Thursday, April 25, 2013

How to save Meta-Constructs


last week I was working on programming the "Link"-functionality of two or more sensors or constructs.

Click button "Link" on start screen:

This window pops up:

After finding a link-connection, there must run a background process, which reads the existing sensor data, connects them and saves a new brunch in the versioning system.

At the beginning I was not sure, how I should realize that with C#. I was thinking of stuff like threads.
After research in the Internet and asking friends, I now decided to use Windows Services.

When the user clicks on the button "Add" a new service is added to the system with the name of the new meta construct. This service takes over all the work in the background:

It works really well! :-)

My C#-Project called "Simulation" installs and starts my Windows Service project called "MetaConstructService". Witch clicking the button "Delete" it is also possible to uninstall it.

The Service reads out the parameter it needs from a XML-configuration file, that looks like that:

     <add key="ServiceName" value="Simulation_NewConstruct" />
     <add key="Destination" value="D:\newconst.txt" />
     <add key="CommitMsg" value="(Humditiy + Temperature) * 3" />
     <add key="data_Humditiy" value="D:\\newconst2.txt" />
     <add key="data_Temperature" value="D:\\newconst2.txt" />

All the Code is available at Github ( At the moment I am just storing a dummy content. I am not sure, how I link the sensors together. They won't have the exact timestamp. Maybe just linking the datasets with the most actual dates.

Concerning your comments of an older post of mine, I store each sensor data now like that in my .txt-files: timestamp;data


Wednesday, April 17, 2013

Theoretical Part


I finished the first three (theoretical) chapters of the thesis according to my proposal:

I also added a chapter called "Challenges" and changed the order of the chapters a bit.

Please find my text here:

Theoretical Part - PDF

Theoretical Part - DOC

  • Is it okay like that?
  • Is anything missing or should I change or add something?

I wrote it in Microsoft Word, cause I had a lot of formatting problems with Latech :-(
I will put it all in Latech before handing the thesis in ... but I think for the moment word is much nicer for me - the spelling correction is really useful and I know how to handle the software.

I have another question: does anybody of you know, where I can correct my text? I am no English native speaker, I am sure there are a lot of English grammar mistakes in it :-(
Sam, do you may know someone at HPU who can help me correct it?

Thank you very much for your help,

Thursday, April 4, 2013


Dear readers,

this week I started with some GUI mockups.


Start Screen:

Related user story:
John is a meteorologist. He has many sensors in a field study each generating temperature readings. In order to conduct his research he wants to have a general overview of all the current sensors he is currently working with. He also wants to see in his overview, if the data is generated from a sensor or a construct. A construct is a combination of several sensors.

 Adding a New Sensor:

Press Button „Add“ on start screen.

Related user story:
John has already stored his data securely in a sensor. He wants to add a new sensor to the system for further processing, like creating new constructs or showing the data.

Link two sensors to a new construct:

Press Button „Link“ on start screen.

Related user story:
John likes to create visualizations that combine humidity data with data on temperature that another scientist has been storing. He wants to save these combinations of data securely to show them to his colleagues in a few weeks.

Visualize data:

Press Button „Show“ on start screen.

Related user story:
John wants to view his new data combination to Alfred graphically to show him his results. He can show Alfred the raw data (Timestamp and Data) or he can visualize it by choosing one out of two visualization options.

The above shown GUIs are examples, how I want to realise my program.
Some of the buttons are already working, but not all of them.
I haven't started with the visualization part yet.

Open questions at the moment:
  • The visualization-window shows the date of the sensor data
    Should I store a date in my GIT/SVN .txt.-file which I display here.
    Or is it better to show the date, when the actuall data has been stored in the versioning system? (reading the log-File of the versioning system)
    Currently each sensor is just a text-File with data like that:
    But I can also store the data like that:
    2013-04-04 13:20:55;93
    2013-04-04 13:25:55;94
    2013-04-04 13:30:55;95
  • I was looking for a standardized way to store the data
    At the website I just find standards for .xml-schemas
    I haven't found an appropriate standard for my data yet ...
    I downloaded some test-data from They also provide .txt. files.
    So I think I will keep my .txt-File storing schema

  • For the first visualization option I am thinking of a x/y-coordination system. Where x is the timestamp and y the actual value. I haven't decided on the second visualization option yet.
  • I am not sure if I should allow to mix GIT and SVN in my solution. At the moment it is possible to load a sensor from GIT or from SVN in the system.
I appreciate every comment or help on that topic :-)
Mahalo, Tanja

Monday, April 1, 2013

Business Paper 2: Geo-Information - Value and economic feasibility


here you find my second German business paper about "Geo-Information - Value and economic feasibility" for the class "International Economics".

Business Paper 2