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.

UI Implementation with different OS tested with different Browser

We tried to design a OS and Browser independent website. Our working devices had three different OS systems: windows, linux, macOS (which is based on linux but still works different). We first ran into the issue that our application was Linux and MacOS compatible but not for windows. After solving that by adding some settings our windows developer started to implement our first UI which worked pretty fine for him in Chrome and Mozilla Firefox.

Automate the enabling/disabling of Apache NiFi controller services

In our company we are using cloudera manager to manage our CDH (Cloudera Data Hub) cluster and to automate cluster operations. We recently had to upgrade our CDH to CDP (Cloudera Data Platform), since we are using Apache NiFi to control our real-time data, every time we had to restart NiFI during the upgrade all the controller services got disabled and after the restart we had to enable them manually which is very time consuming due to vast number of controller services.

How can I make usage statistics of a website without breaching privacy?

I am running a small static website and would like to see statistics about unique visits. My understanding of popular solutions such as Google Analytics is that they track an excessive amount of user data I am not interested in. I would prefer to only count the number of unique visits and not collect any further data in order not to scare away privacy-conscious users.

Linking BPMN Model with Java Classes and HTML Pages

Our goal was to create a simple webpage using a bpmn model as the base. Linking java classes was our first issue which we could solve pretty easily. Therefore we just had to define for the task in the bpmn model to link to a class in our project and then use the RIGHT(!!) path and not only the name. It does not get linked just by the name in the project. The bigger issue was to link out HTML pages with a bpmn task. It didn't matter what we did it never took the right class.

Recreate Oracle Standby logfiles

In our company we are using Oracle Databases. For the productive Databases we use some Standby Databases as Data Guard. Apparently they worked as they should but nowadays one standby is not able to access the standby logfiles. How can I recreate those files ?

How to use Pearl within a HTML based on Mason

I would like to use perl within my HTML file to get some informations from my Database. Apparently I am not able to get things working since the error messages are confusing me a lot. Could someone show me how I am able to call the information of my Database with perl ?

How to try out web application using multiple logins at once

I am developing a web application that uses JWT tokens to authenticate users which have different roles. In order to test the application I would need to switch between different user's accounts, ideally without switching browser. Is it possible to constrain session data to a tab so that I can login to my application as different users from different tabs using the same browser?

Configure a Bridge network between Docker container

Currently I try to configure the network between two Docker Container. On the first container my application is running, on the other Container a simple NGINX server is running.

Running amd64 Docker Container with Mac M1-Chip ( arm64)

Since i switched my Laptop towards a new Mac Book Pro which is running with the newly created M1 Chip, Docker Container are not able to find mandatory packages anymore. The Problem might be the M1 Chip for which an CPU architecture was reinvented and is based on arm64. Is it necessary to refactor and rebuild all the images that were created before this setup change ? Or is there another way on how to solve this issue ?

NumPy array append slow

For a university project I need to implement an inverted index in python. This consists of a dictionary containing NumPy arrays, to which I append new values as I process more text. We've been told to use NumPy instead of regular Python lists, to decrease memory usage as it is possible to use smaller defined datatypes. However using list append and then swapping the value in the dictionary proves to be terribly slow. Is there a better way to implement this?


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