Preferencje help
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 3

Liczba wyników na stronie
first rewind previous Strona / 1 next fast forward last
Wyniki wyszukiwania
help Sortuj według:

help Ogranicz wyniki do:
first rewind previous Strona / 1 next fast forward last
EN
One of the widespread sources of river pollution is the wastewater coming from both wastewater treatment plants and the stormwater system. Wastewater can vary significantly in composition and concentration of substances introduced into water bodies. Municipal effluents may contain significant amounts of organic matter and ammonia. Storm drains are diverse in composition and depend on the nature of the surface from which the water collects, but carry more suspended solids and less nutrients. The research was aimed at assessing the effect of surface runoff collected by the stormwater system from the territory of the city of Lublin on the Bystrica River using popular environmental indices, calculated on the basis of periphytonic algae species abundances: species number, Shannon’s H, rarefied species number, Pielou’s evenness, trophic diatom index (TDI). It was observed that the correspondence between a species diversity and the quality of the environment is not always straightforward. Therefore, the periphytonic algae diversity increases under the influence of runoff, as evidenced by the Shannon index. Nevertheless, pronounced changes are noted in the structure of the algal community, as shown by the Pielou index and NMDS. However, these changes in the structure are invisible if the trophic diatom index (TDI) is relied upon.
EN
The article is devoted to the analysis of watermarking algorithms in terms of their use in marking medical images. The algorithms based on the Integer Wavelet Transform (IWT), Discrete Cosine Transform (DCT), and Singular Value Decomposition (SVD) were compared. The algorithms were implemented using the combinations: IWT, IWT-DCT, and IWT-SVD. As part of the research, the level of disturbances caused by embedding the watermark was checked using subjective and objective methods. The attack resistance of the watermarked images was tested and the steganographic capacity was measured. All algorithms are based on IWT, however, each has different advantages. The algorithm based on the IWT showed the highest capacity. The most resistant to attacks is IWT-SVD, and the lowest level of interference was obtained for the IWT-DCT algorithm.
PL
Artykuł poświęcono analizie algorytmów znakowania wodnego pod kątem wykorzystania w znakowaniu obrazów medycznych. Porównano algorytmy oparte o całkowitą transformatę falkową (IWT), dyskretną transformatę kosinusową (DCT) i rozkład według wartości osobliwych (SVD). Zaimplementowano algorytmy stosując kombinacje: IWT, IWT-DCT i IWT-SVD. W ramach badań sprawdzono poziom zakłóceń spowodowanych osadzaniem znaku wodnego przy pomocy metod subiektywnych i obiektywnych. Przeprowadzono badania odporności oznakowanych obrazów na ataki i zmierzono pojemność steganograficzną. Wszystkie algorytmy bazują na IWT, jednakże każdy z nich ma inne zalety. Największą pojemność wykazał algorytm oparty o IWT. Najodporniejszy na ataki jest IWT-SVD, a najmniejszy poziom zakłóceń uzyskano dla algorytmu IWT-DCT.
3
Content available Effect of Stormwater System on the Receiver
EN
The surface water quality assessment could be based on a combined physical and chemical analysis, but it could also be determined with bioindication methods. Classical physicochemical analysis is in most cases more expensive and time-consuming than the bioindication methods. This type of analysis also requires expensive equipment and shows the situation in the water only at the moment of sampling. Although the bioindication methods are often complicated, they allow a relatively inexpensive estimation of the water quality. Moreover, during their implementation, the substances harmful to the environment are not generated, and the obtained results usually reflect the total interaction of all factors and substances to the analyzed living organisms. Indicator organisms or their communities applied to the research, with identified ranges of tolerance to selected factors, could help to determine the physical and chemical parameters of water. This paper presents a bioindication study with an effect of stormwater system on the receiver – the Bystrzyca river, in Lublin, Poland. The level of saprophyty of the river sector was calculated based on the selected species of algae (diatoms and green algae) and the influence of the stormwater discharge on the communities of these organisms was determined.
first rewind previous Strona / 1 next fast forward last
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.