Professor Adam Letchford

Professor of Analytics and Optimisation

Research Overview

My research is in optimisation, i.e., finding the best solution to problems that have a huge (possibly infinite) number of solutions. Optimisation is an inter-disciplinary subject, lying at the interface between Operational Research, Computer Science, Applied Mathematics and Engineering. I concentrate mainly on methods for solving optimisation problems to proven optimality, rather than heuristic methods. I have a particular interest in combinatorial optimisation problems, i.e., problems in which variables are restricted to take integer (whole-number) values.

Newsvendor Problems
01/01/2020 → 31/12/2022
Research

STORi: Route optimisation for waste collection
01/10/2019 → 31/03/2023
Research

The 2013 Newton Institute Programme on Polynomial Optimisation
15/07/2013 → 09/08/2013
Other

Mixed-Integer Nonlinear Programming
01/10/2009 → …
Research

Fellowship: The Cut Polytope and Related Convex Bodies
01/08/2006 → 31/07/2011
Research

Algorithms for Vehicle Routing Problems
01/01/2003 → …
Research

Algorithms for the Travelling Salesman Problem
01/01/1999 → …
Research

Cutting-Plane Approaches to Integer Programming
01/01/1997 → …
Research

Integer Programming and Combinatorial Optimisation
01/01/1900 → …
Research

36th Conference of the European Chapter on Combinatorial Optimization
Participation in conference - Academic

4th Joint IMA/ORS Conference on the Mathematics of Operational Research
Participation in conference -Mixed Audience

4th Joint IMA/ORS Conference on the Mathematics of Operational Research
Participation in conference -Mixed Audience

4th Joint IMA/ORS Conference on the Mathematics of Operational Research
Participation in conference -Mixed Audience

A new approach to quadratic unconstrained binary optimisation
Invited talk

Insertion heuristics for a class of dynamic vehicle routing problems
Invited talk

Insertion heuristics for a class of dynamic vehicle routing problems
Invited talk

University of L'Aquila
Visiting an external academic institution

Improving a constructive heuristic for the general routing problem
Invited talk

2022 International Conference on Optimization and Decision Science (ODS 2022)
Participation in conference - Academic

4th Workshop on Arc Routing Problems
Participation in conference - Academic

2022 STOR-i Workshop on Prediction and Optimisation
Participation in conference -Mixed Audience

34th Conference of the European Chapter on Combinatorial Optimization (ECCO XXXIV)
Participation in conference - Academic

3rd IMA/ORS Conference on the Mathematics of Operational Research
Participation in conference -Mixed Audience

34th Annual Conference of the Belgian Operational Research Society (ORBEL34)
Participation in conference - Academic

61st Annual Conference of the Operational Research Society (OR61)
Participation in conference -Mixed Audience

30th European Conference on Operational Research (EURO XXX)
Participation in conference - Academic

2nd Joint IMA/ORS Conference on the Mathematics of Operational Research
Participation in conference -Mixed Audience

University of Pisa
Visiting an external academic institution

60th Annual Conference of the Operational Research Society (OR60)
Participation in conference -Mixed Audience

23rd International Symposium on Mathematical Programming (ISMP XXIII)
Participation in conference - Academic

23rd International Symposium on Mathematical Programming (ISMP XXIII)
Participation in conference - Academic

5th International Symposium on Combinatorial Optimization (ISCO)
Participation in conference - Academic

5th International Symposium on Combinatorial Optimization (ISCO)
Participation in conference - Academic

1st Joint IMA/ORS Conference on the Mathematics of Operational Research
Participation in conference -Mixed Audience

Bit representations of mixed-integer quadratic programs
Invited talk

20th Combinatorial Optimisation Conference (CO2016)
Participation in conference - Academic

4th International Symposium on Combinatorial Optimization (ISCO)
Participation in conference - Academic

20th Combinatorial Optimisation Conference (CO2016)
Participation in conference - Academic

27th European Conference on Operational Research (EURO XXVII)
Participation in conference - Academic

17th British-French-German Optimisation Conference (BFG 2015)
Participation in conference - Academic

An introduction to approximation algorithms (and inapproximability)
Invited talk

Mathematical Programming (Journal)
Editorial activity

Stronger multi-commodity flow formulations of the capacitated vehicle routing problem
Invited talk

LANCS International Workshop on Discrete and Nonlinear Optimisation
Participation in conference -Mixed Audience

Some unbounded convex sets arising in non-convex MIQP
Invited talk

Strengthening the reformulation-linearisation technique with cutting planes
Invited talk

18th Combinatorial Optimisation Conference (CO2012)
Participation in conference - Academic

25th European Conference on Operational Research (EURO XXV)
Participation in conference - Academic

25th European Conference on Operational Research (EURO XXV)
Participation in conference - Academic

10th International Conference on Applied Mathematical Optimization and Modelling (APMOD 2012)
Participation in conference - Academic

Second order cone programming and its applications
Invited talk

25th European Conference on Operational Research (EURO XXV)
Participation in conference - Academic

21st International Symposium on Mathematical Programming (ISMP)
Participation in conference - Academic

Operations Research (Journal)
Editorial activity

EURO Journal on Computational Optimization (Journal)
Editorial activity

10th International Conference on Applied Mathematical Optimization and Modelling (APMOD 2012)
Participation in conference - Academic

8th Mixed-Integer Programming Workshop (MIP 2011)
Participation in conference - Academic

SIAM Conference on Optimization
Participation in conference - Academic

LANCS Workshop on Modelling and Solving Complex Optimisation Problems
Participation in conference -Mixed Audience

Reformulating mixed-integer quadratically-constrained quadratic programmes
Invited talk

Convex relaxations of the stable set problem
Invited talk

A tutorial on mixed-integer non-linear programming
Invited talk

Mixed-integer non-linear programming: a survey
Invited talk

Reformulation of 0-1 quadratically constrained quadratic programs
Invited talk

An introduction to second-order cone programming
Invited talk

London School of Economics
Visiting an external academic institution

14th Conference on Integer Programming and Combinatorial Optimization (IPCO XIV)
Participation in conference - Academic

2010 Joint ECCO-CO Conference
Participation in conference - Academic

Optimisation over cones
Invited talk

The Travelling Salesman Problem
Invited talk

2nd LANCS Workshop on Discrete and Nonlinear Optimisation
Participation in conference -Mixed Audience

2nd LANCS Workshop in Heuristic Understanding
Participation in conference -Mixed Audience

2010 Joint ECCO-CO Conference
Participation in conference - Academic

Algorithmic Aspects in Information and Management
Participation in conference - Academic

51st Annual Conference of the Operational Research Society (OR51)
Participation in conference -Mixed Audience

23rd European Conference on Operational Research (EURO XXIII)
Participation in conference - Academic

Fifty years of cutting planes
Invited talk

On non-convex quadratic programming with box constraints
Invited talk

4th International Network Optimization Conference (INOC 2009)
Participation in conference - Academic

1st Student Conference on Operational Research
Participation in conference - Academic

1st LANCS Workshop on Discrete and Nonlinear Optimisation
Participation in conference -Mixed Audience

4th International Network Optimization Conference (INOC 2009)
Participation in conference - Academic

Recent progress on knapsack-based cutting planes
Invited talk

23rd European Conference on Operational Research (EURO XXIII)
Participation in conference - Academic

51st Annual Conference of the Operational Research Society (OR51)
Participation in conference -Mixed Audience

Discrete Optimization (Journal)
Editorial activity

Bonn Workshop on Combinatorial Optimisation
Participation in conference - Academic

Binary positive semidefinite matrices and some related polytopes
Invited talk

Mixed-Integer Programming Workshop (MIP 2008)
Participation in conference - Academic

13th Conference on Integer Programming and Combinatorial Optimization (IPCO XIII)
Participation in conference - Academic

15th Combinatorial Optimisation Conference (CO2008)
Participation in conference - Academic

12th Aussois Workshop on Combinatorial Optimisation
Participation in conference - Academic

Mathematical Programming Computation (Journal)
Editorial activity

Discrete Applied Mathematics (Journal)
Editorial activity

2nd INFORMS Optimization Society Conference (2008)
Participation in conference - Academic

ALIO/EURO Conference on Combinatorial Optimization
Participation in conference - Academic

An introduction to conic programming
Invited talk

Optimization 2007
Participation in conference - Academic

3rd International Network Optimization Conference (INOC 2007)
Participation in conference - Academic

Stronger upper bounds for the maximum stable set problem
Invited talk

Discrete Optimization (Journal)
Editorial activity

Semidefinite programming and combinatorial optimization
Invited talk

21st European Conference on Operational Research (EURO XXI)
Participation in conference - Academic

Canadian Operational Research Society Annual Conference (CORS)
Participation in conference - Academic

Spring School on Vehicle Routing
Participation in conference - Academic

Algorithms for planar graphs
Invited talk

Journées de l'Optimisation 2005
Participation in conference - Academic

Vehicle routing games
Invited talk

Planar graphs and the traveling salesman problem
Invited talk

Solving discrete optimization problems by branch-and-cut
Invited talk

Vehicle routing games
Invited talk

Computational Optimization and Applications (Journal)
Editorial activity

11th Conference on Integer Programming and Combinatorial Optimization (IPCO XI)
Participation in conference - Academic

Mixed-Integer Programming Workshop
Participation in conference - Academic

Exploring the relationship between max-cut and stable set relaxations
Invited talk

The traveling salesman problem: inequalities and separation
Invited talk

Bertinoro Workshop on Combinatorial Optimisation
Participation in conference - Academic

The traveling salesman problem: inequalities and separation
Invited talk

Solving discrete optimization problems by branch-and-cut
Invited talk

13th Combinatorial Optimisation Conference (CO2004)
Participation in conference - Academic

8th Aussois Workshop on Combinatorial Optimisation
Participation in conference - Academic

13th Combinatorial Optimisation Conference (CO2004)
Participation in conference - Academic

The traveling salesman problem: inequalities and separation
Invited talk

The traveling salesman problem: inequalities and separation
Invited talk

Solving discrete optimization problems by branch-and-cut
Invited talk

34th Annual Conference of the Italian Operational Research Society (AIRO)
Participation in conference - Academic

18th International Symposium on Mathematical Programming (ISMP 2003)
Participation in conference - Academic

Solving discrete optimisation problems by branch-and-cut
Invited talk

2nd Conference on Routing and Location (CORAL)
Participation in conference - Academic

On traveling salesman games
Invited talk

Mathematical Programming (Journal)
Editorial activity

16th Conference of the International Federation of Operational Research Societies (IFORS)
Participation in conference - Academic

Integer Programming Conference in Honor of Egon Balas
Participation in conference - Academic

9th Conference in Integer Programming and Combinatorial Optimization (IPCO IX)
Participation in conference - Academic

6th Aussois Workshop on Combinatorial Optimisation
Participation in conference - Academic

15th Annual Conference of the Italian Operational Research Society (AIRO)
Participation in conference - Academic

Primal separation algorithms
Invited talk

5th Aussois Workshop on Combinatorial Optimization
Participation in conference - Academic

Associazione Italiana di Ricerca Operativa (External organisation)
Member of an organisation

17th International Symposium on Mathematical Programming (ISMP)
Participation in conference - Academic

12th Combinatorial Optimisation Conference (CO2000)
Participation in conference - Academic

4th Aussois Workshop on Combinatorial Optimisation
Participation in conference - Academic

The Operational Research Society (External organisation)
Member of an organisation

The polyhedral approach to the TSP
Invited talk

Symposium on Operations Research
Participation in conference - Academic

7th Conference on Integer Programming and Combinatorial Optimization (IPCO VII)
Participation in conference - Academic

3rd Aussois Workshop on Combinatorial Optimization
Participation in conference - Academic

Oberwolfach Workshop on Combinatorial Optimisation
Participation in conference - Academic

11th Combinatorial Optimisation Conference (CO98)
Participation in conference - Academic

2nd Aussois Workshop on Combinatorial Optimisation
Participation in conference - Academic

10th Combinatorial Optimisation Conference (CO96)
Participation in conference - Academic

37th Annual Conference of the Operational Research Society (OR37)
Participation in conference -Mixed Audience

Fellow of the Operational Research Society (FORS)
Fellowship awarded competitively

Recipient of IBM Faculty Award
Prize (including medals and awards)

  • Centre for Transport & Logistics (CENTRAL)
  • DSI - Foundations
  • Optimisation
  • STOR-i Centre for Doctoral Training