bluuebunny/crossref_metadata_2025 huggingface dataset:
Smart Ambient Learning with Physical Artifacts Using Wearable Technologies
Authors: Koren István  , Klamma Ralf
Published: February 2025

Wearable technologies have been developing a momentum recently. However, integrated concepts for teaching and learning with wearable technologies are still not existing in the moment. In this paper, we report about a multi-contextual framework for such an integrated concept. It consists of a number of real-world use-cases coming from a third-party funded project, an entrepreneurial teaching course from a technical university and an open source software development strategy. Conceptual as well as technical issues and first experiences draw an optimistic picture while we outline further needs in research and development.
Coupled Cognitive and Functional Change in Alzheimer's Disease and the Influence of Depressive Symptoms
Authors: Zahodne Laura B.  , Devanand D.P.  , Stern Yaakov
Published: February 2025

In Alzheimer's disease (AD), cognition and function are only moderately correlated in cross-sectional studies, and studies of their longitudinal association are less common. One potential non-cognitive contributor to function is depression, which has been associated with poorer clinical outcomes. The current study investigated longitudinal associations between functional abilities, cognitive status, and depressive symptoms in AD. 517 patients diagnosed with probable AD and enrolled in The Multicenter Study of Predictors of Disease Course in Alzheimer's Disease were included. Patients were followed at 6-month intervals over 5.5 years. Longitudinal changes in the Blessed Dementia Rating Scale, modified Mini-Mental State Exam, and the depression subscale of the Columbia University Scale for Psychopathology in AD were examined in a multivariate latent growth curve model that controlled for gender, age, education, and recruitment site. Results showed that cognition and function worsened over the study period, whereas depressive symptoms were largely stable. Rates of change in cognition and function were correlated across participants and coupled within participants, indicating that they travel together over time. Worse initial cognitive status was associated with faster subsequent functional decline, and vice versa. Higher level of depressive symptoms was associated with worse initial functioning and faster subsequent cognitive and functional decline. These findings highlight the importance of both cognitive and psychiatric assessment for functional prognosis. Targeting both cognitive and depressive symptoms in the clinical treatment of AD may have incremental benefit on functional abilities.
Depression and Alzheimer's Disease: Is Stress the Initiating Factor in a Common Neuropathological Cascade?
Authors: Aznar Susana  , Knudsen Gitte M.
Published: February 2025

The existence of a high co-morbidity between Alzheimer's disease (AD) and depression has been known for a long time. More interesting though are recent studies indicating that depression and number of depressive episodes earlier in life is associated with increased risk of AD development. This suggests the existence of common neuropathological mechanisms behind depression and AD. Here we propose that the brain changes associated with depressive episodes that compromise the brain's ability to cope with stress may constitute risk factors for development of AD. Furthermore, in individuals with a genetic linkage to depression, there may be an increased vulnerability towards the initiation of a detrimental neurodegenerative cascade. The following review will deal with the various observations reported within the different neurobiological systems known to be involved and affected in depression, like serotonergic and cholinergic system, hypothalamic-pituitary-adrenal axis and brain derived neurotrophic factor, and discussed in relation to AD.
Apathy and Depression in Mild Alzheimer's Disease: A Cross-sectional Study using Diagnostic Criteria
Authors: Benoit Michel  , Berrut Gilles  , Doussaint Johanna  , Bakchine Serge  , Bonin-Guillaume Sylvie  , Frémont Patrick  , Gallarda Thierry  , Krolak-Salmon Pierre  , Marquet Thierry  , Mékiès Claude  , Sellal François  , Schuck Stéphane  , David Renaud  , Robert Philippe
Published: February 2025

Apathy and depression are the most frequent neuropsychiatric symptoms symptoms in Alzheimer's disease (AD). In a cross-sectional observational study of 734 subjects with probable mild AD, we evaluated the prevalence of apathy and depression. After the use of specific diagnostic criteria, we tested the interaction between the two syndromes and their relation with specific comorbidities, and different functional outcomes. Depression was diagnosed using the diagnostic criteria for depression in AD, and apathy with the diagnostic criteria for apathy in neuropsychiatric disorders.
Hippocampal Volume in Older Adults at Risk of Cognitive Decline: The Role of Sleep, Vascular Risk, and Depression
Authors: Elcombe Emma L.  , Lagopoulos Jim  , Duffy Shantel L.  , Lewis Simon J.G.  , Norrie Louisa  , Hickie Ian B.  , Naismith Sharon L.
Published: February 2025

Background and Objectives: Decreased hippocampal volume in older adults is associated with neurodegenerative and psychiatric diseases. Several modifiable risk factors have been associated with the size of this structure, however the relative contribution of these factors to hippocampal atrophy is unclear. This study aimed to examine the relationship between modifiable risk factors and hippocampal volume in older adults at risk of cognitive decline.
The Default Mode Network may be the Key Substrate of Depressive Symptom-Related Cognitive Changes
Authors: Royall Donald R.  , Palmer Raymond F.  , Vidoni Eric D.  , Honea Robyn A.
Published: February 2025

Depressive symptoms are associated with an increased risk of Alzheimer's disease (AD) but the mechanism(s) involved has not been well established. In a convenience sample of participants in the University of Kansas' Brain Aging Project, we use structural equation modeling (SEM) to explicitly distinguish depressive symptom-related variance in cognitive task performance (i.e., DEPCOG) from that which is unrelated to a depressive symptoms. DEPCOG is strongly associated with the cognitive correlates of functional status (δ), which we previously associated with elements of the Default Mode Network (DMN). Both δ and DEPCOG map to a posterior cingulate seeded network that has recently been associated with amyloid-β deposition and includes elements of the DMN. Both contribute significantly to clinical dementia status and dementia severity, as measured by the Clinical Dementia Rating Scale Sum of Boxes. These findings suggest that the cognitive correlates of depressive symptoms, even in the absence of a major depressive episode, may contribute to dementia in their own right, and could be responsible for some cases of incident clinical “AD”. This conclusion suggests new opportunities for the latter's diagnosis, prevention, and treatment.
BDNF Genetic Variations Increase the Risk of Alzheimer's Disease-Related Depression
Authors: Borroni Barbara  , Grassi Mario  , Archetti Silvana  , Costanzi Chiara  , Bianchi Marta  , Caimi Luigi  , Caltagirone Carlo  , Di Luca Monica  , Padovani Alessandro
Published: February 2025

The gene encoding the brain-derived neurotrophic factor (BDNF) has been demonstrated as a candidate for Alzheimer's disease-related depression (AD-D) susceptibility. Additionally, an association between AD-D and the functional valine to methionine (Val66Met) polymorphism has been reported. The aim of this study was to assess the genetic contribution of other BDNF variants to AD-D. Two-hundred forty-five AD patients were divided into two subgroups according to the presence (AD-D) or the absence (AD-nD) of depressive symptoms. Four single-nucleotide polymorphisms within BDNF gene were considered, i.e., C270T, rs2049045 C/G, G196A (Val66Met), and G11757C. In our sample, 35.5% of patients (n = 87) reported AD-related depressive symptoms. The individual SNP analysis showed an association between G196A and G11757C genotypes and AD-D. Accordingly, considering the allele frequencies, BDNF 196*A allele was significantly overrepresented in AD-D compared to AD-nD (OR = 1.80, 95% CI = 1.19–2.72), as well as BDNF 11757*C allele (OR = 1.90, 95% CI = 1.25–2.90). Haplotype analyses revealed that the alleles at four loci (C270T, rs2049045 C/G, G196A, G11757C) interacted to further increase the risk of AD-D. Compared to the most common not-at-risk C-C-G-G haplotype, C-G-A-C (OR = 3.55, 95% CI = 1.44–8.76, P = 0.006) and C-C-A-C haplotypes (OR = 1.72, 95% CI = 1.03–2.87, P = 0.037) were overrepresented in AD-D. This study suggests that BDNF genetic variations play a role in the susceptibility to AD-related depression.
A Review of Pharmacological Treatments for Depression in Alzheimer's Disease
Authors: Siarkos Kostas T.  , Katirtzoglou Everina A.  , Politis Antonios M.
Published: February 2025

Depression in Alzheimer's disease (dAD) is one of the most common behavioral and psychological symptoms of dementia, with devastating consequences not only for the affected individuals, but for caregivers as well. So far, pharmacological treatment of dAD has been based on the “monoamine hypothesis”. However, the reported moderate effects of approved antidepressants, as well as an increasing body of research evidence, suggest a more complex pathophysiologic mechanism. In the present paper, a systematic review of different treatments for dAD is presented that can inform the study of alternative neuropathological and neurobiological aspects of the disease aimed at the development of more effective treatment targets.
Randomized Controlled Trial of a Healthy Brain Ageing Cognitive Training Program: Effects on Memory, Mood, and Sleep
Authors: Diamond Keri  , Mowszowski Loren  , Cockayne Nicole  , Norrie Louisa  , Paradise Matthew  , Hermens Daniel F.  , Lewis Simon J.G.  , Hickie Ian B.  , Naismith Sharon L.
Published: February 2025

Background: With the rise in the ageing population and absence of a cure for dementia, cost-effective prevention strategies for those ‘at risk’ of dementia including those with depression and/or mild cognitive impairment are urgently required.
Late-Life Depression as a Risk Factor for Mild Cognitive Impairment or Alzheimer's Disease in 30 US Alzheimer's Disease Centers
Authors: Steenland Kyle  , Karnes Conny  , Seals Ryan  , Carnevale Claudine  , Hermida Adriana  , Levey Allan
Published: February 2025

Identification of potentially modifiable risk factors for cognitive deterioration is important. We conducted a prospective study of 5,607 subjects with normal cognition and 2,500 subjects with mild cognitive impairment (MCI) at 30 Alzheimer's Disease Centers in the Unites States between 2005 and 2011. Cox regression was used to determine whether depression predicted transition from normal to MCI, or MCI to Alzheimer's disease (AD). Over an average of 3.3 visits, 15% of normal subjects transitioned to MCI (62/1000 per year), while 38% of MCI subjects transitioned to AD (146/1000 per year). At baseline, 22% of participants had recent (within the last two years) depression defined by clinician judgment; 9% and 17% were depressed using the Geriatric Depression Scale (GDS score ≥5) and the Neuropsychiatric Inventory Questionnaire (NPI-Q), respectively. At baseline, depressed subjects performed significantly worse on cognitive tests. Those always depressed throughout follow-up had an increased risk for progression from normal to MCI (RR=2.35; 95% CI 1.93–3.08) versus never depressed. Normal subjects, identified as depressed at first visit but subsequently improved, were found to have an increased but lower risk of progression (RR=1.40 (1.01–1.95)). The ‘always depressed’ had only a modest increased risk of progression from MCI to AD (RR=1.21 (1.00–1.46). Results were similar using time-dependent variables for depression or when defining depression via the GDS or NPI-Q. We found no effect of earlier depression (>2 years past). The effect of recent depression did not differ by antidepressant treatment, APOE4 allele status, or type of MCI. In conclusion, late-life depression is a strong risk factor for normal subjects progressing to MCI.
Evaluation of Support System Architecture for Air Warfare Destroyers
Authors: Mo John P.T.  , Thompson Douglas
Published: February 2025

The Australian Government and its group of defence organisations struggled over the years to effectively support defence capabilities throughout their life. Numerous reports pointed to management and structural failures that started during the procurement phase when insufficient budget was apportioned to the through life costs through to failure to learn from previous projects, poor risk management practices, lack of responsibility and accountability and failure to adequately communicate between stakeholders. Government thinking has flavoured the use performance based contracts known as Contract for Availability (CfA). However, research has shown that effective CfA type contracts only work by adopting proven enterprise architecture frameworks. This paper evaluated a number of reference architecture framework (AF) and suggested a suitable AF for establishing a through life support system of the Hobart Class Air Warfare Destroyer (AWD) throughout its 30 year in-service life.
CE Challenges – Work to Do
Authors: Stjepandić Josip  , Verhagen Wim  , Wognum Nel
Published: February 2025

CE has been used for more than two decades now. Despite many successes and advantages, there are still many challenges to be addressed. These challenges are both technical and organisational. In the paper we will address the current challenges of CE. Many challenges are related to the exchange of data and knowledge and to the systems that make data and knowledge exchange possible. Although much progress has been made in enabling extensive data and knowledge exchange and use, much remains to be wished. For example, there are still barriers to data exchange. Technically, these barriers may consist of different formats, differences in infrastructures and systems, and different semantics. There are also organisational and political barriers. For example, investment in information system may heavily impact upstream suppliers, while revenues of better information exchange may predominantly be gained by downstream actors. Without sharing costs and revenues, chain-wide information exchange will not be easily realised. Another barrier is the possible lack of willingness to share information, because of potential misuse of knowledge and loss of power. The paper is organised as follows. First we will describe the current manifestation of CE as described in a recent book. Second, we will list current trends in CE. Third, we will present some Critical Success Factors (CSFs) that are considered relevant for implementing and adapting CE practices. Last, we indicate some research and practical questions to be addressed, especially for areas that have a high potential and actual impact.
Gen-T. Terrorist Infosphere and i-Volution of Lone Wolf Terrorism
Authors: Antinori Arije
Published: February 2025

This paper explores the change in contemporary terrorism scenario to point out the translation process from a well-organized archetype of terrorism based on ideology, strategic vision and goals to a totally de-structured and atomized phenomenon, the Lone Wolf Terrorism. The Lone Wolf actor has to be retained not a mere criminal but a complex product of the cultural globalization of terror. He belongs to a “pollinated” generation of terrorist actors. The present contribution focuses on the role of cyber-culture, creating the infosphere, to ignite the cyber-individualism. That explains the appeal of the “Culture of Terrorism” based on “cool” cyber-media products sharing especially in the Web. The Lone Wolf self-proclamed jihadi Terrorist is not just a radicalized actor but he builds his own Self (step-by-step) interacting through the “terrorist infosphere” and “i-volving” because of the force of the decennial (cyber-) enculturation multilevel process.
Biological and Chemical Agents in the Hands of Lone Actors – A Different View
Authors: Negranu Jacob  , Vaturi Asher  , Sharan Yair
Published: February 2025

The threat of biological and chemical weapons is one of the more threatening threats. This is a consequence of the fact that if used against unprotected population it will result in a very great number of casualties a mass effect. The possible use of such weapons by terrorists as well as lone actors is thus very worrying. However, fortunately enough, such a threat has not really been realized in the last decades. In very few cases in which such weapons/agents were used by terrorists the number of casualties was small. A mass effect has not happened. Such a scenario can still be considered a wild card. A wild card is an event with a small probability but a high impact. Technology might change this situation in the far future giving lone actors new potential means to terrorize society. Being a wild card such a possibility calls for necessary protection means and relevant defense response.
Laboratory investigation on the mechanics of soft-rigid soil mixtures
Authors: Rouhanifar Salman  , Ibraim Erdin
Published: February 2025

Rubber particles derived from recycled tyres are used as a practical materials in construction industry, including geotechnical systems. Drained triaxial compression tests are conducted to investigate the mechanical behavior of Leighton Buzzard and rubber particles mixtures, bot materials with identical particle size distributions. Distribution of constituents throughout the sample is also explored through x-ray CT testing.
Travel time measurements of shear waves in Bío Bío sand using bender elements
Authors: Ayala Juan  , Villalobos Felipe  , Alvarado Giovanny
Published: February 2025

The design and set up of a system to measure the travel time of shear waves in Bío Bío sand samples using bender elements, is described. An oedometer device was adapted to install bender elements. Measurements were carried out for sand samples with different relative density, pressure/deformation, diameter/height, dry/saturated and varying the frequency, amplitude and type of the triggered electric signals. Repetitiveness and calibration were evaluated. Travel times are evaluated using criteria in the time and frequency domain. From the theory of elasticity, results are interpreted as shear wave velocity and elastic shear modulus as a function of vertical effective stress, void ratio and vertical deformation. The shear wave velocity and shear modulus increased with relative density and effective vertical stress as found previously by other authors. Finally, well known formulae for estimating the elastic shear modulus are used to compare with the experimental results. The estimations were good for effective vertical stresses around 100 kPa, but underestimation and overestimation of the shear modulus occurred for stresses below and above that value, respectively. Soil stiffness during unloading/reloading cycles was underestimated with the expressions used for loading.
Three-dimensional quantification of the morphology and intragranular void ratio of a shelly carbonate sand
Authors: Fonseca Joana  , Reyes-Aldasoro Constantino Carlos  , Wils Laure
Published: February 2025

Shelly carbonate sands represent an extreme soil type in terms of their mechanical behavior which derives from the bioclastic nature of the constituent grains. In their uncemented form, these deposits exhibit very high compressibility, which has posed a number of geotechnical engineering problems; in most cases related to the reduction in the bearing capacities of both shallow and deep foundations. Remarkable features of these carbonate sands include the complex shape and the structural weakness of the grains and the high inter and intra granular porosity. Previous studies, have quoted the interlocking of the angular shelly particles to be at the origin of their high friction angles and high initial void ratio, however, up until now, no scientific micro-scale examination has been carried out. This paper presents a non-invasive image based investigation into the grain morphology of a carbonate sand from the Persian Gulf. This sand has a median grain size of 570μm and a high CaCO3content in the form of aragonite and calcite. Three-dimensional images from x-ray computed tomography (3DXRCT) with a size of 6μm were used. The presence of various skeletal bodies such as shells of small organisms with distinct densities and composition poses real challenges for an accurate segmentation. Image processing algorithms were developed in order to identify the individual sand grains and quantify their properties. Earlier work on silica sands has highlighted the importance of 3D non-invasive techniques in providing an accurate distribution of the grain sizes when compared to more traditional techniques such as sieving analysis and 2D microscopy. The methodology here proposed allows an accurate quantification of grain shape and size and the assessment of grain damage following mechanical deformation. This study, contributes towards improving our understanding of the engineering properties of carbonate sands and thus, predicting their response under loading.
Sampling and sample preparation on structure effects
Authors: Rodrigues Carlos  , Lemos Luís
Published: February 2025

This paper evaluates the disturbance during the process of sampling and specimen preparation using natural and artificial samples, of a residual soils from a granite saprolite located in Guarda NE region of Portugal. This soil profile is described and the soil characterized and classified. The intrinsic mechanical behaviour of these materials is evaluated on samples compacted to different densities. Also, this behaviour is analysed on natural and artificial structured materials.
Deformation of Structured Soil with Cementation
Authors: Horpibulsuk Suksun  , Liu Martin D.
Published: February 2025

In this paper, a study on the deformation of structured soil with cementation is made. The Structured Cam Clay model with cementation effect is introduced. The Structured Cam Clay model was generated for the cementation effect via the concept of “the operative mean effective stress” in which the cementation effect is represented as an isotropic increment of the effective stress. The removal of cementation structure is also simplified and described in the model. The Structured Cam Clay model thus formed has the capacity to describe the behaviour of soils with a wide range of structures as reconstituted state, natural state, and cemented state. Model simulations are made and validated against experimental data. Discussions on modeling soil behaviour with various cementation structures are also presented.
Improvement of the dynamic behavior of soil structures underlain by liquefiable soil using the Geosynthetics-encased columns
Authors: Alkayyal Hassan  , Awwad Talal
Published: February 2025

From the simple separating layers up to the high strength tension elements, the geosynthetics and their wide-range applications has innovated the geotechnical engineering. After their successful application as reinforcement elements, the concept of the geosynthetics-encased columns has developed to benefit their mechanisms so they could improve the behavior of soil structures constructed on weak soils. Due to the successive developments in the numerical simulation and the constitutive modeling, very complex geotechnical problems have modeled and the realistic behavior of the studied structure has obtained. In this paper, a 3D finite-elements-analysis has been conducted to investigate the enhancement, which was resulted by using the geosynthetics-encased columns on the dynamic behavior of soil embankments that underlain by liquefiable sandy soil. The results of the study analyzed and some recommendations, concerning the improvement of the dynamic behavior of soil structures using the geosynthetics-encased columns against liquefaction, have derived.
Visualization of Shear bands in cohesionless soils
Authors: Soltanbeigi Behzad  , Altunbas Adlen  , Cinicioglu Ozer
Published: February 2025

This study attempts to link the dilatancy angle to shear band thickness and inclination. For this purpose, a small scale physical retaining wall model was manufactured. Model wall is capable of translating horizontally to facilitate active states in the backfill. On the other hand, transparent Plexiglas sidewalls of the physical model test set-up both constrains the backfill in plain strain condition and also allows observation of the progressive failure mechanism by employing Particle Image velocimetry (PIV) method. Model backfills can be prepared at various relative densities. Using the knowledge of density and stress state in the backfill, dilatancy angles are estimated using a novel equation. As a result, shear strain profiles of the deformed backfills, obtained from post-processing of the displacement data captured using PIV technique, are presented and analyzed as functions of the backfill dilatancy angles. The visualized intense shearing zones, widely known as shear bands, were characterized with respect to dilative behavior and mean grain size of the granular assembly. In this respect, the shear band thickness and inclination along the retaining wall were assessed. Eventually, geometric properties of generated shear bands were compared with the available experimental and numerical data in the literature.
A microstructure-based finite element analysis of the response of sand
Authors: Nadimi Sadegh  , Fonseca Joana  , Taylor Neil
Published: February 2025

This paper presents a novel contribution towards understanding the stress distribution amongst the constituent grains of an intact sand under loading. Photoelasticity using birefringent materials has shown that forces in granular media are transmitted from particle-to-particle via their contacts and the mode of load propagation forms a complex force network. Particles carrying above average load appear to form a network with special characteristics where stronger forces are carried through chain-like particle groups, often referred as force chains. Fonseca et al. (2013) showed that for a sand under shearing, the contact normals tend to be orientated along the direction of the major principal stress, which suggests the formation of force chains. Moreover, these quasi-vertically oriented vectors were shown to be associated with contacts having large surface areas, contributing to the formation of solid columnar structures of stress transmitting grains. This early study demonstrates that a full characterization of force chains for real soils requires accounting for the effects of the soil microstructure, including grain morphology and contact topology, which the idealized nature of the particles used for discrete element method simulations and photoelasticity studies cannot capture. In the present work, high resolution x-ray tomographic data of an intact sand is converted into a two dimensional finite element mesh, so that the microstructural details, such as the geometrical arrangement of the grains and pores, as well as grain shape and contact topology are incorporated in the model. In other words, the soil microstructure is modelled using a computation approach that considers all available geometrical data. The results suggested that the ability of the grains to transmit stress via their contacts is directly associated to the degrees of freedom they have to move and rearrange, which in turn is controlled by the topology of the contacts. The insights into the effects of microstructure on the stress transmission mechanisms provided in this study are fundamental to better understand and predict the macro scale response of soil.
Transitional Behaviour in Asphalt Derived Aggregate Specimens
Authors: Kwa Katherine Ailiang  , Airey David
Published: February 2025

A Critical State Soil Mechanics approach has been taken to understand the interactions between the different aggregates and bitumen present in an asphalt mix. A series of conventional drained triaxial tests have been performed on samples of the aggregate used in Dense Asphaltic Concrete (DAC). These aggregate samples contained no bitumen and were prepared at two densities. The dense aggregate samples had a void ratio equivalent to the asphalt (DAC) samples where the bitumen was assumed to be part of the void space. The loose aggregate samples were prepared at a void ratio that was as loose as physically possible. The behaviour of the aggregate samples was compared to the asphalt samples when loaded continuously at a rate of 0.3% strain/hour. It has been found that at these slow rates of loading, the aggregates control the behaviour of the asphalt and the 5% bitumen content had little effect. Transitional soil behaviour of the aggregates was also observed as the dense and loose aggregate samples did not approach a unique critical state line when sheared to failure. The microstructure of the particle arrangements in the dense and loose aggregate samples was also observed under optical microscopes. Different particle arrangements were characteristic of the dense and loose samples. More bulky grain-to grain contacts were evident in the dense aggregate samples as the fines in the loose aggregate samples tended to flock together and form bridges between the bulky grains. As a result of this transitional soil behaviour, it was difficult to define Critical State Soil Mechanics parameters for DAC as required for advanced numerical modeling. This difficulty was also a consequence of the challenges in performing triaxial tests on the dense aggregate material.
Hybrid Coarrays: a PGAS Feature for Many-Core Architectures
Authors: Cardellini Valeria  , Fanfarillo Alessandro  , Filippone Salvatore  , Rouson Damian
Published: February 2025

Accelerators such as NVIDIA GPUs and Intel MICs are currently provided as co-processor devices, usable only through a CPU host. For Intel MICs it is planned that this constraint will be lifted in the near future: CPU and accelerator(s) will then form a single, many-core, processor capable of peak performance of several Teraflops with high energy efficiency. In order to exploit the available computational power, the user will be compelled to write a code more “hardware-aware”, in contrast to the common philosophy of hiding hardware details as much as possible. The simple two-sided communication approach often used in message-passing applications introduces synchronization costs that may limit the performance on the next generation machines. PGAS languages, like coarray Fortran and UPC, propose a one-sided approach where a process accesses directly the remote memory of another process without interrupting its execution. In this paper, we propose a CUDA-aware coarray implementation, capable of merging the expressive syntax of coarrays with the computational power of GPUs. We propose a new keyword for the Fortran language, which allows the user to map with a high-level syntax some hardware features of the many-core machines. Our hybrid coarray implementation is based on OpenCoarrays, the coarray transport layer currently adopted by the GNU Fortran compiler.
Harnessing CUDA Dynamic Parallelism for the Solution of Sparse Linear Systems
Authors: Aliaga José  , Davidović Davor  , Pérez Joaquín  , Quintana-Ortí Enrique S.
Published: February 2025

We leverage CUDA dynamic parallelism to reduce execution time while significantly reducing energy consumption of the Conjugate Gradient (CG) method for the iterative solution of sparse linear systems on graphics processing units (GPUs). Our new implementation of this solver is launched from the CPU in the form of a single “parent” CUDA kernel, which invokes other “child” CUDA kernels. The CPU can then continue with other work while the execution of the solver proceeds asynchronously on the GPU, or block until the execution is completed. Our experiments on a server equipped with an Intel Core i7-3770K CPU and an NVIDIA “Kepler” K20c GPU illustrate the benefits of the new CG solver.
Programming GPUs with C++14 and Just-In-Time Compilation
Authors: Haidl Michael  , Hagedorn Bastian  , Gorlatch Sergei
Published: February 2025

Systems that comprise accelerators (e.g., GPUs) promise high performance, but their programming is still a challenge, mainly because of two reasons: 1) two distinct programming models have to be used within an application: one for the host CPU (e.g., C++), and one for the accelerator (e.g., OpenCL or CUDA); 2) using Just-In-Time (JIT) compilation and its optimization opportunities in both OpenCL and CUDA requires a cumbersome preparation of the source code. These two aspects currently lead to long, poorly structured, and error-prone GPU codes. Our PACXX programming approach addresses both aspects: 1) parallel programs are written using exclusively the C++ programming language, with modern C++14 features including variadic templates, generic lambda expressions, as well as STL containers and algorithms; 2) a simple yet powerful API (PACXX-Reflect) is offered for enabling JIT in GPU kernels; it uses lightweight runtime reflection to modify the kernel's behaviour during runtime. We show that PACXX codes using the PACXX-Reflect are about 60% shorter than their OpenCL and CUDA Toolkit equivalents and outperform them by 5% on average.
An Embedded C++ Domain-Specific Language for Stream Parallelism
Authors: Griebler Dalvan  , Danelutto Marco  , Torquati Massimo  , Fernandes Luiz Gustavo
Published: February 2025

This paper proposes a new C++ embedded Domain-Specific Language (DSL) for expressing stream parallelism by using standard C++11 attributes annotations. The main goal is to introduce high-level parallel abstractions for developing stream based parallel programs as well as reducing sequential source code rewriting. We demonstrated that by using a small set of attributes it is possible to produce different parallel versions depending on the way the source code is annotated. The performances of the parallel code produced are comparable with those obtained by manual parallelization.
Adapting a Finite-Element Type Solver for Bioelectromagnetics to the DEEP-ER Platform
Authors: Léger Raphaël  , Mallón Damian A.  , Duran Alejandro  , Lanteri Stéphane
Published: February 2025

In this paper, we report on our recent efforts towards adapting a Discontinuous Galerkin Time-Domain solver for computational bioelectromagnetics to the novel, heterogeneous architecture proposed in the DEEP-ER european project on exascale computing. This architecture is based on the Cluster/Booster division concept which will be recalled. As a first step, we summarize the key features of the application and present the outcomes of a profiling of the code using the tools developed by DEEP-ER partners. We then go through the subsequent general improvements of the application as well as specific developments aimed at exploiting efficiently the DEEP-ER platform. This particularly includes porting the application to the Intel®Many Integrated Core Architecture. We conclude with an outlook on next steps, including the different Cluster/Booster division strategies.
CAHTR: Communication-Avoiding Householder TRidiagonalization
Authors: Imamura Toshiyuki  , Fukaya Takeshi  , Hirota Yusuke  , Yamada Susumu  , Machida Masahiko
Published: February 2025

The present paper describes an efficient communication optimization technique for Householder tridiagonalization called CAHTR and evaluates its parallel performance. CAHTR is intended to reduce the number of problems in collective communication, especially MPI_Allreduce operations. We demonstrate the optimal version of CAHTR(3) compared with a naive implementation CAHTR(0). The CAHTR algorithms are evaluated on the K supercomputer system, and speedup exceeds x1.4 for the case of N=5000 and P=1024.
Developing a scalable and flexible high-resolution DNS code for two-phase flows
Authors: Bethune Iain  , Collis Antonia B.K.  , Náraigh Lennon Ó.  , Scott David  , Valluri Prashant
Published: February 2025

We introduce TPLS (Two-Phase Level Set), an MPI-parallel Direct Numerical Simulation code for two-phase flows in channel geometries. Recent developments to the code are discussed which improve the performance of the solvers and I/O by using the PETSc and NetCDF libraries respectively. Usability and functionality improvements enabled by code refactoring and merging of a separate OpenMP-parallelized version are also outlined. The overall scaling behaviour of the code is measured, and good strong scaling up to 1152 cores is observed for a 5.6 million element grid. A comparison is made between the legacy serial text-formatted I/O and new NetCDF implementations, showing speedups of up to 17x. Finally, we explore the effects of output file striping on the Lustre parallel file system on ARCHER, a Cray XC30 supercomputer, finding performance gains of up to 12% over the default striping settings.
FPGA Acceleration of SAT Preprocessor
Authors: Suzuki Masayuki  , Maruyama Tsutomu
Published: February 2025

The satisfiability (SAT) problem is to find an assignment of binary values to the variables which satisfy a given formula. Many practical application problems can be transformed to SAT problems and many SAT solvers have been developed. In many SAT solvers, preprocessors are widely used to reduce the computational cost. In this paper, we describe an approach for implementing a preprocessor (Unhiding) on FPGA. In the Unhiding, literals and clauses are eliminated to reduce the search space by finding the redundancies in the formula. The data size of the formula is very large in general, and the acceleration is limited by the throughput of the off-chip DRAM banks. In our approach, N clauses are processed in parallel, and the literals in them are sorted into K shift registers so that K banks in the external DRAMs can be accessed in round robin order to achieve higher memory throughout.
High-Speed Calculation of Convex Hull in 2D Images Using FPGA
Authors: Kanazawa Kenji  , Kemmotsu Kahori  , Mori Yamato  , Aibe Noriyuki  , Yasuanga Moritoshi
Published: February 2025

Given a set of points, a convex hull is the smallest convex polygon containing all the points. In this paper, we describe a high-speed method for calculating the convex hull of 2D images based on Andrew's monotone chain algorithm using FPGA. This algorithm arranges input points in ascending order, according to their y-coordinates, and repeatedly checks for convexity using every group of three subsequent points by calculating the cross product of the vectors they generate. In order to arrange the points in ascending order, they must be sorted by their y-coordinates, which tends to significantly increase the total execution time when calculating the convex hull in larger images. In our method, (1) all the points on a row in a given image are acquired in parallel, (2) only the points that can compose the convex hull are selected, and (3) the convex hull is concurrently built from the selected points during the previous steps. These three steps are successively executed until all rows in the image have been processed. The FPGA implementation of our method produces throughput 23.2 times faster than the GPU implementation.
Is the Programming Environment ready for hybrid supercomputers?
Authors: Hart Alistair  , Richardson Harvey
Published: February 2025

We introduce the Mini Symposium, placing the contributions in context and detail points made during the talks and discussion sessions.
Energy Minimization on Heterogeneous Systems through Approximate Computing
Authors: Spyrou Michalis  , Kalogirou Christos  , Konstantas Christos  , Koutsovasilis Panos  , Maroudas Manolis  , Antonopoulos Christos D.  , Bellas Nikolaos
Published: February 2025

Energy efficiency is a prime concern for both HPC and conventional workloads. Heterogeneous systems typically improve energy efficiency at the expense of increased programmer effort. A novel, complementary approach is approximating selected computations in order to minimize the energy footprint of applications. Not all applications or application components are amenable to this method, as approximations may be detrimental to the quality of the end result. Therefore the programmer should be able to express algorithmic wisdom on the importance of specific computations for the quality of the end-result and thus their tolerance to approximations.
Monotonicity Based Imaging Method In Time Domain Eddy Current Testing
Authors: Tamburrino Antonello  , Su Zhiyi  , Ventre Salvatore  , Udpa Lalita  , Udpa Satish S.
Published: February 2025

This article presents the monotonicity property of time constants in pulsed eddy current testing problems. A fast non-iterative imaging method based on this monotonicity property is also presented. The focus of this paper is to achieve 3d reconstructions and address the problem of isometry encountered in a real world structure.
Numerical Modelling for Electromagnetic Testing of Composite Anisotropic Materials
Authors: Forestiere Carlo  , Rubinacci Guglielmo  , Tamburrino Antonello  , Ventre Salvatore  , Udpa Lalita  , Ye Chaofeng
Published: February 2025

This manuscript presents a numerical model for Electromagnetic Nondestructive Evaluation of composite materials. In this framework, the challenge is devising a single numerical model that is capable of handling different operational regimes: (i) from static to almost microwave frequencies, (ii) from dielectric to conducting anisotropic composite materials. Numerical cross-validation proves the effectiveness of the numerical model and makes it suitable for benchmarks.
Development of a Magnetic Phase Map for Analysis of the Internal Structure of a Spot Weld
Authors: Song Nannan  , Shiga Keisyu  , Sakai Kenji  , Kiwa Toshihiko  , Tsukada Keiji
Published: February 2025

Resistance spot welding technologies are widely used in industry. We previously reported an analysis method for examining the strength of spot-welded parts with the eddy current test (ECT) by using a wide range of frequencies from high to low. However, liftoff has a non-negligible effect. Increasing the liftoff significantly decreases the magnetic field intensity for mapping. The magnetic field phase is not affected by changes in liftoff. The measured phase map of the magnetic field showed a good correlation with the results of the destructive shear test. In this paper, we report an analysis and imaging method for examining spot-welded parts based on the phase of a magnetic field by using a wide range of frequencies from high to low. With the magnetic phase map, the internal structure of a spot weld was visualized for easy understanding of the results of this method. Thus, this method can easily be applied to industrial production. This new method was validated through both experimental and simulation results.
Conflict Transformation and the Russia–Ukraine Crisis
Authors: Giessmann Hans J.
Published: February 2025

The rapid deterioration of Russia–Ukraine relations in 2014 has reopened a discussion amongst European policymakers and experts about whether Putin's Russia can still be considered a reliable security partner. Russia's flagrant violation of the Budapest Agreement in annexing Crimea seems to indicate the opposite. Retrospectively, it looks as if Europe and Russia have missed their chance to transform the previous Cold War order into a trusted relationship. A new East–West conflict is on the rise, as even the mutual deterrence vocabulary of the past has re-entered the political stage. It is difficult to imagine how this conflict could be ‘de-escalated’ without tackling the underlying motivations and mutual perceptions on either side. Certainly, mistrust can hardly be negotiated away if the facts seem to tell the opposite tale. The current crisis management needs to be complemented by conflict transformation efforts. This paper elaborates how conflict transformation can help rebuild trust through cooperation.
Automatic Generation of a Detailed Outfitting Planning and Determining the Effect of Multi-Skilled Mounting Teams
Authors: Rose Christopher  , Coenen Jenny
Published: February 2025

Automatic planning literature for shipbuilding has historically only addressed the hull-related production processes, such as section building and erection. However, the outfitting process has become increasingly important for shipyards building complex ships. Rose et al. [1] developed a method for automatically generating a detailed outfitting planning, but never test the method's feasibility on a complete complex ship. This paper presents a test case of a pipelaying ship where this planning method produced a high quality outfitting planning. Furthermore, the method also allows shipyards to quantitatively assess outfitting-related strategic decisions. This paper uses the developed method to determine the impact of implementing multi-skilled mounting teams on the outfitting process. This analysis found that such teams can improve the flexibility of workforce allocation, but have little effect on the required movement of mounting teams between work-sites.
A Decision Support Tool for Improving Value Chain Resilience to Critical Materials in Manufacturing
Authors: Gardner Liam  , Colwill James
Published: February 2025

Certain non-energy materials have been identified by the EU as critical to the manufacturing sector and wider economy. A material is defined as critical when it has “high economic importance combined with a high risk of supply shortage” relative to other materials. Criticality of materials will become increasingly acute as the escalating use of finite resources continues, driven by increasing consumer demand from a growing population for an ever wider variety of products. Critical materials are vital elements in the value chain yet many manufacturers are unaware if they are affected by the use of a critical material in their operations. We have previously developed a framework that takes a systematic approach to identifying, assessing and mitigating risk associated with critical materials bilaterally along the value chain. This paper examines how this framework can be facilitated for application in industry through the specification and development of a decision support tool.
Simulation of Material Removal in Mould Polishing for Polymer Optic Replication
Authors: Almeida Rui  , Börret Rainer  , Rimkus Wolfgang  , Harrison David K.  , De Silva Anjali
Published: February 2025

The quality of injection moulded polymer optic parts depends on the surface finish of the respective mould. The aim of this research is to predict the material removal that occurs during the polishing process and hence control the surface finish of steel moulds. Eight to fourteen parameters affect the material removal during the polishing process. A finite element simulation model, based on abrasive wear theory, is developed to predict the removal of material and thus the final surface topology. This simulation model will eliminate the iterative trial and error polishing, thus facilitating fast and accurate mould production.
Challenges of Redesigning a Planetary Transmission to Be Made by Additive Manufacturing
Authors: Cubillo Adrian  , Perinpanayagam Suresh
Published: February 2025

This paper investigates the opportunities and limitations of using Additive Manufacturing (AM) in rotating machinery, focusing on Selective Laser Melting (SLM). A planetary transmission is used as a case study; the components are redesigned to avoid the limitations of the AM technology. The redesigned parts are manufactured by SLM; this study reveals different challenges that are encountered during the redesign of a component that is made using AM technology when it is originally designed for traditional manufacturing processes. The modifications in the design necessary to adapt a part for AM along with the proposed solution to deal with the limitations of the technology are presented on this paper.