Welcome to TechScreen

Welcome to the TechScreen site. This side shall support the exchange of knowledge in the domain of Web Engineering and related aspects. As a side effect, this side is used for research on knowledge management technologies. User can pose challenges in the problem domain and can participate in quizzes. Further a bibliography about arcticles in different related domains is continously extended. Finally, questionnaires on different issues are provided. To be able to participate you need an account and a password from TU Wien's TISS system.

open source conversion

To solve the problem I had to read a lot about the implementation and the used algorithms of the current solution and then I had to find the equivalent functions in the open source framework. With knowledge about the algorithms I could develop the computer vision functions and got better results than the old solution.

Establishing of RS232 connection

To find a solution for the problem I asked a colleague to measure the output at the cable. Together we looked at the hex-commands that are sent to the generator. We found out that whenever the generator measured a certain value the connection was terminated, because this value was interpreted as an end flag by the software.

Group conversations on Skype faulty, if one member's OS is Linux

The most recent version for Skype on a Linux machine is 4.3. The age of this adaption is very apparent due to the outdated appearance of the application. Apart from its out-of-date presentation, Skype on Linux also lacks the options to video chat in a group as well as to share one's screen. This Skype version therefore exclusively offers chatting, Skype calling and video calling. However, invitations to screen shares can be accepted and viewed, even though they cannot be executed personally. The described issue occurs, if several users try to converse in a group conversation.

Replace missing value with median of attribute for the corresponding class

There exist several strategies to overcome missing values in machine learning, like ignoring and replacing the missing value with a logical replacement. One very challenging, but extra rewarding strategy is to replace the value with the median of the attribute for the corresponding class. So given an attribute that has missing values, and obviously has a class outcome, you have to calculate the median for each class and replace it for the corresponding class in the selected attribute column.

TPLink Powerline Adapter loosing connection

The TPLink Powerline Adapters occasionally loose their network connection and you have to disable and reenable the network-card of the computer to get it working again. A solution is needed to fix this network connection loss, as it makes these Powerline Adapters unreliable.

Creating a Custom WorkItemHandler in jBPM for Eclipse

I had to create a custom WorkItemHandler for jBPM in Eclipse to execute my own code when reaching a specific node in a Business Process, since a ScriptTask (which allows to execute code) was not enough because it does not allow to manipulate Process variables. A custom WorkItemHandler would also allow for better maintainability of the Business Process because it does not depend on scripts hidden in the process definition, but is directly visible in its own java class.

Manipulating machine learning datasets in VS .net

As a task for a Business Intelligence exercise I was looking for a simple C#-library to read/write/manipulate Weka attribute-relation file format (ARFF) files. The library should ideally already be pulished in the official NuGet Gallery repository to simply be used within Visual Studio 15 and the integrated NuGet-package manager.

Wake on LAN not working under Windows 10

After upgrading from Windows 7 to Windows 10, wake on LAN does not work anymore.

Spotify always opens on primary screen

I have Spotify premium, using the desktop application. On my computer I have two monitors, the second is dedicated for additional programms, such as my music player. When I logon my Computer, the app always starts on my main window, blocking all my view. This occures, when I start "cold", restart and after hibernating.

Pass value from one Android activity to another

Since two activities have no shared space (by default), it is not possible to grab that value/variable from the original activity. One has to not only find a way to store this value in the original activity, but find a way to access it from the newly created activity. This allows data sharing between activities to some extent. The value has to accessible at activity initialization as well as at any other point in activity life-cycle.


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