Simplified Measurements Research Articles

Case study of simplified reverberation time measurement under multiple conditions using a sound level meter

Recent advancements in the computational capacity of sound level meters have facilitated the simultaneous recording of diverse calculation results and waveform recording data. Traditionally, reverberation time determination entailed manually adjusting a linear regression line to the reverberation decay curve derived from recorded sound levels, followed by reverberation time computation based on the gradient of said line. However, automated techniques have made reverberation time calculation via a sound level meter feasible. This paper discusses a case study evaluating the efficacy and considerations of simplified reverberation time measurements conducted across various conditions, encompassing scenarios with multiple sound sources and diverse indoor environments. The study leveraged recorded data from a sound level meter and employed automated methods simulated on a personal computer.

Mueller matrix symmetry for both reciprocal and nonreciprocal metamaterials

Mueller matrices relate the Stokes parameters of the incident and emerging light, providing useful information about the radiative properties and other characteristics of the medium. Determining all elements of the 4 × 4 Mueller matrix requires complete polarimetry, which is often challenging to perform. Partial polarimetry, on the other hand, uses simpler optical components in generating and/or analyzing states of polarization, thereby measuring only a subset of the Mueller matrix. However, it may determine the full Mueller matrix under specific symmetry conditions. The present study develops a symmetry classification scheme to categorize the Mueller matrix of materials. It is shown that the symmetry of the Mueller matrix is directly determined from the information of symmetries of the sample's optical properties. Numerical calculations of various measurement scenarios, structures, and materials (with or without Lorentz reciprocity) are carried out to validate the methodology. This study offers an insightful understanding of Mueller matrix symmetry and practical guidance for simplified ellipsometry measurements.

On the influence of sorbents on the static stiffness of Air Springs

Air Springs are deployed in many technical areas today. In the premium segment of the automotive industry in particular, they are being used more and more frequently. The load-independent spring rate results in a better ride comfort. Since the stiffness of the Air Spring is significantly influenced by the enclosed air volume, this usually leads to a conflict of objectives between the available installation space and the stiffness optimum. To reduce the spring stiffness while maintaining the same design space, Coackley and Elliot describe in their patent the use of adsorbents such as activated carbon in the enclosed air volume of the spring. By binding air molecules to the adsorbent, more air molecules fit into the enclosed Air Spring volume, while the size and pressure of the Air Spring remain the same.This paper describes how the so-called “virtual volume” is created by adsorption and how it can be determined by simplified measurements using a gas pycnometer. Furthermore, it is shown how these measurements are related to the static stiffness of an Air Spring, so that a prediction of the static stiffness of an Air Spring filled with sorbent, in this case activated carbon, is possible by simple pycnometric measurements.

What is good? Exploring the applicability of a one item measure as a proxy for measuring acceptance in driver-vehicle interaction studies

New driver assistance systems play an important role to rise safety and comfort in todays´ traffic. Those systems should be developed with the needs of the user in mind and tested for the users´ requirements. In this, user acceptance is a central variable of interest – both in scientific and in practical applications of user-centered research on driver assistance systems. In some cases, applied research settings need simplified measurements in order to be efficiently applicable in the driving situations. In the present paper, we explored the applicability and validity of a single-item acceptance measurement (SIAM) for practical study settings covering the attitude towards using new driver assistance systems. To provide a theoretical framing, we tested the one-item measure against the widely used Technology Acceptance Model (TAM) and the van der Laan acceptance scale (VDL) in a driving simulator study. Participants experienced four different complex driving scenarios using a driver assistance system. Acceptance was measured repeatedly throughout the drive. The results supported construct validity for the SIAM, correlating with the VDL. The SIAM further predicted the intention to use the system. Being carefully aware of the psychometric drawbacks of short scales and acknowledging the importance of multi-item scales, the SIAM is promising for efficiently approaching the acceptance of driver assistance systems in applied settings.

A scalable, passive sampling method for the quantification of airborne allergens

Traditionally, airborne concentrations of aeroallergens are sampled in a single location by an active sampler, which requires electricity and regular maintenance. However, aeroallergen concentrations may vary widely over urban and rural environments, requiring a method that is cost-effective and scalable so that many measurements can be made across an air shed. We developed such a method that uses passive sampling and light microscopy for analysis. Inexpensive and easy to operate, passive samplers rely on the gravitational settling of particles onto microscope slides. This determines airborne pollen concentration through: 1) sample collection using a modified Durham sampler, 2) preparation of samples for microscopy and strategic sample imaging, and 3) simplified particle measurements and calculation of pollen concentration following deposition velocity models proposed by Scheppegrell [1] and Wagner and Leith [2]. This method was verified with two sampling campaigns during the ragweed season of 2020 and the tree pollen season of 2021. The concentrations determined with the passive and Burkard sampling methods were found to be well-correlated (r > 0.99, r = 0.87) and precise (%CV = 20 %, 21 %). The validation of passive samplers will enable measurements of aeroallergens over wider spatial scales and help determine where aeroallergen exposure risks are greatest.•An inexpensive and low-cost method was developed to determine airborne pollen counts.•The method was evaluated for its accuracy and reproducibility.•The method can be applied to examine the concentrations and spatial variability of airborne pollen.

Estimating nonlinear wind-induced response of roof cable nets by aeroelastic experiments and ML modeling

The paper examines the structural engineering challenges related to the assessment of the wind-induced vertical displacements of lightweight, hyperbolic-paraboloid cable-supported membrane roofs. Analysis and comparisons are conducted using three distinct methods for calculating the roof vertical, out-of-plane displacements. Finite element method (FEM) analysis is employed using: (i) estimated static nodal forces obtained from wind pressure coefficients determined by aerodynamic wind tunnel tests on a rigid building model, and (ii) loads found from wind pressure coefficients, estimated through machine learning (ML) methods, and (iii) measured roof response found from aeroelastic wind tunnel tests on a flexible model. The study examines three different roof geometries (square, rectangular and circular) and two distinct membrane curvatures for each geometry. Furthermore, wind directionality (three mean-wind incidence angles) and Reynolds number effects (seven mean wind velocities) are studied. Comparisons show that the non-linear FEM analysis, based on estimated static wind loads, underestimates the roof displacements at the roof center, compared to the direct measurements on the aeroelastic model. The main contribution of the study consists of a novel application of ML models, and Artificial Neural Networks (ANNs) in particular, which are employed to correct roof displacement estimations, found by simplified aerodynamic test pressure measurements on rigid roof models. The goal is to better describe the complex fluid-structure interaction of the roof membranes, which can only be achieved by direct aeroelastic tests that are difficult to design and execute. Finally, the study demonstrates that ANNs can be used not only for the preliminary design of the full-scale structure but also for construction of wind tunnel scale models.

Influence of short-lived radioiodines other than 131I on screening direct thyroid measurements with TCS-172 NAI(TL) survey meters.

In a nuclear emergency, one of the actions taken for the sake of public is to monitor thyroid exposure to radioiodines. Japan's Nuclear Regulation Authority recently published a report on such monitoring and proposed direct thyroid measurements with conventional NaI(Tl) survey meters (e.g. Hitachi model TCS-172) as a primary screening method. A previous study proposed screening levels (SLs) used in these simplified measurements as the net reading values of the TCS-172 device. Age-specific SLs were derived from a thyroid equivalent dose of 100mSv due to the inhalation intake of 131I. This study addressed the possible influence of short-lived iodine isotopes other than 131I on the simplified measurements. In preparation for such measurements, the responses of the device for 132I as an ingrowth component from 132Te, 133I, 134I and 135I in the thyroid were evaluated by numerical simulations using age-specific stylized phantoms in addition to those obtained for 131I in the previous study. The radioactivity ratios of the relevant isotopes were taken from the inventory data of the Fukushima Daiichi Nuclear Power Plant. The results were used to predict the net readings of the device when 132Te-132I and 133I as well as 131I were inhaled at 24 or 72h after the shutdown of a nuclear power plant. In these cases, the signals from 132Te-132I and 133I become undetectable a couple of days after intake, which could lead to underestimations of the thyroid dose. To estimate the thyroid dose accurately from the simplified measurements, it is necessary to identify the exact time of intake after the shutdown and the actual physiochemical property of 132Te that affects the thyroid uptake of 132I.

Dynamic Young's modulus measurement by incident wave extracting for viscoelastic materials under variable water pressure

This study presents a method for measuring the complex Young's modulus of viscoelastic materials under several water pressures. A Butterworth impulse is generated by an electromagnetic shaker and is employed to excite a bar-like sample which was attached inside the pressure vessel. The broadband mechanical parameters (including the storage modulus and loss factor) under variable water pressure conditions (0.1-5MPa) for two types of viscoelastic materials were obtained by incident wave extracting. The experimental results agree well with those obtained using a standard dynamic mechanical thermal analyzer and those obtained using resonant method, which proved that the method proposed in this study can directly determine the Young's modulus at frequencies ranging from 500 to 5000Hz under variable water pressure. This method provides simplified processing for underwater dynamic mechanical parameters measurements.

Screening levels of TCS-172 NaI(Tl) survey meters used for direct thyroid measurements in nuclear disasters.

It is a challenging task to establish a feasible and robust method for the population monitoring of individuals' thyroid exposure following an accidental intake of radioiodines in a nuclear emergency, because of the time restriction. The authors previously proposed a method for such monitoring to obtain as many reliable human data as possible and one of the components is simplified measurements by conventional NaI(Tl) survey meters that are intended to be used for the initial triage to identify significantly exposed individuals and get an overall picture of the exposure levels in a target population in a timely manner. This study determined screening levels (SLs) for a conventional NaI(Tl) survey meter (model TCS-172, Hitachi, Japan) using the conversion factor (131I kBq in the thyroid per μSv h-1) that were obtained from experiments and simulations with age-specific phantoms. The results demonstrated that the derived SLs for 100mSv thyroid equivalent dose were as follows: 0.2μSvh-1 (SL1) for the age group≤5-y-olds, 0.5μSvh-1 (SL2) for the 10- and 15-y-old age groups and 1.0μSvh-1 (SL3) for adults. These SLs would be reasonably available within 1week after the intake of 131I on the safe side.

Deep-learning method for fully automatic segmentation of the abdominal aortic aneurysm from computed tomography imaging.

Abdominal aortic aneurysm (AAA) is one of the leading causes of death worldwide. AAAs often remain asymptomatic until they are either close to rupturing or they cause pressure to the spine and/or other organs. Fast progression has been linked to future clinical outcomes. Therefore, a reliable and efficient system to quantify geometric properties and growth will enable better clinical prognoses for aneurysms. Different imaging systems can be used to locate and characterize an aneurysm; computed tomography (CT) is the modality of choice in many clinical centers to monitor later stages of the disease and plan surgical treatment. The lack of accurate and automated techniques to segment the outer wall and lumen of the aneurysm results in either simplified measurements that focus on few salient features or time-consuming segmentation affected by high inter- and intra-operator variability. To overcome these limitations, we propose a model for segmenting AAA tissues automatically by using a trained deep learning-based approach. The model is composed of three different steps starting with the extraction of the aorta and iliac arteries followed by the detection of the lumen and other AAA tissues. The results of the automated segmentation demonstrate very good agreement when compared to manual segmentation performed by an expert.

Study on Sound Velocity and Attenuation of Underwater Cobalt-Rich Crust Based on Biot and BISQ Theories

A prediction model of the sound velocity and sound attenuation of underwater cobalt-rich crusts (CRCs) was established to solve the problem that it is difficult to predict the sound velocity in thickness measurements of cobalt-rich crusts. Based on Biot theory and BISQ theory, a simplified Biot and BISQ model was proposed for the prediction of the sound velocity and sound attenuation of CRCs by using the Kozeny–Carman (KC) equation. The models could calculate the sound velocity and attenuation by the porosity and detection frequency. Based on the physical and mechanical properties of CRCs, a similarity model of the sound velocity and sound attenuation of CRCs was made by using the similarity theory to solve the problem that it is difficult to measure the acoustic propagation characteristics of CRCs. The sound velocity and sound attenuation of CRC similarity models with different porosities were measured by an underwater transmission experiment and the results of the simplified model calculation and experimental measurements were compared. The results showed that the simplified Biot model was suitable for the CRC sound velocity prediction and the simplified BISQ model was suitable for the CRC sound attenuation prediction, which had a high prediction accuracy.

Evaluation of cost-effective measures for the renovation of existing dwellings in the framework of the energy certification system: A case study in Norway

The Energy Performance Certificate (EPC) for existing dwellings has not been able to promote the renovation rate. The main reasons are associated with the low quality of the assessment and renovation recommendations provided. These are not able to provide the information or confidence needed to undertake a renovation project. So far, neither reports for the EPBD nor studies by researchers have proposed modifications to the model used to assess existing buildings under the EPBD. The present research proposes a procedure to evaluate, design improvements, store and share data on the renovation process of each building. Specifically, the procedure is based on three steps, the first one is to apply simplified measurements on the dwelling, laser scanning and envelope testing. The second stage, using the electricity consumption data, was to calibrate and calculate the thermal properties of the building. Finally, tailor-made recommendations for the whole life cycle of the house are proposed and stored in a database. After an optimisation and life cycle analysis of different measurement packages. The results show that by incorporating currently available tools, such as scanners, smart meters and BIM, a complete building condition profile can be obtained, stored and shared, and renovation measures with their benefits and costs can be realistically proposed. This study is in line with what has been proposed by previous studies, the need to digitise the certification system, to use new technologies and to capture the trust of the users.

Effective population monitoring for determination of the thyroidal radioiodine content of the public following a nuclear accident in Japan

After a nuclear accident, population monitoring is necessary to determine the radiation exposure levels of the affected population. One of the monitoring components is direct thyroid measurements to assess the internal thyroid dose (mainly from 131I with a relatively short physical half-life: 8.02 days). These measurements are particularly important for young children but were not adequately performed after the 2011 Fukushima Daiichi Nuclear Power Plant (FDNPP) accident. Herein we propose a feasible and robust method to obtain as much reliable human data as possible for the dose reconstructions following a nuclear accident. The method employs three types of measurements: simplified, additional, and detailed measurements. The simplified measurements are performed using conventional NaI(Tl) survey meters to quickly triage heavily exposed individuals. The additional measurements are conducted using mobile whole-body counters to detect cesium (Cs; with longer retention in the body) as a tracer of 131I. And the detailed measurements are taken using spectrometric devices; they provide the most reliable data and are used to confirm the other measurements. We also discussed the target subjects and the monitoring period based on the experiences gained following the FDNPP accident. The early post-nuclear-accident phase is the most important period for the dose reconstruction for the affected populations; however, it is also the most challenging period in terms of allocating the necessary monitoring resources. It is thus vital that all countries that operate nuclear power plants establish and maintain a system for nuclear emergency preparedness and response.

Home Sleep Testing of Sleep Apnea.

Measurement methods with graded complexity for use in the lab as well as for home sleep testing (HST) are available for the diagnosis of sleep apnea, and there are different classification systems in existence. Simplified HST measurements, which record fewer parameters than traditional four- to six-channel devices, can indicate sleep apnea and can be used as screening tool in high-prevalence patient groups. Peripheral arterial tonometry (PAT) is a technique which can be suitable for the diagnosis of sleep apnea in certain cases. Different measurement methods are used, which has an influence on the significance of the results. New minimal-contact and non-contact technologies of recording and analysis of surrogate parameters are under development. If they are validated by clinical studies, it will be possible to detect sleep apnea in need of treatment more effectively. In addition, this could become a solution to monitor the effectiveness of such treatment.

Fuzzy Logic based Vegetable Price prediction in IoT

Agriculture is an integral part of every economy with research in this domain mainly aimed at not only increasing food quality and production but also reducing expenditure while maximizing profit. Climate is a major factor that affects production of vegetables and other crops there by having direct impact on pricing. Among the main challenges faced by farmers is accurate prediction of vegetable prices. Farmers therefore need to acquire a better and advanced knowledgeable model to assist them in taking proper decisions when budgeting on how much to spend on planting so that it's proportional to the expected prices of the produce, in prediction of the climatic change effects on vegetable prices, a call for variables and parameters that show the response of vegetable prices, production, consumption and storage with weather conditions is necessary. The most common approach is using the statistical models that are trained using historical yield data with simplified weather measurements, for example average temperature in the growing season, humidly and rainfall. However, such approaches do not take into consideration the weather effects on entire vegetable lifecycle inclusive of the prices for yields necessitating the need for this study. This paper presents a study on Fuzzy based vegetable price prediction considering various changes in climatic parameters including humidity, rainfall and temperature. This system model was developed based on a 4- year vegetable price data and climatic data of the same period for Kisumu (Kenya). The results show that this model can indeed be used by farmers to predict prices and hence assist them to make informed vegetable farming and investment decisions.

Practical and simplified measurements for representative photovoltaic array temperatures robust to climate variations

A precise and practical power generation forecasting method for outdoor photovoltaic (PV) arrays and its performance evaluation are essential for advancements in solar power generation. Specifically, accurate temperature measurements of each of the PV modules in an array, the entire outdoor PV array, and the power generation system are crucial regardless of climatic and irradiance conditions. However, outdoor PV temperatures are often affected by environmental factors, such as wind direction, wind speed, solar irradiance, and outdoor air temperature fluctuations. Hence, the temperature data vary greatly depending on the measurement point of the module, which is affected by the above environmental factors. The variations of and uncertainties in temperature often extend over long arrays of PV modules common to large-scale PV systems. Therefore, it is necessary to establish a straightforward and reproducible inspection method to determine a single and robust representative PV module temperature for an array. In this study, we have established one such inspection method for outdoor PV arrays. It was observed that the temperature at the center of the array was closest to the average temperature regardless of the measurement period and climatic conditions; thus, it can be considered as the unbiased and robust representative temperature for the PV array. Moreover, lower irradiance conditions are better for accurate and repeatable PV module temperature measurements. The mean temperature differences of the PV array from its average measured at the center of the array were 0.2 °C for low irradiance and 0.5 °C for high irradiance. The temperature difference observed will have 0.1% to 0.2% impact on the power estimation for monitoring purposes.

Energetic refurbishment of the historic windows of the listed heritage building Alte Schäfflerei and its influence on the overall energy balance

This study examines compatibility of monument conservation and modernization of historic windows of old buildings on the example of the Alte Schäfflerei (Old Cooperage) housing the Fraunhofer Centre for Conservation and Energy Performance of Historic Buildings at Benediktbeuern monastery. Several historic windows are extended to box-type windows and examined in detail. The calculation of the thermal bridges and the resulting U-values of the windows as well as the linear thermal bridge heat loss coefficients result in a reliable estimation of the thermal behaviour of the box-type windows. Via measurements of the surface temperature and heat fluxes on a box-type window the thermal resistance and heat transfer coefficient are estimated. The heat transfer coefficient is calculated in accordance to DIN 10077 with simple and detailed calculation and compared to the estimated calculation of simplified measurements. The energy efficiency of the whole building of the Old Cooperage is calculated in accordance to DIN V 18599 and shows the rate of heat losses of the windows compared to the overall energy demand of the building. For this purpose, the Old Cooperage is implemented with a hypothetical historic usage in DIN V 18599.

Experimental and Numerical Analysis of Sunroof Buffeting of a Simplified Mercedes-Benz S-Class

<div class="section abstract"><div class="htmlview paragraph">Sunroof buffeting is examined experimentally and numerically in this paper. Despite the fact that some consider the simulation process for sunroof buffeting to be mature, there remain substantial uncertainties even in recently published methodologies. Capturing the frequencies and especially the sound pressure levels correctly is essential if CFD simulations are intended to be used during early stages of a car development process. Numerous experimental results of sunroof buffeting and the interior low-frequency characteristics of a 2013 Mercedes-Benz S-Class have been used to develop a simplified car model: a full-size S-Class model with slightly simplified geometries in the interior as well as at the exterior. To avoid the effects of numerous different materials in the interior, it is solely made from polyurethane and aluminum and built to maximize its structural rigidity and air-tightness. The air-tightness of the cabin and structural modes of body parts have the greatest impact on the Helmholtz frequencies, which are excited by the vortex shedding in the sunroof opening.</div><div class="htmlview paragraph">With this simplified car model various measurements are carried out to validate the numerical simulation method. The measurement data consists of acoustic data as well as flow quantities. In this paper, Star-CCM+ is used to conduct improved delayed detached eddy simulations with direct noise calculation in order to predict the buffeting frequencies that occur at different wind speeds correctly. Due to the rigid and acoustically hard walls of the simplified car model, which fairly match the numerical boundary conditions, it is possible to predict the interior sound pressure levels correctly as well.</div><div class="htmlview paragraph">The presented results demonstrate that state-of-the-art CFD codes are capable of predicting sunroof buffeting frequencies and noise levels correctly if the experimental and numerical boundary conditions match.</div></div>

Lubrication state identification of the line contact tribo-pair under a pure rolling condition with ultrasonic method

A line contact tribo-pair is a key mechanism unit in rolling bearings, which is often characterized by ultra-high contact pressure and ultra-thin oil film. Elastohydrodynamic lubrication is often adopted to characterize the lubrication state of such a tribo-pair. As a primary parameter for elastohydrodynamic lubrication, the oil film thickness is often evaluated with simplified theoretical models or complicated measurements. So far, a comprehensive verification of the lubrication states in a real line-contact tribo-pair, however, is rarely reported. Focusing on the roller/ring tribo-pair of a wet-lubricated rolling bearing under pure rolling conditions, this study investigates the lubrication states by integrating multiple theories. Five regions including isoviscous hydrodynamic, piezoviscous hydrodynamic, elastohydrodynamic lubrication, mixture lubrication, and boundary lubrication regions can be identified using the framework. Then, validation experiments are carried out on a line contact tribo-pair test rig under the same operating conditions applied in the theoretical analysis. The oil film thickness is measured by the ultrasonic method. The analysis results demonstrate that only two regions, the elastohydrodynamic lubrication and mixture lubrication regions, can be identified using the experimental data. The identified elastohydrodynamic lubrication and mixture lubrication regions are consistent with theoretical analysis; and the Blok equation and elastohydrodynamic lubrication theory are suggested to calculate the oil film thickness in the elastohydrodynamic lubrication and mixture lubrication regions, respectively. Moreover, the oil film thickness calculated by the Dowson equation is larger than that based on the elastohydrodynamic lubrication theory due to a different viscous pressure equation.

Cost Effective and Sustainable Test Methods to Investigate Vulnerabilities of EMP Attack on Existing Buildings Using Public Frequency Devices

High-power electromagnetic pulses are electromagnetic shock waves with strong energy, which can cause the destruction or malfunction of both electrical and electronic systems. The measurement of the electromagnetic wave shielding performance of buildings is effective for determining the level of EMP protection for each facility. However, it is extremely inefficient to practically measure the electromagnetic wave shielding performance using methods based on various standards for general buildings, in term of testing cost and time. Therefore, cost effective and sustainable test methods to investigate vulnerabilities of electromagnetic pulses attack on existing buildings using public frequency is proposed in this study. The study focuses on a simpler and more reliable method such as the use of broadcast or communication signals. From the results, it was concluded that the shielding performance can be measured approximately −45 dB using broadcast devices, −70 dB using walkie-talkie as simplified measurements of the electromagnetic-wave shielding performance. Therefore, if the test methods which are proposed in this study are allowed for preliminary investigation to find the vulnerabilities of existing buildings, cost and energy in the investigation can be reduced and it is expected to bring out frequency inspection and sustainable EMP protection performance of buildings.