Computer Engineering Commons^™

Video Surveillance Over Wireless Sensor And Actuator Networks Using Active Cameras, Dalei Wu, Song Ci, Haiyan Luo, Yun Ye, Haohong Wang

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

Although there has been much work focused on the camera control issue on keeping tracking a target of interest, few has been done on jointly considering the video coding, video transmission, and camera control for effective and efficient video surveillance over wireless sensor and actuator networks (WSAN). In this work, we propose a framework for real-time video surveillance with pan-tilt cameras where the video coding and transmission as well as the automated camera control are jointly optimized by taking into account the surveillance video quality requirement and the resource constraint of WSANs. The main contributions of this work are: i) …

Transparent Interconnections Formed By Rapid Single-Step Fabrication Of Graphene Patterns, J. B. Park, W. Xiong, Z. Q. Xie, Y. Gao, M. Qian, M. Mitchell, M. Mahjouri-Samani, Y. S. Zhou, L. Jiang, Yongfeng Lu

Department of Electrical and Computer Engineering: Faculty Publications

We developed a process to form transparent interconnections using graphene patterns that were synthesized by laser chemical vapor deposition. The number of graphene layers was tightly controlled by laser scan speed. Graphene patterns were fabricated at a high scan speed of up to 200 µm/s with a single-step process. The process time is about a million times faster than the conventional chemical vapor deposition method. The fabricated graphene patterns on nickel foils were directly transferred to desired positions on patterned electrodes. The position-controlled transfer with rapid single-step fabrication of graphene patterns provides an innovative pathway for graphene-based interconnections.

Fast Growth Of Graphene Patterns By Laser Direct Writing, J. B. Park, W. Xiong, Y. Gao, M. Qian, Z. Q. Xie, M. Mitchell, Y. S. Zhou, G. H. Han, L. Jiang, Yongfeng Lu

Department of Electrical and Computer Engineering: Faculty Publications

Rapid single-step fabrication of graphene patterns was developed using laser-induced chemical vapor deposition (LCVD). A laser beam irradiates a thin nickel foil in a CH₄ and H₂ environment to induce a local temperature rise, thereby allowing the direct writing of graphene patterns in precisely controlled positions at room temperature. Line patterns can be achieved with a single scan without pre- or post-processes. Surprisingly, the growth rate is several thousand times faster than that of general CVD methods. The discovery and development of the LCVD growth process provide a route for the rapid fabrication of graphene patterns for various …

Small Molecule Inhibitors Of Staphylococcus Aureus Rnpa Alter Cellular Mrna Turnover, Exhibit Antimicrobial Activity, And Attenuate Pathogenesis, Patrick D. Olson, Lisa J. Kuechenmeister, Kelsi L. Anderson, Sonja Daily, Karen E. Beenken, Christelle M. Roux, Michelle L. Reniere, Tami L. Lewis, William J, Weiss, Mark Pulse, Phung Nguyen, Jerry W. Simecka, John M. Morrison, Khalid Sayood, Oluwatoyin A. Asojo, Mark S. Smeltzer, Eric P. Skaar, Paul M. Dunman

Department of Electrical and Computer Engineering: Faculty Publications

Methicillin-resistant Staphylococcus aureus is estimated to cause more U.S. deaths annually than HIV/AIDS. The emergence of hypervirulent and multidrug-resistant strains has further amplified public health concern and accentuated the need for new classes of antibiotics. RNA degradation is a required cellular process that could be exploited for novel antimicrobial drug development. However, such discovery efforts have been hindered because components of the Gram-positive RNA turnover machinery are incompletely defined. In the current study we found that the essential S. aureus protein, RnpA, catalyzes rRNA and mRNA digestion in vitro. Exploiting this activity, high through-put and secondary screening assays identified …

A Novel Adaptive Distributed Cooperative Relaying Mac Protocol For Vehicular Networks, Ting Zhou, Hamid Sharif, Michael Hempel, Puttipong Mahasukhon, Wei Wang, Tao Ma

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

Explosive growth in Information Technology has enabled many innovative application areas such as large-scale outdoor vehicular networks for vehicle-to-vehicle communications. By providing time-sensitive and location-aware information, vehicular networks can contribute to a safer and more efficient driving experience. However, the performance of vehicular networks requires robust and real-time data communications and is impacted by high mobility, intermittent connectivity, and unreliability of the wireless channel. In this paper, a novel adaptive distributed cooperative medium access control (ADCMAC) protocol is proposed in order to address the inherent problems in the IEEE 802.11 standard when employed in vehicular networks. ADC-MAC exploits spatial diversities …

Quantitative Analysis Of Propagation Characteristics For Mobile Wimax, Pradhumna Shrestha, Puttipong Mahasukhon, Michael Hempel, Tao Ma, Hamid Sharif

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

In wireless networks, careful planning and link budget analysis is required for delivering maximum throughput reliably with minimum overhead. The efficiency of planning and eventual network performance is totally dependent upon the accuracy and quality of data used for analysis. In most studies, computer simulations and analytical models are used for generating such data. However these simulations are limited to many assumptions which are different from the actual implemented hardware, therefore, the data generated are not accurate. In this paper, we analyze the performance of Mobile WiMAX utilizing the empirical data measured from leading WiMAX equipment. We believe this data …

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 …

A Study On Energy Efficient Multi-Tier Multi-Hop Wireless Sensor Networks For Freight-Train Monitoring, Puttipong Mahasukhon, Hamid Sharif, Michael Hempel, Ting Zhou, Tao Ma, Pradhumna Shrestha

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

The North American freight railroad industry is trying to leverage wireless sensor networks (WSN) onboard railcars for advanced monitoring and alerting. In railroad environments, freight train WSNs exhibit a linear chain-like topology of significant length. Thus, existing wireless technologies such as the IEEE 802.15.4 communication protocol, based on a star topology, are unable to provide reliable service. The end-to-end communication between nodes generally relies on individual nodes communicating with their respective neighbors to carry the information over multiple hops and deliver it to the preferred destination. The routing performance and reliability significantly degrades with increasing number of hops. We proposed …

A High-Quality Mach-Zehnder Interferometer Fiber Sensor By Femtosecond Laser One-Step Processing, Longjiang Zhao, Lan Jiang, Sumei Wang, Hai Xiao, Yongfeng Lu, Hai-Lung Tsai

Department of Electrical and Computer Engineering: Faculty Publications

During new fiber sensor development experiments, an easy-to-fabricate simple sensing structure with a trench and partially ablated fiber core is fabricated by using an 800 nm 35 fs 1 kHz laser. It is demonstrated that the structure forms a Mach-Zehnder interferometer (MZI) with the interference between the laser light passing through the air in the trench cavity and that in the remained fiber core. The fringe visibilities are all more than 25 dB. The transmission spectra vary with the femtosecond (fs) laser ablation scanning cycle. The free spectral range (FSR) decreases as the trench length increases. The MZI structure is …

Dynamic Video Object Detection With Single Ptu Camera, Yun Ye, Song Ci, Yanwei Liu, Hui Tang

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

This paper presents a video object detection method under dynamic background with single PTU (pantilt unit) camera. The overall procedure contains two steps. First the moving object is tracked through interactive Mean Shift estimation and PTU control. Camera angular speed is updated online according to the estimated object position, whereby the object can remain in the center area of the image plane. In the second step, the foreground is detected through background subtraction and shape contour. An adaptive correlation thresholding method is applied to mitigate the detection distortion in boundary areas. Variational level set contour is then applied to further …

Priority Preemption For Real-Time Application Qos Guarantees In Cooperative Vehicular Networks, Ting Zhou, Hamid Sharif, Michael Hempel, Puttipong Mahasukhon, Tao Ma, Pradhumna Shrestha

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

Inter-vehicle and roadside-to-vehicle communications can contribute to a safer and more efficient driving experience by providing time-sensitive and location-aware information. However, its performance suffers from vehicle mobility, intermittent user connectivity, and wireless channel unreliability. In this paper, we propose a novel cross-layer optimization approach based on our Adaptive Distributed Cooperative Medium Access Control (ADC-MAC) protocol to guarantee the quality-of-service (QoS) of real-time applications. Markov chain based theoretical analysis show that our proposed priority preemption approach can improve the quality of a real-time application by guaranteeing its bandwidth and reducing its transmission latency.

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 …

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 …

Reprogrammed Transcriptome In Rhesus-Bovine Interspecies Somatic Cell Nuclear Transfer Embryos, Kai Wang, Hasan H. Otu, Ying Chen, Young Lee, Keith Latham, Jose B. Cibelli

Department of Electrical and Computer Engineering: Faculty Publications

Background: Global activation of the embryonic genome (EGA), one of the most critical steps in early mammalian embryo development, is recognized as the time when interspecies somatic cell nuclear transfer (iSCNT) embryos fail to thrive.

Methodology/Principal Findings: In this study, we analyzed the EGA-related transcriptome of rhesus-bovine iSCNT 8- to 16- cell embryos and dissected the reprogramming process in terms of embryonic gene activation, somatic gene silencing, and maternal RNA degradation. Compared with fibroblast donor cells, two thousand and seven genes were activated in iSCNT embryos, one quarter of them reaching expression levels comparable to those found in in vitro …

Power Controlled Multirate Multimedia Transmission In Self-Encoded Spread Spectrum Over Dynamic Fading Channels, Liang Chi, Poomathi Duraisamy, 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 self-encoded spread spectrum (SESS) in multirate and multimedia applications. The transmitter employs power control to to combat dynamic channel fading and the receiver employs decorrelation to reduce interference from multiple applications. We show that iterative detection can significantly improve the system performance. The proposed approach also improves the power efficiency which is essential in battery-driven communications such as mobile cellular systems.

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 …

A Novel Channel Probing/Scanning Scheme For Secure Fast Handoff In Ieee 802.11-Based Wireless Networks, Ye Yan, Yi Qian, Rose Qingyang Hu

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

With the proliferation of wireless networks for practical deployments in recent years, secure fast handoff has become significantly important to provide secured access while reduce the latency caused by handoff procedure. Channel probing/scanning delay has been a major contribution to the overall latency of handoff in IEEE 802.11 based wireless networks. In this paper, we present a novel secure fast handoff scheme that adopts network-assisted radio statement (NACS) to eliminate lengthy probing/scanning delay by taking advantage of the knowledge of network topology of neighboring nodes in the network. We apply an opportunistic mechanism to retrieve the channel condition from neighboring …

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 …

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 Channel Estimation Errors On Effectiveness Of Eigenvector-Based Jamming For Physical Layer Security In Wireless Networks, James M. Taylor, Michael Hempel, Hamid Sharif, Shichuan Ma, Yaoqing Lamar Yang

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

In this paper, we present our study of an Eigenvector-based artificial noise-based jamming technique developed to provide increased wireless physical layer security in transmit-receive diversity systems and analyze the impact of channel estimation errors on system performance. Our simulation results showed that with knowledge of perfect channel state information, the technique provided secrecy capacity of approximately 7 bits/s/Hz for a normalized transmit power of 25 dB for a variety of transmit, receive, and eavesdropper configurations. We also describe a novel method to simulate generalized channel state information estimation errors. While other publications neglect the impact of these estimation errors, our …

Prof. Dr. Marek E. Bialkowski (1951 – 2011), Tadeusz Wysocki, Salman Durrani, Rodney A. Kennedy

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

It is our sad duty to report the untimely death of Prof. Dr. Marek E. Bialkowski, who passed away on Thursday, October 27, 2011 after a short unexpected illness caused by pneumonia. He was a remarkable researcher and a mentor and friend to many us and he will be greatly missed.

Marek was born in Sochaczew, Poland, in 1951. He received the M.Eng.Sc. degree in applied mathematics and the Ph.D. degree in electrical engineering, both from the Warsaw University of Technology, Warsaw, Poland, in 1974 and 1979, respectively. He received the Doctor of Engineering (higher doctorate) degree in computer science …

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 …

Priority Preemption For Real-Time Application Qos Guarantees In Cooperative Vehicular Networks, Ting Zhou, Hamid Sharif, Michael Hempel, Puttipong Mahasukhon, Tao Ma, Pradhumna Shrestha

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

Inter-vehicle and roadside-to-vehicle communications can contribute to a safer and more efficient driving experience by providing time-sensitive and location-aware information. However, its performance suffers from vehicle mobility, intermittent user connectivity, and wireless channel unreliability. In this paper, we propose a novel cross-layer optimization approach based on our Adaptive Distributed Cooperative Medium Access Control (ADC-MAC) protocol to guarantee the quality-of-service (QoS) of real-time applications. Markov chain based theoretical analysis show that our proposed priority preemption approach can improve the quality of a real-time application by guaranteeing its bandwidth and reducing its transmission latency.

Testing Embedded System Applications, Tingting Yu

School of Computing: Dissertations, Theses, and Student Research

Embedded systems are becoming increasingly ubiquitous, controlling a wide variety of popular and safety-critical devices. Testing is the most commonly used method for validating software systems, and effective testing techniques could be helpful for improving the dependability of these systems. However, there are challenges involved in developing such techniques. Embedded systems consist of layers of software – application layers utilize services provided by underlying system service and hardware support layers. A typical embedded application consists of multiple user tasks. Interactions between application layers and lower layers, and interactions between the various user tasks that are initiated by the application layer, …