26 research outputs found

    A Vision of Digitalization in Supply Chain Management and Logistics

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    Digitalization requires a new form of management to master the transformation process of corporations and companies. The Dortmund Management Model structures the focus areas of the digital transformation along the management tasks goal, planning, decision, realization and monitoring as well as the common socio-technical subsystems technological, organizational and personnel - enriched by a fourth dimension: information. Additionally, the acceleration factors transformation, migration and change management are taken into account. This paper embraces a vision for a persistent management of production and supply chain networks in order to achieve a holistic Management 4.0. The emerging developments of technology, methods, tools and models in production and supply chain research are connected and merged into a big picture of digital supply chain management and logistics. The interfaces between management tasks show specific characteristics of digital business processes in particular, which are hereinafter exemplarily outlined: New business models and value-creation networks are based on adaption intelligent production systems, which are interconnected with digital models for continuous planning and reconfiguration. At the shop floor and between sites orders are completed by autonomous guided vehicles (AGV) with intelligent load carriers. Decentralized negotiations and decisions across company boundaries concluded with smart contracts are enabling reasonable and sustainable distribution of the value creation processes. Humans are still in the center of action – abilities are developed by integrated competence management, new learning approaches and human-centered assistance systems coupled with AI-based decision-making support. New types of organizations allow a synergetic collaboration of humans and machines. The benefit of integrating new production and transport technologies becomes assessable and accelerates the ongoing renewal of existing networks. This paper provides an overview of possible potential and connecting factors by linking different technological developments towards supply chain, logistics, production and management research and shows further research demands

    Visualizing Escherichia coli Sub-Cellular Structure Using Sparse Deconvolution Spatial Light Interference Tomography

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    Studying the 3D sub-cellular structure of living cells is essential to our understanding of biological function. However, tomographic imaging of live cells is challenging mainly because they are transparent, i.e., weakly scattering structures. Therefore, this type of imaging has been implemented largely using fluorescence techniques. While confocal fluorescence imaging is a common approach to achieve sectioning, it requires fluorescence probes that are often harmful to the living specimen. On the other hand, by using the intrinsic contrast of the structures it is possible to study living cells in a non-invasive manner. One method that provides high-resolution quantitative information about nanoscale structures is a broadband interferometric technique known as Spatial Light Interference Microscopy (SLIM). In addition to rendering quantitative phase information, when combined with a high numerical aperture objective, SLIM also provides excellent depth sectioning capabilities. However, like in all linear optical systems, SLIM's resolution is limited by diffraction. Here we present a novel 3D field deconvolution algorithm that exploits the sparsity of phase images and renders images with resolution beyond the diffraction limit. We employ this label-free method, called deconvolution Spatial Light Interference Tomography (dSLIT), to visualize coiled sub-cellular structures in E. coli cells which are most likely the cytoskeletal MreB protein and the division site regulating MinCDE proteins. Previously these structures have only been observed using specialized strains and plasmids and fluorescence techniques. Our results indicate that dSLIT can be employed to study such structures in a practical and non-invasive manner

    Evaluation of flight efficiency for Stockholm Arlanda Airport arrivals

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    Analysis of punctuality of airport arrivals, as well as identification of causes of the delays within transition airspace, is an important step in evaluating performance of the Terminal Maneuvering Area (TMA) Air Navigation Services: without knowing the current performance levels, it is difficult to identify which areas could be improved. Deviations from the flight plans is one of the major reasons for arrival delays. In this work, we quantified the impact of the deviations from the flight plans on the fuel burn. One of the main reasons of fuel waste is non- optimal vertical profiles during the descent phase. We calculated how much extra fuel is wasted due to vertical flight inefficiency within Stockholm TMA.Peer ReviewedPostprint (published version

    A survey for variable young stars with small telescopes: IX - Evolution of spot properties on YSOs in IC 5070

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    We present spot properties on 32 periodic young stellar objects in IC 5070. Long term, ∼5 yr, light curves in the V, R, and I-bands are obtained through the HOYS (Hunting Outbursting Young Stars) citizen science project. These are dissected into six months long slices, with 3 months oversampling, to measure 234 sets of amplitudes in all filters. We fit 180 of these with reliable spot solutions. Two thirds of spot solutions are cold spots, the lowest is 2150 K below the stellar temperature. One third are warm spots that are above the stellar temperature by less than ∼2000 K. Cold and warm spots have maximum surface coverage values of 40 per cent, although only 16 per cent of warm spots are above 20 per cent surface coverage as opposed to 60 per cent of the cold spots. Warm spots are most likely caused by a combination of plages and low density accretion columns, most common on objects without inner disc excess emission in K − W2. Five small hot spot solutions have <3 percent coverage and are 3000 – 5000 K above the stellar temperature. These are attributed to accretion, and four of them occur on the same object. The majority of our objects are likely to be accreting. However, we observe very few accretion hot spots as either the accretion is not stable on our timescale or the photometry is dominated by other features. We do not identify cyclical spot behaviour on the targets. We additionally identify and discuss a number of objects that have interesting amplitudes, phase changes, or spot properties

    A survey for variable young stars with small telescopes – VIII. Properties of 1687 Gaia selected members in 21 nearby clusters

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    The Hunting Outbursting Young Stars (HOYS) project performs long-term, optical, multi-filter, high cadence monitoring of 25 nearby young clusters and star forming regions. Utilising Gaia DR3 data we have identified about 17000 potential young stellar members in 45 coherent astrometric groups in these fields. Twenty one of them are clear young groups or clusters of stars within one kiloparsec and they contain 9143 Gaia selected potential members. The cluster distances, proper motions and membership numbers are determined. We analyse long term (≈ 7 yr) V, R, and I-band light curves from HOYS for 1687 of the potential cluster members. One quarter of the stars are variable in all three optical filters, and two thirds of these have light curves that are symmetric around the mean. Light curves affected by obscuration from circumstellar materials are more common than those affected by accretion bursts, by a factor of 2 – 4. The variability fraction in the clusters ranges from 10 to almost 100 percent, and correlates positively with the fraction of stars with detectable inner disks, indicating that a lot of variability is driven by the disk. About one in six variables shows detectable periodicity, mostly caused by magnetic spots. Two thirds of the periodic variables with disk excess emission are slow rotators, and amongst the stars without disk excess two thirds are fast rotators – in agreement with rotation being slowed down by the presence of a disk

    A survey for variable young stars with small telescopes: VIII — Properties of 1687 Gaia selected members in 21 nearby clusters

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    The Hunting Outbursting Young Stars (HOYS) project performs long-term, optical, multi- filter, high cadence monitoring of 25 nearby young clusters and star forming regions. Utilising Gaia DR3 data we have identified about 17000 potential young stellar members in 45 coherent astrometric groups in these fields. Twenty one of them are clear young groups or clusters of stars within one kiloparsec and they contain 9143 Gaia selected potential members. The cluster distances, proper motions and membership numbers are determined. We analyse long term ( 7 yr) V, R, and I-band light curves from HOYS for 1687 of the potential cluster members. One quarter of the stars are variable in all three optical filters, and two thirds of these have light curves that are symmetric around the mean. Light curves affected by obscuration from circumstellar materials are more common than those affected by accretion bursts, by a factor of 2 – 4. The variability fraction in the clusters ranges from 10 to almost 100 percent, and correlates positively with the fraction of stars with detectable inner disks, indicating that a lot of variability is driven by the disk. About one in six variables shows detectable periodicity, mostly caused by magnetic spots. Two thirds of the periodic variables with disk excess emission are slow rotators, and amongst the stars without disk excess two thirds are fast rotators – in agreement with rotation being slowed down by the presence of a disk

    Design and comparative evaluation of an iterative contact point estimation method for static stability estimation of mobile actively reconfigurable robots

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    Due to the advancements of robotic systems, they are able to be employed in more unstructured outdoor environments. In such environments the robot-terrain interaction becomes a highly non-linear function. Several methods were proposed to estimate the robot-terrain interaction: machine learning methods, iterative geometric methods, quasi-static and fully dynamic physics simulations. However, to the best of our knowledge there has been no systematic evaluation comparing those methods. In this paper, we present a newly developed iterative contact point estimation method for static stability estimation of actively reconfigurable robots. This new method is systematically compared to a physics simulation in a comprehensive evaluation. Both interaction models determine the contact points between robot and terrain and facilitate a subsequent static stability prediction. Hence, they can be used in our state space global planner for rough terrain to evaluate the robot's pose and stability. The analysis also compares deterministic versions of both methods to stochastic versions which account for uncertainty in the robot configuration and the terrain model. The results of this analysis show that the new iterative method is a valid and fast approximate method. It is significantly faster compared to a physics simulation while providing good results in realistic robotic scenarios

    Nuclear positioning facilitates amoeboid migration along the path of least resistance

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    During metazoan development, immune surveillance and cancer dissemination, cells migrate in complex three-dimensional microenvironments1,2,3. These spaces are crowded by cells and extracellular matrix, generating mazes with differently sized gaps that are typically smaller than the diameter of the migrating cell4,5. Most mesenchymal and epithelial cells and some—but not all—cancer cells actively generate their migratory path using pericellular tissue proteolysis6. By contrast, amoeboid cells such as leukocytes use non-destructive strategies of locomotion7, raising the question how these extremely fast cells navigate through dense tissues. Here we reveal that leukocytes sample their immediate vicinity for large pore sizes, and are thereby able to choose the path of least resistance. This allows them to circumnavigate local obstacles while effectively following global directional cues such as chemotactic gradients. Pore-size discrimination is facilitated by frontward positioning of the nucleus, which enables the cells to use their bulkiest compartment as a mechanical gauge. Once the nucleus and the closely associated microtubule organizing centre pass the largest pore, cytoplasmic protrusions still lingering in smaller pores are retracted. These retractions are coordinated by dynamic microtubules; when microtubules are disrupted, migrating cells lose coherence and frequently fragment into migratory cytoplasmic pieces. As nuclear positioning in front of the microtubule organizing centre is a typical feature of amoeboid migration, our findings link the fundamental organization of cellular polarity to the strategy of locomotion

    Endogenous Il10 Alleviates the Systemic Antiviral Cellular Immune Response and T Cell-Mediated Immunopathology in Select Organs of Acutely LCMV-Infected Mice

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    The immunoregulatory cytokine IL-10 suppresses T-cell immunity. The complementary question, whether IL-10 is also involved in Limiting the collateral damage of vigorous T cell responses, has not been addressed in detail. Here, we report that the particularly strong virus-specific immune response during acute primary infection with the Lymphocytic choriomeningitis virus (LCMV) in mice is significantly further increased in Il10 deficient mice, particularly regarding frequencies and cytotoxic activity of CD8(+) T cells. This increase results in exacerbating immunopathology in select organs, ranging from transient local swelling to an increased risk for mortality. Remarkably, LCMV-induced, T cell mediated hepatitis is not affected by endogenous Il10. The alleviating effect of Il10 on LCMV-induced immunopathology was found to be operative in delayed-type hypersensitivity footpad-swelling reaction and in debilitating meningitis in mice of both the C57BL/6 and BALB/c strains. These strains are prototypic counterpoles for genetically imprinted type 1-biased versus type 2-biased T cell mediated immune responses against various infectious pathogens. However, during acute LCMV infection, neither systemic cytokine patterns nor the impact of Il10 on LCMV-induced immunopathology differed conspicuously between these two strains of mice. This study documents a physiological role of Il10 in the regulation of a balanced T-cell response limiting immunopathological damage
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