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Physical Sciences and Mathematics Commons™

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Journal

2014

Stability

Articles 1 - 4 of 4

Full-Text Articles in Physical Sciences and Mathematics

Modelling The Dynamics Of A Renewable Resource Under Harvesting With Taxation As A Control Variable, B. Dubey, Atasi Patra, S. K. Sahani Dec 2014

Modelling The Dynamics Of A Renewable Resource Under Harvesting With Taxation As A Control Variable, B. Dubey, Atasi Patra, S. K. Sahani

Applications and Applied Mathematics: An International Journal (AAM)

The present paper describes a model of resource biomass and population with a non-linear catch rate function on resource biomass. The harvesting effort is assumed to be a dynamical variable. Tax on per unit harvested resource biomass is used as a tool to control exploitation of the resource. Pontryagin’s Maximum Principle is used to find the optimal control to maintain the resource biomass and population at an optimal level. A numerical simulation is also carried out to support the analytical results.

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Electrochemical Catalysis: A Dft Study, Li Li, Zi-Dong Wei Aug 2014

Electrochemical Catalysis: A Dft Study, Li Li, Zi-Dong Wei

Journal of Electrochemistry

In this review, we focus on achievements in electro-catalysis based on the density function theory study. The relationships among the electrode potential, electronic structure of catalysts and electro-catalytic activity are summarized in three parts: the adsorption and desorption of species, electron transfer, and stability of catalysts. The electrode potential and the electronic structure (d-band center or Fermi (HOMO) energy) of catalysts significantly influence the formation, adsorption and desorption of surface species on electrode. The electro-catalytic activity can be improved by modulating the electrode potential and electronic structure of catalysts.

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Dynamics Of Phytoplankton, Zooplankton And Fishery Resource Model, B. Dubey, Atasi Patra, R. K. Upadhyay Jun 2014

Dynamics Of Phytoplankton, Zooplankton And Fishery Resource Model, B. Dubey, Atasi Patra, R. K. Upadhyay

Applications and Applied Mathematics: An International Journal (AAM)

In this paper, a new mathematical model has been proposed and analyzed to study the interaction of phytoplankton- zooplankton-fish population in an aquatic environment with Holloing’s types II, III and IV functional responses. It is assumed that the growth rate of phytoplankton depends upon the constant level of nutrient and the fish population is harvested according to CPUE (catch per unit effort) hypothesis. Biological and bionomical equilibrium of the system has been investigated. Using Pontryagin’s Maximum Principal, the optimal harvesting policy is discussed. Chaotic nature and bifurcation analysis of the model system for a control parameter have been observed through …

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Dynamics, Stability, And Actuation Methods For Powered Compass Gait Walkers, Koray Kadi̇r Şafak Jan 2014

Dynamics, Stability, And Actuation Methods For Powered Compass Gait Walkers, Koray Kadi̇r Şafak

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, methods to achieve actively powered walking on level ground using a simple 2-dimensional walking model (compass-gait walker) are explored. The walker consists of 2 massless legs connected at the hip joint, a point mass at the hip, and an infinitesimal point mass at the feet. The walker is actuated either by applying equal joint torques at the hip and ankle, by an impulse applied at the toe off, immediately before the heel strike, or by the combination of both. It is shown that actuating the walker by equal joint torques at the hip and ankle on level …

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