exchange rates; Stationarity; economic policy; Nationalekonomi; ekonometri; ekonomisk teori; ekonomiska system; ekonomisk politik;

    Sammanfattning : This thesis consists of five papers on different aspects of parametervariation in some common exchange rate models.The first paper investigates the stability in the real exchange rate, witch is equivalent to purchasing power parity (PPP). LÄS MER