On finite-difference approximations for normalized Bellman equations

A class of stochastic optimal control problems involving optimal stopping is considered. Methods of Krylov are adapted to investigate the numerical solutions of the corresponding normalized Bellman equations and to estimate the rate of convergence of finite difference approximations for the optimal reward functions.Comment: 36 pages, ArXiv version updated to the version accepted in Appl. Math. Opti

Rate of Convergence of Space Time Approximations for stochastic evolution equations

Stochastic evolution equations in Banach spaces with unbounded nonlinear drift and diffusion operators driven by a finite dimensional Brownian motion are considered. Under some regularity condition assumed for the solution, the rate of convergence of various numerical approximations are estimated under strong monotonicity and Lipschitz conditions. The abstract setting involves general consistency conditions and is then applied to a class of quasilinear stochastic PDEs of parabolic type.Comment: 33 page

Characteristics of stress-induced defects under positive bias in high-k/InGaAs stacks

The introduction of InGaAs as a channel material for complementary metal-oxide-semiconductor technology presents major challenges in terms of the characterization of the various defects that affect the performance and reliability. Understanding the generation of defects by constant voltage stresses is crucial in terms of their concentration profiles and energy levels. In particular, we want to understand the real nature of the defects responsible for the dispersion of C-V in strong accumulation. Here, we show that the degradation under positive bias of metal/Al2O3/n-InGaAs capacitors reveals two contributions depending on the temperature that affects the C-V curves in a different way. Based on features of stressed C-V curves, it is possible to estimate the onset point of the distribution of border traps near the midgap condition. The results suggest that these defects are strongly related to the characteristics of the InGaAs substrate.Fil: Palumbo, Félix Roberto Mario. Technion - Israel Institute of Technology; Israel. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Winter, R.. Technion - Israel Institute of Technology; IsraelFil: Krylov, I.. Technion - Israel Institute of Technology; IsraelFil: Eizenberg, M.. Technion - Israel Institute of Technology; Israe

Abelian groups as artinian or noetherian modules above endomorphism rings

The A and B Abellian groups, such that the Hom(A, B) homomorphism group is the Artin module over the ring of the B group endomorphism, are described. Description of the A and B group for which the Hom(A,B) group is the Artin module over the ring of the A group endomorphism is reduced to the case when the A group has no torsion and the B group is either a quasi-cyclic group or a divisible group without torsion. The A and B Abellian groups for which the Hom(A,B) group is the Neter module over the E(A) or E(B) ring are characterized. The research of arbitrary Abellian group with the link Neter ring of endomorphisms is reduced to the research of the group without torsion with the link Neter ring of endomorphisms. The research of the right Neter ring of endomorphisms remained uncompleted. The separable Abele groups without torsion with the link and right Neter rings of endomorphisms are described

To Be or Not To Be a Molecular Ion: The Role of the Solvent in Photoionization of Arginine.

Application of photoionization mass spectroscopy, a technique capable of assessing protonation states in complex molecules in the gas phase, is challenging for arginine due to its fragility. We report photoionization efficiencies in the valence region of aqueous aerosol particles produced from arginine solutions under various pH and vaporization conditions. By using ab initio calculations, we investigate the stability of different conformers. Our results show that neutral arginine fragments upon ionization in the gas phase but solvation stabilizes the molecular ion, resulting in different photoionization dynamics. We also report the valence-band photoelectron spectra of the aerosol solutions obtained at different pH values

Determination of the input filter parameters of the active rectifier with a fixed modulation frequency

Goal. Development of a methodology for calculating the parameters of the active rectifier-voltage source input filter operating with a fixed modulation frequency to ensure electromagnetic compatibility with the supply network acceptable by standards at minimum values of the input inductance and checking its main characteristics on a mathematical model. Methodology. The authors have developed a methodology for calculating the parameters of the input filter of an active rectifier-voltage source. The calculation results are verified on the constructed mathematical model of a frequency converter, the scheme of which is an active rectifier and an autonomous voltage inverter. A series of experiments was carried out on a mathematical model to study the dependence of the total harmonic distortion of current and mains voltage on the value of the input inductance for various parameters of the input filter. Results. The structure and calculation procedure the input filter of an active rectifier operating with a fixed modulation frequency are proposed. The simulation results showed that the inclusion of a filter at the input of the active rectifier significantly improves its electromagnetic compatibility with the supply network in the entire range of variation of the input inductance of the circuit and makes it possible to achieve the values of the total harmonic distortion permissible by the norms. Originality. A structure and a calculation procedure the input filter of an active rectifier-voltage source operating with a fixed modulation frequency are proposed. Practical significance. The dependencies obtained in the article allow us to evaluate the relationship between the parameters of the filter elements and its characteristics among themselves and come to a compromise between them when designing a scheme for specific technical conditions.В статті запропоновано структуру та методику розрахунку вхідного фільтру активного випрямляча-джерела напруги, який працює з фіксованою частотою модуляції. Отримані залежності дозволяють оцінити взаємозв'язок параметрів елементів фільтра та його характеристик між собою та дійти компромісу між ними під час проектування схеми для конкретних технічних умов. Результати моделювання показали, що включення додаткового ланцюга RC фільтра на вході активного випрямляча істотно покращує його електромагнітну сумісність з мережею живлення у всьому діапазоні зміни вхідної індуктивності схеми та дозволяє досягати допустимих нормами значень сумарного коефіцієнту гармонічних спотворень