Search

The parallel performance of the three-level fast and robust overlapping Schwarz (FROSch) preconditioners is investigated for linear elasticity. The FROSch framework is part of the Trilinos software library and contains a parallel implementation of different preconditioners with energy minimizing coarse spaces of generalized Dryja--Smith--Widlund type. The three-level extension is constructed by a recursive application of the FROSch preconditioner to the coarse problem. In this paper, the additional steps in the implementation in order to apply the FROSch preconditioner recursively are described in detail. Furthermore, it is shown that no explicit geometric information is needed in the recursive application of the preconditioner. In particular, the rigid body modes, including the rotations, can be interpolated on the coarse level without additional geometric information. Parallel results for a three-dimensional linear elasticity problem obtained on the Theta supercomputer (Argonne Leadership Computing Facility, Argonne, IL) using up to 220 000 cores are discussed and compared to results obtained on the SuperMUC-NG supercomputer (Leibniz Supercomputing Centre, Garching, Germany). Notably, it can be observed that a hierarchical communication operation in FROSch related to the coarse operator starts to dominate the computing time on Theta, which has a dragonfly interconnect, for 100 000 message passing interface (MPI) ranks or more. The same operation, however, scales well and stays within the order of a second in all experiments performed on SuperMUC-NG, which uses a fat tree network. Using hybrid MPI/OpenMP parallelization, the onset of the MPI communication problem on Theta can be delayed. Further analysis of the performance of FROSch on large supercomputers with dragonfly interconnects will be necessary. [ABSTRACT FROM AUTHOR]

Background: In the hospital, human resource planning has to consider the needs and preferences of personnel and planners as well as the financial interest of the hospital. Additionally, staff planning has become more complex due to a growing number of part-time doctors as well as a variety of working shifts.Objectives: The aim of the study was to describe existing human resource planning in German anesthesiology departments. Furthermore, we evaluated existing software solutions supporting human resource planning.Materials and Methods: Anesthesiology departments of German university hospitals were enrolled in the study. The aspects covered were tools and time needed for planning, amount of conflicts while planning, components of the software solutions and the efficiency and satisfaction according to the users. This was evaluated for short-, intermediate- and long-term planning. Two groups were compared: departments with and without software exchanging information among the three planning periods.Results: Out of 35 university anesthesiology departments, 23 took part in the survey. On average they employed 105.8 ± 27.8 doctors who had to cover 13.5 ± 6.3 different shifts during a weekday. Personnel planning is mostly done by senior physicians. In some departments, other staff, such as residents and junior doctors, were involved as well. Software that exchanged information between short-, intermediate- and long-term planning was used in 53 % of the departments (12 out of 23). Five departments used commercially available planning software: Polypoint Deutschland (PolypointDeutschland), Atoss (Atoss AG) and SP Expert (Interflex Datensysteme). The time needed for short-term planning was slightly reduced in the exchanging software group. No difference was shown for the intermediate planning period. The use of this software led to a slight reduction in planning conflicts and increased the self-estimated efficiency of the users (p = 0.02). Throughout all groups, the major complaint was missing interfaces, for example between the software and human resources department. The ideal planning software should reduce time needed for planning and prevent planning conflicts according to the interviewed physicians. Furthermore it should be flexible and transparent for all involved staff.Conclusions: This study analyzed structures established in human resource planning in the anesthesiology departments for the first time. Time for planning varies significantly in comparable departments indicating suboptimal processes. Throughout Germany, the requirements for human resources planning are similar; for example, the software should integrate all aspects of HR planning. Different approaches are under evaluation but so far no software solution has prevailed. The used solutions vary substantially and therefore a comparison is difficult. There is no software solution with wide adoption. [ABSTRACT FROM AUTHOR]

The Tor network is a widely deployed anonymity system on the Internet used by thousands of users every day. A basic monitoring system has been designed and implemented to allow long-term statistics, provide feedback to the interested user, and detect certain attacks on the network. The implementation has been added to TorStatus, a project to display the current state of the Tor network. During a period of six months, this monitoring system collected data, where information and patterns have been extracted and analyzed. Interestingly, the Tor network is very stable with more than half of all the servers located in Germany and the United States. The data also shows a sinusoidal pattern every 24 h in the total number of servers. [ABSTRACT FROM AUTHOR]

Stuttgart Airport has undertaken a series of projects to enhance its cost and revenue controlling system in order to support decision making and strategy in the changing market. The system answers questions like: Where can we achieve additional efficiency? Which market segments and which customers account for profits, which add to losses, and why? What drives the degree of resource utilisation and which resources show efficient utilisation and which do not? How many passengers will there be next year? With which airlines and on which routes? What resources will be needed in order to meet the demand and what cost impact will this have? The system also responds to 'what if' scenarios, such as a new airline entering the Stuttgart market, an airline ceasing operations, a particular destination performing well or poorly etc. The system considers both airport operations as well as ground handling. [ABSTRACT FROM AUTHOR]

Germany and Japan have both used regionalism as a hedge against American power in the area of telecommunications, but this strategy has taken very different forms. Germany's regionalism is within the European Union. Since 2002 Japan has developed an ad hoc technology alliance in telecommunications with China and South Korea. Both the European Union and Northeast Asian countries have used industrial policy to promote telecommunications technology and both regional organizations have expressed concern about American dominance in telecommunications. Both Germany and Japan have looked to their lower income neighboring countries for investment opportunities in telecommunications, but each has taken a different approach. Japanese telecommunications firms have not been very successful in investing in other countries or in exporting Japan's very sophisticated and expensive telecommunications equipment. The Japanese government and business organizations have taken the lead in trying to promote joint research and pursue development of joint standards. Germany's Deutsche Telekom has been much more active than Japanese firms in international investment. The European Union differs from the Northeast Asian group in that it has pressed Germany to keep its domestic telecommunications market open and to make Deutsche Telekom compete internationally. It is surprising that China, Japan and South Korea have reached out to each other to cooperate on technology and standards development despite longstanding mutual antagonisms. The Northeast Asian agreements on telecommunications recall the European Coal and Steel Community (ECSC) of 1952, an initiative that also sought to link economically states divided by deep resentments. Like the ECSC, the current Asian initiative targets some of the most important economic sectors of the day. However, strong market pressures tend to undermine cooperation, and it is uncertain how much impact the agreements on telecommunications will really have. [ABSTRACT FROM AUTHOR]

Background: Stereotactic radiosurgery (SRS) and stereotactic body radiotherapy (SBRT) are well established local treatment approaches in several cancer settings. Although SBRT is still under investigation for spinal metastases, promising results in terms of a high effectiveness and optimal tolerability have been recently published on this topic. For spinal SBRT, one of the most relevant issues is represented by the inter-observer variability in target definition. Recently, several technological innovations, including specific tools such as multimodality-imaging (computed tomography (CT), magnetic resonance imaging (MRI) and positron emission tomography (PET-CT), automated volumes contouring and planning, could allow clinicians to minimize the uncertainties related to spinal SBRT workflow. Aim of this study is to report the feasibility of the clinical application of a dedicated software (Element®, Brainlab™ Germany) for spinal metastases SBRT.Material and Method: The patient selection criteria for SBRT in spinal metastases were the following: age > 18 years, diagnosis of spinal metastases (n ≤ 3), life expectancy > 3 months, controlled primary tumor or synchronous diagnosis and Spinal Instability Neoplastic Score (SINS) ≤ 12 points. All radiation target volumes were defined and planned with the support of the dedicated software Elements® (Brainlab™ Germany). Different dose prescription have been used: 12 Gy in single fraction, 12 Gy, 18 Gy, 21 Gy and 24 Gy in 3 fractions. Toxicity was assessed according to the Common Terminology Criteria for Adverse Events (CTCAE) v4.0. SPSS version 20 was used for statistical analysis.Results: From April 2018 to April 2019, 54 spinal metastases in 32 recruited patients were treated with Linac-based SBRT. With a median follow-up of 6 months (range 3-12), local control rates at 6 months and 9 months were 86 and 86%, respectively. No adverse events ≥3 grade were observed.Conclusions: This preliminary experience shows that with respect to acute toxicity and early clinical response, linac-based using Elements® Spine SRS is a feasible and effective approach. [ABSTRACT FROM AUTHOR]