05.12.2015 I have translated my article on Kalman filter into English david.wf/kalmanfilter

22.09.2014 Devoted to my lovely wife, click to see it.

28.08.2014 My new programm - cube generator. It generates different kind of irregular cubes, which four side faces can be obtained from folding a paper strip. Writen on JavaScript and HTML5.

13.08.2012 Kempe’s universality theorem (”signature theorem”) claims that any certain type of curve may be traced out by the motion of one of the joints in a suitably chosen linkage. I proved the modified version of this theorem for trigonometric curves and used this proof for writing a web application, where one can draw his signature and the software generates a mechanical linkage, which can trace it.

27.04.2012 Update of section About me.

28.03.2012 Triangle paradox.

27.03.2012 Ellipse paradox.

26.03.2012 Derivation paradox.

26.03.2012 Quadratic equation paradox.

26.03.2012 Now we have Fun science section.