Engineering Commons^™

Design And Operation Of A Pilot Plant For Biodiesel Production From Triglycerides, Balasubramaniam Karthikeyan

Masters Theses

"In the wake of the events of September 11th 2001, the quest to relieve the nation’s dependence on petroleum fuels have taken a new urgency, there is a renewed interest in use of renewable biogenic fuels in particular -- the “biodiesel.” Biodiesel generally refers to fatty acid methyl esters of monohydric alcohols -- predominantly the methyl alcohol.

The principal sources of fatty acids are vegetable oils - soybean oil and canola oil. However, there are other “cheaper” sources of fatty acids that include beef tallow, poultry fats, pork fats and the used cooking oils. The first two are available in …

Misinformation [1], Hollis P. Leighly

Materials Science and Engineering Faculty Research & Creative Works

No abstract provided.

Evaluating And Monitoring Nucleation And Growth In Copper Foil, Ye Kun Lee, Thomas J. O'Keefe

Materials Science and Engineering Faculty Research & Creative Works

The electrodeposition of copper foil for use in electronic materials applications is a complex and demanding process. The specific aspects of producing and controlling the structure-property-performance requirements of the foil are important because of the stringent demands placed on their use in printed circuit boards and similar products. In this paper, a brief review of the electrodeposition process for raw copper foil is presented. Since electrolyte additives play such a significant role in the copper-deposition process, the effects of two essential additives, chloride ion and an organic (e.g., glue or gelatine), on the foil are described. Also, the influence of …

A New Method For Suboptimal Control Of A Class Of Nonlinear Systems, Ming Xin, S. N. Balakrishnan

Mechanical and Aerospace Engineering Faculty Research & Creative Works

In this paper, a new nonlinear control synthesis technique (θ - D approximation) is presented. This approach achieves suboptimal solutions to nonlinear optimal control problems in the sense that it solves the Hamilton-Jacobi-Bellman (HJB) equation approximately by adding perturbations to the cost function. By manipulating the perturbation terms both semi-globally asymptotic stability and suboptimality properties can be obtained. The convergence and stability proofs are given. This method overcomes the large control for large initial states problem that occurs in some other Taylor expansion based methods. It does not need time-consuming online computations like the state dependent Riccati equation (SDRE) technique. …

Experimental Implementation Of Adaptive-Critic Based Infinite Time Optimal Neurocontrol For A Heat Diffusion System, Prashant Prabhat, S. N. Balakrishnan, Dwight C. Look

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Recently the synthesis methodology for the infinite time optimal neuro-controllers for PDE systems in the framework of adaptive-critic design has been developed. In this paper, first we model an experimental setup representing one dimensional heat diffusion problems. Then we synthesize and implement an adaptive-critic based neuro-controller for online temperature profile control of the experimental setup.

Proper Orthogonal Decomposition Based Feedback Optimal Control Synthesis Of Distributed Parameter Systems Using Neural Networks, Radhakant Padhi, S. N. Balakrishnan

Mechanical and Aerospace Engineering Faculty Research & Creative Works

A new method for optimal control design of distributed parameter systems is presented in this paper. The concept of proper orthogonal decomposition is used for the model reduction of distributed parameter systems to form a reduced order lumped parameter problem. The optimal control problem is then solved in the time domain, in a state feedback sense, following the philosophy of ''adaptive critic'' neural networks. The control solution is then mapped back to the spatial domain using the same basis functions. Numerical simulation results are presented for a linear and nonlinear one-dimensional heat equation problem in an infinite time regulator framework.

The Changing Roles Of Analog And Digital Signal Processing In Cmos Image Sensors, John G. Harris

Electrical and Computer Engineering Faculty Research & Creative Works

Throughout the years digital signal processing has been encroaching more and more into what had previously been exclusive analog circuit domains. Here we briefly summarize various lines of research in CMOS imaging sensoring technology paying special attention to the gradual transition from analog to digital processing. The transition from continuous-time continuous-value pixels to digital (discrete-time binary-value) pixels could be viewed as the natural final step in the evolution of these imaging circuits in order to achieve wide dynamic range with acceptable signal to noise ratio. After data is read off a digital pixel imager chip, digital signal processing is required …

Increased Mfcc Filter Bandwidth For Noise-Robust Phoneme Recognition, Mark D. Skowronski, John G. Harris

Electrical and Computer Engineering Faculty Research & Creative Works

Many speech recognition systems use mel-frequency cepstral coefficient (MFCC) feature extraction as a front end. In the algorithm, a speech spectrum passes through a filter bank of mel-spaced triangular filters, and the filter output energies are log-compressed and transformed to the cepstral domain by the DCT. The spacing of filter bank center frequencies mimics the known warped-frequency characteristics of the human auditory system, yet the bandwidths of these filters are not chosen through biological inspiration. Instead, they are set by aligning endpoints of the triangle, which is itself an arbitrary shape. It is surprising that for such a popular speech …

A New Optimal Nonlinear Control Method And Its Application To Missile Guidance Law Design, Ming Xin, S. N. Balakrishnan

Mechanical and Aerospace Engineering Faculty Research & Creative Works

In this paper, a new nonlinear control synthesis technique (q-D approximation) is discussed. By adding perturbations to the cost function this approach achieves a suboptimal solution to the Hamilton-Jacobi- Bellman (HJB) equation. By manipulating the perturbation terms both asymptotic stability and optimality properties are obtained. An application to the design of missile guidance law is presented and is compared with a similar technique (State Dependent Riccati Equation technique) used in problems of this class. © 2002 by the author(s).

Accuracy And Efficiency In Fem Modeling Of Turbofan Acoustic Radiation, Eivind Listerud, Walter Eversman

Mechanical and Aerospace Engineering Faculty Research & Creative Works

It is shown that there is an increase in efficiency of acoustic radiation finite element modeling with the incorporation of cubic rather than quadratic serendipity elements. Cubic serendipity elements produce a given level of accuracy for acoustic pressure using a coarser mesh than required using quadratic elements, thus decreasing the CPU time needed for accurate modeling. These elements have been applied to the near field inlet and aft acoustic radiation models for a turbofan engine with the result of considerable reduction in the dimensionality of the problem without sacrificing accuracy. Visual observations of the gain in computational efficiency is supported …

End To End Congestion Control In High-Speed Networks, Sarangapani Jagannathan

Electrical and Computer Engineering Faculty Research & Creative Works

This paper proposes an adaptive methodology to prevent congestion in packet switched networks such as the Internet, where the internal network nodes convey very little information to the ingress nodes. Two architectures of preventing the congestion are presented: the first one when the traffic arrival rates, and bottleneck queue levels are known and the other when these are unknown. In the latter, the network traffic is estimated online using an adaptive system by measuring the buffer occupancy. In both architectures, the congestion is controlled by adjusting the transmission rates of non real-time and certain real-time sources in response to the …

Distributed Power Control In Wireless Communication Systems, Sarangapani Jagannathan, A. T. Chronopoulos, S. Ponipireddy

Electrical and Computer Engineering Faculty Research & Creative Works

Energy efficiency is a measure of performance in wireless networks. Therefore, controlling the transmitter power at a given node increases not only battery operating life, but also overall system capacity by successfully admitting new links. It is essential to find effective means of power control in point-to-point, broadcasting and multicasting scenarios. Wireless networking presents formidable challenges, and we consider the problem of unicast or point-to-point (peer-to-peer) communication in wireless networks in the presence of other nodes. We study the feasibility of admitting new links in an wireless network operating area while maintaining quality of service (QoS), in terms of signal-to-interference …

A Hybrid System Theoretic Approach For Admission Controller Design In Multimedia Networks, Sarangapani Jagannathan

Electrical and Computer Engineering Faculty Research & Creative Works

A novel real-time discrete-event admission control (AC) scheme for high-speed networks is proposed with the aim of attaining a desired quality of service (QoS) and high network utilization. The AC uses the available capacity from a novel adaptive bandwidth estimation scheme, a congestion indicator derived from a congestion controller, peak bit/cell rate (PBR/PCR) estimate from new sources, along with the desired QoS metrics, and makes decisions whether to 'admit' or 'reject' new sources. The novel aspect of the proposed approach is the application of hybrid system theory to prove the performance of the admission controller, stability and the development of …

Study Of Relative Effectiveness Of Features In Content-Based Image Retrieval, S. R. Subramanya, Jui Che Teng, Yongjian Fu

Electrical and Computer Engineering Faculty Research & Creative Works

Content-based retrieval in image databases requires appropriate features of images to be derived and used in the indexing and searching process. Fast and accurate retrieval is crucial from a user point of view. The kinds of features used, their organization in suitable data structures, and the similarity search scheme, directly affect the speed and quality of content-based retrieval. In this paper, we evaluate the relative significance of three different image features - geometry, moments, and Fourier descriptors in the context of content-based retrieval, and present experimental results. The evaluation metrics are retrieval quality and search time. These could be used …

Incorporation Of Cerium And Neodymium In A Uranyl Hydroxide Solid, Chang-Soo Kim, David J. Wronkiewicz, R. J. Finch, E. C. Buck

Electrical and Computer Engineering Faculty Research & Creative Works

The migration behavior of radionuclides in a nuclear-waste repository will be influenced, in part, by their equilibrium solubilities in the presence of radionuclide-bearing solids and/or adsorption affinities as trace components onto the surfaces of solid host phases. Uranium phases that precipitate on the surface of altered spent nuclear fuel may thus influence the mobility of radionuclides released in the near-field environment, since by proximity, these will be the first phases that the radionuclides encounter following their release from the spent fuel matrix. We have evaluated the potential for incorporating radionuclides into crystalline compounds by precipitating uranyl phases from aqueous solutions …

Development Of A Testbed For Design And Evaluation Of Power Electronic Based Systems, S. Pekarek, J. Tichenor, N. Benavides, A. Koenig, H. Wang, Scott D. Sudhoff, B. Kuhn, S. Glover, D. Aliprantis, J. Byoun, J. Sauer

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, a detailed technical description of a new hardware-based integrated power system testbed is presented. The testbed consists of an AC generation and propulsion system that is coupled to a DC zonal distribution system. A primary objective of the testbed is to provide a resource to the academic and industrial community by providing a non-proprietary system on which to demonstrate controls, survivability algorithms, and validate computer-aided design (CAD) tools. Copyright © 2002 Society of Automotive Engineers, Inc.

Comparison Of Mlp And Rbf Neural Networks Using Deviation Signals For On-Line Identification Of A Synchronous Generator, Jung-Wook Park, Ganesh K. Venayagamoorthy, Ronald G. Harley

Electrical and Computer Engineering Faculty Research & Creative Works

This paper compares the performances of a multilayer perceptron network (MLPN) and a radial basis function network (RBFN) for the online identification of the nonlinear dynamics of a synchronous generator. Deviations of signals from their steady state values are used. The computational complexity required to process the data for online training, generalization and online global minimum testing are investigated by time-domain simulations. The simulation results show that, compared to the MLPN, the RBFN is simpler to implement, needs less computational memory, converges faster and global minimum convergence is achieved even when operating conditions change.

Second-Order Statistical Properties Of The Wss Jakes' Fading Channel Simulator, Chengshan Xiao, Y. Rosa Zheng, N. C. Beaulieu

Electrical and Computer Engineering Faculty Research & Creative Works

An improved Jakes' (1994) fading channel simulator was proposed by Pop and Beaulieu (see ibid., vol.49, p.699-708, Apr. 2001) to eliminate the stationarity problem occurring in Jakes' original design. In this paper, second-order statistical properties of the improved Jakes' simulator are analyzed. Consistent with Pop and Beaulieu's caution about high-order statistics of the simulator, it is proved that some second-order statistics of both the quadrature components and the envelope do not match the desired ones even if the number of sinusoids approaches infinity. Therefore, care must be taken when the simulator is employed to evaluate algorithms and systems.

Software Engineering As A Business, Ann K. Miller, C. Ebert

Electrical and Computer Engineering Faculty Research & Creative Works

No abstract provided.

Tissue Classification Through Analysis Of Gene Expression Data Using A New Family Of Art Architectures, Rui Xu, Georgios C. Anagnostopoulos, Donald C. Wunsch

Electrical and Computer Engineering Faculty Research & Creative Works

Correct classification is crucial to cancer diagnosis and treatment. We demonstrate that a new family of neural network architectures-Ellipsoid ART and ARTMAP (EA/EAM)-can cluster and classify tissues successfully through analysis of gene expression data generated by DNA microarray experiments

A Cascaded Converter-Based Statcom With Energy Storage, Chang Qian, Mariesa Crow

Electrical and Computer Engineering Faculty Research & Creative Works

Due to their advantages in high power applications, multi-level converters have been introduced to flexible AC Transmission Systems (FACTS) to enhance power transmission system operation. Although several multi-level StatCom topologies have been proposed to verify the high performance of multi-level converters used in reactive power compensation, they are not capable of controlling active power flow. To make multi-level converters more flexible and effective for active power flow control, energy storage systems, such as flywheels and batteries are incorporated into StatComs. In this paper, battery energy storage systems (BESS) are incorporated into a cascaded converter-based StatCom to implement both active and …

A Diode-Clamped Multi-Level Inverter For The Statcom/Bess, Cheng Ying, Mariesa Crow

Electrical and Computer Engineering Faculty Research & Creative Works

Flexible AC transmission systems (FACTS) are potentially becoming more flexible and more economical local controllers in the power system. The integration of traditional FACTS devices with energy storage system (ESS) will increase FACTS device functionality. The voltage-sourced inverter is an important part of many FACTS devices, such as the StatCom and SSSC. Considerable research has been done on 2-level inverter usage in FACTS. Multilevel inverters, however, can improve the voltage quality and reduce the voltage stress on the power electronic devices. This paper uses a diode-clamped multilevel inverter in the StatCom/BESS. The multilevel inverter switching strategy and output voltage model …

Node Splitting Algorithms In Tree-Structured High-Dimensional Indexes For Similarity Search, Yongjian Fu, Jui Che Teng, S. R. Subramanya

Computer Science Faculty Research & Creative Works

Content-based searches and retrievals in multimedia and image databases use high-dimensional indexing structures for organizing the features of the objects. Most of those index structures are tree-structured whose nodes have a limit on the number of entries describing the subtrees rooted at those nodes. When index trees are built by repeated insertion of entries, nodes need to be split and the tree balanced accordingly. Node-splitting algorithms eventually determine the final structure of the tree which will have a profound effect on the search performance. This paper presents a comparative study of several node splitting algorithms for a typical high-dimensional indexing …

Interdisciplinary Graduate Experience: Lessons Learned, Steve Eugene Watkins, V. M. Eller, Josh Corra, M. J. Molander, Bethany Konz, Richard H. Hall, K. Chandrashekhara, Abdeldjelil Belarbi

Electrical and Computer Engineering Faculty Research & Creative Works

Engineers interact in the workplace with technical peers in other disciplines at all stages of design, development, and application. Awareness of the constraints and needs of the other disciplines can be key in many situations. Such interdisciplinary activity and the associated communication are facilitated if the all participants have a solid knowledge of discipline-specific terminology and an understanding of connecting concepts. Consequently, experience relating to interdisciplinary teamwork is a necessary component of engineering education. The Smart Engineering Group at the University of Missouri-Rolla was established to conduct interdisciplinary research and to create interdisciplinary educational resources. The topical interest area is …

A Distributed Discrete-Time Neural Network Architecture For Pattern Allocation And Control, A.T. Chronopoulos, Jagannathan Sarangapani

Computer Science Faculty Research & Creative Works

No abstract provided.

A Unified Theory On Residual Oil Saturation And Irreducible Water Saturation, Nick P. Valenti, R. M. Valenti, Leonard Koederitz

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

In many mature fields, there is a growing debate as to how much of the remaining oil is mobile in the unswept regions versus immobile in the swept regions. Log measured oil saturations behind the flood front are substantially lower than the residual oil saturations measured from special core analysis. In order to explain this contradiction, data from several fields is analyzed with special emphasis on capillary pressure. The concept of irreducible water saturation, connate water saturation, residual oil saturation and "critical water saturation" are discussed. The conclusions which are supported by experiment and theory, have substantial commercial implications concerning …

Effect Of Oxygen Vacancies On The Magnetic Structure Of The La₀.₆Sr₀.₄Feo3-Δ Perovskite: A Neutron Diffraction Study, Zili Chu, William B. Yelon, Jinbo Yang, William Joseph James, Harlan U. Anderson, Yixiang Xie, Satish K. Malik

Physics Faculty Research & Creative Works

Magnetic interactions in perovskite compounds of the type La_1-xSr_xMO_3-δ (M=3d transition such as Mn and Fe) are presumed to arise through a super exchange between 3d electrons of the magnetic ions via oxygen orbitals. The magnetic structure of La_0.6Sr_0.4FeO_3-δ has been studied with neutron diffraction. Oxygen vacancies were created by annealing samples under various gases including N₂, air and mixtures of CO/CO₂. All La_0.6Sr_0.4FeO_3-δ compounds maintain the rhombohedral structure (space group R3̄c). The air- or oxygen-annealed samples have almost no oxygen …

Experimental Verification Of Derivatives Adaptive Critic Based Neurocontroller Performance On Single Turbogenerators On The Electric Power Grid, Ganesh K. Venayagamoorthy, Donald C. Wunsch, Ronald G. Harley

Electrical and Computer Engineering Faculty Research & Creative Works

The design and real-time implementation of derivatives adaptive critic based neurocontrollers that replace the conventional automatic voltage regulators (AVRs) and turbine governors are presented in this paper. The feedback variables to the neurocontroller are completely based on local measurements from the turbogenerator. Experimental verification results are presented to show the superior performance of the derivatives adaptive critic based neurocontroller, compared to the conventional AVR and turbine governor controllers equipped with a power system stabilizer.

Finite-Element Modeling Of Coaxial Cable Feeds And Vias In Power-Bus Structures, Hao Wang, Yun Ji, Todd H. Hubing

Electrical and Computer Engineering Faculty Research & Creative Works

This paper presents three different models that can be used to represent coaxial cable feeds or vias in printed circuit board power-bus structures. The probe model represents a coaxial feed or via as a current filament with unknown radius. The coaxial-cable model enforces an analytical field distribution at the cable opening or via clearance hole. The strip model employs the equivalent radius concept to represent cylindrical feeds and vias as rectangular strips. Although the strip model is functionally equivalent to two closely positioned probe models, it accurately represents the conductor radius and is more accurate in situations where the via …

Full Binary Combination Schema For Floating Voltage Source Multi-Level Inverters, X. Kou, Keith Corzine, Yakov L. Familiant

Electrical and Computer Engineering Faculty Research & Creative Works

This paper presents schema of operation for floating voltage source multi-level inverters. The primary advantage of the proposed schema is that the number of voltage levels (and thus power quality) can be increased for a given number of semiconductor devices when compared to the conventional "flying capacitor" topology. However, the new schema requires fixed floating sources instead of capacitors and therefore is more suitable for battery power applications such as electric vehicles, flexible AC transmission systems and submarine propulsion. Alternatively transformer/rectifier circuits may be used to supply the floating sources in a similar way to cascaded H-bridge inverters. Computer simulation …