I was looking at arial photos of north-western Europe in Google Maps when I noticed a big white dot on the map! I thought, what the hell? To satisfy my curiosity I decided to zoom in for further investigation. It…
Datasets: – Urban morphological zones 2000 (EU): – Population count (World): – Administrative regions (World): The map is European since the “urban” data from the European Environmental Agency (EEA) only covers Europe. Caveats The UMZ data ended…
The GADM database contains geographical data for administrative regions, e.g. countries, regions and municipalities. As always, once you have the data in the right format, it is easy to import it into a database. The data is available from GADM…
I teach children how to programm and do other things with technology in an organisation called Coding Pirates in Denmark, which aims to be a kind of scout movement for geeks. A best seller among the kids is learning how…
Airbag sensors There is a small amount of gold inside the Airbag sensor. The sensor contains a small gold-plated marble, which amounts to some tiny amount of gold. Integrated Chips One kilogram of chips contains 1-8 grams of gold (according…
These guys found that road-side dust contains 1000 DKK worth of platinum per 1 ton of dust. Cody explains that this concentration of platinum equals the amount found in good-quality platinum ore. Does the stretch of road matter? In a…
While I intuitively like the concept of Urban Mining – we have all these precious raw materials within easy reach of robots – I know nothing about it. I want to remedy that with the best ignorance cure of all:…
I have adapted an example neural net written in Python to illustrate how the back-propagation algorithm works on a small toy example. My modifications include printing, a learning rate and using the leaky ReLU activation function instead of sigmoid. import…
In this post I will give a brief overview of my father’s (Georgios Kefaloukos) many activities in the early part of his life. After dinner today I decided to ask him about his life story, and took as many notes…
I work in the ad tech industry, which means that I track people online for a living. Mainly, I do it because the industry has interesting computer science problems and because the job pays well. I will not defend ad…