Calibration Monitoring Research Articles

Electronic Design of a Cotton Harvester Yield Monitor Calibration System

Several yield monitors are available for use on cotton harvesters, but none are able to maintain yield measurement accuracy across cultivars and field conditions that vary spatially and/or temporally. Thus, the utility of yield monitors as tools for on-farm research is limited unless steps are taken to calibrate the systems as cultivars and conditions change. This technical note details the electronic system design for a harvester-based yield monitor calibration system for basket-type cotton strippers. The system was based upon the use of pressure sensors to measure the weight of the basket by monitoring the static pressure in the hydraulic lift cylinder circuit. To ensure accurate weighing, the system automatically lifted the basket to a target lift height, allowed the basket time to settle, then weighed the contents of the basket. The software running the system was split into two parts that were run on an embedded low-level micro-controller and a mobile computer located in the harvester cab. The system was field tested under commercial conditions and found to measure basket load weights within 2.5% of the reference scale. As such, the system was proven to be capable of providing an on-board auto-correction to a yield monitor for use in multi-variety field trials.

Man-Machine-Interface Software Design of a Cotton Harvester Yield Monitor Calibration System

Several yield monitors are available for use on cotton harvesters, but none are able to maintain yield measurement accuracy across cultivars and field conditions that vary spatially and/or temporally. Thus, the utility of yield monitors as tools for on-farm research is limited unless steps are taken to calibrate the systems as cultivars and conditions change. This technical note details the man-machine-interface software system design portion of a harvester-based yield monitor calibration system for basket-type cotton strippers. The system was based upon the use of pressure sensors to measure the weight of the basket by monitoring the static pressure in the hydraulic lift cylinder circuit. To ensure accurate weighing, the system automatically lifted the basket to a target lift height, allowed basket time to settle, then weighed the contents of the basket. The software running the system was split into two parts that were run on an embedded low-level micro-controller, and a mobile computer located in the harvester cab. The system was field tested under commercial conditions and found to measure basket load weights within 2.5% of the reference scale. As such, the system was proven to be capable of providing an on-board auto-correction to a yield monitor for use in multi-variety field trials.

Embedded Micro-Controller Software Design of a Cotton Harvester Yield Monitor Calibration System

Several yield monitors are available for use on cotton harvesters, but none are able to maintain yield measurement accuracy across cultivars and field conditions that vary spatially and/or temporally. Thus, the utility of yield monitors as tools for on-farm research is limited unless steps are taken to calibrate the systems as cultivars and conditions change. This technical note details the embedded micro-controller software system design portion of a harvester-based yield monitor calibration system for basket-type cotton strippers. The system was based upon the use of pressure sensors to measure the weight of the basket by monitoring the static pressure in the hydraulic lift cylinder circuit. To ensure accurate weighing, the system automatically lifted the basket to a target lift height, allowed the basket time to settle, and then weighed the contents of the basket. The software running the system was split into two parts, which were run on an embedded low-level micro-controller and a mobile computer located in the harvester cab. The system was field tested under commercial conditions and found to measure basket load weights within 2.5% of the reference scale. As such, the system was proven to be capable of providing an on-board auto-correction to a yield monitor for use in multi-variety field trials.

Application study of self-made standard dust in atmospheric particulate monitor calibration device

The ISO12103-1 A2 test dust was used as the reference in the calibration device of the atmospheric particle monitor to investigate the performance of the self-made standard dust in this study. The result indicated that when the aerosol concentration of the calibration device was 500μg/m3,400μg/m3, 200μg/m3,100μg/m3 and 50μg/m3, the stability of self-made standard dust was close to the ISO12103-1 A2 test dust. In addition, when the aerosol with high concentration of 500μg/m3, medium concentration of 200μg/m3 and low concentration of 50μg/m3, the homogeneity and obtained concentration of the self-made standard dust and the ISO12103-1 A2 test dust evaluated by filter membrane sampling were not much differencd. Therefore, the self-made standard dust can replace ISO12103-1 A2 test dust to be used in the calibration device of particle monitor.

Inaccuracy and Overconfidence in Metacognitive Monitoring of University Students

The aim of the paper is to stress the relationship between individual metacognitive accuracy and academic performance. Moreover, we tested the relationship between the accuracy, items difficulty and bias score and exam results. Metacognitive monitoring calibration of 100 university students was tested in exam settings, using postdicted confidence judgments. Absolute local and global accuracy and total bias score were related with test performance, difficulty and types of the items: multiple choice and open ended items. The most important results show local and local inaccuracy or overconfidence, but also an unexpected greater accuracy on low performing subjects compared with there’s more performing counterparts. The open ended items low, but positively correlate with metacognitive monitoring inaccuracy, both local and global, a possible illustration of the hard-easy effect. The bias score is globally negatively related with performance, but the more the subjects respond to the difficult open-ended items, the lower the bias in self-appreciation. We conclude that there is a global expected relationship between test results and both accuracy and bias score. Also, particular results show a more nuanced relationship between local and global accuracy, items difficulty and type and bias score. Some theoretical and methodological issues are discussed and futures research direction is proposed.

Stochastic Modeling of the Time Variability of ALMA Calibrators

Characterizing the variability of the extragalactic sources used for calibration in the Atacama Large Millimeter/submillimeter Array (ALMA) is key to assess the flux scale uncertainty of science observations. To this end, we model the variability of 39 quasars which have been used by ALMA as secondary flux calibrators using continuous time stochastic processes. This formalism is specially adapted to the multi-frequency, quasi-periodic sampling which characterizes the calibration monitoring of ALMA. We find that simple mixtures of Ornstein–Uhlenbeck processes can describe well the flux and spectral index variability of these sources for Bands 3 and 7 (91.5 and 103.5, and 343.5 GHz, respectively). The spectral shape of the calibrators are characterized by negative spectral indices, mostly between −0.35 and −0.80, and with additional concavity. The model provides forecasts, interpolations, and uncertainty estimations for the observed fluxes that depend on the intrinsic variability of the source. These can be of practical use for the ALMA data calibrator survey and data quality assurance.

Condition Monitoring for Submodule Capacitors in Modular Multilevel Converters

This letter proposes a method for the condition monitoring of submodule (SM) capacitors in modular multilevel converters (MMCs) without additional circuitry or computationally heavy algorithm. The proposed method leverages the discharging curve of SM capacitors in connection with the parallel bleeding resistors. It is independent of the MMC control and modulation schemes. Moreover, it potentially does not require thermal and load-related calibration for capacitor degradation monitoring. The principle, case study, and proof of concept of the proposed method are presented.

Does domain matter? Monitoring accuracy across domains

Confidence and its accuracy have been most commonly examined in domains such as general knowledge and learning, with less study of other domains, such as applied knowledge and problem solving. Monitoring accuracy in real-world competencies may depend on characteristics of the domain. In this study, we examined whether monitoring accuracy, both calibration (resistance to overconfidence) and resolution (discrimination) indices, are stable within individuals across tasks that represent highly diverse domains. We examined the well-established domain of general knowledge and three understudied applied domains of financial calculation, probability calculation, and the social skill of emotion recognition. In addition, we examined correlations between monitoring accuracy and cognitive abilities (intellectual ability and working memory) and several aggregated judgments regarding each task as a whole (ratings of predicted performance, task difficulty, and effort required) as well as the classic postdictive itemized confidence ratings. We found that resistance to overconfidence (calibration) was significantly positively correlated across tasks, reflecting a confidence trait, but not resolution. We also found that cognitive abilities were more consistently predictive of calibration than of resolution. Aggregated judgments and postdictive confidence were significant predictors of both calibration and resolution, but associations were task specific. Emotion recognition displayed the most unique profile of findings relative to other tasks. We conclude that when considering a wide range of domains, calibration displays domain generality, but resolution may display specificity across tasks.

Real-time data processing in the ALICE High Level Trigger at the LHC

At the Large Hadron Collider at CERN in Geneva, Switzerland, atomic nuclei are collided at ultra-relativistic energies. Many final-state particles are produced in each collision and their properties are measured by the ALICE detector. The detector signals induced by the produced particles are digitized leading to data rates that are in excess of 48GB/s. The ALICE High Level Trigger (HLT) system pioneered the use of FPGA- and GPU-based algorithms to reconstruct charged-particle trajectories and reduce the data size in real time. The results of the reconstruction of the collision events, available online, are used for high level data quality and detector-performance monitoring and real-time time-dependent detector calibration. The online data compression techniques developed and used in the ALICE HLT have more than quadrupled the amount of data that can be stored for offline event processing.

A Two-Stage Local Positioning Method With Misalignment Calibration for Robotic Structural Monitoring of Buildings

In structural health monitoring (SHM) applications carried out by mobile robots, the precise locating of the SHM robot is essential for accurate detection and quantification of defects. The traditional dead reckoning (DR) approach can only provide local position in the horizon, which is not enough for SHM applications in three dimensions in large buildings. In this paper, a new robot positioning algorithm for active building structural defect detection and localization is proposed. The two-stage robot positioning scheme is designed through the self-misalignment calibration and the positioning during SHM task stages, fusing the absolute and relative measurements. In order to overcome the drawback of the DR algorithm, in the full analysis of existing localization mode that can be applied to mobile robots, this paper adopted the inertial navigation system (INS) approach to measure the absolute motion information of a moving robot. On this basis, through the transformation between the absolute positioning coordinates and the local positioning coordinates of buildings, the mobile robot's optimal trajectory on building surface was designed for self-calibration of coordinate misalignments. The proposed method could effectively achieve the robot local positioning in building coordinate frame by fusing the external relative assistant measurements with absolute measurement. By using the designed strategies, the coordinate misalignment can also be self-calibrated effectively, improving local positioning accuracy.

Selection and Characterization of Glaciers on the Tibetan Plateau as Potential Pseudoinvariant Calibration Sites

Vicarious calibration using pseudoinvariant calibration sites (PICS) has become increasingly popular, as it is the most cost-effective method for on-orbit calibration of space-borne optical sensors. Glaciers on the Tibetan Plateau (TP) are located at more than 4500 m above sea level. These snow targets, exhibiting much brighter reflectance and less affected by aerosol and water vapor than desert targets, can help to reduce the uncertainties associated with vicarious calibration. In contrast to polar snow, the TP is not limited by polar night, thus ensuring continuous calibration monitoring. This study investigated the potential role of TP glaciers as PICS for the first time. To accomplish this, the coefficient of variation (CV) was applied to characterize the spatial uniformity and temporal stability of five relatively larger and flatter TP glaciers based on several independent Landsat Thematic Mapper and Operational Land Imager datasets over 20 years. The criteria of CV < 3% (both spatial and temporal) through Landsat visible and near-infrared channels were used to identify potential PICS across the candidate glaciers. Finally, three snow PICS with areas of at least 7.2 km2 and two snow PICS with areas of 1.2–2.1 km2 were identified. The area of the snow PICS is smaller in autumn and winter due to the snow cover. The feasibility of using these sites for long-term calibration monitoring of satellite sensors is also discussed. Results indicate that although the snow PICS exhibits stronger BRDF than the invariant desert target, the MODIS calibration trends detected from snow PICS are comparable to those from the desert target.

Scanned Proton Beam Performance and Calibration of the Shanghai Advanced Proton Therapy Facility

The Shanghai Advanced Proton Therapy facility (SAPT) is a hospital-based facility that began construction in December of 2014 with commissioning of the first scanned proton beam line starting in October of 2017. Proton beams are extracted from a synchrotron accelerator with energies between 70 and 235 MeV. Beam delivery uses the modulated scanning and energy stacking techniques to produce a maximal scanning area of 40 × 30 cm2 at the iso-center. Prior to clinical use, the beam delivery system was characterized and calibrated following the guidelines of the IEC 62667 medical electronic equipment standard including the spot size in air, spot position, depth dose distributions, and lateral dose profiles, as well as the beam monitor calibrations following the IAEA TRS-398 recommendations with small differences.•The measured dosimetric results showed that the full width at half maximum (FWHM) for the beam spot size in air varied approximately from 6 mm to 13 mm. The dose fall-off (DDF) derived from the measured depth dose in water varied from 4.7 mm at 235 MeV to 0.7 mm at 70 MeV. The homogeneity of the scanned field was better than 2% for various energies as expected.•Furthermore, the beam reproducibility and proportionality delivery accuracy was also stable with the results better than 0.1% and 1% respectively. Finally, the dose monitor calibration factor, its reproducibility and stability were tested. Reproducibility tests exhibited a standard deviation (SD) result of less than 1% during the test period.•All the measured dosimetric parameters showed that the design specifications were well achieved and the results are suitable for being used as a part of the clinical commissioning and quality assurance program for treating patients.

Variety Effects on Cotton Yield Monitor Calibration

Abstract.Cotton ( L.) producers were some of the earliest adopters of practices employing site-specific management. Yield monitors are an essential component of those precision agriculture methods. The agreement between measured cotton yields and those estimated with yield monitors must be improved to adequately advance precision agriculture, particularly the site-specific planting of multiple varieties. Six site-years of observations with two yield monitor systems were studied with the objective to compare yield monitor-estimated weights to observed weights in replicated cotton variety trials and investigate factors that could relate to any observed varietal effect. The results supported the findings of earlier research indicating that cotton yield monitor calibration is affected by variety. For the six site-years and three combinations of two site-years, correlations were sometimes observed between calibration errors and turnout or some of the High Volume Instrument (HVI) fiber quality measurements, but no factor was consistently correlated across multiple studies. In one study, none of the included factors was significantly correlated with calibration error, while the HVI properties reflectance (Rd) and leaf grade were both significantly correlated in three comparisons, which was more than any other factor. Data from additional site-years must be collected and analyzed and other factors investigated to find what variety-related properties affect yield monitor errors and to allow the determination of calibration adjustments based on those factors. Keywords: Cotton, Cotton picker, Harvest, Precision agriculture, Yield monitor.

Metrological Properties Analysis of Portable Dc Voltage Calibrator with Errors Correction

It is shown that, it is expedient to use a DC voltage calibrator with automatic error correction by double switching inverting method and averaging the output voltage with a low frequency filter for operational monitoring and remote calibration of measuring channels was shown in this paper (Figre 1). A comparison of the dynamic and metrological characteristics of DC voltage calibrators with single- and two-period demodulation has been carried out and operator and time mathematical models have been proposed (Figure 2). Computer simulation of both structures of voltage calibrators in manual and automatic control modes was carried out. The results of experimental studies of a DC voltage calibrator model with single-phase demodulation and averaging by an active low frequency filter are described (Figure 3). Conclusions about the good convergence of experimental results with theoretical assumptions were made; the unadjusted value of the additive displacements in the manual control mode did not exceed ±1 μV. A certain frequency dependence of the additive displacements unadjusted value of the made model has been established and it is determined that its minimum value is at a frequency near 1.2 kHz. Conditions of practical realization of a DC voltage calibrator with automatic correction of additive displacements by the proposed method of switching inverting in the basis of programmable systems on a chip are discussed. Emphasized that in the future it will also adjust the multiplier and additional errors during the reproduction of DC voltage small values in working conditions.&#x0D; The scientific results, presented in this article, were obtained in the frame of research project number 0115U000446, 01.01.2015 - 31.12.2017, financially supported by the Ministry of Education and Science of Ukraine.

Yield monitor data: Collection, management, and usage

Yield monitors provide information that is valuable for a multitude of management purposes, including estimating the amount of nutrients removed by the harvested crop, estimating profitability, developing management zones, and analyzing impacts of treatments used in on‐farm studies. However, proper yield monitor calibration and maintenance is necessary to ensure that production and farm business assessments based on yield data are accurate and reliable. This article provides guidance on preparing to harvest a field, improving accuracy, cleaning and identifying potential errors in yield monitor data, and using the data to improve field understanding. Earn 1 CEU in Crop Management by reading this article and taking the quiz at www.certifiedcropadviser.org/education/classroom/classes/598.

Influence of tetanic stimulation on the staircase phenomenon and the acceleromyographic time-course of neuromuscular block: a randomized controlled trial.

During neuromuscular monitoring, repeated electrical stimulation evokes muscle responses of increasing magnitude ('staircase phenomenon', SP). We aimed to evaluate whether SP affects time course and twitches' values of an acceleromyographic assessed neuromuscular block with or without previous tetanic stimulation. Fifty adult patients were randomized to receive a 50Hz tetanic stimulus (S group) or not (C group) before monitor calibration. After 20min of TOF ratio (TOFr) stimulation rocuronium was administered. Onset time of block (primary endpoint), recovery of T1 to 25%, TOFr to 0.9, and recovery index were compared. We also compared T1 and TOFr at baseline, post-stimulation, and during recovery from block. Moreover the correlation between T1 at maximum recovery and (a) baseline T1 and (b) post-stimulation T1 along with T1/TOFr ratio during recovery were evaluated. After stimulation median T1 increased (32%) in group C and decreased (16%) in group S (P = 0.0001). Onset time (Median [IQR] in seconds) was 90 (29-77) vs. 75 (28-60) in C and S group (P = 0.002). Time [Mean (SD) in minutes] to normalized TOFr 0.9 were 70.13 (14.9) vs. 62.1 (21.2) in C and S groups (P = 0.204). TOFr showed no differences between groups at any time point. T1 at maximum recovery showed a stronger correlation with post-stabilization T1 compared to baseline. (ρ = 0.80 and ρ = 0.85, for C and S groups.) Standard calibration does not ensure twitch baseline stabilization and prolongs onset time of neuromuscular block. TOF ratio is not influenced by SP.

A Comparison and Calibration of a Wrist-Worn Blood Pressure Monitor for Patient Management: Assessing the Reliability of Innovative Blood Pressure Devices.

BackgroundClinical guidelines recommend monitoring of blood pressure at home using an automatic blood pressure device for the management of hypertension. Devices are not often calibrated against direct blood pressure measures, leaving health care providers and patients with less reliable information than is possible with current technology. Rigorous assessments of medical devices are necessary for establishing clinical utility.ObjectiveThe purpose of our study was 2-fold: (1) to assess the validity and perform iterative calibration of indirect blood pressure measurements by a noninvasive wrist cuff blood pressure device in direct comparison with simultaneously recorded peripheral and central intra-arterial blood pressure measurements and (2) to assess the validity of the measurements thereafter of the noninvasive wrist cuff blood pressure device in comparison with measurements by a noninvasive upper arm blood pressure device to the Canadian hypertension guidelines.MethodsThe cloud-based blood pressure algorithms for an oscillometric wrist cuff device were iteratively calibrated to direct pressure measures in 20 consented patient participants. We then assessed measurement validity of the device, using Bland-Altman analysis during routine cardiovascular catheterization.ResultsThe precalibrated absolute mean difference between direct intra-arterial to wrist cuff pressure measurements were 10.8 (SD 9.7) for systolic and 16.1 (SD 6.3) for diastolic. The postcalibrated absolute mean difference was 7.2 (SD 5.1) for systolic and 4.3 (SD 3.3) for diastolic pressures. This is an improvement in accuracy of 33% systolic and 73% diastolic with a 48% reduction in the variability for both measures. Furthermore, the wrist cuff device demonstrated similar sensitivity in measuring high blood pressure compared with the direct intra-arterial method. The device, when calibrated to direct aortic pressures, demonstrated the potential to reduce a treatment gap in high blood pressure measurements.ConclusionsThe systolic pressure measurements of the wrist cuff have been iteratively calibrated using gold standard central (ascending aortic) pressure. This improves the accuracy of the indirect measures and potentially reduces the treatment gap. Devices that undergo auscultatory (indirect) calibration for licensing can be greatly improved by additional iterative calibration via intra-arterial (direct) measures of blood pressure. Further clinical trials with repeated use of the device over time are needed to assess the reliability of the device in accordance with current and evolving guidelines for informed decision making in the management of hypertension.Trial RegistrationClinicalTrials.gov NCT03015363; https://clinicaltrials.gov/ct2/show/NCT03015363 (Archived by WebCite at http://www.webcitation.org/6xPZgseYS)

An integrated approach to assessing marine seismic impacts: Lessons learnt from the Gippsland Marine Environmental Monitoring project

Marine seismic surveys are a fundamental tool for geological research, including the exploration of offshore oil and gas resources, but the sound generated during these surveys represents a source of noise pollution in the marine environment. Recent evidence has shown that seismic surveys may negatively affect some cetaceans, fish and invertebrates, although the magnitude of these impacts remains uncertain. This paper applies a case study on marine seismic impacts (the Gippsland Marine Environmental Monitoring (GMEM) project) to the critical assessment of the advantages and challenges of field-based methods in the context of future research and management priorities. We found that an interdisciplinary approach, using both conventional (e.g. dredging) and innovative (e.g. autonomous imagery) experimental components, make for more robust interpretations and also provide a failsafe in case of limited suitable data (e.g. equipment issues related to image acquisition). Field observational studies provide an unparalleled capability to undertake ecologically realistic research, although their practical challenges must be considered during research planning. We also note the need for appropriate environmental baselines and accessible time-series data to account for spatiotemporal variability of environmental and biological parameters that may mask effects, as well as the need for a standardised technique in sound monitoring and equipment calibration to ensure accuracy and comparability among studies.

A model to assess microphytobenthic primary production in tidal systems using satellite remote sensing

Quantifying spatial variability in intertidal benthic productivity is necessary to guide management of estuaries and to understand estuarine ecological processes, including the amount of benthic organic carbon available for grazing, burial and transport to the pelagic zone.We developed a model to assess microphytobenthic (MPB) primary production using (1) remotely sensed information on MPB biomass and remotely sensed information on sediment mud content, (2) surface irradiance and ambient temperature (both from local meteorological observations), (3) directly-measured photosynthetic parameters and (4) a tidal model. MPB biomass was estimated using the normalized-difference vegetation index (NDVI) and mud content was predicted using surface reflectance in the blue and near-infrared, both from Landsat 8 satellite imagery. The photosynthetic capacity (maximum photosynthesis rate normalized to MPB chl-a) was estimated from ambient temperature, while photosynthetic efficiency and the light saturation parameter were derived from in situ fluorometry-based production measurements (PAM). The influence of tides (submergence by turbid water) on MPB production was accounted for in the model. The method was validated on several locations in two temperate tidal basins in the Netherlands (Oosterschelde and Westerschelde). Model based production rates (mg C m−2 h−1) matched well with an independent set of in situ (PAM) measurement based production rates (Oosterschelde: RMSE = 9.7, mean error = 1.5, χ = 0.57; Westerschelde: RMSE = 46.7, mean error = −17.6, χ = 0.9). The relationship between photosynthetic capacity and temperature shows considerable variation and may be improved by using sediment surface temperature instead of ambient temperature. A sensitivity analysis revealed that emersion duration and mud content determine most of the variability in MPB production. Our results demonstrate that it is possible to derive a satellite remote sensing-based overview of average hourly and daily MPB primary production rates at the macro scale. As the proposed model is generic, the model can be applied to other tidal systems to assess spatial variability in MPB primary production at the macro scale after calibration at the site of interest. Model calibration, results and possible applications for regular monitoring of MPB production are discussed below.

Wideband stripline fed tapered slot antenna with integral coupler for wide scan angle active phased array

A stripline fed tapered slot antenna (STSA) with integral coupler operating as an active array element over 1.5 octave bandwidth is presented. The proposed STSA with integral coupler features wideband transition which allows a direct 50 Ω stripline feed and enables the coupler to be integrated along with the feed. The coupler helps in taking a sample of signal for online performance monitoring and active phased array calibration. The measured results of antenna element have exhibited good radiation pattern performance with low cross-polarisation in principal plane and low beam squint. Using this, a 16-element H -plane linear phased array antenna designed for the frequency range of 6-18 GHz and azimuth scan coverage of 60° is also presented. The active reflection coefficient of the array is calculated from measured mutual coupling coefficients and the array pattern over different scan angles is demonstrated. The grating lobe free scan coverage of 60° is obtained. The antenna array finds application in airborne systems.