The absolute gravity measurements are an important tool for reliable monitoring geodynamic phenomena. Based on the experience with the absolute gravimeter FG5#215 (gravimeter of the Center for Earth Dynamics Research), the accuracy of FG5 absolute gravimeters is presented in this study. The instrumental reproducibility of this meter is characterized by the value of 0.7 μGal. Discussed are important environmental effects on gravity measurements, such as atmospheric and hydrological effects, understanding of which is necessary for correct and reliable interpretation of the repeated absolute gravity measurements in geodynamics., Vojtech Pálinkáš, Jakub Kostelecký and Jaroslav Šimek., and Obsahuje bibliografii
River runoff is not only a crucial part of the global water cycle, but it is also an important source for hydropower and an essential element of water balance. This study presents a system-theory-based model for river runoff forecasting taking the Hailiutu River as a case study. The forecasting model, designed for the Hailiutu watershed, was calibrated and verified by long-term precipitation observation data and groundwater exploitation data from the study area. Additionally, frequency analysis, taken as an optimization technique, was applied to improve prediction accuracy. Following model optimization, the overall relative prediction errors are below 10%. The system-theory-based prediction model is applicable to river runoff forecasting, and following optimization by frequency analysis, the prediction error is acceptable.
According to John Broome, akrasia consists in a failure to intend to do something that one believes one ought to do, and such akrasia is necessarily irrational. In fact, however, failing to intend something that one believes one ought to do is only guaranteed to be irrational if one is certain of a maximally detailed proposition about what one ought to do; if one is uncertain about any part of the full story about what one ought to do, it could be perfectly rational not to intend to do something that one believes one ought to do. This paper seeks to remedy this problem, by proposing an anti-akrasia principle that covers cases of uncertainty (as well as cases of such complete certainty). It is argued that this principle is in effect the fundamental principle of practical rationality., Podle Johna Broome, akrasia spočívá v selhání v úmyslu udělat něco, co člověk věří, kdo by měl dělat, a takové akrasia nutně iracionální. Ve skutečnosti se však nedaří v úmyslu něco, co člověk věří, kdo by měl udělat, je zaručeno, že iracionální, pokud je jen jistá o maximálně podrobným tvrzením o tom, co kdo měl dělat; pokud si člověk není jistý, jakou část celého příběhu by měl udělat, mohlo by to být naprosto rozumné, kdybychom neměli v úmyslu dělat něco, co by člověk věřil. Tento dokument se snaží tento problém napravit tím, že navrhne protiarasiizásada, která se vztahuje na případy nejistoty (jakož i případy takové úplné jistoty). Tvrdí se, že tato zásada je ve skutečnosti základním principem praktické racionality., and Ralph Wedgwood
The information-theoretical entropy is an effective measure of uncertainty connected with an information source. Its transfer from the classical probabilistic information theory models to the fuzzy set theoretical environment is desirable and significant attempts were realized in the existing literature. Nevertheless, there are some open topics for analysis in the suggested models of fuzzy entropy - the main of them regard the formal aspects of the fundamental concepts. Namely their rather additive (i. e., probability-like) than monotonous (typical for fuzzy set theoretical models) structure. The main goal of this paper is to describe briefly the existing state of art, and to suggest and analyze alternative, more fuzzy set theoretical, approaches to the fuzzy entropy developed as a significant characteristic of the information sources, in the information-theoretical sense.
The authors analysed so-called light-cut method which is suitable for the quick and accurate measurement of the profile. The main attention is paid to mathematical methods of evaluation of the laser spot centre on a measured surface. A novel method of centre evaluation is based upon approximation of laser spot intensity distribution by polynomial of second order. This method gives the best results from the point of view of minimizing measurement uncertainty. and Autori analyzovali metódu svetelného rezu, ktorá je vhodná pre rýchle a presné meranie profilu. Hlavná pozornosť je venovaná matematickým metódam vyhodnotenia stredu laserovej stopy na meranom povrchu. Nový spôsob vyhodnotenia stredu je založený na aproximácii rozloženia intenzity laserovej stopy polynómom druhého rádu. Tento spôsob dáva najlepšie výsledky z hľadiska minimalizácie neistoty merania.
Fault tolerant control for uncertain systems with time varying state-delay is studied in this paper. Based on sliding mode controller design, a fault tolerant control method is proposed. By means of the feasibility of some linear matrix inequalities (LMIs), delay dependent sufficient condition is derived for the existence of a linear sliding surface which guarantees quadratic stability of the reduced-order equivalent system restricted to the sliding surface. A reaching motion controller, which can be seen as a fault tolerant controller, can retain the stability of the closed loop system in the present of uncertainties, disturbances and actuator fault is designed. A numerical simulation shows the effectiveness of the approach.
The measurement of information emitted by sources with uncertainty of random type is known and investigated in many works. This paper aims to contribute to analogous treatment of information connected with messages from other uncertain sources, influenced by not only random but also some other types of uncertainty, namely with imprecision and vagueness. The main sections are devoted to the characterization and quantitative representation of such uncertainties and measures of information produced by sources of the considered type.
In this paper, the robust counterpart of the linear fractional programming problem under linear inequality constraints with the interval and ellipsoidal uncertainty sets is studied. It is shown that the robust counterpart under interval uncertainty is equivalent to a larger linear fractional program, however under ellipsoidal uncertainty it is equivalent to a linear fractional program with both linear and second order cone constraints. In addition, for each case we have studied the dual problems associated with the robust counterparts. It is shown that in both cases, either interval or ellipsoidal uncertainty, the dual of robust counterpart is equal to the optimistic counterpart of dual problem.
The paper presents theoretical description of the focal length of optical system, in combination with the third-order aberration effect and the influence of the uncertainty of image point position. These phenomena have significant impact on the measurement of focal lengths. Afterwards, the methods realizing direct or indirect measurement of terms in equations for an ideal optical system are presented. The uncertainty description based on the law of variance propagation is derived as well. and Práce představuje teoretický popis termínu ohnisková vzdálenost optické soustavy, společně s vlivy aberací třetího řádu a vlivu nejistoty v určení polohy obrazového bodu, které mají výrazný dopad na měření hodnot ohniskových vzdáleností. Jsou dále představeny vybrané metody realizující přímé nebo nepřímé měření veličin ze vztahů pro zobrazení ideální optickou soustavou, společně srozborem nejistot, založeným na zákoně přenášení variancí.
The paper presents methods for measurement of the focal lengths of optical systems with the use of diffraction and interference of light and with the use of the detectors of wavefront parameters where the wavefronts pass through the tested optical system. The description of methods is supplemented by the description of uncertainty of measured focal length. and Práce představuje vybrané metody pro měření ohniskových vzdáleností optických soustav, které využívají difrakce a interference světla, a dále také detektorů parametrů vlnoploch prošlých testovanou optickou soustavou. Metody jsou doplněny rozborem nejistot výsledných měřených ohniskových vzdáleností.