Last updated: 10 July 2026 · applies to perceptualcontroltheory.org
This is an independent, non-commercial research portal. It has no user accounts, no newsletter, no comment system, and it does not sell anything or share personal data with advertisers. The little data it does process is described below, in plain language, as required by the EU General Data Protection Regulation (GDPR).
Łukasz Diener — independent researcher, Kraków, Poland
Contact: [email protected]
ORCID: 0009-0006-6103-8514
a) Server logs. Like virtually every website, the web server (hosted by Hetzner Online GmbH, in the European Union) automatically records technical data for each request: IP address, date and time, requested URL, browser type (user agent), and referrer. This data is used solely to keep the site secure and to diagnose technical problems. Legal basis: legitimate interest (Art. 6(1)(f) GDPR). Logs are kept for a limited period necessary for these purposes and are not merged with any other data.
b) Visitor statistics. This site uses two analytics tools to understand, in aggregate, which pages are read:
Statistics are used only to see what content is useful — never to identify individual visitors. Legal basis: legitimate interest (Art. 6(1)(f) GDPR).
c) Contact. If you write to the email address above or via WhatsApp, the data you provide (your address or number, the content of your message) is processed only to answer you and to conduct the resulting correspondence. WhatsApp is a service of Meta Platforms; its own privacy terms apply to that channel. Legal basis: legitimate interest in responding to inquiries (Art. 6(1)(f) GDPR), or steps taken at your request (Art. 6(1)(b) GDPR).
The site itself does not require cookies to function. The analytics tools described above may set cookies (e.g. Google Analytics identifiers, Matomo identifiers) to distinguish visits in aggregate statistics. You can delete or block cookies at any time in your browser settings; the site remains fully readable without them.
Data is disclosed only to the technical service providers named above (Hetzner as hosting provider, Google as analytics provider) and, where legally required, to competent public authorities. Nothing is sold, rented, or shared for marketing.
Under the GDPR you have the right to access your data, to rectification, to erasure, to restriction of processing, to data portability, and to object to processing based on legitimate interest. To exercise any of these rights, write to [email protected].
You also have the right to lodge a complaint with a supervisory authority — in Poland, the President of the Personal Data Protection Office (UODO, Warsaw), or the data protection authority of your own EU member state.
This site makes no automated decisions about visitors and performs no profiling within the meaning of Art. 22 GDPR.
If the site's tooling changes (for example, analytics configuration), this page will be updated and the date above revised.