Sorting Omega Networks Simulated with P Systems: Optimal Data Layouts

The paper introduces some sorting networks and their simulation with P systems, in which each processor/membrane can hold more than one piece of data, and perform operations on them internally. Several data layouts are discussed in this context, and an optimal one is proposed, together with its implementation as a P system with dynamic communication graphs

A Lower Bound Technique for Communication in BSP

Communication is a major factor determining the performance of algorithms on current computing systems; it is therefore valuable to provide tight lower bounds on the communication complexity of computations. This paper presents a lower bound technique for the communication complexity in the bulk-synchronous parallel (BSP) model of a given class of DAG computations. The derived bound is expressed in terms of the switching potential of a DAG, that is, the number of permutations that the DAG can realize when viewed as a switching network. The proposed technique yields tight lower bounds for the fast Fourier transform (FFT), and for any sorting and permutation network. A stronger bound is also derived for the periodic balanced sorting network, by applying this technique to suitable subnetworks. Finally, we demonstrate that the switching potential captures communication requirements even in computational models different from BSP, such as the I/O model and the LPRAM

Overlapping Community Detection in Networks: the State of the Art and Comparative Study

This paper reviews the state of the art in overlapping community detection algorithms, quality measures, and benchmarks. A thorough comparison of different algorithms (a total of fourteen) is provided. In addition to community level evaluation, we propose a framework for evaluating algorithms' ability to detect overlapping nodes, which helps to assess over-detection and under-detection. After considering community level detection performance measured by Normalized Mutual Information, the Omega index, and node level detection performance measured by F-score, we reached the following conclusions. For low overlapping density networks, SLPA, OSLOM, Game and COPRA offer better performance than the other tested algorithms. For networks with high overlapping density and high overlapping diversity, both SLPA and Game provide relatively stable performance. However, test results also suggest that the detection in such networks is still not yet fully resolved. A common feature observed by various algorithms in real-world networks is the relatively small fraction of overlapping nodes (typically less than 30%), each of which belongs to only 2 or 3 communities.Comment: This paper (final version) is accepted in 2012. ACM Computing Surveys, vol. 45, no. 4, 2013 (In press) Contact: [email protected]

Spiking Neural P Systems – A Natural Model for Sorting Networks

This paper proposes two simulations of sorting networks with spiking neural P systems. A comparison between different models is also made

Analyze Large Multidimensional Datasets Using Algebraic Topology

This paper presents an efficient algorithm to extract knowledge from high-dimensionality, high- complexity datasets using algebraic topology, namely simplicial complexes. Based on concept of isomorphism of relations, our method turn a relational table into a geometric object (a simplicial complex is a polyhedron). So, conceptually association rule searching is turned into a geometric traversal problem. By leveraging on the core concepts behind Simplicial Complex, we use a new technique (in computer science) that improves the performance over existing methods and uses far less memory. It was designed and developed with a strong emphasis on scalability, reliability, and extensibility. This paper also investigate the possibility of Hadoop integration and the challenges that come with the framework

Modeling of Topologies of Interconnection Networks based on Multidimensional Multiplicity

Modern SoCs are becoming more complex with the integration of heterogeneous components (IPs). For this purpose, a high performance interconnection medium is required to handle the complexity. Hence NoCs come into play enabling the integration of more IPs into the SoC with increased performance. These NoCs are based on the concept of Interconnection networks used to connect parallel machines. In response to the MARTE RFP of the OMG, a notation of multidimensional multiplicity has been proposed which permits to model repetitive structures and topologies. This report presents a modeling methodology based on this notation that can be used to model a family of Interconnection Networks called Delta Networks which in turn can be used for the construction of NoCs

Neural networks optimization through genetic algorithm searches: A review

Neural networks and genetic algorithms are the two sophisticated machine learning techniques presently attracting attention from scientists, engineers, and statisticians, among others. They have gained popularity in recent years. This paper presents a state of the art review of the research conducted on the optimization of neural networks through genetic algorithm searches. Optimization is aimed toward deviating from the limitations attributed to neural networks in order to solve complex and challenging problems. We provide an analysis and synthesis of the research published in this area according to the application domain, neural network design issues using genetic algorithms, types of neural networks and optimal values of genetic algorithm operators (population size, crossover rate and mutation rate). This study may provide a proper guide for novice as well as expert researchers in the design of evolutionary neural networks helping them choose suitable values of genetic algorithm operators for applications in a specific problem domain. Further research direction, which has not received much attention from scholars, is unveiled

Design of regenerative supply networks

The strategy of environmental impact minimisation has not been effective enough to revert the damage caused to the environment by production systems; a shift is needed towards promoting environmental benefits. These production systems must also cope with disturbances, while ensuring that their function is fulfilled - a capability known as Resilience - to deploy environmental benefits in the long term. Initiatives in the field of Supply Network Design - a specific type of production system - have focused on improving eco-efficiency, proposing eco-effective networks, or enhancing their Resilience. However, it could not be found in the literature any initiative that merge these three approaches, with a focus on environmental regeneration. This thesis aims to contribute in this direction, proposing a procedure to design supply networks that regenerate the environment as it simultaneously fulfil its function. This procedure is approached as an artefact, and Design Science Research Methodology (DSRM) is used for its development. The scientific progress of Sustainable Design (SD) in the context of Operations Management (OM) is mapped through a holistic literature review, based in the ProKnow-C - a methodology to perform bibliometrics and systemic analysis. The Regenerative Supply Network is characterised through the concepts of transdisciplinarity, eco-effectiveness, eco-efficiency and resilience. A definition for the RSND process is proposed, and the RSND procedure is designed, consisting of four stages: (i) description of the network surroundings and identification of a regenerative purpose; (ii) redesign of outputs, inputs and transformation processes; (iii) system conceptualisation, where interactions are depicted using the SocioTechnical and the Socio-Ecological System views, and resilience principles are addressed. (iv), the network environmental and economic performance are optimised, and resilience is quantitatively checked using the Ecosystem Network Analysis. The activities of Demonstration and Evaluation are described in Chapter Four, where the RSND procedure is used to design a household waste management network which regenerates the environment. The regenerative purpose was identified after scrutiny of the Norte Pioneiro region. Twenty-three sites degraded from improper waste disposal were identified; the primary purpose of the waste management network is to regenerate these sites into solar farms, recreational parks or reforested areas. Inputs are identified and outputs are redefined, according to waste recovery options of recyclables sorting, aerobic composting, anaerobic digestion and gasification. Two models were developed: first, a system dynamics model to forecast waste generation, disposal and collection for a 21-year period (2018-2038). Second, a Multi-Scenario, Multi-Period, Multi-Objective, Mixed Integer Linear Programming (MS-MP-MO-MILP) model was developed to solve the capacitated facility location-allocation problem, producing network configurations through two optimisation strategies: maximisation of profit and maximisation of net greenhouse gas (GHG) savings. Economic, environmental and social performance of the solutions obtained for each of the four scenarios are presented and discussed. The main contribution of this research is to show the potential of supply networks to contribute with the regeneration of ecosystems inthe long term, with a sustainable performance in the three dimensions. Limitations and future research are also presented.Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)A estratégia de minimização de impactos ambientais não tem sido efetiva suficiente para reverter os danos causados ao meio ambiente por sistemas de produção. É necessário ir além, maximizando os benefícios e engajando-se ativamente na regeneração de ecossistemas degradados. Estes sistemas de produção também devem ser capazes de se adaptar a distúrbios, garantindo o cumprimento da sua função - habilidade denominada de Resiliência - e a manutenção destes benefícios ambientais no longo prazo. Iniciativas voltadas para o projeto de redes de fornecimento - um tipo específico de sistemas de produção - tem focado em melhorar sua eco eficiência, propor definições mais eco-efetivas para estas redes, ou melhorar sua Resiliência. No entanto, nenhuma iniciativa que conjugue estas três abordagens, com enfoque em regeneração ambiental, pode ser encontrada na literatura. Esta tese tem como objetivo contribuir nesta direção, propondo um procedimento para a realização de projeto de redes de fornecimento que promovam a regeneração do meio ambiente enquanto cumprem sua função operacional. Este procedimento foi elaborado utilizando a metodologia de Design Science Research (DSRM). O progresso científico do Projeto Sustentável no contexto da Gestão de Operações foi mapeado em uma revisão de literatura realizada utilizando-se a metodologia ProKnow-C. A Rede de Fornecimento Regenerativa é caracterizada, e o processo de Projeto de Redes de Fornecimento Regenerativas (PRFR) é definido a partir dos conceitos de Redes de Fornecimento Sustentáveis, Projeto de Cadeias de Fornecimento, Abordagem Sistêmica e Projeto Regenerativo. O procedimento PRFR é definido em quatro etapas: (i) descrever os entornos da rede e identificar um propósito regenerativo; (ii) reprojetar as saídas, entradas e processos de transformação; (iii) executar o projeto conceitual do sistema, onde as interações são decompostas, e princípios de resiliência são adotados. No quarto estágio, o desempenho da rede é otimizado, e a resiliência é quantificada e verificada por meio do Ecosystem Network Analysis. O procedimento PRFR é utilizado para projetar uma rede de gestão de resíduos domésticos, cuja função de dar disposição aos resíduos é cumprida, enquanto o meio ambiente é regenerado. O propósito de regeneração é identificado após escrutínio da região do Norte Pioneiro, Paraná. Vinte e três áreas degradadas por descarte inadequado de resíduos foram identificadas; o propósito regenerativo da rede é recuperar estas áreas. Entradas são identificadas e saídas redefinidas, de acordo com os processos de recuperação: seleção, compostagem aeróbica, digestão anaeróbica e gaseificação. Um modelo de sistema dinâmico que prevê o volume de resíduos gerados, descartados e coletados para um período de vinte e um anos (2018-2038) e um modelo de programação linear multi-cenário, multi-período, multiobjetivo, inteira mista (MC-MP-MO-PLIM) foram desenvolvidos, produzindo configurações para a rede por meio da maximização do lucro e da economia líquida na emissão de gases de efeito estufa. Os desempenhos econômico, ambiental e social das soluções obtidas para os quatro cenários são apresentados e discutidos. A principal contribuição desta pesquisa é demonstrar o potencial que redes de fornecimento possuem de regenerar ecossistemas no longoprazo, apresentando um desempenho sustentável nas dimensões econômica, ambiental e social. Limitações e pesquisas futuras também são apresentadas