|
|
Two Composition Operators for Belief Functions Revisited
Jiroušek, Radim ; Kratochvíl, Václav ; Shenoy, P. P.
In probability theory, compositional models are as powerful as Bayesian networks. However, the relation between belief-function graphical models and the corresponding compositional models is much more complicated due to several reasons. One of them is that there are two composition operators for belief functions. This paper deals with their main properties and presents sufficient conditions under which they yield the same results.
|
|
|
Computing the Decomposable Entropy of Graphical Belief Function Models
Jiroušek, Radim ; Kratochvíl, Václav ; Shenoy, P. P.
In 2018, Jiroušek and Shenoy proposed a definition of entropy for Dempster-Shafer (D-S) belief functions called decomposable entropy. Here, we provide an algorithm for computing the decomposable entropy of directed graphical D-S belief function models. For undirected graphical belief function models, assuming that each belief function in the model is non-informative to the others, no algorithm is necessary. We compute the entropy of each belief function and add them together to get the decomposable entropy of the model. Finally, the decomposable entropy generalizes Shannon’s entropy not only for the probability of a single random variable but also for multinomial distributions expressed as directed acyclic graphical models called Bayesian networks.
|
|
|
On Experimental Part of Behavior under Ambiguity
Kratochvíl, Václav ; Jiroušek, Radim
People are risk-takers, risk-averse, or neutral. In the literature, one can find experiments illustrating the ambiguity aversion of human decision-makers. Recently, a personal coefficient of ambiguity aversion has been introduced. We have decided to measure the coefficient and its stability during the time. In this paper, we describe performed experiments and their structure to launch a discussion of possible design weaknesses or to suggest other methods of measuring it.
|
|
|
Preliminary Results from Experiments on the Behavior under Ambiguity
Jiroušek, Radim ; Kratochvíl, Václav
In the literature, some experiments proving that human decision-makers manifest an ambiguity aversion are described. In our knowledge, no one has studied a possibility to measure the strength of this aversion and its stability in time. The research, we have recently started to realize should find out answers to these and similar questions. The goal of this paper is to present some preliminary results to initiate a discussion that should help us to modify either the process of data collection and/or the analysis of the collected data.
|
|
|
Proceedings of the 22nd Czech-Japan Seminar on Data Analysis and Decision Making
Inuiguchi, M. ; Jiroušek, Radim ; Kratochvíl, Václav
The history of the series of the Czech-Japan seminars started in 1999. Thus, it is now more than 20 years ago when the first Czech-Japan Seminar on Data Analysis and Decision Making under Uncertainty was held in JAIST, Hokuriku. Since that time, these seminars were held in eleven splendid places in Japan, offering the Czech participants possibility to discover different parts of the Japanese islands. In reciprocity, it was the goal of the Czech partners organizing the past ten seminars to show the beauty of Czechia to Japanese colleagues, who, during the long Japan–Czech cooperation, became our close friends. This is also why the seminar has never visited one place two times.
|
|
|
Causality and Intervention in Business Process Management
Bína, V. ; Jiroušek, Radim
The paper presents an algebraic approach to the modeling of causality in systems of stochastic variables. The methodology is based on an operator of a composition that provides the possibility of composing a multidimensional distribution from low-dimensional building blocks taking advantage of the dependence structure of the problem variables. The authors formally define and demonstrate on a hypothetical example a surprisingly elegant unifying approach to conditioning by a single variable and the evaluation of the effect of an intervention. Both operations are realized by the composition with a degenerated distribution and differ only in the sequence in which the operator of the composition is performed.
|
|
|
Avoiding overfitting of models: an application to research data on the Internet videos
Jiroušek, Radim ; Krejčová, I.
The problem of overfitting is studied from the perspective of information theory. In this context, data-based model learning can be viewed as a transformation process, a process transforming the information contained in data into the information represented by a model. The overfitting of a model often occurs when one considers an unnecessarily complex model, which usually means that the considered model contains more information than the original data. Thus, using one of the basic laws of information theory saying that any transformation cannot increase the amount of information, we get the basic restriction laid on models constructed from data: A model is acceptable if it does not contain more information than the input data file.
|
|
|
O problémech seřazení při řízení servisních operací
Lín, Václav ; Vomlel, Jiří (advisor) ; Jiroušek, Radim (referee) ; Kouba, Zdeněk (referee) ; Ottosen, Thorsten Jorgen (referee)
The subject of the thesis belongs to the field of operations management. We deal with sequencing problems arising when there are multiple repair operations available to fix a broken man-made system and the true cause of the system failure is uncertain. It is assumed that the system is formally described by a probabilistic model, and it is to be repaired by a sequence of troubleshooting operations designed to identify the cause of the malfunction and fix the system. The challenge is to find a course of repair which has minimal expected cost. We study several variants of the problem proposed in the literature. We analyze computational complexity of those variants, apply integer linear programming to one variant of the problem, and examine the relation to machine scheduling.
|
|
|
Manažerské propočty z hlediska logiky, analytické mikroekonomie a dalších teoretických disciplin
Hašková, Simona ; Jiroušek, Radim (advisor) ; Mrkvička, Tomáš (referee) ; Peregrin, Jaroslav (referee) ; Volf, Petr (referee)
It is no secret that 'managerial' solutions are not, on average, nearly as reliable as 'technical' solutions. The focus of this work is to clarify the reasons why this is so, and to seek ways to increase the reliability of managerial solutions. The causes of this situation are both subjective (human factor failure), which can be influenced, and objective (complexity of the problem, the specifics of human behaviour, etc.) that can be only minimally influenced. Significant subjective causes at work were identified as: a. cognitive distortions at the mental level of thinking of the problem solvers; b. deficiencies in making inference and drawing conclusions; c. incorrect argumentation. There are two ways to reduce these causes: 1. cultivation of managerial thinking of the problem solvers; 2. the use of reserves in the implementation of approaches and tools of theoretical disciplines that already operate successfully elsewhere and are beneficial for managerial solutions. The first way deals with procedures for managerial solutions formulated in the language of the relevant discipline (the language of management), expressed by natural language and the chain of formulas (calculations) and visual (graphic) tools in the form of managerial decision trees, diagrams and charts with the rules of 'managerial logic'. This is generally defined as a set of approaches, tools, methods and skills needed for credible justification when solving managerial problems. Specifically it deals with: - the 'case-based reasoning' approach, which aims at finding the best point of view on a given problem and analysing all considered aspects within its context step-by-step in detail; - translating the tools and methods of modern logic (especially its intuitionistic version) from the language of logic into the language of management taking into account the factual content of expressive means of the language of management including the ability of their effective application; - respecting the principles of rational and ethical argumentation within managerial solutions. The second way circumvents managerial solution procedures by recasting the managerial task to the task of a scientific discipline (logic, game theory, etc.) and derives the correct result therein. In this context we talk about the use of knowledge of theoretical disciplines in management. Both of these ways are demonstrated in the work in a number of illustrative examples and the annexed case studies addressing the specific tasks of managerial practice.
|
|
|
Eye-tracking methods and use of DIY (do it yourself) devices a open-source software
Bajer, Ondřej ; Novák, Michal (advisor) ; Jiroušek, Radim (referee)
The main Target is to compare commercial device for eye tracking analysis with a device made by DIY (Do it yourself) in the chosen environment. The work includes basic analysis methods Eye tracking. It offers a list of devices suitable for comparison, or marginally list of alternatives. A significant part of the thesis deals with construction of DIY tracker. The comparison is made on the basis of experimental measurements of commercial device and DIY device. The result is that in the selected conditions we can DIY device used because it is comparable with the commercial product. One of the sub-chapters is devoted also to question of the application DIY. In the last part was used the DIY device to analyse on realistic object. Specifically outdoor - print ads of Zubr brewery with evaluation.
|
guest ::
RSS feed.