Research

19 pages, 3824 KiB

Open AccessArticle

Enhancing Urban Data Analysis: Leveraging Graph-Based Convolutional Neural Networks for a Visual Semantic Decision Support System

by Nikolaos Sideris, Georgios Bardis, Athanasios Voulodimos, Georgios Miaoulis and Djamchid Ghazanfarpour

Sensors 2024, 24(4), 1335; https://doi.org/10.3390/s24041335 - 19 Feb 2024

Viewed by 580

Abstract

The persistent increase in the magnitude of urban data, combined with the broad range of sensors from which it derives in modern urban environments, poses issues including data integration, visualization, and optimal utilization. The successful selection of suitable locations for predetermined commercial activities [...] Read more.

The persistent increase in the magnitude of urban data, combined with the broad range of sensors from which it derives in modern urban environments, poses issues including data integration, visualization, and optimal utilization. The successful selection of suitable locations for predetermined commercial activities and public utility services or the reuse of existing infrastructure arise as urban planning challenges to be addressed with the aid of the aforementioned data. In our previous work, we have integrated a multitude of publicly available real-world urban data in a visual semantic decision support environment, encompassing map-based data visualization with a visual query interface, while employing and comparing several classifiers for the selection of appropriate locations for establishing parking facilities. In the current work, we challenge the best representative of the previous approach, i.e., random forests, with convolutional neural networks (CNNs) in combination with a graph-based representation of the urban input data, relying on the same dataset to ensure comparability of the results. This approach has been inspired by the inherent visual nature of urban data and the increased capability of CNNs to classify image-based data. The experimental results reveal an improvement in several performance indices, implying a promising potential for this specific combination in decision support for urban planning problems. Full article

(This article belongs to the Special Issue Sensors and New Trends in Global Metrology)

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13 pages, 3559 KiB

Open AccessCommunication

Time Constant as the Main Component to Optimize the Resistance Temperature Sensors’ Calibration Process

by Maciej Klebba, Arkadiusz Frącz, Michal Brodzicki, Adrianna Rzepkowska and Mariusz Wąż

Sensors 2024, 24(2), 487; https://doi.org/10.3390/s24020487 - 12 Jan 2024

Viewed by 548

Abstract

Temperature sensor calibration in the majority of measurement laboratories is performed on the ground of measurement procedures. The procedures specify the timespan for the temperature of the tested sensor to stabilize. In practice, the fact of time constant increase above expectations can be [...] Read more.

Temperature sensor calibration in the majority of measurement laboratories is performed on the ground of measurement procedures. The procedures specify the timespan for the temperature of the tested sensor to stabilize. In practice, the fact of time constant increase above expectations can be observed. This results from the method of operation, time of use, and level of contamination of individual sensors. The paper proposes a method to optimize the calibration process of resistance temperature sensors based on the measurement of the time constant and, on this basis, to determine the sensor stabilization time during calibration. Full article

(This article belongs to the Special Issue Sensors and New Trends in Global Metrology)

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16 pages, 6149 KiB

Open AccessArticle

Optimization of an Inductive Displacement Transducer

by Bogdan Mociran and Marian Gliga

Sensors 2023, 23(19), 8152; https://doi.org/10.3390/s23198152 - 28 Sep 2023

Viewed by 875

Abstract

This paper presents the optimization of an inductive displacement transducer or linear variable differential transformer (LVDT). The method integrates design software (SolidWorks 2023), simulation tools (COMSOL Multiphysics), and MATLAB. The optimization phase utilizes the non-dominated sorting genetic algorithm (NSGA)-II and -III to fine-tune [...] Read more.

This paper presents the optimization of an inductive displacement transducer or linear variable differential transformer (LVDT). The method integrates design software (SolidWorks 2023), simulation tools (COMSOL Multiphysics), and MATLAB. The optimization phase utilizes the non-dominated sorting genetic algorithm (NSGA)-II and -III to fine-tune the geometry configuration by adjusting six inner parameters corresponding to the dimension of the interior components of the LVDT, thus aiming to improve the overall performance of the device. The outcomes of this study reveal a significant achievement in LVDT enhancement. By employing the proposed methodology, the operational range of the LVDT was effectively doubled, extending it from its initial 8 (mm) to 16 (mm). This expansion in the operational range was achieved without compromising measurement accuracy, as all error values for the working range of 0–16 (mm) (NSGA-II with a maximum final relative error of 2.22% and NSGA-III with 2.44%) remained below the imposed 3% limit. This research introduces a new concept in LVDT optimization, capitalizing on the combined power of NSGA-II and NSGA-III algorithms. The integration of these advanced algorithms, along with the interconnection between design, simulation, and programming tools, distinguishes this work from conventional approaches. This study fulfilled its initial objectives and generated quantifiable results. It introduced novel internal configurations that substantially improved the LVDT’s performance. These achievements underscore the validity and potential of the proposed methodology in advancing LVDT technology, with promising implications for a wide range of engineering applications. Full article

(This article belongs to the Special Issue Sensors and New Trends in Global Metrology)

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28 pages, 7857 KiB

Open AccessArticle

Experimental Determination Influence of Flow Disturbances behind the Knife Gate Valve on the Indications of the Ultrasonic Flow Meter with Clamp-On Sensors on Pipelines

by Piotr Piechota, Piotr Synowiec, Artur Andruszkiewicz, Wiesław Wędrychowicz, Elżbieta Wróblewska and Andrzej Mrowiec

Sensors 2023, 23(10), 4677; https://doi.org/10.3390/s23104677 - 11 May 2023

Cited by 1 | Viewed by 1487

Abstract

The aim of this work is to experimentally determine and evaluate the value of the correction factor for ultrasonic flow meters in order to improve their accuracy. This article concerns flow velocity measurement with the use of an ultrasonic flow meter in the [...] Read more.

The aim of this work is to experimentally determine and evaluate the value of the correction factor for ultrasonic flow meters in order to improve their accuracy. This article concerns flow velocity measurement with the use of an ultrasonic flow meter in the area of disturbed flow behind the distorting element. Clamp-on ultrasonic flow meters are popular among measurement technologies due to their high accuracy and easy, non-invasive installation, because the sensors are mounted directly on the outer surface of the pipe. In industrial applications, installation space is usually limited and, therefore, flow meters frequently have to be mounted directly behind flow disturbances. In such cases, it is necessary to determine the value of the correction factor. The disturbing element was a knife gate valve, a valve often used in flow installations. Water flow velocity tests were performed using an ultrasonic flow meter with clamp-on sensors on the pipeline. The research was performed in 2 series of measurements with different Reynolds numbers of 35,000 and 70,000, which correspond to a velocity of approximately 0.9 m/s and 1.8 m/s. The tests were carried out at different distances from the source of interference, within the range of 3–15 DN (pipe nominal diameter). The position of the sensors at successive measurement points on the circuit of the pipeline was changed by 30 degrees. Flow velocity measurements were carried out for two different levels of the valve’s closure: 1/3 and 1/2 of the valve’s height. For the collected velocity values at single measurement points, the values of the correction coefficient, K, were determined. The results of the tests and calculations prove that compensation error of measurement performed behind the disturbance without keeping the required straight sections of the pipeline is possible by using the factor K*. The analysis of the results made it possible to identify the optimal measuring point at a distance from the knife gate valve as being smaller than specified in the standards and recommendations. Full article

(This article belongs to the Special Issue Sensors and New Trends in Global Metrology)

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12 pages, 3876 KiB

Open AccessArticle

Development of a Real-Time Pixel Array-Type Detector for Ultrahigh Dose-Rate Beams

by Young Jae Jang, Tae Keun Yang, Jeong Hwan Kim, Hong Suk Jang, Jong Hwi Jeong, Kum Bae Kim, Geun-Beom Kim, Seong Hee Park and Sang Hyoun Choi

Sensors 2023, 23(10), 4596; https://doi.org/10.3390/s23104596 - 09 May 2023

Viewed by 1309

Abstract

Although research into ultrahigh dose-rate (UHDR) radiation therapy is ongoing, there is a significant lack of experimental measurements for two-dimensional (2D) dose-rate distributions. Additionally, conventional pixel-type detectors result in significant beam loss. In this study, we developed a pixel array-type detector with adjustable [...] Read more.

Although research into ultrahigh dose-rate (UHDR) radiation therapy is ongoing, there is a significant lack of experimental measurements for two-dimensional (2D) dose-rate distributions. Additionally, conventional pixel-type detectors result in significant beam loss. In this study, we developed a pixel array-type detector with adjustable gaps and a data acquisition system to evaluate its effectiveness in measuring UHDR proton beams in real time. We measured a UHDR beam at the Korea Institute of Radiological and Medical Sciences using an MC-50 cyclotron, which produced a 45-MeV energy beam with a current range of 10–70 nA, to confirm the UHDR beam conditions. To minimize beam loss during measurement, we adjusted the gap and high voltage on the detector and determined the collection efficiency of the developed detector through Monte Carlo simulation and experimental measurements of the 2D dose-rate distribution. We also verified the accuracy of the real-time position measurement using the developed detector with a 226.29-MeV PBS beam at the National Cancer Center of the Republic of Korea. Our results indicate that, for a current of 70 nA with an energy beam of 45 MeV generated using the MC-50 cyclotron, the dose rate exceeded 300 Gy/s at the center of the beam, indicating UHDR conditions. Simulation and experimental measurements show that fixing the gap at 2 mm and the high voltage at 1000 V resulted in a less than 1% loss of collection efficiency when measuring UHDR beams. Furthermore, we achieved real-time measurements of the beam position with an accuracy of within 2% at five reference points. In conclusion, our study developed a beam monitoring system that can measure UHDR proton beams and confirmed the accuracy of the beam position and profile through real-time data transmission. Full article

(This article belongs to the Special Issue Sensors and New Trends in Global Metrology)

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19 pages, 2572 KiB

Open AccessArticle

Application of Multi-Criteria Optimization Methods in the Calibration Process of Digital Measuring Instruments

by Maciej Klebba, Arkadiusz Adamczyk, Mariusz Wąż and Dominik Iwen

Sensors 2023, 23(6), 2984; https://doi.org/10.3390/s23062984 - 09 Mar 2023

Viewed by 1308

Abstract

The article describes the use of multi-criteria optimization methods during the calibration of digital multimeters. Currently, calibration is based on a single measurement of a specific value. The aim of this research was to confirm the possibility of using a series of measurements [...] Read more.

The article describes the use of multi-criteria optimization methods during the calibration of digital multimeters. Currently, calibration is based on a single measurement of a specific value. The aim of this research was to confirm the possibility of using a series of measurements in order to reduce the measurement uncertainty without significantly extending the calibration time. The automatic measurement loading laboratory stand used during the conducted experiments was essential to obtain results that allowed confirming the thesis. This article presents the applied optimization methods and the results of the calibration of sample digital multimeters obtained thanks to them. As a result of the research, it was found that the use of a series of measurements increased the accuracy of the calibration, reduced the measurement uncertainty, and shortened the calibration time compared to traditional methods. Full article

(This article belongs to the Special Issue Sensors and New Trends in Global Metrology)

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16 pages, 6710 KiB

Open AccessArticle

Preparation of Discontinuous Cu/SiO₂ Multilayers—AC Conduction and Determining the Measurement Uncertainty

by Aleksandra Wilczyńska, Andrzej Kociubiński and Tomasz N. Kołtunowicz

Sensors 2023, 23(5), 2842; https://doi.org/10.3390/s23052842 - 06 Mar 2023

Cited by 2 | Viewed by 1402

Abstract

This paper presents a test stand for testing alternating current electrical parameters of Cu–SiO₂ multilayer nanocomposite structures obtained by the dual-source non-reactive magnetron sputtering method (resistance, capacitance, phase shift angle, and dielectric loss angle tangent δ). In order to confirm the dielectric [...] Read more.

This paper presents a test stand for testing alternating current electrical parameters of Cu–SiO₂ multilayer nanocomposite structures obtained by the dual-source non-reactive magnetron sputtering method (resistance, capacitance, phase shift angle, and dielectric loss angle tangent δ). In order to confirm the dielectric nature of the test structure, measurements in the temperature range from room temperature to 373 K were carried out. The alternating current frequencies in which the measurements were made ranged from 4 Hz to 7.92 MHz. To improve the implementation of measurement processes, a program was written to control the impedance meter in the MATLAB environment. Structural studies by SEM were conducted to determine the effect of annealing on multilayer nanocomposite structures. Based on the static analysis of the 4-point method of measurements, the standard uncertainty of type A was determined, and taking into account the manufacturer’s recommendations regarding the technical specification, the measurement uncertainty of type B. Full article

(This article belongs to the Special Issue Sensors and New Trends in Global Metrology)

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19 pages, 20589 KiB

Open AccessArticle

Design and Shape Optimization of Strain Gauge Load Cell for Axial Force Measurement for Test Benches

by Omar Sabah Al-Dahiree, Mohammad Osman Tokhi, Nabil Hassan Hadi, Nassar Rasheid Hmoad, Raja Ariffin Raja Ghazilla, Hwa Jen Yap and Emad Abdullah Albaadani

Sensors 2022, 22(19), 7508; https://doi.org/10.3390/s22197508 - 03 Oct 2022

Cited by 1 | Viewed by 6190

Abstract

The load cell is an indispensable component of many engineering machinery and industrial automation for measuring and sensing force and torque. This paper describes the design and analysis of the strain gauge load cell, from the conceptional design stage to shape optimization (based [...] Read more.

The load cell is an indispensable component of many engineering machinery and industrial automation for measuring and sensing force and torque. This paper describes the design and analysis of the strain gauge load cell, from the conceptional design stage to shape optimization (based on the finite element method (FEM) technique) and calibration, providing ample load capacity with low-cost material (aluminum 6061) and highly accurate force measurement. The amplifier circuit of the half Wheatstone bridge configuration with two strain gauges was implemented experimentally with an actual load cell prototype. The calibration test was conducted to evaluate the load cell characteristics and derive the governing equation for sensing the unknown load depending on the measured output voltage. The measured sensitivity of the load cell is approximately 15 mV/N and 446.8 µV/V at a maximum applied load of 30 kg. The findings are supported by FEM results and experiments with an acceptable percentage of errors, which revealed an overall error of 6% in the worst situation. Therefore, the proposed load cell meets the design considerations for axial force measurement for the laboratory test bench, which has a light weight of 20 g and a maximum axial force capacity of 300 N with good sensor characteristics. Full article

(This article belongs to the Special Issue Sensors and New Trends in Global Metrology)

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