scholarly journals Oscillation in Pest Population and Its Management: A Mathematical Study

2013 ◽  
Vol 2013 ◽  
pp. 1-12
Author(s):  
Samit Bhattacharyya ◽  
Suma Ghosh
Keyword(s):  
Pest Control ◽  
Control Function ◽  
Control Process ◽  
Control Model ◽  
Pest Population ◽  
Optimal Analysis ◽  
Insect Ecology ◽  
And Control ◽  
Special Case

We study the role of predation dynamics in oscillation of pest population in insect ecology. A two-dimensional pest control model (under the use of insecticides) with time delay in predation is considered in this paper. By the Hopf bifurcation theory, we prove the existence of the stable oscillation of the system. We also consider the economic viability of the control process. First we improve the Pontryagin maximum principle (PMP) where the delay in the system is sufficiently small and control function is linear, and then we apply the improved version of PMP to perform the optimal analysis of the pest control model as a special case.

scholarly journals Dynamics of a Stage Structure Pest Control Model with Impulsive Effects at Different Fixed Time

2009 ◽  
Vol 2009 ◽  
pp. 1-15 ◽  
Author(s):  
Bing Liu ◽  
Ying Duan ◽  
Yinghui Gao
Keyword(s):  
Time Delay ◽  
Pest Control ◽  
Natural Enemies ◽  
Stage Structure ◽  
Threshold Level ◽  
Fixed Time ◽  
Control Model ◽  
Pest Population ◽  
Maturation Time ◽  
Maturation Time Delay

Many existing pest control models, which control pests by releasing natural enemies, neglect the effect that natural enemies may get killed. From this point of view, we formulate a pest control model with stage structure for the pest with constant maturation time delay (through-stage time delay) and periodic releasing natural enemies and natural enemies killed at different fixed time and perform a systematic mathematical and ecological study. By using the comparison theorem and analysis method, we obtain the conditions for the global attractivity of the pest-eradication periodic solution and permanence of the system. We also present a pest management strategy in which the pest population is kept under the economic threshold level (ETL) when the pest population is uniformly permanent. We show that maturation time delay, impulsive releasing, and killing natural enemies can bring great effects on the dynamics of the system. Numerical simulations confirm our theoretical results.

Knowledge Management

2012 ◽  
Vol 3 (3) ◽  
pp. 58-67 ◽  
Author(s):  
Hesham Bin-Abbas ◽  
Saad Haj Bakry
Keyword(s):  
Knowledge Management ◽  
Six Sigma ◽  
Knowledge Society ◽  
Control Process ◽  
Economic Benefits ◽  
Knowledge Based ◽  
Multi Level ◽  
And Control ◽  
Future Work

Building a knowledge-based society is widely recognized as leading to human, social and economic benefits. This paper explores the issue of using knowledge management as an instrument for the development and sustainability of this knowledge society. The paper attempts to achieve its purpose through four main integrated steps: providing a brief review of knowledge management and the knowledge society; viewing knowledge management according to the STOPE “strategy, technology, organization, people and the environment” scope; incorporating knowledge management into the six-sigma DMAIC “define, measure, analyze, improve, and control” process; and deriving observations on the outcome, and producing guidelines for future work. The paper emphasizes the claim that developing and continuously sustaining the knowledge society can be achieved by applying knowledge management through building it into the STOPE scope and the six-sigma process, and by considering the multi-level nature of the society. The paper enjoys a high potential as a guide to knowledge management driven development and sustainability of the knowledge society at all levels. This would be beneficial to all those interested and concerned with supporting the role of knowledge in their own societies.

scholarly journals Online Allies and Tricky Freelancers: Understanding the Differences in the Role of Social Media in the Campaigns for the Scottish Independence Referendum

2019 ◽  
Vol 67 (4) ◽  
pp. 834-854 ◽  
Author(s):  
Ana Ines Langer ◽  
Michael Comerford ◽  
Des McNulty
Keyword(s):  
Social Media ◽  
Strategic Change ◽  
Digital Communications ◽  
Command And Control ◽  
Control Model ◽  
Grassroots Organizations ◽  
Communications Technologies ◽  
Scottish Independence ◽  
And Control

Using the 2014 Scottish independence referendum as a case study, this article asks first, to what extent is the use of digital communications technologies, in particular social media, associated with fundamental changes to campaign organizations, specifically to the command and control model? Second, under what conditions are challenges to the model more likely to emerge? Using mixed methods, our analysis of the case demonstrates that radical organizational or strategic change is not inevitable, nor is there a one-size-fits-all approach. Technologies are not ‘just tools’ that any campaign with enough resources will adopt in similar ways. Instead, depending on a number of interdependent factors (i.e. context, resources, strategy, organizational structure and culture), some campaigns – like Better Together – selectively adopt digital tools that fit with the command and control model; in other cases – like Yes Scotland – the application of digital communications technologies and the dynamics created by linking to other (digital-enabled) grassroots organizations can have transformative effects.

Role of latency period in viral infection: A pest control model

2007 ◽  
Vol 210 (2) ◽  
pp. 619-646 ◽  
Author(s):  
S. Ghosh ◽  
S. Bhattacharyya ◽  
D.K. Bhattacharya
Keyword(s):  
Viral Infection ◽  
Pest Control ◽  
Latency Period ◽  
Control Model

scholarly journals Local CPG Self Growing Network Model with Multiple Physical Properties

2020 ◽  
Vol 10 (16) ◽  
pp. 5497
Author(s):  
Ming Liu ◽  
Mantian Li ◽  
Fusheng Zha ◽  
Pengfei Wang ◽  
Wei Guo ◽  
...  
Keyword(s):  
Neural Network ◽  
Growth And Development ◽  
Control Function ◽  
Axon Growth ◽  
Control Model ◽  
Control Network ◽  
Transfer Model ◽  
Axon Membrane ◽  
Control Functions ◽  
And Control

Compared with traditional control methods, the advantage of CPG (Central Pattern Generator) network control is that it can significantly reduce the size of the control variable without losing the complexity of its motion mode output. Therefore, it has been widely used in the motion control of robots. To date, the research into CPG network has been polarized: one direction has focused on the function of CPG control rather than biological rationality, which leads to the poor functional adaptability of the control network and means that the control network can only be used under fixed conditions and cannot adapt to new control requirements. This is because, when there are new control requirements, it is difficult to develop a control network with poor biological rationality into a new, qualified network based on previous research; instead, it must be explored again from the basic link. The other direction has focused on the rationality of biology instead of the function of CPG control, which means that the form of the control network is only similar to a real neural network, without practical use. In this paper, we propose some physical characteristics (including axon resistance, capacitance, length and diameter, etc.) that can determine the corresponding parameters of the control model to combine the growth process and the function of the CPG control network. Universal gravitation is used to achieve the targeted guidance of axon growth, Brownian random motion is used to simulate the random turning of axon self-growth, and the signal of a single neuron is established by the Rall Cable Model that simplifies the axon membrane potential distribution. The transfer model, which makes the key parameters of the CPG control network—the delay time constant and the connection weight between the synapses—correspond to the axon length and axon diameter in the growth model and the growth and development of the neuron processes and control functions are combined. By coordinating the growth and development process and control function of neurons, we aim to realize the control function of the CPG network as much as possible under the conditions of biological reality. In this way, the complexity of the control model we develop will be close to that of a biological neural network, and the control network will have more control functions. Finally, the effectiveness of the established CPG self-growth control network is verified through the experiments of the simulation prototype and experimental prototype.

A pest control model with state-dependent impulses

2015 ◽  
Vol 08 (01) ◽  
pp. 1550009 ◽  
Author(s):  
Xuehui Ji ◽  
Sanling Yuan ◽  
Lansun Chen
Keyword(s):  
Periodic Solution ◽  
Pest Control ◽  
Control Model ◽  
Point Of View ◽  
Successor Function ◽  
Pest Population ◽  
Single Measure ◽  
State Dependent ◽  
Two Measures ◽  
Order One Periodic Solution

In this paper, a pest control model with state-dependent impulses is firstly established, which relies on releasing of natural enemies, together with spraying pesticides. By using the successor function of differential equation geometry rules, the existence of order one periodic solution is discussed. According to the Analogue of Poincaré's Criterion, the orbitally asymptotic stability of the order one periodic solution is obtained. Furthermore, we investigated the global attractor of the system. From a biological point of view, our results indicate that: (1) the pest population can be controlled below some threshold; (2) compared to single measure, it is more efficient to take two measures for reducing the level of the pests.

Based on Multi-Estimator Technology to Control Speed of Induction Motor

2014 ◽  
Vol 577 ◽  
pp. 329-333
Author(s):  
Su Mei Feng ◽  
Zhi Ping Yan ◽  
Xue Mei Wu
Keyword(s):  
Induction Motor ◽  
Control Function ◽  
Control Process ◽  
Motor Speed ◽  
Speed Sensor ◽  
Control Scheme ◽  
Self Tuning ◽  
Rotor Flux ◽  
On Line ◽  
And Control

In order to improve the reliability of the control system, and to reduce the uncertainty of control process, this paper presents an excellent algorithm to control the induction motor speed using series estimator technology. The physical speed sensor is not used to detect speed of the motor, while applying the vector analysis method, through the stator current and the rotor flux are calculated to estimate motor speed. Corresponding to sensorless control drawbacks, the self-tuning control scheme is proposed through control scheme reformed. The double estimator technology is applied to reform scheme, the first order estimator is used to identify the system parameters, the second order estimator is used to calculate the parameters of the controller on-line, and control function is given real-time to control the speed of the motor, the simulation results show that the given control technology is advanced.

scholarly journals The Role of the Energy Sector in the Command and Control Function of Cities in Conditions of Sustainability Transitions

Energies ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 7579
Author(s):  
Piotr Raźniak ◽  
Sławomir Dorocki ◽  
Tomasz Rachwał ◽  
Anna Winiarczyk-Raźniak
Keyword(s):  
Financial Performance ◽  
Control Function ◽  
Command And Control ◽  
Energy Sector ◽  
Financial Health ◽  
Economic Recessions ◽  
The World ◽  
And Control

The largest companies that are part of the energy sector are defined by Forbes as those associated with the production of energy from nonrenewable sources and they play a very significant role in the world economy and in the generation of the command and control (C & C) function of cities. No comprehensive studies are available at the present time illustrating changes in financial performance in relation to the share of the largest firms in the energy sector in terms of their role in the generation of the C & C function. Thus, the aim of the paper is to show changes in financial performance and the impacts of energy sector companies on the C & C function of cities as well as to show spatial variances in the sector’s geography. The energy sector is developing most rapidly in Chinese cities, although it does not play a major role in the most important cities in the world via its impact on the C & C function—this may be due to rapid growth in other sectors of the economy. It is, however, very important in smaller cities. On the other hand, a large share of the energy sector involved in the development of renewable sources of energy may disturb the position of cities whose C & C function relies on energy sector companies. Thus, forecasts are needed for the sector and its impact on the command and control function of cities for the period of transition from nonrenewable sources to renewable ones. One new area of research is the formulation of methods that would allow the determination of the effects of economic recessions in the future on the financial health and C & C function impacts of the energy sector.

The role of dialogue between executives and ground-level employees mediated by MACS

2014 ◽  
Vol 9 (2) ◽  
pp. 189-212 ◽  
Author(s):  
Ülle Pärl
Keyword(s):  
Control Function ◽  
Ground Level ◽  
Business Environment ◽  
Open Communication ◽  
Content Type ◽  
Lack Of Information ◽  
And Control ◽  
A Company

Purpose – The purpose is to understand the manner in which companies use management accounting and control systems (MACS) for dialogical communication in assisting collaboration and the coordination of actions. The task of the research is to answer the following questions: why is it important to support dialogical communication by MACS in the organisation? Who are the salient stakeholder(s) in a company implementing collaboration and cooperation? How does one analyse and understand the role of MACS as a medium for supporting dialogical communication? Which aspects of dialogical communication are (not) fulfilled in the implementation of MACS and why? Design/methodology/approach – This study's philosophical assumptions are based on relational constructivism as a social science perspective. This study uses a participative action and observation case study as its methodology. Findings – Based on this case study, it can be concluded that most of the assumptions that dialogue could take place were fulfilled in departments in need of changes for competition and economic reasons. In the departments that did not need changes, assumptions of mutual openness, mutual confirmation and non-manipulation were not fulfilled – information from MACS was hidden and censored. The open dialogue by MACS between ground and senior groups was prevented resulting in a lack of information on different practices at the organisational level. One assumption that was problematic even in departments in need of changes was the assumption of non-evaluation. There is a paradox or contradiction between the contemporary business environment needing innovativeness and creativity, which means free and open communication without evaluation, and the coordination and control function which is a common part of MACS. Research limitations/implications – In this study, the data collection, documentation and analysis were carefully conducted and several methods applied to deal with possible bias. Nevertheless, the problem of the observer bias cannot be entirely eliminated since an individual researcher can never be separated from his or her background, philosophical views and experiences. Practical implications – The paper makes a strong practical contribution. Based on this case study, it has been demonstrated that MACS could be a medium to support dialogue between senior and ground levels if: senior management sees the need for dialogue between organisational members; management and other organisational members support and believe in dialogue which could be mediated by MACS. Originality/value – The conceptual novelty of the research lies in tying the concept of dialogue in the environment of stakeholder capitalism with the MACS framework. The contribution of this research is to shed more light on the role of MACS as one option of mediums for supporting dialogue between top and ground-level managers.

scholarly journals On optimal boundary and distributed control of partial integro–differential equations

2014 ◽  
Vol 24 (1) ◽  
pp. 5-25 ◽  
Author(s):  
Asatur Zh. Khurshudyan
Keyword(s):  
Differential Equations ◽  
Control Problem ◽  
Integral Transform ◽  
Control Function ◽  
Sufficient Conditions ◽  
Control Process ◽  
Problem Solution ◽  
Control Functions ◽  
Minimization Procedure ◽  
And Control

Abstract A method of optimal control problems investigation for linear partial integro-differential equations of convolution type is proposed, when control process is carried out by boundary functions and right hand side of equation. Using Fourier real generalized integral transform control problem solution is reduced to minimization procedure of chosen optimality criterion under constraints of equality type on desired control function. Optimality of control impacts is obtained for two criteria, evaluating their linear momentum and total energy. Necessary and sufficient conditions of control problem solvability are obtained for both criteria. Numerical calculations are done and control functions are plotted for both cases of control process realization.

Sign in / Sign up

Export Citation Format

Share Document