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Electron Transport Through Two Irreducibly-Coupled Aharonov-Bohm Rings With Applications To Nanostructure Quantum Computing Circuits, C. A. Cain, Cheng-Hsiao Wu Sep 2011

Electron Transport Through Two Irreducibly-Coupled Aharonov-Bohm Rings With Applications To Nanostructure Quantum Computing Circuits, C. A. Cain, Cheng-Hsiao Wu

Electrical and Computer Engineering Faculty Research & Creative Works

We investigated several classes of two coupled Aharonov-Bohm rings that share a finite center common path, where the phase of the electron wave function can be modulated by two distinct magnetic fluxes. The coupling is similar to two coupled atoms. The behavior of charge accumulation along the center common path or, equivalently, the bonding and anti-bonding of the two rings can be achieved as the two applied fluxes are varied. Thus, when three external terminals are connected to such coupled rings, the behavior of the electron transport is divided into several classes, depending on the number of atoms in each …

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Stoichiometric H2ice With Water Injection And Exhaust And Coolant Heat Recovery Through Organic Rankine Cycles, Alberto Boretti Sep 2011

Stoichiometric H2ice With Water Injection And Exhaust And Coolant Heat Recovery Through Organic Rankine Cycles, Alberto Boretti

Mechanical and Aerospace Engineering Faculty Research & Creative Works

High power density, stoichiometric, turbocharged, directly injected engines with water injection and a three-way catalytic converter after treatment have been proposed as one of the most promising H2ICE [1]. These throttle-controlled engines have top brake efficiencies exceeding 40%, but large penalties in efficiency reducing the load with 1 bar BMEP values approaching 10%. Recovery of the large amount of fuel energy lost in the coolant especially at low loads as well as the fuel energy lost in the exhaust that is significant at high loads and speeds may push not only the top brake efficiencies to exceed the 45% mark, …

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Earthquake-Induced Deformation Analysis Of A Bridge Approach Embankment In Missouri, W. Liu, Ronaldo Luna, Richard Wesley Stephenson, S. Wang Sep 2011

Earthquake-Induced Deformation Analysis Of A Bridge Approach Embankment In Missouri, W. Liu, Ronaldo Luna, Richard Wesley Stephenson, S. Wang

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Earthquake-Induced Deformations for a Bridge Approach Earth Embankment Are Predicted using a Calibrated Numerical Model. the Constitutive Soil Model is a Modified Hyperbolic Model that Uses Masing Rules and Incremental Pore Pressure Relations. the Model Was Calibrated using Both Laboratory and Field Data. a Shaking Table Physical Model Was Used to Verify the Numerical Simulation. Additionally, the Upper San Fernando Dam Was Modeled to Reproduce the Deformations in the 1971 Earthquake. the Subsurface and Embankment Soil Conditions Were Characterized using Field and Laboratory Methods. the Model Developed Was Used to Predict the Earthquake-Induced Deformations of an Approach Embankment to Bridge …

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Smartpark As A Virtual Statcom, Pinaki Mitra, Ganesh K. Venayagamoorthy, Keith Corzine Sep 2011

Smartpark As A Virtual Statcom, Pinaki Mitra, Ganesh K. Venayagamoorthy, Keith Corzine

Electrical and Computer Engineering Faculty Research & Creative Works

Power electronic-Based FACTS devices such as STATCOMs are sometimes essential for voltage support in transmission networks. They can also be used for continuous operation of doubly fed induction generator-Based wind turbines during faults. However, these devices are quite expensive and therefore cannot be used extensively. This paper explores the potential of a low-cost solution that utilizes the reactive power and voltage support capabilities of plug-in vehicles parked in charging stations (SmartParks) so that they can behave as virtual STATCOMs. for this solution, a 12-bus multimachine power system is considered wherein one of the conventional units is replaced by a 400 …

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Robust Cns Regeneration After Complete Spinal Cord Transection Using Aligned Poly-L-Lactic Acid Microfibers, Andres Hurtado, Jared M. Cregg, Han B. Wang, Dane F. Wendell, Martin Oudega, Ryan J. Gilbert, John W. Mcdonald Sep 2011

Robust Cns Regeneration After Complete Spinal Cord Transection Using Aligned Poly-L-Lactic Acid Microfibers, Andres Hurtado, Jared M. Cregg, Han B. Wang, Dane F. Wendell, Martin Oudega, Ryan J. Gilbert, John W. Mcdonald

Chemical and Biochemical Engineering Faculty Research & Creative Works

Following spinal cord injury, axons fail to regenerate without exogenous intervention. In this study we report that aligned microfiber-based grafts foster robust regeneration of vascularized CNS tissue. Film, random, and aligned microfiber-based conduits were grafted into a 3 mm thoracic rat spinal cord gap created by complete transection. Over the course of 4 weeks, microtopography presented by aligned or random poly- l-lactic acid microfibers facilitated infiltration of host tissue, and the initial 3 mm gap was closed by endogenous cell populations. This bulk tissue response was composed of regenerating axons accompanied by morphologically aligned astrocytes. Aligned fibers promoted long distance …

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Cross-Layer Throughput Optimization With Power Control In Sensor Networks, Maggie Xiaoyan Cheng, Xuan Gong, Lin Cai, Xiaohua Jia Sep 2011

Cross-Layer Throughput Optimization With Power Control In Sensor Networks, Maggie Xiaoyan Cheng, Xuan Gong, Lin Cai, Xiaohua Jia

Computer Science Faculty Research & Creative Works

In wireless sensor networks, transmission power has a significant impact on network throughput as wireless interference increases with transmission power, and interference negatively impacts the network throughput. in this paper, we try to improve the network throughput through cross-layer optimization. We first present two algorithms to compute the transmission power of each node with the objectives of minimizing the total transmission power and minimizing the total interference, respectively, from which we can obtain a network topology that ensures a connected path from each source to the sink; then, we compute the maximum achievable throughput from the obtained topology by using …

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Providing End-To-End Secure Communications In Wireless Sensor Networks, Wenjun Gu, Neelanjana Dutta, Sriram Chellappan, Xiaole Bai Sep 2011

Providing End-To-End Secure Communications In Wireless Sensor Networks, Wenjun Gu, Neelanjana Dutta, Sriram Chellappan, Xiaole Bai

Computer Science Faculty Research & Creative Works

In many Wireless Sensor Networks (WSNs), providing end to end secure communications between sensors and the sink is important for secure network management. While there have been many works devoted to hop by hop secure communications, the issue of end-to-end secure communications is largely ignored. in this paper, we design an end-to-end secure communication protocol in randomly deployed WSNs. Specifically, our protocol is based on a methodology called differentiated key pre-distribution. the core idea is to distribute different number of keys to different sensors to enhance the resilience of certain links. This feature is leveraged during routing, where nodes route …

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Missouri S&T Magazine Fall 2011, Missouri S&T Marketing And Communications Department, Miner Alumni Association Sep 2011

Missouri S&T Magazine Fall 2011, Missouri S&T Marketing And Communications Department, Miner Alumni Association

Missouri S&T Magazine

No abstract provided.

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Planned Tournament Selection, Douglas Mccorkle, Daniel Ashlock, Steven Corns, Kenneth Mark Bryden Sep 2011

Planned Tournament Selection, Douglas Mccorkle, Daniel Ashlock, Steven Corns, Kenneth Mark Bryden

Engineering Management and Systems Engineering Faculty Research & Creative Works

Tournament selection is a versatile method of selection and replacement used in evolutionary computation. Normally tournaments are chosen uniformly at random. This study demonstrates the effectiveness of planning tournaments in advance to control information flow within a population being evolved for optimization. Tests are performed on a variety of evolutionary test problems, finding that different planned tournament schemes yield significant differences in performance. the correct type of planned tournament is found to be problem dependent. in addition to a linear-function scheme for planning tournaments, this study also introduces a technique called multi-deme planned tournaments selection which permits simpler cases of …

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Low-Complexity Soft-Decision Feedback Turbo Equalization For Mimo Systems With Multilevel Modulations, Amirhossein Rafati, Huang Lou, Chengshan Xiao Sep 2011

Low-Complexity Soft-Decision Feedback Turbo Equalization For Mimo Systems With Multilevel Modulations, Amirhossein Rafati, Huang Lou, Chengshan Xiao

Electrical and Computer Engineering Faculty Research & Creative Works

Many communication systems today encounter the problem of data transmission over a channel with InterSymbol interference (ISI). the purpose of this paper is to develop a low-complexity iterative soft-decision feedback equalization (SDFE) receiver for severe frequency-selective ISI channels in multiple-input-multiple-output (MIMO) communication systems. the proposed SDFE algorithm offers a novel approach to combat error propagation. in addition, its computational complexity only linearly grows with the number of equalizer coefficients, compared with the quadratic complexity of minimum mean square error (MMSE)-Based linear turbo equalizer with time-varying coefficients. the performance of the proposed detection scheme is verified through simulations using different signal …

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Proportionate Affine Projection Sign Algorithms For Network Echo Cancellation, Zengli Yang, Yahong Rosa Zheng, Steven L. Grant Aug 2011

Proportionate Affine Projection Sign Algorithms For Network Echo Cancellation, Zengli Yang, Yahong Rosa Zheng, Steven L. Grant

Electrical and Computer Engineering Faculty Research & Creative Works

Two proportionate affine projection sign algorithms (APSAs) are proposed for network echo cancellation (NEC) applications where the impulse response is often real valued with sparse coefficients and long filter length. the proposed proportionate-type algorithms can achieve fast convergence and low steady-state misalignment by adopting a proportionate regularization matrix to the APSA. Benefiting from the characteristics of l1-norm optimization, affine projection, and proportionate matrix, the new algorithms are more robust to impulsive interferences and colored input than the proportionate least mean squares (PNLMS) algorithm and the robust proportionate affine projection algorithm (Robust PAPA). the new algorithms also achieve much faster convergence …

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Femtosecond Laser Fabricated All-Optical Fiber Sensors With Ultrahigh Refractive Index Sensitivity: Modeling And Experiment, Lan Jiang, Longjiang Zhao, Sumei Wang, Jinpeng Yang, Hai Xiao Aug 2011

Femtosecond Laser Fabricated All-Optical Fiber Sensors With Ultrahigh Refractive Index Sensitivity: Modeling And Experiment, Lan Jiang, Longjiang Zhao, Sumei Wang, Jinpeng Yang, Hai Xiao

Mechanical and Aerospace Engineering Faculty Research & Creative Works

All-optical fiber sensors based on ultracompact fiber inline Mach-Zehnder interferometer (MZI) are fabricated by side-ablating a Ushape microcavity in a single-mode optical fiber with the fiber core partially removed using femtosecond (fs) laser pulses, in which the two light paths are accordingly formed in the remaining D-type fiber core and the U-shape microcavity. Beam propagation method (BPM) analysis is utilized to illustrate the dependences of good transmission spectra on parameters including the ablation depth, ablation length and the refractive index of Ushape microcavity, which gives some guidelines to optimize parameters for fs laser micromachining and predicts RI (refractive index) sensitivities …

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On The Effects Of Graph Based Evolutionary Algorithms For Training Finite State Classifiers, Steven M. Corns Aug 2011

On The Effects Of Graph Based Evolutionary Algorithms For Training Finite State Classifiers, Steven M. Corns

Engineering Management and Systems Engineering Faculty Research & Creative Works

This work presents a method for evolving finite state machines for the classification of polymerase chain reaction primers in mice using graph based evolutionary algorithms. using these machine learning tools we can compensate for many lab, organism, and chemical specific factors that can cause these primers to fail. using Finite State Classifiers can help to decrease the number of primers that fail to amplify correctly. for training these classifiers, fifteen different graph based evolutionary algorithms were used in two different experiments to explore the effects of diversity preservation on the development of these classifiers. by controlling the rate at which …

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Influence Of Geotechnical Dataset On The Range Of Influence Of Undrained Shear Strength, Site Onyejekwe, Louis Ge Aug 2011

Influence Of Geotechnical Dataset On The Range Of Influence Of Undrained Shear Strength, Site Onyejekwe, Louis Ge

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The knowledge of the spatial variability of geotechnical parameters, which can be described statistically by the mean, the variance, and the scale of fluctuation, is important in reliability-Based design. of particular importance is the scale of fluctuation. It can be used to compute the variance reduction factor, a factor of spatial averaging of geotechnical properties to reduce their point variance. the most prevalent method of determining the scale of fluctuation uses datasets whose data points are at close and regular intervals, e.g. measurements from cone penetrometer soundings. Another method, when continuous measurements are not available, uses datasets that are widely …

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Note: Miniature 120-Kv Autonomous Generator Based On Transverse Shock-Wave Depolarization Of Pb(Zr0.52ti0.48)O₃ Ferroelectrics, S. I. Shkuratov, Jason Baird, E. F. Talantsev Aug 2011

Note: Miniature 120-Kv Autonomous Generator Based On Transverse Shock-Wave Depolarization Of Pb(Zr0.52ti0.48)O₃ Ferroelectrics, S. I. Shkuratov, Jason Baird, E. F. Talantsev

Mining Engineering Faculty Research & Creative Works

The design of autonomous ultrahigh-voltage generators with no moving metallic parts based on transverse explosive shock wave depolarization of Pb(Zr0.52Ti0.48)O3 (PZT 5248) poled ferroelectrics was explored and studied. It follows from experimental results that the output voltage produced by the shock-wave ferroelectric generators (FEGs) is directly proportional to the number of PZT 5248 elements connected in series. It was demonstrated that miniature FEGs (volume less than 180 cm3) were capable of reliably producing output voltage pulses with amplitudes exceeding 120 kV which is the record reported in open literature.

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Proportionate Affine Projection Sign Algorithms For Sparse System Identification In Impulsive Interference, Zengli Yang, Yahong Rosa Zheng, Steven L. Grant Aug 2011

Proportionate Affine Projection Sign Algorithms For Sparse System Identification In Impulsive Interference, Zengli Yang, Yahong Rosa Zheng, Steven L. Grant

Electrical and Computer Engineering Faculty Research & Creative Works

Two proportionate affine projection sign algorithms (APSAs) are proposed for system identification applications, such as network echo cancellation (NEC), where the impulse response is often real valued with sparse coefficients and long filter length. the proposed proportionate-type algorithms can achieve fast convergence and low steady-state misalignment by adopting a proportionate regularization matrix to the APSA. Benefiting from the characteristic of l1-norm algorithms, affine projection, and proportionate matrix, the new algorithms are robust to impulsive interferences and colored input and achieve much faster convergence rate in sparse impulse responses than the original APSA, the normalized sign algorithm (NSA), and the proportionate …

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Design Optimization Of Linear Precoders For Complex Vector Gaussian Channelswith Finite Alphabet Inputs, Chengshan Xiao, Yahong Rosa Zheng, Zhi Ding Aug 2011

Design Optimization Of Linear Precoders For Complex Vector Gaussian Channelswith Finite Alphabet Inputs, Chengshan Xiao, Yahong Rosa Zheng, Zhi Ding

Electrical and Computer Engineering Faculty Research & Creative Works

We study the design optimization of linear precoders that maximize the mutual information in complex-valued vector Gaussian channels under finite alphabet inputs. It is well known that mutual information of a vector channel with discrete constellation source is a highly nonlinear and nonconcave function of the linear precoder matrix G, thereby complicating the precoder design optimization. in this paper, we show that the mutual information is a concave function of W = GhHhHG, where H is the complex-valued channel matrix and superscript "h" represents conjugate transpose. We further propose an iterative algorithm for solving the globally optimal linear precoder G. …

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Comparison Of Tdnn And Rnn Performances For Neuro-Identification On Small To Medium-Sized Power Systems, Diogenes Molina, Jiaqi Liang, Ron Harley, Ganesh K. Venayagamoorthy Aug 2011

Comparison Of Tdnn And Rnn Performances For Neuro-Identification On Small To Medium-Sized Power Systems, Diogenes Molina, Jiaqi Liang, Ron Harley, Ganesh K. Venayagamoorthy

Electrical and Computer Engineering Faculty Research & Creative Works

For Artificial Neural Networks (ANN) to become more widely used in power systems and the future smart grids, ANN based algorithms must be capable of scaling up as they try to identify and control larger and larger parts of a power system. This paper goes through the process of scaling up an ANN based identifier as it is driven to identify increasingly larger portions of a power system. Distributed and centralized approaches for scaling up are taken and the pros and cons of each are presented. the New England/New York 68-bus power network is used as the test bed for …

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Adaptive Critic Design Based Dynamic Optimal Power Flow Controller For A Smart Grid, Jiaqi Liang, Ronald G. Harley, Ganesh K. Venayagamoorthy Aug 2011

Adaptive Critic Design Based Dynamic Optimal Power Flow Controller For A Smart Grid, Jiaqi Liang, Ronald G. Harley, Ganesh K. Venayagamoorthy

Electrical and Computer Engineering Faculty Research & Creative Works

An adaptive critic design (ACD) based dynamic optimal power flow control (DOPFC) is proposed in this paper as a solution to the smart grid operation in a high short-term uncertainty and variability environment. with the increasing penetration of intermittent renewable generation, power system stability and security need to be ensured dynamically as the system operating condition continuously changes. the proposed DOPFC dynamically tracks the power system optimal operating point by continuously adjusting the steady state set points from the traditional OPF algorithms. the ACD technique, specifically the dual heuristic dynamic programming (DHP), is used to provide nonlinear optimal control, where …

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Wide Area Monitoring In Power Systems Using Cellular Neural Networks, Bipul Luitel, Ganesh K. Venayagamoorthy Aug 2011

Wide Area Monitoring In Power Systems Using Cellular Neural Networks, Bipul Luitel, Ganesh K. Venayagamoorthy

Electrical and Computer Engineering Faculty Research & Creative Works

The demand of power and the size and complexity of the power system is increasing. Wide area monitoring and control is an integral part in transitioning from the traditional power system to a Smart Grid. However, wide area monitoring becomes challenging as the size of the electric power grid, and consequently the number of components to be monitored, grows. Wide area monitor (WAM) designed using feed-forward and feedback neural network architectures do not scale up to handle the growing complexity of the Smart Grid. in this paper, cellular neural network (CNN) is presented as a way to provide scalability in …

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Optimal Location And Sizing Of Energy Storage Modules For A Smart Electric Ship Power System, Chuan Yan, Ganesh K. Venayagamoorthy, Keith Corzine Aug 2011

Optimal Location And Sizing Of Energy Storage Modules For A Smart Electric Ship Power System, Chuan Yan, Ganesh K. Venayagamoorthy, Keith Corzine

Electrical and Computer Engineering Faculty Research & Creative Works

The Navy's next generation electric ship's power system will support high energy loads and critical equipment. Energy storage modules will be needed to meet the demands of these loads as well as increase the overall high quality of service. This paper describes an approach to evaluate the impact of energy storage module location and sizing for ship survivability and quality of service. Specifically, a multi-objective optimization algorithm, the multi-objective particle swarm optimization -, is used to obtain Pareto optimal solutions considering survivability, quality of service, and cost. Results based multi-objective particle swarm optimization study show that optimal ESM location and …

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Adaptive Kernel Smoothing Regression Using Vector Quantization, Federico Montesino Pouzols, Amaury Lendasse Aug 2011

Adaptive Kernel Smoothing Regression Using Vector Quantization, Federico Montesino Pouzols, Amaury Lendasse

Engineering Management and Systems Engineering Faculty Research & Creative Works

A Method for Performing Kernel Smoothing Regression in an Online Adaptive Manner is Presented. the Approach Proposed is to Apply Kernel Smoothing Regression on an Incremental Estimation of the (Evolving) Probability Distribution of the Incoming Data Stream Rather Than the Sequence of Observations. This is Achieved by Performing Vector Quantization on the Incoming Stream. in Addition, the Kernel Bandwidth is Adapted Online using a Criterion based on the Median Absolute Deviation Estimator Which Can Be Computed Efficiently Online. Thus, Adaptive Kernel Smoothing Regression is Computed on an Evolving Density Estimation. the Method is Fast and Suitable for Modeling Streams of …

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Faculty Senate Minutes August 11, 2011, Missouri University Of Science And Technology Faculty Senate Aug 2011

Faculty Senate Minutes August 11, 2011, Missouri University Of Science And Technology Faculty Senate

Minutes & Agendas

No abstract provided.

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Bio-Inspired Design Of Bipolar Plate Flow Fields For Polymer Electrolyte Membrane Fuel Cells, Nannan Guo, Ming-Chuan Leu, Maoliang Wu Aug 2011

Bio-Inspired Design Of Bipolar Plate Flow Fields For Polymer Electrolyte Membrane Fuel Cells, Nannan Guo, Ming-Chuan Leu, Maoliang Wu

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The flow field of a bipolar plate distributes hydrogen and oxygen for polymer electrolyte membrane (PEM) fuel cells and removes the produced water from the fuel cells. It greatly influences the performance of fuel cells, especially regarding reduction of mass transport loss. Flow fields with good gas distribution and water removal capabilities reduce the mass transport loss, thus allowing higher power density. Inspired by natural structures such as veins in tree leaves and blood vessels in lungs, which efficiently feed nutrition from one central source to large areas and are capable of removing undesirable by-products, a mathematic model has been …

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Octree Approach For Simulation Of Additive Manufacturing Toolpath, Ch. Sweta Dhaveji, Todd E. Sparks, Jianzhong Ruan, Frank W. Liou Aug 2011

Octree Approach For Simulation Of Additive Manufacturing Toolpath, Ch. Sweta Dhaveji, Todd E. Sparks, Jianzhong Ruan, Frank W. Liou

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Machine simulation is an effective way of checking additive manufacturing tool paths for both interferences and errors in part produced. This paper presents an algorithm to visually simulate a multi axis additive manufacturing system as it executes a process plan. Simulation results are intended to be used as a verification step before physically producing the part. Verification is particularly important for large builds of expensive materials. The algorithm uses an octree approach to efficiently model the deposition of part geometry and its changes. This paper discusses development of the simulation algorithm, including both the representation of the additive manufacturing machine …

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Effect Of Particle Size, Binder Content And Heat Treatment On Mechanical Properties Of 13-93 Bioactive Glass Scaffolds, Krishna C. R. Kolan, Ming-Chuan Leu, Greg Hilmas, Mariano Garcia Velez Aug 2011

Effect Of Particle Size, Binder Content And Heat Treatment On Mechanical Properties Of 13-93 Bioactive Glass Scaffolds, Krishna C. R. Kolan, Ming-Chuan Leu, Greg Hilmas, Mariano Garcia Velez

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Particle size, binder content and the post-processing schedule are important parameters that affect the microstructure, and, hence, the mechanical properties of parts produced using the indirect selective laser sintering process. 13-93 bioactive glass, with mean particle sizes ranging from 10 μm to 44 μm, is mixed with different amounts of stearic acid binder to fabricate green scaffolds. Through the design of the post-processing schedule, the time required for postprocessing the green scaffolds is reduced from the initial 80 hrs to 12 hrs. The compressive strength varies from 41 MPa for a part with~60% porosity to 157 MPa for a part …

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A Strategy For Fabricating Complex Structures Via A Hybrid Manufacturing Process, Tarak A. Amine, Todd E. Sparks, Frank W. Liou Aug 2011

A Strategy For Fabricating Complex Structures Via A Hybrid Manufacturing Process, Tarak A. Amine, Todd E. Sparks, Frank W. Liou

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The purpose of this paper is to introduce a strategy for fabricating complex structures via a hybrid manufacturing process. The Laser Aided Manufacturing Process (LAMP) lab at Missouri S&T has developed a hybrid process combining both a direct metal deposition process and a five-axis CNC milling. Accessibility is a difficulty when finish machining internal features. The concept is to pause the deposition process to finish machine an internal feature while it is still visible is one possible solution to this issue. However, this must be done in a manner that will not be spoiled when the deposition process continues. This …

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A Trustworthiness Fusion Model For Service Cloud Platform Based On D-S Evidence Theory, Rong Hu, Jianxun Liu, Xiaoqing Frank Liu Aug 2011

A Trustworthiness Fusion Model For Service Cloud Platform Based On D-S Evidence Theory, Rong Hu, Jianxun Liu, Xiaoqing Frank Liu

Computer Science Faculty Research & Creative Works

Trustworthiness plays an important role in service selection and usage. However, it is not easy to define and compute the service trustworthiness because of its subject meaning and also the different views on it. in this paper, we describe the meaning of trustworthiness and the computation method for trustworthiness fusion. through extracting trustworthiness from service provider, service requestor and service broker, we creatively adopted D-S (Dempster-Shafer) evident theory to fuse the tripartite trustworthiness. Finally, we completed some comparison experiments on our web service supermarket platform and certified the efficiency of our method. © 2011 IEEE.

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Numerical Simulation Of Ram Extrusion Process For Ceramic Materials, Mingyang Li, Lie Tang, Fei Xue, Robert G. Landers Aug 2011

Numerical Simulation Of Ram Extrusion Process For Ceramic Materials, Mingyang Li, Lie Tang, Fei Xue, Robert G. Landers

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The freeze–form extrusion process for aqueous-based ceramic paste is complex due to the non-Newtonian behavior of the paste. In this paper the process is studied numerically using a developed mathematical model. The ceramic paste viscosity is characterized by the Herschel-Bulkley model. The relationship between plunger velocity and extrusion force is computed numerically. The influence of air, which is mixed with the paste during the loading process, is also examined. Due to the compressibility introduced by the trapped air, the plunger force dynamic response is typically dominated by a first order response. It is also shown that the extrusion plunger force …

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Process Planning And Control For Functionally Graded Material Fabrication Using Freeze-Form Extrusion Fabrication, Brad Deuser, Lie Tang, Jeff Geldmeier, Robert G. Landers, Ming-Chuan Leu Aug 2011

Process Planning And Control For Functionally Graded Material Fabrication Using Freeze-Form Extrusion Fabrication, Brad Deuser, Lie Tang, Jeff Geldmeier, Robert G. Landers, Ming-Chuan Leu

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Using multiple materials in additive manufacturing technologies is critical for building parts with functionally gradient geometries. In order to achieve a desired material gradient, an advanced process planning and control system is required. This paper details the development of a process planning method and control system for functionally graded material fabrication using a triple extruder Freeze-form Extrusion Fabrication (FEF) system including motion code generation, extruder dynamic modeling and control, and composition gradient control. The effect that extruding multiple materials from a single orifice via static mixing has on the time delay of the resulting mixture is taken into account for …

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