Table of Contents Table of Contents 1 Introduction PART I SOLID STATE PHYSICS, ELECTRONICS AND OPTICS Section 1 Materials and Fabrication Chapter 1 Heterostructures for High Performance Devices ..................................................... 7 Professor Clifton J. Fonstad, Jr. 1.1 *1.2 *1.3 *1.4 *1.5 1.6 1.7 1.8 1.9 1.10 1.11 1.12 1.13 1.14 1.15 7 Introd uctio n ....................................................................... Growth Optimization of MBE-Grown InAIAs on InP ....................................................... 7 Fabrication of Ridge Waveguide Distributed Feedback Lasers by 8 ............................. X-ray Lithography ................................................................... Numerical Calculation of Coupling Coefficients in Ridge Waveguide 9 .......................... D istributed Feedback Lasers .......................................................... Measurement of Excited-state Lifetimes in Narrow Quantum Wells ................................ 11 11 Tunable Sem iconductor Lasers ........................................................ Integration of Vertically-emitting, In-plane Cavity Laser Diodes on 13 G aA s V LS IC ircuitry ................................................................. ......... 14 Thermal Stability of GaAs MESFET VLSI Circuits ...................................... Gas Source MBE of InGaAsP Laser Diodes on GaAs Substrates ................................. 15 High-Density OEIC Neural Systems Produced by Monolithic Integration of GaAIAs Light Emitting Diodes on GaAs MESFET 15 VLSI Circuits .................................................. Surface-Normal Optical Input and Output Cells for High-Density, ... ............. 18 High-Speed GaAs MESFET-based OEICs ..................................... ........... 19 Fiber-coupled GaAs MESFET-based OEICs ......................................... Low-temperature, Selective-area MBE Growth of GaAllInAs Laser Diodes and 20 Optical Waveguides on Semi-insulating GaAs Substrates ....................................... Applications of Resonant Tunneling Diodes in GaAs MESFET VLSI .............................. 21 Polarization-resolved Infrared Spectra of Very Narrow AIAs/InGaAs/InP 22 Q uantum W ells ......................................................... 1.16 1.17 1.18 1.19 Chapter 2 Symmetry Properties of Quantum Well Subband Energy Levels and ............ 24 Selection Rules for Intersubband Transitions ..................................... .. Investigation of Infrared Intersubband Emission from InGaAs/AIAs/InP Quantum .................................................... 25 W ell Heterostructures ................................................ High-Frequency/High-Speed Characterization, Analysis and Modeling of Heterojunction Bipolar Transistors, Laser Diodes, and ................................................... 26 m -s-m Photodetectors ................................................. Damage-Free In-Situ UHV Etching and Cleaning of Ill-V Heterostructures ............................. 26 Using Molecular Beam s .............................................................. Physics of InAIAs/InGaAs Heterostructure Field-Effect Transistors ........................ 29 Professor Jess A. del Alamo *2.1 *2.2 * 29 Introduction .................................................. Physics of Breakdown in InAIAs/InGaAs MODFETs ..................................... ....... 30 Sponsored by the Joint Services Electronics Program. Table of Contents *2.3 * 2.4 Chapter 3 Impact Ionization in InAIAs/InGaAs HFETs ......................................... ............. 33 Publications and Conference Papers ......................................................................... 34 Gas Source Molecular Beam Epitaxy of Compound Semiconductors ..................... 35 Professor Leslie A. Kolodziejski S3 .1 *3.2 3.3 3.4 3.5 3.6 3.7 Section 2 Chapter 1 Introd uctio n ............................. .............................. ............................................. . ..... Gas Source Molecular Beam Epitaxy of ZnSe, ZnSe:CI and ZnSe:N ............................. Novel Epitaxial Ill-V Buffer Layers for Wide Bandgap II-VI Visible Sources ................... Integrated Photonic Devices: The Channel-Dropping Filter ....................................... Heterovalent Interfaces Composed of II-VI/Il-V Heterostructures ................................... ....... Optoelectronic Very Large Scale Integrated Circuits ...................................... Heteroepitaxy of GaAs onto Corrugated Surfaces of Si ............................................ 35 37 42 45 46 48 48 Quantum-Effect Devices ............. 51 ................................................................. P roject D escription ..................... ...... ............ ........................................... P ub licatio ns ..................... .................... 51 52 Single-Electron Transistors .............................................................................................. 53 Statistical Mechanics of Quantum Dots ..................................... ... Professor Boris L. Altshuler * 1.1 * 1.2 Chapter 2 Professor Marc A. Kastner *2.1 * 2.2 Chapter 3 P roject D escription ......................... Publications ................................. ............................................................. 53 ................... 56 ........................ Edge Structure of a Quantum Dot in a Large Magnetic Field ................................... 57 Professor Patrick A. Lee 3.1 * 3.2 Chapter 4 Project Description ...................................... Publications .................................. ..................... ............ ................... 57 . ....... ...... ...... .... .................. 58 Nanostructures Technology, Research, and Applications ..................................... 61 Professor Henry I. Smith 4.1 * 4.2 * 4.3 *4.4 *4.5 *4.6 4.7 * 4.8 S4.9 *4.10 4.11 *4.12 4.13 *4.14 iv ....... ........................ .. NanoStructures Laboratory ........................... ... ........ Scanning Electron-Beam Lithography Facility ......................................................... ........ Spatial-Phase-Locked Electron-Beam Lithography ..................................... ............. ................... ......... ..... X-Ray Nanolithography ............................. ......... Improved Mask Technology for X-Ray Lithography ..................................... ............. A High Precision Mask Alignment System .......................................... Optimization of Synchrotron-Based X-ray Lithography ..................................... ..... Achromatic Holographic Lithography ............................................................... Ion Beam Lithography ............................................................................. High Performance Self-aligned Sub-100 nm MOSFETs Using X-ray Lithography ............. Fabrication of T-gate Devices Using X-ray Lithography ......................................... Studies of Coulomb Charging Effects and Tunneling in Semiconductor Na no stru ctu re s ..................................................................................................................... Dual Electron Waveguide Device Fabricated Using X-ray Lithography ......................... ................ Novel Mesoscopic Superconducting Devices .................. RLE Progress Report Number 136 61 61 62 64 65 66 69 70 70 72 73 76 79 79 Table of Contents *4.15 *4.16 4.17 *4.18 4.19 * 4.20 4 .2 1 Chapter 5 Channel-Dropping Filters Fabricated Using X-ray Lithography ................................... . Ridge-Grating Distributed-Feedback Lasers Fabricated by X-ray Lithography ............... Fabrication of Sub-micron MSM Photodiodes by X-ray Lithography ............................... Submicrometer-Period Transmission Gratings for X-ray and Atom-Beam Spectroscopy and Interferometry ......................................................................................... High-Dispersion, High Efficiency Transmission Gratings for Astrophysical .............................................. X -ray Spectroscopy ............................................................. GaAs Epitaxy on Sawtooth-Patterned Silicon ......................................................... ... P ub licatio ns ..................................................................................................................... Single-Electron Spectroscopy ........................................................................................ 79 83 85 86 86 88 88 91 Professor Raymond C. Ashoori *5.1 *5 .2 Section 3 Chapter 1 * 1.1 S1.2 1.3 1.4 1.5 * 1.6 * 1.7 * 1.8 1.9 S1.10 * 1.11 * 1.12 * 1.13 1.14 1.15 1.16 1.17 1.18 1.19 1.20 1.2 1 1.22 Chapter 2 P roject D escription .............................................................................................................. P ublicatio ns .......................................................................................................................... 91 95 Optics and Devices Optics and Quantum Electronics ..................................................................................... Professor Hermann A. Haus, Professor Erich P. Ippen, Professor James G. Fujimoto, Professor Peter L. Hagelstein, Dr. Santanu Basu 99 99 A dditive Pulse M odelocking ................................................................................................. 100 Fiber Ring Laser ........................................................................................................... 101 Long Distance Fiber Communications ............................................................................. 10 1 Sq u e e z ing .......................................................................................................................... 103 ................................... Filter Dropping Integrated Photonic Components: The Channel 104 ......... Ultrafast Nonlinearities in Active Semiconductors .............................................. 105 Femtosecond Raman Measurements in Optical Fibers .................................................... 106 ..................................... Materials Solid-State Coherent Phonons in 107 Publications and Meeting Papers ..................................... 109 ..................................... Lasers State Solid in Ultrashort Pulse Generation Cavity Dumping Techniques for Modelocked Ti:A1203 Lasers ..................................... 110 Spectrally Resolved Autocorrelation for Femtosecond Diagnostics .................................. 113 113 Ultrafast Phenomena in Materials and Devices ..................................... 118 Lase r Med icine ................................................................................................................... 124 E UV Laser Studies ............................................................................................................ 124 ............................................................................................................. N i-like N b Studies 125 ... H-like Boron Recombination X-ray Laser ............................... .......................................... 129 Pum p Laser C onversion .................................................... 130 Development of a Densitometer .................................................................................. 131 ...................................................................................... Detector X-ray Quantum-Well .............................................. 133 Lineshape T heory ............................................................. ......................................... 133 Lattice-induced Reactions ................................................... Optical Propagation and Communication .................................................................. 139 Professor Jeffrey H. Shapiro, Dr. Robert H. Rediker, Dr. Ngai C. Wong 2 .1 2.2 2.3 2.4 2.5 Intro d uctio n ........................................................................................................................ Squeezed States of Light ................................................ Multiresolution Laser Radar Range Profiling ..................................................................... Optical Frequency Division and Synthesis .................................................................. Analog Processing of Optical Wavefronts Using Integrated Guided-Wave Optics ........ 13 9 139 140 141 143 Table of Contents Chapter 3 High-Frequency (> 100 GHz) and High-Speed (< 1 ps) Electronic Devices .............. 145 Professor Qing Hu 3.1 3.2 3.3 3.4 3.5 3.6 3 .7 Section 4 Chapter 1 Facility for Millimeter-wave and THz Frequencies ..................................................... Far-infrared Studies of Antenna-coupled Quantum-effect Devices ................................ Femtosecond Dynamical Studies of Quantum Devices for Ultrafast E lectronic A pplications ................................................................... .............................. High-Tc Superconducting Josephson Devices ..................................... ............... Millimeter-wave and Infrared Superconducting Focal-plane Receiver Arrays ............... Far-infrared (THz) Lasers Using Multiple Quantum Wells .......................................... P ublicatio ns ............................................................................... ................................... 145 145 148 149 153 154 158 Surfaces and Interfaces Statistical Mechanics of Constrained Electronic Systems and Semiconductor Structures ................................................................................ 161 Professor A. Nihat Berker *1.1 *1.2 *1.3 *1.4 *1.5 *1.6 Chapter 2 Intro d uctio n ...................................................................................................................... Renormalization-Group Approach to Highly Correlated Electronic Systems .................. Statistical Mechanics of Mesoscopic Systems and Quantum Dots ............................... Collective Phenomena in Systems with Quenched Impurities and Frustration ............. Surface and Bulk Structures of Semiconductor Alloys .................................... .......... P u blicatio ns ......................................................................... ......................................... 161 161 164 164 165 166 Synchrotron X-Ray Studies of Surface Disordering ............................................ 169 Professor Robert J. Birgeneau * 2.1 *2.2 *2.3 *2.4 * 2 .5 Chapter 3 In tro d u ctio n ........................................................................................................................ Vicinal Semiconductor Surfaces ........................................... Chiral Melting of the Si(113) (3x1) Reconstruction ................................................. Tw o-D im ensional Melting ........................................................... ................................... P ub licatio ns ......................................................................................... ....................... 169 169 170 171 171 Chemical Reaction Dynamics at Surfaces ...................................... 175 ............... Professor Sylvia T. Ceyer *3.1 *3.2 *3.3 *3.4 Chapter 4 A New Mechanism for Dissociative Chemisorption on Si: Atom Abstraction ............. A Model for Atom Abstraction by Surfaces ... .................................................... Atom Abstraction and its Relationship to Thin Film Growth .......... ............................ Etching of Si(100) by Energetic Fluorine .................................... . ............... 175 177 178 179 Semiconductor Surface Studies .................................................................................... 181 Professor John D. Joannopoulos *4.1 *4.2 * 4.3 *4.4 vi Intro du ctio n ............................................................................. Defects on Surfaces .................................................. ...................................... Cross-sectional Scanning Tunneling Microscopy ..................................... Publications ................... ...... ................................. RLE Progress Report Number 136 181 ................................................... 181 .............. 184 185 Table of Contents Chapter 5 Step Structures and Epitaxy on Semiconductor Surfaces ...................................... 187 Professor Simon G.J. Mochrie *5.1 *5.2 *5.3 *5 .4 P roject D escription ...................................................................... ................................. The Structure of the (3x1) Reconstruction of the Si(113) Surface ................................ .................. Morphology of Stepped Si(113) Surfaces ....................................... ................................... P ublications ............................................................................... PART II APPLIED PHYSICS Section 1 Atomic, Molecular and Optical Physics Chapter 1 187 188 189 190 195 Quantum Optics and Photonics ...................................................... Professor Shaoul Ezekiel, Dr. M. Selim Shahriar 1.1 1.2 1.3 1.4 1.5 1.6 Chapter 2 195 197 Data Storage Using Raman Induced Optical Spectral Holeburning .............................. Observation of Cooling Assisted Velocity Selective Coherent Population Trapping ........ Suppression of Absorption of Resonance Fluorescence in a Folded T hree-Level Atom ....................................................................... ................................. Inversionless Raman Lasing ........................................................... Creating a Large Angle Coherent Atomic Beamsplitter without a Magnetic Field ............ Stimulated Brillouin Scattering Ring Laser Gyroscope ..................................... ......... 199 201 202 204 Basic Atomic Physics ............................................................................................... 209 Professor Daniel Kleppner, Professor David E. Pritchard, Professor Wolfgang Ketterle 2.1 *2.2 *2.3 *2.4 * 2.5 Section 2 Chapter 1 Testing Quantum Chaos with Rydberg Atoms in Strong Fields .................................... Millimeter-Wave Frequency Measurement of the Rydberg Constant ............................. Precision Mass Spectroscopy of Ions ......................................................................... .................................................... A tom Interferom etry ................................................. Atoms .......................................................................... Neutral Trapping Cooling and 209 215 218 221 225 Plasma Physics Plasm a Dynam ics ...................................................................... ................................ 231 Professor George Bekefi, Professor Abraham Bers, Professor Bruno Coppi, Professor Jonathan S. Wurtele, Dr. Stefano Migliuolo, Dr. Abhay K. Ram, Dr. Barrett Rogers, Dr. Linda E. Sugiyama 1.1 1.2 1.3 Section 3 Chapter 1 R elativistic Electron Beam s .............................................................. ........................... 231 Plasma Wave Interactions - RF Heating And Current Generation ................................ 237 249 Physics of Thermonuclear Plasmas ........................................................ Electromagnetics Electromagnetic Wave Theory and Applications ..................................... ........ 263 Professor Jin Au Kong, Professor Terry Orlando, Dr. Robert T. Shin, Dr. Y. Eric Yang 1.1 *1.2 1.3 1.4 Remote Sensing of Earth Terrain ......................................................... ................. Electromagnetic W aves in Multilayer Media ...................................... .............. Simulation of Electromagnetic Wave Scattering ..................................... ................. Superconducting Transmission Lines ..................................... 263 265 266 269 Table of Contents Section 4 Chapter 1 Radio Astronomy Radio Astronomy ........................................ 277 Professor Bernard F. Burke, Professor David H. Staelin, Professor Jacqueline N. Hewitt, Dr. Philip W. Rosenkranz 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 1.9 1.10 Extragalactic Radio Source Studies ...................................... Studies of Gravitational Lenses ..................................... Radio Interferometry of Nearby dMe Stars ..................................... The Detection of Astronomical Radio Transients ..................................... Algorithms for Advanced Microwave Sounding Unit Operational Use ........................... Earth Observing System: Advanced Microwave Sounding Unit ................................... High-Resolution Passive Microwave Imaging of Atmospheric Structure ....................... Rapid Precision Net-Form Manufacturing ..................................... Conformal Experiment Design ...................................... Recognition of Natural Nearly Repetitive Signals ..................................... PART III SYSTEMS AND SIGNALS Section 1 Computer-Aided Design Chapter 1 Custom Integrated Circuits ....................................... 277 279 280 280 282 282 283 284 284 284 289 Professor Jonathan Alien, Professor John L. Wyatt, Jr., Professor Jacob White, Professor Srinivas Devadas 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 1.9 1.10 Chapter 2 289 Custom Integrated Circuits ........................................ Analog VLSI Systems for Integrated Image Acquisition and Early V ision P rocessing .............................................................................................................. Parallel Algorithms for Device Simulation ..................................... Numerical Simulation of Short Channel MOS Devices ..................................... Coupled Simulation Algorithms for Microelectromechanical CAD ................................. Numerical Techniques for Simulating Josephson Junction Arrays ................................ Efficient 3-D Interconnect Analysis ..................................... Adaptive Gridding Techniques for Multipole-Accelerated Solution . of Integral Equations ...................................................................................................... Circuit Simulation Algorithms ....................................... Techniques for Embedded System Design, Formal Verification, and Synthesis for Low Power Dissipation ........................................ 305 Computer-Integrated Design and Manufacture of Integrated Circuits ................... 309 292 300 301 302 303 303 304 304 Professor Donald E. Troxel 2.1 2.2 2.3 2.4 2.5 2 .6 viii Introduction .................................................. Principal Objectives ........................................ Principal Accom plishm ents ................................................................................................ Process Flow Representation ....................................... Technology CAD Framework ....................................... P ublicatio ns ............................................................. ............................................ . ..... RLE Progress Report Number 136 309 309 310 311 312 3 13 Table of Contents Section 2 Chapter 1 Digital Signal Processing Digital Signal Processing Research Program ..................................... 317 Professor Alan V. Oppenheim, Professor Arthur B. Baggeroer, Professor Gregory W. Wornell 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 1.9 1.10 1.11 1.12 1.13 1.14 1.15 1.16 1.17 1.18 Chapter 2 Introduction .................................................. Active Noise Cancellation in Automobiles ..................................... Single Mode Excitation in the Shallow Water Acoustic Channel ................................... Self-Synchronization of Chaotic Systems: Analysis, Synthesis, and A pp licatio ns ........................................................................................................................ Algebraic and Probabilistic Structure in Fault-Tolerant Computation ............................ Signal Processing Applications of Chaotic Dynamical Systems .................................... Wavelet-Based Representation and Algorithms for Generalized Fractal Signals .......... Approximate Signal Processing ................................................................................... .. Code Division Multiple Access for Digital Storage ......................... ........................................... Signals Chaotic of a Class of Detection and Estimation Real-Time Active Noise Cancellation ................................................................................ State and Parameter Estimation with Chaotic Systems .................................................... Model-Based Analysis of Music ......................................................................................... .... Nonlinear Models for Signal Processing .............................. Environmental Robustness in Automatic Speech Recognition .................. .... ............ ..... ... Active Noise Cancellation .................... Oceanographic Signal Processing ............................................................................... P ub licatio ns ........................................................................................................................ 317 318 318 Advanced Telecommunications and Signal Processing Program .......................... 329 3 18 319 319 320 320 321 321 322 322 323 323 323 324 325 32 6 Professor Jae S. Lim 2 .1 2 .2 2.3 2.4 2.5 2.6 2.7 2.8 2.9 2.10 2.11 2.12 Chapter 3 Intro d uctio n ........................................................................................................................ A T R P Facilities ................................................................................................................. Very-low-bit-rate Video Representations ........................................................................... Audio Compression Using Hierarchical Nonuniform Filterbanks ................................... Transform Coding for High-Definition Television ..................................... Pre-Echo Detection and Reduction ..................................... ............................. Video Source Coding for High-Definition Television .... Error Concealment for an All-Digital HDTV System ..................................... Transmission of HDTV Signals in a Terrestrial Broadcast Environment ....................... Position-Dependent Encoding ..................................................................................... HDTV Transmission Format Conversion and the HDTV Migration Path ....................... Speech Enhancement ........................................ 32 9 329 330 331 331 332 332 333 333 334 334 334 Combined Source and Channel Coding for High-Definition Television ................. 337 Professor William F. Schreiber 3 .1 3.2 3.3 3.4 ..... ..... ................................ Intro d u ctio n ......................................................................... System Development ........................................ ............................................................ ............................................... Error C orrection C hannel Equalization ........................................................................................................ 3 37 337 338 338 Table of Contents PART IV BIOELECTRONICS Section 1 Genetic Analysis Chapter 1 Genosensor Technology Development ..................................... 345 Dr. Mark Hollis 1.1 1.2 1.3 1.4 Introduction .................................................. Development of Genosensor Arrays for DNA Decoding ..................................... Microdetection Technology for Automated DNA Sequencing ........................................ Publications ................................................. PART V LANGUAGE, SPEECH AND HEARING Section 1 Speech Communication Chapter 1 Speech Communication ........................................ 345 345 348 349 355 Professor Kenneth N. Stevens, Dr. Joseph S. Perkell, Dr. Stefanie Shattuck-Hufnagel 1.1 1.2 1.3 1.4 1.5 1.6 1.7 Section 2 Chapter 1 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 1.9 1.10 1.11 1.12 1.13 Section 3 Chapter 1 Introduction .................................................. Studies of the Acoustics, Perception, and Modeling of Speech Sounds .................. Studies of Normal Speech Production ..................................... Speech Research Relating to Special Populations ..................................... Speech Production Planning and Prosody ..................................... Models for Lexical Representation and Lexical Access ..................................... Publications .................................................. 356 356 358 359 361 362 363 Sensory Communication Sensory Communication ........................................ 367 Professor Louis D. Braida, Nathaniel I. Durlach, Dr. William M. Rabinowitz, Dr. Charlotte M. Reed, Dr. Mandayam A. Srinivasan, Dr. David Zeltzer, Dr. Patrick M. Zurek Introd uctio n ........................................................................................................................ 367 Hearing Aid Research ........................................ 367 Cochlear Prostheses ........................................ 374 Tactile Communication of Speech ..................................... 375 Multimicrophone Hearing Aids ...................................... 378 Superauditory Localization for Improved Human-Machine Interfaces ........................... 379 Mechanistic Modeling of the Primate Fingerpad ..................................... 380 Peripheral Neural Mechanisms of Haptic Touch ..................................... 382 Biomechanics of Skin-Object Contact ..................................... 383 Human and Robot Hands: Mechanics, Sensorimotor Functions and Cognition .............. 384 Virtual Environment Technology for Training (VETT) ..................................... 388 The Virtual Sailor: Synthetic Humans for Virtual Environments ..................................... 390 Research on Improved Sonar Displays: A Human/Machine Processing System ........... 391 Auditory Physiology Signal Transmission in the Auditory System ..................................... 397 Professor Lawrence S. Frishkopf, Professor Nelson Y.S. Kiang, Professor William T. Peake, Professor William M. Siebert, Professor Thomas F. Weiss, Dr. Bertrand Delgutte, Dr. Donald K. Eddington, Dr. Dennis M. Freeman, Dr. John J. Guinan, Jr., Dr. John J. Rosowski x RLE Progress Report Number 136 Table of Contents 1.1 1.2 1.3 1.4 1.5 1.6 1.7 Section 4 Chapter 1 1.1 1.2 Intro d u ctio n ............................................................................. ..................................... ................................ Signal Transmission in the External and Middle Ear .................. .. ........................................ Cochlear Mechanisms ................................... Stimulus Coding in the Auditory Nerve and Cochlear Nucleus ...................................... Interactions of Middle-Ear Muscles and Olivocochlear Efferents .................................... Cochlear Efferent System ........................................... Cochlear Implants ................................................................................... 397 397 399 400 402 403 404 Linguistics Linguistics ........................................................................................................................ Professor Noam Chomsky, Professor Morris Halle 411 .................................... Introduction ..................................... ....................................... ................................................................................... Abstracts of Doctoral Dissertations 411 411 APPENDICE. S ..................................... 417 M eeting Pape rs ................................................................................... Jo u rna l A rticles ..................................................................................... Books/Chapters in Books/Published Proceedings ........................... RL E Pu b licatio ns ................................................................................... ....... ..................... ... ............... .............. RLE Theses ...................... ............................................... ...... ......................... Miscellaneous 417 431 442 444 444 446 Appendix B Current RLE Personnel ........................................ 449 Appendix C Milestones ........................................................................................................................ 455 New Faculty and Staff ............................................ ... Retirements ....................................................................................................... .. .............. ....... ..... ...... Chair Appointments ....................... .......... Awards and Honors .............................................. 455 455 455 455 RLE Research Support Index ..................................... 457 Appendix A A.1 A.2 A.3 A.4 A.5 A.6 C.1 C.2 C.3 C.4 Appendix D RLE Publications and Papers Presented ........................... Project Staff and Subject Index 461 xii RLE Progress Report Number 136