Today we have presented our first international paper on the scope of 5G. I have used for that my favourite metaheuristic: Ant Colony Optimization, which has been adapted to solve a problem of network service composition, i.e., the so-called Service Function Chaining.
The growth of data traffic and the demand for new services are two of the main challenges to take into account in the design of next-generation networks. Service Function Chaining (SFC) is a technique that allows the execution of advanced services, routing network traffic through an ordered list of virtual functions. This mechanism is getting great relevance due to the rise of Software-defined Networks (SDNs) and the use of Network Function Virtualization (NFV), as well as the offered possibilities in terms of flexibility and automation. Given the existing need for operators to offer low latency services in 5G networks, the composition of this chain is a critical process that affects the performance of these services. Inside this context, this paper presents the design and implementation of an Ant Colony Optimization algorithm (ACO) for the minimization of the routing cost of service chain composition. ACO is a specially designed metaheuristic to work with weighted graphs, also considering restrictions, as is the case of the addressed problem. To test the value of the implemented algorithm, two different instances have been solved. The first one (with only 6 nodes) is a proof of concept, which easily allows to analyze the obtained solutions. The second one (19 nodes) models a medium-size 5G network, and tries to show the performance of this method in a wider graph. The results show that the proposed algorithm can lead to optimal solutions in many cases, even in a short time (less than 0.5 seconds) in the largest instance, so we consider this method as a very promising solution in this field.
Last week we presented at the IEEE Conference on Game 2019, held in London (UK), our new paper titled “Beating uncertainty in racing bot evolution through enhanced exploration and pole position selection“.
The abstract of the work is:
One of the main problems in the design through optimization of car racing bots is the inherent noise in the optimization process: besides the fact that the fitness is a heuristic
based on what we think are the keys to success and as such just a surrogate for the ultimate objective, winning races, fitness itself is uncertain due to the stochastic behavior of racing conditions and the rest of the (simulated) racers. The fuzzy-based genetic controller for the car racing simulator TORCS that we have defined in previous works is based on two fuzzy subcontrollers, one for deciding on the wheel steering angle and another to set the car target speed at the next simulation tick. They are both optimized by means of an Evolutionary Algorithm, which considers an already tested fitness function focused on the maximization of the average speed during the race and the minimization of the car damage. The noisy environment asks for keeping diversity high during evolution, that is why we have added a Blend Crossover (BLX-alpha) operator, which is, besides, able to exploit current results at the same time it explores. Additionally, we try to address uncertainty in selection by introducing a novel selection policy of parents based in races, where the individuals are grouped and compete against others in several races, so just the firsts ranked will remain in the population as parents. Several experiments have been conducted, testing the value of the different controllers. The results show that the combination of a dynamic BLX-alpha crossover operator plus the pole position selection policy clearly beats the rest of approaches. Moreover, in the comparison of this controller with one of the participants of the prestigious international Simulated Car Racing Championship, our autonomous driver obtains much better results than the opponent.
The talk had two parts; the first focused on how AI is improving in performance and decreasing its energy footprint via design of specific chips, many of them based on the RISC-V open hardware architecture. The second part was mainly devoted to concurrent programming and how algorithms and whole applications must be changed to meet the challenges of creating cloud-native programs.
Our research group fully supports free software and open science, and the field of AI is ratcheting up its achievements by working on free stacks, from free hardware to the whole set of programs and services that support them. Understanding these stacks will help us design better algorithms and frameworks in the future.
El próximo día 1 de julio yo mismo (@amorag) daré una charla titulada “Inteligencia Computacional en Juegos“. :D
En la charla hablaré sobre todo tipos de juegos y puzles y las técnicas de inteligencia artificial que se suelen usar para crear o imitar comportamientos inteligentes o parecidos a los de los humanos, tanto a nivel de juegos comerciales, como en el entorno académico e investigador.
Last 24 of April we presented the work “Free Form Evolution for Angry Birds Level Generation” at EVOApplications 2019 (EvoGAMES) a conference part of EVO* 2019, held in Leipzig (Germany).
The abstract of the work is:
This paper presents an original approach for building structures that are stable under gravity for the physics-based puzzle game Angry Birds, with the ultimate objective of creating fun and aesthetically pleasing Angry Birds levels with the minimum number of constraints. This approach consists of a search-based procedural level generation method that uses evolutionary algorithms. In order to evaluate the stability of the levels, they are executed in an adaptation of an open source version of the game called Science Birds. In the same way, an open source evolutionary computation framework has been implemented to fit the requirements of the problem. The main challenge has been to design a fitness function that, first, avoids if possible the actual execution of the simulator, which is time consuming, and, then, to take into account the different ways in which a structure is not structurally sound and consider them in different ways to provide a smooth landscape that eventually achieves that soundness. Different representations and operators have been considered and studied. In order to test the method four experiments have been carried out, obtaining a variety of stable structures, which is the first path for the generation of levels that are aesthetically pleasing as well as playable.
@amorag did a short presentation and later ‘defended’ a poster during the reception act. The presentation is a description of the poster:
Actually the poster was selected as the second best of the conference by the attendants. :D