Artykuł prezentuje stochastyczny model dryfu rozlewu olejowego na morzu. Model rozlewu olejowego to model kontroli rozlewu na morzu; zawiera on algorytm przeprowadzenia akcji ratowniczej, polegającej na otoczeniu rozlewu oraz analizę czasu trwania akcji ratowniczej. W celu uwzględnienia parametrów prądów morskich i wiatrów na ruch plamy rozlewu powstała koncepcja przemieszczania się plamy rozlewu olejowego.
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In the article the stochastic model of the oil spill drift is presented. The oil spill model is a model of oil spill control on the sea; it includes an algorithm of rescue action performance consisting in surrounding the spill, and an analysis of the rescue action time. In order to take into account the influence of sea currents and winds parameters on the spill slick movement, a concept of the model of oil spill slick movement has been developed.
W pracy przedstawiono problem dryfu występującego w skaningowym mikroskopie tunelowym (STM). Dryf ten występuje w osiach X, Y oraz Z. Na przykładzie pomiarów wysokozorientowanego grafitu pyrolitycznego omówiono jego wpływ na pracę mikroskopu, oraz możliwe zakłócenia procedury pomiarowej. Zaproponowano modyfikację konstrukcji mikroskopu STM tak, aby negatywny wpływ dryfu w osi Z uległ minimalizacji. W tym celu wykonano i zaprezentowano konstrukcję precyzyjnego układu elektronicznego z precyzyjnym przetwornikiem cyfrowo-analogowym i porównano go z dostępnym rozwiązaniem komercyjnym. Przedstawiono również możliwości rozszerzenia opracowanego systemu.
EN
In this work drift issues appearing in scanning tunneling microscope (STM) was discussed. This drift appears in X, Y and Z axis. Based on measurements of the highly oriented pyrolytic graphite its influence on the work of the microscope and possible disturbances of the measurement procedure was described. Modification of the construction of the STM microscope minimizing the negative impact of the drift in Z axis was proposed. To do that a precise electronic circuit based on precise digital-to-analog converter was developed and it was compared with available commercial solution. At the end possibilities of the expansion of the realized system was shown.
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Stream invertebrates use ‘drift’ or downstream transport in the water column to disperse, but they also actively move upstream against current. These movements have important role in re-colonization of empty stream reaches and in regulation of population size. For more than half a century, research of stream drift was stimulated by the problem of ‘drift paradox’, i.e. the question how upstream reaches of streams remain inhabited despite constant and often ample losses of individuals by drift. In this study we examined drift and upstream movements of the amphipod Gammarus fossarum through monthly sampling over one-year period at two sites in the upper and middle course of a small unaltered stream in the northwest Croatia. Differences in tendency to drift and to move upstream and effects of environmental factors (temperature, flow, population density and detritus dry weight) on the movement dynamics on both temporal and spatial scale were examined for three size categories (adults, subadults and juveniles). While seasonal variations of drift and upstream movements were similar at two examined sites, at the middle course we recorded higher density, and higher drift and upstream movement rates. In both drift and upstream movements, adults were the most represented size category. In subadults and juveniles, both type of movements depended on population density. Adult upstream movements peaked in November and May/June, with massive upstream movements in May in the middle course. Seasonality of diurnal and nocturnal drift was very similar at both sites, while seasonality of diurnal and nocturnal upstream movements differed between the sites. Out of four examined independent environmental factors, density and temperature had the most important positive effect on spatiotemporal variations of diurnal drift, while nocturnal drift was more strongly affected by density and flow. Temperature was the most significant driver of diurnal upstream movements, while nocturnal upstream movements were most significantly positively affected by density. Massive upstream movements were driven by overcrowding and enabled adults to colonize microhabitats where food is more abundant and competition is less severe.
W pracy zaproponowano nową metodę identyfikacji dryfów żyroskopów w Systemach Nawigacji Lądowej (SNL), działającą w czasie procesu Orientacji Wstępnej (OW). Zakładamy, że znamy błąd azymutu początkowego, który jest wyznaczany algorytmem DISUPT (Dynamic Initial Settings UPdaTe) [12], w czasie początkowego odcinka jazdy. W pierwszej części pracy określimy kryterium, według którego będziemy dokonywać identyfikacji dryfów oraz zbadamy jego właściwości. Następnie dokonamy prezentacji metody o nazwie GDI (Gyroscope Drifts Identification) oraz przedstawimy wyniki optymalizacji i symulacji sprawdzając poprawność funkcjonowania metody. Wykorzystano do tego celu zbiory danych, zarejestrowane w czasie jazd kontrolnych. Na zakończenie, sformułujemy wnioski oraz perspektywy dalszych prac.
EN
The paper presents a new method for identifying gyroscope drifts during, the Alignment Process (AP) in inertial navigation systems UNZ-50. We assume that initial azimuth error is known as result of applying the DISUPT technique [12] when the vehicle is in the navigation mode. The first part of the work describes the quality criteria on the base which the gyroscope drifts are identified. Nex, their properties are examined, including computation algorithms, examples of characteristics and the simulation results. Further the GDI method and the optimization results have been presented. In order to check proper functioning the GDI method, a series of simulations in MATLAB 6.0 environment have been carried out on the data collected during terrain tests of UNZ-50 system prototype mounted on a cross - country light vehicle. Finally, conclusions have been formulated.