34 research outputs found

    Octree-based, GPU implementation of a continuous cellular automaton for the simulation of complex, evolving surfaces

    Get PDF
    Presently, dynamic surface-based models are required to contain increasingly larger numbers of points and to propagate them over longer time periods. For large numbers of surface points, the octree data structure can be used as a balance between low memory occupation and relatively rapid access to the stored data. For evolution rules that depend on neighborhood states, extended simulation periods can be obtained by using simplified atomistic propagation models, such as the Cellular Automata (CA). This method, however, has an intrinsic parallel updating nature and the corresponding simulations are highly inefficient when performed on classical Central Processing Units (CPUs), which are designed for the sequential execution of tasks. In this paper, a series of guidelines is presented for the efficient adaptation of octree-based, CA simulations of complex, evolving surfaces into massively parallel computing hardware. A Graphics Processing Unit (GPU) is used as a cost-efficient example of the parallel architectures. For the actual simulations, we consider the surface propagation during anisotropic wet chemical etching of silicon as a computationally challenging process with a wide-spread use in microengineering applications. A continuous CA model that is intrinsically parallel in nature is used for the time evolution. Our study strongly indicates that parallel computations of dynamically evolving surfaces simulated using CA methods are significantly benefited by the incorporation of octrees as support data structures, substantially decreasing the overall computational time and memory usage. © 2010 Elsevier B.V. All rights reserved.We thank the anonymous reviewers for their valuable comments and suggestions. This work has been supported by Programa de Becas de Excelencia de la Universidad Politecnica de Valencia (PAID-09-09), MEXT Grant in Aid Research (Kakenhi: Silicon etching (A) 19201026), and the Global COE program of Japan (GCOE, Wakate JSPS Young Scientist Fund).Ferrando Jódar, N.; Gosalvez, M.; Cerdá Boluda, J.; Gadea Gironés, R.; Sato, K. (2011). Octree-based, GPU implementation of a continuous cellular automaton for the simulation of complex, evolving surfaces. Computer Physics Communications. 182(3):628-640. https://doi.org/10.1016/j.cpc.2010.11.004S628640182

    Endophytes vs tree pathogens and pests: can they be used as biological control agents to improve tree health?

    Get PDF
    Like all other plants, trees are vulnerable to attack by a multitude of pests and pathogens. Current control measures for many of these diseases are limited and relatively ineffective. Several methods, including the use of conventional synthetic agro-chemicals, are employed to reduce the impact of pests and diseases. However, because of mounting concerns about adverse effects on the environment and a variety of economic reasons, this limited management of tree diseases by chemical methods is losing ground. The use of biological control, as a more environmentally friendly alternative, is becoming increasingly popular in plant protection. This can include the deployment of soil inoculants and foliar sprays, but the increased knowledge of microbial ecology in the phytosphere, in particular phylloplane microbes and endophytes, has stimulated new thinking for biocontrol approaches. Endophytes are microbes that live within plant tissues. As such, they hold potential as biocontrol agents against plant diseases because they are able to colonize the same ecological niche favoured by many invading pathogens. However, the development and exploitation of endophytes as biocontrol agents will have to overcome numerous challenges. The optimization and improvement of strategies employed in endophyte research can contribute towards discovering effective and competent biocontrol agents. The impact of environment and plant genotype on selecting potentially beneficial and exploitable endophytes for biocontrol is poorly understood. How endophytes synergise or antagonise one another is also an important factor. This review focusses on recent research addressing the biocontrol of plant diseases and pests using endophytic fungi and bacteria, alongside the challenges and limitations encountered and how these can be overcome. We frame this review in the context of tree pests and diseases, since trees are arguably the most difficult plant species to study, work on and manage, yet they represent one of the most important organisms on Earth

    Knowledge management in the context of sustainability: Literature review and opportunities for future research

    Get PDF
    © 2019 The use of knowledge management in the context of sustainability has been increasingly important over the years. Despite this importance, it is observed that this area is still little explored and there are many possibilities of academic research. Following a structured research protocol, the authors of this article performed a systematic review of the literature and identified plausible gaps to be explored in the development of future research. These gaps are presented in relation to the themes, strategies, objectives and research approach. From the point of view of the themes, there are opportunities related to the study of sustainability in small and medium enterprises, in relation to the potential of universities as engines for the generation of knowledge and in concerning the insertion of knowledge management to propose guidelines for obtaining productive systems. Regarding research strategies, the lack of studies that use action research as central focus stands out. Focusing on the objectives, there are many research approaches used with the goal of developing models and specific tools directed to the sharing of information. Finally, regarding the approach, there are few studies with a quantitative approach. We believe that the information presented here can contribute to the evolution of knowledge management focused on sustainability. No similar studies were found in the literature

    Die akute mesenteriale Ischämie - eine retrospektive Analyse über 6 Jahre

    No full text

    Vorrichtung und Verfahren zur Darstellung eines Objektes mittels Durchstrahlung

    No full text
    The invention relates to a device comprising a radiation source (18) and a radiation receiver (20), two robot arms (10, 14) for positioning the radiation source and the radiation receiver, a control device (22) for controlling the robot arms, and a processing device (24) for reconstructing a data set for imaging the object (26), in order to display the object by means of x-ray examination

    Secure collaborative supply-chain management

    Get PDF
    The SecureSCM project demonstrates the practical applicability of secure multiparty computation to online business collaboration. A prototype supply-chain management system protects the confidentiality of private data while rapidly adapting to changing business needs
    corecore