A simulation model to evaluate control strategies for the grasshopper Oedaleus senegalensis in West Africa

2007 ◽  
Vol 26 (4) ◽  
pp. 592-601 ◽  
Author(s):  
Eva Nølke Fisker ◽  
Jesper Bak ◽  
Abdoulaye Niassy
Keyword(s):  
West Africa ◽  
Simulation Model ◽  
Control Strategies ◽  
Oedaleus Senegalensis

A migrant pest in the Sahel: the Senegalese grasshopper Oedaleus senegalensis

1990 ◽  
Vol 328 (1251) ◽  
pp. 539-553 ◽  
Keyword(s):  
West Africa ◽  
Control Strategies ◽  
Egg Laying ◽  
Subsistence Agriculture ◽  
Arid Areas ◽  
Major Pest ◽  
Oedaleus Senegalensis ◽  
Semi Arid

The Senegalese grasshopper Oedaleus senegalensis is periodically a major pest of millet and other crops of subsistence agriculture in the Sahel zone of West Africa. Aspects of the species’ biology are described. Eggs can survive several seasons and adults sometimes migrate up to 350 km per night, adaptations that contribute to the species’ success in semi-arid areas. Evidence for migrations, both northwards with the S.W. monsoon and southwards with N.E. harmattan winds, is reviewed with particular reference to studies in Mali and Niger. Control strategies such as monitoring migrations and egg-laying to predict the sites of future outbreaks, possibly up to three years after heavy infestations, are considered.

Comparison of Application of SVC and STATCOM on Suppressing Subsynchronous Oscillation

2014 ◽  
Vol 1070-1072 ◽  
pp. 1144-1149 ◽  
Author(s):  
Qin Lei Chen ◽  
Chun Lin Guo
Keyword(s):  
Simulation Model ◽  
Time Domain ◽  
Reactive Power ◽  
Control Strategies ◽  
Basic Function ◽  
Time Domain Simulation ◽  
Dynamic Compensation ◽  
Benchmark Model ◽  
Subsynchronous Oscillation ◽  
Facts Devices

As the main types of parallel FACTS devices, the basic function of SVC and STATCOM is to realize the dynamic compensation of reactive power and maintain system voltage stability. However, when new control strategies are added to them .Both of them can suppress SSO effectively. Based on IEEE first benchmark model, this paper established simulation model by PSCAD/EMTDC. The effects of suppressing SSO by SVC/STATCOM are verified with time domain simulation, and the comparative analyses are carried out on the effects of suppressing SSO by SVC and STATCOM.

scholarly journals Tactics and Strategies for Managing Ebola Outbreaks and the Salience of Immunization

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Wayne M. Getz ◽  
Jean-Paul Gonzalez ◽  
Richard Salter ◽  
James Bangura ◽  
Colin Carlson ◽  
...  
Keyword(s):  
West Africa ◽  
Simulation Model ◽  
Sierra Leone ◽  
Ebola Virus ◽  
Viral Disease ◽  
Current Generation ◽  
Vaccination Programs ◽  
Contact Rates ◽  
Transmission Chain ◽  
Educational Campaigns

We present a stochastic transmission chain simulation model for Ebola viral disease (EVD) in West Africa, with the salutary result that the virus may be more controllable than previously suspected. The ongoing tactics to detect cases as rapidly as possible and isolate individuals as safely as practicable is essential to saving lives in the current outbreaks in Guinea, Liberia, and Sierra Leone. Equally important are educational campaigns that reduce contact rates between susceptible and infectious individuals in the community once an outbreak occurs. However, due to the relatively low R0 of Ebola (around 1.5 to 2.5 next generation cases are produced per current generation case in naïve populations), rapid isolation of infectious individuals proves to be highly efficacious in containing outbreaks in new areas, while vaccination programs, even with low efficacy vaccines, can be decisive in curbing future outbreaks in areas where the Ebola virus is maintained in reservoir populations.

Research on Modeling and Simulation of Electric Power Steering System for Electric Power Bus

2012 ◽  
Vol 215-216 ◽  
pp. 3-8 ◽  
Author(s):  
Rong Wei Shen ◽  
Xiao Hong Tai
Keyword(s):  
Simulation Model ◽  
Electric Power ◽  
Control Strategies ◽  
Steering System ◽  
Matlab Simulation ◽  
Test Bed ◽  
Power Steering System ◽  
Power Steering ◽  
Power Bus ◽  
Electric Power Steering System

A kind of recirculating ball-type power steering system for electric power bus was designed. The dynamics equations of EPS were analyzed. The simulation model based Matlab/Simulation was build and verified by the experiments on test-bed. Then the simulation test was carried out when vehicle was stationary. The simulation results verify the validity of the simulation model, which creates the research basis for further research of control strategies.

Nocturnal grasshopper migration in West Africa: transport and concentration by the wind, and the implications for air-to-air control

1990 ◽  
Vol 328 (1251) ◽  
pp. 655-672 ◽  
Keyword(s):  
West Africa ◽  
Gravity Waves ◽  
Gravity Currents ◽  
Strategic Control ◽  
Migratory Flight ◽  
Flying Insects ◽  
Convergence Zones ◽  
Air Control ◽  
Atmospheric Gravity ◽  
Oedaleus Senegalensis

During radar observations of the migratory flight of Oedaleus senegalensis and of other grasshoppers in West Africa, we have observed that nocturnally flying insects are sometimes concentrated by mesoscale zones of wind convergence. The concentrations were typically 1.2-2.0 km wide, often more than 20 km long, and were similar to those observed elsewhere. The convergence zones appeared to be usually caused by atmospheric gravity currents. Some of these currents were cold air outflows from rain storms, and others were possibly of katabatic origin. Occasionally zones may also have been caused by bores and gravity waves set off by these currents. In this paper, we investigate the practicability of controlling populations of sahelian grasshoppers by the air-to-air spraying of insecticide onto such concentrations of insects. Using our data on concentration in convergence zones and a rudimentary model of zone distribution and behaviour, we estimate that less than 30% of the flying population of grasshoppers would be entrained in convergence zones, and that effective search for the concentrations might require the simultaneous use of at least two aircraft per 500 km square. These results imply that strategic control by air-to-air spraying is unlikely to be practicable. It is necessary to emphasize, however, that the evidence on which this deduction is based is fragmentary. A much more definitive conclusion could be expected from the results of further research with an aircraft equipped with a windfinding system and a radar able to measure and delineate insect concentrations.

Bovine tuberculosis in badger (Meles Meles ) populations in southwest England: an assessment of past, present and possible future control strategies using simulation modelling

1995 ◽  
Vol 349 (1330) ◽  
pp. 415-432 ◽  
Keyword(s):  
Simulation Model ◽  
Stochastic Simulation ◽  
Bovine Tuberculosis ◽  
Control Strategies ◽  
Oral Vaccine ◽  
Simulation Modelling ◽  
Meles Meles ◽  
Comparative Assessment ◽  
Localized Disease ◽  
Stochastic Simulation Model

A spatial stochastic simulation model was used to compare the efficacy of different badger control policies and to determine the theoretical requirements for the control of endemic bovine tuberculosis in badger populations in southwest England. Culling-based strategies for controlling endemic disease were compared with strategies employing a yet-to-be-developed oral vaccine which would provide uninfected badgers with immunity to the infection. A comparative assessment was made of the efficacy of previous and proposed culling-based strategies employed by the Ministry of Agriculture, Fisheries and Food for the control of localized disease, and the potential for an oral vaccine-based strategy for the control of localized disease was examined.

scholarly journals Control strategies against COVID-19 in China: Significance of effective testing in the long run

PLoS ONE ◽  
2021 ◽  
Vol 16 (7) ◽  
pp. e0253901
Author(s):  
Yatang Lin ◽  
Fangyuan Peng
Keyword(s):  
Simulation Model ◽  
Real Time ◽  
Detection Rate ◽  
Control Strategies ◽  
Human Mobility ◽  
Significant Growth ◽  
Mobility Data ◽  
Time Horizons ◽  
Long Run

The COVID-19 pandemic has become a long-term crisis that calls for long-term solutions. We combined an augmented SEIR simulation model with real-time human mobility data to decompose the effects of lockdown, travel bans and effective testing measures in the curtailment of COVID-19 spread in China over different time horizons. Our analysis reveals that the significant growth in the detection rate of infectious cases, thanks to the expansion in testing efficiency, were as effective as city lockdowns in explaining the reduction in new infections up to mid-March. However, as we extended the analysis to July, increasing the detection rate to at least 50% is the only reliable way to bring the spread under control.

Impact on sludge inventory and control strategies using the benchmark simulation model no. 1 with the Bürger-Diehl settler model

2015 ◽  
Vol 71 (10) ◽  
pp. 1524-1535 ◽  
Author(s):  
E. Torfs ◽  
T. Maere ◽  
R. Bürger ◽  
S. Diehl ◽  
I. Nopens
Keyword(s):  
Simulation Model ◽  
Control Strategies ◽  
Treatment Plant ◽  
Sludge Waste ◽  
Plant Modelling ◽  
Modelling Effort ◽  
And Control ◽  
The Impact ◽  
D Model ◽  
Entire Treatment

An improved one-dimensional (1-D) model for the secondary clarifier, i.e. the Bürger-Diehl model, was recently presented. The decisive difference to traditional layer models is that every detail of the implementation is in accordance with the theory of partial differential equations. The Bürger-Diehl model allows accounting for hindered and compressive settling as well as inlet dispersion. In this contribution, the impact of specific features of the Bürger-Diehl model on settler underflow concentration predictions, plant sludge inventory and mixed liquor suspended solids based control actions are investigated by using the benchmark simulation model no. 1. The numerical results show that the Bürger-Diehl model allows for more realistic predictions of the underflow sludge concentration, which is essential for more accurate wet weather modelling and sludge waste predictions. The choice of secondary settler model clearly has a profound impact on the operation and control of the entire treatment plant and it is recommended to use the Bürger-Diehl model as of now in any wastewater treatment plant modelling effort.

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