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Articles 18691 - 18720 of 22017
Full-Text Articles in Entire DC Network
Commemoration Practices Of The Roman Soldier, Brandon R. Olson
Commemoration Practices Of The Roman Soldier, Brandon R. Olson
Theses and Dissertations
No abstract provided.
All Saints Day, J. Ellsworth Kalas
Route Aware Predictive Congestion Control Protocol For Wireless Sensor Networks, Carl Larsen, Maciej Jan Zawodniok, Jagannathan Sarangapani
Route Aware Predictive Congestion Control Protocol For Wireless Sensor Networks, Carl Larsen, Maciej Jan Zawodniok, Jagannathan Sarangapani
Electrical and Computer Engineering Faculty Research & Creative Works
Congestion in wireless sensor networks (WSN) may lead to packet losses or delayed delivery of important information rendering the WSN-based monitoring or control system useless. In this paper a routing-aware predictive congestion control (RPCC) yet decentralized scheme for WSN is presented that uses a combination of a hop by hop congestion control mechanism to maintain desired level of buffer occupancy, and a dynamic routing scheme that works in concert with the congestion control mechanism to forward the packets through less congested nodes. The proposed adaptive approach restricts the incoming traffic thus preventing buffer overflow while maintaining the rate through an …
Control Of Nonholonomic Mobile Robot Formations: Backstepping Kinematics Into Dynamics, Jagannathan Sarangapani, Travis Alan Dierks
Control Of Nonholonomic Mobile Robot Formations: Backstepping Kinematics Into Dynamics, Jagannathan Sarangapani, Travis Alan Dierks
Electrical and Computer Engineering Faculty Research & Creative Works
In this paper, we seek to expand framework developed to control a single nonholonomic mobile robot to include the control of formations of multiple nonholonomic mobile robots. A combined kinematic/torque control law is developed for leader-follower based formation control using backstepping in order to accommodate the dynamics of the robots and the formation in contrast with kinematic-based formation controllers. The asymptotic stability of the entire formation is guaranteed using Lyapunov theory, and numerical results are provided The kinematic controller is developed around control strategies for single mobile robots and the idea of virtual leaders. The virtual leader is replaced with …
Reinforcement Learning Neural-Network-Based Controller For Nonlinear Discrete-Time Systems With Input Constraints, Pingan He, Jagannathan Sarangapani
Reinforcement Learning Neural-Network-Based Controller For Nonlinear Discrete-Time Systems With Input Constraints, Pingan He, Jagannathan Sarangapani
Electrical and Computer Engineering Faculty Research & Creative Works
A novel adaptive-critic-based neural network (NN) controller in discrete time is designed to deliver a desired tracking performance for a class of nonlinear systems in the presence of actuator constraints. The constraints of the actuator are treated in the controller design as the saturation nonlinearity. The adaptive critic NN controller architecture based on state feedback includes two NNs: the critic NN is used to approximate the "strategic" utility function, whereas the action NN is employed to minimize both the strategic utility function and the unknown nonlinear dynamic estimation errors. The critic and action NN weight updates are derived by minimizing …
Frequency-Domain Measurement Method For The Analysis Of Esd Generators And Coupling, Jayong Koo, Qing Cai, Giorgi Muchaidze, Andrew Martwick, Kai Wang, David Pommerenke
Frequency-Domain Measurement Method For The Analysis Of Esd Generators And Coupling, Jayong Koo, Qing Cai, Giorgi Muchaidze, Andrew Martwick, Kai Wang, David Pommerenke
Electrical and Computer Engineering Faculty Research & Creative Works
A method for analyzing electrostatic discharge (ESD) generators and coupling to equipment under test in the frequency domain is proposed. In ESD generators, the pulses are excited by the voltage collapse across relay contacts. The voltage collapse is replaced by one port of a vector network analyer (VNA). All the discrete and structural elements that form the ESD current pulse and the transient fields are excited by the VNA as if they were excited by the voltage collapse. In such a way, the method allows analyzing the current and field-driven linear coupling without having to discharge an ESD generator, eliminating …
The Electronic Passport And The Future Of Government-Issued Rfid-Based Identification, G. Matthew Ezovski, Steve Eugene Watkins
The Electronic Passport And The Future Of Government-Issued Rfid-Based Identification, G. Matthew Ezovski, Steve Eugene Watkins
Electrical and Computer Engineering Faculty Research & Creative Works
Passports and other identification documents may be enhanced using recent advancements in technology. Various national and international bodies are pursuing machine-readable approaches with biometric information. In particular, the international civil aviation organization (ICAO) has adopted standards whereby passports can store biometric identifiers. Countries that participate in the visa waiver program (VWP) began issuing electronic passports in 2006. However, the selection of technologies remains questionable due to privacy and security concerns. This paper examines policy regarding these electronic approaches and developments toward electronic data storage and transmission. Radio-frequency identification (RFID) devices for electronic passports and other existing identity documents are discussed.
Physical Analysis Of Human Hair, Lea Marie Dankers
Physical Analysis Of Human Hair, Lea Marie Dankers
Masters Theses
"Physical analysis of human hair has been performed to determine the effects of chemical treatments on hair samples. Five samples including an untreated sample were analyzed using various methods. The methods included differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FTIR), and carbon-13 cross polarization/magic-angle spinning nuclear magnetic resonance (¹³C CP/MAS NMR)"--Abstract, page iii.
Channel Estimation And Phase-Correction For Robust Underwater Acoustic Communications, Y. Rosa Zheng
Channel Estimation And Phase-Correction For Robust Underwater Acoustic Communications, Y. Rosa Zheng
Electrical and Computer Engineering Faculty Research & Creative Works
This paper presents a new channel estimation, equalization, and phase correction scheme to combat the convergence and stability problem encountered by time-domain adaptive equalizers in underwater acoustic communication systems. Large Doppler spread and symbol scaling in underwater channels have been challenging problems causing significant phase drift and performance degradation. Our new method targets this problem by first allowing phase errors in the estimation of the fading channel coefficients and then perform group-wise (rather than symbol-wise) phase estimation and correction after equalization and multiple channel combining. Single transmitter and multiple receiver data obtained through ocean experiments have been processed using the …
Frequency-Domain Channel Estimation And Equalization For Single Carrier Underwater Acoustic Communications, Y. Rosa Zheng, Chengshan Xiao, T. C. Yang, Wen-Bin Yang
Frequency-Domain Channel Estimation And Equalization For Single Carrier Underwater Acoustic Communications, Y. Rosa Zheng, Chengshan Xiao, T. C. Yang, Wen-Bin Yang
Electrical and Computer Engineering Faculty Research & Creative Works
A new frequency-domain channel estimation and equalization (FDE) scheme is proposed for single carrier (SC) underwater acoustic communications. The proposed SC-FDE employs a small training signal block for initial channel estimation in the frequency domain and converts the estimated transfer function to a desired DFT (discrete Fourier transform) size for channel equalization of the data blocks. The frequency domain equalizer is designed using the linear minimum mean square error criterion. A new phase coherent detection scheme is also proposed and deployed to combat the phase drift due to the instantaneous Doppler in the underwater channels. The channel transfer functions and …
Health Monitoring Of A Truss Bridge Using Adaptive Identification, James W. Fonda, Steve Eugene Watkins
Health Monitoring Of A Truss Bridge Using Adaptive Identification, James W. Fonda, Steve Eugene Watkins
Electrical and Computer Engineering Faculty Research & Creative Works
Integration of structural analysis, system identification, and sensor networks provide health monitoring capabilities that benefit many aspects of infrastructure management. This work presents an adaptive identification method based on Lyapunov methods for a truss structure. Lyapunov methods in the identification provide guaranteed convergence for the parameter estimation. Identification is carried out on a simulation model based on FEA methods. The FEA model offers realistic results from a truss structure and allows verification of the identification method for a rolling load case. A rolling load scenario provides use of realistic loading of a structure so that identification methods may be extended …
Implementation Of A Converter In Sequence Domain To Counter Voltage Imbalances, Murali M. Baggu, Badrul H. Chowdhury
Implementation Of A Converter In Sequence Domain To Counter Voltage Imbalances, Murali M. Baggu, Badrul H. Chowdhury
Electrical and Computer Engineering Faculty Research & Creative Works
This paper demonstrates the basic problem of the conventional d-axis and q-axis control applied to a voltage source converter (VSC) during a system imbalance. The specific imbalances studied are a balanced fault and an unbalanced fault at the terminals of the converter. The dc link voltage of the VSC is disturbed during the unbalanced fault due to negative sequence components in the system. The sequence characteristics of the system during an imbalance are further analyzed. A novel controller in the sequence domain is proposed. The positive sequence components of the control are implemented in the positive synchronous reference frame and …
Mobile Speed Estimation For Broadband Wireless Communications, Y. Rosa Zheng, Chengshan Xiao
Mobile Speed Estimation For Broadband Wireless Communications, Y. Rosa Zheng, Chengshan Xiao
Electrical and Computer Engineering Faculty Research & Creative Works
In this paper, a new algorithm is proposed to estimate mobile speed for broadband wireless communications, which often encounter large number of fading channel taps causing severe intersymbol interference. Theoretical analysis is first derived and practical algorithm is proposed based on the analytical results. The algorithm employs a modified auto-covariance of received signal power to estimate the speed of mobiles. The algorithm is based on the received signals which contain unknown transmitted data, unknown frequency selective multipaths possibly including line-of-sight (LOS) component, and random receiver noise. The algorithm works well for frequency selective Rayleigh and Rician channels. The algorithm is …
Near Optimal Neural Network-Based Output Feedback Control Of Affine Nonlinear Discrete-Time Systems, Qinmin Yang, Jagannathan Sarangapani
Near Optimal Neural Network-Based Output Feedback Control Of Affine Nonlinear Discrete-Time Systems, Qinmin Yang, Jagannathan Sarangapani
Electrical and Computer Engineering Faculty Research & Creative Works
In this paper, a novel online reinforcement learning neural network (NN)-based optimal output feedback controller, referred to as adaptive critic controller, is proposed for affine nonlinear discrete-time systems, to deliver a desired tracking performance. The adaptive critic design consist of three entities, an observer to estimate the system states, an action network that produces optimal control input and a critic that evaluates the performance of the action network. The critic is termed adaptive as it adapts itself to output the optimal cost-to-go function which is based on the standard Bellman equation. By using the Lyapunov approach, the uniformly ultimate boundedness …
Neural Network Based Method For Predicting Nonlinear Load Harmonics, Joy Mazumdar, Ronald G. Harley, Frank C. Lambert, Ganesh K. Venayagamoorthy
Neural Network Based Method For Predicting Nonlinear Load Harmonics, Joy Mazumdar, Ronald G. Harley, Frank C. Lambert, Ganesh K. Venayagamoorthy
Electrical and Computer Engineering Faculty Research & Creative Works
Generation of harmonics and the existence of waveform pollution in power system networks are important problems facing the power utilities. The increased use of nonlinear devices in industry has resulted in direct increase of harmonic distortion in the industrial power system in recent years. Interaction between loads and sources in a power distribution network is a complex process and often not possible to explain analytically without making assumptions. The determination of true harmonic current distortion of a load is further complicated by the fact that the supply voltage waveform at the point of common coupling (PCC) is rarely a pure …
Neural Network Controller Development And Implementation For Spark Ignition Engines With High Egr Levels, Jonathan B. Vance, Atmika Singh, Brian C. Kaul, Jagannathan Sarangapani, J. A. Drallmeier
Neural Network Controller Development And Implementation For Spark Ignition Engines With High Egr Levels, Jonathan B. Vance, Atmika Singh, Brian C. Kaul, Jagannathan Sarangapani, J. A. Drallmeier
Electrical and Computer Engineering Faculty Research & Creative Works
Past research has shown substantial reductions in the oxides of nitrogen (NOx) concentrations by using 10% -25% exhaust gas recirculation (EGR) in spark ignition (SI) engines (see Dudek and Sain, 1989). However, under high EGR levels, the engine exhibits strong cyclic dispersion in heat release which may lead to instability and unsatisfactory performance preventing commercial engines to operate with high EGR levels. A neural network (NN)-based output feedback controller is developed to reduce cyclic variation in the heat release under high levels of EGR even when the engine dynamics are unknown by using fuel as the control input. A separate …
Performance Of Doubly Fed-Induction Machine Wind-Generators During Grid And Wind Disturbances, Badrul H. Chowdhury, Murali M. Baggu
Performance Of Doubly Fed-Induction Machine Wind-Generators During Grid And Wind Disturbances, Badrul H. Chowdhury, Murali M. Baggu
Electrical and Computer Engineering Faculty Research & Creative Works
A doubly fed induction generator is under study for application with a wind turbine. The operation of the Doubly Fed Induction Generator (DFIG) under different disturbances namely, response to gradual increase or decrease in wind speeds, sudden change of wind speeds like wind gust and different fault scenarios near and farther to the wind turbine are demonstrated in this paper using the wind model developed by DIgSILENT® in their PowerFactory software.
Design Of An Fpga Logic Element For Implementing Asynchronous Null Convention Logic Circuits, Scott C. Smith
Design Of An Fpga Logic Element For Implementing Asynchronous Null Convention Logic Circuits, Scott C. Smith
Electrical and Computer Engineering Faculty Research & Creative Works
Two versions of a reconfigurable logic element are developed for use in constructing afield-programmable gate array NULL convention logic (NCL) field-programmable gate array (FPGA): one with extra embedded registration capability, which requires additional area, and one without. Both versions can be configured as any of the 27 fundamental NCL gates, including resettable and inverting variations, and both can utilize embedded registration for gates with three or fewer inputs; however, only the version with the additional embedded registration capability can utilize embedded registration with four-input gates. These two approaches are compared with each other and with an existing approach, showing that …
Frequency-Domain Channel Estimation And Equalization For Broadband Wireless Communications, Y. Rosa Zheng, Chengshan Xiao
Frequency-Domain Channel Estimation And Equalization For Broadband Wireless Communications, Y. Rosa Zheng, Chengshan Xiao
Electrical and Computer Engineering Faculty Research & Creative Works
Frequency-domain equalization (FDE) is an effective technique for high data rate wireless communication systems suffering from very long intersymbol interference. Most of existing FDE algorithms are limited to quasi-static or slow time-varying fading channels, where least mean squares (LMS) or recursive least squares (RLS) adaptive algorithms were utilized for channel estimation. In this paper, we employ interpolation method to develop channel estimation algorithm in the frequency domain. We show that the new channel estimation algorithm can significantly outperform LMS and RLS algorithms. Numerical examples demonstrate that the new algorithm can track time-varying fading channels with Doppler up to 300-400 Hz. …
Hybrid Ac/Dc Power Distribution Solution For Future Space Applications, Sushant Barave, Badrul H. Chowdhury
Hybrid Ac/Dc Power Distribution Solution For Future Space Applications, Sushant Barave, Badrul H. Chowdhury
Electrical and Computer Engineering Faculty Research & Creative Works
As NASA readies itself for new space exploration initiatives starting with a human return to the Moon by the year 2020 eventually leading to human exploration of Mars, the requirements for a safe and reliable power system will become important issues. A preliminary study of a proposed hybrid AC/DC distribution system with a power electronic interface is investigated. A Static synchronous Compensator (STATCOM) is considered as the power electronic interface between the AC and the DC portions of the hybrid AC/DC distribution system. The system is modeled in EMTDC/PSCAD and tested for certain operating conditions and contingencies. High reliability and …
Improvement Of Can Bus Performance By Using Error-Correction Codes, Krishna Chaitanya Emani, Maciej Jan Zawodniok, Y. Rosa Zheng, Jagannathan Sarangapani, Keong W. Kam
Improvement Of Can Bus Performance By Using Error-Correction Codes, Krishna Chaitanya Emani, Maciej Jan Zawodniok, Y. Rosa Zheng, Jagannathan Sarangapani, Keong W. Kam
Electrical and Computer Engineering Faculty Research & Creative Works
In this paper, two variants of the Hybrid Automatic Repeat Request (HARQ) scheme for CAN bus are presented. The basic HARQ uses error-correction code based on the Reed- Solomon (RS) technique and the Cyclic Redundancy Check (CRC) method to detect errors. The second scheme uses the cyclic error-correction method instead of the CRC error-detection method to further improve the throughput. Moreover, the second scheme uses no additional bit overhead when compared with the basic HARQ scheme. This paper presents the performance of the proposed schemes using MATLAB and NS2 simulations. Experimental data of error patterns were used for realistic evaluation. …
Incorporating The Effects Of Magnetic Saturation In A Coupled-Circuit Model Of A Claw-Pole Alternator, Hua Bai, Steven Pekarek, Jerry L. Tichenor, Walter Eversman, Duane J. Buening, Gregory R. Holbrook, Ronald J. Krefta
Incorporating The Effects Of Magnetic Saturation In A Coupled-Circuit Model Of A Claw-Pole Alternator, Hua Bai, Steven Pekarek, Jerry L. Tichenor, Walter Eversman, Duane J. Buening, Gregory R. Holbrook, Ronald J. Krefta
Electrical and Computer Engineering Faculty Research & Creative Works
A method of representing the effects of magnetic saturation in a coupled-circuit model of a claw-pole alternator is presented. In the approach considered, the airgap flux density produced by each winding is expressed as a function of magnetic operating point. A challenge in the implementation is that the airgap flux densities consist of several significant harmonics, each of which changes at a distinct rate as iron saturates. Despite this complication, it is shown that relatively simple measurements can be used to determine model parameters. The model is implemented in the analysis of several alternator/rectifier systems using a commercial state-model-based circuit …
Mode Suppressed Tem Cell Design For High Frequency Ic Measurements, Shaowei Deng, David Pommerenke, Todd H. Hubing, James L. Drewniak, Daryl G. Beetner, Dongshik Shin, Sungnam Kim, Hocheol Kwak
Mode Suppressed Tem Cell Design For High Frequency Ic Measurements, Shaowei Deng, David Pommerenke, Todd H. Hubing, James L. Drewniak, Daryl G. Beetner, Dongshik Shin, Sungnam Kim, Hocheol Kwak
Electrical and Computer Engineering Faculty Research & Creative Works
TEM cells or GTEM cells can be used to evaluate the radiated emissions of integrated circuits (ICs). The applicable frequency bandwidth of a TEM cell is limited due to the resonances of higher order modes. This paper describes how a TEM cell can be modified to extend the frequency range without changing the test topology. Several methods are proposed and implemented to suppress the higher order modes. The magnetic field coupling and electric field coupling are evaluated for the new design. The frequency bandwidth of the modified TEM cell is extended from original 1 GHz to 2.5 GHz.
Multiclass Cancer Classification Using Semisupervised Ellipsoid Artmap And Particle Swarm Optimization With Gene Expression Data, Georgios C. Anagnostopoulos, Donald C. Wunsch, Rui Xu
Multiclass Cancer Classification Using Semisupervised Ellipsoid Artmap And Particle Swarm Optimization With Gene Expression Data, Georgios C. Anagnostopoulos, Donald C. Wunsch, Rui Xu
Electrical and Computer Engineering Faculty Research & Creative Works
It is crucial for cancer diagnosis and treatment to accurately identify the site of origin of a tumor. with the emergence and rapid advancement of DNA microarray technologies, constructing gene expression profiles for different cancer types has already become a promising means for cancer classification. In addition to research on binary classification such as normal versus tumor samples, which attracts numerous efforts from a variety of disciplines, the discrimination of multiple tumor types is also important. Meanwhile, the selection of genes which are relevant to a certain cancer type not only improves the performance of the classifiers, but also provides …
Near Optimal Output-Feedback Control Of Nonlinear Discrete-Time Systems In Nonstrict Feedback Form With Application To Engines, Peter Shih, Brian C. Kaul, Jagannathan Sarangapani, J. A. Drallmeier
Near Optimal Output-Feedback Control Of Nonlinear Discrete-Time Systems In Nonstrict Feedback Form With Application To Engines, Peter Shih, Brian C. Kaul, Jagannathan Sarangapani, J. A. Drallmeier
Electrical and Computer Engineering Faculty Research & Creative Works
A novel reinforcement-learning based output-adaptive neural network (NN) controller, also referred as the adaptive-critic NN controller, is developed to track a desired trajectory for a class of complex nonlinear discrete-time systems in the presence of bounded and unknown disturbances. The controller includes an observer for estimating states and the outputs, critic, and two action NNs for generating virtual, and actual control inputs. The critic approximates certain strategic utility function and the action NNs are used to minimize both the strategic utility function and their outputs. All NN weights adapt online towards minimization of a performance index, utilizing gradient-descent based rule. …
Online Reinforcement Learning Control Of Unknown Nonaffine Nonlinear Discrete Time Systems, Qinmin Yang, Jagannathan Sarangapani
Online Reinforcement Learning Control Of Unknown Nonaffine Nonlinear Discrete Time Systems, Qinmin Yang, Jagannathan Sarangapani
Electrical and Computer Engineering Faculty Research & Creative Works
In this paper, a novel neural network (NN) based online reinforcement learning controller is designed for nonaffine nonlinear discrete-time systems with bounded disturbances. The nonaffine systems are represented by nonlinear auto regressive moving average with exogenous input (NARMAX) model with unknown nonlinear functions. An equivalent affine-like representation for the tracking error dynamics is developed first from the original nonaffine system. Subsequently, a reinforcement learning-based neural network (NN) controller is proposed for the affine-like nonlinear error dynamic system. The control scheme consists of two NNs. One NN is designated as the critic, which approximates a predefined long-term cost function, whereas an …
Optimal Neuro-Fuzzy External Controller For A Statcom In The 12-Bus Benchmark Power System, Salman Mohagheghi, Ganesh K. Venayagamoorthy, Ronald G. Harley
Optimal Neuro-Fuzzy External Controller For A Statcom In The 12-Bus Benchmark Power System, Salman Mohagheghi, Ganesh K. Venayagamoorthy, Ronald G. Harley
Electrical and Computer Engineering Faculty Research & Creative Works
An optimal neuro-fuzzy external controller is designed in this paper for a static compensator (STATCOM) in the 12-bus benchmark power system. The controller provides an auxiliary reference signal for the STATCOM in such a way that it improves the damping of the rotor speed deviations of its neighboring generators. A Mamdani fuzzy rule base constitutes the core of the controller. A heuristic dynamic programming-based approach is used to further train the controller and enable it to provide nonlinear optimal control at different operating conditions of the power system. Simulation results are provided that indicate the proposed neuro-fuzzy external controller is …
Optimal Wide Area Controller And State Predictor For A Power System, Salman Mohagheghi, Ganesh K. Venayagamoorthy, Ronald G. Harley
Optimal Wide Area Controller And State Predictor For A Power System, Salman Mohagheghi, Ganesh K. Venayagamoorthy, Ronald G. Harley
Electrical and Computer Engineering Faculty Research & Creative Works
An optimal wide area controller is designed in this paper for a 12-bus power system together with a Static Compensator (STATCOM). The controller provides auxiliary reference signals for the automatic voltage regulators (AVR) of the generators as well as the line voltage controller of the STATCOM in such a way that it improves the damping of the rotor speed deviations of the synchronous machines. Adaptive critic designs theory is used to implement the controller and enable it to provide nonlinear optimal control over the infinite horizon time of the problem and at different operating conditions of the power system. Simulation …
Reinforcement Learning Based Output-Feedback Controller For Complex Nonlinear Discrete-Time Systems, Peter Shih, Jagannathan Sarangapani
Reinforcement Learning Based Output-Feedback Controller For Complex Nonlinear Discrete-Time Systems, Peter Shih, Jagannathan Sarangapani
Electrical and Computer Engineering Faculty Research & Creative Works
A novel reinforcement-learning based output-adaptive neural network (NN) controller, also referred as the adaptive-critic NN controller, is developed to track a desired trajectory for a class of complex feedback nonlinear discrete-time systems in the presence of bounded and unknown disturbances. This nonlinear discrete-time system consists of a second order system in nonstrict form and an affine nonlinear discrete-time system tightly coupled together. Two adaptive critic NN controllers are designed - primary one for the nonstrict system and the secondary one for the affine system. A Lyapunov function shows the uniformly ultimate boundedness (UUB) of the closed-loop tracking error, weight estimates …
Rfid Instrumentation In A Field Application, Theresa M. Swift, Martha J. Molander, Steve Eugene Watkins
Rfid Instrumentation In A Field Application, Theresa M. Swift, Martha J. Molander, Steve Eugene Watkins
Electrical and Computer Engineering Faculty Research & Creative Works
The behavior of radio-frequency identification (RFID) tags is investigated in a field application. The RFID instrumentation is used to mark the position of point strain sensors in a fiber-reinforced polymer (FRP), short-span bridge. The tags are surface mounted on carbon FRP structural elements and covered with a resin wear layer, i.e. the deck of the bridge. The smart composite bridge was installed in 2000 and serves as a field testbed for various sensor technologies including the RFID tags. The operation of the RFID network is tested in the field and compared to laboratory tags. Specific research issues include long-term survivability …