Number of found documents: 842
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The Computational Power of Neural Networks and Representations of Numbers in Non-Integer Bases.
Šíma, Jiří
2017 - English
We briefly survey the basic concepts and results concerning the computational power of neural networks which basically depends on the information content of weight parameters. In particular, recurrent neural networks with integer, rational, and arbitrary real weights are classified within the Chomsky and finer complexity hierarchies. Then we refine the analysis between integer and rational weights by investigating an intermediate model of integer-weight neural networks with an extra analog rational-weight neuron (1ANN). We show a representation theorem which characterizes the classification problems solvable by 1ANNs, by using so-called cut languages. Our analysis reveals an interesting link to an active research field on non-standard positional numeral systems with non-integer bases. Within this framework, we introduce a new concept of quasi-periodic numbers which is used to classify the computational power of 1ANNs within the Chomsky hierarchy. Keywords: neural network; Chomsky hierarchy; beta-expansion; cut language Available at various institutes of the ASCR
The Computational Power of Neural Networks and Representations of Numbers in Non-Integer Bases.

We briefly survey the basic concepts and results concerning the computational power of neural networks which basically depends on the information content of weight parameters. In particular, recurrent ...

Šíma, Jiří
Ústav informatiky, 2017

Semigroup Structure of Sets of Solutions to Equation X^s = X^m
Porubský, Štefan
2017 - English
Using an idempotent semigroup approach we describe the semigroup and group structure of the set of solutions to equation X^m = X^s in successive steps over a periodic commutative semigroup, over multiplicative semigroups of factor rings of residually finite commutative rings and finally over multiplicative semigroups of factor rings of residually finite commutative principal ideal domains. The analysis is done through the use of the maximal subsemigroups and groups corresponding to an idempotent of the corresponding semigroup and in the case of residually finite PID’s employing the available analysis of the Euler-Fermat Theorem as given in [11]. In particular the case when this set of solutions is a union of groups is handled. As a simple application we show a not yet noticed group structure of the set of solutions to x^n = x connected with the message space of RSA cryptosystems and Fermat pseudoprimes. Keywords: set of solutions; idempotent; maximal semigroup corresponding to an idempotent; maximal group corresponding to an idempotent; equation X^s = X^m; finite commutative ring with identity element; residually finite commutative principal ideal domains Available on request at various institutes of the ASCR
Semigroup Structure of Sets of Solutions to Equation X^s = X^m

Using an idempotent semigroup approach we describe the semigroup and group structure of the set of solutions to equation X^m = X^s in successive steps over a periodic commutative semigroup, over ...

Porubský, Štefan
Ústav informatiky, 2017

Stav předaných dat a úprava rozdělení vybraných měření 2017
Novák, Jakub; Jiřina jr., M.; Benešová, Michaela
2017 - Czech
Keywords: typový diagram dodávky; TDD; spotřeba plynu; měřící místa; kritéria; filtrace; náhrady Available at various institutes of the ASCR
Stav předaných dat a úprava rozdělení vybraných měření 2017

Novák, Jakub; Jiřina jr., M.; Benešová, Michaela
Ústav informatiky, 2017

Popis TDD modelu verze 3.8.
Novák, Jakub; Jiřina jr., M.; Benešová, Michaela
2017 - Czech
Keywords: typový diagram dodávky; TDD; spotřeba plynu; popis modelu Available at various institutes of the ASCR
Popis TDD modelu verze 3.8.

Novák, Jakub; Jiřina jr., M.; Benešová, Michaela
Ústav informatiky, 2017

Idempotents, Group Membership and their Applications
Porubský, Štefan
2017 - English
S.Schwarz in his paper [165] proved the existence of maximal subgroups in periodic semigroups and a decade later he brought [167] into play the maximal subsemigroups and thus he embodied the idempotents in the structural description of semigroups. Later in his papers he showed that a proper description of these structural elements can be used to (re)prove many useful and important results in algebra and number theory. The present paper gives a survey of selected results scattered throughout the literature where an semigroup approach based on tools like idempotent, maximal subgroup or maximal subsemigroup either led to a new insight into the substance of the known results or helped to discover new approach to solve problems. Special attention will be given to some disregarded historical connections between semigroup and ring theory. Keywords: multiplicative semigroup; finite semigroups; power semigroups; idempotent elements; finite commutative rings; principal ideal domain; Euler-Fermat theorem; Wilson theorem; matrices over fields; maximal groups contained in a semigroup; periodic sequence; multiplicative semigroup of Zm; semigroup of circulant Boolean matrices Available on request at various institutes of the ASCR
Idempotents, Group Membership and their Applications

S.Schwarz in his paper [165] proved the existence of maximal subgroups in periodic semigroups and a decade later he brought [167] into play the maximal subsemigroups and thus he embodied the ...

Porubský, Štefan
Ústav informatiky, 2017

The Computational Power of Neural Networks and Representations of Numbers in Non-Integer Bases
Šíma, Jiří
2017 - English
We briefly survey the basic concepts and results concerning the computational power of neural networks which basically depends on the information content of weight parameters. In particular, recurrent neural networks with integer, rational, and arbitrary real weights are classified within the Chomsky and finer complexity hierarchies. Then we refine the analysis between integer and rational weights by investigating an intermediate model of integer-weight neural networks with an extra analog rational-weight neuron (1ANN). We show a representation theorem which characterizes the classification problems solvable by 1ANNs, by using so-called cut languages. Our analysis reveals an interesting link to an active research field on non-standard positional numeral systems with non-integer bases. Within this framework, we introduce a new concept of quasi-periodic numbers which is used to classify the computational power of 1ANNs within the Chomsky hierarchy. Keywords: neural network; Chomsky hierarchy; beta-expansion; cut language Available at various institutes of the ASCR
The Computational Power of Neural Networks and Representations of Numbers in Non-Integer Bases

We briefly survey the basic concepts and results concerning the computational power of neural networks which basically depends on the information content of weight parameters. In particular, recurrent ...

Šíma, Jiří
Ústav informatiky, 2017

Vývoj a ověření nového modelu tepelných poměrů městského prostředí v jemném měřítku
Resler, Jaroslav; Krč, Pavel; Belda, Michal; Juruš, Pavel; Benešová, N.; Lopata, J.; Vlček, O.; Damašková, D.; Eben, Kryštof; Derbek, P.; Maronga, P.; Kanani-Sühring, F.
2017 - Czech
Naším úkolem v rámci projektu UrbanAdapt bylo kvantifikovat dopady různých scénářů rozvoje města na kvalitu ovzduší a tepelný komfort obyvatel v prostoru uličních kaňonů. Z toho vyplývá potřeba modelu, který je schopen simulovat proudění v jemném rozlišení (jednotky metrů) a dostatečně realisticky predikovat turbulence ve složitém terénu uliční sítě a v okolí budov. Takovým požadavkům vyhovují LES modely, avšak rešerše ukázala, že volně dostupný LES model, který by zároveň popisoval energetickou výměnu v městském prostředí, interakci toků energie a proudění vzduchu včetně efektů vegetace a různých vlastností městských povrchů a materiálů v praxi zatím neexistoval. Proto jsme se rozhodli rozšířit existující LES model PALM o nový modul USM (Urban Surface Model) popisující nejdůležitější procesy energetické výměny v městském prostředí. Model by ověřován proti měřením získaným IR kamerou během měřící kampaně v průběhu vlny veder v červenci 2015. The assessment of different scenarios of the city development to air quality and thermal comfort in the areas of street canyons was our main goal inside the project UrbanAdapt. It follows the need for a model which allows to simulate air flows in fine resolution of the order of meter and realistically predict turbulence in the complex terrain of streets and buildings. The LES models comply with such requirements but the review showed that there was no free available LES model which could model the energy exchange in urban environment, i.e. the interaction of energy and air flows including effects of vegetation and different properties of urban surfaces and materials. Thus we decided to extend the existing LES model PALM by a new module USM (Urban Surface Model) which describes the most important energy exchanges in the urban environment. The validation of the model was done against observations obtained by IR camera in the course of heat wave episode in July 2015. Keywords: urban surface model; PALM; LES; urban modelling; turbulent flow; energy balance; radiative transfer model; UHI Available at various institutes of the ASCR
Vývoj a ověření nového modelu tepelných poměrů městského prostředí v jemném měřítku

Naším úkolem v rámci projektu UrbanAdapt bylo kvantifikovat dopady různých scénářů rozvoje města na kvalitu ovzduší a tepelný komfort obyvatel v prostoru uličních kaňonů. Z toho vyplývá potřeba ...

Resler, Jaroslav; Krč, Pavel; Belda, Michal; Juruš, Pavel; Benešová, N.; Lopata, J.; Vlček, O.; Damašková, D.; Eben, Kryštof; Derbek, P.; Maronga, P.; Kanani-Sühring, F.
Ústav informatiky, 2017

Modelové vyhodnocení urbanistických scénářů na kvalitu ovzduší a tepelný komfort v uliční síti
Resler, Jaroslav; Krč, Pavel; Belda, Michal; Juruš, Pavel; Benešová, N.; Vlček, O.; Damašková, D.; Eben, Kryštof; Derbek, P.
2017 - Czech
V projektu UrbanAdapt byl vyvinut nový model pro simulaci městského prostředí USM integrovaný do LES modelu PALM. Model umožňuje výpočet proudění vzduchu, radiačního záření, teplot vzduchu i materiálů země a zdí, kvality ovzduší a indexů MRT a PET ve velmi jemném měřítku. Pro výpočet scénářů byla ve spolupráci s IPR Praha jako pilotní vybrána oblast Holešovic v okolí křižovatky ulic Komunardů a Dělnická. Navržené scénáře zahrnovaly jak změny zástavby oblasti, zhodnocení různých typů výsadby zeleně a citlivostní studii na vliv barvy materiálů zdí, střech, silnic a chodníků. A new model for simulations of urban environment USM was developed and integrated into LES model PALM inside the project UrbanAdapt. The model allows simulations of air flow, radiation, air temperature and temperature of materials, air pollution and indices MRT and PET in fine resolution. The surrounding of a crossroad of the streets Komunardu and Delnicka in Praha-Holesovice was chosen as a pilot area in collaboration with IPR Prague. Studied scenarios included changes of housing development as well as assessment of different types of plant canopy and sensitivity studies of the colour of walls, roofs, streets and pavements. Keywords: USM; PALM; LES; UHI; air quality; development scenarios Available at various institutes of the ASCR
Modelové vyhodnocení urbanistických scénářů na kvalitu ovzduší a tepelný komfort v uliční síti

V projektu UrbanAdapt byl vyvinut nový model pro simulaci městského prostředí USM integrovaný do LES modelu PALM. Model umožňuje výpočet proudění vzduchu, radiačního záření, teplot vzduchu i materiálů ...

Resler, Jaroslav; Krč, Pavel; Belda, Michal; Juruš, Pavel; Benešová, N.; Vlček, O.; Damašková, D.; Eben, Kryštof; Derbek, P.
Ústav informatiky, 2017

Application and Misapplication of the Czechoslovak STP Cipher During WWII - Report on an Unpublished Manuscript
Porubský, Štefan
2017 - English
Keywords: STP cipher; Josef Růžek; Karol Cigáň; František Moravec; Czechoslovak military cryptography; Word War II Available on request at various institutes of the ASCR
Application and Misapplication of the Czechoslovak STP Cipher During WWII - Report on an Unpublished Manuscript

Porubský, Štefan
Ústav informatiky, 2017

Robust Regression Estimators: A Comparison of Prediction Performance
Kalina, Jan; Peštová, Barbora
2017 - English
Regression represents an important methodology for solving numerous tasks of applied econometrics. This paper is devoted to robust estimators of parameters of a linear regression model, which are preferable whenever the data contain or are believed to contain outlying measurements (outliers). While various robust regression estimators are nowadays available in standard statistical packages, the question remains how to choose the most suitable regression method for a particular data set. This paper aims at comparing various regression methods on various data sets. First, the prediction performance of common robust regression estimators are compared on a set of 24 real data sets from public repositories. Further, the results are used as input for a metalearning study over 9 selected features of individual data sets. On the whole, the least trimmed squares turns out to be superior to the least squares or M-estimators in the majority of the data sets, while the process of metalearning does not succeed in a reliable prediction of the most suitable estimator for a given data set. Keywords: robust estimation; linear regression; prediction; outliers; metalearning Available at various institutes of the ASCR
Robust Regression Estimators: A Comparison of Prediction Performance

Regression represents an important methodology for solving numerous tasks of applied econometrics. This paper is devoted to robust estimators of parameters of a linear regression model, which are ...

Kalina, Jan; Peštová, Barbora
Ústav informatiky, 2017

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