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Organizational dynamics in adaptive distributed search processes: effects on performance and the role of complexity

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Frontiers of Information Technology & Electronic Engineering 2016年第4期17卷 283-295页

作者： Friederike WALL Department of Controlling and Strategic Management Alpen-Adria-Universitaet Klagenfurt

In this paper, the effects of altering the organizational setting of distributed adaptive search processes in the course of search are investigated. We put particular emphasis on the complexity of interactions between partial search problems assigned to search agents. Employing an agent-based simulation based on the framework of NK landscapes we analyze different temporal change modes of the organizational set-up. The organizational properties under change include, for example, the coordination mechanisms among search agents. Results suggest that inducing organizational dynamics has the potential to increase the effectiveness of distributed adaptive search processes with respect to various performance measures like the final performance achieved at the end of the search, the chance to find the optimal solution of the search problem, or the average performance per period achieved during the search process. However, results also indicate that the mode of temporal change in conjunction with the complexity of the search problem considerably affects the order of magnitude of these beneficial effects. In particular, results suggest that organizational dynamics induces a shift towards more exploration, i.e., discovery of new areas in the fitness landscape, and less exploitation, i.e., stepwise improvement.

关键词： Agent-based simulation Complexity Coordination Distributed search NK landscapes

Flow-regime transitions in fluidized beds of non-spherical particles

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Particuology 2016年第6期14卷 1-15页

作者： H. Kruggel-Emden K. Vollmari Ruhr-universitaet Bochum Universitaetsstrasse 150 D-44780 Bochum Germany

Fluidized beds frequently involve non-spherical particles, especially if biomass is present. For spheri- cal particles, numerous experimental investigations have been reported in the literature. In contrast, complex-shaped particles have received much less attention. There is a lack of understanding of how par- ticle shape influences flow-regime transitions. In this study, differently shaped Geldart group D particles are experimentally examined. Bed height, pressure drop, and their respective fluctuations are analyzed. With increasing deviation of particle shape from spheres, differences in flow-regime transitions occur with a tendency for the bed to form channels instead of undergoing smooth fluidization. The correlations available in the literature for spherical particles are limited in their applicability when used to predict regime changes for complex-shaped particles. Hence, based on existing correlations, improvements are derived.

关键词： Fluidized bed Flow regimes Non-spherical particles Pressure drop and fluctuations Bed height

Dynamical behavior of a mobile system with two degrees of freedom near the resonance

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Acta Mechanica Sinica 2011年第1期27卷 7-17页

作者： Klaus Zimmermann Igor Zeidis Faculty of Mechanical Engineering Technische Universitaet Ilmenau

The design of mobile robots that can move without wheels or legs is an important engineering and technological ***-propelling mechanisms consisting of a body that has contact with a rough surface and moveable internal masses are *** models of such systems are presented in this ***,a model of a vibration driven robot that moves along a rough horizontal plane with isotropic dry friction is *** is shown that by changing the off-resonance frequency detuning in sign,one can control the direction of motion of the *** addition,a locomotion system which moves in an environment with anisotropic viscous friction is *** all models,the method of averaging to obtain an algebraic equation for the steady-state＂average＂velocity of the system is used. Prototypes were constructed to compare the theoretical results with experimental ones.

关键词： Dynamics Friction Resonance Vibrationdriven systems

A study on turbulence modulation via an analysis of turbulence anisotropy-invariants

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Science China(Physics,Mechanics & Astronomy) 2010年第3期53卷 508-513页

作者： Michael MANHART Fachgebiet Hydromechanik Technische Universitaet Muechen Munich 80333 Germany

We investigate the turbulence modulation by particles in a turbulent two-phase channel flow via an analysis of turbulence anisotropy-invariants. The fluid turbulence is calculated by a large eddy simulation with a point-force two-way coupling model and particles are tracked by the Lagrangian trajectory method. The channel turbulence follows the two-component turbulence state within the viscous sub-layer region and outside the region the turbulence tends to follow the right curve of the anisotropy-invariant. The channel turbulence, interacting with heavy particles, is modulated to the two-component turbulence limit state near the wall and is separate from the axisymmetric turbulence state in the turbulence anisotropy-invariants map. The fluctuations of streamwise component are transferred to the other two components and hence the anisotropy decreases due to particle modulation. The study has deepened the understanding of the turbulence modulation mechanism in two-phase turbulent flows.

关键词： turbulence modulation turbulence anisotropy turbulent two-phase channel flow large eddy simulation two-way coupling

Enrichment of topographic road database for the purpose of routing and navigation

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International Journal of Digital Earth 2014年第5期7卷 411-431页

作者： Meng Zhang Wei Yao Liqiu Meng Department of Earth and Environmental Sciences Xi’an Jiaotong UniversityXi’anChina Department of Photogrammetry and Remote Sensing Technische Universitaet MuenchenMunichGermany Department of Cartography Technische Universitaet MuenchenMunichGermany

With growing demand on multi-purpose or multi-modal navigation,the route calculation needs to traverse semantically enriched road networks for different transportation ***,operational route planning algorithms reveal rather limited performances or their potential for comprehensive applications are constrained by the unavailable or insufficient interoperation among the under-lying geo-data that are separately maintained in different spatial *** overcome this limitation,a novel approach has been proposed to integrate the routing-relevant information from different data sources,which involves three processes:(1)automatic matching to identify the corresponding road objects between different datasets;(2)interaction to refine the automatic matching result;and(3)transferring the routing-relevant information from one data-set to *** process(1),the Delimited Stroke Oriented algorithm is employed to achieve the automatic data matching between different datasets,which has revealed a high matching rate and *** uncertain matching problems occur in areas where topological conditions are too complicated or *** remaining unmatched or wrongly matched objects are treated in process(2),with the help of a series of interaction *** the basis of refined matching results after the interaction,process(3)is dedicated to automatic integration of the routing-relevant information from different data sources.

关键词： data matching data integration routing-relevant geospatial data-set road network

The Role of Organic Matter During Metal Enrichment in Permian Kupferschiefer of the Rudna Mine,Southwest Poland

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Chinese Journal Of Geochemistry 2003年第1期22卷 1-10页

作者：孙玉壮 WILHELM PüTTMANN Hebei Institute of Architectural Science and Technology Johann Wolfgang Goethe-universitaet Frankfurt

The bulk composition of organic matter and saturated and aromatic hydrocarbons extracted from 16 samples collected from two Kupferschiefer profiles in the Rudna mine, Southwest Poland has been analyzed to study the role of organic matter during base metal enrichment in the Kupferschiefer shale. The results indicated that the extract yields and saturated hydrocarbon yields decreased with increasing base metal contents. GC and GC/MS analyses indicated that n-alkanes and alkylated aromatic compounds were depleted and may have served as hydrogen donators for thermochemical sulfate reduction. The enrichment of base metals is closely connected with the destruction of hydrocarbons.

关键词：烃有机物铜页岩热化学作用硫酸盐贱金属波兰二叠纪欧洲

Factorizations of groups and related topics

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Science China Mathematics 2009年第2期52卷 217-230页

作者： AMBERG Bernhard KAZARIN Lev Fachbereich 08 Universitaet MainzGermany Department of Mathematics Yaroslavl State University

This is a survey of some recent progress in the theory of groups with factorizations. Some of the methods can be used to obtain information about finite groups in general, nilpotent algebras and nearrings.

关键词： products of groups factorizations 20D40

Cortisol levels in skimmed milk during the first 22 weeks of lactation and response to short-term metabolic stress and lameness in dairy cows

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Journal of Animal Science and Biotechnology 2015年第4期6卷 485-491页

作者： Katharina Gellrich Tanja Sigl Heinrich H.D.Meyer Steffi Wiedemann Physiology Weihenstephan Technische Universitaet Muenchen Animal Health Institute of Animal Breeding and HusbandryKiel University

Background： Cortisol is secreted into blood in reaction to acute stress, but also in phases of diminished feed intake and changed animal behavior. As cows do not always show clear signs of discomfort, reliable diagnostic markers could be used to provide information regarding individual cows＇ distress. The objective of this study was to establish an ether free immunoassay for the detection of cortisol and to determine values during the first 22 weeks of lactation. Furthermore, the response in milk cortisol levels was assessed during times of metabolic stress and pain associated symptoms of lameness. Methods： Milk yield and composition, blood serum glucose, NEFA and BHBA as well as milk cortisol were determined in 24 multiparous Holstein-Friesian cows over the course of the first 22 weeks of lactation. Animals were further checked for signs of clinical diseases on a daily basis. Two feed restrictions over three days （FR; 70 % of precious ad libitum intake） were performed during the 4th wk and the 21st wk, respectively. An ELISA for cortisol measurement in easily accessible bovine skimmed milk was established and applied. Results： On the last day of FR in early lactation, a reduction in milk yield and changes in serum metabolites compared to respective previous values were detected. The FR in mid-lactation resulted in no changes in milk production and serum metabolites. Milk cortisol was highest during first wk of lactation and remained on comparable levels thereafter. Milk yield and composition were not influenced by FR. Lameness resulted in enhanced milk cortisol levels. Conclusion： Milk cortisol could be used as an indicator of painful symptoms such as lameness. Higher values of milk cortisol levels during first wk of lactation should be taken into account for interpretation.

关键词： Cortisol Dairy cow ELISA Feed restriction Milk

IRF1 and BATF—transcription factors that set the epigenetic landscape for Tr1 cell differentiation?

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Cellular & Molecular Immunology 2017年第9期14卷 727-729页

作者： Katarina Stanko Birgit Sawitzki Charité-universitaetsmedizin Berlin Corporate Member of Freie Universitaet BerlinHumboldt-Universitaet zu Berlinand Berlin Institute of HealthInstitute of Medical ImmunologyAugustenburger Platz 113353 BerlinGermany

Type 1 regulatory T(Tr1)cells are Foxp3-negative regulatory CD4+T cells that develop outside of the thymus and mediate regulatory functions in large part by producing the immunosuppressive cytokine IL-10.

关键词： Foxp3 Tr1 landscape