Air Pollution Application

 

First we will explain the functionatility of the application and then we will describe step by step the tutorial exercise.

 

The air pollution application uses an Eulerian Model (called STEM-II) to simulate the environment of As Pontes Power Plant in A Coruņa (Spain). With the aim of helping the experts to make decisions, besides to generate the files with the exact concentration of pollutants in each point of the simulated mesh, we have developed a graphical plugin that allows the user to set the input/output parameters, and see the concentrations of pollutants graphically.

 

Fig. 1. Input parameters plugin

 

First, we must launch the Migrating Desktop (http://ras.man.poznan.pl/crossgrid/), click on the Start Jobs Wizard button and select the Air Pollution application. The input parameters plugin of the application will be shown (Fig. 1).

 

The input parameters of the model can be set in this plugin. These parameters are the date, the start hour and the number of hours of the simulation. Besides, a flag for the execution of an only transport simulation or a simulation with chemical reactions can be set.

 

 In the Description Tab (Fig. 2) we can write a brief description of our simulation and specify the path of the executable (It is already installed in the testbed)

Fig. 2. Description Tab

 

Fig. 3. Resources Tab

In the Resources Tab (Fig.3) we can specify the node where we want to execute the application, the jobtype, the number of processors and other parameters (not required for this exercise).

 

Finally, in the files tab (Fig. 4) we have to specify the input an output files of our application. For this exercise the user must only specify an output file that contains the graphical representation of the pollutant concentration after each temporal iteration of the program. (This is the mapadebits.bmp file in Fig. 4).

We also have to specify the type of the file (out in our case), and a refresh period (5 or 10 seconds). This refresh period indicates how often the file is downloaded. This is used for a refreshable output purposes, the first step in the interactivity.

 

Fig. 4. Files Tab

 

Fig. 5. Job Monitoring Dialog

 

After all the input parameters have been set, we can submit the application to the Grid. From the Job monitoring Dialog (Fig.5) we can see the status of the job. We must refresh this status manually pressing the refresh or refresh all buttons.

When the status of the job turn to be running, our application will be executing in the grid and we will be able to see the output by pressing the button Visualize (Fig 6).

 

Fig. 6. Application Viewer (Output Plugin)

 

For a refreshable visualization of the image we must press the Details button in the Job Monitoring Dialog window. A new window with several tabs will be open (Fig. 7). We must select the tab files, select the file that we have chosen as output and press the button visualize. A new window with the output will be opened (Fig. 8). This image can be refreshed automatically setting a refresh period and pressing the apply button.

 

Fig. 7. Job Monitoring Dialog

 

Fig. 8. File Viewer

 

STEP-BY-STEP EXERCISE

  1. Launch the Migrating Desktop (http://ras.man.poznan.pl/crossgrid/)
  2. Click on the Start Jobs Wizard button.
  3. Select Applications -> Air Pollution
  4. The input arguments panel will be opened (Fig. 1)
  5. Chose the date of the simulation (YYYYMMDD format), the start hour and the number of hours of simulation. (Input files for the date 20030215 are provided, please select this in the exercise).
  6. Select the Description Tab.
  7. Set the Executable Path (/flatfiles/SE00/cg/wp1_4_4/STEMII_SE00-par-p4.exe in this exercise)
  8. Select the Resources Tab
  9. Set the hostname (cg01.ific.uv.es:2119/jobmanager-pbs-infinite) , the jobType (MPICH) and the nodeNumber (2). The maximum number of processors available in the testbed used in this exercise is 4.
  10. Select the Files Tab.
  11. Add a new file, rename it to mapadebits.bmp, set a local filename in the Virtual Directory with the same name, set the type to out and the refresh to 5 or 10 seconds
  12. Press the Submit button.
  13. Click on the Starts Job Monitoring Dialog button, refresh the list of jobs and then refresh the last job until its status turn to Running.
  14. Press the Details Button and select the Files Tab.
  15. Select mapadebits.bmp and press Visualize, a new window with the output view will be opened.
  16. Set the refresh period to 5 or 10 seconds, and press apply.
  17. The image will change along the time while the program is running.
  18. This image represents the concentration of SO2 at 300 m high.
  19. If you press the Visualize button in the Job Monitoring Dialog window the output plugin of the application will be shown. The image represents the concentration of the pollutant in each point of the simulated space. The representation scale is shown in the right part. The represented pollutant and the level of the representation are also indicated. This output plugin still do not have refreshable images

 

NOTE:

    • The input parameters can not be changed during an execution,  only the output parameters will allow interaction modification in the future.
    • The program has been prepared to perform a simulation of 1 hour for this tutorial.