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Modelling Heat Conduction Between Two Contacting Particles in Vacuum Insulation Panels Made with Granular Porous Media
No full textSolid thermal conduction is the dominant heat transfer mechanism for Vacuum Insulation Panels (VIPs) made with granular porous media, especially under vacuum conditions. Researchers tend to analyse heat transfer using numerical methods for granular porous media with complicated structures. However, the minimal contacts between spherical particles introduce significant complexity to numerical methods to solve heat transfer problems. To improve computational efficiency, this study quantitatively investigates the relationship between heat conduction and the contact radius between two contacting particles. A more accurate closed-form relation is proposed, and a scaling model is built to address the limitations of existing works that suffer from systematic errors and limited applicability. Compared to oversimplified relations in existing studies, numerical validation demonstrates that the proposed scaling model in this study achieves a maximum error of less than 1% in the range of 1/1000 to 1, significantly and fundamentally improving the predictive accuracy. This work provides a theoretical foundation for computing conductive heat transfer effectively in future studies in multiparticle systems.The project leading to this paper has received funding from the European Union’s Horizon 2020 research and innovation programme under Grant Agreement No. 869898
Enhanced SPS Velocity-Adaptive Scheme: Access Fairness in 5G NR V2I Networks
Get PDFVehicle-to-Infrastructure (V2I) technology enables information exchange between vehicles and road infrastructure. Specifically, when a vehicle approaches a roadside unit (RSU), it can exchange information with the RSU to obtain accurate data that assists in driving. As the 3rd Generation Partnership Project (3GPP) Release 16, which includes the 5G New Radio (NR) Vehicle-to-Everything (V2X) standards, vehicles typically adopt mode- 2 communication using sensing-based semi-persistent scheduling (SPS). By this approach, vehicles identify resources through a selection window and exclude ineligible resources based on information from a sensing window. However, vehicles often drive at different speeds, resulting in varying amounts of data transmission with RSUs as they pass by, which leads to unfair access. Therefore, developing an scheme that accounts for different vehicle speeds to achieve fair access across the network is essential. This paper formulates an optimization problem for vehicular environment and proposes a multi-objective optimization scheme to address it by adjusting the selection window size. Experimental results validate the efficiency of the proposed method.This work was supported in part by Jiangxi Province Science and Technology Development Programme under Grant No. 20242BCC32016, in part by the National Natural Science Foundation of China under Grant No. 61701197, in part by the National Key Researchand Development Program of China under Grant No. 2021YFA1000500(4) and in part by the 111 Project under Grant No. B23008. (Corresponding author: Qiong Wu.
Measurement of the W boson decay branching fraction ratio ℬ(W → cq)/ℬ(W → qq̄′) in proton-proton collisions at √ = 13 TeV
Get PDFA version of the article is available at arXiv:2412.16296v2 [hep-ex] (https://arxiv.org/abs/2412.16296). Comments: Replaced with the published version. Added the journal reference and the DOI. All the figures and tables can be found at https://cms-results.web.cern.ch/cms-results/public-results/publications/SMP-24-009 (CMS Public Pages). Report number: CMS-SMP-24-009, CERN-EP-2024-314. Journal reference: Phys. Lett. B 868 (2025) 139754. Submission history: From: The CMS Collaboration: [v1] Fri, 20 Dec 2024 19:12:32 UTC (564 KB); [v2] Fri, 1 Aug 2025 20:33:07 UTC (565 KB).Data availability: Release and preservation of data used by the CMS Collaboration as the basis for publications is guided by the CMS data preservation, re-use and open access policy (https://doi.org/10.7483/OPENDATA.CMS.1BNU.8V1W).The most precise measurement to date of the W boson hadronic decay branching fraction ratio cW ═ ℬ(W → cq)/ℬ(W → qq̄′) is presented. The measurement is based on a sample of proton-proton collision data from the CERN LHC collected by the CMS experiment at a center-of-mass energy of 13 TeV in 2016–2018 with an integrated luminosity of 138 fb⁻¹. The large cross section of top quark-antiquark production at the LHC offers a sizable high-purity sample of W bosons suitable for this measurement. Events with one charged lepton (electron or muon) and at least four jets, two tagged as bottom quark jets, are analyzed. Charm jets are tagged using the presence of a muon inside the jet. The result, cW ═ 0.489 ± 0.020, is consistent with the standard model prediction and is twice as precise as the current world-average value.SCOAP³
Guest editorial: Bordering, othering and reconceptualizing the inter/national subject in higher education
No full textThis special issue is concerned with a timely and seemingly neutralized issue; internationalization of higher education institutions and the making and unmaking of the “international” subject in the UK and across different social-cultural, national and political contexts. Our international/transnational/migrant standpoint and research track record in critical perspectives to Equality, Diversity and Inclusion (EDI) and Intercultural Communication respectively, sparked interest in this topic and is discussed in detail later in this editorial. In what follows we briefly discuss the introduction and current challenges of internationalization in the UK, its implementation in other Anglophone and non-Anglophone contexts, in an attempt to unravel the highly politicized assertions underpinning dominant discourses of internationalization and conceptualizations of “international” in different geo-political contexts. We contend that processes and practices of internationalization and discourses of “international” are in fact inherently antithetical rather than synergistic with social justice goals and largely endemic and epidemic to the neo-liberalized ethos, colonial structures and white patriarchal, capitalist regimes of higher education institutions. Critical internationalization research that problematizes the popular framing of internationalization in terms of economic, intellectual and multi/intercultural benefits and the formation of international academic staff and students as disembodied subjects–reduced to indicators of cosmopolitanism, enhanced human capital and global competitiveness–has potential to advance theorizations of difference and equality, and to inform, enrich and transform social justice agendas in higher education institutions. ..
An audit of machine learning experiments on software defect prediction
Get PDFData and Code Availability:
The dataset used in this study and the code to analyse it are available from here https://zenodo.org/records/17696089 and DOI https://doi.org/10.5281/zenodo.13927601 .Background:
Machine learning algorithms are increasingly being proposed to solve the problem of predicting defect-prone software components. In this literature, computational experiments are the primary means of evaluating and comparing learners and the credibility of findings depends critically on their experimental design and reporting.
Objective:
This paper audits recent software defect prediction (SDP) experiments by assessing their experimental design, analysis and reporting practices against widely accepted norms from statistics, machine learning and empirical software engineering. Our aim is to characterise the current state of practice and evaluate the reproducibility of published findings.
Method:
We undertook an audit of relevant studies published from the SCOPUS database (2019-2023) focusing on their experimental design and analysis choices e.g., the outcome variables such as F-measure and the type of out of sample (OOS) validation regime, e.g., cross-validation, plus the statistical analysis and inference mechanisms. In all, we evaluated nine different study issues. This was complemented by an assessment of reproducibility using the instrument proposed by González-Barahona and Robles.
Results:
Our search located approximately 1,585 experiments in SDP (2019-2023), a substantial body of work. From this, we randomly sampled 101 (≈ 6.4%) papers, 61 journal and 40 conference papers. Almost 50% are behind ‘paywalls’. We found considerable divergence in research practice. The number of datasets used ranged 1-365, the number of learners or learner variants evaluated from 1-34 and the number of performance metrics from 1 to 9. Approximately 45% of papers made use of formal statistical inference. We detected a total of 427 issues distributed across 101 papers (median=4) with only one paper being entirely issue-free. In terms of reproducibility, experiments ranged from near perfect to lacking almost all required information. We also found two examples of tortured phrases and potential “paper mill” activity.
Conclusions:
Approaches to designing and reporting computational experiments varied greatly, but almost half the studies provided insufficient information such that reproduction would be challenging. Overall, our audit suggests that as a research community, we have considerable scope for improvement. Fortunately, many improvements should be neither difficult nor costly to achieve.No specific funding was received for conducting this study
Power, cardiorespiratory fitness and physical activity in young people with cerebral palsy
Get PDFData availability: Research data are not shared.Objectives:
Physical activity (PA) levels in young people with cerebral palsy (YPwCP) remain consistently low. Previous research suggests that fitness parameters such as muscular strength and cardiovascular capacity are interrelated with mobility and PA levels in YPwCP. This study aimed to (1) describe fitness parameters and PA levels in YPwCP, (2) explore associations between fitness parameters and PA, and (3) evaluate the reliability of accelerometer-based PA measurement.
Methods:
A cross-sectional study was conducted with an embedded test–retest reliability assessment of accelerometer-measured PA over a one-month interval. Participants included 36 YPwCP (19 males, 17 females; mean age 15.5 ± 0.7 years), classified within GMFCS levels I–III. Cardiorespiratory endurance (VO2max) was assessed using an incremental cycle ergometer test, and leg power was measured using the Five-Times Sit-to-Stand (5xSTS). PA was measured via self-report using the Physical Activity Questionnaire for Adolescents (PAQ-A) and via device-measured data using a wrist-worn accelerometer over seven consecutive days.
Results:
We found low levels of PA. The 5xSTS completion time showed moderate to strong correlations with self-reported PA (ρ=−0.384, p≤0.01) and device-measured vigorous PA (ρ=−0.566, p≤0.01). VO2max was positively but not significantly associated with total PA (ρ=0.173) and moderate-to-vigorous PA (ρ=0.115). Accelerometry demonstrated good reliability (ICC=0.796).
Conclusions:
These findings suggest that accelerometer has good reliability in YPwCP but highlight low levels of PA measured by self-report and accelerometer. Higher lower-limb power, assessed by faster 5xSTS test, was associated with greater PA.This work was supported by the Action Medical Research UK and Chartered Society of Physiotherapy the Charitable Trust
Towards a unification of measurement, AI, quality and sustainability: Foundations and principles
Get PDFNote to the reader: Figure 6 has been corrected in the PDF, on October 6, 2025.Measurement, artificial intelligence (AI), quality, and sustainability are traditionally treated as distinct domains. To underpin and advance the science and technological developments, it is important and beneficial to develop a principled unifying framework for these fields. This paper first examines the deep connections of the concepts, models and mathematical characterisations of measurement, AI, quality and sustainability, and then proposes three foundational principles, formulated as three Laws to guide the integration of these domains, including Law of Oneness, Law of Dual Processes and Law of Measurement and Control Duality. These principles further lead to a generalised communication model supporting the unification of the four domains. They together will facilitate the advancement of the fields of measurement, AI, quality and sustainability, and underpin the development of the core science and technologies of Industry 4.0 and future Industry 4.0+
A dataset to support wildland fire and fuel management in Greece created with stochastic wildfire simulations
Get PDFData Availability:
A dataset to support wildland fire and fuel management in Greece created with stochastic wildfire simulations (Original data) (Zenodo).Supplementary materials are available online at: https://www.sciencedirect.com/science/article/pii/S2352340925010248#sec0030 .Refers to:
Pan-European fuel map server: An open-geodata portal for supporting fire risk assessment,
Geomatica, Volume 76, Issue 2, December 2024, Pages 100036.
Erico Kutchartt, José Ramón González-Olabarria, Núria Aquilué, Jordi Garcia-Gonzalo, Antoni Trasobares, Brigite Botequim, Marius Hauglin, Palaiologos Palaiologou, Vassil Vassilev, Adrian Cardil, Miguel Ángel Navarrete, Christophe Orazio, Francesco PirottiThe potential spread and intensity of wildfires can be estimated with fire modelling simulators that produce valuable datasets which can be used during the prevention and suppression stages by fire management agencies. In the absence of observational data for all potential ignition sources, since a fire has not yet occurred or has burned many decades ago, fire behavior algorithms such as the Minimum Travel Time incorporated in the FSim simulator can be used to reveal these hidden fire patterns and trajectories. FSim is widely used in the USA for that purpose and its outputs, i.e., fire perimeters, ignition locations, fire intensity and burn probability are used in numerous assessments and applications, from fireshed delineation and community protection planning to exposure calculations of wildfire risk by the reinsurance industry. However, no country-scale application exists for Europe, due to the previous lack of essential model input data at an adequate spatial resolution (∼100 m), specifically fuel models, canopy base height and canopy bulk density. The EU H2020 funded project “FIRE-RES” filled that gap and produced the necessary input dataset at a pan-European level, enabling the first large scale nationwide stochastic fire behavior modelling application for Greece. The methods can be replicated and the datasets produced and presented in this work can be produced for every continental EU country. After retrieving the necessary spatial datasets from on-line open access repositories, we assembled them to create a landscape file. Greece was divided into 23 Pyromes that are regions with similar vegetation, climate and fire behavior. Then, weather patterns were summarized in a format compatible with FSim using hourly data of air temperature, dewpoint temperature, incident solar radiation, precipitation, and northward and eastward wind components for the years 2000–2021 from the state-of-the-art global reanalysis dataset ERA5-Land. Ignition locations were distributed across each Pyrome using an ignition probability grid, ensuring that we simulated enough fires so that each burnable pixel of the landscape experiences at least one event. Simulations were validated by comparing the historic fire size distribution of each Pyrome with the simulated one. The dataset includes the burn probability and conditional flame length rasters at 100 m spatial resolution, and the 3.65 million fire perimeters and ignition locations in vector format. In addition, we provide those input datasets that are not available in other repositories, specifically the modified fuel models and the ignition probability rasters. The data provided in this article offers a valuable resource for fire management and civil protection agencies, enabling them to understand the fire size potential of each area and the expected burning intensity. In addition, metanalyses of fire perimeters intersecting them with settlement boundary polygons can provide their exposure profiles to inform fuel treatment and community protection plans. Risk profiles may also be produced by linking exposure with expected fire intensity, even at building level, providing useful datasets for insurance purposes and spatial planning.This research was funded by the European Union’s Horizon 2020 Research and Innovation Programme through the project entitled “Innovative technologies & socio-ecological-economic solutions for fire resilient territories in Europe – FIRE-RES” under grant agreement N°101037419
Safeguarding from power: trauma, violence and the case of Israel
No full textEditorial Commentary.Since October 2023, numerous international human rights organisations, special observers, journalists and scholars have documented the genocidal violence inflicted on Palestinians by the Israeli army and the settlers – violence that is often live-streamed. Their calls to safeguard the Palestinian people in Gaza and the West Bank from Israeli violence have largely fallen on deaf ears. I will therefore try to provide additional evidence and justification for international intervention by shifting the focus to the Israeli side, which is holding and abusing unrestrained powers...The author received no financial support for the research, authorship, and/or publication of this article
Chance-Constrained Dynamic Encoding-Based Control Over Noisy Communication Channels: An Active Bit-Flip-Error-Resistant Approach
Get PDFThis paper investigates the chance-constrained control problem for uncertain systems, with a focus on the distortion of signal transmission between the controller and the actuator caused by noisy and bandwidth-limited communication channels, and its impact on the system's control performance. Initially, a binary dynamic encoding mechanism (DEM) is employed to encode the system's amplitude-continuous signal into a finite-length binary string, aiming to mitigate the communication burden. In the DEM-based control scheme, a critical issue is that the control performance is seriously affected by the bit-flip error (BFE), which inevitably occurs during the transmission of binary data through a noisy channel. To address this problem, a novel active BFE-resistant controller is proposed to effectively accomplish the desired control task by thoroughly considering the dynamic coupling effects between the BFE and the DEM. Subsequently, a chance constraint index is jointly considered to ensure the safe operation of the uncertain system under a guaranteed probability bound. Sufficient conditions are established for the existence of the active BFE-resistant controller such that the mean-square boundedness and the chance constraint index are ensured simultaneously. Finally, the validity of the proposed algorithm is verified by a simulation study targeting the remote control problem for autonomous ground vehicles.This work was supported in part by the National Natural Science Foundation of China under Grant 61933007, Grant 62403318, and Grant 52572354; in part by the Science and Technology Development Fund of Macao SAR under Grant 0123/2022/AFJ, Grant 0081/2022/A2, Grant 0122/2024/RIB2, Grant 0215/2024/AGJ, and Grant 001/2024/SKL; in part by the Science and Technology Planning Project of Guangdong under Grant 2025A0505010016; in part by the Royal Society of the UK; and in part by the Alexander von Humboldt Foundation of Germany
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