Digital Commons Network^™

Missouri River Recovery Program: Adaptive Management Process Framework, Joe Bonneau, Tim Fleeger, Craig Flemming, Carol Hale, Mike Anderson, Kate Buenau, Tim L. Hiller, Doug Latka, Ron Thom, Drew Tyre, Steve Fischer, Casey Kruse, Brad Thompson

United States Army Corps of Engineers, Omaha District

The purpose of this Adaptive Management (AM) Process Framework is to describe the AM process for the U.S. Army Corps of Engineers (USACE) Missouri River Recovery Program (MRRP) and explain how AM principles will be used in the MRRP to reduce uncertainty and ensure that Program objectives are achieved over time. The AM Process Framework is intended to be broad so that it can be applied to all aspects of the MRRP and be understood by a diverse audience of managers, federal and state agencies, scientists, engineers, the Missouri River Recovery Implementation Committee (MRRIC), stakeholders, Tribes, and the public.

To Google Or Not To Google: Graduate Students’ Use Of The Internet To Access Personal Information About Clients, David K. Dilillo, Emily B. Gale

Department of Psychology: Faculty Publications

The emergence of Internet search and social media sites now permits therapists to obtain a plethora of personal information about their clients online. These behaviors raise a number of ethical issues related to client privacy, self-determination, and informed consent. The purpose of this study is to examine student therapists’ opinions and behaviors in regard to the use these websites to search for information about their clients. A national sample of 854 psychology doctoral students was surveyed in regard to their online activities, attitudes, and frequency of searching for client information online. Results showed that Internet usage is pervasive in this …

Space Tourism, Private Spaceflight And The Law: Key Aspects, Frans G. Von Der Dunk

Space, Cyber, and Telecommunications Law Program: Faculty Publications

The arrival of ‘space tourism,’ or more appropriately ‘private spaceflight,’ requires the law of outer space to change and adapt to this revolutionary development, as deriving precisely from the principled private participation in these activities. After defining the proper concepts, this paper discusses key legal aspects of authorization and supervision, liability and registration, and how they re.ect and impact on space tourism. Key legal aspects related to certification of craft, crew and passengers, while not yet much articulated at the international level will also be touched upon precisely in order to demonstrate that the law could well be driven first …

Space For Celestial Symphonies? Towards The Establishment Of International Radio Quiet Zones, Frans G. Von Der Dunk

Space, Cyber, and Telecommunications Law Program: Faculty Publications

The growth of low- and medium-Earth orbit mobile satellite communications poses a threat to radio astronomers which could be mitigated by the establishment of international radio quiet zones (IRQZs), where communications traffic is managed (not eliminated) to allow radio astronomy to continue. Using the prototype of national such zones in the USA, this article explains how the system would work and discusses the international legal parameters that would bound it, drawing on current aerospace, outer space and high seas legislation. Precedents for an IRQZ—Exclusive Economic Zones, denuclearized zones and the Antarctic regime—are also examined.

The Legal Framework For Space Projects In Europe: Aspects Of Applicable Law And Dispute Resolution, Frans G. Von Der Dunk

Space, Cyber, and Telecommunications Law Program: Faculty Publications

Space projects in Europe take place in a complicated environment involving many public, private and intergovernmental actors, where the participation of the private sector, as independent space operators or as sub-contractors to others, is usually subsumed under the label of 'the space industry,' producing hardware, software and services to be used in outer space, in support of space activities, or using products, data or information generated with the help of space activities.

Such private, semi-private and quasi-private actors use contracts as the main mechanism to protect their interests, the freedom to contract within the rule oflaw being the paramount overarching …

The Issue Of National Security In The Context Of National Space Legislation—Comparing European And Non-European States, F. G. Von Der Dunk

Space, Cyber, and Telecommunications Law Program: Faculty Publications

First three paragraphs:

The inherent dual-use character of most, if not all space activities cannot fail to exercise a considerable impact also on the involvement of private actors in space. Much technology used for and/or developed by private space activities may potentially be put at the use of those wishing to change a particular political status quo, and likewise the material results of some private space activities may, consciously or inadvertently, come to be used against the national security interests of one state or another. Hence, issues of national security will likely also have an effect on the issue of …

Current And Future Aac Research Considerations For Adults With Acquired Cognitive And Communication Impairments, Melanie Fried-Oken, David R. Beukelman, Karen Hux

Department of Special Education and Communication Disorders: Faculty Publications

Adults with acquired language impairments secondary to stroke, traumatic brain injury, and neurodegenerative diseases are candidates for communication supports outside of the traditional restoration-based approaches to intervention. Recent research proves repeatedly that augmentative and alternative communication (AAC) provides a means for participation, engagement, conversation, and message transfer when individuals can no longer expect full return of premorbid communication skills and that inclusion of communication supports should begin early. We discuss current research and future directions for integrated systems of technical supports that include low-technology, high tech, and partner-dependent strategies for adults with severe and chronic aphasia, cognitive-communication problems resulting from …

Energy-Efficient Feedback Tracking On Embedded Smart Cameras By Hardware-Level Optimization, Mauricio Casares, Senem Velipasalar, Paolo Santinelli, Rita Cucchiara, Reggio Emilia, Andrea Prati

Department of Electrical and Computer Engineering: Faculty Publications

Embedded systems have limited processing power, memory and energy. When camera sensors are added to an embedded system, the problem of limited resources becomes even more pronounced. In this paper, we introduce two methodologies to increase the energy-efficiency and battery-life of an embedded smart camera by hardware-level operations when performing object detection and tracking. The CITRIC platform is employed as our embedded smart camera. First, down-sampling is performed at hardware level on the micro-controller of the image sensor rather than performing software-level down-sampling at the main microprocessor of the camera board. In addition, instead of performing object detection and tracking …

Goodput Maximization In Cooperative Networks With Arq, Qing Chen, M. Cenk Gursoy

Department of Electrical and Computer Engineering: Faculty Publications

In this paper, the average successful throughput, i.e., goodput, of a coded 3-node cooperative network is studied in a Rayleigh fading environment. It is assumed that a simple automatic repeat request (ARQ) technique is employed in the network so that erroneously received packets are retransmitted until successful delivery. The relay is assumed to operate in either amplify-and-forward (AF) or decode-and-forward (DF) mode. Under these assumptions, retransmission mechanisms and protocols are described, and the average time required to send information successfully is determined. Subsequently, the goodput for both AF and DF relaying is formulated. The tradeoffs and interactions between the …

On The Performance Limits Of Cognitive Mimo Channels, Sami Akin, M. Cenk Gursoy

Department of Electrical and Computer Engineering: Faculty Publications

In this paper, throughput of cognitive multiple-input multiple-output (MIMO) systems operating under quality-of service (QoS) constraints is studied. It is assumed that transmission power and the covariance of the input signal vector are varied depending on the sensed activities of primary users in the system. Considering the reliability of the transmission and channel sensing results, a state-transition model is provided. Effective capacity is determined, and expressions for the first and second derivatives of the effective capacity are obtained at SNR = 0. The minimum bit energy requirements in the presence of QoS limitations are identified. Numerical results are provided.

Risk-Based Failure Mode And Effect Analysis For Wind Turbines (Rb-Fmea), Salman Kahrobaee, Sohrab Asgarpoor

Department of Electrical and Computer Engineering: Faculty Publications

Failure Mode and Effect Analysis (FMEA) has already been used as a qualitative measure for identifying failure modes and causes, in order to mitigate the effects of failure in different sectors of power systems. This paper presents a quantitative approach called Risk-Based-FMEA, based on the failure probabilities and incurred failure costs instead of rating scales. As a case study, this approach has been applied to a direct drive wind turbine. The results show that the definition of failure modes priorities based on their contribution to the total failure cost of the wind turbine is more realistic and practical than the …

Series-Connected Self-Reconfigurable Multicell Battery, Taesic Kim, Wei Qiao, Liyan Qu

Department of Electrical and Computer Engineering: Faculty Publications

This paper proposes a novel series-connected, self-reconfigurable, multi-cell battery design. A new cell switching circuit topology is proposed and implemented by using high efficiency semiconductor devices for dynamic configuration of the multi-cell battery. Each cell in the battery only uses two switches to fully control its operation independently. The proposed design can maximally utilize the battery’s capacity and is tolerant to failures of single or multiple cells. These prolong the operating time and lifespan and enhance the reliability of the battery system. By using the proposed design, additional monitoring, control, protection and optimization functions can be readily added to each …

A Dual-Network Testbed For Wireless Sensor Applications, Jedrzej Kowalczuk, Mehmet C. Vuran, Lance C. Pérez

Department of Electrical and Computer Engineering: Faculty Publications

A dual-network Cyber-physical Networking (CPN) testbed developed at the University of Nebraska-Lincoln is described. The CPN testbed consists of two geographically disparate wireless sensor networks connected by a traditional TCP/IP network and enables peer-to-peer communication between each sensor in the network. The functionality of the testbed is enhanced by a range of software tools that support remote programming and network monitoring, and real-time visualization of sensor data. The resulting architecture supports easy deployment and evaluation of applications for both traditional and interconnected wireless sensor networks. To demonstrate the features of this testbed, a novel ping application was developed and deployed …

Analysis Of The Accuracy-Latency-Energy Tradeoff For Wireless Embedded Camera Networks, Alvaro Pinto, Zhe Zhang, Xin Dong, Senem Velipasalar, Mehmet C. Vuran, M. Cenk Gursoy

Department of Electrical and Computer Engineering: Faculty Publications

Wireless embedded smart cameras provide flexibility in camera deployment in terms of the locations and number of the cameras. However, these battery-powered embedded vision sensors have very limited energy, memory, and processing power. Energy consumption and latency are two major concerns in wireless embedded camera networks. In multi-camera tracking applications, the amount of data exchanged between cameras has an effect on the tracking accuracy, the energy consumption of the camera nodes and the latency. In this paper, we provide a detailed quantitative analysis of the accuracy-latency-energy tradeoff for overlapping and non-overlapping camera setups when different-sized data packets are transferred in …

On The Effective Capacity Of Two-Hop Communication Systems, Deli Qiao, M. Cenk Gursoy, Senem Velipasalar

Department of Electrical and Computer Engineering: Faculty Publications

In this paper, two-hop communication between a source and a destination with the aid of an intermediate relay node is considered. Both the source and intermediate relay node are assumed to operate under statistical quality of service (QoS) constraints imposed as limitations on the buffer overflow probabilities. It is further assumed that the nodes send the information at fixed power levels and have perfect channel side information. In this scenario, the maximum constant arrival rates that can be supported by this two-hop link are characterized by finding the effective capacity. Through this analysis, the impact upon the throughput of having …

Support Vector Machine-Based Short-Term Wind Power Forecasting, Jianwu Zeng, Wei Qiao

Department of Electrical and Computer Engineering: Faculty Publications

This paper proposes a support vector machine (SVM)-based statistical model for wind power forecasting (WPF). Instead of predicting wind power directly, the proposed model first predicts the wind speed, which is then used to predict the wind power by using the power-wind speed characteristics of the wind turbine generators. Simulation studies are carried out to validate the proposed model for very short-term and short term WPF by using the data obtained from the National Renewable Energy Laboratory (NREL). Results show that the proposed model is accurate for very short-term and short-term WPF and outperforms the persistence model as well as …

An Achievable Rate Region For Imperfectly-Known Two-Way Relay Fading Channels, Junwei Zhang, M. Cenk Gursoy

Department of Electrical and Computer Engineering: Faculty Publications

In this paper, achievable rates and resource allocation strategies for imperfectly known two-way relay fading channels are studied. Decode-and-forward (DF) relaying is considered. It is assumed that communication starts with the network training phase in which the users and the relay estimate the fading coefficients, albeit imperfectly. Subsequently, data transmission is performed in multiple-access and broadcast phases. In both phases, achievable rate regions are identified by treating the terms that arise due to channel estimation errors and imperfect interference cancellation as Gaussian distributed noise components. The achievable rate region of the two-way relay channel is given by the intersection of …

Energy-Efficient Foreground Object Detection On Embedded Smart Cameras By Hardware-Level Operations, Mauricio Casares, Paolo Santinelli, Senem Velipasalar, Andrea Prati, Rita Cucchiara

Department of Electrical and Computer Engineering: Faculty Publications

Embedded smart cameras have limited processing power, memory and energy. In this paper, we introduce two methodologies to increase the energy-efficiency and the battery-life of an embedded smart camera by hardware level operations when performing foreground object detection. We use the CITRIC platform as our embedded smart camera. We first perform down-sampling at hardware level on the micro-controller of the image sensor rather than performing software-level down-sampling at the main microprocessor of the camera board. In addition, we crop an image frame at hardware level by using the HREF and VSYNC signals at the micro-controller of the image sensor to …

On The Interplay Between Channel Sensing And Estimation In Cognitive Radio Systems, M. Cenk Gursoy, Sinan Gezici Sinan Gezici

Department of Electrical and Computer Engineering: Faculty Publications

Cognitive radio transmissions in the presence of channel uncertainty are considered. In practical scenarios, cognitive secondary users need to perform both channel sensing in order to identify whether the channel is being occupied by the primary users or not, and also channel estimation in order to learn the channel fading coefficients. Generally, errors occur in both channel sensing and estimation, and this leads to a coupling between the two. More specifically, imperfect sensing affects both the structure and the performance of channel estimation schemes. With this motivation, the interactions between channel sensing and estimation are studied in this paper. In …

An Honors Alumni Mentor Program At Butler University, Jaclyn Dowd, Lisa Markus, Julie Schrader, Anne M. Wilson

Honors in Practice Online Archive

Butler University is a comprehensive master’s university of approximately 4,000 undergraduate students with five colleges: the College of Liberal Arts and Sciences; the College of Education; the College of Business; the Jordan College of Fine Arts; and the College of Pharmacy and Health Sciences. The Butler University Honors Program is an interdisciplinary program open to undergraduates from all five colleges. Incoming students admitted to Butler who meet certain benchmark requirements (1320/30 or higher SAT/ACT or top five percent of graduating class) are invited to apply to our honors program. If students perform well in their first year at the university, …

A Hybrid Battery Model Capable Of Capturing Dynamic Circuit Characteristics And Nonlinear Capacity Effects, Taesic Kim, Wei Qiao

Department of Electrical and Computer Engineering: Faculty Publications

A high-fidelity battery model capable of accurately predicting battery performance is required for proper design and operation of battery-powered systems. However, the existing battery models have at least one of the following drawbacks: 1) requiring intensive computation due to high complexity; 2) not applicable for electrical circuit design and simulation; and 3) not capable of accurately capturing the state of charge (SOC) and predicting run time of the battery due to neglecting the nonlinear capacity effects. This paper proposes a novel hybrid battery model, which takes the advantages of an electrical circuit battery model to accurately predicting the dynamic circuit …

Bearing Fault Detection For Direct-Drive Wind Turbines Via Stator Current Spectrum Analysis, Xiang Gong, Wei Qiao

Department of Electrical and Computer Engineering: Faculty Publications

Bearing faults constitute a significant portion of all faults in wind turbine generators (WTGs). Current-based bearing fault detection has significant advantages over traditional vibration-based methods in terms of cost, implementation, and system reliability. This paper proposes a method based on stator current power spectral density (PSD) analysis for bearing fault detection of direct-drive WTGs. In the proposed method, appropriate interpolation/up-sampling and down-sampling algorithms are designed to convert the variable fundamental frequency of the stator current to a fixed frequency according to the estimated fundamental speed of the WTG. Consequently, the characteristic frequencies of bearing faults can be clearly identified form …

Non-Binary Joint Network-Channel Decoding Of Correlated Sensor Data In Wireless Sensor Networks, Arindra Guha, Eric T. Psota, Lance C. Pérez

Department of Electrical and Computer Engineering: Faculty Publications

The performance of non-binary joint network channel decoding (NB-JNCD) is examined in wireless sensor networks with correlated sensors. The operating assumption is that systems containing multiple sensors in close proximity obtain correlated measurements. It is shown that, when the correlation model between sensors is known at the sink, the addition of a correlation based decoder within the decoding framework greatly improves the error rate performance. Simulation results also indicate that the proposed correlation-based decoder is comparable to source coding across the correlated sensors in terms of error rate, while eliminating the need for costly sensor-to-sensor communication.

Computational Intelligence For Control Of Wind Turbine Generators, Wei Qiao, Jiaqi Liang, Ganesh K. Venayagamoorthy, Ronald Harley

Department of Electrical and Computer Engineering: Faculty Publications

This paper summarizes past and ongoing research in the area of the application of computational intelligence (CI) for control of wind turbine generators (WTGs). Several intelligent design approaches and control strategies, including optimal design of WTG controllers using particle swarm optimization (PSO) and mean-variance optimization (MVO) algorithms and adaptive critic design-based coordinated optimal adaptive control for wind plants and shunt FACTS devices, are presented for dynamic performance and fault ride-through enhancement of WTGs and the associated power grid. The effectiveness of these intelligent design approaches and control strategies are demonstrated by nonreal- and real-time simulations in PSCAD/EMTDC and RSCAD/RTDS, respectively.

A Novel Sol-Gel Route To Pinhole-Free Iron Sulfide Thin Films, S. Kment, H. Kmentova, A. Sarkar, Rodney J. Soukup, Natale J. Ianno, J. Krysa, Z. Hubicka, J. Olejnicek, C. L. Exstrom, S. A. Darveau

Department of Electrical and Computer Engineering: Faculty Publications

The general purpose of the study is to fabricate and improve upon FeS₂ thin films which can be used as the photon absorber layer for a heterojunction or homojunction solar cell. This work deals with the preparation of the pyrite by an unconventional sol-gel approach. Thin pyrite films were prepared by sulfurizing the iron oxide films previously deposited through the sol-gel method using iron (III) chloride as a precursor. The structural, morphological, electronic and optical properties of the deposited films were determined using X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy, Auger electron spectroscopy (AES), UV-Vis absorption spectroscopy, Hall …

Wind/Solar Hybrid Generation-Based Roadway Microgrids, Wei Qiao, Anuj Sharma, Jerry L. Hudgins, Elizabeth G. Jones, Laurence Rilett

Department of Electrical and Computer Engineering: Faculty Publications

This paper presents the concept and design of a novel roadway microgrid. It operates as a smart microgrid that optimally utilizes the public right-of-way and roadway infrastructure to provide cost-effective, highly efficient, and reliable wind/solar electric power production, distribution, storage, and utilization. The fundamental unit of the microgrid is called the energy-plus roadway/traffic signal light (EPRTL), which contains a grid-connected wind/solar hybrid generation system installed on the pole of a roadway/traffic signal light for clean electric power production. The term “energy-plus” stands for annual energy consumption that is less than production. The generated electric power will be consumed locally by …

A Third-Order Sliding-Mode Controller For Dcmc Converters With Constant Power Loads, Yue Zhao, Wei Qiao

Department of Electrical and Computer Engineering: Faculty Publications

Incorporating a medium-voltage DC (MVDC) integrated power system is a goal for future surface combatants and submarines. In a MVDC shipboard power system, DCIDC converters are commonly employed to supply constant power to electric loads. These constant-power loads have a characteristic of negative incremental impedance, which may cause system instability during disturbances if the system is not properly controlled. This paper proposes a third-order sliding-mode controller (SMC) for DCIDC buck converters with constant power loads. The SMC is able to stabilize the DC power systems over the entire operating range in the presence of significant variations in the load power …

Secure Relay Beamforming Over Cognitive Radio Channels, Junwei Zhang, Mustafa Cenk Gursoy

Department of Electrical and Computer Engineering: Faculty Publications

In this paper, a cognitive relay channel is considered, and amplify-and-forward (AF) relay beam forming designs in the presence of an eavesdropper and a primary user are studied. Our objective is to optimize the performance of the cognitive relay beamforming system while limiting the interference in the direction of the primary receiver and keeping the transmitted signal secret from the eavesdropper. We show that under both total and individual power constraints, the problem becomes a quasiconvex optimization problem which can be solved by interior point methods. We also propose two sub-optimal null space beamforming schemes which are obtained in a …

Formation Of Graphene Sheets Through Laser Exfoliation Of Highly Ordered Pyrolytic Graphite, Min Qian, Yun-Shen Zhou, Yang Gao, Jong Bok Park, Tao Feng, Su Mei Huang, Zhuo Sun, Lan Jiang, Yongfeng Lu

Department of Electrical and Computer Engineering: Faculty Publications

Freestanding two-dimensional (2D) few-layer graphene was formed through laser exfoliation of highly ordered pyrolytic graphite, using a pulsed neodymium-doped yttrium aluminum garnet (Nd:YAG) laser. Graphene sheets of several nanometers in thickness and micrometers in size were obtained. The laser exfoliation process was investigated at different laser fluences and distances between target and substrate. Three different phases, amorphous carbon, few-layer graphene sheets, and thin graphite films, were obtained as the laser fluence increased. This study reveals an existing route of forming freestanding 2D nanostructures through laser exfoliation.

Terahertz Optical-Hall Effect Characterization Of Two-Dimensional Electron Gas Properties In Algan/Gan High Electron Mobility Transistor Structures, S. Schöche, Junxia Shi, A. Boosalis, P. Kühne, C. M. Herzinger, John A. Woollam, W. J. Schaff, L. F. Eastman, M. Schubert, Tino Hofmann

Department of Electrical and Computer Engineering: Faculty Publications

The free-charge carrier mobility, sheet density, and effective mass of a two-dimensional electron gas are exemplarily determined in the spectral range from 640 GHz to 1 THz in a AlGaN/GaN heterostructure using the optical-Hall effect at room temperature. Complementary midinfrared spectroscopic ellipsometry measurements are performed for analysis of heterostructure constituents layer thickness, phonon mode, and free-charge carrier parameters. The electron effective mass is determined to be (0.22 ± 0.04)m₀. The high-frequency sheet density and carrier mobility parameters are in good agreement with results from dc electrical Hall effect measurements, indicative for frequency-independent carrier scattering mechanisms of the …