We prove a general stability theorem of an n-dimensional quadratic-additive type functional equation [Formula: see text]by applying the direct method.

Transcranial direct current stimulation (tDCS), a simple means of brain stimulation, possesses a trifecta of appealing features: it is relatively safe, relatively inexpensive and relatively effective. It is also relatively easy to obtain a device and the do-it-yourself (DIY) community has become galvanised by reports that tDCS can be used as an all-purpose cognitive enhancer. We provide practic...

We shall start by telling tile story of the discovery of the Dirac equation. There is no better way of telling it than in the words of the protagonists themselves and this is the way we shall do it. In this, we are greatly helpe.d by the excellent book "Inward Bound" by Abraham Pals (Pals 1986). Almost all our quotations are taken from this source. Every serious student of physics must read thi...

We introduce a new class of systems holding Parity Time (PT)-symmetry locally whereas being globally Psymmetric. The potential is globally symmetric, U=U(|r|), and fulfills PT-symmetry with respect to periodically distributed points r0: U(|r0+r|)=U*(|r0-r|) being r0∫ 0. We show that such systems hold novel properties arising from the merging of the two different symmetries, leading to a strong ...

Lucia Terrenghi LMU University of Munich,

This paper presents an investigation of the best suitable package formats for long term digital preservation. The choice of a package format for preservation is crucial for future access, thus a thorough analysis of choice is important. The investigation presented here covers setting up requirements for package formats used for long term preserved digital material, and using these requirements ...

Im vorliegenden Artikel wird ein Ansatz zur prozessorientierten Ermittlung von eGovernment-Anforderungen aus Unternehmenssicht entwickelt. Als Ergebnis einer explorativen Untersuchung können Merkmale von Unternehmenslagen identifiziert werden, die ausschlaggebend sind für technische und organisatorische Gestaltungsaspekte unternehmerischer Behördenkontakte. Aus den ermittelten Anforderungen wir...