Calibration Conditions Research Articles

Nanoparticle emission characteristics and reduction strategies by boost pressure control and injection strategies in a passenger diesel engine

This research attempted to analyze nanoparticles and other harmful exhaust emissions in accordance with injection strategies and air-fuel ratio (AFR) changes for small diesel engines. The emission characteristics were analyzed in the medium-speed condition, which is the main driving range of a diesel engine. In the case of particulate matter (PM), the number of particles was measured, analyzed, and compared to identify the correlation and emission characteristics of nanoparticles by using a dilution device and condensation particle counter (CPC), which are international standards for particle measurement recommended by the Particulate Measurement Programme (PMP). The engine torque tended to be reduced as pilot injections were added, and the torque was increased by the increased boost pressure, but reduced by the exhaust pressure increase in a part of the low-load range. The number of nanoparticles was not influenced greatly by the change in AFR, but the reduction effect on the PM weight was great depending on the boost pressure increase. In addition, the number of nanoparticles tended to increase as the fuel injection timing became closer to TDC in all conditions, and its difference became larger with an increase in AFR. In addition, in the case of the pilot injection, nanoparticle emission showed similar characteristics depending on the main injection timing, but it was increased by advanced injection timing when performing the main injection only, and the number of the nanoparticles increased as pilot injections were added. Last, the optimal conditions for EMS calibration were analyzed by selecting the conditions of torque reduction and NOx increase within 5 % from all of the engine operating conditions; optimized conditions are presented.

SU-G-IeP2-04: Dosimetric Accuracy of a Monte Carlo-Based Tool for Cone-Beam CT Organ Dose Calculation: Validation Against OSL and XRQA2 Film Measurements

Purpose: The intensive use of Cone-Beam Computed Tomography (CBCT) during radiotherapy treatments raise some questions about the dose to healthy tissues delivered during image acquisitions. We hence developed a Monte Carlo (MC)-based tool to predict doses to organs delivered by the Elekta XVI kV-CBCT. This work aims at assessing the dosimetric accuracy of the MC tool, in all tissue types. Methods: The kV-CBCT MC model was developed using the PENELOPE code. The beam properties were validated against measured lateral and depth dose profiles in water, and energy spectra measured with a CdTe detector. The CBCT simulator accuracy then required verification in clinical conditions. For this, we compared calculated and experimental dose values obtained with OSL nanoDots and XRQA2 films inserted in CIRS anthropomorphic phantoms (male, female, and 5-year old child). Measurements were performed at different locations, including bone and lung structures, and for several acquisition protocols: lung, head-and-neck, and pelvis. OSLs and film measurements were corrected when possible for energy dependence, by taking into account for spectral variations between calibration and measurement conditions. Results: Comparisons between measured and MC dose values are summarized in table 1. A mean difference of 8.6% was achieved for OSLs when the energy correction was applied, and 89.3% of the 84 dose points were within uncertainty intervals, including those in bones and lungs. Results with XRQA2 are not as good, because incomplete information about electronic equilibrium in film layers hampered the application of a simple energy correction procedure. Furthermore, measured and calculated doses (Fig.1) are in agreement with the literature. Conclusion: The MC-based tool developed was validated with an extensive set of measurements, and enables the organ dose calculation with accuracy. It can now be used to compute and report doses to organs for clinical cases, and also to drive strategies to optimize imaging protocols.

TU-FG-209-04: Testing of Digital Image Receptors Using AAPM TG-150's Draft Recommendations - Investigating the Impact of Different Processing Parameters

Purpose: To evaluate implementation of AAPM TG-150's draft recommendations via a parameter study for testing the performance of digital image receptors. Methods: Flat field images were acquired from 9 calibrated digital image receptors associated with 9 new portable digital radiography systems (Carestream Health, Inc.) based on the draft recommendations and manufacturer-specified calibration conditions (set of 4 images at input detector air kerma ranging from 1 to 25 µGy). Effects of exposure response function (linearized and logarithmic), ‘Presentation Intent Type’ (‘For Processing’ and ‘For Presentation’), detector orientation with respect to the anode-cathode axis (4 orientations; 900 rotations per iteration), different ROI sizes (5×5–40×40 mm2) and elimination of varying dimensions of image border (0 mm i.e., without boundary elimination to 150 mm) on signal, noise, signal-to-noise ratio (SNR) and the associated nonuniformities were evaluated. Images were analyzed in Matlab and quantities were compared using ANOVA. Results: Signal, noise and SNR values averaged over 9 systems with default parameter values in draft recommendations were 4837.2±139.4, 19.7±0.9 and 246.4±10.1 (mean ± standard deviation), respectively (at input detector air kerma: 12.5 µGy). Signal, noise and SNR showed characteristic dependency on exposure response function and on ‘Presentation Intent Type’. These values were not affected by ROI size and detector orientation, but analysis showed that eliminating the edge pixels along the boundary was required for the noise parameter (coefficient of variation range for noise: 72%–106% and 3%–4% without and with boundary elimination; respectively). Local and global nonuniformities showed a similar dependence on the need for boundary elimination. Interestingly, computed non-uniformities showed agreement with manufacturer-reported values except for noise non-uniformities in two units; artifacts were seen in images from these two units highlighting the importance of independent evaluations. Conclusion: The effect of different parameters on performance characterization of digital image receptors was evaluated based on TG-150's draft recommendations.

SU-G-BRB-15: Verifications of Absolute and Relative Dosimetry of a Novel Stereotactic Breast Device: GammaPodTM

Purpose: A dedicated stereotactic breast radiotherapy device, GammaPod, was developed to treat early stage breast cancer. The first clinical unit was installed and commissioned at University of Maryland. We report our methodology of absolute dosimetry in multiple calibration conditions and dosimetric verifications of treatment plans produced by the system. Methods: GammaPod unit is comprised of a rotating hemi-spherical source carrier containing 36 Co-60 sources and a concentric tungsten collimator providing beams of 15 and 25 mm. Absolute dose calibration formalism was developed with modifications to AAPM protocols for unique geometry and different calibration medium (acrylic, polyethylene or liquid water). Breast cup-size specific and collimator output factors were measured and verified with respect to Monte-Carlo simulations for single isocenter plans. Multiple isocenter plans were generated for various target size, location and cup-sizes in phantoms and 20 breast cancer patients images. Stereotactic mini-farmer chamber, OSL and TLD detectors as well as radio-chromic films were used for dosimetric measurements. Results: At the time of calibration (1/14/2016), absolute dose rate of the GammaPod was established to be 2.10 Gy/min in acrylic for 25 mm for sources installed in March 2011. Output factor for 15 mm collimator was measured to be 0.950. Absolute dose calibration was independently verified by IROC-Houston with a TLD/Institution ratio of 0.99. Cup size specific output measurements in liquid water for single isocenter were found to be within 3.0% of MC simulations. Point-dose measurements of multiple isocenter treatment plans were found to be within −1.0 ± 1.2 % of treatment planning system while 2-dimensional gamma analysis yielded a pass rate of 97.9 ± 2.2 % using gamma criteria of 3% and 2mm. Conclusion: The first GammaPod treatment unit for breast stereotactic radiotherapy was successfully installed, calibrated and commissioned for patient treatments. An absolute dosimetry and dosimetric verification protocols were successfully created.

Local Volatility Models Enhanced with Jumps

In this paper, we study the calibration to market call prices C^{mkt}(t;K) of a local volatility model enhanced with jumps. Instead of giving an exact calibration condition on the local volatility, we introduce an approximate process S_t^\epsilon satisfying a well-defined nonlinear McKean SDE driven by a Cox process, such that E[(S_t^\epsilon - K) _ ] converges to C^{mkt}(t;K) as \epsilon goes to 0 for all (t;K). This implies that the particle method, applied to the process S_t^\epsilon, which is used for the calibration of the local volatility, converges numerically. We illustrate the accuracy of our calibration algorithm with various numerical experiments. Finally, we extend this model by allowing jumps in the local volatility.

Impact of the calibration conditions of XR-RV3 films on peak skin dose measurements in interventional radiology.

In this study, the impact of radiochromic films' (XR-RV3) calibration on PSD measurements was investigated under various peak kilovoltage (kVp) and additional filtration conditions. Films were calibrated free-in-air for six beam qualities with Allura Xper FD20 system (Philips). Six calibration curves (CCs) were constructed. Each beam quality was characterized in terms of mean energy (ME)in the air, with table, with table and water phantom using Monte Carlo simulations. A cohort of 155 patient films from cardiology (37) and vascular (118) procedures were read with each CC. Routine calibration beam quality was taken as reference (DoseNorm). Overall, it was observed that for a wider ME difference between the exposed film and the CC used, a larger deviation (from -28% to +41%) was observed. The choice of beam quality for the calibration is a key point when additional filtration and kVp are automatically controlled in clinical conditions.

Fusion strategies for selecting multiple tuning parameters for multivariate calibration and other penalty based processes: A model updating application for pharmaceutical analysis

New multivariate calibration methods and other processes are being developed that require selection of multiple tuning parameter (penalty) values to form the final model. With one or more tuning parameters, using only one measure of model quality to select final tuning parameter values is not sufficient. Optimization of several model quality measures is challenging. Thus, three fusion ranking methods are investigated for simultaneous assessment of multiple measures of model quality for selecting tuning parameter values. One is a supervised learning fusion rule named sum of ranking differences (SRD). The other two are non-supervised learning processes based on the sum and median operations. The effect of the number of models evaluated on the three fusion rules are also evaluated using three procedures. One procedure uses all models from all possible combinations of the tuning parameters. To reduce the number of models evaluated, an iterative process (only applicable to SRD) is applied and thresholding a model quality measure before applying the fusion rules is also used. A near infrared pharmaceutical data set requiring model updating is used to evaluate the three fusion rules. In this case, calibration of the primary conditions is for the active pharmaceutical ingredient (API) of tablets produced in a laboratory. The secondary conditions for calibration updating is for tablets produced in the full batch setting. Two model updating processes requiring selection of two unique tuning parameter values are studied. One is based on Tikhonov regularization (TR) and the other is a variation of partial least squares (PLS). The three fusion methods are shown to provide equivalent and acceptable results allowing automatic selection of the tuning parameter values. Best tuning parameter values are selected when model quality measures used with the fusion rules are for the small secondary sample set used to form the updated models. In this model updating situation, evaluation of all possible models, thresholding, and iterative SRD performed equivalently for the three fusion rules with TR and PLS performed worse. While the application is model updating, the fusion processes are applicable to other situations requiring selection of multiple tuning parameter values.

Comparison of EBT and EBT3 RadioChromic Film Usage in Parotid Cancer Radiotherapy.

EBT and EBT3 radioChromic films have been used in radiotherapy dosimetry for years. The aim of the current study is to compare EBT and EBT3 radioChromic films in dosimetry of radiotherapy fields for treatment of parotid cancer. Calibrations of EBT and EBT3 films were performed with identical setups using a 6 MV photon beam of a Siemens Primus linac. Skin dose was measured at different points in the right anterior oblique (RAO) and right posterior oblique (RPO) fields by EBT and EBT3 films on a RANDO phantom. While dosimetry was performed with the same conditions for the two film types for calibration and in phantom in parotid cancer radiotherapy, the measured net optical density (NOD) in EBT film was found to be higher than that from EBT3 film. The minimum difference between these two films under calibration conditions was about 2.9% (for 0.2 Gy) with a maximum difference of 35.5% (for 0.5 Gy). In the therapeutic fields of parotid cancer radiotherapy at different points, the measured dose from EBT film was higher than the EBT3 film. In these fields the minimum and maximum measured dose differences were 16.0% and 25.5%, respectively. EBT film demonstrates higher NOD than EBT3 film. This effect may be related to the higher sensitivity of EBT film over EBT3 film. However, the obtained dose differences between these two films in low dose range can be due to the differences in fitting functions applied following the calibration process.

A novel data reduction technique for single slanted hot-wire measurements used to study incompressible compressor tip leakage flows

The single slanted hot-wire technique has been used extensively as a method for measuring three velocity components in turbomachinery applications. The cross-flow orientation of probes with respect to the mean flow in rotating machinery results in detrimental prong interference effects when using multi-wire probes. As a result, the single slanted hot-wire technique is often preferred. Typical data reduction techniques solve a set of nonlinear equations determined by curve fits to calibration data. A new method is proposed which utilizes a look-up table method applied to a simulated triple-wire sensor with application to turbomachinery environments having subsonic, incompressible flows. Specific discussion regarding corrections for temperature and density changes present in a multistage compressor application is included, and additional consideration is given to the experimental error which accompanies each data reduction process. Hot-wire data collected from a three-stage research compressor with two rotor tip clearances are used to compare the look-up table technique with the traditional nonlinear equation method. The look-up table approach yields velocity errors of less than 5 % for test conditions deviating by more than 20 °C from calibration conditions (on par with the nonlinear solver method), while requiring less than 10 % of the computational processing time.

Inertial Sensor Error Reduction through Calibration and Sensor Fusion.

This paper presents the comparison between cooperative and local Kalman Filters (KF) for estimating the absolute segment angle, under two calibration conditions. A simplified calibration, that can be replicated in most laboratories; and a complex calibration, similar to that applied by commercial vendors. The cooperative filters use information from either all inertial sensors attached to the body, Matricial KF; or use information from the inertial sensors and the potentiometers of an exoskeleton, Markovian KF. A one minute walking trial of a subject walking with a 6-DoF exoskeleton was used to assess the absolute segment angle of the trunk, thigh, shank, and foot. The results indicate that regardless of the segment and filter applied, the more complex calibration always results in a significantly better performance compared to the simplified calibration. The interaction between filter and calibration suggests that when the quality of the calibration is unknown the Markovian KF is recommended. Applying the complex calibration, the Matricial and Markovian KF perform similarly, with average RMSE below 1.22 degrees. Cooperative KFs perform better or at least equally good as Local KF, we therefore recommend to use cooperative KFs instead of local KFs for control or analysis of walking.

Influence of camera calibration conditions on the accuracy of 3D reconstruction.

For stereoscopic systems designed for metrology applications, the accuracy of camera calibration dictates the precision of the 3D reconstruction. In this paper, the impact of various calibration conditions on the reconstruction quality is studied using a virtual camera calibration technique and the design file of a commercially available lens. This technique enables the study of the statistical behavior of the reconstruction task in selected calibration conditions. The data show that the mean reprojection error should not always be used to evaluate the performance of the calibration process and that a low quality of feature detection does not always lead to a high mean reconstruction error.

Simulation of constructed wetlands treating combined sewer overflow using HYDRUS/CW2D

Constructed Wetland 2D (CW2D) is a biokinetic model describing microbial dynamics and transformation and degradation processes in subsurface flow constructed wetlands (CWs). The implementation of CW2D in HYDRUS (©PC Progress s.r.o.) was verified for application on CWs treating combined sewer overflow (CSO CWs). CSO CWs mitigate pollutant and hydraulic shock on receiving waters. Their loadings are stochastic in terms of periodicity, volume and quality. Their storage basin and outflow limitation causes cycles of saturated (intra-event) and unloaded (inter-event) states. The need for verification is due to this stochasticity. Key parameters to overcome the limitations identified by earlier studies were (1) biokinetic parameters, (2) fractionation of COD between readily and slowly biodegradable and inert forms and (3) adsorption of inert COD. With the new settings inoculation runs yielded stable biomass and domain conditions. These were successfully used as initial conditions for calibration and validation. Laboratory column experiments formed the basis of comparison, including single loads and a load series. The goodness of fit was quantified by an updated method. Good fit was reached to COD and NH4-N. Fitting to NO3-N was not a target; still, dynamics are discussed.

UNCONTROLLED PHOTOMULTIPLIER CURRENT IN PHOTOEMISSION ANALYSIS

The dependence of photon energy from energy of photoelectron is base of photoemission radiation analysis. In such photoemission measurements except current of photocathode is always exist a reverse current from the collector of electrons to the photocathode in two-electrode sensors. There are various ways of reverse and uncontrolled current eliminating or reducing their influence. The constructive method is based on creating an electron-optical system of photoelectronic device, which would be a photoelectron energy analyzer. The second method – technological. However, it requires the manufacture of the photocathode and the dynode system in different vacuum chamber with subsequent connection to a single device in vacuum environment without exposure to the atmosphere. The purpose of this article is to determinate the effect of photoemission from photocathode chamber and the first dynode of photomultiplier on energy distribution of the photoelectrons from photocathode. To solve this problem authors obtained calibration curves for measuring pyrometer module ПИФ 4/2 with ФЭУ-114 as a sensor at supply voltage 1350 V and different decelerating voltages. The effect of illumination on the value of modulation coefficient on temperature k(T) and wavelength k(λ) is shown. In temperature measurements, this effect is evident in fact that at temperatures below 1400 K linear dependence ln k – T-1 is broken. Still this linear dependence is a necessary consequence of the fact that the measured temperature is color temperature. However, this calibration curve can be used to measure low temperature if the target measurements condition and calibration conditions are identical. In wavelength calibration, curve k(λ) at λ > 760 nm is two-valued, that doesn’t allow to identify monochromatic radiation by this method and bring in errors in temperature measurements.

Monte Carlo simulation of gamma-ray interactions in an over-square high-purity germanium detector for in-vivo measurements

The developments of high-purity germanium detectors match very well the requirements of the in-vivo human body measurements regarding the gamma energy ranges of the radionuclides intended to be measured, the shape of the extended radioactive sources, and the measurement geometries. The Whole Body Counter (WBC) from IFIN-HH is based on an “over-square” high-purity germanium detector (HPGe) to perform accurate measurements of the incorporated radionuclides emitting X and gamma rays in the energy range of 10 keV–1500 keV, under conditions of good shielding, suitable collimation, and calibration. As an alternative to the experimental efficiency calibration method consisting of using reference calibration sources with gamma energy lines that cover all the considered energy range, it is proposed to use the Monte Carlo method for the efficiency calibration of the WBC using the radiation transport code MCNP5. The HPGe detector was modelled and the gamma energy lines of [Formula: see text]Am, [Formula: see text]Co, [Formula: see text]Ba, [Formula: see text]Cs, [Formula: see text]Co, and [Formula: see text]Eu were simulated in order to obtain the virtual efficiency calibration curve of the WBC. The Monte Carlo method was validated by comparing the simulated results with the experimental measurements using point-like sources. For their optimum matching, the impact of the variation of the front dead layer thickness and of the detector photon absorbing layers materials on the HPGe detector efficiency was studied, and the detector’s model was refined. In order to perform the WBC efficiency calibration for realistic people monitoring, more numerical calculations were generated simulating extended sources of specific shape according to the standard man characteristics.

Design of a Hot-wire Rake for Measurements in Temperature-varying Flow Fields

The present work deals with the design of a multi-probe support for simultaneous multi-point measurements. The article analyses the effects of the insertion of a hot-wire rake in a test section where the flow shows not constant temperatures. The constant temperature anemometry technique is known to have a relevant sensibility to both fluid temperature variations during the measurements and temperature differences between calibration and testing conditions. Therefore a technique to take into account for the flow temperature drifts influence is proposed and validated. The temperature correction presented allows reducing the influence of temperature variations on the measured velocity. This is achieved introducing a correction term, namely the temperature-loading factor that can be optimized for the individual probe and measurement conditions. The correction also takes into account for variations in fluid property values (Prandtl number, dynamic viscosity, heat conductivity and density) with temperature.

Commissioning optically stimulated luminescence in vivo dosimeters for fast neutron therapy.

Clinical in vivo dosimeters intended for use with photon and electron therapies have not been utilized for fast neutron therapy because they are highly susceptible to neutron damage. The objective of this work was to determine if a commercial optically stimulated luminescence (OSL) in vivo dosimetry system could be adapted for use in fast neutron therapy. A 50.5 MeV fast neutron beam generated by a clinical neutron therapy cyclotron was used to irradiate carbon doped aluminum oxide (Al2O3:C) optically simulated luminescence dosimeters (OSLDs) in a solid water phantom under standard calibration conditions, 150 cm SAD, 1.7 cm depth, and 10.3 × 10.0 cm field size. OSLD fading and electron trap depletion studies were performed with the OSLDs irradiated with 20 and 50 cGy and monitored over a 24-h period to determine the optimal time for reading the dosimeters during calibration. Four OSLDs per group were calibrated over a clinical dose range of 0-150 cGy. OSLD measurement uncertainties were lowered to within ±2%-3% of the expected dose by minimizing the effect of transient fading that occurs with neutron irradiation and maintaining individual calibration factors for each dosimeter. Dose dependent luminescence fading extended beyond the manufacturer's recommended 10 min period for irradiation with photon or electron beams. To minimize OSL variances caused by inconsistent fading among dosimeters, the observed optimal time for reading the OSLDs postirradiation was between 30 and 90 min. No field size, wedge factor, or gantry angle dependencies were observed in the OSLDs irradiated by the studied fast neutron beam. Measurements demonstrated that uncertainties less than ±3% were attainable in OSLDs irradiated with fast neutrons under clinical conditions. Accuracy and precision comparable to clinical OSL measurements observed with photons can be achieved by maintaining individual OSLD calibration factors and minimizing transient fading effects.

An NTC Zone Compliant Knock Onset Prediction Model for Spark Ignition Engines

Pollutant emissions reduction and energy saving policies increased the production of Spark Ignition (SI) engines operated with gaseous fuels. Natural Gas (NG) and Liquefied Petroleum Gas (LPG), thanks to their low cost and low environmental impact represent the best alternative. Bi-fuel engines, which may run either with gasoline or with gas (NG or LPG), widely spread in many countries thanks to their versatility, high efficiency and low pollutant emissions: gas fueled vehicles, as example, are allowed to run in many limited traffic zones. In the last years, supercharged SI engines fueled with either gasoline or gaseous fuel, spread in the market. Thermodynamic simulations, widely used to reduce costs during engine development and optimization process, require proper combustion and knock onset prediction models. In particular the fuel knocking resistance is a crucial issue in supercharged engines development. Starting from these considerations the authors developed and calibrated an original knock onset prediction model for knock-safe performances optimization of engines fueled by gasoline and gaseous fuels. The proposed model, despite its very simple formulation, takes into account the Negative Temperature Coefficient (NTC) behavior exhibited by many hydrocarbons fuels such as gasoline, propane and methane. The knock prediction model has been calibrated by a great number of light-knocking pressure cycles sampled using a Cooperative Fuel Research (CFR) engine. The engine Compression Ratio (CR), inlet mixture temperature and spark advance have been varied to obtain very different operative conditions for model calibration; as a result the model can be used in the development of different kind of engines, i.e. naturally aspirated or supercharged. Five fuels have been tested: gasoline, LPG, NG, propane and methane. The calibrated model showed a very high reliability with a maximum knock onset prediction error of only 4 crank angle degrees (CAD) and an overall mean absolute error lower than 1 CAD, that are negligible quantities from an engine control point of view.

Evaluation of the effects of subject thickness on the exposure index in digital radiography

The exposure index (EI) was proposed as a new X-ray dose index by the International Electrotechnical Commission (IEC) and has since been implemented as an international standard. The EI is calculated by use of an approximation equation under IEC-specified calibration conditions. However, several factors encountered in clinical practice, including the patient's body thickness and the tube voltage, differ with regard to these calibration conditions. We, therefore, require a solid water phantom-based function that can incorporate the IEC-specified conditions and different subject thicknesses to evaluate the effects of subject thickness on the EI. Here, we assumed average thicknesses of 10cm for a child, 15cm for slender patients, and 21cm for an average adult abdomen and we evaluated errors, that are included in the EI, which were calculated by use of the function. Our results suggested that the EI depends on the subject thickness. At the 21-cm thickness (average adult abdomen), the display EI exhibited a small error level. In contrast, EI values calculated from the calibration conditions exhibited maximum errors that were as high as 34% at the lower subject thicknesses (10 and 15cm), suggesting a significant influence of the subject thickness on the EI. In conclusion, the EI should be used cautiously during the examination of children and thin patients, with a complete understanding of the discrepancy revealed by our study results.

Investigation of ductility limits based on bifurcation theory coupled with continuum damage mechanics

The ductility limits of an St14 steel are investigated using an elastic–plastic-damage model and bifurcation theory. An associative J2-flow theory of plasticity is coupled with damage within the framework of continuum damage mechanics. For strain localization prediction, the bifurcation analysis is adopted. Both the constitutive equations and the localization bifurcation criterion are implemented into the finite element code ABAQUS, within the framework of large strains and a fully three-dimensional formulation. The material parameters associated with the fully coupled elastic–plastic-damage model are calibrated based on experimental tensile tests together with an inverse identification procedure. The above-described approach allows the forming limit diagrams of the studied material to be determined, which are then compared with experimental measurements. A main conclusion of the current study is that the proposed approach is able to provide predictions that are in good agreement with experiments under the condition of accurate material parameter calibration. The latter requires a careful identification strategy based on both calibrated finite element simulations of tensile tests at large strains and appropriately selected necking measurements. The resulting approach represents a useful basis for setting up reliable ductility limit prediction tools as well as effective parameter identification strategies.

Error Modeling and Calibration of MEMS-Based IMUs Including Accelerometers and Gyroscopes

The objective of this paper is to describe the calibration test method and conditions for MEMS-based IMUs including accelerometers and gyroscopes. This method is mainly used to derive deterministic error bounds within the acceptable range of accuracy. After a detailed description of the error model, the calibration process, test procedure, and test results as well as practical challenges are discussed. The presented method is simple, cheap and fast that takes only a few hours for calibration and validation of these sensors.