Article
Computer Science, Interdisciplinary Applications
Cristian C. Lalescu, Berenger Bramas, Markus Rampp, Michael Wilczek
Summary: The study introduces a particle tracking algorithm for large-scale parallel pseudo-spectral simulations of turbulence that can handle billions of tracer particles efficiently. By using a task-based method, resource utilization is improved and computational costs of particle tracking are reduced.
COMPUTER PHYSICS COMMUNICATIONS
(2022)
Article
Mathematics, Applied
M. Beckmann, P. Maass, J. Nickel
Summary: Filtered back projection (FBP) methods are widely used in the reconstruction of computerized tomography (CT), but the study of reconstruction errors has limitations in terms of optimal filter design and estimating FBP approximation errors in Sobolev spaces.
Article
Computer Science, Theory & Methods
Inaki Amatria-Barral, Jorge Gonzalez-Dominguez, Juan Tourino
Summary: This paper presents pRIblast, a highly efficient parallel application for comprehensive lncRNA-RNA interaction prediction. Compared to other tools, pRIblast has advantages in terms of computational speed and accuracy, and can handle large-scale datasets.
FUTURE GENERATION COMPUTER SYSTEMS-THE INTERNATIONAL JOURNAL OF ESCIENCE
(2023)
Article
Computer Science, Theory & Methods
Rohit Zambre, Damodar Sahasrabudhe, Hui Zhou, Martin Berzins, Aparna Chandramowlishwaran, Pavan Balaji
Summary: Supercomputing applications are increasingly adopting the MPI+threads programming model to address the challenge of handling a disproportionate increase in the number of cores compared with other on-node resources. However, poor communication performance remains a bottleneck with MPI+threads, and recent research efforts are focused on mapping logically parallel communication to the underlying network parallelism. While the upcoming MPI-4.0 standard allows applications to express logical communication parallelism and relax unnecessary semantics, further exploration is needed to maximize the performance benefits of logical communication parallelism on applications.
IEEE TRANSACTIONS ON PARALLEL AND DISTRIBUTED SYSTEMS
(2021)
Article
Computer Science, Hardware & Architecture
Jorge Gonzalez-Dominguez, Jose M. Martin-Martinez, Roberto R. Exposito
Summary: Tandem Repeats (TRs) are DNA segments that occur multiple times in a sequence and have gained attention for their potential relation with human diseases. Dot2dot, a tool for identifying TRs, has been improved with MPI-dot2dot, which combines MPI and OpenMP to reduce execution time in multicore clusters. This new version performs more than 100 times faster on a 16-node multicore cluster while providing the same biological results as Dot2dot.
JOURNAL OF SUPERCOMPUTING
(2022)
Article
Thermodynamics
Asif Afzal, C. Ahamed Saleel, K. Prashantha, Suvanjan Bhattacharyya, Mohammed Sadhikh
Summary: This research explores the parallelization of inhouse developed code for numerical computations on heterogeneous computing machines using four different schemes. The study found that the RBSOR scheme achieved the highest speedup and performed the best under different flow conditions.
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
(2021)
Article
Computer Science, Artificial Intelligence
Patricia Gonzalez, Roberto Prado-Rodriguez, Attila Gabor, Julio Saez-Rodriguez, Julio R. Banga, Ramon Doallo
Summary: Understanding the deregulation of cell signaling networks is crucial for studying diseases. Computational models, such as CellNOpt, provide a systematic tool to analyze these complex biochemical networks. In this paper, the use of ant colony optimization is proposed as a novel method to improve the limitations of the existing genetic algorithm in CellNOpt, and its performance is demonstrated in liver cancer therapy research.
EXPERT SYSTEMS WITH APPLICATIONS
(2022)
Article
Environmental Sciences
Guangyuan Kan, Chenliang Li, Depeng Zuo, Xiaodi Fu, Ke Liang
Summary: The Monte Carlo sampling (MCS) method is a practical approach for hydrological model parameter optimization, which can be parallelized and executed on multi-node computer clusters equipped with multiple CPUs and GPUs. It has shown improved computational efficiency and scalability compared to single-core CPU code, with the multi-GPU code achieving the fastest speed.
Article
Materials Science, Characterization & Testing
Pengxiang Ji, Yiming Jiang, Ruobing Zhao, Jing Zou
Summary: Computed laminography (CL) is a non-destructive imaging technique for plate-like samples that has challenges in exact reconstruction. Fusion laminography (FL) combines Fourier information from CL and CT to achieve precise reconstruction, showing superiority in artifact removal and edge preservation, particularly for irregular sample structures.
NDT & E INTERNATIONAL
(2024)
Article
Computer Science, Theory & Methods
Dongxia Wang, Yongmei Lei, Jianhui Zhou
Summary: This paper proposes an asynchronous distributed ADMM based on a hybrid parallel model, which combines OpenMP for parallelization within nodes and MPI for message passing between nodes, to improve the scalability of distributed ADMM and reduce system time without compromising convergence or increasing communication cost and memory consumption. Furthermore, efficient parallelized algorithms are designed for solving sub-problems in different applications, resulting in higher scalability and reduced system time compared to state-of-the-art distributed ADMM.
Article
Geosciences, Multidisciplinary
Biao Lu, Zhicai Luo, Bo Zhong, Hao Zhou
Summary: The development of a parallel algorithm that combines MPI and OpenMP programming models has greatly improved the efficiency of calculating high-degree/order gravity field models. By utilizing the symmetrical feature of normal equations, the calculation time for generating the normal equation of a degree/order 240 model was significantly reduced. Additionally, modifications were made to the MPI parallel Gaussian-Jordan elimination method, allowing for matrix inversion on a larger number of processor cores.
FRONTIERS IN EARTH SCIENCE
(2023)
Article
Computer Science, Hardware & Architecture
Alberto S. Garea, Dora B. Heras, Francisco Arguello, Begum Demir
Summary: This paper presents a hybrid parallel TCA-based domain adaptation technique for solving the classification of very high-resolution multispectral images. By utilizing MPI for efficient execution and combining the use of GPUs and OpenMP, it achieves accurate DA technique and high speedup values.
JOURNAL OF SUPERCOMPUTING
(2023)
Article
Computer Science, Hardware & Architecture
Karl K. Sabelfeld, Sergey Kireev, Anastasiya Kireeva
Summary: The paper presents the results of a parallel implementation of a randomized vector algorithm for solving systems of linear equations. The algorithm computes the solution using a Neumann series by sampling random columns only, avoiding matrix multiplication operations. Two approaches for solving the problem of large matrices are presented, with the efficiency of the parallel implementations analyzed.
JOURNAL OF SUPERCOMPUTING
(2023)
Article
Computer Science, Software Engineering
Beata Dmitruk, Przemyslaw Stpiczynski
Summary: The aim of this paper is to demonstrate the efficient vectorization and parallelization of Kahan's and Gill-Moller compensated summation algorithms using Intel AVX-512 intrinsics and OpenMP constructs to achieve high accuracy in summing floating-point number sequences. Numerical experiments show that the new implementations of these algorithms outperform ordinary summation in terms of accuracy and performance. The vectorized Gill-Moller algorithm is faster than the vectorized Kahan's algorithm, but with slightly worse accuracy in single precision, which can be improved by using mixed-precision. Overall, both compensated summation algorithms offer the same accuracy, with Gill-Moller algorithm being faster than Kahan's algorithm.
CONCURRENCY AND COMPUTATION-PRACTICE & EXPERIENCE
(2023)
Article
Computer Science, Information Systems
Huda Basloom, Mohamed Dahab, Abdullah Saad Al-Ghamdi, Fathy Eassa, Ahmed Mohammed Alghamdi, Seif Haridi
Summary: Recently, there has been increasing interest among researchers in combining multiple programming models to achieve exascale in high performance computing systems. This integration of programming paradigms, such as MPI, OpenMP, and OpenACC, can improve computation speed and performance. However, the integration of these models increases the probability of runtime errors, making their detection challenging. This paper proposes a hybrid testing technique that combines static and dynamic technologies to detect runtime errors in systems using C++ programming language with the three models.
CMC-COMPUTERS MATERIALS & CONTINUA
(2023)
Article
Thermodynamics
L. Laiarinandrasana, T. F. Morgeneyer, Y. Cheng, L. Helfen, V Le Saux, Y. Marco
CONTINUUM MECHANICS AND THERMODYNAMICS
(2020)
Article
Thermodynamics
Sebastian Bornschlegel, Chris Conrad, Alexander Durst, Richard Welss, Michael Wensing, Margie Olbinado, Lukas Helfen, Tilo Baumbach
Summary: Flash boiling in gasoline direct injection engines can produce smaller droplets and reduce spray penetration depth, but also decrease the stability of fuel sprays and potentially cause spray contraction. Research shows that flash boiling leads to a significant radial expansion of the jet after nozzle exit, affecting the spray front velocity and penetration depth.
INTERNATIONAL JOURNAL OF ENGINE RESEARCH
(2021)
Article
Engineering, Multidisciplinary
Xinchen Ni, Reed Kopp, Estelle Kalfon-Cohen, Carolina Furtado, Jeonyoon Lee, Albertino Arteiro, Gregor Borstnar, Mark N. Mavrogordato, Lukas Helfen, Ian Sinclair, S. Mark Spearing, Pedro P. Camanho, Brian L. Wardle
Summary: In situ X-ray synchrotron radiation computed tomography (SRCT) was used to compare the damage effects of two mechanical enhancement technologies on carbon fiber composite laminates. The study found that nanostitching can improve the tensile strength and reduce delaminations, while thin-ply laminates inherently suppress matrix damage. The research provides insights for mechanical enhancement approaches and damage models.
COMPOSITES PART B-ENGINEERING
(2021)
Article
Materials Science, Multidisciplinary
Thomas Tancogne-Dejean, Christian C. Roth, Thilo F. Morgeneyer, Lukas Helfen, Dirk Mohr
Summary: This study investigates the fracture mechanism of aluminum alloy AA2024-T3 under shear loading using X-ray synchrotron laminography, revealing the microscale defects population and their evolution, and proposing a specific fracture mechanism based on these observations.
Article
Engineering, Mechanical
Thilo F. Morgeneyer, Mikhail Khadyko, Ante Buljac, Lukas Helfen, Hild Francois, Ahmed Benallal, Tore Borvik, Odd S. Hopperstad
Summary: Crystallographic aspects of heterogeneous plastic flow during ductile tearing are assessed experimentally by combining in situ synchrotron laminography imaging with numerical simulations using the crystal plasticity finite element method. The study reveals the early onset of slant strained bands which eventually lead to the formation of slant cracks. The simulation results show similar trends to the experimental observations, indicating the stability of the slant strained bands over the loading history.
INTERNATIONAL JOURNAL OF PLASTICITY
(2021)
Article
Materials Science, Composites
J. Castro, F. Sket, L. Helfen, C. Gonzalez
Summary: The impregnation process during injection experiments in fibre-reinforced polymer composites was analyzed using the SR-CL method, revealing capillary forces dominate the flow front. Intratow and intertow voids were accurately segmented and their time and spatial distribution directly measured using machine learning algorithms.
COMPOSITES SCIENCE AND TECHNOLOGY
(2021)
Article
Thermodynamics
Anastasiia Karabanova, Perizat Berdiyeva, Lukas Helfen, Alessandro Tengattini, Thomas Buecherl, Malgorzata G. Makowska, Stefano Deledda, Didier Blanchard
Summary: Thermochemical heat storage technology has the potential to balance intermittent renewables and increase energy system efficiency, but commercial products are limited and technology improvement is needed for larger market penetration. To advance this technology, particular attention must be paid to studying processes inside reactors and developing validated numerical models for optimization.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2021)
Article
Materials Science, Multidisciplinary
Xiang Kong, Lukas Helfen, Mathias Hurst, Daniel Haenschke, Djamel Missoum-Benziane, Jacques Besson, Tilo Baumbach, Thilo F. Morgeneyer
Summary: This study investigates the behavior of an aluminum alloy sheet material during a load path change from shear to tension using three-dimensional X-ray imaging and image correlation. The results show significant effects of the load path change on the material's formability and damage mechanisms.
Article
Instruments & Instrumentation
Tomas Farago, Sergey Gasilov, Iain Emslie, Marcus Zuber, Lukas Helfen, Matthias Vogelgesang, Tilo Baumbach
Summary: Tofu is a toolkit for processing large amounts of images and for tomographic reconstruction. It offers workflows for various image processing tasks and includes a wide range of pre-processing and post-processing algorithms. It is optimized for GPU workstations and provides graphical user interfaces and pre-configured workflows for users.
JOURNAL OF SYNCHROTRON RADIATION
(2022)
Article
Multidisciplinary Sciences
Josefin Martell, Carl Alwmark, Luke Daly, Stephen Hall, Sanna Alwmark, Robin Woracek, Johan Hektor, Lukas Helfen, Alessandro Tengattini, Martin Lee
Summary: This study explores the three-dimensional distribution of hydrous phases within the nakhlite meteorite and reveals that the alteration is localized and of short duration. This implies that habitable environments could not have been sustained on Mars during the Amazonian period.
Article
Multidisciplinary Sciences
Joey Disch, Luca Bohn, Susanne Koch, Michael Schulz, Yiyong Han, Alessandro Tengattini, Lukas Helfen, Matthias Breitwieser, Severin Vierrath
Summary: In this study, the authors use high-resolution neutron imaging to uncover the water distribution and salt precipitation issues in CO2 electrolyzers, which are major hurdles for their steady operation.
NATURE COMMUNICATIONS
(2022)
Article
Chemistry, Multidisciplinary
Robert Bradbury, Nikolay Kardjilov, Georg F. Dewald, Alessandro Tengattini, Lukas Helfen, Wolfgang G. Zeier, Ingo Manke
Summary: The elucidation of lithium ion transport pathways through a solid electrolyte separator is important for the development of all-solid-state batteries. Neutron imaging was performed on an all-solid-state lithium-sulfur battery using an increased Li-6 content in the anode. This allowed for differentiation between the mobile lithium ions diffusing through the cell and those initially located in the solid electrolyte, and demonstrated the lithium ion diffusion through the cell and the distribution of trapped lithium ions in charged and discharged states.
ADVANCED FUNCTIONAL MATERIALS
(2023)
Article
Materials Science, Multidisciplinary
Ante Buljac, Xiang Kong, Lukas Helfen, Francois Hild, Thilo F. Morgeneyer
Summary: Damage and strain changes during shear dominated loading were studied using synchrotron laminography and digital volume correlation (DVC). The results showed localized strain fields and grain-related elongated cracks in the shear zone, with damage primarily concentrated in the gage section subjected to shear. The total Hencky von Mises strain close to failure was measured in the material bulk, reaching values between 0.6 and 0.7.
MECHANICS OF MATERIALS
(2023)
Article
Electrochemistry
Ralf F. Ziesche, James B. Robinson, Henning Markoetter, Robert Bradbury, Alessandro Tengattini, Nicolas Lenoir, Lukas Helfen, Winfried Kockelmann, Nikolay Kardjilov, Ingo Manke, Dan J. L. Brett, Paul R. Shearing
JOURNAL OF THE ELECTROCHEMICAL SOCIETY
(2020)
Article
Biochemistry & Molecular Biology
Victoria Schemenz, Andre Gjardy, Fereshteh F. Chamasemani, Andreas Roschger, Paul Roschger, Paul Zaslansky, Lukas Helfen, Manfred Burghammer, Peter Fratzl, Richard Weinkamer, Roland Brunner, Bettina M. Willie, Wolfgang Wagermaier
JOURNAL OF STRUCTURAL BIOLOGY
(2020)