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Background: When studying the association between treatment and a clinical outcome, a parametric multivariable model of the conditional outcome expectation is often used to adjust for covariates. The treatment coefficient of the outcome model targets a conditional treatment effect. Model-based standardization is typically applied to average the model predictions over the target covariate distribution, and generate a covariate-adjusted estimate of the marginal treatment effect. Methods: The standard approach to model-based standardization involves maximum-likelihood estimation and use of the non-parametric bootstrap. We introduce a novel, general-purpose, model-based standardization method based on multiple imputation that is easily applicable when the outcome model is a generalized linear model. We term our proposed approach multiple imputation marginalization (MIM). MIM consists of two main stages: the generation of synthetic datasets and their analysis. MIM accommodates a Bayesian statistical framework, which naturally allows for the principled propagation of uncertainty, integrates the analysis into a probabilistic framework, and allows for the incorporation of prior evidence. Results: We conduct a simulation study to benchmark the finite-sample performance of MIM in conjunction with a parametric outcome model. The simulations provide proof-of-principle in scenarios with binary outcomes, continuous-valued covariates, a logistic outcome model and the marginal log odds ratio as the target effect measure. When parametric modeling assumptions hold, MIM yields unbiased estimation in the target covariate distribution, valid coverage rates, and similar precision and efficiency than the standard approach to model-based standardization. Conclusion: We demonstrate that multiple imputation can be used to marginalize over a target covariate distribution, providing appropriate inference with a correctly specified parametric outcome model and offering statistical performance comparable to that of the standard approach to model-based standardization. [ABSTRACT FROM AUTHOR]

In 2020 several member states initiated at IMO forum (NCSR subcommittee) a process to create a single set of generic performance standards consolidating all existing performance standards for shipborne satellite navigation system receiver equipment without creating any new requirements. After over 4 years the resultant generic framework for GNSS/RNSS subsystems has not been adopted yet and awaits further amendments. Analysis of the proposed standards with stress on harmonization issues of the existing, IMO recognized, global and regional navigation satellite systems and the expected impact of these generic standards of satellite navigation receivers on the maritime user are presented in this paper. Additionally the strengths, weaknesses, opportunities, and threats awaiting maritime or shipborne GNSS/RNSS equipment standardization process are outlined in the paper. [ABSTRACT FROM AUTHOR]

The growing use of renewable energy sources and sustainable technologies has increased the attractiveness of low-voltage DC distribution grids. Despite initial research and standardization work, the definition of power quality (PQ) issues and their related compatibility levels in DC grids and the related measurement techniques remain in their infancy. The lack of available measurement results obtained in real-world situations is a major shortcoming. In this paper, the results of a measurement campaign obtained in a configurable bipolar 350 V/700 V DC microgrid in an urban environment are presented. Voltage and current signals were registered continuously at different positions in the microgrid with a sampling rate of 500 kSa/s while changing the configuration of the microgrid; the resulting data were analyzed afterwards, with a focus on DC voltage and current variation, ripple, and spectral analysis. The measurements were taken with custom-designed metrology-sound measurement equipment. The measurement results provide input to the development of DC PQ analysis tools and the standardization of DC PQ measurement methods. Furthermore, the experience obtained will be beneficial for utility companies and regulatory authorities for reliable planning-level and compatibility-level surveys. [ABSTRACT FROM AUTHOR]

Radiomic approaches in precision medicine are promising, but variation associated with image acquisition factors can result in severe biases and low generalizability. Multicenter datasets used in these studies are often heterogeneous in multiple imaging parameters and/or have missing information, resulting in multimodal radiomic feature distributions. ComBat is a promising harmonization tool, but it only harmonizes by single/known variables and assumes standardized input data are normally distributed. We propose a procedure that sequentially harmonizes for multiple batch effects in an optimized order, called OPNested ComBat. Furthermore, we propose to address bimodality by employing a Gaussian Mixture Model (GMM) grouping considered as either a batch variable (OPNested + GMM) or as a protected clinical covariate (OPNested − GMM). Methods were evaluated on features extracted with CapTK and PyRadiomics from two public lung computed tomography (CT) datasets. We found that OPNested ComBat improved harmonization performance over standard ComBat. OPNested + GMM ComBat exhibited the best harmonization performance but the lowest predictive performance, while OPNested − GMM ComBat showed poorer harmonization performance, but the highest predictive performance. Our findings emphasize that improved harmonization performance is no guarantee of improved predictive performance, and that these methods show promise for superior standardization of datasets heterogeneous in multiple or unknown imaging parameters and greater generalizability. [ABSTRACT FROM AUTHOR]

The development of a hydrogen energy-based society is becoming the solution for more and more countries. Fuel cell electric vehicles are the best carriers for developing a hydrogen energy-based society. The current research on hydrogen leakage and the diffusion of fuel cell electric vehicles has been sufficient. However, the study of hydrogen safety has not reduced the safety concerns for society and government management departments, concerning the large-scale promotion of fuel cell electric vehicles. Hydrogen safety is both a technical and psychological issue. This paper aims to provide a comprehensive overview of fuel cell electric vehicles' hydrogen dispersion and the burning behavior and introduce the relevant work of international standardization and global technical regulations. The CFD simulations in tunnels, underground car parks, and multistory car parks show that the hydrogen escape performance is excellent. At the same time, the research verifies that the flow, the direction of leakage, and the vehicle itself are the most critical factors affecting hydrogen distribution. The impact of the leakage location and leakage pore size is much smaller. The relevant studies also show that the risk is still controllable even if the hydrogen leakage rate is increased ten times the limit of GTR 13 to 1000 NL/min and then ignited. Multi-vehicle combustion tests of fuel cell electric vehicles showed that adjacent vehicles were not ignited by the hydrogen. This shows that as long as the appropriate measures are taken, the risk of a hydrogen leak or the combustion of fuel cell electric vehicles is controllable. The introduction of relevant standards and regulations also indirectly proves this point. This paper will provide product design guidelines for R&D personnel, offer the latest knowledge and guidance to the regulatory agencies, and increase the public's acceptance of fuel cell electric vehicles. [ABSTRACT FROM AUTHOR]

The Wechsler Intelligence Scale for Children -- Fifth Edition is the most recent update to this scale, launched originally in 2014 in the United Stated. WISC-V includes several improvements from previous versions, such as an updated factorial structure that includes more indexes, new process scores and new procedures for norming. These improvements are particularly relevant in the Chilean context, since the previous version available in the country was the WISC-IIIv.ch, whose factorial structure dates from 1991, although it was standardized for Chilean population in 2007. This article presents the standardization process for the WISC-V, which includes the translation, adaptation and norming procedures for the Chilean population. It includes evidence for reliability and validity, and also results for various special groups samples, such as intellectual disability (24), attentional deficit disorder with hyperactivity (27), autism spectrum disorder (26), specific language disorder (56) and rural population (47). The Chilean data shows excellent reliability results and an excellent adjustment to the factorial model used in the North American version. This research provides evidence for convergent validity between WISC-V and other versions of these scales, such as the WAIS-IV and the WISC-IIIv.ch. Finally, we perform a comparison between private, voucher and public schools using this scale and a comparison between male and female performance in this scale. The main finding of this research is that the Chilean standardization of the WISC-V has excellent psychometric properties that allow recommending the use of this instrument in the country. [ABSTRACT FROM AUTHOR]

In December 1972, the Sub Department of Design of the Corporación de la Vivienda (CORVI) published a document with eighteen housing prototypes developed by its teams between 1966 and 1971. This document was the result of the previous experience of those teams in developing a large part of the social housing built in Chile, of the work of systematization and standardization of that set of works, and of the design indications given by the managers of these teams. Drawing on the document itself, secondary sources that report on CORVI's decisions, and interviews with Orlando Sepúlveda Mellado, an architect member of CORVI's design teams, this paper analyzes the practical meaning of "Tipología de viviendas racionalizadas 1966-1972" and suggests that it performs a non-canonical mode of the notion of typology, articulates a standardization of project ideas, and responds to the contingencies of the sociomaterial environment. This helps to conclude that the inaccuracies observed in the document are part of an objectual strategy of communication of the technical aspect that aims at its practicality, that is, to efficiently narrate the complexity of architectonic rationalization as a political and socio-technical program. [ABSTRACT FROM AUTHOR]

Agent-based models (ABMs) are an increasingly popular choice for simulating large systems of interacting components, and have been applied across a wide variety of natural and environmental systems. However, ABMs can be incredibly disparate and often opaque in their formulation, implementation, and analysis. This can impede critical assessment and re-implementation, and jeopardize the reproducibility and conclusions of ABM studies. In this review, we survey recent work towards standardization in ABM methodology in several aspects: model description and documentation, model implementation, and model analysis and inference. Based on a critical review of the literature, focused on ABMs of environmental and natural systems, we describe a recurrent trade-off between flexibility and standardization in ABM methodology. We find that standard protocols for model documentation are beginning to establish, although their uptake by the ABM community is inhibited by their sometimes excessive level of detail. We highlight how implementation options now exist at all points along a spectrum from ad hoc, 'from scratch' implementations, to specific software offering 'off-the-shelf' ABM implementations. We outline how the main focal points of ABM analysis (behavioural and inferential analysis) are facing similar issues with similar approaches. While this active development of ABM analysis techniques brings additional methods to our analysis toolbox, it does not contribute to the development of a standardized framework, since the performance and design of these methods tends to be highly problem-specific. We therefore recommend that agent-based modellers should consider multiple approaches simultaneously when analysing their model. Well-documented software packages, and critical comparative reviews of such, will be important facilitators in these advances. ABMs can additionally make better use of developments in other fields working with high-dimensional problems, such as Bayesian statistics and machine learning. • We review advances in ABM methodology, focusing on standardization. • A recurrent trade-off between flexibility and standardization is observed. • We describe similar developments in tools for behavioural and inferential analysis. • The future of ABM methodology depends on usable, well-documented software. [ABSTRACT FROM AUTHOR]