- Ji Liu, Guang Li and Hosam Kadry Fathy, 2016, ""

- Iyswarya Narayanan, Di Wang, Anand Sivasubramaniam, Hosam Kadry Fathy and others, 2016, "Battery health-conscious online power management for stochastic datacenter demand response", pp. 3206–3211

- Ji Liu, Michael Rothenberger, Sergio Mendoza, Partha Mishra, Yun-sik Jung and Hosam Kadry Fathy, 2016, "Can an identifiability-optimizing test protocol improve the robustness of subsequent health-conscious lithium-ion battery control? an illustrative case study", pp. 6320–6325

- Partha P Mishra and Hosam Kadry Fathy, 2016, "Can Photovoltaic Battery Energy Storage Systems Be Self-Balancing?", pp. V001T15A002–V001T15A002

- Ji Liu, Sergio Mendoza, Guang Li and Hosam Kadry Fathy, 2016, "Efficient total least squares state and parameter estimation for differentially flat systems", pp. 5419–5424

- Mitchell Cobb, Christopher Vermillion and Hosam Kadry Fathy, 2016, "Lab-scale experimental crosswind flight control system prototyping for an airborne wind energy system", pp. V001T04A003–V001T04A003

- Sergio Mendoza, Ji Liu, Partha Mishra and Hosam Kadry Fathy, 2016, "Statistical Quantification of Least-Squares Battery State of Charge Estimation Errors", pp. V001T15A001–V001T15A001

- Ji Liu, Guang Li and Hosam Kadry Fathy, 2016, "A computationally efficient approach for optimizing lithium-ion battery charging", Journal of Dynamic Systems, Measurement, and Control,
**138**, (2), pp. 021009

- A Mamun, I Narayanan, D Wang, A Sivasubramaniam and Hosam Kadry Fathy, 2016, "Multi-objective optimization of demand response in a datacenter with lithium-ion battery storage", Journal of Energy Storage,
**7**, pp. 258–269

- Mohammad Ghanaatpishe and Hosam Kadry Fathy, 2016, "On the Structure of the Optimal Solution to a Periodic Drug Delivery Problem", Journal of Dynamic Systems, Measurement, and Control

- Sergio Mendoza, Michael Rothenberger, Alison Hake and Hosam Kadry Fathy, 2016, "Optimization and experimental validation of a thermal cycle that maximizes entropy coefficient fisher identifiability for lithium iron phosphate cells", Journal of Power Sources,
**308**, pp. 18–28

- Hosam Kadry Fathy and Guang Li, 2015, "First observations from a partially inverted dynamic systems course", Proceedings of the 2015 American Control Conference

- Mohammad Ghanaatpishe, Michelle A Kehs and Hosam Kadry Fathy, 2015, "Development of online solution algorithms for optimal periodic control problems with plant uncertainties", Proceedings of the 2015 American Control Conference

- Abdullah Al-Mamun, Ishwarya Narayanan, Di Wang, Anand Sivasubramanian and Hosam Kadry Fathy, 2015, "Multi-objective optimization to minimize battery degradation and electricity cost for demand response in datacenters"

- Donald Docimo and Hosam Kadry Fathy, 2015, "Characterization of damping and beating effects within the aggregate power demand of heterogeneous thermostatically controlled loads", Proceedings of the 2015 ASME Dynamic Systems and Control Conference

- Ji Liu, Guang Li and Hosam Kadry Fathy, 2015, "Efficient lithium-ion battery model predictive control using differential flatness-based pseudospectral methods", Proceedings of the 2015 ASME Dynamic Systems and Control Conference

- Michelle A Kehs, Christopher Vermillion and Hosam Kadry Fathy, 2015, "Maximizing average power output of an airborne wind energy generator under parametric uncertainties", Proceedings of the 2015 ASME Dynamic Systems and Control Conference

- Michael J Rothenberger and Hosam Kadry Fathy, 2015, "Robust Bayesian sequential input shaping for optimal lithium-ion battery model parameter identifiability"

- Abdullah Al-Mamun, Di Wang, Ishwirya Naraynan, Anand Sivasubramanian and Hosam Kadry Fathy, 2015, "Physics-based simulation of the impact of demand response on lead-acid emergency power availability in a datacenter", Journal of Power Sources

- Wei Zhu, C Zhang, J Li and Hosam Kadry Fathy, 2015, "A pseudospectral strategy for optimal power management in series hybrid electric powertrains", IEEE Transactions on Vehicular Technologies

- Michael Rothenberger, Donald Docimo, Mohammad Ghanaatpishe and Hosam Kadry Fathy, 2015, "Genetic optimization and experimental validation of a test cycle that maximizes parameter identifiability for a Li-ion equivalent circuit battery model", Journal of Energy Storage

- Benjamin L. Pence, Joseph Hays, Hosam Kadry Fathy, Corina Sandu and Jeffrey L. Stein, 2013, "Vehicle sprung mass estimation for rough terrain", International Journal of Vehicle Design,
**61**, pp. 3-26

- Tulga Ersal, Brent Gillespie, Mark Brudnak, Jeffrey L. Stein and Hosam Kadry Fathy, 2013, "Effect of coupling point selection on distortion in internet-distributed hardware-in-the-loop simulation", International Journal of Vehicle Design,
**61**, pp. 67-85

- Saied Bashash and Hosam Kadry Fathy, 2012, "Transport-based load modeling and sliding mode control of plug-in electric vehicles for robust renewable power tracking", IEEE Transactions on the Smart Grid,
**3**, pp. 526-534

- Rakesh M. Patil, Zoran S. Filipi and Hosam Kadry Fathy, 2012, "A framework for the integrated optimization of charging and power management in plug-in hybrid electric vehicles", Proceedings of the 2012 American Control Conference

- Kelsey B. Hatzell, Aabhas Sharma and Hosam Kadry Fathy, 2012, "A survey of long-term health modeling, estimation, and control challenges and opportunities for lithium-ion batteries", Proceedings of the 2012 American Control Conference

- Rakesh Patil, Jared Kelley, Zoran Filipi and Hosam Kadry Fathy, 2012, "A framework for the integrated optimization of charging and power management in plug-in hybrid electric vehicles", IEEE Transactions on Vehicular Technology

- Joel C. Forman, Scott J. Moura, Jeffrey L. Stein and Hosam Kadry Fathy, 2012, "Optimal experimental design for modeling battery degradation", Proceedings of the 2012 ASME Dynamic Systems and Control Conference

- Saeid Bashash and Hosam Kadry Fathy, 2012, "Power grid stabilization through setpoint control of frequency-responsive air conditioning loads", Proceedings of the 2012 ASME Dynamic Systems and Control Conference

- Rakesh Patil, Zoran Filipi and Hosam Kadry Fathy, 2012, "Minimizing CO2 emissions and dollar costs for plug-in hybrid vehicles using multi-objective dynamic programming", Proceedings of the 2012 ASME Dynamic Systems and Control Conference

- Saeid Bashash and Hosam Kadry Fathy, 2012, "Modeling and control of aggregate air conditioning loads for robust renewable power management", IEEE Transactions on Control System Technology,
**21**, (4)

- Rakesh M. Patil, Zoran S. Filipi and Hosam Kadry Fathy, 2012, "Computationally efficiency combined design and controller optimization using a coupling measure", ASME Journal of Mechanical Design,
**134**, (7)

- Scott J. Moura, Jeffrey L. Stein and Hosam Kadry Fathy, 2012, "Battery health conscious power management in plug-in hybrid electric vehicles via electrochemical modeling and stochastic control", IEEE Transactions on Control System Technology,
**21**, (3)

- Scott J. Moura and Hosam Kadry Fathy, 2012, "Optimal boundary control of reaction-diffusion PDEs via weak variations", ASME Journal of Dynamic Systems, Measurement, and Control

- Joel C. Forman, Scott J. Moura, Jeffrey L. Stein and Hosam Kadry Fathy, 2012, "Genetic identification and Fisher identifiability analysis of the Doyle-Fuller-Newman model from experimental cycling of a LiFePO4 cell", Journal of Power Sources,
**210**, pp. 263-275

- Di Wang, Chuangang Ren, Anand Sivasubramanian, Bhuvan Urgaonkar and Hosam Kadry Fathy, 2012, "Energy storage in datacenters: What, where, and how much?", Proceedings of the 2012 ACME SIGMETRICS/Performance Conference

- Saeid Bashash, Scott J. Moura and Hosam Kadry Fathy, 2011, "Plug-in hybrid electric vehicle charge pattern optimization for energy cost and battery longevity", Journal of Power Sources,
**196**, (1), pp. 541-549

- Tulga Ersal, Mark Brudnak, Ashwin Salvi, Jeffrey L. Stein, Zoran S. Filipi and Hosam Kadry Fathy, 2011, "Development and model-based transparency analysis of an internet-distributed hardware-in-the-loop platform", Journal of Mechatronics,
**21**, (1), pp. 22-29

- Scott J. Moura, Joel C. Forman, Saeid Bashash, Jeffrey L. Stein and Hosam Kadry Fathy, 2011, "Control of film growth in lithium-ion battery packs via switches", IEEE Transactions on Industrial Electronics,
**58**, (8), pp. 3555-3566

- Joel C. Forman, Saeid Bashash, Jeffrey L. Stein and Hosam Kadry Fathy, 2011, "Reduction of an electrochemistry-based Li-ion battery model via quasi-linearization and Padé approximation", Journal of the Electrochemical Society,
**158**, (2), pp. A93-A101

- Benjamin L. Pence, Hosam Kadry Fathy and Jeffrey L. Stein, 2011, "Recursive maximum likelihood parameter estimation for state-space systems using polynomial chaos theory", Automatica,
**47**, (11), pp. 2420-2424

- Saeid Bashash, Scott J. Moura and Hosam Kadry Fathy, 2011, "On the aggregate load imposed by battery health-conscious charging of plug-in hybrid electric vehicles", Journal of Power Sources,
**196**, (20), pp. 8747-8754

- Tulga Ersal, Mark Brudnak, Jeffrey L. Stein and Hosam Kadry Fathy, 2011, "Statistical transparency analysis in internet-distributed hardware-in-the-loop simulation", IEEE/ASME Transactions on Mechatronics

- Tulga Ersal, R. Brent Gillespie, Jeffrey L. Stein and Hosam Kadry Fathy, 2011, "Effect of coupling point selection on distortion in internet-distributed hardware-in-the-loop simulation", Proceedings of the 2011 American Control Conference

- Scott J. Moura and Hosam Kadry Fathy, 2011, "Optimal boundary control and estimation of diffusion-reaction PDEs", Proceedings of the 2011 American Control Conference

- Joel C. Forman, Scott J. Moura, Jeffrey L. Stein and Hosam Kadry Fathy, 2011, "Genetic parameter identification of the Doyle-Fuller-Newman model from experimental cycling of a LiFePO4 battery", Proceedings of the 2011 American Control Conference

- Saeid Bashash and Hosam Kadry Fathy, 2011, "Robust demand-side plug-in electric vehicle load control for renewable energy management", Proceedings of the 2011 American Control Conference

- Saeid Bashash and Hosam Kadry Fathy, 2011, "Modeling and control insights into demand-side energy management through setpoint control of thermostatic loads", Proceedings of the 2011 American Control Conference

- Rahul Ahlawat, Hosam Kadry Fathy and Jeffrey L. Stein, 2011, "Iterative learning based driver input synthesis for evaluating transient diesel soot emissions", Proceedings of the 2011 ASME Dynamic Systems and Control Conference

- Rakesh M. Patil, Hosam Kadry Fathy and Zoran S. Filipi, 2011, "Comparison of optimal supervisory control strategies for a series plug-in hybrid electric vehicle powertrain", Proceedings of the 2011 ASME Dynamic Systems and Control Conference

- Rahul Ahlawat, Hosam Kadry Fathy, Chengyun Guo, Byungchan Lee, Dohoy Jung and Jeffrey L. Stein, 2010, "Modeling and simulation of a dual-clutch transmission vehicle to analyze the effect of pump selection on fuel economy", Vehicle System Dynamics,
**48**, (7), pp. 851-868

- Scott J. Moura, Hosam Kadry Fathy, Duncan S. Callaway and Jeffrey L. Stein, 2010, "A stochastic optimal control approach for power management in plug-in hybrid electric vehicles", IEEE Transactions on Control System Technology,
**PP**, (99), pp. 1-11

- Tulga Ersal, H. Fuller, Omer Tsimhoni, Jeffrey L. Stein and Hosam Kadry Fathy, 2010, "Model-based analysis and classification of driver distraction under secondary tasks", IEEE Transactions on Intelligent Transportation Systems,
**11**, (3), pp. 692-701

- Benjamin L. Pence, Hosam Kadry Fathy and Jeffrey L. Stein, 2010, "A maximum likelihood approach to recursive polynomial chaos parameter estimation", Proceedings of the 2010 American Control Conference

- Saeid Bashash, Scott J. Moura and Hosam Kadry Fathy, 2010, "Charge trajectory optimization of plug-in hybrid electric vehicles for energy cost reduction and battery health enhancement", Proceedings of 2010 American Control Conference

- Rahul Ahlawat, Jonathan R. Hagena, Zoran S. Filipi, Jeffrey L. Stein and Hosam Kadry Fathy, 2010, "Volterra series estimation of transient soot emissions from a diesel engine", Proceedings of the 2010 IEEE Vehicle Power and Propulsion Conference

- Scott J. Moura, Jason B. Siegel, Donald J. Siegel, Hosam Kadry Fathy and Anna G. Stefanopoulou, 2010, "Education on electric vehicle propulsion: Battery systems, fuel cells, and hydrogen", Proceedings of the 2010 IEEE Vehicle Power and Propulsion Conference

- Joel C. Forman, Saeid Bashash, Jeffrey L. Stein and Hosam Kadry Fathy, 2010, "Reduction of an electrochemistry-based lithium-ion battery health degradation model via constraint linearization and Padé approximation", Proceedings of the 2010 ASME Dynamic Systems and Control Conference

- Saeid Bashash, Scott J. Moura and Hosam Kadry Fathy, 2010, "Battery health-conscious plug-in hybrid electric vehicle grid demand prediction", Proceedings of the 2010 ASME Dynamic Systems and Control Conference

- Scott J. Moura, Jeffrey L. Stein and Hosam Kadry Fathy, 2010, "Battery health-conscious power management for plug-in hybrid electric vehicles via stochastic control", Proceedings of the 2010 ASME Dynamic Systems and Control Conference

- Rakesh Patil, Zoran Filipi and Hosam Kadry Fathy, 2010, "Computationally efficient combined design and control optimization using a coupling measure", Proceedings of the 2010 IFAC Mechatronics Symposium

- Scott J. Moura, Duncan S. Callaway, Hosam Kadry Fathy and Jeffrey L. Stein, 2010, "Impact of battery sizing on stochastic optimal power management in plug-in hybrid electric vehicles", Journal of Power Sources,
**195**, (9), pp. 2979-2988

- Rahul Ahlawat, Hosam Kadry Fathy, Chengyun Guo, Byungchan Lee, Dohoy Jung and Jeffrey L. Stein, 2009, "Effect of pump selection on fuel economy in a dual clutch transmission vehicle", Proceedings of the 2009 American Control Conference

- Benjamin L. Pence, Hosam Kadry Fathy and Jeffrey L. Stein, 2009, "Sprung mass estimation for off-road vehicles via base-excitation suspension dynamics and recursive least squares", Proceedings of the 2009 American Control Conference

- Scott J. Moura, Joel C. Forman, Jeffrey L. Stein and Hosam Kadry Fathy, 2009, "Control of film growth in lithium-ion battery packs via switches", Proceedings of the 2009 ASME Dynamic Systems and Control Conference

- Tulga Ersal, Mark Brudnak, Jeffrey L. Stein and Hosam Kadry Fathy, 2009, "Variation-based transparency analysis of an internet-distributed hardware-in-the-loop simulation platform for vehicle powertrain systems", Proceedings of the 2009 ASME Dynamic Systems and Control Conference

- Tulga Ersal, Mark Brudnak, Ashwin Salvi, Jeffrey L. Stein, Zoran Filipi and Hosam Kadry Fathy, 2009, "Development of an internet-distributed hardware-in-the-loop simulation platform for an automotive application", Proceedings of the 2009 ASME Dynamic Systems and Control Conference

- Benjamin L. Pence, Hosam Kadry Fathy and Jeffrey L. Stein, 2009, "A base-excitation approach to polynomial chaos-based estimation of sprung mass for off-road vehicles", Proceedings of the 2009 ASME Dynamic Systems and Control Conference

- Tulga Ersal, Hosam Kadry Fathy and Jeffrey L. Stein, 2009, "Realization-preserving structure and order reduction of nonlinear energetic system models using energy trajectory correlations", Journal of Dynamic Systems, Measurement, and Control,
**131**, (3), pp. 031004

- Tulga Ersal, Burit Kittirungsi, Hosam Kadry Fathy and Jeffrey L. Stein, 2009, "Model reduction in vehicle dynamics using importance analysis", Vehicle System Dynamics,
**47**, (7), pp. 851-865

- Hosam Kadry Fathy, Dongsoo Kang and Jeffrey L. Stein, 2008, "Online vehicle mass estimation using recursive least squares and supervisory data extraction", Proceedings of the 2008 American Control Conference

- Scott Moura, Hosam Kadry Fathy, Duncan S. Callaway and Jeffrey L. Stein, 2008, "A stochastic optimal control approach for power management in plug-in hybrid electric vehicles", Proceedings of the 2008 ASME Dynamic Systems and Control Conference

- Rajeev Verma, Domitilla Del Vecchio and Hosam Kadry Fathy, 2008, "Longitudinal vehicle dynamics scaling and implementation on a HIL setup", Proceedings of the 2008 ASME Dynamic Systems and Control Conference

- Tulga Ersal, Burit Kitirungsi, Hosam Kadry Fathy and Jeffrey L. Stein, 2008, "Model reduction in vehicle dynamics using importance analysis", Proceedings of the 2008 ASME Dynamic Systems and Control Conference

- Tulga Ersal, Hosam Kadry Fathy, Loucas S. Louca, D. Geoff Rideout and Jeffrey L. Stein, 2008, "A review of proper modeling techniques", Journal of Dynamic Systems, Measurement, and Control,
**130**, (6), pp. 061008.1-13

- Tulga Ersal, Hosam Kadry Fathy and Jeffrey L. Stein, 2008, "Orienting body coordinate frames using Karhunen-Loéve expansion for more efficient structural simplification", Simulation Modeling Practice & Theory,
**17**, (1), pp. 197-210

- Tulga Ersal, Hosam Kadry Fathy and Jeffrey L. Stein, 2008, "Structural simplification of modular Bond graph models based on junction inactivity", Simulation Modeling Practice and Theory,
**17**, (1), pp. 175-196

- Rajeev Verma, Domitilla Del Vecchio and Hosam Kadry Fathy, 2008, "Development of a scaled vehicle with longitudinal dynamics of a HMMWV for an ITS testbed", IEEE/ASME Transactions on Mechatronics,
**13**, (1), pp. 46-67

- Zoran S. Filipi, Jonathan R. Hagena and Hosam Kadry Fathy, 2008, "Investigating the effect of in-vehicle transients on diesel soot emissions", Thermal Science,
**12**, (1), pp. 53-72

- Michael J. Martin, Hosam Kadry Fathy and Brian H. Houston, 2008, "Dynamic simulation of atomic force microscope cantilevers oscillating in liquid", Journal of Applied Physics,
**104**, (4), pp. 044316.1-8

- Scott Moura, Duncan S. Callaway, Hosam Kadry Fathy and Jeffrey L. Stein, 2008, "Impact of battery sizing on stochastic optimal power management in plug-in hybrid electric vehicles", Proceedings of the 2008 IEEE International Conference on Vehicle Electronics and Safety

- Burit Kittirungsi, Hosam Kadry Fathy and Jeffrey L. Stein, 2007, "Approximate similitude in energetic multi-domain systems: Quantification and use in multiobjective scaling", Proceedings of the 2007 ASME International Mechanical Engineering Congress and Exposition (IMECE)

- Tulga Ersal, Hosam Kadry Fathy, Loucas S. Louca, D. Geoff Rideout and Jeffrey L. Stein, 2007, "A review of proper modeling techniques", Proceedings of the 2007 ASME International Mechanical Engineering Congress and Exposition (IMECE)

- Tulga Ersal, Hosam Kadry Fathy and Jeffrey L. Stein, 2007, "Realization-preserving structure and order reduction of nonlinear energetic system models using energy trajectory correlations", Proceedings of the 2007 ASME International Mechanical Engineering Congress and Exposition (IMECE)

- Zoran Filipi, Hosam Kadry Fathy, Jonathan Hagena, Alexander Knafl, Rahul Ahlawat, Jinming Liu, Dohoy Jung, Dennis Assanis, Huei Peng and Jeffrey L. Stein, 2006, "Engine-in-the-loop testing for evaluating hybrid propulsion concepts and transient emissions - HMMWV case study", Proceedings of the 2006 SAE World Congress

- Zoran Filipi, Hosam Kadry Fathy and Jeffrey L. Stein, 2006, "Review of hardware-in-the-loop simulation and its prospects in the automotive area", Proceedings of the SPIE Conference on Modeling and Simulation for Military Applications

- Jongchul Jung, Kunsoo Huh, Hosam Kadry Fathy and Jeffrey L. Stein, 2006, "Optimal robust adaptive observer design for a class of nonlinear systems via an H-infinity approach", Proceedings of the 2006 American Control Conference

- Burit Kittirungsi, Hosam Kadry Fathy and Jeffrey L. Stein, 2006, "An efficient scaling methodology for dynamic models using dimensional and activity analyses", Proceedings of the ASME International Mechanical Engineering Congress and Exposition (IMECE)

- Tulga Ersal, Hosam Kadry Fathy and Jeffrey L. Stein, 2006, "Orienting body reference frames using Karhunen-Loeve expansion for more effective structural simplification", Proceedings of the 2006 ASME International Mechanical Engineering Congress and Exposition (IMECE)

- Tulga Ersal, Hosam Kadry Fathy and Jeffrey L. Stein, 2006, "Structural simplification of Bond graph models based on junction structure inactivity", Proceedings of the 2006 ASME International Mechanical Engineering Congress and Exposition (IMECE)

- Zoran S. Filipi, Hosam Kadry Fathy, Jonathan R. Hagena, Alexander Knafl, Rahul Ahlawat, Jinming Liu, Dohoy Jung, Dennis Assanis, Huei Peng and Jeffrey L. Stein, 2006, "Engine-in-the-loop testing for evaluating hybrid propulsion concepts and transient emissions - HMMWV case study", Journal of Commercial Vehicles, pp. SAE #2006-1-0443

- Mohamed El Gendy, Kang Shin and Hosam Kadry Fathy, 2005, "CONNET: Self-controlled access links for delay and jitter requirements", Proceedings of the 13th IEEE International Conference on Network Protocols

- Hosam Kadry Fathy, Rahul Ahlawat and Jeffrey L. Stein, 2005, "Proper powertrain modeling for engine-in-the-loop simulation", Proceedings of the 2005 ASME International Mechanical Engineering Congress and Exposition

- Tetsuji Kozaki, Hiroshi Mori, Hosam Kadry Fathy and Swaminathan Gopalswamy, 2004, "Balancing the speed and fidelity of automotive powertrain models through surrogation", Proceedings of the 2004 ASME International Mechanical Congress and Exposition (IMECE)

- Hosam Kadry Fathy, Panos Y. Papalambros, A. Galip Ulsoy and Davor Hrovat, 2003, "Nested plant/controller optimization with application to combined passive/active automotive suspensions", Proceedings of the 2003 American Control Conference

- Hosam Kadry Fathy, Panos Y. Papalambros and A. Galip Ulsoy, 2003, "Integrated plant, observer, and controller optimization with application to combined passive-active automotive suspensions", Proceedings of the 2003 International Mechanical Engineering Congress and Exposition (IMECE)

- Hosam Kadry Fathy, Scott A. Bortoff, G. Scott Copeland, Panos Y. Papalambros and A. Galip Ulsoy, 2002, "Nested optimization of an elevator and its gain-scheduled LQG controller", Proceedings of the 2002 ASME International Mechanical Engineering Congress and Exposition

- Julie A. Reyer, Hosam Kadry Fathy, Panos Y. Papalambros and A. Galip Ulsoy, 2001, "Comparison of combined embodiment design and control optimization strategies using optimality conditions", Proceedings of the 2001 ASME Design Engineering Technical Conferences

- Hosam Kadry Fathy, Julie A. Reyer, Panos Y. Papalambros and A. Galip Ulsoy, 2001, "On the coupling between the plant and controller optimization problems", Proceedings of the 2001 American Control Conference

- Hosam Kadry Fathy, J. Garth Thompson and Peter J. Gorder, 1999, "Direct determination of aircraft quaternion parameters using a combined inertial-GPS instrumentation system", Proceedings of the 1999 ION GPS Conference