By a relational system we mean a couple (A, R) where A is a set and R is a binary relation on A, i.e. R ⊆ A × A. To every directed relational system A = (A, R) we assign a groupoid G(A) = (A, ·) on the same base set where xy = y if and only if (x, y) ∈ R. We characterize basic properties of R by means of identities satisfied by G(A) and show how homomorphisms between those groupoids are related to certain homomorphisms of relational systems.
The DF III 1 Strahov Manuscript, which preserves the only version of the Vincencius and Jarloch chronicle, has a rich and not too happy history behind it. For a long time it was housed in the Prague Chapter Library, from which it was lost under mysterious circumstances sometime before 1764. It was not discovered again until 1826 by Josef Dietrich, curate at Postoloprty, who donated it to Josef Dobrovský. Dobrovský used it for his edition of what is known as the Ansbert Chronicle and then donated it to the Strahov Monastery Library. If we follow the fortunes of the Codex before its disappearance from the Chapter Library, we find that this evidently happened "thanks" to Václav Prokop Duchovský, Secretary to the Archbishop's Consistory, who did not return the borrowed manuscript to its original place, and kept this fact from Gelasius Dobner, who was looking for the Codex in the library a year later in order to compile an edition of both chronicles. The motive for this behaviour was evidently their mutual poor relations due to Dobner's criticism of Hájek's Chronicle.
Morphological and physiological traits of Crepis pygmaea L. subsp. pygmaea and Isatis apennina Ten. ex Grande growing at different altitudes in the Gran Sasso Massif (Abruzzo, Italy) were analyzed. The two populations of C. pygmaea and I. apennina growing at the highest altitude (Cp2 and Ip2 at 2,310 m a.s.l. and 2,350 m a.s.l., respectively) had a lower leaf mass area (LMA) than the two populations growing at the lowest altitude (Cp1 and Ip1 at 2,250 m a.s.l. and 2,310 m a.s.l., respectively). Leaf tissue density (LTD) had the same LMA trend, decreasing 23 and 10% in C. pygmaea and I. apennina, respectively, from the highest to the lowest altitude. C. pygmaea and I. apennina had the highest photosynthetic rates
(PN) in July decreasing on an average 17 and 30%, respectively, in August and 50 and 38%, respectively, in September. Leaf respiration (R) in Ip1 and Ip2 had the same trend as Cp1 and Cp2, showing the highest rates in September. Global warming could drive C. pygmaea and I. apennina toward higher altitudes in the Gran Sasso Massif. Nevertheless, C. pygmaea with the higher plasticity index (PI) both at physiological and at morphological levels (0.50 and 0.35, respectively) might have a competitive advantage over I. apennina over the long term., L. Gratani ... [et al.]., and Obsahuje bibliografii
This study seeks to derive an original multicriterial decision making model for operative control of water quality in the water reservoir. The model design is based on the theory of dynamic systems control. It incorporates simulation modelling methods with the hydrodynamic reservoir and multicriterial optimization methods. The research aims to derive an algorithm for operating rules of the reservoir under any operating conditions and for the given criteria of control. The study presents the outcomes of the application of model quality control of water withdrawal from the Římov reservoir on the Malše River. and Studie odvozuje původní vícekriteriální rozhodovací model pro operativní řízení kvality odebírané vody z vodárenské nádrže. Model vychází z teorie řízení dynamických systémů a propojuje se v něm metodologie simulačního modelování s hydrodynamikou nádrží a metodami vícekriteriální optimalizace. Cílem řešení je odvodit algoritmus pro regulační zásahy (manipulace) na nádrži při libovolných provozních podmínkách a pro stanovená kritéria řízení. Studie uvádí výsledky aplikace modelového řízení kvality vody v nádrži Římov na Malši.