R. Herpers, D. Scherfgen, M. Kutz, J. Bongartz, U. Hartmann, O. Schulzyk, S. Boronas, T. Saitov, H. Steiner, D. Reinert: Multimedia Sensory Cue Processing in the FIVIS Simulation Environment in: Multiple Sensorial Media Advances and Applications: New Developments in MulSeMedia IGI Global, 2011

H.Ihne, R. Clement, and R. Herpers: Graduierteninstitut an Fachhochschulen als Nukleus wissenschaftlicher Nachwuchsförderung, Die Neue Hochschule, p. 84-87, No. 02,  2011.

M. Schlösser, R. Herpers, and K. Kent: Accelerating the MMD algorithm using Multi-core Environments, Proceedings IEEE Pacific Rim Conference on Communications, Computers and Signal Processing (RacRim 2011) Victoria, Canada, pp 340-345, 2011.

A. Bochem, K. Kent, and R. Herpers: FPGA based Real-Time Object Detection Approach with Validation of Precision and Performance, Proceedings IEEE International Symposium on Rapid System Prototyping (RSP 2011), Karlsruhe, 2011.

R. Herpers, D. Scherfgen, M. Kutz, S. Boronas, U. Hartmann, J. Bongartz, and O. Schulzyk: The FIVIS Project: An Immersive Bicycle Simulation System. 4th Russian-German Workshop  Innovation Information Technologies: Theory and Practice, Ufa, Russia, 2011.

D. Scherfgen, T. Saitov, R. Herpers, E. Dayangac: An Optical Laser-based User Interaction System for CAVE-type Virtual Reality Environments. 4th Russian-German Workshop  Innovation Information Technologies: Theory and Practice, Ufa,  Russia, 2011.

R. Herpers, D. Scherfgen, M. Kutz, J. Bongartz, U. Hartmann, O. Schulzyk, S. Boronas, T. Saitov, H. Steiner, D. Reinert: Multimedia Sensory Cue Processing in the FIVIS Simulation Environment in: Multiple Sensorial Media Advances and Applications: New Developments in MulSeMedia IGI Global, 2010

R. Herpers, M. Kaul, and S. Bursner: Why don’t young adults choose computer science study programs? In Challenges of global eLearning, Soul, Spirit and Skill, T. Varis and P. Mika (Eds.) ISBN 978-951-44-8037-9, pp. 85-102, 2010.

R.S. Allison, J. Schumacher, S. Sadr, and R. Herpers,: Apparent motion during long saccadic suppression periods, Experimental Brain Research , Vol. 202, No. 1 (ISSN 0014-4819 print, 1432-1106 online), Springer-Verlag, 2010.

M. Schlösser, R. Herpers, and K. Kent, Acceleration the MMD Algorithm using the Cell Broadband Engine, TR 10-202, 2010, Faculty of Computer Science, University of  New Brunswick.   http://www.cs.unb.ca/tech-reports/documents/TR_10_202.pdf

A. Bochem, R. Herpers, and K.Kent: Hardware Acceleration of BLOB Detection for Image Processing, The Third International Conference on Advances in Circuits, Electronics and Micro- electronics, CENICs 2010, July 18-25th, Venice, Italy, 2010. (accepted)

D. Scherfgen, R. Herpers, and T. Saitov: Single Webcam 3D Tracking for Video Games, Internat. Conf. of Future of Game Design and Technology, ACM FuturePlay 2010, May 06.-07., Vancouver, BC, Canada, 2010.

L. R. Harris, R. Herpers, M. Jenkin, R. Allison, H. Jenkin, B. Kapralos, D. Scherfgen, S. Boronas: The perception of linear self motion induced by a virtual reality display while viewing eccentrically, 11th International Multisensory Research Forum ( IMRF 2010), Liverpool, 2010.  http://imrf.mcmaster.ca/IMRF/ocs2/index.php/imrf/2010/paper/view/169.

J. Blank, R. Herpers, and H. Otten,  Zentrale Archivierung und verteilte Kommunikation digitaler Bilddaten in der Pneumokoniosevorsorge, 50. Jahrestagung der Deutschen Gesellschaft für Arbeitsmedizin und Umweltmedizin, Dortmund 2010.

B. Krausz, R. Herpers: MetroSurv: Detecting Events in Subway Stations, Multimedia Tools and Applications, Springer, ISSN 1380-7501 (Print) 1573-7721 (Online), Sept. 2009.

R. Herpers, G.W.Dueck, and N. Frobel,: International Distributed Computer Science Degree - Cooperative Education Efforts between Canada, Poland, Greece and Germany, IEE IV 2009, Informatics Education Europe IV, Freiburg, Germany, Nov. 05-06, 2009.

M. Kaul, S. Bursner and R. Herpers,: How does self-perception influence the choice of study? E-portfolio and gender issues in Informatics, IEE IV 2009, Informatics Education Europe IV, Freiburg, Germany, Nov. 05-06, 2009 .

R. Herpers, D. Scherfgen, M.Kutz, U. Hartmann, O. Schulzyk, D. Reinert, and H.Steiner: FIVIS – A Bicycle Simulation System, World Congress on Medical Physics and Biomedical Engineering (WC 2009), Munich, O. Dossel and W. Schlegel (Eds.), IFMBE Proceedings 25/IV, , pp. 2132-2135, Springer, 2009.

D. Scherfgen and R. Herpers,: 3D Tracking using multiple Nintendo Wii Remotes, Internat. Conf. of Future of Game Design and Technology, ACM FuturePlay 2009, 12-13. 05., Vancouver, BC, Canada, pp. 31-32, 2009.

R. Herpers, W. Heiden, M. Kutz, D. Scherfgen: Immersion Square – A cost-effective multi- screen VR Visualisation Technology. Electronic displays 2009 Conference. ED2009, 3.-4.03. 2009, WEKA Fachmedien GmbH (edt), ISBN 978-3-7723-3797-0, 2009.

R. Herpers, W. Heiden, M. Kutz, D. Scherfgen, U. Hartmann, J. Bongartz, O. Schulzyk: FIVIS - Bicycle Simulator in the Immersive Visualisation Environment “Immersion Square”, in: Forschungsspitzen und Spitzenforschung, C. Zacharias et al. (eds.), Physica-Verlag, pp. 61 -68, 2008.

Noelle, G., Herpers, R., Hellmuth, D., Christ-Kohler, R.: Entwicklung eines elektronischen Mutterpasses, in: Forschungsspitzen und Spitzenforschung, C. Zacharias et al. (eds.), Physica- Verlag, pp. 51 -60, 2008.

W. Heiden, R. Herpers und A. Hinkenjann: Visual Computing an der FH Bonn-Rhein-Sieg, in: Forschungsspitzen und Spitzenforschung, C. Zacharias et al. (eds.), Physica-Verlag, pp. 69 -76, 2008.

R. Herpers, W. Heiden, M.Kutz, D. Scherfgen, U. Hartmann, J. Bongartz, O. Schulzyk: FIVIS- Bicycle Simulator – An Immersive Game Plattform for Physical Activities. Internat. Conf. of Future of Game Design and Technology, ACM FuturePlay 2008, 3.-5.11., pp. 244-249, 2008.

M. Kutz, R. Herpers: Urban Traffic Simulation for Games. Internat. Conf. of Future of Game Design and Technology, ACM FuturePlay 2008, Toronto, 3.-5.11., pp. 181-185, 2008.

B. Krausz, R. Herpers: Event Detection for Video Surveillance Using an Expert System 1st ACM Internat. Workshop in Analysis and Retrieval of Events/Actions and Workflows in Video Streams (AREA 2008), Vancouver, 31.10.2008.

Schulzyk, J. Bongartz, T. Bildhauer, U. Hartmann, R. Herpers, A real bicycle simulator in a virtual reality environment: The FIVIS project, ECIFMBE- BMT Conference, IFMBE Procee- dings 22, J Vander Sloten et al (eds.) Antwerp, Belgium, Springer, pp. 2628-2631, 2008.

M. Vieth, R. Herpers, M. Huelke, M. Schafer, D. Chhabra: A low-cost based 6DoF Head Tracker for Usability Application Studies in Virtual Environments, 5th INTUITION Conference on Virtual Reality and Virtual Environments, No 85, 2008.

M. Vieth, O. Zilken, R. Herpers , D. Reinert: Vision Based Hand and Finger Detection at Machines with Manual Operation, Robotik 2008, VDI-Berichte 2012, pp. 255-258, Munchen, 2008.

M. Foursa, G. Wesche, D. d’Angelo, M. Bogen, R. Herpers: A Two-user Virtual Environment for Rapid Assembly of Product Models within an Integrated Process Chain. X Symposium of Virtual and Augmented Reality 2008 (SVR 2008), ISBN 857669167-1, pp. 143-150, Joao Pessoa, Brasil, 2008.

M. Lanser, A. Hau, W. Heiden, and R. Herpers:  GL-Wrapper for Stereoscopic Rendering of Standard Applications for a PC-based Immersive Environment, 4th INTUITION Conference on Virtual Reality and Virtual Environments, 2007.

A. Barth, R. Herpers, M. Greßnich,:  Real-time Applicable Visual Quality Control in Industrial Line Production, Proc. of the IEEE/ASME International Conference on Advanced Intelligent Mechatronics, IEEE, 2007.

R. Herpers , N. Jung, D. Reinert, O. Schwaneberg, S. Hahne, A. Barth, O. Zilken, M. Vieth: Hand and Finger protection for circular saws, 5^th . Int. Conf. on Safety of Industrial Automated Systems (SIAS 2007), pp. 119-124, Tokio Japan, 2007

O. Schulzyk, J. Bongartz, T. Bildhauer, U. Hartmann, R. Herpers, B. Goebel, D. Reinert:  A bicycle simulator based on a motion platform in a virtual reality environment FIVIS project in Buzug, Holz, Weber, Bongartz, Kohl-Bareis, Hartmann (Hrsg.), Proceeding in Physics 114: Advances in Medical Engineering, Springer-Verlag: Berlin New York, pp.323-328, 2007.

D. Reinert, R. Herpers:  From the health and safety research, hand or wood? That is the question, video-based detection of hands on circular saws, BG - Prevention, pp 312-313, 2007

A. Barth, R. Herpers, M. Greßnich,: Visual Quality Comtrol in Heat Shrink Tubes, Proc. of the 5th International Conference on Computer Vision Systems (ICVS 2007), 21.-24.03., elect. Publishing, University of Bielefeld, Germany, ISBN 978-3-00-020933-8 , 2007 . http://dx.doi.org/10.2390/biecoll-icvs2007-104

A. Barth, R. Herpers, M.Greßnich, D. Reinert: Visual Inspection of fast moving heat shrink tubes in real-time. Proc. Research and Education in Mechatronics, REM 2006, KTH Stockholm, Schweden, 15.-16. June, elect. Publishing, No. 63, 2006 .

S. Hahne, R. Herpers, A. Barth, D. Reinert: Real-time detection and tracking of human body parts in real workshop environments. Proc. Research and Education in Mechatronics, REM 2006, KTH Stockholm, Schweden, 15.-16. June, elect. Publishing, No. 64, 2006.

D. Reinert, B. Klumbies, M. Rabenda, A. Barth, S. Hahne, F. Dücker, R. Herpers, N. Jung, N. Becker, P. Melcher, S. Ullmann, W. Olbert, D. Kamin, and R. Kohler:  Finger and hand protection on circular table and panel saws, 4^th . Int. Conf. on Safety of Industrial Automated Systems, elect. Publishing, 2005, Chicago, USA.

A. Barth and R. Herpers (2005, 30.08.-02.09.). R obust head detection and tracking in cluttered workshop environments using GMM, 27th Annual meeting of the German Association for Pattern Recognition, W.G. Kropatsch et al. (eds.), Springer LNCS 3663, pp. 442-450, 2005.

M. Enzweiler, R. Wildes and R. Herpers (2005, 05.-06.01.).  Unified target detection and tracking using motion coherence, Proc. of the IEEE Workshop on Motion and Video Computing (Motion 2005), IEEE Computer Society Press, pp. 66-71, 2005.

R. Herpers, F. Hetmann, A. Hau, and W. Heiden (2005).  The Immersion Square – A mobile platform for immersive visualizations, Aktuelle Methoden der Laser- und Medizinphysik, 2nd Remagener Physiktage, Remagen, Germany, VDE Verlag, pp. 54-59

D. Schmitz, D. Seibt, R. Herpers, and W. Heiden (2005).  3D-Reconstruction of microscopic translucent silicate-based marine and freshwater organisms, Aktuelle Methoden der Laser- und Medizinphysik, 2nd Remagener Physiktage, Remagen, Germany, VDE Verlag, pp. 43-48

A. Kläser, S. Stankovic, and R. Herpers (2004).  Enhancing motion trajectories in noisy video sequences, IEEE Int. Symposium on Signal Processing and Information Technology (ISSPIT 2004) , IEEE Computer Society Press, pp. 99 – 102

R. Herpers, J. Schumacher, and R.S. Allison (2004).  Hiding graphic updates during long saccadic suppression periods, Dynamische Perception 2004, 18.-19.11. Tübingen, U.J. Ilg et al. (edts. ), Infix- IOS Press BV Amsterdam, pp. 77- 82

J. Schumacher, R.S. Allison, and R. Herpers (2004).  Using saccadic suppression to hide graphic updates, ACM Eurographics Symposium on Virtual Environments, p. Coquillart, M. Göbel (Editors), Eurographics EGVE’04, Grenoble, pp. 17-24

S. Stankovic, R. Herpers, and I. Djurovic (2003, 14.-17. Dez.).  Motion parameter estimation of moving objects and ego motion applying an active camera system, IEEE Int. Symposium on Signal Processing and Information Technology (ISSPIT 2003) , IEEE Computer Society Press, elect. Publishing, Darmstadt

D. Reinert, S. Ullmann, M. Hauke, R. Herpers, A. Bunzemeier, and R. Kohler (2003, 3.-5. Oct.).  Non-contact protective device for finger detection on circular saws, 3rd. Int. Conf. on Safety of Industrial Automated Systems, elect. Publishing, Nancy, France.

S. Stankovic, I. Djurovic, R. Herpers und L.J. Stankovic (2003). An approach to optimal watermark detection, Int. J. of Electron. and Commun. (AEUE), Vol.57, No. 5, pp. 355-357

R. Herpers und G. Noelle (2003). Education and training situation in e-health - status and perspectives, in: Telemedicine and eHealth in Germany: And recommendations for a national telematics platform, reports of DIMDI for the Federal Ministry of Health and Social Protection, pp. 219-233

S. Stankovic, I. Djurovic und R. Herpers (2003).  Velocity and acceleration estimation in video sequences by the local polynomial periodogram, Signal Processing and its Applications, IEEE Computer Society Press, Vol. 1, pp. 145 -148

F. Hetmann, R. Herpers and W. Heiden (2002). The Immersion Square - Immersive VR with standard components, Proc. of Virtual Environment on PC, Russia, ISBN 5-88835-011-7, pp. 23-32

R. Herpers, K. Derpanis, W. J. MacLean, G. Verghese, M. Jenkin, E. Milios, A. Jepson, J.K. Tsotsos (2001).  SAVI: an actively controlled teleconferencing system (PDF-1003kB) Journal Image and Vision Computing, Vol. 19(11), pp. 793-804

R. Herpers, W. J. MacLean, C. Pantofaru, L. Wood, K. Derpanis, D. Topalovic, J. Tsotsos (2001).  Fast hand gesture recognition for real-time teleconferencing applications. IEEE Proc. of the Second int. Workshop on Recognition, Analysis and Tracking of Faces and Gestures in Real-Time Systems, RATFG-RTS'01, Vancouver, Canada, IEEE Computer Society, pp. 133-144

R. Herpers, S. Olufs, N. Blanck-Wehde, S. Sertel, R. Pöllath, C. Frühling (2001).  go2 - a game platform for interacting with mixed realities. Proc. CAST 01, living in mixed realities, netzspannung.org - journal special issue, M. Fleischmann, W. Strauss (eds), ISSN 1617-6855, pp. 365-368

R. Herpers, K. Derpanis, D. Topalovic, C. Pantofaru, W. J. MacLean, G. Verghese, A. Jepson, J.K. Tsotsos (2000).  Active visual control by stereo active vision interface SAVI (PDF-242kB) Proc. in Artificial Intelligence, 3rd GI Workshop Dynamische Perzeption, G. Baratoff, H. Neumann (eds), Ulm, Germany, Infix Verlag, pp. 81-86

Herpers R., G. Verghese, K.Derpanis, R. McCready, J. MacLean, A. Levin, D. Topalovic, L. Wood, A. Jepson, J.K. Tsotsos (1999).  Detection and tracking of faces in real environments. (PDF-335kB) Proc. of IEEE Int. Workshop on Recognition, Analysis and Tracking of Faces and Gestures in Real-Time Systems (RATFG-RTS'99), Corfu, Greece, IEEE Computer Society Press, pp. 96-104

R. Herpers, G. Verghese, L. Chang, K. Darcourt, K. Derpanis, R.F. Enenkel, J. Kaufman, M. Jenkin, E. Milios, A. Jepson and J.K. Tsotsos (1999). An active stereo vision system for recognition of faces and related hand gestures. (ps.gz-3,4MB) Proc. of 2nd Int. Conf. on Audio- and Video-based Biometric Person Authentication, University of Maryland, USA, pp. 211-216, 242

Krüger V., R. Herpers, K. Daniilidis, and G. Sommer: Teleconferencing using an attentive camera system. (ps.gz-1,03MB) Proc. of 2nd Int. Conf. on Audio- and Video-based Biometric Person Authentication, University of Maryland, USA, pp. 136-141

R. Herpers, G. Verghese, M. Jenkin, E. Milios, A. Jepson and J.K. Tsotsos (1999). SAVI An actively controlled teleconferencing system, Proc. of IEEE 2^nd Workshop on Perception of Mobile Agents (WPMA2), Fort Collins, Colorado, pp. 44-50

V. Krüger, R. Herpers, K. Daniilidis, and G. Sommer (1999). Teleconferencing using an attentive camera system. Proc. of 2nd Int. Conf. on Audio- and Video-based Biometric Person Authentication, University of Maryland, USA, pp. 136-141

Herpers R. and G. Sommer (1998). An attentive processing strategy for the analysis of facial features. (ps.gz-1MB) Face Recognition: From Theory to Applications, H. Wechsler et al. (eds), NATO ASI Series F, Springer-Verlag, Vol. 163, pp. 457-468

G. Sommer, M. Michaelis and R. Herpers (1998). The SVD approach for steerable filter design. (ps.gz-155kB) Proc. of IEEE Int. Symposium on Circuits and Systems ISCAS'98, Monterey, California, USA, IEEE Computer Society Press, Vol. 5, pp. 349-353

Herpers R. and G. Sommer (1998, June). Discrimination of facial parts based on dynamic grids of point representations. Guest-Editor: Special Issue on Neeurocomputing Topics in Computer Vision Applications, in Int. Journal of Pattern Recognition and Artificial Intelligence (IJPRAI), Special issue on 'Neural networks in computer vision applications', Vol. 12, No. 4

Herpers R. and G. Sommer (1997).  Facial Analysis applying an attentive processing strategy. Proc. of Int. Conference on Systems, Man, and Cybernetics, IEEE Computer Society Press, Vol. 5, p. 4069-4074

Herpers R., GAZE (1997). A common attentive processing strategy for the detection and investigation of salient image regions. Dissertation Technische Fakultät der Christian-Albrechts-Universität zu Kiel, Technische Fakultät, Mai 1997, CAU-Report 9714, 1997, and GSF-Report 16/97, GSF- Forschungszentrum, Neuherberg

Herpers R., D. Müller, M. Michaelis and G. Sommer (1997). Invariant classification of image parts using a dynamic grid of point representations. Neural Networks in Engineering Systems, Proc. of Int. Conf. on Engineering Applications of Neural Networks, EANN'97, Stockholm, A. B. Bulsari et al. (eds.), p. 41-45

Herpers R., L. Witta, J. Bruske and G. Sommer (1997). Dynamic Cell Structures for the Evaluation of Keypoints in Facial Images. Int. J. of Neural Systems, Vol. 8, No. 1, p. 27-39

Michaelis M., Herpers R., L. Witta and G. Sommer (1997). Hierarchical Filtering Scheme for the detection of facial keypoints. Proc. of the Int. Conf on Acoustics, Speech and Signal Processing ICASSP'97, IEEE Computer Society Press, p. 2541-2544

Herpers R., M. Michaelis, K.-H. Lichtenauer and G. Sommer (1996). Edge and Keypoint Detection in Facial Regions. (ps.gz-506kB) Proceedings of Int. Conf. on Automatic Face- and Gesture-Recognition, FG'96, Killington, Vermont, IEEE Computer Society Press, p. 212-217

Englmeier K.-H., R. Herpers, I. Künzer, M. Obermaier and M. Altmann (1996). Displacement Correction and Surface Reconstruction of the Retina using Scanning-Laser-Ophthalmoscopic Images. Int. Journal of Bio-Medical Computing, Vol. 42, p. 191-204

Englmeier K.-H., R. Herpers, R. S. Jacoby and F. M. Zwiebel (1996). A Method for the Estimation of Hemoglobin Distribution in Gastroscopic Images. Int. Journal of Bio-Medical Computing, Vol. 41, p. 153-165

Herpers R., L. Witta, M. Michaelis, J.Bruske und G. Sommer (1996). Detektion und Verifikation von charakteristischen Bildpunkten in Gesichtsbildern. Tagungsband des 18. Symposiums der DAGM, Mustererkennung 1996, Heidelberg, B. Jähne et al. (eds), Springer-Verlag, Reihe Informatik aktuell, p. 435-446

Herpers R., M. Michaelis, L. Witta and G. Sommer (1996). Context based Detection of Keypoints and Features in Eye Regions. Proc. of 13th Int. Conf. on Pattern Recognition ICPR'96, Wien, Österreich, IEEE Computer Society Press, p. 23-28

Herpers R., L. Witta, J. Bruske and G. Sommer (1996). Evaluation of local image structures applying a DCS network. Int. Conf. on Engineering Applications of Neural Networks, EANN'96, London A. B. Bulsari et al. (eds.), Solving Engineering Problems with Neural Networks, p. 305-312

Michaelis M., R. Herpers and G. Sommer (1995). A common framework for preattentive and attentive vision using steerable filters. Proc. of 6th Int. Conf. CAIP'95, Prag, Tschechische Republik, V. Hlavac et al. (eds.), Springer-Verlag, LNCS 970, p. 912-919

Jacoby R. S., F. M. Zwiebel, R. Herpers and K.-H. Englmeier (1995). Estimation of Blood Flow in the upper gastrointestinal Tract by Analysis of Endoscopic True Color Images. Proceedings: MedInfo´95, 8th World Congress on Medical Informatics, R.A. Greenes et al. (eds.), Vancouver, Canada, Vol. 8(1), p. 714-717

Herpers R., H. Kattner, H. Rodax and G. Sommer (1995). GAZE: An Attentive Processing Strategy to Detect and Analyze the Prominent Facial Regions. (ps.gz-649kB) Proc. of Int. Workshop on Automatic Face- and Gesture-Recognition, IWAFGR'95, M. Bichsel (edt.), Zürich, Schweiz, p. 214 - 220

K.-H. Englmeier, M. Haubner, R. Herpers, U. Fink, B. Fink (1994). Methodology of medical image processing. Information technology and technical computer science, 12. 94; Vol. it+ti 6/94, p. 8 - 16

Herpers R., H. Kattner and G. Sommer (1994). GAZE: An attentive processing strategy for identifying and learning of visually striking facial regions. In Kropatsch W.G. and H. Bischof (Hrsg.), Proceedings of the 16th Symposium of the DAGM, Pattern Recognition 1994, computer science Xpress 5, Vienna, p. 341 - 349

Künzer I., M. Altmann, R. Herpers and K.-H. Englmeier (1994). Volumetric 3D surface reconstruction of the blind spot by scanning-laser-ophthalmoscope image sequences of the fundus. Medical computer science - An integrated part doctor supporting technologies, Proceedings of the 38th Annual Meeting of the GMDS, Lübeck, S.J. Pöppl et al. (eds.), MVV-Medizin Verlag München, Vol. 77, p. 232-235

Reul J., H. Handels, A. Thron, Ch. Lakenberg and R. Herpers (1992, June). Relaxometric differentiation of normal and pathological brain tissue with MRI using a histogram-based cluster analysis. Clinical Neuroradiology 2, pp. 55-63

Handels H., A. Hiestermann, R. Herpers and T. Tolxdorff (1991). Automatic 3D-Segmentation and classification of tissues in medical diagnostics. In Radig B. (Hrsg.), Mustererkennung 1991, 13. DAGM-Symposium München, Informatik Fachberichte 290, Springer Verlag Berlin, p. 295-303.
This entry was awardedby the DAGM-Anerkennungspreis '91 (DAGM Award-'91).