Engineering Commons^™

Thyristor-Controlled Switch Capacitor Placement In Large-Scale Power Systems Via Mixed Integer Linear Programming And Taylor Series Expansion, Omid Ziaee, F. Fred Choobineh

Department of Electrical and Computer Engineering: Faculty Publications

Allocation of flexible alternating current transmission system (FACTS) devices to an electric power transmission network may be formulated as a nonlinear mathematical program. Solving such a nonlinear program for a large transmission network is computationally very expensive, and obtaining the optimal solution may be impossible. We present a Taylor series expansion approximation of the nonlinearities of the problem and propose a mixed integer linear program (MILP) for finding the optimum location and proper settings of a Thyristor-Controlled Series Capacitor (TCSC) in an electric power network. The objective of this problem is to minimize total generation cost based on the DC …

Tunable Plasmonic And Hyperbolic Metamaterials Based On Enhanced Nonlinear Response, Christos Argyropoulos, Francesco Monticone, Nasim Mohammadi Estakhri, Andrea Alu

Department of Electrical and Computer Engineering: Faculty Publications

We present here tunable and reconfigurable designs of linear and nonlinear plasmonic and hyperbolic metamaterials. Rich scattering features of multilayered composite nanoparticles are demonstrated, which include complex and exotic scattering signatures combining multiple dipolar Fano resonances and electromagnetic induced transparency (EIT) features. These dipoledipole multi-Fano scattering responses can be further tuned through altering the plasmonic properties of the concentric layers or the permittivity of the core, for instance, by the presence of nonlinearities. Strong third-order nonlinear effects, such as optical bistability, may also be induced in the scattering response of nonlinear nanoparticles due to the highly enhanced and confined fields …

Bayesian Network Prior: Network Analysis Of Biological Data Using External Knowledge, Senol Isci, Haluk Dogan, Cengizhan Ozturk, Hasan H. Otu

Department of Electrical and Computer Engineering: Faculty Publications

Motivation: Reverse engineering GI networks from experimental data is a challenging task due to the complex nature of the networks and the noise inherent in the data. One way to overcome these hurdles would be incorporating the vast amounts of external biological knowledge when building interaction networks. We propose a framework where GI networks are learned from experimental data using Bayesian networks (BNs) and the incorporation of external knowledge is also done via a BN that we call Bayesian Network Prior (BNP). BNP depicts the relation between various evidence types that contribute to the event ‘gene interaction’ and is used …

Student Self-Assessment Of Ace 10 Outcomes, Yaşar Demirel

Accreditation Quality Initiative

ACE 10 Question

The ACE Outcome 10 requires students to generate a creative or scholarly product that requires broad knowledge, appropriate technical proficiency, information collection, synthesis, interpretation, presentation, and reflection.

Will the student selfassessment of the extent of attainment of outcomes in a student output improve learning and teaching?

Student Work

Method of Analysis

Student Self-Assessment Survey Form

Findings

Improving ACE 10 Learning

Element Dependence Of Enhancement In Optics Emission From Laser-Induced Plasma Under Spatial Confinement, Changmao Li, Lianbo Guo, Xiangnan He, Zhongqi Hao, Xiangyou Li, Meng Shen, Xiaoyan Zeng, Yongfeng Lu

Department of Electrical and Computer Engineering: Faculty Publications

In this study, the element dependence of spatial confinement effects in LIBS has been studied. Hemispheric cavities were used to confine laser-induced plasmas from aluminum samples with other trace elements. The enhancement factors were found to be dependent on the elements. Equations describing the element dependent enhancement factors were successfully deduced from the local thermodynamic equilibrium conditions, which have also been verified by the experimental results. Research results show that enhancement factors in LIBS with spatial confinement depend on the temperature, electron density, and compression ratio of plasmas, and vary with elements and atomic/ionic emission lines selected. Generally, emission lines …

Design Optimization Of Single-Sided Axial Flux Permanent Magnet Machines By Differential Evolution, Xu Yang, Dean Patterson, Jerry Hudgins

Department of Electrical and Computer Engineering: Faculty Publications

In this paper, a design optimization approach for single-sided axial flux permanent magnet (AFPM) machines using a differential evolution algorithm for is presented. The objectives of the design optimization are to maximize the output torque per unit cost (Nm/$) and maximize the efficiency. A paremetric 2-D FEA model of an AFPM is built. A sensitivity study of design variables is carried out to determine the correlation between the design variables and the objectives, enabling the removal of insignificant design variables. Design constraints including geometrical and operating limits are considered. A total of five independent variables are employed in the optimization …

A Low-Power Compact Nqr Based Explosive Detection System, Xinwang Zhang, Nathan Schemm, Sina Balkır, Michael W. Hoffman

Department of Electrical and Computer Engineering: Faculty Publications

Nuclear quadruple resonance (NQR) has been studied for explosive detection for years. Some prototype NQR-based detection systems have been reported, but were all designed from the laboratory perspective, with bulky sizes and high power consumption. To achieve a portable NQR-based detection system for field applications, a low-power compact system utilizing state-of-the-art semiconductor technologies is presented in this paper. Several novel circuits for the key modules are proposed, including a Class-D type power amplifier, a power multiplexing and matching network, a customized IC with integrated analog signal processing chain, and a microcontroller-based logic control unit. An advanced digital signal processor platform …

Workplace Monitoring Of Employee Health Using The Workstation Pc As A Platform, Priyankar Bhattacharjee

Department of Electrical and Computer Engineering: Faculty Publications

A country’s biggest asset is its workforce, given the fact that a healthy workforce can contribute to rapid growth of the economy. Chronic illnesses reduce productivity, are responsible for rising healthcare costs, and should be managed by the employer to reduce healthcare expenditures. This can be done through employee health and wellness programs, and well-designed health management initiatives. In addition, new information and communication technologies make it possible to monitor employee health with wearable devices and telehealth assisted surveillance techniques. This paper introduces a unique new approach to workplace healthcare monitoring, using the office workstation PC itself to monitor worker …

Clu: Co-Optimizing Locality And Utility In Thread-Aware Capacity Management For Shared Last Level Caches, Dongyuan Zhan, Hong Jiang, Sharad C. Seth

Department of Electrical and Computer Engineering: Faculty Publications

Most chip-multiprocessors nowadays adopt a large shared last-level cache (SLLC). This paper is motivated by our analysis and evaluation of state-of-the-art cache management proposals which reveal a common weakness. That is, the existing alternative replacement policies and cache partitioning schemes, targeted at optimizing either locality or utility of co-scheduled threads, cannot deliver consistently the best performance under a variety of workloads. Therefore, we propose a novel adaptive scheme, called CLU, to interactively co-optimize the locality and utility of co-scheduled threads in thread-aware SLLC capacity management. CLU employs lightweight monitors to dynamically profile the LRU (least recently used) and BIP (bimodal …

Intelligent Maximum Power Extraction Control For Wind Energy Conversion Systems Based On Online Q-Learning With Function Approximation, Chun Wei, Zhe Zhang, Wei Qiao, Liyan Qu

Department of Electrical and Computer Engineering: Faculty Publications

This paper proposes an intelligent maximum power point tracking (MPPT) algorithm for variable-speed wind energy conversion systems (WECSs) based on an online Q-learning algorithm. Instead of using the conventional Qlearning that uses a lookup table to store the action values for the discretized states, artificial neural networks (ANNs) are used as function approximators to output the action values by using the electrical power and rotor speed of the generator as inputs. This eliminates the need for a large storage memory. The proposed method learns the optimal speed control strategy of the WECS by updating the connecting weights of the ANNs, …

Effects Of Droplet Diameter On The Leidenfrost Temperature Of Laser Processed Multiscale Structured Surfaces, Anton Hassebrook, Corey Kruse, Chris Wilson, Troy P. Anderson, Craig Zuhlke, Dennis R. Alexander, George Gogos, Sidy Ndao

Department of Electrical and Computer Engineering: Faculty Publications

In this paper, an experimental investigation of the effects of droplet diameters on the Leidenfrost temperature and its shifts has been carried out. Tests were conducted on a 304 stainless steel polished surface and a stainless steel surface which was processed by a femtosecond laser to form Above Surface Growth (ASG) nano/microstructures. To determine the Leidenfrost temperatures, the droplet lifetime method was employed for both the polished and processed surfaces. A precision dropper was used to vary the size of droplets from 1.5 to 4 millimeters. The Leidenfrost temperature was shown to display shifts as high as 85 ˚C on …

Optimum Renewable Generation Capacities In A Microgrid Using Generation Adequacy Study, Salman Kahrobaee, Sohrab Asgarpoor, Milad Kahrobaee

Department of Electrical and Computer Engineering: Faculty Publications

Microgrids, as small power systems, may be comprised of different types of loads and distributed generation. As the integration of renewable power generation increases, the total available generation capacity of the system will be more derated due to the effect of equipment failures and the intermittent nature of these resources. Therefore, it is critical to determine optimum renewable generation capacities and provide enough reserve margin to meet the target reliability of the microgrid. In this paper, we first model a microgrid, including conventional and renewable distributed generation and the loads. Second, we determine the renewable generation capacity required to meet …

State Of Charge Estimation Based On A Realtime Battery Model And Iterative Smooth Variable Structure Filter, Taesic Kim, Yebin Wang, Zafer Sahinoglu, Toshihiro Wada, Satoshi Hara, Wei Qiao

Department of Electrical and Computer Engineering: Faculty Publications

This paper proposes a novel real-time model-based state of charge (SOC) estimation method for lithium-ion batteries. The proposed method includes: 1) an electrical circuit battery model incorporating the hysteresis effect, 2) a fast upper-triangular and D-diagonal recursive least square (FUDRLS)-based online parameter identification algorithm for the electrical battery model, and 3) an iterated smooth variable structure filter (ISVSF) for SOC estimation. The proposed method enables an accurate and robust condition monitoring for lithium-ion batteries. Due to its low complexity, the proposed method is suitable for the real-time embedded battery management system (BMS) application. Simulation and experiment are performed to validate …

Design And Implementation Of A Low-Cost Embedded Linux Gateway For Smart Home Health Monitoring, Mateusz Mittek, Jay D. Carlson, Lance C. Pérez

Department of Electrical and Computer Engineering: Faculty Publications

Many wireless sensor network applications require a gateway device to interface with services running on the Internet. Because of the software complexity involved in this device, it is often realized using a real-time operating system running on an application processor. Most systems burden the user with developing the protocol handling and device configuration and management inside the application. In this paper, we present the Angelos Gateway – a turnkey, low-cost, Linux-powered WSN gateway that provides a socket-based environment for rapid network-enabled application development. Experimental results demonstrate that the proposed device is capable of high-throughput packet I/O, confirming the efficacy of …

Automated Indoor Rfid Inventorying Using A Self-Guided Micro-Aerial Vehicle, Steven A. Parkison, Eric T. Psota, Lance C. Pérez

Department of Electrical and Computer Engineering: Faculty Publications

A Micro-Aerial Vehicle (MAV) system is presented for automated indoor inventorying using passive radio frequency identification (RFID). This system utilizes a combination of onboard sensing and processing in order to achieve flight stabilization, generate floor maps, and perform path planning. The proposed state estimation method along with a control feedback strategy are demonstrated to be sufficiently accurate for operation in the indoor environment and the proposed path planning technique is shown to be effective for guiding the MAV while it performs automated RFID scanning.

Achieving Robustness And Capacity Gains In Covert Timing Channels, Fahimeh Rezaei, Michael Hempel, Pradhumna Lal Shrestha, Hamid Sharif

Department of Electrical and Computer Engineering: Faculty Publications

In this paper, we introduce a covert timing channel (CTC) algorithm and compare it to one of the most prevailing CTC algorithms, originally proposed by Cabuk et al. CTC is a form of covert channels – methods that exploit network activities to transmit secret data over packet-based networks – by modifying packet timing. This algorithm is a seminal work, one of the most widely cited CTCs, and the foundation for many CTC research activities. In order to overcome some of the disadvantages of this algorithm we introduce a covert timing channel technique that leverages timeout thresholds. The proposed algorithm is …

Monitoring Igbt’S Health Condition Via Junction Temperature Variations, Bo Tian, Wei Qiao, Ze Wang, Tanya Gachovska, Jerry L. Hudgins

Department of Electrical and Computer Engineering: Faculty Publications

Insulated gate bipolar transistor (IGBT) failures are a major issue in modern power electronics applications. Two most dominated failure mechanisms of IGBTs are solder fatigue and bond wire wear-out. This paper proposes a new method to online monitor an IGBT’s health condition by using the instantaneous junction temperature variation between present and the first operating cycles of the IGBT with the same operating current. In this work, the instantaneous junction temperature of an IGBT is estimated from a thermal network model. The proposed method is validated by experimental results obtained from accelerated aging tests for IGBTs.

On Target For People And Planet: Setting And Achieving Water-Related Sustainable Development Goals, Julie Van Der Bliek, Peter G. Mccornick, James Clarke

Daugherty Water for Food Global Institute: Faculty Publications

Our specific focus in this book is on securing water for sustainable food production. This links to sustainable water resources management, delivering on the water supply and sanitation requirements and provisioning water for energy and the urban sector. A specific intent is to ensure that the realities in low- and middle-income countries in Africa and Asia are recognized and to provide practical pathways to change that fit these realities and the aspirations of those countries. This will help to prepare for the next step in the SDG [sustainable development goals] process: devolving the SDGs to the national level. It will …

Nebraska Water Center, Robert B. Daugherty Water For Food Institute, University Of Nebraska (Handout), Nebraska Water Center

Nebraska Water Center: Administrative Materials

Who We Are: The Nebraska Water Center (NWC), established by Congress in 1964 as one of 54 Water Resources Research Institutes nationwide, focuses on helping the University of Nebraska (NU) become an international leader in water research, teaching, extension and outreach by facilitating programs that will result in NU becoming a premiere institution in the study of agricultural and domestic water use. The NWC helps arrange research addressing water problems or water understanding; helps new water researchers and engineers; and publishes research results to water professionals and the public through publications, colloquiums and conferences, lectures and tours. The NWC is …

2014 Acuta/Nacubo/Acuho-1 State Of Resnet Report

ACUTA: Other Publications

In This Issue

Introduction

Methodology

Executive Summary

Findings

Bandwidth Management

Wireless Coverage

ResNet Management & Support

Planning & Measurement

Costs & Funding

Outsourcing

Overwintering Biology And Tests Of Trap And Relocate As A Conservation Measure For Burying Beetles, W. Wyatt Hoback, Adrienne Conley

Nebraska Department of Transportation: Research Reports

Burying beetles are carrion beetles and utilize dead animal carcasses for feeding and reproductive efforts. They assist with decomposition, prevent the spread of disease, and reduce the number of pest species. The largest species of carrion beetle, the American burying beetle, is a federally endangered insect and its distribution has been reduced by 90%. The conservation of this species is important in maintaining a healthy ecosystem. Overwintering biology and trap and relocation were studied to determine how this beetle survives freezing temperatures and to find whether trap and relocation could be a suitable conservation management measure.

Trap and relocation is …

Co-Occurrence Of The Cyanotoxins Bmaa, Daba And Anatoxin-A In Nebraska Reservoirs, Fish, And Aquatic Plants, Maitham Ahmed Al-Sammak, Kyle D. Hoagland, David A. Cassada, Daniel D. Snow

Nebraska Water Center: Faculty Publications

Several groups of microorganisms are capable of producing toxins in aquatic environments. Cyanobacteria are prevalent blue green algae in freshwater systems, and many species produce cyanotoxins which include a variety of chemical irritants, hepatotoxins and neurotoxins. Production and occurrence of potent neurotoxic cyanotoxins β-N-methylamino-L-alanine (BMAA), 2,4-diaminobutyric acid dihydrochloride (DABA), and anatoxin-a are especially critical with environmental implications to public and animal health. Biomagnification, though not well understood in aquatic systems, is potentially relevant to both human and animal health effects. Because little is known regarding their presence in fresh water, we investigated the occurrence and potential for bioaccumulation of cyanotoxins …

Seed Tape Effects On Corn Emergence Under Greenhouse Conditions, Ramarao Venkatesh, Peter R. Thomison, Colette K. Gabriel, Mark A. Bennett, Elaine M. Grassbaugh, Matthew D. Kleinhenz, Scott A. Shearer, Santosh Pitla

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Seed tape has recently received attention as an alternative planting system for smallholder farmers in underdeveloped regions of South America, Africa, China, and India (Mateus, 2014). Seed companies are also developing seed-tape planting systems for germplasm evaluations (Deppermann et al., 2013). Although seed tape has been promoted as a method for ensuring uniform seed spacing and plant density of small-seeded flowers, herbs, and vegetables (Chancellor, 1969), little or no information is available on the use of seed tape for larger-seeded row crops and its effect on crop emergence. The objective of this study was to compare the emergence of corn …

Alternative Funding Mechanisms For State Transportation Systems In Predominantly Rural States, John E. Anderson, Eric Thompson

Bureau of Business Research Publications

The Transportation Research Board of the National Academies has identified a number of research needs related to alternative transportation finance systems. Alternatives are needed because motor fuels taxes are proving to be insufficient to fund operation and maintenance costs of the transportation system. The long-term trend is likely to be continuing use of motor fuel taxes, supplemented by, or transitioning to, use-based fees. Current research in progress in this area is focused on designing variable fees that will internalize congestion externalities in urban areas. These approaches are particularly well suited to highly urbanized areas, but other approaches may be required …

The Hydraulic Conductivity Structure Of Gravel-Dominated Vadose Zones Within Alluvial Floodplains, Ronald B. Miller, Derek M. Heeren, Garey A. Fox, Todd Halihan, Daniel E. Storm, Aaron R. Mittelstet

Department of Agricultural and Biological Systems Engineering: Faculty Publications

The floodplains of many gravel-bed streams have a general stratigraphy that consists of a layer of topsoil covering gravel-dominated subsoil. Previous research has demonstrated that this stratigraphy can facilitate preferential groundwater flow through focused linear features, such as paleochannels, or gravelly regions within the vadose zone. These areas within the floodplain vadose zone may provide a route for interactions between the floodplain surface and alluvial groundwater, effectively extending the hyporheic zone across the floodplain during high stream stage. The objective of this research was to assess the structure and scale of texture heterogeneity within the vadose zone within the gravel …

Dynamic Fracture Analysis Of Polycarbonate By The Optical Method Of Caustics, Guiyun Gao, Zheng Li, Mehrdad Negahban

Department of Mechanical and Materials Engineering: Faculty Publications

Glassy polycarbonate (PC) is a widely used engineering material in industries, since it has high strength and toughness as well as good transparency. However, these advantages of PC can be suppressed by physical aging, especially its dynamic fracture toughness. In addition, the material properties of PC can be changed dramatically after large plastic compressive deformation, and it can show obvious orthotropic behavior. Here, the combined effect of aging and plastic compressive deformation on dynamic facture of PC was investigated by the optical method of caustics. The dynamic reflective method of caustics for orthotropic materials was developed here to study the …

Test 2082: John Deere 7210r, Nebraska Tractor Test Lab

Nebraska Tractor Tests

ABOUT THE TEST REPORT AND USE OF THE DATA The test data contained in this report are a tabulation of the results of a series of tests. Due to the restricted format of these pages, only a limited amount of data and not all of the tractor specifications are included. The full OECD report contains usually about 30 pages of data and specifications. The test data were obtained for each tractor under similar conditions and therefore, provide a means of comparison of performance based on a limited set of reported data. EXPLANATION OF THE TEST PROCEDURES Purpose The purpose of …

Test 2097: New Holland T9.565, Nebraska Tractor Test Lab

Nebraska Tractor Tests

ABOUT THE TEST REPORT AND USE OF THE DATA The test data contained in this report are a tabulation of the results of a series of tests. Due to the restricted format of these pages, only a limited amount of data and not all of the tractor specifications are included. The full OECD report contains usually about 30 pages of data and specifications. The test data were obtained for each tractor under similar conditions and therefore, provide a means of comparison of performance based on a limited set of reported data. EXPLANATION OF THE TEST PROCEDURES Purpose The purpose of …

Test 2093a: New Holland T9.480, Nebraska Tractor Test Lab

Nebraska Tractor Tests

ABOUT THE TEST REPORT AND USE OF THE DATA The test data contained in this report are a tabulation of the results of a series of tests. Due to the restricted format of these pages, only a limited amount of data and not all of the tractor specifications are included. The full OECD report contains usually about 30 pages of data and specifications. The test data were obtained for each tractor under similar conditions and therefore, provide a means of comparison of performance based on a limited set of reported data. EXPLANATION OF THE TEST PROCEDURES Purpose The purpose of …

Test 2100: John Deere 8295r, Nebraska Tractor Test Lab

Nebraska Tractor Tests

ABOUT THE TEST REPORT AND USE OF THE DATA The test data contained in this report are a tabulation of the results of a series of tests. Due to the restricted format of these pages, only a limited amount of data and not all of the tractor specifications are included. The full OECD report contains usually about 30 pages of data and specifications. The test data were obtained for each tractor under similar conditions and therefore, provide a means of comparison of performance based on a limited set of reported data. EXPLANATION OF THE TEST PROCEDURES Purpose The purpose of …