Publications

Most Recent Publications

J. Pace, J. P. Rao, J. Williams, and L. He, “Unsupervised anomaly detection using batteries in electric aerial vehicle propulsion test-bed,” Annual Conference of the Prognostics and Health Management Society, 2022. Read here.

L. Barama, Z. Peng, A. V. Newman, and J. Williams, “Gtune: An assembled global seismic dataset of underground nuclear test blasts,” Seismological Research Letters, 2022. Read here.

J. P. Rao, J. E. Holzager, M. Maia, and F. J. Diez, “Experimental study into optimal configuration and operation of two-four rotor coaxial systems for e-vtol vehicles,” MDPI Aerospace, 2022. Read here.

S. J. Corrado, T. G. Puranik, O. J. Pinon-Fischer, D. Mavris, R. Rose, J. Williams, and R. Heidary, “Deep Autoencoder for Anomaly Detection in Terminal Airspace Operations,” in AIAA AVIATION 2021 FORUM. DOI: 10.2514/6.2021-2405. Read here.

L. Barama, J. Williams, Z. Peng, and A. V. Newman, “Nuclear Blast Discrimination using a Convolutional Neural Network,” in AGU Fall Meeting Abstracts, vol. 2020, Dec. 2020, S053-0009. Abstract here.

M. Mohseni, S. Santhanam, J. Williams, A. Thakker, C. Nataraj, “Systematic fatigue spectrum editing by fast wavelet transform and genetic algorithm,” Fatigue Fract Eng Mater Struct, Vol.45, No. 1, pp. 69-83, 2022. Read here.

Autonomous Systems

J. Rao, J. Pace, J. Williams, R. Mackey, L. He, C. Menegazzo, “A Reusable Framework for Fault Detection and Isolation in Small Satellites,” in Small Satellites Conference, 2023. Read here.

M.R. Rines, M. Balchanos, D.N. Mavris, J. Rao, and J. Williams, “A Resource Allocation Algorithm For A Space Habitat ECLSS,” in ASCEND 2021. DOI: 10.2514/6.2021-4028. Read here.

F. Rufus, B. Heck, and G. Vachtsevanos, “Software-Enabled Adaptive Mode Transition Control for Autonomous Unmanned Vehicles,” in 19th DASC. 19th Digital Avionics Systems Conference. Proceedings (Cat. No. 00CH37126), vol. 1, IEEE, 2000, pp. 1E1/1–1E1/8, vol.1, ISBN: 0780363957. Read here.

P. Frederick, S. Lee, J. Ajitsaria, and N. Propes, “A Hierarchical Fault Tolerant Control System for UGVs Experiencing Mobility Failures,” in IASTED Robotics and Applications Conf., 2010.

N.C. Propes, “Hybrid system diagnosis and control reconfiguration for manufacturing systems,” Ph.D Dissertation, 2004, ISBN: 0496740148. Read here.

F. Rufus, G. Vachtsevanos, and B. Heck, “Real-time adaptation of mode transition controllers,” J. Guid. Control Dyn., vol. 25, no. 1, pp. 167–175, 2002, ISSN: 0731-5090. Read here.

F. Rufus and G. Vachtsevanos, “Design of Mode-to-Mode Fuzzy Controllers,” Int. J. Intell. Syst., vol. 15, no. 7, pp. 657–685, 2000, ISSN: 0884-8173. Read here.

F. Rufus, G. Vachtsevanos and B. Heck, “Adaptive Mode Transition Control of Nonlinear Systems Using Fuzzy Neural Networks,” 8th IEEE Mediterranean Conf. on Control & Automation (MED 2000), Patras, 17-19 July 2000.

F. Rufus and G. Vachtsevanos, “Robust stability of mode-to-mode fuzzy controllers,” J. Guid. Control Dyn., vol. 22, no. 6, pp. 823–832, 1999, ISSN: 0731-5090. Read here.

Seismic AI

Barama, L., Williams, J., Newman, A. V., & Peng, Z. (2023). Global nuclear explosion discrimination using a convolutional neural network. Geophysical Research Letters, 50, e2022GL101528. https://doi.org/10.1029/2022GL101528. Read here.

Prognostics & Health Management (PHM)

Battery PHM

O. Linda, E. William, M. Huff, M. Manic, V. Gupta, J. Nance, H. Hess, F. Rufus, A. Thakker, J. Govar, “Intelligent neural network implementation for SOCI development of Li/CFx batteries,” in 2009 2nd Int. Symp. Resilient Control Syst., IEEE, 2009, pp. 57–62, ISBN: 1424448530. Read here.

E. William, V. Gupta, M. Huff, O. Linda, J. Nance, H. Hess, M. Manic, F. Rufus, A. Thakker, J. Govar, “A Comparative Study of Lithium Poly-Carbon Monoflouride (Li/CFx) and Lithium Iron Phosphate (LiFePO4) Battery Chemistries for State of Charge Indicator Design,” in 2009 IEEE Int. Symp. on Industrial Electronics, IEEE, 2009, pp. 2006–2009, ISBN: 9781424443475. Read here.

F. Rufus, S. Lee, A. Thakker, “Health Monitoring Algorithms for Space Application Batteries,” 2008 IEEE Int. Conf. Progn. Health Manag. ICPHM, IEEE, 2008 pp. 1–8, ISBN: 1424419352. Read here.

Vehicle Systems PHM

D. Finigan, F. DiRosa, N. Propes, F. Heimes, and C. Thompson, “A Health Monitoring Methodology for On- and Off-board Vehicle Systems using Data-driven and Model-based Techniques” in NDIA-GVSETS, 2009.

R.A. Hess, F.O. Heimes, N.C. Propes, “A Health Management Solution for Hybrid Electric Vehicle Transit Fleets,” in 2008 Int. Conf. Progn. Health Manag., 2008.

PHM of Electric Generators & Motors

E. Liu, G. Niu, S. Tang, B. Zhang, J. Williams, R. Martin, and C. Moore, “Permanent Magnet Synchronous Motor Winding Fault Simulation and Diagnosis,” in Annual Conference of the PHM Society, vol. 11, 2019. Read here.

F. Rufus and N. Propes, “Assessing Health Degradation in Aircraft Generators,” RMC Newsletters, Vol. 15, No. 4, pp. 3–5, 2010. Read here.

F. Rufus, S. Lee, A.B. Thakker, S.A. Field, and N. Kumbar, “Advanced electrical signature analysis of aircraft electrical generators,” SAE Int. J. Aerosp., vol. 3, no. 1, pp. 25–31, 2009, ISSN: 1946-3855. Read here.

F. Rufus, S. Lee, A. Thakker, S. Field and N. Kumbar, “Advanced Diagnostics of Aircraft Electrical Generators,” SAE Int. J. Aerosp., vol. 1, no. Paper # 2008-01-2923, 2008. Read here.

PHM of Chillers, Valves & Pumps

B. Jeffries, N. Propes, A.B. Thakker, B.R. Upadhyaya, and J.W. Hines, “Monitoring and Prognostics of Hydraulically Operated Butterfly Valves,” NPIC & HMIT 2012, 2012. Read here.

N. Propes, A. Thakker, G. Vachtsevanos, T. Galie, M. McGovern, and M. Franks, “Diagnostic and Prognostic Health Monitoring of Chillers On-board Naval Vessels”, ASNE Sea Basing Conf., 2005. Read here.

PHM Frameworks & Analysis Tools

R. Heidary and K. M. Groth, “A hybrid population-based degradation model for pipeline pitting corrosion,” Reliab. Eng. Syst. Saf., Vol. 214, pp. 107740-1–12, 2021, ISSN: 0951-8320. Read here.

R. Heidary and K. M. Groth, “A hybrid model of internal pitting corrosion degradation under changing operational conditions for pipeline integrity management,” Struct. Health Monit., Vol. 19, no. 4, pp. 1075–1091, 2020. Read here.

R. Heidary, K.M. Groth, and M. Modarres, “Fusing More Frequent and Accurate Structural Damage Information from One Location to Assess Damage at another Location with Less Information,” in Proc. of the 14th Probabilistic Safety Assessment and Management Conf. (PSAM 14), 2018. Read here.

R. Heidary, K.M.Groth, M. Modarres, and N. Vahdati, “Finding optimal maintenance policy for pipeline corrosion using data fusion,” inRDPETRO 2018: Research and Development Petroleum Conf.and Exhibition. 2018, pp. 232–233. Read here.

F. Rufus, S. Lee, and A. Thakker, “ Health monitoring algorithms for space application batteries, ” in 2008 Int. Conf. Progn. Health Manag., 2008, pp. 1–8. Read here.

G. Zhang, S. Lee, N. Propes, Y. Zhao, G. Vachtsevanos, A. Thakker, T. Gailie, “A Novel Architecture for an Integrated Fault Diagnostic or Prognostic System,” 2002 AAAI Spring Symp. Tech. Proc., 2002, SS-02-03, ISBN 1-57735-148-7. Read here.

N. Propes, S. Lee, G. Zhang, Y. Zhao, G. Vachtsevanos, A. Thakker, T. Gailie, “A Real Time Architecture for Prognostic Enhancements to Diagnostic Systems,” MARCON 2002, 2002

N. Khiripet, G. Vachtsevanos, A. Thakker, T. Gailie, “A New Confidence Prediction Neural Network for Machine Failure Prognosis,” Proc. of Intelligent Ships Symp. IV, 2001.

G. Vachtsevanos, P. Wang, T. Gailie, A. Thakker, “Fault Prognosis Using Dynamic Wavelet Neural Networks,” Proc. of AUTOTESTCON 2001 Conf., 2001. Read here.

G. Vachtsevanos, P. Wang, N. Khiripet, A. Thakker, T. Gailie, “An Intelligent Approach to Prognostic Enhancements of Diagnostic Systems,” Proc. of SPIE 15th Annu. Int. Symp. on Aerospace/Defense Sensing, Simulation, and Controls, 2001. Read here.

B.G. Zhang, N. Propes, G. Vachtsevanos, T. Galie, and A.B. Thakker, “Addressing Uncertainty and Confidence in Prognosis,” Intelligent Ship Symp., 2003.

B.G. Zhang, N. Propes, and G. Vachtsevanos, “Confidence Metrics and Uncertainty Management in Prognosis,” MARCON 2003, 2003.

N. Propes, and G. Vachtsevanos, “A Fuzzy Petri Net Based Mode Identification Algorithm for Fault Diagnosis of Complex Systems,” AeroSense, 2003. Read here.

G. Zhang, S. Lee, N. Propes, Y. Zhao, G. Vachtsevanos, A. Thakker, and T. Galie, “A Novel Architecture for an Integrated Fault Diagnostic/Prognostic System,” AAAI Symp., 2002.

N. Propes, S. Lee, G. Zhang, I. Barlas, Y. Zhao, G. Vachtsevanos, A. Thakker, and T. Galie, “A Real-Time Architecture for Prognostic Enhancements to Diagnostic Systems,” MARCON 2002, 2002.

N. Propes, G. Vachtsevanos and Y. Wardi, “An Object-Oriented Hybrid Modeling Framework for Manufacturing Systems,” IASTED Applied Simulation and Modeling Conf., 2002.

P. Wang, N. Propes, N. Khiripet, Y. Li, and G. Vachtsevanos, “An Integrated Approach to Machine Fault Diagnosis,” IEEE Annual Textile Fiber and Film Industry Technical Conf., 1999. Read here.

Material Analysis & Life Prediction

R. Heidary, S.A. Gabriel, M. Modarres, K.M. Groth, and N. Vahdati, “A Review of Data-Driven Oil and Gas Pipeline Pitting Corrosion Growth Models Applicable for Prognostic and Health Management,” Int. J. Progn. Health Manag., Vol. 9, No. 1, 2018. Read here.

A.B. Thakker, H.F. Brinson, R.A. Heller, “Accelerated Characterization of Fiber/Epoxy Composites. Part 1: Viscoelastic Methods. Final Report,” AD-A014266, AFML-TR-74-256-PT-1, Feb. 1975.

R.A. Heller, H.F. Brinson, A.B. Thakker “Environmental Effects on Fiber Reinforced Composites“, Int. Conf. on Mater Technology, 4th, Proc., 1975. pp. 464-471.

A.B. Thakker, “Viscoelastic Characterization of Angle Ply Advanced Composites (including boron and graphite reinforced materials),” Ph.D. Dissertation, Dept. of Mechanical Engineering, Virginia Polytechnic Inst. and State Univ., Blacksburg, VA, 1974. Read here.

R. Heller, A. Thakker, and C. Arthur, “Temperature dependence of the complex modulus for fiber-reinforced materials,” in Composite Reliability, 1975, pp. 298–308, ISBN: 9780803103092.

D. Hooke, E. Armanios, D. Dancila, A. Thakker, and P. Doorbar, “Failure of a titanium metal-matrix composite cylindrical shell under internal pressure,” in Composite Materials: Fatigue and Fracture (Sixth Volume), 1997, pp. 27–44, ISBN: 0803124112

E.A. Armanios, A.M. Badir, D.S. Dancila, A.B. Thakker, P. Doorbar, “Free Vibration of a Metal Matrix Composite Shell with Circumferential Reinforcement,” 35th AIAA/ASME/AHS/ASC Structures, Structural Dynamics and Materials (SDM) Conf., 1994

D.E. Larsern Jr., M. Behrendt, N. Walker, A.B. Thakker, D. Davidson, D. Clemmens, “Fatigue Behavior of Cast XD Gamma Titanium Aluminide Alloys,” Fatigue and Fracture of Ordered Intermetallic Materials 1 Conf., 1993.

F.C. Toriz, A.B. Thakker, S.K. Gupta, R. Doxstader, “Surfprep Flash-Lamp Depaint System Evaluation,” 17th Int. Conf. on Metallurgical Coatings, 1990. Read here.

F.C. Toriz, A.B. Thakker, S.K. Gupta, “Flight Service Evaluation of Thermal Barrier Coatings by Physical Vapor Deposition at 5200 H,” 16th Int. Conf. on Metallurgical Coatings (ICMC) – Part I (of 3), San Diego, CA, Apr. 17-21 1989; Surface & Coatings Technology vol. 39-40 1-3 PT1, 1989, pp. 161-172. Read here.

F.C. Toriz, A.B. Thakker, S.K. Gupta, “Thermal Barrier Coatings For Jet Engines,” ASME Gas Turbine and Aeroengine Congress and Exposition, 1988. pp. 88-GT-279. Read here.

F.C. Toriz, A.B. Thakker and S.K. Gupta, “Particulate Erosion of Ceramic Thermal Barrier Coatings,” Presented at American Ceramic Society, 1987. Published 40th Pacific Coast Meeting Proc., 8-A-87P, 1988.

J.A. Morrison, A.B. Thakker, A.J. Armini, “Ion Implantation of Silicon Nitride for Rolling Element Bearing Applications,” Presented at ACS 12th Annu. Conf. on Composites and Advanced Ceramic Materials, 1988. Published in Ceramic Engineering and Science Proc., Vol. 9, 1988, pp. 1265-1275.

A. Bennett, F.C. Toriz, A.B. Thakker, “A Philosophy for Thermal Barrier Coating Design and its Corroboration by 10000-H Service Experience on RB211 Nozzle Guide Vanes,” Surface & Coatings Technology, Vol. 32, No. 1-4, pp. 359-375, 1987. Read here.

A.F. Grandt, Jr., A.B. Thakker,, D.E. Tritsch, “An Experimental and Numerical Investigation of the Growth and Coalescence of Multiple Fatigue Cracks at Notches,” in Fracture Mechanics: 17th Vol., 1986, pp. 239-252. ISBN: 0803104723.

R. Heller, A.B. Thakker, and C. Arthur, “Temperature dependence of the complex modulus for fiber-reinforced materials,” in Composite Reliability, 1975, pp. 298–308, ISBN: 9780803103092.

R. Bucci, A. Thakker, T. Sanders, R. Sawtell, and J. Staley, “Ranking 7XXX aluminum alloy fatigue crack growth resistance under constant amplitude and spectrum loading, ” in Effect of Load Spectrum Variables on Fatigue Crack Initiation and Propagation, 1980, pp. 41–78, ISBN: 080310720X

J.T. Staley, W.G. Truckner, R.J. Bucci, A.B. Thakker “Improving Fatigue Resistance of Aluminum Aircraft Alloys.“ Aluminum vol. 53 no.1977 pp. 667–669.

W.G. Truckner, J.T. Staley, R.J. Bucci, and A.B. Thakker, Effects of Microstructure on Fatigue Crack Growth of High-Strength Aluminum Alloys. 1976. Accession No. ADA037156. Read here.

Advanced Materials

C. Mercer, J. Williams, D. Clarke, and A. Evans, “On a ferroelastic mechanism governing the toughness of metastable tetragonal-prime (t’) yttria-stabilized zirconia,” in Proc. of the Royal Society A: Mathematical, Physical and Engineering Sciences, Vol. 463, pp. 1393–1408, 2007. Read here.

P. Tavernier, T. Margalith, J. Williams, et al., “The growth of N-face GaN by MOCVD: effect of Mg, Si, and In,” in J. Cryst. Growth, Vol. 264, pp. 150–158, 2004, ISSN: 0022-0248. Read here.

K.E. Sickafus, J.A. Valdez, J.R. Williams, R.W. Grimes, and H.T. Hawkins, “Radiation induced amorphization resistance in A₂O₃–BO₂ oxides,” in Nucl. Instr. and Meth. in Phys. Res. B, Vol. 191, pp. 549–558, 2002, ISSN: 0168-583X. Read here.

Y. Adachi, N. Ohashi, T. Ohgaki, T. Ohnishi, I. Sakaguchi, S. Ueda, H. Yoshikawa, K. Kobayashi, J.R. Williams, T. Ogino and H. Haneda, “Polarity of heavily doped ZnO films grown on sapphire and SiO₂ glass substrates by pulsed laser deposition,” in Thin Solid Films, Vol. 519, No. 18, pp. 5875–5881, 2011, ISSN: 0040-6090. Read here.

J. Williams, H. Yoshikawa, S. Ueda, et al., “Polarity-dependent photoemission spectra of wurtzite-typezinc oxide,”in Appl. Phys. Lett., Vol. 100, No. 5, pp. 051902-1–051902–3, 2012, ISSN: 0003-6951. Read here.

T. Kolodiazhnyi, M. Valant, J.R. Williams, et al., “Evidence of Eu²⁺ 4f electrons in the valence band spectra of EuTiO₃ and EuZrO₃,” in J. Appl. Phys., Vol. 112, No. 8, pp. 083719-1–083719-5, 2012. Read here.

J.R. Williams, M. Kobata, I. Pis, et al., “Polarity determination of wurtzite-type crystals using hard x-ray photoelectron diffraction,”in Surf. Sci., Vol. 605, No. 13, pp. 1336–1340, 2011, ISSN: 0039-6028. Read here.

T. Ohsawa, S. Ueda, M. Suzuki, Y. Tateyama, J.R. Williams, and N. Ohashi, “Investigating crystalline-polarity-dependent electronic structures of GaN by hard x-ray photoemission and ab-initio calculations,” in Appl. Phys. Lett., Vol. 107, No. 17, pp. 171604-1–171604-5, 2015. Read here.

J.R. Williams, H. Furukawa, Y. Adachi, S. Grachev, E. Søndergård, and N. Ohashi, “Polarity control of intrinsic ZnO films using substrate bias,” in Appl. Phys. Lett., Vol. 103, No. 4, pp. 042107-1–042107-4, 2013. Read here.

J.R. Williams and D.R. Clarke, “Strengthening gold thin films with zirconia nanoparticles for MEMS electrical contacts,” in Acta Materialia, Vol. 56, No. 8, pp. 1813–1819, 2008, ISSN: 1359-6454. Read here.

T. Ogino, J.R. Williams, K. Watanabe, et al., “Effect of crystalline polarity on microstructure and optoelectronic properties of gallium-doped zinc oxide films deposited onto glass substrates,” in Thin Solid Films, Vol. 552, pp. 56–61, 2014, ISSN: 0040-6090. Read here.

J. R. Williams, I. Píš, M. Kobata, et al., “Observation and simulation of hard x ray photoelectron diffraction to determine polarity of polycrystalline zinc oxide films with rotation domains,” in J. Appl. Phys., Vol. 111, No. 3, pp. 033 525, 2012. Read here.

L.K. Shrestha, J.-S. Wi, J. Williams, M. Akada, and K. Ariga, “Facile fabrication of silver nanoclusters as promising surface-enhanced raman scattering substrates,”in J. Nanosci. Nanotechnol., Vol. 14, No. 3, 2245—2251, 2014, ISSN: 1533-4880.

I. Afanasyev-Charkin, D. Cooke, M. Ishimaru, B.L. Bennet, V.T.Gritsyna, J.R. Williams, K.E. Sickafus, “Refractive indices of metastable and amorphousphases in Ne⁺-ion irradiated magnesium–aluminate spinel,” in Optical Materials, Vol. 16, No. 3, pp. 397–402, 2001, ISSN: 0925-3467. Read here.

Energy

Energy Harvesting

J. Ajitsaria, S.-Y. Choe, P. Ozmun, D. Shen, and D.-J. Kim, “Modeling and Analysis of a Bimorph PZT Cantilever Beam Based Micropower Generator,” Sens. Transducers, Vol. 105, Iss. 6, pp. 81–93, 2009, ISSN: 2306-8515. Read here.

D.-J. Kim, J.-H. Park, D. Shen, J. Ajitsaria, and S.-Y. Choe, “PZT-based MEMS Devices for Vibration Energy Harvesting,” Proc. of the 17th Int. Symp. on the Applications of Ferroelectrics & 2008 Meeting of the Electronics Division of the American Ceramic Society, EH004, 2008.

D. Shen, J.-H. Park, J. Ajitsaria, S.-Y. Choe, H. C. Wikle, and D.-J. Kim, “The design, fabrication and evaluation of a MEMS PZT cantilever with an integrated Si proof mass for vibration energy harvesting,” J. Micromech. Microeng., Vol. 18, pp. 055017, (7 pp.), 2008, ISSN: 0960-1317. Read here.

J. Ajitsaria, S. Y. Choe, D. Shen, and D. J. Kim, “Modeling and analysis of a bimorph piezoelectric cantilever beam for voltage generation,” Smart Mater. Struct., Vol. 16, No. 2, pp. 447–454, 2007, ISSN: 0964-1726. Read here.

J. Ajitsaria, S. Choe, D. Kim, and D. Shen, “Modeling of bimorph piezoelectric cantilever beam for voltage generation,” in Proceedings of SPIE, vol. 6529, SPIE, 2007, pp. 652910-1–652910-11, ISBN: 9780819466501. Read here.

D. Shen, J. Ajitsria, S.-Y. Choe, and D.-J. Kim, “Evaluation and modeling of power generator with bimorph PZT cantilever,” MRS Proc., vol. 966, pp. 275–280, 2006, ISSN: 0272-9172.

D. Shen, J. Ajitsaria, S.-Y. Choe, and D.-J. Kim, “The optimal design and analysis of piezoelectric cantilever beams for power generation devices,” in Mater. Res. Soc. Symp. Proc., vol. 888, 2006, pp. 271–276, ISBN: 9781558998421

Energy Management

A. Villegas, J. Prasad Rao, A. Ray, et al., “Aerodynamic flow deflector to increase large scale wind turbinepower generation by 10%,” Rutgers University. Center for Advanced Infrastructure & Transportation, Tech. Rep., 2015. Read here.

J. Prasad Rao, F.J. Diez, “Development of a Cyclic Pitch Turbine.” Proceedings of the ASME/JSME/KSME 2015 Joint Fluids Engineering Conf. Vol. 2: Fora. 2015. V002T34A010. ASME. Read here.

J. Prasad Rao, F.J. Diez, “Experimental Analysis of a Cyclic Pitch Turbine.” Proc. of the ASME 2017 Fluids Engineering Division Summer Meeting. Vol. 1B, 2017. Read here.

J. Prasad Rao and F. J. Diez, “Novel cyclic blade pitching mechanism for wind and tidal energy turbine applications,” Energies, vol. 11, no. 12, 2018, ISSN: 1996-1073. DOI: 10.3390/en11123328. Read here.