Standardized Spectrum Research Articles

Upper-bound vibration response spectrum computation for deployable membrane structures with uncertainty effects

Real-time monitoring technology is essential for establishing a control technology for large-sized membrane space structures. However, numerous measurement points are necessary to capture the maximum vibration response, which renders the real-time monitoring technology impractical. Thus, this study proposed an upper-bound vibration spectrum computation approach using a few measurement points samples on a deployable membrane structure. The proposed method exhibits characteristics of applying the standardized upper-bound spectrum, including uncertainty effects for the computations. The experiment results indicated that the upper-bound spectrum calculated from only 30 measured data points appropriately covered the measured spectra, thus confirming the effectiveness of the proposed method.

IN-FLIGHT AND ON-ORBIT CALIBRATION OF LUNAR IMAGING SPECTROMETERS – A REVIEW

Lunar imaging spectrometers play a leading role in the study of the Moon’s mineral composition. The accuracy and reliability of the acquired data depend on the calibration process. Key stages of it include laboratory calibration, in-flight validation, on-orbit calibration, and cross-calibration. During these stages, a variety of techniques and methods are used for calibration with the aim of achieving higher radiometric accuracy when recording the spectral reflective characteristics of materials in scenes from the lunar surface. These methods include capturing well-known calibration astronomical targets and calibration sites, comparing data from previous lunar surface studies obtained from orbital devices or ground-based telescopes. On-board sources for calibration, such as lamps with a standardized emission spectrum, are also used. Capturing the Earth’s atmosphere for validation and calibration of data recorded by optical spectrometers is another method. The review presents an overview of techniques and methods used to calibrate optical spectrometers in flight to the Moon and in lunar orbit. This paper provides a review of the techniques and methods utilized for in-flight and on-orbit calibration of lunar imaging spectrometers, drawing from an extensive overview of referenced science papers.

Fish Community Structure and Biomass Particle-Size Spectrum in the Upper Reaches of the Jinsha River (China)

To understand the characteristics of the fish community structure and biomass particle-size spectrum in the upper reaches of the Jinsha River, fish and environmental surveys were conducted in 21 segments of the upper reaches of the Jinsha River in September 2019 and June 2020. A total of 4062 fish belonging to 2 orders, 5 families, 18 genera, and 28 species were collected. Among them, Cyprinidae fish were the most abundant (14 species), accounting for 50.00%. The Shannon index and Pielou evenness index values varied from 0.402-1.770 and 0.254-0.680, respectively. The dominant species of fish were Triplophysa stenura, Schizothorax wangchiachii, and Schizopygopsis malacanthus. Redundancy analysis (RDA) was used to analyse the relationship between the fish community and environmental factors. Velocity, altitude, and dissolved oxygen were the main influencing factors of fish community structure differences in the upper reaches of the Jinsha River. The abundance/biomass curves showed that the fish communities in the upper reaches of the Jinsha River were moderately or severely disturbed. The standardized biomass particle-size spectrum of fish showed that the degree of disturbance of fish in tributaries was much lower than that in the main stream. Compared with the historical data, the fish community structure in the Jinsha River has changed significantly, with the number of exotic species increasing, and the individual fish showing miniaturization and younger ages. It is suggested that habitat conservation strategies be adopted in the upper tributaries of the Jinsha River to provide a reference for the restoration of fishery resources and the conservation of fish diversity in the Yangtze River.

Using Copernicus Atmosphere Monitoring Service (CAMS) Products to Assess Illuminances at Ground Level under Cloudless Conditions

Natural daylight is recognized as an important variable in the energy performance of buildings. A method that estimates the global illuminance received on a horizontal surface at ground level and its direct component at normal incidence under cloudless conditions is presented. The method uses the k-distribution method and the correlated-k approximation to compute a set of clearness indices integrated over 13 spectral bands covering the range 380–780 nm. A spectral resampling technique, including a spectral disaggregation and a spectral linear interpolation, is applied to these indices for providing a detailed set of solar irradiances at 1 nm in spectral resolution over the whole range. Then, these are weighted by the standardized CIE action spectrum for human eye for assessing the illuminance. Inputs to the method include the total column contents of ozone and water vapor as well as aerosol optical properties produced by the Copernicus Atmosphere Monitoring Service. Estimates of illuminance were compared to high-quality 1 min measurements of illuminance that were collected from two experimental sites located in two different climatic zones. A slight overestimation is observed for the global illuminance: the bias is between +1 klx and +3 klx, i.e., between +1% and +4% in relative value. The root mean square error varies between 5 klx (8%) and 6 klx (9%). The squared correlation coefficient ranges between 0.95 and 0.97. At the site providing the direct illuminance at normal incidence, the performance of the method is lower compared to global illuminance with a lower squared correlation coefficient of 0.53. The bias, relative bias, RMSE, and rRMSE are +7 klx, +9%, 12 klx, and 15%, respectively. The uncertainty of the method is of the order of the uncertainty of the measurements. The method offers accurate estimates of illuminance in cloudless conditions at high spatial and temporal resolutions useful for construction industries and operators as well as thermal simulation tools for optimal building design strategies.

Connecting the Dots: a cluster-randomized clinical trial integrating standardized autism spectrum disorders screening, high-quality treatment, and long-term outcomes

BackgroundAutism spectrum disorder (ASD) affects one in 54 children in the United States of America, and supporting people with ASD across the lifespan presents challenges that impact individuals, families, and communities and can be quite costly. The American Academy of Pediatrics has issued recommendations for routine ASD screening at 18 and 24 months, but some research suggests that few pediatricians perform high-fidelity, standardized screening universally. Furthermore, the United States Preventive Services Task Force (USPSTF) found insufficient evidence to recommend for or against universal ASD screening. The objective of this study is to test the hypothesis that children with ASD who have high fidelity; standardized screening will achieve superior outcomes at 5 years of age compared to children receiving usual care ASD detection strategies.MethodsThis is a cluster-randomized, controlled clinical trial in 3 sites in the USA. Pediatric practices will be randomized to implement universal, standardized, high-fidelity toddler screening or usual care, with randomization stratified by the practice size. The study will enroll 3450 children, approximately half in each group. From this sample, we anticipate 100 children to be diagnosed with ASD. Children in both groups receiving an ASD diagnosis will be administered the Early Start Denver Model, an evidence-based early intervention addressing social, communication, and cognitive functioning. Treatment will last for 1 year, with up to 20 h per week of therapy for children with ASD.ResultsPrimary outcomes measured at baseline, following treatment, and at 4 and 5 years of age include ASD symptom severity (Brief Observation of Social Communication Change (BOSCC)) and cognitive functioning (Mullen Scales of Early Learning (MSEL) and Differential Abilities Scale-II (DAS-II)). Secondary outcomes in children include measures of adaptive functioning, ASD symptoms, and kindergarten readiness; secondary analyses will also examine stress and empowerment among parents. Several novel exploratory measures will be included as well. The study will utilize a modified intention-to-treat analysis.ConclusionsThis trial will evaluate the impact of universal, standardized, high-fidelity screening for ASD among children at 18 months of age, with a goal of providing evidence to support this strategy to detect ASD in toddlers in order to start treatment as young as possible and maximize outcomes.Ethics and disseminationThis study was approved by the Institutional Review Board at Drexel University (IRB protocol: 1607004653). All findings will be provided by the principal investigator via email; data will be available through the NIMH Data Archive (https://nda.nih.gov/).Trial registrationClinicalTrials.gov NCT03333629. Registered on November 7, 2017

Triaged Treatment-Based Conventional Weapon Combat Wound Classification Code Design and Injury Spectrum Statistical Analysis.

We create an expandable combat wound classification coding system and a stratified standardized combat wound injury spectrum to support triage according to the treatment echelon and to provide the basis for the rapid and efficient classification of combat casualties. The coding system simultaneously assists in identifying injuries with a high incidence of fatality that require emergency treatment, and provides a framework for the triage of combat wounds in mass casualty situations. The three-tiered treatment echelon consisting of battlefield on-site first aid, emergency treatment, and early treatment was used to design an expanded combat wound classification coding system according to the differential needs of combat wound treatment. The Herfindahl-Hirschman Index (HHI) index was used as the key indicator for injury spectrum ranking and was applied to select the key anatomical structures that require the highest priority treatment in the three treatment echelons. The combat wound classification codes were based on the results of consultations with selected experts and results from the HHI index calculations. The use of the classification codes at the battlefield on-site first aid stage and emergency treatment stage was evaluated in exercises to test and compare the effectiveness of the classification codes against current classification systems. We obtained exhaustive combinations from the vast number of combat wound factors in combat wound classification codes, constructed injury spectrum frameworks within the different treatment echelons, and identified injuries with a high-incidence of fatality in each of the treatment echelons. Compared with traditional methods, the time spent on coding was reduced and classification accuracy was improved when using the new classification codes, which led to improved efficiency of classification and a reduced workload for hospital staff. The combat wound classification codes that were established through the HHI index and expert consultations achieved good results in terms of having higher classification speed and accuracy than traditional methods. This means they could be used to identify injuries with a high-incidence of fatality and provide guidance to improve the efficiency of treatment among all treatment echelons in the army.

Tidal Disruptions of Main-sequence Stars. V. The Varieties of Disruptions

Abstract Tidal disruption events (TDEs) are generally imagined as the complete disruption of a star when it passes close to a supermassive black hole (SMBH). Relativistic apsidal precession is thought to quickly “circularize” the bound debris, forming a compact accretion disk, which then emits a flare of standardized light curve and spectrum. We show here that this picture holds in only a minority of cases. TDEs are more diverse and can be grouped into several categories distinguished by stellar pericenter distance r p ; we estimate the relative frequency of these categories. Rapid circularization is rare both because it requires ( ) and because most events with lead to direct capture. For larger pericenter distances, (for M BH = 106 M ⊙), main-sequence stars with M * ≲ 3 are completely disrupted, but the bound debris orbits are highly eccentric and possess semimajor axes ∼100× the scale of the expected compact disk. Partial disruptions with fractional mass loss ≳10% occur with a rate similar to that of total disruptions; for fractional mass loss ≳50%, the rate is ≈1/3 as large. Partial disruptions—which must precede total disruptions when the stars’ angular momenta evolve in the “empty loss-cone” regime—change the orbital energy by factors ≳O(1). Partial disruption remnants are in general far from thermal equilibrium. Depending on its orbital energy and conditions within the stellar cluster surrounding the SMBH, a remnant may return after ∼O(100)–O(1000) yr and be fully disrupted, or it may rejoin the stellar cluster.

A Novel Deconvolution Cascaded Variational Mode Decomposition for Weak Bearing Fault Detection With Unknown Signal Transmission Path

Rolling element bearing is one of the most widely used component in mechanical equipment, whose reliability requirements are also increasing. In complex working conditions, the measured signals often contain so strong noisy interferences that the weak bearing fault features are difficult to be detected. Variational mode decomposition (VMD) is a widely used method for bearing fault features extraction. However, it also encountered some problems when dealing with weak fault signals, especially the number determination of decomposition modes, the influence of strong noise and unknown transmission path. In order to solve these problems, a novel deconvolution cascaded variational mode decomposition is proposed for weak bearing fault detection in this article. Considering the influence of transmission path and strong noise, a monitored signal is enhanced by compensation transfer function and optimized resonance component to reduce the impact of noise. Firstly, to compensate the transfer function of a complex unknown transmission path, a deconvolution method with multi-point kurtosis is used, which adjusts the filter adaptively to enhance the periodic impact component in the signal. Then, to determine the decomposition modes number and furtherly remove interferences noise, a cascaded variational mode decomposition is proposed for multi-layer noise suppression. Subsequently, a standardized square envelope spectrum is employed to detect fault characteristics of the resonant mode. Experiments verified the effectiveness of the proposed method, and comparisons show that the envelope factor is increased from 1.0762 to 34.8781, which mean that the fault signal is enhanced by the proposed method.

A Characterization of Periodicity in the Voltage Time Series of a Riometer

AbstractThis paper reveals unprecedented periodicity in the voltage series of relative ionospheric opacity meters (riometers) of the Canadian Riometer Array (CRA). In quiet times, the riometer voltage series is accurately modeled by a stochastic process whose components include both a six term expansion in harmonic functions and some amplitude modulated modes of lower signal to noise ratio (SNR). In units of cycles per sidereal day (cpsd), the frequencies of the six harmonic functions lie within 0.01 cpsd of an integer. Earth's rotation induces a splitting of the low SNR components, resulting in the appearance of nine multiplets in standardized power spectrum estimates of the considered CRA voltage series. A second feature of these spectrum estimates is a 6 min periodic element appearing in both the CRA voltage series and the proton mass density series of the Advanced Composition Explorer (ACE). Spectral peak frequencies have been detected, which lie near established solar mode frequency estimates. In addition, some of these peak frequency estimates are coincident with peak frequency estimates of the standardized power spectra for the time series of proton mass density and interplanetary magnetic field strength (IMF) at ACE.

Seismic hazard assessment for mainland China based on spatially smoothed seismicity

Probabilistic seismic hazard assessment for mainland China is carried out by using spatially smoothed seismic source models obtained using the historical earthquake catalogue and two kernel smoothing techniques. The first one smooths the cumulative event count and the second one smooths the earthquake occurrence rate. For the analysis, the completeness of the catalogue is assessed and the k-mean seismic analysis results are used to aid the assignment of the regions. It is shown that the estimated parameters for the Gutenberg-Richter relation by using the maximum likelihood–based approach are consistent with those estimated by using the least-squares based approach by considering unequal observation periods. The developed seismic hazard maps indicate that the use of the smoothed source model obtained by smoothing the cumulative event count leads to spatially smeared seismic hazard. The use of the smoothed source model obtained based on smoothing the occurrence rate results in the seismic hazard map to have more spatial details. The seismic hazard assessment results indicate that, on average, the ratio of the 2475-year to 475-year return period values of PGA is about 2 and the ratio of the 2475-year to 50-year return period values of PGA is about 8. These ratios are associated with large scatters. A comparison of the normalized UHS and the Chinese design code recommended standardized design spectrum indicates that the latter is conservative as compared to the former for vibration periods outside of 0.1 to 0.2 s, and that the shape of the latter differs from that of former.

Indoor sound level spectra of public entertainment premises for rating airborne sound insulation.

Public entertainment premises are significant sources of urban noise pollution. In this paper, indoor sound level spectra for different types of entertainment premises have been analyzed. While most of the spectra lie between two standardized curves proposed by the ISO 717-1:2013 (The International Organization for Standardization) standard, spectra recorded in discotheques show a pronounced spectral level below 160 Hz as a result of an intensive use of subwoofers. This indicates potentially inappropriate rating of sound insulation against such specific low-frequency noise by standardized spectrum adaptation terms. A modified spectrum adaptation term for a single-number rating of sound insulation under such circumstances has been proposed.

Differentiation of Heart Failure Patients by the Ratio of the Scaling Exponents of Cardiac Interbeat Intervals.

Heart failure (HF) is one of the most frequent heart diseases. It is usually characterized with structural and functional cardiac abnormalities followed by dysfunction of autonomic cardiac control. Current methods of heartbeat interval analysis are not capable to differentiate HF patients and some new differentiation of HF patients could be useful in the determination of the direction of their treatment. In this study, we examined potential of the ratio of the short-term and long-term scaling exponents (α1 and α2) to separate HF patients with similar level of reduced cardiac autonomic nervous system control and with no significant difference in age, left ventricular ejection fraction (LVEF) and NYHA class. Thirty-five healthy control subjects and 46 HF patients underwent 20 min of continuous supine resting ECG recording. The interbeat interval time series were analyzed using standardized power spectrum analysis, detrended fluctuation analysis method and standard Poincaré plot (PP) analysis with measures of asymmetry of the PP. Compared with healthy control group, in HF patients linear measures of autonomic cardiac control were statistically significantly reduced (p < 0.05), heart rate asymmetry was preserved (Cup > Cdown, p < 0.01), and long-term scaling exponent α2 was significantly higher. Cluster analysis of the ratio of short- and long-term scaling exponents showed capability of this parameter to separate four clusters of HF patients. Clusters were determined by interplay of presence of short-term and long-term correlations in interbeat intervals. Complementary measure, commonly accepted ratio of the PP descriptors, SD2/SD1, showed tendency toward statistical significance to separate HF patients in obtained clusters. Also, heart rate asymmetry was preserved only in two clusters. Finally, a multiple regression analysis showed that the ratio α1/α2 could be used as an integrated measure of cardiac dynamic with complex physiological background which, besides spectral components as measures of autonomic cardiac control, also involves breathing frequency and mechanical cardiac parameter, left ventricular ejection fraction.

Study on establishment of standardized load spectrum on bogie frames of high-speed trains

Establishing a structural load spectrum under actual operating conditions is a major problem in structural fatigue life analysis. This study introduces a load measuring method for the bogie frame structure. The quasi-static load-measuring frame can measure different load systems synchronously. The t test method is employed to evaluate the least test time to deduce the parent distribution. In order to fit the load spectrum distribution accurately, the kernel density estimation method is employed, which is based on the sample characteristics. The expansion factor method is used to deduce the maximum load. The formula for a standardized load spectrum is derived from the deduced maximum load, the linear factor between operating condition length and cumulative frequency, and the parent distribution of each load system. The damage consistency criterion is performed by solving the objective function with constraint conditions. The calibrated damage provides a suitable representation of the real damage under actual operating conditions. By processing and analyzing the load and stress spectral data of the measured lines, it is verified that the standardized load spectrum established in this paper is superior to the European specification and the Japanese specification in evaluating the fatigue reliability of the structure.

Operational modal identification of structures based on improved empirical wavelet transform

This paper proposes an improved Empirical Wavelet Transform (EWT) approach for structural operational modal identification based on measured dynamic responses of structures under ambient vibrations. Two steps are involved in the improved EWT approach. In the first step, the standardized autoregressive power spectrum of the measured response is calculated to define the boundaries of frequency components for the subsequent EWT analysis. The second step is to decompose the measured response into a number of Intrinsic Mode Functions (IMFs) by using EWT. When the Intrinsic Mode Functions are obtained, structural modal information such as natural frequencies, mode shapes, and damping ratios can be identified by using Hilbert transform and Random Decrement Technique. In numerical studies, a simulated signal is used to investigate the effectiveness of the proposed approach. Operational modal identification based on the proposed approach and procedure is conducted to identify the modal parameters of a simulated spatial frame structure under the ambient excitations. The proposed approach is further used for operational modal identification of a seven-storey shear type steel frame structure in the laboratory and a real footbridge under ambient vibrations to verify the accuracy and performance. The modal identification results from both numerical simulations and experimental validations demonstrate that the proposed approach can effectively and accurately decompose the vibration responses and identify the structural modal parameters under operational conditions.

Identification of noise sources using a time domain beamforming on pneumatic, gas and electric nail guns

In the construction industry, many workers are exposed daily to harmful levels of impulsive noise from nail guns. Therefore, a better knowledge of the noise generated by these tools is required in order to propose noise reduction solutions. The objective of this work is to propose an approach for source identification using a microphone array together with a source identification algorithm based on recent development in the generalized cross-correlation technique. In addition to the pneumatic nail gun, for which sources have been partially identified in the literature, the proposed approach is applied to two other types of nail guns, an electric and a gas powered one. First, the standardized acoustic power spectrum of these three nail guns is measured for global comparison purposes and result in a ranking of the three nail guns. Second, the generalized cross-correlation technique applied to nail gun noise source identification is presented. Third, acoustic maps for successive small time segments are presented, providing a fine identification of noise sources for the three nail guns and an explanation of the observed sound power level ranking.

Porous stones increase the noise shielding of a gabion

Gabions – metal-wired cages filled up with stones – are increasingly becoming popular as decorative elements and land property boundaries. It has been shown before that such structures can be used as road traffic noise barriers as well. However, the types of stones used in gabions have not been experimentally studied so far. Exploratory measurements at full scale in a semi-anechoic room were performed to study the effect of both porous and rigid stones on their noise reducing potential. At the 1/3 octave bands below 1 kHz, low-height gabions (with depths of 20 cm and 30 cm) hardly provide any sound pressure level reduction. At higher sound frequencies, in contrast, the shielding rapidly increases. Porous lava stones were found to significantly increase the shielding compared to rigid stones. Reflections on such non-deep low-height barriers towards the source side were found to be of minor importance when considering a standardized A-weighted road traffic noise spectrum.

Role of standardized broad spectrum prophylaxis in patients with biliary drainage undergoing pancreatic surgery. A single center experience

Introduction: Biliary tree colonization by multidrug-resistant germs (MDR) frequently follows biliary stent placement and may negatively impact on overall outcome after pancreatic surgery. The role of a standardized broad spectrum antibiotic prophylaxis in this subgroup of patients is still unknown. Methods: Between July 2016 and August 2017 intraoperative bile culture was routinely performed on 56 consecutive patients undergoing either pancreaticoduodenectomy or total pancreatectomy for pancreatic malignancies. We administered a standard antibiotic prophylaxis (Amoxicillin/Clavulanic acid) for unstented patients (group A) and a broad spectrum association (Tazobactam/Piperacillin plus Fluconazole ) for those patients who had preoperatively undergone biliary drainage (group B). Perioperative data were prospectively collected and statistically analysed. Results: 20 (35.7%) patients were in group A and 36 (64.3%) in group B. Group B showed a significantly higher incidence of MDR bile colonization if compared to group A (n = 23 (63.9%) vs 1 (5%); P < 0.0001). However, broad spectrum antibiotic prophylaxis revealed to be fully appropriate in 83.3% of group A patients, based on MDR's antibiograms. No statistically differences were found between the two groups comparing median length of stay (12 vs 13 days; P = 0.843), mortality rate (0% vs 2,8%; P = 1.000), post-operative complications (80% vs 66.7%; P=0.453) and pancreatic fistula rate (35% vs 25%; P=0.628). Conclusion: Our series seems to show that preoperative broad spectrum prophylaxis based on Tazobactam/Piperacillin plus Fluconazole may prevent a negative impact on overall surgical outcome by MDR infection secondary to preoperative biliary stenting. However, further prospective trials are needed to achieve firm evidences.

The Identification of Green Tea Based on Feature Extraction

In order to identify the green tea quickly and accurately, the infrared spectra of teas measured by Fourier transform infrared spectroscopy are analyzed by using informatics method of feature extraction in this work. By comparing the different characteristic bases found by different feature genes of different tea samples, it is concluded that when green tea, yellow tea and white tea are chosen to constitute the standardized spectrum data matrix, and its first and third feature gene are selected to build characteristic basis, the green tea can be visually distinguished and the same samples have a very good aggregation. While when the characteristic basis is built by the first and second feature gene or the second and third feature gene, or the samples which are used to make up of standardized spectrum data matrix are all green tea, the recognition effect of green tea is bad. A linear arbiter of green tea is set up according to neutrality line principle on the above effectively characteristic basis, when all samples are projected onto the characteristic basis it is shown that all the green tea fall on the right of arbiter, and all not green teas are on the left of arbiter, consequently, the green tea can be identified.

Performance of Traffic Noise Barriers with Varying Cross-Section

The efficiency of noise barriers largely depends on their geometry. In this paper, the performance of noise barriers was simulated using the numerical Boundary Element Method (BEM). Traffic noise was particularly considered with its standardized noise spectrum adapted to human hearing. The cross-section of the barriers was varied with the goal of finding the optimum shape in comparison to classical rectangular barriers. The barrier performance was calculated at different receiver points for a fixed barrier height and source position. The magnitude of the insertion loss parameter was used to evaluate the performance change, both in one-third octave bands and as the broadband mean insertion loss value. The proposed barriers of varying cross-section were also compared with a typical T-shape barrier of the same height.

SU‐D‐301‐04: Development of a Simple Method for Measuring the DQE of An X‐Ray Imaging System with Unspecified Characteristic Response

Purpose: To develop a method of measuring the detective quantum efficiency (DQE) of an x‐ray imaging system with unspecified characteristic response for use in a hospital quality assurance program. Methods: Measurement of the DQE of radiographic systems in a hospital setting is made difficult by the fact that many systems have a non‐linear or unspecified characteristic response curve. This makes it difficult to determine the detector signal as a function of a number of incident x‐ray quanta as required to linearize the system response. We solve this problem with what we call a “neutral attenuator” method that uses a copper stepwedge to attenuate the beam and incorporate a theoretical correction for spectral beam hardening effects. Using a standardized spectrum (IEC 61267 RQA‐5, 7.1mm hvl), a copper stepwedge consisting of 5 steps with transmissions ranging from 0.94 to 0.01 was placed in the beam to determine the characteristic curve. The method was validated by comparing a conventional (IEC 62220‐1) DQE assessment with the DQE obtained using our method based on both raw (linear) and processed (non‐linear) image data from a General Electric Revolution Xrd Q/i detector. Results: The DQE obtained using the conventional method had a zero‐frequency value of 0.49 with an estimated uncertainty of 0.03. Our new method generated a value of 0.50 using raw image data and 0.47 using processed image data. Conclusions: A simple method has been developed to determine the DQE of an x‐ray system that can be used on both linear image data and non‐linear image data. While not IEC 62220‐1 compliant, it is simple enough to be incorporated into a hospital quality assurance program.