bluuebunny/crossref_metadata_2025 huggingface dataset:
The need of regional cooperation in crisis response capacities developement
Authors: Petrovski Dimce
Published: February 2025

Brigadier General Dimce Petrovski was speaking on the regional challenges that are possibility for the region and how they should be anticipated, the potential regional threats sources which can highly endanger the population and the directions for regional crisis and conflict response capacities development. After the brief explanation of the key topics he concluded that the upgrade on the regional cooperation is a necessity for all of the countries in the region and it has to be a process that will have continuity.
Macedonian Red Cross
Authors: Samet Ali
Published: February 2025

Mr. Samet ALI gave briefing on the work in the past of the Red Cross and how they handled the emergency situations during the last 15 years. On the end of his presentation, he played two movies from the joint exercises of the Red Cross Macedonia.
Building and Sustaining Regional Capabilities for Emergency Relief
Authors: King Kyle
Published: February 2025

Mr. Kyle King started with the critical questions for the region such as the standardization and interoperability. As very important part for the functioning of the systems are the equipment and training, he briefly explained in the presentation. After that, Mr. King very strictly underlined that the legal implications and duty to care / act and the legal liability concerns are one of the key parts for the systems in the region. Towards the end of his presentation he dedicated to the balancing regional and international requests through EADRCC, the cost reimbursement methods and the very important status of Forces Agreements (SOFA).
Current Technological Advances and their Impact on Terrorism and Counterterrorism Efforts
Authors: Üçer Ahmet Ş.
Published: February 2025

This paper is an attempt to describe the affect of technology advances on global terrorism. It also reports how terrorism has influenced the research and technology for countering terrorism. Activities that are adopted in NATO Research and Technology Organization's various panels are also described.
Transportation Technology and Its Effect on the Speed, Distance and Magnitude of Terrorist Attacks
Authors: Szyliowicz Joseph S.
Published: February 2025

Technology has been a powerful force driving change in transportation systems for centuries and will continue to be powerful force in decades to come. Until the industrial revolution, most people seldom travelled more than a short distance from home. With the coming of railroads, steamships and later jet travel, distances have shrunk and the process of globalization has created a totally new environment. Terrorism involves two dimensions – social distance and physical distance. Historically, terrorists staged their attacks on opponents who were geographically close by. Now, with the elimination of physical distance, they are able to strike anywhere at anytime. Moreover, globalization has created a new international trade system whose disruption would have catastrophic results. Also, the extensive use of hazardous materials provides terrorists with new opportunities to inflict mass casualties. Although states and international organizations have implemented various measures to safeguard both passenger and freight transportation systems, the new environment poses has created a context that requires new, integrated national, and especially international approaches.
Terrorist Use of Communication Technology and Social Networks
Authors: Espeseth Craig  , Gibson Jessica  , Jones Andy  , Goodman Seymour
Published: February 2025

The various uses of information and communications technologies (ICT), by terrorist organization, particularly cell phone networks and the Internet, are reviewed. ICT is demonstrated to enhance the ability of terrorist organizations to support their own organizational efforts, and may also serve as a domain for attack.
ACO-based dynamic job scheduling of parametric computational mechanics studies on Cloud Computing infrastructures
Authors: García Garino Carlos  , Mateos Cristian  , Pacini Elina
Published: February 2025

Parameter Sweep Experiments (PSEs) allow scientists to perform simulations by running the same code with different input data, which typically results in many CPU-intensive jobs and thus computing environments such as Clouds must be used. Job scheduling is however challenging due to its inherent NP-completeness. Therefore, some Cloud schedulers based on Swarm Intelligence (SI) techniques, which are good at approximating combinatorial problems, have arisen. We describe a Cloud scheduler based on Ant Colony Optimization (ACO), a popular SI technique, to allocate Virtual Machines to physical resources belonging to a Cloud. Simulated experiments performed with real PSE job data and alternative classical Cloud schedulers show that our scheduler allows a fair assignment of VMs, which are requested by different users, while maximizing the number of jobs executed every time a new user connects to the Cloud. Unlike previous experiments with our algorithm [9], in which batch execution scenarios for jobs were used, the contribution of this paper is to experiment with our proposal in dynamic scheduling scenarios. Results suggest that our scheduler provides a better balance to the number of executed jobs per unit time versus serviced users, i.e., the number of Cloud users that the scheduler is able to successfully serve.
Ephemeral Materialization Points in Stratosphere Data Management on the Cloud
Authors: Höger Mareike  , Kao Odej  , Richter Philipp  , Warneke Daniel
Published: February 2025

Data streaming frameworks like stratosphere [1] are designed to work in the cloud on a large number of parallel working nodes. The increase of nodes together with the expected long run-time of data processing tasks causes an increase of failure probability. Therefore fault tolerance becomes an important issue in these systems. Existing fault tolerance strategies for data streaming systems usually accept full restarts or work in a blocking manner.
Achieving scalability in the presence of Asynchrony for Exascale Computing
Authors: Sterling Thomas  , Anderson Matthew  , Brodowicz Maciej
Published: February 2025

This paper explores asynchrony in the context of high performance computing. We explore where asynchrony comes from, why it matters, and how exascale computing impacts our consideration of asynchrony. We present a list of key concepts that are expected to permit practical exascale computing in the presence of asynchrony. We then introduce the ParalleX execution model along with its open source runtime system implementation, High Performance ParalleX (HPX). Performance examples of HPX using open source benchmarks are then presented.
On the Role of Co-design in High Performance Computing
Authors: Barrett Richard F.  , Borkar Shekhar  , Dosanjh Sudip S.  , Hammond Simon D.  , Heroux Michael A.  , Hu X. Sharon  , Luitjens Justin  , Parker Steven G.  , Shalf John  , Tang Li
Published: February 2025

Preparations for Exascale computing have led to the realization that future computing environments will be significantly different from those that provide Petascale capabilities. This change is driven by energy constraints, which is compelling architects to design systems that will require a significant re-thinking of how algorithms are developed and implemented. Co-design has been proposed as a methodology for scientific application, software and hardware communities to work together. This chapter gives an overview of co-design and discusses the early application of this methodology to High Performance Computing.
Exascale Computing & Beyond: Meeting the Challenges
Authors: Vaidyanathan Karthikeyan  , Avancha Sasikanth  , Sherlekar Sunil
Published: February 2025

Development of Exascale Computers before the end of this decade is an ambitious goal being pursued by the international HPC community. The challenges are numerous; the important ones being power consumption & dissipation, application scaling and reliability. The challenges also occur at all levels of abstraction: materials & devices, circuit design, logic design, architecture, the software stack, algorithms. We need to meet these challenges not only at every level of abstraction but also need to look at the interaction between levels.
Scalable Dense Linear Algebra on Heterogeneous Hardware
Authors: Bosilca George  , Bouteiller Aurelien  , Danalis Anthony  , Herault Thomas  , Kurzak Jakub  , Luszczek Piotr  , Tomov Stanimire  , Dongarra Jack J.
Published: February 2025

Design of systems exceeding 1 Pflop/s and the push toward 1 Eflop/s, forced a dramatic shift in hardware design. Various physical and engineering constraints resulted in introduction of massive parallelism and functional hybridization with the use of accelerator units. This paradigm change brings about a serious challenge for application developers, as the management of multicore proliferation and heterogeneity rests on software. And it is reasonable to expect, that this situation will not change in the foreseeable future. This chapter presents a methodology of dealing with this issue in three common scenarios. In the context of shared-memory multicore installations, we show how high performance and scalability go hand in hand, when the well-known linear algebra algorithms are recast in terms of Direct Acyclic Graphs (DAGs), which are then transparently scheduled at runtime inside the Parallel Linear Algebra Software for Multicore Architectures (PLASMA) project. Similarly, Matrix Algebra on GPU and Multicore Architectures (MAGMA)schedules DAG-driven computations on multicore processors and accelerators. Finally, Distributed PLASMA (DPLASMA), takes the approach to distributed-memory machines with the use of automatic dependence analysis and the Direct Acyclic Graph Engine (DAGuE) to deliver high performance at the scale of many thousands of cores.
Electromagnetic NDT System for Inspection of Train Hollow Axles
Authors: Chady Tomasz  , Psuj Grzegorz  , Kowalczyk Jacek  , Spychalski Ireneusz
Published: February 2025

The paper presents a newly developed magnetic flux leakage transducer designated for a hollow axle testing. The transducer allows measuring three components of the magnetic residual field. Results of measurements obtained for planar and cylindrical samples with artificial defects are presented.
Artificial Neural Networks and Fuzzy Logic in Nondestructive Evaluation
Authors: Sikora Ryszard  , Baniukiewicz Piotr  , Chady Tomasz  , Lopato Przemyslaw  , Psuj Grzegorz  , Grzywacz Bogdan  , Misztal Leszek
Published: February 2025

The paper carried a brief overview of artificial intelligence algorithms applicable to nondestructive testing. It focuses on three methods: artificial neural networks, fuzzy logic and rough sets. Selected examples of applications of these methods in digital radiography are given.
Quantitative Evaluation of Dielectric Medium Arising in Cable Degradation Using Microwave Guided Measurement System
Authors: Fujiwara Yuki  , Usami Teruo  , Kojima Fumio  , Knopp Jeremy S.
Published: February 2025

This paper is concerned with aging degradation of cable insulation used in airplane and power plants. Material degradation is associated with dielectric property. To prove availability of evaluating dielectric properties, first, a relationship between Q-factor and dielectric permittivity is identified. Secondly, to develop a method of identifying dielectric permittivity, mathematical model of the nondestructive testing for system is simply described by Maxwell's equations in two spatial dimensions. Thirdly, numerical scheme is developed using the finite-difference time-domain method (FDTD). Finally, parameters of dielectric property are estimated using information through numerical experiments by computational algorithm based on Markov Chain Monte Carlo (MCMC) method.
EM Material Characterization of Conductor Backed Media using a NDE Microstrip Probe
Authors: Havrilla Michael  , Bogle Andrew  , Hyde IV Milo  , Rothwell Ed
Published: February 2025

A nondestructive material characterization technique for obtaining the permittivity and permeability of conductor-backed media using a conformable broadband microstrip probe is detailed. The material properties are extracted via comparison of theoretical and measured scattering parameters using an iterative solver. Expressions for the theoretical scattering parameters are obtained via an EFIE formulation and a network analyzer is utilized to acquire the measured scattering parameters. Advantages of the flexible microstrip probe are discussed and experimental results for sample materials are provided and compared to stripline and waveguide measurements in order to validate the analysis.
Radiographic Inspection of Composite Materials
Authors: Baniukiewicz Piotr  , Chady Tomasz  , Sikora Ryszard
Published: February 2025

The composite materials are very popular and widely used in various branches of industry for over fifty years. The issues associated with corrosion of steel and its reduced resistance to aggressive environments brought upon the introduction of new, very durable composite materials to almost all applications. Constantly growing participation of composites in many constructions causes the need of extensive testing of those materials. Radiography is one of the methods that can be successfully applied in evaluation of composites. Nevertheless, due to high opacity of composite materials and low contrast of defects, the application of radiography in this area is limited and needs some additional preprocessing of specimens before investigation.
Evaluation by Ferritoscope and Eddy Currents of Duplex UNS S32205 and Lean Duplex UNS S32304 Stainless Steels Aged at 800 °C
Authors: Tavares Sérgio S.M.  , Pardal Juan M.  , Corte Raíssa R.A.  , Areiza Maria C.L.  , Rebello João M.A.
Published: February 2025

Duplex and lean duplex stainless steels are high strength and corrosion resistant alloys extensively used in chemical and petrochemical industries. The development of non destructive methods for detection and quantification of deleterious phases in these materials are of great interest in nowadays. Sigma phase is the most deleterious phase which can precipitate at 800 °C in duplex and lean duplex steels. Due to its lower Mo content, lean duplex UNS S32304 is much less susceptible to sigma embrittlement and corrosion decay than duplex grade UNS S32205. The non destructive detection and quantification of σ phase precipitation and other microstructural changes in these two alloys was the objective of this work. Specimens of duplex UNS S32205 and lean duplex UNS S32304 were heat treated at 800 °C for different periods of time to produce different microstructures, with different amounts of sigma phases. These microstructures were analyzed by optical microscopy. The samples were investigated by eddy currents and ferritoscope. The amplitude and phase angle were the main parameters obtained in the eddy current tests and the ferrite content was the parameter measured with the ferritoscope.
Electromagnetic Inverse Analysis of Inclined Defect for Ferromagnetic Structural Materials
Authors: Nakasumi Shogo  , Suzuki Takayuki  , Teramoto Tokuo
Published: February 2025

In this study, defect shape evaluation based on the magnetic flux leakage (MFL) technique for inclined defects was conducted. A magnetic dipole method was used to represent the defect surface, and the Tikhonov regularization technique was used to reconstruct the magnitude of magnetic dipole moments. The result of the inverse analysis using magnetic flux obtained from numerical calculation showed good agreement with shape of the original defect. In case of inverse analysis using magnetic flux obtained from experimental measurement, the L-curve did not indicate clear kink point. However, applying the optimal regularization parameter defect shapes could be reconstructed with acceptable errors.
Noniterative Methods for Real Time Imaging of Conducting Materials
Authors: Tamburrino Antonello  , Rubinacci Guglielmo  , Ventre Salvatore
Published: February 2025

Real-time imaging is a either a mandatory or an attractive feature in practical applications of Nondestructive Evaluation of structures and materials. To date, real-time imaging in commercial systems is achieved only by means of calibration charts or pre-computed databases containing the “signatures” corresponding to a finite number of defect configurations and inspection parameters. Situations beyond these sets of signatures cannot be treated and may cause misinterpretations of the data. This paper is a review on the electromagnetic imaging of defects in conducting materials by Noniterative Imaging methods. The class of Noniterative Imaging methods has attracted considerable interest because is suitable for real-time imaging. The paper discuss in detail the Monotonicity Imaging Method (MIMe), that is a specific Noiterative Imaging method successfully applied in Electrical Resistance Tomography and Eddy Current Tomography.
Critical Infrastructure and Its Impact on Energy Security
Authors: Çelikpala Mitat
Published: February 2025

Energy security has emerged as an issue of great importance. As well as the traditional aspects of energy security, a myriad of new aspects has emerged and continues to emerge such as tight oil and gas markets, increasing prices, alternative energy sources and their role, the threat of terrorism, instability in some exporting and importing countries, geopolitical rivalries, and the increasing need for energy to fuel economic growth. The concept of energy security is vague. Energy security is an umbrella term that covers many concerns linking energy, economic growth and political power.
Strategies to Counter Cyberattacks: Cyberthreats and Critical Infrastructure Protection
Authors: Karabacak Bilge  , Tatar Ünal
Published: February 2025

Today, cyberthreats have the potential to harm critical infrastructure which may result in the interruption of life-sustaining services, catastrophic economic damages or severe degradation of national security. The diversity and complexity of cyberthreats that exploit the vulnerabilities of critical infrastructures increase every day. In order to lessen the potential harm of cyberthreats, countermeasures have to be applied and the effectiveness of these countermeasures has to be monitored continuously. In this study, a brief definition and history of critical infrastructure are introduced. Cyberthreats are examined in four fundamental categories with the vulnerabilities of critical infrastructure categorized and examined. Finally, countermeasures that may play a key role in critical infrastructure protection programs are discussed.
Transportation Security in the Context of Defense against Terrorism
Authors: Coman Cristian
Published: February 2025

Terrorist threats to transportation systems, particularly the air transportation systems, are of great concern because of the magnitude of the possible effects, both direct and indirect. Although multiple layers of security are in place at airports using technological tools, they are still not enough to deal with emerging threats. Not only do we need to continue improving our security technology, we also need to address the terrorist attack systems as a whole. NATO has learned in recent operations that air hubs are the main entry and exits points from an area of operation and protecting these nodes is of significant importance.
Planning Methodology for Critical Infrastructures Protection Capabilities
Authors: Bordas Maria  , Tomolya Janos
Published: February 2025

The importance of critical infrastructure is seen through its potential to enable the functional continuity of vital societal functions from economic and social perspective. The present state of critical infrastructure protection is related to the creation of a robust security and protection management system, where the effectiveness of this system should be important also in relation to business continuity and disaster recovery. In planning the capabilities for protection of critical infrastructure protection, policymakers and planners need to define and find the balance between four key components: goals, strategy and respective distribution among variety of private and public organizations means or capabilities to implement the strategy and planning risks. The protection of critical infrastructure is just one of the 21st Century security challenges that require a comprehensive approach, plus sound coordination among and, in time, integration of governmental agencies. The planning methodology for critical infrastructures protection capabilities of the kind presented in this article may contribute to finding effective and efficient solutions in the best interest of society.
Coordination and Cooperation in Cyber Network Defense: the Dutch Efforts to Prevent and Respond
Authors: van den Heuvel Elly  , Klein Baltink Gerben
Published: February 2025

Effective Computer Network Defense requires close cooperation and collaboration between government and industry, science and education, national and international efforts. The Netherlands offers a concrete example of a successful public-private partnership aimed at improving overall cyber security for its society in general, including government, industry, and citizens. This requires more that a mere national cyber security strategy. Mutual trust between parties and close international cooperation and collaboration are essential. The Dutch approach has been successful so far, but it needs the constant attention and focus of all parties involved. The lessons learned from this approach can help build NATO's non-traditional networks and enhance its overall cyber defense posture through cooperation with partner countries, organizations, and commercial entities.
Beyond Perimeter Defense: Defense-in-Depth Leveraging Upstream Security
Authors: McMahon Dave
Published: February 2025

Cyber threats are now so pervasive, sophisticated, and targeted that traditional, reactive computer network defense is no longer sufficient to counter them. Upstream security, which represents a new layer of safeguards that can be deployed well beyond the enterprise perimeter, intercepts malicious activity before it reaches an organization's network. Telecommunications providers are well positioned to offer this type of proactive cyber defense and defense-in-depth, as they possess significant technical capabilities and a unique view on traffic flow. Together, these assets can create a security layer that may operate at higher efficiencies and effectiveness than any enterprise security program. The evidence demonstrates that upstream security and upstream intelligence provide innovative and effective techniques for network defense.
Formalizing Bottlenecks in Task-Based OpenMP Applications
Authors: Benedict Shajulin  , Gerndt Michael  , Gudu Diana-Mihaela
Published: February 2025

Task support was introduced into OpenMP to address irregular parallelism in shared memory architectures. Creating tasks that are extremely fine granular in applications, however, impedes performance. In this paper, a methodology for analyzing the performance of task-based OpenMP programs and its implementation in Periscope is presented. The paper unveils and concentrates on the newly formulated high-level performance properties that formalize typical performance bottlenecks of task-based programs. In addition, the paper reports on the experimental results which were accomplished for the codes of the Barcelona OpenMP Tasks Suite (BOTS) using Periscope in the SuperMUC supercomputing machine at Garching, Germany.
Variable Block Algebraic Recursive Multilevel Solver (VBARMS) for Sparse Linear Systems
Authors: Carpentieri Bruno  , Liao Jia  , Sosonkina Masha
Published: February 2025

We present and discuss the parallel implementation of a multi-elimination incomplete LU factorization method for solving sparse linear systems. The proposed solver exploits any available block structure during the factorization, achieving increased throughput during the computation and improved reliability on realistic applications.
A Proposal of a Single-Synchronized Solver Suited to Large Scale Linear Systems on Parallel Computers with Distributed Memory
Authors: Fujino Seiji  , Murakami Keiichi  , Iwasato Kosuke
Published: February 2025

We propose a new iterative method based on two strategies, improvement stabilization by applying two-term recurrences and utilization of associate residual. The former adopts the coupled two-term recurrences proposed by Rutishauser as stabilizing polynomials, and the latter adopts the associate residual vector for computation of the recurrence parameters ζk,ηkinstead of that of the residual vector. Through numerical experiments, we make clear that the proposed method outperforms other methods from the view points of computational and elapsed time and speed-up on both serial and parallel computers.
Approximate Inverse Preconditioners for Krylov Methods on Heterogeneous Parallel Computers
Authors: Bertaccini Daniele  , Filippone Salvatore
Published: February 2025

The popularity of GPGPUs in high performance platforms for scientific computing in recent times has renewed interest in approximate inverse preconditioners for Krylov methods. We have recently introduced some new algorithmic variants [6] of popular approximate inverse methods. We now report on the behaviour of these variations in high performance multilevel preconditioning frameworks, and we present the software framework that enables us to easily deal with heterogeneous computing platforms that include GPGPUs.
Performance Analysis Techniques for the Exascale Co-Design Process
Authors: Schulz Martin  , Belak Jim  , Bhatele Abhinav  , Bremer Peer-Timo  , Bronevetsky Greg  , Casas Marc  , Gamblin Todd  , Isaacs Katherine E.  , Laguna Ignacio  , Levine Joshua  , Pascucci Valerio  , Richards David  , Rountree Barry
Published: February 2025

Efficient and effective performance analysis techniques are critical for the development of future generation systems. They are the drivers behind the required co-design process that helps establish the principles needed for their design. In this paper, we will highlight two such approaches: PAVE, a project that investigates mapping of performance data to more intuitive domains and uses advanced visualization techniques to expose problems, and GREMLIN, a system evaluation environment capable of emulating expected properties of exascale architectures on petascale machines. Combined with other approaches in system modeling and simulation, these projects enable us to provide a meaningful introspection into a target application's characteristics as well as its expected behavior and, more importantly, likely bottlenecks on future generation machines.
MapReduce Streaming Algorithms for Laplace Relaxation on the Cloud
Authors: Radenski Atanas  , Norris Boyana
Published: February 2025

A MapReduce (MR) technique known as MR message passing enables the development of distributed relaxation algorithms for the Laplace and Poisson equations. While a message-based MR relaxation solver can handle data grids in a fault-tolerant and scalable distributed execution, it also may generate a large number of messages to be routed from mapper to reducer tasks. The volume of intermediate data in the MR network can become a performance bottleneck for larger-scale grids and thus offset the benefits of distributed MR execution. In this paper, we introduce two optimizations, local in-mapper aggregation and strip partitioning, that reduce the volume of MR messages. Technically, we propose relaxation algorithms for the Laplace equation in MR streaming, including a basic message-passing algorithm and algorithms optimized with local aggregation and strip partitioning. We evaluate empirically the optimizations' effect through experiments on Elastic MR, the Amazon MR cloud. Our results can be beneficial to others who would like to develop and optimize MR streaming algorithms for grid-based models, such as PDE and optimization solvers, and cellular automata.
A space-time parallel solver for the three-dimensional heat equation
Authors: Speck Robert  , Ruprecht Daniel  , Emmett Matthew  , Bolten Matthias  , Krause Rolf
Published: February 2025

The paper presents a combination of the time-parallel “parallel full approximation scheme in space and time” (PFASST) with a parallel multigrid method (PMG) in space, resulting in a mesh-based solver for the three-dimensional heat equation with a uniquely high degree of efficient concurrency. Parallel scaling tests are reported on the Cray XE6 machine “Monte Rosa” on up to 16,384 cores and on the IBM Blue Gene/Q system “JUQUEEN” on up to 65,536 cores. The efficacy of the combined spatial-and temporal parallelization is shown by demonstrating that using PFASST in addition to PMG significantly extends the strong-scaling limit. Implications of using spatial coarsening strategies in PFASST's multi-level hierarchy in large-scale parallel simulations are discussed.
Porting Large HPC Applications to GPU Clusters: The Codes GENE and VERTEX
Authors: Dannert Tilman  , Marek Andreas  , Rampp Markus
Published: February 2025

We have developed GPU versions for two major high-performance-computing (HPC) applications originating from two different scientific domains. GENE [1,2] is a plasma microturbulence code which is employed for simulations of nuclear fusion plasmas. VERTEX [3,4,5] is a neutrino-radiation hydrodynamics code for “first principles”-simulations of core-collapse supernova explosions [6,7,8]. The codes are considered state of the art in their respective scientific domains, both concerning their scientific scope and functionality as well as the achievable compute performance, in particular parallel scalability on all relevant HPC platforms. GENE and VERTEX were ported by us to HPC cluster architectures with two NVidia Kepler GPUs mounted in each node in addition to two Intel Xeon CPUs of the Sandy Bridge family. On such platforms we achieve up to twofold gains in the overall application performance in the sense of a reduction of the time to solution for a given setup with respect to a pure CPU cluster. The paper describes our basic porting strategies and benchmarking methodology, and details the main algorithmic and technical challenges we faced on the new, heterogeneous architecture.
Performance Measurements of MHD Simulation for Planetary Magnetosphere on Peta-Scale Computer FX10
Authors: Fukazawa Keiichiro  , Nanri Takeshi  , Umeda Takayuki
Published: February 2025

Magnetohydrodynamic (MHD) simulations are often applied to study the global dynamics and configuration of the planetary magnetosphere. The computational performance of an MHD code is evaluated on a massive parallel scalar type supercomputer system with one PFlops ideal performance. We have made the performance tuning of our three-dimensional MHD code for the planetary magnetosphere on the FX10 which has 76,800 cores, distributed on 4,800 SPARC64 IXfx nodes. For the parallelization of the MHD code, we use four different methods, i.e. one-dimensional, two-dimensional, three-dimensional regular domain decomposition methods and a cache-hit type of three-dimensional domain decomposition method. We found that the cache-hit type of three-dimensional decomposition of the MHD model is suitable for the FX10 system. We also found the pack/unpack operation for the inter-node communications decreases the execution efficiency by 2 %. After asynchronous communication is introduced and the pack/unpack operation is overlapped, we achieved a computing performance of 230 TFlops and an efficiency of almost 20 % for the MHD code.
POLCA – A Programming Model for Large Scale, Strongly Heterogeneous Infrastructures
Authors: Schubert Lutz  , Kuper Jan  , Gracia José
Published: February 2025

Parallel and portable development of programs becomes an increasingly important subject for usage of future computing systems. With the introduction of heterogeneous many-core systems and the increasing impact of the memory wall, classical software development paradigms no longer hold true. In particular the lack of consideration for data access and communication cost poses a crucial performance obstacle. Dataflow models are therefore getting attention from large scale and performance oriented developers. Such models however are principally error prone, and require reorganization of the code to maximize usability.
A distributed algorithm for the Permutation Flow Shop Problem – An empirical analysis
Authors: Kouki Samia  , Jemni Mohamed  , Ladhari Talel
Published: February 2025

The Permutation Flow Shop Problem (PFSP) is considered as one of the most complex and hard combinatorial optimization scheduling problem to solve. To address the computational complexity of the PFSP, parallel and distributed algorithms using grid computing are considered in this work. Indeed, our contributions focuses on two parallel algorithms: the recent one, called Grid Algorithm with Load Balancing (GALB), is an improvement of our previous algorithm, called Grid Algorithm Updating the Upper Bound (GAUUB), with a new strategy of scheduling jobs leading to a better load balancing between processors. In this paper, we present first, the core idea of GALB algorithm which consists on a dynamic and efficient distribution of the load of all available processors. The objective is to minimize the running times of large and hard instances. Second, we present an empirical study addressing the performance comparison between the GAUUB and GALB algorithms. All conducted experiments used the Taillard's benchmark data sets. Our algorithm (GALB) generated high quality solutions and outperforms the GAUUB algorithm in terms of resolution of new instances, speed, scalability and load balancing.
High performance CPU/GPU multiresolution Poisson solver
Authors: Van Rees Wim M.  , Rossinelli Diego  , Hadjidoukas Panagiotis  , Koumoutsakos Petros
Published: February 2025

We present a multipole-based N-body solver for 3D multiresolution, block-structured grids. The solver is designed for a single heterogeneous CPU/GPU compute node, and evaluates the multipole expansions on the CPU while offloading the compute-heavy particle-particle interactions to the GPU. The regular structure of the destination points is exploited for data parallelism on the CPU, to reduce data transfer to the GPU and to minimize memory accesses during evaluation of the direct and indirect interactions. The algorithmic improvements together with HPC techniques lead to 81% and 96% of the upper bound performance for the CPU and GPU parts, respectively.
High-Level Synthesis Revised
Authors: Schmid Moritz  , Hannig Frank  , Tanase Alexandru  , Teich Jürgen
Published: February 2025

The continuous progress in semiconductor technology allows for more and more complex processor architectures. The downside of these technological advances is that computing has already hit a power wall and clock frequencies can barely be increased. In order to scale computing performance in the future, systems' energy efficiency and the degree of parallelism have to be significantly improved. The design of heterogeneous hardware with different specialized resources seems to be a promising solution. When highest performance (throughput, short latencies) and energy efficiency are important, as a remedy, we consider the generation of dedicated FPGA accelerators to address these stringent requirements. In this work, we present the PARO high-level synthesis framework for the automated generation of massively parallel FPGA accelerators. The framework is tailored for compute-intensive applications from the domains of image, video, and other digital signal processing, as well as algorithms from linear algebra. Unique features of PARO include: (1) The design entry in form of a compact and intuitive domain-specific language that is closely related to a mathematical problem description, (2) support for integer, fixed point, floating point, and custom arithmetic, (3) advanced loop transformations (e.g., partitioning) and scheduling techniques in the polyhedron model, (4)generation of accelerator IP cores (VHDL code) that can be easily integrated into a system design such as an SoC or in a networked scenario. Finally, we showcase the capabilities of our framework for the development of a range image conditioning pipeline for smart cameras for range sensing.
Timing Driven C-Slow Retiming on RTL for MultiCores on FPGAs
Authors: Strauch Tobias
Published: February 2025

In this paper C-Slow Retiming (CSR) on RTL is discussed. CSR multiplies the functionality of cores by adding the same number of registers into each path. The technique is ideal for FPGAs with their already existing registers. Previously publications are limited to adding registers on netlist level, which generates a lot of system verification problems and which is assumed to be the major drawback to use this technology in the modern multicore times. The paper shows how CSR can efficiently be done with timing driven automatic RTL modification. The methodology provided with this paper can be used as guidance for using CSR in high level synthesis (HLS). The paper shows the results of a CSR-ed complex RISC core on RTL implemented on FPGAs.
Performance and Resource Modeling for FPGAs using High-Level Synthesis tools
Authors: Da Silva Bruno  , Braeken An  , D'Hollander Erik H.  , Touhafi Abdellah
Published: February 2025

High-performance computing with FPGAs is gaining momentum with the advent of sophisticated High-Level Synthesis (HLS) tools. The performance of a design is impacted by the input-output bandwidth, the code optimizations and the resource consumption, making the performance estimation a challenge. This paper proposes a performance model which extends the roofline model to take into account the resource consumption and the parameters used in the HLS tools. A strategy is developed which maximizes the performance and the resource utilization within the area of the FPGA. The model is used to optimize the design exploration of a class of window-based image processing application.
Load Balancing for Massively Parallel Computations with the Sparse Grid Combination Technique
Authors: Heene Mario  , Kowitz Christoph  , Pflüger Dirk
Published: February 2025

Massively parallel simulations of plasma microturbulence using GENE are facing the curse of dimensionality, since the discretization of the five-dimensional gyrokinetic equations requires a large amount of grid points even for only moderate resolutions. The sparse grid combination technique can be used to tackle the curse of dimensionality. Being based on a superposition of anisotropic full grid solutions that can be computed independently of each other, it introduces a second layer of parallelism that will equip GENE for exascale computing. Since the anisotropy of the discretizations of the partial solutions results in massive load imbalances, effective scheduling is crucial in order to exploit this parallelism. In this paper a load model for linear initial value runs with GENE is introduced for effective load balancing for the combination technique.
Application-independent Autotuning for GPUs
Authors: Tillmann Martin  , Karcher Thomas  , Dachsbacher Carsten  , Tichy Walter F.
Published: February 2025

Autotuning is an established technique for adjusting performance-critical parameters of applications to their specific run-time environment. In this paper, we investigate the potential of online autotuning for general purpose computation on GPUs. Our application-independent autotuner AtuneRT optimizes GPU-specific parameters such as block size and loop-unrolling degree. We also discuss the peculiarities of autotuning on GPUs. We demonstrate tuning potential using CUDA and by instrumenting the parallel algorithms library Thrust. We evaluate our online autotuning approach with various GPUs and sample applications.
Extreme Scaling Workshop at the LRZ
Authors: Allalen Momme  , Bazin Gurvan  , Bernau Christoph  , Bode Arndt  , Brayford David  , Brehm Matthias  , Diemand Jürg  , Dolag Klaus  , Engels Jan  , Hammer Nicolay  , Huber Herbert  , Jamitzky Ferdinand  , Kamakar Anupam  , Kutzner Carsten  , Marek Andreas  , Navarrete Carmen  , Satzger Helmut  , Schmidt Wolfram  , Trisjono Philipp
Published: February 2025

In July 2013, the Leibniz Supercomputing Centre (LRZ) held the first workshop to test extreme scaling on SuperMUC, the 3 PFLOP/s system with 147,456 Intel Sandy Bridge CPU cores. Groups from 15 international projects came to the LRZ with codes that had already shown scaling up to 4 islands (32,768 cores). During the workshop, the participants could test the scaling capabilities of their codes on the whole system. Application experts from the LRZ, Intel and IBM were on site to resolve issues and assist in the performance optimization. New techniques like fast startup were successfully tested which helped to reduce the startup time by a factor of 2-3. At the end of the workshop, 6 applications were successfully running on the full machine, while the other 8 applications managed to run on half of the system. The LRZ is already planning a follow-up workshop where the improvements and feedback from the experts will be tested. More information available at http://www.lrz.de.
A Scalable Farm Skeleton for Heterogeneous Parallel Programming
Authors: Ernsting Steffen  , Kuchen Herbert
Published: February 2025

Nowadays, multi-core processors and GPUs with thousands of cores are omnipresent. Fully exploiting their resources involves dealing with low-level concepts of parallel programming. These low-level concepts still constitute a high barrier to efficient development of parallel applications. That is why we need high-level tools for parallel programming.
Theoretical Measures of Cache Efficiency for Tetrahedral Adaptive Meshes
Authors: Kunst Oliver  , Behrens Jörn
Published: February 2025

We present a case study to improve the cache efficiency for a simulation on a tetrahedral bisection-based adaptive mesh, which does not support common space-filling curve (SFC) approaches to enumerate and sort the elements.
May/Must Abstraction-Based Software Model Checking for Sound Verification and Falsification
Authors: Godefroid Patrice
Published: February 2025

Three-valued models, in which properties of a system are either true, false or unknown, have recently been advocated as a better representation for reactive program abstractions generated by automatic techniques such as predicate abstraction. Indeed, for the same cost, model checking three-valued abstractions, also called may/must abstractions, can be used to both prove and disprove any temporal-logic property, whereas traditional conservative abstractions can only prove universal properties. Also, verification results can be more precise with generalized model checking, which checks whether there exists a concretization of an abstraction satisfying a temporal-logic formula. Generalized model checking generalizes both model checking (when the model is complete) and satisfiability (when everything in the model is unknown), probably the two most studied problems related to temporal logic and verification.
E-Voting Systems
Authors: Küsters Ralf
Published: February 2025

Systems for electronic voting (e-voting systems), including systems for voting over the Internet and systems for voting in a voting booth, are employed in many countries. However, most of the systems used in practice today do not provide a sufficient level of security. For example, programming errors and malicious behavior easily go undetected. In fact, numerous problems with e-voting systems have been reported in various countries.
Probabilistic Model Checking for Biology
Authors: Kwiatkowska Marta  , Thachuk Chris
Published: February 2025

Probabilistic model checking is an automated method for verifying the correctness and performance of probabilistic models. Property specifications are expressed in probabilistic temporal logic, denoting, for example, the probability of a given event, the probability of its occurrence within a given time interval, or expected number of times it has occurred in a time period. This chapter focuses on the application of probabilistic model checking to biological systems modelled as continuous-time Markov chains, illustrating the usefulness of these techniques through relevant case studies performed with the probabilistic model checker PRISM. We begin with an introduction to discrete-time Markov chains and the corresponding model checking algorithms. Then continuous-time Markov chain models are defined, together with the logic CSL (Continuous Stochastic Logic), and an overview of model checking for CSL is given, which proceeds mainly by reduction to discrete-time Markov chains. The techniques are illustrated with examples of biochemical reaction networks, which are verified against quantitative temporal properties. Next a biological case study analysing the Fibroblast Growth Factor (FGF) molecular signalling pathway is summarised, highlighting how probabilistic model checking can assist in scientific discovery. Finally, we consider DNA computation, and specifically the DSD formalism (DNA Strand Displacement), and show how errors can be detected in DNA gate designs, analogous to model checking for digital circuits.
Frameworks for Interprocedural Analysis of Concurrent Programs
Authors: Seidl Helmut  , Apinis Kalmer  , Vojdani Vesal
Published: February 2025

This tutorial is about infra-structures for general-purpose interprocedural analyses. It consists of two parts. The first part, following the lines of [2], argues that side-effecting constraint systems may serve as kind of swiss army knife for specifying analyses, while the second part provides an overview on solving techniques for such systems. Side-effecting constraint systems were originally introduced for the analysis of multi-threaded code by Müller-Olm, Seidl and Vene in [41]. Here, we explain how this formalism provides a unified framework for realizing efficient interprocedural analyses of programs, possibly with dynamic function calls, where the amount of context-sensitivity can be tweaked and where the context-sensitive analyses of local properties can be combined with flow-insensitive analyses of global properties, e.g., about the heap. One infrastructure realizing this intermediate format, is the analyzer generator GOBLINT, which we use to practically evaluate this approach on real-world examples.
Program Synthesis
Authors: Gulwani Sumit
Published: February 2025

Program Synthesis is the task of searching for programs over some underlying space that realize user's intent. There are three key dimensions in program synthesis: expression of user intent, space of programs over which to search, and the search technique. This article illustrates these dimensions while taking an application centric view.
Contesting Religious Authority in Jordanian Salafi Networks
Authors: Wagemakers Joas
Published: February 2025

This chapter concentrates on debates among and between Jordanian Salafi networks of quietist (a-political) and jihadi (violently radical) Salafis. These debates focus especially on the discrediting of Salafis' opponents through theological labels and accusations and how these actually mask the real and much more personal sources of tension between them. As such, this chapter seeks to give greater insight into religious authority among Salafi networks in Jordan and intends to show that the disputes between Jordanian Salafis dealt with here originate less in theological and doctrinal differences than in conflicts over religious leadership and authority.
Two faces of Islam in the Western Balkans: Between Political Ideology and Islamist Radicalization
Authors: Babić Marko
Published: February 2025

The paper aims to explain specificities of Islam in the post Yugoslav political space which we today describe as the Western Balkans. It focuses on two aspects of Islam in the region: Islam understood as political ideology and Islam through its Islamist face providing some basic concepts related to both phenomenons. To what extent these aspects of Islam have been “imported” and do they truly impose a real threat to political stability in the region? Can we consider any threat in terms of terrorist acts in the region? These are some questions and doubts to which the paper using the descriptive method of analysis tries to give answers.