62 research outputs found
Using MapReduce Streaming for Distributed Life Simulation on the Cloud
Distributed software simulations are indispensable in the study of large-scale life models but often require the use of technically complex lower-level distributed computing frameworks, such as MPI. We propose to overcome the complexity challenge by applying the emerging MapReduce (MR) model to distributed life simulations and by running such simulations on the cloud. Technically, we design optimized MR streaming algorithms for discrete and continuous versions of Conway’s life according to a general MR streaming pattern. We chose life because it is simple enough as a testbed for MR’s applicability to a-life simulations and general enough to make our results applicable to various lattice-based a-life models. We implement and empirically evaluate our algorithms’ performance on Amazon’s Elastic MR cloud. Our experiments demonstrate that a single MR optimization technique called strip partitioning can reduce the execution time of continuous life simulations by 64%. To the best of our knowledge, we are the first to propose and evaluate MR streaming algorithms for lattice-based simulations. Our algorithms can serve as prototypes in the development of novel MR simulation algorithms for large-scale lattice-based a-life models.https://digitalcommons.chapman.edu/scs_books/1014/thumbnail.jp
Structural damage monitoring based on machine learning and bio-inspired computing
For a few decades, systems for supervising structures have become increasingly irnportant. In origin, the strategies had as a goal only the detection of damages. Furthermore, now monitoring the civil or military structures permanently and offering sufficient and relevant information helping make the right decisions. The SHM is applicable, carrying out preventive or corrective maintenance decisions, reducing the possibility of accidents, and promoting the reduction of costs that more extensive repairs imply when the damage is detected early. The current work focused on three elements of diagnosis of structural damage: detection, classification, and location, either in metaltic or cornposite material structures, given their wide use in air, land, rnaritime transport vehicles, aerospace, wind turbines, civil and military infrastructure. This work used the tools offered by machine leaming and bio-inspired computing. Given the right results to solve complex problems and recognizing pattems. It also involves changes in temperature since it is one of the parameters that influence real environments' structures. Information of a statistical nature applied to recognizing pattems and reducing the size of the information was used with tools such as PCA (principal component analysis), thanks to the experience obtained in works developed by the CoDAlab research group. The document is divided into five parts. The first includes a general description of the problem, the objecti.-es, and the results obtained, in addition to a brief theoretical introduction. Chapters 2, 3, and 4 include articles published in different joumals. Chapter 5 shows the results and conclusions. Other contributions, such as a book chapter and sorne papers presented at conferences, are included in appendix A. Finally, appendix B presents a multiplexing system used to develop the experiments carried out in this work.Desde hace algunas décadas los sistemas para supervisar estructuras han tenido cada vez más relevancia. En esta evolución se ha pasado de estrategias que tenían como meta sólo la detección de fallas a otras que buscan monitorizar permanentemente las estructuras bien sean éstas civiles o militares, ofreciendo información suficiente y pertinente que incide positivamente en el momento de tomar buenas decisiones, dentro de las cuales cabe destacar por ejemplo, las orientadas a realizar mantenimientos preventivos o correctivos si es del caso, reduciendo la posibilidad de accidentes, además de propiciar la disminución de costos que implican las reparaciones más extensas cuando el daño se logra detectar de manera temprana. El presente trabajo se enfocó en tres elementos de diagnóstico de daños en estructuras, siendo estos en particular la detección, clasificación y localización, bien sea en estructuras metálicas o de material compuesto, dado su amplio uso en vehículos de transporte aéreo, terrestre, marítimo, aeroespacial, aerogeneradores, infraestructura civil y militar. Se utilizaron las herramientas que ofrecen el aprendizaje automático (machine leaming) y la computación bio-inspirada, dados los buenos resultados que han ofrecido en la solución de problemas complejos y el reconocimiento de patrones. Involucrando cambios de temperatura dado que es uno de los parámetros a los que se ven enfrentadas las estructuras en ambientes reales. Se utilizó información de naturaleza estadística aplicada al reconocimiento de patrones y reducción del tamaño de la información con herramientas como el PCA (análisis de componentes principales), gracias a la experiencia lograda en trabajos desarrollados por el grupo de investigación CoDAlab. El documento está dividido en cinco capítulos. En el primerio se incluye una descripción general del problema, los objetivos y los resultados obtenidos, además de un breve introducción teórica. Los Capítulos 2,3 y 4 incluyen los artículos publicados en diferentes revistas. En el Capítulo 5 se realiza una presentación de los resultados y conclusiones. En el Anexo A se incluyen otras contribuciones tales como un capítulo de libro y algunos trabajos presentados en conferencias. Finalmente en el anexo B se presenta el diseño de un sistema de multipliexación utilizado en el desarrollo de los experimentos realizados en el presente trabajo.Postprint (published version
An Embryonics Inspired Architecture for Resilient Decentralised Cloud Service Delivery
Data-driven artificial intelligence applications arising from Internet of Things technologies can have
profound wide-reaching societal benefits at the cross-section of the cyber and physical domains. Usecases are expanding rapidly. For example, smart-homes and smart-buildings provide intelligent monitoring, resource optimisation, safety, and security for their inhabitants. Smart cities can manage
transport, waste, energy, and crime on large scales. Whilst smart-manufacturing can autonomously
produce goods through the self-management of factories and logistics. As these use-cases expand further, the requirement to ensure data is processed accurately and timely is ever crucial, as many of these
applications are safety critical. Where loss off life and economic damage is a likely possibility in the
event of system failure. While the typical service delivery paradigm, cloud computing, is strong due
to operating upon economies of scale, their physical proximity to these applications creates network
latency which is incompatible with these safety critical applications. To complicate matters further,
the environments they operate in are becoming increasingly hostile. With resource-constrained and
mobile wireless networking, commonplace. These issues drive the need for new service delivery architectures which operate closer to, or even upon, the network devices, sensors and actuators which
compose these IoT applications at the network edge. These hostile and resource constrained environments require adaptation of traditional cloud service delivery models to these decentralised mobile
and wireless environments. Such architectures need to provide persistent service delivery within the
face of a variety of internal and external changes or: resilient decentralised cloud service delivery.
While the current state of the art proposes numerous techniques to enhance the resilience of services
in this manner, none provide an architecture which is capable of providing data processing services in
a cloud manner which is inherently resilient. Adopting techniques from autonomic computing, whose
characteristics are resilient by nature, this thesis presents a biologically-inspired platform modelled
on embryonics. Embryonic systems have an ability to self-heal and self-organise whilst showing capacity to support decentralised data processing. An initial model for embryonics-inspired resilient
decentralised cloud service delivery is derived according to both the decentralised cloud, and resilience
requirements given for this work. Next, this model is simulated using cellular automata, which illustrate the embryonic concept’s ability to provide self-healing service delivery under varying system
component loss. This highlights optimisation techniques, including: application complexity bounds,
differentiation optimisation, self-healing aggression, and varying system starting conditions. All attributes of which can be adjusted to vary the resilience performance of the system depending upon
different resource capabilities and environmental hostilities.
Next, a proof-of-concept implementation is developed and validated which illustrates the efficacy
of the solution. This proof-of-concept is evaluated on a larger scale where batches of tests highlighted
the different performance criteria and constraints of the system. One key finding was the considerable
quantity of redundant messages produced under successful scenarios which were helpful in terms of
enabling resilience yet could increase network contention. Therefore balancing these attributes are
important according to use-case. Finally, graph-based resilience algorithms were executed across
all tests to understand the structural resilience of the system and whether this enabled suitable
measurements or prediction of the application’s resilience. Interestingly this study highlighted that
although the system was not considered to be structurally resilient, the applications were still being
executed in the face of many continued component failures. This highlighted that the autonomic
embryonic functionality developed was succeeding in executing applications resiliently. Illustrating
that structural and application resilience do not necessarily coincide. Additionally, one graph metric,
assortativity, was highlighted as being predictive of application resilience, although not structural
resilience
A metaheuristic and simheuristic approach for the p-Hub median problem from a telecommunication perspective
Tese (doutorado)—Universidade de Brasília, Faculdade de Tecnologia, Departamento de Engenharia Elétrica, 2018.Avanços recentes no setor das telecomunicações oferecem grandes oportunidades para cidadãos
e organizações em um mundo globalmente conectado, ao mesmo tempo em que surge um vasto
número de desafios complexos que os engenheiros devem enfrentar. Alguns desses desafios podem
ser modelados como problemas de otimização. Alguns exemplos incluem o problema de alocação
de recursos em redes de comunicações, desenho de topologias de rede que satisfaça determinadas
propriedades associadas a requisitos de qualidade de serviço, sobreposição de redes multicast e
outros recursos importantes para comunicação de origem a destino.
O primeiro objetivo desta tese é fornecer uma revisão sobre como as metaheurísticas têm sido
usadas até agora para lidar com os problemas de otimização associados aos sistemas de telecomunicações, detectando as principais tendências e desafios. Particularmente, a análise enfoca os
problemas de desenho, roteamento e alocação de recursos. Além disso, devido á natureza desses
desafios, o presente trabalho discute como a hibridização de metaheurísticas com metodologias
como simulação pode ser empregada para ampliar as capacidades das metaheurísticas na resolução
de problemas de otimização estocásticos na indústria de telecomunicações.
Logo, é analisado um problema de otimização com aplicações práticas para redes de telecomunica
ções: o problema das p medianas não capacitado em que um número fixo de hubs tem
capacidade ilimitada, cada nó não-hub é alocado para um único hub e o número de hubs é conhecido
de antemão, sendo analisado em cenários determinísticos e estocásticos. Dada a sua variedade
e importância prática, o problema das p medianas vem sendo aplicado e estudado em vários contextos.
Seguidamente, propõem-se dois algoritmos imune-inspirados e uma metaheurística de dois estágios, que se baseia na combinação de técnicas tendenciosas e aleatórias com uma estrutura de
busca local iterada, além de sua integração com a técnica de simulação de Monte Carlo para resolver
o problema das p medianas. Para demonstrar a eficiência dos algoritmos, uma série de testes
computacionais é realizada, utilizando instâncias de grande porte da literatura. Estes resultados
contribuem para uma compreensão mais profunda da eficácia das metaheurísticas empregadas
para resolver o problema das p medianas em redes pequenas e grandes. Por último, uma aplicaçã
o ilustrativa do problema das p medianas é apresentada, bem como alguns insights sobre novas
possibilidades para ele, estendendo a metodologia proposta para ambientes da vida real.Recent advances in the telecommunication industry o er great opportunities to citizens and
organizations in a globally-connected world, but they also arise a vast number of complex challenges
that decision makers must face. Some of these challenges can be modeled as optimization
problems. Examples include the framework of network utility maximization for resource allocation
in communication networks, nding a network topology that satis es certain properties associated
with quality of service requirements, overlay multicast networks, and other important features for
source to destination communication.
First, this thesis provides a review on how metaheuristics have been used so far to deal with
optimization problems associated with telecommunication systems, detecting the main trends and
challenges. Particularly the analysis focuses on the network design, routing, and allocation problems.
In addition, due to the nature of these challenges, this work discusses how the hybridization
of metaheuristics with methodologies such as simulation can be employed to extend the capabilities
of metaheuristics when solving stochastic optimization problems.
Then, a popular optimization problem with practical applications to the design of telecommunication
networks: the Uncapacitated Single Allocation p-Hub Median Problem (USApHMP) where
a xed number of hubs have unlimited capacity, each non-hub node is allocated to a single hub
and the number of hubs is known in advance is analyzed in deterministic and stochastic scenarios.
p-hub median problems are concerned with optimality of telecommunication and transshipment
networks, and seek to minimize the cost of transportation or establishing.
Next, two immune inspired metaheuristics are proposed to solve the USApHMP, besides that,
a two-stage metaheuristic which relies on the combination of biased-randomized techniques with
an iterated local search framework and its integration with simulation Monte Carlo technique for
solving the same problem is proposed. In order to show their e ciency, a series of computational
tests are carried out using small and large size instances from the literature. These results contribute
to a deeper understanding of the e ectiveness of the employed metaheuristics for solving
the USApHMP in small and large networks. Finally, an illustrative application of the USApHMP
is presented as well as some insights about some new possibilities for it, extending the proposed
methodology to real-life environments.Els últims avenços en la industria de les telecomunicacions ofereixen grans oportunitats per
ciutadans i organitzacions en un món globalment connectat, però a la vegada, presenten reptes als
que s'enfronten tècnics i enginyers que prenen decisions. Alguns d'aquests reptes es poden modelitzar
com problemes d'optimització. Exemples inclouen l'assignació de recursos a les xarxes de
comunicació, trobant una topologia de xarxa que satisfà certes propietats associades a requisits de
qualitat de servei, xarxes multicast superposades i altres funcions importants per a la comunicació
origen a destinació.
El primer objectiu d'aquest treball és proporcionar un revisió de la literatura sobre com s'han
utilitzat aquestes tècniques, tradicionalment, per tractar els problemes d'optimització associats a
sistemes de telecomunicació, detectant les principals tendències i desa aments. Particularment,
l'estudi es centra en els problemes de disseny de xarxes, enrutament i problemes d'assignació de
recursos. Degut a la naturalesa d'aquests problemes, aquest treball també analitza com es poden
combinar les tècniques metaheurístiques amb metodologies de simulació per ampliar les capacitats
de resoldre problemes d'optimització estocàstics.
A més, es tracta un popular problema d'optimització amb aplicacions pràctiques per xarxes de
telecomunicació, el problema de la p mediana no capacitat, analitzant-lo des d'escenaris deterministes
i estocàstics. Aquest problema consisteix en determinar el nombre d'instal lacions (medianes)
en una xarxa, minimitzant la suma de tots els costs o distàncies des d'un punt de demanda a la
instal lació més propera. En general, el problema de la p mediana està lligat amb l'optimització de
xarxes de telecomunicacions i de transport, i busquen minimitzar el cost de transport o establiment
de la xarxa.
Es proposa dos algoritmes immunològics i un algoritme metaheurístic de dues etapes basat en
la combinació de tècniques aleatòries amb simulacions Monte Carlo. L'e ciència de les algoritmes
es posa a prova mitjançant alguns dels test computacionals més utilitzats a la literatura, obtenint
uns resultats molt satisfactoris, ja que es capaç de resoldre casos petits i grans en qüestió de segons i amb un baix cost computacional. Finalment, es presenta una aplicació il lustrativa del problema
de la p mediana, així com algunes noves idees sobre aquest, que estenen la metodologia proposta
a problemes de la vida real
Feature Papers of Drones - Volume I
[EN] The present book is divided into two volumes (Volume I: articles 1–23, and Volume II: articles 24–54) which compile the articles and communications submitted to the Topical Collection ”Feature Papers of Drones” during the years 2020 to 2022 describing novel or new cutting-edge designs, developments, and/or applications of unmanned vehicles (drones). Articles 1–8 are devoted to the developments of drone design, where new concepts and modeling strategies as well as effective designs that improve drone stability and autonomy are introduced. Articles 9–16 focus on the communication aspects of drones as effective strategies for smooth deployment and efficient functioning are required. Therefore, several developments that aim to optimize performance and security are presented. In this regard, one of the most directly related topics is drone swarms, not only in terms of communication but also human-swarm interaction and their applications for science missions, surveillance, and disaster rescue operations. To conclude with the volume I related to drone improvements, articles 17–23 discusses the advancements associated with autonomous navigation, obstacle avoidance, and enhanced flight plannin
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