We report on the design and long-term use of a digital tracking system for the consumption and payment tracing of beverages, called “Barkeeper”. It is based on tags wearing QR-codes and its design was not primarily guided by efficiency, but rather everyday use during the last three years in our lab. In this trusted environment, we collected extensive usage data, making this a serious long-term ...

In this paper an implicit (double) shifted QR-method for computing the eigenvalues of companion and fellow matrices will be presented. Companion and fellow matrices are Hessenberg matrices, that can be decomposed into the sum of a unitary and a rank 1 matrix. The Hessenberg, the unitary as well as the rank 1 structures are preserved under a step of the QR-method. This makes these matrices suita...

An electrocardiogram (ECG) is an indispensable tool to diagnose cardiac diseases, such as ischemic heart disease, myocarditis, arrhythmia, and cardiomyopathy. Since ECG patterns vary depend on patient status, it is also used to monitor patients during treatment and comparison with ECGs with previous results is important for accurate diagnosis. However, the comparison requires connection to ECG ...

BAR CODE BASICS Labeling our world requires, well, labels. Today, this typically amounts to what’s commonly called a bar code. This term is synonymous with the Universal Product Code (UPC) and European Article Number (EAN) codes found on nearly every manufactured good and familiar to most consumers through their nearly ubiquitous use at grocery store checkouts. Depending on the exact type (www....

Nowadays, the research on robot on-map localization while using landmarks is more intensively dealing with visual code recognition. One of the most popular landmarks of this type is the QR-code. This paper is devoted to the experimental evaluation of vision-based on-map localization procedures that apply QR-codes or NAO marks, as implemented in service robot control systems. In particular, the ...

This paper proposes a challenge-response authentication system for web applications called Snap2Pass that is easy to use, provides strong security guarantees, and requires no browser extensions. The system uses QR codes which are small two-dimensional pictures that encode digital data. When logging in to a site, the web server sends the PC browser a QR code that encodes a cryptographic challeng...