Workshop on Discrete Optimization     


Workshop on Discrete Optimization - overview

Workshop Attendees


A Workshop on Discrete Optimization in honor of William Pulleyblank is being held on May 31-June 1, 2018 at the IBM T. J. Watson Research Center Auditorium to mark the 70th birthday of Bill Pulleyblank, who turned 70 in October, 2017. The organizers are Sanjeeb Dash and Baruch Schieber from IBM Research, and William Cook, from the University of Waterloo. The workshop is sponsored by IBM Research AI and the Office of Naval Research. George Nemhauser from ISYE, Georgia Tech. is the Principal Investigator of the ONR grant for the workshop.

Bill Pulleyblank is a member of the National Academy of Engineering with numerous honors in the fields of Operations Research, discrete optimization and high-performance computing. He is currently a Professor of Operations Research at the US Military Academy at West Point. Prior to this, he worked at IBM Research for many years. He was the head of the Mathematical Sciences Department for some time, and subsequently led the Blue Gene project. Before IBM Research, Dr. Pulleyblank was a Professor at the University of Waterloo, where he made numerous contributions to Discrete Optimization.

The workshop will run from Thursday morning to Friday evening, with six-eight technical sessions featuring many distinguished academics and researchers (current list of invited attendees).

The topics covered in the lectures include mixed-integer linear programming, combinatorial optimization, and applications of these topics, and also high-performance computing. See the full list of abstracts below.

Speaker Abstracts


Thu, May 31, 2018

9:40 AM Opening Remarks  
10-10:30 AM  Jack Edmonds Blossom Programs and Their Polytopes by Pulleyblank et al.
10:30-11 AM Bruce Shepherd (British Columbia) When do Gomory-Hu Subtrees Exist?
11-11:30 AM  Coffee break  
11:30-12 PM  Gerard Cornuejols (CMU) Total Dual Integrality and the Packing Property
12-12:30 PM

 David Hartvigsen(U. Notre Dame)

Packing k-matchings and k-critical Graphs
12:30-2 PM  Lunch  
2-2:30 PM  Michel Goemans (MIT) Some of my favorite results of Bill Pulleyblank
2:30-3 PM Sandor Fekete  (Technische Universitaet Braunschweig) Combinatorial Optimization meets Computational Geometry
3-3:30 PM  Bruce Reed (McGill) Iterative Compaction and the Two Disjoint Rooted Path Problem
3:30-4 PM  Coffee  
4-4:30 PM  Ajay Royyuru (IBM) The Sizzle of Simulations in Life Sciences
4:30-5 PM  Brian Macdonald (Florida Panthers) Optimization problems in professional sports
6:15-9:30PM Conference Dinner  
  Brenda Dietrich (Cornell)  
  Alan Hoffman  
  Steven Horton (USMA)  
  George Nemhauser (Georgia Tech.)  


Fri, June 1, 2018

10-10:30 AM  Mike Trick (CMU) Combining Realignment with Scheduling for Sports Leagues
10:30-11 AM

 Andrew Conn (IBM)

An l1-Augmented Lagrangian algorithm and why, at least sometimes, it is a very good idea

11-11:30 AM  Coffee break  
11:30-12 PM  Baruch Schieber (IBM) Constrained Submodular Maximization via Greedy Local Search
12-12:30 PM  Donald Wagner (Office of Naval Research) Nonseparating cocircuits in binary matroids
12:30-2 PM  Lunch  
2-2:30 PM  Dimitris Bertsimas (MIT) From Data to Decisions
2:30-3 PM  David Applegate (Google) Some scheduling problems for TensorFlow computations
3-3:30 PM  George Nemhauser (Georgia Tech.) Machine Learning for Integer Programming
3:30-4 PM  Coffee  
4-4:30 PM Francisco Barahona (IBM) On two cooperative games related to shortest paths and minimum cuts
4:30-5 PM Thomas Magnanti (MIT) A Bit About Bill, A Bit About Scheduling with Testing



There is no fee for workshop attendance, and the invited attendees do not pay any fees for the conference dinner or transportation either. For all other attendees (IBM staff or otherwise), there is a registration fee of $100 for the conference dinner. No registration is needed for IBM Yorktown members and registration is required for all non-IBM attendees. The registration form will ask for affiliation, email id, and country of citizenship; these are  needed for all IBM visitors. The registration form is available at:


There is free visitor parking in front of the main lobby at the IBM T. J. Watson Research Center. In case this fills up, the receptionist will direct you to alternate parking spots behind the main building. The auditorium is right above/behind the main lobby.

Internet Access

All visitors at IBM can access the IBMInternet wifi network. However this requires an account. When you connect to this network or SSID, and open a browser, you will be asked to give your email and register/create an account. Login details will be sent to your email. If you have cellular access to your email, you can retrieve the login details and then connect to IBMInternet. As some visitors may not have cellular data connections, we will try to provide all registered guests an account in advance. 


We have blocked rooms in the Holiday Inn, Mt Kisco, NY for check-in up to 3 days on or before May 31, and check-out up to 3 days on or after Jun 1, 2018. The rate is US $132 a night (taxes are extra). This rate includes breakfast. These rooms/rates are available till May 6, 2018 and can be obtained by calling the hotel directly and referring to group code WDO. This is not available online.

The hotel address is:

1 Holiday Inn Dr, Mount Kisco, New York 10549
Phone: +1-914-241-2600

Please contact Sanjeeb Dash ( if the hotel runs out of rooms at this rate.


We will provide bus transportation from the hotel to IBM and back on both May 31 and June 1. On the evening of May 31, a bus will be available to go the restaurant where the conference dinner is held, and again from the restaurant to Holiday Inn Mt Kisco.

May 31, Thursday, 9 am: shuttle from hotel to IBM

May 31, Thursday, 5:45 pm: shuttle from IBM to restaurant for conference dinner

May 31, Thursday, 9:30 pm: shuttle from restaurant to hotel

June 1, Friday, 9am: shuttle from hotel to IBM

June 1, Friday, 5:30 pm: shuttle from IBM to hotel

Conference Dinner

The conference dinner, will be held on May 31, starting at 6:30 (arriving any time after 6 is fine) and going up to 9/9:30, at:

Crabtree Kittle house
11 Kittle Road, Chappaqua, New York 10514
+1 914 666 8044

Travel Information


There are trains from New York city to Mt Kisco. You can take a Metro North Harlem Line train from either Grand Central Station or Harlem 125th Street Metro North Train Station in New York City.
The Metro North Harlem Line train to Mt Kisco costs about $10-15 depending on off-peak or peak times and takes about 50 minutes. Make sure you take a train with a destination of "Wassaic" or "Southeast". Some of the trains from NYC terminate at "North White Plains", and do not reach Mt Kisco. One can then get a cab from Mt Kisco Train station to the hotel for about $6-$8.

Driving to IBM

Driving directions can be found at:

The official address of the IBM T. J. Watson Research Center is:
1101 Kitchawan Rd, Yorktown Heights, NY 10598

NOTE: This address will likely not work in a GPS. The above webpage states: 'If you are using a GPS system, please enter "200 Aqueduct Road, Ossining NY" for accurate directions to the lab entrance.'
The IBM Main entrance is opposite this address.

You will need to talk to security at the main gate and state that you are attending a workshop in the auditorium, then drive up to the visitor parking lot in front of the lobby. The auditorium is right behind the lobby.


The closest airport to the Holiday Inn Mt Kisco is the Westchester County/White Plains airport (code: HPN). However, this only has nonstop flights from/to Atlanta and Chicago, which are also more expensive than flights to the major NYC airports. This is airport has very short check-in/security lines and is a $60 (30 minute) cab ride away from the hotel.

Besides HPN, La Guardia Airport (LGA) is the closest (45 minute drive), and then JFK (1:15 minute drive) and Newark (EWR, 1:20 minute drive).

The fastest way to get to/from La Guardia besides driving is to take a cab from La Guardia to the Harlem 125th Street Metro North Train Station (roughly $30-$35), and then take a train on the Metro North Harlem Line. You can also take public buses (M60) from La Guardia to Harlem 125th street; please see the NYC transit pages for details on how to pay.

From JFK, one can either take public transit to Grand Central Station (1 hr) and then a Harlem Line train to Mt Kisco (1 hr), or a taxi to the Harlem Metro North Station for a flat rate of roughly $53-$58 plus tip, and then the Harlem Line train.

Uber fares from JFK to Mt Kisco are about $100-$110. Taxi fares are likely to be closer to $150. Uber fares from La Guardia to Mt Kisco are about $80, and taxi fares are likely to be $120.