scholarly journals Efficiency analysis of control algorithms in spatially distributed systems with chaotic behavior

2014 ◽  
Vol 24 (4) ◽  
pp. 759-770 ◽  
Author(s):  
Łukasz Korus
Keyword(s):  
Numerical Simulation ◽  
Distributed Systems ◽  
Lyapunov Method ◽  
Chaotic Behavior ◽  
Efficiency Analysis ◽  
Control Algorithms ◽  
Controlling Chaos ◽  
Qualitative And Quantitative ◽  
Spatially Distributed ◽  
Definition Of

Abstract The paper presents results of examination of control algorithms for the purpose of controlling chaos in spatially distributed systems like the coupled map lattice (CML). The mathematical definition of the CML, stability analysis as well as some basic results of numerical simulation exposing complex, spatiotemporal and chaotic behavior of the CML were already presented in another paper. The main purpose of this article is to compare the efficiency of controlling chaos by simple classical algorithms in spatially distributed systems like CMLs. This comparison is made based on qualitative and quantitative evaluation methods proposed in the previous paper such as the indirect Lyapunov method, Lyapunov exponents and the net direction phase indicator. As a summary of this paper, some conclusions which can be useful for creating a more efficient algorithm of controlling chaos in spatially distributed systems are made.

scholarly journals Simple environment for developing methods of controlling chaos in spatially distributed systems

2011 ◽  
Vol 21 (1) ◽  
pp. 149-159
Author(s):  
Łukasz Korus
Keyword(s):  
Numerical Simulation ◽  
Mathematical Model ◽  
Distributed Systems ◽  
Lyapunov Method ◽  
Initial Conditions ◽  
System State ◽  
Simple Mathematical Model ◽  
Controlling Chaos ◽  
Spatially Distributed ◽  
Spatiotemporal Behavior

Simple environment for developing methods of controlling chaos in spatially distributed systemsThe paper presents a simple mathematical model called a coupled map lattice (CML). For some range of its parameters, this model generates complex, spatiotemporal behavior which seems to be chaotic. The main purpose of the paper is to provide results of stability analysis and compare them with those obtained from numerical simulation. The indirect Lyapunov method and Lyapunov exponents are used to examine the dependence on initial conditions. The net direction phase is introduced to measure the symmetry of the system state trajectory. In addition, a real system, which can be modeled by the CML, is presented. In general, this article describes basic elements of environment, which can be used for creating and examining methods of chaos controlling in systems with spatiotemporal dynamics.

scholarly journals Exploring International and Inter-Sector Differences of Social Enterprises in the UK and India

2021 ◽  
Vol 13 (11) ◽  
pp. 5870
Author(s):  
Philipp Kruse
Keyword(s):  
Social Entrepreneurship ◽  
Social Enterprise ◽  
Social Enterprises ◽  
Future Research ◽  
Shape Features ◽  
Qualitative And Quantitative ◽  
Clear Cut ◽  
The One ◽  
Definition Of ◽  
The Uk

Social Entrepreneurship (SE) describes a new entrepreneurial form combining the generation of financial and social value. In recent years, research interest in SE increased in various disciplines with a particular focus on the characteristics of social enterprises. Whereas a clear-cut definition of SE is yet to be found, there is evidence that culture and economy affect and shape features of SE activity. In addition, sector-dependent differences are supposed. Building on Institutional Theory and employing a mixed qualitative and quantitative approach, this study sheds light on the existence of international and inter-sector differences by examining 161 UK and Indian social enterprises. A content analysis and analyses of variance were employed and yielded similarities as well as several significant differences on an international and inter-sector level, e.g., regarding innovativeness and the generation of revenue. The current study contributes to a more nuanced picture of the SE landscape by comparing social enterprise characteristics in a developed and a developing country on the one hand and different sectors on the other hand. Furthermore, I highlight the benefits of jointly applying qualitative and quantitative methodologies. Future research should pay more attention to the innate heterogeneity among social enterprises and further consolidate and extend these findings.

Modelling global computations with Klaim

2008 ◽  
Vol 366 (1881) ◽  
pp. 3737-3745 ◽  
Author(s):  
Rocco De Nicola ◽  
Michele Loreti
Keyword(s):  
Distributed Systems ◽  
Formal Semantics ◽  
Wide Area ◽  
Wide Area Networks ◽  
Qualitative And Quantitative ◽  
Global Computing ◽  
New Models ◽  
And Control ◽  
Tuple Spaces ◽  
Coordination And Control

A new area of research, known as Global Computing, is by now well established. It aims at defining new models of computation based on code and data mobility over wide-area networks with highly dynamic topologies, and at providing infrastructures to support coordination and control of components originating from different, possibly untrusted, fault-prone, malicious or selfish sources. In this paper, we present our contribution to the field of Global Computing that is centred on Kernel Language for Agents Interaction and Mobility ( Klaim ). Klaim is an experimental language specifically designed to programme distributed systems consisting of several mobile components that interact through multiple distributed tuple spaces. We present some of the key notions of the language and discuss how its formal semantics can be exploited to reason about qualitative and quantitative aspects of the specified systems.

Chaos Control for a Fractional-Order Jerk System via Time Delay Feedback Controller and Mixed Controller

2021 ◽  
Vol 5 (4) ◽  
pp. 257
Author(s):  
Changjin Xu ◽  
Maoxin Liao ◽  
Peiluan Li ◽  
Lingyun Yao ◽  
Qiwen Qin ◽  
...  
Keyword(s):  
Time Delay ◽  
Fractional Order ◽  
Chaos Control ◽  
Chaotic Behavior ◽  
Control Strategies ◽  
Feedback Controller ◽  
Research Approach ◽  
Controlling Chaos ◽  
The Stability ◽  
Jerk System

In this study, we propose a novel fractional-order Jerk system. Experiments show that, under some suitable parameters, the fractional-order Jerk system displays a chaotic phenomenon. In order to suppress the chaotic behavior of the fractional-order Jerk system, we design two control strategies. Firstly, we design an appropriate time delay feedback controller to suppress the chaos of the fractional-order Jerk system. The delay-independent stability and bifurcation conditions are established. Secondly, we design a suitable mixed controller, which includes a time delay feedback controller and a fractional-order PDσ controller, to eliminate the chaos of the fractional-order Jerk system. The sufficient condition ensuring the stability and the creation of Hopf bifurcation for the fractional-order controlled Jerk system is derived. Finally, computer simulations are executed to verify the feasibility of the designed controllers. The derived results of this study are absolutely new and possess potential application value in controlling chaos in physics. Moreover, the research approach also enriches the chaos control theory of fractional-order dynamical system.

scholarly journals ROLE OF CARTOGRAPHIC ONLINE SERVICES IN FORMATION OF PROFESSIONAL COMPETENCES WHEN TRAINING SPECIALIST IN THE FIELD “EARTH SCIENCES”

2020 ◽  
Vol 1 ◽  
pp. 56-61
Author(s):  
Lyudmila K. Trubina ◽  
Olga N. Nikolaeva ◽  
Yevgeniy I. Baranova
Keyword(s):  
Natural Resource ◽  
Thinking Skills ◽  
Geospatial Data ◽  
Spatial Thinking ◽  
Insufficient Attention ◽  
Spatially Distributed ◽  
Resource Data ◽  
Training Specialist ◽  
Definition Of

The article discusses the possibilities of using geoportals as the main source of open digital cartographic data for the development of spatial thinking and skills among students. Currently insufficient attention is being paid to the development of spatial thinking skills among students. The definition of the concept of "geoportal" is given. An analysis of a number of regional geoportals in terms of their content with spatially distributed natural resource data is made as well as the variety of tools provided for working with these data. Conclusions about the criteria that a geoportal recommended for use by students to consolidate their skills in working with geospatial data should meet are made.

scholarly journals FOUND: A DEFINITION OF INTELLIGENCE

2021 ◽  
Vol IV(1) ◽  
Author(s):  
Adewunmi Falode ◽  
Keyword(s):  
21St Century ◽  
Pivotal Role ◽  
Process Data ◽  
Effective Utilization ◽  
Qualitative And Quantitative ◽  
Political Group ◽  
Military Planning ◽  
Critical Edge ◽  
State Actors ◽  
Definition Of

Intelligence has come to play a pivotal role in the affairs of states and non-state actors in the 21st century. It not only determines the outcome of conflict when it breaks out but also provides critical edge and foresight in military planning and engagements. However, the effective utilization and deployment of intelligence in any strategic environment may be hampered by the lack of a holistic and generally accepted definition of it. The search for a robust definition has not also been helped by the differing views on what should constitute the basic elements of it. To overcome these challenges, this work argues for and provides a holistic definition of intelligence. It uses both qualitative and quantitative methodologies to provide a more robust and holistic definition of intelligence. The work concludes that any acceptable definition of intelligence must contain five key elements: process, data, actionable information, political group and security.

scholarly journals Dynamic Analysis and Cryptographic Application of a Sinusoidal-polynomial Composite Chaotic System

2021 ◽  
Author(s):  
Hegui Zhu ◽  
Jiangxia Ge ◽  
Wentao Qi ◽  
Xiangde Zhang ◽  
Xiaoxiong Lu
Keyword(s):  
Image Encryption ◽  
Chaotic System ◽  
Chaotic Behavior ◽  
Initial Conditions ◽  
Encryption Algorithm ◽  
Topological Transitivity ◽  
Detailed Simulation ◽  
Definition Of ◽  
Image Encryption Algorithm ◽  
Sensitivity To Initial Conditions

Abstract Owning to complex properties of ergodicity, non-periodic ability and sensitivity to initial states, chaotic systems are widely used in cryptography. In this paper, we propose a sinusoidal--polynomial composite chaotic system (SPCCS), and prove that it satisfies Devaney's definition of chaos: the sensitivity to initial conditions, topological transitivity and density of periodic points. The experimental results show that the SPCCS has better unpredictability and more complex chaotic behavior than the classical chaotic maps. Furthermore, we provide a new image encryption algorithm combining pixel segmentation operation, block chaotic matrix confusing operation, and pixel diffusion operation with the SPCCS. Detailed simulation results verify effectiveness of the proposed image encryption algorithm.

scholarly journals Mechatronic Device for Locomotor Training

2016 ◽  
Vol 10 (4) ◽  
pp. 310-315 ◽  
Author(s):  
Sławomir Duda ◽  
Damian Gąsiorek ◽  
Grzegorz Gembalczyk ◽  
Sławomir Kciuk ◽  
Arkadiusz Mężyk
Keyword(s):  
Experimental Data ◽  
Numerical Simulation ◽  
Measurement Data ◽  
Healthy Person ◽  
Control Algorithms ◽  
Design Team ◽  
Locomotor Training ◽  
Interdisciplinary Design ◽  
Machine Control ◽  
Simulation Results

Abstract This paper presents a novel mechatronic device to support a gait reeducation process. The conceptual works were done by the interdisciplinary design team. This collaboration allowed to perform a device that would connect the current findings in the fields of biomechanics and mechatronics. In the first part of the article shown a construction of the device which is based on the structure of an overhead travelling crane. The rest of the article contains the issues related to machine control system. In the prototype, the control of drive system is conducted by means of two RT-DAC4/PCI real time cards connected with a signal conditioning interface. Authors present the developed control algorithms and optimization process of the controller settings values. The summary contains a comparison of some numerical simulation results and experimental data from the sensors mounted on the device. The measurement data were obtained during the gait of a healthy person.

scholarly journals Theoretical Design and Circuit Implementation of Integer Domain Chaotic Systems

2014 ◽  
Vol 24 (10) ◽  
pp. 1450128 ◽  
Author(s):  
Qianxue Wang ◽  
Simin Yu ◽  
Christophe Guyeux ◽  
Jacques M. Bahi ◽  
Xiaole Fang
Keyword(s):  
Chaotic Systems ◽  
Chaotic Behavior ◽  
Random Sequence ◽  
Noise Signal ◽  
Circuit Implementation ◽  
New Approach ◽  
Uniform Noise ◽  
Definition Of ◽  
First Time ◽  
Hybrid Circuit

In this paper, a new approach for constructing integer domain chaotic systems (IDCS) is proposed, and its chaotic behavior is mathematically proven according to Devaney's definition of chaos. Furthermore, an analog-digital hybrid circuit is also developed for realizing the designed basic IDCS. In the IDCS circuit design, chaos generation strategy is realized through a sample-hold circuit and a decoder circuit so as to convert the uniform noise signal into a random sequence, which plays a key role in circuit implementation. The experimental observations further validate the proposed systematic methodology for the first time.

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