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Missouri University of Science and Technology

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Articles 10891 - 10920 of 21805

Full-Text Articles in Engineering

The Processing, Mechanical Properties And Bioactivity Of Strontium Based Glass Polyalkenoate Cements, Anthony Wren, Daniel Boyd, Mark R. Towler Apr 2008

The Processing, Mechanical Properties And Bioactivity Of Strontium Based Glass Polyalkenoate Cements, Anthony Wren, Daniel Boyd, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

The suitability of zinc-based glass polyalkenoate cements (GPCs) for use in orthopaedics can be improved by the substitution of strontium into the glass phase which should impart improved radiopacity and bone forming properties to the cements without retarding strength. The purpose of this research was to produce novel GPCs based on calcium-strontium-zinc-silicate glasses and to evaluate their mechanical properties and biocompatibility with the ultimate objective of developing a new range of cements for skeletal applications. Three glass compositions, based on incremental substitutions of strontium for calcium, were synthesized; BT100 (0.16CaO, 0.36ZnO, 0.48SiO2), BT101 (0.04SrO, 0.12CaO, 0.36ZnO, 0.48SiO2 …

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Executable Modeling For System Of Systems Architecting: An Artificial Life Framework, Kilicay-Ergin Nil, Cihan H. Dagli Apr 2008

Executable Modeling For System Of Systems Architecting: An Artificial Life Framework, Kilicay-Ergin Nil, Cihan H. Dagli

Engineering Management and Systems Engineering Faculty Research & Creative Works

There is a diversity of frameworks and methodologies for enabling architecture developments. Static representation frameworks provide a standardized way to communicate the architecture to stakeholders, but do not provide means to analyze the system states and system behavior. Therefore, there is a need to convert static representation frameworks to executable models. The aim of this paper is to present Artificial Life approaches as a methodology for understanding behavior of System of Systems. For this, an Artificial Life based framework for modeling System of Systems is presented. The framework comprises cognitive architectures embedded in multi-agent models. Financial markets are selected as …

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Dual-Function Neuron-Based External Controller For A Static Var Compensator, Ganesh K. Venayagamoorthy, Sandhya R. Jetti Apr 2008

Dual-Function Neuron-Based External Controller For A Static Var Compensator, Ganesh K. Venayagamoorthy, Sandhya R. Jetti

Electrical and Computer Engineering Faculty Research & Creative Works

The use of wide-area measurements for power system stabilization has recently been given a lot of attention by researchers and the power industry to avoid cascading failures and blackouts, such as the one in North America in August 2003. This paper presents the design of a nonlinear external damping controller based on wide-area measurements as inputs to a single dual-function neuron (DFN)-based controller. This DFN controller is specifically designed to enhance the damping characteristics of a power system over a wide range of operating conditions using an existing static var compensator (SVC) installation. The major advantage of the DFN controller …

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Channel Estimation, Equalization And Phase Correction For Single Carrier Underwater Acoustic Communications, Jun Tao, Y. Rosa Zheng, Chengshan Xiao, Wen-Bin Yang, T. C. Yang Apr 2008

Channel Estimation, Equalization And Phase Correction For Single Carrier Underwater Acoustic Communications, Jun Tao, Y. Rosa Zheng, Chengshan Xiao, Wen-Bin Yang, T. C. Yang

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, we employ a time-domain channel estimation, equalization and phase correction scheme for single carrier single input multiple output (SIMO) underwater acoustic communications. In this scheme, Doppler shift, which is caused by relative motion between transducer (source) and hydrophones (receiver), is estimated and compensated in the received baseband signals. Then the channel is estimated using a small training block at the front of a transmitted data package, in which the data is artificially partitioned into consecutive data blocks. The estimated channel is utilized to equalize a block of received data, then the equalized data is processed by a …

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Further Results On Frequency-Domain Channel Equalization For Single Carrier Underwater Acoustic Communications, Y. Rosa Zheng, Chengshan Xiao, Xin Liu, Wen-Bin Yang, T. C. Yang Apr 2008

Further Results On Frequency-Domain Channel Equalization For Single Carrier Underwater Acoustic Communications, Y. Rosa Zheng, Chengshan Xiao, Xin Liu, Wen-Bin Yang, T. C. Yang

Electrical and Computer Engineering Faculty Research & Creative Works

A frequency-domain channel equalization and phase correction method was proposed in a previous work published in Oceans'07 conference, in which 10^-4 BER performance was presented for fixed-to-fixed source/receiver channels. The method is improved by using minimum mean square error (MMSE) estimation in channel updates rather than least squares estimation. It is applied to moving-to-fixed channels in the AUVFest'07 ocean experiment where single-carrier wideband transmission was employed with quadrature phase shift keying modulation. The moving source channels exhibit higher Doppler shift and larger Doppler drift than the fixed-to-fixed channels. Therefore, the number of symbols required for initial phase estimation is increased …

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Design And Implementation Of Fpga Configuration Logic Block Using Asynchronous Static Ncl, Waleed K. Al-Assadi, T. Tammina, Scott C. Smith, Indira P. Dugganapally Apr 2008

Design And Implementation Of Fpga Configuration Logic Block Using Asynchronous Static Ncl, Waleed K. Al-Assadi, T. Tammina, Scott C. Smith, Indira P. Dugganapally

Electrical and Computer Engineering Faculty Research & Creative Works

This paper proposes the design of a FPGA configurable logic block (CLB) using asynchronous static NULL convention logic (NCL) Library. The proposed design uses three static LUT's for implementing NCL logic functions. Each LUT can be configured to function as any one of the 27 fundamental NCL Static gates. The proposed CLB supports 10 inputs and three different outputs, each with resettable and inverting variations. The CLB has two modes: Configuration mode and operation mode. The static NCL FPGA CLB is simulated at the transistor level using the 1.8 V, 180 nm TSMC CMOS process.

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Reinforcement Schemes For Cfs Joists Having Web Openings, K. S. Sivakumaran Apr 2008

Reinforcement Schemes For Cfs Joists Having Web Openings, K. S. Sivakumaran

CCFSS Library (1939 - present)

No abstract provided.

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Missouri S&T Mote-Based Demonstration Of Energy Monitoring Solution For Network Enabled Manufacturing Using Wireless Sensor Networks (Wsn), James W. Fonda, Maciej Jan Zawodniok, Al Salour, Jagannathan Sarangapani, Donald Miller Apr 2008

Missouri S&T Mote-Based Demonstration Of Energy Monitoring Solution For Network Enabled Manufacturing Using Wireless Sensor Networks (Wsn), James W. Fonda, Maciej Jan Zawodniok, Al Salour, Jagannathan Sarangapani, Donald Miller

Electrical and Computer Engineering Faculty Research & Creative Works

In this work, an inexpensive electric utilities monitoring solution using wireless sensor networks is demonstrated that can easily be installed, deployed, maintained and eliminate unnecessary energy costs and effort. The monitoring solution is designed to support network enabled manufacturing (NEM) program using Missouri University of Science and Technology (MST), formerly the University of Missouri-Rolla (UMR), motes.

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Modeling Of Substrate Noise Effects In Dynamic Cmos Circuits, Waleed K. Al-Assadi, S. Burugapalli, Sagar R. Gosavi Apr 2008

Modeling Of Substrate Noise Effects In Dynamic Cmos Circuits, Waleed K. Al-Assadi, S. Burugapalli, Sagar R. Gosavi

Electrical and Computer Engineering Faculty Research & Creative Works

The decrease in the feature size has led to the integration of both digital and analog circuits on the same silicon die which has led to many crosstalk issues. The crosstalk due to the substrate interactions also plagiarizes complete digital systems. This paper lays emphasis on this fact and because of the vulnerability of dynamic CMOS circuits to noise; a brief study of the effects of substrate variations on the performance of the dynamic CMOS circuits is carried out in this paper. The effects of substrate noise at very high frequencies (above 10 GHz) are also depicted in this paper. …

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An Executable System Architecture Approach To Discrete Events System Modeling Using Sysml In Conjunction With Colored Petri Net, Renzhong Wang, Cihan H. Dagli Apr 2008

An Executable System Architecture Approach To Discrete Events System Modeling Using Sysml In Conjunction With Colored Petri Net, Renzhong Wang, Cihan H. Dagli

Engineering Management and Systems Engineering Faculty Research & Creative Works

This paper proposes an executable system architecting paradigm for discrete event system modeling and analysis through integration of a set of architecting tools, executable modeling tools, analytical tools, and visualization tools. The essential step is translating SysML-based specifications into colored Petri nets (CPNs) which enables rigorous static and dynamic system analysis as well as formal verification of the behavior and functionality of the SysML-based design. A set of tools have been studied and integrated that enable a structured architecture design process. Some basic principles of executable system architecture for discrete event system modeling that guide the process of executable architecture …

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System Of Systems Architecture Generation And Evaluation Using Evolutionary Algorithms, Joseph J. Simpson, Cihan H. Dagli Apr 2008

System Of Systems Architecture Generation And Evaluation Using Evolutionary Algorithms, Joseph J. Simpson, Cihan H. Dagli

Engineering Management and Systems Engineering Faculty Research & Creative Works

Evolutionary algorithms and computational intelligence represent a developing technology and science that provides great potential in the area of system and system-of-systems architecture generation, categorization and evaluation. Classical system engineering analysis techniques have been used to represent a system architecture in a manner that is compatible with evolutionary algorithms and computational intelligence techniques. This paper focuses on specific system relationship configurations and attributes that are required to successfully aggregate the best-fit function in a fuzzy associative memory that is used in an evolutionary algorithm to generate and evaluate system architectures.

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Systems Methodology And Framework For Problem Definition In Mobile Ad Hoc Networks, Reghu Anguswamy, Maheswaran Thiagarajan, Cihan H. Dagli Apr 2008

Systems Methodology And Framework For Problem Definition In Mobile Ad Hoc Networks, Reghu Anguswamy, Maheswaran Thiagarajan, Cihan H. Dagli

Engineering Management and Systems Engineering Faculty Research & Creative Works

Mobile Ad Hoc Networks are communication networks built up of a collection of mobile devices which can communicate through wireless connections. Mobile Ad Hoc Networks have many challenges such as routing, which is the task of directing data packets from a source node to a given destination. This task is particularly hard in Mobile Ad Hoc Networks: due to the mobility of the network elements and the lack of central control, robustness and adaptability in routing algorithms and work in a decentralized and self organizing way. Through the principles of systems architecting and Engineering; the problem statement in Mobile Ad …

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Modeling The Cellular Level Of Natural Sensing With The Functional Basis For The Design Of Biomimetic Sensor Technology, Jacquelyn K. Stroble, Robert B. Stone, Daniel A. Mcadams, L. H. Shu, Steve Eugene Watkins Apr 2008

Modeling The Cellular Level Of Natural Sensing With The Functional Basis For The Design Of Biomimetic Sensor Technology, Jacquelyn K. Stroble, Robert B. Stone, Daniel A. Mcadams, L. H. Shu, Steve Eugene Watkins

Electrical and Computer Engineering Faculty Research & Creative Works

After surveying biology for natural sensing solutions six main types of extraneous sensing were identified across the biological kingdoms. Natural sensing happens at the cellular level with receptor cells that respond to photo, chemo, eletro, mechano, thermo and magnetoreceptor-type stimuli. At the highest level, all natural sensing systems have the same reaction sequence to stimuli: perception, transduction, and response. This research is exploring methods for knowledge transfer between the biological and engineering domains. With the use of the Functional Basis, a well-defined modeling language, the ingenuity of natural sensing can be captured through functional models and crossed over into the …

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Performance Of A Quaternary Logic Design, M. Dornajafi, B. Cooper, Steve Eugene Watkins, M. Ryan Bales Apr 2008

Performance Of A Quaternary Logic Design, M. Dornajafi, B. Cooper, Steve Eugene Watkins, M. Ryan Bales

Electrical and Computer Engineering Faculty Research & Creative Works

This paper analyzes the performance of a quaternary logic circuit and its components. The multi-valued logic design consisting of two drivers and a transistor matrix is simulated using Mentor Graphic software. Functional operation of the circuit is shown and propagation delay and power consumption are determined. The design is dependent on the voltage values for the multi-valued logic. Three logic cases are investigated. The performance of the logic circuit as a quaternary difference calculator is described.

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Secured Hardware Design - An Overview, S. Burugapalli, Waleed K. Al-Assadi Apr 2008

Secured Hardware Design - An Overview, S. Burugapalli, Waleed K. Al-Assadi

Electrical and Computer Engineering Faculty Research & Creative Works

Security is a prime concern in the design of a wide variety of embedded systems and security processors. So the customer security devices such as smart cards and security processors are prone to attack and there are on going research to protect these devices from attackers who intend to extract key information from these devices. Also an active attacker can induce errors during computation and exploit the faulty result to extract the key information embedded in the processor. Due to the design time issues weakness in the design is often revealed in the manufactured chips. Also because the post- manufacture …

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Uav Autopilot Integration And Testing, David Erdos, Steve Eugene Watkins Apr 2008

Uav Autopilot Integration And Testing, David Erdos, Steve Eugene Watkins

Electrical and Computer Engineering Faculty Research & Creative Works

The development of an Unmanned Aerial Vehicle (UAV) platform and the integration of avionics for a search and rescue UAV is examined. The project follows the guidelines for the UAV Challenge - Outback Rescue which is an international aerospace competition. The selection process for a commercial autopilot and avionics package is described. The selected system is integrated into a standard hobby remote control aircraft and configured for autonomous flight and navigation. The autopilot system must be tuned to the aircraft platform and flight characteristics. Flight tests are described for a GPS-based grid search pattern.

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Design And Fpga Prototyping Of A Flood Prediction System, Sandeep Gandla, Waleed K. Al-Assadi, Sahra Sedigh, Raghu A. R. Rao Apr 2008

Design And Fpga Prototyping Of A Flood Prediction System, Sandeep Gandla, Waleed K. Al-Assadi, Sahra Sedigh, Raghu A. R. Rao

Electrical and Computer Engineering Faculty Research & Creative Works

This paper explains the chip design of a flood prediction system based on piezoelectric pressure sensors, and its FPGA prototyping. The sensors are placed at different water levels and can dependably predict the occurrence of a flood. The main criteria considered in design of the system are low cost, low power consumption, ease of installation, autonomy, reliability, and most importantly, provision of early alerts. Predicting the flood before its actual occurrence can buy sufficient time for residents to evacuate nearby areas, preventing loss of life and property. The design has been prototyped on Altera's Cyclone DE2 FPGA board.

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Testing Of Asynchronous Null Conventional Logic (Ncl) Circuits, Sindhu Kakarla, Waleed K. Al-Assadi Apr 2008

Testing Of Asynchronous Null Conventional Logic (Ncl) Circuits, Sindhu Kakarla, Waleed K. Al-Assadi

Electrical and Computer Engineering Faculty Research & Creative Works

Due to the absence of a global clock and presence of more state holding elements that synchronize the control and data paths, conventional automatic test pattern generation (ATPG) algorithms would fail when applied to asynchronous circuits, leading to poor fault coverage. This paper focuses on design for test (DFT) techniques aimed at making asynchronous NCL designs testable using existing DFT CAD tools with reasonable gate overhead, by enhancing controllability of feedback nets and observability for fault sites that are flagged unobservable. The proposed approach performs scan and test points insertion on NCL designs using custom ATPG library. The approach has …

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A Fast And Efficient Frequency-Domain Method For Convolutive Blind Source Separation, Peng Xie, Steven L. Grant Apr 2008

A Fast And Efficient Frequency-Domain Method For Convolutive Blind Source Separation, Peng Xie, Steven L. Grant

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, the problem of blind separation of a convolutive mixture of audio signals is considered. A fast and efficient frequency-domain blind source separation (BSS) method using Independent component analysis (ICA) is investigated. The main difficulties of this approach lie in the so called permutation and amplitude problems. In order to solve the permutation ambiguity, the final value of the ICA derived separation matrix of one frequency bin, is used to initialize the ICA iterations in the next frequency bin. The amplitude problem is addressed by utilizing the elements in the inverse of the separation matrix. Experimental results demonstrate …

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Electrochemical Durability Of Carbon Nanotubes At 80 °C, Liang Li, Yangchuan Xing Mar 2008

Electrochemical Durability Of Carbon Nanotubes At 80 °C, Liang Li, Yangchuan Xing

Chemical and Biochemical Engineering Faculty Research & Creative Works

Carbon nanotubes (CNTs) have been studied as an alternative catalyst support in polymer electrolyte membrane (PEM) fuel cells. Recent studies showed that CNTs appear to be more resistant to electrochemical corrosion than carbon black (CB). in a previous study, we have demonstrated the room temperature durability of multiwalled CNTs in both non-catalyzed and catalyzed electrochemical oxidations. This paper is to report results conducted at 80 °C-an operational temperature of PEM fuel cells. It was found that multiwalled CNTs are still more resistant than CB at the elevated temperature. However, the electrochemical oxidation rate is more rapid than that at the …

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Monotonic Convergence Of Iterative Learning Control For Uncertain Systems Using A Time-Varying Filter, Douglas A. Bristow, Andrew G. Alleyne Mar 2008

Monotonic Convergence Of Iterative Learning Control For Uncertain Systems Using A Time-Varying Filter, Douglas A. Bristow, Andrew G. Alleyne

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Iterative learning control (ILC) is a learning technique used to improve the performance of systems that execute the same task multiple times. Learning transient behavior has emerged as an important topic in the design and analysis of ILC systems. In practice, the learning control is often low-pass filtered with a ldquoQ-filterrdquo to prevent transient growth, at the cost of performance. In this note, we consider linear time-invariant, discrete-time, single-input single-output systems, and convert frequency-domain uncertainty models to a time-domain representation for analysis. We then develop robust monotonic convergence conditions, which depend directly on the choice of the Q-filter and are …

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Macro-Mixing In A Draft-Tube Airlift Bioreactor, Hu Ping Luo, Muthanna H. Al-Dahhan Mar 2008

Macro-Mixing In A Draft-Tube Airlift Bioreactor, Hu Ping Luo, Muthanna H. Al-Dahhan

Chemical and Biochemical Engineering Faculty Research & Creative Works

Airlift Reactors Are Pneumatically Agitated Reactors that Have Been Widely Used in Industries, Particularly in Bioprocesses. Extensive Studies About the Flow Dynamics in Airlift Column Reactors Exist; However, Most of These Studies Have Focused on Global Hydrodynamic Parameters using Conventional Techniques. the Local Flow Characteristics, such as the Macro-Mixing and the Turbulence Intensity, Are Crucial for Reliable Design and Scale-Up, and They Remain Unclear. This Work Focuses on Studying the Macro-Mixing in a Draft-Tube Airlift Bioreactor Utilizing an Advanced Flow Dynamic Measurement Technique, Computer Automated Radioactive Particle Tracking (CARPT). True Residence Time Distribution Analyses for the overall Column as Well …

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A Fast Adaptive Wavelet Scheme In Rbf Collocation For Nearly Singular Potential Pdes, Nicolas Ali Libre, Arezoo Emdadi, Edward J. Kansa, Mohammad Shekarchi, Mohammad Rahimian Mar 2008

A Fast Adaptive Wavelet Scheme In Rbf Collocation For Nearly Singular Potential Pdes, Nicolas Ali Libre, Arezoo Emdadi, Edward J. Kansa, Mohammad Shekarchi, Mohammad Rahimian

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

We present a wavelet based adaptive scheme and investigate the efficiency of this scheme for solving nearly singular potential PDEs. Multiresolution wavelet analysis (MRWA) provides a firm mathematical foundation by projecting the solution of PDE onto a nested sequence of approximation spaces. The wavelet coefficients then were used as an estimation of the sensible regions for node adaptation. The proposed adaptation scheme requires negligible calculation time due to the existence of the fast DiscreteWavelet Transform (DWT). Certain aspects of the proposed adaptive scheme are discussed through numerical examples. It has been shown that the proposed adaptive scheme can detect the …

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A Note On Discrete-Time Triply-Selective Mimo Rayleigh Fading Channel Models, Jan Mietzner, Chengshan Xiao, Peter A. Hoeher, Khaled Ben Letaief Mar 2008

A Note On Discrete-Time Triply-Selective Mimo Rayleigh Fading Channel Models, Jan Mietzner, Chengshan Xiao, Peter A. Hoeher, Khaled Ben Letaief

Electrical and Computer Engineering Faculty Research & Creative Works

We discuss recent results on discrete-time models for triply-selective multiple-input multiple-output (MIMO) Rayleigh fading channels. Our key finding is that a previously proposed model (Xiao et al., 2004), which allows for efficient computer simulations, is sufficiently accurate for a wide range of practical scenarios.

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Computational Models Of Tandem Src Homology 2 Domain Interactions And Application To Phosphoinositide 3-Kinase, Dipak Barua, James R. Faeder, Jason M. Haugh Mar 2008

Computational Models Of Tandem Src Homology 2 Domain Interactions And Application To Phosphoinositide 3-Kinase, Dipak Barua, James R. Faeder, Jason M. Haugh

Chemical and Biochemical Engineering Faculty Research & Creative Works

Intracellular signal transduction proteins typically utilize multiple interaction domains for proper targeting, and thus a broad diversity of distinct signaling complexes may be assembled. Considering the coordination of only two such domains, as in tandem Src homology 2 (SH2) domain constructs, gives rise to a kinetic scheme that is not adequately described by simple models used routinely to interpret in vitro binding measurements. To analyze the interactions between tandem SH2 domains and bisphosphorylated peptides, we formulated detailed kinetic models and applied them to the phosphoinositide 3-kinase p85 regulatory subunit/platelet-derived growth factor β-receptor system. Data for this system from different in …

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Maxwellian Circuits-Based Analysis Of Loaded Wire Antennas And Scatterers, Mohamed A. Abou-Khousa, R. Zoughi Mar 2008

Maxwellian Circuits-Based Analysis Of Loaded Wire Antennas And Scatterers, Mohamed A. Abou-Khousa, R. Zoughi

Electrical and Computer Engineering Faculty Research & Creative Works

Based on the recently proposed Maxwellian circuit (MC) theory, a new method to analyze wire antennas and scatterers loaded with linear lumped elements is demonstrated in this letter. To effectively incorporate the load boundary condition into the numerical solution, the MC model is solved herein using finite element method (FEM).

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Effects Of Ionic Strength, Temperature, And Ph On Degradation Of Selected Antibiotics, Keith A. Loftin, Craig D. Adams, Michael T. Meyer, Rao Surampalli Mar 2008

Effects Of Ionic Strength, Temperature, And Ph On Degradation Of Selected Antibiotics, Keith A. Loftin, Craig D. Adams, Michael T. Meyer, Rao Surampalli

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Aqueous degradation rates, which include hydrolysis and epimerization, for chlorretracycline (CTC), oxytetracycline (OTC), tetracycline (TET), lincomycin (LNC), sulfachlorpyridazine (SCP), sulfadimethoxine (SDM), sulfathiazole (STZ), trimethoprim (TRM), and tylosin a (TYL) were studied as a function of ionic strength (0.0015, 0.050, or 0.084 mg/L as Na2HPO4), temperature (7, 22, and 35°C), and pH (2, 5, 7, 9, and 11). Multiple linear regression revealed that ionic strength did not significantly affect (α = 0.05) degradation rates for all compounds, but temperature and pH affected rates for CTC, OTC, and TET significand (α = 0.05). Degradation also was observed for TYL at pH 2 …

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Simulation Of Doubly-Selective Compound K Fading Channels For Mobile-To-Mobile Communications, Yuan Liu, Jian Zhang, Y. Rosa Zheng Mar 2008

Simulation Of Doubly-Selective Compound K Fading Channels For Mobile-To-Mobile Communications, Yuan Liu, Jian Zhang, Y. Rosa Zheng

Electrical and Computer Engineering Faculty Research & Creative Works

A computer simulation model is proposed for discrete-time doubly-selective compound-K fading channel. It first generates multiple independent mobile-to-mobile Rayleigh fading Channel Impulse Response (CIR) using the non-isotropic scattering model, then generates the cross- and auto-correlated gamma shadowing matrix using the combination of the memoryless nonlinear transformation (MNLT) method and the decomposition methods. It then combines the complex Rayleigh CIR with the gamma shadowing matrix to yield the doubly-selective fading channel CIR whose envelop follows the compound K distribution. Simulation examples demonstrate that the proposed method can effectively produce compound K fading channel responses with satisfactory statistical properties.

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Particle Swarm Optimization: Basic Concepts, Variants And Applications In Power Systems, Yamille Del Valle, Ganesh K. Venayagamoorthy, Salman Mohagheghi, Ronald G. Harley, J. C. Hernandez Mar 2008

Particle Swarm Optimization: Basic Concepts, Variants And Applications In Power Systems, Yamille Del Valle, Ganesh K. Venayagamoorthy, Salman Mohagheghi, Ronald G. Harley, J. C. Hernandez

Electrical and Computer Engineering Faculty Research & Creative Works

Many areas in power systems require solving one or more nonlinear optimization problems. While analytical methods might suffer from slow convergence and the curse of dimensionality, heuristics-based swarm intelligence can be an efficient alternative. Particle swarm optimization (PSO), part of the swarm intelligence family, is known to effectively solve large-scale nonlinear optimization problems. This paper presents a detailed overview of the basic concepts of PSO and its variants. Also, it provides a comprehensive survey on the power system applications that have benefited from the powerful nature of PSO as an optimization technique. For each application, technical details that are required …

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Output Feedback Controller For Operation Of Spark Ignition Engines At Lean Conditions Using Neural Networks, Jonathan B. Vance, Brian C. Kaul, Jagannathan Sarangapani, J. A. Drallmeier Mar 2008

Output Feedback Controller For Operation Of Spark Ignition Engines At Lean Conditions Using Neural Networks, Jonathan B. Vance, Brian C. Kaul, Jagannathan Sarangapani, J. A. Drallmeier

Electrical and Computer Engineering Faculty Research & Creative Works

Spark ignition (SI) engines operating at very lean conditions demonstrate significant nonlinear behavior by exhibiting cycle-to-cycle bifurcation of heat release. Past literature suggests that operating an engine under such lean conditions can significantly reduce NO emissions by as much as 30% and improve fuel efficiency by as much as 5%-10%. At lean conditions, the heat release per engine cycle is not close to constant, as it is when these engines operate under stoichiometric conditions where the equivalence ratio is 1.0. A neural network controller employing output feedback has shown ability in simulation to reduce the nonlinear cyclic dispersion observed under …

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