Abstract: A device and a computer-implemented method for determining a variable of a technical system, using a machine learning model. A kernel for the model is selected from a set of kernels as a function of a selection criterion, and a first data set which includes mutually assigned input variables and output variables of the technical system. The selection criterion is determined for a kernel that is selected from the set of kernels as a function of an acquisition function, the acquisition function being determined as a function of a second data set that includes pairs of kernels from the set of kernels and a selection criterion. The pairs of kernels are determined over respectively one pair of kernels from the set of kernels and as a function of the second data set. Representations of a first and second kernel are provided.

Abstract: The invention relates to a process for the preparation of activated chitosans, in which process a chitosan is reacted with an acid for salt formation, preferably followed by a reaction with a base. The addition of acid and the addition of bases which is preferably to be effected in the activation are carried out in a suspending agent which largely prevents the chitosan salts from dissolving, suitable suspending agents can be both aqueous solutions of inorganic salts and organic or aqueous-organic solvents. The invention also relates to a process for the preparation of both water-soluble and water-insoluble chitosan derivatives by reacting the activated chitosans with reagents which are generally suitable for the reaction of polysaccharides or amines.

Abstract: The invention relates to water-soluble cellulose ethers, containing at least one fluorine-free radical attached via an ether link and selected from the group hydroxyethyl, hydroxypropyl, methyl, ethyl and carboxymethyl, and a hydrophobic substituent which comprises one fluorine-containing alkyl radical of 3 to 24, in particular 5 to 18, carbon atoms, the fluorine content being 0.05 to 5, in particular 0.1 to 1% by weight, based on the dry weight of the cellulose ether.