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Full-Text Articles in Mechanical Engineering

Sharprazor: Automatic Removal Of Hair And Ruler Marks From Dermoscopy Images, Reda Kasmi, Jason Hagerty, Reagan Harris Young, Norsang Lama, Januka Nepal, Jessica Miinch, William V. Stoecker, R. Joe Stanley Apr 2023

Sharprazor: Automatic Removal Of Hair And Ruler Marks From Dermoscopy Images, Reda Kasmi, Jason Hagerty, Reagan Harris Young, Norsang Lama, Januka Nepal, Jessica Miinch, William V. Stoecker, R. Joe Stanley

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Background: The removal of hair and ruler marks is critical in handcrafted image analysis of dermoscopic skin lesions. No other dermoscopic artifacts cause more problems in segmentation and structure detection. Purpose: The aim of the work is to detect both white and black hair, artifacts and finally inpaint correctly the image. Method: We introduce a new algorithm: SharpRazor, to detect hair and ruler marks and remove them from the image. Our multiple-filter approach detects hairs of varying widths within varying backgrounds, while avoiding detection of vessels and bubbles. The proposed algorithm utilizes grayscale plane modification, hair enhancement, segmentation using tri-directional …


Glass-Based Biodegradable Pressure Sensor Toward Biomechanical Monitoring With A Controllable Lifetime, Devdatt Chattopadhyay, Jonghyun Park, Chang-Soo Kim Feb 2023

Glass-Based Biodegradable Pressure Sensor Toward Biomechanical Monitoring With A Controllable Lifetime, Devdatt Chattopadhyay, Jonghyun Park, Chang-Soo Kim

Mechanical and Aerospace Engineering Faculty Research & Creative Works

A New Class of Potentially Implantable Solid-State Sensors is Demonstrated Utilizing Biodegradable Glass as the Main Structural Material. the Device Behavior is Manipulated Via Chemical Decomposition, and Then Physically Disintegrated in a Controlled Manner. It is based on the Capacitive Sensing Mechanism, Comprising an Elastic Insulator between Two Borate-Rich Glass Substrates. This Mesoscale Pressure Sensor is Characterized by a Range of Pressure of Up to 14 MPa in a Phosphate Buffer Solution Environment. the Sensor Exhibits Good Sensitivity and Reversibility Responding to Compressive Pressures and Remains Fully Functional Before a Desired, Sudden Failure Caused by Dissolution. the Operational Lifetime Can …


Static I-V Based Pim Evaluation For Spring And Fabric-Over-Foam Contacts, Kalkidan W. Anjajo, Yang Xu, Shengxuan Xia, Yuchu He, Haicheng Zhou, Hanfeng Wang, Jonghyun Park, Chulsoon Hwang Jan 2023

Static I-V Based Pim Evaluation For Spring And Fabric-Over-Foam Contacts, Kalkidan W. Anjajo, Yang Xu, Shengxuan Xia, Yuchu He, Haicheng Zhou, Hanfeng Wang, Jonghyun Park, Chulsoon Hwang

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Spring Clips and Fabric-Over-Foams (FOFs) Are Widely Used in Mobile Devices for Electrical Connection Purposes. However, the Imperfect Metallic Connections Tend to Induce Passive Intermodulation (PIM), Resulting in a Receiver Sensitivity Degradation, Known as RP Desensitization. Due to the Complexity of the PIM Characterization, there is Not Yet a Way to Evaluate PIM Performance using a Simple Setup for Environments Like Factories. in This Paper, a Current-Voltage (I-V) Behavior-Based PIM Evaluation Method is Proposed and Validated with Various Metallic Contacts and Contact Forces. the Test Results Demonstrated the Feasibility of the PIM Performance Evaluation based on the Measured Static I-V …


Polarization-Sensitive Optical Responses From Natural Layered Hydrated Sodium Sulfosalt Gerstleyite, Ravi P. N. Tripathi, Xiaodong Yang, Jie Gao Mar 2022

Polarization-Sensitive Optical Responses From Natural Layered Hydrated Sodium Sulfosalt Gerstleyite, Ravi P. N. Tripathi, Xiaodong Yang, Jie Gao

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Multi-element layered materials have gained substantial attention in the context of achieving the customized light-matter interactions at subwavelength scale via stoichiometric engineering, which is crucial for the realization of miniaturized polarization-sensitive optoelectronic and nanophotonic devices. Herein, naturally occurring hydrated sodium sulfosalt gerstleyite is introduced as one new multi-element van der Waals (vdW) layered material. The mechanically exfoliated thin gerstleyite flakes are demonstrated to exhibit polarization-sensitive anisotropic linear and nonlinear optical responses including angle-resolved Raman scattering, anomalous wavelength-dependent linear dichroism transition, birefringence effect, and polarization-dependent third-harmonic generation (THG). Furthermore, the third-order nonlinear susceptibility of gerstleyite crystal is estimated by the probed …


Passive Intermodulation Under Different Spring Contact Conditions, Shengxuan Xia, Emmanuel Olugbade, Yuchu He, Yansheng Wang, Hanfeng Wang, Krishna Rao, Marco Poort, Haicheng Zhou, Warren Lee, Nicholas Mcdonnell, Jonghyun Park, Chulsoon Hwang Jan 2022

Passive Intermodulation Under Different Spring Contact Conditions, Shengxuan Xia, Emmanuel Olugbade, Yuchu He, Yansheng Wang, Hanfeng Wang, Krishna Rao, Marco Poort, Haicheng Zhou, Warren Lee, Nicholas Mcdonnell, Jonghyun Park, Chulsoon Hwang

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Modularized designs have been widely used in today's consumer electronic devices and flexible RF springs are used for electrical connections between the modules. In the meantime, aluminum alloy material becomes a common chassis option. It is well known that the oxidized chassis surface introduces a certain level of nonlinearity when contacted by the springs, as known as passive intermodulation (PIM). PIM is one of the well-known root causes of the RF desensitization (desense). This paper is focused on investigating the relationship between PIM and contact conditions of the springs, especially contact area. The PIM level behavior is explained mathematically by …


Comparison Of Magnetic Probe Calibration At Nano And Millitesla Magnitudes, Ryan A. Pahl, Joshua L. Rovey, David Pommerenke Jan 2014

Comparison Of Magnetic Probe Calibration At Nano And Millitesla Magnitudes, Ryan A. Pahl, Joshua L. Rovey, David Pommerenke

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Magnetic field probes are invaluable diagnostics for pulsed inductive plasma devices where field magnitudes on the order of tenths of tesla or larger are common. Typical methods of providing a broadband calibration of Ḃ probes involve either a Helmholtz coil driven by a function generator or a network analyzer. Both calibration methods typically produce field magnitudes of tens of microtesla or less, at least three and as many as six orders of magnitude lower than their intended use. This calibration factor is then assumed constant regardless of magnetic field magnitude and the effects of experimental setup are ignored. This work …


Development Of An Experimental Testbed For Research In Lithium-Ion Battery Management Systems, Nima Lotfi, Poria Fajri, Samuel Novosad, Jack Savage, Robert G. Landers, Mehdi Ferdowsi Oct 2013

Development Of An Experimental Testbed For Research In Lithium-Ion Battery Management Systems, Nima Lotfi, Poria Fajri, Samuel Novosad, Jack Savage, Robert G. Landers, Mehdi Ferdowsi

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Advanced electrochemical batteries are becoming an integral part of a wide range of applications from household and commercial to smart grid, transportation, and aerospace applications. Among different battery technologies, lithium-ion (Li-ion) batteries are growing more and more popular due to their high energy density, high galvanic potential, low self-discharge, low weight, and the fact that they have almost no memory effect. However, one of the main obstacles facing the widespread commercialization of Li-ion batteries is the design of reliable battery management systems (BMSs). An efficient BMS ensures electrical safety during operation, while increasing battery lifetime, capacity and thermal stability. Despite …


Structural Health Monitoring Data Transmission For Composite Hydrokinetic Turbine Blades, A. Heckman, Joshua L. Rovey, K. Chandrashekhara, Steve Eugene Watkins, Daniel S. Stutts, Arindam Banerjee, Rajiv S. Mishra Jun 2013

Structural Health Monitoring Data Transmission For Composite Hydrokinetic Turbine Blades, A. Heckman, Joshua L. Rovey, K. Chandrashekhara, Steve Eugene Watkins, Daniel S. Stutts, Arindam Banerjee, Rajiv S. Mishra

Mechanical and Aerospace Engineering Faculty Research & Creative Works

No abstract provided.


Computer Program And Method For Detecting And Predicting Valve Failure In A Reciprocating Compressor, Ming-Chuan Leu, Jagannathan Sarangapani, Raghuram Puthall Ramesh Apr 2010

Computer Program And Method For Detecting And Predicting Valve Failure In A Reciprocating Compressor, Ming-Chuan Leu, Jagannathan Sarangapani, Raghuram Puthall Ramesh

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Embodiments of the present invention provide a method implemented by a computer program for detecting and identifying valve failure in a reciprocating compressor and further for predicting valve failure in the compressor. Embodiments of the present invention detect and predict the valve failure using wavelet analysis, logistic regression, and neural networks. A pressure signal from the valve of the reciprocating compressor presents a non-stationary waveform from which features can be extracted using wavelet packet decomposition. The extracted features, along with temperature data for the valve, are used to train a logistic regression model to classify defective and normal operation of …


Torque Ripple Sensor And Mitigation Mechanism, Jason Neely, Steven Pekarek, Jason M. Banaskavich, Daniel S. Stutts Oct 2006

Torque Ripple Sensor And Mitigation Mechanism, Jason Neely, Steven Pekarek, Jason M. Banaskavich, Daniel S. Stutts

Mechanical and Aerospace Engineering Faculty Research & Creative Works

A torque ripple sensor and method for torque ripple sensing and/or mitigation. A piezoelectric sensor is positioned relative to a motor so that torque fluctuations due to torque ripple of the motor are transmitted to the sensor, resulting in strain of a piezoelectric element. A resulting signal can be amplified and conditioned for determining a magnitude of the torque ripple and/or fed into a feedback loop for applying current control or a counter-torque to the motor for torque ripple mitigation.


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

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

Mechanical and Aerospace Engineering Faculty Research & Creative Works

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


Empirical Modeling And Vision Based Control For Laser Aided Metal Deposition Process, Mallikharjuna R. Boddu, Srinivas Musti, Robert G. Landers, Sanjeev Agarwal, Frank W. Liou Aug 2001

Empirical Modeling And Vision Based Control For Laser Aided Metal Deposition Process, Mallikharjuna R. Boddu, Srinivas Musti, Robert G. Landers, Sanjeev Agarwal, Frank W. Liou

Mechanical and Aerospace Engineering Faculty Research & Creative Works

This paper gives a brief description of the laser aided manufacturing process. Empirical models describing the process dynamics of the laser aided metal deposition process is developed based on some of the models found in the literature. These models provide the basis for process planning and real time control. An embedded vision system, a two color temperature sensor, and a laser displacement sensor are incorporated for real time monitoring and control of the deposition process. The temperature profile of the surface and geometric characteristics of the melt pool are studied to ensure consistent operation of the process.


Research And Development Of A Hybrid Rapid Manufacturing Process, Frank W. Liou, J. Choi, Robert G. Landers, Vijayakumar Janardhan, S. N. Balakrishnan, Sanjeev Agarwal Aug 2001

Research And Development Of A Hybrid Rapid Manufacturing Process, Frank W. Liou, J. Choi, Robert G. Landers, Vijayakumar Janardhan, S. N. Balakrishnan, Sanjeev Agarwal

Mechanical and Aerospace Engineering Faculty Research & Creative Works

This paper presents the research and development of a hybrid rapid manufacturing process being developed at the University of Missouri--Rolla. This process includes a laser deposition and a 5- axis CNC milling system. By combining laser deposition and machining processes, the resulting hybrid process can provide greater build capability and better accuracy and surface finish. The hybrid process can build some features that are difficult to build in using a purely deposition processes. The issues and related approaches in the research and development of the hybrid deposition-machining process, including laser deposition process, system design and integration, process planning, and sensor …


Effect Of Viscoplastic Flow Rules On The Initiation And Growth Of Shear Bands At High Strain Rates, R. C. Batra, Chang-Soo Kim Jan 1990

Effect Of Viscoplastic Flow Rules On The Initiation And Growth Of Shear Bands At High Strain Rates, R. C. Batra, Chang-Soo Kim

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Marchand and Duffy have reported detailed measurements of the temperature and strain as a shear band develops in a HY-100 steel. Assuming their torsional tests in thin-wall tubes can be adequately modeled by a viscoplastic block undergoing overall adiabatic simple shearing deformations, we investigate the effect of modeling the viscoplastic response of the material by a.power law, and flow rules proposed by Litonski, Bodner and Partom, and Johnson and Cook. Each of these flow rules is first calibrated by using the test data at a nominal strain-rate of 3300 s-1. Then predictions from the use of these flow rules at …


Decision-Directed Detector For Overlapping Pcm/Nrz Signals, Cheng Wang, Thomas L. Noack Jan 1973

Decision-Directed Detector For Overlapping Pcm/Nrz Signals, Cheng Wang, Thomas L. Noack

Mechanical and Aerospace Engineering Faculty Research & Creative Works

A decision-directed (DD) technique for the detection of overlapping PCM/NRZ signals in the presence of white Gaussian noise is investigated. The performance of the DD detector is represented by probability of error PE versus input signal-to-noise ratio (SNR). To examine how much improvement in performance can be achieved with this technique, PE's with and without DD feedback are evaluated in parallel. Further, analytical results are compared with those found by Monte Carlo simulations. The results are shown in good agreement. © 1973, IEEE. All rights reserved.