Immersive audio formats compete for adoption, yet objective comparisons across them remain limited, and the behaviour of the objective models under cross-format conditions is largely uncharacterised. This study applies two binaural models, BAM-Q (perceptual quality) and BINAQUAL (localization similarity), to binaural renderings of 11 format variants derived from 3 professional recordings differing in genre and Ambisonic provenance, under three reference anchors and with a controlled test of stimulus alignment. Two properties of the evaluation influence the outcome more strongly than many format differences, and affect the two models differently. First, immersive renderers impose transport delays up to 510 ms that are not quality degradations; because BINAQUAL compares phase representations, leaving them uncompensated makes its score track delay rather than fidelity (ρ=−0.86), and correcting them changes localization similarity by a median of 149.3%. BAM-Q, operating on modulation-domain representations, is unaffected (median 0.0%). Second, under BINAQUAL the apparent advantage of one format family over another depends on the reference anchor, reversing in all 3 items when the channel-based anchor replaces a scene-based one; the BAM-Q composite never reverses. With aligned stimuli the models are moderately correlated (r=0.51), not independent. Format orderings are reproducible across content (Kendall’s W=0.94 for localization similarity, permutation p<0.001). The results yield prescriptions for cross-format evaluation (compensate and report latency, treat the anchor as an experimental factor, refer cue measures to discrimination thresholds) and identify subjective validation as the next step.
Rapid urban growth and increasing climate pressure on coastal zones are driving interest in Floating Architecture (FA) as an extension of urban infrastructure into marine environments. The long-term viability of such developments depends on the operability of maritime transport systems ensuring accessibility under variable environmental conditions.This study proposes a decision-support framework for assessing offshore transport accessibility under environmental and vessel-stability constraints. The developed Floating Architecture Location Adviser (FALA) integrates spatial parameters, long-term sea-state statistics, and operational ship stability assessment within a deterministic screening procedure constrained by selected aspects of the Second Generation Intact Stability Criteria.The approach enables systematic evaluation of transport operability by classifying the feasibility of shuttle-vessel operations and calculating a Navigation Unavailability Index for candidate movement directions. Application to three European coastal regions demonstrates significant directional variability in transport performance driven by vessel response to representative sea-state conditions.The results show that environmental forcing can lead to loss of operability under specific directional and sea-state conditions. The proposed methodology supports preliminary decision-making for Floating Architecture location assessment and contributes to the planning of more resilient offshore infrastructure.
We propose a new analytical approach based on ordinal pattern analysis to investigate respiratory heart rate variability (RespHRV, also called respiratory sinus arrhythmia), specifically modulation of heart rate across different phases of the respiratory cycle. The method uses RR interval time series derived from ECG signals, along with simultaneous respiratory recordings obtained with a respiratory belt. The method produces distributions of ordinal patterns that reflect the dynamics of heart rate variability throughout the respiratory cycle. We systematically test how variations in parameters defining ordinal patterns affect the results and interpretation, and discuss the optimal parameter configuration for quantification of RespHRV in short-term recordings. Finally, we demonstrate the ability of the method to differentiate between healthy controls and patients with obstructive sleep apnea based on daytime cardiorespiratory data.
We investigate abstract convexity generated by the coupling function \varphi(x,A)=|A[x]^2|,\quad x\in \mathbb{R}^n,\ A\in \mathcal{L}^2_{sym}(\mathbb{R}^n,\mathbb{R}). φ ( x , A ) = ∣ A [ x ] 2 ∣ , x ∈ R n , A ∈ L s y m 2 ( R n , R ) . We study the \varphi φ -convexity of four classes of sets: subsets of \mathbb{R}^n R n , subsets of \mathcal{L} L , epigraphic subsets of \mathbb{R}^n\times \mathbb{R} R n × R and epigraphic subsets of \mathcal{L}\times\mathbb{R} L × R . We show that all families consist of closed, star-shaped sets and subsets of \mathcal{L} L and \mathcal{L}\times\mathbb{R} L × R are convex. For epigraphic subsets of X\times\mathbb{R} X × R , we derive a condition partially characterizing them in analogy with classical convexity, where line segments are replaced by parabolas. In the one-dimensional case we obtain a complete characterization
One of the main challenges in welding dissimilar joints between steels and nickel-based alloys for power engineering applications is carbon diffusion and the formation of brittle interfacial phases. The aim of this work was to evaluate the effect of the buttering layer composition on the microstructure and mechanical behavior of welded joints between AISI 304 H steel and Inconel 617 alloy. Multi-pass Gas Tungsten Arc Welding (GTAW) using Inconel 617 filler, with prior application of Inconel 82 and Inconel 617 buttering layers on the AISI 304 H steel side, was performed and compared with the structural integrity of joints produced without buttering using conventional and pulsed GTAW processes. The welded joints were characterized by optical microscopy (OM), scanning electron microscopy (SEM) coupled with energy-dispersive X-ray spectroscopy (EDS), tensile testing at room and elevated temperatures, Vickers hardness measurements, and Charpy impact testing. Significant metallurgical interactions and local element diffusion during solidification and cooling are reflected in the presence of Type I and Type II grain boundaries as well as intricate morphological characteristics including peninsula structures and isolated austenitic islands near the interfaces. Considerable diffusion of Ni, Cr, and Fe, as well as localized segregation near the AISI 304 H/buttering interface, was observed. Additionally, TiC and NbC precipitates were detected in the Inconel 82 buttering layer, and the Inconel 617 buttering and weld metal were enriched with Cr and Mo-based carbides (M₂₃C₆, Mo₆C). The application of a buttering layer significantly improved the mechanical performance of AISI 304 H-Inconel 617 welded joints. The buttering process resulted in increased and more uniform hardness across the weld metal ( 221 HV0.5 for IN82 and 239 HV0.5 for IN617 in non-buttered welds, with higher values observed in buttered welds). At room temperature, the IN617 buttered joint exhibited the highest ultimate tensile strength (UTS) of approximately 682 MPa, compared with 581 MPa for the IN82 buttered joint. The IN617 buttered joint also exhibited significantly higher ductility ( 50
