Peer-Reviewed Conference Papers

  1. Rubin, E.S., J.S. Salmento, and H.C. Frey, “Evaluating Combined SO2/NOx Processes,” Proceedings:  Fourth Symposium on Integrated Environmental Control, Report No. GS-6519, Electric Power Research Institute, Palo Alto, California, September 1989, pp. 6-1 to 6-15.
  2. Frey, H.C., E.S. Rubin, and U.M. Diwekar, “An Evaluation Method for Integrated Gasification Combined Cycle (IGCC) Power Systems,” Paper No. 90-103.6, Proceedings of the 83rd Annual Meeting (held June 24-29 in Pittsburgh, PA), Air and Waste Management Association, Pittsburgh, Pennsylvania, June 1990.
  3. Rubin, E.S., H.C. Frey, and U.M. Diwekar, “Probabilistic Modeling of the Performance and Economics of IGCC Systems,” Integrating Environmental Controls and Energy Production, Report No. EC-Vol. 2, American Society of Mechanical Engineers, New York, New York, 1991, p. 59-66.
  4. Frey, H.C., and E.S. Rubin, “Evaluating Advanced Technologies for Acid Rain Compliance,” Energy in the 90’s, B.F. Hobbs, ed., American Society of Civil Engineers, New York, 1991, p. 172-178.
  5. Frey, H.C., and E.S. Rubin, “High Efficiency Integrated Environmental Control for Coal-Based Power Generation,” Paper No. 92-108.02, Proceedings of the 85th Annual Meeting (held June 21-26 in Kansas City, MO), Air and Waste Management Association, Pittsburgh, Pennsylvania, June 1992.
  6. Frey, H.C., “Performance Model of the Fluidized Bed Copper Oxide Process for SO2/NOxControl,” Paper No. 93-WA-79.01, Proceedings of the 86th Annual Meeting (held June 13-18 in Denver, CO), Air and Waste Management Association, Pittsburgh, Pennsylvania, June 1993.
  7. Frey, H.C., “Separating Variability and Uncertainty in Exposure Assessment: Motivation and Methods,” Paper No. 93-RA-116A.02, Proceedings of the 86th Annual Meeting, (held June 13-18 in Denver, CO), Air and Waste Management Association, Pittsburgh, Pennsylvania, June 1993.
  8. Rubin, E.S., M.B. Berkenpas, H.C. Frey, and B. Toole-O’Neil, “Modeling the Uncertainty in Hazardous Air Pollutant Emissions,” Proceedings of the Second International Conference on Managing Hazardous Air Pollutants, Electric Power Research Institute, Palo Alto, CA, July 1993.
  9. Frey, H.C., “Probabilistic Performance, Environmental, and Economic Evaluation of an Advanced Coal Gasification System,” Paper No. 94-TA260.05P, Proceedings of the 87th Annual Meeting (held June 19-24 in Cincinnati, OH), Air and Waste Management Association, Pittsburgh, Pennsylvania, June 1994.
  10. Frey, H.C., “Quantitative Analysis of Uncertainty and Variability in Exposure and Risk Assessment: Some Guidance on Why and How,” Paper No. 94-TP55.03, Proceedings of the 87th Annual Meeting (held June 19-24 in Cincinnati, OH), Air and Waste Management Association, Pittsburgh, Pennsylvania, June 1994.
  11. Diwekar, U.M., E.S. Rubin, and H.C. Frey, “Optimal Design and Synthesis of Advanced Power Systems under Uncertainty,” Proceedings of the Coal-Fired Power Systems 94—Advances in IGCC and PFBC Review Meeting, Volume 1, U.S. Department of Energy, Morgantown, West Virginia, June 21-23, 1994, pp. 499-512.
  12. Frey, H.C., U.M. Diwekar, and E.S. Rubin, “Probabilistic Modeling of High Efficiency Environmental Control for Advanced Coal Gasification Power Generation,” Proceedings, 5th Pollution Prevention Topical Conference, American Institute of Chemical Engineers, New York, 1994
  13. Haimes, Y.Y., T. Barry, and J.H. Lambert (Eds), “When and How Can You Specify a Probability Distribution When You Don’t Know Much?,” Risk Analysis, 14(5):661-706 (October 1994). Steering Committee Member and Workshop Participant/Contributor (see pp. 703-706).
  14. Frey, H.C., and A.C. Cullen, “Distribution Development for Probabilistic Exposure Assessment,” Paper No. 95-42.02, Proceedings of the 88th Annual Meeting (held June 18-23 in San Antonio, TX), Air and Waste Management Association, Pittsburgh, Pennsylvania, June 1995.
  15. Agarwal, P., and H.C. Frey, “Performance Model of the Externally-Fired Combined Cycle (EFCC) System,” Paper No. 95-7.02, Proceedings of the 88th Annual Meeting (held June 18-23 in San Antonio, TX), Air and Waste Management Association, Pittsburgh, Pennsylvania, June 1995.
  16. Frey, H.C., M.D. Kini, S.R. Ranjithan, and S.Y. Fu, “Uncertainty, Bias, and Variability in Emission Factors for Light Duty Gasoline Vehicles,” Paper No. 96-108B.03, Proceedings of the 89th Annual Meeting (held June 23-28 in Nashville, TN), Air and Waste Management Association, Pittsburgh, Pennsylvania, June 1996.
  17. Frey, H.C., and P. Agarwal, “Probabilistic Modeling and Optimization of Clean Coal Technologies: Case Studies of the Externally-Fired Combined Cycle (EFCC) System,” Paper No. 96-119.02, Proceedings of the 89th Annual Meeting (held June 23-28 in Nashville, TN), Air and Waste Management Association, Pittsburgh, Pennsylvania, June 1996.
  18. Tran, L.K., and H.C. Frey, “Methods for Evaluating the Costs of Utility NOx Control Technologies,” Paper No. 96-139.06, Proceedings of the 89th Annual Meeting (held June 23-28 in Nashville, TN), Air and Waste Management Association, Pittsburgh, Pennsylvania, June 1996.
  19. Frey, H.C., “Comparison of Classroom and Video-Based Instruction: A Case Study for a Graduate-Level Air Pollution Control Course,” Paper No. 96-125.03, Proceedings of the 89th Annual Meeting (held June 23-28 in Nashville, TN), Air and Waste Management Association, Pittsburgh, Pennsylvania, June 1996.
  20. Rubin, E.S., U.M. Diwekar, and H.C. Frey, “Optimizing Advanced Power Systems Design Under Uncertainty,” DOE/MC/29094-97/C0713, Proceedings of the Advanced Coal-Fired Power Systems Review Meeting, U.S. Department of Energy, Morgantown, West Virginia, July 16-18, 1996 (CD-ROM).
  21. Frey, H.C., “Bootstrap Methods for Quantitative Analysis of Variability and Uncertainty in Exposure and Risk Assessment,” Paper No. 97-RA100B.03, Proceedings of the 90th Annual Meeting (held June 18-13 in Toronto, Canada), Air and Waste Management Association, Pittsburgh, Pennsylvania, June 1997.
  22. Frey, H.C., and D.A. Eichenberger, “Quantification of Uncertainty in Remote Sensing-Based School Bus CO and Hydrocarbon Emission Factors,” Paper No. 97-RP143.07, Proceedings of the 90th Annual Meeting (held June 18-13 in Toronto, Canada), Air and Waste Management Association, Pittsburgh, Pennsylvania, June 1997.
  23. Frey, H.C., and Z. Iwanski, “Probabilistic Methodology for Risk Assessment of New Energy Technologies and Application to Gasification Repowering for an Oil Refinery in Poland,” FLOWERS ‘97: Florence World Energy Symposium, SGEditorial: Padova, Italy, 1997, pp. 267-274.
  24. Frey, H.C., and R. Bharvirkar, “Desktop Modeling of the Performance, Emissions, and Cost of Gasification Systems,” Paper No. 98-RAA.02P, Proceedings of the 91st Annual Meeting (held June 14-18 in San Diego, CA), Air and Waste Management Association, Pittsburgh, Pennsylvania, June 1998 (CD-ROM).
  25. Frey, H.C., “Methods for Quantitative Analysis of Variability and Uncertainty in Hazardous Air Pollutant Emissions,” Paper No. 98-RP105B.01, Proceedings of the 91st Annual Meeting (held June 14-18 in San Diego, CA), Air and Waste Management Association, Pittsburgh, Pennsylvania, June 1998 (CD-ROM).
  26. Akunuri, N.V., and H.C. Frey, “Modeling the Performance, Emissions, and Cost of an Entrained-Flow Gasification Combined Cycle System Using ASPEN,” Paper No. 99-379, Proceedings of the 92nd Annual Meeting (held June 20-24 in St. Louis, MO), Air and Waste Management Association, Pittsburgh, Pennsylvania, June 1999.
  27. Unal, A., R.H. Dalton, H.C. Frey, and N.M. Rouphail, “Simultaneous Measurement of On-Road Vehicle Emissions and Traffic Flow Using Remote Sensing and an Area-Wide Detector,” Paper No. 99-712, Proceedings of the 92nd Annual Meeting (held June 20-24 in St. Louis, MO), Air and Waste Management Association, Pittsburgh, Pennsylvania, June 1999.
  28. Frey, H.C., R. Bharvirkar, and J. Zheng, “Quantification of Variability and Uncertainty in Emission Factors,” Paper No. 99-267, Proceedings of the 92nd Annual Meeting (held June 20-24 in St. Louis, MO), Air and Waste Management Association, Pittsburgh, Pennsylvania, June 1999.
  29. Zheng, J., A. Unal, and H.C. Frey, “Variability and Uncertainty Analysis of CO Exposure to Vehicle Passengers During Cold-Start,” Proceedings of 93rd Annual Meeting of the Air & Waste Management Association, Salt Lake City, Utah, June 18-22, 2000.
  30. Rouphail, N.M, H.C. Frey, A. Unal, and J.D. Colyar, “Vehicle Emissions and Traffic Measures: Exploratory Analysis of Field Data at Signalized Intersections,” Proceedings of 2001 Annual Meeting of the Transportation Research Board, Washington, DC, January 7-12, 2001.
  31. Frey, H.C., and J. Zheng, “Quantification of Variability and Uncertainty in Emission Inventories: A Prototype Software Tool with Application to Utility NOx Emissions,” Proceedings, Annual Meeting of the Air & Waste Management Association, Pittsburgh, PA, June 2001.
  32. Coehlo, M., and H.C. Frey, “Evaluation of Alternative Future Energy Scenarios for Brazil Using an Energy Mix Model,” Proceedings, Annual Meeting of the Air & Waste Management Association, Pittsburgh, PA, June 2001.
  33. Zheng, J., and H.C. Frey, “Quantitative Analysis of Variability and Uncertainty in Emission Estimation: An Illustration of Methods Using Mixture Distributions,” Proceedings, Annual Meeting of the Air & Waste Management Association, Pittsburgh, PA, June 2001.
  34. Bammi, S., and H.C. Frey, “Quantification Of Variability and Uncertainty In Lawn And Garden Equipment NOx and Total Hydrocarbon Emission Factors,” Proceedings, Annual Meeting of the Air & Waste Management Association, Pittsburgh, PA, June 2001.
  35. Frey, H.C., N.M. Rouphail, A. Unal, and J. Colyar, “Measurement of On-Road Tailpipe CO, NO, and Hydrocarbon Emissions Using a Portable Instrument,” Proceedings, Annual Meeting of the Air & Waste Management Association, Pittsburgh, PA, June 2001.
  36. Frey, C., and S. Li, “Quantification of Variability and Uncertainty in Stationary Natural Gas-fueled Internal Combustion Engine NOx and Total Organic Compounds Emission Factor,” Proceedings, Annual Meeting of the Air & Waste Management Association, Pittsburgh, PA, June 2001.
  37. Unal, A., H.C. Frey, N.M. Rouphail, J.D. Colyar, “Hot Spot Analysis of Real-World Vehicle Emissions Based Upon a Portable On-Board Measurement System,” Proceedings, Annual Meeting of the Air & Waste Management Association, Pittsburgh, PA, June 2001.
  38. Li, S., and H.C. Frey, “Methods and Example for Development of a Probabilistic Per-Capita Emission Factor for VOC Emissions from Consumer/Commercial Product Use”, Proceedings, Annual Meeting of the Air & Waste Management Association, Pittsburgh, PA, June 2002.
  39. Abdel-Aziz, A., and H.C. Frey, “Quantification of Variability and Uncertainty in Hourly NOx Emissions from Coal-Fired Power Plants,” Proceedings, Annual Meeting of the Air & Waste Management Association, Pittsburgh, PA, June 2002.
  40. Zheng, J., and H.C. Frey, “Development of a Software Module for Statistical Analysis of Variability and Uncertainty,” Proceedings, Annual Meeting of the Air & Waste Management Association, Pittsburgh, PA, June 2002.
  41. Unal, A., N.M. Rouphail, and H.C. Frey, “Effect of Arterial Signalization and Level of Service on Measured Vehicle Emissions,” TRB Paper No. 03-2884, Proceedings, 82nd Annual Meeting of the Transportation Research Board, Washington, DC, January 12-16, 2003.
  42. Zhao, Y., and H.C. Frey, “Quantification of Uncertainty and Variability for Air Toxic Emission Factor Data Sets Containing Non-Detects,” Proceedings, Annual Meeting of the Air & Waste Management Association, Pittsburgh, PA, June 2003.
  43. Abdel-Aziz, A. and H.C. Frey, “Quantification of Hourly Variability in Hourly Activity and NOx Emissions for Baseload Coal-Fired Power Plants,” Proceedings, Annual Meeting of the Air & Waste Management Association, Pittsburgh, PA, June 2003.
  44. Frey, C., A. Unal, J. Chen, and S. Li, “Modeling Mobile Source Emissions Based Upon In-Use and Second-by-Second Data:  Development of Conceptual Approaches for EPA’s New MOVES Model,” Proceedings, Annual Meeting of the Air & Waste Management Association, Pittsburgh, PA, June 2003.
  45. Zheng, J., and H.C. Frey, “Windows-Based Software Implementation and Uncertainty Analysis of the EPA SHEDS/Pesticides Model,” Proceedings, Annual Meeting of the Air & Waste Management Association, Pittsburgh, PA, June 2003.
  46. Zhao, Y., and H.C. Frey, “Development of Probabilistic Emission Inventory of Air Toxics for Jacksonville, FL,” Proceedings, Annual Meeting of the Air & Waste Management Association, June 22-25, 2004, Indianapolis, IN, published by Air & Waste Management Association, Pittsburgh, PA, June 2004.
  47. Hanna, A., J. Vukovich, S. Arunachalam, D. Loughlin, H.C. Frey, J. Touma, J. Irwin, and V. Isakov, “Assessment of Uncertainty in Benzene Concentration Estimates in the Houston, TX, Area,” Proceedings, Annual Meeting of the Air & Waste Management Association, June 22-25, 2004, Indianapolis, IN, published by Air & Waste Management Association, Pittsburgh, PA, June 2004.
  48. Hanna, S.R., D. Heinold, R. Paine, H.C. Frey, D. Baker, R. Karp, and H. Feldman, “A Monte Carlo Study of the Uncertainties in Predictions by ISC3ST and AERMOD of Annual Average Benzene and 1,3-Butadiene Concentrations around the Houston Ship Channel,” Proceedings, Annual Meeting of the Air & Waste Management Association, June 22-25, 2004, Indianapolis, IN, published by Air & Waste Management Association, Pittsburgh, PA, June 2004.
  49. Frey, H.C., and K. Kim, “In-Use Emissions of Heavy-Duty Diesel Dump Trucks on Petroleum Diesel and B20 Biodiesel Fuels,” Proceedings, Annual Meeting of the Air & Waste Management Association, June 20-23, 2005, Minneapolis, MN.
  50. Zhang, K., and H.C. Frey, “Road Grade Estimation for On-Road Vehicle Emissions Modeling Using LIDAR Data,” Proceedings, Annual Meeting of the Air & Waste Management Association, June 20-23, 2005, Minneapolis, MN.
  51. Frey, H.C., and K. Kim, “Comparison of Real-World Fuel Use and Emissions for Dump Trucks Fueled with B20 Biodiesel Versus Petroleum Diesel,” Paper 06-1078, 2006 Annual Meeting of the Transportation Research Board, Washington, DC, January 2006.
  52. Frey, H.C., N.M. Rouphail, and H. Zhai, “Speed- and Facility-Specific Emission Estimates for On-Road Light-Duty Vehicles based on Real-World Speed Profiles,” Paper 06-1096, 2006 Annual Meeting of the Transportation Research Board, Washington, DC, January 2006.
  53. Frey, H.C., “Incorporating Risk and Uncertainty into the Assessment of Impacts of Global Climate Change on Transportation Systems,” Proceedings, 2nd Workshop on Impacts of Global Climate Change On Hydraulics and Hydrology and Transportation, Center for Transportation and the Environment, NC State, held in Washington, DC, March 29, 2006.
  54. Kim, K., S. Abolhasani, S.H. Pang, and H.C. Frey, “Real-world Data Collection Procedure for Non-road Construction Equipment: Problems, Solutions, and Data Quality Assurance,” Paper No. 548, Proceedings, Annual Meeting of the Air & Waste Management Association, New Orleans, LA, June 20-23, 2006.
  55. Zhai, H., H.C. Frey, and N.M. Rouphail, “Speed- and Facility-Specific Emissions Estimates for Transit Buses based on Measured Speed Profiles,” Paper No. 195, Proceedings, Annual Meeting of the Air & Waste Management Association, New Orleans, LA, June 20-23, 2006.
  56. Rouphail, N.M., H.C. Frey, and H. Zhai, “Measuring the Effect of Level of Service on Vehicle Emissions,” Fifth International Symposium on Highway Capacity and Quality of Service, Transportation Research Board, Yokohama, Japan, July 25-29, 2006.
  57. Rouphail, N.M, and H.C. Frey, “Advances in Measuring and Modeling Traffic Impacts on Vehicle Emissions: An Overview,” Proceedings, Seventh International Congress on Advances in Civil Engineering, Yildiz Technical University, Istanbul, Turkey, October 11-13, 2006.
  58. Zhai, H., H.C. Frey, N.M. Rouphail, G.A. Gonçalves, and T.L. Farias, “Fuel Consumption and Emissions Comparisons between Ethanol 85 and Gasoline Fuels for Flexible Fuel Vehicles,” Paper No. 2007-AWMA-444, Proceedings, 100th Annual Meeting of the Air & Waste Management Association, Pittsburgh, PA, June 26-28, 2007.
  59. Frey, H.C., and K. Zhang, “Spatial and Temporal Analysis of Real-World Empirical Fuel Use and Emissions,” Paper No. 2007-AWMA-285, Proceedings, 100th Annual Meeting of the Air & Waste Management Association, Pittsburgh, PA, June 26-28, 2007.
  60. Frey, H.C., and P.Y. Kuo, “Potential Best Practices for Reducing Greenhouse Gas (GHG) Emissions in Freight Transportation,” Paper No. 2007-AWMA-443, Proceedings, 100th Annual Meeting of the Air & Waste Management Association, Pittsburgh, PA, June 26-28, 2007.
  61. Frey, H.C., W. Rasdorf, S.-H. Pang, K. Kim, S. Abolhasani, and P. Lewis, “Methodology for Activity, Fuel Use, and Emissions Data Collection and Analysis for Nonroad Construction Equipment,” Paper No. 2007-AWMA-447, Proceedings, 100th Annual Meeting of the Air & Waste Management Association, Pittsburgh, PA, June 26-28, 2007.
  62. Zhai, H., H.C. Frey, N.M. Rouphail, G. Goncalves, and T. Farias, “Impact of Alternative Vehicle Technologies on Vehicle Emissions,” Proceedings of Transportation Land Use, Planning, and Air Quality 2007, Orlando, FL, July 9-11, 2007.
  63. Zheng, J., and H.C. Frey, “Treatment of Censored Data and Dependency Among Sampling Distributions in Probabilistic Human Health Exposure Assessment,” in Advances in Studies on Risk Analysis and Crisis Response, C. Huang, C. Frey, and J. Feng, eds., Atlantis Press: Paris, France, 2007, pp. 802-808.  (Proceedings of 1st International Conference on Risk Assessment and Crisis Response, Shanghai, China, September 25-26, 2007).
  64. Frey, H.C., W.J. Rasdorf, K. Kim, S.H. Pang, P. Lewis, “Comparison of Real-World Emissions of Backhoes, Front-End Loaders and Motor Graders for B20 Biodiesel vs. Petroleum Diesel for Selected Engine Tiers,” Proceedings, 87th Annual Meeting of the Transportation Research Board, January 13-17, 2008.
  65. Frey, H.C., P.Y. Kuo, and C. Villa, “Methodology for Characterization of Long-Haul Truck Idling Activity under Real-World Conditions,” Proceedings, 87th Annual Meeting of the Transportation Research Board, January 13-17, 2008.
  66. Frey, H.C., N.M. Rouphail, and H. Zhai, “Link-Based Emission Factors for Heavy-Duty Diesel Trucks Based on Real-World Data,” Proceedings, 87th Annual Meeting of the Transportation Research Board, January 13-17, 2008.
  67. Frey, H.C., W. Rasdorf, S.-H. Pang, K. Kim, S. Abolhasani, and P. Lewis, “Vehicle-Specific Emissions Modeling For Non-Road Construction Vehicles Based Upon Real-World Measurements,” Paper No. 569, Proceedings, 101st Annual Meeting of the Air & Waste Management Association, Portland, OR, June 24-27, 2008.
  68. Frey, H.C., Kim, S. Pang, W. Rasdorf, P. Lewis, “Characterization of Real-World Activity, Fuel Use and Emissions for Selected Motor Graders Fueled with Petroleum Diesel and B20 Biodiesel,” Paper No. 607, Proceedings, 101st Annual Meeting of the Air & Waste Management Association, Portland, OR, June 24-27, 2008.
  69. Frey, H.C., P.Y. Kuo, and C. Villa, “Measurement and Modeling of Fuel Use and Exhaust Emissions from Idling Long-Haul Freight Truck and Auxiliary Power Unit Engines,” Paper No. 616, Proceedings, 101st Annual Meeting of the Air & Waste Management Association, Portland, OR, June 24-27, 2008.
  70. Frey, H.C., and H.W. Choi, “Estimating Light Duty Gasoline Vehicle Emission Factors at High Transient and Constant Speeds for Short Road Segments to Support Near-Roadway Air Quality Studies,” Paper No. 625, Proceedings, 101st Annual Meeting of the Air & Waste Management Association, Portland, OR, June 24-27, 2008.
  71. Frey, H.C., H. Zhai, N. Rouphail, G. Gonçalves, T. Farias, “Fuel Consumption and Tailpipe Emissions Comparisons between Ethanol 85 and Gasoline Fuels for Flexible Fuel Vehicles,” Paper No. 637, Proceedings, 101st Annual Meeting of the Air & Waste Management Association, Portland, OR, June 24-27, 2008.
  72. Lewis, P., H.C. Frey, W.J. Rasdorf, “Development and Use of Emissions Inventories for Construction Vehicles,” Proceedings, 88th Annual Meeting of the Transportation Research Board, January 2009.
  73. Frey, H.C., H. Zhai, and N.M. Rouphail, “Regional On-Road Vehicle Running Emissions Modeling and Evaluation for Conventional and Alternative Vehicle Technologies,” Proceedings, 88th Annual Meeting of the Transportation Research Board, January 2009.
  74. Deshpande, B., H.C. Frey, Y. Cao, and Z. Liu, “Modeling of the Penetration of Ambient PM5 to Indoor Residential Microenvironment,” Paper 2009-A-86-AWMA, Proceedings, 102nd Annual Conference and Exhibition, Air & Waste Management Association, Detroit, Michigan, June 16-19, 2009.
  75. Frey, H.C., and B. Hubbell, “A Risk-based Assessment And Management Framework For Multipollutant Air Quality,” Paper 2009-A-235-AWMA, Proceedings, 102nd Annual Conference and Exhibition, Air & Waste Management Association, Detroit, Michigan, June 16-19, 2009.
  76. Liu, Z., H.C. Frey, Y. Cao, and B. Deshpande, “Modeling of In-vehicle PM5 Exposure Using the Stochastic Human Exposure and Dose Simulation Model,” Paper 2009-A-238-AWMA, Proceedings, 102nd Annual Conference and Exhibition, Air & Waste Management Association, Detroit, Michigan, June 16-19, 2009.
  77. Cao, Y., H.C. Frey, Z. Liu, and B. Deshpande, “Evaluation of the Modeling of Exposure to Environmental Tobacco Smoke (ETS) in the SHEDS-PM Model,” Paper 2009-A-239-AWMA, Proceedings, 102nd Annual Conference and Exhibition, Air & Waste Management Association, Detroit, Michigan, June 16-19, 2009.
  78. Frey, H.C., H.W. Choi, E. Pritchard, and J. Lawrence, “In-Use Measurement of the Activity, Energy Use, and Emissions of a Plug-in Hybrid Electric Vehicle,” Paper 2009-A-242-AWMA, Proceedings, 102nd Annual Conference and Exhibition, Air & Waste Management Association, Detroit, Michigan, June 16-19, 2009.
  79. Frey, H.C., H.W. Choi, and K. Kim, “Measurement of the Energy Use and Emissions of Passenger Rail Locomotives Using a Portable Emission Measurement System,” Paper 2009-A-243-AWMA, Proceedings, 102nd Annual Conference and Exhibition, Air & Waste Management Association, Detroit, Michigan, June 16-19, 2009.
  80. Graver, B., and H.C. Frey, “Estimation of Air Carrier Emissions at Raleigh-Durham International Airport,” Paper 2009-A-486-AWMA, Proceedings, 102nd Annual Conference and Exhibition, Air & Waste Management Association, Detroit, Michigan, June 16-19, 2009.
  81. Choi, H.W., and H.C. Frey, “Estimating Diesel Vehicle Emission Factors at Constant and High Speeds for Short Road Segments,” Paper 10-0382, Proceedings, 89th Annual Meeting of the Transportation Research Board, January 2010.
  82. Graver, B., and H.C. Frey, “Estimation of Per Seat and Per Passenger Air Carrier Emissions at Raleigh-Durham International Airport,” Paper TRB 10-1417, Proceedings, 89th Annual Meeting of the Transportation Research Board, January 2010.
  83. Frey, H.C., W. Rasdorf, P. Lewis, “Results of a Comprehensive Study of Fuel Use and Emissions of Nonroad Diesel Construction Equipment,” Paper TRB 10-2763, Proceedings, 89th Annual Meeting of the Transportation Research Board, January.
  84. Coelho, M.C., J. Andrade, D. Soares, H.C. Frey, and N.M. Rouphail, “A Vehicle Energy Use and Safety Information Support System,” Paper TRB 10-3034, Proceedings, 89th Annual Meeting of the Transportation Research Board, January 2010.
  85. Liu, X., H.C. Frey, and Y. Cao, “Estimation of In-Vehicle Concentration and Human Exposure for PM5 Based on Near Roadway Ambient Air Quality and Variability in Vehicle Operation,” Paper TRB 10-3564, Proceedings, 89th Annual Meeting of the Transportation Research Board, January 2010.
  86. Liu, X., Y. Cao, and H.C. Frey, “Modeling of In-vehicle PM2.5 Exposure Using the Stochastic Human Exposure and Dose Simulation Model,” Paper 2010-A-975-AWMA, Proceedings, 103rd Annual Conference and Exhibition, Air & Waste Management Association, Calgary, Canada, June 2010.
  87. Frey, H.C., H.W. Choi, B.M. Graver, and G.S. Sandhu, “Comparative Assessment of Passenger Railroad Locomotives Using Portable Emission Measurement Systems,” Paper 2010-A-970-AWMA, Proceedings, 103rd Annual Conference and Exhibition, Air & Waste Management Association, Calgary, Canada, June 2010.
  88. M. Graver, and H.C. Frey, “Quantifying the Microscale Activity, Energy Use, and Emissions of a Plug-In Hybrid Electric Vehicle Based on In-Use Data,” Paper 2010-A-946-AWMA, Proceedings, 103rd Annual Conference and Exhibition, Air & Waste Management Association, Calgary, Canada, June 2010.
  89. Lewis, P., M. Leming, H.C. Frey, and W. Rasdorf, “Assessing the Effects of Operational Efficiency on Pollutant Emissions of Nonroad Diesel Construction Equipment,” TRB 11-3186, Proceedings, 90th Annual Meeting of the Transportation Research Board, January 2011.
  90. Zhai, H., H.C. Frey, and N.M. Rouphail, “Development of A Modal Emissions Model for A Hybrid Electric Vehicle,” TRB 11-1190, Annual Meeting of the Transportation Research Board, January 2011.
  91. Frey, H.C., G. Sandhu, Y. Sun, T. Lee, H. Swidan, B. Liu, and S. Babaee, “Incorporating Vehicle Portable Emissions Measurement Systems Into the Classroom,” 2011-A-146-AWMA, Proceedings, 104th Annual Meeting of the Air & Waste Management Association, Orlando, FL, June 21-24, 2011.
  92. Jiao, W., and H.C. Frey, “Assessment of Inter-individual Geographic and Seasonal Variability in Estimated Human Exposure to PM2.5,” 2011-A-176-AWMA, Proceedings, 104th Annual Meeting of the Air & Waste Management Association, Orlando, FL, June 21-24, 2011.
  93. Sun, Y., and H.C. Frey, “Comparison of Real-world Activity, Fuel Use, and Emissions for Selected Light Duty Gasoline Vehicles Based on Driving Cycles,” 2011-A-306-AWMA, Proceedings, 104th Annual Meeting of the Air & Waste Management Association, Orlando, FL, June 21-24, 2011.
  94. Lee, T., and H.C. Frey, “Variability in Gram Per Gallon Vehicle Emission Factors With Engine Load and Among Driving Cycles,” 2011-A-328-AWMA, Proceedings, 104th Annual Meeting of the Air & Waste Management Association, Orlando, FL, June 21-24, 2011.
  95. Liu, X., and H.C. Frey, “Apportionment of Human Exposure to Fine Particulate Matter Among Indoor and Outdoor Emission Sources and Processes,” 2011-A-365-AWMA, Proceedings, 104th Annual Meeting of the Air & Waste Management Association, Orlando, FL, June 21-24, 2011.
  96. Graver, B.M., and H.C. Frey, “Fuel Use and Emission Rates for F59PH Locomotive Engines Tested on an Engine Dynamometer,” 2011-A-586-AWMA, Proceedings, 104th Annual Meeting of the Air & Waste Management Association, Orlando, FL, June 21-24, 2011.
  97. Graver, B.M., and H.C. Frey, “Modeling of Hybrid and Plug-In Hybrid Electric Vehicle Energy Use and Emissions Based on In-Use Measurement,” 2011-A-590-AWMA, Proceedings, 104th Annual Meeting of the Air & Waste Management Association, Orlando, FL, June 21-24, 2011.
  98. Liu, B., and H.C. Frey, “Comparison of Driving Schedule Project Level MOVES Emission Factors to Empirical Data,” 2011-A-645-AWMA, Proceedings, 104th Annual Meeting of the Air & Waste Management Association, Orlando, FL, June 21-24, 2011.
  99. Frey, H.C., and S. Pierce, “Comparison of the Performance, Emissions, and Cost of Fossil-Fuel Combustion and Gasification Based “Zero Emissions” Power Plant Designs,” 2011-A-646-AWMA, Proceedings, 104th Annual Meeting of the Air & Waste Management Association, Orlando, FL, June 21-24, 2011.
  100. Frey, H.C., H.W. Choi, and K. Kim, “Measurement of Emissions of Passenger Rail Locomotives Using a Portable Emissions Measurement System,” 12-0739, Proceedings, Annual Meeting, Transportation Research Board, Washington, DC, January 2012.
  101. Sandhu, G.S., and H.C. Frey, “Real-World Measurement and Evaluation of Heavy Duty Truck Duty Cycles, Fuels, and Emission Control Technologies,” 12-4674, Proceedings, Annual Meeting, Transportation Research Board, Washington, DC, January 2012.
  102. Lewis, P., W. Rasdorf, M. Leming, and H.C. Frey, “Effects of Engine Idling on NAAQS Criteria Pollutant Emissions from Nonroad Diesel Construction Equipment,” 12-0219, Proceedings, Annual Meeting, Transportation Research Board, Washington, DC, January 2012.
  103. Jiao, W., and H.C. Frey, “Characterization of PM5 Concentration in Indoor Residential Microenvironments,” 2012-A-262-AWMA, Proceedings, Annual Meeting of the Air & Waste Management Association, San Antonio, TX, June 19-22, 2012.
  104. Graver, B.M., and H.C. Frey, “Estimation of Light-Duty Gasoline Vehicle Emissions Avoided by Passenger Rail Service in North Carolina,” 2012-A-270-AWMA, Proceedings, Annual Meeting of the Air & Waste Management Association, San Antonio, TX, June 19-22, 2012.
  105. Liu, B., and H.C. Frey, “Development and Evaluation of a Simplified Version of MOVES for Coupling with a Traffic Simulation Model,” 2012-A-645-AWMA, Proceedings, Annual Meeting of the Air & Waste Management Association, San Antonio, TX, June 19-22, 2012.
  106. Yazdani, B., and H.C. Frey, “Quantification of Road Grade Based on GPS Receiver with Barometric Altimeter,” 2012-A-262-AWMA, Proceedings, Annual Meeting of the Air & Waste Management Association, San Antonio, TX, June 19-22, 2012.
  107. Frey, H.C., and B. Liu, “Development and Evaluation of a Simplified Version of MOVES for Coupling with a Traffic Simulation Model,” Paper 13-1201, Proceedings of 92nd Annual Meeting of the Transportation Research Board, Washington, DC, January 13-17, 2013.
  108. Graver, B.M., and H.C. Frey, “Comparison of Locomotive Emissions Measured during Dynamometer versus Rail Yard Engine Load Tests,” Paper 13-1415, Proceedings of 92nd Annual Meeting of the Transportation Research Board, Washington, DC, January 13-17, 2013.
  109. Yazdani, B., and H.C. Frey, “Quantifying Road Grade Based on In-Vehicle Measurements with Global Positioning System Receivers,” Paper 13-1417, Proceedings of 92nd Annual Meeting of the Transportation Research Board, Washington, DC, January 13-17, 2013.
  110. Jiao, W., and H.C. Frey, “Method for Measuring the Ratio of In-Vehicle to Near-Vehicle Exposure Concentrations of Airborne Fine Particles,” Paper 13-1518, Proceedings of 92nd Annual Meeting of the Transportation Research Board, Washington, DC, January 13-17, 2013.
  111. Sandhu, G.S., and H.C. Frey, “Effects of Errors on Vehicle Emission Rates from Portable Emissions Measurement Systems,” Paper 13-4018, Proceedings of 92nd Annual Meeting of the Transportation Research Board, Washington, DC, January 13-17, 2013.
  112. Anya, A.R., N.M. Rouphail, H.C. Frey, and B. Liu, “Method and Case Study for Quantifying Local Emissions Impacts of a Transportation Improvement Project Involving Road Re-Alignment and Conversion to a Multi-Lane Roundabout,” Paper 13-5243, Proceedings of 92nd Annual Meeting of the Transportation Research Board, Washington, DC, January 13-17, 2013.
  113. Salamati, K., M.C. Coelho, P.J. Fernandes, N.M. Rouphail, H.C. Frey, and J. Bandeira, “Emission Estimation at Multilane Roundabouts: Effect of Movement and Approach Lane,” Paper 13-0420, Proceedings of 92nd Annual Meeting of the Transportation Research Board, Washington, DC, January 13-17, 2013.
  114. Frey, H.C., B. Yazdani-Boroujeni, J. Hu, G. Sandhu, B. Liu, W. Jiao, and B. Graver, “Field Measurements of 1996 to 2013 Model Year Light Duty Gasoline Vehicles,” Proceedings, 106th Annual Conference, Air & Waste Management Association, Chicago, IL, June 25-28, 2013.
  115. Frey, H.C., B. Yazdani-Boroujeni, J. Hu, and B. Liu, “Measurement of Cold Starts and Their Contribution to Real-World Total Trip Emissions for Light Duty Gasoline Vehicles,” 106th Annual Conference, Air & Waste Management Association, Chicago, IL, June 25-28, 2013.
  116. Graver, B.M., and H.C. Frey, “Measurement of Locomotive Emissions During Real-World Duty Cycles,” Proceedings, 106th Annual Conference, Air & Waste Management Association, Chicago, IL, June 25-28, 2013.
  117. Hu, J., H.C. Frey, G.S. Sandhu, and B.M. Graver, “Modeling Driving Cycle, Fuel Use, and Emissions based on Real-World Measurements of Over-Snow Vehicles,” 106th Annual Conference, Air & Waste Management Association, Chicago, IL, June 25-28, 2013.
  118. Jiao, W., and H.C. Frey, “Comparison of Predicted Exposures Versus Ambient Fine Particulate Matter Concentrations,” 106th Annual Conference, Air & Waste Management Association, Chicago, IL, June 25-28, 2013.
  119. Liu, B., and H.C. Frey, “Development of a Simplified Version of MOVES and Application to Iterative Case Studies,” 106th Annual Conference, Air & Waste Management Association, Chicago, IL, June 25-28, 2013.
  120. Sandhu, G.S., and H.C. Frey, “Energy Use and Emissions from Diesel and Biodiesel Blends for Earthmoving Equipment,” 106th Annual Conference, Air & Waste Management Association, Chicago, IL, June 25-28, 2013.
  121. Sandhu, G.S., H.C. Frey, S. Bartelt-Hunt, and E. Jones, “In-Use Measurement of the Activity, Fuel Use, and Emissions of Front-Loader Refuse Trucks,” Paper 14-1267, 93rd Annual Meeting of the Transportation Research Board, January 12-16, 2014.
  122. Hu, J., and H.C. Frey, “Comparison of Real World Light-Duty Gasoline Vehicle Emissions for High Altitude Mountainous Versus Low Altitude Piedmont Study Areas,” Paper 14-1267, 93rd Annual Meeting of the Transportation Research Board, January 12-16, 2014.
  123. Jiao, W., and H.C. Frey, “Comparison of PM5 and CO Exposure Concentrations for Selected Transportation Modes,” Paper 14-0584, Proceedings of the 93rd Annual Meeting of the Transportation Research Board, January 12-16, 2014.
  124. Zhou, X., H. Lei, J. Taylor, B. Liu, N.M. Rouphail, and H.C. Frey, “Integrating Simplified Emission Estimate Model and Mesoscopic Dynamic Traffic Simulator to Evaluate Emission Impacts of Traffic Management Strategies,” Paper 14-4968, 93rd Annual Meeting of the Transportation Research Board, January 12-16, 2014.
  125. Sandhu, G.S., H.C. Frey; S. Bartelt-Hunt; E. Jones, “In-Use Measurement of the Activity, Fuel Use, and Emissions of Diesel Roll-Off Refuse Trucks,” Proceedings, Annual Meeting of the Air & Waste Management Association, Long Beach, CA, June 24-27, 2014.
  126. Hu, J., X. Zheng, and H.C. Frey, “Evaluation of Real-World Activity, Energy Use, and Emissions of A Plug-In Hybrid Electric Vehicle,” Proceedings, Annual Meeting of the Air & Waste Management Association, Long Beach, CA, June 24-27, 2014.
  127. Gonçalves, G., G. Duarte, H.C. Frey, “Effect of Topography on Fuel Use and NOx Emissions of Hybrid and Conventional Vehicles,” Proceedings, Annual Meeting of the Air & Waste Management Association, Long Beach, CA, June 24-27, 2014.
  128. Delavarrafiee, M., X. Zheng, H.C. Frey, R. Weaver, “Comparison of Fuel Use and Emissions for E85 Versus Gasoline Fueled Vehicles Based on In-Use Measurements,” Proceedings, Annual Meeting of the Air & Waste Management Association, Long Beach, CA, June 24-27, 2014.
  129. Liu, B., and H.C. Frey, “Estimating Sensitivity of Onroad Vehicle Emission Factors to Emission Standards based on In-Use Measurement Data,” Proceedings, Annual Meeting of the Air & Waste Management Association, Long Beach, CA, June 24-27, 2014.
  130. Graver, B., J. Hu, and H.C. Frey, “Comparison of Real-World Emission Rates of a Locomotive Engine Operating on Diesel and Biodiesel,” Proceedings, Annual Meeting of the Air & Waste Management Association, Long Beach, CA, June 24-27, 2014.
  131. Salamati, K., N.M. Rouphail, H.C. Frey, B. Liu, and B.J. Schroeder, “A Simplified Method for Comparing Emissions at Roundabouts and Signalized Intersections,” TRB 15-2316, Proceedings, 94th Annual Meeting of the Transportation Research Board, Washington, DC, January 11-15, 2015.
  132. Delavarrafiee, M., X. Zheng, H.C. Frey, and R. Weaver, “Empirical Comparison of Fuel Consumption and Tailpipe Emissions for Light Duty Vehicles Fueled with E85 and Conventional Gasoline,” TRB 15-3545, Proceedings, 94th Annual Meeting of the Transportation Research Board, Washington, DC, January 11-15, 2015.
  133. Tanvir, S., B. Liu, X. Zhou, H.C. Frey, and N.M. Rouphail, “Asssesing Emissions Impacts of Transportation Management Strategies for Large Scale Regional Networks,” TRB 15-4446, Proceedings, 94th Annual Meeting of the Transportation Research Board, Washington, DC, January 11-15, 2015.
  134. Liu, B., and H.C. Frey, “Quantification and Application of Real-World Light Duty Vehicle Performance Envelope for Speed and Acceleration,” TRB 15-5287, Proceedings, 94th Annual Meeting of the Transportation Research Board, Washington, DC, January 11-15, 2015.
  135. Che, W.W., H.C. Frey, and A.K.H. Lau, “Exposure Assessment of Children’s Exposure to Ambient O3 and PM5 in Hong Kong,” Extended Abstract No. 563, Proceedings, Annual Meeting of the Air & Waste Management Association, Raleigh, NC, June 22-25, 2015.
  136. Delavarrafiee, M., and H.C. Frey, “Comparison of Hybrid Electric Vehicle and Conventional Gasoline Vehicle Energy Use and Emissions Based on Real-World Measurements,” Paper No. 203, Proceedings, Annual Meeting of the Air & Waste Management Association, Raleigh, NC, June 22-25, 2015.
  137. Frey, H.C., “Lessons Learned from Field Measurements of Onroad and Nonroad Vehicles Using Portable Emissions Measurement Systems,” Paper No. 9, Proceedings, Annual Meeting of the Air & Waste Management Association, Raleigh, NC, June 22-25, 2015.
  138. Frey, H.C., M. Graver, J. Hu, “Evaluation of the Effect of Biofuels on Exhaust Emissions of Diesel Locomotives,” Extended Abstract No 177, Proceedings, Annual Meeting of the Air & Waste Management Association, Raleigh, NC, June 22-25, 2015.
  139. Graver, B.M., and H.C. Frey, “Effect of Engineer Behavior on Passenger Locomotive Fuel Use and Emissions,” Extended Abstract No. 185, Proceedings, Annual Meeting of the Air & Waste Management Association, Raleigh, NC, June 22-25, 2015.
  140. Hu, J., B.M. Graver, H.C. Frey, “Comparison of Nitrogen Oxides and Hydrocarbon Exhaust Concentration Detection Methods for Portable Emission Measurement Systems Applied to Locomotive Engines,” Extended Abstract No. 55, Proceedings, Annual Meeting of the Air & Waste Management Association, Raleigh, NC, June 22-25, 2015.
  141. Khan, T., and H.C. Frey, “Illustrative Comparison between Rated and Real-World Fuel Economy and Emissions,” Paper No. 192, Proceedings, Annual Meeting of the Air & Waste Management Association, Raleigh, NC, June 22-25, 2015.
  142. Zheng, X., and H.C. Frey, “Energy Use and Emissions Rates for A Plug-In Hybrid Electric Vehicle Based on Real-World Measurements,” Paper No. 295, Proceedings, Annual Meeting of the Air & Waste Management Association, Raleigh, NC, June 22-25, 2015.
  143. Sandhu, G.S., H.C. Frey, S. Bartelt-Hunt, E. Jones, “Comparison of Real-World and MOVES Estimated Emissions for Heavy-Duty Diesel Refuse Trucks,” Paper No. 332, Proceedings, Annual Meeting of the Air & Waste Management Association, Raleigh, NC, June 22-25, 2015
  144. Khan, T., and H.C. Frey, “Evaluation of Light Duty Gasoline Vehicle Rated Fuel Economy based on in-use Measurements,” Paper 16-6058, Proceedings, Annual Meeting of the Transportation Research Board, Washington, DC, January 10-14, 2016.
  145. Hu, J., H.C. Frey, and S.S. Washburn, “Comparison of Vehicle-Specific Fuel Use and Emissions Models Based on Externally and Internally Observable Activity Data,” Paper 16-6315, Proceedings, Annual Meeting of the Transportation Research Board, Washington, DC, January 10-14, 2016.
  146. Delavarrafiee, M., and H.C. Frey, “A Method for Comparison of Gaseous Emission Rates for Flex Fuel Vehicle Operated on E85 versus Gasoline Based on In-Use Measurements, Certification Data, and Model Predictions,” Paper 954, Proceedings, Annual Meeting of the Air & Waste Management Association, New Orleans, LA, June 20-23, 2016.
  147. Khan, T., and H.C. Frey, “Geospatial Variation of Real-World Emissions from a Passenger Car,” Paper 950, Proceedings, Annual Meeting of the Air & Waste Management Association, New Orleans, LA, June 20-23, 2016.
  148. Rastogi, N., and H.C. Frey, “Quantifying the Emission Impacts of Passenger Cars Using Real World In-Use Emission Rates,” Paper 1095, Proceedings, Annual Meeting of the Air & Waste Management Association, New Orleans, LA, June 20-23, 2016.
  149. Singh, S., and H.C. Frey, “Gasoline Vehicle Fuel Efficiency and Emissions for Gas-Direct Injection Versus Port-Fuel Injection,” Paper 953, Proceedings, Annual Meeting of the Air & Waste Management Association, New Orleans, LA, June 20-23, 2016.
  150. Frey, H.C., M. Delavarrafiee, and S. Singh, “Real-World Freeway and Ramp Activity and Emissions for Light Duty Gasoline Vehicles,” Paper 17-04473, Proceedings, Annual Meeting, Transportation Research Board, Washington, DC January 8-12, 2017.
  151. Liu, B., and H.C. Frey, “Comparative Assessment of Variability in Light Duty Vehicle Exhaust Emission Rates Based on Vehicle Types, Age, Driving Cycles, and Ambient Conditions,” Paper 257303, Annual Conference and Exhibition of the Air & Waste Management Association, Pittsburgh, PA, June 5-8, 2017.
  152. Hu, J., and H.C. Frey, “Comparison of Real World Light-Duty Gasoline Vehicle Emissions for High Altitude Mountainous Versus Low Altitude Piedmont Study Areas,” Paper 258455, Annual Conference and Exhibition of the Air & Waste Management Association, Pittsburgh, PA, June 5-8, 2017.
  153. Hu, J., and H.C. Frey, “Evaluation of the Effect of Biodiesel on Exhaust Emissions of Locomotive Head End Power Engines,” Paper 258453, Annual Conference and Exhibition of the Air & Waste Management Association, Pittsburgh, PA, June 5-8, 2017.
  154. Rastogi, N., and H.C. Frey, “Procedure for Evaluation of Retrofitted SCR-Based Emission Control System for a Passenger Railroad Locomotive,” Paper 261700, Annual Conference and Exhibition of the Air & Waste Management Association, Pittsburgh, PA, June 5-8, 2017.
  155. Wei, T., T. Khan, and H.C. Frey, “Development of Simplified Models of CNG, Diesel, and Hybrid Transit Bus Energy Use,” Paper 261821, Annual Conference and Exhibition of the Air & Waste Management Association, Pittsburgh, PA, June 5-8, 2017.
  156. Yuan, W., H.C. Frey, Y. Sun, “Quantification of Transit Train Activity Data for Energy Consumption Estimation,” Paper 264161, Annual Conference and Exhibition of the Air & Waste Management Association, Pittsburgh, PA, June 5-8, 2017.
  157. Singh, S., and H.C. Frey, “Procedure for Measuring and Comparing Fuel Use and Gaseous Emissions for Gas-Direct Injection versus Port Fuel Injection Vehicles,” Paper 263949, Annual Conference and Exhibition of the Air & Waste Management Association, Pittsburgh, PA, June 5-8, 2017.
  158. Tanvir, S., H.C. Frey, and N.M. Rouphail, “Effect of Light Duty Vehicle Performance on a Driving Style Metric,” Paper Number 18-02023, Proceedings, 97th Annual Meeting of the Transportation Research Board, Washington, DC, January 7-11, 2018.
  159. Wei, T., and H.C. Frey, “Evaluation of the Effect of Passenger Load on Transit Bus Energy Use,” Paper Number 18-04323, Proceedings, 97th Annual Meeting of the Transportation Research Board, Washington, DC, January 7-11, 2018.
  160. Yuan, W., and H.C. Frey, “Evaluation of General Transit Feed Specification Data for Route Characteristics and Travel Activity Data of an Electric Train System,” Paper Number 18-05638, Proceedings, 97th Annual Meeting of the Transportation Research Board, Washington, DC, January 7-11, 2018.
  161. Rastogi, N., and H.C. Frey, “Estimation of Rail Grade and Horizontal Curvature from Non-Proprietary Data Sources,” Paper Number 18-06366, Proceedings, 97th Annual Meeting of the Transportation Research Board, Washington, DC, January 7-11, 2018.
  162. Rastogi, N., and H.C. Frey, “Procedure for Estimating Fuel Use by a Diesel Passenger Train,” Annual Conference and Exhibition of the Air & Waste Management Association, Hartford, CT, June 25-28, 2018.
  163. Khan, T., and H.C. Frey, “Development of Updated MOVES Lite: A Simplified Version of MOVES,” Annual Conference and Exhibition of the Air & Waste Management Association, Hartford, CT, June 25-28, 2018.
  164. Wei, T., and H.C. Frey, “Development and Validation of Transit Bus Energy Use Rate Models,” Annual Conference and Exhibition of the Air & Waste Management Association, Hartford, CT, June 25-28, 2018.
  165. Yuan, W., and H.C. Frey, “An Algorithm to Simulate Segment Speed Trajectories of a Metrorail Line,” Annual Conference and Exhibition of the Air & Waste Management Association, Hartford, CT, June 25-28, 2018.
  166. Rastogi, N., and H.C. Frey, “Comparison of Methods Based on Portable Emission Measurement systems for Evaluation of A Diesel Locomotive Retrofitted NOx Emission Control System,” TRR-S-18-05882, Proceedings, 98th Annual Meeting of the Transportation Research Board, Washington, DC, January 7-11, 2019.
  167. Khan, T., and H.C. Frey, “Effect of Air-Conditioning on Light Duty Gasoline Vehicles Fuel Economy,” TRR-S-02234, Proceedings, 98th Annual Meeting of the Transportation Research Board, Washington, DC, January 7-11, 2019.
  168. Yuan, W., H.C. Frey, and N. Rastogi, “Quantification of Energy Saving Potential for a Passenger Train based on Inter-run Variability in Speed Trajectories,” TRR-S-05906, Proceedings, 98th Annual Meeting of the Transportation Research Board, Washington, DC, January 7-11, 2019.
  169. Frey, H.C., T.Wei, T. Khan, W.Yuan, N. Rastogi, “Trends in Light Duty Gasoline Vehicle Emissions Based on Real-World Measurements,” Proceedings, 23rd International Transport and Air Pollution Conference 15-17 May 2019, Thessaloniki, Greece.
  170. Wong, C.K.L. , T.S. Lo, H.L.A. Wong, K.L. Lam, H. C. Frey, R. Smit, S. Hausberger, K. Weller and L. Ntziachristos, Microscale Vehicle emission modelling in Hong Kong, Proceedings, 23rd International Transport and Air Pollution Conference 15-17 May 2019, Thessaloniki, Greece.
  171. Wei, T., and H.C. Frey, “Evaluation of the Precision and Accuracy of Cycle Average Light Duty Gasoline Vehicles Tailpipe Emission Rates Predicted by Modal Models,” 20-04673, Proceedings, 99th Annual Meeting of the Transportation Research Board, Washington, DC, January 12-16, 2020.
  172. Frey, H.C., D. Gadre, S. Singh, and P. Kumar, “Quantification of Sources of Variability of Air Pollutant Exposure Concentrations Among Selected Transportation Microenvironments,” 20-05235, Proceedings, 99th Annual Meeting of the Transportation Research Board, Washington, DC, January 12-16, 2020.
  173. Wei, T., H.C. Frey, and W. Yuan, “Application of Transit Bus Emissions Model to Emission Estimation: Case Study for A Wolfline Transit Bus Line at North Carolina State University,” Full-Length Paper No. 793778, Proceedings, 113th Annual Conference & Exhibition of the Air & Waste Management Association (virtual), June 30-July 2, 2020.
  174. Eluri, S., and H.C. Frey, “An Illustrative Case Study of the Contribution of Commuting to PM5 Exposures in Hong Kong,” 114th Annual Conference and Exhibition (virtual), Air & Waste Management Association, June 14-17, 2021.
  175. Eluri, S., H.C. Frey, W. Che, M.S. Hossain, A.K.H. Lau, “Procedure to Quantify Variability in Air Pollution Infiltration Factors for a Selected Pollutant and Selected Homes,” 115th Annual conference and Exhibition, Air & Waste Management Association, San Francisco, June 27-30, 2022.
  176. Eluri, S., and H.C. Frey, “Identification of Best Practices for Calibrating Portable Devices for Simultaneous In-Vehicle and Out-Vehicle Measurements,” Paper # 1398128, 116th Annual Conference and Exhibition, Air & Waste Management Association, Orlando, FL, June 5-8, 2023.