Digital Commons Network^™

Self-Encoded Spread Spectrum For Multirate Multimedia Communication In Multipath Channel, Liang Chi, Won Mee Jang, Lim Nguyen

Department of Electrical and Computer Engineering: Faculty Publications (to 2015)

In this paper, we propose the self-encoded spread spectrum (SESS) with multirate multimedia communication in multipath channel. In multirate multimedia SESS system, each application has their own transmission bit rate. The signal is transmitted through multipath channels each with different channel gain and time delay. We view the main path as the signal resource and other paths as interference. At the receiver side, decorrelation scheme is employed for the main path combined signal not only to reduce the crosstalk between different applications, but also to provide a better estimation for the despreading sequence in the main path. Interference cancellation(IC) in …

Low-Complexity Image Coder/Decoder With An Approaching-Entropy Quad-Tree Search Code For Embedded Computing Platforms, Tao Ma, Pradhumna Shrestha, Michael Hempel, Dongming Peng, Hamid Sharif

Department of Electrical and Computer Engineering: Faculty Publications (to 2015)

In this paper, we propose a fast, simple and efficient image codec applicable for embedded processing systems. Among the existing image coding methods, wavelet quad-tree is a foundation leading to an efficient structure to encode images. By searching significant coefficients along quad-trees, an embedded efficient code can be obtained. In this work, we exploit hierarchical relations of the quad-tree structure in terms of searching entropy and present a quad-tree searching model that is very close to the searching entropy. By applying this model, our codec surpasses SPIHT [1] by 0.2-0.4 db over wide code rates, and its performance is comparable …

Impact Of Interference On Secrecy Capacity In A Cognitive Radio Network, Zhihui Shu, Yaoqing Lamar Yang, Yi Qian, Rose Qingyang Hu

Department of Electrical and Computer Engineering: Faculty Publications (to 2015)

In this paper, we investigate secrecy capacity of a cognitive radio network based on stochastic geometry distributions. We consider the Poisson process of both the secondary users and the eavesdroppers, and analyze how the stochastic interference from the secondary users can influence the secrecy capacity of the primary users. First, we describe a network model with primary users, secondary users and eavesdroppers in a cognitive radio communication network environment, and derive the expression of secrecy capacity in an additive white Gaussian noise channel. Then, we study the outage probability of secrecy capacity of a primary node from a secure communication …

A Secure Data Aggregation And Dispatch Scheme For Home Area Networks In Smart Grid, Yun Ye, Yi Qian, Hamid Sharif

Department of Electrical and Computer Engineering: Faculty Publications (to 2015)

Cyber security for smart grid communication systems is one of the most critical requirements need to be assured before smart grid can be operationally ready for the market. Privacy is one of a very important security services. The customer information privacy in smart grid need to be protected. Smart grid data privacy encompasses confidentiality and anonymity of the information extracted from smart devices and metering transmission in a smart grid communication system. In this paper, we consider a home area network as a basic reading data aggregation and dispatch unit in smart grid systems, and we propose a secure in-network …

A Secure And Reliable In-Network Collaborative Communication Scheme For Advanced Metering Infrastructure In Smart Grid, Yun Ye, Yi Qian, Hamid Sharif

Department of Electrical and Computer Engineering: Faculty Publications (to 2015)

We consider various security vulnerabilities of deploying Advanced Metering Infrastructure (AMI) in smart grid, and explore the issues related to confidentiality for customer privacy and customer behavior as well as message authentication for meter reading and control messages. There are only a very few research work on AMI authentications, and no work exists on confidentiality for user privacy and user behavior, from the best of our knowledge. In this paper, we propose an in-network collaborative scheme to provide secure and reliable AMI communications in smart grid, with smart meters interconnected through a multihop wireless network. In this approach, an AMI …

A Cross-Layer Parallel Handover Optimization Scheme For Wimax Networks, Ting Zhou, Hamid Sharif, Michael Hempel, Puttipong Mahasukhon, Tao Ma, Pradhumna Shrestha

Department of Electrical and Computer Engineering: Faculty Publications (to 2015)

The handover performance plays a crucial role in guaranteeing the quality of real-time applications in WiMAX networks. In general, a handover process can be divided into four stages: i) cell reselection, ii) handover preparation, iii) link layer handover, and iv) IP layer handover. A cross-layer parallel handover optimization (CPHO) scheme is proposed in this paper to reduce the handover signaling overhead and latency in each stage. The key idea of our proposed scheme is that uses the knowledge achieved from the backhaul inter-BS communications to reduce the HO control message load in wireless links and overlaps the executions of the …

Power Controlled Coded-Sequence Self-Encoded Spread Spectrum Communications, Poomathi Duraisamy, Liang Chi, Won Mee Jang, Lim Nguyen

Department of Electrical and Computer Engineering: Faculty Publications (to 2015)

In this paper, we propose to apply power control to coded-sequence self-encoded spread spectrum (CS-SESS) communications in dynamic fading channels. We determine the statistical characteristics of the power enhancement in the transmitter due to power control and show that the proposed approach improves the power efficiency in mobile cellular systems.

In addition, we propose to mitigate self interference in CSSESS by exploiting the information that the transmitter obtains, through feedback training sequences, about the de-spreading code in the receiver. The results show that the mitigation is significant even with only selective training chips from the de-spreading sequence. Similar improvement can …

Mobile Wimax Throughput And Delay Measurements In Railroad Environment, Puttipong Mahasukhon, Hamid Sharif, Michael Hempel, Tao Ma, Pradhumna Shrestha

Department of Electrical and Computer Engineering: Faculty Publications (to 2015)

The railroad industry in North America is heavily involved in improving the broadband wireless connectivity of their railroad operations. We propose our approach of establishing a Mobile WiMAX test bed as a part of our collaborations with the Federal Railroad Administration (FRA) for investigating the performance of current and upcoming broadband wireless technologies in a railroad environment. The focus is on studying the impact of mobility on the wireless system throughput for moving trains at high velocities. Our goal is to provide a comprehensive measurement that will assist others in understanding Mobile WiMAX performance and guiding future network deployment. In …

Message From The Chair Of Technical Program Committee, Tadeusz Wysocki

Department of Electrical and Computer Engineering: Faculty Publications (to 2015)

On behalf of all the members of the Organizing Committee, I would like to welcome you to the 5th International Conference on Signal Processing and Telecommunication Systems, ICSPCS’2011. The ICSPCS conferences evolved from the series of successful symposia and workshops, i.e. International Symposia on DSP and Communication Systems (DSPCS), and Workshops on the Internet, Telecommunications and Signal Processing (WITSP). As in the past, the Organizing Committee has succeeded this year in achieving an official technical co-sponsorship of the IEEE Communications Society for conference. As a result the ICSPCS’2011 conference has been listed in the IEEE database of the conferences and …

Battery-Aware Multimedia Coding Optimization By Dynamic Frequency Scaling, Jianxin Sun, Xueyi Wang, Song Ci

Department of Electrical and Computer Engineering: Faculty Publications (to 2015)

Nowadays, multimedia application and video streaming have gained a great popularity because of the boasting development on mobile hardware, and battery driven devices have emerged with a tremendous speed. Due to the important issue of battery efficiency on mobile devices, many optimization algorithms have being proposed toward various of battery powered platforms and scenarios. Most of the provided solutions choose to aim at the minimization of energy usage under a given task scheduling by adjusting parameters reside in the processes of different schemes. However, the battery discharging characteristics and its instant output pattern are still ignored if the optimization is …

Impact Of Signal Timing Information On Safety And Efficiency Of Signalized Intersections, Anuj Sharma

Department of Civil and Environmental Engineering: Faculty Publications

Signalized intersections are provided in traffic networks to improve the safety and efficiency of vehicular and pedestrian movement. There are various measures under education, enforcement and engineering headings that are being attempted to improve safety and efficiency of operations at a signalized intersection. Provision of signal countdown timer, a timer showing the remaining red and green time in a phase, is one such measure and is commonly adopted in India. However, studies on effects of countdown timer under Indian traffic conditions are very scarce. Traffic heterogeneity and lack of lane discipline makes transferability of models developed in other countries (with …

Role Of Information On Probability Of Traffic Conflict On The Onset Of Yellow, Nathaniel P. Burnett, Anuj Sharma

Department of Civil and Environmental Engineering: Faculty Publications

This paper examines the effect of information provided to drivers through advance warning flashers (AWFs) on driver’s probability of conflict at the onset of yellow at a high-speed intersection. AWFs are specifically designed to minimize the number of vehicles trapped in their respective dilemma zones at the onset of yellow. A probit modeling technique was used to establish dilemma zone boundaries. Based on the dilemma zone boundaries probability of a perceived conflict curves was computed and compared against actual conflicts observed at each of the studied intersections. The comparison between the actual and theoretical probability of conflict curves generated a …

Role Of Information On Probability Of Traffic Conflict On The Onset Of Yellow, Nathaniel P. Burnett, Anuj Sharma

Department of Civil and Environmental Engineering: Faculty Publications

This paper examines the effect of information provided to drivers through advance warning flashers (AWFs) on driver’s probability of conflict at the onset of yellow at a high-speed intersection. AWFs are specifically designed to minimize the number of vehicles trapped in their respective dilemma zones at the onset of yellow. A probit modeling technique was used to establish dilemma zone boundaries. Based on the dilemma zone boundaries probability of a perceived conflict curves was computed and compared against actual conflicts observed at each of the studied intersections. The comparison between the actual and theoretical probability of conflict curves generated a …

Analysis Of Turbulent Hydraulic Jump Over A Transitional Rough Bed Of A Rectangular Channel: Universal Relations, Noor Afzal, A. Bushra, Abu Seena

Department of Civil and Environmental Engineering: Faculty Publications

The streamwise flow structure of a turbulent hydraulic jump over a rough bed rectangular channel has been investigated. The flow is divided into inner and outer layers, where upstream supercritical flow changes to downstream subcritical flow. The analysis is based on depth averaged Reynolds momentum equations. The molecular viscosity on the rough bed imposes the no slip boundary condition, but close to the wall the turbulent process in inner layer provides certain matching conditions with the outer layer, where molecular viscosity has no dominant role. It is shown that the bed roughness in the inner layer has a passive role …

Effects Of Solution Chemistry And Aging Time On Prion Protein Adsorption And Replication Of Soil-Bound Prions, Samuel E. Saunders, Qi Yuan, Jason C. Bartz, Shannon L. Bartelt-Hunt

Department of Civil and Environmental Engineering: Faculty Publications

Prion interactions with soil may play an important role in the transmission of chronic wasting disease (CWD) and scrapie. Prions are known to bind to a wide range of soil surfaces, but the effects of adsorption solution chemistry and long-term soil binding on prion fate and transmission risk are unknown. We investigated HY TME prion protein (PrP^Sc) adsorption to soil minerals in aqueous solutions of phosphate buffered saline (PBS), sodium chloride, calcium chloride, and deionized water using western blotting. The replication efficiency of bound prions following adsorption in these solutions was also evaluated by protein misfolding cyclic amplification …

Analysis Of Existing Work-Zone Sign Supports Using Manual For Assessing Safety Hardware Safety Performance Criteria, Jennifer D. Schmidt, Ronald K. Faller, Karla A. Lechtenberg, Dean L. Sicking

Department of Civil and Environmental Engineering: Faculty Publications

Over the years, numerous work-zone, portable sign support systems have been successfully crash tested according to the Test Level 3 safety performance guidelines provided in the National Cooperative Highway Research Program Report 350 and accepted for use along our nation’s highways. For this study, several crashworthy sign support systems were analyzed to predict their safety performance according to the new evaluation criteria provided in the Manual for Assessing Safety Hardware (MASH). More specifically, this analysis was conducted to determine which hardware parameters negatively affect a system’s safety performance. To verify the accuracy of the analysis, eight systems, four with the …

Topology Analysis Of Wireless Sensor Networks For Sandstorm Monitoring, P. Wang, Z. Sun, Mehmet C. Vuran, M. A. Al-Rodhaan, A. M. Al-Dhelaan, I. F. Akyildiz

School of Computing: Conference and Workshop Papers

Sandstorms are serious natural disasters, which are commonly seen in the Middle East, Northern Africa, and Northern China.In these regions, sandstorms have caused massive damages to the natural environment, national economy, and human health. To avoid such damages, it is necessary to effectively monitor the origin and development of sandstorms. To this end, wireless sensor networks (WSNs) can be deployed in the regions where sandstorms generally originate so that sensor nodes can collaboratively perform sandstorm monitoring and rapidly convey the observations to remote administration center. Despite the potential advantages, the deployment of WSNs in the vicinity of sandstorms faces many …

Diagnosis Of Multiple Scan-Chain Faults In The Presence Of System Logic Defects, Zhen Chen, Sharad C. Seth, Dong Xiang, Bhargab B. Bhattacharya

School of Computing: Conference and Workshop Papers

We present a combined hardware-software based approach to scan-chain diagnosis, when the outcome of a test may be affected by system faults occurring in the logic outside of the scan chain. For the hardware component we adopt the double-tree scan (DTS) chain architecture, which has previously been shown to be effective in reducing power, volume, and application time of tests for stuck-at and delay faults. We develop a version of flush test which can resolve a multiple fault in a DTS chain to a small number of suspect candidates. Further resolution to a unique multiple fault is enabled by the …

Nutrient Management Record Keeping Calendar, July 2011-December 2012, Leslie J. Johnson, Charles Shapiro, Charles Wortmann, Chris G. Henry, Larry Howard, Tamilee D. Nennich

Nebraska Cooperative Extension: Faculty and Staff Publications

Records for Nebraska Concentrated Animal Feeding Operations

Record the initials of the person performing the inspection each time. Check marks will not satisfy the record-keeping requirements.

Record any maintenance and/or repairs.

Correct all deficiencies within 30 days.

Multipacting Analysis Of The Superconducting Parallel-Bar Cavity, Subashini De Silva, Jean R. Delayen

Physics Faculty Publications

The superconducting parallel-bar cavity [1] is a deflecting/crabbing cavity with attractive properties, compared to other conventional designs, that is being considered for a number of applications. Multipacting can be a limiting factor to the performance of in any superconducting structure. In the parallel-bar cavity the main contribution to the deflection is due to the transverse deflecting voltage, between the parallel bars, making the design potentially prone to multipacting. This paper presents the results of analytical calculations and numerical simulations of multipacting in the parallel-bar cavity with resonant voltage, impact energies and corresponding particle trajectories.

Interactions Of Transgenic Bacillus Thuringiensis Insecticidal Crops With Spiders (Araneae), Julie A. Peterson, Jonathan Lundgren, James D. Harwood

Department of Entomology: Faculty Publications

Genetically modified crops expressing insecticidal proteins from Bacillus thuringiensis (Bt) have dramatically increased in acreage since their introduction in the mid-1990’s. Although the insecticidal mechanisms of Bt target specific pests, concerns persist regarding direct and indirect effects on non-target organisms. In the field, spiders may be exposed to Bt toxins via multiple routes, including phytophagy and pollenivory, consumption of Bt-containing prey, and soil exudates in the detrital food web. Beyond direct toxicity, Bt crops may also have indirect impacts, including pleiotropic and preymediated effects. Here, we comprehensively review the literature and use meta-analyses to reveal that foliar spider abundance is …

Suppression Of Away-Side Jet Fragments With Respect To The Reaction Plane In Au + Au Collisions At √Snn=200 Gev, Andrew Marshall Adare, Gyöngyi Baksay, László A. Baksay, Szabolcs Rembeczki, Marcus Hohlmann

Aerospace, Physics, and Space Science Faculty Publications

Pair correlations between large transverse momentum neutral pion triggers (pT=4 - 7 GeV/c) and charged hadron partners (pT=3 - 7 GeV/c) in central (0%-20%) and midcentral (20%-60%) Au+Au collisions at √sNN=200 GeV are presented as a function of trigger orientation with respect to the reaction plane. The particles are at larger momentum than where jet shape modifications have been observed, and the correlations are sensitive to the energy loss of partons traveling through hot dense matter. An out-of-plane trigger particle produces only 26±20% of the away-side pairs that are observed opposite of an in-plane trigger particle for midcentral (20%-60%) collisions. …

Suppression Of Away-Side Jet Fragments With Respect To The Reaction Plane In Au + Au Collisions At √Snn=200 Gev, Andrew Marshall Adare, Gyöngyi Baksay, László A. Baksay, Szabolcs Rembeczki, Marcus Hohlmann, Phenix Collaboration

Aerospace, Physics, and Space Science Faculty Publications

Pair correlations between large transverse momentum neutral pion triggers (pT=4 - 7 GeV/c) and charged hadron partners (pT=3 - 7 GeV/c) in central (0%-20%) and midcentral (20%-60%) Au+Au collisions at √sNN=200 GeV are presented as a function of trigger orientation with respect to the reaction plane. The particles are at larger momentum than where jet shape modifications have been observed, and the correlations are sensitive to the energy loss of partons traveling through hot dense matter. An out-of-plane trigger particle produces only 26±20% of the away-side pairs that are observed opposite of an in-plane trigger particle for midcentral (20%-60%) collisions. …

Melting Kinetics In Microgravity, Martin E. Glicksman

Aerospace, Physics, and Space Science Faculty Publications

We analyzed the large data archive obtained from microgravity experiments called the Isothermal Dendritic Growth Experiment (IDGE). The final orbital mission of the IDGE allowed streaming of real-time video of crystal growth and melting in low-Earth orbit of high-purity pivalic acid anhydride (PVA). Melting kinetics was observed in detail for the first time under microgravity conditions. Normally, terrestrial gravity precludes observation and analysis of conduction-limited melting by stimulating buoyancy flows and inducing collapse of the solid-liquid structure. The initial dendritic mushy zone melts under steady heating into isolated crystallite clusters that remain stationary within the melt, and eventually shrink toward …

The Lightning-Tgf Relationship On Microsecond Ttimescales, Steven A. Cummer, Gaopeng Lu, Michael S. Briggs, Valerie Connaughton, Shaolin Xiong, Gerald Jerry Fishman, Joseph R. Dwyer

Aerospace, Physics, and Space Science Faculty Publications

We analyze the count rates of two terrestrial gamma-ray flashes (TGFs) detected by the Fermi Gamma-ray Burst Monitor (GBM) with the broadband magnetic fields (1 to 300 kHz) produced by the simultaneous lightning processes. The microsecond-scale absolute time accuracy for these data, combined with independent geolocations of the source lightning, enable this analysis with higher accuracy than previously possible. In both events, fast discharge-like processes occur within several tens of microseconds of the gamma-ray generation, although not with a consistent relationship. The magnetic field data also show a slower signal component produced by a source current that in both events …

The Rarity Of Terrestrial Gamma-Ray Flashes, D. M. Smith, Michael E. Splitt, Steven M. Lazarus, W. Ulrich, Jospeh R. Dwyer

Aerospace, Physics, and Space Science Faculty Publications

We report on the first search for Terrestrial Gamma-ray Flashes (TGFs) from altitudes where they are thought to be produced. The Airborne Detector for Energetic Lightning Emissions (ADELE), an array of gamma-ray detectors, was flown near the tops of Florida thunderstorms in August/September 2009. The plane passed within 10 km horizontal distance of 1213 lightning discharges and only once detected a TGF. If these discharges had produced TGFs of the same intensity as those seen from space, every one should have been seen by ADELE. Separate and significant nondetections are established for intracloud lightning, negative cloud-to-ground lightning, and narrow bipolar …

Robust Decentralized Formation Flight Control, Weihua Zhao, Tiauw Hiong Go

Aerospace, Physics, and Space Science Faculty Publications

Motivated by the idea of multiplexed model predictive control (MMPC), this paper introduces a new framework for unmanned aerial vehicles (UAVs) formation flight and coordination. Formulated using MMPC approach, the whole centralized formation flight system is considered as a linear periodic system with control inputs of each UAV subsystem as its periodic inputs. Divided into decentralized subsystems, the whole formation flight system is guaranteed stable if proper terminal cost and terminal constraints are added to each decentralized MPC formulation of the UAV subsystem. The decentralized robust MPC formulation for each UAV subsystem with bounded input disturbances and model uncertainties is …

High-Speed X-Ray Images Of Triggered Lightning Dart Leaders, Joseph R. Dwyer, M. M. Schaal, Hamid K. Rassoul, Martin A. Uman, Douglas M. Jordan, Dustin Hill

Aerospace, Physics, and Space Science Faculty Publications

We present the first high-time resolution two-dimensional images of X-ray emissions from lightning. The images were recorded at a rate of 10 million per second using a new pinhole-type camera, located 44 m from rocket-and-wire- triggered lightning. We report observations of two dart leaders, one in each of two lightning flashes triggered during the summer of 2010 in north-central Florida. In both events, as the dart leader approached the ground, the X-ray source was also seen to descend along the previous lightning channel. For the second event, the X-ray source exhibited a downward speed of 4.5 × 10 7 m/s, …

Thinking About Technology – Standard Bar Codes Beware- Smart Phone Users May Prefer Qr Codes, Darla Jackson

Faculty Articles

Quick Response (QR) codes are free to produce, allow access to data, and can be read with most smartphones. QR codes are already popular in some other countries and are gaining popularity in the United States. This article discusses this growing popularity and the reasons for it, how QR codes are being used in law libraries and the legal profession, and how they may be used by librarians in the future to add value through the marketing of professional and library services and by providing easy access to information from library resources.

Western Australia's Biosecurity, Department Of Agriculture And Food, Western Australia, Department Of Environment And Conservation, Western Australia, Department Of Fisheries, Western Australia, Forest Products Commission, Western Australia

Biosecurity published reports

Biosecurity is the protection of the economy, environment and human health from the negative impacts of pests, weeds and diseases, including the management of invasive species if they become established (definition adopted by AusBIOSEC).

This requires steps to prevent the entry of harmful organisms, as well as the timely and efficient management of them if they do enter.

Biosecurity threats range from catastrophic diseases such as Foot and Mouth Disease, which causes rapid and widespread animal deaths, to more subtle and slower spreading problems such as invasive weeds, mussels that foul vessel hulls and fungus-induced dieback disease of trees. These …