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Biomimetics in Production Organization -A Literature Study and Framework

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Journal of Bionic Engineering 2016年第2期13卷 200-212页

作者： Kirsten Reisen Ulrich Teschemacher Michael Niehues Gunther Reinhart Institute for Machine Tools and Industrial Management Technische Universitat Miinchen ( TUM) Boltzmannstrafle 15 85748 Garch ing Germany

Biomimetics is an established field in research and industry. Current approaches focus on the use of biological principles in product development, while large potentials have also been identified for transferring organisational principles from nature to production organisation. This study gives a comprehensive overview of existing literature and illustrates that only fragmented research is being conducted at present. In order to enable systematic translation into methods that are available to practitioners, a framework is developed which allows the body of literature to be structured and potential fields not being researched at present to be identified. It also points out that some biological principles receive more attention in research approaches and practical implementation in production organisation than others. Furthermore, correlations between biological principles and principles in production are identified that there have already been successful translations of biomimetic approaches to production organisation. On the other hand, it suggests that there are numerous promising approaches only described in an initial paper that need further research before they can be implemented in practice.

关键词： biomimetics framework production organisation optimization

A MULTIGRID SEMISMOOTH NEWTON METHOD FOR SEMILINEAR CONTACT PROBLEMS

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Journal of Computational Mathematics 2017年第4期35卷 486-528页

作者： Michael Ulbrich Stefan Ulbrich Daniela Bratzke technische universitat miinchen Department of Mathematics Garching b. Munchen Germany technische Universitiit Darmstadt Department of Mathematics Darmstadt Germany technische universitat Darmstadt Department of Mathematics Darmstadt Germany

This paper develops and analyzes multigrid semismooth Newton methods for a class of inequality-constrained optimization problems in function space which are motivated by and include linear elastic contact problems of Signorini type. We show that after a suitable Moreau-Yosida type regularization of the problem superlinear local convergence is obtained for a class of semismooth Newton methods. In addition, estimates for the order of tile error introduced by the regularization are derived. The main part of the paper is devoted to the analysis of a multilevel preconditioner for the semismooth Newton system. We prove a rigorous bound for the contraction rate of the multigrid cycle which is robust with respect to sufficiently small regularization parameters and the number of grid levels. Moreover, it applies to adaptively refined grids. The paper concludes with numerical results.

关键词： Contact problems Semismooth Newton methods Multigrid methods Errorestimates.

Current Soil Nutrient Status of Intensively Managed Greenhouses

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Pedosphere 2012年第6期22卷 825-833页

作者： HU Yun-Cai SONG Zhi-Wen LU Wen-Long C. POSCHENRIEDER U. SCHMIDHALTER Chair of Plant Nutrition Technische Universitat Miinchen D-85350 Freising (Germany) Institute of Information Tianjin Academy of Agricultural Sciences Tianjin (China)

Nine districts covering the main greenhouse vegetable areas in Tianjin Municipality of the North China Plain were selected for the soil investigation in 2010 to survey the current soil nutrient status (soil available N, P and K), acidification and salinization due to excessive input of fertilizers in greenhouses in Tianjin. The study showed that, in particular, soil available P content increased with the age of greenhouses. In contrast, our results did not reveal higher K accumulation and lowered pH in the greenhouse soils compared with cultivation in open fields. Over-fertilization, causing high NO 3 accumulation, most likely resulted in salinity problems in the greenhouses. Ninety percent of the investigated greenhouse soils had electrical conductivity values of saturated paste extracts of 2-10 d S m-1 , which might affect the yields of vegetable crops like green bean, pepper, cabbage, carrot, eggplant, lettuce, spinach, celery, cucumber and tomato. The findings of our survey of the current fertility and salinity problems in greenhouse soils suggest that there is an urgent need to improve the farmers' practices and strategies in fertilization management in greenhouses of China. Because education and the agricultural technical extension services may play a more important role in avoiding overuse of fertilizers, we suggest that current nutrient management practices should be improved in the near future through training of local farmers in farmers' schools and through strengthening the agricultural extension services with practical techniques.

关键词： electrical conductivity greenhouse vegetables over-fertilization soil pH soil survey

Flow-structure interaction of an inverted flag in a water tunnel

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Science China(Physics,Mechanics & Astronomy) 2019年第12期62卷 57-67页

作者： YaoWei Hu JiangSheng Wang JinJun Wang Christian Breitsamter Key Laboratory of Fluid Mechanics(Beihang University) Ministry of EducationBeijing 100191China Lehrstuhl fur Aerodynamik und Stromungsmechanik Technische Universitat MiinchenGarching 85748Germany

Herein, the dynamics and flow fields of an inverted flag are studied using hydrogen bubble flow visualization and particle image velocimetry technologies at different height-to-length ratios and flow velocities in a water tunnel. Results show that the heightto-length ratio of the inverted flag at which the critical flow velocity remains nearly constant is approximately 1.4. Moreover, a nonperiodic flapping phenomenon is observed under various height-to-length ratios. This phenomenon may be attributed to the existence of multiple equilibrium solutions to the self-excited vibration system, thus engendering chaos in the system comprising an inverted flag and surrounding fluid. Other indications that the system has entered chaos include multiple frequencies, nonoverlapping phase diagram, and positive Lyapunov exponent. Further discussion of the flow fields around the inverted flag reveals that the large-amplitude oscillation is due to the flow separation, while the flapping instability is a static divergence instability. In the large flapping mode, the starting leading-edge vortex(LEV) is wrapped by Kelvin-Helmholtz instabilities,which are arranged at almost uniform spacing along a circular path. In addition, the variation in position, circulation, and radius of the starting LEV are discussed in detail.

关键词： inverted flag modes aperiodic flapping LEV

Machine leaming for internet of things data analysis： a survey

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Digital Communications and Networks 2018年第3期4卷 161-175页

作者： Mohammad Saeid Mahdavinejad Mohammadreza Rezvan Mohammadamin Barekatain Peyman Adibi Payam Barnaghi Amit P. Sheth University of Isfahan Iran Kno.e.sis - Wright State University USA technische universitat miinchen Germany University of Surrey UK

Rapid developments in hardware, software, and communication technologies have facilitated the emergence of Internet-connected sensory devices that provide observations and data measurements from the physical world. By 2020, it is estimated that the total number of Internet-connected devices being used will be between 25 and 50 billion. As these numbers grow and technologies become more mature, the volume of data being published will increase. The technology of Internet-connected devices, referred to as Internet of Things （IoT）, continues to extend the current Internet by providing connectivity and interactions between the physical and cyber worlds. In addition to an increased volume, the IoT generates big data characterized by its velocity in terms of time and location dependency, with a variety of multiple modalities and varying data quality. Intelligent processing and analysis of this big data are the key to developing smart IoT applications. This article assesses the various machine learning methods that deal with the challenges presented by IoT data by considering smart cities as the main use case. The key contribution of this study is the presentation of a taxonomy of machine learning algorithms explaining how different techniques are applied to the data in order to extract higher level information. The potential and challenges of machine learning for IoT data analytics will also be discussed. A use case of applying a Support Vector Machine （SVM） to Aarhus smart city traffic data is presented for a more detailed exploration.

关键词： Machine learning Internet of Things Smart data Smart City

Wettability and Thermodynamic Adhesion of Liquid Metals on Solid Uranium Dioxide

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Rare Metals 1990年第2期10卷 95-100页

作者： Li Jian’guo Wang Juan Institut fur Nichtmetallische Werkstoffe, technische universitat Berlin, Englische Str. 20. D-1000Berlin 12, FRG. technische universitat Berlin 德国

Using the experimental results given in literatures about the contact angle, θ and the work of adhesion, W, for nonreactive liquid metal / solid UO_2 systems, the validity and feasibility of the different existing models for calculating W in the metal /ox- ide systems are discussed. It can be shown that the models assuming that only metal atom-oxygen ion interactions existing at the interfaces are unable to explain the experimental results for W. More reasonable model should take into account both metal atom-oxygen ion and metal atom-oxide metal cation interactions, the proportion of the latter is balanced by the stoichiometry of the oxide. By applying the model recently set up by the authors for binary alloy / oxide systems, one can use the experimental and calculated values of θ and W for various metal / UO_2 systems to predict the influence of metallic additions on the contact angle and the work of adhesion of a given metal / UO_2 system.

关键词： Wettability and Thermodynamic Adhesion of Liquid Metals on Solid Uranium Dioxide der

Wettability　of　Monocrystalline　Silicon　Carbide　by　Molten　Metals　and　Binary　Metal－Silicon　Alloys

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Rare Metals 1995年第2期14卷 96-105页

作者：李建国 technische universitat Berlin 德国

The wettability of monocrystalline silicon carbide by liquid metals (Au , Ge, Ag , Sn and Cu) and binarymetal-silicon (Ag-Si and Sn-Si) alloys was investigated between their melting points and 1430℃ with the ses-sile drop method in argon with an extremely low oxygen partial pressure. For Au and Ge on SiC, the contactangles exhibited a weak temperature dependence. Under the same experimental conditions, however, complexwetting behaviours were observed for Ag , Sn and Cu on SiC , which could be attributed to the chemical reactivi-ties between the metals and the *** experirnents were also performed for binary Ag-Si and Sn-Si alloys on the same SiC substratesunder the same experimental conditions. The obtained coiitact angle isotherms for the two binary alloy/SiC sys-tems were discussed and interpreted by using a statistical thermedynamics mixlel.

关键词： Wetting Liquid metals and alloys Silicon carbide Reactivityand adsorption

Importance of Metal－Oxide Support Wettingandinteractions on Understanding of Physical and Chemical Behaviours of Supported Metal Catalysts

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Rare Metals 1994年第3期13卷 179-187页

作者：李建国 technische universitat Berlin 德国

It has been generally recognised that the metal catalysts supported on oxide ceramic and non-oxide ceramic supports exhibit completely different characteristics as compared with the homogeneous ones. The na-ture of bonding and interactions occurring at the metal / ceramic interfaces are believed to be of importancefor the characteristics of such catalysts. The recently developed microscopic theory of adhesion and wettingin metal/ ceramic systems is briefly presented here with the emphasis on the ionocovalent oxide *** its consequence on the understanding of the physical and chemical behaviours of supported metal cata-lysts is exploited.

关键词： Wetting and adhesion Metal-ceramic interaction Dissolved oxygen,Supported metal catalysts Physical and chemical behaviours

TRANSFORMATIONS FOR THE PRIZE-COLLECTING STEINER TREE PROBLEM AND THE MAXIMUM-WEIGHT CONNECTED SUBGRAPH PROBLEM TO SAP

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Journal of Computational Mathematics 2018年第3期36卷 459-468页

作者： Daniel Rehfeldt Thorsten Koch Department of Mathematics Technische Universitat Berlin Germany Zuse Institute Berlin and technische universitat Berlin Germany

Transformations of Steiner tree problem variants have been frequently discussed in the literature. Besides allowing to easily transfer complexity results, they constitute a central pillar of exact state-of-the-art solvers for well-known variants such as the Steiner tree problem in graphs. In this article transformations for both the prize-collecting Steiner tree problem and the maximum-weight connected subgraph problem to the Steiner arborescence problem are introduced for the first time. Furthermore, the considerable implications for practical solving approaches will be demonstrated, including the computation of strong upper and lower bounds.

关键词： Prize-collecting Steiner tree problem Maximum-weight connected subgraphproblem Graph transformations Dual-ascent heuristics.