Wyniki wyszukiwania - BazTech

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Wybór rozkładu oddziaływań klimatycznych z wykorzystaniem metody Bayes’a

Pytlowany T., Woliński S.

Czasopismo Inżynierii Lądowej, Środowiska i Architektury / Journal of Civil Engineering, Environment and Architecture

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2016

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z. 63, nr 1/I

43--52

PL

Wybór typu zmiennej losowej na podstawie wyników badań polega najczęściej na aproksymacji parametrów przyjętego rozkładu. Jednak dostępne wyniki badań lub obserwacji często nie pozwalają na dostatecznie precyzyjne dopasowanie jednego z powszechnie stosowanych typów rozkładu zmiennej losowej. W artykule przedstawiono metodę opartą na wnioskowaniu Bayesa, która umożliwia oszacowanie miary dopasowania i optymalnego wyboru jednego z typowych rozkładów zmiennej losowej oraz wyznaczenie dystrybuanty liniowej kombinacji testowanych rozkładów. Zastosowanie przedstawionej metody zilustrowano na przykładzie oceny i wyboru dystrybuanty rozkładu reprezentującego obciążenie śniegiem gruntu oraz wyznaczenia kombinacji testowanych rozkładów w celu określenia wartości charakterystycznej obciążenia śniegiem dla przyjętego okresu powrotu.

EN

Single distribution functions are usually selected based on a best-fit approach theorem but often available random data cannot be accurately described by any of the commonly used types of the random variables. The paper presents a method based on Bayesian approach which solves problems of selecting the single distribution function and combining of probabilities contending different probability functions. The method is illustrated on the selection of single distribution function and application of Bayesian method in combining these functions to determine the characteristic value of snow load for an assumed return period.

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Effect of weather change on flock size of the Snow Bunting (Plectrophenax nivalis L.) wintering in south-western Poland

Orłowski Grzegorz, Gębski Paweł

Polish Journal of Ecology

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2007

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Vol. 55, nr 1

181-185

EN

In winter 2004/2005 some exceptionally large (on the Central European scale) concentrations of Snow Bunting (Plectrophenax nivalis), up to 1600 individuals, were recorded in Lower Silesia (south-western Poland). The Snow Bunting flock size was positively correlated with the mean daily air temperature (P = 0.002). The average flock size during snowless days was 11 times higher than in the snowy period (P = 0.0017). One of the factors encouraging the more abundant wintering of Snow Bunting in Central Europe may be the milder climatic conditions, especially higher temperature and lack of snow cover. During the last four decades the rise of mean temperatures and shrinking of the snow cover period in winter months (December-February) have been observed in Lower Silesia.

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Changes of flowering phenology of six herbal species in a beech forest (Central Slovakia): a decade analysis

Schieber Branislav

Polish Journal of Ecology

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2007

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Vol. 55, nr 2

233-244

EN

The variability in flowering phenology of six forest herbaceous species: Pulmonaria officinalis L. (early spring species), Dentaria bulbifera L. (mid spring), Galium odoratum Scop, (late spring), Veronica officinalis L. (early summer), Mycelis muralis (L.) Dumort. (mid summer) and Campanula trachelium L. (mid/late summer) was analysed over the period of the past ten years (1995-2004). Observations were done in a beech forest at the Ecological Experimental Stationary in Kremnicke vrchy Mts (Central Slovakia, 48[degree] 38'N, 19[degree] 04'E, 450-520 m a.s.l.)- Two phenological events - the first flowering and full flowering as well as the duration of interphase interval were analysed. The timing of observed phenological events was related to selected climatic factors (temperature and precipitation). The highest variation in the first flowering date was observed in early spring species- standard deviation (SD) was equal to 7.2 days. As for full flowering date, the highest value of standard deviation was detected in late summer species (SD = 8.5 days). In respect to the duration of inter-phase interval (in days), the highest relative vari.ability (c[v] > 53%) was ascertained in early spring species. The significant correlations (P <0.001) were detected between dating of full flowering and cumulative temperatures in all phenological types (excepting early spring); the coefficients of correlation (r) moved from - 0.85 (early summer and mid summer species) to - 0.91 (mid spring species). Significant correlations were revealed between precipitation and timing of flowering only for mid summer (r = +0.70) and late summer species (r = +0.75), respectively. Despite of the fact, that no significant trends were detected in timing of flowering in the species, the effect of the global warming is evident. The values of the possitive deviations of the mean air temperatures averaged for the period of the last decade were increased in comparison to the long-term mean. Onsetof flowering has been shifted earlier a few days in majority of the spe.cies during the past decade. Decade tendency showed a slight increasing of values of cumulative temperatures during the periods crucial for the development of the phenophases.

4

Wpływ tradycji na nowoczesność

Lewowicki S., Al-Zamzami M.

Warstwy

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2000

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nr 3

105-107