Dynamic Measurement Capabilities Research Articles

DMSCTS: Dynamic measurement scheme for the containers-hybrid-deployment based on trusted subsystem

Hybrid deployment of containers with different kernel types offers a novel solution for cloud service providers. While extensive research has been conducted on shared kernel containers, the security risks associated with diverse kernel types in hybrid deployment scenarios present more complex challenges. Establishing trusted relationships from hardware to containers for hybrid deployment has become a primary concern. Additional challenges include the lack of measurement and communication methods for independent kernel containers and insufficient dynamic measurement capabilities for containers. To address these issues, we propose a novel approach of achieving secure hybrid deployment of containers through the provision of trusted assurance in three layers: container infrastructure, container application environment, and container runtime. We propose the corresponding measurement schemes for each trust layer. Through functional verification and performance evaluation, we demonstrate that our architecture exhibits improved feasibility and effectiveness.

Dynamic phase measurement based on two-step phase-shifting interferometry with geometric phase grating

Abstract This paper proposes a novel dynamic 2-step phase-shifting interferometry method with a geometric phase grating and direct aberration-free object phase recovery algorithm. By exploring the amplitude-phase modulation property of the geometric phase grating, two-step phase-shifting interferograms with π / 2 phase shift can be obtained in a single shot through two kinds of spatial-multiplexing arrangements. Then the restriction on the background uniformity of the 2-step phase-shifting algorithms and the system aberration can be avoided simultaneously, based on the presented direct and fast object phase demodulation strategy with an object-free state recorded in advance, so an accurate object measurement result can be guaranteed. Accordingly, a detailed analysis of the theoretical model of error sources is conducted by taking the depolarization error of geometric phase grating and phase measurement model error into consideration, with a Least Squares Iteration optimization strategy established to further improve the measurement accuracy. Experiments on various types of phase objects, such as a photo-etched quartz substrate, the spatial light modulator, and a silicon chip, validate the effectiveness and accuracy of our method when compared with the reference phase obtained from 4-step temporal phase-shifting method. The dynamic phase measurement capability is demonstrated by exhibiting the evaporation process of alcohol droplet.

Dynamic distributed Brillouin sensing based on pump frequency-agile quadrupling modulation

We propose a dynamic distributed Brillouin sensing based on a frequency-agile quadrupling method. A common low-bandwidth direct digital frequency synthesizer (DDS) is employed to generate a few hundred MHz of frequency-agile pump pulses for Brillouin gain spectrum (BGS) scanning, and polarization multiplexing technology is utilized to further decrease the bandwidth requirement for the frequency-agile microwave signal to one-quarter. This method has low requirements for electronic devices and significantly reduces costs in systems. Static and dynamic measurement capabilities of 2 km fiber were demonstrated experimentally, the vibration frequencies of 183 Hz were measured with a sampling rate of 400 Sa/s.

Pulsed-Mode Magnetic Field Measurements with a Single Stretched Wire System.

In synchrotrons, accurate knowledge of the magnetic field generated by bending dipole magnets is essential to ensure beam stability. Measurement campaigns are necessary to characterize the field. The choice of the measurement method for such campaigns is determined by the combination of magnet dimensions and operating conditions and typically require a trade-off between accuracy and versatility. The single stretched wire (SSW) is a well-known, polyvalent method to measure the integral field of magnets having a wide range of geometries. It, however, requires steady-state excitation. This work presents a novel implementation of this method called pulsed SSW, which allows the system to measure rapidly time-varying magnetic fields, as is often needed, to save power or gain beam time. We first introduce the measurement principle of the pulsed SSW, followed by a combined strategy to calculate the absolute magnetic field by incorporating the classic DC SSW method. Using a bending magnet from the Proton Synchrotron Booster located at the European Organization for Nuclear Research as a case study, we validate the pulsed SSW method and compare its dynamic measurement capabilities to a fixed induction coil, showing thereby how the coil calibration must be adjusted according to the field level. Finally, we assess the method's measurement accuracy using the standard SSW as a reference and present an analysis of the primary noise contributors.

Composite structures with embedded fiber optic sensors: A smart propellant tank for future spacecraft applications

Modern spacecraft and launch vehicle design is more oriented towards reducing system-level design and assembly complexities. In order to maintain high overall system performance while reducing these complexities, the use of smart materials and smart structural components is a well-known practice and is currently of rising interest to space systems' designers. The paper discusses a concept of smart space structures, in particular, a carbon fiber composites structure embedded with Optical Fiber Sensors (OFS) for spacecraft and launch vehicle applications. This study highlights the operational requirements for such tank and the smart features enabled by the optical fiber sensors. For the latter aspect, a quantitative comparison between Fiber Bragg Grating sensors (FBGs) and Distributed Optical Fiber Sensors (DOFS) based on Optical Frequency Domain Reflectometry (OFDR) is presented to state their core performance parameters, such as the sensitivity, sensing range, dynamic measurement capability, and spatial resolution. The increased performance and reliability in harsh environments associated with fiber optic sensors come with a reduction in size, mass, and power consumption compared to the conventional electronic sensors. Optical fiber sensors embedded in carbon fiber structures have proven their capability in providing accurate real-time measurements of temperature and monitoring structural integrity while detecting precisely possible points of rupture and failure as discussed and demonstrated in the literature review. The applications of fiber optic sensing in smart propellant tanks may extend to detecting fluid leakage, also providing increased precision in propellant gauging through temperature mapping, and can be used in on-ground qualification, pre-flight testing, as well as in-orbit operation, condition, and structural health monitoring. The article presents a statement for an optimal FOS embedding approach in composite pressure vessels and discusses the related placement and orientation method for the fiber optic sensors, coupled with a one component simplified analytical stress-strain transfer model deriving the stress component along the maximum principal direction (i.e., σMaxPrincipal). The novel approach is believed to serve the optimal employment of embedded FOS in composite structures, e.g., pressure vessels and light-weight structures in spacecraft, among other applications. The simplified model is believed to pave the way for effective data interpretation and processing, utilizing the available limited computational resources on-board the spacecraft.

Optofluidic force induction as a process analytical technology

Manufacturers of nanoparticle-based products rely on detailed information about critical process parameters, such as particle size and size distributions, concentration, and material composition, which directly reflect the quality of the final product. These process parameters are often obtained using offline characterization techniques that cannot provide the temporal resolution to detect dynamic changes in particle ensembles during a production process. To overcome this deficiency, we have recently introduced Optofluidic Force Induction (of2i) for optical real-time counting with single particle sensitivity and high throughput. In this paper, we apply of2i to highly polydisperse and multi modal particle systems, where we also monitor evolutionary processes over large time scales. For oil-in-water emulsions we detect in real time the transition between high-pressure homogenization states. For silicon carbide nanoparticles, we exploit the dynamic of2i measurement capabilities to introduce a novel process feedback parameter based on the dissociation of particle agglomerates. Our results demonstrate that of2i provides a versatile workbench for process feedback in a wide range of applications.Graphical abstract

Development of a novel strategy based on in-process compensation of charge leakage for static force measurement by piezoelectric force sensors

Ordinary piezoelectric force sensors are only capable of measuring dynamic forces but not static forces because of the charge leakage due to the finite resistance of piezoelectric materials and charge amplifiers. This paper presents a new strategy for in-process compensation of charge leakage for force measurement with wide spectrum from static to dynamic realized by piezoelectric force sensors. The compensation is in-process operated based on the concept of dynamic accumulation. In order to improve the measurement accuracy and long-term stability by the compensation, the zero offset generated by normalization, bias current and temperature drift are all theoretically analyzed and experimentally validated. Measurement experiments of four different types of force signals, which contain static, triangular, sinusoidal and random force signals acting on the piezoelectric force sensor, are conducted to validate the proposed strategy. In addition, the effect of different time constant of the piezoelectric sensor under different applied forces on the compensated results is analyzed. Performance tests containing accuracy, resolution, span and bandwidth have been conducted. It is validated that the proposed method has high sensitivity of sub-millinewton, long-term stability and wide spectrum from static signal to dynamic measurement capabilities, which would provide an effective and precise method for micro force measurement and control in ultra-precision machining, semiconductor industry and biomechanics fields.

A novel millimeter-wave channel measurement platform for 6G intelligent railway scenarios

This paper presented a novel millimeter-wave channel measurement platform for the 6G intelligent railway. This platform used phased array antenna with 64 elements and can support instant bandwidth up to 1 GHz. Combined with improved multi-tone sounding signals, the platform can enhance dynamic measurement capability in high-speed railway scenarios. We performed calibration works about frequency flatness, frequency offset and proved platform reliability with channel emulator based closed-loop verification. We also carried out field trials in high-speed railway carriage scenarios. Based on measurement results, we extracted channel characteristic parameters of path loss, power delay profile and delay spread to further verify the field measurement performance of the platform.

Single-shot quantitative phase imaging with phase modulation of a liquid crystal spatial light modulator (LC-SLM) under white light illumination.

We propose a novel, to the best of our knowledge, single-shot quantitative phase imaging (QPI) technique with the phase modulation of a liquid crystal spatial light modulator (LC-SLM) under white light illumination. By studying the phase modulation characteristics of an LC-SLM under white light illumination, images captured at different wavelengths are equivalent to those captured at different defocus distances when loading a Fresnel lens pattern on the LC-SLM. Consequently, a color camera is able to simultaneously acquire multi-intensity images at different defocus distances. Finally, the phase is retrieved from a single-shot color image using the transport of intensity equation. To demonstrate the flexibility and accuracy of our method, a photoetched phase object and human red blood cells are quantitatively measured. An investigation of living yeast cells is conducted to verify the dynamic measurement capability. The proposed method provides a simple, efficient, and flexible means to accomplish real-time high-resolution quantitative phase imaging without sacrificing the field of view (FOV), which can be further integrated into a conventional microscope to achieve real-time microscopic QPI.

Fast FBG Interrogator on Chip Based on Silicon on Insulator Ring Resonator Add/Drop Filters

A fast FBG sensor interrogator on chip based on SOI ring resonator (RR) filters is presented. The measurement of the Bragg wavelength shift is based on the detection of multiple signals at the output ports of the RR filter, providing fast dynamic strain measurement capabilities, fundamentally limited by the photodetector bandwidth and signal processing. The ring resonator resonance wavelength is tuned and fixed by an integrated heater and the ring acts as a passband filter for the reflected FBG spectrum. After a theoretical analysis of the interrogation method, which allows the optimization of the RR characteristics depending on the specific application and requirements, we present experimental results on a single RR based interrogation scheme applying high frequency dynamic strain up to 40 kHz. We also theoretically evaluate the performance of multi-ring resonators. The proposed scheme provides low cost, high scalability to mass-volume market applications as well as an extremely fast interrogation method.

A novel interferometric method for simultaneous measurement of film thickness and film interface temperature for a horizontal tube falling film evaporator for MED systems

Horizontal tube falling film evaporation spans a lot of applications, especially in multi-effect desalination application. Hence, the improvement of its gain output ratio is of prime importance, and for that, the studies on the characteristics associated with the flow, mainly falling film thickness and falling film interface temperature, are inevitable. As the falling film flow is a delicate fluid structure, non-intrusive measurement techniques have to be preferred for the experiment. In this work, we introduce a novel interferometric method to calculate film interface temperature and a shadowgraph approach to estimate film thickness simultaneously. A Mach-Zehnder interferometer with infinite fringe setting was used to capture the thermal fluctuations around the horizontal tube falling film evaporator. Interferometric method implemented in this work also serves as an image visualization technique and does the purpose of qualitative as well as quantitative analysis. An in house designed experimental setup was fabricated for producing a thin and uniform falling film with a fully wetted flow over the horizontal copper tube. A heater controller setup was incorporated into it for accurate temperature control. This method holds the advantage of scanning falling film thickness over circumferential angle for the range 5∘≤θ≤175∘, which is an improvement to state of the art. Furthermore, dynamic film thickness and instantaneous film interface temperature studies were also incorporated to prove the efficacy of the technique and to test the robustness of the algorithms implemented. CFD analysis was also carried out for the entire process by means of VOF scheme and was found to be in good agreement with the experimental results, which proves our technique to be a good one. A standard error of mean analysis was performed on every data set, which validates the reproducibility and the dynamic measurement capability of the technique used.

Distributed Optical Fiber Sensor for Dynamic Measurement

Distributed optical fiber sensors (DOFS), which can distributed measure static parameters such as temperature and strain, have been extensively researched and applied in industrial fields over the past several decades. Recently, in consideration of the explosive demand for dynamic sensing, the DOFS with the capability of dynamic phenomena measurement has attracted amounts of attentions. Various techniques that could realize and enhance the dynamic performance of DOFS have been proposed. In this article, DOFS for dynamic measurement is discussed. Firstly, the principles of DOFS based on Rayleigh and Brillouin scattering are introduced. Then, the most recent advances of fast DOFS especially those based on phase sensitive optical time domain reflectometry (φ-OTDR) and Brillouin optical time domain analysis (BOTDA), are analyzed. Furthermore, DOFS for multi-parameter sensing is also reviewed.

Interferometric analysis of flow around a horizontal tube falling film evaporator for MED systems

In this work, an optical shadow method (non-intrusive) was used to evaluate the falling film thickness around the circumference of a horizontal tube. A Mach-Zehnder Interferometer was used to visualize the isotherm formation. Most of the well established non-intrusive techniques for measuring film thickness around the cylinder fails to measure the film thickness near to entry region (θ<30∘) and towards the exit region (θ>140∘) because of the limitation and complexity of the apparatus. Relavance of this work lies on the simplicity of the measurement and the range of circumferential angles that can be investigated (10∘≤θ≤170∘). This technique involves image visualization, thus, serves as a tool for analyzing the film both quantitatively and qualitatively. A lucid algorithm was developed for image processing along with a set of intensity profile tracking procedures making the whole process of film thickness measurement more obvious. The measured film thickness is showing good agreement with the commonly used empirical formula, and the effectiveness of using those empirical formulas for the small diameter tubes was analyzed. Further, this study was extended to determine the effects of flow rate and feed inlet temperature on film thickness. Film thickness variation around the circumference of the cylinder is showing an increase in trend with increasing Reynolds number, but a change in trend with the varying feed inlet temperature is found to be marginal. This study is further extended for different positions of the tube in the order of impingement of film or feed inlet as top, middle and bottom tubes and the film thickness variation was again found to be marginal. Dynamic characterization at θ=10∘ was studied and the maximum film thickness variation was found to be 11.8%. A standard error of mean analysis was performed on every data set which validates the reproducibility and the dynamic measurement capability of the technique used.

Boronate probe-based hydrogen peroxide detection with AlGaN/GaN HEMT sensor.

The results from this study demonstrate the potential of an AlGaN/GaN high electron mobility transistor sensor for the detection of reactive and transient biological molecules such as hydrogen peroxide. A boronate-based fluorescent probe was used with this device to detect the presence of micromolar levels of hydrogen peroxide typically associated with intracellular processes. The real-time electrical response of the high electron mobility transistor sensor showed a gradual decrease in the two-dimensional electron gas current as the reaction proceeded over time. A corresponding increase in the emission intensity was measured from the fluorescent probe with the progression of the reaction. The fluorescence from the boronate probe was used as an indicator to confirm the detection of hydrogen peroxide. These results demonstrate the dynamic measurement capability of AlGaN/GaN high electron mobility transistor sensors in monitoring real-time reactions of reactive oxygen species such as hydrogen peroxide.

Falling film thickness measurement using air-coupled ultrasonic transducer

In this work, a new, non-intrusive, increased sensitivity technique based on air-coupled ultrasonics was developed to measure the falling liquid film thickness. Air-coupled transducer of frequency 1 MHz was used to make static and dynamic measurements of water level/film thickness. The air-coupled method were compared with a metal-side contact ultrasonic approach as well as calculating water levels in the collection tank. The falling film thickness measurement over inclined plate was used in this study. Measurement of film thickness was taken at flow rates in the range of 0.34–0.9 lpm. Relatively good agreement was found between the readings, which validates the dynamic measurement capability of the new technique. The technique was applied to measure the horizontal tube falling film thickness for falling film Reynolds number ranging from 130 to 350, at different circumferential angles ranging from 40° to 130° and at tube spacing of 5 mm and 15 mm. Measurements were compared with correlations available in the literature and found to be in good agreement.

Suspension force measuring system for hypersonic wind tunnel test: Design and tests

Suspension force measuring system is a new type of measuring system for dynamometric test of hypersonic aircraft wind tunnel. The system alters the measuring solution of internal balance placed in the model chamber for wind tunnel test in the past to the new design without internal balance, which dramatically reduces design difficulty of aircraft model with engine. The processing, installation and calibration test of this system were carried out, it turns out that the system performs well in repeatability and linearity in various measure components, line repeatability of calibration data point by least squares fit is good, and maximum interference between components is less than 2.3%. Dynamic test was also carried out, frequency spectrum shows the first-order frequency with the greatest contribution to the vibration of the system reach to 137 Hz, dynamic measurement capability performs well. Finally, the system is used in hypersonic wind tunnel test and the stress state of the model under the action of high-speed airflow was correctly reflected.

Research and Application on GMR Current Sensing Technology

With the development of smart grid, and ever-increasing kinds of electrical loads, the power system requires current measurement technology with wider measurement range, this thesis designs a new type of current sensor based on Giant magnetoresistance (GMR) material. Firstly, this thesis introduces principles and characteristic of GMR current sensor. For the shortcomings of low sensitivity and poor linearity of GMR chip, this thesis presents a structure of open-loop current sensor using GMR chip as magnetic probe, which improves the sensitivity of sensor effectively. Based on the open-loop GMR current sensor structure, a closed-loop GMR current sensor design is proposed. This design compensates the magnetic field through the feedback circuit and improves the accuracy and dynamic measurement range of GMR current sensor. Finally, we tested the GMR sensor system we developed, include DC characteristic test and AC characteristic test, it shows the current sensor has the capability of high dynamic current measurement.

A Fiber-Optic Displacement Sensor Based on High-Precision Differential Phase Measurement

A fiber-optic displacement sensing scheme based on high-precision detection of differential phase is proposed, with advantages of simple structure, low cost, high precision, large dynamic range, polarization independent, and remote sensing ability. The designed displacement sensor is composed of a sensing fiber, a reference fiber, a Fabry-Perot laser diode, five couplers, two photodiodes and a signal processing circuit. The reference fiber is used for temperature compensation. The optical path difference (OPD) between the two fibers varies with the stretch of the sensing fiber. By high-frequency sinusoidal modulation of the laser source, the OPD can be converted to the differential phase between the reflected lights from the endfaces of the two fibers. The differential phase is detected by cross-correlation method. Experimental results show that, the resolution of the static displacement measurement has been achieved to be 1.4 μm. In addition, the dynamic range is estimated to be 2.66 m. Furthermore, the designed sensor shows the capability of dynamic displacement measurement.

Spatial resolution improvement of single-shot digital optical frequency comb-based Brillouin optical time domain analysis utilizing multiple pump pulses.

A spatial resolution improvement scheme for the digital optical frequency comb (DOFC)-based single-shot Brillouin optical time domain analysis (BOTDA) by utilizing multiple pump pulses is demonstrated. Assisted by four pump pulses, the spatial resolution can be improved by four times without decreasing the detection resolution. The response time, and the spatial resolution of our scheme over 10km fiber, are 0.1ms and 12.5m. Distributed temperature and strain measurements are carried out with detection resolutions of 1.6°C and 44 μϵ, respectively, and the capability of dynamic measurement of this proposed BOTDA is also demonstrated by probing a vibration with frequency up to 1.2kHz.

Calibration Method for Dynamic Deflection Measurement of Bridges by Photogrammetry

Heavy vehicular traffic and aggressive environmental conditions can cause unexpected bridge deterioration, thus, periodic inspections to identify and assess possible defects are required. One indicator is the amount of vertical deflection that occurs during loading. Some different types of transducers can be used to measure the deflection. One of them is the photogrammetry. It is a typical noncontact measurement method. Unfortunately, it is difficult to calibrate this type of instruments. The key point is the evaluation of the dynamic deflection measurement capability. A dynamic calibration system of bridge photogrammetric measurement system was composed of the motorized linear stage, LED target and computer. The Fréchet distance was used as a model to evaluate the dynamic deflection measurement capability of bridge deflection photogrammetry. The photogrammetric bridge deflection measuring instruments are products of BIOET, which are used to carry out the measurement experiment. The results show that this system can calibrate the dynamic deflection measurement error of photogrammetric bridge deflection measuring instruments. Fréchet distance can reflect the relationship between the curves. This evaluation method is more accurate than the current evaluation method based on the error of indication of maximum dynamic deflection.