Engineering Commons^™

Study On Interior Permanent Magnet Synchronous Motors For Hybrid Electric Vehicle Traction Drive Application Considering Permanent Magnet Type And Temperature, Javad Soleimani, Abolfazl Vahedi, Abdolhossein Ejlali, Mohammadhossein Barzegari Bafghi

Turkish Journal of Electrical Engineering and Computer Sciences

Recently, interior permanent magnet synchronous motors (Interior-PMSMs) have become known as a good candidate for hybrid electric vehicle (HEV) traction drive application due to their unique merits. However, the dynamic and steady-state behaviors of these motors are quite dependent on the permanent magnet (PM) type, configuration, and volume in rotor structures. This paper uses a novel structure of Interior-PMSMs for traction applications with fragmental buried rotor magnets in order to achieve low torque ripple, iron losses, and cogging torque. In this paper, first, the effect of the PM type on a d-q equivalent circuit model is examined. Next, the design …

A New Psfb Converter-Based Inverter Arc Welding Machine With High Power Density And High Efficiency, İsmai̇l Aksoy

Turkish Journal of Electrical Engineering and Computer Sciences

In this study, a high-performance single-phase inverter arc welding machine is presented. Power control of the developed welding machine is realized with a high-frequency, phase-shifted full bridge (PSFB) pulse-width modulation (PWM) converter. The PSFB PWM converter operates with soft switching at no load and full load. There is no need to use a passive snubber in the converter. Welding machine control is implemented with a digital signal processor (DSP) and phase-shift PWM IC. By means of the DSP, advanced arc welding functions and protection features such as short-circuit, over-current, and temperature protection are achieved. The current and voltage waveforms given …

Frequency-Emulated Uniform Cellular Automata, Hürevren Kiliç

Turkish Journal of Electrical Engineering and Computer Sciences

The notion of a frequency-emulated (f-emulated) uniform cellular automata (CA) that enables the behavior emulation of some elementary CA via memory usage is introduced. An algorithm that generates f-emulated uniform CA sets is developed and an upper bound for its output size is given. It is observed that traffic rule 184 together with its 2-emulator version, which generates the behavior of the known majority rule 232, performs the density classification task perfectly. Moreover, it is possible to use a 2-emulated uniform CA for the solution of the parity problem.

Dynamics, Stability, And Actuation Methods For Powered Compass Gait Walkers, Koray Kadi̇r Şafak

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, methods to achieve actively powered walking on level ground using a simple 2-dimensional walking model (compass-gait walker) are explored. The walker consists of 2 massless legs connected at the hip joint, a point mass at the hip, and an infinitesimal point mass at the feet. The walker is actuated either by applying equal joint torques at the hip and ankle, by an impulse applied at the toe off, immediately before the heel strike, or by the combination of both. It is shown that actuating the walker by equal joint torques at the hip and ankle on level …

Simulation Of A Flowing Snow Avalanche Using Molecular Dynamics, Deni̇zhan Güçer, Hali̇l Bülent Özgüç

Turkish Journal of Electrical Engineering and Computer Sciences

This paper presents an approach for the modeling and simulation of a flowing snow avalanche, which is formed of dry and liquefied snow that slides down a slope, using molecular dynamics and the discrete element method. A particle system is utilized as a base method for the simulation and marching cubes with real-time shaders are employed for rendering. A uniform grid-based neighbor search algorithm is used for collision detection for interparticle and particle-terrain interactions. A mass-spring model of the collision resolution is employed to mimic the compressibility of the snow and particle attraction forces are put into use between the …

Fault Tolerant Broadcasting Analysis In Wireless Monitoring Networks, Akbar Ghaffarpour Rahbar

Turkish Journal of Electrical Engineering and Computer Sciences

Wireless monitoring networks can be used for security applications such as the monitoring of narrow passages and operational fields. These networks can be designed based on sensor networks. In sensor networks, each node can hear a message and broadcast the message to its neighbor nodes. Nevertheless, nodes may fail, so that faulty nodes cannot hear or cannot transmit any message, where the locations of the faulty nodes are unknown and their failures are permanent. In this paper, the nodes are situated on a line or a square grid-based topology in a plane for security/monitoring applications. For each topology, 2 nonadaptive …

Online Feature Selection And Classification With Incomplete Data, Habi̇l Kalkan

Turkish Journal of Electrical Engineering and Computer Sciences

This paper presents a classification system in which learning, feature selection, and classification for incomplete data are simultaneously carried out in an online manner. Learning is conducted on a predefined model including the class-dependent mean vectors and correlation coefficients, which are obtained by incrementally processing the incoming observations with missing features. A nearest neighbor with a Gaussian mixture model, whose parameters are also estimated from the trained model, is used for classification. When a testing observation is received, the algorithm discards the missing attributes on the observation and ranks the available features by performing feature selection on the model that …

Non-Local Model For The Spatial Distribution Of Impact Ionization Events In Avalanche Photodiodes, David A. Ramirez, Majeed M. Hayat, Andrew S. Huntington, George M. Williams

Electrical and Computer Engineering Faculty Research and Publications

We report an extension of the analytical dead space multiplication theory that provides the means to theoretically determine the spatial distribution of electron and hole impact-ionization events in an arbitrarily specified heterojunction multiplication region. The model can be used to understand the role of the dead space in regularizing the locations of impact ionization. It can also be utilized to analyze, design, and optimize new generations of ultra-low noise, multistaged gain avalanche photodiodes based upon judiciously energizing and relaxing carriers to enhance electron impact ionization and suppress hole impact ionization.

Thermal Tuning Of Mems Buckled Membrane Actuator Stiffness, Robert A. Lake, Kyle K. Ziegler, Ronald A. Coutu Jr.

Electrical and Computer Engineering Faculty Research and Publications

The thermal tuning characteristics of a microelectromechanical systems (MEMS) buckled membrane exhibiting regions of both positive and negative stiffness is examined and analyzed using finite element method (FEM) simulation and through experimentation. The membranes are fabricated by releasing a silicon/silicon dioxide (Si/SiO₂) laminated membrane from a silicon on insulator (SOI) wafer. The difference in thermal expansion coefficients between Si and SiO2 induces a compressive stress in the SiO₂ layer causing out-of-plane buckling of the membrane. This structure is found to have positive and negative stiffness regions when actuated with a transverse force. It is demonstrated that the …

Robust And Resilient State-Dependent Control Of Continuous-Time Nonlinear Systems With General Performance Criteria, Xin Wang, Edwin E. Yaz, James Long

Electrical and Computer Engineering Faculty Research and Publications

A novel state-dependent control approach for continuous-time nonlinear systems with general performance criteria is presented in this paper. This controller is optimally robust for model uncertainties and resilient against control feedback gain perturbations in achieving general performance criteria to secure quadratic optimality with inherent asymptotic stability property together with quadratic dissipative type of disturbance reduction. For the system model, unstructured uncertainty description is assumed, which incorporates commonly used types of uncertainties, such as norm-bounded and positive real uncertainties as special cases. By solving a state-dependent linear matrix inequality at each time, sufficient condition for the control solution can be found …

Simultaneous Robotic Manipulation And Functional Magnetic Resonance Imaging: Feasibility In Children With Autism Spectrum Disorders, Nicole Marie Gregor Salowitz, Bridget K. Dolan, Rheanna Remmel, Amy V. Van Hecke, Kristine M. Mosier, Lucia S. Simo, Robert A. Scheidt

Biomedical Engineering Faculty Research and Publications

An unanswered question concerning the neural basis of autism spectrum disorders (ASD) is how sensorimotor deficits in individuals with ASD are related to abnormalities of brain function. We previously described a robotic joystick and video game system that allows us to record functional magnetic resonance images (FMRI) while adult humans make goal- directed wrist motions. We anticipated several challenges in extending this approach to studying goal-directed behaviors in children with ASD and in typically developing (TYP) children. In particular we were concerned that children with autism may express increased levels of anxiety as compared to typically developing children due to …

Emerging Optical Techniques For Detection Of Oral, Cervical And Anal Cancer In Low-Resource Settings, Bing Yu, Daron G. Ferris, Yang Liu, Vivek K. Nagarajan

Biomedical Engineering Faculty Research and Publications

Cancers of the oral and anogenital regions are a growing global health problem that disproportionately impact women and men living in developing countries. The high death rate in developing countries is largely due to the fact that these countries do not have the appropriate medical infrastructure and resources to support the organized screening and diagnostic programs that are available in the developed world. Emerging optical diagnostics techniques, such as optical spectroscopy, reflectance imaging, and fluorescence imaging, are noninvasive techniques that are sensitive to multiple cancer biomarkers and have shown the potential as a cost–effective and fast tool for diagnosis of …

Harmonic Power Compensation Capacity Of Shunt Apf And Its Relationship To Design Parameters, Shafiuzzaman Khadem, Malabika Basu, Michael Conlon

Articles

VSI-based three-phase; power exchange mechanism; switching dynamics; three-phase systems; active losses; single-phase systems; power tetrahedron phasor diagram; shunt active power filter; harmonic power compensation capacity; four-wire systems; hysteresis band current control

Photonic Crystal Fiber Half-Taper Probe Based Refractometer, Pengfei Wang, Ming Ding, Lin Bo, Chunying Guan, Yuliya Semenova, Weimin Sun, Libo Yuan, Gilberto Brambilla, Gerald Farrell

Articles

A compact singlemode - photonic crystal fibre - singlemode fibre tip (SPST) refractive index sensor is demonstrated in this paper. A CO₂ laser cleaving technique is utilsed to provide a clean-cut fibre tip which is then coated by a layer of gold to increase reflection. An average sensitivity of 39.1 nm/RIU and a resolvable index change of 2.56×10^-4 are obtained experimentally with a ~3.2 µm diameter SPST. The temperature dependence of this fiber optic sensor probe is presented. The proposed SPST refractometer is also significantly less sensitive to temperature and an experimental demonstration of this reduced sensitivity is …

Cmos-Compatible 2-Bit Optical Spectral Quantization Scheme Using A Silicon-Nanocrystal-Based Horizontal Slot Waveguide, Zhe Khang, Jinhui Yuan, Gerald Farrell, Chongxiu Yu, Feng Li, Hwa Yaw Tam, P. K.A. Wai

Articles

All-optical analog-to-digital converters based on the third-order nonlinear effects in silicon waveguide are a promising candidate to overcome the limitation of electronic devices and are suitable for photonic integration. In this paper, a 2-bit optical spectral quantization scheme for on-chip all-optical analog-to-digital conversion is proposed. The proposed scheme is realized by filtering the broadened and split spectrum induced by the self-phase modulation effect in a silicon horizontal slot waveguide filled with silicon-nanocrystal. Nonlinear coefficient as high as 8708 W21 /m is obtained because of the tight mode confinement of the horizontal slot waveguide and the high nonlinear refractive index of …

Enhanced Broadband Parametric Wavelength Conversion In Silicon Waveguide With The Multi-Period Grating, Xianting Zhang, Jinhui Yuan, Jiaziu Zou, Boyuan Jin, Xinzhu Sang, Qiang Wu, Chongxiu Yu, Gerald Farrell

Articles

No abstract provided.

Analysis Of Bfsa Based Anti-Collision Protocol In Lf, Hf, And Uhf Rfid Environments, Varun Bhogal

UNF Graduate Theses and Dissertations

Over the years, RFID (radio frequency identification) technology has gained popularity in a number of applications. The decreased cost of hardware components along with the recognition and implementation of international RFID standards have led to the rise of this technology.

One of the major factors associated with the implementation of RFID infrastructure is the cost of tags. Low frequency (LF) RFID tags are widely used because they are the least expensive. The drawbacks of LF RFID tags include low data rate and low range. Most studies that have been carried out focus on one frequency band only. This thesis presents …

Educational Programmes For Spatial Information Sciences In The Technological University Of Dublin, William Prendergast, Eamonn Murphy, Audrey Martin, Avril Behan

Conference papers

The ever increasing spatial information needs of society, the rapid development of new surveying technologies, and the global demand for appropriately qualified surveyors, have triggered a radical re-evaluation of geomatics education worldwide. Significant enhancements have been made to the educational programmes in the spatial information science discipline in the Technological University of Dublin’s (DIT) during the last decade including the provision of a BSc in Geomatics and various masters’ programmes to cater for the increasingly specialised needs of the Geographic Information sector in Ireland.

Standoff Methods For The Detection Of Threat Agents: A Review Of Several Promising Laser-Based Techniques, J. Bruce Johnson, Susan D. Allen, Jonathan Merten, Lewis Johnson, Daniel Pinkham, Scott W. Reeve

Publications

Detection of explosives, explosive precursors, or other threat agents presents a number of technological challenges for optical sensing methods. Certainly detecting trace levels of threat agents against a complex background is chief among these challenges; however, the related issues of multiple target distances (from standoff to proximity) and sampling time scales (from passive mines to rapid rate of march convoy protection) for different applications make it unlikely that a single technique will be ideal for all sensing situations. A number of methods for spanning the range of optical sensor technologies exist which, when integrated, could produce a fused sensor system …

Measuring The Educational Benefits Of Diversity In Engineering Education: A Multi-Institutional Survey Analysis Of Women And Underrepresented Minorities, Terrell Lamont Strayhorn, Leroy L. Long Iii, Michael Steven Williams, Marjorie Luce Dorime-Williams, Derrick L. Tillman-Kelly

Publications

Changing demographics of the U.S. population drive growing emphases on diversity in engineering education. Still, questions persist about the educational benefits of race and gender diversity within the student population, despite decades of supportive research. The present study sought to estimate the educational benefits that accrue to undergraduate engineering students who interact with diverse peers and perspectives. Furthermore, differences across gender and race were explored. Multi-institutional survey data were analyzed for over 100 undergraduate engineering students using a 2007 administration of the National Survey of Student Engagement (NSSE). Findings show that encouraging contact among students from different economic, social, or …

African American And Hispanic Stem Students' Engagement At Predominantly White Institutions, Terrell Lamont Strayhorn, Fei Bie, Leroy L. Long Iii, Blossom A. Barrett

Publications

Although research has shown that involvement is a helpful predictor of students’ future success, underrepresented minorities (i.e., African Americans and Hispanics) face unique obstacles at predominantly White institutions, which limit their engagement in educationally purposeful activities. Survey data from a 2007 administration of the National Survey of Student Engagement (NSSE) were analyzed to measure African American and Hispanic students’ engagement in educationally purposeful activities. Results from the present study found that student satisfaction in college is positively related to time spent preparing for class and frequency of interactions with faculty members about careers. Furthermore, African American and Hispanic science, technology, …

Which Design And Biomaterial Factors Affect Clinical Wear Performance Of Total Disc Replacements? A Systematic Review, Sai Y. Veruva, Marla J. Steinbeck, Jeffrey M. Toth, Dominik D. Alexander, Steven M. Kurtz

Biomedical Engineering Faculty Research and Publications

Background

Total disc replacement was clinically introduced to reduce pain and preserve segmental motion of the lumbar and cervical spine. Previous case studies have reported on the wear and adverse local tissue reactions around artificial prostheses, but it is unclear how design and biomaterials affect clinical outcomes.

Questions/purposes

Which design and material factors are associated with differences in clinical wear performance (implant wear and periprosthetic tissue response) of (1) lumbar and (2) cervical total disc replacements?

Methods

We performed a systematic review on the topics of implant wear and periprosthetic tissue response using an advanced search in MEDLINE and Scopus …

Testing And Strengthening Bridge Connections, Christopher Higgins, Peter Dusicka, Michael Scott

TREC Project Briefs

Researchers evaluate and improve the strength of gusset plate connections, essential pieces in bridge design that can fail due to buckling.

Making Concrete From Recycled Materials, Jason Ideker

TREC Project Briefs

Making concrete out of recycled concrete aggregate, or RCA, can be a sustainable and cost-saving alternative to other aggregates. However, the quality of concrete made with RCA is dependent on the quality of the recycled material used. OTREC researchers Jason Ideker of Oregon State University and Jennifer Tanner of the University of Wyoming, with graduate student researchers Matthew P. Adams and Angela Jones, sought to determine some of the primary concerns involved with the use of RCA and to arrive at methods of assessing its durability for use in new concrete.

Alkali-silica reaction occurs in concrete over time, causing it …

High Fidelity Chemistry And Radiation Modeling For Oxy-Combustion Scenarios, Hassan A. Abdul Sater

Theses and Dissertations

To account for the thermal and chemical effects associated with the high CO₂ concentrations in an oxy-combustion atmosphere, several refined gas-phase chemistry and radiative property models have been formulated for laminar to highly turbulent systems. This thesis examines the accuracies of several chemistry and radiative property models employed in computational fluid dynamic (CFD) simulations of laminar to transitional oxy-methane diffusion flames by comparing their predictions against experimental data. Literature review about chemistry and radiation modeling in oxy-combustion atmospheres considered turbulent systems where the predictions are impacted by the interplay and accuracies of the turbulence, radiation and chemistry models. Thus, …

Lightweight Data Compression In Wireless Sensor Networks Using Huffman Coding, Henry P. Medeiros, Marcos C. Maciel, Richard D. Souza, Marcelo E. Pellenz

Electrical and Computer Engineering Faculty Research and Publications

This paper presents a lightweight data compression method for wireless sensor networks monitoring environmental parameters with low resolution sensors. Instead of attempting to devise novel ad hoc algorithms, we show that, given general knowledge of the parameters that must be monitored, it is possible to efficiently employ conventional Huffman coding to represent the same parameter when measured at different locations and time periods. When the data collected by the sensor nodes consists of integer measurements, the Huffman dictionary computed using statistics inferred from public datasets often approaches the entropy of the data. Results using temperature and relative humidity measurements show …

Evaluation Of Upper Extremity Movement Characteristics During Standardized Pediatric Functional Assessment With A Kinect®-Based Markerless Motion Analysis System, Jacob R. Rammer, Joseph J. Krzak, Susan A. Riedel, Gerald F. Harris

Biomedical Engineering Faculty Research and Publications

A recently developed and evaluated upper extremity (UE) markerless motion analysis system based on the Microsoft® Kinect® has potential for improving functional assessment of patients with hemiplegic cerebral palsy. 12 typically-developing adolescents ages 12-17 were evaluated using both the Kinect-based system and the Shriners Hospitals for Children Upper Extremity Evaluation (SHUEE), a validated measure of UE motion. The study established population means of UE kinematic parameters for each activity. Statistical correlation analysis was used to identify key kinematic metrics used to develop automatic scoring algorithms. The Kinect motion analysis platform is technically sound and can be applied to standardized task-based …

Age-Related Differentiation Of Sensorimotor Control Strategies During Pursuit And Compensatory Tracking, Megan L. Heenan, Robert A. Scheidt, Scott A. Beardsley

Biomedical Engineering Faculty Research and Publications

Motor control deficits during aging have been well-documented. Various causes of neuromotor decline, including both peripheral and central neurological deficits, have been hypothesized. Here, we use a model of closed-loop sensorimotor control to examine the functional causes of motor control deficits during aging. We recruited 14 subjects aged 19-61 years old to participate in a study in which they performed single-joint compensatory and pursuit tracking tasks with their dominant hand. We found that visual response delay and visual noise increased with age, while reliance on visual feedback, especially during compensatory tracking decreased. Increases in visual noise were also positively correlated …

Diffusion Tensor Imaging Of The Spinal Cord: Insights From Animal And Human Studies, Aditya Vedantam, Michael B. Jirjis, Brian D. Schmit, Marjorie C. Wang, John L. Ulmer, Shekar N. Kurpad

Biomedical Engineering Faculty Research and Publications

Diffusion tensor imaging (DTI) provides a measure of the directional diffusion of water molecules in tissues. The measurement of DTI indexes within the spinal cord provides a quantitative assessment of neural damage in various spinal cord pathologies. DTI studies in animal models of spinal cord injury indicate that DTI is a reliable imaging technique with important histological and functional correlates. These studies demonstrate that DTI is a noninvasive marker of microstructural change within the spinal cord. In human studies, spinal cord DTI shows definite changes in subjects with acute and chronic spinal cord injury, as well as cervical spondylotic myelopathy. …

Simultaneous Monitoring Of Singlet And Triplet Exciton Variations In Solid Organic Semiconductors Driven By An External Static Magnetic Field, Baofu Ding, Kamal Alameh

Research outputs 2014 to 2021

The research field of organic spintronics has remarkably and rapidly become a promising research area for delivering a range of high-performance devices, such as magnetic-field sensors, spin valves, and magnetically modulated organic light emitting devices (OLEDs). Plenty of microscopic physical and chemical models based on exciton or charge interactions have been proposed to explain organic magneto-optoelectronic phenomena. However, the simultaneous observation of singlet- and triplet-exciton variations in an external magnetic field is still unfeasible, preventing a thorough theoretical description of the spin dynamics in organic semiconductors. Here, we show that we can simultaneously observe variations of singlet excitons and triplet …