Value-added Services on the WEB June 1996 Gio - - PDF document

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Gio Wiederhold 1995 1

Value-added Services

• n the WEB

June 1996 Gio Wiederhold

Stanford University

prepared for WETICE96

Gio Wiederhold 1995 2

Abstract

To exploit existing and potential resources on the Web for effective engineering a number of services are needed. We will indicate some of the opportunities and prerequisites for such services. Collaboration, security, and payment schemes are some of the issues. Many traditional relationships among consumers and vendors will change. Reliable predictions are not possible, but exploring the range of choices is a challenge in itself.

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Industry Needs Information

• Engineering and Manufacturing

✔own capability suppliers’ capabilities ✔demand global demand

• Distribution and Transportation

✔costs for alternate means of shipping

• Finance

✔project demand ✓ ✓ project cost of funds

• Marketing and Service

taste and style demographics more from remote sources

Gio Wiederhold 1995 4

Information Leverage

Tactical

• Customers
• Inventory
• Suppliers

Strategic

• Planning
• Capabilities
• Opportunities

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Information overload Data starvation

• More databases

– public & corporate

• Faster communication

– digital – packeting: TCP-IP, ATM

• World-wide connectivity

– internet – world-wide web

• Disintermediation

– ubiquitous publishing

Gio Wiederhold 1995 6

Transforming Data to Information

data and simulation resources value-added services users at workstations Application Layer Mediation Layer Foundation Layer

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Definition*

A mediator is a software module that exploits encoded knowledge about certain sets or subsets of data to create information for a higher layer of applications. It should be small and simple, so that it can be maintained by one expert or, at most, a small and coherent group of experts.

* Wiederhold: IEEE Computer March 1992

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Functional Layer

Service Service interface interface Resource access Resource access interface interface User interface User interface Real-world Real-world interface interface Human-computer Human-computer Interaction Interaction Application- Application- specific code specific code Domain- Domain- specific specific code code Source- Source- specific specific code code

MEDIATION MEDIATION

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Function of Mediation

Apply Domain-specific Specialist Knowledge to add value

• to locate data sources
• to describe data for use
• to convert for consistency
• to abstract for insight / models
• to extrapolate to new situations
• to integrate from diverse sources
• to re-abstract for presentation

➜ INFORMATION

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Mediation exploits Knowledge

• Discover sources
• Search likely files
• Obtain descriptions
• Scan texts
• Select relevant data
• Abstract to right level
• Integrate from all
• Validate consistency
• Apply to problem model
• Test stability of extrapolations

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Making data relevant

• Data reduction
• Data abstraction

– Summarization – Exception search – Level change to integrate with other data sources

• Follow Customer Model:

hierarchical, divide-and-conquer, a common paradigm

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Mediator Design Principle

Transform Data into Information Match Costumer Model Hierarchical to Resource Model General network (and maintain models)

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Access Maintenance Tasks

• Selection of relevant source material

– using Yahoo, Knowbots, Harvest, federated schemas, GLOSS – evaluate descriptions. meta-data

• Focused access to the variety of resources

– using SQL, wrappers, CORBA, . . .

• Caching

– to resolve asynchrony in sources – create consistent histories

• Tracking Resources, their cost, and response

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Mediation on the WWW

• Resources on the World-Wide-Web

– are plentiful – autonomous – incoherent

• Opportunity for value-added services

– select best source – improve coverage – minimize overlap – resolve inconsistencies – summarize results

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Abstraction / Summarization

• Abstraction to match

levels of granularity

• Assessment of quality
• f diverse sources
• Seeking exceptions from

expected values or trends

• Omission of replicated or

known information

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Integration

• Resolution of scope

mismatches

• Integration of material

from diverse domains

• Ranking of material from

diverse sources

transistors transistors semi- semi- conductors conductors

• 1. 45
• 2. 43
• 3. 33
• 4. 28

.. . .

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Result modes for ranking

Databases:

• Completeness
• All the answers

Prolog

• Correctness
• The first answer

Optimization

• The best one
• Assumes all

factors are known, no human decision Customer:

• wants choices
• explanation
• background

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Ranking

Qualitative Significant Differences: in terms of the customer model

Plan 1. UA59 dep.Wash.Dulles 17:10, arr. LAX 19:49 Plan 2. AA75 dep.Wash.Dulles 18:00, arr. LAX 20:10 Plan 3. UA119 dep.Wash.Dulles 9:25, arr. LAX 12:00 Busy Joe: P1= P2, P3 Speedy Mike: P2, P1=P3 Greedy Pete: P1=P3, P2

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Opportunities in Engineering

• On-line presentation services, appropriate for audience
• Integration of documents and figures for WWW access
• Abstraction services: summaries of papers, reports

(with references to base mat.)

• Review services over suppliers, technologies, services
• Alternative ranking of suppliers, parts, materials, . . .
• Active documents with function evaluation, plotting
• Test generators and checkers (people, equipment)

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Control Valve Sizing, Future

• Interpretation

– Programmatic

• Analysis

– Integrated

• Evaluation

– Integrated

• Transformation

– Automated

From Andrew Arnold: Civ. Eng. Qualification Exam

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F-22 IWSDB Phase 6

Integration Services User Interfaces S S Q Q L L

PD DS

Wrappers Databases Domain Model Match maker Domain Matching Change Notification Query Re- formulation

Provi- sioner Engi- neer

Appli- cation PRIDE IWSDB client GUI WAIS server

Index Suppliers

Sy- base

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Evolution of mediation

W2 W1

D2 D6 D4

W3 I1

D1 D5 I2 M1 M2 A1 A4 A5 A2 A6 a. b. A3 c. d. e. datasources wrappers mediators network integrators applications D3

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Central Solutions do not Scale

What works with 7 modules and one person in charge fails when there are 100 modules and a committee is needed Any changes in resources affect the central module

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Domain-specific Mediation

• User application

– Workstations

• Mediator

– Expert-owned nodes

• Data sources

– Remote primary and byproduct services

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Integration at two levels

Application

• Informal, pragmatic
• User-control

Mediation

• Formal service
• Domain-Expert control

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Allocation Flexibility

User Interfaces Databases

Provider of Mediator M

Copy- if high intensity of interaction with

• 1. Application (M2)
• 2. Resources (N1,2)
• 3. Processing (M1)

Provider

• f medi-

ator N

N M HPC DB P M1 Application C Application B Application I M2 N 1 N 2 DBS R DB Q copy copy Mediators are

• nly code

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Getting there: Available Technology/Science

Caching Caching Uncertainty algebras Uncertainty algebras GIS GIS Temporal Algebras Temporal Algebras Active Databases Active Databases Agents Agents Web Search Tools Web Search Tools Security Filters Security Filters Object Bases Object Bases Knobots Knobots Wrappers Wrappers DB Views DB Views High Perf.Comm. High Perf.Comm. Simulation Access Simulation Access Database Models Database Models Internet Billing Internet Billing Customer Models Customer Models Constraint Management Constraint Management Case-based Reasoning Case-based Reasoning Distributed Storage Systems Distributed Storage Systems Multimedia Interfaces Multimedia Interfaces Circumscription Circumscription Communication Standards Communication Standards Domain Ontologies Domain Ontologies Text & Speech Processing Text & Speech Processing Public Databases Public Databases GIS GIS

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Current Technologies

• SQL

– One Verb - SELECT with primitive aggregation – One Database at a time – One Datatype: Tables

• Object-orientation

– Group data into objects = predefined aggregation – Program snippets -- methods -- with the data

• Midleware (ex.: CORBA)

– Fetch objects from server – Assume coherent domains

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Middleware

CORBA (Common Object Request Broker) – IBM SOM, DSOM

• DOE (Distributed Objects Everywhere)

– SunSoft

• DOME
• EZ-bridge

– System Strategies inc.

• ILU (InterLanguage Unification) Xerox
• ISIS
• KQML (Knowledge Query & Manipulation Lang.)
• MQM (Message Queing Middleware)

– IBM (for mainframe connections)

• OLE (Microsoft: Object embedding and Linking)
• OpenDOC (Apple)
• PDES (Product Data Interchange using STEP)
• TIB (Teknekron Information Bus)

{ {

Shared Shared speci- speci- fication fication

Many standards by many vendor groups

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Status of Mediation Technology

Today

• Handcrafted
• Expert consults with

programmer

• Programmer codes the

knowledge needed

• Resource changes

require advise, program update Future

• Generated from models
• Domain Expert

maintains models

• Specification

determines functions

• Resource changes

trigger regeneration

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Databases / Web / Text / Simulation

Coverage of Current DARPA I3 Efforts

Facilitation

(auto linking)

Maintenance

(rule technology?)

Discovery

(web,schema searching)

Wrapping (syntactical heterogeneity) Integration

• ver sources

Abstraction

for relevance to customer

Mediators

for multiple domains

Caching /

History Good progress Good progress / / active research active research / / related work related work / / poor coverage poor coverage

:-[ :-[ :-[ :-( :-( :-) :-) :-( :-[ :-) :-(

( ( ] ] | | ) ) Security

for cooperation

:-( :-| :-| :-)

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A mediator is not just static software: Knowledge ages

Application Interface Resource Interfaces Owner / Creator Maintainer Lessor - Seller Advertisor Changes of user needs Domain changes Resource changes Models, programs, rules, caches, . . .

Software & People

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Maintenance is good for you

relative annual maintenance cost depreciation = 1 / lifetime automobile hardware software automobile hardware software 100% 100%

40 40 20 20 70 70 30 30 10 10 80 80 90 90 60 60 50 50

lifetime lifetime

years

years 10

10 4 4 2 2 7 7 3 3 1 1 8 8 9 9 6 6 5 5 13 13 11 11 12 12

? ?

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Fat versus thin mediators

• too broad:

hard to maintain, needs a committee

• too thin: insufficient added value
• Too fat: hard to

compose

• Too narrow: few costumers

domain scope service scope Just right t right

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Mediation as a Service

Service Paradigm

• Customer views understood within server domain
• Processes use stored and maintained knowledge
• Processing adds value to data objects accessed
• Payment received for services and results

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E-money

Services must be paid for

• Incentive for creation and improvement
• price proportional to value added
• profit f (cost, market, price, overhead )
• Price low per item, so overhead must be low

Simple payment (no credit accounts, checks) Enabled through secure signatures

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CommerceNet Vision

Purchase components

• initially electronics and

electro-mecanical Rapid, economical building of equipment Get good choice

• competent supplier
• resolve variety of term &

classifications Use e-mail, e-money

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Simulation services

• 1. Continously executing: weather prediction

– SimQL result reports best match samples

• 2. Execution specific to query: what-if assessment, spreadsheets

– may require HPC power for adequate response

• 3. Complement base data: materials data, assembly

– performs inter- or extra-polations to match query parameters

• 4. Combinations of 2. and 3.: top layer simulation using stored

partial lower level results: weapon performance in 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

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Domain Specialization

• Knowledge Acquisition &
• Knowledge Maintenance

require

• Domain specialists
• Professional organizations

Empowerment

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New Role for Consultants

Old

• Used at Design Time

and

• To Explain Failures

Future

• Available as a Service
• Responsible for

Knowledge Maintenance

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Industrial Needs Served

NEEDS

• Access to relevant

Information

• Rapid response to

changing situations

• Remain current with

global conditions

• External services can

be shared effectively FEATURES

• Linkages to networks

and resources

• Incremental update of

information systems avoids legacy problem

• Equal access to local

and remote sources

• Value-added services

live in the network

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Integration Science

Integration Science Artificial Intelligence knowledge mgmt models uncertainty Artificial Intelligence knowledge mgmt models uncertainty Systems Engineering analysis documentation costing Databases access storage algebras