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Articles 12721 - 12750 of 21751

Full-Text Articles in Engineering

Automatic Feedback Control Of Mechanical Gas Face Seals Via Clearance Control, Sachin S. Yelma, Robert G. Landers, Brad A. Miller Jan 2004

Automatic Feedback Control Of Mechanical Gas Face Seals Via Clearance Control, Sachin S. Yelma, Robert G. Landers, Brad A. Miller

Mechanical and Aerospace Engineering Faculty Research & Creative Works

An approach based on proper orthogonal decomposition and Galerkin projection is presented for developing low-order nonlinear models of the gas film pressure within mechanical gas face seals. A technique is developed for determining an optimal set of global basis functions for the pressure field using data measured experimentally or obtained numerically from simulations of the seal motion. The reduced-order gas film models are shown to be computationally efficient compared to full-order models developed using the conventional semidiscretization methods. An example of a coned mechanical gas face seal in a flexibly mounted stator configuration is presented. Axial and tilt modes of …

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Design And Technologies For A Smart Composite Bridge, K. Chandrashekhara, Prakash Kumar, Steve Eugene Watkins, Antonio Nanni Jan 2004

Design And Technologies For A Smart Composite Bridge, K. Chandrashekhara, Prakash Kumar, Steve Eugene Watkins, Antonio Nanni

Mechanical and Aerospace Engineering Faculty Research & Creative Works

An all-composite, smart bridge design for shortspan applications is described. The bridge dimensions are 9.14-m (30-ft.) long and 2.74-m (9-ft.) wide. A modular construction based on assemblies of pultruded fiber-reinforced-polymer (FRP) composite tubes is used to meet American Association of State Highway and Transportation Officials (AASHTO) H20 highway load ratings. The hollow tubes are 76 mm (3 in.) square and are made of carbon/vinyl-ester and glass/vinyl-ester. An extensive experimental study was carried out to obtain and compare properties (stiffness, strength, and failure modes) for a quarter portion of the full-sized bridge. The bridge response was measured for design loading, two-million-cycle …

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Development And Analysis Of A Feedback Treatment Strategy For Parturient Paresis Of Cows, Radhakant Padhi, S. N. Balakrishnan Jan 2004

Development And Analysis Of A Feedback Treatment Strategy For Parturient Paresis Of Cows, Radhakant Padhi, S. N. Balakrishnan

Mechanical and Aerospace Engineering Faculty Research & Creative Works

An intelligent on-line feedback treatment strategy based on nonlinear optimal control theory is presented for the parturient paresis of cows. A limitation in the development of an existing nonlinear mathematical model for the homogeneous system is addressed and further modified to incorporate a control input. A neural network based optimal feedback controller is synthesized for the treatment of the disease. Detailed studies are used to analyze the effectiveness of a feedback medication strategy and it is compared with the current "impulse" strategy. The results show that while the current practice may fail in some cases, especially if it is carried …

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Optimal Control Synthesis Of A Class Of Nonlinear Systems Using Single Network Adaptive Critics, Radhakant Padhi, Nishant Unnikrishnan, S. N. Balakrishnan Jan 2004

Optimal Control Synthesis Of A Class Of Nonlinear Systems Using Single Network Adaptive Critics, Radhakant Padhi, Nishant Unnikrishnan, S. N. Balakrishnan

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Adaptive critic (AC) neural network solutions to optimal control designs using dynamic programming has reduced the need of complex computations and storage requirements that typical dynamic programming requires. In this paper, a "single network adaptive critic" (SNAC) is presented. This approach is applicable to a class of nonlinear systems where the optimal control (stationary) equation is explicitly solvable for control in terms of state and costate variables. The SNAC architecture offers three potential advantages; a simpler architecture, significant savings of computational load and reduction in approximation errors. In order to demonstrate these benefits, a real-life micro-electro-mechanical-system (MEMS) problem has been …

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Solid State Aircraft Concept Overview, M. Shahinpoor, P. Jenkins, C. Smith, Kakkattukuzhy M. Isaac, T. Dalbello, Anthony Colozza Jan 2004

Solid State Aircraft Concept Overview, M. Shahinpoor, P. Jenkins, C. Smith, Kakkattukuzhy M. Isaac, T. Dalbello, Anthony Colozza

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Due to recent advances in polymers, photovoltaics, and batteries a unique type of aircraft may be feasible. This is a "solid-state" aircraft, with no conventional mechanical moving parts. Airfoil, propulsion, energy production, energy storage and control are combined in an integrated structure. The key material of this concept is an ionic polymeric-metal composite (IPMC) that provides source of control and propulsion. This material has the unique capability of deforming in an electric field and returning to its original shape when the field is removed. Combining the IPMC with thin-film batteries and thin-film photovoltaics provides both energy source and storage in …

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Discrete-Time Neural Network Output Feedback Control Of Nonlinear Systems In Non-Strict Feedback Form, P. He, Sarangapani Jagannathan Jan 2004

Discrete-Time Neural Network Output Feedback Control Of Nonlinear Systems In Non-Strict Feedback Form, P. He, Sarangapani Jagannathan

Electrical and Computer Engineering Faculty Research & Creative Works

An adaptive neural network (NN) -Based output feedback controller is proposed to deliver a desired tracking performance for a class of discrete-time nonlinear systems, which is represented in non-strict feedback form. the NN backstepping approach is utilized to design the adaptive output feedback controller consisting of 1) a NN observer to estimate the system states with the input-output data, and 2) two NNs to generate the virtual and actual control inputs, respectively. the non-causal problem in the discrete time backstepping design is avoided by using the universal NN approximator. the persistence excitation (PE) condition is relaxed both in the NN …

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Position Sensorless Control, Babak Fahimi, Ali Emadi, Raymond B. Sepe Jan 2004

Position Sensorless Control, Babak Fahimi, Ali Emadi, Raymond B. Sepe

Electrical and Computer Engineering Faculty Research & Creative Works

The switched reluctance machines (SRM) drives applications are studied. the introduction of SRM drives in mission critical applications calls for high levels of survivability and fault tolerance. the various methods are proposed for the sensor less control of SRM drives. the best version of the sensor less technique is selected by continuous monitoring of the back-EMF. the results show that four-quadrant sensor less control of the SRM drive is a feasible technique and can be considered as a technology ready for application.

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A Theoretical And Numerical Study Of Thin Film Delamination Using The Pull-Off Test, Zuo Sun, Kai-Tak Wan, David A. Dillard Jan 2004

A Theoretical And Numerical Study Of Thin Film Delamination Using The Pull-Off Test, Zuo Sun, Kai-Tak Wan, David A. Dillard

Mechanical and Aerospace Engineering Faculty Research & Creative Works

An accurate closed-form analytical solution for the strain energy release rate for a thin rectangular film loaded by a central line force using the pull-off test is derived in the presence of a tensile residual stress. the theoretical constitutive relation and the strain energy release rate agree very well with two-dimensional nonlinear finite element analysis for the entire deformation regime ranging from bending plate to stretching membrane. Fracture modes for this pull-off test are also investigated based upon the finite element analysis, offering additional insights to the interfacial delamination. © 2003 Elsevier Ltd. All rights reserved.

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Optimizing Sequential Dual Tracer P.E.T. Studies Using A Combined 2d/3d Imaging Protocol, John W. Wilson, S. Borges-Neto, Timothy G. Turkington, James G. Colsher, R. E. Reiman, R. E. Coleman Jan 2004

Optimizing Sequential Dual Tracer P.E.T. Studies Using A Combined 2d/3d Imaging Protocol, John W. Wilson, S. Borges-Neto, Timothy G. Turkington, James G. Colsher, R. E. Reiman, R. E. Coleman

Mining Engineering Faculty Research & Creative Works

We have investigated a combined 2D/3D protocol for minimizing contamination in dual tracer P.E.T. studies in which the tracers are administered on a timescale that is short compared to the half-lives. We have performed a series of phantom studies on an Advance and a Discovery ST (GE Healthcare Technologies), using a torso phantom with cardiac insert (Data Spectrum Corporation) to simulate a combined FDG and NH3 scan protocol for a patient with ischemia. The phantom was imaged in a series of alternating 2D/3D acquisitions as it decayed over 6 half-lives. By comparing 2D and 3D images, we have verified that …

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Laboratory Automation Education, James D. Sterling Jan 2004

Laboratory Automation Education, James D. Sterling

Business and Information Technology Faculty Research & Creative Works

No abstract provided.

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Laboratory Automation Curriculum At Keck Graduate Institute, James D. Sterling Jan 2004

Laboratory Automation Curriculum At Keck Graduate Institute, James D. Sterling

Business and Information Technology Faculty Research & Creative Works

A novel curriculum in laboratory automation and high-throughput technologies has been developed at the Keck Graduate Institute (KGI) over the past five years as part of the professional master's degree program in applied life sciences. The goal of this curriculum has been four-fold: (1) motivate study by describing the need for automation through several example problems in combinatorial biological discovery, (2) provide elements of fundamental engineering science that are required for the development of the technologies and tools that enable automation, (3) provide opportunities for the students to see and use state-of-the-art instruments, learn about existing industry standards, and to …

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Radiated Emissions From Populated Printed Circuit Boards Due To Power Bus Noise, Hwan-Woo Shim, Todd H. Hubing, Yan Fu Jan 2004

Radiated Emissions From Populated Printed Circuit Boards Due To Power Bus Noise, Hwan-Woo Shim, Todd H. Hubing, Yan Fu

Electrical and Computer Engineering Faculty Research & Creative Works

Previous studies have demonstrated that power plane pairs in a printed circuit board are capable of generating significant radiated emissions at resonance frequencies if these resonances are not damped by material or component losses. The paper shows that board resonances may be readily damped by component losses. However, radiated emissions from a damped power bus may still exceed FCC or CISPR limits over a broad band of frequencies.

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Robust Near-Field Adaptive Beamforming With Distance Discrimination, Y. Rosa Zheng, M. El-Tanany, R. A. Goubran Jan 2004

Robust Near-Field Adaptive Beamforming With Distance Discrimination, Y. Rosa Zheng, M. El-Tanany, R. A. Goubran

Electrical and Computer Engineering Faculty Research & Creative Works

This paper proposes a robust near-field adaptive beamformer for microphone array applications in small rooms. Robustness against location errors is crucial for near-field adaptive beamforming due to the difficulty in estimating near-field signal locations especially the radial distances. A near-field regionally constrained adaptive beamformer is proposed to design a set of linear constraints by filtering on a low rank subspace of the near-field signal over a spatial region and frequency band such that the beamformer response over the designed spatial-temporal region can be accurately controlled by a small number of linear constraint vectors. The proposed constraint design method is a …

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Robust Resource Allocation For Sensor-Actuator Distributed Computing Systems, Shoukat Ali, Jong-Kook Kim, A. A. Maciejewski, Howard Jay Siegel Jan 2004

Robust Resource Allocation For Sensor-Actuator Distributed Computing Systems, Shoukat Ali, Jong-Kook Kim, A. A. Maciejewski, Howard Jay Siegel

Electrical and Computer Engineering Faculty Research & Creative Works

This research investigates two distinct issues related to a resource allocation: its robustness and the failure rate of the heuristic used to determine the allocation. The target system consists of a number of sensors feeding a set of heterogeneous applications continuously executing on a set of heterogeneous machines connected together by high-speed heterogeneous links. There are number of quality of service (QoS) constraints that must be satisfied. A heuristic failure occurs if the heuristic cannot find an allocation that allows the system to meet its QoS constraints. The system is expected to operate in an uncertain environment where the workload, …

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The Pcb Level Esd Immunity Study By Using 3 Dimension Esd Scan System, Kai Wang, David Pommerenke, Jian Min Zhang, Ramachandran Chundru Jan 2004

The Pcb Level Esd Immunity Study By Using 3 Dimension Esd Scan System, Kai Wang, David Pommerenke, Jian Min Zhang, Ramachandran Chundru

Electrical and Computer Engineering Faculty Research & Creative Works

The use of high-speed logic makes modern electronic systems highly susceptible to electrostatic discharge (ESD). Because of their wider bandwidth, faster digital devices are more susceptible to high frequency ESD transient fields. In the analysis of ESD problems, an exact knowledge of the affected PINs and nets is essential for an optimal solution. A three dimensional ESD scanning system, which has been developed to record the ESD susceptibility map for a printed circuit board, is presented, and the mechanisms that the ESD event couples into the digital devices is studied.

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The Robustness Of Resource Allocation In Parallel And Distributed Computing Systems, Shoukat Ali, Howard Jay Siegel, A. A. Maciejewski Jan 2004

The Robustness Of Resource Allocation In Parallel And Distributed Computing Systems, Shoukat Ali, Howard Jay Siegel, A. A. Maciejewski

Electrical and Computer Engineering Faculty Research & Creative Works

This paper gives an overview of the material to be discussed in the invited keynote presentation by H. J. Siegel. Performing computing and communication tasks on parallel and distributed systems involves the coordinated use of different types of machines, networks, interfaces, and other resources. Decisions about how best to allocate resources are often based on estimated values of task and system parameters, due to uncertainties in the system environment. An important research problem is the development of resource management strategies that can guarantee a particular system performance given such uncertainties. We have designed a methodology for deriving the degree of …

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Unmanned Vehicle Navigation Using Swarm Intelligence, Sheetal Doctor, Ganesh K. Venayagamoorthy Jan 2004

Unmanned Vehicle Navigation Using Swarm Intelligence, Sheetal Doctor, Ganesh K. Venayagamoorthy

Electrical and Computer Engineering Faculty Research & Creative Works

Unmanned vehicles are used to explore physical areas where humans are unable to go due to different constraints. There have been various algorithms that have been used to perform this task. This paper explores swarm intelligence for searching a given problem space for a particular target(s). The work in this paper has two parts. In the first part, a set of randomized unmanned vehicles are deployed to locate a single target. In the second part, the randomized unmanned vehicles are deployed to locate various targets and are then converged at one of targets of a particular interest. Each of the …

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Via Coupling Within Power-Return Plane Structures Considering The Radiation Loss, J. Chen, Todd H. Hubing, Weimin Shi, R. L. Chen Jan 2004

Via Coupling Within Power-Return Plane Structures Considering The Radiation Loss, J. Chen, Todd H. Hubing, Weimin Shi, R. L. Chen

Electrical and Computer Engineering Faculty Research & Creative Works

An accurate analytical model to predict via coupling within rectangular power-return plane structures is developed. Loss mechanisms, including radiation loss, dielectric loss, and conductor loss, are considered. The radiation loss is incorporated into a complex propagating wavenumber as an artificial loss mechanism. The quality factors associated with the three loss mechanisms are calculated and compared. The effects of radiation loss on input impedances and reflection coefficients are investigated for both high-dielectric-loss and low-dielectric-loss PCBs. Measurements are performed to validate the effectiveness of the model.

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A Distributed Power Control Mac Protocol For Wireless Ad-Hoc Networks., Maciej Jan Zawodniok, Jagannathan Sarangapani Jan 2004

A Distributed Power Control Mac Protocol For Wireless Ad-Hoc Networks., Maciej Jan Zawodniok, Jagannathan Sarangapani

Electrical and Computer Engineering Faculty Research & Creative Works

A novel distributed power control (DPC)⋅ scheme and a MAC protocol for wireless ad hoc networks in the presence of radio channel uncertainties such as path loss, Shadowing and Rayleigh fading is presented. The DPC quickly estimates the time-varying nature of the channel and uses the information to select a suitable transmitter power value in order to maintain a target Signal-to-Interference ratio (SIR) at the receiver. The standard assumption of a constant interference during a link's power update used in other works is relaxed. The performance of the proposed DPC is demonstrated analytically. The power used for all RTS-CTS-DATA-ACK frames …

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A Taxonomy Of Network Computing Systems, Muthucumaru Maheswaran, Shoukat Ali Jan 2004

A Taxonomy Of Network Computing Systems, Muthucumaru Maheswaran, Shoukat Ali

Electrical and Computer Engineering Faculty Research & Creative Works

Rapid advances in networking and microprocessor technologies have led to the emergence of Internet-wide distributed computing systems ranging from simple LAN-based clusters to planetary-scale networks. As these network computing systems evolve by combining the best features of existing systems, differences among NCs are blurring. To address this problem, researchers have proposed formal taxonomies of NC systems. We propose a new taxonomy that is both broad enough to encompass all NC systems and simple enough to be widely used.

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Adaptive Critic Neural Network-Based Object Grasping Control Using A Three-Finger Gripper, Gustavo Galan, Jagannathan Sarangapani Jan 2004

Adaptive Critic Neural Network-Based Object Grasping Control Using A Three-Finger Gripper, Gustavo Galan, Jagannathan Sarangapani

Electrical and Computer Engineering Faculty Research & Creative Works

Grasping of objects has been a challenging task for robots. The complex grasping task can be defined as object contact control and manipulation subtasks. In this paper, object contact control subtask is defined as the ability to follow a trajectory accurately by the fingers of a gripper. The object manipulation subtask is defined in terms of maintaining a predefined applied force by the fingers on the object. A sophisticated controller is necessary since the process of grasping an object without a priori knowledge of the object's size, texture, softness, gripper, and contact dynamics is rather difficult. Moreover, the object has …

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Adaptive Critics For Dynamic Particle Swarm Optimization, Ganesh K. Venayagamoorthy Jan 2004

Adaptive Critics For Dynamic Particle Swarm Optimization, Ganesh K. Venayagamoorthy

Electrical and Computer Engineering Faculty Research & Creative Works

This work introduces a novel technique for dynamic particle swarm optimization (DPSO) using adaptive critic designs. The adaptation between global and local search in an optimization algorithm is critical for optimization problems especially in a dynamically changing environment or process over time. The inertia weight in particle swarm optimization (PSO) is dynamically adjusted in this paper in order to provide a nonlinear search capability for the PSO algorithm. Results on benchmark functions in the literature are provided.

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An Intelligent Dissolved Oxygen Microsensor System With Electrochemically Actuated Fluidics, Chang-Soo Kim, Jongwon Park, Xinbo He Jan 2004

An Intelligent Dissolved Oxygen Microsensor System With Electrochemically Actuated Fluidics, Chang-Soo Kim, Jongwon Park, Xinbo He

Electrical and Computer Engineering Faculty Research & Creative Works

A new dissolved oxygen monitoring microsystem is proposed to achieve in situ intelligent self-calibration by using an electrochemically actuated fluidic system. The electrochemical actuation, based on water electrolysis, plays two critical roles in the proposed microsystem. First, the electrochemically generated gases serve as the calibrants for the in situ 2-point calibration/diagnosis procedure of the microsensor in a chip. Secondly, the electrochemical generation and collapse of gas bubbles provide the driving force of the bidirectional fluidic manipulation for sampling and dispensing of the sample solution. A microsystem including a dissolved oxygen microprobe, electrochemical actuators, and a fluidic structure are prepared by …

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Partial Discharge On-Line Monitoring For Hv Cable Systems Using Electrooptic Modulators, Paul L. Lewin, David Pommerenke, Simon J. Sutton, Yuan Tian, James S. Wilkinson Jan 2004

Partial Discharge On-Line Monitoring For Hv Cable Systems Using Electrooptic Modulators, Paul L. Lewin, David Pommerenke, Simon J. Sutton, Yuan Tian, James S. Wilkinson

Electrical and Computer Engineering Faculty Research & Creative Works

A technique for the remote inspection and monitoring of partial discharge (PD) activity using an optical network is described. The network uses a LiNbO3, modulator to modulate the intensity of the transmitted laser light approximately proportional to the voltage applied across the modulator. The laser light is transmitted along an optical fibre and measured remotely by a high-speed optical receiver. A capacitive coupler has been used to detect partial discharge activity and act as the modulator's input voltage source. The electro-optic modulator is passive and does not require a power supply at the site of the PD detection sensor. The …

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A Discrete-Time Model For Triply Selective Mimo Rayleigh Fading Channels, Chengshan Xiao, Jingxian Wu, Sang-Yick Leong, Y. Rosa Zheng, Khaled Ben Letaief Jan 2004

A Discrete-Time Model For Triply Selective Mimo Rayleigh Fading Channels, Chengshan Xiao, Jingxian Wu, Sang-Yick Leong, Y. Rosa Zheng, Khaled Ben Letaief

Electrical and Computer Engineering Faculty Research & Creative Works

A statistical discrete-time model is proposed for simulating wideband multiple-input multiple-output (MIMO) fading channels which are triply selective due to angle spread, Doppler spread, and delay spread. The new discrete-time MIMO channel model includes the combined effects of the transmit filter, physical MIMO multipath channel fading, and receive filter, and it has the same sampling period as that of the MIMO receiver. This leads to very efficient simulation of physical continuous-time MIMO channels. A new method is also presented to efficiently generate the MIMO channel stochastic coefficients. The statistical accuracy of the discrete-time MIMO channel model is rigorously verified through …

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A Method For Enhancing The Snapshot Performance In San Volume Manager, Chang-Soo Kim, Dong-Jae Kang, Young-Ho Kim, Hag-Young Kim, Myoung-Jun Kim, Yu-Hyeon Bak Jan 2004

A Method For Enhancing The Snapshot Performance In San Volume Manager, Chang-Soo Kim, Dong-Jae Kang, Young-Ho Kim, Hag-Young Kim, Myoung-Jun Kim, Yu-Hyeon Bak

Electrical and Computer Engineering Faculty Research & Creative Works

No abstract provided.

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A Multiple Principal Components Based Adaptive Filter, Steven L. Grant Jan 2004

A Multiple Principal Components Based Adaptive Filter, Steven L. Grant

Electrical and Computer Engineering Faculty Research & Creative Works

Proportionate normalized least mean squares (PNLMS) is an adaptive filter that has been shown to provide exceptionally fast convergence and tracking when the underlying system parameters are sparse. A good example of such a system is a network echo canceller. Principal components based PNLMS (PCP) extends this fast convergence property to certain nonsparse systems by applying PNLMS while using the principal components of the underlying system as basis vectors. An acoustic echo canceller is a possible example of this type of nonsparse system. Simulations of acoustic echo paths and cancellers indicate that PCP converges and tracks much faster than the …

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A New Estimative Current Mode Control Technique For Dc-Dc Converters Operating In Discontinuous Conduction Mode, Mehdi Ferdowsi, Zhong Nie, Ali Emadi Jan 2004

A New Estimative Current Mode Control Technique For Dc-Dc Converters Operating In Discontinuous Conduction Mode, Mehdi Ferdowsi, Zhong Nie, Ali Emadi

Electrical and Computer Engineering Faculty Research & Creative Works

A new digital control technique for power converters operating in discontinuous conduction mode (DCM) is introduced and applied to a boost converter. In contrast to the conventional analogue control methods, the principal idea of this new control scheme is to use real-time analysis and estimate the required on-time of the switch based on the dynamic of the system. The proposed control algorithm can easily be programmed in a digital signal processor (DSP). This novel technique is applicable to any converter operating in DCM including power factor correctors (PFC). However, this work mainly focuses on the boost topology. In this paper, …

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Choice Of Utility Functions For Adaptive Critic Designs, Ganesh K. Venayagamoorthy Jan 2004

Choice Of Utility Functions For Adaptive Critic Designs, Ganesh K. Venayagamoorthy

Electrical and Computer Engineering Faculty Research & Creative Works

This paper first presents a general overview of Adaptive Critic Designs (ACDs) and their existing control applications. It describes the importance of the right choice of utility functions for the development of critic networks and their convergence to the cost-to-go function J. A closer look into the step by step derivation of a utility function for the design of an ACD nonlinear optimal neurocontroller to replace/augment the conventional controllers, the automatic voltage regulator and governor, in a power system consisting of a generator connected to the power grid is described and some results are presented.

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Laser Writing Of Semiconductor Nanoparticles And Quantum Dots, Massimo F. Bertino, Raghuveer Reddy Gadipalli, J. Greg Story, C. G. Williams, Guo-Hui Zhang, Chariklia Sotiriou-Leventis, Akira Tokuhiro, Suchi Guha, Nicholas Leventis Jan 2004

Laser Writing Of Semiconductor Nanoparticles And Quantum Dots, Massimo F. Bertino, Raghuveer Reddy Gadipalli, J. Greg Story, C. G. Williams, Guo-Hui Zhang, Chariklia Sotiriou-Leventis, Akira Tokuhiro, Suchi Guha, Nicholas Leventis

Physics Faculty Research & Creative Works

Silica aerogels were patterned with CdS using a photolithographic technique based on local heating with infrared (IR) light. The solvent of silica hydrogels was exchanged with an aqueous solution of the precursors CdNO3 and NH4 OH, all precooled to a temperature of 5°C. Half of the bathing solution was then replaced by a thiourea solution. After thiourea diffused into the hydrogels, the samples were exposed to a focused IR beam from a continuous wave, Nd-YAG laser. The precursors reacted in the spots heated by the IR beam to form CdS nanoparticles. We lithographed features with a diameter of …

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