Jako dobový dokument zde nejdříve přinášíme podstatné části Šafránkova vlastního životopisu, jež vydal vlastním nákladem v roce 1936. Tato, dnes naprosto běžná sebeprezentace vyvolala u starší generace univerzitních fyziků podrážděnou reakci. Důkaz o tom nalezeneme v příslušné (zde rovněž přetištěné) autobiografie Vladimíra Nováka. Je velmi pravděpodobné, že Novák na Šafránka přenesl svou averzi k některým fyzikům starší generace, jmenovitě profesorům Felixovi a Posejpalovi. Třetím dokumentem je ukázka z knihy právě vydané nakladatelstvím Academia, v niž autorka líčí události provázející Šafránkovy přednášky ve Společnosti pro šíření vědeckých a politických znalostí v padesátých letech., Jaroslav Šafránek ; úvod redakce společný dalším dvěma článkům je uveden na straně 318., and Části Šafránkova vlastního životopisu [Curriculum vitae. Vlastním nákladem, Praha 1935, s. 5-8, 13-28]
After having given the general variational formula for the functionals indicated in the title, the critical points of the integral of the equi-affine curvature under area constraint and the critical points of the full-affine arc-length are studied in greater detail. Notice. An extended version of this article is available on arXiv:0912.4075.
We give a complete characterization of those $f\colon [0,1] \to X$ (where $X$ is a Banach space) which allow an equivalent $C^{1,\rm BV}$ parametrization (i.e., a $C^1$ parametrization whose derivative has bounded variation) or a parametrization with bounded convexity. Our results are new also for $X= \mathbb R^n$. We present examples which show applicability of our characterizations. For example, we show that the $C^{1,\rm BV}$ and $C^2$ parametrization problems are equivalent for $X=\mathbb R$ but are not equivalent for $X = \mathbb R^2$.
In this paper we study the notions of finite turn of a curve and finite turn of tangents of a curve. We generalize the theory (previously developed by Alexandrov, Pogorelov, and Reshetnyak) of angular turn in Euclidean spaces to curves with values in arbitrary Banach spaces. In particular, we manage to prove the equality of angular turn and angular turn of tangents in Hilbert spaces. One of the implications was only proved in the finite dimensional context previously, and equivalence of finiteness of turn with finiteness of turn of tangents in arbitrary Banach spaces. We also develop an auxiliary theory of one-sidedly smooth curves with values in Banach spaces. We use analytic language and methods to provide analogues of angular theorems. In some cases our approach yields stronger results (for example Corollary 5.12 concerning the permanent properties of curves with finite turn) than those that were proved previously with geometric methods in Euclidean spaces.
The Ongota language, recently (1981) rediscovered idiom from southwest Ethiopia, paradoxically belongs to the best described languages of the region, although today the number of its speakers oscillate around 10 old persons, while most of the members of the tribe speak Tsamay. The recent descriptions were realized thanks to three scientific expeditions to Ongota: (1) Fleming et al. (including Pavel Mikeš, a former member of the Oriental Institute of the Academy of Sciences of the Czech Republic) - 1990; (2) Kusia & Siebert - 1994; (3) Sáva & Tosco - 2000-01. On the basis of these three sources the present article analyzes the lexical data of Ongota common with Cushitic and Omotic.
Eighteen open problems posed during FSTA 2010 (Liptovský Ján, Slovakia) are presented. These problems concern copulas, triangular norms and related aggregation functions. Some open problems concerning effect algebras are also included.