Wyniki wyszukiwania - BazTech

Ograniczanie wyników

Powiadomienia systemowe

Sesja wygasła!

Znaleziono wyników: 2

Liczba wyników na stronie

Wyniki wyszukiwania

Wyszukiwano:
w słowach kluczowych: przestrzeń drzew

Sortuj według:

Ogranicz wyniki do:

Analiza wypełnienia leśnej przestrzeni na podstawie modeli typu CAD

Chirrek M., Strzeliński P., Wencel A., Sugiero D., Węgiel A.

Roczniki Geomatyki

2008

T. 6, z. 4

27-34

The filling of forest space should be defined by a set of synthetic indicators describing structural and dynamic features. The utilization of these indicators in forest sciences, such as forest management or forest nurcery could help in research of development processes in forests. This is necessary in planning the activity related to forest management and protection, in particular . to forest regeneration, maintenance and utilization. An attempt to analyze the filling of forest space was taken in 2007. The experimental material was collected from 50 circular test plots located in the community of fertile Carpathian beech forests in lower-mountain zone of Bieszczady National Park. The results of measurements were imported to AutoCAD 2007 software that was used for spatial analyses. The range of works in the field included measurements of many different structural features in all plant layers of the stand. Moreover, on all test plots azimuths of each tree, as well as distance from the center of the plot to all trees from old-tree layer were measured. These measurements were used for spatial analyses of the distribution of trees in forest space. Area of one tree is contained at a range of 7,69.50,00 m2 and on most test plots it did not deviate very much from the average value (18,13 m2). Average space of one tree amounted to 475,17 m3. On plots in the younger development phases, where there were more trees with small dimensions, value of space of one tree amounted to ca. 120 m3. Besides, random spatial type of distribution of trees dominated on most plots (72%) and not many cases pointed at group distribution. In this study, some indicators were suggested to make forest space characteristics possible. Determination of these parameters may serve analyses of the structure of forest space within the stand. In the future, the indicators can provide some important hints in forest silvicultural and management planning. Further research is needed related to spatial analysis in order to create the synthetic indicators describing structural and dynamic features of all types of stands.

Porównywanie topologii drzew i sieci filogenetycznych z wykorzystaniem metryki błędu

Bogdanowicz D., Małafiejska A.

Zeszyty Naukowe Wydziału ETI Politechniki Gdańskiej. Technologie Informacyjne

2007

T. 12

117-124

Podstawowymi modelami historii ewolucji organizmów są drzewa i sieci filogenetyczne. Ponieważ algorytmy konstrukcji filogenów zwracają różne wyniki dla tych samych danych wejściowych, powstaje problem oceny, który filogen najlepiej reprezentuje historię ewolucji dla zadanego zbioru gatunków. W pracy podano definicję metryki dla przestrzeni drzew o n liściach, zwanej metryką błędu. Dokonano przeglądu miar odległości na przestrzeni sieci filogenetycznych, bazujących na metryce wprowadzonej dla drzew, wraz z analizą modelu, dla które-go miary te spełniają nierówność trójkąta. Z wykorzystaniem programu phylonet przeprowadzono porównanie przykładowych topologii zarówno drzew, jak i sieci, oraz dokonano oceny, na ile wprowadzone miary odzwierciedlają rzeczywistość.

Phylogenetic trees and networks are based models of evolution history. Because algorithm for constructions phylogenies output different values for the same input data, there is a problem of which one from phylogenies is the best representation of history of evolution for given set of species. There is given a metric definition for n-leaves tree space called error metric in this paper. For phylogenetic network space, there are defined few distance funcion based on error metric for trees, which satisfy triangle inequality only in specific case of networks. Using phylonet software there is made a comparison between topology of trees and networks, and a conclusion about reality of each metric function.