Event-driven simulation of digital circuits using modified Petri nets algorithm

This paper presents a modified Petri nets simulation algorithm applied as an engine for a logic simulator in digital integrated circuit design. The simulator uses an event-driven algorithm and eliminates the delta delay which occurs in the majority of modern simulation algorithms. The algorithm has been tested for the logic simulation of combinational digital circuits and demonstrated more accurate simulation results. This has been achieved due to solving the issue of the priority choice problem when two or more events are occurring simultaneously

Method of penalization for the state equation for an elliptical optimal control problem

© 2015, Allerton Press, Inc. We solve by finite difference method an optimal control problem of a system governed by a linear elliptic equation with pointwise control constraints and non-local state constraints. A discrete optimal control problem is approximated by a minimization problem with penalized state equation. We derive the error estimates for the distance between the exact and regularized solutions. We also prove the rate of convergence of block Gauss–Seidel iterative solution method for the penalized problem. We present and analyze the results of the numerical experiments

Solution of elliptic optimal control problem with pointwise and non-local state constraints

© 2017, Allerton Press, Inc.We study an optimal control problem of a system governed by a linear elliptic equation, with pointwise control constraints and pointwise and non-local (integral) state constraints. We construct a finite-difference approximation of the problem, we prove the existence and the convergence of the approximate solutions to the exact solution. We construct and study mesh saddle point problem and its iterative solution method and analyze the results of numerical experiments

Calculating partial expected value of perfect information via Monte Carlo sampling algorithms

Partial expected value of perfect information (EVPI) calculations can quantify the value of learning about particular subsets of uncertain parameters in decision models. Published case studies have used different computational approaches. This article examines the computation of partial EVPI estimates via Monte Carlo sampling algorithms. The mathematical definition shows 2 nested expectations, which must be evaluated separately because of the need to compute a maximum between them. A generalized Monte Carlo sampling algorithm uses nested simulation with an outer loop to sample parameters of interest and, conditional upon these, an inner loop to sample remaining uncertain parameters. Alternative computation methods and shortcut algorithms are discussed and mathematical conditions for their use considered. Maxima of Monte Carlo estimates of expectations are biased upward, and the authors show that the use of small samples results in biased EVPI estimates. Three case studies illustrate 1) the bias due to maximization and also the inaccuracy of shortcut algorithms 2) when correlated variables are present and 3) when there is nonlinearity in net benefit functions. If relatively small correlation or nonlinearity is present, then the shortcut algorithm can be substantially inaccurate. Empirical investigation of the numbers of Monte Carlo samples suggests that fewer samples on the outer level and more on the inner level could be efficient and that relatively small numbers of samples can sometimes be used. Several remaining areas for methodological development are set out. A wider application of partial EVPI is recommended both for greater understanding of decision uncertainty and for analyzing research priorities

Hydrogen sensors based on In2O3 thin films with bimetallic Pt/Pd catalysts on the surface and tin and dysprosium impuri-ties in the bulk

This paper presents the results of studying the characteristics of hydrogen sensors based on thin In2O3 films modified with tin and dysprosium with dispersed double Pt/Pd catalysts deposited on the surface. To control the content of Sn and Dy in the films, an original technology was developed, and ceramic targets were fabricated from powders of the In–Dy–O, Dy–Sn–O, and In–Dy–Sn–O systems synthesized by the sol–gel method. Films of complex composition were obtained by RF magnetron sputtering of the corresponding targets. Structural features of the obtained thin films were studied by Raman spectroscopy. It is shown that various combinations of tin and dysprosium concentrations, as well as the presence of Pt/Pd catalysts on the surface, have a significant effect on the defectiveness of the films and the density of oxygen adsorption centers. As a result, the resistance of sensors in pure air (R0), the activation energies of the temperature dependences of R0, the bending of the energy bands at the grain boundaries of the semiconductor, and the responses to the action of hydrogen in the concentration range of 20–25,000 ppm change. A unique feature of Pt/Pd/ In2O3: Sn (0.5 at%), Dy (4.95 at%) films is their high sensitivity at 20–100 ppm and the absence of signal saturation in the region of high hydrogen concentrations of 5000–25,000 ppm, allowing them to be used to detect H2 in a wide range of concentrations

Transnational strategy on the sustainable management and responsible use of non-native trees in the Alpine Space

Abstract Non-native tree species – defined as those species intentionally or unintentionally introduced by humans – have long been a part of the Alpine Space, providing numerous benefits, but also posing a potential threat to native biodiversity and related ecosystem services. Compared to the urban space where non-native trees comprise most tree species, the number of non-native trees in forests and plantations is relatively low. To evaluate potential risks and benefits of non-native trees in the Alpine Space, a transnational strategy for the responsible use and management of non-native trees is needed. The goals of the strategy are to tailor management practices for a sustainable and responsible use or admixture of non-native trees, to reduce the risks connected with the invasive potential of some non-native tree species, to help forests and urban areas to adapt to climate change, and to improve coordination and cooperation regarding best practices between different regions of the Alpine Space. A proposal was developed in a four-step process including expert-based assessment, stakeholder mapping, an extensive data review, and a public consultation. For implementing the strategy fully, strong collaboration among diverse stakeholders is anticipated and robust governance and an adequate long-term and fair funding scheme is needed

СПЕЦИФИЧЕСКИЕ ПРИЗНАКИ ФИНАНСОВОГО КОНТРОЛЯ И ФОРМЫ ЕГО ОСУЩЕСТВЛЕНИЯ

The article focuses on theoretical issues of the government control in the financial sector, the trends in legislation development, as well as forms and methods of financial monitoring. The recent decade has seen the rapid development of scientific concepts exploring financial control issues. The authors and leading scholars discuss the essence of the concept of “financial monitoring”, its characteristics and classifications. The legal regulation for financial monitoring purposes is rapidly developing along with academic approaches. The article offers a comprehensive review of trends in the development of the financial monitoring institution and genesis of legal regulation. The author suggests ways to improve the financial monitoring legislation. The methodological basis of the article uses the latest achievements in the cognitive theory. The study employed the following methods: general philosophical, systematic, analysis, synthesis, analogy, deduction, as well as traditional legal methods (formal-logical, comparative legal) and expert estimates. The main conclusion drawn from the results of the study is that there is a need to harmonize the forms and methods of control activities; systematize and unify risk analysis tools applied in the process of government control in the financial sector; amend the regulatory legislation, since financial monitoring is just a kind of government control. The novelty of the paper is in developing proposals towards further development of the financial monitoring institution.Предметом статьи являются теоретические проблемы института государственного контроля в финансовой сфере, тенденции развития законодательства, закрепляющие формы и методы финансового контроля. Последнее десятилетие ознаменовалось активным развитием научных концепций, исследующих финансовый контроль. Авторы вступают в дискуссию с ведущими учеными о сущности понятия «финансовый контроль», его признаках и классификациях. Наряду с научными подходами интенсивно развивается нормативно-правовое регулирование финансового контроля. В статье комплексно рассматриваются как научные тенденции развития института финансового контроля, так и тенденции генезиса нормативно-правового регулирования. Предлагаются пути правового совершенствования финансового контроля. Методологическую основу статьи составили современные достижения теории познания. В процессе исследования применялись общефило- софский, системный методы, анализ, синтез, аналогия, дедукция, традиционно правовые методы (формально- логический, сравнительно-правовой), а также экспертные оценки. Основной вывод, который сделан по ито- гам исследования, состоит в том, что необходимы унификация форм и методов осуществления контрольной деятельности, систематизация и унификация применяемых инструментов риск-анализа при осуществлении государственного контроля в финансовой сфере. Основной вывод, который сделан авторами в статье, - необходимость развития и унификации нормативно-правового регулирования финансового контроля как раз- новидности контроля государственного. Новизна статьи заключается в разработке предложений по дальней- шему развитию института финансового контроля

Fast flowing populations are not well mixed

In evolutionary dynamics, well-mixed populations are almost always associated with all-to-all interactions; mathematical models are based on complete graphs. In most cases, these models do not predict fixation probabilities in groups of individuals mixed by flows. We propose an analytical description in the fast-flow limit. This approach is valid for processes with global and local selection, and accurately predicts the suppression of selection as competition becomes more local. It provides a modelling tool for biological or social systems with individuals in motion.Comment: 19 pages, 8 figure