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 "DRIFT" wg kryterium: Wszystkie pola

  Lista filtrów

Dostawca treści

Podbaza

Wyrównaj
Wyświetlanie 1-15 z 147
Tytuł:
Dryf genetyczny
Genetic drift
Autorzy:
Łomnicki, Adam
Powiązania:
https://bibliotekanauki.pl/articles/1196004.pdf
Data publikacji:
2009
Wydawca:
Polskie Towarzystwo Przyrodników im. Kopernika
Opis:
This article is a short account of the theory of the genetic drift and some of its important consequences. In order to explain this theory simple simulation in Microsoft Excel is applied to show what one can expect in a large population divided into many small populations and some very basic formula concerning the genetic drift are introduced. These introductions allow the presentation of the fate of neutral mutations in small and large populations and the Kimura theory. The relations of drift to other pressures: mutation and selection are shortly discussed.
Źródło:
Kosmos; 2009, 58, 3-4; 377-384
0023-4249
Pojawia się w:
Kosmos
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
ON STOCK TRADING WITH STOCK PRICE DRIFT AND MARKET IMPACT
Autorzy:
Kociński, Marek Andrzej
Powiązania:
https://bibliotekanauki.pl/articles/453904.pdf
Data publikacji:
2018
Wydawca:
Szkoła Główna Gospodarstwa Wiejskiego w Warszawie. Katedra Ekonometrii i Statystyki
Tematy:
transaction cost
market impact
stock price drift
trading speed
Opis:
The drift in the stock price and the occurring of the transaction costs in the stock market can significantly affect the profitability of the investment in the stock. In the article the model of the market is described with the stock price drift and two sources of the transaction costs: bid-ask spread and market impact. In the considered model, the trading strategy which maximizes the expected amount of money received from selling the shares of the stock of the market participant subject to the constraint of the constant trading velocity is explicitly determined. The numerical example is also included.
Źródło:
Metody Ilościowe w Badaniach Ekonomicznych; 2018, 19, 4; 388-397
2082-792X
Pojawia się w:
Metody Ilościowe w Badaniach Ekonomicznych
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Diffusion limit for the phenomenon of random genetic drift
Autorzy:
Marciniak, Anna
Powiązania:
https://bibliotekanauki.pl/articles/1208221.pdf
Data publikacji:
2000
Wydawca:
Polska Akademia Nauk. Instytut Matematyczny PAN
Tematy:
genetic drift
telegraph equations
singularly perturbed systems
diffusion equation
random walk
Opis:
The paper deals with mathematical modelling of population genetics processes. The formulated model describes the random genetic drift. The fluctuations of gene frequency in consecutive generations are described in terms of a random walk. The position of a moving particle is interpreted as the state of the population expressed as the frequency of appearance of a specific gene. This leads to a continuous model on the microscopic level in the form of two first order differential equations (known as the telegraph equations). Applying the modified Chapman-Enskog procedure we show the transition from this system to a macroscopic model which is a diffusion type equation. Finally, the error of approximation is estimated.
Źródło:
Applicationes Mathematicae; 2000, 27, 1; 81-101
1233-7234
Pojawia się w:
Applicationes Mathematicae
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Semi-supervised approach to handle sudden concept drift in Enron data
Autorzy:
Kmieciak, M. R.
Stefanowski, J.
Powiązania:
https://bibliotekanauki.pl/articles/206052.pdf
Data publikacji:
2011
Wydawca:
Polska Akademia Nauk. Instytut Badań Systemowych PAN
Tematy:
concept drift
incremental learning of classifiers
email foldering
Enron data
Opis:
Detection of concept changes in incremental learning from data streams and classifier adaptation is studied in this paper. It is often assumed that all processed learning examples are always labeled, i.e. the class label is available for each example. As it may be difficult to satisfy this assumption in practice, in particular in case of data streams, we introduce an approach that detects concept drift in unlabeled data and retrains the classifier using a limited number of additionally labeled examples. The usefulness of this partly supervised approach is evaluated in the experimental study with the Enron data. This real life data set concerns classification of user's emails to multiple folders. Firstly, we show that the Enron data are characterized by frequent sudden changes of concepts. We also demonstrate that our approach can precisely detect these changes. Results of the next comparative study demonstrate that our approach leads to the classification accuracy comparable to two fully supervised methods: the periodic retraining of the classifier based on windowing and the trigger approach with the DDM supervised drift detection. However, our approach reduces the number of examples to be labeled. Furthermore, it requires less updates of retraining classifiers than windowing.
Źródło:
Control and Cybernetics; 2011, 40, 3; 667-695
0324-8569
Pojawia się w:
Control and Cybernetics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of Drift on Efficiency of Optimal Analog Adaptive Communication Systems with Feedback and Its Compensation
Autorzy:
Jędrzejewski, K.
Powiązania:
https://bibliotekanauki.pl/articles/227312.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
communication systems
feedback
drift compensation
optimal adaptive estimation
Opis:
Results of analysis of drift influence on operation and efficiency of optimal analog adaptive communication systems with feedback and a new approach to drift compensation in these systems are presented in the paper. The proposed approach is based on application of the extended multidimensional adaptive algorithm that estimates simultaneously the value of a transmitted sample and the value of an unknown drift rate. The knowledge of the drift rate enables drift compensation and improves transmission efficiency of systems suffering problems related to drifts.
Źródło:
International Journal of Electronics and Telecommunications; 2013, 59, 1; 51-58
2300-1933
Pojawia się w:
International Journal of Electronics and Telecommunications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Offset Drift Dependence of Hall Cells with their Designed Geometry
Autorzy:
Paun, M. A.
Sallese, J. M.
Kayal, M.
Powiązania:
https://bibliotekanauki.pl/articles/226531.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
hall effect sensor
individual and residual offset drift
temperature coefficient
Opis:
In this paper, the performance of CMOS Hall Effect Sensors with four different geometries has been experimentally studied. Using a characteristic measurement system, the cells residual offset and its temperature behavior were determined. The offset, offset drift and sensitivity are quantities that were computed to determine the sensors performance. The temperature coefficient of specific parameters such as individual, residua offset and resistance has been also investigated. Therefore the optimum cell to fit the best in the performance specifications was identified. The variety of tested shapes ensures a good analysis on how the sensors performance changes with geometry.
Źródło:
International Journal of Electronics and Telecommunications; 2013, 59, 2; 169-175
2300-1933
Pojawia się w:
International Journal of Electronics and Telecommunications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Prediction of ship's speed through ground using the previous voyage's drift speed
Autorzy:
Yamane, D.
Kano, T.
Powiązania:
https://bibliotekanauki.pl/articles/24201461.pdf
Data publikacji:
2023
Wydawca:
Uniwersytet Morski w Gdyni. Wydział Nawigacyjny
Tematy:
machine learning
weather routing
ship's speed estimation
drift speed
algorithm
route planning
tidal current
Opis:
In recent years, 'weather routing' has been attracting increasing attention as a means of reducing costs and environmental impact. In order to achieve high-quality weather routing, it is important to accurately predict the ship's speed through ground during a voyage from ship control variables and predicted data on weather and sea conditions. Because sea condition forecasts are difficult to produce in-house, external data is often used, but there is a problem that the accuracy of sea condition forecasts is not sufficient and it is impossible to improve the accuracy of the forecasts because the data is external. In this study, we propose a machine learning method for predicting speed through ground by considering the actual values of the previous voyage’s drift speed for ships that regularly operate on the same route, such as ferries. Experimental results showed that this method improves the prediction performance of ship’s speed through ground.
Źródło:
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation; 2023, 17, 1; 129--137
2083-6473
2083-6481
Pojawia się w:
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Enhancing bubble bize prediction in flotation processes: a drift flux model accounting for frother type
Autorzy:
Leiva, Claudio
Acuña, Claudio
Luukkanen, Saija
Cruz, Constanza
Powiązania:
https://bibliotekanauki.pl/articles/24603667.pdf
Data publikacji:
2023
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
drift flux flotation
surfactant
bubble terminal velocity
Opis:
This communication presents a methodology, based on a modified drift flux model, to determine bubble size distribution in column flotation. The modified drift flux model incorporates a surfactant-type parameter. This parameter considers the impact of surfactant on bubble hydrodynamics. The methodology aims to improve the accuracy of bubble size distribution prediction, which presents deviation depending on surfactant type (i.e. polyglycolic based or alcoholic base). Many authors have proposed different mathematical improvements to reduce de experimental data deviations in the presence of different surfactants. However, from 1988 to 2022, the determination coefficient, or the quality of the adjustments, from the proposed mathematical models is, at the most, 92% (relative error). The proposed methodology improves the quality of the adjustments to 98.6, adding a single parameter for groups of surfactants. This methodology incorporates a single parameter in the terminal velocity calculation that can compensate for the impact of surfactant type in bubble hydrodynamic (bubble skin friction or drag coefficient, bubble wake, bubble shape, bubble rigidity). This parameter is a function of the gas holdup calculated from gas velocity measured and the bubble size distribution calculated (deviated) from gas holdup and gas velocity measured. The methodology is validated with reported experimental results and proposed modifications from various authors. The confidence interval (2 σ) is reduced from 0.11mm to 0.05mm in the case of (Yianatos, Banisi, Ostadrahimi). In the case of the recently reported experimental results from Maldonado and Gomez, the confidence interval is reduced from 0.31 mm to 0.09 mm. These results improve bubble size estimation based on drift flux in column flotation, contributing to a better understanding of surfactant impact on bubble swarm hydrodynamics.
Źródło:
Physicochemical Problems of Mineral Processing; 2023, 59, 5; art. no. 178234
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Verification of automatic drift calculation accuracy using an automatic radar plotting aid
Autorzy:
Juszkiewicz, W.
Nowy, A.
Powiązania:
https://bibliotekanauki.pl/articles/135236.pdf
Data publikacji:
2016
Wydawca:
Akademia Morska w Szczecinie. Wydawnictwo AMSz
Tematy:
automatic drift calculation
ARPA
safety of navigation
radar simulator
radar picture stabilization
IMO performance standards
Opis:
One consideration required in the resolution concerning radar and automatic radar plotting aid (ARPA) equipment is the possibility of an automatic drift calculation being realized in the base of fixed target tracking. This information is very important to providing safe navigation, especially in restricted areas. This paper presents an analysis of the present regulations contained in IMO resolutions and the results of an experiment conducted in the ARPA simulator. The aim of the simulations was to verify the reliability of the information presented on the ARPA display and to determine the accuracy of the automatic drift calculation implemented in the simulator.
Źródło:
Zeszyty Naukowe Akademii Morskiej w Szczecinie; 2016, 46 (118); 88-94
1733-8670
2392-0378
Pojawia się w:
Zeszyty Naukowe Akademii Morskiej w Szczecinie
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Regression function and noise variance tracking methods for data streams with concept drift
Autorzy:
Jaworski, M.
Powiązania:
https://bibliotekanauki.pl/articles/329716.pdf
Data publikacji:
2018
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
data stream
concept drift
Parzen kernel
regression function
variance estimation
strumień danych
funkcja regresji
estymacja wariancji
Opis:
Two types of heuristic estimators based on Parzen kernels are presented. They are able to estimate the regression function in an incremental manner. The estimators apply two techniques commonly used in concept-drifting data streams, i.e., the forgetting factor and the sliding window. The methods are applicable for models in which both the function and the noise variance change over time. Although nonparametric methods based on Parzen kernels were previously successfully applied in the literature to online regression function estimation, the problem of estimating the variance of noise was generally neglected. It is sometimes of profound interest to know the variance of the signal considered, e.g., in economics, but it can also be used for determining confidence intervals in the estimation of the regression function, as well as while evaluating the goodness of fit and in controlling the amount of smoothing. The present paper addresses this issue. Specifically, variance estimators are proposed which are able to deal with concept drifting data by applying a sliding window and a forgetting factor, respectively. A number of conducted numerical experiments proved that the proposed methods perform satisfactorily well in estimating both the regression function and the variance of the noise.
Źródło:
International Journal of Applied Mathematics and Computer Science; 2018, 28, 3; 559-567
1641-876X
2083-8492
Pojawia się w:
International Journal of Applied Mathematics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The MEMS-based barometric altimeter inaccuracy and drift phenomenon
Autorzy:
Matyja, Tomasz
Kubik, Andrzej
Stanik, Zbigniew
Powiązania:
https://bibliotekanauki.pl/articles/2203068.pdf
Data publikacji:
2022
Wydawca:
Politechnika Śląska. Wydawnictwo Politechniki Śląskiej
Tematy:
barometric altimeter
MEMS
error correction
drift phenomenon
bicycle computer
wysokościomierz barometryczny
korekcja błędu
zjawisko dryfu
licznik rowerowy
Opis:
MEMS technology has made sensors for measuring barometric pressure and altitude above sea level very cheap and widely used in many consumer electronic devices. This paper presents a theoretical analysis of the sources and types of errors in the barometric altimeter using the standard atmosphere model (ISA). Methods for correcting principal errors caused by non-standard sea level conditions are described and compared. A method of correcting errors in the case of altimeter horizontal movement to the air column and total pressure measurement was proposed. It was compared with another method known from the literature. In the numerical experiment, data recorded by a bicycle computer equipped with a MEMS-based barometric altimeter was analyzed. As the GPS data of the route covered was also known, it was possible to compare the recorded altimeter data with the heights determined from the digital terrain model (DTM), which in this case were considered accurate. The error of the measured altitude calculated in this way was tried to be divided into the principal error, the external error caused by the sensor movement, and the barometer drift. Hence, a numerical experiment was carried out in which, based on the recorded data, an attempt was made to reconstruct non-standard sea level conditions and the impact of speed on the sensor measurements. Furthermore, a method of solving such a reverse problem was proposed. The results of the presented studies can be used in the design of systems correcting the indications of barometric altimeters. The accuracy of the altitude measurement is especially important for small controlled flying objects (UAH) and when recording the route of vehicles moving on the ground.
Źródło:
Zeszyty Naukowe. Transport / Politechnika Śląska; 2022, 116; 141--162
0209-3324
2450-1549
Pojawia się w:
Zeszyty Naukowe. Transport / Politechnika Śląska
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Leakage Current Degradation Due to Ion Drift and Diffusion in Tantalum and Niobium Oxide Capacitors
Autorzy:
Kuparowitz, M.
Sedlakova, V.
Grmela, L.
Powiązania:
https://bibliotekanauki.pl/articles/221515.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
niobium oxide capacitors
tantalum capacitors
leakage current
ion diffusion
ion drift
Opis:
High temperature and high electric field applications in tantalum and niobium capacitors are limited by the mechanism of ion migration and field crystallization in a tantalum or niobium pentoxide insulating layer. The study of leakage current (DCL) variation in time as a result of increasing temperature and electric field might provide information about the physical mechanism of degradation. The experiments were performed on tantalum and niobium oxide capacitors at temperatures of about 125°C and applied voltages ranging up to rated voltages of 35 V and 16 V for tantalum and niobium oxide capacitors, respectively. Homogeneous distribution of oxygen vacancies acting as positive ions within the pentoxide layer was assumed before the experiments. DCL vs. time characteristics at a fixed temperature have several phases. At the beginning of ageing the DCL increases exponentially with time. In this period ions in the insulating layer are being moved in the electric field by drift only. Due to that the concentration of ions near the cathode increases producing a positively charged region near the cathode. The electric field near the cathode increases and the potential barrier between the cathode and insulating layer decreases which results in increasing DCL. However, redistribution of positive ions in the insulator layer leads to creation of a ion concentration gradient which results in a gradual increase of the ion diffusion current in the direction opposite to the ion drift current component. The equilibrium between the two for a given temperature and electric field results in saturation of the leakage current value. DCL vs. time characteristics are described by the exponential stretched law. We found that during the initial part of ageing an exponent n = 1 applies. That corresponds to the ion drift motion only. After long-time application of the electric field at a high temperature the DCL vs. time characteristics are described by the exponential stretched law with an exponent n = 0.5. Here, the equilibrium between the ion drift and diffusion is achieved. The process of leakage current degradation is therefore partially reversible. When the external electric field is lowered, or the samples are shortened, the leakage current for a given voltage decreases with time and the DCL vs. time characteristics are described by the exponential stretched law with an exponent n = 0.5, thus the ion redistribution by diffusion becomes dominant.
Źródło:
Metrology and Measurement Systems; 2017, 24, 2; 255-264
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Electron drift mobility in amorphous antrachinone layers
Ruchliwość dryftowa elektronów w amorficznych warstwach antrachinonu
Autorzy:
Kania, S.
Powiązania:
https://bibliotekanauki.pl/articles/296452.pdf
Data publikacji:
2010
Wydawca:
Politechnika Łódzka. Wydawnictwo Politechniki Łódzkiej
Tematy:
amorficzne warstwy antrachinonu
ruchliwość dryftowa elektronów
transport nośników ładunku
amorphous antrachinone films
electron drift mobility
carrier transport
Opis:
There were investigated the magnitude of the mobility and the type of the mechanism of the electron transport in the amorphous antrachinone layers. Antrachinone (C14H8O2) is the molecular crystal. The antrachinone molecules are planar, centrosymmetric and posses permanent dipole moment practically equal zero. The antrachinone layerss were obtained by evaporation in vacuum under the pressure of the order of 10-5 Torr on glass plates with reduced substrate temperatures. Structural examination of the obtained antrachinone layers was made using X - ray diffraction. In order to attain that one employed an automatic diffractometer DAR. Drift electron mobility for obtained amorphous layers were determined with TOP method. Obtained mobility value, were less then 10-3 cm2 /Vs and activation energy value was on the kT level.
Badano proces transportu elektronów w amorficznych warstwach antrachinonu. Uzyskane wyniki nie przesądzają jednoznacznie, z jakim rodzajem transportu mamy do czynienia. Niemniej uzyskane wyniki mogą sugerować występowanie również transportu hoppingowego, który wydaje się bardziej prawdopodobny, niż transport w paśmie z udziałem pułapek.
Źródło:
Scientific Bulletin. Physics / Technical University of Łódź; 2010, 31; 43-50
1505-1013
2449-982X
Pojawia się w:
Scientific Bulletin. Physics / Technical University of Łódź
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Spraying of wheat by field sprayer equipped with an air sleeve and drift guard nozzles
Autorzy:
Gajtkowski, A
Powiązania:
https://bibliotekanauki.pl/articles/65044.pdf
Data publikacji:
2001
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
spraying quality
air sleeve
Turbo TeeJet 110 02 VP nozzle
drift guard nozzle
wheat
coverage
spraying
Opis:
The quality of wheat spraying obtained white applying drift guard Turbo TeeJet 110 02 VP nozzles was tested. A standard boom and a boom equipped with an air sleeve were applied. Krukowiak-Bravo sprayer was used to test the influence of the air flux. The coverage was estimated on water sensitive papers. The spray coverage of wheat with TT 110 02 VP nozzles was satisfactory, both in case of conventional and air assisted applications.
W celu zmniejszenia znoszenia cieczy w czasie opryskiwania roślin na sąsiednie pola, opryskiwacze polowe mogą być wyposażone w belki opryskujące standardowe z rozpylaczami antyznoszeniowymi lub eżektorowymi. Mogą też być wyposażone w belki z rękawami powietrznymi. Dodatkowy strumień powietrza ma również wpływ na jakość opryskiwania roślin. W badaniach zastosowano wariant podwójnego zabezpieczenia przed znoszeniem, czyli oprócz rękawa powietrznego na belce opryskującej zamontowano rozpylacze antyznoszeniowe. Do opryskiwania wykorzystano opryskiwacz Krukowiak-Bravo i rozpylacze Turbo TeeJet TT 110 02 VP. Jakość pokrycia powierzchni liści opryskiwanej pszenicy jest zadowalająca zarówno przy stosowaniu badanych rozpylaczy bez dodatkowego strumienia powietrza, jak i z dodatkowym strumieniem. Wpływ wydatku strumienia powietrza na jakość pokrycia wierzchołków roślin i liści w połowie wysokości roślin był zróżnicowany. Dodatkowy strumień powietrza z rękawa poprawiał jakość opryskiwania. Najlepiej jest to widoczne przy stosowaniu dawki 137 l/ha. Stopień pokrycia powierzchni dla tej dawki oraz małego i średniego wydatku powietrza (poz. 1 i 3) uzyskuje się w granicach 30- 37%. Ze względu na dość duże straty cieczy opadającej na glebę, należałoby stosowa dodatkowy strumień powietrza o małym wydatku.
Źródło:
Journal of Plant Protection Research; 2001, 41, 3
1427-4345
Pojawia się w:
Journal of Plant Protection Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Wyświetlanie 1-15 z 147

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