Symmetries, almost symmetries, and lazy clause generation

Chu, Geoffrey; Banda, Maria García de la; Mears, Christopher; Stuckey, Peter J.

doi:10.1007/s10601-014-9163-9

Cited by 18 publications

(19 citation statements)

References 24 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…We first compared the performance of five different state-of-the-art CP solvers, namely, Or-Tools v6.7 [24], Choco 4.0.4 [25], JaCoP [26] Gecode [27], Chuffed [28] and two Mixed Integer Programming (MIP) solvers, Gurobi [29] (one of the most performing MILP solvers [30]) and CBC [31] 5 on the optimal SFC design problem. The solvers were run on scenario with 300 nodes and different number of domains (from 3 to 30), each request was combined with 2 random domain constraints.…”

Section: Empirical Validationsmentioning

confidence: 99%

Constraint Programming for Flexible Service Function Chaining Deployment

Liu¹,

Callegati²,

Cerroni³

et al. 2019

Proceedings of the Annual Hawaii International Conference on System Sciences

View full text Add to dashboard Cite

Network Function Virtualization (NFV) and Software Defined Networking (SDN) are technologies that recently acquired a great momentum thanks to their promise of being a flexible and cost-effective solution for replacing hardware-based, vendor-dependent network middleboxes with software appliances running on general purpose hardware in the cloud. Delivering end-to-end networking services across multiple NFV/SDN network domains by implementing the so-called Service Function Chain (SFC) i.e., a sequence of Virtual Network Functions (VNF) that composes the service, is a challenging task.In this paper we address two crucial sub-problems of this task: i) the language to formalize the request of a given SFC to the network and ii) the solution of the SFC design problem, once the request is received. As for i) in our solution the request is built upon the intent-based approach, with a syntax that focuses on asking the user "what" she needs and not "how" it should be implemented, in a simple and high level language. Concerning ii) we define a formal model describing network architectures and VNF properties that is then used to solve the SFC design problem by means of Constraint Programming (CP), a programming paradigm which is often used in Artificial Intelligence applications. We argue that CP can be effectively used to address this kind of problems because it provides very expressive and flexible modeling languages which come with powerful solvers, thus providing efficient and scalable performance. We substantiate this claim by validating our tool on some typical and non trivial SFC design problems.

show abstract

Section: Empirical Validationsmentioning

confidence: 99%

Constraint Programming for Flexible Service Function Chaining Deployment

Liu¹,

Callegati²,

Cerroni³

et al. 2019

Proceedings of the Annual Hawaii International Conference on System Sciences

View full text Add to dashboard Cite

show abstract

“…More recently, constraint solvers incorporating learning have been developed, such as Chufed [6,7]. The current work can be viewed as a learning constraint solver over the class of integer diference constraints.…”

Section: Related Workmentioning

confidence: 99%

Theory learning with symmetry breaking

Howe

Robbins

King

2017

Proceedings of the 19th International Symposium on Principles and Practice of Declarative Programming

View full text Add to dashboard Cite

This paper investigates the use of a Prolog coded SMT solver in tackling a well known constraints problem, namely packing a given set of consecutive squares into a given rectangle, and details the developments in the solver that this motivates. The packing problem has a natural model in the theory of quantiier-free integer diference logic, a theory supported by many SMT solvers. The solver used in this work exploits a data structure consisting of an incremental Floyd-Warshall matrix paired with a watch matrix that monitors the entailment status of integer diference constraints. It is shown how this structure can be used to build unsatisiable theory cores on the ly, which in turn allows theory learning to be incorporated into the solver. Further, it is shown that a problem-speciic and non-standard approach to learning can be taken where symmetry breaking is incorporated into the learning stage, magnifying the efect of learning. It is argued that the declarative framework allows the solver to be used in this white box manner and is a strength of the solver. The approach is experimentally evaluated. CCS CONCEPTS· Theory of computation → Shortest paths; Packing and covering problems; · Software and its engineering → Constraint and logic languages;

show abstract

“…-publicRating a complete function A → N that associates to an activity a possible rating. 6 Ratings are represented with natural numbers: the bigger the rating, the better the activity is considered.…”

Section: Nightsplitmentioning

confidence: 99%

“…We compared the performance of three different state-of-the-art CP solvers, namely Chuffed [6], Or-Tools [11], and HCSP [13], 9 and the SA method described in the previous section.…”

Section: Empirical Experimentsmentioning

confidence: 99%

NightSplitter: A Scheduling Tool to Optimize (Sub)group Activities

Liu

Cosmo

Gabbrielli

et al. 2017

Lecture Notes in Computer Science

View full text Add to dashboard Cite

Humans are social animals and usually organize activities in groups. However, they are often willing to split temporarily a bigger group in subgroups to enhance their preferences. In this work we present NightSplitter, an on-line tool that is able to plan movie and dinner activities for a group of users, possibly splitting them in subgroups to optimally satisfy their preferences. We first model and prove that this problem is NP-complete. We then use Constraint Programming (CP) or alternatively Simulated Annealing (SA) to solve it. Empirical results show the feasibility of the approach even for big cities where hundreds of users can select among hundreds of movies and thousand of restaurants.

show abstract

Symmetries, almost symmetries, and lazy clause generation

Cited by 18 publications

References 24 publications

Constraint Programming for Flexible Service Function Chaining Deployment

Constraint Programming for Flexible Service Function Chaining Deployment

Theory learning with symmetry breaking

NightSplitter: A Scheduling Tool to Optimize (Sub)group Activities

Contact Info

Product

Resources

About