Hybridization of Constraint Programming for Scheduling Problems with Complex Criteria (Ph.D.)

Czech Technical University in Prague, Czech

Updated: 3 months ago
Job Type: FullTime
Deadline: 30 Apr 2024

8 Feb 2024
Job Information
Organisation/Company

Czech Technical University in Prague
Research Field

Computer science » Informatics
Mathematics » Algorithms
Researcher Profile

First Stage Researcher (R1)
Country

Czech Republic
Application Deadline

30 Apr 2024 - 23:45 (Europe/Prague)
Type of Contract

Temporary
Job Status

Full-time
Hours Per Week

40
Offer Starting Date

1 Jul 2024
Is the job funded through the EU Research Framework Programme?

H2020
Is the Job related to staff position within a Research Infrastructure?

No

Offer Description

Today, Large Neighborhood Search (LNS) [PER] is the preferred heuristic algorithm in solvers like CP Optimizer, Google OR-Tools, or OptalCP, as it offers a better ability to escape local optima and higher diversity in the exploration than previously often used Local Search. At the same time, Failure-Directed Search (FDS) [VIL] is used to efficiently explore the whole search space using a Fail-First principle to prove that no solution or better solution than the one found so far exists.

Nevertheless, CP solvers are less efficient when a criterion is more complex than, e.g., makespan minimization in scheduling.

 

But any algorithm that quickly provides a good solution, even without optimality guarantees, can be used inside the CP solver in the same way as LNS. The objective values of found solutions can be used as bounds (hard constraints on objective value), limiting the search space for the FDS. Thus, the better the provided solution is, the faster FDS explores the whole solution space.

 

This opens up research areas like a hybridization of problem-oriented heuristics and CP solvers that can lead to better performance while sharing the objective value and no-goods among heuristics and CP workers. We expect to explore utilizing machine learning (ML) in search algorithms, such as guiding search branching. Due to our collaboration with Petr Vilím, OptalCP [OPT] developer, we expect to exchange more information between the heuristic and the solver during the algorithm run.

 

About the group: The Industrial Informatics Department, led by Zdenek Hanzalek, is oriented towards scheduling, combinatorial optimization, and automated cars.  The group has strong collaboration with high-tech companies (Porsche Engineering Services, EATON, Skoda Auto, ST Microelectronics, CEZ, Volkswagen, PPL, …).

 

[PER] L. Perron, P. Shaw, V. Furnon, Propagation guided large neighborhood search, in: M. Wallace (Ed.), Principles and Practice of Constraint Programming – CP 2004, Springer Berlin Heidelberg, Berlin, Heidelberg, 2004, pp. 468–481.

[OPT] ScheduleOpt: OptalCP’s solver landing page (2023). URL https://scheduleopt.com/

[VIL ]P. Vilím, P. Laborie, P. Shaw, Failure-directed search for constraint-based scheduling, in: International Conference on Integration of Constraint Programming, Artificial Intelligence, and Operations Research,
Springer, 2015, pp. 437–453.


Requirements
Research Field
Computer science » Informatics
Education Level
Master Degree or equivalent

Skills/Qualifications
  • Motivation to perform excellent research, become part of the world's research communities in your field, and publish in first-tier scientific conferences and journals,
  • MSc degree or equivalent (awarded or to be completed soon) in informatics, operations research or a related field, 
  • Proficiency in spoken/written English (knowledge of the Czech language is not required).

Specific Requirements
  • Good background in scheduling, combinatorial optimization and algorithm design/implementation.

Languages
ENGLISH
Level
Excellent

Additional Information
Benefits
  • An initial appointment for 1 year (with an extension of up to 4 years, based on annual performance evaluation),
  • Full waiver of tuition fees, 
  • Net compensation of about 1,600 EUR monthly (includes salary and student stipends) plus publication bonuses; check the Numbeo database for the cost of living in Prague,
  • Full social and health insurance.
  • 30 days of paid annual leave.
  • An informal and inclusive international working environment at the Industrial Informatics Department, CIIRC , CTU in Prague.

Selection process

Interested candidates are invited to submit their applications at:

https://forms.gle/Q7Rxn4R4NZFyWZuY7 [using PhD Position ID: 01-PhD-Hanzalek]


Work Location(s)
Number of offers available
1
Company/Institute
Czech Technical University in Prague
Country
Czech Republic
Geofield


Where to apply
Website

https://forms.gle/Q7Rxn4R4NZFyWZuY7

Contact
State/Province

Czech Republic
City

Prague
Website

https://www.ciirc.cvut.cz/cs/roboprox/
Street

Jugoslávských partyzánů 1580/3
Postal Code

16000
E-Mail

[email protected]

STATUS: EXPIRED

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