Publications
Unpublished work
Raising the Bar for the CAPTCHA-breaking Economy
Graduate Research Project
We examine methods of raising the cost of paid CAPTCHA solving. We propose two potential solutions, named PayCAPTCHA and Local CAPTCHA, to this problem, which not only make large-scale paid solving more costly, but can also be combined with traditional systems, such as reCaptcha, establishing a defense in depth against both manual and automated attacks.
Functional Dependencies in PostgreSQL Databases – Information System
Bachelor’s thesis
This thesis describes the development of an application for manipulating functional dependencies, as well as for normalizing PostgreSQL data bases. The information system is suitable for evaluating and improving relational schemas and for teaching purposes.
Hybrid Vehicular Sensor Networks
Term Paper
hybrid_sensor_vehicular_networks.pdf
A relatively new research topic are hybrid sensor vehicular networks, which combine wireless sensor networks with vehicular ad-hoc networks. This paper gives an outline of research goals and contemporary projects.
FireFly – A Real-Time Platform for Wireless Sensor Networks
Term Paper
This paper introduces the WSN platform FireFly, whose multi-layer approach enables developers to build real-time applications with respect to the node’s energy supply. Quality of service requirements, such as low end-to-end delay, high throughput, etc. are met at a high level.
Experiments with the Michelson Interferometer
Term Paper for Advanced Physics Course
In an advanced physics course, Orkun Sensebat and I conducted experiments to determine the wavelength of an helium neon laser, both at school and in close collaboration with the PTB (Physikalisch-Technische Bundesanstalt) Braunschweig, using high precision instruments. Moreover, basics and fields of application of modern laser interferometry, as well as the historical context of the special theory of relativity and new developments like quantum eraser experiments, are described.
