Research:

1. "Influence of Defects on Nonlinear Optical Properties in One-Dimensional Photonic Crystals," G.J. Schneider and ghw
   -- 2002 March APS Meeting, Indianapolis, IN

2. "Optical measurements of band structure and impurity states in colloidal crystals," G.J. Schneider and ghw (poster)
   -- Delaware Valley Symposium on Particle Science and Engineering, Newark, DE

3. "Optical measurements of band structure and impurity states in 3-D colloidal crystals," ghw (Invited), with B.J. Rosner, G.J. Schneider, and R.D. Pradhan
   -- Particles 2001, Orlando, FL

4. "Effects of impurities on photonic band structure in coaxial photonic crystals," S. Hanna, G.J. Schneider, and ghw, BAPS 45 (1), 508 (2000)
   -- 2000 March APS Meeting, Minneapolis, MN

5. "Photonic Band Structure and Impurity States in Colloidal Crystals," ghw
   -- 9^th International Conference on Unconventional Photoactive Systems (UPS'99), Würzburg, Germany.

6. "Photonic Band Structure and Impurity States in Colloidal Crystals," ghw (Invited)
   -- Optical Properties of Complex Functional Materials, 1999 Emil-Warburg Symposium, Bayreuth, Germany.

7. "Effect of Defect States on Photonic Dispersion in Colloidal Crystals," B.J. Rosner, G.J. Schneider, and ghw,
   -- 1999 Conference on Lasers and Electro-Optics, Baltimore, MD

8. "Interferometric measurements of dispersion in pure and doped photonic colloidal crystals," B.J. Rosner, G.J. Schneider, R.D. Pradhan, and ghw, BAPS 43 (1), 702 (1998)
   -- 1998 March APS Meeting, Los Angeles, CA

9. "Photonic Band Structure and Impurity States in Colloidal Crystals," ghw (Invited)
   -- 71st Colloid and Surface Science Symposium of the American Chemical Society, Newark, DE

10. "Impurity modes and band widening in doped photonic colloidal crystals," R.D. Pradhan, I.I. Tarhan, and ghw CLEO'97 Technical Digest 11, 526
11. "Zone-edge dispersion in photonic colloidal crystals," B.T. Rosner, R.D. Pradhan, I.I. Tarhan, and ghw CLEO'97 Technical Digest 11, 255
12. "Optical stop bands in bcc colloidal crystals," J.A. Bloodgood, R.D. Pradhan, and ghw CLEO'97 Technical Digest 11, 256
    -- 1997 Conference on Lasers and Electro-Optics, Baltimore, MD

13. "Coaxial connector photonic crystal," ghw, R.D. Pradhan, and J.A. Bloodgood, BAPS 42(1), 387 (1997)
14. "Photonic band structure of bcc colloidal crystals," R. D. Pradhan, J.A. Bloodgood, and ghw, BAPS 42(1), 388 (1997)
    -- 1997 March APS Meeting, Kansas City, KS

15. "Optical Stopbands in Doped Colloidal Crystals," R.D. Pradhan, I. I. Tarhan and ghw, OSA Annual Meeting/ILS-XII Program, 187 (1996)
16. "Stopband Optimization in fcc Photonic Crystals with Spherical Atoms," I. I. Tarhan and ghw (presented by R.D. Pradhan), OSA Annual Meeting/ILS-XII Program, 187 (1996)
    -- 1996 Annual Meeting of OSA, Rochester, NY.

17. "Photonic Band Structure of Colloidal Crystals," ghw (Invited), BAPS 41(1), 518 (1996)
18. "Optimized Stop Bands in fcc Photonic Crystals with Spherical `Atoms'," I. I. Tarhan and ghw, BAPS 41(1), 704 (1996)
19. "Impurity Modes in Optical Stop Bands of fcc Colloidal Crystals," R. D. Pradhan, I. I. Tarhan, and ghw, BAPS 41(1), 705 (1996)
    -- 1996 March APS Meeting, St. Louis, MO

20. "Kossel line analysis and measurement of optical photonic band structure," I. I. Tarhan and ghw, OSA Annual Meeting/ILS-XI Program, 135 (1995)
    -- Annual Meeting of OSA, Portland, OR.

21. "Properties of Group IV - Carbon Alloys Grown on Si Substrates," D. Hits, B. A. Orner, F. Chen, A. Khan, X. Shao, M. McClory, M. A. Barteau, ghw, P. R. Berger, and J. Kolodzey,
    -- 15th North American Conference on Molecular Beam Epitaxy, College Park, MD, Sept. 1995.

22. "Optical techniques for measuring photonic band structure," I. I. Tarhan and ghw, QELS'95 Digest 16, 198 (1995)
    -- 1995 Quantum Electronics and Laser Science Conference, Baltimore, MD

23. "Photonic Band Structure Measurements in the Visible Regime," I. I. Tarhan and ghw, BAPS 40(1), 810 (1995)
    -- 1995 March APS Meeting, San Jose, CA

24. "Accurate determination of transport parameters of intralipid and polystyrene suspensions," S. Zilker and ghw, BAPS 39(1), 428 (1994)
    -- 1994 March APS Meeting, Pittsburgh, PA

25. "Bestimmung von Photondiffusionsparametern fur Intralipid und Latexsuspensionen," S. Zilker and ghw, (1994)
    -- Fruhjahrstagung des Arbeitskreises Festkorperphysik bei der Deutsche Physikalische Gesellschaft, Munster, Germany

26. "Measurement of photonic band structure in colloidal crystals," I. I. Tarhan, M. P. Zinkin, and ghw, BAPS 38(8), 1722 (1993)
    -- ILS-IX: Interdisciplinary Laser Science Conference IX, Toronto, Canada

27. "Polarization Microstatistics of Laser Speckle," I. I. Tarhan and ghw QELS '93 Technical Digest, 99 (1993)
    -- 1993 Quantum Electronics and Laser Science Conference, Baltimore, MD

28. "Measurement of Photonic Band Structure in Colloidal Crystals," I. I. Tarhan, M. P. Zinkin, and ghw BAPS 38(1), 76 (1993)
    -- 1993 March APS Meeting, Seattle, WA

29. "Photon Transport Measurements in Dense Random Media," ghw, P. M. Saulnier, I. I. Tarhan, and M. P. Zinkin, OSA Annual Meeting Tech. Digest 23, 83 (1992)
    -- 1992 Annual Meeting of OSA, Albuquerque, NM

30. "Intensity Statistics of Laser Speckle from Highly-Scattering Media," I. I. Tarhan and ghw, BAPS 37(1), 600 (1992)
31. "Experimental Consequences of Surface Reflectivity on Coherent Backscattering," P. M. Saulnier and ghw, BAPS 37(1), 600 (1992)
    -- 1992 March APS Meeting, Indianapolis, IN

32. "Transmission Microstatistics of Laser Speckle from Random Media," I. I. Tarhan and ghw, BAPS 36(3), 601 (1991)
33. "Suppression of Coherent Backscattering of Light by a Magnetic Field," P. M. Saulnier and ghw, BAPS 36(3), 601 (1991)
    -- 1991 March APS Meeting, Cincinnati, OH

34. "Scatterer Correlation Effects on Photon Transport in Dense Disorder Media," P. M. Saulnier, ghw, and M. P. Zinkin, BAPS 35(3), 642 (1990)
    -- 1990 March APS Meeting, Anaheim, CA

35. "Photon Diffusion in Random Media," ghw (Invited), BAPS 33(3), 683 (1988)
    -- 1988 March APS Meeting, New Orleans, LA

36. "A Search for Photon Localization in the Time Domain," ghw, P. A. Fleury, and S. L. McCall, BAPS 32(3), 792 (1987)
37. "Non-Linear Line Broadening in Fluid n-H2 at High Pressure," N. E. Moulton, D. M. Brown, ghw, and W. B. Daniels, BAPS 32(3), 396 (1987)
    -- 1987 March APS Meeting, New York, NY

38. "Raman Scattering from Solid Argon at High Pressure," ghw and W. B. Daniels, BAPS 31(3), 608 (1986)
    -- 1986 March APS Meeting, Las Vegas, NV

39. "Raman Scattering from Fluid Helium at High Pressure," ghw and W. B. Daniels, BAPS 30(4), 752 (1985)
40. "Raman Scattering from Fluid Hydrogen at High Pressure," N. E. Moulton, ghw, and W. B. Daniels, BAPS 30(4), 752 (1985)
    -- 1985 Spring APS Meeting, Crystal City, VA

41. "Raman Scattering from Solid Helium at High Pressure," ghw and W. B. Daniels, BAPS 30(3), 271 (1985)
    -- 1985 March APS Meeting, Baltimore, MD

42. "Measurements of Raman Intensities and Pressure Dependence of Phonon Frequencies in Sapphire," ghw, C. S. Wang, and W. B. Daniels, BAPS 24(4), 680 (1979)
    -- 1979 Spring APS Meeting, Washington, DC

1. "Problem-Based Learning: Moving from Design to Reality, Parts 1 and 2"
   two invited presentations with Deborah Allen and Hal White
   -- 2008 Lilly-East Conference on College and University Teaching, Newark, DE, April 2008

2. "The Group from Hell: Strategies for Resolving Conflicts in PBL Groups", (3-hour invited preconference workshop), Mark Serva and ghw (with Deborah Allen)
3. "The Importance of Professional Development and Training in PBL", (Invited panel session), David Chapman, ghw, and Peter Bouhoijs
   -- PBL2008: Learning without Limits, Colima, México, January 2008.
4. "Problem-Based Learning: Real World Problems as Blueprints for Learning"
5. "Problem-Based Learning: Models for Implementation Learning"
   two invited presentations with Deborah Allen and Hal White
   -- 2007 Lilly-East Conference on College and University Teaching, Newark, DE, April 2007

6. "The Role of General Education in Developing Leadership for a Sustainable Future"
   -- International Conference on Leadership for a Sustainable Future, Jaypee Institute of Information Technology University, Noida, India, March 2007

7. "An Active Partnership: An Advisory Committee's Role", Nancy Campbell, Delaware Technical and Community College, and ghw
   -- 2007 meeting of National Association of Community College Teacher Education Programs, New Orleans, March 2007.

8. "Delaware GK-12: Improvement of Science Education in Vocational Technical High Schools through Collaborative Learning and Co-Teaching" (poster)
   --2006 Annual Meeting of Geological Society of America, Philadelphia, October 2006.

9. "Elaboration and Development of Problems and Scenarios in PBL Courses" (Two four-hour workshops), Deborah Allen, Richard Donham, and ghw
10. "PBL in Diverse Disciplines and Careers" (Invited panel session), Peter Bouhoijs, Ramón Cedillo, Antoni Font, Annette Kolmos, and ghw
11. "The Group from Hell: Strategies for Resolving Conflicts in PBL Groups" (90-min workshop), Deborah Allen and ghw
    -- PBL2006: Connecting Learning to the Real World, Lima, Perú, July 2006.
12. "Problem-Based Learning: A Student-Centered Approach for Engagement", (invited workshop) Deborah Allen, ghw, and Hal White
    -- Lilly-East Conference on College and University Teaching, Newark, DE, April 2006.

13. "Modeling and Assessing Online Discussions for Faculty Development", Janet de Vry, Barbara Frey, and ghw
    -- 2006 EDUCAUSE Mid-Atlantic Regional Conference, Baltimore, MD, January 2006.

14. "Ethics in Research" (Students as Teachers: A Competition to Develop Problem Based Learning Units for Teaching Research Ethics), invited Chapter Session, presented with Carol Beck
    -- Sigma Xi 2005 annual meeting, Seattle (11/5/05)

15. "Problem-Based Learning in Perúvian Higher Education: Quality Science and Math Education for Future Public School Teachers", Ana Pastor, Victoria Landa, and ghw
    -- ALO Synergy in Development 2005 Annual Meeting, Washington DC, July 2005.

16. "Promoting Student Engagement through Teamwork: Partnering Faculty Leaders with IT User Services", ghw and Janet de Vry
17. Student Engagement through Problem-Based Learning", ghw and Deborah Allen
    -- AAC&U Network for Academic Renewal, "Pedagogies of Engagement: Deepening Learning In and Across the Disciplines" Bethesda. MD, April 2005.

18. "Partnerships for Educational Reform", ghw, Martha Carothers, and Leila Lyons
    -- 2005 CSMS Computer Services Management Symposium of ACM's Special Interest Group on University and College Computing Services (SIGUCCS), Charleston, SC, March 2005.

19. "Interactivity and Student Engagement", invited panel presentation (supporting material for my initial remarks)
    -- 2005 EDUCAUSE Mid-Atlantic Regional Conference, Baltimore, MD, January 2005.

20. "Students as Teachers: A Competition to Develop Problem Based Learning Units for Teaching Research Ethics", ghw and Carol Beck, Thomas Jefferson University (chapter poster, presentation at RDU constituency group)
    -- 2004 Annual Meeting of Sigma Xi, Montréal, Québec, November 2004.
    
    
21. "The First Day of Class: Introducing Change to Your Students", (invited plenary presentation), ghw
22. "The Power of PBL: Bringing Problem-Based Learning into Your Classroom", (invited workshop), ghw
    -- Annual Conference on Case Study Teaching in Science, Buffalo, NY, October 2004

23. "Problem-Based Learning in Perúvian Higher Education: Quality Science and Math Education for Future Public School Teachers", Ana Pastor, Deb Allen, and ghw
    -- ALO Synergy in Development 2004 Annual Meeting, Washington DC, August 2004.

24. "Problem-Based Learning and Physics: Developing Problem Solving Skills in All Students" (Brief paper), ghw, Barb Duch, and Ed Nowak
25. "Using PBL to Integrate Content and Pedagogy in an Interdisciplinary “Science Semester” for Future Elementary Teachers" (Panel session), Deborah Allen, Danielle Ford, Richard Donham, , Steven Fifield, and ghw
26. "PBL2006 and Beyond" (Panel session), David Chapman, ghw, Enrique León, Rodrigo Polanco, and Juan Carlos Crespo
27. "Problem-Based Learning in Perúvian Higher Education: Quality Science and Math Education for Future Public School Teachers" (Panel session), ghw, Deborah Allen, Patricia Morales, and Luis Bretel
28. "Institute for Transforming Undergraduate Education and the Problem-Based Learning Clearinghouse" (Poster), ghw
29. "Integrating Problem-Based Learning and Technology in Education" (Invited plenary presentation), ghw
    
-- PBL2004: Pleasure By Leaning, Cancun, Mexico, June 2004.
30. "Educational Transformation Through Teamwork: Partnering Faculty and IT", ghw (Invited)
    -- AAC&U Network for Academic Renewal, Technology, Learning, and Intellectual Development", Cambridge, MA, November 2003.

31. "Problem-Based Learning in Perúvian Higher Education: Quality Science and Math Education for Future Public School Teachers", Ana Pastor and ghw
    -- ALO Synergy in Development 2003 Annual Meeting, Washington DC, August 2003.

32. Professional Development of University Professors: Case Study from the University of Delaware, Deborah Allen (invited), Barb Duch, Susan Groh, ghw, and Hal White (Capacitacion Docente de Professore Uniiversitarios: Un Estudio de Casos de la Universidad de Delaware)
    -- internation conference "Docencia Universitaria en Tiempos de Cambio" [University Teaching in Times of Change] at Pontificia Universidad Católica del Perú, Lima, (August 2003).

33. "Faculty/IT Partnering to Transform Learning", Janet de Vry, ghw, and Leila Lyons
    -- WebCT !mpact 2003, San Diego, July 2003.

34. "Shifting Sand: Integrating Problem-Based Learning and Technology in Education" ghw (Invited)
35. "The Power of PBL: Bringing Problem-Based Learning into Your Classroom", ghw (Invited)
    -- Asia Pacific Conference on Education, National Institute of Education, Singapore, June 2003.
    

36. "Student-Centered Learning: A Challenging Odyssey in PBL", ghw (Invited)
    -- 4th Asia Pacific Conference on PBL, Hat Yai, Songkla, Thailand, December 2002.

37. "La Pédagogie par Problèmes", ghw (Invited)
    -- "Colloque sur l'Apprentissage dans l'Engeignement Superiéur", the 10th anniversary celebration of FORMASUP, Lille, France , October 2002

38. "Problem-Based Learning and Wireless Technology in the Science Classroom", ghw (Invited), Announcer 32(2), 91 (2002)
    -- 125th National AAPT Meeting, Boise, ID, August 2002

39. "PBL in Engineering and Physics" (preconference workshop), ghw
40. "Experience It Yourself: A Model for Acitve/Problem-Based Learning for All Classes" (introductory workshop), Barbara Duch, Valerie Hans, Susan Groh, ghw, and Hal White
41. "Integrating Technology with PBL" (workshop), ghw
42. "The First Week of Class" (introductory workshop), ghw
43. "Orientation to the PBL Clearinghouse: An Electronic Peer-Reviewed Publication" (workshop), ghw
44. "Problem-Based Learning for Introductory Physics Laboratories" (poster), Edmund Nowak, Travis Mitchell, Norbert Mulders, Karl Unruh, Barry Walker, and ghw
45. "Technology in a PBL Science Course for Non-Science Majors" (paper), ghw
46. "Faculty/IT Partnership that Transforms Learning" (paper), Janet de Vry and ghw
    -- PBL2002: A Pathway to Better Learning, Baltimore, MD, June 2002.

47. "Web-Based Interactive Circuit Simulator for Introductory Physics," ghw and Becky Kinney
    -- Spring 2002 Meeting of the Chesapeake Section, AAPT, Fairfax, VA , April 2002.

48. "Web-Based Interactive Circuit Simulator for Introductory Physics," ghw and Becky Kinney
    -- 124th National AAPT Meeting, Philadelphia, PA, January 2002.

49. "Faculty Technology Development Strategies for Supporting Curriculum Enhancement," Julius Bianchi, Janet de Vry, and ghw - preconference workshop
    
50. "Faculty Technology Development Programs that Work," David G. Brown, Janet R. de Vry, Terry Morrow, and ghw - panel presentation
    -- EDUCAUSE 2001, Indianapolis, IN, Oct. 2001

51. "Integrating Problem-Based Learning and Instructional Media," ghw (Invited) and Barb Duch, Announcer 31(2), 121 (2001)
    -- 123rd National AAPT Meeting, Rochester, NY, July 2001

52. "Science for Everyone: A Problem-Based Learning Approach," ghw and Barbara Duch
    -- First IOSTE Symposium in Southern Europe, Paralimni, Cyprus, April 2001

53. "Problem-Based Learning Online Clearinghouse: Introductory Physics Curriculum," ghw and Barbara Duch
    -- Spring 2001 Meeting of the Chesapeake Section, AAPT, Baltimore, MD, April 2001

54. "The Power of Problem-Based Learning: Transforming How Faculty Teach," ghw, Conrado Gempesaw, and Barbara Duch
    -- AAHE 2001 National Conference on Higher Education, Washington, DC, March 2001

55. "Problem-Based Learning and Circuits for Nonscience Majors," ghw, Announcer 30(4), 70 (2001)
    
56. "Problem-Based Learning Online Clearinghouse: Introductory Physics Curriculum," Barbara Duch and ghw,
    Announcer 30(4), 116 (2001)
    -- 122nd National AAPT Meeting, San Diego, CA, January 2001

57. "Circuits for Everyone: A Problem-Based Learning Approach," ghw
    -- Fall 2000 Meeting of the Chesapeake Section, AAPT, Virginia Beach, VA, November 2000

58. "Circuits for Everyone: A Problem-Based Learning Approach," ghw
    
59. "Integrating Real-World Problems with Internet Resources," ghw (4.1MB PowerPoint presentation)
    
60. "Promoting PBL & Institutional Wide Reform of Undergraduate Education with a Faculty-Led Institute," Deborah Allen, Barbara Duch, and ghw
    - PBL2000: Promises, Breakthroughs, and Lessons, Birmingham, AL, Oct. 2000

61. "Designing and Implementing Faculty Development Programs," Julius Bianchi, Janet de Vry, and ghw
    -- Preconference Workshop at EDUCAUSE 2000, Nashville, TN, Oct. 2000

62. "Promoting PBL and Institution-Wide Reform of Undergraduate Education with a Faculty-Led Institute," ghw, Barbara Duch, Deborah Allen, Susan Groh, and Hal White
    -- 2nd International Conference on PBL in Higher Education, Linköping, Sweden, Sept. 2000

63. "Circuits for Everyone: A Problem-Based Learning Approach," ghw, Announcer 30(2), 92 (2000)
    -- 2000 Summer Meeting of AAPT, Guelph, Ontario, July 2000

64. "Problem-Based Learning: A Different Model of How We Teach, Barbara Duch, ghw, and Deborah Allen
    -- Preconference Workshop at the Eighth AAHE Conference on Faculty Roles & Rewards, New Orleans, LA, Feb. 2000

65. "Teaching with Technology: Designing and Implementing Faculty Development Programs," Julius Bianchi, Janet de Vry, and ghw
    -- Preconference Workshop at EDUCAUSE'99, Long Beach, CA, Oct. 1999

66. "Promoting Institution-Wide Reform of Undergraduate Education: Stirring up Faculty Development with a Faculty-Led Institute," ghw, Deborah Allen, and Hal White
    -- 24th Annual POD Network Conference, Lake Harmony, PA, Oct. 1999

67. "Electrical Engineering in the Physics Laboratory: ABETter Way?," ghw
    -- Spring 1999 Meeting of the Chesapeake Section, AAPT, Newark, DE

68. "Stretching Your Web: Reaching the Next Level," ghw
    -- Spring 1998 Meeting of the Chesapeake Section, AAPT, Baltimore, MD

69. "Web-Based Physics Courses, "Technology for Poets" and "Calculus-Based Electricity and Magnetism," ghw
    -- Fall 1997 Meeting of the Chesapeake Section, AAPT, Annapolis, MD

70. "A New Web-Based Course on Science and Technology for Non-Science Majors," ghw, Announcer 26(2), 100 (1996)
    
71. "Right to your Doorstep: E-Mail Resources for Physics Teachers," A. Dagenais and ghw,
    Announcer 26(2), 101 (1996)
    -- 1996 Summer Meeting of AAPT, College Park, MD

72. "Technology: A Tool in PBL," ghw as panel member with M.V. Barnhill, J.L. Johnson, and D.E. Sheppard (6/10/96).
    
73. "On-Line Resources for Problem-Based Learning," ghw (6/11/96).
    -- 5th Annual Conference on Problem-Based Learning in Undergraduate Science Education, U. Delaware, Newark, DE.

74. "Transmission line exercises for the introductory physics laboratory (or Why is There a 50 ohm Resistor at the End of My Ethernet Cable?)" ghw,
75. "Right to your Doorstep: E-Mail Resources for Physics Teachers," A. Dagenais and ghw,
    -- 1995 Northeast Regional Conference of AAPT, Princeton, NJ

76. "The Role of Physics in Engineering Education," ghw as panel member, (1994)
    -- Fifth Northeast Regional Conference of AAPT, Abington, PA

77. "Transmission line exercises for the introductory physics laboratory," ghw, Announcer 24, 95 (1994)
    -- 1995 Winter Meeting of AAPT, Orlando, FL

78. "Student Preparation for an Undergraduate Research Experience with an 'Instrumentation for Scientists' Course Based on Integrated Circuits," ghw and J. B. Mehl, Announcer 22, 100 (1992)
    -- 1992 Summer Meeting of AAPT, Orono, ME