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 "time-series" wg kryterium: Temat

  Lista filtrów
Wyrównaj
Wyświetlanie 1-25 z 286
Tytuł:
Radon variability due to floor level in two typical residential buildings in Serbia
Autorzy:
Udovicic, Vladimir
Veselinovic, Nikola
Maletic, Dimitrije
Banjanac, Radomir
Dragic, Aleksandar
Jokovic, Dejan
Savic, Mihailo
Knezevic, David
Eremic Savkovic, Maja
Powiązania:
https://bibliotekanauki.pl/articles/146821.pdf
Data publikacji:
2020
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
radon variability
time series
Opis:
It is well known that one of the factors that influence the indoor radon variability is the floor level of the buildings. Considering the fact that the main source of indoor radon is radon in soil gas, it is expected that the radon concentration decreases at higher floors. Thus at higher floors the dominant source of radon is originating from building materials, and in some cases there may be deviations from the generally established regularity. In such sense, we chose one freestanding single-family house with loft and other 16-floor high-rise residential building for this study. The indoor radon measurements were performed by two methods: passive and active. We used passive devices based on track-etched detectors: Radtrak2 Radonova. For the short-term indoor radon measurements, we used two active devices: SN1029 and SN1030 (manufactured by Sun Nuclear Corporation). The first device was fixed in the living room at the ground level and the second was moved through the floors of the residential building. Every measuring cycle at the specified floor lasted seven days with the sampling time of 2 h. The results show two different indoor radon behaviours regarding radon variability due to floor level. In the single-family house with loft we registered intense difference between radon concentration in the ground level and loft, while in the high-rise residential building the radon level was almost the same at all floors, and hence we may conclude that radon originated mainly from building materials.
Źródło:
Nukleonika; 2020, 65, 2; 121-125
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
On the estimation of the autocorrelation function
Autorzy:
Ortigueira, Manuel
Powiązania:
https://bibliotekanauki.pl/articles/730001.pdf
Data publikacji:
2010
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
time-series autocorrelation
regression
Opis:
The autocorrelation function has a very important role in several application areas involving stochastic processes. In fact, it assumes the theoretical base for Spectral analysis, ARMA (and generalizations) modeling, detection, etc. However and as it is well known, the results obtained with the more current estimates of the autocorrelation function (biased or not) are frequently bad, even when we have access to a large number of points. On the other hand, in some applications, we need to perform fast correlations. The usual estimators do not allow a fast computation, even with the FFT. These facts motivated the search for alternative ways of computing the autocorrelation function. 9 estimators will be presented and a comparison in face to the exact theoretical autocorrelation is done. As we will see, the best is the AR modified Burg estimate.
Źródło:
Discussiones Mathematicae Probability and Statistics; 2010, 30, 1; 103-115
1509-9423
Pojawia się w:
Discussiones Mathematicae Probability and Statistics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Model selection criteria for reduced rank multivariate time series with application in identification of periodic components
Autorzy:
Hławka, Marcin
Kawecki, Maciej
Powiązania:
https://bibliotekanauki.pl/articles/658353.pdf
Data publikacji:
2011
Wydawca:
Uniwersytet Łódzki. Wydawnictwo Uniwersytetu Łódzkiego
Tematy:
multivariate time series
periodicity
Opis:
W pracy jest przedstawione zastosowanie kryteriów wyboru modelu dla wektorowego mode- lu autoregresji o zredukowanym rzędzie (Reduced Rank Vector Autoregression (RRVAR(p.r)). W analizie uwzględniono najbardziej popularne kryteria wyboru modela podzielone na dwie grupy: kryteria równoczesnego wyboru oraz tzw. kryteria dwukrokowe. Model RRVAR został użyty w zagadnieniu identyfikacji składowych okresowych dla wielo- wymiarowych szeregów czasowych, zawierających dużą liczbę, zazwyczaj istotnie skorelowanych składowych, obserwowanych w krótkim horyzoncie czasowym. Przedstawione zostaną rezultaty porównujące efektywność metody opartej na dopasowaniu wektorowego modelu autoregresji o zredukowanym rzędzie z tradycyjnymi jednowymiarowymi metodami. Wykorzystano bazę rze- czywistych danych mikromacierzowych Spellman'a (1998), służącą do identyfikacji genów droż- dży, związanych z cyklem podziału komórki.
Źródło:
Acta Universitatis Lodziensis. Folia Oeconomica; 2011, 255
0208-6018
2353-7663
Pojawia się w:
Acta Universitatis Lodziensis. Folia Oeconomica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Jackknife Forecasts of Time Series
Wykorzystanie metody jackknife do prognozowania szeregów czasowych
Autorzy:
Wywiał, Janusz
Żądło, Tomasz
Powiązania:
https://bibliotekanauki.pl/articles/906889.pdf
Data publikacji:
2007
Wydawca:
Uniwersytet Łódzki. Wydawnictwo Uniwersytetu Łódzkiego
Tematy:
jackknife
time series
seasonal fluctuations
Opis:
In the paper we present the examples of forecasts of time series with seasonal fluctuations. Based on the jackknife method we estimate variances of seasonal factors and the MSE of prediction. Jackknife method has been introduced by M. Quenouille (1949) and then it has been developed among others by J. Tukey (1958) and J. Shao, D. Tu (1995).
W pracy zaproponowano wykorzystanie metody jackknife do prognozowania szeregów czasowych. Oprócz problemu prognozowania tą metodą, podjęto także problem oceny średniego błędu tak wyznaczanych prognoz. W oparciu o rzeczywiste dane zaprezentowane zostały przykłady prognozowania szeregów czasowych z wahaniami sezonowymi przy wykorzystaniu wersji jackknife metody wskaźników sezonowości. Oprócz wyznaczenia wartości prognozowanej w rozważanym przypadku będzie możliwa ocena wariancji błędu predykcji. Metodę jackknife wprowadził M. Quenouille (1949), a była rozwijana m. in. przez J. Tukey’a (1958) oraz J. Shao i D. Tu (1995).
Źródło:
Acta Universitatis Lodziensis. Folia Oeconomica; 2007, 206
0208-6018
2353-7663
Pojawia się w:
Acta Universitatis Lodziensis. Folia Oeconomica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
On Time Series Prediction Based on Control Chart
O prognozowaniu szeregów czasowych z wykorzystaniem kart kontrolnych
Autorzy:
Polko, Dominika
Kończak, Grzegorz
Powiązania:
https://bibliotekanauki.pl/articles/904563.pdf
Data publikacji:
2013
Wydawca:
Uniwersytet Łódzki. Wydawnictwo Uniwersytetu Łódzkiego
Tematy:
time series
prediction
control chart
Opis:
Control charts are the most commonly used quality control tools. These tools are dedicated to monitoring processes characteristic over time. Control charts may be successfully applied in other statistical areas. The non-classical use of control charts for time series prediction has been presented by Z. Pawłowski in the paper Predykcja za pomocą kart kontrolnych (Control Chart Based Prediction, 1969). The forecasts obtained by this method are quantitative or qualitative. The modification of this method is presented in the paper. It leads to quantitative predictions in all cases. The proposal was compared to some well-known classical prediction methods in the Monte Carlo study.
Metody statystyczne opracowane na potrzeby kontroli jakości produktów z powodzeniem mogą być stosowane w analizie innych zagadnień. Do najczęściej wykorzystywanych narzędzi kontroli jakości należy zaliczyć karty kontrolne. Nieklasyczne zastosowanie kart kontrolnych związane z wykorzystaniem ich do prognozowania przedstawił Z. Pawłowski w artykule Predykcja za pomocą kart kontrolnych (1969). Prognozy otrzymywane tą metodą mają charakter ilościowy lub jakościowy. W artykule przedstawiono propozycję modyfikacji tej metody w celu uzyskania wszystkich prognoz o charakterze ilościowym. Proponowaną metodę porównano symulacyjnie z wybranymi metodami predykcji.
Źródło:
Acta Universitatis Lodziensis. Folia Oeconomica; 2013, 286
0208-6018
2353-7663
Pojawia się w:
Acta Universitatis Lodziensis. Folia Oeconomica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Identification of stable elementary bilinear time-series model
Autorzy:
Malinski, L.
Powiązania:
https://bibliotekanauki.pl/articles/229601.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
bilinear model
time-series
identification
Opis:
The paper presents new approach to estimation of the coefficients of an elementary bilinear time series model (EB). Until now, a lot of authors have considered different identifiability conditions for EB models which implicated different identifiability ranges for the model coefficient. However, all of these ranges have a common feature namely they are significantly narrower than the stability range of the EB model. This paper proposes a simple but efficient solution which makes an estimation of the EB model coefficient possible within its entire stability range.
Źródło:
Archives of Control Sciences; 2016, 26, 4; 577-595
1230-2384
Pojawia się w:
Archives of Control Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Deterministic chaos and forecasting in Amazon?s share prices
Autorzy:
Hanias, Michael
Tsakonas, Stefanos
Magafas, Lykourgos
Thalassinos, Eleftherios I.
Zachilas, Loukas
Powiązania:
https://bibliotekanauki.pl/articles/22444422.pdf
Data publikacji:
2020
Wydawca:
Instytut Badań Gospodarczych
Tematy:
time series
chaos theory
econophysics
forecasting
Opis:
Research background: The application of non-linear analysis and chaos theory modelling on financial time series in the discipline of Econophysics. Purpose of the article: The main aim of the article is to identify the deterministic chaotic behavior of stock prices with reference to Amazon using daily data from Nasdaq-100. Methods: The paper uses nonlinear methods, in particular chaos theory modelling, in a case study exploring and forecasting the daily Amazon stock price. Findings & Value added: The results suggest that the Amazon stock price time series is a deterministic chaotic series with a lot of noise. We calculated the invariant parameters such as the maxi-mum Lyapunov exponent as well as the correlation dimension, managed a two-days-ahead forecast through phase space reconstruction and a grouped data handling method.
Źródło:
Equilibrium. Quarterly Journal of Economics and Economic Policy; 2020, 15, 2; 253-273
1689-765X
2353-3293
Pojawia się w:
Equilibrium. Quarterly Journal of Economics and Economic Policy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Dynamics of Cryptocurrency Price Volatility in the Face of the Crisis on the Example of Bitcoin and Ethereum
Autorzy:
Przyłuska-Schmitt, Judyta
Jegorow, Dorota
Bučková, Jaroslava
Powiązania:
https://bibliotekanauki.pl/articles/16729161.pdf
Data publikacji:
2023
Wydawca:
Uniwersytet Marii Curie-Skłodowskiej. Wydawnictwo Uniwersytetu Marii Curie-Skłodowskiej
Tematy:
cryptocurrency pricing
financial crisis
time series
Opis:
Theoretical background: Over the years, investing in cryptocurrencies has become very popular, and until recently, investors have predicted Bitcoin as a “safe haven”. Belief in a decentralized virtual currency even prompted the Salvadoran government to recognize Bitcoin as a legal tender in September 2021. However, cryptocurrency has depreciated significantly since then. The high amplitude of the fluctuations shows that on November 10, 2021, Bitcoin hit an all-time high of USD 68,979, and on June 18, 2022, it fell to its low of USD 17,601. Today, investors are wondering if investing in Bitcoin and other cryptocurrencies still make sense. Purpose of the article: The aim of the article is to compare the price fluctuations of the most popular cryptocurrencies, i.e. Bitcoin and Ethereum in the currently observed economic crisis in the world and the collapse of the cryptocurrency market. Research methods: Observations of the cryptocurrency market and theoretical issues of its functioning were combined with the analysis of empirical data of Bitcoin and Ethereum quotations from January 2022 to June 2022. The basic research instruments were based on the analysis of dependencies and descriptive statistics. The conducted analysis of the time series was aimed at detecting the nature of the studied phenomenon represented by the sequence of observations of daily quotations and forecasting future values of the time series. In this context, the course of Bitcoin and Ethereum quotations was examined in two categories: Close and Market Cap in search of a potential development pattern. Main findings: The conducted research shows that strong and unpredictable fluctuations in the prices of the studied cryptocurrencies, especially in the period of market shocks, imply unknown uncertainty, much more important than investment decisions made under the conditions of measurable risk. Cryptocurrencies cannot function as an alternative to gold, enabling value to be stored, as confirmed by market quotations over the past months.
Źródło:
Annales Universitatis Mariae Curie-Skłodowska, sectio H – Oeconomia; 2023, 57, 2; 101-113
0459-9586
2449-8513
Pojawia się w:
Annales Universitatis Mariae Curie-Skłodowska, sectio H – Oeconomia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Optimal selection of numerical models for flood embankment pore pressure and temperature data
Autorzy:
Chuchro, M.
Dwornik, M.
Szostek, K.
Leśniak, A.
Powiązania:
https://bibliotekanauki.pl/articles/305609.pdf
Data publikacji:
2017
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
flood embankmnet
numerical modelling
time series
Opis:
The aim of the ISMOP project is to study processes in earthen flood embankments: water filtration, pore pressure changes, and temperature changes due to varying water levels in the riverbed. Developing a system for continuous monitoring of flood embankment stability is the main goal of this project. A full-size earthen flood embankment with built-in sensors was built in Czernichow and used to conduct experiments involving the simulation of different flood waves, with parameters mostly measured at time intervals of 15 minutes. Numerical modelling—in addition to providing information about phenomena occurring in the embankment due to external factors and changes in water level—could be used to assess the state of the embankment. Modelling was performed using Itasca Flac 2D 7.0 with an assumed grid cell size of 10x10 cm. The water level in the embankment simulated the water flow in the Wisła River and the temperature of the air and water. Data about the state of the flood embankment was exported every hour. Using numerical models and real experiment data, a model-driven module was used to perform comparisons. Analyses of each half-section of the flood embankment were carried out separately using similarity measures and an aggregate window. For the tests, the North-West (NW) half cross-section of the embankment was chosen, which contains pore pressure and temperature sensors UT6 to UT10. The water level in the embankment was raised to a height of 3m; the best numerical model was considered the one that best matched the actual data recorded by the sensors during the experiment. The experiment period was from 9pm on 29/08/2016 to 9am on 03/09/2016. Seventeen numerical models of the water level rising to 2, 3, and 4 meters were compared against real experimental data from the NW half cross-section. The first step was to verify the similarity between the incoming data from the sensors. If the correlation value exceeded 0.8, the data from the sensors was averaged. The experimental data was then compared against the numerical models using least absolute deviations L1-Norm. The L1-Norm varied from 26 to 32, depending on window length and the numerical model used.
Źródło:
Computer Science; 2017, 18 (4); 399-412
1508-2806
2300-7036
Pojawia się w:
Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Non Linear Analysis of S&P Index
Autorzy:
Hanias, Mike
Magafas, Lykourgos
Konstantaki, Pagania
Powiązania:
https://bibliotekanauki.pl/articles/517166.pdf
Data publikacji:
2013
Wydawca:
Instytut Badań Gospodarczych
Tematy:
Exchange rates
Time series
Chaos theory
Opis:
This paper applies non-linear methods to analyze and predict the daily open S&P index which is one of the most important stock index in the world. The aim of the analysis is to quantitatively show if the corresponding time series is a deterministic chaotic one and if one or more days ahead prediction can be achieved. These results make the present work a valuable tool for traders investors and funds.
Źródło:
Equilibrium. Quarterly Journal of Economics and Economic Policy; 2013, 8, 4; 125-135
1689-765X
2353-3293
Pojawia się w:
Equilibrium. Quarterly Journal of Economics and Economic Policy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of simultaneous time series of indoor, outdoor and soil air radon concentrations, meteorological and seismic data
Autorzy:
Janik, M.
Bossew, P.
Powiązania:
https://bibliotekanauki.pl/articles/148289.pdf
Data publikacji:
2016
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
radon
time series
meteorological conditions
seismic
Opis:
It is well known that the temporal dynamic of indoor and outdoor radon concentrations show complex patterns, which are partly not easy to interpret. Clearly, for physical reasons, they must be related to possibly variable conditions of radon generation, migration and atmospheric dispersion and accumulation. The aim of this study was to analyse long-time series of simultaneously measured indoor and outdoor radon concentrations, together with environmental quantities, which may act as control variables of Rn. The study was performed in Chiba, Japan, using two ionization chambers for parallel indoor and outdoor radon concentrations measurements over 4 years. Meteorological and seismic data were obtained from the Japan Metrological Agency (JMA).
Źródło:
Nukleonika; 2016, 61, 3; 295-302
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Clustering companies listed on the Warsaw Stock Exchange according to time-varying beta
Autorzy:
Szczepocki, Piotr
Powiązania:
https://bibliotekanauki.pl/articles/424953.pdf
Data publikacji:
2019
Wydawca:
Wydawnictwo Uniwersytetu Ekonomicznego we Wrocławiu
Tematy:
time series clustering
cluster analysis
time-varying beta
Opis:
The beta parameter is a popular tool for the evaluation of portfolio performance. The Sharpe single-index model is a simple regression model in which the stock’s returns are regressed against the returns of a broader index. The beta parameter is a measure of the strength of this relation. Extensive recent research has proved that the beta is not constant in time and should be modelled as a time-variant coefficient. One of the most popular methods of the estimation of a time-varying beta is the Kalman filter. As the output of the Kalman filter, one obtains a sequence of the estimates of a time-varying beta. This sequence shows the historical dynamics of sensitivity of a company’s returns to the variations of market returns. The article proposes a method of clustering companies listed on the Warsaw Stock Exchange according to time-varying betas.
Źródło:
Econometrics. Ekonometria. Advances in Applied Data Analytics; 2019, 23, 2; 63-79
1507-3866
Pojawia się w:
Econometrics. Ekonometria. Advances in Applied Data Analytics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Opis procesu badawczego
Methods of research
Autorzy:
Adamowicz, Elżbieta
Dudek, Sławomir
Pachucki, Dawid
Walczyk, Konrad
Powiązania:
https://bibliotekanauki.pl/articles/499916.pdf
Data publikacji:
2012
Wydawca:
Szkoła Główna Handlowa w Warszawie
Tematy:
analiza koniunktury
analiza szeregów czasowych
dekompozycja szeregów czasowych
business cycles analysis
time series analysis
time series decomposition
Opis:
Praca opisuje metody analizy statystyczno-ekonometrycznej stosowane w celu: identyfikacji wahań cyklicznych zmiennych makroekonomicznych, zbadania cech morfologicznych wahań koniunkturalnych, obejmującego identyfikację punktów zwrotnych, czas trwania zarówno całego cyklu jak i poszczególnych jego faz, wartości ekstremalne, amplitudy i intensywność zachodzących zmian, analizy synchronizacji wahań cyklicznych (chronologii punktów zwrotnych, korelacji jednoczesnych, korelacji krzyżowych, korelacji rekursywnych, koherencji i przesunięcia fazowego), analizy graficznej i analizy zbieżności reakcji gospodarek na szoki podażowe i popytowe zidentyfikowane za pomocą modeli SVAR.
The paper presents the statistical and econometrical methods used to: (1) identify cyclical components of economic aggregates, (2) examine morphological characteristics of cyclical fluctuations, including turning points, duration of cycles and their phases, maximum and minimum values, amplitudes and intensity, (3) analyse synchronicity of cyclical fluctuations, including leads/lags of turning points, correlation and cross-correlation, recursive correlation, coherence and mean delay), (4) perform graphical analysis and (5) examine coincidence of economies’ reactions to supply and demand shocks identified by SVAR modelling.
Źródło:
Prace i Materiały Instytutu Rozwoju Gospodarczego SGH; 2012, 89: Wahania cykliczne w Polsce i w strefie euro; 11-22
0866-9503
Pojawia się w:
Prace i Materiały Instytutu Rozwoju Gospodarczego SGH
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Economic Freedom and FDI: Co-Integration Analysis
Autorzy:
Corekcioglu, Selim
Powiązania:
https://bibliotekanauki.pl/articles/1013713.pdf
Data publikacji:
2020-12-30
Wydawca:
Uniwersytet Ekonomiczny w Poznaniu
Tematy:
foreign direct investment;
time series;
economic freedom;
Opis:
These days, economic growth is very important for all countries and this article will discuss the main factors associated with this problem and propose some possible solutions which can be implemented. The importance and relationship of foreign direct investment, economic growth and economic freedom are presented and evaluated by considering literature, and a long run relationship between foreign direct investment and economic freedom in Turkey is empirically analysed in the article. The time period covers the years 1996 to 2018. The data has been obtained from the World Bank and from theHeritage Foundation database. The analysis is based on the time series analysis. An Augmented Dickey-Fuller test hasindicated that the variables are not stationary at levels, but they are stationary at the first difference. The Johansen test hasshown that variables are co-integrated, which means that they move together in the long run.
Źródło:
Research Papers in Economics and Finance; 2020, 4, 3; 37-45
2543-6430
Pojawia się w:
Research Papers in Economics and Finance
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Applying Python’s Time Series Forecasting Method in Microsoft Excel – Integration as a Business Process Supporting Tool for Small Enterprises
Autorzy:
Litwin, Jolanta
Olech, Marcin
Szymusik, Anna
Powiązania:
https://bibliotekanauki.pl/articles/2069739.pdf
Data publikacji:
2021
Wydawca:
Uniwersytet Warmińsko-Mazurski w Olsztynie
Tematy:
time series forecasting
python integration
excel integration
Opis:
The paper describes the current state of research, where integration of Microsoft Excel and Python interpreter, gives the business user the right tool to solve chosen business process analysis problems like: forecasting, classification or clustering. The integration is done by using Visual Basic for Application (VBA), as well as XLWings Python’s library. Both mechanisms serve as an interfaces between MS Excel and Python to allow the data exchange between each other. Creating the suitable Graphical User Interface (GUI) in Microsoft Excel, gives the business user opportunity to select specific data analysis method available in Python’s environment and set its parameters, without Python’s programming. Running the method by Python’s interpreter can bring the results, which are hard or even impossible to obtain by using Microsoft Excel only. However, the data analysis methods stored in the Python’s script, which are available to the business user, as well as VBA source code, must be designed and implemented by the data scientist. Sample, basic integration between Microsoft Excel and Python’s interpreter is presented in the paper. To present value-added of the proposed software solution, simple case study according to time series forecasting problem is described, where forecasting errors of different methods available in the Microsoft Excel and Python are presented and discussed. The paper ends with conclusions according to the results of the current researches and suggested directions of further research.
Źródło:
Technical Sciences / University of Warmia and Mazury in Olsztyn; 2021, 24(1); 115--133
1505-4675
2083-4527
Pojawia się w:
Technical Sciences / University of Warmia and Mazury in Olsztyn
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Functional Regression in Short-Term Prediction of Economic Time Series
Autorzy:
Kosiorowski, Daniel
Powiązania:
https://bibliotekanauki.pl/articles/465836.pdf
Data publikacji:
2014
Wydawca:
Główny Urząd Statystyczny
Tematy:
functional data analysis
functional time series
prediction
Opis:
We compare four methods of forecasting functional time series including fully functional regression, functional autoregression FAR(1) model, Hyndman & Shang principal component scores forecasting using one-dimensional time series method, and moving functional median. Our comparison methods involve simulation studies as well as analysis of empirical dataset concerning the Internet users behaviours for two Internet services in 2013. Our studies reveal that Hyndman & Shao predicting method outperforms other methods in the case of stationary functional time series without outliers, and the moving functional median induced by Frainman & Muniz depth for functional data outperforms other methods in the case of smooth departures from stationarity of the time series as well as in the case of functional time series containing outliers.
Źródło:
Statistics in Transition new series; 2014, 15, 4; 611-626
1234-7655
Pojawia się w:
Statistics in Transition new series
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Volatility Persistence and Predictability of Squared Returns in GARCH(1,1) Models
Autorzy:
Triacca, Umberto
Powiązania:
https://bibliotekanauki.pl/articles/483247.pdf
Data publikacji:
2009
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
GARCH Models
returns
time series
volatility persistence
Opis:
Volatility persistence is a stylized statistical property of financial time-series data such as exchange rates and stock returns. The purpose of this letter is to investigate the relationship between volatility persistence and predictability of squared returns.
Źródło:
Central European Journal of Economic Modelling and Econometrics; 2009, 1, 3; 285-291
2080-0886
2080-119X
Pojawia się w:
Central European Journal of Economic Modelling and Econometrics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Volatile ARMA Modelling of GARCH Squares
Autorzy:
Lawrance, Anthony J.
Powiązania:
https://bibliotekanauki.pl/articles/483293.pdf
Data publikacji:
2010
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
ARCH
ARMA
GARCH
prediction
time series
volatility
Opis:
This paper points out that the ARMA models followed by GARCH squares are volatile and gives explicit and general forms of their dependent and volatile innovations. The volatility function of the ARMA innovations is shown to be the square of the corresponding GARCH volatility function. The prediction of GARCH squares is facilitated by the ARMA structure and predictive intervals are considered. Further, the developments suggest families of volatile ARMA processes.
Źródło:
Central European Journal of Economic Modelling and Econometrics; 2010, 2, 3; 195-203
2080-0886
2080-119X
Pojawia się w:
Central European Journal of Economic Modelling and Econometrics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Time-series dynamics of Baltic trade flows: Structural breaks, regime shifts, and exchange-rate volatility
Autorzy:
Hegerty, Scott W.
Powiązania:
https://bibliotekanauki.pl/articles/2054532.pdf
Data publikacji:
2022
Wydawca:
Uniwersytet Ekonomiczny w Katowicach
Tematy:
Baltics
Structural breaks
Time series
Trade flows
Opis:
Aim/purpose – In the decades since their reintegration with the West, the small open economies of Estonia, Latvia, and Lithuania have seen their trade flows grow substantially. While the mix of trade partners has evolved over time, the region has been affected by various political and economic shocks. This study examines the bilateral trade balances between the Baltic countries and nine partners to investigate whether there have been structural breaks due to political or economic events. Because these events may have been “priced into” exchange rates or increased these rates’ volatility, connections between these variables and trade balances are also considered. Design/methodology/approach – Monthly data beginning in 1994 are taken from the International Monetary Fund’s Direction of Trade Statistics [DOTS]. Trade partners include the Nordic countries of Finland, Sweden, and Norway, as well as Poland, Russia, and the United States and country groupings such as the CIS, Advanced Economies, and the World. Ratios of the export and import values are used to create bilateral trade balances. The Bai–Perron (1998) structural break test is then used to identify “break points” that can classify time periods into regimes. Baltic nominal and real effective exchange rates, both in log changes and as a GARCH-based volatility measure, show whether regimes correspond to competitiveness or risk. Correlations are calculated to show links between bilateral trade balances and real exchange rates. Findings – Each trade balance has at least one structural break; many have more. In fewer than half of the cases do these correspond to specific events such as EU accession or the Global Financial Crisis. Trade with Russia has decreased, particularly for Estonia and Latvia. But many partners with historical ties, such as Estonia-Finland, Latvia-Sweden, and Lithuania-Poland have more breaks than do other partners (such as Estonia-Poland). Structural breaks in real exchange-rate returns and volatility do not match those of trade balances, and correlations between returns and trade balances are low. Research implications/limitations – These findings open the door to future research on the macroeconomic and cultural/historical factors behind these trade linkages and any changes in regimes. However, no structural determinants have yet been estimated. Originality/value/contribution – This study isolates changes in trade regimes, which can be further explained by specific events or particular dates. It also shows that variance has changed as well as the mean, but this differs by country and by the partner.
Źródło:
Journal of Economics and Management; 2022, 44; 96-118
1732-1948
Pojawia się w:
Journal of Economics and Management
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Comparing changes over time for two phenomena
Autorzy:
Miłek, Michał
Powiązania:
https://bibliotekanauki.pl/articles/584959.pdf
Data publikacji:
2015
Wydawca:
Wydawnictwo Uniwersytetu Ekonomicznego we Wrocławiu
Tematy:
time series comparing
permutation test
distance measure
Opis:
Statistical analyses in economics are often based on explaining the phenomena by comparing time series. The purpose of such types of analyses is to find out the similarity and schematic behavior of phenomena which appear in the data. Usual time series are compared with the use of a different similarity measure which, in accordance with the literature, could be divided into four categories. In this article, I propose a method that allows to indicate whether two time series are generated by the same stochastic processes. For this purpose, I analyze a method based on a permutation test. The idea of this test is much simpler than the tests based on theoretical distributions. I also conducted a simulation analysis based on the data generated according to different scenarios, subsequently comparing the results of that analysis.
Źródło:
Mathematical Economics; 2015, 11(18); 89-98
1733-9707
Pojawia się w:
Mathematical Economics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Clustering macroeconomic time series
Grupowanie makroekonomicznych szeregów czasowych
Autorzy:
Augustyński, Iwo
Laskoś-Grabowski, Paweł
Powiązania:
https://bibliotekanauki.pl/articles/424890.pdf
Data publikacji:
2018
Wydawca:
Wydawnictwo Uniwersytetu Ekonomicznego we Wrocławiu
Tematy:
time series clustering
similarity
cluster analysis
GDP
Opis:
The data mining technique of time series clustering is well established. However, even when recognized as an unsupervised learning method, it does require making several design decisions that are nontrivially influenced by the nature of the data involved. By extensively testing various possibilities, we arrive at a choice of a dissimilarity measure (compression-based dissimilarity measure, or CDM) which is particularly suitable for clustering macroeconomic variables. We check that the results are stable in time and reflect large-scale phenomena, such as crises. We also successfully apply our findings to the analysis of national economies, specifically to identifying their structural relations.
Źródło:
Econometrics. Ekonometria. Advances in Applied Data Analytics; 2018, 22, 2; 74-88
1507-3866
Pojawia się w:
Econometrics. Ekonometria. Advances in Applied Data Analytics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The design of forecasting system used for prediction of electro-motion spare parts demands as an improving tool for an enterprise management
Autorzy:
Kačmáry, Peter
Malindžák, Dušan
Spišák, Ján
Powiązania:
https://bibliotekanauki.pl/articles/409825.pdf
Data publikacji:
2019
Wydawca:
STE GROUP
Tematy:
forecast
spare parts
time series
order
model
Opis:
This article describes the design of a simple forecasting system and its practical application to predict the sporadic needs for a spare part. The article shows new approach already implemented in the special servicing and production company in Slovakia and its results during a short period of performance after its implementation. Such a proposed model can be a part of the purchase planning of spare parts within the company's logistics system. In some companies, the material flow of spare parts is dominant element in terms of logistics costs. Their management is therefore important for cost optimization, customer satisfaction and market sustainability in a competitive environment. The article, in its introductory part, provides an overview of similar practical solutions within the research of this topic, but many models are designed to be applied in a global market environment and predict the amount of spare parts needed in different industries. However, these models are difficult to use for the needs of a small enterprise, because the main problem lies in the time of a spare part demand rather than its quantity. If there is a need for a specific spare part, which costs several hundred or thousands of euros, but the consumption is only a few pieces per year or more than a year, the time prediction of required spare parts is therefore crucial.
Źródło:
Management Systems in Production Engineering; 2019, 4 (27); 242-249
2299-0461
Pojawia się w:
Management Systems in Production Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Comparative analysis of methods for hourly electricity demand forecasting in the absence of data - a case study
Analiza porównawcza metod prognozowania godzinnego zapotrzebowania na energię elektryczną przy brakach w danych - studium przypadku
Autorzy:
Zawadzki, Jan
Powiązania:
https://bibliotekanauki.pl/articles/2194900.pdf
Data publikacji:
2023
Wydawca:
Akademia Bialska Nauk Stosowanych im. Jana Pawła II w Białej Podlaskiej
Tematy:
forecasting
missing data
time series
high frequency
Opis:
Scope and purpose of work: This paper examines the impact of the number of gaps in data, the analytical form, and the model type selection criterion on the accuracy of interpolation and extrapolation forecasts for hourly data. Materials and methods: Forecasts were developed on the basis of predictors that are based on: classical time series forecasting models and regression time series forecasting models, hybrid time series forecasting models and hybrid regression forecasting models for uncleared series, and exponential smoothing models for cleared series of two or three types of seasonal fluctuations, with minimum estimates of errors in interpolation or extrapolation forecasts. Results: Adaptive and hybrid regression models have proved to have the most favorable predictive properties. Most hybrid time series models for systematic and non-systematic gaps and for both analytical forms are single models that generally describe fluctuations within a 24-hour cycle. Conclusions: The lowest estimators of prediction errors involving interpolation were obtained for exponential smoothing models, followed by hybrid regression models. A reverse sequence was obtained for extrapolative forecasting.
Źródło:
Economic and Regional Studies; 2023, 16, 1; 34-50
2083-3725
2451-182X
Pojawia się w:
Economic and Regional Studies
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Nowoczesna analiza wizualna ekonomicznych szeregów czasowych
Modern Visual Analysis of Economic Time Series
Autorzy:
Nowiński, Marek
Powiązania:
https://bibliotekanauki.pl/articles/593452.pdf
Data publikacji:
2015
Wydawca:
Uniwersytet Ekonomiczny w Katowicach
Tematy:
Analiza ilościowa
Analiza szeregów czasowych
Metoda graficzna
Szeregi czasowe
Graphical method
Quantitative analysis
Time-series
Time-series analysis
Opis:
Artykuł przedstawia metody zaawansowanej analizy wizualnej, która nie polega jedynie na badaniu podstawowych, statystycznych własności szeregów czasowych, ale przede wszystkim na próbie wykrycia pewnej złożonej, ukrytej w nich struktury. Uzyskanie takich informacji nie jest możliwe na podstawie podstawowych badań statystycznych danych szeregu czasowego ani jego wykresu w postaci pierwotnej, który jest w rzeczywistości kompletnie nieczytelny. Współczesna analiza szeregu czasowego często przypomina przepuszczenie danych szeregu przez pewien pryzmat oraz przedstawienie wyników na odpowiednio skonstruowanym wykresie w celu wizualnej identyfikacji jego określonych własności. Istnieją również metody dwustopniowe, które dodatkowo zawierają analizę ilościową i możliwości szacowania specjalnych wskaźników uzyskanych wyłącznie na podstawie takich wykresów, które same niosą wiele przydatnych informacji i mogą stanowić wskazówki przy wyborze innych metod i narzędzi badawczych (por. np. metody Recurrence Quantification Analysis lub Artificial Insymmetrised Patterns). Metody te pozwalają na odróżnienie badanego szeregu czasowego od losowego szumu, wykrycie zakłóconych procesów deterministycznych, ocenę rodzaju zależności w nim występujących, określenie stopnia stacjonarności, determinizmu i rekurencji. Mogą także pomóc w doborze metod pozwalających wykryć w danych elementy nieliniowości (a nawet chaosu deterministycznego). Inną zaletą tego podejścia jest możliwość ujawnienia w danych cykli okresowych o różnych długościach (co pozwala na bardziej skuteczne stosowanie modeli ARIMA lub wyrównywania wykładniczego, gdzie okres składnika cyklicznego musi być znany i może być wykorzystywany w pewnych modelach teoretycznych, np. średnich ruchomych lub autokorelacji). Takie własności nowoczesnej wersji metod wizualnej analizy szeregów czasowych musiały wzbudzić zainteresowanie badaczy skomplikowanych zjawisk i procesów ekonomicznych, którzy próbują je wykorzystywać do pogłębionej analizy nieliniowej, a także do efektywnego modelowania i prób prognozowania tych procesów. Jest to również powód przedstawienia urozmaiconego przeglądu tych metod w niniejszym artykule.
The paper presents an advanced visual analysis method that does not rely only on examining of basic statistical properties of the time series, but also on attempting to detect a complex structure, hidden in the original dynamic process. Obtaining such information is not possible on the basis of the basic survey of time series data, or its graph in the original form, which is in fact completely illegible. Contemporary time series analysis of time series data is often reminiscent of passing it through a prism, and presenting the results on a properly constructed plots for visual identification of its specific properties. There are also two-step methods, which include both the possibility of quantitative analysis and estimation of specific indicators derived on the basis of such plots. They can carry a lot of useful information and provide us the guidance for the further selection of proper research of nonlinear analysis methods and tools (see eg. the methods of Recurrence Quantification Analysis and Artificial Insymmetrised Patterns). These methods allow to distinguish the analyzed time series from the random noise, to detect real deterministic processes biased with noise, to assess the type of dependencies in time series data, and to determine the degree of stationarity, determinism or recurrence. They can also help in the selection of methods to detect the nonlinearity in the data (or even deterministic chaos). Another advantage of this approach is the possibility of disclosure in data periodic cycles with periods of different lengths (for more efficient use of ARIMA and exponential smoothing models, where the period of the cyclical component must be known and can be used in certain theoretical models, eg. moving average or autocorrelation). Such properties of the modern version of visual time series analysis caused the interest of scientists trying to understand the complex economic phenomena and processes. They are trying to use it for in-depth nonlinear analysis, economic modeling and attempts of effective forecasting of these processes. This is the main reason for presenting a review of these methods in this paper.
Źródło:
Studia Ekonomiczne; 2015, 237; 79-91
2083-8611
Pojawia się w:
Studia Ekonomiczne
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The application of the arima model in forecasting the passenger traffic on the example of border crossings between the subcarpathian province and Ukraine
Autorzy:
Dejniak, D.
Powiązania:
https://bibliotekanauki.pl/articles/94741.pdf
Data publikacji:
2018
Wydawca:
Szkoła Główna Gospodarstwa Wiejskiego w Warszawie. Wydawnictwo Szkoły Głównej Gospodarstwa Wiejskiego w Warszawie
Tematy:
passenger border traffic
ARIMA models
time series analysis
Opis:
Accession of Poland to the European Union meant that its eastern border became the external frontier of the Community. The next step in the European integration was joining the Schengen Zone by Poland. Polish citizens may freely travel throughout the Schengen Zone and the state was obliged to tighten its eastern border. Under these circumstances conducting research on passenger traffic has become a vital issue, with particular focus on the eastern frontier. In the article an attempt is made at examining the possibility of forecasting passenger traffic on the example of border crossing points between the Subcarpathian Province and Ukraine using the ARIMA models. Confirmation of these possibilities seems to be crucial as the number of people crossing the border is characterized by high variability and sensitivity to the political situation. The study is based on the information provided by the Polish Border Guard. The conducted time series analysis is of a multi-purpose character. It may be used to support decision making processes of investment, organizational, as well as socio-political nature.
Źródło:
Information Systems in Management; 2018, 7, 3; 155-170
2084-5537
2544-1728
Pojawia się w:
Information Systems in Management
Dostawca treści:
Biblioteka Nauki
Artykuł
Wyświetlanie 1-25 z 286

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