Kotlin Cheat Sheet

For a project I was involved in at short notice, I had to become familiar with the Kotlin programming language. Before starting to code, I wanted to get familiar with the syntax and the language itself. As writing on a paper is the best way to learn (for me), I created the following Cheat sheet. Enjoy! … read more …

Role Based Access Control and Big O

Didapptic.com is a research based web application that measures Android and iOS Apps from a didactic point of view. Actually, we work on a new release in order to provide a fresh layout and smarter handling of app data. Among other things, the new release introduces also a new user management handling which allows and/or permits … read more …

Comparing Objects with PHP

Yesterday, I was working on PHPAlgorithms (again). When trying to implement Graphs (Directed and Undirected), I found out that a node could not be found in the graph although I was sure it was there. After a lot of debugging and reverse engineering, I found out that: the adjacency list, which contains all adjacent nodes … read more …

PHPAlgorithms is there

Frankfurt, May 2018 – Today, the first BETA version of PHPAlgorithms is launched! The repository is available via GitHub and Packagist. Originally launched as a research project, PHPAlgorithms provides currently a basic set of data structures. The repository has been designed to provide simple usage of common data structures such as lists, maps and trees. … read more …

PHP HashMap Implementation

A few days ago I have started working on a PHP library for algorithms and data structures. PHPAlgorithms is still in progress and thus has a early beta status. But today, I have pushed the first data structure which is nearly full implemented: HashMaps. A HashMap is characterized among others by its key-value storage property. … read more …

TF-IDF keyword extraction

For my masters thesis I have researched Content-Based Recommendation and keyword extraction as a part of it in detail. One interesting point regarding to keyword extraction is the “quality” of keywords, meaning that if a keyword is descriptive for a document or not. TF-IDF Definition For TF-IDF keyword extraction it is necessary to have a … read more …

Item-Based Collaborative Filtering

Für ein Projekt an der Uni beschäftige ich mich seit längerer Zeit mit Empfehlungssystemen (Recommender Systems), welche i.d.R. aus Collaborative Filtering und Content-Based Recommendation Techniken bestehen. In diesem Blogpost möchte ich auf die Collaborative Filtering-Komponente, genauer auf das Item-Based Collaborative Filtering eingehen. Das Item-Based Collaborative Filtering wurde ursprünglich von Amazon entwickelt. “Traditionelles” Collaborative Filtering, besser … read more …

erste Versuche mit Machine Learning *UPDATE 5*

nach langer Zeit finde ich wieder Mal Zeit für meinen Blog.. Heute will ich über ein Thema schreiben, welches mich aktuell begleitet – Machine Learning. Überall werden Begriffe wie künstliche Intelligenz, maschinelles Lernen, Personal Assistant etc. genannt. Jüngst hat Google seinen Assistant vorgestellt, der Einzug auf vielen Geräten wie dem Smartphone, Lautsprechern, Fernsehern und weiteren … read more …