Informacja

Drogi użytkowniku, aplikacja do prawidłowego działania wymaga obsługi JavaScript. Proszę włącz obsługę JavaScript w Twojej przeglądarce.

English (EN)·Polski (PL)·Yкраїнський (UK)
Przejdź do strony domowej biblioteki Centralna Biblioteka Wojskowa Link otwiera się w nowym oknie Logo biblioteki Prolib Integro - strona głównaCentralna Biblioteka Wojskowa

Wyszukujesz frazę "standard error" wg kryterium: Temat

  Lista filtrów
Wyrównaj
    Wyświetlanie 1-3 z 3
    Tytuł:
    Statystyczna małopowierzchniowa metoda oceny zdrowotności drzew. Część II. Przykład: oszacowanie stopnia uszkodzenia wybranych gatunków drzew na Chełmowej Górze w Świętokrzyskim Parku Narodowym
    Small-scale survey statistical method for evaluation of tree health. Part II. Example: assessment of the defoliation level in the selected tree species on Chełmowa Góra, Świętokrzyski National Park
    Autorzy:
    Podlaski, R.
    Powiązania:
    https://bibliotekanauki.pl/articles/1022861.pdf
    Data publikacji:
    2005
    Wydawca:
    Polskie Towarzystwo Leśne
    Tematy:
    Chelmowa Gora
    modrzew
    sosna
    Swietokrzyski Park Narodowy
    buk
    lasy
    metoda malopowierzchniowa
    lesnictwo
    dab
    jodla
    zdrowotnosc drzew
    metody oceny
    small−scale method
    standard error
    maximum total error
    świętokrzyski national park
    Opis:
    The purpose of the paper was to verify the efficacy of the proposed tree health assessment method involv− ing the assessment of the defoliation level and calculation of errors of this assessment for fir, beech, pine, larch and indigenous oak species growing on the Chełmowa Góra in the Świętokrzyski National Park. Standard errors and maximum total errors calculated at α=0.05 and αz=0.0167 (jointly, three defoliation classes were analysed) did not exceed 5% and 13%, respectively. Application of the simple random sampling design allowed, in a simple manner, to improve assessment accuracy by way of additional sampling of the most endangered or valuable tree species.
    Źródło:
    Sylwan; 2005, 149, 01; 8-14
    0039-7660
    Pojawia się w:
    Sylwan
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Dokładność określenia zasobności na poziomie warstw gatunkowo-wiekowych w obrębowej metodzie inwentaryzacji
    Accuracy of volume determination on the level of age-species layers in the stratified sampling method
    Autorzy:
    Banaś, J.
    Drozd, M.
    Bujoczek, L.
    Zięba, S.
    Zygmunt, R.
    Powiązania:
    https://bibliotekanauki.pl/articles/986687.pdf
    Data publikacji:
    2017
    Wydawca:
    Polskie Towarzystwo Leśne
    Tematy:
    powierzchnie probne
    forest inventory
    stratification
    standard error
    sample plot
    variability coefficient
    lesnictwo
    drzewostany swierkowe
    warstwy gatunkowo-wiekowe
    inwentaryzacja lasu
    zasobnosc drzewostanu
    miazszosc drzewostanow
    metoda obrebowa
    dokladnosc pomiaru
    Opis:
    Statistical representative method of inventory based on stratified sampling is used for elaborate forest management plans in Poland. Strata are created according to the dominant tree species and age of stands. First stratum include stands with age from 21 to 30 years and the interval in the next strata is 10 years. Sample plot size depends on stand age and varies from 0.005 to 0.05 ha. According to the allocation pattern number of samples is proportional to age and total area of stands in a stratum. Diversification of number and size of sample plots has a profound influence of inventory precision in an age classes. The aim of the study is to analyse the accuracy of the stand volume determination on the level of age−species strata. Research was conducted based on the data obtained from periodic forest inventory in seven mountainous forest subdistricts located in the Kłodzko Basin (SW Poland). Norway spruce stands with total area of 39,935.45 ha and 6102 sample plots were chosen for analysis. Sampling fraction, mean number and volume of trees on a sample plot, coefficient of volume variability and standard error of volume were calculated for each stratum in analyzed forest subdistricts. Sample plots with size of 0.005 ha established in young stands (21−30 years) are characterized by small number of trees (4.3−7.6 in average) and the highest coefficient of volume variability (93%). Additionally, because of low age of stands, the number of plots is also small (18 on average), which influences the low precision of volume inventory in this stratum. Standard error of volume was on the mean level of 23% in the youngest age stratum and decreased with age of stands to 5% in the stands of 41−71 years and below this level in the strata with the older stands. Increasing the plot size in the youngest stratum will be effective way to improve accuracy of forest inventory in the method based on stratified sampling.
    Źródło:
    Sylwan; 2017, 161, 09; 715-722
    0039-7660
    Pojawia się w:
    Sylwan
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Liczba i wielkość jednostek próbnych do pomiaru leżących martwych drzew metodą liniową
    Number and size of sample units for the estimation of coarse woody debris volume using the line intersect method
    Autorzy:
    Miścicki, S.
    Sołtys, A.
    Powiązania:
    https://bibliotekanauki.pl/articles/980334.pdf
    Data publikacji:
    2019
    Wydawca:
    Polskie Towarzystwo Leśne
    Tematy:
    lesnictwo
    obszary chronione
    obszar ochrony scislej Bukowa Gora
    drzewa martwe
    zasoby drzewne
    miazszosc drzew
    metody pomiarow
    metoda liniowa
    linie probne
    bukowa góra
    protected forest
    sampling line
    single−tree−plot coefficient of variation
    standard error
    time of measurements
    Opis:
    The line intersect method is recommended for coarse woody debris (CWD) inventories. This is due to the fact that for the CWD volume estimation with the assumed standard error (SE), the total time of measurements using line sampling units is shorter than when using the fixed−area sample units. The aim of the research was to determine: (1) the number and size of sample units whose use will allow achieving the assumed SE of the CWD volume estimation, and (2) dependence of this number and size of sample units on the quantity of CWD. The research material was collected from 131 sample units (sampling lines) with a length of 50.48 m each. They were systematically located in the stands (128 ha) on Bukowa Góra in the Roztocze National Park (south−east Poland). Data concerning the intersection points of the sampling line (in relation to its beginning) with the axis of a downed log, made it possible to simulate the measurement using shorter sampling lines (4, 8, …, 44 m) than the original ones. The simulation was performed using the original data (when the average CWD volume was 73 m3/ha), which also represented an inventory unit in which the CWD volume accounted for 10, 40 and 70% of the original value. These data were obtained by a random elimination of the appropriate portion of trees. The relationship between the single−tree−plot coefficient of variation (calculated for such a size of a sample unit which on average contains only one log) and the length of the sampling line was determined (figs. 2 and 3). On this basis the number of sample units necessary to obtain the assumed SE value of the target variable was determined (tab. 1). Using the data on labour consumption of individual measurement operations, the total working time was calculated for such a number of sample units that would guarantee obtaining the assumed SE of the CWD volume estimation (tab. 2). The total time of measurements was longer in an inventory unit with scarcer CWD resources (figs. 5 and 6). The optimal (due to the time of measurements needed to achieve the assumed SE of the CWD volume estimation) line length occurred within the range of 4−150 m. The use of sample units with a length of 60−150 m each was recommended in forests with the average CWD volume over 30 m3/ha, and with a length of 150−200 m in forest with sparser CWD resources.
    Źródło:
    Sylwan; 2019, 163, 01; 35-46
    0039-7660
    Pojawia się w:
    Sylwan
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
      Wyświetlanie 1-3 z 3

      Ta witryna wykorzystuje pliki cookies do przechowywania informacji na Twoim komputerze. Pliki cookies stosujemy w celu świadczenia usług na najwyższym poziomie, w tym w sposób dostosowany do indywidualnych potrzeb. Korzystanie z witryny bez zmiany ustawień dotyczących cookies oznacza, że będą one zamieszczane w Twoim komputerze. W każdym momencie możesz dokonać zmiany ustawień dotyczących cookies