The ACM Computing Classification System (1998)

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The ACM Computing Classification System (1998)

A. General Literature
- A.0 GENERAL
  - Biographies/autobiographies
  - Conference proceedings
  - General literary works (e.g., fiction, plays)
- A.1 INTRODUCTORY AND SURVEY
- A.2 REFERENCE (e.g., dictionaries, encyclopedias, glossaries)
- A.m MISCELLANEOUS
B. Hardware
- B.0 GENERAL
- B.1 CONTROL STRUCTURES AND MICROPROGRAMMING (D.3.2)
  - B.1.0 General
  - B.1.1 Control Design Styles
    - Hardwired control [**]
    - Microprogrammed logic arrays [**]
    - Writable control store [**]
  - B.1.2 Control Structure Performance Analysis and Design Aids
    - Automatic synthesis [**]
    - Formal models [**]
    - Simulation [**]
  - B.1.3 Control Structure Reliability, Testing, and Fault-Tolerance [**] (B.8)
    - Diagnostics [**]
    - Error-checking [**]
    - Redundant design [**]
    - Test generation [**]
  - B.1.4 Microprogram Design Aids (D.2.2, D.2.4, D.3.2, D.3.4)
    - Firmware engineering [**]
    - Languages and compilers
    - Machine-independent microcode generation [**]
    - Optimization
    - Verification [**]
  - B.1.5 Microcode Applications
    - Direct data manipulation [**]
    - Firmware support of operating systems/instruction sets [**]
    - Instruction set interpretation
    - Peripheral control [**]
    - Special-purpose [**]
  - B.1.m Miscellaneous
- B.2 ARITHMETIC AND LOGIC STRUCTURES
  - B.2.0 General
  - B.2.1 Design Styles (C.1.1, C.1.2)
    - Calculator [**]
    - Parallel
    - Pipeline
  - B.2.2 Performance Analysis and Design Aids [**] (B.8)
    - Simulation [**]
    - Verification [**]
    - Worst-case analysis [**]
  - B.2.3 Reliability, Testing, and Fault-Tolerance [**] (B.8)
    - Diagnostics [**]
    - Error-checking [**]
    - Redundant design [**]
    - Test generation [**]
  - B.2.4 High-Speed Arithmetic
    - Algorithms
    - Cost/performance
  - B.2.m Miscellaneous
- B.3 MEMORY STRUCTURES
  - B.3.0 General
  - B.3.1 Semiconductor Memories (B.7.1)
    - Dynamic memory (DRAM)
    - Read-only memory (ROM)
    - Static memory (SRAM)
  - B.3.2 Design Styles (D.4.2)
    - Associative memories
    - Cache memories
    - Interleaved memories [**]
    - Mass storage (e.g., magnetic, optical, RAID)
    - Primary memory
    - Sequential-access memory [**]
    - Shared memory
    - Virtual memory
  - B.3.3 Performance Analysis and Design Aids [**] (B.8, C.4)
    - Formal models [**]
    - Simulation [**]
    - Worst-case analysis [**]
  - B.3.4 Reliability, Testing, and Fault-Tolerance [**] (B.8)
    - Diagnostics [**]
    - Error-checking [**]
    - Redundant design [**]
    - Test generation [**]
  - B.3.m Miscellaneous
- B.4 INPUT/OUTPUT AND DATA COMMUNICATIONS
  - B.4.0 General
  - B.4.1 Data Communications Devices
    - Processors [**]
    - Receivers (e.g., voice, data, image) [**]
    - Transmitters [**]
  - B.4.2 Input/Output Devices
    - Channels and controllers
    - Data terminals and printers
    - Image display
    - Voice
  - B.4.3 Interconnections (Subsystems)
    - Asynchronous/synchronous operation
    - Fiber optics
    - Interfaces
    - Parallel I/O
    - Physical structures (e.g., backplanes, cables, chip carriers) [**]
    - Topology (e.g., bus, point-to-point)
  - B.4.4 Performance Analysis and Design Aids [**] (B.8)
    - Formal models [**]
    - Simulation [**]
    - Verification [**]
    - Worst-case analysis [**]
  - B.4.5 Reliability, Testing, and Fault-Tolerance [**] (B.8)
    - Built-in tests [**]
    - Diagnostics [**]
    - Error-checking [**]
    - Hardware reliability [**]
    - Redundant design [**]
    - Test generation [**]
  - B.4.m Miscellaneous
- B.5 REGISTER-TRANSFER-LEVEL IMPLEMENTATION
  - B.5.0 General
  - B.5.1 Design
    - Arithmetic and logic units
    - Control design
    - Data-path design
    - Memory design
    - Styles (e.g., parallel, pipeline, special-purpose)
  - B.5.2 Design Aids
    - Automatic synthesis
    - Hardware description languages
    - Optimization
    - Simulation
    - Verification
  - B.5.3 Reliability and Testing [**] (B.8)
    - Built-in tests [**]
    - Error-checking [**]
    - Redundant design [**]
    - Test generation [**]
    - Testability [**]
  - B.5.m Miscellaneous
- B.6 LOGIC DESIGN
  - B.6.0 General
  - B.6.1 Design Styles
    - Cellular arrays and automata
    - Combinational logic
    - Logic arrays
    - Memory control and access [**]
    - Memory used as logic [**]
    - Parallel circuits
    - Sequential circuits
  - B.6.2 Reliability and Testing [**] (B.8)
    - Built-in tests [**]
    - Error-checking [**]
    - Redundant design [**]
    - Test generation [**]
    - Testability [**]
  - B.6.3 Design Aids
    - Automatic synthesis
    - Hardware description languages
    - Optimization
    - Simulation
    - Switching theory
    - Verification
  - B.6.m Miscellaneous
- B.7 INTEGRATED CIRCUITS
  - B.7.0 General
  - B.7.1 Types and Design Styles
    - Advanced technologies
    - Algorithms implemented in hardware
    - Gate arrays
    - Input/output circuits
    - Memory technologies
    - Microprocessors and microcomputers
    - Standard cells [**]
    - VLSI (very large scale integration)
  - B.7.2 Design Aids
    - Graphics
    - Layout
    - Placement and routing
    - Simulation
    - Verification
  - B.7.3 Reliability and Testing [**] (B.8)
    - Built-in tests [**]
    - Error-checking [**]
    - Redundant design [**]
    - Test generation [**]
    - Testability [**]
  - B.7.m Miscellaneous
- B.8 PERFORMANCE AND RELIABILITY (C.4)
  - B.8.0 General
  - B.8.1 Reliability, Testing, and Fault-Tolerance
  - B.8.2 Performance Analysis and Design Aids
  - B.8.m Miscellaneous
- B.m MISCELLANEOUS
  - Design management
C. Computer Systems Organization
- C.0 GENERAL
  - Hardware/software interfaces
  - Instruction set design (e.g., RISC, CISC, VLIW)
  - Modeling of computer architecture
  - System architectures
  - Systems specification methodology
- C.1 PROCESSOR ARCHITECTURES
  - C.1.0 General
  - C.1.1 Single Data Stream Architectures
    - Multiple-instruction-stream, single-data-stream processors (MISD) [**]
    - Pipeline processors [**]
    - RISC/CISC, VLIW architectures
    - Single-instruction-stream, single-data-stream processors (SISD) [**]
    - Von Neumann architectures [**]
  - C.1.2 Multiple Data Stream Architectures (Multiprocessors)
    - Array and vector processors
    - Associative processors
    - Connection machines
    - Interconnection architectures (e.g., common bus, multiport memory, crossbar switch)
    - Multiple-instruction-stream, multiple-data-stream processors (MIMD)
    - Parallel processors [**]
    - Pipeline processors [**]
    - Single-instruction-stream, multiple-data-stream processors (SIMD)
  - C.1.3 Other Architecture Styles
    - Adaptable architectures
    - Analog computers
    - Capability architectures [**]
    - Cellular architecture (e.g., mobile)
    - Data-flow architectures
    - Heterogeneous (hybrid) systems
    - High-level language architectures [**]
    - Neural nets
    - Pipeline processors
    - Stack-oriented processors [**]
  - C.1.4 Parallel Architectures
    - Distributed architectures
    - Mobile processors
  - C.1.m Miscellaneous
    - Analog computers [**]
    - Hybrid systems [**]
- C.2 COMPUTER-COMMUNICATION NETWORKS
  - C.2.0 General
    - Data communications
    - Open Systems Interconnection reference model (OSI)
    - Security and protection (e.g., firewalls)
  - C.2.1 Network Architecture and Design
    - Asynchronous Transfer Mode (ATM)
    - Centralized networks [**]
    - Circuit-switching networks
    - Distributed networks
    - Frame relay networks
    - ISDN (Integrated Services Digital Network)
    - Network communications
    - Network topology
    - Packet-switching networks
    - Store and forward networks
    - Wireless communication
  - C.2.2 Network Protocols
    - Applications (SMTP, FTP, etc.)
    - Protocol architecture (OSI model)
    - Protocol verification
    - Routing protocols
  - C.2.3 Network Operations
    - Network management
    - Network monitoring
    - Public networks
  - C.2.4 Distributed Systems
    - Client/server
    - Distributed applications
    - Distributed databases
    - Network operating systems
  - C.2.5 Local and Wide-Area Networks
    - Access schemes
    - Buses
    - Ethernet (e.g., CSMA/CD)
    - High-speed (e.g., FDDI, fiber channel, ATM)
    - Internet (e.g., TCP/IP)
    - Token rings
  - C.2.6 Internetworking (C.2.2)
    - Routers
    - Standards (e.g., TCP/IP)
  - C.2.m Miscellaneous
- C.3 SPECIAL-PURPOSE AND APPLICATION-BASED SYSTEMS (J.7)
  - Microprocessor/microcomputer applications
  - Process control systems
  - Real-time and embedded systems
  - Signal processing systems
  - Smartcards
- C.4 PERFORMANCE OF SYSTEMS
  - Design studies
  - Fault tolerance
  - Measurement techniques
  - Modeling techniques
  - Performance attributes
  - Reliability, availability, and serviceability
- C.5 COMPUTER SYSTEM IMPLEMENTATION
  - C.5.0 General
  - C.5.1 Large and Medium (``Mainframe'') Computers
    - Super (very large) computers
  - C.5.2 Minicomputers [**]
  - C.5.3 Microcomputers
    - Microprocessors
    - Personal computers
    - Portable devices (e.g., laptops, personal digital assistants)
    - Workstations
  - C.5.4 VLSI Systems
  - C.5.5 Servers
  - C.5.m Miscellaneous
- C.m MISCELLANEOUS
D. Software
- D.0 GENERAL
- D.1 PROGRAMMING TECHNIQUES (E)
  - D.1.0 General
  - D.1.1 Applicative (Functional) Programming
  - D.1.2 Automatic Programming (I.2.2)
  - D.1.3 Concurrent Programming
    - Distributed programming
    - Parallel programming
  - D.1.4 Sequential Programming
  - D.1.5 Object-oriented Programming
  - D.1.6 Logic Programming
  - D.1.7 Visual Programming
  - D.1.m Miscellaneous
- D.2 SOFTWARE ENGINEERING (K.6.3)
  - D.2.0 General (K.5.1)
    - Protection mechanisms
    - Standards
  - D.2.1 Requirements/Specifications (D.3.1)
    - Elicitation methods (e.g., rapid prototyping, interviews, JAD)
    - Languages
    - Methodologies (e.g., object-oriented, structured)
    - Tools
  - D.2.2 Design Tools and Techniques
    - Computer-aided software engineering (CASE)
    - Decision tables
    - Evolutionary prototyping
    - Flow charts
    - Modules and interfaces
    - Object-oriented design methods
    - Petri nets
    - Programmer workbench [**]
    - Software libraries
    - State diagrams
    - Structured programming [**]
    - Top-down programming [**]
    - User interfaces
  - D.2.3 Coding Tools and Techniques
    - Object-oriented programming
    - Pretty printers
    - Program editors
    - Reentrant code [**]
    - Standards
    - Structured programming
    - Top-down programming
  - D.2.4 Software/Program Verification (F.3.1)
    - Assertion checkers
    - Class invariants
    - Correctness proofs
    - Formal methods
    - Model checking
    - Programming by contract
    - Reliability
    - Statistical methods
    - Validation
  - D.2.5 Testing and Debugging
    - Code inspections and walk-throughs
    - Debugging aids
    - Diagnostics
    - Distributed debugging
    - Dumps [**]
    - Error handling and recovery
    - Monitors
    - Symbolic execution
    - Testing tools (e.g., data generators, coverage testing)
    - Tracing
  - D.2.6 Programming Environments
    - Graphical environments
    - Integrated environments
    - Interactive environments
    - Programmer workbench
  - D.2.7 Distribution, Maintenance, and Enhancement
    - Corrections [**]
    - Documentation
    - Enhancement [**]
    - Extensibility [**]
    - Portability
    - Restructuring, reverse engineering, and reengineering
    - Version control
  - D.2.8 Metrics (D.4.8)
    - Complexity measures
    - Performance measures
    - Process metrics
    - Product metrics
    - Software science [**]
  - D.2.9 Management (K.6.3, K.6.4)
    - Copyrights [**]
    - Cost estimation
    - Life cycle
    - Productivity
    - Programming teams
    - Software configuration management
    - Software process models (e.g., CMM, ISO, PSP)
    - Software quality assurance (SQA)
    - Time estimation
  - D.2.10 Design [**] (D.2.2)
    - Methodologies [**]
    - Representation [**]
  - D.2.11 Software Architectures
    - Data abstraction
    - Domain-specific architectures
    - Information hiding
    - Languages (e.g., description, interconnection, definition)
    - Patterns (e.g., client/server, pipeline, blackboard)
  - D.2.12 Interoperability
    - Data mapping
    - Distributed objects
    - Interface definition languages
  - D.2.13 Reusable Software
    - Domain engineering
    - Reusable libraries
    - Reuse models
  - D.2.m Miscellaneous
    - Rapid prototyping [**]
    - Reusable software [**]
- D.3 PROGRAMMING LANGUAGES
  - D.3.0 General
    - Standards
  - D.3.1 Formal Definitions and Theory (D.2.1, F.3.1, F.3.2, F.4.2, F.4.3)
    - Semantics
    - Syntax
  - D.3.2 Language Classifications
    - Applicative (functional) languages
    - Concurrent, distributed, and parallel languages
    - Constraint and logic languages
    - Data-flow languages
    - Design languages
    - Extensible languages
    - Macro and assembly languages
    - Microprogramming languages [**]
    - Multiparadigm languages
    - Nondeterministic languages [**]
    - Nonprocedural languages [**]
    - Object-oriented languages
    - Specialized application languages
    - Very high-level languages
  - D.3.3 Language Constructs and Features (E.2)
    - Abstract data types
    - Classes and objects
    - Concurrent programming structures
    - Constraints
    - Control structures
    - Coroutines
    - Data types and structures
    - Dynamic storage management
    - Frameworks
    - Inheritance
    - Input/output
    - Modules, packages
    - Patterns
    - Polymorphism
    - Procedures, functions, and subroutines
    - Recursion
  - D.3.4 Processors
    - Code generation
    - Compilers
    - Debuggers
    - Incremental compilers
    - Interpreters
    - Memory management (garbage collection)
    - Optimization
    - Parsing
    - Preprocessors
    - Retargetable compilers
    - Run-time environments
    - Translator writing systems and compiler generators
  - D.3.m Miscellaneous
- D.4 OPERATING SYSTEMS (C)
  - D.4.0 General
  - D.4.1 Process Management
    - Concurrency
    - Deadlocks
    - Multiprocessing/multiprogramming/multitasking
    - Mutual exclusion
    - Scheduling
    - Synchronization
    - Threads
  - D.4.2 Storage Management
    - Allocation/deallocation strategies
    - Distributed memories
    - Garbage collection
    - Main memory
    - Secondary storage
    - Segmentation [**]
    - Storage hierarchies
    - Swapping [**]
    - Virtual memory
  - D.4.3 File Systems Management (E.5)
    - Access methods
    - Directory structures
    - Distributed file systems
    - File organization
    - Maintenance [**]
  - D.4.4 Communications Management (C.2)
    - Buffering
    - Input/output
    - Message sending
    - Network communication
    - Terminal management [**]
  - D.4.5 Reliability
    - Backup procedures
    - Checkpoint/restart
    - Fault-tolerance
    - Verification
  - D.4.6 Security and Protection (K.6.5)
    - Access controls
    - Authentication
    - Cryptographic controls
    - Information flow controls
    - Invasive software (e.g., viruses, worms, Trojan horses)
    - Security kernels [**]
    - Verification [**]
  - D.4.7 Organization and Design
    - Batch processing systems [**]
    - Distributed systems
    - Hierarchical design [**]
    - Interactive systems
    - Real-time systems and embedded systems
  - D.4.8 Performance (C.4, D.2.8, I.6)
    - Measurements
    - Modeling and prediction
    - Monitors
    - Operational analysis
    - Queueing theory
    - Simulation
    - Stochastic analysis
  - D.4.9 Systems Programs and Utilities
    - Command and control languages
    - Linkers [**]
    - Loaders [**]
    - Window managers
  - D.4.m Miscellaneous
- D.m MISCELLANEOUS
  - Software psychology [**]
E. Data
- E.0 GENERAL
- E.1 DATA STRUCTURES
  - Arrays
  - Distributed data structures
  - Graphs and networks
  - Lists, stacks, and queues
  - Records
  - Tables [**]
  - Trees
- E.2 DATA STORAGE REPRESENTATIONS
  - Composite structures [**]
  - Contiguous representations [**]
  - Hash-table representations
  - Linked representations
  - Object representation
  - Primitive data items [**]
- E.3 DATA ENCRYPTION
  - Code breaking
  - Data encryption standard (DES) [**]
  - Public key cryptosystems
  - Standards (e.g., DES, PGP, RSA)
- E.4 CODING AND INFORMATION THEORY (H.1.1)
  - Data compaction and compression
  - Error control codes
  - Formal models of communication
  - Nonsecret encoding schemes [**]
- E.5 FILES (D.4.3, F.2.2, H.2)
  - Backup/recovery
  - Optimization [**]
  - Organization/structure
  - Sorting/searching
- E.m MISCELLANEOUS
F. Theory of Computation
- F.0 GENERAL
- F.1 COMPUTATION BY ABSTRACT DEVICES
  - F.1.0 General
  - F.1.1 Models of Computation (F.4.1)
    - Automata (e.g., finite, push-down, resource-bounded)
    - Bounded-action devices (e.g., Turing machines, random access machines)
    - Computability theory
    - Relations between models
    - Self-modifying machines (e.g., neural networks)
    - Unbounded-action devices (e.g., cellular automata, circuits, networks of machines)
  - F.1.2 Modes of Computation
    - Alternation and nondeterminism
    - Interactive and reactive computation
    - Online computation
    - Parallelism and concurrency
    - Probabilistic computation
    - Relations among modes [**]
    - Relativized computation
  - F.1.3 Complexity Measures and Classes (F.2)
    - Complexity hierarchies
    - Machine-independent complexity [**]
    - Reducibility and completeness
    - Relations among complexity classes
    - Relations among complexity measures
  - F.1.m Miscellaneous
- F.2 ANALYSIS OF ALGORITHMS AND PROBLEM COMPLEXITY (B.6, B.7, F.1.3)
  - F.2.0 General
  - F.2.1 Numerical Algorithms and Problems (G.1, G.4, I.1)
    - Computation of transforms (e.g., fast Fourier transform)
    - Computations in finite fields
    - Computations on matrices
    - Computations on polynomials
    - Number-theoretic computations (e.g., factoring, primality testing)
  - F.2.2 Nonnumerical Algorithms and Problems (E.2, E.3, E.4, E.5, G.2, H.2, H.3)
    - Complexity of proof procedures
    - Computations on discrete structures
    - Geometrical problems and computations
    - Pattern matching
    - Routing and layout
    - Sequencing and scheduling
    - Sorting and searching
  - F.2.3 Tradeoffs between Complexity Measures (F.1.3)
  - F.2.m Miscellaneous
- F.3 LOGICS AND MEANINGS OF PROGRAMS
  - F.3.0 General
  - F.3.1 Specifying and Verifying and Reasoning about Programs (D.2.1, D.2.4, D.3.1, E.1)
    - Assertions
    - Invariants
    - Logics of programs
    - Mechanical verification
    - Pre- and post-conditions
    - Specification techniques
  - F.3.2 Semantics of Programming Languages (D.3.1)
    - Algebraic approaches to semantics
    - Denotational semantics
    - Operational semantics
    - Partial evaluation
    - Process models
    - Program analysis
  - F.3.3 Studies of Program Constructs (D.3.2, D.3.3)
    - Control primitives
    - Functional constructs
    - Object-oriented constructs
    - Program and recursion schemes
    - Type structure
  - F.3.m Miscellaneous
- F.4 MATHEMATICAL LOGIC AND FORMAL LANGUAGES
  - F.4.0 General
  - F.4.1 Mathematical Logic (F.1.1, I.2.2, I.2.3, I.2.4)
    - Computability theory
    - Computational logic
    - Lambda calculus and related systems
    - Logic and constraint programming
    - Mechanical theorem proving
    - Modal logic
    - Model theory
    - Proof theory
    - Recursive function theory
    - Set theory
    - Temporal logic
  - F.4.2 Grammars and Other Rewriting Systems (D.3.1)
    - Decision problems
    - Grammar types (e.g., context-free, context-sensitive)
    - Parallel rewriting systems (e.g., developmental systems, L-systems)
    - Parsing
    - Thue systems
  - F.4.3 Formal Languages (D.3.1)
    - Algebraic language theory
    - Classes defined by grammars or automata (e.g., context-free languages, regular sets, recursive sets)
    - Classes defined by resource-bounded automata [**]
    - Decision problems
    - Operations on languages
  - F.4.m Miscellaneous
- F.m MISCELLANEOUS
G. Mathematics of Computing
- G.0 GENERAL
- G.1 NUMERICAL ANALYSIS
  - G.1.0 General
    - Computer arithmetic
    - Conditioning (and ill-conditioning)
    - Error analysis
    - Interval arithmetic
    - Multiple precision arithmetic
    - Numerical algorithms
    - Parallel algorithms
    - Stability (and instability)
  - G.1.1 Interpolation (I.3.5, I.3.7)
    - Difference formulas [**]
    - Extrapolation
    - Interpolation formulas
    - Smoothing
    - Spline and piecewise polynomial interpolation
  - G.1.2 Approximation
    - Approximation of surfaces and contours
    - Chebyshev approximation and theory
    - Elementary function approximation
    - Fast Fourier transforms (FFT)
    - Least squares approximation
    - Linear approximation
    - Minimax approximation and algorithms
    - Nonlinear approximation
    - Rational approximation
    - Special function approximations
    - Spline and piecewise polynomial approximation
    - Wavelets and fractals
  - G.1.3 Numerical Linear Algebra
    - Conditioning
    - Determinants [**]
    - Eigenvalues and eigenvectors (direct and iterative methods)
    - Error analysis
    - Linear systems (direct and iterative methods)
    - Matrix inversion
    - Pseudoinverses [**]
    - Singular value decomposition
    - Sparse, structured, and very large systems (direct and iterative methods)
  - G.1.4 Quadrature and Numerical Differentiation (F.2.1)
    - Adaptive and iterative quadrature
    - Automatic differentiation
    - Equal interval integration [**]
    - Error analysis
    - Finite difference methods
    - Gaussian quadrature
    - Iterative methods
    - Multidimensional (multiple) quadrature
  - G.1.5 Roots of Nonlinear Equations
    - Continuation (homotopy) methods
    - Convergence
    - Error analysis
    - Iterative methods
    - Polynomials, methods for
    - Systems of equations
  - G.1.6 Optimization
    - Constrained optimization
    - Convex programming
    - Global optimization
    - Gradient methods
    - Integer programming
    - Least squares methods
    - Linear programming
    - Nonlinear programming
    - Quadratic programming methods
    - Simulated annealing
    - Stochastic programming
    - Unconstrained optimization
  - G.1.7 Ordinary Differential Equations
    - Boundary value problems
    - Chaotic systems
    - Convergence and stability
    - Differential-algebraic equations
    - Error analysis
    - Finite difference methods
    - Initial value problems
    - Multistep and multivalue methods
    - One-step (single step) methods
    - Stiff equations
  - G.1.8 Partial Differential Equations
    - Domain decomposition methods
    - Elliptic equations
    - Finite difference methods
    - Finite element methods
    - Finite volume methods
    - Hyperbolic equations
    - Inverse problems
    - Iterative solution techniques
    - Method of lines
    - Multigrid and multilevel methods
    - Parabolic equations
    - Spectral methods
  - G.1.9 Integral Equations
    - Delay equations
    - Fredholm equations
    - Integro-differential equations
    - Volterra equations
  - G.1.10 Applications
  - G.1.m Miscellaneous
- G.2 DISCRETE MATHEMATICS
  - G.2.0 General
  - G.2.1 Combinatorics (F.2.2)
    - Combinatorial algorithms
    - Counting problems
    - Generating functions
    - Permutations and combinations
    - Recurrences and difference equations
  - G.2.2 Graph Theory (F.2.2)
    - Graph algorithms
    - Graph labeling
    - Hypergraphs
    - Network problems
    - Path and circuit problems
    - Trees
  - G.2.3 Applications
  - G.2.m Miscellaneous
- G.3 PROBABILITY AND STATISTICS
  - Contingency table analysis
  - Correlation and regression analysis
  - Distribution functions
  - Experimental design
  - Markov processes
  - Multivariate statistics
  - Nonparametric statistics
  - Probabilistic algorithms (including Monte Carlo)
  - Queueing theory
  - Random number generation
  - Reliability and life testing
  - Renewal theory
  - Robust regression
  - Statistical computing
  - Statistical software
  - Stochastic processes
  - Survival analysis
  - Time series analysis
- G.4 MATHEMATICAL SOFTWARE
  - Algorithm design and analysis
  - Certification and testing
  - Documentation
  - Efficiency
  - Parallel and vector implementations
  - Portability [**]
  - Reliability and robustness
  - User interfaces
  - Verification [**]
- G.m MISCELLANEOUS
  - Queueing theory [**]
H. Information Systems
- H.0 GENERAL
- H.1 MODELS AND PRINCIPLES
  - H.1.0 General
  - H.1.1 Systems and Information Theory (E.4)
    - General systems theory
    - Information theory
    - Value of information
  - H.1.2 User/Machine Systems
    - Human factors
    - Human information processing
    - Software psychology
  - H.1.m Miscellaneous
- H.2 DATABASE MANAGEMENT (E.5)
  - H.2.0 General
    - Security, integrity, and protection [**]
  - H.2.1 Logical Design
    - Data models
    - Normal forms
    - Schema and subschema
  - H.2.2 Physical Design
    - Access methods
    - Deadlock avoidance
    - Recovery and restart
  - H.2.3 Languages (D.3.2)
    - Data description languages (DDL)
    - Data manipulation languages (DML)
    - Database (persistent) programming languages
    - Query languages
    - Report writers
  - H.2.4 Systems
    - Concurrency
    - Distributed databases
    - Multimedia databases
    - Object-oriented databases
    - Parallel databases
    - Query processing
    - Relational databases
    - Rule-based databases
    - Textual databases
    - Transaction processing
  - H.2.5 Heterogeneous Databases
    - Data translation [**]
    - Program translation [**]
  - H.2.6 Database Machines
  - H.2.7 Database Administration
    - Data dictionary/directory
    - Data warehouse and repository
    - Logging and recovery
    - Security, integrity, and protection
  - H.2.8 Database Applications
    - Data mining
    - Image databases
    - Scientific databases
    - Spatial databases and GIS
    - Statistical databases
  - H.2.m Miscellaneous
- H.3 INFORMATION STORAGE AND RETRIEVAL
  - H.3.0 General
  - H.3.1 Content Analysis and Indexing
    - Abstracting methods
    - Dictionaries
    - Indexing methods
    - Linguistic processing
    - Thesauruses
  - H.3.2 Information Storage
    - File organization
    - Record classification [**]
  - H.3.3 Information Search and Retrieval
    - Clustering
    - Information filtering
    - Query formulation
    - Relevance feedback
    - Retrieval models
    - Search process
    - Selection process
  - H.3.4 Systems and Software
    - Current awareness systems (selective dissemination of information--SDI) [**]
    - Distributed systems
    - Information networks
    - Performance evaluation (efficiency and effectiveness)
    - Question-answering (fact retrieval) systems [**]
    - User profiles and alert services
  - H.3.5 Online Information Services
    - Commercial services
    - Data sharing
    - Web-based services
  - H.3.6 Library Automation
    - Large text archives
  - H.3.7 Digital Libraries
    - Collection
    - Dissemination
    - Standards
    - Systems issues
    - User issues
  - H.3.m Miscellaneous
- H.4 INFORMATION SYSTEMS APPLICATIONS
  - H.4.0 General
  - H.4.1 Office Automation (I.7)
    - Desktop publishing
    - Equipment [**]
    - Groupware
    - Spreadsheets
    - Time management (e.g., calendars, schedules)
    - Word processing
    - Workflow management
  - H.4.2 Types of Systems
    - Decision support (e.g., MIS)
    - Logistics
  - H.4.3 Communications Applications
    - Bulletin boards
    - Computer conferencing, teleconferencing, and videoconferencing
    - Electronic mail
    - Information browsers
    - Videotex
  - H.4.m Miscellaneous
- H.5 INFORMATION INTERFACES AND PRESENTATION (e.g., HCI) (I.7)
  - H.5.0 General
  - H.5.1 Multimedia Information Systems
    - Animations
    - Artificial, augmented, and virtual realities
    - Audio input/output
    - Evaluation/methodology
    - Hypertext navigation and maps [**]
    - Video (e.g., tape, disk, DVI)
  - H.5.2 User Interfaces (D.2.2, H.1.2, I.3.6)
    - Auditory (non-speech) feedback
    - Benchmarking
    - Ergonomics
    - Evaluation/methodology
    - Graphical user interfaces (GUI)
    - Haptic I/O
    - Input devices and strategies (e.g., mouse, touchscreen)
    - Interaction styles (e.g., commands, menus, forms, direct manipulation)
    - Natural language
    - Prototyping
    - Screen design (e.g., text, graphics, color)
    - Standardization
    - Style guides
    - Theory and methods
    - Training, help, and documentation
    - User-centered design
    - User interface management systems (UIMS)
    - Voice I/O
    - Windowing systems
  - H.5.3 Group and Organization Interfaces
    - Asynchronous interaction
    - Collaborative computing
    - Computer-supported cooperative work
    - Evaluation/methodology
    - Organizational design
    - Synchronous interaction
    - Theory and models
    - Web-based interaction
  - H.5.4 Hypertext/Hypermedia (I.7, J.7)
    - Architectures
    - Navigation
    - Theory
    - User issues
  - H.5.5 Sound and Music Computing (J.5)
    - Methodologies and techniques
    - Modeling
    - Signal analysis, synthesis, and processing
    - Systems
  - H.5.m Miscellaneous
- H.m MISCELLANEOUS
I. Computing Methodologies
- I.0 GENERAL
- I.1 SYMBOLIC AND ALGEBRAIC MANIPULATION
  - I.1.0 General
  - I.1.1 Expressions and Their Representation (E.1, E.2)
    - Representations (general and polynomial)
    - Simplification of expressions
  - I.1.2 Algorithms (F.2.1, F.2.2)
    - Algebraic algorithms
    - Analysis of algorithms
    - Nonalgebraic algorithms
  - I.1.3 Languages and Systems (D.3.2, D.3.3, F.2.2)
    - Evaluation strategies
    - Nonprocedural languages [**]
    - Special-purpose algebraic systems
    - Special-purpose hardware [**]
    - Substitution mechanisms [**]
  - I.1.4 Applications
  - I.1.m Miscellaneous
- I.2 ARTIFICIAL INTELLIGENCE
  - I.2.0 General
    - Cognitive simulation
    - Philosophical foundations
  - I.2.1 Applications and Expert Systems (H.4, J)
    - Cartography
    - Games
    - Industrial automation
    - Law
    - Medicine and science
    - Natural language interfaces
    - Office automation
  - I.2.2 Automatic Programming (D.1.2, F.3.1, F.4.1)
    - Automatic analysis of algorithms
    - Program modification
    - Program synthesis
    - Program transformation
    - Program verification
  - I.2.3 Deduction and Theorem Proving (F.4.1)
    - Answer/reason extraction
    - Deduction (e.g., natural, rule-based)
    - Inference engines
    - Logic programming
    - Mathematical induction
    - Metatheory [**]
    - Nonmonotonic reasoning and belief revision
    - Resolution
    - Uncertainty, ``fuzzy,'' and probabilistic reasoning
  - I.2.4 Knowledge Representation Formalisms and Methods (F.4.1)
    - Frames and scripts
    - Modal logic
    - Predicate logic
    - Relation systems
    - Representation languages
    - Representations (procedural and rule-based)
    - Semantic networks
    - Temporal logic
  - I.2.5 Programming Languages and Software (D.3.2)
    - Expert system tools and techniques
  - I.2.6 Learning (K.3.2)
    - Analogies
    - Concept learning
    - Connectionism and neural nets
    - Induction
    - Knowledge acquisition
    - Language acquisition
    - Parameter learning
  - I.2.7 Natural Language Processing
    - Discourse
    - Language generation
    - Language models
    - Language parsing and understanding
    - Machine translation
    - Speech recognition and synthesis
    - Text analysis
  - I.2.8 Problem Solving, Control Methods, and Search (F.2.2)
    - Backtracking
    - Control theory
    - Dynamic programming
    - Graph and tree search strategies
    - Heuristic methods
    - Plan execution, formation, and generation
    - Scheduling
  - I.2.9 Robotics
    - Autonomous vehicles
    - Commercial robots and applications
    - Kinematics and dynamics
    - Manipulators
    - Operator interfaces
    - Propelling mechanisms
    - Sensors
    - Workcell organization and planning
  - I.2.10 Vision and Scene Understanding (I.4.8, I.5)
    - 3D/stereo scene analysis
    - Architecture and control structures [**]
    - Intensity, color, photometry, and thresholding
    - Modeling and recovery of physical attributes
    - Motion
    - Perceptual reasoning
    - Representations, data structures, and transforms
    - Shape
    - Texture
    - Video analysis
  - I.2.11 Distributed Artificial Intelligence
    - Coherence and coordination
    - Intelligent agents
    - Languages and structures
    - Multiagent systems
  - I.2.m Miscellaneous
- I.3 COMPUTER GRAPHICS
  - I.3.0 General
  - I.3.1 Hardware Architecture (B.4.2)
    - Graphics processors
    - Hardcopy devices [**]
    - Input devices
    - Parallel processing
    - Raster display devices
    - Storage devices [**]
    - Three-dimensional displays [**]
    - Vector display devices [**]
  - I.3.2 Graphics Systems (C.2.1, C.2.4, C.3)
    - Distributed/network graphics
    - Remote systems [**]
    - Stand-alone systems [**]
  - I.3.3 Picture/Image Generation
    - Antialiasing [**]
    - Bitmap and framebuffer operations
    - Digitizing and scanning
    - Display algorithms
    - Line and curve generation
    - Viewing algorithms
  - I.3.4 Graphics Utilities
    - Application packages
    - Device drivers [**]
    - Graphics editors
    - Graphics packages
    - Meta files [**]
    - Paint systems
    - Picture description languages [**]
    - Software support
    - Virtual device interfaces
  - I.3.5 Computational Geometry and Object Modeling
    - Boundary representations
    - Constructive solid geometry (CSG) [**]
    - Curve, surface, solid, and object representations
    - Geometric algorithms, languages, and systems
    - Hierarchy and geometric transformations
    - Modeling packages
    - Object hierarchies
    - Physically based modeling
    - Splines
  - I.3.6 Methodology and Techniques
    - Device independence [**]
    - Ergonomics
    - Graphics data structures and data types
    - Interaction techniques
    - Languages
    - Standards
  - I.3.7 Three-Dimensional Graphics and Realism
    - Animation
    - Color, shading, shadowing, and texture
    - Fractals
    - Hidden line/surface removal
    - Radiosity
    - Raytracing
    - Virtual reality
    - Visible line/surface algorithms
  - I.3.8 Applications
  - I.3.m Miscellaneous
- I.4 IMAGE PROCESSING AND COMPUTER VISION
  - I.4.0 General
    - Image displays
    - Image processing software
  - I.4.1 Digitization and Image Capture
    - Camera calibration
    - Imaging geometry
    - Quantization
    - Radiometry
    - Reflectance
    - Sampling
    - Scanning
  - I.4.2 Compression (Coding) (E.4)
    - Approximate methods
    - Exact coding [**]
  - I.4.3 Enhancement
    - Filtering
    - Geometric correction
    - Grayscale manipulation
    - Registration
    - Sharpening and deblurring [**]
    - Smoothing
  - I.4.4 Restoration
    - Inverse filtering [**]
    - Kalman filtering
    - Pseudoinverse restoration [**]
    - Wiener filtering [**]
  - I.4.5 Reconstruction
    - Series expansion methods
    - Summation methods [**]
    - Transform methods
  - I.4.6 Segmentation
    - Edge and feature detection
    - Pixel classification
    - Region growing, partitioning
    - Relaxation
  - I.4.7 Feature Measurement
    - Feature representation
    - Invariants
    - Moments
    - Projections
    - Size and shape
    - Texture
  - I.4.8 Scene Analysis
    - Color
    - Depth cues
    - Motion
    - Object recognition
    - Photometry
    - Range data
    - Sensor fusion
    - Shading
    - Shape
    - Stereo
    - Surface fitting
    - Time-varying imagery
    - Tracking
  - I.4.9 Applications
  - I.4.10 Image Representation
    - Hierarchical
    - Morphological
    - Multidimensional
    - Statistical
    - Volumetric
  - I.4.m Miscellaneous
- I.5 PATTERN RECOGNITION
  - I.5.0 General
  - I.5.1 Models
    - Deterministic [**]
    - Fuzzy set
    - Geometric
    - Neural nets
    - Statistical
    - Structural
  - I.5.2 Design Methodology
    - Classifier design and evaluation
    - Feature evaluation and selection
    - Pattern analysis
  - I.5.3 Clustering
    - Algorithms
    - Similarity measures
  - I.5.4 Applications
    - Computer vision
    - Signal processing
    - Text processing
    - Waveform analysis
  - I.5.5 Implementation (C.3)
    - Interactive systems
    - Special architectures
  - I.5.m Miscellaneous
- I.6 SIMULATION AND MODELING (G.3)
  - I.6.0 General
  - I.6.1 Simulation Theory
    - Model classification
    - Systems theory
    - Types of simulation (continuous and discrete) [*]
  - I.6.2 Simulation Languages
  - I.6.3 Applications
  - I.6.4 Model Validation and Analysis
  - I.6.5 Model Development
    - Modeling methodologies
  - I.6.6 Simulation Output Analysis
  - I.6.7 Simulation Support Systems
    - Environments
  - I.6.8 Types of Simulation
    - Animation
    - Combined
    - Continuous
    - Discrete event
    - Distributed
    - Gaming
    - Monte Carlo
    - Parallel
    - Visual
  - I.6.m Miscellaneous
- I.7 DOCUMENT AND TEXT PROCESSING (H.4, H.5)
  - I.7.0 General
  - I.7.1 Document and Text Editing
    - Document management
    - Languages [**]
    - Spelling [**]
    - Version control
  - I.7.2 Document Preparation
    - Desktop publishing
    - Format and notation
    - Hypertext/hypermedia
    - Index generation
    - Languages and systems
    - Markup languages
    - Multi/mixed media
    - Photocomposition/typesetting
    - Scripting languages
    - Standards
  - I.7.3 Index Generation [**]
  - I.7.4 Electronic Publishing (H.5.4, J.7)
  - I.7.5 Document Capture (I.4.1)
    - Document analysis
    - Graphics recognition and interpretation
    - Optical character recognition (OCR)
    - Scanning
  - I.7.m Miscellaneous
- I.m MISCELLANEOUS
J. Computer Applications
- J.0 GENERAL
- J.1 ADMINISTRATIVE DATA PROCESSING
  - Business
  - Education
  - Financial (e.g., EFTS)
  - Government
  - Law
  - Manufacturing
  - Marketing
  - Military
- J.2 PHYSICAL SCIENCES AND ENGINEERING
  - Aerospace
  - Archaeology
  - Astronomy
  - Chemistry
  - Earth and atmospheric sciences
  - Electronics
  - Engineering
  - Mathematics and statistics
  - Physics
- J.3 LIFE AND MEDICAL SCIENCES
  - Biology and genetics
  - Health
  - Medical information systems
- J.4 SOCIAL AND BEHAVIORAL SCIENCES
  - Economics
  - Psychology
  - Sociology
- J.5 ARTS AND HUMANITIES
  - Architecture
  - Arts, fine and performing [**]
  - Fine arts
  - Language translation
  - Linguistics
  - Literature
  - Music [**]
  - Performing arts (e.g., dance, music)
- J.6 COMPUTER-AIDED ENGINEERING
  - Computer-aided design (CAD)
  - Computer-aided manufacturing (CAM)
- J.7 COMPUTERS IN OTHER SYSTEMS (C.3)
  - Command and control
  - Consumer products
  - Industrial control
  - Military
  - Process control
  - Publishing
  - Real time
- J.m MISCELLANEOUS
K. Computing Milieux
- K.0 GENERAL
- K.1 THE COMPUTER INDUSTRY
  - Markets
  - Standards
  - Statistics
  - Suppliers
- K.2 HISTORY OF COMPUTING
  - Hardware
  - People
  - Software
  - Systems
  - Theory
- K.3 COMPUTERS AND EDUCATION
  - K.3.0 General
  - K.3.1 Computer Uses in Education
    - Collaborative learning
    - Computer-assisted instruction (CAI)
    - Computer-managed instruction (CMI)
    - Distance learning
  - K.3.2 Computer and Information Science Education
    - Accreditation
    - Computer science education
    - Curriculum
    - Information systems education
    - Literacy
    - Self-assessment
  - K.3.m Miscellaneous
    - Accreditation [**]
    - Computer literacy [**]
- K.4 COMPUTERS AND SOCIETY
  - K.4.0 General
  - K.4.1 Public Policy Issues
    - Abuse and crime involving computers
    - Computer-related health issues
    - Ethics
    - Human safety
    - Intellectual property rights
    - Privacy
    - Regulation
    - Transborder data flow
    - Use/abuse of power
  - K.4.2 Social Issues
    - Abuse and crime involving computers [**]
    - Assistive technologies for persons with disabilities
    - Employment
    - Handicapped persons/special needs [**]
  - K.4.3 Organizational Impacts
    - Automation
    - Computer-supported collaborative work
    - Employment
    - Reengineering
  - K.4.4 Electronic Commerce (J.1)
    - Cybercash, digital cash
    - Distributed commercial transactions
    - Electronic data interchange (EDI)
    - Intellectual property
    - Payment schemes
    - Security
  - K.4.m Miscellaneous
- K.5 LEGAL ASPECTS OF COMPUTING
  - K.5.0 General
  - K.5.1 Hardware/Software Protection
    - Copyrights
    - Licensing
    - Patents
    - Proprietary rights
    - Trade secrets [**]
  - K.5.2 Governmental Issues
    - Censorship
    - Regulation
    - Taxation
  - K.5.m Miscellaneous
    - Contracts [**]
    - Hardware patents [**]
- K.6 MANAGEMENT OF COMPUTING AND INFORMATION SYSTEMS
  - K.6.0 General
    - Economics
  - K.6.1 Project and People Management
    - Life cycle
    - Management techniques (e.g., PERT/CPM)
    - Staffing
    - Strategic information systems planning
    - Systems analysis and design
    - Systems development
    - Training
  - K.6.2 Installation Management
    - Benchmarks
    - Computer selection
    - Computing equipment management
    - Performance and usage measurement
    - Pricing and resource allocation
  - K.6.3 Software Management (D.2.9)
    - Software development
    - Software maintenance
    - Software process
    - Software selection
  - K.6.4 System Management
    - Centralization/decentralization
    - Management audit
    - Quality assurance
  - K.6.5 Security and Protection (D.4.6, K.4.2)
    - Authentication
    - Insurance [*]
    - Invasive software (e.g., viruses, worms, Trojan horses)
    - Physical security [**]
    - Unauthorized access (e.g., hacking, phreaking)
  - K.6.m Miscellaneous
    - Insurance [*]
    - Security [*]
- K.7 THE COMPUTING PROFESSION
  - K.7.0 General
  - K.7.1 Occupations
  - K.7.2 Organizations
  - K.7.3 Testing, Certification, and Licensing
  - K.7.4 Professional Ethics (K.4)
    - Codes of ethics
    - Codes of good practice
    - Ethical dilemmas
  - K.7.m Miscellaneous
    - Codes of good practice [**]
    - Ethics [**]
- K.8 PERSONAL COMPUTING
  - Games [*]
  - K.8.0 General
    - Games
  - K.8.1 Application Packages
    - Data communications
    - Database processing
    - Freeware/shareware
    - Graphics
    - Spreadsheets
    - Word processing
  - K.8.2 Hardware
  - K.8.3 Management/Maintenance
  - K.8.m Miscellaneous
- K.m MISCELLANEOUS

* Indicates that the classification is no longer used as of January 1991, but that the item is still searchable for previously classified documents.

** Indicates that the classification is no longer used as of January 1998, but that the item is still searchable for previously classified documents.