A Jack of All Trades Pamela J. Williams LMI March 26, 2010.
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Transcript of A Jack of All Trades Pamela J. Williams LMI March 26, 2010.
A Jack of All Trades
Pamela J. WilliamsLMI
March 26, 2010
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Application 1:
Controlling Mass Transit Systems
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Numerous optimization problems arise in the area of advanced automatic train control
• On a daily basis, the control system
experiences approximately 20 delays
of 5 or more minutes
• Decrease in travel time will reduce
number of needed trains, thereby
saving $2M per car
• Short Term - improve passenger
comfort for the Bay Area Rapid
Transit (BART) District
• Long Term - minimize energy
consumption
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Our enhanced control objective is to smooth interference during acceleration
• while– adhering to the
schedule,
– maintaining the worst case stopping distance,
– making required station stops,
– travelling at safe speeds, and
– braking into a station at a controlled rate.
0 g(x)
0, (x) t.s.
f(x) min
h
x
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What tools are needed to solve this problem?
• Disciplines– Physics– Numerical Analysis– Operations Research
• Programming– C++ (for UNIX systems)– Java
• Software Tools– Matlab– Excel
• Soft skills learned– Teamwork– Client Interactions
Items in orange font indicate my knowledgebase at the start of the project.
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Application 2:
Detecting protein phosphorylation sites
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Why is phosphorylation important?
• Controls DNA repair• Regulates metabolism• Can prevent diseases
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What was the research question?
• Problem Statement– Given a set of known phosphorylated sites, can we use
machine learning techniques to accurately detect the sites?
• Approach– Apply neural networks, Hidden Markov Models, etc. – Use majority vote to identify a site– Compare accuracy of individual methods and majority vote
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Integration of existing tools was the heart of this project
• Disciplines– Data mining
• Programming Languages– CSH– Perl– Python
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How to stock shelves?
• Key Questions– How much to buy?– When to buy?
• Driving metrics– Customer wait time– Inventory investment– Workload
• Items with sporadic demand are hard to manage. – The past may not be a perfect barometer for the future
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What is Sporadic Demand?
Frequent Demand
0
1
2
3
4
5
6
1 3 5 7 9 11 13 15 17 19 21 23 25 27 29
Months
Dem
and
s
Sporadic Demand
02468
101214
1 3 5 7 9 11 13 15 17 19 21 23 25 27 29
MonthsD
eman
ds
Infrequent demands, quantities vary greatly (not always low quantities!)
Frequent demands, quantities vary moderately
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What tools are needed to solve this problem?
• Disciplines– Statistics– Inventory control
• Programming– Visual Studio C++
• Database Tools– FoxPro– Microsoft Access
• Soft skills learned– Project management
Items in orange font indicate my knowledgebase at the start of the project.
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Who is LMI?
• Formerly known as Logistics Management Institute• A not-for-profit government consulting company• Headquarters in Northern, VA• We are hiring!
– Go to http://www.lmi.org/careers/careers.aspx– Computer scientist/mathematician posting