Zadanie 5
Transkrypt
Zadanie 5
GÓRNOLSKA WYSZA SZKOA HANDLOWA Imi¦ i nazwisko NR ALBUMU 000000 PRACA INYNIERSKA PIERWSZA LINIA TEMATU PRACY DRUGA LINIA TEMATU PRACY PROMOTOR TYTU IMI NAZWISKO PROMOTORA K A T O W I C E ROK STWORZENIA PRACY Wst¦p In the paper we discuss the analysis of meteorological data. We consider the relationship between them using a special fuzzy number form. We also use a set of historical data. For the weather forecast chosen we nd similar weather forecasts. Next, we nd real meteorological situations from the historical data which correspond to them and we create fuzzy numbers, that is, the fuzzy weather forecasts. Then we estimate the validity of the weather forecast on the basis of the historical data and its checkability. We investigate it with the help of an indicators set, which corresponds to the parameters of the weather forecast, using the similarities rule of the weather forecast to the meteorological situation, a proper distance and data analysis. This comprehensive analysis allows us to investigate the eectiveness of forecasting fuzzy numbers, putting the dependence between particular attributes describing the weather forecast in order and proving the legitimacy of the applicable fuzzy numbers in air pollution forecasting. Rozdziaª 1 A fuzzy weather forecast is determined for each attribute individually and it is evenly distributed on T hours. It is valued on basis of data similarity and proper weights of classications. We researched the behavior of fuzzy weather forecast using dierent sets of forecast data. This is necessary because we have weather forecasts from a short period of time (only six years). Therefore, continuous work in a model COSMO LM weather forecast is not heterogenous to nding the period of a weather forecast which is the best estimate real meteorlogocal situations. In Fig fuzzy weather forecasts are shown along with real meteorological situations. The fuzziness is a good measure to mark the quality of a weather forecast both its elements and the whole weather forecast because fuzziness characterises the scattering of real data around the prognosis in 1. Meteorological situations Aerosanitary situations Weather forecasts 1. Meteorological situations 2. Aerosanitary situations 3. Weather forecasts Rozdziaª 2 Hurtownia danych Wybranym narz¦dziem do przechowywania danych meteorlogicznych jest hurtownia danych. Jest to specyczny rodzaj bazy danych, który charakteryzuje si¦ czterema cechami: 1. nieulotno±¢ - dane raz umieszczone w hurtowni pozostaj¡ w niej niezmienione, czyli u»ytkownicy maj¡ pewno±¢, »e takie samo zapytanie zawsze zwróci ten sam wynik, 2. zorientowanie na temat - dane znajduj¡ce si¦ w hurtowni dotycz¡ pewnego tematu np. prognozy pogody, a nie dziaªa«, 3. zintegrowanie - dane s¡ jednolite np. daty przechowywane s¡ w tym samym formacie, 4. zmienno±¢ w czasie - gromadzone dane zmieniaj¡ si¦ w czasie, gdy» w tym przypadku tj. dla danych meteorologicznych zapytania kierowane do hurtowni danych wymagaj¡ prze±ledzenia pewnego odcinka danych. Dzi¦ki temu, »e dane przechowywane s¡ w hurtowni danych to mog¡ one by¢ w sposób ªatwy dzielone wedªug odpowiednich wycinków terminów: czas, b¡d¹ rodzaj przechowywanych danych. Dost¦p do danych jest ªatwy i szybko otrzymywane s¡ w postaci przebiegów czasowych. Na rysunku 2.1 widoczny jest zaproponowany sposób gromadzenia danych meteorologicznych. Rozdziaª 2. Hurtownia danych Rysunek 2.1. Hurtownia dla danych meteorlogicznych 5 Rozdziaª 3 The rst trials of forecasting everyday phenomena, particularly meteorological, began around 650 B.C. [1] by the Babylonians. They tried to predict short-term weather changes based on the appearance of clouds. Methods of weather forecasting were increasingly perfected in subsequent centuries. In the XX century, as a result of the development of mathematics and physics, models which used partial dierential equations were formulated. These equations which describe the state of the atmosphere, could be solved numerically. However, in 1961 E.Lorenz showed the limitation of possibilities of these models rst of all their chaotic character. These models are only eective for few a days maximum a week. However, for a 3-day term their eectiveness is high. In recent years many prediction approaches, such as statistical [2], fuzzy [3, 4], neural networks [5, 6], neuro-fuzzy predictor [7] have emerged. Using numerical short-term weather prediction, research into the forecasting of air pollution concentrations began [8, 9]. This task is very dicult because apart from the information about meteorological conditions, the emission of air pollution depends rst of all on the immission. At this moment, emission is quite accurately measured from a single, high pointer emitter (e.g. carbon power stations). Measurement of low emission, communal and municipal, is almost impossible. Moreover, 3D models of immission calculating (e.g. Gaussian pu modelling system) require a eld of wind and a eld of temperature measure from several hundred metres above ground level. Such measurements are only conducted in a very few places in the world with the help of a sodar. Thus, input data for an Air Pollution Forecasting Model (APFM) must be estimated, therefore, they are both incomplete and imprecise. In this situation Fuzzy sets theory is helpful [10, 11, 12]. Use of this method is known in many mathematical forecasting models. It is usually used when the information transferred to the model is imprecise or incomplete [13, 14]. Many everyday phenomena of an ambiguous, continuous and imprecise nature may be eectively described using this theory. In [15] B. Hansen presented a very interesting way of using fuzzy sets and case-based 7 reasoning in weather forecasting. On the other hand fuzzy logic allows the inuence of meteorological conditions on changes of air pollution levels and their quantication to be researched. Being inspired by the paper [15], we propose a model to serve as a forecaster of air pollution concentrations. We assume: 1. Aerosanitary situations air pollution concentration over several hours, the result of the emission of this pollution and the meteorological situations (previous and present). The progressive methodology for all pollutions will be homogeneous. 2. Future based on similar situations from the past similar meteorological situations bring about similar aerosanitary situations in a similar area. The basic idea for forecasting is searching through history for meteorological situations which are close to the expected meteorological situation. Rozdziaª 3. Zako«czenie Ze wzgl¦du na to, »e interesuj¡ nas ró»ne warto±ci aerosanitarne np. o warto±ciach skrajnych to ko«cowy przebieg rozmyty mo»e by¢ defuzykowany na ró»ne sposoby. Bior¡c pod uwag¦ to, »e interesuje nas jedynie defuzykacja liczby rozmytej w postaci dyskretnej to zajmiemy si¦ poni»ej tylko takimi metodami. 1. metoda ±rodka ci¦»ko±ci, 2. metoda maksimum funkcji przynale»no±ci. Odwzorowujemy wtedy dany zbiór rozmyty w jedn¡ warto±¢ y ∈ Y nazywa¢ to b¦dziemy wyostrzeniem. Poni»ej zostan¡ przedstawione znane metody wyostrzenia. 1. Metoda ±rodka ci¦»ko±ci, 2. Metoda maksimum funkcji przynale»no±ci. Zgodnie z metod¡ 1 otrzymujemy lepsze wyniki, w przeciwie«stwie do metody 2. Napiszemy jeszce teraz nast¦puj¡ce symbole: ∞ ∗ $ ⇐⇒ ... 1 19 β α Bibliograa [1] Weather Forecasting Through the Ages, NASA Facts, http://aqua.nasa.gov, 2002. [2] G. Rigatosa, Q. Zhangb, Fuzzy model validation using the local statistical approach, Fuzzy Sets and Systems 160(7) (2009) 882-904. [3] C. Lee, A. Liu and W. Chen, Pattern Discovery of Fuzzy Time Series for Financial Prediction, IEEE Trans. Knowl. Data Eng 18(5) (2006) 613-625. [4] H. Kunhuang, Heuristic Models of Fuzzy Time Series for Forecasting, Fuzzy Sets and Systems 123(3) (2001) 369-386. [5] W. Jiang and P. Wang, Research on Interval Prediction of Nonlinear Chaotic Time Series Based on New Neural Networks, in: Proc. 6th World Congress Intell. Control and Automation, 2006, pp. 2835-2839. [6] Ajit Kumar Gautam, A.B. Chelani, V.K. Jain, S. Devotta, A new scheme to predict chaotic time series of air pollutant concentrations using articial neural network and nearest neighbor searching, Atmospheric Environ. 42(18) (2008) 4409-4417. [7] M.J.L. Aznarte, J. Manuel Benítez Sánchez, D. Nieto Lugilde, C. de Linares Fernández, C. Díaz de la Guardia, and F. Alba Sánchez, Forecasting Airborne Pollen Concentration Time Series with Neural and Neuro-Fuzzy Models, Expert Systems with Applications 32(4) (2007) 1218-1225. [8] L. O±ródka, E. Krajny, M. Wojtylak, The use of numerical weather forecast for air pollution forecasting in an urban industrial agglomeration, in: Proc. 4th Annual Meeting EMS and 5th EC on Applied Climatology, 2004, EMS Vol. 1. [9] L. O±ródka, M. Wojtylak, E. Krajny, K. Rorbek, Doskonalenie metod prognozowania wysokich st e»e« zanieczyszcze« w aglomeracjach miejsko-przemysªowych przy wykorzystaniu numerycznych modeli prognoz meteorologicznych, Wiad. IMGW 27(1) (2004) 105-116. [10] L.A.Zadeh, Fuzzy Sets, Inf. and Control 8 (1965) 338-353. [11] G. Klir, T. Folger, Fuzzy Sets, Uncertainty and Information, Prentice Hall PTR, Englewood Clis, NJ, 1988. [12] H.J. Zimmerman, Fuzzy Set Theory and its Applications, second ed., Kluwer, Dordrecht, 1991. [13] W. Silvert, Ecological impact classication with fuzzy sets, Ecol. Model. 96 (1997) 1-10. Bibliograa 10 [14] B.K.Hansen, D.Riordan, Weather Prediction Using Case-Based Reasoning and Fuzzy Set Theory, in: Proc. Workshop on Soft Computing in Case-Based Reasoning, International Conf. on Case-Based Reasoning, Canada, 2001, pp.175-178. [15] B.K. Hansen, Weather Prediction Using Case-Based Reasoning and Fuzzy Set Theory, MSc Thesis, Technical University of Nova Scotia, Halifax, Nova Scotia, Canada, 2000.