Engineering Commons^™

Elm-Som: A Continuous Self-Organizing Map For Visualization, Renjie Hu, Venous Roshdibenam, Hans J. Johnson, Emil Eirola, Anton Akusok, Yoan Miche, Kaj Mikael Björk, Amaury Lendasse

Engineering Management and Systems Engineering Faculty Research & Creative Works

This Paper Presents a Novel Dimensionality Reduction Technique: Elm-Som. This Technique Preserves the Intrinsic Quality of Self-Organizing Maps (Som): It is Nonlinear and Suitable for Big Data. It Also Brings Continuity to the Projection using Two Extreme Learning Machine (Elm) Models, the First One to Perform the Dimensionality Reduction and the Second One to Perform the Reconstruction. Elm-Som is Tested Successfully on Six Diverse Datasets. Regarding Reconstruction Error, Elm-Som is Comparable to Som While Bringing Continuity.

Meta-Learning Related Tasks With Recurrent Networks: Optimization And Generalization, Thy Nguyen, A. Steven Younger, Emmett Redd, Tayo Obafemi-Ajayi

Electrical and Computer Engineering Faculty Research & Creative Works

There have been recent interest in meta-learning systems: I.e., networks that are trained to learn across multiple tasks. This paper focuses on optimization and generalization of a meta-learning system based on recurrent networks. The optimization investigates the influence of diverse structures and parameters on its performance. We demonstrate the generalization (robustness) of our meta-learning system to learn across multiple tasks including tasks unseen during the meta training phase. We introduce a meta-cost function (Mean Squared Fair Error) that enhances the performance of the system by not penalizing it during transitions to learning a new task. Evaluation results are presented for …

Off-Policy Integral Reinforcement Learning For Semi-Global Constrained Output Regulation Of Continuous-Time Linear Systems, Yongliang Yang, Xianzhong Chen, Yixin Yin, Donald C. Wunsch

Electrical and Computer Engineering Faculty Research & Creative Works

This paper presents a data-driven method based on off-policy integral reinforcement learning to solve the semi-global output regulation of continuous-time linear systems with input saturation. A family of state feedback laws for the input constrained output regulation problem is designed based on solving an algebraic Riccati equation. In contrast to the existing methods, complete knowledge of the system dynamics is no longer required in this paper. Instead, the data collected from online implementation is efficiently utilized to design the controller. Therefore, the controller design in this paper is data driven. It is shown that the presented method can find feedback …

Load Bearing Clip Angle Design -- Phase Ii, Cheng Yu, Zhishan Yan, Wenying Zhang, Lanping Qian

American Iron and Steel Institute (AISI) Specifications, Standards, Manuals and Research Reports (1946 - present)

The report presents the second phase of a research project aimed at developing design methods for three limit states of CFS clip angles: shear, compression, and pull-over of the screw connections. In the Phase II work, the research focus was on investigating (1) the fastener pattern effects on the behavior and strength of clip angles; (2) the serviceability of clip angles subjected to tension; (3) the strength and behavior of clip angles subjected to combined shear and bending. Based on the research findings, revision to the Phase I method was proposed to account for the impact of the fastener spacing. …

Radiation Detector Deadtime And Pile Up: A Review Of The Status Of Science, Shoaib Usman, Amol Patil

Nuclear Engineering and Radiation Science Faculty Research & Creative Works

Since the early forties, researchers from around the world have been studying the phenomenon of deadtime in radiation detectors. Many have attempted to develop models to represent this phenomenon. Two highly idealized models; paralyzable and non-paralyzable are commonly used by most individuals involved in radiation measurements. Most put little thought about the operating conditions and applicability of these ideal models for their experimental conditions. So far, there is no general agreement on the applicability of any given model for a specific detector under specific operating conditions, let alone a universal model for all detectors and all operating conditions. Further the …

Low-Profile Diplexing Filter/Antenna Based On Common Radiating Cavity With Quasi-Elliptic Response, Kirti Dhwaj, Xiaoqiang Li, Li (Lijun) Jun Jiang, Tatsuo Itoh

Electrical and Computer Engineering Faculty Research & Creative Works

A low-profile single-layer substrate integrated waveguide (SIW) diplexing filtering antenna with two-pole response in each channel is presented. Synthesis technique is proposed, which allows independent design of the filtering networks for the two channels. A common slot loaded SIW cavity is used to obtain the desired radiation in both channels. The diplexing filtering antenna provides quasi-elliptic response in both channels due to source-load coupling. The filtering antenna provides a maximum broadside gain of 2.65 and 2.7 dBi at operating frequencies of 5.25 (lower channel) and 5.8 GHz (upper channel), respectively. The interchannel isolation is more than 29 dB with a …

Study Of Cost Overrun And Delays Of Department Of Defense (Dod)'S Space Acquisition Program, Nazareen Sikkandar Basha, Benjamin J. Kwasa, Christina Bloebaum

Engineering Management and Systems Engineering Faculty Research & Creative Works

Defense and Aerospace Systems Acquisition projects, just like any other Large-Scale Complex Engineered Systems (LSCES) experience delays and cost overrun during the acquisition process. Cost overrun and delays in LSCES are due, in part, to high complexity, size of the project, involvement of various stakeholders, organizations, political disruptions, changes in requirements and scope. These uncertainties, due to the exogenous factors, have cost the federal government billions of dollars and delays in completion of the programs. Cost estimation of federal programs is usually based on previous generations of systems produced and almost all the time the costs are underestimated. Underestimation of …

Rare Earth Elements Removal Techniques From Water/Wastewater: A Review, Omoniyi Pereao, Chris Bode-Aluko, Olanrewaju Fatoba, Katri Laatikainen, Leslie Petrik

Mining Engineering Faculty Research & Creative Works

The rare-earth elements (REEs) remain very important due to the growing increase in their demand and for their critical and indispensable use in many high-tech industries today. This growing demand for REEs has led to an increased environmental exposure and water pollution from numerous REEs commercial products and as a result, the recovery of REEs is a significant issue that requires appropriate consideration. There are diverse and various strategic techniques available to remove metal ions from aqueous solutions, but nanofiber adsorbent appears to be quite innovative due to their outstanding characteristics such as cost effectiveness, flexibility, high surface area, porosity, …

Impulsive Dynamics And Control Of The Inertia-Wheel Pendulum, Nilay Kant, Ranjan Mukherjee

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The dynamics of the inertia-wheel pendulum, when subjected to impulsive inputs, can be described by algebraic equations. Optimal sequences of these inputs, that minimize their infinity norm, are designed for rest-to-rest maneuvers. The results are applied to the well-studied swing-up problem, and high-gain feedback is used for continuous approximation of the inputs and simulation of the impulsive dynamics. Analytical and simulation results establish a direct link between high wheel velocities during swing-up and control strategies that take the pendulum directly to the upright configuration. They also indicate that optimal trajectories resemble those of energy-based controllers and can be designed to …

Revealing Particle-Scale Powder Spreading Dynamics In Powder-Bed-Based Additive Manufacturing Process By High-Speed X-Ray Imaging, Luis I. Escano, Niranjan D. Parab, Lianghua Xiong, Qilin Guo, Cang Zhao, Kamel Fezzaa, Wes Everhart, Tao Sun, Lianyi Chen

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Powder spreading is a key step in the powder-bed-based additive manufacturing process, which determines the quality of the powder bed and, consequently, affects the quality of the manufactured part. However, powder spreading behavior under additive manufacturing condition is still not clear, largely because of the lack of particle-scale experimental study. Here, we studied particle-scale powder dynamics during the powder spreading process by using in-situ high-speed high-energy x-ray imaging. Evolution of the repose angle, slope surface speed, slope surface roughness, and the dynamics of powder clusters at the powder front were revealed and quantified. Interactions of the individual metal powders, with …

An Efficient Mode-Based Domain Decomposition Hybrid 2-D/Q-2d Finite-Element Time-Domain Method For Power/Ground Plate-Pair Analysis, Ping Li, Li (Lijun) Jun Jiang, Yao Jiang Zhang, Shuai Xu, Hakan Bagci

Electrical and Computer Engineering Faculty Research & Creative Works

Generally, with a surface magnetic current excitation, only the TM zmn modes are activated between the power/ground plate pair. As a result, the magnetic field only has azimuthal component while the longitude component is zero. To make full use of this quasi-2-D (Q-2D) property, a Q-2D finite-element time-domain (FETD) method combined with the basic 3-D triangular prism mesh elements is firstly proposed to solve the magnetic field wave equation. It is further noted that the higher order modes are confined in the proximity of the antipads (labeled as via domain) due to the exponential attenuation property along the propagating direction. …

Circuitry Design And Magnetic Susceptibility Evaluation Of 7t Fmri Implantable Rf Coil, Rong Wang, Celia M. Dong, Ed X. Wu, Robert C. Roberts, Li (Lijun) Jun Jiang

Electrical and Computer Engineering Faculty Research & Creative Works

Implantable coils have been widely utilized in functional magnetic resonance imaging (fMRI) owing to their superior signal to noise ratio. To effectively minimize the magnetic field distortion and image artifacts, the magnetic susceptibility of the implantable coil needs to be evaluated before practical use. In this work, we experimentally identify the magnetic susceptibility of each component of the implantable coil with the 7T Bruker NMR imaging scanner and provide useful guidelines for the following manufacturing. A 5 5 mm 2 implantable surface coil with a tunable frequency range is subsequently introduced for the 7T fMRI of the rat primary somatosensory …

Effects Of Nearwall Modeling In The Improved-Delayed-Detached-Eddy-Simulation (Iddes) Methodology, Rohit Saini, Nader Karimi, Lian Duan, Amsini Sadiki, Amirfarhang Mehdizadeh

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The present study aims to assess the effects of two different underlying RANS models on overall behavior of the IDDES methodology when applied to different flow configurations ranging from fully attached (plane channel flow) to separated flows (periodic hill flow). This includes investigating prediction accuracy of first and second order statistics, response to grid refinement, grey area dynamics and triggering mechanism. Further, several criteria have been investigated to assess reliability and quality of the methodology when operating in scale resolving mode. It turns out that irrespective of the near wall modeling strategy, the IDDES methodology does not satisfy all criteria …

Sensor-Enhanced Analysis And Behavior Of Steel Beams In Fire, Genda Chen

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Traditionally, strain data are difficult, if not impossible, to obtain from steel structures in fire due to their harsh environment and temperature measurements are limited to the locations of thermocouples. This paper presents high-temperature measurements using a Brillouin scattering based (distributed) fiber optic sensor and the application of the measured temperatures and material parameters recommended in building codes into the enhanced thermo-mechanical analysis of simply-supported steel beams subjected to combined thermal and loading effects. The distributed temperature sensor captures detailed, non-uniform temperature distributions that are compared locally with thermocouple measurements by less than 5% at a 95% confidence level. The …

The Bridge Newsletter Winter 2018, Missouri University Of Science And Technology

The Bridge Newsletter

-Pouring the cornerstone for the ACML
-Showalter selected as Kiewit Faculty Scholar
-Ma tests a low-cost method of strengthening concrete

Ultra-Thin Coating And Three-Dimensional Electrode Structures To Boosted Thick Electrode Lithium-Ion Battery Performance, Jie Li, Yan Gao, Xinhua Liang, Jonghyun Park

Chemical and Biochemical Engineering Faculty Research & Creative Works

This paper reports a multiscale controlled three‐dimensional (3D) electrode structure to boost the battery performance for thick electrode batteries with LiMn_1.5Ni_0.5O₄ as cathode material, which exhibits a high areal capacity (3.5 mAh/cm²) along with a high specific capacity (130 mAh/g). This excellent battery performance is achieved by a new concept of cell electrode fabrication, which simultaneously controls the electrode structure in a multiscale manner to address the key challenges of the material. Particles with ultrathin conformal coating layers are prepared through atomic layer deposition followed by a nanoscale‐controlled, thermal diffusion doping. The particles …

Explosive Dust Test Vessel Comparison Using Pulverized Pittsburgh Coal, Jacob Miller, Jay Schafler, Phillip R. Mulligan, Robert Eades, Kyle A. Perry, Catherine E. Johnson

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Explosions of coal dust are a major safety concern within the coal mining industry. The explosion and subsequent fires caused by coal dust can result in significant property damage, loss of life in underground coal mines and damage to coal processing facilities. The United States Bureau of Mines conducted research on coal dust explosions until 1996 when it was dissolved. In the following years, the American Society for Testing and Materials (ASTM) developed a test standard, ASTM E1226, to provide a standard test method characterizing the “explosibility” of particulate solids of combustible materials suspended in air. The research presented herein …

A High-Entropy Alloy With Hierarchical Nanoprecipitates And Ultrahigh Strength, Zhiqiang Fu, Lin Jiang, Haiming Wen, For Full List Of Authors, See Publisher's Website.

Materials Science and Engineering Faculty Research & Creative Works

High-entropy alloys (HEAs) are a class of metallic materials that have revolutionized alloy design. They are known for their high compressive strengths, often greater than 1 GPa; however, the tensile strengths of most reported HEAs are limited. Here, we report a strategy for the design and fabrication of HEAs that can achieve ultrahigh tensile strengths. The proposed strategy involves the introduction of a high density of hierarchical intragranular nanoprecipitates. To establish the validity of this strategy, we designed and fabricated a bulk Fe₂₅Co₂₅Ni₂₅Al₁₀Ti₁₁₅ HEA to consist of a principal face-centered cubic …

Ultralow Dispersion Multicomponent Thin-Film Chalcogenide Glass For Broadband Gradient-Index Optics, Myungkoo Kang, Andrew M. Swisher, Alexej V. Pogrebnyakov, Liu Liu, Andrew Kirk, Stephen Aiken, Laura Sisken, Charmayne Lonergan, Justin Cook, Teodor Malendevych, Fedor Kompan, Ivan Divliansky, Leonid B. Glebov, Martin C. Richardson, Clara Rivero-Baleine, Carlo G. Pantano

Materials Science and Engineering Faculty Research & Creative Works

A novel photothermal process to spatially modulate the concentration of sub-wavelength, high-index nanocrystals in a multicomponent Ge-As-Pb-Se chalcogenide glass thin film resulting in an optically functional infrared grating is demonstrated. The process results in the formation of an optical nanocomposite possessing ultralow dispersion over unprecedented bandwidth. The spatially tailored index and dispersion modification enables creation of arbitrary refractive index gradients. Sub-bandgap laser exposure generates a Pb-rich amorphous phase transforming on heat treatment to high-index crystal phases. Spatially varying nanocrystal density is controlled by laser dose and is correlated to index change, yielding local index modification to ≈+0.1 in the mid-infrared.

Toward Autonomous Wall-Climbing Robots For Inspection Of Concrete Bridges And Tunnels, Jizhong Xiao

INSPIRE Archived Webinars

In addition to visual inspection for surface flaws, inspectors are often required to detect subsurface defects (e.g., delamination and voids) using nondestructive evaluation (NDE) instruments, such as ground penetration radar (GPR) and impact sounding device, in order to determine the structural integrity of bridges and tunnels. In these cases, access to critical locations for reliable and safe inspections is a challenge.

Since 2002, Dr. Jizhong Xiao’s group has developed four generations of wall-climbing robots for NDE inspection of bridges and tunnels. These robots combine the advantages of aerodynamic attraction and suction to achieve a desirable balance of strong adhesion and …

Decoupling Of Multi-Element Mimo Antennas, Min Li, L. (Lijun) J. Jiang

Electrical and Computer Engineering Faculty Research & Creative Works

An efficient decoupling technique for multi-element MIMO antennas is proposed in this paper. A general model of using parasitic decoupling structure (PDS) to satisfy the criterions derived from antenna impedances for perfect isolation is presented. A prototype of three monopole antennas is realized on a Rogers PCB for demonstration purpose. The simulation results show that good impedance matching and high port isolation are achieved simultaneously.

Optical-Fiber-Based Smart Concrete Thermal Integrity Profiling: An Example Of Concrete Shaft, Ruoyu Zhong, Ruichang Guo, Wen Deng

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Concrete is currently the most widely used construction material in the world. The integrity of concrete during the pouring process could greatly affect its engineering performance. Taking advantage of heat production during the concrete curing process, we propose an optical-fiber-based thermal integrity profiling (TIP) method which can provide a comprehensive and accurate evaluation of the integrity of concrete immediately after its pouring. In this paper, we use concrete shaft as an example to conduct TIP by using the optical fiber as a temperature sensor which can obtain high spatial resolution temperature data. Our method is compared with current thermal infrared …

Rheological Properties Of Warm Mix Asphalt Binders And Warm Mix Asphalt Binders Containing Polyphosphoric Acid, Jun Liu, Kezhen Yan, Jenny Liu

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This paper presents the laboratory investigation of properties of warm mix asphalt (WMA) binders and WMA binders containing polyphosphoric acid (PPA).Two types of warm mix additives were used to produce the WMA binders. Superpave tests were carried out on original and short-term aged binders through the rotational viscometer, the dynamic shear rheometer (DSR), and the bending beam rheometer (BBR). The results indicated that the WMA binders with different warm mix additives showed different viscosity values, however, the addition of PPA remarkably increased the viscosity values of these two kinds of WMA binders used, in the present study, to a similar …

Numerical Simulation Study On Miscible Eor Techniques For Improving Oil Recovery In Shale Oil Reservoirs, Dheiaa Alfarge, Mingzhen Wei, Baojun Bai

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Shale formations in North America such as Bakken, Niobrara, and Eagle Ford have huge oil in place, 100—900 billion barrels of oil in Bakken only. However, the predicted primary recovery is still below 10%. Therefore, seeking for techniques to enhance oil recovery in these complex plays is inevitable. Although most of the previous studies in this area recommended that CO₂ would be the best EOR technique to improve oil recovery in these formations, pilot tests showed that natural gases performance clearly exceeds CO₂ performance in the field scale. In this paper, two different approaches have been integrated to …

Ultrafast X-Ray Imaging Of Laser-Metal Additive Manufacturing Processes, Niranjan D. Parab, Cang Zhao, Ross Cunningham, Luis I. Escano, Kamel Fezzaa, Wes Everhart, Anthony D. Rollett, Lianyi Chen, Tao Sun

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The high-speed synchrotron X-ray imaging technique was synchronized with a custom-built laser-melting setup to capture the dynamics of laser powder-bed fusion processes in situ. Various significant phenomena, including vapor-depression and melt-pool dynamics and powder-spatter ejection, were captured with high spatial and temporal resolution. Imaging frame rates of up to 10 MHz were used to capture the rapid changes in these highly dynamic phenomena. At the same time, relatively slow frame rates were employed to capture large-scale changes during the process. This experimental platform will be vital in the further understanding of laser additive manufacturing processes and will be particularly …

Deformation Of A Ferrofluid Droplet In Simple Shear Flows Under Uniform Magnetic Fields, Md Rifat Hassan, Jie Zhang, Cheng Wang

Mechanical and Aerospace Engineering Faculty Research & Creative Works

We numerically investigate the deformation and orientation of a ferrofluid droplet in a simple shear flow under a uniform magnetic field. The numerical simulation is based on the finite element method and couples the magnetic and flow fields. A level set method is used to model the dynamic motion of the droplet interface. Systematic numerical simulations are used to assess the effects of the direction and the strength of the magnetic field. Focusing on low Reynolds number flows (Re ≲ 0.02), the numerical results indicate that at a small capillary number (Ca ≈ 0.02), the magnetic field dominates over the …

Locomotion Of A Cylindrical Rolling Robot With A Shape Changing Outer Surface, Michael G. Puopolo, Jamey D. Jacob, Emilio Gabino

Mechanical and Aerospace Engineering Faculty Research & Creative Works

A cylindrical rolling robot is developed that generates roll torque by changing the shape of its flexible, elliptical outer surface whenever one of four elliptical axes rotates past an inclination called trigger angle. The robot is equipped with a sensing/control system by which it measures angular position and angular velocity, and computes error with respect to a desired step angular velocity profile. When shape change is triggered, the newly assumed shape of the outer surface is determined according to the computed error. A series of trial rolls is conducted using various trigger angles, and energy consumed by the actuation motor …

Advanced Metal Oxides And Nitrides Thermoelectric Materials For Energy Harvesting, Yining Feng, Evan Witkoske, Elizabeth S. Bell, Yang Wang, Athanasios Tzempelikos, Ian T. Ferguson, Na Lu

Electrical and Computer Engineering Faculty Research & Creative Works

Metal oxides and nitrides are widely used in many applications as a result of their high mechanical, chemical, and electrical properties. In high temperature thermoelectric applications, oxides and nitrides exhibit high thermopower and thermal stability. Moreover, most oxides and nitrides are consisted of earth abundant elements, which are non-toxic, cost effective and easy for large-scale synthesis. In this article, we reviewed the recent advances of metal oxides and nitrides and their applications in thermoelectric. The materials that are examined include both p-type semiconductors (e.g. NaxCoO₂, Ca₃Co₄O₉, GaN) and n-type semiconductors (e.g. ZnO-based, …

Shape-Based Separation Of Micro-/Nanoparticles In Liquid Phases, Behrouz Behdani, Saman Monjezi, Mason J. Carey, Curtis G. Weldon, Jie Zhang, Cheng Wang, Joontaek Park

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The production of particles with shape-specific properties is reliant upon the separation of micro-/nanoparticles of particular shapes from particle mixtures of similar volumes. However, compared to a large number of size-based particle separation methods, shape-based separation methods have not been adequately explored. We review various up-to-date approaches to shape-based separation of rigid micro-/nanoparticles in liquid phases including size exclusion chromatography, field flow fractionation, deterministic lateral displacement, inertial focusing, electrophoresis, magnetophoresis, self-assembly precipitation, and centrifugation. We discuss separation mechanisms by classifying them as either changes in surface interactions or extensions of size-based separation. The latter includes geometric restrictions and shape-dependent transport …

An Overview Of Direct Current Distribution System Architectures & Benefits, Venkata Anand Prabhala, Bhanu Prashant Baddipadiga, Poria Fajri, Mehdi Ferdowsi

Electrical and Computer Engineering Faculty Research & Creative Works

This paper examines existing and future direct current (DC) distribution systems with a wide range of applications in data centers, telecommunication systems, commercial buildings, residential homes, electric vehicles, spacecraft, and aircrafts. DC distribution systems have many advantages and disadvantages over their alternating current (AC) counterparts. There are a few surviving examples of DC distribution systems; among them are the telecommunication systems and data centers that use the low-voltage 48 Vdc systems. However, recently, there has been a move towards higher DC bus voltages. In this paper, a comparative study of different DC distribution architectures and bus structures is presented and …