Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 44 for “"shape control"”.
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Algorithms for closed loop shape control
… tool is used in conjunction with a self-tuning shape control algorithm, which guides the die to the correct shape. There have been many simulations, and lab scale successes with these algorithms, but production scale implementations have experienced difficulties. These problems are related to …
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Synthesis and shape control of functionalized cadmium telluride nanoparticles
… The mechanisms of particle growth and shape control are also discussed. Finally some key applications of CdTe are described. The second chapter deals with the synthesis of HDA and TOPO-capped CdTe nanoparticles. The reaction parameters such as reaction time, reduction time of tellurium, …
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Performance enhancement of segmented infrared reflectors via quasistatic shape control
Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 1992.
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Effects of uncertainty on closed loop shape control in stretch forming
Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2002.
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Shape control of high degree-of-freedom Variable Geometry Truss manipulators
… It also illustrates how the concept of shape control can be applied to simplify the computational aspects of controlling these devices. To serve as examples, algorithms are developed for the control of both a thirty degree of freedom planar manipulator and a sixty degree-of-freedom …
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A static model of a Sendzimir mill for use in shape control.
The design of shape control systems is an area of current interest in the steel industry. Shape is defined as the internal stress distribution resulting from a transverse variation in the reduction of the strip thickness. The object of shape control is to adjust the mill so that the rolled strip is …
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Design and shape control of lightweight mirrors for dynamic performance and athermalization
… segmented or sparse apertures and active optical control. Many of these technologies have no flight heritage, so determining what combinations of technologies will create favorable designs requires detailed modeling and analysis. This thesis examines the design of a lightweight mirror for an …
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Closed-loop control of roll bending/twisting : a shape control system for beams
Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 1986.
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A closed-loop shape control methodology for flexible stretch forming over a reconfigurable tool
… to this, a methodology combining a self-tuning shape control algorithm and reconfigurable forming tool is developed and implemented for stretch forming. This methodology is based on empirical estimation of the process characteristics from the calibration forming trials, and is capable of …
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Analysis and finite element approximation of an optimal shape control problem for the steady-state Navier-Stokes equations
An optimal shape control problem for the steady-state Navier-Stokes equations is considered from an analytical point of view. We examine a rather specific model problem dealing with 2-dimensional channel flow of incompressible viscous fluid: we wish to determine the shape of a bump on a part of the …
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An investigation into the design and performance of an automatic shape control system for a Sendzimir cold rolling mill.
Shape (or flatness) control for rolled steel strip is becoming increasingly important as customer requirements become more stringent. Automatic shape control is now more or less mandatory on all new four-high cold mills, but no comprehensive scheme yet exists on a Sendzimir mill. This is due to the …
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An investigation into the design and performance of an automatic shape control system for a sedzimir cold rolling mill
Shape (or flatness) control for rolled steel strip is becoming increasingly important as customer requirements become more stringent. Automatic shape control is now more or less mandatory on all new four-high cold mills, but no comprehensive scheme yet exists on a Sendzimir mill. This is due to the …
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Position and strain feedback control for shaping an active truss
… to aid the evaluation of active airfoil and wing shape control using an active truss. This specific research addresses the effect of replacing position feedback with strain feedback for shape control of an active truss. There are two research objectives: a comparison of multiple-beam shape control …
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Synthesis and alignment of gold nanorods for optical applications
… are simple synthesis methods that allow for shape control and the ability to change the chemistry on the surface of the gold nanorods. One of the interesting properties of gold nanorods is their ability to locally enhance electromagnetic fields in the vicinity of the ends of the nanorods. …
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Design of optimal control systems and industrial applications.
… describes work on the selection of the optimal control criterion weighting matrices, based on multivariable root loci and frequency domain properties. The case with a crossproduct weighting term in the cost function is examined and a design algorithm is proposed. The frequency domain solution to …
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Sonoelectrochemical synthesis of submicron metal powders
… useful mechanisms for particle size and shape control in continuous reactors are discussed. A continuous sonoelectrochemical reactor was designed and demonstrated to produce submicron copper powders. Improvements to the batch reactor design are proposed to extend the technique to a flow …
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Thermoelastic control of adaptive composites for aerospace applications using embedded nitinol actuators
Aerospace structures have stringent pointing and shape control requirements during long-term exposure to a hostile environment with no scheduled maintenance. This makes them excellent candidates for a smart structures approach as current passive techniques prove insufficient. This study …
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The design of adaptive structures for wing morphing
… adaptive structures for achieving global multi-shape morphing aerodynamic configurations, by using slender structures. The proposed methodologies pursue two threads towards global optimisation of morphing structures, by providing means of aerodynamic enhancement, using efficient structural shape …
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Fine surface control of flexible space mirrors using adaptive optics and robust control
… flexible, segmented mirrors. Traditional control approaches for mirror alignment and shape control may be inadequate due to flexibilities and low natural frequencies. Using adaptive optics for space telescopes presents a possible solution. This research proposes innovative H[infinity] …
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Issues in the design of shape memory alloy actuators
This thesis considers the application of shape memory alloy (SMA) actuators for shape control of the undertray of a sports car. By deforming the shape of the structure that provides aerodynamic stability to the car, we expect to improve the overall performance of the vehicle by adapting its …
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