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11. Maximizing the Bregman divergence from a Bregman family

Creator:
Rauh, Johannes
Format:
print, bez média, and svazek
Type:
model:article and TEXT
Subject:
optimalizace, optimization, exponential family, relative entropy, Bregman divergence, 23, and 007
Language:
English
Description:
The problem to maximize the information divergence from an exponential family is generalized to the setting of Bregman divergences and suitably defined Bregman families., Johannes Rauh., and Obsahuje bibliografické odkazy
Rights:
http://creativecommons.org/publicdomain/mark/1.0/ and policy:public

12. Metoda kvantitativního vyhodnocování interferenčního pole pomocí korelace mezi měřeným a virtuálním interferogramem

Creator:
Novák, Jiří, Novák, Pavel, Mikš, Antonín, and Pokorný, Petr
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
optical metrology, interferometry, surface topography, evaluation methods, optimization, correlation, optická metrologie, interferometrie, měření tvaru ploch, vyhodnocovací metody, optimalizace, and korelace
Language:
Czech
Description:
This work describes a quantitative evaluation of interference patterns applied for testing of optical surfaces. The proposed method is based on the correlation between measured and virtual (nominal) interferograms and employment of mathematical nonlinear optimization. In contrast to most of common phase evaluation methods the proposed method does not need a detailed analysis of the interference patterns and phase unwrapping. The deviation of the measured surface from its nominal shape is modeled using a suitable function with unknown parameters, which are calculated by optimization of the merit function. The merit function is the correlation coefficient between measured and nominal interferogram, which characterizes the similarity of both interferograms. The functionality of the method was verified both by computer simulations and practical experiments. The method is applicable for the interferometric testing of flat, spherical and aspherical surfaces. and V práci je popsána metoda kvantitativního vyhodnocování interferenčního pole při kontrole tvaru optických ploch. Navržená metoda využívá korelace mezi měřeným a virtuálním (nominálním) interferogramem a matematických metod nelineární optimalizace. Na rozdíl od většiny běžně používaných metod nevyžaduje navržená metoda detailní analýzu interferenčního pole a odstranění nespojitostí fázových hodnot (tzv. phase unwrapping). Odchylka kontrolované plochy od jejího nominálního tvaru je modelována pomocí vhodné funkce s neznámými parametry, které jsou získány optimalizací meritní funkce. Za meritní funkci je zvolen korelační koeficient mezi měřeným a virtuálním (nominálním) interferogramem, který charakterizuje podobnost obou interferogramů. Funkčnost metody byla ověřena jak pomocí počítačových simulací, tak i na reálných případech měření. Metoda je použitelná pro interferometrickou kontrolu rovinných, sférických i asférických ploch.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

13. Modelirovanije i optimizacija dopplerovskich nabljudenij ISZ

Creator:
Gergov, Ca. and Georgijev, N.
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
Doppler satellite observations, modelling, and optimization
Language:
Czech
Description:
A model experimental investigation of the accuracy of ground station coordinates, determined by Doppler satellite observations is made, depending on the number of passes, satellite altitude, orbit inclination, frequency of Doppler transmitter, intervals of Doppler counts, etc. Using satellite pases at altitudes of 1000, 3000 a 5000 km, optimization of the Doppler observations is also achieved.
Rights:
http://creativecommons.org/publicdomain/mark/1.0/ and policy:public

14. Noise analysis and optimization of gearboxes

Creator:
Hajžman, Michal and Zeman, Vladimír
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
vibrations, noise, optimization, gearbox, and modal synthesis method
Language:
English
Description:
Gearboxes and similar machines containing rotating parts are complex systems with complicated structure and couplings. Generally they can be decomposed into more simple subsystems. These subsystems are usually rotating shafts with gears joined by gear couplings and housing coupled with rotating shafts by bearings. The paper is aimed at the mathematical modelling of gearboxes with spur helical gears considered including their interior rotating shaft system and housing. The used bearing model respects real number of rolling elements and roller contact forces acting between the journals and the outer housing. The model of a complete gearbox is created using the modal synthesis method. The kinematic transmission errors in gear couplings are viewed as sources of excitation. Vibration and noise analysis of the gearbox housing is performed by means of the created model. Four types of objective functions suitable for optimization from the radiated noise point of view are proposed. The presented methodology is applied to the simple test-gearbox. and Obsahuje seznam literatury
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

15. Notes to optimization of solar engine

Creator:
Stojan, Petr
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
endoreversible thermodynamics, heat engine, solar collector, solar energy, and optimization
Language:
English
Description:
Solar engine is discussed as integration of solar collector with linear heat loss and Curzon-Ahlborn engine is considered. This simple endoreversible model is used to discuss some applications of results of endoreversible heat engine in the field of solar engine. Optimum operating temperature of the solar collector and relevant maximum overall efficiency of solar engine is calculated, the results being compared with those by the models where Carnot and Curzon-Ahlborn efficiences were used. Conclusions obtained for endoreversible model are used for simple optimal design of solar engine. The size of heat engine for a given solar collector is optimized. The investment costs of solar collector and heat engine per unit of output power are used as optimization criterion. and Obsahuje seznam literatury
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

16. Numerical optimization of the capacitive micro-switch

Creator:
Kovács, Ádám
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
capacitive micro-switch, MEMS, FEM, and optimization
Language:
English
Description:
The paper deals with design optimization of a capacitive micromachined switch consisting of a thin membrane suspended over a central conductor. The aim is to achieve as small necessary electrostatic pull-in force as possibble while ensuring fast switching. Optimum parameters are searched using fast linear and nonlinear beam models verified by the finite element method. and Obsahuje seznam literatury
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

17. On precision of stochastic optimization based on estimates from censored data

Creator:
Volf, Petr
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
optimization, censored data, product-limit estimate, and consistency
Language:
English
Description:
In the framework of a stochastic optimization problem, it is assumed that the stochastic characteristics of optimized system are estimated from randomly right-censored data. Such a case is frequently encountered in time-to-event or lifetime studies. The analysis of precision of such a solution is based on corresponding theoretical properties of estimated stochastic characteristics. The main concern is to show consistency of optimal solution even in the random censoring case. Behavior of solutions for finite data sizes is studied with the aid of randomly generated example.
Rights:
http://creativecommons.org/publicdomain/mark/1.0/ and policy:public

18. On quantile optimization problem based on information from censored data

Creator:
Petr
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
optimization, censored data, product-limit estimator, empirical quantile, and newsvendor problem
Language:
English
Description:
Stochastic optimization problem is, as a rule, formulated in terms of expected cost function. However, the criterion based on averaging does not take in account possible variability of involved random variables. That is why the criterion considered in the present contribution uses selected quantiles. Moreover, it is assumed that the stochastic characteristics of optimized system are estimated from the data, in a non-parametric setting, and that the data may be randomly right-censored. Therefore, certain theoretical results concerning estimators of distribution function and quantiles under censoring are recalled and then utilized to prove consistency of solution based on estimates. Behavior of solutions for finite data sizes is studied with the aid of randomly generated example of a newsvendor problem.
Rights:
http://creativecommons.org/publicdomain/mark/1.0/ and policy:public

19. Optimal PPF controller for multimodal vibration suppression

Creator:
Fenik, Štefan and Starek, Ladislav
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
vibration, suppression, PPF control, root-locus method, optimization, and piezoactuator
Language:
English
Description:
Positive Position Feedback (PPF) is one of the most attractive vibration control method due to its stability and ease of implementation. On the other hand, low robustness makes the PPF design more complicated in multimodal control case. It is known that a little change in optimal parameters setup, especially the change in controller frequency, can strongly degrade the control effort. Thus knowing a good approximation of optimal PPF parameters can be very helpful in practical implementations and simplified analytical relations between optimal parameters and modal properties of the structure are inevitable for efficient control design. In this paper derivation of such relations is introduced, based on simplified transfer function of controlled structure. Furthermore influence of the parallel PPF controllers in multimodal vibration suppression is analyzed and formulae for optimal parameters updating are suggested. Optimal multimodal PPF control design is demonstrated on experimental example of vibration suppression of beam structure. and Obsahuje seznam literatury
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

20. Optimal tuning of the two-degree-of-freedom system

Creator:
Bach, Pavel
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
machine tool, chatter, stability, performance, and optimization
Language:
English
Description:
Performance of any machine tool is, under certain technological conditions, limited by chatter, which occurs during machining. The limit between machining without and with chatter is called limit of stability. It is expressed by so called stable depth of cut, which is defíned under certain conditions. The article deals with the investigation of optimal modal parameters for machine tool models. The criterion for this optimum is the highest limit of stability.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public