scholarly journals Friction laws from dimensional-analysis point of view

2015 ◽  
Vol 202 (3) ◽  
pp. 2159-2162 ◽  
Author(s):  
Takahiro Hatano
Keyword(s):  
Friction Coefficient ◽  
Dimensional Analysis ◽  
The State ◽  
Point Of View ◽  
State Variables ◽  
Simple Assumption ◽  
Friction Laws ◽  
State Dependent ◽  
The Difference ◽  
Logarithmic Dependence

Abstract Friction laws, which are a key to the understanding of the diversity of earthquakes, are considered theoretically. Using dimensional analysis, the logarithmic dependence of the friction coefficient on the slip velocity and the state variable is derived without any knowledge of the underlying physical processes on the frictional surface. This is based on a simple assumption that the friction coefficient is expressed as the difference from a reference state. Therefore, the functional form of the rate and state dependent friction law itself does not necessarily mean that thermal activation processes dominate friction. It is also shown that if there are two (or more) state variables having the same dimension, we need not assume the logarithmic dependence on the state variables.

TO THE PROBLEMS OF COMBATING CORRUPTION IN MODERN RUSSIA AND INTERNATIONAL COOPERATION IN THE FIELD OF ANTI-CORRUPTION

2020 ◽  
Author(s):  
Angela Dranishnikova
Keyword(s):  
Large Scale ◽  
The State ◽  
Point Of View ◽  
Modern Life ◽  
Existing Problems ◽  
Moral Point ◽  
Material Goods ◽  
The Russian Federation ◽  
The Difference ◽  
The Government

In the article, the author reflects the existing problems of the fight against corruption in the Russian Federation. He focuses on the opacity of the work of state bodies, leading to an increase in bribery and corruption. The topic we have chosen is socially exciting in our days, since its significance is growing on a large scale at all levels of the investigated aspect of our modern life. Democratic institutions are being jeopardized, the difference in the position of social strata of society in society’s access to material goods is growing, and the state of society is suffering from the moral point of view, citizens are losing confidence in the government, and in the top officials of the state.

scholarly journals Exploring the Limits of Floating-Point Resolution for Hardware-In-the-Loop Implemented with FPGAs

Electronics ◽  
2018 ◽  
Vol 7 (10) ◽  
pp. 219 ◽  
Author(s):  
Alberto Sanchez ◽  
Elías Todorovich ◽  
Angel de Castro
Keyword(s):  
The State ◽  
Floating Point ◽  
Hardware In The Loop ◽  
State Variables ◽  
Numerical Resolution ◽  
Digital Devices ◽  
State Variable ◽  
Simulation Step ◽  
Field Programmable ◽  
The Difference

As the performance of digital devices is improving, Hardware-In-the-Loop (HIL) techniques are being increasingly used. HIL systems are frequently implemented using FPGAs (Field Programmable Gate Array) as they allow faster calculations and therefore smaller simulation steps. As the simulation step is reduced, the incremental values for the state variables are reduced proportionally, increasing the difference between the current value of the state variable and its increments. This difference can lead to numerical resolution issues when both magnitudes cannot be stored simultaneously in the state variable. FPGA-based HIL systems generally use 32-bit floating-point due to hardware and timing restrictions but they may suffer from these resolution problems. This paper explores the limits of 32-bit floating-point arithmetics in the context of hardware-in-the-loop systems, and how a larger format can be used to avoid resolution problems. The consequences in terms of hardware resources and running frequency are also explored. Although the conclusions reached in this work can be applied to any digital device, they can be directly used in the field of FPGAs, where the designer can easily use custom floating-point arithmetics.

Difference Synchronization of Identical and Nonidentical Chaotic and Hyperchaotic Systems of Different Orders Using Active Backstepping Design

2018 ◽  
Vol 13 (5) ◽  
Author(s):  
Eric Donald Dongmo ◽  
Kayode Stephen Ojo ◽  
Paul Woafo ◽  
Abdulahi Ndzi Njah
Keyword(s):  
Chaotic System ◽  
Initial Conditions ◽  
Lyapunov Stability Theory ◽  
The State ◽  
State Variables ◽  
State Variable ◽  
New Type ◽  
The Difference ◽  
Synchronization Scheme ◽  
Hyperchaotic Systems

This paper introduces a new type of synchronization scheme, referred to as difference synchronization scheme, wherein the difference between the state variables of two master [slave] systems synchronizes with the state variable of a single slave [master] system. Using the Lyapunov stability theory and the active backstepping technique, controllers are derived to achieve the difference synchronization of three identical hyperchaotic Liu systems evolving from different initial conditions, as well as the difference synchronization of three nonidentical systems of different orders, comprising the 3D Lorenz chaotic system, 3D Chen chaotic system, and the 4D hyperchaotic Liu system. Numerical simulations are presented to demonstrate the validity and feasibility of the theoretical analysis. The development of difference synchronization scheme has increases the number of existing chaos synchronization scheme.

scholarly journals STACK with state

2017 ◽  
Vol 15 (2) ◽  
pp. 60 ◽  
Author(s):  
Matti Harjula ◽  
Jarmo Malinen ◽  
Antti Rasila
Keyword(s):  
Finite State Machine ◽  
State Machine ◽  
The State ◽  
Point Of View ◽  
State Variables ◽  
State Variable ◽  
Finite State ◽  
Input Event ◽  
Single Input ◽  
The Right

The question model of STACK provides an easy way for building automatically assessable questions with mathematical content, but it requires that the questions and their assessment logic depend only on the current input, given by the student at a single instant. However, the present STACK question model already has just the right form to be extended with state variables that would remove this limitation. In this article, we report our recent work on the state-variable extension for STACK, and we also discuss combining the use of state variables with our previous work on conditional output processing. As an outcome, we propose an expansion to the STACK question model, allowing the questions to act as state machines instead of pure functions of a single input event from the studentWe present a model question using the state variable extension of STACK that demonstrates some of the new possibilities that open up for the question author. This question is based on a finite state machine in its assessment logic, and it demonstrates aspects of strategic planning to solve problems of recursive nature. The model question also demonstrates how the state machine can interpret the solution path taken by the student, so as to dynamically modify the question behaviour and progress by, e.g., asking additional questions relevant to the path. We further explore the future possibilities from the point of view of learning strategic competencies in mathematics (Kilpatrick et al., 2001; Rasila et al., 2015).

A Design of Observers of Control State and Uncertainty via Transformation of T-S Fuzzy Models

2018 ◽  
Vol 22 (2) ◽  
pp. 194-202 ◽  
Author(s):  
Hugang Han ◽  
Yuki Sueyama ◽  
Chun-Jun Chen ◽  
◽  
Keyword(s):  
Fuzzy Model ◽  
The State ◽  
Point Of View ◽  
Matrix Transformation ◽  
Control Performance ◽  
Fuzzy Models ◽  
State Observers ◽  
Traditional Sense ◽  
The Difference ◽  
Control State

When employing the widely used T-S fuzzy model as a model to represent a system concerned with controller designs, it is necessary to consider the precision of the model from the point of view of control performance. Adding a term called uncertainty in the T-S fuzzy model to compensate for the difference between the concerned system and its T-S fuzzy model, this paper focuses on a design of observers for both the control state and uncertainty. Unlike a state observer in the traditional sense, which is usually designed as a whole, the state is divided into two parts by performing a unique matrix transformation; and two observers from the two divided parts of the state are designed separately in order to eliminate the influence of the uncertainty. Finally, an observer of the aforementioned uncertainty based on one of the state observers is suggested.

scholarly journals New Approaches for the Assimilation of LAI Measurements into a Crop Model Ensemble to Improve Wheat Biomass Estimations

Agronomy ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 446 ◽  
Author(s):  
Andreas Tewes ◽  
Holger Hoffmann ◽  
Gunther Krauss ◽  
Fabian Schäfer ◽  
Christian Kerkhoff ◽  
...  
Keyword(s):  
Grain Yield ◽  
Simulation Models ◽  
Crop Model ◽  
The State ◽  
State Variables ◽  
Model Ensemble ◽  
Crop Simulation Models ◽  
The Difference ◽  
Improved Accuracy ◽  
Ensemble Generation

The assimilation of LAI measurements, repeatedly taken at sub-field level, into dynamic crop simulation models could provide valuable information for precision farming applications. Commonly used updating methods such as the Ensemble Kalman Filter (EnKF) rely on an ensemble of model runs to update a limited set of state variables every time a new observation becomes available. This threatens the model’s integrity, as not the entire table of model states is updated. In this study, we present the Weighted Mean (WM) approach that relies on a model ensemble that runs from simulation start to simulation end without compromising the consistency and integrity of the state variables. We measured LAI on 14 winter wheat fields across France, Germany and the Netherlands and assimilated these observations into the LINTUL5 crop model using the EnKF and WM approaches, where the ensembles were created using one set of crop component (CC) ensemble generation variables and one set of soil and crop component (SCC) ensemble generation variables. The model predictions for total aboveground biomass and grain yield at harvest were evaluated against measurements collected in the fields. Our findings showed that (a) the performance of the WM approach was very similar to the EnKF approach when SCC variables were used for the ensemble generation, but outperformed the EnKF approach when only CC variables were considered, (b) the difference in site-specific performance largely depended on the choice of the set of ensemble generation variables, with SCC outperforming CC with regard to both biomass and grain yield, and (c) both EnKF and WM improved accuracy of biomass and yield estimates over standard model runs or the ensemble mean. We conclude that the WM data assimilation approach is equally efficient to the improvement of model accuracy, compared to the updating methods, but it has the advantage that it does not compromise the integrity and consistency of the state variables.

Pleasure as a Sign of Efficacy of Mental Activity

1997 ◽  
Vol 2 (3) ◽  
pp. 226-234 ◽  
Author(s):  
Michel Cabanac ◽  
Chantal Pouliot ◽  
James Everett
Keyword(s):  
Evolutionary Psychology ◽  
Magnitude Estimation ◽  
Mental Activity ◽  
Point Of View ◽  
Macintosh Computer ◽  
Science Students ◽  
Cognitive Efficiency ◽  
Sensory Pleasure ◽  
The Difference ◽  
Mental Tasks

Previous work has shown that sensory pleasure is both the motor and the sign of optimal behaviors aimed at physiological ends. From an evolutionary psychology point of view it may be postulated that mental pleasure evolved from sensory pleasure. Accordingly, the present work tested empirically the hypothesis that pleasure signals efficacious mental activity. In Experiment 1, ten subjects played video-golf on a Macintosh computer. After each hole they were invited to rate their pleasure or displeasure on a magnitude estimation scale. Their ratings of pleasure correlated negatively with the difference par minus performance, i.e., the better the performance the greater the pleasure reported. In Experiments 2 and 3, the pleasure of reading poems was correlated with comprehension, both rated by two groups of subjects, science students and arts students. In the majority of science students pleasure was significantly correlated with comprehension. Only one arts student showed this relationship; this result suggests that the proposed relationship between pleasure and cognitive efficiency is not tautological. Globally, the results support the hypothesis that pleasure is aroused by the same mechanisms, and follows the same laws, in physiological and cognitive mental tasks and also leads to the optimization of performance.

COMBINATORIAL POLYNOMIALLY COMPUTABLE CHARACTERISTICS OF SUBSTITUTIONS AND THEIR PROPERTIES

2020 ◽  
Vol 7 (2) ◽  
pp. 34-41
Author(s):  
VLADIMIR NIKONOV ◽  
◽  
ANTON ZOBOV ◽  
Keyword(s):  
Mathematical Expectation ◽  
Point Of View ◽  
Small Range ◽  
Computational Point ◽  
Wide Range ◽  
Bijective Function ◽  
The Difference ◽  
Element Base ◽  
Selection Of

The construction and selection of a suitable bijective function, that is, substitution, is now becoming an important applied task, particularly for building block encryption systems. Many articles have suggested using different approaches to determining the quality of substitution, but most of them are highly computationally complex. The solution of this problem will significantly expand the range of methods for constructing and analyzing scheme in information protection systems. The purpose of research is to find easily measurable characteristics of substitutions, allowing to evaluate their quality, and also measures of the proximity of a particular substitutions to a random one, or its distance from it. For this purpose, several characteristics were proposed in this work: difference and polynomial, and their mathematical expectation was found, as well as variance for the difference characteristic. This allows us to make a conclusion about its quality by comparing the result of calculating the characteristic for a particular substitution with the calculated mathematical expectation. From a computational point of view, the thesises of the article are of exceptional interest due to the simplicity of the algorithm for quantifying the quality of bijective function substitutions. By its nature, the operation of calculating the difference characteristic carries out a simple summation of integer terms in a fixed and small range. Such an operation, both in the modern and in the prospective element base, is embedded in the logic of a wide range of functional elements, especially when implementing computational actions in the optical range, or on other carriers related to the field of nanotechnology.

ANALYSIS OF MEASURES TO REDUCE ECOLOGICAL AND ECONOMIC DAMAGE FROM AUTOMOBILE TRANSPORT

2020 ◽  
Author(s):  
V.N. Kurdyukov ◽  
◽  
T.V. Lebedeva ◽  
Keyword(s):  
Resource Allocation ◽  
Negative Impact ◽  
The State ◽  
Point Of View ◽  
Motor Vehicles ◽  
Economic Damage ◽  
Agriculture Education

The article considers common classifications of measures to reduce environmentaleconomic damage from motor vehicles. Classification from the point of view of control impact is proposed, which allows to take into account relations between the state and citizens in the field of reduction of negative impact of motor vehicles on the environment. The analysis of the classification made it possible to identify areas of activity for improving the efficiency of management impacts, taking into account the incentives of citizens to comply with the requirements of the legislation and to create conditions for their exceeding. Increasing the efficiency of resource allocation in the Territory will allow the released funds to be allocated to the development of industry, agriculture, education and science.

Russian Parliamentarism Party Model

2018 ◽  
Vol 42 ◽  
pp. 245-255
Author(s):  
Rostislav F. Turovsky
Keyword(s):  
The State ◽  
Point Of View ◽  
Soviet Period ◽  
Political Situation ◽  
Managerial Positions ◽  
Post Soviet Period

The article is devoted to the study of the party model of Russian parliamentarism in post-soviet period. The focus is on the issues of party representation and its correlation with the distribution of the managerial positions and introduction of collective legislation at State Duma. These issues are examined from the point of view of reaching cross-party consensus and implementation of fair parliament party representation principle. According to the author Russian parliamentarism model aims at reaching full-fledged party consensus that corresponds better to the principles of popular representation than strict parliament polarization along the line of “authority-opposition”. Understanding of those issues by the majority of the players was noted from the very start of the State Duma activities, in spite of the acute conflicts in the 1990-ies.The author draws the conclusion that the equation of party representation continues to grow at the level of managerial positions in the parliament that allows to improve cooperation of the parties and to reduce authority and opposition conflicts. Thereby the Russian parliamentarism model makes an important contribution to the stabilization of socio-political situation of the country.

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