579 research outputs found
Entwicklung einer schnellen Pulsformanalyse für asymmetrische AGATA-Germanium-Detektoren
No full textOnTEAM metadata: GDSID: DOC-2007-May-32; Attribute ID: LIBRARY-thesis_diss-2007-005; Title: [GSI Diss 2007-05] Entwicklung einer schnellen Pulsformanalyse für asymmetrische AGATA-Germanium-Detektoren; Author(s): Beck, Torsten; Corporate author(s): ; Publication date: 20070501; Creator: manton; Creation date: 15.05.2007 16:02:12; Change date: 29.10.2008 16:29:34; Access: nur berechtigte Gruppen; Attribute type: Text.Thesis.Diss; Directory path: ['GSI Publications', 'GSI as Publisher']; Attribute path: ['Infrastructure', 'Library and Documentation', 'thesis_diss', 'Added in 2007']; File name(s): ['DOC-2007-May-32-1.pdf']; File title(s): ['']; File access: ['nur berechtigte Gruppen'
Manifolds, sheaves, and cohomology
No full textThis book explains techniques that are essential in almost all branches of modern geometry such as algebraic geometry, complex geometry, or non-archimedian geometry. It uses the most accessible case, real and complex manifolds, as a model. The author especially emphasizes the difference between local and global questions. Cohomology theory of sheaves is introduced and its usage is illustrated by many examples. Content Topological Preliminaries - Algebraic Topological Preliminaries - Sheaves - Manifolds - Local Theory of Manifolds - Lie Groups - Torsors and Non-abelian Cech Cohomology - Bundles - Soft Sheaves - Cohomology of Complexes of Sheaves - Cohomology of Sheaves of Locally Constant Functions - Appendix: Basic Topology, The Language of Categories, Basic Algebra, Homological Algebra, Local Analysis Readership Graduate Students in Mathematics / Master of Science in Mathematics About the Author Prof. Dr. Torsten Wedhorn, Department of Mathematics, Technische Universität Darmstadt, Germany
James Watson, Maclyn McCarty, and Torsten Wiesel
No full textTorsten Wiesel (right) with Professor Emeritus Maclyn McCarty (center), co-author of the paper with Oswald Avery and Colin MacLeod, and James D. Watson, director of Cold Spring Harbor Laboratory, 1994
Photo by Leif Carlsson
To commemorate the fiftieth anniversary of the discovery at The Rockefeller University that genes are made of DNA - considered by many to be the single most important biological discovery of the twentieth century - the university has kicked off a year-long series of events that were running through May 1994. The celebration was formally inaugurated in November 1993 with a lecture by Nobel laureate James D. Watson, best known for discovering the double-helical structure of DNA.
See also Search Winter 1994, vol. 4, no. 1https://digitalcommons.rockefeller.edu/group-portraits/1013/thumbnail.jp
Seltsame Schauspiele. Torsten Fogelqvists Deutschlandreise 1934
No full textIn 1934 Torsten Fogelqvist, a prominent member of the Swedish Academy and a well-known journalist and intellectual, visits Nazi Germany. He writes about his visit to the Third Reich in 17 articles published in the Stockholm daily newspaper Dagens Nyheter. The author, highly critical of the Hitler regime, scrutinizes several aspects of the nazified German society such as the attempts to re-educate the German citizen in accordance with the ideology of the new regime, the hero cult in the Nazi movement, and the relationship between the German state and the churches. In order to further an understanding of political and social developments in Germany Fogelqvist uses a specific strategy. He “translates” them into an imaginary Swedish context. This paper compares his views with those of other Swedish visitors
A pilot study to assess peak systolic velocity as possible marker of atherosclerotic burden using ultrasound
No full textIntroduction: Ischemic heart disease (IHD) has been associated with lower peak systolic velocity (PSV) on penile Doppler measurements [1]. This study establishes whether carotid ultrasound (US) PSV was associated with computational fluid dynamics (CFD) outputs, which in turn may contribute to IHD pathogenesis. Methods: A sample of 57 subjects (with IHD: 27, without IHD: 30) had US velocity profiles (left- common carotid artery) determined between 10e12 equispaced points. Bezier curve fitting was used to fit the profile through the measured velocity points for a normalised diameter. PSV was correlated against CFD results such as wall shear stress (WSS) [2]. Difference in PSV between individuals with/without IHD was studied via t-test. Linear regression was carried out to see if peak systolic velocity was associated with CFD outputs. Any significant associations were analysed within stratified groups (with/without IHD). Results: PSV was significantly lower (p Z 0.042) in subjects with IHD (with IHD: 53.6 17.3 cm/s, without IHD: 62.8 16.1 cm/s). PSV was associated with carotid bulb average pressure drop (p < 0.001), area of average bulb WSS (<1 Pa: p Z 0.016, <2 Pa: p Z 0.006, <3 Pa: p Z 0.001). All the above associations remained significant in individuals with IHD (average bulb pressure drop: p Z 0.001, average bulb WSS (<1 Pa: p Z 0.013, <2 Pa: p Z 0.008, <3 Pa: p Z 0.003). In subjects without IHD, PSV was associated with only average bulb pressure drop (p Z 0.016). Conclusions: This study suggests that further work on PSV and its associations with CFD outputs is required in individuals with and without IHD in various vascular beds
PISM glacial cycle sensitivity experiments of the Antarctic Ice Sheet
No full textThis dataset contains PISM simulation results (http://www.pism-docs.org) of the Antarctic Ice Sheet based on code release v1.0-paleo-ensemble (https://doi.org/10.5281/zenodo.3574033). PISM is the open-source Parallel Ice Sheet Model developed mainly at UAF, USA and PIK, Germany.
With the help of added python scripts, all figures can be reproduced as in the journal publication:
- Albrecht et al., 2020, doi:10.5194/tc-14-599-2020.
---
Data:
Find PISM results as netCDF data. See 'README.md' for a list of all performed experiment.
All forcing input data for the experiments and plots can be downloaded and remapped via https://github.com/pism/pism-ais. Some of the original input data files are freely available, for others please contact the author or the corresponding data publisher.
Figure plotting scripts (jupyter notebook based on python, see https://jupyter.org) in 'plot_scripts' access the uploaded PISM results in 'model_data' and save the plots to 'final_figures'. Jupyter notebook can be run in the browser and shared, see https://nbviewer.jupyter.org/url/www.pik-potsdam.de/~albrecht/notebooks/paleo_paper/paleo_paper_final.ipynb.
---
Contact:
Albrecht, Torsten ([email protected]) ; Potsdam-Institute for Climate Impact Research (PIK), Potsdam, German
Die Erfolgsfaktoren für unternehmerisches E-Mail-Marketing nach Dr. Torsten Schwarz am Praxisbeispiel ERGOTOPIA GmbH
No full textThis scientific document reveals the results of an empirical examination within the realm of entrepreneurial e-mail-marketing which is based on a literature review by technical author Dr. Torsten Schwarz. Using the start-up company ERGOTOPIA as a practical example, the author of the master thesis investigates whether the explanations of Dr. Schwarz match with the practical implementation of ERGOTOPIA.
Precisely, the scientific paper focuses on the examination of the four aspects lead generation, newsletter-design, software-requirements and performance measurement through monitoring with regard to successful realization of e-mail-marketing campaigns. The empirical part of this examination is made of the introduction as well as the analysis of two conducted so called split-tests that compare specific aspects of the newsletter-design and measure data-driven results to show which kind of aspect produced the more successful campaign.
This way the author proves whether the recommendations by Dr. Schwarz are practically relevant for the company ERGOTOPIA
Tree Awareness for Relational DBMS Kernels: Staircase Join
No full textRelational database management systems (RDBMSs) derive much of their eciency from the versatility of their core data structure: tables of tuples. Such tables are simple enough to allow for an ecient representation on all levels of the memory hierarchy, yet suciently generic to host a wide rang
Development of explicit and constitutive lattice-Boltzmann models for food product rheology
No full textEmulsions are found throughout various industries including oil extraction, biological
materials, and food products such as milk, condiments, and spreads. The study
of their rheology is therefore important due to its impact on manufacturing efficiency
and end product desirability. A key rheological measure is the emulsion viscosity,
the fluid’s resistance to flow, which affects the power required in production as well
as the taste and texture. An emulsion’s viscosity displays complex behaviour due
to the droplet interfaces and interactions. Similarly, the sheared self-diffusion coefficient
measures the amount of movement the droplets exhibit, due to the interactions
between droplets.
The presented mesoscopic lattice-Boltzmann models allow for these macroscopic
properties to emerge from the simulations due to the explicit modelling of the
droplets. A continuous surface force is applied to the lattice fluids to model droplet
interfaces. The model is implemented in such a way as to allow the simulation of
hundreds of droplets with limited computing power.
The model is initially applied to a pipe flow, with the development of a pressure
boundary condition. Boundary effects from the solid walls require their removal,
using Lees-Edwards boundary conditions to represent bulk flow in a sheared system.
The boundary conditions are extended to the multi-component flow, which allowed
simulations to provide results for various emulsion systems with varying droplet
concentrations, surface tensions, viscosity ratios, and shear rates. Trends and results
from experimental and theoretical literature are recovered and constitutive models
of emulsion viscosity have been evaluated. The agreement of these two dimensional
lattice-Boltzmann models with three dimensional experimental results shows the
usefulness of the method. The structure of the droplets and clustering behaviour
they exhibit are examined and compared to solid particle suspension literature.
Finally, the model is used in exploratory simulations to examine the effect of droplet
bidispersity on the macroscopic properties; the witnessed effect agrees well with solid
suspension literature.
This mesoscopic model will allow for phenomenon on this scale to be more easily
studied and may provide more accurate information for multi-scale analysis
Uncertainty quantification and personalisation of lumped parameter models of the cardiovascular system
No full textPersonalised medicine, facilitated by the growing capacity to collect comprehensive patient
data, aims to provide personalised therapies for each individual. Computational models
are boosting the capacity to draw diagnosis and prognosis, and future treatments will be
tailored not only to current health status and data, but also to an accurate projection of
the pathways to restore health by model predictions. These models, which are based on
physiology and physics rather than on population statistics, enable computational simulations
to reveal diagnostic information that would have otherwise remained concealed and to predict
treatment outcomes for individual patients. The inherent need for patient-specific models in
cardiology is clear and is driving the rapid development of tools and techniques for creating
personalised methods to guide pharmaceutical therapy, deployment of devices and surgical
interventions.
For computational models to have clinical utility, we must be able to provide a quantification
of the risk associated with any predictions or interpretations which are made from the model.
Lumped parameter models (LPM) represent the cardiovascular system as a series of electrical
segments, each characterised by parameter values that offer insights into the associated health
status. Given one can constrain the model with patient specific data such that the parameter
values are updated, one obtains a digital representation of a patient’s cardiovascular system.
This research investigates the crucial offline stage of uncertainty quantification for models,
primarily employing sensitivity analysis, with the goal of achieving personalisation. As
such, this work first examines the process of performing a global sensitivity analysis of a
cardiovascular LPM, establishing some best practices to ensure accurate model interpretations.
Then we assess the impact of the chosen outputs of a model when looking to quantify
uncertainty. We demonstrate how variation in the chosen outputs can significantly impact
one’s interpretation of a model. Following the enhanced understanding of the best practices
around sensitivity analysis, we extend a method for obtaining a personalised subset of input
parameters, acknowledging the inherent variability among individuals in medicine. Alongside
this, a novel examination of the sensitivity indices is proposed within the context of
personalised medicine to provide insight associated with the calibration of model parameters.
Finally, we investigate a data assimilation technique and explore the method’s effectiveness
for model personalisation. The primary outcome of this research is the development of an
offline model personalisation workflow, designed to reduce the uncertainty associated with
calibrating models to patient data to the greatest extent possible
- …
