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Representations of Bayesian Networks by Low-Rank Models
Tichavský, Petr; Vomlel, Jiří
2018 - English
Conditional probability tables (CPTs) of discrete valued random variables may achieve high dimensions and Bayesian networks defined as the product of these CPTs may become intractable by conventional methods of BN inference because of their dimensionality. In many cases, however, these probability tables constitute tensors of relatively low rank. Such tensors can be written in the so-called Kruskal form as a sum of rank-one components. Such representation would be equivalent to adding one artificial parent to all random variables and deleting all edges between the variables. The most difficult task is to find such a representation given a set of marginals or CPTs of the random variables under consideration. In the former case, it is a problem of joint canonical polyadic (CP) decomposition of a set of tensors. The latter fitting problem can be solved in a similar manner. We apply a recently proposed alternating direction method of multipliers (ADMM), which assures that the model has a probabilistic interpretation, i.e., that all elements of all factor matrices are nonnegative. We perform experiments with several well-known Bayesian networks.\n\n
Keywords:
canonical polyadic tensor decomposition; conditional probability tables; marginal probability tables
Fulltext is available at external website.
Representations of Bayesian Networks by Low-Rank Models
Conditional probability tables (CPTs) of discrete valued random variables may achieve high dimensions and Bayesian networks defined as the product of these CPTs may become intractable by conventional ...
Risk-sensitive and Mean Variance Optimality in Continuous-time Markov Decision Chains
Sladký, Karel
2018 - English
In this note we consider continuous-time Markov decision processes with finite state and actions spaces where the stream of rewards generated by the Markov processes is evaluated by an exponential utility function with a given risk sensitivitycoefficient (so-called risk-sensitive models). If the risk sensitivity coefficient equals zero (risk-neutral case) we arrive at a standard Markov decision process. Then we can easily obtain necessary and sufficient mean reward optimality conditions and the variability can be evaluated by the mean variance of total expected rewards. For the risk-sensitive case, i.e. if the risk-sensitivity coefficient is non-zero, for a given value of the risk-sensitivity coefficient we establish necessary and sufficient optimality conditions for maximal (or minimal) growth rate of expectation of the exponential utility function, along with mean value of the corresponding certainty equivalent. Recall that in this case along with the total reward also its higher moments are taken into account.
Keywords:
continuous-time Markov decision chains; exponential utility functions; certainty equivalent; mean-variance optimality; connections between risk-sensitive and risk-neutral optimality
Fulltext is available at external website.
Risk-sensitive and Mean Variance Optimality in Continuous-time Markov Decision Chains
In this note we consider continuous-time Markov decision processes with finite state and actions spaces where the stream of rewards generated by the Markov processes is evaluated by an exponential ...
Proceedings of the 11th Workshop on Uncertainty Processing
Kratochvíl, Václav; Vejnarová, Jiřina
2018 - English
The Workshop on Uncertainty Processing, better known under its abbreviation WUPES, celebrates its 30-year anniversary this year. In 1988, when the first Workshop took place, Czechoslovakia was still a communist country and a part of the Soviet bloc. Since then, many things have changed. For example, Czechoslovakia no longer exists as a country (because in 1993 it was peacefully split into two independent countries - Czechia and Slovakia). From this perspective, it is hard to believe that we have several participants who have attended most workshops in the the thirty-year history of WUPES. As of now, the Program Committee has accepted, based on the extended abstracts, 21 papers to be presented at the Workshop, and 19 out of them are to be published in the present Conference Proceedings. These papers cover diverse topics, such as information processing, decision making, and data analysis, but what is common to most of them is that they are related to uncertainty calculus - Bayesian Networks, Dempster-Shafer Theory, Belief Functions, Probabilistic Logic, Game Theory, etc.
Keywords:
uncertainty processing; artificial intelligence; bayesian networks
Fulltext is available at external website.
Proceedings of the 11th Workshop on Uncertainty Processing
The Workshop on Uncertainty Processing, better known under its abbreviation WUPES, celebrates its 30-year anniversary this year. In 1988, when the first Workshop took place, Czechoslovakia was still a ...
Internet věcí v praxi
Zajíček, Milan
2018 - Czech
Předpokladem práce s mikrokontrolery je pochopení základních principů jejich komunikace s okolím a možné způsoby jejich programování. Mikrokontroler ESP8266 je jedním z nejznámějších obvodů používaných v aplikacích pro internet věcí. Jednou z vývojových platforem, která se o ESP8266 opírá, je modulární systém Wemos D1 mini, který umožňuje přímou komunikaci s PC prostřednictvím USB portu a disponuje dostatkem vstupních a výstupních periférií pro stavbu jednoduchých IoT zařízení. Pro programování je použito vývojové prostředí ArduinoIde. Tento tutorial provede úplného začátečníka od instalace software až k sestavení termostatu pro spínání silové zátěže. Prerequisite of working with microcontrollers is understanding the basic principles of their communication with the environment and possible ways of their programming. The ESP8266 microcontroller is one of the most popular chips used in Internet of things applications. Wemos D1 mini is one of development platforms behind the ESP8266,which allows direct communication with the PC via a USB port and has plenty of input and output peripherals to build simple IoT devices. The ArduinoIde development environment is used for programming. The thermostatic switch is made as a result of this tutorial.
Keywords:
microcontrollers; Internet of things; ESP8266
Fulltext is available at external website.
Internet věcí v praxi
Předpokladem práce s mikrokontrolery je pochopení základních principů jejich komunikace s okolím a možné způsoby jejich programování. Mikrokontroler ESP8266 je jedním z nejznámějších obvodů ...
DCTOOL-A5
Bakule, Lubomír; Papík, Martin; Rehák, Branislav
2018 - English
DCTOOL-A5 presents draft of a manuscript, which is intended to be submitted for publication. This report presents a new method for the decentralized event-triggered control design for large-scale uncertain systems. The results are formulated and proved in terms of linear matrix inequalities. Two design problems are solved: For interconnected systems without any quantization and for interconnected systems with local logarithmic quantizers. Results are illustrated by an example.
Keywords:
decentralized event-triggered control; networked control systems; large scale complex systems
Available at various institutes of the ASCR
DCTOOL-A5
DCTOOL-A5 presents draft of a manuscript, which is intended to be submitted for publication. This report presents a new method for the decentralized event-triggered control design for large-scale ...
Multi-Objective Optimization Problems with Random Elements - Survey of Approaches
Kaňková, Vlasta
2018 - English
Many economic and financial situations depend simultaneously on a random element and a decision parameter. Mostly, it is possible to influence the above mentioned situation only by an optimization model depending on a probability measure. This optimization problem can be static (one-stage), dynamic with finite or infinite horizon, single-objective or multi-objective. We focus on one-stage multi-objective problems corresponding to applications those are suitable to evaluate simultaneously by a few objectives. The aim of the contribution is to give a survey of different approaches (as they are known from the literature) of the above mentioned applications. To this end we start with well-known mean-risk model and continue with other known approaches. Moreover, we try to complete every model by a suitable application. Except an analysis of a choice of the objective functions type we try to discuss suitable constraints set with respect to the problem base, possible investigation and relaxation. At the end we mention properties of the problem in the case when the theoretical „underlying“ probability measure is replaced by its „deterministic“ or „stochastic“ estimate.
Keywords:
multi-objective optimization problems; random element; mean-risk model; deterministic approach; stochastic multi-objective problems; constraints set; relaxation
Fulltext is available at external website.
Multi-Objective Optimization Problems with Random Elements - Survey of Approaches
Many economic and financial situations depend simultaneously on a random element and a decision parameter. Mostly, it is possible to influence the above mentioned situation only by an optimization ...
Analýza korozního poškození potrubí s proudící párou pomocí akustické emise: výsledky pro potrubí 6. odběru v EBO
Tichavský, Petr
2018 - Czech
V práci je studována akustická emise na potrubí s proudící párou, měřená v elektrárně Jaslovské Bohunice. V signálu vyhledáváme výrony akustické emise která amplitudově vyčnívají nad okolním signálem, a jejich relativní frekvence výskytu je považována za indikátor poškození potrubí. We studied acoustics emission of steem pipes from measurements from EBO. We counted frequency of sudden increases of the acoustics emission, which can be used as indicator of corosion demage of the pipes.
Keywords:
acoustic emission
Available at various institutes of the ASCR
Analýza korozního poškození potrubí s proudící párou pomocí akustické emise: výsledky pro potrubí 6. odběru v EBO
V práci je studována akustická emise na potrubí s proudící párou, měřená v elektrárně Jaslovské Bohunice. V signálu vyhledáváme výrony akustické emise která amplitudově vyčnívají nad okolním signálem, ...
On attempts to characterize facet-defining inequalities of the cone of exact games
Studený, Milan; Kroupa, Tomáš; Kratochvíl, Václav
2018 - English
The sets of balanced, totally balanced, exact and supermodular games play an important role in cooperative game theory. These sets of games are known to be polyhedral cones. The (unique) non-redundant description of these cones by means of the so-called facet-defining inequalities is known in cases of balanced games and supermodular games, respectively. The facet description of the cones of exact games and totally balanced games are not known and we present conjectures about what are the facet-defining inequalities for these cones. We introduce the concept of an irreducible min-balanced set system and conjecture that the facet-defining inequalities for the cone of totally balanced games correspond to these set systems. The conjecture concerning exact games is that the facet-defining inequalities for this cone are those which correspond to irreducible min-balanced systems on strict subsets of the set of players and their conjugate inequalities. A consequence of the validity of the conjectures would be a novel result saying that a game m is exact if and only if m and its reflection are totally balanced.
Keywords:
exact game; extremity; irreducible; balanced
Fulltext is available at external website.
On attempts to characterize facet-defining inequalities of the cone of exact games
The sets of balanced, totally balanced, exact and supermodular games play an important role in cooperative game theory. These sets of games are known to be polyhedral cones. The (unique) non-redundant ...
Solution of Emission Management Problem
Šmíd, Martin; Kozmík, Václav
2018 - English
Optimal covering of emissions stemming from random production is a multistage stochastic programming problem. Solving it in a usual way - by means of deterministic equivalent - is possible only given an unrealistic approximation of random parameters. There exists an efficient way of solving multistage problems - stochastic dual dynamic programming (SDDP), however, it requires the inter-stage independence of random parameters, which is not the case which our problem. In the paper, we discuss a modified version of SDDP, allowing for some form of interstage dependence.
Keywords:
Multi-stage stochastic programming; Emission management; SDDP; time dependence
Fulltext is available at external website.
Solution of Emission Management Problem
Optimal covering of emissions stemming from random production is a multistage stochastic programming problem. Solving it in a usual way - by means of deterministic equivalent - is possible only given ...
Platební regulační mechanismus jako zdroj zvyšování platů ve zdravotnictví
Grim, Jiří
2018 - Czech
Princip zdravotního pojištění předpokládá, že se pacient v případě potřeby obrátí na lékaře, který mu poskytne odbornou pomoc, přičemž výkon lékaře, výdaje za léky a doplňující vyšetření proplácí zdravotní pojišťovna. Výsledkem je spontánní nárůst nákladů zdravotní péče u nás dobře známý z devadesátých let. Je zřejmé, že v systému, ve kterém o poskytnuté zdravotní péči musí rozhodovat lékaři v kontaktu s pacienty a její náklady následně hradí zdravotní pojišťovny, chybí záporná zpětná vazba, která by působila proti růstu nákladů. Důsledkem této hrubé systémové chyby je trvalý tlak na zvyšování výdajů za poskytnutou zdravotní péči a hrozící platební neschopnost nutí zdravotní pojišťovny zavádět regulační opatření k omezení růstu nákladů. The principle of health insurance presupposes that the patient will contact a doctor who will provide him / her with professional help, whereby the doctor, medical expenses and additional examinations are paid by the health insurance company. The result is a spontaneous increase in health care costs well-known in the nineties. It is clear that there is no negative feedback in the system where the healthcare provided must be made by doctors in contact with patients and its costs are being covered by health insurance companies. As a result of this gross systemic error, there is a continuing pressure to increase healthcare spending and imminent insolvency forces the health insurers to introduce regulatory measures to curb the cost increase.
Keywords:
Medical care; finance; regulation mechanismus
Fulltext is available at external website.
Platební regulační mechanismus jako zdroj zvyšování platů ve zdravotnictví
Princip zdravotního pojištění předpokládá, že se pacient v případě potřeby obrátí na lékaře, který mu poskytne odbornou pomoc, přičemž výkon lékaře, výdaje za léky a doplňující vyšetření proplácí ...
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