Building Knowledge Bases from Reusable Components Bruce Porter Computer Science Dept, Univ of Texas at Austin Peter Clark Boeing Applied Research and Technology

Fragment of a Knowledge-Base “What steps are involved in bioremediation?” “How does pollutant volume affect rate?” “What equipment is needed?” “What do the microbes do?”... Example queries: BioremediationAmount OilFertilizer GetApply Break Down Absorb MicrobesScript Bio- technologist Soil Rate environment contains Q+ I- Q- I- amount product absorbed then agent patientagent script pollutant se rate agent then product se patient remediator amount Person isa...

The Botany KB Experience 10 year effort, 20k concepts, 100k facts Supports sophisticated question-answering –description –prediction But: –KB still highly incomplete –laborious to build/maintain –difficult to achieve reuse  want a better approach!

Fundamental Problem Reliance on specific, comprehensive representations –impractical, unmaintainable –can’t anticipate them all But: –representations contain repeated abstractions production occurs in photosynthesis, mitosis, growth germination includes conversion, production, expansion Goal: Capture abstractions in a recomposable way

BioremediationAmount OilFertilizer GetApply Break Down Absorb MicrobesScript Bio- technologist Soil Rate environment contains Q+ I- Q- I- amount product absorbed then agent patientagent script pollutant se rate agent then product se patient remediator amount Representation of Bioremediation

BioremediationAmount OilFertilizer GetApply Break Down Absorb MicrobesScript Bio- technologist Soil Rate environment contains Q+ I- Q- I- amount product absorbed then agent patientagent script pollutant se rate agent then product se patient remediator Conversion Amount Substance Rate Q+ I- Q- I- amountraw- materials rate product Substance amount An underlying abstraction...

BioremediationAmount OilFertilizer GetApply Break Down Absorb MicrobesScript Bio- technologist Soil Rate environment contains Q+ I- Q- I- amount product absorbed then agent patientagent script pollutant se rate agent then product se remediator amount Digest Substance Break Down Absorb AgentScript absorbed agent script food se then se patient eater agent Another abstraction... patient

BioremediationAmount Oil Fertilizer Break Down Absorb Bio- technologist Soil Rate environment contains Q+ I- Q- I- amount product absorbed then agent pollutant se rate agent GetApply MicrobesScript patient script then product se remediator amount TreatmentAgent Another abstraction... patient GetApply substanceScript patient script then substance patient se

A Component-Based Approach Represent component abstractions explicitly Define concepts as compositions Construct representations on-demand to answer qns KB Architecture Component theories = abstract, reusable models Definitions = specifications of compositions Inference = construct compositions as needed to answer questions.

Lessons from a Dictionary... Car: a Vehicle for Passengers Vehicle: a Means for Transporting something Transport: to Move from one Place to another Move: to GoGo: to Move Specific concepts defined as compositions of abstract concepts  Most abstract concepts appeal to core, foundational theories 

2. Definitions and Composition Definition = specification of a composition –a Fuel-Cell is a Producer of Electricity –a Bulb is an Electrical Resistor producing Light –a Camera is an Image Recording Device –a Wire is a Conduit of Electricity Automated composition: –Elaboration: component supplies info to answer query –Classification: recognize concepts in the composition

( Camera has (superclasses ( Device ))) (every Camera has (behavior ((a Recording with (input (a Image ))))) 2. Composition (example) Composition: Camera = an Image Recording Device Recording Image Device behavior input Query: Failure modes of a camera?

( Device has (superclasses ( Physobj ))) ;;; the failure modes of a device are the ;;; failure modes of its functional parts (every Device has (behavior ((a Activity ))) (failure-modes ( (the failure-modes of (the participants of (the behavior of Self ))))))) Activity Physobj Device Failure- Mode Failure- Mode failure- mode failure- mode failure- mode failure- mode behavior participants Physobj Component Theory: Devices Physobj part. Failure- Mode Failure- Mode failure- mode failure- mode failure- mode failure- mode Recording Image Device behavior input

Physobj part. Failure- Mode Failure- Mode failure- mode failure- mode failure- mode failure- mode Recording Image Device behavior input Query: Failure modes of a camera? Sub-query: Participants in its behavior?

Component Theory: Recording ( Recording has (superclasses ( Activity ))) (every Recording has (input ((a Signal ))) (participants ( (a Receptor with (input ((the input of Self )))... Recording Signal Receptor Memory-Unit ReceivingWriting Signal input agent subevents patient input output input participant Physobj part. Failure- Mode Failure- Mode failure- mode failure- mode failure- mode failure- mode Recording Image Device behavior input Receptor Memory-Unit ReceivingWriting Signal input agent subevents patient part. input output part.

Image Receptor Signal Recording Device behavior input Memory-Unit ReceivingWriting input agent subevents patient part. input output part. Failure- Mode Failure- Mode failure- mode failure- mode failure- mode failure- mode Run-Time Classification: Aperture = an Image Receptor

Image Receptor Signal Recording Device behavior input Memory-Unit ReceivingWriting input agent subevents patient part. input output part. Failure- Mode Failure- Mode failure- mode failure- mode failure- mode failure- mode input output failure- mode Image Aperture Image Blockage Run-Time Classification: Aperture = an Image Receptor Aperture - inputs an image - outputs an image - might be blocked -... input output failure- mode Image Aperture Image Blockage

Run-Time Classification: Aperture = an Image Receptor Film= an Image Memory-Unit Blockage Recording Device behavior input Memory-Unit ReceivingWriting agent subevents patient part. input part. Failure- Mode failure- mode failure- mode failure- mode input output failure- mode Image Aperture Image

Run-Time Classification: Aperture = an Image Receptor Film= an Image Memory-Unit Film - includes a sheet coated with image-sensitive chemical - might age -... Blockage Recording Device behavior input Memory-Unit ReceivingWriting agent subevents patient part. input part. Failure- Mode failure- mode failure- mode failure- mode input output failure- mode Image Aperture Image Aging Film input failure- mode Image Chemical sensitive-to covering Sheet parts Aging Film input failure- mode Image Chemical sensitive-to covering Sheet parts

Blockage Recording Device behavior input Receiving Writing agent subevents patient part. input part. failure- mode failure- mode failure- mode input output failure- mode Image Aperture Image Aging Film input failure- mode Chemical sensitive-to covering Sheet Query: Failure modes of a camera? Blockage, Aging Sub-query: Participants in its behavior? Aperture, Film

Other Compositions... Activity Signal Recording Vibration Sound Image Producing Camera VibratorSeismograph Stereo Tape Recorder Projector

Definitions ;;; "A CAMERA is an IMAGE RECORDING DEVICE." (Camera has (superclasses (Device))) (every Camera has-definition (instance-of (Device)) (behavior ((a Recording with (input ((a Image))))))) ;;; "A SEISMOGRAPH is a VIBRATION RECORDING DEVICE." (Seismograph has (superclasses (Device))) (every Seismograph has-definition (instance-of (Device)) (behavior ((a Recording with (input ((a Vibration))))))) ;;; "A STEREO is a SOUND PRODUCING DEVICE." (Stereo has (superclasses (Device))) (every Stereo has-definition (instance-of (Device)) (behavior ((a Producing with (output ((a Sound))))))) ;;; "A TAPE-RECORDER is a SOUND RECORDING DEVICE." ;;; "A Projector is an IMAGE PRODUCING DEVICE." ;;; "A Vibrator is a VIBRATION PRODUCING DEVICE."

Generic Devices (Device has (superclasses (Physobj))) ;;; "The failure-modes of a device are the failure-modes of its ;;; (functional) parts." (every Device has (behavior ((a Activity))) (parts ((the participants of (the behavior of Self)))) (failure-modes ( (the failure-modes of (the parts of Self)))))

Generic Activity: Recording a Signal (Recording has (superclasses (Activity))) ;;; "Recording involves receiving a signal, then writing it to a memory." (every Recording has (input ((a Signal))) (subevents ( (a Receiving with (object ((the input of Self))) (agent ((the Receptor participants of Self)))) (a Writing with (object ((the output of (the Receptor participants of Self)))) (patient ((the Memory-Unit participants of Self)))))) (participants ( (a Receptor with (input ((the input of Self)))) (a Memory-Unit with (input ((the output of (the Receptor participants of Self))))))))

Generic Activity: Producing a Signal (Producing has (superclasses (Activity))) ;;; "Producing a signal involves converting power ;;; (provided by a Power-Supply) into a target signal." (every Producing has (output ((a Signal))) (subevents ( (a Supplying with (agent ((the Power-Supply participants of Self)))) (a Converting with (agent ((the Converter participants of Self))) (object ((the output of Self))) (after ((the Supplying subevents of Self)))))) (participants ( (a Power-Supply with (output ((the input of (the Converter participants of Self))))) (a Converter with (input ((the output of (the Power-Supply participants of Self)))) (output ((the output of Self)))))))

Particular Devices ;;; "An APERTURE is an IMAGE DETECTOR..." (every Aperture has-definition (instance-of (Receptor)) (input ((a Image)))) ;;; "...which outputs an image, and might get blocked." (every Aperture has (output ((a Image))) (failure-modes ((a Blockage with (object (Self)))))) ;;; "a FILM is an IMAGE MEMORY-UNIT..." (every Film has-definition (instance-of (Memory-Unit)) (input ((a Image)))) ;;; "...which might age, and includes a chemical-covered sheet." (every Film has (failure-modes ((a Aging with (object (Self))))) (parts ((a Sheet with (covering ((a Chemical with (sensitive-to ((Self input)))))))))) ;;; and other descriptions for: microphone, loud-speaker, tape, movement-sensor, light, motor

Particular Activities ;;; "EXPOSING is WRITING on FILM." (every Exposing has-definition (instance-of (Writing)) (patient ((a Film)))) ;;; "TAPING is WRITING to TAPE." (every Taping has-definition (instance-of (Writing)) (patient ((a Tape)))) ;;; "SHINING is GENERATING an IMAGE." (every Shining has-definition (instance-of (Generating)) (object ((a Image))))

Natural Language Generation (every Blockage has (text ((Self object) "is blocked, preventing" (the input of (the object of Self)) "from reaching" (the parts-of of (the object of Self))))) (every Discharged has (text ((Self object) "that powers" (the Converter parts of ;the converter part of... (the parts-of of ; the system containing... (the object of Self))) ; the battery "is discharged"))) (every Recording has (text ("First," (the Receptor participants of Self) "captures" (the input of Self) ", then" (the Memory-Unit participants of Self) "records" (the input of Self)))) ;;; and so on for the other activities, devices, and failure-modes

Compound Concepts are Ubiquitous –Botany: leaf mesophyll cell aerial root system plant material distribution photosynthetic organ level structure... –Aerospace: turbine gearbox assembly logic speed control unit case drain fluid aircraft hydraulic system performance analysis program …(43k acronyms!)...

Composing Representations: What are the building blocks? Events: Levin (1993) classifies about 3000 events into about 25 categories sharing common components. Objects: Ogden (1934) identifies about 800 basic objects. Shapes and Places: Landau and Jackendoff (1993) systematize descriptions of objects' shapes and locations. Compound Objects: Barker (1998) identified 20 ways that noun phrases are built from components; similar studies underway for verb phrases. Core Theories: Forbus, Kuipers, Allen, et.al. contribute representations of time, space, quantities, and causation.

Levin's Verb Classes (B. Levin, English Verb Classes and Alternations, University of Chicago Press, 1993) put remove send and carry push and pull give and take hold and keep conceal touch and contact combine and attach separate and disassemble create and transform search communicate ingest emit destroy appear, disappear, and occur about 10 more

Building a Component Library examples from the move cluster ;;; Movement is an event that changes location (Move has (superclasses (Event))) (every Move has (patient ((a Physical-thing))) (changes ((a Change with (property ((the location of (the patient of Self)))) (from ((the source of Self))) (to ((the destination of Self)))))) (source ((a Place))) (destination ((a Place))))

Adding constraints to define new members of the cluster ;;; Locomotion is self movement (Locomotion has (superclasses (Move))) (every Locomotion has (agent ((the patient of Self))))

Adding constraints to define Flow ;;; Flow is movement of a liquid or gas through a channel or across a surface (Flow has (superclasses (Move))) (every Flow has (patient ((a Liquid) or (a Gas))) (direction ((a Direction with (path-relation (through)) (reference-object ((a Channel)))) or (a Direction with (path-relation (across)) (reference-object ((a Surface)))))))

Combining Components: Role Filling ;;; an Enter is a Move from outside a container to inside that container, ;;; through the container's portal (Enter has (superclasses (Move))) (every Enter has (source ((a Place with (place-relation (outside)) (reference-object ((a Container)))))) (destination ((a Place with (place-relation (in)) (reference-object ((Self source Place reference-object Container)))))) (direction ((a Direction with (path-relation (through)) (reference-object ((the portal of (Self destination Place reference-object Container))))))))

Combining Components: multiple inheritance Inflow is a movement {from flow} of a liquid or gas through a channel or across a surface {from enter} from outside a container to inside that container, through the container's portal (Inflow has (superclasses (Flow Enter)))

Combining Components: Sequencing events ;;; A carry is locomotion while supporting something (Carry has (superclasses (Move))) (every Carry has (subevent ((a Support with (agent ((the agent of Self))) (patient ((the patient of Self))) (concurrent-with ((the Locomotion subevent of Self)))) (a Locomotion with (agent ((the agent of Self))) (concurrent-with ((the Support subevent of Self)))))))

Combining Components: Causal Connection ;;; a push is the application of a force causing a movement (Push has (superclasses (ApplyForce))) (every Push has (direction ((a Direction with (path-relation (away)) (reference-object ((the agent of Self)))))) (causes ((a Move with (patient ((the patient of Self))) (direction ((the direction of Self)))))))

Combining Components: Iteration over a Set ;;; Convey is the movement of a container and all its contents (Convey has (superclasses (Move))) (every Convey has (patient ((a Container))) (causes ((forall ((the contents of (the patient of Self))) ((a Move with (patient (It)) (source ((the source of Self))) (destination ((the destination of Self))) (concurrent-with ((Self)))))))))

Experimental Design Measuring Successful Reuse Small scale reuse: build component library for a subset of the "Pumps Dictionary". Measure successful reuse of components for representing the remainder. Examples: Air Driven Pump, Water Circulating Pump Medium scale reuse: do the same for abstracts of the "Flight Incident Database". Example: "Lost hydraulic controls; deployed air driven pump; returned to airport." Large scale reuse: do the same for the full accounts in the Database.

Measuring Successful Reuse The success of a reuse effort is measured by the role of the components in answering questions in novel domains. Measured in three ways: – recall: the fraction of the KB-structure (that's built to answer each question) that's contributed by components – accuracy: the correctness of the knowledge contributed by the components – completeness: the comprehensiveness of the knowledge contributed by the components

Discussion A knowledge base contains: –explicit representations of "building block" concepts – specifications for building representations of other concepts using these building blocks –methods for composing concepts on-demand and (possibly) caching the results This approach improves reuse and reduces representational drift

Discussion How broad should each component be? three versions of drop: –downward movement –a release followed by downward movement –… until something breaks the fall Will idiosyncratic variations within real domains overwhelm the regularities in a library of components?

Potentials… Growth of on-line, structured information –XML –On-line databases (eg. commercial, geographic) –eCommerce Search / Information Access –best search engine wins... Knowledge Management NL understanding / MLT / Speech Knowledge-Based Engineering The growing demand for knowledge processing:

Combining Components: Sequencing events Bus-ride is a Movement with an instrument of a Bus, modeled as a container an Enter event with destination: in the bus a Convey with agent: the bus an Exit with source: in the bus (Bus-ride has (superclasses (Ride))) (every Bus-ride has (instrument ((a Bus))) (subevent ((a Enter with (patient ((the patient of Self))) (destination ((a Place with (reference-object ((the instrument of Self)))))) (followed-by ((the Convey subevent of Self))))) ((a Convey with (patient ((the instrument of Self))) (followed-by ((the Exit subevent of Self))))) ((a Exit with (patient ((the patient of Self))) (source ((the instrument of Self)))))))

Demo... KM> (every Recording has (input ((a Signal))) (participants (... KM> (showme ‘Recording) (a Device with (behavior ((a Recording with (input (Image)))))) (Blockage Aging) KM> _Device01 KM> (the parts of _Device01) (trace: _Receptor31 satisfies definition of Aperture) (trace: _Memory-Unit33 satisfies definition of Film) (_Aperture32 _Film34) KM> (the failure-modes of _Device01) (“The aperture is blocked.” “The film is aged.”) KM> (the text of (the failure-modes of _Device01)) (trace: _Writing40 satisfies definition of Exposing) (_Receiving41 _Exposing42) KM> (the subevents of (the behavior of _Device01)) _Film34 KM> (the patient of _Exposing42)

Overall Architecture 2. Component theories (computational clockwork) Producer Consumer Circuit... Distn.Network Physobj Move Location... Movement 1. Ontology (conceptual vocabulary)... Thing

Overall Architecture 1. Ontology (conceptual vocabulary) 2. Component theories (computational clockwork) Producer Consumer Circuit... Distn.Network Physobj Move Location... Movement... Producer Consumer Circuit Thing

Overall Architecture 1. Ontology (conceptual vocabulary) 2. Component theories (computational clockwork) Producer Consumer Circuit... Distn.Network Physobj Move Location... Movement... Physobj Activity Move Thing

Overall Architecture 1. Ontology (conceptual vocabulary) 3. Definitions and Descriptions (describe concepts in terms of others) 2. Component theories (computational clockwork) Producer Consumer Circuit... Distn.Network Physobj Move Location... Movement... Thing Bulb = Light-producing Electrical Consumer 4. Databases of basic facts (instances)... Materials Chemicals Countries

Summary Demand and potential of knowledge processing Component-based architecture –ontology –component theories –definitions (specifications of compositions) –basic fact libraries Benefits –KB development: modular, reusable architecture –KB application: deal with novel concepts at run-time

1. Component Theories A coherent, encapsulated system of concepts & relns Contains: –ontology (vocabulary of concepts and relations) –axioms (rules) relating these Provides semantics for these concepts in the KB Can layer these theories (define one using others)

Example: Distribution Network Rules (axioms): PRODUCERS produce TRANSPORT- MATERIAL. CONSUMERS can consume TRANSPORT-MATERIAL. A network element may be BLOCKED or UNBLOCKED. If an element directly connects with an UNBLOCKED element, then it has an ACCESS to that element. A CONSUMER is SUPPLIED if it has ACCESS to a PRODUCER. …. P I I C C P Ontology Producer Intermediary Consumer Transport-Material connects supplied state

Axiom Representation (example) e1:Element connected- element Unblocked state e2:Element e1:Element access-to e2:Element   e1,e2:Element connected-element(e1,e2)  state(e2,Unblocked)  access-to(e1,e2) (every Element has (access-to ( (allof (the connected-element of Self ) where ((the state of It) = Unblocked ))))) “If an element connects to an UNBLOCKED element, then it has ACCESS to that element.” (iii) Implementation (KM) (ii) Logic (i) Semantic network

Other component theories... Supply-and-demand Containment Machines Production network Two-state object Transportation...