cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Sheet-Metal Production Scheduling Using AlphaGo Zero
Creators: name: Rinciog, Alexandru
name: Mieth, Carina
name: Scheikl, Paul Maria
name: Meyer, Anney
Publisher: name: Hannover : publish-Ing.
Year: 2020
Subjects: subject: Sheet-Metal Production
subject: Production Scheduling
subject: Reinforcement Learning
subject: Job Shop Scheduling Problem
subject: Monte Carlo Tree Search
subject: AlphaGo Zero
subject: Konferenzschrift
subject: Dewey Decimal Classification::600 | Technik::620 | Ingenieurwissenschaften und Maschinenbau

description: This work investigates the applicability of a reinforcement learning (RL) approach, specifically AlphaGo Zero (AZ), for optimizing sheet-metal (SM) production schedules with respect to tardiness and material waste. SM production scheduling is a complex job shop scheduling problem (JSSP) with dynamic operation times, routing flexibility and supplementary constraints. SM production systems are capable of processing a large number of highly heterogeneous jobs simultaneously. While very large relative to the JSSP literature, the SM-JSSP instances investigated in this work are small relative to the SM production reality. Given the high dimensionality of the SM-JSSP, computation of an optimal schedule is not tractable. Simple heuristic solutions often deliver bad results. We use AZ to selectively search the solution space. To this end, a single player AZ version is pretrained using supervised learning on schedules generated by a heuristic, fine-tuned using RL and evaluated through comparison with a heuristic baseline and Monte Carlo Tree Search. It will be shown that AZ outperforms the other approaches. The work’s scientific contribution is twofold: On the one hand, a novel scheduling problem is formalized such that it can be tackled using RL approaches. On the other hand, it is proved that AZ can be successfully modified to provide a solution for the problem at hand, whereby a new line of research into real-world applications of AZ is opened.
Conceptual Approach of Robustness in Logistical Control
Creators: name: Bader, Alexander
name: Onken, Ann-Kathrin
name: Tracht, Kirsten
Publisher: name: Hannover : publish-Ing.
Year: 2020
Subjects: subject: Planning
subject: Robustness
subject: Logistics
subject: Konferenzschrift
subject: Dewey Decimal Classification::600 | Technik::620 | Ingenieurwissenschaften und Maschinenbau

description: The logistical control and order release of structurally dynamic systems represent a great challenge. In contrast to classical shop floor production, these systems can involve transitions between the two different organizational forms job shop production and flow production. This results in a system that is susceptible to turbulence and malfunctions. This paper presents an approach that improves the robustness of these systems and achieves a stable system state even under external influences. Decentralized stock control loops control the WIP of the individual stations in a closed loop. When organizational transitions occur, interlinking losses arise, which reduce the productivity of the system. Similar effects can cause disturbances and blockages. The introduction of a robustness controller adapts the input parameters of the order release to the current system status, so that an adapted reaction takes place in the event of strong disturbances.
Image segmentation by optimal and hierarchical piecewise constant approximations
Creators: name: Kharinov, M.
Publisher: name: arXiv
Year: 2013
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: FOS: Computer and information sciences

description: Piecewise constant image approximations of sequential number of segments or clusters of disconnected pixels are treated. The method of majorizing of optimal approximation sequence by hierarchical sequence of image approximations is proposed. A generalization for multidimensional case of color and multispectral images is foreseen.
description: 4 pages, 5 formulas, 3 figures, 1 table, submitted to the Eleventh International Conference on Pattern Recognition and Image Analysis September 23-28, 2013, Samara, Russia
Managing Disruptions in Production with Machine Learning
Creators: name: Samsonov, Vladimir
name: Enslin, Christmarie
name: Lütkehoff, Ben
name: Steinlein, Felix
name: Lütticke, Daniel
name: Stich, Volker
Publisher: name: Hannover : publish-Ing.
Year: 2020
Subjects: subject: Disruption Management
subject: Machine Learning
subject: Production Control
subject: Visual Analytics
subject: Deviation Detection
subject: Similarity Analysis
subject: Konferenzschrift
subject: Dewey Decimal Classification::600 | Technik::620 | Ingenieurwissenschaften und Maschinenbau

description: Changing customer demands lead to increasing product varieties and decreasing delivery times, which in turn pose great challenges for production companies. Combined with high market volatility, they lead to increasingly complex and diverse production processes. Thus, the susceptibility to disruptions in manufacturing rises, turning the task of Production Planning and Control (PPC) into a complex, dynamic and multidimensional problem. Addressing PPC challenges such as disruption management in an efficient and timely manner requires a high level of manual human intervention. In times of digitization and Industry 4.0, companies strive to find ways to guide their workers in this process of disruption management or automate it to eliminate human intervention altogether. This paper presents one possible application of Machine Learning (ML) in disruption management on a real-life use case in mixed model continuous production, specifically in the final assembly. The aim is to ensure high-quality online decision support for PPC tasks. This paper will therefore discuss the use of ML to anticipate production disruptions, solutions to efficiently highlight and convey the relevant information, as well as the generation of possible reaction strategies. Additionally, the necessary preparatory work and fundamentals are covered in the discussion, providing guidelines for production companies towards consistent and efficient disruption management.
nparcomp: An R software package for nonparametric multiple comparisons and simultaneous confidence intervals
Creators: name: Konietschke, Frank
name: Placzek, Marius
name: Schaarschmidt, Frank
name: Hothorn, Ludwig A.
Publisher: name: Alexandria, VA : American Statistical Association
Year: 2015
Subjects: subject: Nonparametric
subject: nparcomp
subject: One-way layout
subject: Dewey Decimal Classification::300 | Sozialwissenschaften, Soziologie, Anthropologie::310 | Statistik

description: One-way layouts, i.e., a single factor with several levels and multiple observations at each level, frequently arise in various fields. Usually not only a global hypothesis is of interest but also multiple comparisons between the different treatment levels. In most practical situations, the distribution of observed data is unknown and there may exist a number of atypical measurements and outliers. Hence, use of parametric and semipara-metric procedures that impose restrictive distributional assumptions on observed samples becomes questionable. This, in turn, emphasizes the demand on statistical procedures that enable us to accurately and reliably analyze one-way layouts with minimal conditions on available data. Nonparametric methods offer such a possibility and thus become of particular practical importance. In this article, we introduce a new R package nparcomp which provides an easy and user-friendly access to rank-based methods for the analysis of unbalanced one-way layouts. It provides procedures performing multiple comparisons and computing simultaneous confidence intervals for the estimated effects which can be easily visualized. The special case of two samples, the nonparametric Behrens-Fisher problem, is included. We illustrate the implemented procedures by examples from biology and medicine.
Automated production data feedback for adaptive work planning and production control
Creators: name: Denkena, Berend
name: Dittrich, Marc-André
name: Wilmsmeier, Sören
Publisher: name: Amsterdam : Elsevier B.V.
Year: 2019
Subjects: subject: Adaptive production planning
subject: Digital manufacturing system
subject: Production data
subject: Dewey Decimal Classification::600 | Technik::620 | Ingenieurwissenschaften und Maschinenbau

description: Higher customer's expectations and new technological developments have resulted in an increased complexity of manufacturing systems. Consequently, work planning and production control have become more crucial than ever to the success of companies. Adaptive work planning and production control approaches offer high potential with respect to flexibility and complexity management. However, the approaches find little use in practice, since the automatic acquisition of all potentially relevant information with additional sensors is cost-intensive and not feasible in many cases. At the same time, the potential of already existing production data, that is stored in Manufacturing Execution Systems (MES), remains untapped. This paper presents a method for automated production data feedback that guarantees a systematic update of production plan data only based on MES data. The functionality of the method is validated exemplarily at a thread manufacturer. The results reveal that an MES can provide a sufficient database for adaptive work planning and production control approaches. Moreover, the developed method can be applied to identify suitable workstations and measurement categories for additional sensor implementation.
Coarse-grained forms for equations describing the microscopic motion of particles in a fluid
Creators: name: Das, Shankar P.
name: Yoshimori, Akira
Publisher: name: arXiv
Year: 2013
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: Equations of motion for the microscopic number density $\hatρ({\bf x},t)$ and the momentum density $\hat{\bf g}({\bf x},t)$ of a fluid have been obtained in the past from the corresponding Langevin equations representing the dynamics of the fluid particles. In the present work we average these exact equations of microscopic dynamics over the local equilibrium distribution to obtain stochastic partial differential equations for the coarse grained densities with smooth spatial and temporal dependence. In particular, we consider Dean's exact balance equation for the microscopic density of a system of interacting Brownian particles to obtain the basic equation of the dynamic density functional theory. In the thermally averaged equation for the coarse grained density $ρ({\bf x},t)$, the related dependence on the bare interaction potential in Dean's equation is converted to that on the corresponding direct correlation functions of the density functional theory.
description: 10 pages
Hardware-Abbildung eines videobasierten Verfahrens zur echtzeitfähigen Auswertung von Winkelhistogrammen auf eine modulare Coprozessor-Architektur [Hardware mapping of a video-based approach for real-time evaluation of angular histograms on a modular coprocessor architecture]
Creators: name: Flatt, H.
name: Tarnowsky, A.
name: Blume, Holger
name: Pirsch, Peter
Publisher: name: Göttingen : Copernicus GmbH
Year: 2010
Subjects: subject: Clock frequency
subject: Co-processor architecture
subject: Configurable architectures
subject: FPGA implementations
subject: Parallel processing
subject: Processing elements
subject: RISC processors
subject: Video-based approach
subject: Graphic methods
subject: Hardware
subject: Image resolution
subject: Reduced instruction set computing
subject: Table lookup
subject: Video streaming
subject: Architecture
subject: FOS: Civil engineering
subject: Dewey Decimal Classification::600 | Technik::620 | Ingenieurwissenschaften und Maschinenbau::621 | Angewandte Physik::621,3 | Elektrotechnik, Elektronik

description: This paper presents the mapping of a video-based approach for real-time evaluation of angular histograms on a modular coprocessor architecture. The architecture comprises several dedicated processing elements for parallel processing of computation-intensive image processing tasks and is coupled with a RISC processor. A configurable architecture extension, especially a processing element for evaluating angular histograms of objects in conjunction with a RISC processor, provides a real-time classification. Depending on the configuration of the architecture extension, 3 300 to 12 000 look-up tables are required for a Xilinx Virtex-5 FPGA implementation. Running at a clock frequency of 100 MHz and independently of the image resolution per frame, 100 objects of size 256 × 256 pixels are analyzed in a 25 Hz video stream by the architecture.
description: Dieser Beitrag behandelt die Abbildung eines videobasierten Verfahrens zur echtzeitfähigen Auswertung von Winkelhistogrammen auf eine modulare Coprozessor-Architektur. Die Architektur besteht aus mehreren dedizierten Recheneinheiten zur parallelen Verarbeitung rechenintensiver Bildverarbeitungsverfahren und ist mit einem RISC-Prozessor verbunden. Eine konfigurierbare Architekturerweiterung um eine Recheneinheit zur Auswertung von Winkelhistogrammen von Objekten ermöglicht in Verbindung mit dem RISC eine echtzeitfähige Klassifikation. Je nach Konfiguration sind für die Architekturerweiterung auf einem Xilinx Virtex-5-FPGA zwischen 3300 und 12 000 Lookup-Tables erforderlich. Bei einer Taktfrequenz von 100 MHz können unabhängig von der Bildauflösung pro Einzelbild in einem 25-Hz-Videodatenstrom bis zu 100 Objekte der Größe 256×256 Pixel analysiert werden.
Fannie Mae's National Housing Survey Monthly Home Purchase Sentiment Index (HPSI) and Key Indicators-September, 2022 (a subset of the complete monthly Fannie Mae National Housing Survey)
Creators: name: Foundation, Fannie Mae
Publisher: name: Roper Center for Public Opinion Research
Year: 2023

description: Economy on right/wrong track (1); personal financial situation (1); good/bad time to buy a house (1); good/bad time to sell a house (1); home price changes (3); rental price changes (3); mortgage interest rate changes (1); ability to obtain a home mortgage today (1); current homeownership status (1); renting vs. buying a home in the future (1); concern about unemployment (1); change in income (1).
Nonlinear photoemission from metal surfaces induced by short laser pulses: the effect of field enhancement by surface plasmons
Creators: name: Varro, Sandor
name: Kroo, Norbert
Publisher: name: arXiv
Year: 2013
Subjects: subject: Optics (physics.optics)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Nonlinear electron emission processes induced by surface plasmon oscillations have been studied both experimentally and theoretically. The measured above-threshold electron spectra extend up to energies whose appearance cannot be explained solely by standard non-perturbative methods, which predict photon energy separated discrete energy line spectra with the known fast fall - plateau - cutoff envelope shape, even when taking the large field enhancement into account. The theoretical analysis of our data, based on the concept of plasmon-induced near-field effects, gives reasonably good explanation and qualitative agreement in the whole intensity range.
description: 14 pages and 4 figures
The value of weather radar data for the estimation of design storms - an analysis for the Hannover region
Creators: name: Haberlandt, Uwe
name: Berndt, Christian
Publisher: name: Göttingen : Copernicus GmbH
Year: 2016
Subjects: subject: duration-frequency curves
subject: rain-gauge
subject: Dewey Decimal Classification::500 | Naturwissenschaften::550 | Geowissenschaften

description: Pure radar rainfall, station rainfall and radar-station merging products are analysed regarding extreme rainfall frequencies with durations from 5 min to 6 h and return periods from 1 year to 30 years. Partial duration series of the extremes are derived from the data and probability distributions are fitted. The performance of the design rainfall estimates is assessed based on cross validations for observed station points, which are used as reference. For design rainfall estimation using the pure radar data, the pixel value at the station location is taken; for the merging products, spatial interpolation methods are applied. The results show, that pure radar data are not suitable for the estimation of extremes. They usually lead to an overestimation compared to the observations, which is opposite to the usual behaviour of the radar rainfall. The merging products between radar and station data on the other hand lead usually to an underestimation. They can only outperform the station observations for longer durations. The main problem for a good estimation of extremes seems to be the poor radar data quality.
Platform Deformation Phase Correction for the AMiBA-13 Co-planar Interferometer
Creators: name: Liao, Yu-Wei
name: Lin, Kai-Yang
name: Huang, Yau-De
name: Wu, Jiun-Huei Proty
name: Ho, Paul T. P.
name: Chen, Ming-Tang
name: Huang, Chih-Wei Locutus
name: Koch, Patrick M.
name: Nishioka, Hiroaki
name: Cheng, Tai-An
name: Fu, Szu-Yuan
name: Liu, Guo-Chin
name: Molnar, Sandor M.
name: Umetsu, Keiichi
name: Wang, Fu-Cheng
name: Chang, Yu-Yen
name: Han, Chih-Chiang
name: Li, Chao-Te
name: Martin-Cocher, Pierre
name: Oshiro, Peter
Publisher: name: arXiv
Year: 2013
Subjects: subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: We present a new way to solve the platform deformation problem of co-planar interferometers. The platform of a co-planar interferometer can be deformed due to driving forces and gravity. A deformed platform will induce extra components into the geometric delay of each baseline, and change the phases of observed visibilities. The reconstructed images will also be diluted due to the errors of the phases. The platform deformations of The Yuan-Tseh Lee Array for Microwave Background Anisotropy (AMiBA) were modelled based on photogrammetry data with about 20 mount pointing positions. We then used the differential optical pointing error between two optical telescopes to fit the model parameters in the entire horizontal coordinate space. With the platform deformation model, we can predict the errors of the geometric phase delays due to platform deformation with given azimuth and elevation of the targets and calibrators. After correcting the phases of the radio point sources in the AMiBA interferometric data, we recover 50% - 70% flux loss due to phase errors. This allows us to restore more than 90% of a source flux. The method outlined in this work is not only applicable to the correction of deformation for other co-planar telescopes but also to single dish telescopes with deformation problems. This work also forms the basis of the upcoming science results of AMiBA-13.
description: 12 pages, 11 figures
Selaginella selaginoides
Creators: name: Becherer
Publisher: name: Zenodo
Year: 1956
Subjects: Biodiversity
Taxonomy

description: S.Selaginoides (L.) Link (S. spinulosa A.Er.) Cat. 410und 433. Bis 2750m. l: Lovenex (J.); Barmaz (J., IVtarietan) und Bonavau (J.)ob Champery; Les Gietes ob St-Maurice (Mari^tan); Dent de Valerette (idem); Alpen von Salvan ziemlich verbreitet, unter Leizettes bis 700m herabsteigend (Coquoz); Arpille (Beauverd). - 3:ValdesDix (J.); Col deTorrent (Beauverd); Plan de Madeleine ob Chandolin (Marietan); Meiden (Mantz); Zermatt: Schwarzsee, 2550m (Thellung), Riffelsee, 2750m (Braun-Blanquet1919);Saas-Fee,häufig,obderGletscheralp bis mindestens 2600 m (Hirschmann); Almagell (A. Keller); Bistinenpass (Beauverd). - 3a:Rossbodengletscher (Chiovenda). - 4:Binntal: vielfach (Binz, P., Schmid); Gletsch (Wilczek).
description: Published as part of Becherer, 1956, Florae Vallesiacae Supplementum, pp. 1-556 in Denkschriften der Schweizerischen Naturforschenden Gesellschaft 71 on pages 1-556
Action bodies / acting bodies : performing corpo-realities in Shakespeare's late romances
Creators: name: Oesterlen, Eve-Marie
Publisher: name: Hannover : Gottfried Wilhelm Leibniz Universität Hannover
Year: 2017
Subjects: subject: Shakespeare
subject: body
subject: performance
subject: Körper
subject: Performanz
subject: Dewey Decimal Classification::800 | Literatur, Rhetorik, Literaturwissenschaft::820 | Englische Literatur

description: [no abstract]
Wind turbine rotor blade monitoring using digital image correlation: a comparison to aeroelastic simulations of a multi-megawatt wind turbine
Creators: name: Winstroth, J.
name: Schoen, L.
name: Ernst, Benedikt
name: Seume, Jörg R.
Publisher: name: Bristol : IOP Publishing Ltd.
Year: 2014
Subjects: subject: Energy & Fuels
subject: Engineering, Mechanical
subject: Physics, Applied
subject: Konferenzschrift
subject: Dewey Decimal Classification::600 | Technik::620 | Ingenieurwissenschaften und Maschinenbau

description: Optical full-field measurement methods such as Digital Image Correlation (DIC) provide a new opportunity for measuring deformations and vibrations with high spatial and temporal resolution. However, application to full-scale wind turbines is not trivial. Elaborate preparation of the experiment is vital and sophisticated post processing of the DIC results essential. In the present study, a rotor blade of a 3.2 MW wind turbine is equipped with a random black-and-white dot pattern at four different radial positions. Two cameras are located in front of the wind turbine and the response of the rotor blade is monitored using DIC for different turbine operations. In addition, a Light Detection and Ranging (LiDAR) system is used in order to measure the wind conditions. Wind fields are created based on the LiDAR measurements and used to perform aeroelastic simulations of the wind turbine by means of advanced multibody codes. The results from the optical DIC system appear plausible when checked against common and expected results. In addition, the comparison of relative out-of-plane blade deflections shows good agreement between DIC results and aeroelastic simulations.
A unified normal mode approach to dynamic tides and its application to rotating Sun-like stars
Creators: name: Ivanov, P. B.
name: Papaloizou, J. C. B.
name: Chernov, S. V.
Publisher: name: arXiv
Year: 2013
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We determine the response of a uniformly rotating star to tidal perturbations due to a companion. General periodic orbits and parabolic flybys are considered. We evaluate energy and angular momentum exchange rates as a sum of contributions from normal modes allowing for dissipative processes. We consider the case when the response is dominated by the contribution of an identifiable regular spectrum of low frequency modes, such as gravity modes and evaluate it in the limit of very weak dissipation. Our formalism may be applied both to Sun-like stars with radiative cores and convective envelopes and to more massive stars with convective cores and radiative envelopes. We provide general expressions for transfer of energy and angular momentum valid for an orbit with any eccentricity. Detailed calculations are made for Sun-like stars in the slow rotation regime where centrifugal distortion is neglected in the equilibrium and the traditional approximation is made for the normal modes. We use both a WKBJ procedure and direct numerical evaluation which are found to be in good agreement for regimes of interest. Finally we use our formalism to determine the evolution time scales for an object, in an orbit of small eccentricity, around a Sun-like star in which the tidal response is assumed to occur. Systems with either no rotation or synchronous rotation are considered. Only rotationally modified gravity modes are taken into account under the assumption that wave dissipation occurs close to the stellar centre.
description: Accepted for publication in MNRAS
Adaptive time domain boundary element method for sound radiation of tyres
Creators: name: Nezhi, Zouhair
Publisher: name: Hannover : Gottfried Wilhelm Leibniz Universität Hannover
Year: 2014
Subjects: subject: Boundary element method
subject: retarded potentials
subject: absorbing half-space
subject: a priori
subject: a posteriori error estimates
subject: tyre
subject: Randelementemethode
subject: retardierte Potentiale
subject: absorbierender Halbraum
subject: a posteriori Fehlerabschätzungen
subject: Reifen
subject: Dewey Decimal Classification::500 | Naturwissenschaften::510 | Mathematik

description: [no abstract]
Single Print Metal Stencils for High-efficiency PERC Solar Cells
Creators: name: Hannebauer, H.
name: Falcon, T.
name: Cunnusamy, J.
name: Dullweber, Thorsten
Publisher: name: London : Elsevier Ltd.
Year: 2016
Subjects: subject: Dual print
subject: Metallization
subject: PERC
subject: Screen-printing
subject: Silicon solar cell
subject: Stencil printing
subject: Busbars
subject: Conversion efficiency
subject: Crystalline materials
subject: Efficiency
subject: Electric resistance
subject: Integrated circuit interconnects
subject: Metallizing
subject: Metals
subject: Screen printing
subject: Silicon
subject: Silver
subject: Solar cells
subject: Cell conversion efficiency
subject: Cell performance
subject: High-efficiency
subject: PERC solar cells
subject: Screen-printing process
subject: Series resistances
subject: Silicon solar cells
subject: Konferenzschrift
subject: Dewey Decimal Classification::600 | Technik::620 | Ingenieurwissenschaften und Maschinenbau

description: Industrial silicon solar cells like Passivated Emitter and Rear Cells (PERC) typically apply a screen-printed (Ag) front contact with a single print process using a mesh screen. It has been shown that using stencils instead of screens improves the finger profile leading to slightly higher cell conversion efficiencies. However, so far stencil printing required an extra printing step for the busbars since conventional stencils do not support H-pattern designs. In this paper, we evaluate a novel "single print" stencil from ASM AE that allows to print busbars and fingers in a single print step. We apply the novel single print stencil to high-efficiency PERC solar cells and compare it to today's industrial screen printing processes (single print and dual print) as well as to a high performance dual-printed front side grid applying a stencil for the fingers and a screen for the busbars. The printed finger width ranges from 35.8 ± 2.3μm for 30μm stencil opening to 46.7 ± 3.4μm for 40μm screen opening which leads to an 0.5%abs increased metallized area on the front side of the screen printed fingers compared to the stencil printed fingers. The resulting average finger height is 22.3μm for the stencil groups and 11.9μm for the screen printed Ag finger which leads to a difference in the finger line resistance and an additional series resistance contribution for the screen-printed cells of 0.05Ωcm2. We achieve almost identical PERC cell efficiencies with the single print stencil and the dual print stencil process obtaining best values up to 21.1% and average values of 21.0%. In contrast, both screen printed groups achieve 0.2%abs lower average conversion efficiencies mostly due to the lower Jsc and FF. The advantage of the dual print process compared to single print is shown in the increased Voc by 1 to 2mV due to the used non-firing through Ag busbar paste. With these results we demonstrate that the single print stencil process saves two process steps compared to dual print using a stencil while obtaining the same PERC cell performance with an efficiency gain of 0.2%abs compared to today's industrial screen print processes.
Potentials Of Blockchain In Crowdsourcing Platforms – An Outlook For Industrial Services
Creators: name: Große, Nick
name: Eisenmann, Martin
Publisher: name: Hannover : publish-Ing.
Year: 2021
Subjects: subject: Crowdworking
subject: Regulation
subject: Behavioural Uncertainty
subject: Industrial Services
subject: Blockchain
subject: Trust
subject: Konferenzschrift
subject: Dewey Decimal Classification::600 | Technik::620 | Ingenieurwissenschaften und Maschinenbau

description: Companies increasingly outsource services with the intention to disseminate risks and workload (problem) with other organizations. Reasons for that may be the lack of internal expertise, reduced execution costs, and network effects such as focus on the core business. Crowdsourcing is a way of disseminate the workload, utilizing external expertise and solving problems of a project with other, partly unknown, network participants. The goal of crowdsourcing is to separate responsibility and to balance the workload of employees (peer) or to make use of suitable external workforces coordinated by network mechanisms (platform). Crowdsourcing appears in an ambivalent way and needs regulating and participatory structures of employment. Due to the fact that a failure of a single entity may lead to the failure of the whole project, the mutually unknown participants have to rely on each other’s quality (performance). Cooperations are prone to information asymmetry and its corresponding uncertainty in terms of the partners’ behaviour which leads to the question of trust between the cooperating partners (principal and peer). This paper addresses the entities of a crowdsourcing system under the scope of the principal agent theory and its underlying behavioural assumptions. Five essential elements will be derived: principal, peer, problem, platform and performance (5 Ps). Based on this, the potentials of the blockchain technology will be explored by reflecting its functionalities to the derived elements and its contributions to ensure trust despite of information asymmetry in crowdsourcing platforms.
A Simple And Modular Approach To Path Planning For Tractor-Trailer Robots Based On Modification Of Pre-Existing Trajectories
Creators: name: Recker, Tobias
name: Matour, Mohammad Ehsan
name: Raatz, Annika
Publisher: name: Hannover : publish-Ing.
Year: 2021
Subjects: subject: Tractor-trailer mobile robots
subject: Path planning
subject: Object transport
subject: Konferenzschrift
subject: Dewey Decimal Classification::600 | Technik::620 | Ingenieurwissenschaften und Maschinenbau

description: Tractor-trailer Mobile Robot systems consist of a nonholonomic mobile robot regarded as a tractor and several passive trailers linked to the tractor via a hinge. As these systems are in many cases more economical compared to multi mobile robot systems, they are nowadays used for the transport of various objects in the field of logistics. Hence an exact and efficient path planning algorithm is required. Due to the highly nonlinear characteristics of such a system, path planning is always a challenging problem. Many path planning algorithms have already been proposed for mobile robots. While some of these approaches can solve the path planning problem for robots with multiple trailers, the solutions are usually complex, limited to a specific hardware configuration, or very computationally expensive. In this work, we present an algorithm that, although still computationally expensive in its current form, provides a very simple, extensible, and flexible solution for path planning of tractor-trailer robots. Based on a conventional global planner for mobile robots (like A* or Dijkstra), our algorithm adjusts the global path according to the dimension of the carried object so that the whole system traverses a collision-free path. We take advantage of the fact that the global planner has already planned a collision-free path for the mobile robot (tractor), which the trailer follows almost exactly on straight paths. Accordingly, collisions occur predominantly in or shortly after curves. We designed our algorithm to detect these particular curves and adjust the curve radius so that no collision occurs. This way, we do not need to re-plan the whole trajectory. Also, we can upgrade almost any planning algorithm for mobile robots to work with tractor-trailer systems. We validate our method based on a series of simulations. First real-world experiments are also very promising.
Ablation and functionalization of flexographic printing forms using femtosecond lasers for additively manufactured polymer-optical waveguides
Creators: name: Wienke, A.
name: Hoffmann, G.-A.
name: Koch, J.
name: Jäschke, P.
name: Overmeyer, Ludger
name: Kaierle, Stefan
Publisher: name: Amsterdam : Elsevier B.V.
Year: 2020
Subjects: subject: Ablation
subject: Adjustable Material Transfer
subject: Femtosecond Laser
subject: Flexographic Printing
subject: Functionalization
subject: Femtosecond lasers
subject: Offset printing
subject: Printing presses
subject: Pulsed lasers
subject: Ablation parameters
subject: Flexographic printing
subject: Functionalizations
subject: Interconnect devices
subject: Laser-induced structures
subject: Polymer optical waveguide
subject: Spatially resolved
subject: Ultrashort-pulsed laser
subject: Optical waveguides
subject: Konferenzschrift
subject: Dewey Decimal Classification::600 | Technik
subject: Dewey Decimal Classification::600 | Technik::670 | Industrielle und handwerkliche Fertigung

description: An efficient and low-cost approach to manufacture Opto-Mechatronic Interconnect Devices will be obligatory to handle the strongly increasing amount of data. The presented approach is based on a flexographic printing process. To adjust the transferred material the printing form is functionalized by means of laser-induced structures using an ultrashort-pulsed laser. The long-term goal is to adjust the printing result through microstructures in the printing form in order to create spatially resolved material transfer. In this work, first the ablation parameters are investigated at different repetition rates using a femtosecond laser. Further, a line structure is inserted in the material transferring areas of the printing form, which is consequently widened. Its influence on the printing result is presented. © 2020 The Authors. Published by Elsevier B.V.
Hanbury Brown - Twiss type correlations with surface plasmon light
Creators: name: Varro, Sandor
name: Kroo, Norbert
name: Oszetzky, Daniel
name: Nagy, Attila
name: Czitrovszky, Aladar
Publisher: name: arXiv
Year: 2013
Subjects: subject: Quantum Physics (quant-ph)
subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: Intensity-intensity correlations are studied for light signals stemming from the spontaneous decay of surface plasmon oscillations, generated in the Kretschmann geometry. Non-classical photon statistics and the the transition from antibunching to bunching of the electron counts have been found experimentally and analysed on a new theoretical basis.
description: 24 pages and 5 figures
title: Fr. J. Löhrer, Geschichte d. Stadt Neuss / J. Gottfried Broix, Erinnerungen an das alte berühmte Tolbiacum
Creators: name: Düntzer, Heinrich
Publisher: name: University Library Heidelberg
Year: 2015

description: Fr. J. Löhrer, Geschichte der Stadt Neuss von ihrer Gründung an bis jetzt nach gedruckten und handschriftlichen Quellen verfasst (Neuss 1840 S. XV, 447 und VIII in 8) J. Gottfried Broix, Erinnerungen an das alte berühmte Tolbiacum, die jetzige Stadt Zülpich, mit Berücksichtigung der Umgegend. Ein Beitrag zur vaterländischen Geschichte
Different Recruitment Processes for an Online-Survey Among German Livestock Farmers - Impacts on Sampling Bi-ases and Data Quality
Creators: name: Mergenthaler, Marcus
name: Kemnade, Miriam
name: Schröter, Iris
Publisher: name: Proceedings in Food System Dynamics
Year: 2024

description: This paper discusses the methodological challenges of conducting online surveys for agricultural social science research, with a focus on the potential biases introduced by sampling processes. Online surveys often use convenience or quota sampling, which can lead to self-selection biases that compromise the validity, reliability, and generalizability of research findings. Response quality issues, such as straight-lining and response fatigue, further exacerbate these challenges. The study examines data from a survey of more than 600 German livestock farmers who were recruited through three different methods: informally through social media channels, formally through professional networks, and commercially through a market research service provider. Results show that the commercial sub-sample had shorter response times and higher rates of incorrect responses for a control question. The sub-samples also showed demographic variations and differences in personality traits, agricultural land areas, and farm characteristics. The role of quota requirements in shaping differences within the commercial sub-sample is emphasized in the discussion. This reveals limitations in online surveys' ability to represent objectively defined target populations. The interpretation of results is complicated by the absence of consistent theoretical concepts and clear ex-ante hypotheses. The paper concludes by recommending that agricultural social science researchers transparently disclose their sampling procedures. This will enable readers to make informed judgments on the reliability and validity of their findings.
description: Proceedings in Food System Dynamics, Proceedings in System Dynamics and Innovation in Food Networks 2024
Entwurfskonzept einer Car2Car-Multiband-Dachantenne
Creators: name: Wang, Yuanhao
name: Reit, Marco
name: Mathis, Wolfgang
Publisher: name: Göttingen : Copernicus GmbH
Year: 2012
Subjects: subject: Antenna length
subject: Antenna system
subject: Design concept
subject: Multiband
subject: Simulations and measurements
subject: Wideband antenna
subject: Wireless services
subject: Bandwidth
subject: Design
subject: Directional patterns (antenna)
subject: Roofs
subject: Wi-Fi
subject: Wireless telecommunication systems
subject: Antennas
subject: Dewey Decimal Classification::600 | Technik

description: Due to the vastly increasing use of wireless services in the car, such as WiFi, Car2Car and LTE, the requirements on bandwidth and radiation pattern of the roof antenna systems become more challenging. In this work, a design concept for multi-band roof antenna systems is presented. We aim to get a higher bandwidth and an almost circular radiation pattern on the horizontal plane. Moreover, the antenna length is considered in order to fulfill the requirements set by construction ECE-regulations (ECE, 2010). The applicability of the design concept is not limited to multi-band roof antennas, it can also be used for a general wideband antenna design. For illustration of this concept, a multi-band roof antenna with a bandwidth of 780 MHz to 5.9 GHz and a near circular radiation pattern with an average gain of Combining double low line 3 dBi (at 5.9 GHz) on the horizontal plane is designed. The simulation and measurement results are presented. © 2012 Author(s).
description: Aufgrund der immer umfangreicheren Nutzung neuer Funkdienste im KFZ, wie WLAN, Car2Car und LTE, steigen die Anforderungen bezüglich der Bandbreite und der Strahlungscharakteristik der verwendeten Antennensysteme stetig an. In dieser Arbeit wird ein Entwurfskonzept für eine Car2Car-Multiband-Dachantenne vorgestellt. Ziele bei einem solchen Entwurf sind eine möglichst hohe Bandbreite sowie ein in horizontaler Ebene hoher und gleichmäßig verteilter Antennengewinn. Hierbei muss die amtliche Vorgabe (ECE, 2010) für die Antennenhöhe berücksichtigt werden. Die Anwendbarkeit des Verfahrens beschränkt sich nicht nur auf Multiband-Dachantennen, sondern kann ebenso für den allgemeinen Breitbandantennenentwurf genutzt werden. Als Beispielanwendung wird mit dem hier vorgestellten Konzept eine Multiband-Dachantenne mit einer Bandbreite von 780 MHz bis 5,9 GHz und einer nahezu runden Strahlungscharakteristik sowie einem durchschnittlichen Antennengewinn von G = 3 dBi (bei 5,9 GHz, in horizontaler Ebene) entworfen. Zusätzlich werden die Simulations- und Messergebnisse vorgestellt.
An investigation of star formation and dust attenuation in major mergers using ultraviolet and infrared data
Creators: name: Yuan, F. -T.
name: Takeuchi, T. T.
name: Matsuoka, Y.
name: Buat, V.
name: Burgarella, D.
name: Iglesias-Páramo, J.
Publisher: name: arXiv
Year: 2012
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: Merger processes play an important role in galaxy formation and evolution. To study the influence of merger processes on the evolution of dust properties and cosmic star formation rate, we investigate a local sample of major merger galaxies and a control sample of isolated galaxies using GALEX ultraviolet (UV) and Spitzer infrared (IR) images. Through a statistical study, we find that dust attenuation in merger galaxies is enhanced with respect to isolated galaxies. We find this enhancement is contributed mainly by spiral galaxies in spiral-spiral (S-S) pairs, and increases with the increasing stellar mass of a galaxy. Combining the IR and UV parts of star formation rates (SFRs), we then calculated the total SFRs and specific star formation rates (SSFRs). We find the SSFRs to be enhanced in merger galaxies. This enhancement depends on galaxy stellar mass and the companion's morphology, but depends little on whether the galaxy is a primary or secondary component or on the separation between two components. These results are consistent with a previous study based only on IR images. In addition, we investigate the nuclear contributions to SFRs. SFRs in paired galaxies are more concentrated in the central part of the galaxies than in isolate galaxies. Our studies of dust attenuation show that the nuclear parts of pairs most resemble ULIRGs. Including UV data in the present work not only provides reliable information on dust attenuation, but also refines analyses of SFRs.
description: 21 pages, 21 figures
Modellierung und Simulation des Substrat-Rauschens in integrierten RF CMOS-Schaltungen [Modeling and simulation of substrate noise in RF CMOS integrated circuits]
Creators: name: Lin, L.
name: Xiong, J.
name: Mathis, Wolfgang
Publisher: name: Göttingen : Copernicus GmbH
Year: 2009
Subjects: subject: Model and simulation
subject: RF CMOS integrated circuits
subject: Substrate noise
subject: Computer simulation
subject: CMOS integrated circuits
subject: Dewey Decimal Classification::600 | Technik::620 | Ingenieurwissenschaften und Maschinenbau::621 | Angewandte Physik::621,3 | Elektrotechnik, Elektronik

description: Im integrierten CMOS-Schaltungsentwurf kann das Substrat-Rauschen, das vom digitalen Teil entsteht, die Funktionalität des analogen Teils stark beeinflussen. Es wird daher immer wichtiger, das Substrat als ein Medium der Rauschen-Propagation genau zu modellieren. Im vorliegenden Artikel wird ein auf der Finite Elemente Methode (FEM) und Modellordnungsreduktion (MOR) basiertes Modellierungsverfahren zur Admittanzen-Extraktion im Halbleitersubstrat vorgestellt. Nach der Diskretisierung mit FEM wird das Substrat im Allgemeinen als ein resistives/kapazitives Netz angesehen. Durch Bestimmung der Admittanz-Matrix und MOR ist es möglich ein äquivalentes Dreipol-Modell zwischen digitalem und analogem Teil über das Substrat zu bilden. Das Ergebnis der Modellierung wird dargestellt und mit numerischer Simulation des Substrat-Rauschens verglichen. Die Modellierung ermöglicht es, die Einflüsse des Substrat-Rauschens im Schaltungsentwurf zu berücksichtigen und so bestehende CMOS-Schaltungsarchitekturen zu optimieren.
A universal relationship between optimum drift voltage and resolving power
Creators: name: Kirk, Ansgar T.
name: Bakes, Kai
name: Zimmermann, Stefan
Publisher: name: Berlin, Heidelberg : Springer
Year: 2017
Subjects: subject: Analytical model
subject: Drift tube
subject: Ideality
subject: Non-idealities
subject: Ion mobility spectrometry
subject: Dewey Decimal Classification::600 | Technik::620 | Ingenieurwissenschaften und Maschinenbau::621 | Angewandte Physik::621,3 | Elektrotechnik, Elektronik

description: The drift voltage is one of the key experimental parameters of any drift tube ion mobility spectrometer. In this work, we show that a universal relationship between optimum drift voltage and the resolving power reached at this point exists, governed only by temperature and ion charge state. With these two quantities known, the measured optimum drift voltage and resolving power combination can be used to estimate the ideality of the drift conditions inside a drift tube, since any deviation from the theoretical values must be caused by non-idealities in the ions’ drift. Analyzing drift voltage sweeps from nine different ion mobility spectrometers, a continuous increase in drift tube ideality over the past is observed, reaching from less than 50% thirty years ago to 99% for a current design based on printed circuit boards. Furthermore, possible causes for the observed non-idealities are discussed. The final publication is available at Springer via https://doi.org/10.1007/s12127-017-0219-6.
Shutterless ion mobility spectrometer with fast pulsed electron source
Creators: name: Bunert, Erik
name: Heptner, Andre
name: Reinecke, T.
name: Kirk, Ansgar T.
name: Zimmermann, Stefan
Publisher: name: College Park, MA : American Institute of Physics (AIP)
Year: 2017
Subjects: subject: Atmospheric composition
subject: Photoionization
subject: X-rays
subject: Detection limit
subject: Gas discharges
subject: Electron sources
subject: Tritium
subject: Chemical compounds and components
subject: Radioactive material
subject: Surface collisions
subject: Dewey Decimal Classification::600 | Technik::620 | Ingenieurwissenschaften und Maschinenbau::621 | Angewandte Physik::621,3 | Elektrotechnik, Elektronik
subject: Dewey Decimal Classification::500 | Naturwissenschaften::530 | Physik

description: Ion mobility spectrometers (IMS) are devices for fast and very sensitive trace gas analysis. The measuring principle is based on an initial ionization process of the target analyte. Most IMS employ radioactive electron sources, such as 63Ni or 3H. These radioactive materials have the disadvantage of legal restrictions and the electron emission has a predetermined intensity and cannot be controlled or disabled. In this work, we replaced the 3H source of our IMS with 100 mm drift tube length with our nonradioactive electron source, which generates comparable spectra to the 3H source. An advantage of our emission current controlled nonradioactive electron source is that it can operate in a fast pulsed mode with high electron intensities. By optimizing the geometric parameters and developing fast control electronics, we can achieve very short electron emission pulses for ionization with high intensities and an adjustable pulse width of down to a few nanoseconds. This results in small ion packets at simultaneously high ion densities, which are subsequently separated in the drift tube. Normally, the required small ion packet is generated by a complex ion shutter mechanism. By omitting the additional reaction chamber, the ion packet can be generated directly at the beginning of the drift tube by our pulsed nonradioactive electron source with only slight reduction in resolving power. Thus, the complex and costly shutter mechanism and its electronics can also be omitted, which leads to a simple low-cost IMS-system with a pulsed nonradioactive electron source and a resolving power of 90.
Acoustic resonance in a high-speed axial compressor
Creators: name: Hellmich, Bernd
Publisher: name: Hannover : Gottfried Wilhelm Leibniz Universität Hannover
Year: 2008
Subjects: subject: Acoustic resonance
subject: axial compressor
subject: rotating stall
subject: Dewey Decimal Classification::600 | Technik::620 | Ingenieurwissenschaften und Maschinenbau

description: [no abstract]