bluuebunny/crossref_metadata_2025 huggingface dataset:
The use of foundational ontologies in biomedical research
Authors: Bernabé César H. , Queralt-Rosinach Núria , Silva Souza Vítor E. , Bonino da Silva Santos Luiz Olavo , Mons Barend , Jacobsen Annika , Roos Marco
Published: December 2023

Background

The FAIR principles recommend the use of controlled vocabularies, such as ontologies, to define data and metadata concepts. Ontologies are currently modelled following different approaches, sometimes describing conflicting definitions of the same concepts, which can affect interoperability. To cope with that, prior literature suggests organising ontologies in levels, where domain specific (low-level) ontologies are grounded in domain independent high-level ontologies (i.e., foundational ontologies). In this level-based organisation, foundational ontologies work as translators of intended meaning, thus improving interoperability. Despite their considerable acceptance in biomedical research, there are very few studies testing foundational ontologies. This paper describes a systematic literature mapping that was conducted to understand how foundational ontologies are used in biomedical research and to find empirical evidence supporting their claimed (dis)advantages.

Results

From a set of 79 selected papers, we identified that foundational ontologies are used for several purposes: ontology construction, repair, mapping, and ontology-based data analysis. Foundational ontologies are claimed to improve interoperability, enhance reasoning, speed up ontology development and facilitate maintainability. The complexity of using foundational ontologies is the most commonly cited downside. Despite being used for several purposes, there were hardly any experiments (1 paper) testing the claims for or against the use of foundational ontologies. In the subset of 49 papers that describe the development of an ontology, it was observed a low adherence to ontology construction (16 papers) and ontology evaluation formal methods (4 papers).

Conclusion

Our findings have two main implications. First, the lack of empirical evidence about the use of foundational ontologies indicates a need for evaluating the use of such artefacts in biomedical research. Second, the low adherence to formal methods illustrates how the field could benefit from a more systematic approach when dealing with the development and evaluation of ontologies. The understanding of how foundational ontologies are used in the biomedical field can drive future research towards the improvement of ontologies and, consequently, data FAIRness. The adoption of formal methods can impact the quality and sustainability of ontologies, and reusing these methods from other fields is encouraged.
Inhaled drug delivery: a randomized study in intubated patients with healthy lungs
Authors: Dugernier Jonathan , Le Pennec Déborah , Maerckx Guillaume , Allimonnier Laurine , Hesse Michel , Castanares-Zapatero Diego , Depoortere Virginie , Vecellio Laurent , Reychler Gregory , Michotte Jean-Bernard , Goffette Pierre , Docquier Marie-Agnes , Raftopoulos Christian , Jamar François , Laterre Pierre-François , Ehrmann Stephan , Wittebole Xavier
Published: December 2023

Background

The administration technique for inhaled drug delivery during invasive ventilation remains debated. This study aimed to compare in vivo and in vitro the deposition of a radiolabeled aerosol generated through four configurations during invasive ventilation, including setups optimizing drug delivery.

Methods

Thirty-one intubated postoperative neurosurgery patients with healthy lungs were randomly assigned to four configurations of aerosol delivery using a vibrating-mesh nebulizer and specific ventilator settings: (1) a specific circuit for aerosol therapy (SCAT) with the nebulizer placed at 30 cm of the wye, (2) a heated-humidified circuit switched off 30 min before the nebulization or (3) left on with the nebulizer at the inlet of the heated-humidifier, (4) a conventional circuit with the nebulizer placed between the heat and moisture exchanger filter and the endotracheal tube. Aerosol deposition was analyzed using planar scintigraphy.

Results

A two to three times greater lung delivery was measured in the SCAT group, reaching 19.7% (14.0–24.5) of the nominal dose in comparison to the three other groups (p < 0.01). Around 50 to 60% of lung doses reached the outer region of both lungs in all groups. Drug doses in inner and outer lung regions were significantly increased in the SCAT group (p < 0.01), except for the outer right lung region in the fourth group due to preferential drug trickling from the endotracheal tube and the trachea to the right bronchi. Similar lung delivery was observed whether the heated humidifier was switched off or left on. Inhaled doses measured in vitro correlated with lung doses (R = 0.768, p < 0.001).

Conclusion

Optimizing the administration technique enables a significant increase in inhaled drug delivery to the lungs, including peripheral airways. Before adapting mechanical ventilation, studies are required to continue this optimization and to assess its impact on drug delivery and patient outcome in comparison to more usual settings.
Thermal Cracking in High Volume of Fly Ash and GGBFS Concrete
Authors: Zhang Yingda , Kim Taehwan , Castel Arnaud , Xu Tengfei
Published: December 2023

Supplementary cementitious materials (SCMs) such as fly ash and ground granulated blast furnace slag (GGBFS) are found to control the maximum temperature and the accompanying thermal gradients effectively. However, SCMs also lead to low early age strength development. Thus, it is crucial to understand the cracking behaviour of SCMs-based concrete affected by the mix design parameters. In this paper, the thermal cracking resistance was evaluated using a rigid cracking frame (RCF) with a computer-controlled temperature profile. The temperature profile was determined using the software ConcreteWorks by assuming the centre point of the mass concrete. The free shrinkage frame (FSF) and match-curing oven follow the same temperature profile as RCF to measure the free total deformation and time-dependent mechanical properties of concrete, respectively. An analytical model was proposed to calculate the autogenous shrinkage and the thermal stress separately. A time-dependent cracking risk coefficient allowing to estimate the risk of early age cracking of concrete was also proposed.
Morphological and functional trait divergence in endemic fish populations along the small-scale karstic stream
Authors: Acar Elif , Kaymak Nehir
Published: December 2023

Background

Organisms with broad distribution ranges, such as fish, often exhibit local ecological specializations based on their utilization of food and habitat. Populations of species that live in different habitat types (lotic vs. lentic) show morphological variations. However, the phenotypic differences of endemic fish populations in a small karst river basin under anthropogenic pressure are still not fully understood. In this study, the functional traits and morphological variations of the populations of endemic Pseudophoxinus antalyae Bogutskaya, 1992, in the Düden Stream basin, which is subjected to various anthropogenic disturbances and habitat types in southwestern Anatolia of Türkiye, were examined using linear measurements and geometric morphometric analysis.

Results

Differences have been identified in functional traits, particularly those related to food acquisition between populations. Results of both univariate and multivariate analyses revealed significant differences in body shape and size among populations living at sites along the stream with different habitat and environmental characteristics.

Conclusions

The reason for these differences determined in the morphology and traits of the populations may depend on habitat types, ecological, or environmental, and obstruction of gene flow. More detailed studies are needed to explain the mechanisms (genetic and ecological) that cause these differences.
Δυναμική διαχείριση κυκλοφορίας σε αστικές λιμενικές περιοχές και διαδικασιών ελέγχου σε λιμένες με τη χρήση ευφυών και συνδεδεμένων ευφυών συστημάτων μεταφορών
Authors: Μαρούση Κωνσταντίνα
Published: December 2023

Στην παρούσα διατριβή μελετήθηκε η δυναμική διαχείριση της κυκλοφορίας σε αστικές λιμενικές περιοχές και των διαδικασιών ελέγχου σε λιμένες με την χρήση Ευφυών Συστημάτων Μεταφορών (ITS) και Συνδεδεμένων Ευφυών Συστημάτων Μεταφορών (C-ITS). Ειδικότερα, αναπτύχθηκαν δυναμικά μοντέλα ανίχνευσης επαναλαμβανόμενης συμφόρησης και μη-επαναλαμβανόμενης συμφόρησης λόγω συμβάντος σε αστικές λιμενικές λεωφόρους σε πραγματικό χρόνο βάσει των χαρακτηριστικών της εκάστοτε λεωφόρου και λιμενικής περιοχής. Στην συνέχεια, αναπτύχθηκαν αλγόριθμοι που ενσωματώνουν τα μοντέλα και βάσει των ανιχνεύσεων τους εξετάστηκε η εκτροπή των χρηστών από την αστική λιμενική λεωφόρο με την υποστήριξη κυκλοφοριακής προσομοίωσης. Η εφαρμογή των προτεινόμενων αλγορίθμων πραγματοποιήθηκε για οδικό τμήμα της παραλιακής λεωφόρου Όθωνος-Αμαλίας στην Πάτρα και βάσει ορισμένων δεικτών αξιολόγησης πραγματοποιήθηκε η αξιολόγηση της απόδοσης των αλγορίθμων ανίχνευσης επαναλαμβανόμενης συμφόρησης και μη-επαναλαμβανόμενης συμφόρησης λόγω συμβάντος. Ταυτόχρονα μελετήθηκαν και αξιολογήθηκαν οι ωφέλειες που προκύπτουν από την εκτροπή των χρηστών από το υπό μελέτη οδικό τμήμα, τόσο από την μεριά του μεμονωμένου χρήστη που συνεχίζει να κινείται στην οδό, όσο και της ευρύτερης κοινωνίας και το περιβάλλον. Επιπρόσθετα, πραγματοποιήθηκε μοντελοποίηση των συστημάτων διαδικασιών ελέγχου οχημάτων και επιβαινόντων σε λιμένες. Ειδικότερα, αναλύθηκαν τέσσερα διαφορετικά συστήματα ουρών που θα μπορούσαν να εφαρμοστούν σε μια περιοχή ελέγχου οχημάτων σε λιμένα, πριν αυτά εισέλθουν στις πύλες επιβίβασης. Στην συνέχεια, αναπτύχθηκε αλγόριθμος που εφαρμόζεται σε πραγματικό χρόνο για την επιλογή του εκάστοτε βέλτιστου συστήματος ουρών ανάλογα με τις εκάστοτε συνθήκες εισαγωγής οχημάτων στο σύστημα, με το οποίο θα προτείνεται στους ιθύνοντες να λειτουργεί η περιοχή, ώστε να επωφελούνται οι χρήστες του λιμένα. Η εφαρμογή του δυναμικού μοντέλου ανάλυσης και διαχείρισης της περιοχής ελέγχου λιμένα εφαρμόστηκε στο Νότιο Λιμάνι Πατρών και αξιολογήθηκε βάσει ορισμένων δεικτών αξιολόγησης. Συγκριτική αξιολόγηση πραγματοποιήθηκε και μεταξύ των αποτελεσμάτων των διαφορετικών μοντέλων ουρών που μελετήθηκαν.
The short-term cost-effectiveness of once-weekly semaglutide versus once-weekly dulaglutide for the treatment of type 2 diabetes mellitus in Colombian adults
Authors: Liebisch-Rey Hans , Suarez-Chacon Andrea-Marcela , Fuentes Yuli-V. , Blanco Jhosep , Kock Joshua , Lechtig-Wassermann Sharon , Bustos Rosa Helena
Published: December 2023

Background Type 2 Diabetes Mellitus (T2DM) is a highly prevalent disease worldwide and in Colombia, representing one of the main causes of death and placing a considerable burden on healthcare systems. 13 classes of drugs are approved for the treatment of T2DM, with Glucagon-like Peptide-1 (GLP-1) receptor agonists being a first-line treatment option for patients with or at high risk of certain cardiovascular diseases and chronic kidney disease. The objective of this study is to conduct a short-term cost-effectiveness analysis of once-weekly semaglutide versus once-weekly dulaglutide in Colombian adults with T2DM, from a third-party payer perspective. Methods Numbers needed to treat were calculated for different single and composite endpoints of the SUSTAIN 7 trial, annual costs for once weekly semaglutide 1.0 mg and dulaglutide 1.5 mg were extracted from the public SISMED database. With these inputs a cost of control model was developed, to obtain the annual cost of bringing one T2DM patient to relevant clinical outcomes by using semaglutide or dulaglutide. Results Semaglutide was considered cost-effective compared to dulaglutide across all pre-specified endpoints, even in the different scenarios evaluated in the sensitivity analyses, and in a particularly pronounced manner for weight loss outcomes. Semaglutide at a dose of 1.0 mg once-weekly was cost-effective compared to dulaglutide 1.5 mg across all outcomes in the short-term, making it an appropriate first-line choice in the treatment of T2DM when deciding between these two GLP-1 receptor agonists. Conclusions This is the first short-term cost-effectiveness study of semaglutide and dulaglutide in T2DM Colombian patients. Our modeled results suggest that once-weekly semaglutide represents a cost-effective option for treating individuals with T2DM in Colombia who are not achieving glycaemia control with metformin, and it would be expected to improve HbA1C, promote greater weight loss and reduce costs from a third-payer perspective compared with treatment with dulaglutide.
A cross-sectional survey measuring social norms, personal norms and altruistic values across responsible computer consumption life cycles
Authors: Yee Yen Yuen , Yeow Paul H.P. , Loo WH
Published: December 2023

Purpose This study makes a unique contribution to the knowledge by investigating the mediating role of the social and personal norms across the acquisition, use and disposal stages of the responsible computer consumption lifecycle. Originality As the pioneer study conducted in Asian countries that provides integrative and holistic comparison on the mediating effect of personal and social norms with regards to responsible computer acquisition, use and disposal. Additionally, this study makes a theoretical contribution to the responsible computer value-behaviour relationships in an emerging market context. Methodology A large sample of 1000 questionnaires collected from 8 developed cities in Malaysia with the highest level of computer literacy, making this study capable of being generalized to the Malaysian population. Findings Social norms mediate the relationship between altruistic values and social norms at the acquisition and disposal stages. Personal norms mediate the relationship between altruistic and social norms at the acquisition and disposal stages.
DAMAGE DIAGNOSIS OF COMPLEX CONNECTION STRUCTURES OF AIRCRAFT FUSELAGE STRINGERS WITH GUIDED WAVE-BASED METHOD
Authors: XU YUSEN , CHEN JIAN , YUAN SHENFANG , YANG YAHUI , QIN ZHEN
Published: December 2023

For civil aircraft, structural forms of its components like fuselage and wing are very complicated. Usually, these structural components are manufactured separately and then riveted together. These connection parts, such as stringer joints and skin lap joints, are prone to be cracked and failure. In addition, most structures are inaccessible, making manual maintenance difficult. Therefore, it is of great significance to reliably monitor the fatigue crack damage of complex connection structures. Guided wave (GW) based structural health monitoring (SHM) has attracted wide attention in the aerospace field since it has the characteristics of being sensitive to small damages, and capable of monitoring large areas. However, the complex configuration, the limited space, and the interference of bolts and rivets make sensor deployment difficult. Moreover, during propagation in complex connection structures, guided waves will undergo reflection, transmission, and mode conversion, resulting in mode aliasing and wave packet deformation of response guided wave signals. The structural damage information contained in the signal will also be masked, which brings difficulties to crack monitoring in complex connection structures. Although there have been some related studies on crack monitoring of metal joint structures such as lap joints, there are still other parts in the complex joint structure of the actual fuselage, such as long stringers and belt plates. At present, especially for the multi-layer riveted butt joint structure with stringers, the research is still very limited. In this paper, the amplitude and mode of the guided wave signals of different types of channels between the components of the single strap butt joint structure with stringer are analyzed. By imposing simulated damage, the effect of the damage scattering signal on the damage identification ability after guided waves pass through multiple rivet holes or multi-layer structures of the complex structure is studied. The crack damage diagnosis method for the complex connection structure of aircraft fuselage stringer is studied and verified by the experimental results of real cracks. The diagnostic results demonstrate the effectiveness of the method.
AN INTEGRATED ACOUSTO-MECHANICAL ENERGY APPROACH FOR MONITORING FLEXURAL BOND-SLIP BEHAVIOUR OF GFRP BARS AND CONCRETE
Authors: RATHER AMER ILIYAS , BANERJEE SAUVIK , LASKAR ARGHADEEP
Published: December 2023

Mechanical testing data and acoustic emission (AE) data can be independently analysed to evaluate the bond deterioration process of glass fibre reinforced polymer (GFRP) rebars and concrete. However, one type of data may not be adequate for thorough and accurate damage characterization and assessment. Sentry function, a unitless quantity, which relates mechanical and AE energy, has been efficiently applied in polymer composites and multi-layered laminates to study damage progression, including delamination. The sentry function has not been used in any of the past studies to understand the bond-slip behaviour of reinforcements in concrete. The present study attempts to exploit the effectiveness of the sentry function to evaluate the flexural bondslip behaviour of GFRP rebar and concrete. A thorough AE monitoring experimental programme has been conducted to evaluate and understand the interfacial bond deterioration process between GFRP reinforcement and concrete under flexural loading. The experimental test variables include confinement conditions and embedment length of the GFRP bar. Findings from the study suggest that the sentry function proves to be a successful and effective tool for evaluating the GFRP-concrete flexural bond deterioration. The sentry function captures and delineates the development and utilization of various bond stress transfer mechanisms (chemical adhesion, mechanical interlocking, and frictional resistance) involved in bond-slip behaviour.
REVIEW OF VARIOUS CURING PROCESSES AND TECHNIQUES OF PRINTED CIRCUIT BOARD (PCB) AND INTRODUCTION OF NEW INNOVATIVE THERMAL CURING TECHNIQUE
Authors: ATEEQ MOHAMMED , FEUSER ROLAND , AL-SHROUF LOUI , JELALI MOHIEDDINE
Published: December 2023

This paper examines the history of curing methods of Printed Circuit Boards (PCBs), especially, the thermal-based curing method with its different curing process techniques. In addition, highlighting its importance, hence, an incomplete curing process can lead to delamination, cracking, or other failures, which render the PCB useless. Moreover, various techniques used in the thermal-based curing method with their advantages will be explained. Also, the limitations of each technique will be demonstrated, such as, long curing times, uneven temperature distribution, high energy consumption, and absence of the knowledge-base of different PCBs, like board volume, heating capacity, and electronic elements. Furthermore, factors that affect the thermal-based curing method like type of material used, humidity, temperature, and time duration will be presented. So, each factor must be carefully controlled to ensure that the curing process is effective and consistent. In addition, a new innovative thermal-based curing approach will be introduced to overcome these limitations by using Artificial Intelligence (AI) techniques for the indirect prediction of temperature on PCBs. The proposed approach involves the use of new proper control based on AI technique to obtain an advanced control technique to control the heating process of PCBs during the curing process. This new approach will be developed during an ongoing research and development project.
EFFICIENT LIFECYCLE RELIABILITY ASSESSMENT OF OFFSHORE WIND TURBINES USING DIGITAL TWIN
Authors: ZHANG XUKAI , NOSHADRAVAN ARASH
Published: December 2023

The objective of this study is to develop a reliability assessment framework for the maintenance optimization of offshore wind turbines (OWTs) using an uncertainty-aware digital twin framework. OWTs are typically located far from the coastline to optimize wind utilization efficiency and minimize disruption of human activities. However, the greater distance between OWTs and the coast can increase maintenance costs due to accessibility and exposure to harsh weather conditions. Effective planning is crucial in managing these costs. Therefore, employing digital twin models for OWTs can provide potential benefits. A digital twin framework creates a virtual replica of the turbine and leverages multi-source data for real-time simulations, enabling assessment of the turbine’s performance under various loading conditions, which can substantially enhance the maintenance decision-making process. The proposed framework has two main contributions: (1) uncertainty quantification in the long-term performance of OWTs at both the component and system levels, and (2) digital twin decision support leveraging OWT failure probabilities under various scenarios, which is used to provide maintenance recommendations aimed at optimizing system profitability and structural integrity. Additionally, the digital twin model provides clear and concise warnings regarding potential OWT failures.
EVOLUTIONARY SENSOR NETWORK DESIGN FOR STRUCTURAL HEALTH MONITORING OF STRUCTURES WITH TIME-EVOLVING DAMAGE
Authors: CHADHA MAYANK , YANG YICHAO , HU ZHEN , TODD MICHAEL D.
Published: December 2023

Structural health monitoring (SHM) aims to assess damage intensity and provide engineers with data to make informed maintenance and repair decisions. SHM systems collect crucial information for evaluating a structure's current state, enabling appropriate maintenance decisions and loss mitigation. Therefore, it is crucial to acquire damage-sensitive data by using a well-designed SHM system that is optimal in terms of expenses as well as functionality. In this research, we present an optimal sensor placement framework that considers two stages of the structure’s lifespan: (1) an early-stage pre-posterior design, and (2) a periodically updated sensor design in the operational stage. When the sensors are designed initially in the pre-posterior stage, there is no data available to make informed design assumptions for designing the SHM system. As a result, all the uncertainties and damage evolution models for the structure need to be modeled probabilistically based on reasonable assumptions derived from historical perspective and engineering judgment. The early-stage design of an SHM system initiates the data acquisition and serves two primary purposes: (1) helps update the current state of the structure, and (2) supports data-informed maintenance decisions. As the structure degrades over time, despite periodic maintenance, it is bound to approach the limiting or critical damage state. This warrants an even better inference of damage state with the goal of avoiding the worst scenario of failure. In addition, another reason to update the sensor design while in the operational stage is to optimize the SHM system by making it more suitable to the current structural state and benefit from the data acquired through the pre-posterior design. Periodically updating the design yields the best risk to reward for an SHM system in terms of its expenses and functionality. We demonstrate the application of the proposed framework on a realworld complex miter gate structure.
AUTOMATED CRACK DETECTION FOR UNDERWATER INSPECTION OF MITER GATES WITH UNMANNED UNDERWATER VEHICLE
Authors: WU ZIHAN , HU ZHEN , TODD MICHAEL D. , ZENG JICE
Published: December 2023

The emergence of Unmanned Underwater Vehicles (UUVs) as tools for underwater inspection tasks presents promising potential. This study presents a novel automatic damage detection framework in large-scale underwater structures using a physics-based graphics model (PBGM). A high-fidelity finite element model of the Greenup Miter gate on the Ohio River is utilized to provide the fundamental information for the graphical model development. An open-source software is used as a graphic-based observational system to render images given different inspection distances and environmental conditions, such as light conditions and water quality. A deep neural network for crack detection with segmentation from the existing literature is adopted and then trained using transfer learning, adapting it to the unique conditions of underwater circumstances. Results indicate that the proposed method provides highaccuracy damage detection amidst the unique background noise and uncertainties presented in the underwater environment, contributing significantly to the field of UUV inspection of large-scale structures.
DESIGN OF MULTIFUNCTIONAL STRUCTURAL BATTERY COMPOSITES FOR THE NEXT GENERATION OF ELECTRIC VEHICLES
Authors: FARHANGDOUST SAMAN , AHMED SHABBIR , STRANGE ALEXANDER , ALTUNTAS UMUT , DUAN CHAOQUN , ABDULLAH YAQOUB , LI FRANKLIN , WANG SERENA , CHANG FU-KUO
Published: December 2023

A multifunctional energy storage composite (MESC) combines the high energy density of lithium-ion batteries with the structural benefits of carbon fiber composites, resulting in a lightweight structural battery with excellent mechanical strength and enhanced safety for electric vehicles (EVs). This paper presents the design-tofabrication development of new MESC, with a specific focus on the design, fabrication, and testing of an electronic skateboard (e-skateboard) as a representative system-level study for the EVs. A finite element analysis (FEA) is employed to design the MESC eskateboard. The FEA of the MESC e-skateboard is validated through mechanical testing, demonstrating a significant 24% reduction in weight, leading to an impressive 31.6% improvement in energy density compared to a conventional e-skateboard. As a part of the MESC technology, an embedded smart sensor network is also developed for the e-skateboard, showcasing the capability for real-time battery monitoring, and estimating its state of charge during in-service operation. The promising outcomes of the new MESC technology position it as a novel solution for enabling multifunctional structural battery composites in future electronic vehicles and aircraft applications.
INTEGRATED SENSING SYSTEM FOR AUTOMOTIVE APPLICATIONS
Authors: GHANNAM MAHMOUD , FAROOQ ISKANDER , JOSEPH ROSHAN , GRAY CODY , LI FRANKLIN , KUMAR AMRITA
Published: December 2023

The Department of Energy (DOE) Vehicles Group has identified a need for novel multifunctional composite materials and structures for the automotive industry that have the capability to reduce weight and volume as well as costs of “conventional” structural components by performing engineering functions beyond load carrying. As part of this project, Acellent in collaboration with Ford Motor Company is developing a sensing system for use in automotive applications. An advanced sensing system is needed to effectively distinguish impacts between different objects. Information received from the first contact between object and automobile bumper can be used to identify the object for vehicle applications. This paper will discuss the need and requirements for such a system and provide an overview of the development of a piezoelectric sensor system including the design, development and initial testing of a complete prototype of the system through various tests on bumpers. Acellent’s SMART layer sensor design for the bumpers will be discussed along with their manufacturing and installation on the car bumper. The paper will also discuss potential optimization of the sensor locations. Detection algorithms were developed to distinguish between various objects that were used in the impact on the bumper. Additionally key parameters were considered when building the algorithms: • impact speed, • bumper stiffness and dimensions, • object stiffness, mass and size Testing was conducted using, for example, simulated small animal, stone, wooden board etc. Results from the testing of the complete prototype system for the impact detection for automobile applications will be presented.
AN INVESTIGATION OF THE EFFECT OF MEASUREMENT INTERVAL ON THE AUTOENCODER BASED DAMAGE DETECTION IN UNCONTROLLED STRUCTURAL HEALTH MONITORING
Authors: YANG KANG , HARLEY JOEL B.
Published: December 2023

Unsupervised damage detection in uncontrolled, outdoor environmental and operational conditions (EOCs) is crucial for practical structural health monitoring. While previous research has explored autoencoder-based unsupervised damage detection methods, they require training data only from pristine conditions. In long-term monitoring, irregular environmental and operational conditions, as well as variations in damage, may make it difficult to satisfy this requirement. In this paper, we propose a novel autoencoderbased approach that uses training data containing regular and irregular environmental and operational conditions, as well as damage variations. We also investigate the impact of various factors, such as training epoch, damage duration, and measurement interval on the accuracy of damage detection. Our results indicate that our proposed framework achieves an AUC score of over 0.95 when the measurement interval is around 860 seconds per measurement. Interestingly, this score decreases both when we sampling faster and slower.
OPTIMIZATION OF A VISION-BASED SHM SYSTEM FOR IMAGING SUBSURFACE IMPACT DAMAGE IN COMPOSITE STRUCTURES
Authors: ABBOTT T. BRYCE , YUAN FUH-GWO
Published: December 2023

This paper describes the optimization of a computer vision-based technique for visualizing subsurface barely visible impact damage (BVID) in composite structures. The system uses a piezoshaker for exciting a guided wavefield with a sweeping frequency in the near-ultrasonic frequency range, a digital camera or stereo-camera for recording surface dynamics, and an energy-based damage imaging condition for identifying local resonance from standing waves within damage regions. The method for extracting surface dynamics from the videos was optimized, evolving through three techniques – 3D digital image correlation (DIC), off-axis 2D DIC, and image decorrelation – with the ultimate goal of creating a practical and efficient visionbased method for BVID inspection. Each proposed technique was applied to inspect two CFRP composite-honeycomb panels that had been subjected to low-velocity impacts. Damage images produced with all techniques for a 100-mm  100-mm FOV using a three-second video show accurate damage imaging ability. The processing time required by the optimized decorrelation technique for extracting surface dynamics is approximately 15 times less than 3D DIC and 5 times less than off-axis 2D DIC. The increased efficiency, reduced complexity, and demonstrated accuracy of the system suggests a high potential for practical baseline-free and in-time computer-vision-based structural health monitoring (SHM) and baseline-free subsurface damage imaging for critical composite structures.
ANALYSIS OF RELIABILITY AND EFFECTIVENESS OF REPEATED INSPECTIONS BASED ON PROBABILITY OF DETECTION METHOD
Authors: JUNG SEONHWA , KIM YOUNGCHAN , LEE DOOYOUL
Published: December 2023

Structural health monitoring (SHM) performs the function of evaluating performance and durability for structural life management by monitoring changes in engineering structures such as buildings and bridges. In order to obtain information about a structure's ability to perform its intended function, data collection activities are required through various inspections aimed at detecting the presence of structural damage. Repeated inspections have been proposed to increase the reliability of SHM. Many people considered repeated inspection as a way to increase the chance of detecting damage. If more than one of the individual inspections finds damage, collectively evaluates the damage as detected and produces the results of repeated inspections. Probability of detection (POD) was used as a measure of the sensitivity and reliability of the inspection process. To evaluate structural condition and predict remaining service life, POD is measured and structural life is calculated based on initial defect sizes that are just below the inspection limits of non-destructive testing techniques. Repeated inspections can be considered by multiplying the likelihood function, but if a single inspector performs repeated inspections, they may not be independent because they may be biased by previous inspection results. The repeated inspections is independent if performed by an automated system or another inspector unaware of previous inspection results. It can be assumed that each inspection is independent in that the SHM system can automatically collect data even in areas where general non-destructive testing is impractical due to complex geometries and accessibility limitations, but conversely, due to the dependencies of the data, there is no statistical difference between subsequent measurements. It is also considered to be less independent. In this paper, the effect of repeated inspection on POD improvement was confirmed using eddy current inspection data, and the benefits of repeated inspection differed from those predicted by assuming complete independence. Furthermore, the effectiveness of repeated inspection was discussed.
HIGH SENSITIVITY WIRELESS STRAIN SENSOR FOR SHM APPLICATIONS
Authors: MAHMOUD HASSAN A. , NESSER, HUSSEIN , WAGIH AHMED , LUBINEAU GILLES
Published: December 2023

Our research aims to develop a new generation of ultrasensitive strain sensors with wireless communication of data and energy, low power consumption, and easy installation within structures to be used as in-situ measurement systems. The sensor has been developed based on RFID sensing technology that allows wireless data and power transmission by inductive coupling between the internal inductance of the sensor and the external readout coil. Microfabrication technology is used to fabricate the sensor by patterning a metallic LC circuit on a flexible substrate. Nano cracks are introduced to the electrode to create a piezoresistive effect that leads to a transmission line behavior of the capacitance electrodes. The sensor has been embedded with GFRP and CFRP, a bending test has been performed, and the sensor is used to measure the strain during the test. The sensor proves its ability to detect small strains in the composite structures due to the unconventional change in capacitance of the LC oscillator. This unconventional change in capacitance results in a large shift in resonance frequency, producing a sensitive wireless strain sensor with a Gauge factor of 50 for less than 1% strain.
FLUORESCENCE-BASED FIBER OPTIC SULPHATE SENSOR FOR LONG TERM SULPHATE ION MONITORING IN CONCRETE STRUCTURES
Authors: LIN ZHEN , NI YIQING , SUN TONG
Published: December 2023

Concrete has been one of the most popular construction materials around the world. However, sulphate ion will cause of concrete degradation and lead to the decrease of service life of concrete structures. The formation of ettringite and other reaction products can lead to the decrease of service life of concrete structures, thus, a continuous monitoring of sulphate ions is needed as a reference for the maintenance work of concrete structures. This paper presents the design and development of a fluorescence-based fiber optic sulphate sensor for this purpose. The sensor's design capitalizes on the changes in fluorescent intensity of morin-metal ion complexes induced by sulphate concentration changes. By using cellulose acetate, the complex is transformed from a solution to a thin film, serving as the sensing element in the sensor probe. The sensor provides a response over a sulphate molarity range of 0 mol/l to 0.010 mol/l. And after being embedded inside the cement paste, the sensor still responds to sulphate. These features make this fluorescence-based fiber optic sulphate sensor potentially suited for in field and long-term monitoring of sulphate ions in the concrete structures, thereby enhancing structural health monitoring within the civil engineering sector.
SEMI-SUPERVISED LEARNING FOR ACOUSTIC VISION MONITORING OF TENDONS IN PRE-STRESSED CONCRETE BRIDGES
Authors: LANGE ALEXANDER , KÄDING MAX , XU ROGHUA , MARX STEFFEN , OSTERMANN JÖRN
Published: December 2023

Aging bridge infrastructure appears to become a major challenge in many industrialized countries. Numerous bridges are in bad condition and the current pace of repair and replacement as well as the available financial resources hence demand for a reliable bridge monitoring to facilitate an extended operation period of existing bridges. Nowadays, prestressed concrete bridges are prevalent among other construction types but may suffer from stress corrosion cracking of steel tendons. To detect wire breaks in bridge tendons, recent research suggests the use of acoustic emission analysis. In this work, we propose the use of semi-supervised learning techniques for anomaly detection to detect wire breaks in tendons of prestressed concrete bridges. Particularly, we utilize only acoustic emissions due to traffic and other environmental influences, recorded on a real bridge in operation, to initialize the local outlier factor algorithm. We then apply the initialized local outlier factor algorithm to two separate datasets with more than 500 wire break signals recorded on two different types of bridge girders. It is shown that the anomaly-based approach outperforms a supervised k-nearest neighbors classifier trained using wire breaks from only one girder. An evaluation on the wire break signals from the second bridge girder, not seen during the training phase, shows an improvement of the average recall score from 38 % to more than 99 % for the anomaly-based approach compared to the supervised k-nearest neighbors classifier. Considering the diversity of bridge constructions and the fact that availability of acoustic emission signals due to wire breaks is limited, semi-supervised learning seems to be a suitable approach for wire break detection. Furthermore, acoustic emissions due to normal environmental and operational conditions could be easily and cost-effectively recorded during an initialization phase of any monitoring system and thus be utilized to initialize an anomaly detector for each specific infrastructure.
ACOUSTIC EMISSION SOURCE LOCALIZATION IN FIBER-REINFORCED COMPOSITES BASED ON MULTIMODAL DISPERSION COMPENSATION OF GUIDED WAVES
Authors: HUIJER ARNAUD , KASSAPOGLOU CHRISTOS , PAHLAVAN LOTFOLLAH
Published: December 2023

Fiber-reinforced composite materials are widely used in the aviation, civil, and shipbuilding industries. Especially the latter two industries are typically dealing with thicker composites. At the same time, in these industries the need for structural health monitoring, to assess degradation and failure, is becoming more prevalent. Acoustic emission (AE) measurement and analysis for damage source localization and characterization can be a useful method for the assessment of structural integrity for these structures. In the case of composite panels, acoustic emissions can propagate in the form of elastic guided waves. The location of the AE source exposes regions in a structure that are subject to degradation. Typical acoustic emission source localization methods assume that the recorded AE signals consist of a single dominant fundamental wave mode. However, with thicker composites, the acoustic emissions may propagate in a multitude of modes. This will complicate the signal processing operations for accurate source localization. This research assesses experimentally how guided wave multimodality influences acoustic emission localization. An acoustic emission source is excited in a thick glass fiber-reinforced plastic (GFRP) panel. Measurements from this excitation are first assessed for their content of higher modes. Source localization is carried out based on dispersion compensation through time-distance domain migration. Different possibilities and combinations of wave modes are considered. The localization error is assessed for each option. The results highlight the added complexity of multimodality and show how the inclusion of multiple modes into the procedure can improve the accuracy of source localization.
REVOLUTIONIZING ROAD MAINTENANCE: A DATA FUSION AND AI-BASED APPROACH
Authors: HUANG YU-TING , SANKA NIKKHIL VIJAYA , JAHANSHAHI MOHAMMAD R. , SHEN FANGJIA
Published: December 2023

The deterioration of pavement conditions over time can lead to significant costs for rehabilitation once the pavement conditions fall below a certain level of deterioration. To mitigate these costs, it is possible to extend the service life of pavement through periodic maintenance at a relatively low cost. To increase the frequency of inspections and enhance the effectiveness of maintenance activities, this study proposes a crowdsourcing-based inspection system for autonomous road condition assessment that can be mounted on multiple vehicles. The proposed inspection system can evaluate the pavement condition based on the Pavement Surface and Evaluation Rating (PASER) system. Vehicles equipped with this data acquisition system are driven over the road through the cities twice per week, thus comprehensive RGB-D data of the road surface are collected timely and widely. The system can detect various defects, including transverse cracks, longitudinal cracks, alligator cracking, and 3D defects such as rutting and potholes through a trained deep learning-based classification model. Furthermore, the proposed autonomous road inspection system can monitor the evolutionary changes of defects such as cracks and potholes to enable damage prognosis.
PHOTOREALISTIC RENDERING AND MODIFICATION OF MOTION BLUR FOR THE SIMULATION OF VIDEO DATA FOR STRUCTURAL DYNAMICS
Authors: GREEN ANDRE , SILVA MOISES FELIPE , DAVIS ALLISON , KARPOWICZ ALEXANDER , SOMBORGER ANDREW , CATTANEO ALESSANDRO , MASCAREÑAS DAVID
Published: December 2023

In recent years imager-based approaches to structural dynamics measurements have gained increasing interest. Imager-based approaches to measurement have a number of attractive properties including being able to monitor large areas at a relatively high spatial resolution with a relatively small number of imagers. The stand-off monitoring capabilities of imagers are also highly attractive for many structural dynamics and structural health monitoring applications, particularly those in dangerous, inaccessible, extreme, and high temperature environments. For their advantages though, a number of challenges must be addressed when using imager-based techniques for measuring the deformation and motion of structures. There are issues of lighting conditions that can potentially vary during the measurement period, due to movement of the sun or lights in a facility being turned on and off. In addition, video measurement of dynamic structures also requires making a number of choices associated with the measurement setup including location of the imagers, focal lengths of lenses, numberof- pixels, lens characteristics, framerates, shutter speeds, ISO, aperture settings, planes of focus, and depth-of-field. There can potentially be effects such as specular reflections or shadows which might complicate downstream data processing. The large number of parameters associated with imager measurements make them very flexible, but it also can mean that setting up imager measurements can take substantial time even under controlled laboratory conditions. The complication associated with imager measurements suggests that highfidelity, photorealistic rendering tools that are capable of capturing the interactions between structural dynamics, light transport, and the measurement process at the imaging plane are needed. To date, substantial work has been done by the computer graphics community to develop photorealistic rendering tools which are becoming increasingly accessible. However, in structural dynamics we often care about sub-pixel motion and it is not understood whether current techniques for modeling effects such as motion blur have sufficient fidelity for structural dynamics. Furthermore, photorealistic video renders can take a large amount of time to complete, and given current techniques do not allow for simple changes such as frame-rate/shutter speed in post processing without redoing the entire render. In this work we present an approach based on digital coded exposures for forming frames of dynamic scenes, that allows for the framerate and shutter speed to be changed in post-processing. The proposed approach is inspired by the physical operation of conventional cameras. In addition, the digital coded exposure proposed approach suggests theoretical alternatives to data capture that could potentially be used to control motion blur properties on a per-pixel basis.
STRUCTURAL PARAMETER IDENTIFICATION WITH A PHYSICS-INFORMED NEURAL NETWORKS-BASED FRAMEWORK
Authors: ZHANG WEIJIA , NI YI-QING , YUAN LEI , HAO SHUO , WANG SU-MEI
Published: December 2023

Structural parameter identification is a critical aspect of structural health monitoring and maintenance. It belongs to inverse problems, which aim to discover mechanical parameters, such as the stiffness of the concerned system from collected measurement data. Then, the identified parameters are used to evaluate the status of the structure and detect potential structural damage in advance. As a promising machine learning method that effectively combines domain knowledge and deep neural networks, physicsinformed neural networks (PINNs) have been widely applied in various fields, including structural parameter identification and structural health monitoring. In this study, we propose a novel framework based on PINNs for parameter identification in structural systems. The framework contains two main components, one is called the physical term that employs PINNs to learn the prior physical knowledge of the structural system; the other is called the discrepancy term that involves another PINNs or even a simple feedforward neural network to present the differences between the observed data and the physical term. In a nonlinear structural system, the physical term can be regarded as the linear part of the structural response, while the discrepancy term represents the nonlinear response. In the PINNs configuration, the residuals of the governing equation, which are calculated by substituting collocation points that are randomly sampled within the domain into the governing equation, are directly incorporated into the total loss function. In addition, the boundary conditions, as well as the initial conditions, are softembedded as essential parts in the total loss function. The measurement data is also required by an inverse problem, and the differences between the measurement data and the prediction produced by the PINNs-based physical term will be captured by the discrepancy term. Through the discrepancy term, the nonlinear structural parameter can be figured out. Finally, a two-degree of freedom mass-spring system with nonlinear spring is investigated to illustrate the ability of the proposed framework in structural parameter identification.
Lo grotesco en el surrealismo II. Análisis Práctico
Authors: Duarte María
Published: December 2023

La categoría estética de lo grotesco experimentó una revalorización considerable durante el siglo XX, haciéndose difícil de abarcar por completo sus manifestaciones en este momento. Ello podría deberse en gran medida a la ruptura que propusieron las nuevas vanguardias con respecto al arte académico, ya que lo grotesco, por su carácter transgresor, servía como medio para manifestar las aspiraciones de muchos artistas, y en algunos casos, también de movimientos concretos, como lo fue el surrealismo. Este celebraba los aspectos más subversivos y ocultos del individuo, por lo que muchos de los pertenecientes al grupo se sirvieron de esta categoría como medio para expresarlos.