routine duplication of post-2000 patented inventions by means of genetic programming matthew j....
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Routine Duplication of Post-2000 Patented Inventions by Means of Genetic Programming
Matthew J. Streeter
Genetic Programming, Inc.
Martin A. Keane
Econometrics, Inc.
John R. Koza
Stanford University
EuroGP 2002, Kinsale, Ireland April 3-5
Overview
• Circuit Synthesis using Genetic Programming• Previous Results of Circuit Synthesis using Genetic Programming• Four New Techniques
– NODE function– Geometric coordinates– Two new component-inserting functions
• Five Post-2000 Patented Circuits– Voltage-to-current converter– High-current load circuit– Cubic signal generator– Register-controlled capacitor– Balun circuit
• Results– [Five patented circuits]
• Patent Office variation on Turing Test
Circuit Synthesis using Genetic Programming
Embryo & Test Fixture
• Initial circuit contains input and output circuitry plus specially designated modifiable wires.
• Subcircuit containing modifiable wires is called embryo; remaining circuitry is test fixture.
• Minimal (one-wire) embryo used for all work presented here
Example embryo & test fixture
Developmental Functions
• Component-inserting functions insert electrical component (e.g. resistor, capacitor, transistor) into circuit in place of existing modifiable wire
• Topology-modifying functions (e.g. series division, parallel division) alter topology & create new modifiable wires
• Connection functions connect to predefined component in test fixture (e.g. input voltage source, output probe point, power supply)
Simulation
• SPICE (Simulation Program with Integrated Circuit Emphasis) industry standard circuit simulator
• Modified GP version of SPICE with robust error handling
Fitness measure
• Curve matching: integrated difference between output curve for evolved circuit and ideal output curve (time domain or frequency domain)
• Constraints: number of components, total capacitance, etc.
• Additional objectives: reduction of distortion, noise, etc.
Previous Results of Circuit Synthesis using Genetic Programming
• Rediscovery of Cauer, M-derived half section, and constant K filters
• Voltage reference circuit
• Electronic thermometer
• Computational circuits for squaring, square root, cubing, cube root, logarithm, Gaussian
• RC circuit with gain > 2 (Philbrick circuit)
• NAND gate
• Digital to Analog Converter
• Synthesis and layout of lowpass filter & amplifier• For references, see www.genetic-programming.com
Four New Techniques
NODE function
• Purpose is to connect distant parts of circuit
• A NODE with no ancestor NODEs is a top-most node
• NODE function causes connection to be made to local top-most node
• Old approach (VIA1, VIA2, . . . VIA8) used context-dependent information
Geometric Coordinates
• Coordinates can be assigned to initial modifiable wire(s) and maintained as circuit is developed
• Coordinates used to define behavior of certain developmental functions (Q and PARALLEL)
• Should be better than component numbers (old approach) because local information is used (more robust to crossover)
Two new component-inserting functions
• Q([model], [orientation], [permutation], [development subtree], [development subtree], [development subtree])
• TWO-LEAD([component], [development subtree], [development subtree]
• More parameterized versions of previously used functions
Five Post-2000 Patented Inventions
Voltage-to-current Converter
• Two input voltages; output is stable current proportional to difference
• Four time-domain fitness cases with various input/output voltages
Patented Voltage-to-current Converter (Ikeuchi and Tokuda 2000) Mitsumi Electric Company, Ltd.
High-Current Load Circuit
• A time-varying amount of current is sunk to ground in response to a control signal
• Two time-domain fitness cases with different control signals
Patented High-current Load Circuit (Daun-Lindberg and Miller 2001)IBM Corporation
Cubic Signal Generator
• Cubing computational circuit operating at low voltage (2V power supply)
• Four time-domain fitness cases with various input signals & time scales, plus penalty for harmonic distortion
Patented Cubic Signal Generator (Cipriani and Takeshian 2000)Conexant Systems, Inc.
Register-controlled Capacitor
• Circuit equivalent to capacitor whose capacitance is set by a digital register
• 2 sets of 8 time-domain fitness cases covering all values of 3-bit register
Patented Register-controlled Capacitor (Aytur 2000)Lucent Technologies, Inc.
Balun circuit
• Divides input signal into two half-amplitude signals 180 degrees out of phase; patented circuit is low voltage
• Frequency sweep fitness cases for magnitude & phase of both outputs
• Fourier analysis for harmonic distortion
Patented Balun Circuit (Lee 2001)Information and Communications University, Taejon
Results
Voltage-to-current Converter
• Evolved circuit has 62% of average absolute error of patent circuit on our 4 fitness cases
Best-of-run voltage-to-current conversion circuit from generation 109.
High-Current Load Circuit
• Evolved circuit duplicates parallel FET transistor structure of patented circuit
Best-of-run high-current load circuit from generation 114.
Cubic Signal Generator
• Evolved circuit has 59% of average absolute error of patented circuit on our 4 fitness cases
Best-of-run cubic signal generation circuit from generation 182.
Register-controlled Capacitor
• Evolved circuit error is 100.6% of patent circuit’s error
• Exponential weighting of capacitors duplicated
Parsimonious register-controlled capacitor circuit from generation 98.
Balun circuit
• Evolved solution is better in terms of both frequency response and harmonic distortion
Best-of-run balun circuit from generation 84.
Patent Office Variation on Turing Test
• Original Turing Test involved distinction between male and female typists
• GP-produced circuits satisfy Patent Office’s criterion for novelty and inventiveness
• More than just “chit chat”, analog circuit design is only performed by exceptional and creative humans
Patent Office variation on Turing Test.
Routine Duplication of Post-2000 Patented Inventions by Means of Genetic Programming
Matthew J. Streeter
Genetic Programming, Inc.
Martin A. Keane
Econometrics, Inc.
John R. Koza
Stanford University
EuroGP 2002, Kinsale, Ireland April 3-5