Open Access. Powered by Scholars. Published by Universities.®
- Publication Year
- Publication
- Publication Type
Articles 1 - 23 of 23
Full-Text Articles in Entire DC Network
Parametric Average-Value Modeling, Simulation, And Characterization Of Machine-Rectifier Systems, Isuje Ojo
Parametric Average-Value Modeling, Simulation, And Characterization Of Machine-Rectifier Systems, Isuje Ojo
Theses and Dissertations--Electrical and Computer Engineering
There are many techniques for modeling and simulation of synchronous machine-rectifier systems. The more common approaches are the detailed and average-value modeling techniques. The detailed simulation technique takes into account the details of the diode switching and is both very accurate and very expensive in terms of computational resources. To alleviate this disadvantage, the average-value modeling technique is often utilized. In this approach, the details of diode switching are neglected or averaged. In that light, the work presented herein proposes a unique saliency-sensitive parametric average-value model (SSPAVM) of the synchronous machine-rectifier system. This model extends existing parametric average-value models to …
An Aggregated And Equivalent Home Model For Power System Studies With Examples Of Building Insulation And Hvac Control Improvements, Huangjie Gong, Evan S. Jones, Dan M. Ionel
An Aggregated And Equivalent Home Model For Power System Studies With Examples Of Building Insulation And Hvac Control Improvements, Huangjie Gong, Evan S. Jones, Dan M. Ionel
Power and Energy Institute of Kentucky Faculty Publications
Introducing new technologies into existing residences provides opportunities for the utility to enhance a community's power system performance. To validate the benefits of such technologies, an energy model is required in which their integration with a community's power system may be simulated. It can be difficult or impossible to properly model a power system without sufficient sample data. This paper proposes a method that uses Gaussian kernel density estimation (GKDE) to calculate the aggregated net power flow of a community's distribution system with only limited sample points at each time step. Example case studies that confirm the usefulness of the …
Investigation Of Host Nanotube Parameters For Enhancing The Performance Of Nanostructured Cds-Cdte Solar Cells, Deepak Kumar
Investigation Of Host Nanotube Parameters For Enhancing The Performance Of Nanostructured Cds-Cdte Solar Cells, Deepak Kumar
Theses and Dissertations--Electrical and Computer Engineering
Numerical simulations are performed to investigate the effects of host nanotube parameters (pore diameter and pitch for different CdS coverages) and CdTe doping density on device performance in nanowire CdS/ CdTe solar cells using SCAPS-1D. This research finds the optimum values for these parameters in order to achieve the highest efficiency. Experimentally the effect of anodization voltage and fluoride ion concentration on the pore diameter and the pitch are studied for the Titania nanotubes host. It is observed that in the range of 0.3 mL to 2 mL of ammonium fluoride content, pore diameter and the pitch of the Titania …
Formation Of Two-Way Shape Memory Effect In Niti Alloy Using Pulsed Laser Irradiation, Saidjafarzoda Ilhom, Khomidkhodza Kholikov, Peizhen Li, Dovletgeldi Seyitliyev, Zachary Thomas, Duvall Roberts, Omer San, Haluk E. Karaca, Ali O. Er
Formation Of Two-Way Shape Memory Effect In Niti Alloy Using Pulsed Laser Irradiation, Saidjafarzoda Ilhom, Khomidkhodza Kholikov, Peizhen Li, Dovletgeldi Seyitliyev, Zachary Thomas, Duvall Roberts, Omer San, Haluk E. Karaca, Ali O. Er
Mechanical Engineering Faculty Publications
Shape memory alloys (SMAs) are a unique class of smart materials and they were employed in various applications in engineering, biomedical, and aerospace technologies. Here, we report an advanced, efficient, and low-cost direct imprinting method with low environmental impact to create thermally controllable surface patterns. Patterned microindents were generated on Ni50Ti50 (at. %) SMAs using an Nd:YAG laser with 1064 nm wavelength at 10 Hz. Laser pulses at selected fluences were focused on the NiTi surface and generated pressure pulses of up to a few GPa. Optical microscope images showed that surface patterns with tailorable sizes can …
Advanced Synchronous Machine Modeling, Yuqi Zhang
Advanced Synchronous Machine Modeling, Yuqi Zhang
Theses and Dissertations--Electrical and Computer Engineering
The synchronous machine is one of the critical components of electric power systems. Modeling of synchronous machines is essential for power systems analyses. Electric machines are often interfaced with power electronic components. This work presents an advanced synchronous machine modeling, which emphasis on the modeling and simulation of systems that contain a mixture of synchronous machines and power electronic components. Such systems can be found in electric drive systems, dc power systems, renewable energy, and conventional synchronous machine excitation. Numerous models and formulations have been used to study synchronous machines in different applications. Herein, a unified derivation of the various …
Parallelization Of A Three-Dimensional Full Multigrid Algorithm To Simulate Tumor Growth, Dylan Goodin, Chin F. Ng, Hermann B. Frieboes
Parallelization Of A Three-Dimensional Full Multigrid Algorithm To Simulate Tumor Growth, Dylan Goodin, Chin F. Ng, Hermann B. Frieboes
Commonwealth Computational Summit
We present the performance gains of an openMP implementation of a fully adaptive nonlinear full multigrid (FMG) algorithm to simulate three-dimensional multispecies desmoplastic tumor growth on computer systems of varying processing capabilities. The FMG algorithm is applied to solve a recently published thermodynamic mixture model that uses a diffuse interface approach with fourth-order reaction-advection-diffusion PDEs (Cahn-Hilliard-type equations) that are coupled, nonlinear, and numerically stiff. The model includes multiple cell species and extracellular matrix (ECM), with adhesive and elastic energy contributions in chemical potential terms, as well as including blood and lymphatic vessels represented as continuous vasculatures. Advection-reaction-diffusion PDEs are employed …
An Optimization Model For Operating Room Scheduling To Reduce Blocking Across The Perioperative Process, Amin Abedini, Wei Li, Honghan Ye
An Optimization Model For Operating Room Scheduling To Reduce Blocking Across The Perioperative Process, Amin Abedini, Wei Li, Honghan Ye
Mechanical Engineering Faculty Publications
Operating room (OR) scheduling is important. Because of increasing demand for surgical services, hospitals must provide high quality care more efficiently with limited resources. When constructing the OR schedule, it is necessary to consider the availability of downstream resources, such as intensive care unit (ICU) and post anaesthesia care unit (PACU). The unavailability of downstream resources causes blockings between every two consecutive stages. In this paper we address the master surgical schedule (MSS) problem in order to minimize blockings between two consecutive stages. First, we present a blocking minimization (BM) model for the MSS by using integer programming, based on …
Using The Vehicle Routing Problem To Reduce Field Completion Times With Multiple Machines, Hasan Seyyedhasani, Joseph S. Dvorak
Using The Vehicle Routing Problem To Reduce Field Completion Times With Multiple Machines, Hasan Seyyedhasani, Joseph S. Dvorak
Biosystems and Agricultural Engineering Faculty Publications
The Vehicle Routing Problem (VRP) is a powerful tool used to express many logistics problems, yet unlike other vehicle routing challenges, agricultural field work consists of machine paths that completely cover a field. In this work, the allocation and ordering of field paths among a number of available machines has been transformed into a VRP that enables optimization of completion time for the entire field. A basic heuristic algorithm (a modified form of the common Clarke-Wright algorithm) and a meta-heuristic algorithm, Tabu Search, were employed for optimization. Both techniques were evaluated through computer simulations in two fields: a hypothetical basic …
3d Infrastructure Condition Assessment For Rail Highway Applications, Teng Wang
3d Infrastructure Condition Assessment For Rail Highway Applications, Teng Wang
Theses and Dissertations--Civil Engineering
Highway roughness is a concern for both the motoring public and highway authorities. Roughness may even increase the risk of crashes. Rail-highway grade crossings are particularly problematic. Roughness may be due to deterioration or simply due to the way the crossing was built to accommodate grade change, local utilities, or rail elevation. With over 216,000 crossings in the US, maintenance is a vast undertaking. While methods are available to quantify highway roughness, no method exists to quantitatively assess the condition of rail crossings. Conventional inspection relies on a labor-intensive process of qualitative judgment. A quantifiable, objective and extensible procedure for …
Electron-Beam Patterning Of Teflon Af For Surface Plasmon Resonance Sensing, Mansoor A. Sultan
Electron-Beam Patterning Of Teflon Af For Surface Plasmon Resonance Sensing, Mansoor A. Sultan
Theses and Dissertations--Electrical and Computer Engineering
Variable pressure electron beam etching and lithography for Teflon AF has been demonstrated. The relation between dose and etching depth is tested under high vacuum and water vapor. High resolution structures as small as 75 nm half-pitch have been resolved. Several simulation tools were tested for surface plasmon excitation. Grating based dual mode surface plasmon excitation has been shown numerically and experimentally.
Multifrequency Averaging Of Hysteresis-Current-Controlled Dc-Dc Converters, Yingying Liu
Multifrequency Averaging Of Hysteresis-Current-Controlled Dc-Dc Converters, Yingying Liu
Theses and Dissertations--Electrical and Computer Engineering
Multifrequency averaging is one of the widely used modeling and simulation techniques today for the analysis and design of power electronic systems. This technique is capable of providing the average behavior as well as the ripple behavior of power electronic systems. Hysteresis current control has fast response and internal current stability through controlling switches to maintain the current within a given hysteresis band of a given current command. However the state space variables in a hysteresis controlled system cannot be directly approached by multifrequency averaging method because of time varing switching frequency. In this thesis, a method of applying multifrequency …
Design Of Energy Storage Controls Using Genetic Algorithms For Stochastic Problems, Si Chen
Design Of Energy Storage Controls Using Genetic Algorithms For Stochastic Problems, Si Chen
Theses and Dissertations--Electrical and Computer Engineering
A successful power system in military applications (warship, aircraft, armored vehicle etc.) must operate acceptably under a wide range of conditions involving different loading configurations; it must maintain war fighting ability and recover quickly and stably after being damaged. The introduction of energy storage for the power system of an electric warship integrated engineering plant (IEP) may increase the availability and survivability of the electrical power under these conditions. Herein, the problem of energy storage control is addressed in terms of maximizing the average performance. A notional medium-voltage dc system is used as the system model in the study. A …
Inland Waterway Operational Model & Simulation Along The Ohio River, Doug Kreis, Roy E. Sturgill, Brian K. Howell, Christopher W. Van Dyke, D. Stephen Voss
Inland Waterway Operational Model & Simulation Along The Ohio River, Doug Kreis, Roy E. Sturgill, Brian K. Howell, Christopher W. Van Dyke, D. Stephen Voss
Kentucky Transportation Center Research Report
The inland waterway system of the U.S. is a vital network for transporting key goods and commodities from the point of production to manufacturers and consumers. Shipping materials via the inland waterways is arguably the most economical and environmentally friendly option (compared to hauling freight by trains or railways). Despite the advantages the inland waterways enjoys over competing modes, key infrastructure – such as locks and dams, which help to control water levels on a number of rivers and make navigation possible – is declining. Limited funds have been allocated to make the necessary repairs to lock and dam facilities. …
A Study Of Queuing Theory In Low To High Rework Environments With Process Availability, Adam J. Brown
A Study Of Queuing Theory In Low To High Rework Environments With Process Availability, Adam J. Brown
Theses and Dissertations--Manufacturing Systems Engineering
In manufacturing systems subject to machine and operator resource constraints the effects of rework can be profound. High levels of rework burden the resources unnecessarily and as the utilization of these resources increases the expected queuing time of work in process increases exponentially. Queuing models can help managers to understand and control the effects of rework, but often this tool is overlooked in part because of concerns over accuracy in complex environments and/or the need for limiting assumptions. One aim of this work is to increase understanding of system variables on the accuracy of simple queuing models. A queuing model …
Simulation And Control Of A Quadrotor Unmanned Aerial Vehicle, Michael David Schmidt
Simulation And Control Of A Quadrotor Unmanned Aerial Vehicle, Michael David Schmidt
University of Kentucky Master's Theses
The ANGEL project (Aerial Network Guided Electronic Lookout) takes a systems engineering approach to the design, development, testing and implementation of a quadrotor unmanned aerial vehicle. Many current research endeavors into the field of quadrotors for use as unmanned vehicles do not utilize the broad systems approach to design and implementation. These other projects use pre-fabricated quadrotor platforms and a series of external sensors in a mock environment that is unfeasible for real world use. The ANGEL system was designed specifically for use in a combat theater where robustness and ease of control are paramount. A complete simulation model of …
Multi-Barge Flotilla Impact Forces On Bridges, Peng Yuan, Issam E. Harik, Michael T. Davidson
Multi-Barge Flotilla Impact Forces On Bridges, Peng Yuan, Issam E. Harik, Michael T. Davidson
Kentucky Transportation Center Research Report
The current AASHTO equations for barge impact loads are based on scale models of barges, and may not accurately predict impact loads on bridge piers. The results of this study produce more realistic flotilla impact design loads, potentially leading to a reduction in construction costs of bridges over navigable waterways. The objectives of this study are: (1) To conduct theoretical finite element analysis on various types of flotillas impacting bridge piers. The flotillas and the respective barges will be of the type commonly traversing Kentucky’s waterways; and (2) To generate design equations for barge/flotilla impact loads. The study concludes the …
Equivalent Barge And Flotilla Impact Forces On Bridge Piers, Peng Yuan, Issam E. Harik
Equivalent Barge And Flotilla Impact Forces On Bridge Piers, Peng Yuan, Issam E. Harik
Kentucky Transportation Center Research Report
Bridge piers located in navigable inland waterways are designed to resist impact forces from barges and flotillas in addition to other design considerations (e.g., scour, dead and live loads, etc.). The primary design tool for estimating these forces is the AASHTO Guide Specification which provides a simple hand calculation method for determining an “equivalent impact force”. The simplicity comes at a cost of excluding the effect of the pier shape, impact duration, and interaction between barges in a flotilla. The objective of this report is to present a hand calculation method for determining barge or flotilla equivalent static impact forces …
Aeration Strategies And Fan Cost Comparisons For Wheat In Mid-South Production Regions, Thomas C. Bridges, Michael D. Montross, Samuel G. Mcneill
Aeration Strategies And Fan Cost Comparisons For Wheat In Mid-South Production Regions, Thomas C. Bridges, Michael D. Montross, Samuel G. Mcneill
Biosystems and Agricultural Engineering Faculty Publications
Numerous factors influence the sizing of aeration fans for summer-harvested crops. Thirty years of weather data for Lexington, Kentucky, were analyzed and the cost of aeration was compared for two axial fans (afan1, afan2) and one centrifugal fan (cfan1). Aeration costs were defined as the sum of the following components: the cost of owning the fan, the cost of electricity for operating the fan, a cost for wheat shrinkage during aeration, and a cost for dry matter loss (DML). The fans were selected to deliver airflow rates of approximately one, two, and three times the recommended aeration rate of 0.11 …
The Dayton Its Demonstration Project: Simulating Existing Conditions, Jill A. Swaynos, Nikiforos Stamatiadis
The Dayton Its Demonstration Project: Simulating Existing Conditions, Jill A. Swaynos, Nikiforos Stamatiadis
Kentucky Transportation Center Research Report
The Miami Valley Regional Planning Commission is incorporating an Advanced Traveler Information System to alleviate real-time traffic problems associated with special events at the Ervin J. Nutter Center of the Wright State University. This study of the existing conditions is part of the evaluation plan and addresses two tasks: 1) documentation of the existing conditions; and 2) definition of measures of effectiveness. The existing conditions were depicted with the use of a computer simulation software package, Traffic Software Integrated System and separate scenarios were modeled for three existing conditions: ingress and egress for a special event and a major shopping …
Conversion Of New Circle Road To A Limited Access Highway, Steven M. Henderson, Nikiforos Stamatiadis
Conversion Of New Circle Road To A Limited Access Highway, Steven M. Henderson, Nikiforos Stamatiadis
Kentucky Transportation Center Research Report
The objectives of this study were to first evaluate the existing traffic conditions along the NE part of New Circle Road and investigate the use of unconventional left turn treatments, as well as other access restrictions to improve the operating conditions of New Circle Road. The alternatives examined include a do-nothing alternative, the addition of one through lane per direction, the use of median U-turns at various locations, and combinations of them. Restrictive left turn strategies proved to be a more successful tool for traffic management on New Circle Road than simply adding a lane in each direction. Using median …
Comparison Of Observed And Simulated Grow-Finish Swine Performance Under Summer Conditions, Larry W. Turner, Thomas C. Bridges, Richard D. Coffey, Richard S. Gates, Gary R. Parker, Tami M. Brown-Brandl, Douglas G. Overhults
Comparison Of Observed And Simulated Grow-Finish Swine Performance Under Summer Conditions, Larry W. Turner, Thomas C. Bridges, Richard D. Coffey, Richard S. Gates, Gary R. Parker, Tami M. Brown-Brandl, Douglas G. Overhults
Biosystems and Agricultural Engineering Faculty Publications
As a part of a National Pork Producers Council educational program, our research and extension team at the University of Kentucky was linked with an independent commercial swine producer to test the NCPIG model against observed commercial on-farm data. This experience provided improved information for model development as well as increased producer insight into the data input needs and potential benefits of modeling. Detailed production information comparisons between the NCPIG model and producer data are presented for summer time conditions to assess the validity of the NCPIG model for simulation of grow-finish swine performance. Results demonstrated that the NCPIG model …
Evaluation Of The Crop Growth Component Of The Root Zone Water Quality Model For Corn In Ohio, Sue E. Nokes, Feliks M. Landa, Jon D. Hanson
Evaluation Of The Crop Growth Component Of The Root Zone Water Quality Model For Corn In Ohio, Sue E. Nokes, Feliks M. Landa, Jon D. Hanson
Biosystems and Agricultural Engineering Faculty Publications
The Root Zone Water Quality Model (RZWQM) is a computer model developed to simulate water, chemical, and biological processes in the root zone of agricultural management systems. As of this writing RZWQM is in the beta-testing phase of development. This article reports on a parameterization and evaluation study performed in Ohio on field corn for the crop growth component of RZWQM. The generic crop growth model in RZWQM had not previously been parameterized or tested on field corn. This article reports the results of such a study. One year of data was used to calibrate RZWQM, and two additional years …
Simulation Of Burley Tobacco Harvesting-Housing Systems, Ronald L. Bingner, Larry G. Wells, Thomas C. Bridges, George A. Duncan
Simulation Of Burley Tobacco Harvesting-Housing Systems, Ronald L. Bingner, Larry G. Wells, Thomas C. Bridges, George A. Duncan
Biosystems and Agricultural Engineering Faculty Publications
A computer model has been developed using systems analysis techniques to simulate the labor and equipment aspects of harvesting burley tobacco. By varying the parameters of the model the user can determine a harvesting and housing strategy based on labor and equipment availability.