Gio Wiederhold SimQL 1
Integration of Simulation Results into Information Systems
Gio Wiederhold
April 2002, updated Nov 2002
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Information Integration
Information Integration provides new Information for improved Decision Making when it
presents more data (mediation 1991) Risk: much may be irrelevant
captures new relationships (knowledge bases 1977) Often requires expert inter-domain knowledge
includes current sensor data (fusion, streams 1999) Data reflect the past only
includes predictions about future courses
******* A new, potentially major topic *******
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Decision-making (DM)
Analyze Alternatives
• Current Capabilities
• Future Expectations
Process tasks:
• List resources
• Enumerate alternatives
• Prune alternative
• Compare alternatives
futurenow
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Prediction Requires Tools
E-mail this book, Alfred Knopf, 1997
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Future information systems
Combine data from the past, with current data, knowledge, and predictions into the future
o oo o
o o
Assessment of the values of alternative possible outcomes
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DM support is disjoint
Distribution
Databases
Simulation
Planning Science
extensions to moveto networked supportare also disjoint
does not interoperate
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Current state of DM Support
• Spreadsheets
• Planning of allocations
• Other simulations
various point assessments
past now futurepast now futuretimetime
Data integration
distributed, heterogeneous
x17 @qbfera ffga 67 .78 jjkl,a nsnd nn 23.5a
Databases
Intuition +
organized support disjointed support
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Information Systems should alsoProject into the Futures
Support of decision-making requires dealing with the futures, as well the past
• Databases deal well with the past
• Sensors can provide current status
• Spreadsheets, simulations deal with the likely futures
Information systems should be able to combine all three
timetimepast now futurepast now future
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New Resources for Information
Application Layer
Mediation Layer
Foundation Layer
data and simulation resources
value-added services
decision-makers at workstations
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Interfaces enable integration:SimQL to access Simulations
timetimepast now futurepast now future
Msgsystems,sensors
Databases, accessed via SQL or
XML, CORBA compliant wrappers
Simulations, accessed via SimQL and
compliant wrappers
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Parser
MetadataManager
Querymanager
SchemaManager
Wrapped .. SimulationsMetadata
DevelopmentInteraction
Production Interaction
Filing ofAccessSpecs
Use of AccessSpecs
Initiation and Results of Simulations
SchemaCommands
SchemaCommands
Help
Errorreports
CustomerDeveloper
Help
Query
Prototype ImplementationPrototype Implementation
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Stanford experiment, supported by DARPA & NIST
Phase 1 Architectures
SpreadsheetsEngineering
wrapper wrapperwrapper
LogisticsApplication
ManufacturingApplication
Weather (short-, long-term)
wrapper
TestData
SimQL accessSimQL access
SimQL access
SQL access
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Language - simple for demo
SQL SELECT Temperature, Cloudcover, Windspeed, Winddirection
FROM WeatherDB WHERE Date = `yesterday' AND Location = `ORD'.
----> {75, .30, 5, NW}
SimQL PREDICT Temperature, Cloudcover, Windspeed, Winddirection
FROM WeatherSimulation < name of wrapper accessing web pages >
WHERE Date = `tomorrow' AND Location = `ORD'.
-----> { (75, .8), (.30,.8), (5, .8), (NW, .8) }
Would prefer XML representation
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5 DevelopAssessment Plan
7
2 Develop *Objectives
*: w/Measures
4 AssignTask / Activity
3 Phase & *SequenceObjectives
1Determine
StatusExecution Feedback
Higher Level Objectives, Intel, OB,ROE, Commanders Guidance & Intent, Etc.
Plan Assessment Feedback
Resource Constraints
Required Resources
Phased Sequenced Objectives
Assessment Plan
Prioritized Sequenced Tasks
Campaign Status
Access to Simulations
Req’mtsDetermine
Assess and/orRehearse Plan
SimQL
Place of SimQL in Objective-based Planning
from JFACC PIP
Simulationresults
Simulationparameters
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Types of simulation services
1. Continously executing: weather prediction– SimQL result reports best match samples
2. Execution specific to query: what-if assessment– may require HPC power for adequate response
3. Past simulations collect results in a base: materials– performs inter- or extra-polations to match query parameters
4. Combinations, i.e., 2. + 3.: top layer simulation using stored partial lower level results: device performance in new setting
5. Human-in-the-loop (mediated by an agent program): SAFs
Note• A simulation service program can be written in any language• A simulation service must be compliant to the interface spec.
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Enabling Interoperation
Databases• serve clients via SQL by
Sharing a Model (The Schema)
A query language over the model the SQL interface enables• independence of
application developmentDBMS technology developmentreuse of infrastructure
Today• most new systems use a
DBMS for data storageeven with less performance, inability to handle all problems,but enough of them well enough.
Simulations should • serve clients via SimQL by
Sharing a Model (research q.)A query language over the model
a SimQL interface enables• independence of
application developmentsimulation technology develop’treuse of infrastructure
Objective• build information systems
combining DBMS, Simulationseven with less performance, inability to handle all problems,but enough of them . . .
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Internet requirements
• Ubiquitous access to simulations
of a wide variety of types
• Rapid response to parameter changes– often High-Performance computation is
needed– distributed simulations with synchronization
• Rapid Service Composition – High bandwidth among simulations– Access to multiple services in parallel
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Use of Simulation Results
Simulation results can be composed for alternative Courses-of-actionsComposition should include computation
and recomputation of likelihoods Likelihoods change as now moves forwards
and eliminates earlier alternatives.
timetime0.40.4
0.60.6
0.20.2
0.50.5
0.30.3
0.50.5
0.20.20.10.1
0.10.1
0.10.1
0.030.030.070.07
0.10.1
0.50.5 0.30.3
0.20.2
prob
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The branches can be labeled with probabilities, then assessed using the outcome with values
past now futurepast now future
Next period alternatives
0.4
0.6
& subsequent periods
0.2
0.1
0.5
0.30.2
0.1
0.1
0.13
0.3
0.2
0.07
0.4
0.3
0.1
10001000
20002000
50005000
10001000
00
-6000-6000
-3000-3000
ValuesValues
100100
600600
1100 5001100 500
200 200200 200
-420 0-420 0
-820 -400-820 -400
12001200
6666
134134
-1220-1220
12661266
--10861086
timetime
prob
value
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Integrating data & planning support will make our data reusable and much more valuable
past now futurepast now future
Re-assess as timeRe-assess as timemarches forward !marches forward !
A Pruned Bush A Pruned Bush
Databases, . . .Spreadsheets,
other simulations,
Msgssensors
10001000
20002000
50005000
10001000
00
100 100
600600
1100 5001100 500
200 200200 200
00
12001200
6666
timetime
1266 ?1266 ?
?? ??
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Even the present needs SimQL
timetimepastpast now now futurefuture
last recorded observations
simple simulationsto extrapolate data
Is the delivery truck in X?
• Is the right stuff on the truck?
• Will the crew be at X?
• Will the forces be ready to accept delivery?
point-in-time for situational assessment
Not all data are current:
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Recent State of SimQL Research
Spreadsheets Weather Civil Engineering
wrapper wrapper wrapper
Test Application
GUIcollect language
requirements
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SimQL research questions
• How little of the model needs to be exposed?
• How can defaults be set rationally?
• How should expected execution cost be reported?
• How should uncertainty be reported?
• Are there differences among application areas that require different language structures?
• Are there differences among application areas that require different language features?
• How will the language interface support effective partitioning and distribution?
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Why not use DB-like storage?
• Volume is large --– multiple future alternatives
• Value is transient– tomorrow all values must be updated– expect high write/read ratio
• jut the opposite of typical DB operations
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Research questions for Decision Support
• How to move seamlessly from the past to the future?
• How can multiple futures be managed (indexed)?
• How can multiple futures be compared, selected?
• How should joint uncertainty be computed?
• How can the NOW point be moved automatically?
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Interfaces enables research integration
Research on
• Multiple futures– Uncertainty in databases
• Probability estimation– Expert Systems uncertainty – Fuzzy algebra– Prade algebra
• Planning Models– allocation and distribution– reduction to current values
• Risk management– beta estimation
Distribution
Databases
Simulation
Planning Science
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Prediction as a Service
• Server is an independent contractor, defines service
• Client selects service, and specifies parameters
• Server’s success depends on value provided
• Some form of payment received for services
x,y
Databases are a current example.Simulations have the same potential.
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Summary of SimQL
A new service for Decision Making:• follows database paradigm
– ( by about 25 years )
• coherence in prediction– displacement of ad-hoc practices
• seamless information integration – single paradigm for decision makers
• simulation industry infrastructure– investment has a potential market– should follows database industry model:
Interfaces promote new industries
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Definitions of Integration
• Data Integration: presenting data from multiple sources so that a suite of applications* can deal with it a single (perhaps virtual) database
• Information integration: presenting information, obtained by processing data and metadata from multiple sources so that an suite of application can deal with it as a coherent information resource.
* application suite:: a set of applications (collect, maintain, query, analyze)
that have a consistent domain model
• Application integration: Interoperating processes.The ideal of open systems
Standards are more difficult, because of hidden semantics
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• Application Integration I [Hergula]: include data extracted (via wrappers or transformers) by functions from multiple applications.
• Application Integration II: Use a workflow model to integrate processes into a higher level representation.
• Application Integration III: Creating new, higher-order (query, ...) functions by combining existing application functions and made-to-order functions (in SQL, ...)
Defining Application Integration ?
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