78 results match your criteria: "Fraunhofer Institute for Industrial Mathematics[Affiliation]"
Clin Neurophysiol
August 2019
Department of Neonatology, University Medical Center of the Johannes Gutenberg University Mainz, Germany.
Objectives: In this paper we introduce a novel method for the evaluation of neonatal brain function via multivariate EEG (electroencephalography) signal processing and embedding into a probabilistic graph, the so called Chow-Liu tree.
Methods: Using 28 EEG recordings of preterm and term neonate infants the complex features of the EEG signals were constructed in the form of a Chow-Liu tree. The trees were embedded into a 3 dimensional Euclidean space.
Polymers (Basel)
June 2019
Fraunhofer Institute for Industrial Mathematics ITWM, Fraunhofer-Platz 1, 67663 Kaiserslautern, Germany.
Shape memory polymers (SMPs) are stimuli-responsive materials, which are able to retain an imposed, temporary shape and recover the initial, permanent shape through an external stimulus like heat. In this work, a novel manufacturing method is introduced for thermoresponsive quick response (QR) code carriers, which originally were developed as anticounterfeiting technology. Motivated by the fact that earlier manufacturing processes were sometimes too time-consuming for production, filaments of a polyester urethane (PEU) with and without dye were extruded and processed into QR code carriers using fused filament fabrication (FFF).
View Article and Find Full Text PDFPolymers (Basel)
January 2019
Department Flow and Material Simulation, Fraunhofer Institute for Industrial Mathematics, Fraunhofer-Platz 1, D-67663 Kaiserslautern, Germany.
This paper computationally investigates heterogeneity in the distribution of foam fraction in chemically expanding blown polyurethane foam. The experimentally observed disparity in the volumes of expanded foam when an equal mass of the foaming mixture was injected into tubes of different dimensions motivated this study. To understand this phenomenon, attributed to local variations in the thermal and rheological properties of the expanding system, we explore available data from free-rise foam-expansion experiments in different geometries.
View Article and Find Full Text PDFZ Med Phys
August 2019
OncoRay - National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden - Rossendorf, Fetscherstr. 74, PF 41, 01307 Dresden, Germany; Department of Radiotherapy and Radiation Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Fetscherstr. 74, 01307 Dresden, Germany; German Cancer Consortium (DKTK) partner site Dresden, Germany and German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany; Helmholtz-Zentrum Dresden - Rossendorf, Institute of Radiooncology - OncoRay, Bautzner Landstr. 400, 01328 Dresden, Germany.
Proton radiotherapy (PT) requires accurate target alignment before each treatment fraction, ideally utilizing 3D in-room X-ray computed tomography (CT) imaging. Typically, the optimal patient position is determined based on anatomical landmarks or implanted markers. In the presence of non-rigid anatomical changes, however, the planning scenario cannot be exactly reproduced and positioning should rather aim at finding the optimal position in terms of the actually applied dose.
View Article and Find Full Text PDFSci Rep
July 2018
Department of Physics and State Research Center OPTIMAS, University of Kaiserslautern, Erwin-Schroedinger-Str. 56, 67663, Kaiserslautern, Germany.
We report that in an in-plane magnetised magnetic film the in-plane direction of a propagating spin wave can be changed by up to 90 degrees using an externally induced magnetic gradient field. We have achieved this result using a reconfigurable, laser-induced magnetisation gradient created in a conversion area, in which the backward volume and surface spin-wave modes coexist at the same frequency. Shape and orientation of the gradient control the conversion efficiency.
View Article and Find Full Text PDFSci Rep
December 2017
Fraunhofer Institute for Industrial Mathematics (ITWM), Kaiserslautern, 67663, Germany.
We use a two-scale continuum model to simulate reactive flow and wormhole formation in carbonate rocks under 3-D radial flow conditions. More specifically, we present a new structure-property relationship based on the fractal geometry theory, to describe the evolution of local permeability, pore radius, and specific area with porosity variation. In the numerical calculation, to improve the convergence rate, the heterogeneous medium in question is extended by adding a thin layer of homogeneous porous medium to its inlet.
View Article and Find Full Text PDFRadiother Oncol
December 2017
Department of Radiation Oncology, University Hospital, LMU Munich, Munich, Germany.
Background And Purpose: Our aim was to evaluate the feasibility and potential advantages of dose guided patient positioning based on dose recalculation on scatter corrected cone beam computed tomography (CBCT) image data.
Material And Methods: A scatter correction approach has been employed to enable dose calculations on CBCT images. A recently proposed tool for interactive multicriterial dose-guided patient positioning which uses interpolation between pre-calculated sample doses has been utilized.
J Chem Theory Comput
September 2017
Laboratory of Engineering Thermodynamics (LTD), University of Kaiserslautern, Kaiserslautern, Germany.
Thermodynamic properties are often modeled by classical force fields which describe the interactions on the atomistic scale. Molecular simulations are used for retrieving thermodynamic data from such models, and many simulation techniques and computer codes are available for that purpose. In the present round robin study, the following fundamental question is addressed: Will different user groups working with different simulation codes obtain coinciding results within the statistical uncertainty of their data? A set of 24 simple simulation tasks is defined and solved by five user groups working with eight molecular simulation codes: DL_POLY, GROMACS, IMC, LAMMPS, ms2, NAMD, Tinker, and TOWHEE.
View Article and Find Full Text PDFPhys Med Biol
January 2017
Fraunhofer Institute for Industrial Mathematics (ITWM), Kaiserslautern, Germany.
In intensity-modulated radiation therapy (IMRT), 3D in-room imaging data is typically utilized for accurate patient alignment on the basis of anatomical landmarks. In the presence of non-rigid anatomical changes, it is often not obvious which patient position is most suitable. Thus, dose-guided patient alignment is an interesting approach to use available in-room imaging data for up-to-date dose calculation, aimed at finding the position that yields the optimal dose distribution.
View Article and Find Full Text PDFSci Rep
September 2016
University of Kaiserslautern, Ecology Group, D-67663 Kaiserslautern, Germany.
Illumina reads of the SSU-rDNA-V9 region obtained from the circumglobal Tara Oceans expedition allow the investigation of protistan plankton diversity patterns on a global scale. We analyzed 6,137,350 V9-amplicons from ocean surface waters and the deep chlorophyll maximum, which were taxonomically assigned to the phylum Ciliophora. For open ocean samples global planktonic ciliate diversity is relatively low (ca.
View Article and Find Full Text PDFToxicol Pathol
February 2016
AbbVie Deutschland GmbH & Co. KG, Ludwigshafen, Germany
Hepcidin was originally detected as a liver peptide with antimicrobial activity and it functions as a central regulator in the systemic iron metabolism. Consequently suppression of hepcidin leads to iron accumulation in the liver. AbbVie developed a monoclonal antibody ([mAb]; repulsive guidance molecule [RGMa/c] mAb) that downregulates hepcidin expression by influencing the RGMc/bone morphogenetic protein (BMP)/neogenin receptor complex and causes iron deposition in the liver.
View Article and Find Full Text PDFBeilstein J Nanotechnol
May 2015
Fraunhofer Institute for Industrial Mathematics (ITWM), Kaiserslautern, Germany.
The thermal behavior of lithium ion batteries has a huge impact on their lifetime and the initiation of degradation processes. The development of hot spots or large local overpotentials leading, e.g.
View Article and Find Full Text PDFJ Glob Optim
March 2015
Department of Optimization, Fraunhofer Institute for Industrial Mathematics (ITWM), Kaiserslautern (Germany), Phone: (+)49 (0)631-31600-4609, Fax: (+)49 (0)631-31600-5609.
The appropriate handling of planning criteria on the cumulative dose-volume histogram (DVH) is a highly problematic issue in intensity-modulated radiation therapy (IMRT) plan optimization. The nonconvexity of DVH criteria and globality of the resulting optimization problems complicate the design of suitable optimization methods, which feature numerical efficiency, reliable convergence and optimality of the results. This work examines the mathematical structure of DVH criteria and proves the valuable properties of isotonicity/antitonicity, connectedness, invexity and sufficiency of the KKT condition.
View Article and Find Full Text PDFMath Biosci
January 2015
Department of Optimization, Fraunhofer Institute for Industrial Mathematics (ITWM), Kaiserslautern, Germany.
Mathematical models of chemotherapy planning problems contain various biomedical parameters, whose values are difficult to quantify and thus subject to some uncertainty. This uncertainty propagates into the therapy plans computed on these models, which poses the question of robustness to the expected therapy quality. This work introduces a combined approach for analyzing the quality robustness of plans in terms of dosing levels with respect to model uncertainties in chemotherapy planning.
View Article and Find Full Text PDFHealth Care Manag Sci
September 2015
Department of Optimization, Fraunhofer Institute for Industrial Mathematics (ITWM), Fraunhofer-Platz 1, 67663, Kaiserslautern, Germany,
Breast cancer is the most common carcinosis with the largest number of mortalities in women. Its therapy comprises a wide spectrum of different treatment modalities a breast oncologist decides about for the individual patient case. These decisions happen according to medical guide lines, current scientific publications and experiences acquired in former cases.
View Article and Find Full Text PDFJ Colloid Interface Sci
October 2014
Fraunhofer Institute for Industrial Mathematics ITWM, Fraunhofer-Platz 1, 67663 Kaiserslautern, Germany. Electronic address:
Modeling electro-kinetic effects of aqueous solutions on charged polymer surfaces constitute great challenges. The interplay of water pH and salt concentration with surface charges at the nanoscale and macroscopic collective hydrodynamics leads to a rich phenomenology, including the hydrophobic/hydrophilic nature of the polymer surface. The present work aimed at contributing to the modeling of these phenomena for a specific system: Poly(vinylidene fluoride) (PVDF), including a surface functionalization by carboxylic groups.
View Article and Find Full Text PDFJ Biol Chem
September 2013
the Neurogenetics Group, Carl von Ossietzky University Oldenburg, 26111 Oldenburg, Germany,; the Center for Neuroscience, Carl von Ossietzky University Oldenburg, 26111 Oldenburg, Germany, ; the Center of Excellence Hearing4all, 26111 Oldenburg, Germany. Electronic address:
The superior olivary complex (SOC) is an essential auditory brainstem relay involved in sound localization. To identify the genetic program underlying its maturation, we profiled the rat SOC transcriptome at postnatal days 0, 4, 16, and 25 (P0, P4, P16, and P25, respectively), using genome-wide microarrays (41,012 oligonucleotides (oligos)). Differences in gene expression between two consecutive stages were highest between P4 and P16 (3.
View Article and Find Full Text PDFThe results of a numerical study of the various characteristics of the static contact of a liquid meniscus with a flat but heterogeneous surface, consisting of two types of homogeneous materials, forming regularly and randomly distributed microscopic defects are presented. The solutions for the meniscus shape are obtained numerically using the full expression of the system free energy functional. The goal is to establish how the magnitude and the limits of the hysteresis interval of the equilibrium contact angle, the Cassie's angle, and the contact line (CL) roughness exponent are related to the parameters, characterizing the heterogeneous surface-the equilibrium contact angles on the two materials and their fractions.
View Article and Find Full Text PDFCommon problems in inverse radiotherapy planning are localized dose insufficiencies like hot spots in organs at risk or cold spots inside targets. These are hard to correct since the optimization is based on global evaluations like maximum/minimum doses, equivalent uniform doses or dose-volume constraints for whole structures. In this work, we present a new approach to locally correct the dose of any given treatment plan.
View Article and Find Full Text PDFBMC Syst Biol
January 2013
Fraunhofer-Institut für Techno- und Wirtschaftsmathematik (ITWM; Fraunhofer Institute for Industrial Mathematics), Kaiserslautern, Germany.
Background: When mathematical modelling is applied to many different application areas, a common task is the estimation of states and parameters based on measurements. With this kind of inference making, uncertainties in the time when the measurements have been taken are often neglected, but especially in applications taken from the life sciences, this kind of errors can considerably influence the estimation results. As an example in the context of personalized medicine, the model-based assessment of the effectiveness of drugs is becoming to play an important role.
View Article and Find Full Text PDFA fundamental characteristic of fluid flow is that it causes mixing: introduce a dye into a flow, and it will disperse. Mixing can be used as a method to visualize and characterize flow. Because mixing is a process that occurs over time, it is a 4D problem that presents a challenge for computation, visualization, and analysis.
View Article and Find Full Text PDFScanning
December 2013
Department of Image Processing, Fraunhofer Institute for Industrial Mathematics, (ITWM), Kaiserslautern, Germany.
Focused ion beam nanotomography-scanning electron microscopy tomography yields high-quality three-dimensional images of materials microstructures at the nanometer scale combining serial sectioning using a focused ion beam with SEM. However, FIB-SEM tomography of highly porous media leads to shine-through artifacts preventing automatic segmentation of the solid component. We simulate the SEM process in order to generate synthetic FIB-SEM image data for developing and validating segmentation methods.
View Article and Find Full Text PDFPhys Med Biol
June 2011
Department of Optimization, Fraunhofer Institute for Industrial Mathematics (ITWM), Fraunhofer Platz 1, 67663 Kaiserslautern, Germany.
In the multi-criteria optimization approach to IMRT planning, a given dose distribution is evaluated by a number of convex objective functions that measure tumor coverage and sparing of the different organs at risk. Within this context optimizing the intensity profiles for any fixed set of beams yields a convex Pareto set in the objective space. However, if the number of beam directions and irradiation angles are included as free parameters in the formulation of the optimization problem, the resulting Pareto set becomes more intricate.
View Article and Find Full Text PDFPatient Educ Couns
September 2010
Fraunhofer Institute for Industrial Mathematics, Department of System Analysis, Prognosis and Control, Kaiserslautern, Germany.
Objective: Nearly 30,000 individual inquiries are answered annually by the telephone cancer information service (CIS, KID) of the German Cancer Research Center (DKFZ). The aim was to develop a tool for evaluating these calls, and to support the complete counseling process interactively.
Methods: A novel software tool is introduced, based on a structure similar to a music score.
Phys Med Biol
October 2009
Department of Optimization, Fraunhofer Institute for Industrial Mathematics (ITWM), Fraunhofer Platz 1, 67663 Kaiserslautern, Germany.
One approach to multi-criteria IMRT planning is to automatically calculate a data set of Pareto-optimal plans for a given planning problem in a first phase, and then interactively explore the solution space and decide on the clinically best treatment plan in a second phase. The challenge of computing the plan data set is to ensure that all clinically meaningful plans are covered and that as many clinically irrelevant plans as possible are excluded to keep computation times within reasonable limits. In this work, we focus on the approximation of the clinically relevant part of the Pareto surface, the process that constitutes the first phase.
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