bluuebunny/crossref_metadata_2025 huggingface dataset:
Design of a Table-Top Watt Balance
Authors:   Technische Universitat Ilmenau, Rogge Norbert
Published: March 2022

The main objective of the paper is to propose a new possible design process for controllers in electromagnetic force compensated balances (EMFC). Controllers used in EMFC balances demand a high precision of the measured and generated electrical quantities. Regarding to the achievable uncertainty in static measurements, EMFC balances are state of the art, but in future applications the importance of dynamic applications will probably increase. Therefore the controlled system should possess a high measurement bandwidth to reduce the measurement time in dynamic applications. For digital controller concepts this results in ambitious requirements on the controller hardware especially on the digital-to-analog and analog-to-digital converters. The paper will illuminate the limitations caused by commercial off-the-shelf standard hardware and propose a possible alternative hardware concept. A design process will be presented, which is strongly focused on the disturbance transfer function of the control loop. This can be achieved by building a detailed model of the balance behavior, in particular by modeling the disturbance sensitivity. Based on the consideration of these additional system characteristics in the controller design process, the measurement time of the balance is reduced significantly compared to conventional PID controllers. By using a specially developed controller hardware environment, this is also achievable with a low static uncertainty of the controlled balance.
Extending Oscilloscope Bandwidth Calibrations To 27GHz
Authors:   Fluke Calibration, Roberts Paul
Published: March 2022

Until recently, finding a convenient solution for oscilloscope bandwidth calibrations above 6GHz using levelled sinewaves was problematic, currently the highest frequency provided by oscilloscope calibrators. Imputing equivalent bandwidth from a fast edge rise time measurement is possible (to around 15GHz with the fastest calibrator 25ps risetime edge), but may be impractical or inappropriate. Alternatively, users often resort to the added complexity of a high frequency signal generator, power splitter and power meter. A new RF calibrator greatly speeds up and simplifies oscilloscope bandwidth testing up to 27GHz. This paper overviews oscilloscope calibration, including levelled sine and fast pulse bandwidth testing methods, and describes how such an RF calibrator may be used alongside dedicated oscilloscope calibrators or other multi-product calibrators with oscilloscope calibration options. Considerations for placing trigger signal pick-off devices inside the RF calibrator's automated digital levelling loop and also evaluating and combining mismatch errors are discussed.
Calibration of Optical Fiber Time Domain Reflectometers in Accordance with IEC 61749-1:2009
Authors:   Standards and Calibration Laboratory, Ko Samuel
Published: March 2022

Optical time domain reflectometers (OTDR) are widely used in testing, installation and maintenance of optical communication networks. An OTDR launches a series of high speed pulses into a fibre network and measures the amplitude and the delay time of reflected signals to locate events or faults along a fibre link. Precise measurement capabilities of an OTDR on distance, loss/attenuation and reflectance are required to locate and evaluate the severity of faults accurately. The Standards and Calibration Laboratory (SCL) has developed a calibration system for calibrating single mode OTDRs fitted with FC connectors at wavelength 1310 nm and 1550 nm in accordance with the international standards IEC 61746-1:2009. The characteristic parameters calibrated include the distance deviation, attenuation deviation and reflectance deviation. The principle of the calibration is to apply a set of reference standards, namely distance calibration artifact, attenuation calibration artifact and reflectance calibration artifacts, to the OTDR, and to compare against the displayed values for a given OTDR setting. The distance calibration artifact consists of a recirculating delay line and of a lead-in fiber which generates a series of reflection peaks separated by calculable distances. The linear regression of the measured data is processed in Microsoft Excel to estimate the distance scale deviation and zero location offset. The attenuation artefact consists of a G.652 fibre spool with known spectral attenuation and attenuation uniform. The reflectance artifact is composed of a set of known reflectances ranging from -10 dB to -50 dB. The best measurement uncertainties for the distance, attenuation and reflectance deviation calibration are 2m, 0.06 dB and 1.7 dB respectively.
Uncertainty Evaluation of Profile Projector Calibration
Authors:   Center for Measurement Standards/Industrial Technology  Research Institute, Chen Yi-Ting
Published: March 2022

A profile projector is an optical measuring instrument that magnifies a workpiece's surface features to allow measurement on a linear or circular scale. It is also referred to as an optical comparator, since dimensions can be measured directly on the screen or compared to a standard reference at the correct magnification. Profile projectors are usually used for measuring profiles, dimensions and angles of workpieces. They have been widely used in electronics, semi-conductors, and mechanical industries. Profile projectors are common used as the basic inspection equipment in many factories and laboratories. The accuracy of profile projector is very important, since it influences the finishing quality and reliability of products directly. Thus, profile projector shall be calibrated periodically to ensure its quality of inspections and measurements. This paper detailed describes the uncertainty evaluation procedure of profile projector calibration in accordance with the ISO/IEC Guide 98-3:2008. The effects of error sources in this calibration system are analyzed to estimate the corresponding standard uncertainties and sensitivity coefficients. The combined standard uncertainty and effective degrees of freedom are then calculated. The coverage factor can be found by taking the t value corresponding to the effective degrees of freedom. Finally, the expanded uncertainty can be obtained by multiplying the coverage factor and the combined standard uncertainty. The calibration method of profile projector is also briefly stated. For the calibration of a profile projector at a magnification of 10, the expanded uncertainty of magnification deviation is estimated to be 0.0096 % with a coverage factor of 2.04 corresponding to a level of confidence of approximately 95 %. For the positioning deviation calibration in a measurement range of (0 to 100) mm, the expanded uncertainty is estimated to be 0.005 mm with a coverage factor of 2.01 corresponding to a level of confidence of approximately 95 %.
Expand Capacitor and Inductor Frequency Range Using a Dependent Correction
Authors:   National Instruments, Nieves Dimaries
Published: March 2022

Impedance is the opposition to alternating current flowing in an electric circuit or component. Impedance is expressed in basic circuit elements that include resistance (R), inductive reactance (XL), and capacitive reactance (XC). Real-world components are made up of wires, connections, conductors and dielectric materials combine to make up the impedance characteristics in a circuit. Impedance can change due to signal frequency and voltage level, the presence of a DC bias voltage or current and environmental factors such as operating temperatures or altitude. Of these potential influences signal frequency is often the most significant factor. Most commercial LCR bridges and meters have the capability to make measurements with selectable test frequencies. This feature is important because to obtain accurate measurement results the test frequency should be very close to the desired operational frequency. National Measurement Institutes typically provide traceable values at 1 kHz and 100 Hz, as default option. In order to use a capacitor or inductor over its entire frequency range an additional process is needed. This paper describes a method to determine and use a frequency correction factor to calculate the actual capacitance or inductance values over their entire frequency range using a commercial LCR bridge. Calculation of the uncertainty component associated to the frequency correction factor is included as well as the effect in the calculations of the capacitor or inductor accuracy.
Calibration Due Dates - Daily or End of the Month?
Authors:   TechTrology LLC, Spinks Harry C
Published: March 2022

Much of the test equipment in-use today requires periodic calibration. This is done to ensure a high probability that the equipment will remain in tolerance by the due date or end of the calibration interval. The majority of calibration intervals are monthly with common intervals every 3 months (3, 6, 9, 12, etc.) The calibration interval is based on many factors which this paper will not address. But when, exactly, should the equipment be due? And by due calibration, we mean that it is taken out of service to be calibrated. The purpose of this paper is to examine when (specifically) the equipment is required to be removed from service for calibration. Two of the most popular methods is the day of the month (daily) and end of month due date. But which is better for you? This paper will examine the pros and cons of each method so you can decide which is best for your situation.
The Design of an Instrument to Realize Small Torque at NIST
Authors:   National Institute of Standards and Technology, Chao Leon
Published: March 2022

After the recent redefinition of the International System of Units (SI), torque no longer needs to be traceable to a calibrated mass in a gravitational field suspended from a known lever arm and disseminated through a chain of torque transducers. An SI-traceable torque can be directly realized using the Kibble principle where a torque is generated by a calibrated electromagnetic transducer. Here, a set of theoretical designs for a new instrument aimed at direct realization of torque to 0.1% accuracy is analyzed and examined for feasibility. With careful attention to magnet design, a robust and easily implemented torque calibrator can be built.
Maintaining a Local Reference Scale for Electrical Impedance by Means of a Digital Impedance Bridge
Authors:   Istituto Nazionale di Ricerca Metrologica (INRIM), Callegaro Luca
Published: March 2022

Electrical impedance is one of the most commonly measured electrical quantities and there is a wide variety of impedance meters commercially available. Electrical calibration laboratories usually use sets of artefact impedance standards to calibrate these meters. The traceability chain for electrical impedance is described with a particular emphasis on the use of impedance bridges to calibrate the impedance standards themselves. Up to now, coaxial transformer ratio bridges with outstanding accuracy have been used for this purpose, but these have a number of practical disadvantages. It is shown that digital impedance bridges, which use digital techniques to provide the accurate voltage ratios needed for bridge balancing, offer a viable alternative to transformer ratio bridges. The principles of operation of source-based and sampling-based impedance bridges are described. A joint research project whose aim is to show that digital impedance bridges provide, even for a laboratory with limited resources and expertise, a practical means of calibrating impedance standards at the parts per million level of accuracy is introduced. A source-based digital impedance bridge, designed and constructed within the project, is described and some preliminary measurement results presented.
ISO/IEC 17025:2017 Spreadsheet Validation – the details
Authors:   TechTrology LLC, Spinks Harry C
Published: March 2022

Spreadsheets are one of the most versatile document formats in use today. They can be used for a multitude of purposes: instructional or informative document, financial analysis, data analysis, charts, numerical calculations, checklists, data entry forms, and information management, to name a few. The list is virtually endless. ISO/IEC 17025:2017 General Requirements for the Competence of Testing and Calibration Laboratories requires spreadsheets to be validated if they affect the quality of the laboratory results. This can occur in three distinct areas – measurement uncertainty budgets, information management, and methods. Failure to validate spreadsheets may result in an assessment/audit nonconformance and ss a calibration accreditation assessor, I have rarely seen spreadsheets validated. This is usually because spreadsheets aren’t looked at as part of the method (calibration procedure) or the information management system. Spreadsheets should be validated for any application and in any industry if they contain calculations that may affect the quality of the organizations product or service. Spreadsheets are required to be validated in organizations regulated by the FDA such as medical devices and pharmaceutical manufacturers. This paper will explain why spreadsheets need to be validated, the applicable sections of ISO/IEC 17025:2017, and the basics on how to validate a spreadsheet.
KETERKAITAN STRUKTUR KEPEMILIKAN, STRUKTUR MODAL DAN NILAI PERUSAHAAN
Authors: Subagyo Herry
Published: March 2022

This research aims to test the relation between ownership structures and capital structure firm value of basic industry & chemistry firm. This research places the capital structure as a mediating variable for the relationship between ownership structure and firm value. The sample used is a company listed on the Indonesia Stock Exchange for the period 2014-2019, using a purposive sampling technique got 115 samples that meet the criteria. Data processing using the IBM SPSS 23 series program as an analysis tool. The result is that management's ownership has a negative effect on capital structure, and a positive effect on firm value, while institutional ownership has a positive effect on capital structure, and a negative effect on firm value. This study also found that capital structure is a mediating variable of the relationship between management ownership and firm value.

Keywords: ownership structure, capital structure, firm value
Measurement Report: An Exploratory Study of Fluorescence and CCN Activity of Urban Aerosols in San Juan, Puerto Rico
Authors: Sarangi Bighnaraj , Baumgardner Darrel , Bolaños-Rosero Benjamin , Mayol-Bracero Olga L.
Published: March 2022

Abstract. Many types of atmospheric aerosols cloud condensation nuclei (CCN) capable of activating as cloud droplets. Some primary biological aerosol particles (PBAP), such as plant spores, pollen, or bacteria, have been identified as such CCN. Urban environments are a source of these bioaerosols, those that are naturally produced by the local flora, or are transported from surrounding regions, and others that are a result of human activities. In the latter case, open sewage, uncovered garbage, mold or other products of such activities can be a source of PBAPs. There have been relatively few studies, especially in the tropics, where PBAPs and CCN have been simultaneously studied to establish a causal link between the two. The metropolis of San Juan, Puerto Rico is one such urban area with a population of 2,448,000 (as of 2020). To better understand the fluorescent characteristics and cloud forming efficiency of aerosols in this region, measurements with a Wideband Integrated Bioaerosol Spectrometer (WIBS), a condensing nuclei (CN) counter, and a CCN spectrometer were made at the University of Puerto Rico – Rio Piedras Campus. Results show that the CCN / CN activation ratio and the fraction of fluorescing aerosol particles (FAP) have repetitive daily trends when the FAP fraction is positively correlated with relative humidity and negatively correlated with wind speed, consistent with previous studies of fungi spores collected on substrates. The results from this pilot study highlight the capabilities of ultraviolet-induced fluorescence (UV-IF) measurements for characterizing the properties of FAP as they relate to daily evolution of PBAPs. The use of multiple excitation and emission wavelengths, along with shape detection, allows the differentiation of different PBAP types. These measurements, evaluated with respect to previous, substrate-based analysis of the local fungal and pollen spores, have established a starting database of measurements that future, longer term studies will build upon.
Fate of the nitrate radical at the summit of a semi-rural mountain site in Germany assessed with direct reactivity measurements
Authors: Dewald Patrick , Nussbaumer Clara M. , Schuladen Jan , Ringsdorf Akima , Edtbauer Achim , Fischer Horst , Williams Jonathan , Lelieveld Jos , Crowley John N.
Published: March 2022

Abstract. The reactivity of NO3 plays an important role in modifying the fate of reactive nitrogen species at nighttime. High reactivity (e.g. towards unsaturated VOCs) can lead to formation of organic nitrates and secondary organic aerosol, whereas low reactivity opens the possibility of heterogeneous NOX losses via formation and uptake of N2O5 to particles. We present direct NO3 reactivity measurements (kNO3) that quantify the VOC-induced losses of NO3 during the TO2021 campaign at the summit of the Kleiner Feldberg mountain (825 m, Germany) in July 2021. kNO3 was on average ~ 0.035 s-1 during the daytime, ~ 0.015 s-1 for almost half of the nights and below the detection limit of 0.006 s-1 for the other half, which may be linked to sampling from above the nocturnal surface layer. NO3 reactivities derived from VOC measurements and the corresponding rate coefficient were in good agreement with kNO3, with monoterpenes representing 84 % of the total reactivity. The fractional contribution F of kNO3 to the overall NO3 loss rate (which includes additional reaction of NO3 with NO and photolysis) were on average ~16 % during the daytime and ~50–60 % during the nighttime. The relatively low nighttime value of F is related to the presence of several tens of pptv of NO on several nights. NO3 mixing ratios were not measured but steady-state calculations resulted in nighttime values between < 1 pptv and 12 pptv. A comparison of results from TO2021 with direct measurements of NO3 during previous campaigns between 2008 and 2015 at this site revealed that NO3 loss rates were remarkably high during TO2021, while NO3 production rates were low. We observed NO mixing ratios of up to 80 pptv at night which has implications for the cycling of reactive nitrogen at this site. With O3 present at levels of mostly 25 to 60 ppbv, NO is oxidised to NO2 on a time-scale of a few minutes. We find that to maintain NO mixing ratios of e.g. 40 pptv requires a ground-level NO emission rate of 0.33 pptv s-1 (into a shallow surface layer of 10 m depth). This in turn requires rapid deposition of NO2 to the surface (vdNO2 ~ 0.15 cm s-1) to reduce nocturnal NO2 levels to match the observations.
The impact of stratospheric aerosol intervention on the North Atlantic and Quasi-Biennial Oscillations in the Geoengineering Model Intercomparison Project (GeoMIP) G6sulfur experiment
Authors: Jones Andy , Haywood Jim M. , Scaife Adam A. , Boucher Olivier , Henry Matthew , Kravitz Ben , Lurton Thibaut , Nabat Pierre , Niemeier Ulrike , Séférian Roland , Tilmes Simone , Visioni Daniele
Published: March 2022

Abstract. As part of the Geoengineering Model Intercomparison
Project a numerical experiment known as G6sulfur has been designed in which
temperatures under a high-forcing future scenario (SSP5-8.5) are reduced to
those under a medium-forcing scenario (SSP2-4.5) using the proposed
geoengineering technique of stratospheric aerosol intervention (SAI).
G6sulfur involves introducing sulfuric acid aerosol into the tropical
stratosphere where it reflects incoming sunlight back to space, thus cooling
the planet. Here, we compare the results from six Earth-system models that
have performed the G6sulfur experiment and examine how SAI affects two
important modes of natural variability, the northern wintertime North
Atlantic Oscillation (NAO) and the Quasi-Biennial Oscillation (QBO).
Although all models show that SAI is successful in reducing global mean
temperature as designed, they are also consistent in showing that it forces
an increasingly positive phase of the NAO as the injection rate increases
over the course of the 21st century, exacerbating precipitation
reductions over parts of southern Europe compared with SSP5-8.5. In contrast to the robust result for the NAO, there is less consistency for the impact on the QBO, but the results nevertheless indicate a risk that equatorial SAI could cause the QBO to stall and become locked in a phase with permanent westerly winds in the lower stratosphere.
Truth and uncertainty. A critical discussion of the error concept versus the uncertainty concept
Authors: von Clarmann Thomas , Compernolle Steven , Hase Frank
Published: March 2022

Abstract. Contrary to the statements put forward in “Evaluation of measurement data – Guide to the expression of uncertainty in measurement”, edition 2008
(GUM-2008), issued by the Joint Committee for Guides in Metrology, the error concept and the uncertainty concept are the same. Arguments in favor of the contrary have been analyzed and found not to be compelling. Neither was any evidence presented in GUM-2008 that “errors” and “uncertainties” define a different relation between the measured and true values of the variable of interest, nor does this document refer to a Bayesian account of uncertainty beyond the mere endorsement of a degree-of-belief-type conception of probability.
Carbon isotopic ratios of modern C3 and C4 vegetation on the Indian Peninsula and changes along the plant–soil–river continuum; implications for (paleo-)vegetation reconstructions
Authors: Kirkels Frédérique , de Boer Hugo , Concha Hernández Paulina , Martes Chris , van der Meer Marcel , Basu Sayak , Usman Muhammed , Peterse Francien
Published: March 2022

Abstract. The large difference in the fractionation of stable carbon isotopes between C3 and C4 plants is widely used in vegetation reconstructions, where the predominance of C3 plants suggests wetter and that of C4 plants drier conditions. The isotopic composition of organic carbon (OC) preserved in soils or sediments may be a valuable (paleo-)environmental indicator, based on the assumption that plant-derived material retains the carbon isotopic signature of its photosynthetic pathway during transfer from plant to sediment. In this study, we investigated the carbon isotopic signature of C3 and C4 plants (δ13C) and of organic carbon (δ13Corg) in soils, river Suspended Particulate Matter (SPM) and riverbed sediments, to gain insight in the control of precipitation on C3 and C4 plant δ13C values and to assess changes in δ13Corg values along the plant–soil–river continuum. This information allows us to elucidate the implications of different δ13C end-members on C3/C4 vegetation reconstructions. Our analysis was performed in the Godavari River basin, which has mixed C3 and C4 vegetation and is situated in the Core Monsoon Zone in peninsular India, a region that integrates the hydroclimatic and vegetation changes caused by variation in monsoonal strength. The Godavari C3 and C4 plants revealed more negative δ13C values than global average vegetation values, suggesting region-specific plant δ13C signatures. Godavari C3 plants confirmed a strong control by Mean Annual Precipitation (MAP) on their δ13C values, with an isotopic enrichment of ~2.2 ‰ for the interval between ~500 and 1500 mm y-1. Tracing δ13Corg values from plant to soils and rivers revealed that soils and riverbed sediments reflected the transition from mixed C3 and C4 vegetation in the dry upper basin to more C3 vegetation in the humid lower basin. Soil degradation and stabilisation processes and hydrodynamic sorting within the river altered the plant-derived δ13C signal. Phytoplankton dominated the δ13Corg signal carried by SPM in the dry season and year-round in the upper basin. Our analysis revealed that the reconstructed C3/C4 vegetation composition was sensitive to the plant δ13C end-members used as mixing model input. The %C4 plants in the different subbasins was ~10–19 % higher using Godavari-specific end-members than using global averages, and including a correction for drought enrichment in Godavari C3 plants resulted in a 2–10 % lower estimated C4 plant cover. Hence, incorporating region-specific plant δ13C end-members and drought correction of the C3 end-member in mixing models need to be considered to determine C3 and C4 distributions of modern- and paleo-vegetation in monsoonal regions.
Piloting novel multi-centennial palaeoclimate records from mainland southeast Australia
Authors: O'Connor Jacinda A. , Henley Benjamin J. , Brookhouse Matthew T. , Allen Kathryn J.
Published: March 2022

Abstract. High-resolution palaeoclimate proxies are fundamental to our understanding of the diverse climatic history of the Australian mainland, particularly given the deficiency in instrumental datasets spanning greater than a century. Annually resolved, tree-ring based proxies play a unique role in addressing limitations in our knowledge of interannual to multi-decadal temperature and hydroclimatic variability prior to the instrumental period. Here we present cross-dated ring-width (RW) and minimum blue-intensity (BI) chronologies spanning 70 years (1929 – 1998) for Podocarpus lawrencei Hook.f., the Australian mainland's only alpine conifer, based on nine full-disk cross-sections from Mount Loch in the Victorian Alps. Correlations with climate variables from observation stations and gridded data reveal a significant positive relationship between RW and mean monthly maximum temperatures in winter throughout central Victoria (r = 0.62, p < 0.001), and a significant negative correlation to winter precipitation (r = -0.51, p < 0.001). We also found significant negative correlations between RW and monthly snow depth at Spencer Creek in New South Wales (r = -0.60, p < 0.001). Of the assessed BI parameters, delta blue-intensity (ΔBI; the difference between early- and late-wood BI) displayed the greatest sensitivity to climate, with robust spatial correlations with mean October to December maximum and minimum monthly temperatures (r = -0.43, p < 0.001; r = -0.51, p < 0.001) and July precipitation (r = 0.44, p < 0.001), across large areas of northern Victoria. These promising findings highlight the utility of this species for future work. With the very limited availability of suitable long-lived and cross-datable species on the Australian mainland, these results have significant implications for advancing high-resolution palaeoclimate science in southeastern Australia and for improving our understanding of past climate in the region.
Fast infrared radiative transfer calculations using graphics processing units: JURASSIC-GPU v2.0
Authors: Baumeister Paul F. , Hoffmann Lars
Published: March 2022

Abstract. Remote sensing observations in the mid-infrared spectral region (4–15 µm) play a key role in monitoring the composition of the Earth's
atmosphere. Mid-infrared spectral measurements from satellite, aircraft, balloons, and ground-based instruments provide information on pressure,
temperature, trace gases, aerosols, and clouds. As state-of-the-art instruments deliver a vast amount of data on a global scale, their
analysis may require advanced methods and high-performance computing capacities for data processing. A large amount of computing time is
usually spent on evaluating the radiative transfer equation. Line-by-line calculations of infrared radiative transfer are considered to be the most
accurate, but they are also the most time-consuming. Here, we discuss the emissivity growth approximation (EGA), which can accelerate infrared radiative
transfer calculations by several orders of magnitude compared with line-by-line calculations. As future satellite missions will likely depend on
exascale computing systems to process their observational data in due time, we think that the utilization of graphical processing units (GPUs) for
the radiative transfer calculations and satellite retrievals is a logical next step in further accelerating and improving the efficiency of data
processing. Focusing on the EGA method, we first discuss the implementation of infrared radiative transfer calculations on GPU-based computing
systems in detail. Second, we discuss distinct features of our implementation of the EGA method, in particular regarding the memory needs,
performance, and scalability, on state-of-the-art GPU systems. As we found our implementation to perform about an order of magnitude more
energy-efficient on GPU-accelerated architectures compared to CPU, we conclude that our approach provides various future opportunities for this
high-throughput problem.
A unified framework to estimate the origins of atmospheric moisture and heat using Lagrangian models
Authors: Keune Jessica , Schumacher Dominik L. , Miralles Diego G.
Published: March 2022

Abstract. Despite the existing myriad of tools and models to assess
atmospheric source–receptor relationships, their uncertainties remain
largely unexplored and arguably stem from the scarcity of observations
available for validation. Yet, Lagrangian models are increasingly used to
determine the origin of precipitation and atmospheric heat by scrutinizing the
changes in moisture and temperature along air parcel trajectories. Here, we
present a unified framework for the process-based evaluation of atmospheric
trajectories to infer source–receptor relationships of both moisture and
heat. The framework comprises three steps: (i) diagnosing precipitation,
surface evaporation, and sensible heat from the Lagrangian simulations and
identifying the accuracy and reliability of flux detection criteria; (ii) establishing source–receptor relationships through the attribution of
sources along multi-day backward trajectories; and (iii) performing a bias
correction of source–receptor relationships. Applying this framework to
simulations from the Lagrangian model FLEXPART, driven with ERA-Interim
reanalysis data, allows us to quantify the errors and uncertainties
associated with the resulting source–receptor relationships for three
cities in different climates (Beijing, Denver, and Windhoek). Our results
reveal large uncertainties inherent in the estimation of heat and
precipitation origin with Lagrangian models, but they also demonstrate that
a source and sink bias correction acts to reduce this uncertainty. The
proposed framework paves the way for a cohesive assessment of the
dependencies in source–receptor relationships.
Characteristics of precipitation extremes over the Nordic region: added value of convection-permitting modeling
Authors: Médus Erika , Thomassen Emma D. , Belušić Danijel , Lind Petter , Berg Peter , Christensen Jens H. , Christensen Ole B. , Dobler Andreas , Kjellström Erik , Olsson Jonas , Yang Wei
Published: March 2022

Abstract. It is well established that using kilometer scale grid resolution for simulations of weather systems in weather and climate models enhances their
realism. This study explores heavy- and extreme-precipitation characteristics over the Nordic region generated by the regional climate model
HARMONIE-Climate (HCLIM). Two model setups of HCLIM are used: ERA-Interim-driven HCLIM12 spanning over Europe at 12 km grid spacing with a
convection parameterization scheme and HCLIM3 spanning over the Nordic region with 3 km grid spacing and explicitly resolved deep
convection. The HCLIM simulations are evaluated against a unique and comprehensive set of gridded and in situ observation datasets for the warm
season from April to September regarding their ability to reproduce sub-daily and daily heavy-precipitation statistics across the Nordic
region. Both model setups are able to capture the daily heavy-precipitation characteristics in the analyzed region. At the sub-daily scale, HCLIM3
clearly improves the statistics of occurrence of the most intense heavy-precipitation events and the amplitude and timing of the diurnal cycle of
these events compared to its forcing of HCLIM12. Extreme value analysis shows that HCLIM3 provides added value in capturing sub-daily return levels
compared to HCLIM12, which fails to produce the most extreme events. The results indicate clear benefits of the convection-permitting model in
simulating heavy and extreme precipitation in the present-day climate, therefore, offering a motivating way forward to investigate the climate
change impacts in the region.
The tropical route of QBO teleconnections in a climate model
Authors: García-Franco Jorge L. , Gray Lesley J. , Osprey Scott , Chadwick Robin , Martin Zane
Published: March 2022

Abstract. The influence of the quasi-biennial oscillation (QBO) on tropical climate is demonstrated using a 500-yr pre-industrial control simulation of the Met Office Hadley Centre model. Robust precipitation responses to the phase of the QBO are diagnosed in the model which show zonally asymmetric features, consistent with observational studies. The response in precipitation resembles the El Niño-Southern Oscillation (ENSO) impacts, however, regression analysis shows that there is a QBO signal in precipitation that is independent from ENSO. Moreover, the observed uneven frequency of ENSO events for each QBO phase is also found in these simulations, with more El Niño events found under the westerly phase of the QBO (QBOW) and more La Niña events for the easterly phase (QBOE). No evidence is found to suggest that these QBO-ENSO relationships are caused by ENSO modulating the QBO in the simulations. A previously unknown relationship between the QBO and a dipole of precipitation in the Indian Ocean is found in models and observations in boreal fall, characterized by a wetter western Indian Ocean and drier conditions in the eastern part for QBOW and the opposite under QBOE conditions. QBO W-E differences show a stronger East Pacific Inter-tropical Convergence Zone (ITCZ) in boreal winter and a northward shift of the Atlantic ITCZ in boreal spring and summer. The Walker circulation is found to be significantly weaker during QBOW compared to QBOE, explaining the observed and simulated zonally asymmetric responses at equatorial latitudes. Further work, including targeted model experiments, is required to betters understand the mechanisms causing these relationships between the QBO and tropical convection.
Comparative review of large animal models for suitability of proximal aortic endovascular repair
Authors: Srinivas Abhishekh , Yii Ming , Smith Julian A.
Published: March 2022

Background

The advent of TEVAR heralds a paradigm shift in treating descending aortopathies and is viewed as a potential option for ascending aortic dissection (AD) repair too. Currently, TEVAR’s usage for ascending aortopathies remains limited. Consequently, an urgent requirement exists to choose appropriate animal models to better contemporary understanding of endovascularly treating Type-A ADs.

This review article provides a summary of current literature on this topic. Two broad sections are covered, including the macroscopic differences between adult swine, ovine and porcine species versus that of their human counterparts, as well as the valvular, aortic and coronary vasculature variances.

 

Methods

A narrative review was conducted to integrate current findings of anatomical differences in valvular and ascending aortic anatomy amongst the aforementioned species. An electronic search of PubMed and Ovid Medline databases from January 1965 to June 2020 was performed, limited to articles published in English. 

 

Results

Whilst macroscopic anatomy remains grossly similar, differences in valvular leaflet shape are present, with swine and porcine models possessing anatomic characteristics that are comparable to their human counterparts. Research into inter-species ascending aortic anatomy has not been extensively performed, highlighting a literature gap. Conversely, multiple morphological studies have highlighted that swine coronary vasculature is closely resemblant to that of man.

 

Conclusion

Both swine and ovine species are suitable as appropriate animal models in examining the feasibility of endovascular stent-grafts for ascending ADs. However, given the similarities in coronary and aortic valve anatomy to their human analogues, porcine models are better suited for this purpose.
¿Vocaciones en un sociedad postcristiana?
Authors: Morata Moya Alonso
Published: March 2022

Situados en una sociedad diferente; hemos de  aprender a escuchar lo que los hechos , nos dicen. No negar la realidad sino asumirla, dejándonos guiar por el Espíritu. No hemos de ser temerosos del cambio, sino de hacer el que a nosotros nos guste. En todo cambio hacia fa nueva cultura vocacional está presente Dios. No es fiel el que se enciena con sus rniedos en fonrtas que le dan seguridad, porque funcionaran antes, sino el que se despoja y se deja guiar por la palabra que lo lleva al futuro. Vocaciones nuevas desde la nueva situación.
Aplicativos para o ensino de estatística: avaliação e reflexões sobre seu uso
Authors:   Universidade Federal de Pernambuco, Ribeiro Paulo
Published: March 2022

Com a ênfase que se tem hoje em inserir tecnologia digital na educação, para auxiliar no trabalho do professor e na aprendizagem do estudante, o uso de tablets, smartphones, software, aos poucos estãosendo inseridos no espaço escolar, além de auxiliar nas diversas atividades da nossa vida social. Portanto, o estudo tem como objetivo criar um instrumento para avaliar aplicativos voltados para o ensino de Estatística na Educação Básica, avaliando as dimensões técnicas, pedagógicas e estatística desses software. Assim, buscamos identificar aplicativos com sistema Android, na condição que os mesmos fossem gratuitos e no idioma português, em julho de 2014, identificando assim, apenas três aplicativos. Na análise, verificamos limitações nos aplicativos nas três dimensões. Contudo, o instrumento ainda aponta o que o professor pode verificar para contemplar na sua aula o que o recurso tem a contribuir na prática no ensino de estatística.
Children learning probability through the “bunny’s random walks” game
Authors:   Federal University of Sergipe, Guimarães Ulisses , Vita Aida ,   State University of Santa Cruz, Kataoka Verônica ,   State University of Santa Cruz
Published: March 2022

The purpose of this paper was to investigate the learning of basic concepts of probability by children through a game. The design of this study was the game application “Bunny’s random walks”, involving the concepts of equiprobability, chance and randomness, with 17 elementary students from a public school in Brazil. The participants were asked about a ‘fair’ way (intuitive, informal term for equiprobable, same chance) and unpredictable (intuitive, informal term for random) to choose who would start a game but the students proposed different ways, some not equally likely (using child songs), while others, though equally probable and random. It is observed that the use of playful activities similar to this game can help build probabilistic concepts and contribute to the development of the probabilistic literacy of children. The importance of this study is to contribute to studies about teaching and learning of probability to children through games.
Designing interactive displays to promote effective use of evidence
Authors:   Durham University, Sutherland Sinclair , Hedger Spencer ,   Durham University, Ireland Mark ,   Durham University, Ridgway Jim ,   Durham University
Published: March 2022

Interactive displays are increasing being used to convey information, and are a significant factor in promoting statistical literacy (and illiteracy). Durham University and the House of Commons Library are collaborating to create data visualisations (DV) which will be accessible to politicians, researchers and journalists. The focus of this paper is a DV designed to be useful in the run-up to the 2015 general election. The aim was to assemble a rich resource from multiple sources, and to make it easy for target groups to manipulate data and draw conclusions. We identify important changes to the DV as it evolved over 13 iterations, and draw conclusions about appropriate design processes and validation.
Método ativo de aprendizagem de estatística: uma experiência nos cursos da unirio
Authors:   Universidade Federal do Estado do Rio de Janeiro, Silva Alexandre , Serrano Barbosa Maria ,   Universidade Federal do Estado do Rio de Janeiro, Cunha Luciane ,   Universidade Federal do Estado do Rio de Janeiro, Simões Bruno ,   Universidade Federal do Estado do Rio de Janeiro, Ross Steven ,   Universidade Federal do Estado do Rio de Janeiro, Ribeiro Felipe ,   Universidade Federal do Estado do Rio de Janeiro
Published: March 2022

A Estatística é um componente curricular presente em quase todos os cursos de graduação. O uso crescente deste conhecimento é motivado pela necessidade de gerar informações a partir de grandes volumes de dados disponíveis em nossa sociedade cada vez mais informatizada. Neste trabalho serão apresentadas e discutidas as potencialidades de uma metodologia ativa de aprendizado de Estatística utilizando o programa R. Tendo como objetivo desenvolver a habilidade de raciocínio, a autonomia e em especial, o pensamento crítico por parte dos estudantes, estimulando-os a tornarem-se responsáveis pelo processo de aprendizagem de Estatística. Como resultado desta metodologia, percebemos que a Estatística tornou-se mais interessante aos olhos dos estudantes, uma vez que estes conseguem visualizar a importância e utilidade desse conhecimento na carreira escolhida.
Análise didática do uso dos softwares r e geogebra no desenvolvimento do letramento estatístico
Authors:   Pontifícia Universidade Católica de São Paulo, de Queiroz e Silva Coutinho Cileda , dos Santos Souza Fabiano ,   Universidade Federal Fluminense
Published: March 2022

Pesquisas no campo da Educação Estatística (Batanero; Estepa; Godino, 1991) apontam a análise exploratória de dados como uma filosofia importante e eficaz na abordagem dos conteúdos estatísticos, quando objetiva-se o desenvolvimento do letramento estatístico. Abordamos, neste artigo, aspectos e elementos relevantes para o desenvolvimento desse letramento, tais como, a transnumeração (Wild e Pfannkuch, 1999; Pfunnchuk, 2008) e a utilização de múltiplos registros de representação semiótica (Duval, 2003) são estudados e articulados em textos, tais como Coutinho, Silva e Almouloud (2011). Para tanto, faz-se necessário o uso de ambientes computacionais, de forma a potencializar a construção dos conceitos da estatística descritiva. A partir dessa perspectiva, efetuaremos a análise didática dos softwares Geogebra e R na construção de gráficos; discutindo critérios, identificando contribuições, fragilidades, ou limitações. Tais critérios serão discutidos à luz da contribuição para a construção e mobilização desses conhecimentos conduzindo o aluno no desenvolvimento e evolução do letramento estatístico (Gal, 2002).
Development of a moodle tool for massive group teaching, learning and management in statistics
Authors:   University of Barcelona, Guàrdia-Olmos Joan , Peró-Cebollero Maribel ,   University of Barcelona
Published: March 2022

Statistics should always be taught to groups of students no larger than 120. Unfortunately, that is rarely the case. The strategies for teaching and learning Statistics to larger groups are very complex and yield questionable results. Learning Statistics often requires very personalized work that would be very difficult or simply impossible to achieve in a large classroom. Here we present an application, called UB-Tracking (UB: University of Barcelona), structured within the Moodle environment for teaching and managing large groups in Statistics. The application allows teachers to schedule various simultaneous tasks to monitor all the students, both working individually and in groups, and to profile those tasks by types of students. It also facilitates fast track display yield obtained during the course. Finally, it also provides teachers with more profitable teaching time due to the large amount of information readily available.
A importância da educação a distância na modernização dos processos de trabalho do ibge
Authors:   Escola Nacional de Ciências Estatísticas, Ribeiro da Silva Adilson , Lins de Albuquerque Ana ,   Escola Nacional de Ciências Estatísticas
Published: March 2022

O Instituto Brasileiro de Geografia e Estatística (IBGE) identificou na Educação a Distância (EaD) a possibilidade de oferecer aprendizagem contínua ao quadro de servidores. A responsabilidade foi atribuída à Escola Nacional de Ciências Estatísticas (ENCE), que recebeu em 2005 a missão de consolidar a EaD como atividade permanente, com prioridade de atendimento para a rede de 583 agências, em todo o País. Nos Censos 2007 (Contagem da População e Censo Agropecuário) foram desenvolvidos os primeiros projetos, capacitando 1922 técnicos. Em 2008 foi criada a Escola Virtual IBGE, que adotou o modelo de design instrucional clássico, por meio do qual se articulam a gestão de processos e recursos pedagógicos e tecnológicos, estruturados para facilitar a aprendizagem. Por intermédio da Escola Virtual IBGE alcançou-se o total de 28.524 concluintes, em treinamentos de curta duração. A EaD representa um passo estratégico para reforçar o processo de transformação do IBGE em organização de aprendizagem.
Bayesian reasoning: connecting arithmetic, algebra and tree diagrams. A longitudinal research
Authors:   Universidad Industrial de Santander, Morgado Hernández Cindy , Yáñez Canal Gabriel ,   Universidad Industrial de Santander
Published: March 2022

This paper shows some of the results of the research conducted with the purpose of knowing the Bayesian reasoning of college students doing their first course in probability and statistics. For this there three tests that were designed and implemented at different times during the semester. The results showed three stages in the reasoning of the students: the first, which coincides with the first test, is characterized by the use of mathematical arguments proportions; the second, which coincides with the second test is characterized by the joint use of tree diagrams and algebraic expression of Bayes which had been taught by teachers; the third, which coincides with the third test, is characterized by the failed recall Bayes rule and incomplete use of the tree diagram attempt.
Estadísticas laborales y la incorporación de tics en la universidad nacional de rosario, argentina
Authors:   Rosario State University, Lac Prugent Nora
Published: March 2022

Este trabajo muestra la aplicación de herramientas estadísticas en el análisis de fuentes de datos oficiales para el estudio de la relación trabajo-condiciones de vida. De esta manera, es fruto de la experiencia en la enseñanza de la Estadística aplicada a las Ciencias Sociales plasmado en el dictado de la signatura Metodologías Cuantitativas Aplicadas en la Universidad Nacional de Rosario. Así, resulta de interés que aquellos que están cursando un postgrado aborden el tratamiento integral de temas de candente actualidad como los relacionados con las condiciones socio- económico por la que están atravesando los habitantes de la región. Adicionalmente, surge la necesidad de relacionar la enseñanza tradicional de la Estadística con las nuevas herramientas computacionales. Se posibilita, de esta manera, no sólo preparar a los maestrandos para el ejercicio profesional, sino también ampliar y flexibilizar el razonamiento propio de esta ciencia.
Obtaining the equation of the bivariate least squares regression line in high school using only quadratic functions
Authors:   Fluminense Federal University, Bortolossi Humberto , Pinho David ,   Fluminense Federal University
Published: March 2022

In this paper, following and adapting the ideas of Casella & Berger (2002) and Niven (1981), we present, using only quadratic functions, a simple derivation of the formulas for the coefficients of the bivariate least squares regression line. Therefore, this approach is very suitable for High School students when Calculus and Linear Algebra are not available (as it is the case of Brazil and other countries). We also present an interactive companion GeoGebra applet to enhance graphically and algebraically the keys ideas.