220861 research outputs found
Sort by
Benchmarking benchmarks
No full textFinancial benchmarks such as LIBOR underpin the pricing of trillions of dollars of contracts around the world. We evaluate the quality of benchmark prices using a state-space model to separate information from noise. Applying the method to LIBOR benchmarks and their replacements, we find that alternative reference rates (ARRs) are less noisy in four of the five currencies. However, the USD ARR is considerably more noisy, resulting in billions of dollars of noise-related wealth transfers between contract counterparties. We show that benchmark reforms such as expanding the reference market and using a trimmed mean can reduce noise in ARRs.James Brugler, Marta Khomyn, Tālis Putniņ
Energy balance in women during polar trekking-The POWER study
No full textData source: supporting information, https://doi.org/10.14814/phy2.70443Polar expeditions pose a significant challenge, contributing to a substantial energy deficit. However, few data exist on nonprofessional individuals, and none of them have investigated the regulation of energy balance in female participants during an Arctic expedition. Eleven nonathlete female adults who reached the North Pole by ski in full autonomy were studied. Before and the day after the expedition, resting metabolic rate (RMR) was measured by indirect calorimetry, and fat mass (FM) and fat-free mass (FFM) by bioelectric impedance. Total daily energy expenditure (TDEE) and activity-related energy expenditure (AEE) were assessed with the doubly labeled water (DLW) during the expedition. Before and throughout the expedition, daily physical activity was evaluated using accelerometry and heart rate, while surface skin temperature was measured using an iButton placed on the chest. Additionally, fasting salivary cortisol concentration was measured throughout the expedition as a stress marker. The seven-day trekking was associated with a TDEE of 18.67 [SD 1.72] MJ/d. Body mass decreased by 1.67 (SE 0.42) kg, mostly due to fat mass loss (-1.26 [0.39] kg), indicating a negative energy balance. These findings show that nonathlete females can greatly increase their AEE and, hence TDEE over a short time period. However, their food consumption was insufficient to meet their needs, thus leading to an energy deficit and body mass loss. Future studies should investigate whether this insufficient energy intake was due to a lack of available food or an inability to consume more, thereby deepening our understanding of energy balance regulation in extreme conditions
Diversification patterns of the southwest Australian biodiversity hotspot reveal a novel macroevolutionary pathway to plant hyperdiversity
No full textThe macroevolutionary drivers for disparities in plant species richness across Australia are understudied, hindered by lack of densely sampled comparative phylogenetic data. Here, we address this gap by analysing plant diversification dynamics and quantifying macroevolutionary trajectories of 22 plant clades (4289 species in 14 families) across two Australian regions. We show the southwest Australian (SWA) floristic region differs from southeastern Australia (SEA) in having relatively low speciation and extinction rates, fewer recent rapid radiations, declining speciation rates, relatively high rates of sympatric speciation indicative of greater niche space saturation, and an absence of mass extinction events since the Eocene. We show that low diversification rates in SWA can be attributed to the early diversification and old age of its flora. By contrast, the SEA extant flora largely diversified after the Eocene–Oligocene boundary extinction event. The paucity of diversification rate shifts across the two floras is likely linked to the lack of extreme environmental pulse events on the geologically stable Australian continent. Our results uncover the dynamics, which have shaped the SWA region as a current centre of hyperdiversity in a continental and global context and suggests an alternate pathway to diversity, not found in other biodiversity hotspots.Francis J. Nge, and Alexander Skeel
HAT Swapping: Virtual Agents as Stand-Ins for Absent Human Instructors in Virtual Training
No full textData source: Supplementary material, https://doi.org/10.1109/TVCG.2025.3616749Virtual reality (VR) is increasingly adopted for collaborative teaching and learning, enabling immersive and interactive experiences. As Artificial Intelligence (AI) tutors begin to take on roles alongside human instructors, it becomes crucial to understand how their integration influences interaction dynamics and role perception in these settings. This study investigates the role of Embodied Virtual Agents (EVAs) substituting human instructors in virtual training, specifically addressing the previously underexplored issue of EVA appearance consistency with instructors in Human-Agent Teaming (HAT). We recruited 21 participants to compare three conditions: No Agent, Shared-Appearance (SA) EVA, and Unique-Appearance (UA) EVA, where an EVA substitutes for the instructor during temporary absences. We evaluated collaboration efficiency, user perception/preference, and HAT dynamics. Our findings confirm that EVAs significantly enhance task efficiency compared to no support and reveal a key trade-off regarding appearance: SA fosters perceived continuity and trust but risks ambiguity and uncanny effects, while UA provides transparency and role clarity but may disrupt experiential coherence. These results have implications for designing dynamic HAT systems where control may shift. We discuss the benefits and limitations of each approach and offer design recommendations for future mixed-agency interfaces
Cnidølysis noeëidolon
No full textan hybrid assemblage sculpture, commissioned for the exhibition Crosscurrents, at Flinders University Museum of Ar
A Double-layer Hierarchical Finite-Time Output Consensus Tracking Protocol for Heterogeneous Multi-agent Systems with an Active Leader
No full textAddressed in this paper is the finite-time output consensus tracking (FOCT) problem for general linear heterogeneous multi-agent systems (MASs) with an active leader. Unlike most existing results with a zero-input leader, the active leader under consideration is subject to a bounded non-zero control input. This enables the MASs to accommodate practical tasks and achieve desirable performance, such as tracking sophisticated and various trajectories, interacting with humans and tracking manned vehicles. Despite these advantages, the presence of an active leader introduces challenges for controller design and system stability analysis, especially within the framework of finite-time stability for heterogeneous MASs. In this study, a double-layer-hierarchical control strategy is developed, which consists of a hierarchical structure comprising two layers. The upper layer incorporates finite-time dynamic cooperative compensators and the lower-level layer implements finite-time tracking controllers. Simulations on general linear heterogeneous MASs and heterogeneous connected vehicles are conducted, validating the effectiveness of the proposed algorithm.Haikuo Liu, Changkun Du, Zhen Li, Samson Shenglong Yu, Peng Sh
Comparative structural behaviour of steel and GFRP reinforced box culverts
No full textThis paper studies the structural behaviour differences when steel reinforcement in an inverted U-shape precast concrete culverts is directly replaced with GFRP bars using identical configurations, providing a systematic comparative evaluation of structural, serviceability and ultimate performance, providing guidance to practicing engineers. The AS 1597.1 type testing process for roadway small box culverts was used to assess a steel control culvert and two full-scale GFRP-RC culverts with a height of 600 mm and a clear span of 1232 mm. The first GFRP culvert used the same reinforcement setup as the steel reinforced one, while the second had identical reinforcement but with a reduced cover to 25 mm from 35 mm. Direct substitution of steel with GFRP achieved 84 % of the steel culvert's ultimate capacity, though the GFRP culvert still exceeded design requirements by 15 %. The reduced cover specimen performed notably better, reaching 92 % of steel capacity. Serviceability requirements governed the behaviour rather than ultimate strength. At service loads, crack widths increased from 0.25 mm in steel to 0.74 mm with direct GFRP substitution but decreased to 0.31 mm when cover was reduced to 25 mm, nearly matching steel performance. While GFRP specimens exhibited larger deflections due to lower elastic modulus, traditional limits may be too restrictive for buried structures. These results suggest that current cover requirements intended for steel corrosion protection unnecessarily penalize GFRP culvert performance. All tested culverts failed in punching shear, with the GFRP bars only being at 33-37 % of their tensile strength at failure, and with the punching shear load predicted accurately considering it was calibrated on the results of four-sided culverts
Search for Higgs boson decays into a pair of pseudoscalar particles in the gamma gamma tau had tau had final state using pp collisions at root s = 13 TeV with the ATLAS detector
No full textA search for exotic decays of the 125 GeV Higgs boson into a pair of new spin-0 particles, H → aa, where one decays into a photon pair and the other into a τ -lepton pair, is presented. Hadronic decays of the τ -leptons are considered and reconstructed using a dedicated tagger for collimated τ -lepton pairs. The search uses 140 fb⁻¹ of proton-proton collision data at a centre-of-mass energy of √ s = 13TeV recorded between 2015 and 2018 by the ATLAS experiment at the Large Hadron Collider. The search is performed in the mass range of the a boson between 10 GeV and 60 GeV. No significant excess of events is observed above the Standard Model background expectation. Model-independent upper limits at 95% confidence level are set on the branching ratio of the Higgs boson to the γγτ τ final state, B(H → aa → γγτ τ ), ranging from 0.2% to 2%, depending on the a-boson mass hypothesis.The ATLAS collaboratio
A Likelihood-Free Bayesian Framework for Model-Based Damage Identification Using Guided Waves
No full textGuided wave (GW) has been widely used in engineering structures for structural health monitoring (SHM) because of its capability of long propagation and high sensitivity to local defects. Bayesian methods have been commonly employed to enhance the reliability of GW-based damage identification. In addition to more accurate detection, the corresponding uncertainties within unknown parameters can be quantified by assessing the posterior distributions. However, applications of most existing Bayesian frameworks require a proper likelihood assumption, which tends to restrict the applicability when dealing with a complex or high-dimensional problem. Conversely, approximate Bayesian computation (ABC), a likelihood-free method while still obeying the Bayes theorem, provides a more straightforward alternative to solving the Bayesian inference problem. The posterior distributions of unknowns are estimated using a distance function to assess the similarity between simulation and measurement. Summary statistics, such as signal processing techniques in GW, can also be used to pre-process datasets to enhance comparison sensitivity. In these cases, no explicit likelihood function is needed for posterior estimation. In this paper, A GW-based damage identification framework is proposed using ABC. An experiment of multiple cracks in the isotropic metal rod is carried out. The measurement is used in the proposed ABC framework to detect the corresponding damage locations and sizes. Extensive studies are conducted to evaluate the ABC performance. Recommendations are provided based on identification results. Additionally, this research provides a further understanding of ABC framework development for GW-based SHM.Zijie Zeng and Ching-Tai N
The More, The Better? A Critical Study of Multimodal Context in Radiology Report Summarization
No full textThe Impression section of a radiology report summarizes critical findings of a radiology report and thus plays a crucial role in communication between radiologists and physicians. Research on radiology report summarization mostly focuses on generating the Impression section by summarizing information from the Findings section, which typically details the radiologist’s observations in the radiology images. Recent work start to explore how to incorporate radiology images as input to multimodal summarization models, with the assumption that it can improve generated summary quality, as it contains richer information. However, the real effectiveness of radiology images remains unclear. To answer this, we conduct a thorough analysis to understand whether current multimodal models can utilize radiology images in summarizing Findings section. Our analysis reveals that current multimodal models often fail to effectively utilize radiology images. For example, masking the image input leads to minimal or no performance drop. Expert annotation study shows that radiology images are unnecessary when they write the Impression section