1. A Perspective on Constraint Research in Industry
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A Perspective on Constraint Research in Industry
Lisa Purvis
10 October 2003
Hi Everyone! My name is Lisa Purvis, and I’m delighted to be here today to talk with you about my research work at Xerox that involves constraints.
My goal for today I, really to give you a good insight into what it’s like to do research in industry, and to show you that there are applications for constraints.

2. Outline Background Xerox projects involving constraints
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Background
Xerox projects involving constraints
Constraint-Based Scheduling
Constraint-Based Document Creation
What it’s like to do industry research
So what I’d like to tell you about today is first, a bit about my own background.
And then about the projects that I have been doing that involve constraints
And finally, my own general observations and thoughts about what it’s like to do research in industry.
And please, ask questions during the talk so we can make it interactive! Stop me at any time for questions.
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3. Background BS Computer Science, Clarkson University, 1988
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BS Computer Science, Clarkson University, 1988
Software Developer at IBM in CT, 1988 – 1992
MS Computer Science & Eng, RPI, 1992
Ph.D. Computer Science & Eng, Univ of Connecticut, 1995
Advisor: Dr. Pearl Pu, EPFL
Research Scientist, Jackson Laboratory, Maine,
Research Scientist, Xerox, NY, present
Most of this I think we already sort of went over, but I also want to tell you about the lessons that I learned from these experiences.
A couple of the things that I learned, and these are personal observations.
For me, geography mattered.
Not all big companies are the same.
Figure out what is important to you, and ask questions so you know what it’s like at the companies you interview with.
e.g. typical workweek, overtime expected?
talk to people who would be your peers, ask for 10 minutes with someone who works with your would-be manager
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4. Background “Reasoning By Remembering” Architectural Design
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Ph.D. Thesis: “Intelligent Design Problem Solving Using Case-Based and Constraint-Based Techniques”
“Reasoning By Remembering”
Architectural Design
I’d like a Victorian house, 4 br, 2.5 ba, walkout basement, ...
Let me tell you where I started on this journey of getting into the constraints community.
I finished my Ph.D. thesis in 1995, and it was on the topic of case-based and constraint-based reasoning in design.
In case you’re not familiar with case-based reasoning, it is sometimes called “reasoning by remembering”. And humans use it in their own problem solving every day.
For instance, in architectural design.
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5. Background “Reasoning By Remembering” Medical Diagnosis
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Ph.D. Thesis: “Intelligent Design Problem Solving Using Case-Based and Constraint-Based Techniques”
I have sneezing, headache, achiness.
“Reasoning By Remembering”
Medical Diagnosis
Also in medical diagnosis.
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6. Background Case-Based Reasoning Cycle
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Case-Based Reasoning Cycle
Problem
New case
in design problem solving, likely to be more than one case
how to combine the cases with a formalized process?
use a repair-based CSP algorithm (min-conflicts / Minton)
Revise
Retrieved case(s)
Retrieve
Repaired
case
Revise
Previous cases
Retain
The case-based reasoning cycle is typically described as follows.
My thesis work was looking at this adaptation step. In design problem solving, you can imagine that there are many situations in which more than one case matches the new problem.
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7. Background Jackson Laboratory
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Jackson Laboratory
bioinformatics, intelligent user interfaces to gene development and genome databases.
Xerox
Constraint-based scheduling
Constraint-based document creation
After my Ph.D., I went to work at the Jackson Lab oratory, in the hopes of using AI in the field of bioinformatics….to help biology researchers better understand genes and how they impact human development.
Then I went to Xerox and I have been working on two projects that involve constraints to some degree. The first was a project that had already been started when I joined Xerox, and it had to do with constraint-based scheduling.
The second is a project that I’m working on now and I proposed as a research project, on constraint-based document creation.
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8. Xerox Projects Involving Constraints
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Constraint-Based Scheduling
Constraints model the reprographic system
Constraint solver schedules the operations required to produce a document.
Sheet.exit = sheet.entry + time for 8 pitches
Duplex loop
Sheet in
Sheet out
print
invert
At Xerox we make a lot of different kinds of machines, copiers, printers, multifunction devices, and now also solutions and services.
One of our newest machines is called the “iGen3”. It is a big huge production press, used for high-end production jobs.
An iGen3 is made up of feeders, markers, and stackers. And one of the main benefits of the machine is that you can configure it with any combination of these 3 types of modules.
Within the machine, there are issues such as controlling the paper as it moves through the machine, so everything happens on time. In previous systems, this kind of scheduling was hardcoded. Since the iGen3 can be configured in many different ways, it was impractical to hardcode a scheduling algorithm.
So a constraint-based approach was developed, that allowed each machine module to describe its capabilities in terms of constraints, and then a constraint propagation would occur.
Interesting paper here on constraint tractability theory.
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9. Xerox Projects Involving Constraints
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Constraint-Based Document Creation
Transition of Variable Information Document Applications
Simple Transaction
Bills, Statements
Catalogs, Brochures, Postcards, Reports, Sales Material
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10. Constraint-Based Document Creation
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11. Constraint-Based Document Creation
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12. Constraint-Based Document Creation
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13. Constraint-Based Document Creation
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14. Constraint-Based Document Creation
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Eye-catching flyer for
customer X.
Content Repository
Document Wizard
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20. Constraint-Based Document Creation
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Making document design easier
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21. What It’s Like To Do Industry Research
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pure research vs. applied research
university collaboration
intellectual property (papers vs. patents)
research community
“teaching” aspect
a need to think broadly
Pure research:
- constraint propagation as mutation (research problem comes first)
Applied Research:
- way to automatically compose documents (application comes first)
University Collaboration:
- great opportunity here. Everyone wants to work on “real” problems.
- University Affairs Committee
Intellectual property:
- publishing….mostly applic. Papers. But I don’t find that bad.
- not so many papers as in academia
- patents instead! Patent process. Rewards for patents.
Research Community
- fewer people that are truly doing research in industry. E.g. CBR and GE – best paper. Constraint Tractability – best paper. Opportunities come up, you are one of a few competing for it.
Teaching aspect. Convincing others of the greatness of your work. Relevavnce to the company.
Think broadly: company identifies areas of focus (office document solutions). What technologies could be used to enable new offerings in this area? Not just your own!!
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