Development of a Recognizer for Isolated Hand-Drawn Characters for the Purpose of a Quick-Dial Function in a Phone for the Visually Impaired

Tato práce seznamuje čtenáře s kmenovou aplikací, která je primárně určena pro osoby se zrakovým postižením. Dále navrhuje a implementuje novou funkci zrychleného volání za pomocí ručně psaných znaků, jež je speciálně navržena pro použití v mobilním telefonu s kmenovou aplikací. Řeší vhodné metody rozpoznávání a navrhuje vhodnou variantu, jež je následně implementována do Android aplikace. V této práci jsou představeny i nové originální sady dat, jež jsou použity k rozpoznávání znaků a byly pořízeny za spolupráce s dobrovolníky z více než 10 evropských zemí. V závěru je představeno testování této aplikace na cílových uživatelích a taktéž diskuze nad výsledky tohoto testu.This work familiarises a reader with the root application primarily used for visually impaired users. It proposes and implements a new function of quick-dial with the use of hand-written characters which is specially designed for mobile phone usage with the root application mentioned above. It researches suitable methods of recognition and presents the appropriate approach which is further implemented in the Android application. Moreover, this paper presents new data sets which are used for the character recognition and were gathered with the help of international volunteers from more than ten European countries Lastly, the user testing results are presented together with a discussion of their conclusions

Stanovení aromatických škodlivin ve zbytcích po hoření za pomocí analytických metod

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Antioxidant Active Polysaccharides Extracted with Oxalate from Wild Blackthorn Fruits (<i>Prunus spinosa</i> L.)

Although several therapeutic effects have been attributed to wild blackthorn fruits, their use is still negligible. Purification of the antioxidant-active fraction, obtained from wild blackthorn fruits by hot ammonium oxalate extraction (Ao), yielded seven fractions after successive elution with water, sodium chloride and sodium hydroxide solutions. The purified fractions differ in carbohydrates, proteins, and phenolics. About 60% of the applied Ao material was recovered from the column, with the highest yields eluted with 0.25 M NaCl solution, accounting for up to 70 wt% of all eluted material. Analyses have shown that two dominant fractions (3Fa and 3Fb) contain 72.8–81.1 wt% of galacturonic acids, indicating the prevalence of homogalacturonans (HG) with a low acetyl content and a high degree of esterification. The low content of rhamnose, arabinose and galactose residues in both fractions indicates the presence of RG-I associated with arabinogalactan. In terms of yield, the alkali-eluted fraction was also significant, as a dark brown-coloured material with a yield of ~15 wt% with the highest content of phenolic compounds of all fractions. However, it differs from other fractions in its powdery nature, which indicates a high content of salts that could not be removed by dialysis

Structural properties of the extracellular biopolymer (β-D-xylo-α-D-mannan) produced by the green microalga Gloeocystis vesiculosa Nägeli.

Many species of microalgae produce a relatively diverse range of metabolites that are interesting for biotechnological applications, and among them exopolysaccharides attract attention due to their structural complexity, biological activities, biodegradability or biocompatibility. An exopolysaccharide of high molecular weight (Mp) of 6.8 × 105 g/mol was obtained by cultivation of the freshwater green coccal microalga Gloeocystis vesiculosa Nägeli 1849 (Chlorophyta). Chemical analyses revealed a dominance of Manp (63.4 wt%), Xylp and its 3-O-Me-derivative (22.4 wt%), and Glcp (11.5 wt%) residues. The results of the chemical and NMR analyses showed an alternating branched 1,2- and 1,3-linked α-D-Manp backbone terminated by a single β-D-Xylp and its 3-O-methyl derivative at O2 of the 1,3-linked α-D-Manp residues. The α-D-Glcp residues were found mainly as 1,4-linked and to a lesser extent as the terminal sugar, indicating partial contamination of β-D-xylo-α-D-mannan with amylose (∼10 wt%) in G. vesiculosa exopolysaccharide

Carboxymethylated-, hydroxypropylsulfonated- and quaternized xylan derivative films

Under alkaline/water conditions carboxymethyl, 2-hydroxypropylsulfonate and trimethylammonium-2-hydroxypropyl groups were introduced into xylan in one step with the goal to prepare film specimens. The materials were characterized by NMR, SEC-MALS, TG/DTG/DTA, AFM and mechanical testing. The properties of triple, double and mono-substituted materials were compared. The numerical molar masses of the specimens were from 12.3 to 17.6 kg/mol with Mw/Mn from 1.27 to 1.34. The elastic modulus values are decreasing in order: xylan (X; 7354 MPa)\u3ecarboxymethyl xylan (CX; 6090MPa)\u3e2-hydroxypropylsulfonate xylan (SX; 6000 MPa)\u3ecarboxymethyl/2-hydroxypropylsulfonate xylan (CSX; 4490 MPa)\u3equaternized xylan (QX; 3600 MPa)\u3ecarboxymethyl/quaternary/2-hydroxypropylsulfonate xylan (CQSX; 3380 MPa)\u3ecarboxymethyl/quaternary xylan (CQX; 2805 MPa). The onset temperatures of SX (214°C), CQSX (212°C), QSX (211°C) and CQX (207°C) were higher than for X (205°C). The roughness values of the film surfaces (3.634-18.667 nm) are higher on top than on the bottom of the specimen

Carboxymethylated-, hydroxypropylsulfonated- and quaternized xylan derivative films

Under alkaline/water conditions carboxymethyl, 2-hydroxypropylsulfonate and trimethylammonium-2-hydroxypropyl groups were introduced into xylan in one step with the goal to prepare film specimens. The materials were characterized by NMR, SEC-MALS, TG/DTG/DTA, AFM and mechanical testing. The properties of triple, double and mono-substituted materials were compared. The numerical molar masses of the specimens were from 12.3 to 17.6 kg/mol with Mw/Mn from 1.27 to 1.34. The elastic modulus values are decreasing in order: xylan (X; 7354 MPa)\u3ecarboxymethyl xylan (CX; 6090MPa)\u3e2-hydroxypropylsulfonate xylan (SX; 6000 MPa)\u3ecarboxymethyl/2-hydroxypropylsulfonate xylan (CSX; 4490 MPa)\u3equaternized xylan (QX; 3600 MPa)\u3ecarboxymethyl/quaternary/2-hydroxypropylsulfonate xylan (CQSX; 3380 MPa)\u3ecarboxymethyl/quaternary xylan (CQX; 2805 MPa). The onset temperatures of SX (214°C), CQSX (212°C), QSX (211°C) and CQX (207°C) were higher than for X (205°C). The roughness values of the film surfaces (3.634-18.667 nm) are higher on top than on the bottom of the specimen