scholarly journals Ethno-National Colonialism in South Africa

2021 ◽  
Vol 4 (3) ◽  
pp. 37-47
Author(s):  
Ratau John Tshikosi ◽  
Livhuwani Priscilla Sekhula
Keyword(s):  
South Africa ◽  
Sufficient Conditions ◽  
Power Sharing ◽  
Comparative Approach ◽  
Dominant Group ◽  
Democratic State ◽  
Interpretive Inquiry ◽  
Necessary And Sufficient ◽  
And Control ◽  
Systems Of Domination

The purpose of this dissertation is to answer the question: why do ostensibly similar ethno-national conflicts within a system of settler-colonial domination see such wide variation in their outcomes? How they emerge from conflict through power sharing and social integration versus the endurance of separation and systems of domination and control? The study identifies causal paths that resulted in the decline of domination systems of this type. Ethno-national conflicts that feature certain similarities develop in different trajectories due to certain conditions that culminate in transforming the structures of these conflicts towards integration (the establishment of a single political entity) or separation (independence in separate entities). The goal of the dissertation is to examine the Palestinian-Israeli conflict through a comparative lens in order to specify the conditions that led to the persistence of the two-state solution and to examine the prevalence or lack of necessary and sufficient conditions for the emergence of a one civic-democratic state. Building on the comparative approach I argue that ethno-national territorial underpinnings of the conflict and the “regimes of territorial legitimation” of the dominant group are the most crucial explanatory factor in determining the trajectory and outcome of the conflict. “Regimes of territorial legitimation” are the practices, procedures, systems of meaning, and institutional designs that found the relationship between a nation, people or ethno-national group and geography/territory. The dissertation features a qualitative structured and focused comparison of the conflicts in South Africa, and Palestine. Method of difference is applied for a case-oriented interpretive inquiry that focuses on the complexity of each of the two cases and aims at capturing the historical diversity of these similar cases.

scholarly journals Robust Output Controllability Analysis and Control Design for Incomplete Boolean Networks with Disturbance Inputs

2018 ◽  
Vol 2018 ◽  
pp. 1-9
Author(s):  
Lei Deng ◽  
Shihua Fu ◽  
Ying Li ◽  
Peiyong Zhu
Keyword(s):  
Sufficient Conditions ◽  
Boolean Networks ◽  
Algebraic Form ◽  
Output Control ◽  
Optimal Output ◽  
Product Technique ◽  
Output Controllability ◽  
The Cost ◽  
Necessary And Sufficient ◽  
And Control

This paper addresses the problems of robust-output-controllability and robust optimal output control for incomplete Boolean control networks with disturbance inputs. First, by resorting to the semi-tensor product technique, the system is expressed as an algebraic form, based on which several necessary and sufficient conditions for the robust output controllability are presented. Second, the Mayer-type robust optimal output control issue is studied and an algorithm is established to find a control scheme which can minimize the cost functional regardless of the effect of disturbance inputs. Finally, a numerical example is given to demonstrate the effectiveness of the obtained new results.

AN OPTIMIZATION APPROACH TO THE DESIGN OF CONSTRAINED REGULATORS FOR UNCERTAIN DISCRETE-TIME SYSTEMS

2006 ◽  
Vol 15 (03) ◽  
pp. 373-387
Author(s):  
M. VASSILAKI ◽  
G. BITSORIS
Keyword(s):  
Discrete Time ◽  
Sufficient Conditions ◽  
Optimization Approach ◽  
Control Constraints ◽  
Existence Of A Solution ◽  
Discrete Time Systems ◽  
Necessary And Sufficient ◽  
And Control ◽  
Time Systems ◽  
State And Control Constraints

In this paper the regulation problem of linear discrete-time systems with uncertain parameters under state and control constraints is studied. In the first part of the paper, two theorems concerning necessary and sufficient conditions for the existence of a solution to this problem are presented. Due to the constructive form of the proof of these theorems, these results can be used to the development of techniques for the derivation of a control law transferring to the origin any state belonging to a given set of initial states while respecting the state and control constraints.

ON FLOW BARRIERS AND SWITCHABILITY IN DISCONTINUOUS DYNAMICAL SYSTEMS

2011 ◽  
Vol 21 (01) ◽  
pp. 1-76 ◽  
Author(s):  
ALBERT C. J. LUO
Keyword(s):  
Dynamical Systems ◽  
Vector Fields ◽  
Sufficient Conditions ◽  
Friction Model ◽  
Necessary And Sufficient Conditions ◽  
Separation Boundary ◽  
Boundary Flow ◽  
Pass Through ◽  
Necessary And Sufficient ◽  
And Control

In this paper, the theory of flow barriers in discontinuous dynamical systems is systematically presented as a new theory for the first time, which helps one rethink the existing theories of stability and control in dynamical systems. The concept of flow barriers in discontinuous dynamical systems is introduced, and the passability of a flow to the separation boundary with flow barriers is presented. Because the flow barriers exist on the separation boundary, the switchability of a flow to such a separation boundary is changed accordingly. The coming and leaving flow barriers in passable flows are discussed first, and the necessary and sufficient conditions for a flow to pass through the boundary with flow barrier are developed. Flow barriers for sink and source flows are also discussed. Once the sink flow is formed, the boundary flow will exist. When the boundary flow disappears from the boundary, the boundary flow barrier on the boundary may exist, which is independent of vector fields in the corresponding domains. Thus, the necessary and sufficient conditions for formations and vanishing of the boundary flow are developed. A periodically forced friction model is presented as an example for a better understanding of flow barrier existence in physical problems. The flow barrier theory presented in this paper may provide a theoretic base to further develop control theory and stability.

scholarly journals AN EXPLORATION OF HIGH SCHOOL LEARNERS’ UNDERSTANDING OF GEOMETRIC CONCEPTS

2019 ◽  
Vol 77 (1) ◽  
pp. 82-96 ◽  
Author(s):  
Harrison Ngirishi ◽  
Sarah Bansilal
Keyword(s):  
South Africa ◽  
High School ◽  
Mathematical Proof ◽  
Sufficient Conditions ◽  
Poor Performance ◽  
Class Inclusion ◽  
Van Hiele ◽  
Geometric Thinking ◽  
Semiotic Representations ◽  
Necessary And Sufficient

There is much concern in South Africa about the poor performance of learners in mathematics, particularly in geometry. The aim of this research was to explore the understanding of basic geometry concepts by grade 10 and grade 11 learners in terms of the van Hiele’s levels of geometry thinking. The participants of the research were 147 learners from three high schools in a rural area in the south of KwaZulu Natal, South Africa. The results showed that the learners had difficulties with problems involving definitions of geometric terms, interrelations of properties and shapes, class inclusion and changing semiotic representations. It was also found that most of the learners were operating at the visual and the analysis levels of the van Hiele levels of geometric thinking. It is recommended that teachers should provide learners with tasks that require movements between semiotic representations, and to also focus attention on improving learners’ skills in proving aspects of mathematical relations. Keywords: geometry, high school, van Hiele theory, class inclusion, mathematical proof, necessary and sufficient conditions.

scholarly journals Solvability of the control problem of the asynchronous spectrum of linear almost periodic systems with a lower triangular representation of the averaging of coefficient matrix

2021 ◽  
Vol 65 (3) ◽  
pp. 263-268
Author(s):  
A. K. Demenchuk
Keyword(s):  
Control Problem ◽  
Sufficient Conditions ◽  
Additive Group ◽  
Coefficient Matrix ◽  
Almost Periodic ◽  
Average Value ◽  
The Matrix ◽  
Frequency Module ◽  
Necessary And Sufficient ◽  
And Control

A linear control system with an almost periodic matrix of coefficients and control in the form of the feedback linear in phase variables is considered. It is assumed that the feedback coefficient is almost periodic and its frequency module, i. e. the smallest additive group of real numbers, including all the Fourier exponents of this coefficient, is contained in the frequency module of the coefficient matrix. The system under consideration is studied in the case of a triangular average value of the matrix of coefficients. For the described class of systems, the control problem of the asynchronous spectrum with a target set of frequencies is solved. This task is to construct such a control from an admissible set that the system closed by this control has almost periodic solutions, a set of the Fourier exponents of which contains a predetermined subset, and the intersection of the solution frequency modules and the coefficient matrix is trivial. The necessary and sufficient conditions for the solvability of this problem are obtained.

scholarly journals Bifurcation and control of a predator-prey system with unfixed functional responses

2021 ◽  
Vol 0 (0) ◽  
pp. 0
Author(s):  
Lizhi Fei ◽  
Xingwu Chen
Keyword(s):  
Fixed Points ◽  
Hybrid Control ◽  
Sufficient Conditions ◽  
Rate Function ◽  
Functional Responses ◽  
Predator Prey ◽  
Prey System ◽  
The Stability ◽  
Necessary And Sufficient ◽  
And Control

<p style='text-indent:20px;'>In this paper we investigate a discrete-time predator-prey system with not only some constant parameters but also unfixed functional responses including growth rate function of prey, conversion factor function and predation probability function. We prove that the maximal number of fixed points is <inline-formula><tex-math id="M1">\begin{document}$ 3 $\end{document}</tex-math></inline-formula> and give necessary and sufficient conditions of exactly <inline-formula><tex-math id="M2">\begin{document}$ j $\end{document}</tex-math></inline-formula>(<inline-formula><tex-math id="M3">\begin{document}$ j = 1,2,3 $\end{document}</tex-math></inline-formula>) fixed points, respectively. For transcritical bifurcation and Neimark-Sacker bifurcation, we provide bifurcation conditions depending on these unfixed functional responses. In order to regulate the stability of this biological system, a hybrid control strategy is used to control the Neimark-Sacker bifurcation. Finally, we apply our main results to some examples and carry out numerical simulations for each example to verify the correctness of our theoretical analysis.</p>

scholarly journals The Population Dynamics of File-Sharing Peer-to-Peer Networks

2016 ◽  
Author(s):  
Dang Dinh Trang ◽  
Roland Pereczes ◽  
Sándor Molnár
Keyword(s):  
Population Dynamics ◽  
Branching Processes ◽  
Sufficient Conditions ◽  
File Sharing ◽  
Peer To Peer ◽  
Modeling Framework ◽  
Population Extinction ◽  
P2p Systems ◽  
Necessary And Sufficient ◽  
And Control

Recently  peer-to-peer  file-sharing applications  have  shown  an  extreme  popularity  and the  workload  generated  to  the  Internet  has  been dominated  by  the  traffic  coming  from  these applications.  In  this  paper  we  develop  a  simple  but effective  mathematical  model  to  capture  the  file population  dynamics  of  such  systems.  Our  modeling framework  is  based  on  the  theory  of  branching processes. We describe analytically the behavior of the proposed  model.  The  precise  characterization  of  the necessary  and  sufficient  conditions  of  population extinction  or  explosion  is  given  based  on  the  system parameters.  We  also  present  the  expected  ratio  of active,  passive  and  dead  peers  for  the  long-term regime.  We  validate  and  demonstrate  our  results  in several  simulation  studies.  Based  on  our  results  we propose  a  number  of  engineering  guidelines  to  the design and control of file-sharing P2P systems.

SPECIFYING CONTROL SIGNALS FOR SYSTOLIC ARRAYS BY UNIFORM RECURRENCE EQUATIONS

1991 ◽  
Vol 01 (02) ◽  
pp. 83-93 ◽  
Author(s):  
JINGLING XUE
Keyword(s):  
Sufficient Conditions ◽  
Space Time ◽  
Control Flow ◽  
Necessary And Sufficient Conditions ◽  
Mapping Technique ◽  
Systolic Arrays ◽  
Recurrence Equations ◽  
Control Signals ◽  
Necessary And Sufficient ◽  
And Control

Starting with a system of uniform recurrence equations (source UREs) for a systolic design, we provide a method that allows a specification of control signals by another system of UREs (control UREs), which has no notion of time and space. Necessary and sufficient conditions for the correctness of the control UREs are stated. The standard space-time mapping technique is extended so that systolic arrays with a description of both data and control flow are directly synthesised from the source and control UREs. Optimisations of control signals are discussed. An example is provided.

scholarly journals On very strongly perfect Cartesian product graphs

2021 ◽  
Vol 7 (2) ◽  
pp. 2634-2645
Author(s):  
Ganesh Gandal ◽  
◽  
R Mary Jeya Jothi ◽  
Narayan Phadatare ◽  
Keyword(s):  
Cartesian Product ◽  
Sufficient Conditions ◽  
Perfect Graph ◽  
Finite Graphs ◽  
Cartesian Product Of Graphs ◽  
Product Graphs ◽  
Necessary And Sufficient ◽  
And Control ◽  
Product Of Graphs ◽  
Real Time Application

<abstract><p>Let $ G_1 \square G_2 $ be the Cartesian product of simple, connected and finite graphs $ G_1 $ and $ G_2 $. We give necessary and sufficient conditions for the Cartesian product of graphs to be very strongly perfect. Further, we introduce and characterize the co-strongly perfect graph. The very strongly perfect graph is implemented in the real-time application of a wireless sensor network to optimize the set of master nodes to communicate and control nodes placed in the field.</p></abstract>

scholarly journals Constrained regulator problem for linear uncertain systems: Control of a pH process

2006 ◽  
Vol 2006 ◽  
pp. 1-15 ◽  
Author(s):  
Fouad Mesquine ◽  
Fernando Tadeo ◽  
Abdellatif Benlamkadem
Keyword(s):  
Continuous Time ◽  
Uncertain Systems ◽  
Sufficient Conditions ◽  
Stability And Control ◽  
Regulator Problem ◽  
Continuous Time Systems ◽  
Ph Process ◽  
Necessary And Sufficient ◽  
And Control ◽  
Time Systems

The regulator problem for linear uncertain continuous-time systems having control constraints is considered. Necessary and sufficient conditions of positive invariance of polyhedral domains are extended to the case of continuous-time uncertain systems. Robust constrained regulators are then derived. An application to the control of pH in a stirred tank is then presented. First, the uncertainty in the pH process is evaluated from first-principle models, then the design of a robust constrained regulator is presented. Simulation results show that this control law is easy to implement and that robust asymptotic stability and control admissibility are guaranteed.

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