Physiologically motivated multiplex Kuramoto model describes phase diagram of cortical activity

We derive a two-layer multiplex Kuramoto model from weakly coupled Wilson-Cowan oscillators on a cortical network with inhibitory synaptic time delays. Depending on the coupling strength and a phase shift parameter, related to cerebral blood flow and GABA concentration, respectively, we numerically identify three macroscopic phases: unsynchronized, synchronized, and chaotic dynamics. These correspond to physiological background-, epileptic seizure-, and resting-state cortical activity, respectively. We also observe frequency suppression at the transition from resting-state to seizure activity.Comment: 8 pages, 3 figure

Position and Perspectives of Small Farms with Respect to the Structure Development of Subsequent Vertical Link

The objective of the paper is to find out the position and perspectives of small farms’ production sales with respect to the structure development of subsequent vertical stage. Structure development is evaluated in terms of company’s size, which is defined according to the number of the persons employed. The analysis is based on the assumption that small farms are able to sell their production rather to small than big processors and the question is whether the small processors give stability and certainty for small farms. The paper deals with chosen commodity chains in the Czech Republic. As an example of the variability in the food industry there were chosen two processing sectors that are important processors of diverse commodity sources of production and with different structural characteristics which was mainly affected by divergent development during consolidation process in the Czech Republic. The main methodical approach is based on the share of value added which is as the indicator of performance showing the rate of production factor usage (input) on the final production (output) and on the turnover produced. Furthermore other indicators of financial situation are evaluated by the Spider Analysis of particular size groups of processors.meat and beverages sectors, size structure, small food processors, Livestock Production/Industries,

Utilization of customer satisfaction measurement in Czech tourism

The paper deals with describing the method of satisfaction measurement as a one of marketing techniques used for detecting visitors´ satisfaction in tourist regions in the Czech Republic. In the treatise, we try to analyse visitors´ satisfaction with twenty four partial factors affecting total satisfaction. In the theoretical part of the paper, there are described methodological approaches to satisfaction measurement and presented various methods for satisfaction measurement with focus on the Satisfaction Pyramid method which is also used in the field part. Other presented methods are Customer Satisfaction Index, European Customer Satisfaction Model, Importance-Satisfaction Matrix, SERVQUAL Concept and KANO Model. Data have been collected all over the Czech Republic in years 2013, and 2014 twice every year. In the field part there are presented calculations of data and described total satisfaction, Satisfaction Index and partial satisfactions as well as level of satisfaction by tourist regions and the most important factors influencing total satisfaction, which are accommodation availability and information about region.peer-reviewe

Perception of food quality by consumers : literature review

This study aims to analyse the elements which contribute most to defining the quality of a food product. Geographical provenance, age, propensity to read the label on products, scientific knowledge and self-assessment of knowledge on food safety-related issues emerged as the main differences between the two groups. The perception of quality appears to affect purchase decisions and dietary patterns. The description of the consumer groups who use the same elements to define quality provided a useful insight into consumer choices and potential risk-exposure behaviours. The study of these aspects is therefore relevant for designing effective and targeted communication actions, not only for companies but also for public institutions in charge of safeguarding public health.peer-reviewe

Today situation in online buying of food products in the Czech Republic

Actual news from abroad confirm that online buying is very frequent also in FMCG business. In the Czech Republic, iTesco.cz Rohlik.cz, Košík.cz and ZMarket.cz are pioneers in this area. The newest trends are mapped by professional media, especially the digital ones. Although online buying in the FMCG segment has not reached so significant market shares as in the United Kingdom or in France, this year the situation is expected to be changed dramatically. The iTesco concept prepares expansion in new regions and Rohlík.cz, already operating three quarters of year in Prague and surroundings, acquires new customers every week, Košík.cz has already started too and Koloniál.cz starts the sales at the beginning of the third quarter of 2015. The aim of the article is to present current situation in the area of online food products retailing in the Czech Republic and to outline the future development trends. This is a comprehensive study dealing with description of Czech online food products market and could be a first step for further research.peer-reviewe

Creating Full Individual-level Location Timelines from Sparse Social Media Data

In many domain applications, a continuous timeline of human locations is critical; for example for understanding possible locations where a disease may spread, or the flow of traffic. While data sources such as GPS trackers or Call Data Records are temporally-rich, they are expensive, often not publicly available or garnered only in select locations, restricting their wide use. Conversely, geo-located social media data are publicly and freely available, but present challenges especially for full timeline inference due to their sparse nature. We propose a stochastic framework, Intermediate Location Computing (ILC) which uses prior knowledge about human mobility patterns to predict every missing location from an individual's social media timeline. We compare ILC with a state-of-the-art RNN baseline as well as methods that are optimized for next-location prediction only. For three major cities, ILC predicts the top 1 location for all missing locations in a timeline, at 1 and 2-hour resolution, with up to 77.2% accuracy (up to 6% better accuracy than all compared methods). Specifically, ILC also outperforms the RNN in settings of low data; both cases of very small number of users (under 50), as well as settings with more users, but with sparser timelines. In general, the RNN model needs a higher number of users to achieve the same performance as ILC. Overall, this work illustrates the tradeoff between prior knowledge of heuristics and more data, for an important societal problem of filling in entire timelines using freely available, but sparse social media data.Comment: 10 pages, 8 figures, 2 table

Generative technologies for model animation in the TopCased platform

International audienceDomain Specific Modeling Languages (DSML) are more and more used to handle high level concepts, and thus bring complex software development under control. The increasingly recurring definition of new languages raises the problem of the definition of support tools such as editor, simulator, compiler, etc. In this paper we propose generative technologies that have been designed to ease the development of model animation tools inside the TopCased platform. These tools rely on the automatically generated graphical editors of TopCased and provide additional generators for building model animator graphical interface. We also rely on an architecture for executable metamodel (i.e., the TopCased model execution metamodeling pattern) to bind the behavioral semantics of the modeling language. These tools were designed in a pragmatic manner by abstracting the various model animators that had been hand-coded in the TopCased project, and then validated by refactoring these animators

Analysis of voltage dips in the process of paper production

Naponski propadi u tvornicama papira uzrokuju značajne probleme. Kada do navedenog problema dođe pogon za proizvodnju papira može biti u dugotrajnom zastoju. Zbog toga se traže metode za sprječavanje naponskih propada. Rad proučava tvornicu papira, naponske propade, te rješenja za smanjenje ili ukidanje problema naponskih propada. Postoji velik broj metoda za sprječavanje ili ublažavanje problema naponskih propada. U radu ih je navedeno petnaest. Određene metode djeluju odmah ali samo kratko vrijeme, neke djeluju sa zakašnjenjem, a neke u potpunosti suzbijaju problem. Metoda za borbu s naponskim propadima se bira na temelju kvalitete elektroenergetskog sustava, pozicije u mreži, učestalosti naponskih propada, troškova koje stvaraju naponski propadi, te na temelju troškova koje će stvarati metoda za suzbijanje istih. Na temelju svega navedenog svaka tvornica treba odlučiti koja metoda im je najprihvatljivija.Voltage sag in a paper mill plant causes significant problems. When it comes to that particular problem the whole plant for the paper production must stop with production and clean itself. Beacause of that reason, we search for methods to prevent voltage collapse. This thesis examines the paper factory, voltage dips and solutions for the reduction or elimination of these problems. There are a number of methods to prevent or mitigate the problem of voltage dips. In this thesis it has been noted fifteen of them. Certain methods perform immediately but only a short amount of time, then some of them perform with certain delays, while other methods fully combat the problem. The choice of method to combat the voltage sag depends primarily on the quality of the electric system, then it's position in the network, the frequency of voltage dips, the cost of generating voltage dips, and finally on neccessary costs required to create methods for combating them. Based on the statements above, it can be concluded that each particular factory should decide which method is suitable for them

Generalized Langevin Equations

Diese Arbeit ist wie folgt aufgebaut: Das erste Kapitel stellt verallgemeinerte Langevingleichungen als eine Familie von stochastischen Differential-Integralgleichungen vor, die mittels des Zwanzigschen Projektionsformalismus gewonnen werden. Ausgangspunkt ist ein statistisch-mechanisches Modell, das die Wechselwirkung eines makroskopischen Systems mit einem Wärmebad bestehend aus einer großen Zahl unabhängiger harmonischer Oszillatoren beschreibt. Die Kopplung zwischen System und Bad wird als linear in den Variablen des Wärmebades, aber beliebig in den Systemvariablen angenommen. Diese Struktur ermöglicht eine explizite Integration der Bewegungsgleichungen des Bades und damit eine geschlossene Form der Bewegungsgleichungen des Systems. Letztere werden durch die Annahme, dass die Badvariablen zu einem gewissen Anfangszeitpunkt gemäß einer kanonischen Verteilung verteilt sind, zu stochastischen Gleichungen. Im zweiten Kapitel werden die thermodynamischen und Markovschen Limiten verallgemeinerter Langevingleichungen studiert. Dabei werden einige Querverbindungen zwischen verallgemeinerten Langevingleichungen und stochastischen Differentialgleichungen hergestellt, deren nähere Untersuchung eine dankbare Aufgabe darstellt. Die letzten zwei Kapitel sind Teil des Anhangs und beschäftigen sich mit der Entwicklung der Theorie der schwachen Konvergenz in dem Maße, wie sie zum Verständnis der thermodynamischen Limiten im zweiten Kapitel benötigt wird. Bis auf sehr wenige Ausnahmen werden alle Beweise vollständig durchgeführt.This thesis is organized as follows: In chapter 1 generalized Langevin equations are presented as a class of stochastic differential-integral equations obtained by an application of the Zwanzig projection formalism. The starting point is a statistical mechanical model describing a macroscopic system that interacts with a heat bath consisting of a large number of independent harmonic oscillators. The coupling between system and bath is assumed to be linear in the bath variables, but arbitrary in the system variables. This allows for an explicit integration of the bath equations of motion yielding an effective equation for the system. Stochasticity is introduced by the assumption that at some initial time, the bath variables are drawn at random from a canonical distribution. In chapter 2 thermodynamic- and Markovian limits of generalized Langevin equations are studied. This investigation makes it possible to draw some interesting connections between generalized Langevin equations and stochastic differential equations and points in the direction of future research. The last two chapters constituting the appendix are dedicated to the formal development of convergence theorems for stochastic processes that are necessary to handle the thermodynamic limits discussed in chapter 2. Apart from very few exceptions, all proofs are explicitly carried out