A constellation diagram is a diagram that shows how the information in a digital modulation scheme such as phase shift keying (PSK) is represented in a modulated carrier. This article is a bit of an experiment; instead of introducing the constellation diagram by simply presenting it… read more
The image below shows eight faces that were generated through a machine learning technique called a Generative Adversarial Network (GAN). The faces are completely artificial, and do not correspond to… read more
An analytic signal is a signal without negative frequency components. This might seem a strange concept if you’re not used to it, but analytic signals are used in signal processing, for example in modems for telecommunications. Let’s start from… read more
I’m working on a series of articles on modems. It’ll be a loose collection of posts, and not a true multi-part article such as the one on tomography. Modem technology is not widely known and/or understood, even by a technical audience. However… read more
Quite a while ago, I decided to do all my Python programming in Python 3 as much as possible. This is essentially always for the typically small stand-alone programs that I put on this blog. I did this to encourage people to use Python 3 for their own work, and to be future proof. Additionally… read more
After explaining how amplitude modulation and frequency modulation work, which are both analog modulation schemes, I’d now like to give an example of a digital modulation techique. A basic, but very relevant, example of a digital modulation scheme is… read more
This article is a wrap-up of what happened on TomRoelandts.com in 2018. read more
This article shows how “old style” linear regression looks when implemented with TensorFlow. When you start diving into TensorFlow, an example like this is typically missing from the tutorials. Linear regression is often the first example, but… read more
This is part two of a tutorial that describes how to use the ASTRA Toolbox to create a 3D reconstruction from 2D projection images that were taken with a cone-beam CT scanner. In this second part, I’ll create a reconstruction from the synthetic dataset that… read more
This is part one of a tutorial that describes how to use the ASTRA Toolbox to create a 3D reconstruction from 2D projection images that were taken with a cone-beam CT scanner. In this first part, I’ll create a synthetic dataset… read more
