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  • English
    Authors: 
    Jakobsen, Vibe B.; Trzop, Elzbieta; Gavin, Laurence C.; Dobbelaar, Emiel; Chikara, Shalinee; Ding, Xiaxin; Esien, Kane; Müller-Bunz, Helge; Felton, Solveig; Zapf, Vivien S.; +3 more
    Publisher: Cambridge Crystallographic Data Centre
    Project: NSF | National High Magnetic Fi... (1157490), SFI | Nano-Assembly of Function... (12/IP/1703)

    Related Article: Vibe B. Jakobsen, Elzbieta Trzop, Laurence C. Gavin, Emiel Dobbelaar, Shalinee Chikara, Xiaxin Ding, Kane Esien, Helge Müller-Bunz, Solveig Felton, Vivien S. Zapf, Eric Collet, Michael A. Carpenter, Grace G. Morgan|2020|Angew.Chem.,Int.Ed.|59|13305|doi:10.1002/anie.202003041

  • Open Access English
    Authors: 
    Huss, Jannis-Michael; Zeller, Marie-Louise; Pfister, Lena; Lapo, Karl E.; Littmann, Daniela; Schneider, Johann; Schulz, Alexander; Thomas, Christoph K.;
    Publisher: Zenodo
    Project: EC | DarkMix (724629)

    Atmospheric processes in the weak-wind stable boundary layer are an open field of research since they are poorly represented by theoretical concepts including similarity theories commonly applied in the air layer adjacent to the surface. This lack of understanding affects polar regions the most since the observation density is sparse while the fraction of weak-wind conditions with strong static stability increases drastically during polar night which is characterized by a long-lived stable boundary layer. The atmospheric motions carrying the bulk of the near-surface transport in these conditions occur on scales larger than forced or free convective turbulence, show different characteristics and are known as submeso-scale motions. These submeso-scale motions cannot be resolved by common point measurements due to their quasi-stationary or transient behavior but require distributed observations such as from sensor networks or continuous observational techniques. A suite of observations satisfying these requirements were collected during the Ny-Ålesund TurbulencE Fiber Optic eXperiment, NYTEFOX, which was a field campaign conducted at an Arctic field site at the perimeter of the Ny-Ålesund science station (11.9°E, 78.9°N) in February and March 2020. It was the first field campaign in an Arctic environment to investigate the spatio-temporal variability of airflow and temperature across hundreds of meters horizontally by means of the innovative Fiber-Optic Distributed Sensing (FODS) technique. A 700 m long horizontal, trapezoidal transect of fiber-optic cables installed at 1.2 m above ground level (agl) yielded measurements of temperature and wind speed with a resolution of 0.127 m and 9 s, supplemented by three 7 m tall vertical profiles. A coil-wrapped column of fiber-optic cable, helically wound around a support fabric, added a high-resolution vertical temperature profile from below the snow surface (-0.25 m) up to 2.5 m agl with an effective vertical resolution of 0.0025 m to 0.02 m depending on height. The 14-day FODS data set spanning the period from 26.02.2020 until 10.03.2020 is complemented by observations of three ultrasonic anemometers and one acoustic profiler (miniSodar, SOund Detection And Ranging) measuring a wind profile up to 300 m agl. The NYTEFOX data set allows for exploring the role, as well as the horizontal scales, vertical scales, and the trajectories, of turbulent and submeso-scale motions in the Arctic during the transition from the polar night to spring. The atmospheric observations from this pilot field campaign substantially expand the data set operationally collected by the Basic Surface Radiation Network (BSRN) meteorological data set at Ny-Ålesund, Svalbard by observing airflow and temperatures at turbulent to submeso scales. A technical documentation and file overview is given here (documentation_v1_1.pdf). A more detailed description of the setup and processing steps as well as an exemplary illustration of the observations on 05.03.2020 can be found in Zeller et al. (2021). All data are provided either as comma separated ASCII (csv, for the ultrasonic anemometer statistics) or as self-describing netcdfs. Only changes in Version v1.1: updated data availability in the documentation PDF. This project has received funding from the Alfred Wegener Institute for Polar and Marine Research (AWI) in Potsdam, the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (Grant agreement No. 724629 DarkMix, PI: Christoph Thomas), and the Research Council of Norway (project number 291644) Svalbard Integrated Arctic Earth Observing System (SIOS) – Knowledge Centre, operational phase. The experiment was conducted with the support of the joint French-German AWIPEV-Station operated by the AWI and the Polar Institute Paul Emile Victor (IPEV) in Ny-Ålesund.

  • English
    Authors: 
    Schäfer, F.; Schneider, E.; Lambert, M.;
    Country: Germany
  • English
    Authors: 
    Koch, Sandro G.; Völz, Uwe; Lange, Nicolas; Köble, Sören; Schubert, F.; Richter, F.; Poongodan, P.K .; Vanselow, F.; Urbahn, C.;
    Country: Germany

    A new technology platform is presented that utilized capacitive micromachined ultrasonic transducers (CMUT) for the on-chip integration of proximity and tactile sensing. This platform integrated in robotic grippers enables tactile and reactive grasping. A single channel proximity system is demonstrated to distinguish objects and reveal high spatial resolution to distances of 10 mm.

  • Other research product . 2008
    English
    Authors: 
    Kikuchi, Toru;
    Country: Germany

    This paper considers a two-period model of market entry with homogeneous products and switching costs. It is shown that the pro-competitive effect of a foreign firm's entry (i.e., unilateral trade liberalization) emerges before the entry. Also, conditions that are conducive to a competitive environment in the second-period are shown to yield a less competitive outcome in the first-period. That is, when the marginal cost of the foreign entrant is relatively low, the first-period output of a domestic monopolist is relatively low as well.

  • English
    Authors: 
    Burenkov, A.; Wittl, J.; Schwalke, U.; Lorenz, J.; Ryssel, H.;
    Country: Germany
  • English
    Authors: 
    Pflug, A.; Malkomes, N.; Sittinger, V.; Szyszka, B.;
    Country: Germany

    We present a dynamic coupled model of reactive sputtering suited for description of real in-line processing. In our model we divide the complex volume of a processing chamber into simple cells, e.g. parallelepipeds. For each cell the gettering kinetics of reactive gas at metalized surfaces as well as the sputtering kinetics of the target are calculated using a Runge-Kutta time step method. The inert and reactive gas flow is obtained via flow conductances defined for each connection between adjacent cells. For deposition of sputtered particles on chamber and substrate surfaces, a pressure dependent distribution matrix is used, which is obtained from singleparticle Monte Carlo calculations. The flow conductances for different pressure conditons are calculated using the well known "Direct Simulation Monte Carlo" method implemented on a Linux cluster, where for each volume cell an individual calculation task can be spawned. Tuned with flow conductances and particle distribution factors from Monte Carlo calculations our coupled model is capable of describing real in-line sputtering processes on a single-processor PC at almost real time speed. We present computer aided investigations on (i) the optimization of rate and homogeneity in the reactive sputter process using different target screening arrangements and (ii) the influence of substrate movement during reactive sputtering in transition mode. We apply the simulation on our in-line sputtering system Leybold A700V in comparison with experimental results.

  • Other research product . Other ORP type . 2014
    English
    Authors: 
    Bjørn, P.; Bardram, J.; Avram, G.; Bannon, L.; Boden, A.; Redmiles, D.; Souza, C.R.B. de; Wulf, V.;
    Country: Germany

    Global software development (GSD) has been an important research topic in the CSCW community for more than two decades. CSCW has helped identify a significant number of challenges and solutions for handling distances in time, space and culture in distributed software engineering environments. However, no comprehensive collected body of knowledge concerning research on GSD from a CSCW perspective exists yet. The goal of this workshop is to bring together researchers and practitioners who have studied GSD from a CSCW perspective, and provide an overview of current findings and future challenges. In the workshop, we will facilitate group discussions across the diverse groups of researchers coming from ethnographic studies of software development practices and design studies of CSCW tools and processes for GSD. The goal is to provide an overview of current research, which in turn may form the basis for joint publications or an edited book.

  • Other research product . Other ORP type . 2015
    English
    Authors: 
    Pfeiffer, W.; Höpfel, H.;
    Country: Germany

    Thin ceramic components are often distorted during production due to anisotropic shrinkage and/or residual stresses due to machining. If unwanted distortion is detected in a component in its final shape, me distortion cannot be eliminated by additional material removal. Such ceramic components are usually discarded since their brittleness does not permit further flattening. Ceramic parts with complex shapes must be fabricated by, for example, sintering close to the desired shape followed by a costly 3D machining process. This paper describes the first successful experiments aimed at shaping ceramic specimens using shot peening. Strips of different thicknesses made of silicon nitride ceramic were shot-peened using different shot peening parameters. The residual stress-depth distributions were determined using X-ray diffraction. Based on the experimentally-determined stress states, the curvatures of the strips were determined analytically and using Finite Element (FE) calculations. Silicon nitride flat springs and a concave mirror could be peen-formed without the need of additional hard machining. FE calculations demonstrated me capability of designing peen forming processes on basis of experimentally-determined peening stresses.

  • English
    Authors: 
    Hollis, Aidan; Strauss, Jason;
    Country: Germany

    With new technologies that enable insurers to electronically monitor vehicles and drivers, insurers should be able to price automobile insurance more accurately, creating individualized prices for consumers. The welfare effects of lower prices are straightforward, but we also consider that consumers have heterogeneous valuations of privacy that they may lose if they adopt the monitoring technologies. We examine the voluntary market adoption of these monitoring technologies and its effect on equilibrium prices and welfare. We find a welfare effect equal to the loss in privacy, but conclude that the overall effect is ambiguous without considering moral hazard.

Advanced search in
Research products
arrow_drop_down
Searching FieldsTerms
Any field
arrow_drop_down
includes
arrow_drop_down
Include:
176,645 Research products, page 1 of 17,665
  • English
    Authors: 
    Jakobsen, Vibe B.; Trzop, Elzbieta; Gavin, Laurence C.; Dobbelaar, Emiel; Chikara, Shalinee; Ding, Xiaxin; Esien, Kane; Müller-Bunz, Helge; Felton, Solveig; Zapf, Vivien S.; +3 more
    Publisher: Cambridge Crystallographic Data Centre
    Project: NSF | National High Magnetic Fi... (1157490), SFI | Nano-Assembly of Function... (12/IP/1703)

    Related Article: Vibe B. Jakobsen, Elzbieta Trzop, Laurence C. Gavin, Emiel Dobbelaar, Shalinee Chikara, Xiaxin Ding, Kane Esien, Helge Müller-Bunz, Solveig Felton, Vivien S. Zapf, Eric Collet, Michael A. Carpenter, Grace G. Morgan|2020|Angew.Chem.,Int.Ed.|59|13305|doi:10.1002/anie.202003041

  • Open Access English
    Authors: 
    Huss, Jannis-Michael; Zeller, Marie-Louise; Pfister, Lena; Lapo, Karl E.; Littmann, Daniela; Schneider, Johann; Schulz, Alexander; Thomas, Christoph K.;
    Publisher: Zenodo
    Project: EC | DarkMix (724629)

    Atmospheric processes in the weak-wind stable boundary layer are an open field of research since they are poorly represented by theoretical concepts including similarity theories commonly applied in the air layer adjacent to the surface. This lack of understanding affects polar regions the most since the observation density is sparse while the fraction of weak-wind conditions with strong static stability increases drastically during polar night which is characterized by a long-lived stable boundary layer. The atmospheric motions carrying the bulk of the near-surface transport in these conditions occur on scales larger than forced or free convective turbulence, show different characteristics and are known as submeso-scale motions. These submeso-scale motions cannot be resolved by common point measurements due to their quasi-stationary or transient behavior but require distributed observations such as from sensor networks or continuous observational techniques. A suite of observations satisfying these requirements were collected during the Ny-Ålesund TurbulencE Fiber Optic eXperiment, NYTEFOX, which was a field campaign conducted at an Arctic field site at the perimeter of the Ny-Ålesund science station (11.9°E, 78.9°N) in February and March 2020. It was the first field campaign in an Arctic environment to investigate the spatio-temporal variability of airflow and temperature across hundreds of meters horizontally by means of the innovative Fiber-Optic Distributed Sensing (FODS) technique. A 700 m long horizontal, trapezoidal transect of fiber-optic cables installed at 1.2 m above ground level (agl) yielded measurements of temperature and wind speed with a resolution of 0.127 m and 9 s, supplemented by three 7 m tall vertical profiles. A coil-wrapped column of fiber-optic cable, helically wound around a support fabric, added a high-resolution vertical temperature profile from below the snow surface (-0.25 m) up to 2.5 m agl with an effective vertical resolution of 0.0025 m to 0.02 m depending on height. The 14-day FODS data set spanning the period from 26.02.2020 until 10.03.2020 is complemented by observations of three ultrasonic anemometers and one acoustic profiler (miniSodar, SOund Detection And Ranging) measuring a wind profile up to 300 m agl. The NYTEFOX data set allows for exploring the role, as well as the horizontal scales, vertical scales, and the trajectories, of turbulent and submeso-scale motions in the Arctic during the transition from the polar night to spring. The atmospheric observations from this pilot field campaign substantially expand the data set operationally collected by the Basic Surface Radiation Network (BSRN) meteorological data set at Ny-Ålesund, Svalbard by observing airflow and temperatures at turbulent to submeso scales. A technical documentation and file overview is given here (documentation_v1_1.pdf). A more detailed description of the setup and processing steps as well as an exemplary illustration of the observations on 05.03.2020 can be found in Zeller et al. (2021). All data are provided either as comma separated ASCII (csv, for the ultrasonic anemometer statistics) or as self-describing netcdfs. Only changes in Version v1.1: updated data availability in the documentation PDF. This project has received funding from the Alfred Wegener Institute for Polar and Marine Research (AWI) in Potsdam, the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (Grant agreement No. 724629 DarkMix, PI: Christoph Thomas), and the Research Council of Norway (project number 291644) Svalbard Integrated Arctic Earth Observing System (SIOS) – Knowledge Centre, operational phase. The experiment was conducted with the support of the joint French-German AWIPEV-Station operated by the AWI and the Polar Institute Paul Emile Victor (IPEV) in Ny-Ålesund.

  • English
    Authors: 
    Schäfer, F.; Schneider, E.; Lambert, M.;
    Country: Germany
  • English
    Authors: 
    Koch, Sandro G.; Völz, Uwe; Lange, Nicolas; Köble, Sören; Schubert, F.; Richter, F.; Poongodan, P.K .; Vanselow, F.; Urbahn, C.;
    Country: Germany

    A new technology platform is presented that utilized capacitive micromachined ultrasonic transducers (CMUT) for the on-chip integration of proximity and tactile sensing. This platform integrated in robotic grippers enables tactile and reactive grasping. A single channel proximity system is demonstrated to distinguish objects and reveal high spatial resolution to distances of 10 mm.

  • Other research product . 2008
    English
    Authors: 
    Kikuchi, Toru;
    Country: Germany

    This paper considers a two-period model of market entry with homogeneous products and switching costs. It is shown that the pro-competitive effect of a foreign firm's entry (i.e., unilateral trade liberalization) emerges before the entry. Also, conditions that are conducive to a competitive environment in the second-period are shown to yield a less competitive outcome in the first-period. That is, when the marginal cost of the foreign entrant is relatively low, the first-period output of a domestic monopolist is relatively low as well.

  • English
    Authors: 
    Burenkov, A.; Wittl, J.; Schwalke, U.; Lorenz, J.; Ryssel, H.;
    Country: Germany
  • English
    Authors: 
    Pflug, A.; Malkomes, N.; Sittinger, V.; Szyszka, B.;
    Country: Germany

    We present a dynamic coupled model of reactive sputtering suited for description of real in-line processing. In our model we divide the complex volume of a processing chamber into simple cells, e.g. parallelepipeds. For each cell the gettering kinetics of reactive gas at metalized surfaces as well as the sputtering kinetics of the target are calculated using a Runge-Kutta time step method. The inert and reactive gas flow is obtained via flow conductances defined for each connection between adjacent cells. For deposition of sputtered particles on chamber and substrate surfaces, a pressure dependent distribution matrix is used, which is obtained from singleparticle Monte Carlo calculations. The flow conductances for different pressure conditons are calculated using the well known "Direct Simulation Monte Carlo" method implemented on a Linux cluster, where for each volume cell an individual calculation task can be spawned. Tuned with flow conductances and particle distribution factors from Monte Carlo calculations our coupled model is capable of describing real in-line sputtering processes on a single-processor PC at almost real time speed. We present computer aided investigations on (i) the optimization of rate and homogeneity in the reactive sputter process using different target screening arrangements and (ii) the influence of substrate movement during reactive sputtering in transition mode. We apply the simulation on our in-line sputtering system Leybold A700V in comparison with experimental results.

  • Other research product . Other ORP type . 2014
    English
    Authors: 
    Bjørn, P.; Bardram, J.; Avram, G.; Bannon, L.; Boden, A.; Redmiles, D.; Souza, C.R.B. de; Wulf, V.;
    Country: Germany

    Global software development (GSD) has been an important research topic in the CSCW community for more than two decades. CSCW has helped identify a significant number of challenges and solutions for handling distances in time, space and culture in distributed software engineering environments. However, no comprehensive collected body of knowledge concerning research on GSD from a CSCW perspective exists yet. The goal of this workshop is to bring together researchers and practitioners who have studied GSD from a CSCW perspective, and provide an overview of current findings and future challenges. In the workshop, we will facilitate group discussions across the diverse groups of researchers coming from ethnographic studies of software development practices and design studies of CSCW tools and processes for GSD. The goal is to provide an overview of current research, which in turn may form the basis for joint publications or an edited book.

  • Other research product . Other ORP type . 2015
    English
    Authors: 
    Pfeiffer, W.; Höpfel, H.;
    Country: Germany

    Thin ceramic components are often distorted during production due to anisotropic shrinkage and/or residual stresses due to machining. If unwanted distortion is detected in a component in its final shape, me distortion cannot be eliminated by additional material removal. Such ceramic components are usually discarded since their brittleness does not permit further flattening. Ceramic parts with complex shapes must be fabricated by, for example, sintering close to the desired shape followed by a costly 3D machining process. This paper describes the first successful experiments aimed at shaping ceramic specimens using shot peening. Strips of different thicknesses made of silicon nitride ceramic were shot-peened using different shot peening parameters. The residual stress-depth distributions were determined using X-ray diffraction. Based on the experimentally-determined stress states, the curvatures of the strips were determined analytically and using Finite Element (FE) calculations. Silicon nitride flat springs and a concave mirror could be peen-formed without the need of additional hard machining. FE calculations demonstrated me capability of designing peen forming processes on basis of experimentally-determined peening stresses.

  • English
    Authors: 
    Hollis, Aidan; Strauss, Jason;
    Country: Germany

    With new technologies that enable insurers to electronically monitor vehicles and drivers, insurers should be able to price automobile insurance more accurately, creating individualized prices for consumers. The welfare effects of lower prices are straightforward, but we also consider that consumers have heterogeneous valuations of privacy that they may lose if they adopt the monitoring technologies. We examine the voluntary market adoption of these monitoring technologies and its effect on equilibrium prices and welfare. We find a welfare effect equal to the loss in privacy, but conclude that the overall effect is ambiguous without considering moral hazard.

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