In this paper we present a stabilization procedure for PVTOL (planar vertical take off and landing) aircraft with zero coupling coefficient that is defined as the effect of rolling moment on lateral acceleration. A stabilizing control structure has been designed via Lyapunov’s direct method including almost the whole state space and its asymptotic convergence has been proven using La Salle’s in...

Using the theory of exponential Riordan arrays and orthogonal polynomials, we demonstrate that the Eulerian polynomials and the shifted Eulerian polynomials are moment sequences for a simple family of orthogonal polynomials. The coefficient arrays of these families of orthogonal polynomials are shown to be exponential Riordan arrays. Using the theory of orthogonal polynomials we are then able t...

The Nobel Prize for Physics 1920 was awarded to C.-E. Guillaume for his discovery of properties of nickel steels. He had previously observed that certain iron-nickel alloys exhibit the Invar effect i.e. an extremely low thermal expansion coefficient over a wide range of temperature. The decades since then have seen the observation of similar phenomena in other iron-based materials such as iron-...

The question of whether architectural creativity is more of an artistic or engineering nature is one with a long history but also one with no conclusive answer. The art camp would argue that technology should be treated as a means towards and end, and that technology alone cannot give meaning to our lives. The engineering camp on the other hand would argue that good problem-solving result...

The main purpose of this study was to examine the effect of chalk on the friction coefficient between climber's fingers and two different rock types (sandstone and limestone). The secondary purpose was to investigate the effects of humidity and temperature on the friction coefficient and on the influence of chalk. Eleven experienced climbers took part in this study and 42 test sessions were per...

the question of whether architectural creativity is more of an artistic or engineering nature is one with a long history but also one with no conclusive answer. the art camp would argue that technology should be treated as a means towards and end, and that technology alone cannot give meaning to our lives. the engineering camp on the other hand would argue that good problem-solving results in b...

The effect of nadolol (N) on 24-hour blood pressure (BP) and heart rate (HR) values and on their variability was examined in ambulant patients with essential hypertension, using the Oxford method to obtain continuous intraarterial recording and a computer to have a beat-to-beat analysis of the data. The recording was carried out without treatment and after 10 days' administration of N once dail...