126 research outputs found

    A Certification Framework for Virtual Reality and Metaverse Training Scenarios in the Maritime and Shipping industry

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    The Covid-19 pandemic enable advanced technologies to find areas of application that significantly eliminate physical presence. This paper presents an analysis of the maritime and shipping VR and Metaverse training certification demand, the requirements that need to be fulfilled for VR training scenarios to be certified, and the overall certification process that can be followed. The research is based on primary and secondary research with an extensive academic literature review, a survey with 80 maritime participants, three interviews with industry experts in maritime VR training and certification, case studies on the maturity and the readiness on the VR training in maritime and shipping, and the presentation of the latest virtual training certification standards from a leading maritime classification organization. The research results indicate an initial VR training certification process that can be used as a guide for VR training organizations on their efforts to certify their professional training applications and technologies

    Coordination Behavior of 3-Ethoxycarbonyltetronic Acid towards Cu(II) and Co(II) Metal Ions

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    Tetronic acids, 4-hydroxy-5H-furan-2-ones, constitute a class of heterocyclic compounds with potent biological and pharmacological activity. The β, β′-tricarbonyl moiety plays an integral role in biological systems and forms a variety of metal complexes. In this report, we present the complexation reactions of 3-ethoxycarbonyl tetronic acids with acetates and chlorides of Cu(II) and Co(II). These complexes have been studied by means of EPR spectroscopy and magnetic susceptibility measurements. From the obtained results, a preliminary complexation mode of the ligand is proposed

    Validation of the prognostic performance of Breast Cancer Index (BCI) in hormone receptor-positive (HR+) postmenopausal breast cancer patients in the TEAM trial

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    Purpose: Early-stage HR+ breast cancer patients face a prolonged risk of recurrence even after adjuvant endocrine therapy. The Breast Cancer Index (BCI) is significantly prognostic for overall (0-10 years) and late (5-10 years) distant recurrence risk (DR) in N0 and N1 patients. Here, BCI prognostic performance was evaluated in HR+ postmenopausal women from the TEAM trial.Experimental Design: 3544 patients were included in the analysis (N=1519 N0, N=2025 N+). BCI risk groups were calculated using pre-specified cut-points. Kaplan-Meier analyses and logranktests were used to assess the prognostic significance of BCI risk groups based on DR. Hazard ratios (HR) and confidence intervals (CI) were calculated using Cox models with and without clinical covariates.Results: For overall 10-year DR, BCI was significantly prognostic in N0 (N=1196) and N1 (N=1234) patients who did not receive prior chemotherapy (p<0.001). In patients who were DRfree for 5 years, 10-year late DR rates for low- and high-risk groups were 5.4% and 9.3% (N0 cohort, N=1285) and 4.8% and 12.2% (N1 cohort, N=1625) with multivariate HRs of 2.25 (95% CI: 1.30-3.88; p=0.004) and 2.67 (95% CI: 1.53-4.63; p=<0.001), respectively. Late DR performance was substantially improved using previously optimized cut-points, identifying BCIlow-risk groups with even lower 10-year late DR rates of 3.8% and 2.7% in N0 and N1 patients, respectively.Conclusions: The TEAM trial represents the largest prognostic validation study for BCI to date and provides a more representative assessment of late DR risk to guide individualized treatment decision-making for HR+ early-stage breast cancer patients

    Search for Higgs Bosons in e+e- Collisions at 183 GeV

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    The data collected by the OPAL experiment at sqrts=183 GeV were used to search for Higgs bosons which are predicted by the Standard Model and various extensions, such as general models with two Higgs field doublets and the Minimal Supersymmetric Standard Model (MSSM). The data correspond to an integrated luminosity of approximately 54pb-1. None of the searches for neutral and charged Higgs bosons have revealed an excess of events beyond the expected background. This negative outcome, in combination with similar results from searches at lower energies, leads to new limits for the Higgs boson masses and other model parameters. In particular, the 95% confidence level lower limit for the mass of the Standard Model Higgs boson is 88.3 GeV. Charged Higgs bosons can be excluded for masses up to 59.5 GeV. In the MSSM, mh > 70.5 GeV and mA > 72.0 GeV are obtained for tan{beta}>1, no and maximal scalar top mixing and soft SUSY-breaking masses of 1 TeV. The range 0.8 < tanb < 1.9 is excluded for minimal scalar top mixing and m{top} < 175 GeV. More general scans of the MSSM parameter space are also considered.Comment: 49 pages. LaTeX, including 33 eps figures, submitted to European Physical Journal

    A Measurement of the Product Branching Ratio f(b->Lambda_b).BR(Lambda_b->Lambda X) in Z0 Decays

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    The product branching ratio, f(b->Lambda_b).BR(Lambda_b->Lambda X), where Lambda_b denotes any weakly-decaying b-baryon, has been measured using the OPAL detector at LEP. Lambda_b are selected by the presence of energetic Lambda particles in bottom events tagged by the presence of displaced secondary vertices. A fit to the momenta of the Lambda particles separates signal from B meson and fragmentation backgrounds. The measured product branching ratio is f(b->Lambda_b).BR(Lambda_b->Lambda X) = (2.67+-0.38(stat)+0.67-0.60(sys))% Combined with a previous OPAL measurement, one obtains f(b->Lambda_b).BR(Lambda_b->Lambda X) = (3.50+-0.32(stat)+-0.35(sys))%.Comment: 16 pages, LaTeX, 3 eps figs included, submitted to the European Physical Journal
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