The Experts below are selected from a list of 5706 Experts worldwide ranked by ideXlab platform
Ivan Samylovskiy - One of the best experts on this subject based on the ideXlab platform.
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ECC - Optimal trajectories in a maximal height problem for a simplified version of the Goddard model in case of generalized media resistance function
2015 European Control Conference (ECC), 2015Co-Authors: A V Dmitruk, Ivan SamylovskiyAbstract:We consider a family of the problems on maximization of the height of the vertical flight of a material point in the presence of a nonlinear friction and a constant flat gravity field under a bounded thrust and Fuel Expenditure. Using the maximum principle we obtain classification of trajectories (w.r.t. problem parameters) which are suspected to be optimal and check that for some classical rocket systems optimal control in our model is the classical bang-bang or bang-singular-bang one. We obtain some new types of “potentially-optimal” trajectories which should be investigated.
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Classification of extremals in a simplified Goddard model on the maximal height of rocket flight
arXiv: Optimization and Control, 2014Co-Authors: A V Dmitruk, Ivan SamylovskiyAbstract:We consider a problem on maximizing the height of vertical flight of a material point ("meteorological rocket") in the presence of a nonlinear friction and a constant flat gravity field under a bounded thrust and Fuel Expenditure. The original Goddard problem is simplified by removing the dependence on the rocket mass from the equations of motion. Using the maximum principle we find all possible types of Pontryagin extremals and classify them w.r.t. problem parameters. Since the velocity of the point can be negative, we obtain some new types of extremals with two or three switching points, which optimality should be further investigated.
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on a trolley like problem in the presence of a nonlinear friction and a bounded Fuel Expenditure
Asian Control Conference, 2013Co-Authors: A V Dmitruk, Ivan SamylovskiyAbstract:We consider a problem of maximization of the distance traveled by a material point in the presence of a nonlinear friction under a bounded thrust and Fuel Expenditure. Using the maximum principle we obtain the form of optimal control and establish conditions under which it contains a singular subarc. This problem seems to be the simplest one having a mechanical sense in which singular subarcs appear in a nontrivial way.
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ASCC - On a trolley-like problem in the presence of a nonlinear friction and a bounded Fuel Expenditure
2013 9th Asian Control Conference (ASCC), 2013Co-Authors: A V Dmitruk, Ivan SamylovskiyAbstract:We consider a problem of maximization of the distance traveled by a material point in the presence of a nonlinear friction under a bounded thrust and Fuel Expenditure. Using the maximum principle we obtain the form of optimal control and establish conditions under which it contains a singular subarc. This problem seems to be the simplest one having a mechanical sense in which singular subarcs appear in a nontrivial way.
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A simple trolley-like model in the presence of a nonlinear friction and a bounded Fuel Expenditure
Discussiones Mathematicae. Differential Inclusions Control and Optimization, 2013Co-Authors: A V Dmitruk, Ivan SamylovskiyAbstract:Lomonosov Moscow State UniversityFaculty of Computational Mathematics and CyberneticsRussia, Moscow, Leninskiye Gory, MSUe-mail: barbudo.sam@cs.msu.suAbstractWe consider a problem of maximization of the distance traveled by amaterial point in the presence of a nonlinear friction under a bounded thrustand Fuel Expenditure. Using the maximum principle we obtain the form ofoptimal control and establish conditions under which it contains a singularsubarc. This problem seems to be the simplest one having a mechanicalsense in which singular subarcs appear in a nontrivial way.Keywords: optimal control problem, Pontryagin Maximum Principle,extremals, singular arcs.2010 Mathematics Subject Classification: 49K15, 49N90.
Geoffrey A. Landis - One of the best experts on this subject based on the ideXlab platform.
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Satellite relocation by tether deployment
Journal of Guidance Control and Dynamics, 1991Co-Authors: Geoffrey A. Landis, Frank J. HrachAbstract:Several new uses of satellite tethers are discussed, including: (1) using tether extension to reposition a satellite in orbit without Fuel Expenditure by extending a mass on the end of a tether; (2) using a tether for energy storage to power the satellite during eclipse; and (3) using a tether for eccentricity pumping to correct perturbations in the orbit and as a means of adding energy to the orbit for boosting and orbital transfer.
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Reactionless propulsion using tethers
1990Co-Authors: Geoffrey A. LandisAbstract:An orbiting tethered satellite can propel itself by reaction against the gravitational gradient, with Expenditure of energy but with no use of on-board reaction mass. Energy can be added to the orbit by pumping the tether length in the same way as pumping a swing. Examples of tether propulsion in orbit without use of reaction mass are discussed, including: (1) using tether extension to reposition a satellite in orbit without Fuel Expenditure by extending a mass on the end of a tether; (2) using a tether for eccentricity pumping to add energy to the orbit for boosting an orbital transfer; and (3) length modulation of a spinning tether to transfer angular momentum between the orbit and tether spin, thus allowing changes in orbital angular momentum.
A V Dmitruk - One of the best experts on this subject based on the ideXlab platform.
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ECC - Optimal trajectories in a maximal height problem for a simplified version of the Goddard model in case of generalized media resistance function
2015 European Control Conference (ECC), 2015Co-Authors: A V Dmitruk, Ivan SamylovskiyAbstract:We consider a family of the problems on maximization of the height of the vertical flight of a material point in the presence of a nonlinear friction and a constant flat gravity field under a bounded thrust and Fuel Expenditure. Using the maximum principle we obtain classification of trajectories (w.r.t. problem parameters) which are suspected to be optimal and check that for some classical rocket systems optimal control in our model is the classical bang-bang or bang-singular-bang one. We obtain some new types of “potentially-optimal” trajectories which should be investigated.
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Classification of extremals in a simplified Goddard model on the maximal height of rocket flight
arXiv: Optimization and Control, 2014Co-Authors: A V Dmitruk, Ivan SamylovskiyAbstract:We consider a problem on maximizing the height of vertical flight of a material point ("meteorological rocket") in the presence of a nonlinear friction and a constant flat gravity field under a bounded thrust and Fuel Expenditure. The original Goddard problem is simplified by removing the dependence on the rocket mass from the equations of motion. Using the maximum principle we find all possible types of Pontryagin extremals and classify them w.r.t. problem parameters. Since the velocity of the point can be negative, we obtain some new types of extremals with two or three switching points, which optimality should be further investigated.
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on a trolley like problem in the presence of a nonlinear friction and a bounded Fuel Expenditure
Asian Control Conference, 2013Co-Authors: A V Dmitruk, Ivan SamylovskiyAbstract:We consider a problem of maximization of the distance traveled by a material point in the presence of a nonlinear friction under a bounded thrust and Fuel Expenditure. Using the maximum principle we obtain the form of optimal control and establish conditions under which it contains a singular subarc. This problem seems to be the simplest one having a mechanical sense in which singular subarcs appear in a nontrivial way.
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ASCC - On a trolley-like problem in the presence of a nonlinear friction and a bounded Fuel Expenditure
2013 9th Asian Control Conference (ASCC), 2013Co-Authors: A V Dmitruk, Ivan SamylovskiyAbstract:We consider a problem of maximization of the distance traveled by a material point in the presence of a nonlinear friction under a bounded thrust and Fuel Expenditure. Using the maximum principle we obtain the form of optimal control and establish conditions under which it contains a singular subarc. This problem seems to be the simplest one having a mechanical sense in which singular subarcs appear in a nontrivial way.
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A simple trolley-like model in the presence of a nonlinear friction and a bounded Fuel Expenditure
Discussiones Mathematicae. Differential Inclusions Control and Optimization, 2013Co-Authors: A V Dmitruk, Ivan SamylovskiyAbstract:Lomonosov Moscow State UniversityFaculty of Computational Mathematics and CyberneticsRussia, Moscow, Leninskiye Gory, MSUe-mail: barbudo.sam@cs.msu.suAbstractWe consider a problem of maximization of the distance traveled by amaterial point in the presence of a nonlinear friction under a bounded thrustand Fuel Expenditure. Using the maximum principle we obtain the form ofoptimal control and establish conditions under which it contains a singularsubarc. This problem seems to be the simplest one having a mechanicalsense in which singular subarcs appear in a nontrivial way.Keywords: optimal control problem, Pontryagin Maximum Principle,extremals, singular arcs.2010 Mathematics Subject Classification: 49K15, 49N90.
Frank J. Hrach - One of the best experts on this subject based on the ideXlab platform.
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Satellite relocation by tether deployment
Journal of Guidance Control and Dynamics, 1991Co-Authors: Geoffrey A. Landis, Frank J. HrachAbstract:Several new uses of satellite tethers are discussed, including: (1) using tether extension to reposition a satellite in orbit without Fuel Expenditure by extending a mass on the end of a tether; (2) using a tether for energy storage to power the satellite during eclipse; and (3) using a tether for eccentricity pumping to correct perturbations in the orbit and as a means of adding energy to the orbit for boosting and orbital transfer.
Mihir Dash - One of the best experts on this subject based on the ideXlab platform.
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Firm-Level Determinants of Cost Structure of the Indian Sugar Industry
Journal of Applied Management and Investments, 2020Co-Authors: Mihir DashAbstract:This study examines the firm-level determinants of cost structure for sugar manufacturing companies in India. Cost structure is an important aspect in profitability planning, and particularly so for the Indian sugar manufacturing industry, as sugar production costs have been very high as compared to global sugar production costs. The sample for the study included fifteen listed sugar manufacturing companies for the period 2008-18. The study uses fixed-effects panel regression models, with size (logarithm of total assets), leverage (debt-equity ratio), asset tangibility (fixed assets as a percentage of total assets), growth rate of sales, and profitability (return on assets) as the independent variables, and the raw material Expenditure, power/Fuel Expenditure, employee Expenditure, other manufacturing Expenditure, and selling/administrative Expenditure (as percentages of the total Expenditure) as the dependent variables. The study contributes to the literature by considering an area that has not been addressed in the literature, viz. firm-level determinants of cost structure. The key results of the study were significant positive sales growth effects on raw materials Expenditure and employee Expenditure, and significant negative sales growth effects on power/Fuel Expenditure and selling/administrative Expenditure; a significant negative profitability effect on power/Fuel Expenditure; significant negative size effects on raw materials Expenditure and significant positive size effects on power/Fuel Expenditure and selling/administrative Expenditure; and a significant negative asset tangibility effect on other manufacturing Expenditure.
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Applicability of the CVP Model for the Indian Sugar Sector
2020Co-Authors: Mihir DashAbstract:This study examines the applicability of the Cost-Volume-Profit (CVP) model empirically for Indian sugar manufacturing companies using linear and quadratic regression. The results of the study indicate that the linear CVP model is more appropriate than the quadratic CVP model for Indian sugar manufacturing companies. However, the slope coefficients were not correlated with profitability, which is contrary to the predictions of the model; they were positively correlated with mean and standard deviation of Power & Fuel Expenditure and negatively correlated with mean Employee Expenditure. This suggests that a quadratic regression of TR on the different components of total cost may have been more appropriate.
