ESTIMATION OF CONTROL ENERGY AND CONTROL STRATEGIES FOR COMPLEX NETWORKS

2015 ◽  
Vol 18 (07n08) ◽  
pp. 1550018 ◽  
Author(s):  
DINGJIE WANG ◽  
SUOQIN JIN ◽  
FANG-XIANG WU ◽  
XIUFEN ZOU
Keyword(s):  
Complex Networks ◽  
Numerical Simulations ◽  
Energy Cost ◽  
Control Strategies ◽  
Energy Costs ◽  
Theoretical Derivation ◽  
Complete Control ◽  
Undirected Network ◽  
Normal Networks ◽  
And Control

The controlling of complex networks is one of the most challenging problems in modern network science. Accordingly, the required energy cost of control is a fundamental and significant problem. In this paper, we present the theoretical analysis and numerical simulations to study the controllability of complex networks from the energy perspective. First, by combining theoretical derivation and numerical simulations, we obtain lower bounds of the maximal and minimal energy costs for an arbitrary normal network, which are related to the eigenvalues of the state transition matrix. Second, we deduce that controlling unstable normal networks is easier than controlling stable normal networks with the same size. Third, we demonstrate a tradeoff between the control energy and the average degree (or the maximum degree) of an arbitrary undirected network. Fourth, numerical simulations show that the energy cost is negatively correlated with the degree of nodes. Moreover, the combinations of control nodes with the greater sum of degree need less energy to implement complete control. Finally, we propose a multi-objective optimization model to obtain the control strategy, which not only ensures the fewer control nodes but also guarantees the less energy cost of control.

scholarly journals Modelling, Simulations and Analysis of the First and Second COVID-19 Epidemics in Beijing

2021 ◽  
Author(s):  
Lequan Min
Keyword(s):  
Numerical Simulations ◽  
Prevention And Control ◽  
Control Strategies ◽  
Equation Model ◽  
Control Measures ◽  
Disease Spreading ◽  
Prevention And Control Measures ◽  
Asymptomatic Individuals ◽  
Reported Data ◽  
And Control

AbstractTo date, over 130 million people on infected with COVID-19. It causes more 2.8 millions deaths. This paper introduces a symptomatic-asymptomatic-recoverer-dead differential equation model (SARDDE). It gives the conditions of the asymptotical stability on the disease-free equilibrium of SARDDE. It proposes the necessary conditions of disease spreading for the SARDDE. Based on the reported data of the first and the second COVID-19 epidemics in Beijing and simulations, it determines the parameters of SARDDE, respectively. Numerical simulations of SARDDE describe well the outcomes of current symptomatic and asymptomatic individuals, recovered symptomatic and asymptomatic individuals, and died individuals, respectively. The numerical simulations suggest that both symptomatic and asymptomatic individuals cause lesser asymptomatic spread than symptomatic spread; blocking rate of about 90% cannot prevent the spread of the COVID19 epidemic in Beijing; the strict prevention and control strategies implemented by Beijing government is not only very effective but also completely necessary. The numerical simulations suggest also that using the data from the beginning to the day after about two weeks at the turning point can estimate well or approximately the following outcomes of the two COVID-19 academics, respectively. It is expected that the research can provide better understanding, explaining, and dominating for epidemic spreads, prevention and control measures.

scholarly journals Modelling, Simulations and Analysis of the First COVID-19 Epidemic in Shanghai

2021 ◽  
Author(s):  
Lequan Min
Keyword(s):  
Numerical Simulations ◽  
Prevention And Control ◽  
Control Strategies ◽  
Equation Model ◽  
Control Measures ◽  
Differential Equation Model ◽  
Blocking Rate ◽  
Prevention And Control Measures ◽  
Asymptomatic Individuals ◽  
And Control

To date, over 178 million people on infected with COVID-19. It causes more 3.8 millions deaths. Based on a previous symptomatic-asymptomatic-recoverer-dead differential equation model (SARDDE) and the clinic data of the first COVID-19 epidemic in Shanghai, this paper determines the parameters of SARDDE. Numerical simulations of SARDDE describe well the outcomes of current symptomatic individuals, recovered symptomatic individuals, and died individuals, respectively. The numerical simulations suggest that both symptomatic and asymptomatic individuals cause lesser asymptomatic spread than symptomatic spread; blocking rate of about 95.5\% cannot prevent the spread of the COVID19 epidemic in Shanghai. The strict prevention and control strategies implemented by Shanghai government is not only very effective but also completely necessary. The numerical simulations suggest also that using the data from the beginning to the day after about 19 days at the turning point can estimate well the following outcomes of the COVID-19 academic. It is expected that the research can provide better understanding, explaining, and dominating for epidemic spreads, prevention and control measures.

scholarly journals Modelling, Simulations and Analysis of the First and Second COVID-19 Epidemics in Beijing

2021 ◽  
Author(s):  
Lequan Min
Keyword(s):  
Numerical Simulations ◽  
Prevention And Control ◽  
Control Strategies ◽  
Equation Model ◽  
Control Measures ◽  
Virtual Simulations ◽  
Prevention And Control Measures ◽  
Asymptomatic Individuals ◽  
Reported Data ◽  
And Control

To date, over 182 million people on infected with COVID-19. It causes more 3.9 millions deaths. This paper introduces a symptomatic-asymptomatic-recoverer-dead differential equation model (SARDDE). It gives the conditions of the asymptotical stability on the disease-free equilibrium of SARDDE. It proposes the necessary conditions of disease spreading for the SARDDE. Based on the reported data of the first and the second COVID-19 epidemics in Beijing and simulations, it determines the parameters of SARDDE, respectively. Numerical simulations of SARDDE describe well the outcomes of current symptomatic and asymptomatic individuals, recovered symptomatic and asymptomatic individuals, and died individuals, respectively. The numerical simulations suggest that both symptomatic and asymptomatic individuals cause lesser asymptomatic spread than symptomatic spread; the blocking rates of about 80% and 97.5% to the symptomatic individuals cannot prevent the spread of the first and second COVID19 epidemics in Beijing, respectively. Virtual simulations suggest that the strict prevention and control strategies implemented by Beijing government are not only very effective but also completely necessary. The numerical simulations suggest also that using the data from the beginning to the day after about 14 -- 17 days at the turning point can estimate well the following outcomes of the two COVID-19 academics, respectively. It is expected that the research can provide better understanding, explaining, and dominating for epidemic spreads, prevention and control measures.

DC-DC Micro-Converter Photovoltaic Topology With Sensors Suppression

2020 ◽  
Author(s):  
Douglas Ohf ◽  
Tiago Dezuo ◽  
Bárbara A. de Sá
Keyword(s):  
Numerical Simulations ◽  
System Architecture ◽  
Control Strategies ◽  
Priority Queue ◽  
Fast Response ◽  
Control Techniques ◽  
Global Power ◽  
Converter Topologies ◽  
The Cost ◽  
And Control

This paper presents a novel system architecture intended to improve the cost-eciency of DC micro-converter topologies by reducing the number of local sensors and centralizing the MPPT and control strategies to a single microprocessor. The rst idea is to locally measure only the sensors required by the control, as it runs intermittently and needs a fast response for stability, and to use control techniques that naturally require less sensors. Second, we propose an MPPT strategy that relies on measuring the global power generated, by only acquiring the current reaching the DC link or battery and updating the operating point of each module one at a time. A problem that occurs when sequentially updating the modules is the possibility of power drop in a panel that is far from being re-updated, which may also lead to wrong conclusions about the module being currently updated. For that we also propose a method for detecting power drops and momentarily establishing a priority queue. The advantages of the proposed method are illustrated through numerical simulations.

Dynamic Modelling and Control Strategies of Space Manipulators

1993 ◽  
Vol 46 (11S) ◽  
pp. S165-S172
Author(s):  
A. Ercoli-Finzi ◽  
P. Mantegazza
Keyword(s):  
Numerical Simulations ◽  
Control Strategies ◽  
Equations Of Motion ◽  
Dynamic Modelling ◽  
Mixed Control ◽  
Space Manipulators ◽  
Pick And Place ◽  
Manipulator Arm ◽  
And Control

In this work the dynamics of a manipulator arm is analyzed by Maggi’s formulation and by automatic development of the equations of motion. Two control strategies, that is an adaptive and a standard one, are taken into account in order to satisfactory perform pick and place maneuvers. Numerical simulations emphasize performance qualities and limits of the two choices and suggest a possible implementation of mixed control strategies.

Effective infection prevention and control strategies in a large accredited psychiatric facility in Singapore

2020 ◽  
Author(s):  
Daniel Poremski ◽  
Sandra Henrietta Subner ◽  
Grace Lam Fong Kin ◽  
Raveen Dev Ram Dev ◽  
Mok Yee Ming ◽  
...  
Keyword(s):  
Mental Health ◽  
Prevention And Control ◽  
Infection Prevention ◽  
Control Strategies ◽  
Infection Prevention And Control ◽  
Psychiatric Facility ◽  
Essential Services ◽  
Community Transmission ◽  
And Control

The Institute of Mental Health in Singapore continues to attempt to prevent the introduction of COVID-19, despite community transmission. Essential services are maintained and quarantine measures are currently unnecessary. To help similar organizations, strategies are listed along three themes: sustaining essential services, preventing infection, and managing human and consumable resources.

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