PoLogCem 4. The “Pollution's Modelling” panel The contents 4. The “Pollution's Modelling” panel 4.1. How to manage the measurements during the modelling process? 4.2. How to build nonlinear regression models for the pollution generated by a cement plant? 4.3. How to generate graphical representations? 4.4. How to generate and view the pollution map in a dynamical way? 4-1 PoLogCem 4.1. How to manage the measurements during the modelling process? The functionalities provided by the modelling module were already reported at some conferences like PSAM107 - ESREL’04 in Berlin, ENBIS2 in Copenhagen, and IWES3 in Romania. The approach was covered also in a short paper published by Scientific World Computing4. However, there are some improvements in the final stage, including piecewise modelling and the dynamic pollution map visualization. The user will appreciate, also, a better graphical interface (location of the buttons, visualizing style etc.). According to the Fig. 1, for the model’s output measurements tab, in the left panel are presented the measurements prepared by the plant's logistic module, and in the right panel are presented the output values that are issued in the mathematical models determination. The “>” buttons will permit to obtain the selected line from the 1 H. Madsen, P. Thyregod, Fl. Popentiu Vladicescu, G. Albeanu & L. Serbanescu, A Decision Support System for Pollution Control in Cement Plants, Proceedings of PSAM 07 - ESREL'04, June 14-18, 2004, Berlin. In: C. Spitzer, U. Schmocker si V.N. Dang (editors), Probabilistic Safety Assessment and Management, Vol. 3, pp. 17841789, Springer; ISBN: 1-85233-827-X 2 Henrik Madsen, Poul Thyregod, Florin Popentiu & Grigore Albeanu, Computer Aided Modelling and Pollution Control in Cement Plants, The 4th ENBIS Conference, Copenhagen, 20-22 September 2004, http://www.enbis.org/copenhagenconference/abstracts.html (index by number: 84) 3 Fl. Popentiu, G. Albeanu & L. Serbanescu, A software system for controlling the pollution dynamics in the cements plants, Proc. of the 5th International Word Energy System Conference, May, 17-19, 2004, Oradea, Vol. III, pp. 437-442, ISSN: 1198-0729. 4 Henrik Madsen, Poul Thyregod, Florin Popentiu & Grigore Albeanu, Computer Aided Modelling and Pollution Control in Cement Plants, The 4th ENBIS Conference, Copenhagen, 20-22 September 2004, http://www.enbis.org/copenhagenconference/abstracts.html (index by number: 84) 4-2 right side, while pushing the “>>>” button, the user will obtain data in the whole right table. When the EMPTY TABLE button is pressed then the corresponding table will be emptied. Similar actions are necessary when the Output Measurements tab is selected. Existing measurements provided by the Logistic module To transfer only the selected line To transfer the whole list Fig. 1. Defining the output models The setting procedure dealing with output-input dependences for the models that will be created it is shown in the Fig. 2. For each selected output (made up by module's point name and the parameter's name) will be created a list (the table) with the depending parameters. The user will start to insert and fill the rows in the table with x1, x2, x3, ... symbols, in the symbol field of the table. In the lower part, the user will select the corresponding parameters for each row in the table. The measurement point type (input / output) is compulsory to be selected. The delta [h] (in the fifth column) field is referring to the measurement's displacement (diphase), in this case the measurement lapse of time is bigger than the greatest displacement (diphase). The Date Time 1 and Date Time 2 (in the Fig. 2, see also the Fig. 4) were inserted in order to define the interval of time that will be taken into consideration (if it is nothing inserted then it will assume the already existent interval 4-3 of time). The Tolerance [h] field (the last column in the Fig. 2) will provide the maximal admitted time difference to be considered when two parameters assumed values simultaneously. The format for date / time can be easily set up using the Control Panel module from the Microsoft Windows Environment, as shown in the Fig. 3. Fig. 2. Defining the output-input dependencies for models that will be considered for pollution modelling and other studies Fig. 3. Setting up the format for date / time (by Control Panel) 4-4 Table with values corresponding to the selected variable. Press this button in order to search for the values corresponding to the variable (already selected). Fig. 4. Finding X-values corresponding to the X - variables Also the management of the input-output date is provided as shown in the Fig. 4. For each variable Xi it is obtained the table of values by pushing the FIND X VALUES button. The Scroll bar can be used to see more data in the table (Fig. 5). To delete the corresponding table of values it is enough to push the EMPTY TABLE button. The table with variables and time intervals for the values Fig. 5. The Environmental map example 4-5 PoLogCem 4.2. How to build the nonlinear regression models for the pollution generated by a cement plant? The images presented in the next figures illustrate the steps to follow in designing the data models. Firstly, the user will select the output measurement and then push the DISPLAY TABLE button and the results will be displayed as correspondence table for the selected output measurement with all the values of the input measurements for the corresponding output. Both classical and piecewise modeling is possible. In the Fig. 6, is shown a classical modeling. Considering interval data, the piecewise modeling is possible as shown in the Fig. 7. Press here to see the table of data The selection of the output model Here, there is the table containing the data related to dependent (Y) and independent (X) variables. Fig. 6. The automatic loading of values for the output dependent variable 4-6 The table of intervals to be considered for the selected parameter The data can be exported to XLD / Dbase files Fig. 7. Piecewise modelling Functions defined by user. After solving the model, the coefficients are shown in the third column. Press the button to solve the model. Fig. 8. Defining the structure of the regression model 4-7 In order to determine the mathematical models the following information is valuable: the output measurement must be selected and then in the left-down table will be filled the linear/nonlinear functions in a manner enabling us to obtain a model with the following expression: y = A0+ A1*F1(x1, ..., xm) + A2*F2(x1, ..., xm) + AnFn(x1, x2, …, xm), where m is the number of independent variables, and y is the dependent variable. The functions F1, F2,…, Fm must be defined by the user in the editing window (the right ^ down corner in the Fig. 8). Let us denote by Yk si Yk the measured respective the computed output variable, and by Y , the mean value of the variable Y given by the values Yk , k = 1, 2, … . Let Sy be the deviance to the mean of the measured data, and S ^ be the deviance from the mean of the data obtained after the solving of the y M M ^ regression model. Therefore, S y (Yk Y ) 2 and S ^ (Yk Y ) 2 . To compare the y k 1 k 1 measured model against de regression model, the software uses the following indicator S^ (adequacy level): R 2 Y . SY The adequacy index Press button for more Knowledge to be added in the Database Rules. It is shown the measured versus modeled data in the case of the dependent variable. Fig. 9. Updating the Knowledge Database Note: The software PoLogCem uses the notation R instead of R2 (Fig. 8 and Fig. 9). After the model was created (the structure was established and the coefficients were found) it will be added (using the button APPEND TO DATABASE RULES) to the existing general set of rules (Fig. 9). The name (label) of the new rule is automatically generated. The rules are needed to the optimization module. 4-8 PoLogCem 4.3. How to generate graphical representations? The modeling module also provides graphical representations. Firstly, the output parameter will be selected. All corresponding graphics will be automatically updated. In the upper panel the user will see the model's output and the measured output and, in the lower panel, the difference between them (using the sum of differences). The image provided in the Fig. 10 illustrates the mentioned results. If you want to obtain a WMF / BMP file Press here to select the parameter Y measured (red) versus the model (green) It is shown the difference between the measured data and the model data. Fig. 10. Graphical representations: Y modelled versus Y measured 4-9 PoLogCem 4.4. How to generate and view the pollution map in a dynamical way? Fig. 11 presents the initial state during the pollution map generation. The user can change the time to see a new map. The user will select the parameter which spreading in area to be calculated and viewed. The left-down rectangle will be filled at the moment of time when the view is wanted. Then the QUERY button will be pushed to determinate the values of the selected parameter for all measurement points at the mentioned moment of time. Finally the user will push the MAP PROCESSING button and the map will be built and displayed. The obtained map can be copied in the clipboard as BMP file. The map pollution is shown in the Fig. 12 both in static and dynamic manner. Also the pollution level can be obtaining when moving the mouse over the map (Fig. 13). Firstly, select the polluting parameter Select the position (East, North, South, West – V, PLANT) Here, will be generated the map after pressing the MAP PROCESSING button. Press this button to fill the left table with data. This button will be used for the dynamical visualization Fig. 11. The map generation - initial state 4 - 10 Here is defined the time interval for the map generation. Select the timing and press the MAP EVOLUTION button for the movie. Fig. 12. The Pollution Map The pollution level is viewed here, when moving the mouse over the map. Fig. 13. The Pollution Level 4 - 11