Erratum: Progenitor-explosion connection and remnant birth masses for neutrino-driven supernovae of iron-core progenitors (2012, ApJ, 757, 69)

An erroneous interpretation of the hydrodynamical results led to an incorrect determination of the fallback masses in Ugliano et al. (2012), which also (on a smaller level) affects the neutron star masses provided in that paper. This problem was already addressed and corrected in the follow-up works by Ertl et al. (2015) and Sukhbold et al. (2015). Therefore, the reader is advised to use the new data of the latter two publications. In the remaining text of this Erratum we present the differences of the old and new fallback results in detail and explain the origin of the mistake in the original analysis by Ugliano et al. (2012).Comment: 3 pages, 2 figures; submitted to The Astrophysical Journa

Flux-Limited Diffusion for Multiple Scattering in Participating Media

For the rendering of multiple scattering effects in participating media, methods based on the diffusion approximation are an extremely efficient alternative to Monte Carlo path tracing. However, in sufficiently transparent regions, classical diffusion approximation suffers from non-physical radiative fluxes which leads to a poor match to correct light transport. In particular, this prevents the application of classical diffusion approximation to heterogeneous media, where opaque material is embedded within transparent regions. To address this limitation, we introduce flux-limited diffusion, a technique from the astrophysics domain. This method provides a better approximation to light transport than classical diffusion approximation, particularly when applied to heterogeneous media, and hence broadens the applicability of diffusion-based techniques. We provide an algorithm for flux-limited diffusion, which is validated using the transport theory for a point light source in an infinite homogeneous medium. We further demonstrate that our implementation of flux-limited diffusion produces more accurate renderings of multiple scattering in various heterogeneous datasets than classical diffusion approximation, by comparing both methods to ground truth renderings obtained via volumetric path tracing.Comment: Accepted in Computer Graphics Foru

Die Welt 1250-1500: vormoderne Verflechtungen von Dschingis Khan bis Christoph Columbus

The period between 1250 and 1500 was decisive for modern world history. For the first time a worldwide commercial system arose, which included large parts of Asia, Africa and Europe. On the other the Mongol expansion and the Black Death affected large parts of the Old World. China started with a maritime expansion but later gave up this policy. In the world of Islam new major emires were created. This article gives a survey of the heterogeneous yet strongly interconnected world of the period which is known in Europe as the Late Middle Ages

Stellar Collapse Diversity and the Diffuse Supernova Neutrino Background

The diffuse cosmic supernova neutrino background (DSNB) is observational target of the gadolinium-loaded Super-Kamiokande (SK) detector and the forthcoming JUNO and Hyper-Kamiokande detectors. Current predictions are hampered by our still incomplete understanding of the supernova (SN) explosion mechanism and of the neutron star (NS) equation of state and maximum mass. In our comprehensive study we revisit this problem on grounds of the landscapes of successful and failed SN explosions obtained by Sukhbold et al. and Ertl et al. with parametrized one-dimensional neutrino engines for large sets of single-star and helium-star progenitors, with the latter serving as proxy of binary evolution effects. Besides considering engines of different strengths, leading to different fractions of failed SNe with black-hole (BH) formation, we also vary the NS mass limit, the spectral shape of the neutrino emission, and include contributions from poorly understood alternative NS-formation channels such as accretion-induced or merger-induced collapse events. Since the neutrino signals of our large model sets are approximate, we calibrate the associated degrees of freedom by using state-of-the-art simulations of proto-neutron star cooling. Our predictions are higher than other recent ones because of a large fraction of failed SNe with long delay to BH formation. Our best-guess model predicts a DSNB electron-antineutrino-flux of 28.8^{+24.6}_{-10.9} cm^{-2}s^{-1} with 6.0^{+5.1}_{-2.1} cm^{-2}s^{-1} in the favorable measurement interval of [10,30] MeV, and 1.3^{+1.1}_{-0.4} cm^{-2}s^{-1} with electron-antineutrino energies > 17.3 MeV, which is roughly a factor of two below the current SK limit. The uncertainty range is dominated by the still insufficiently constrained cosmic rate of stellar core-collapse events.Comment: 43 pages, 16 figures, 10 tables; revised version with new Sections 6 & 9, and new Appendix E; accepted by Ap

Visual analysis for spatio-temporal event correlation in manufacturing

The analysis of events with spatio-temporal context and their interdependencies is a crucial task in the manufacturing domain. In general, understanding this context, for example investigating error messages or alerts is important to take corrective actions. In the manufacturing domain, comprehending the relations of errors is often based on the technicians\u27 experience. Validation of cause-effect relations is necessary to understand if an effect has a preceding causality, e.g., if an error is the result of multiple issues from previous working steps. We present an approach to investigate spatio-temporal relations between such events. Based on a time-sensitive correlation measure, we provide multiple coordinated views to analyze and filter the data. In collaboration with an industry partner, we developed a visual analytics approach for error logs reported by machines that covers a multitude of analysis tasks. We present a case study based on real-world event logs of an assembly line with feedback from our industry partner\u27s domain experts. The findings show that experts can effectively identify error dependencies that impair the overall assembly line productivity using our technique. Furthermore, we discuss how our approach is applicable in other domains

BlueCollar: Optimizing Worker Paths on Factory Shop Floors with Visual Analytics

The optimization of a factory\u27s productivity regarding quality and efficiency is an important task in the manufacturing domain. To optimize the productivity, production lines are optimized to have short transportation paths and short processing times at the stations that process intermediate components or the final product. A factory\u27s layout is a key factor in this optimization aspect. This optimization mostly comprises the machine tools\u27 positions with respect to places where supply goods are being delivered and other tools are stationed, often neglecting the paths that workers need to take at the shop floor. This impairs a factory\u27s productivity, as machines may need to wait for workers, who operated another machine and are still on the way due to the long distance between the machines. In this work, we present BlueCollar, a visual analytics approach that supports layout planners to explore and optimize existing factory layouts regarding the paths taken by workers. Planners can visually inspect the paths that workers need to take based on their work schedule and the factory\u27s layout. An estimation of distribution algorithm supports them in choosing which layout elements, e.g., shared tool caches, to relocate. Its intermediate and final results are used to provide visual cues for suitable relocation areas, and to suggest new layouts automatically. We demonstrate our approach through an application scenario based on a realistic prototype layout provided by an external company

How much H and He is "hidden" in SNe Ib/c? -- II. Intermediate-mass objects: a 22 M⊙_{\odot} progenitor case study

Stripped envelope supernovae are a sub-class of core collapse supernovae showing several stages of H/He shell stripping that determines the class: H-free/He-poor SNe are classified as Type Ic, H-poor/He-rich are Type Ib, and H/He-rich are Type IIb. Stripping H/He with only stellar wind requires significantly higher mass loss rates than observed while binary-involved mass transfer may usually not strip enough to produce H/He free SNe. Type Ib/c SNe are sometimes found to include weak H/He transient lines as a product of a trace amount of H/He left over from stripping processes. The extent and mass of the H/He required to produce these lines is not well known. In this work, a 22 M$_{\odot}$ progenitor model is stripped of the H/He shells in five steps prior to collapse and then exploded at four explosion energies. Requiring both optical and NIR He I lines for helium identification does not allow much He mass to be hidden in SE--SNE. Increasing the mass of He above the CO core delays the visibility of O I 7774 in early spectra. Our SN Ib-like models are capable of reproducing the spectral evolution of a set of observed SNe with reasonable estimated $E_\mathrm{k}$ accuracy. Our SN\,IIb-like models can partially reproduce low energy observed SN IIb, but we find no observed comparison for the SN IIb-like models with high $E_\mathrm{k}$.Comment: 19 pages, 15 figures. Accepted by MNRAS, awaiting publicatio