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Sensors, Volume 14, Issue 5 (May 2014), Pages 7580-9368

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Open AccessArticle Real-Time Algebraic Derivative Estimations Using a Novel Low-Cost Architecture Based on Reconfigurable Logic
Sensors 2014, 14(5), 9349-9368; https://doi.org/10.3390/s140509349
Received: 20 January 2014 / Revised: 12 May 2014 / Accepted: 21 May 2014 / Published: 23 May 2014
Cited by 4 | PDF Full-text (895 KB) | HTML Full-text | XML Full-text
Abstract
Time derivative estimation of signals plays a very important role in several fields, such as signal processing and control engineering, just to name a few of them. For that purpose, a non-asymptotic algebraic procedure for the approximate estimation of the system states is
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Time derivative estimation of signals plays a very important role in several fields, such as signal processing and control engineering, just to name a few of them. For that purpose, a non-asymptotic algebraic procedure for the approximate estimation of the system states is used in this work. The method is based on results from differential algebra and furnishes some general formulae for the time derivatives of a measurable signal in which two algebraic derivative estimators run simultaneously, but in an overlapping fashion. The algebraic derivative algorithm presented in this paper is computed online and in real-time, offering high robustness properties with regard to corrupting noises, versatility and ease of implementation. Besides, in this work, we introduce a novel architecture to accelerate this algebraic derivative estimator using reconfigurable logic. The core of the algorithm is implemented in an FPGA, improving the speed of the system and achieving real-time performance. Finally, this work proposes a low-cost platform for the integration of hardware in the loop in MATLAB. Full article
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Open AccessArticle Dynamic Bayesian Networks for Context-Aware Fall Risk Assessment
Sensors 2014, 14(5), 9330-9348; https://doi.org/10.3390/s140509330
Received: 19 March 2014 / Revised: 12 May 2014 / Accepted: 21 May 2014 / Published: 23 May 2014
Cited by 6 | PDF Full-text (468 KB) | HTML Full-text | XML Full-text
Abstract
Fall incidents among the elderly often occur in the home and can cause serious injuries affecting their independent living. This paper presents an approach where data from wearable sensors integrated in a smart home environment is combined using a dynamic Bayesian network. The
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Fall incidents among the elderly often occur in the home and can cause serious injuries affecting their independent living. This paper presents an approach where data from wearable sensors integrated in a smart home environment is combined using a dynamic Bayesian network. The smart home environment provides contextual data, obtained from environmental sensors, and contributes to assessing a fall risk probability. The evaluation of the developed system is performed through simulation. Each time step is represented by a single user activity and interacts with a fall sensors located on a mobile device. A posterior probability is calculated for each recognized activity or contextual information. The output of the system provides a total risk assessment of falling given a response from the fall sensor. Full article
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Open AccessArticle ATHENA: A Personalized Platform to Promote an Active Lifestyle and Wellbeing Based on Physical, Mental and Social Health Primitives
Sensors 2014, 14(5), 9313-9329; https://doi.org/10.3390/s140509313
Received: 14 March 2014 / Revised: 2 May 2014 / Accepted: 14 May 2014 / Published: 23 May 2014
Cited by 13 | PDF Full-text (902 KB) | HTML Full-text | XML Full-text
Abstract
Technology provides ample opportunities for the acquisition and processing of physical, mental and social health primitives. However, several challenges remain for researchers as how to define the relationship between reported physical activities, mood and social interaction to define an active lifestyle. We are
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Technology provides ample opportunities for the acquisition and processing of physical, mental and social health primitives. However, several challenges remain for researchers as how to define the relationship between reported physical activities, mood and social interaction to define an active lifestyle. We are conducting a project, ATHENA(activity-awareness for human-engaged wellness applications) to design and integrate the relationship between these basic health primitives to approximate the human lifestyle and real-time recommendations for wellbeing services. Our goal is to develop a system to promote an active lifestyle for individuals and to recommend to them valuable interventions by making comparisons to their past habits. The proposed system processes sensory data through our developed machine learning algorithms inside smart devices and utilizes cloud infrastructure to reduce the cost. We exploit big data infrastructure for massive sensory data storage and fast retrieval for recommendations. Our contributions include the development of a prototype system to promote an active lifestyle and a visual design capable of engaging users in the goal of increasing self-motivation. We believe that our study will impact the design of future ubiquitous wellness applications. Full article
Open AccessArticle A New Acquisition and Imaging System for Environmental Measurements: An Experience on the Italian Cultural Heritage
Sensors 2014, 14(5), 9290-9312; https://doi.org/10.3390/s140509290
Received: 15 February 2014 / Revised: 5 May 2014 / Accepted: 19 May 2014 / Published: 23 May 2014
Cited by 24 | PDF Full-text (772 KB) | HTML Full-text | XML Full-text
Abstract
A new acquisition system for remote control of wall paintings has been realized and tested in the field. The system measures temperature and atmospheric pressure in an archeological site where a fresco has been put under control. The measuring chain has been designed
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A new acquisition system for remote control of wall paintings has been realized and tested in the field. The system measures temperature and atmospheric pressure in an archeological site where a fresco has been put under control. The measuring chain has been designed to be used in unfavorable environments where neither electric power nor telecommunication infrastructures are available. The environmental parameters obtained from the local monitoring are then transferred remotely allowing an easier management by experts in the field of conservation of cultural heritage. The local acquisition system uses an electronic card based on microcontrollers and sends the data to a central unit realized with a Raspberry-Pi. The latter manages a high quality camera to pick up pictures of the fresco. Finally, to realize the remote control at a site not reached by internet signals, a WiMAX connection based on different communication technologies such as WiMAX, Ethernet, GPRS and Satellite, has been set up. Full article
(This article belongs to the Special Issue Sensors for Cultural Heritage Diagnostics)
Open AccessArticle MLAOS: A Multi-Point Linear Array of Optical Sensors for Coniferous Foliage Clumping Index Measurement
Sensors 2014, 14(5), 9271-9289; https://doi.org/10.3390/s140509271
Received: 6 January 2014 / Revised: 23 April 2014 / Accepted: 16 May 2014 / Published: 23 May 2014
Cited by 6 | PDF Full-text (1261 KB) | HTML Full-text | XML Full-text
Abstract
The canopy foliage clumping effect is primarily caused by the non-random distribution of canopy foliage. Currently, measurements of clumping index (CI) by handheld instruments is typically time- and labor-intensive. We propose a low-cost and low-power automatic measurement system called Multi-point Linear Array of
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The canopy foliage clumping effect is primarily caused by the non-random distribution of canopy foliage. Currently, measurements of clumping index (CI) by handheld instruments is typically time- and labor-intensive. We propose a low-cost and low-power automatic measurement system called Multi-point Linear Array of Optical Sensors (MLAOS), which consists of three above-canopy and nine below-canopy optical sensors that capture plant transmittance at different times of the day. Data communication between the MLAOS node is facilitated by using a ZigBee network, and the data are transmitted from the field MLAOS to a remote data server using the Internet. The choice of the electronic element and design of the MLAOS software is aimed at reducing costs and power consumption. A power consumption test showed that, when a 4000 mAH Li-ion battery is used, a maximum of 8–10 months of work can be achieved. A field experiment on a coniferous forest revealed that the CI of MLAOS may reveal a clumping effect that occurs within the canopy. In further work, measurement of the multi-scale clumping effect can be achieved by utilizing a greater number of MLAOS devices to capture the heterogeneity of the plant canopy. Full article
(This article belongs to the Section Remote Sensors)
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Open AccessArticle A Measuring System for Well Logging Attitude and a Method of Sensor Calibration
Sensors 2014, 14(5), 9256-9270; https://doi.org/10.3390/s140509256
Received: 10 March 2014 / Revised: 12 May 2014 / Accepted: 21 May 2014 / Published: 23 May 2014
Cited by 6 | PDF Full-text (721 KB) | HTML Full-text | XML Full-text
Abstract
This paper proposes an approach for measuring the azimuth angle and tilt angle of underground drilling tools with a MEMS three-axis accelerometer and a three-axis fluxgate sensor. A mathematical model of well logging attitude angle is deduced based on combining space coordinate transformations
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This paper proposes an approach for measuring the azimuth angle and tilt angle of underground drilling tools with a MEMS three-axis accelerometer and a three-axis fluxgate sensor. A mathematical model of well logging attitude angle is deduced based on combining space coordinate transformations and algebraic equations. In addition, a system implementation plan of the inclinometer is given in this paper, which features low cost, small volume and integration. Aiming at the sensor and assembly errors, this paper analyses the sources of errors, and establishes two mathematical models of errors and calculates related parameters to achieve sensor calibration. The results show that this scheme can obtain a stable and high precision azimuth angle and tilt angle of drilling tools, with the deviation of the former less than ±1.4° and the deviation of the latter less than ±0.1°. Full article
(This article belongs to the Special Issue Optical Gyroscopes and Navigation Systems)
Open AccessArticle A Low-Power Integrated Humidity CMOS Sensor by Printing-on-Chip Technology
Sensors 2014, 14(5), 9247-9255; https://doi.org/10.3390/s140509247
Received: 25 April 2014 / Revised: 19 May 2014 / Accepted: 20 May 2014 / Published: 23 May 2014
Cited by 5 | PDF Full-text (299 KB) | HTML Full-text | XML Full-text
Abstract
A low-power, wide-dynamic-range integrated humidity sensing chip is implemented using a printable polymer sensing material with an on-chip pulse-width-modulation interface circuit. By using the inkjet printing technique, poly(3,4-ethylene-dioxythiophene)/polystyrene sulfonate that has humidity sensing features can be printed onto the top metal layer of
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A low-power, wide-dynamic-range integrated humidity sensing chip is implemented using a printable polymer sensing material with an on-chip pulse-width-modulation interface circuit. By using the inkjet printing technique, poly(3,4-ethylene-dioxythiophene)/polystyrene sulfonate that has humidity sensing features can be printed onto the top metal layer of a 0.35 μm CMOS IC. The developed printing-on-chip humidity sensor achieves a heterogeneous three dimensional sensor system-on-chip architecture. The humidity sensing of the implemented printing-on-chip sensor system is experimentally tested. The sensor shows a sensitivity of 0.98% to humidity in the atmosphere. The maximum dynamic range of the readout circuit is 9.8 MΩ, which can be further tuned by the frequency of input signal to fit the requirement of the resistance of printed sensor. The power consumption keeps only 154 μW. This printing-on-chip sensor provides a practical solution to fulfill an ultra-small integrated sensor for the applications in miniaturized sensing systems. Full article
(This article belongs to the Special Issue Printed Sensors)
Open AccessArticle RESTful Discovery and Eventing for Service Provisioning in Assisted Living Environments
Sensors 2014, 14(5), 9227-9246; https://doi.org/10.3390/s140509227
Received: 1 April 2014 / Revised: 18 May 2014 / Accepted: 20 May 2014 / Published: 23 May 2014
Cited by 4 | PDF Full-text (547 KB) | HTML Full-text | XML Full-text
Abstract
Service provisioning in assisted living environments faces distinct challenges due to the heterogeneity of networks, access technology, and sensing/actuation devices in such an environment. Existing solutions, such as SOAP-based web services, can interconnect heterogeneous devices and services, and can be published, discovered and
[...] Read more.
Service provisioning in assisted living environments faces distinct challenges due to the heterogeneity of networks, access technology, and sensing/actuation devices in such an environment. Existing solutions, such as SOAP-based web services, can interconnect heterogeneous devices and services, and can be published, discovered and invoked dynamically. However, it is considered heavier than what is required in the smart environment-like context and hence suffers from performance degradation. Alternatively, REpresentational State Transfer (REST) has gained much attention from the community and is considered as a lighter and cleaner technology compared to the SOAP-based web services. Since it is simple to publish and use a RESTful web service, more and more service providers are moving toward REST-based solutions, which promote a resource-centric conceptualization as opposed to a service-centric conceptualization. Despite such benefits of REST, the dynamic discovery and eventing of RESTful services are yet considered a major hurdle to utilization of the full potential of REST-based approaches. In this paper, we address this issue, by providing a RESTful discovery and eventing specification and demonstrate it in an assisted living healthcare scenario. We envisage that through this approach, the service provisioning in ambient assisted living or other smart environment settings will be more efficient, timely, and less resource-intensive. Full article
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Open AccessArticle Comparative Study on a Solving Model and Algorithm for a Flush Air Data Sensing System
Sensors 2014, 14(5), 9210-9226; https://doi.org/10.3390/s140509210
Received: 17 March 2014 / Revised: 13 May 2014 / Accepted: 19 May 2014 / Published: 23 May 2014
Cited by 2 | PDF Full-text (912 KB) | HTML Full-text | XML Full-text
Abstract
With the development of high-performance aircraft, precise air data are necessary to complete challenging tasks such as flight maneuvering with large angles of attack and high speed. As a result, the flush air data sensing system (FADS) was developed to satisfy the stricter
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With the development of high-performance aircraft, precise air data are necessary to complete challenging tasks such as flight maneuvering with large angles of attack and high speed. As a result, the flush air data sensing system (FADS) was developed to satisfy the stricter control demands. In this paper, comparative stuides on the solving model and algorithm for FADS are conducted. First, the basic principles of FADS are given to elucidate the nonlinear relations between the inputs and the outputs. Then, several different solving models and algorithms of FADS are provided to compute the air data, including the angle of attck, sideslip angle, dynamic pressure and static pressure. Afterwards, the evaluation criteria of the resulting models and algorithms are discussed to satisfy the real design demands. Futhermore, a simulation using these algorithms is performed to identify the properites of the distinct models and algorithms such as the measuring precision and real-time features. The advantages of these models and algorithms corresponding to the different flight conditions are also analyzed, furthermore, some suggestions on their engineering applications are proposed to help future research. Full article
(This article belongs to the Section Physical Sensors)
Open AccessReview Surveying Wearable Human Assistive Technology for Life and Safety Critical Applications: Standards, Challenges and Opportunities
Sensors 2014, 14(5), 9153-9209; https://doi.org/10.3390/s140509153
Received: 18 March 2014 / Revised: 25 April 2014 / Accepted: 14 May 2014 / Published: 23 May 2014
Cited by 76 | PDF Full-text (1312 KB) | HTML Full-text | XML Full-text
Abstract
In this survey a new application paradigm life and safety for critical operations and missions using wearable Wireless Body Area Networks (WBANs) technology is introduced. This paradigm has a vast scope of applications, including disaster management, worker safety in harsh environments such as
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In this survey a new application paradigm life and safety for critical operations and missions using wearable Wireless Body Area Networks (WBANs) technology is introduced. This paradigm has a vast scope of applications, including disaster management, worker safety in harsh environments such as roadside and building workers, mobile health monitoring, ambient assisted living and many more. It is often the case that during the critical operations and the target conditions, the existing infrastructure is either absent, damaged or overcrowded. In this context, it is envisioned that WBANs will enable the quick deployment of ad-hoc/on-the-fly communication networks to help save many lives and ensuring people’s safety. However, to understand the applications more deeply and their specific characteristics and requirements, this survey presents a comprehensive study on the applications scenarios, their context and specific requirements. It explores details of the key enabling standards, existing state-of-the-art research studies, and projects to understand their limitations before realizing aforementioned applications. Application-specific challenges and issues are discussed comprehensively from various perspectives and future research and development directions are highlighted as an inspiration for new innovative solutions. To conclude, this survey opens up a good opportunity for companies and research centers to investigate old but still new problems, in the realm of wearable technologies, which are increasingly evolving and getting more and more attention recently. Full article
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Open AccessArticle Discovery of Pantoea rodasii Strain ND03 that Produces N-(3-Oxo-hexanoyl)-L-homoserine Lactone
Sensors 2014, 14(5), 9145-9152; https://doi.org/10.3390/s140509145
Received: 8 April 2014 / Revised: 13 May 2014 / Accepted: 16 May 2014 / Published: 23 May 2014
Cited by 4 | PDF Full-text (288 KB) | HTML Full-text | XML Full-text
Abstract
Proteobacteria use quorum sensing to regulate target gene expression in response to population density. Quorum sensing (QS) is achieved via so-called signalling molecules and the best-studied QS signalling system uses N-acyl homoserine lactones (AHLs). This study aimed to identify and characterize the
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Proteobacteria use quorum sensing to regulate target gene expression in response to population density. Quorum sensing (QS) is achieved via so-called signalling molecules and the best-studied QS signalling system uses N-acyl homoserine lactones (AHLs). This study aimed to identify and characterize the production of AHLs by a bacterium ND03 isolated from a Malaysian tropical rainforest waterfall. Molecular identification showed that ND03 is a Pantoea sp. closely related to Pantoea rodasii. We used Chromobacterium violaceum CV026, an AHL biosensor for preliminary AHL production screening and then used high resolution triple quadrupole liquid chromatography-mass spectrometry, to confirm that P. rodasii strain ND03 produced N-(3-oxo-hexanoyl)-L-homoserine lactone (3-oxo-C6-HSL). To the best of our knowledge, this is the first report for such a discovery in P. rodasii strain ND03. Full article
(This article belongs to the Section Biosensors)
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Open AccessArticle A Compact Immunoassay Platform Based on a Multicapillary Glass Plate
Sensors 2014, 14(5), 9132-9144; https://doi.org/10.3390/s140509132
Received: 15 April 2014 / Revised: 15 May 2014 / Accepted: 20 May 2014 / Published: 23 May 2014
Cited by 8 | PDF Full-text (918 KB) | HTML Full-text | XML Full-text
Abstract
A highly sensitive, rapid immunoassay performed in the multi-channels of a micro-well array consisting of a multicapillary glass plate (MCP) and a polydimethylsiloxane (PDMS) slide is described. The micro-dimensions and large surface area of the MCP permitted the diffusion distance to be decreased
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A highly sensitive, rapid immunoassay performed in the multi-channels of a micro-well array consisting of a multicapillary glass plate (MCP) and a polydimethylsiloxane (PDMS) slide is described. The micro-dimensions and large surface area of the MCP permitted the diffusion distance to be decreased and the reaction efficiency to be increased. To confirm the concept of the method, human immunoglobulin A (h-IgA) was measured using both the proposed immunoassay system and the traditional 96-well plate method. The proposed method resulted in a 1/5-fold decrease of immunoassay time, and a 1/56-fold cut in reagent consumption with a 0.05 ng/mL of limit of detection (LOD) for IgA. The method was also applied to saliva samples obtained from healthy volunteers. The results correlated well to those obtained by the 96-well plate method. The method has the potential for use in disease diagnostic or on-site immunoassays. Full article
(This article belongs to the Section Biosensors)
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Open AccessReview Point-of-care Diagnostic Tools to Detect Circulating MicroRNAS as Biomarkers of Disease
Sensors 2014, 14(5), 9117-9131; https://doi.org/10.3390/s140509117
Received: 26 February 2014 / Revised: 30 April 2014 / Accepted: 4 May 2014 / Published: 22 May 2014
Cited by 10 | PDF Full-text (356 KB) | HTML Full-text | XML Full-text
Abstract
MicroRNAs or miRNAs are a form of small non-coding RNAs (ncRNAs) of 19–22 nucleotides in length in their mature form. miRNAs are transcribed in the nucleus of all cells from large precursors, many of which have several kilobases in length. Originally identified as
[...] Read more.
MicroRNAs or miRNAs are a form of small non-coding RNAs (ncRNAs) of 19–22 nucleotides in length in their mature form. miRNAs are transcribed in the nucleus of all cells from large precursors, many of which have several kilobases in length. Originally identified as intracellular modulators of protein synthesis via posttranscriptional gene silencing, more recently it has been found that miRNAs can travel in extracellular human fluids inside specialized vesicles known as exosomes. We will be referring to this miRNAs as circulating microRNAs. More interestingly, the miRNA content inside exosomes changes during pathological events. In the present review we analyze the literature about circulating miRNAs and their possible use as biomarkers. Furthermore, we explore their future in point-of-care (POC) diagnostics and provide an example of a portable POC apparatus useful in the detection of circulating miRNAs. Full article
(This article belongs to the Section Biosensors)
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Open AccessArticle A New Method for Ultrasound Detection of Interfacial Position in Gas-Liquid Two-Phase Flow
Sensors 2014, 14(5), 9093-9116; https://doi.org/10.3390/s140509093
Received: 3 December 2013 / Revised: 14 May 2014 / Accepted: 19 May 2014 / Published: 22 May 2014
PDF Full-text (996 KB) | HTML Full-text | XML Full-text
Abstract
Ultrasonic measurement techniques for velocity estimation are currently widely used in fluid flow studies and applications. An accurate determination of interfacial position in gas-liquid two-phase flows is still an open problem. The quality of this information directly reflects on the accuracy of void
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Ultrasonic measurement techniques for velocity estimation are currently widely used in fluid flow studies and applications. An accurate determination of interfacial position in gas-liquid two-phase flows is still an open problem. The quality of this information directly reflects on the accuracy of void fraction measurement, and it provides a means of discriminating velocity information of both phases. The algorithm known as Velocity Matched Spectrum (VM Spectrum) is a velocity estimator that stands out from other methods by returning a spectrum of velocities for each interrogated volume sample. Interface detection of free-rising bubbles in quiescent liquid presents some difficulties for interface detection due to abrupt changes in interface inclination. In this work a method based on velocity spectrum curve shape is used to generate a spatial-temporal mapping, which, after spatial filtering, yields an accurate contour of the air-water interface. It is shown that the proposed technique yields a RMS error between 1.71 and 3.39 and a probability of detection failure and false detection between 0.89% and 11.9% in determining the spatial-temporal gas-liquid interface position in the flow of free rising bubbles in stagnant liquid. This result is valid for both free path and with transducer emitting through a metallic plate or a Plexiglas pipe. Full article
Open AccessArticle Displacement Parameter Inversion for a Novel Electromagnetic Underground Displacement Sensor
Sensors 2014, 14(5), 9074-9092; https://doi.org/10.3390/s140509074
Received: 7 January 2014 / Revised: 1 May 2014 / Accepted: 9 May 2014 / Published: 22 May 2014
Cited by 1 | PDF Full-text (486 KB) | HTML Full-text | XML Full-text
Abstract
Underground displacement monitoring is an effective method to explore deep into rock and soil masses for execution of subsurface displacement measurements. It is not only an important means of geological hazards prediction and forecasting, but also a forefront, hot and sophisticated subject in
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Underground displacement monitoring is an effective method to explore deep into rock and soil masses for execution of subsurface displacement measurements. It is not only an important means of geological hazards prediction and forecasting, but also a forefront, hot and sophisticated subject in current geological disaster monitoring. In previous research, the authors had designed a novel electromagnetic underground horizontal displacement sensor (called the H-type sensor) by combining basic electromagnetic induction principles with modern sensing techniques and established a mutual voltage measurement theoretical model called the Equation-based Equivalent Loop Approach (EELA). Based on that work, this paper presents an underground displacement inversion approach named “EELA forward modeling-approximate inversion method”. Combining the EELA forward simulation approach with the approximate optimization inversion theory, it can deduce the underground horizontal displacement through parameter inversion of the H-type sensor. Comprehensive and comparative studies have been conducted between the experimentally measured and theoretically inversed values of horizontal displacement under counterpart conditions. The results show when the measured horizontal displacements are in the 0–100 mm range, the horizontal displacement inversion discrepancy is generally tested to be less than 3 mm under varied tilt angles and initial axial distances conditions, which indicates that our proposed parameter inversion method can predict underground horizontal displacement measurements effectively and robustly for the H-type sensor and the technique is applicable for practical geo-engineering applications. Full article
(This article belongs to the Section Physical Sensors)
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