bluuebunny/crossref_metadata_2025 huggingface dataset:
State-of-the-Art Knowledge Distillation for Recommender Systems in Explicit Feedback Settings: Methods and Evaluation
Authors:   Korean Institute of Smart Media, Bae Hong-Kyun , Kim Jiyeon , Kim Sang-Wook
Published: November 2023

Recommender systems provide users with the most favorable items by analyzing explicit or implicit feedback of users on items. Recently, as the size of deep-learning-based models employed in recommender systems has increased, many studies have focused on reducing inference time while maintaining high recommendation accuracy. As one of them, a study on recommender systems with a knowledge distillation (KD) technique is actively conducted. By KD, a small-sized model (i.e., student) is trained through knowledge extracted from a large-sized model (i.e., teacher), and then the trained student is used as a recommendation model. Existing studies on KD for recommender systems have been mainly performed only for implicit feedback settings. Thus, in this paper, we try to investigate the performance and accuracy when applied to explicit feedback settings. To this end, we leveraged a total of five state-of-the-art KD methods and three real-world datasets for recommender systems.
Portable IoT-Based Disinfection Box
Authors:   Universiti Tun Hussein Onn Malaysia, Muda Muhammad Ikmal , Mohd Shah Shaharil ,   Universiti Tun Hussein Onn Malaysia
Published: November 2023

The COVID-19 pandemic is an ongoing global health event that began in 2019. It is caused by a novel strain of coronavirus known as SARS-CoV-2. Bacteria and viruses can cause illness in human. Therefore, a Portable IoT-based Disinfection Box is developed in this work to disinfect small electronic devices such as smartphone, smartwatch or even a 13-inch tablet, that may come into contact with bacteria and viruses. There are three special features of this Disinfection Box which are the timer itself, Web Interface Monitoring, portable and spacious with dimensions of 29 × 18 × 14 cm3. The ESP32 Wi-Fi module with NodeMCU-32S Base module as a microcontroller is used in this work and it controls the 2-channel Relay in order to turn ON and OFF the UV-C LED light strip. Besides that, it is also connected to the LCD display with I2C module to display the real-time of disinfection process. The Dashboard of Arduino IoT Cloud allows the user to control and monitor the operation of disinfection process. When a small electronic device is placed inside the Disinfection Box, UV-C LED light strip is turned on to begin the disinfection process. The effectiveness of the UV-C LED light strip is investigated by using the Petri dish with agar. It is shown from the experimental procedures that 10-minute disinfection time provided by the Disinfection Box is sufficient to disinfect small electronic devices such as smartphone and smartwatch. This is based on the great reduction of bacteria colonies on the agar in Petri dish after being kept in a dark place with room temperature for 4 days.
Electric Field Analysis of HDPE/NR Biocomposite Due to Moisture Content Condition
Authors:   Universiti Tun Hussein Onn Malaysia, Aziz Ahmad Farid , Mohd Jamail Nor Akmal ,   Universiti Tun Hussein Onn Malaysia, Kamarudin Qamarul Ezani ,   Universiti Tun Hussein Onn Malaysia
Published: November 2023

It is critical to develop new insulating materials that can improve the performance of next-generation high-voltage cables used in the construction of future electrical networks. The high electric field reduces solid insulation resistance and causes partial discharge through imperfections in a dielectric, causing the dielectric to age and eventually fail. Moisture is one of the most serious factors the effect the high voltage insulation status of High-Density Polyethylene (HDPE) composites. The main goal of this project is to investigate the electric field intensity of HDPE due to moisture content condition when mixed with 10g, 20g, and 30g of various bio-fillers such as coconut coir fibre, pineapple leaves fibre, and oil palm empty fruit bunch. This can be accomplished by using the Finite Element Method Magnetics (FEMM) 4.2 software to create a two-dimensional (2D) axisymmetric electrostatic model. When compared to unfilled HDPE, the inclusion of bio-filler in HDPE increased the maximum electric field intensity due to moisture content condition. The intensity of the electric field varied with the different percentages of biocomposite loading and their permittivity due to moisture content condition. The results showed, due to moisture content condition, the maximum electric field intensity was significantly lower when HDPE was added with a 10% loading of the oil palm empty fruit bunch (EFB). As a result, EFB bio-filler was the best composition because it tends to improve dielectric properties by having a lower maximum electric field intensity which is 4.214Mv/m due to moisture content condition at the top sphere electrode when compared to other compositions.
POTENTIAL AREA ANALYSIS IN THE AGROPOLITAN DEVELOPMENT AREA IN BOJONEGORO REGENCY, EAST JAVA PROVINCE, INDONESIA
Authors: Azizia Via Hamida Dwita Noer , Huda Syamsul
Published: November 2023

The purpose of this study is to analyze the potential of the region in developing an agropolitan area in Bojonegoro Regency, East Java Province through the location quotient, shift share. Data collection techniques generally used primary and secondary survey methods. The results show that based on the results of the Location Quotient (LQ) calculation in Bojonegoro sub-district which are included in the base sector, namely the mining sector, government administration sector, information and communication sector and the mining sector. is; agriculture sector, mining and quarrying sector, manufacturing industry sector, electricity and gas procurement sector, wholesale and retail trade sector, transportation and warehousing sector, accommodation and food and beverage provider sector, information and communication sector, financial and insurance services sector, real estate sector , the corporate service sector and the government administration sector
統計コミュニティは統計不正にどう対応したか: 毎月勤労統計調査問題における政府・専門家・非専門家のはたらき
Authors: Tanaka Sigeto
Published: November 2023

In Japan, we have recently witnessed several cases of long-overlooked misconduct in official statistics. The Japanese statistics community, which comprises people who are interested and skilled in statistics and capable of reading Japanese, does not appear to have made a remarkable contribution to detecting such misconduct. To discover the reason, this study focused on the incorrect method for estimating the number of workers introduced in 2018 to the Monthly Labour Survey by the Ministry of Health, Labour and Welfare (MHLW). On the basis of literature published since 2018, the author revealed that both inspecting committees in the government and external statistical experts overlooked indications of method alteration as well as the biases resulting from it, because they worked only on documents and explanations prepared by the MHLW. The finding suggests that, with the exception of a few non-expert citizens in the periphery, the Japanese statistics community lacks data-based criticism. At the core of the community, statistical experts uncritically and unjustifiably approve what government statisticians contend, without conducting original research on publicly available data.
Air Movement Operations Planning Heuristic Improvement
Authors: Nelson Russell , Werner Jack , Daniels Rebecca , Kay Michael , King Russell , McConnell Brandon , Thoney-Barletta Kristin
Published: November 2023

Purpose - Improve the air movement operations planning heuristic in the literature to generate better solutions in a shorter time period.
Design/Methodology/Approach - Through a rigorous design of experiments, we make significant heuristic improvements by evaluating alternative modular methodologies and tuning heuristic parameters for two scenarios. This includes a new approach to considering refueling operations.
Findings - We find the fine-tuned heuristic averages a 33% objective improvement and 70% reduction in computation time over the heuristic with original parameters for one of the scenarios. Additionally, we analyze the heuristic's quality of solution over time.
Research limitations/implications - Further analysis is required to generalize heuristic settings, which would require significant access to operational data or a portfolio of scenarios of interest.
Originality/value - This research provides novel vehicle assignment and routing heuristic improvement alternatives and demonstrates a design of experiments-based heuristic tuning procedure.
Practical implications - Tuned heuristic parameters reduce the computation time from hours to minutes. This also makes it practically feasible to adjust parameters in the objective function to generate multiple courses of action for a given instance.
INNOVATION AND INVESTMENT PROJECTS: THE DIALECTIC OF THE INFLUENCE ON THE ECONOMIC SECURITY OF THE ENTERPRISE
Authors: VESHKIN Yevhenii , KHUDIAKOV Denys ,   Kharkiv National University of Radio Electronics
Published: November 2023

The purpose of the article is to analyze the impact of the inclusion of innovation and investment projects in the enterprise’s business strategy based on the study of risks and opportunities in the area of the implementation of the goal of strengthening economic security. The methodological basis of its achievement was a critical analysis of the scientific output of domestic researchers in the directions of determining the essence and components of the economic security of the enterprise, management of innovation-investment activities on a project basis, management of innovation-investment risks. The historical process of formation of the modern understanding of the category “economic security of the enterprise” and its interpretation in the scientific literature are revealed. The peculiarities of the implementation of the adaptation mechanism as a means of ensuring the sustainable functioning of the business entity in the conditions of challenges generated by the modern external environment have been studied. It is recognized that the management subsystem of innovation and investment activities is of key importance in achieving the goals of economic security of the enterprise. The stages of its implementation are disclosed and it is proved that the optimal principle of organizing the management of innovation and investment activity is the project principle, since the project activity is non-cyclical and does not have a permanent nature. The category “investment and innovation risk” was analyzed in terms of content and classification in the logical series “types of risks – types of risks – risk factors”. The starting point of the typology was the criterion of the possibility of control by enterprises, which is key in the formation of the management architecture of innovation and investment projects. The dialectic of the influence on the economic security of the enterprise of the inclusion of innovation and investment projects in its business strategy is revealed, which consists in the following: they are both a threat and a guarantee of economic security. The direction of the impact of innovation and investment projects on the economic security of the enterprise depends on the adequacy of risk monitoring and the effectiveness of mechanisms for their neutralization or mitigation.
ASSESSMENT OF THE FINANCIAL POTENTIAL OF TOURISM AND HOSPITALITY ENTERPRISES IN THE CONTEXT OF STRATEGIC DEVELOPMENT
Authors:   University of Customs and Finance, SAIGAK Elizaveta
Published: November 2023

Established the role and significance of the financial condition assessment in the strategic context of the enterprise’s development. Determined the nature of the occurrence is determined and the characteristics of the connection and interdependence of the strategic financial analysis and the strategy formation for the enterprise financial potential development determined. Summarized provisions on determining the content of the company’s financial strategy. Defined the main approaches to establishing the financial strategy essence are: the functional-management approach (the planned sequence of actions, i.e., the implementation of the function regarding the accumulation, distribution, use and reproduction of financial resources); the capital approach (proceeds from the imperative nature recognition of the economic entity market value priority in the strategic development of goal systems; assumes a corresponding increase in the financial strategy importance relative to other functional and operational strategies); behavioral approach (based on the assignment to the scope of the financial strategy implementation, first of all, of the principle guidelines for the enterprise’s financial relations implementation with other participants in the market interaction). Summarized the financial strategy characteristic properties composition in the mechanism of formation and implementation of other elements strategic set is: a long time of implementation orientation; purposefulness, which determines the orientation and subordination of a financial goals set to the company’s fulfilling imperative plans; the financial goals inclusion in the strategic development implementation mechanism priorities; the functional combination optimality and cost parameters implementation of strategic plan individual elements. Proposed a methodical approach to assessing the enterprise financial potential in the tourism industry and the hospitality field. The financial potential components of the enterprise assessment in the tourism industry and the field of hospitality have been established: the parameters of the enterprise’s financial condition; strategic competences in the field of financial management; weighted cost of raising capital.
MAXIMAL OPERATOR IN WEIGHTED MORREY SPACES, ASSOCIATED WITH THE LAPLACE-BESSEL DIFFERENTIAL OPERATOR
Authors:   Institute of Mathematics and Mechanics, Aliyeva L.R. ,   Kirikkale University, Esen Almali Sevgi ,   Azerbaijan State Oil and Industry University, Safarov Zaman
Published: November 2023

We consider the generalized shift operator, associated with the Laplace-Bessel differential operator. The maximal operator Mγ(B-maximal operator), associated with the generalized shift operator is investigated. At first, we prove that the boundedness of maximal operator weighted Morrey spaces Lp,λ,ω1,γ(Rn k,+) to the spaces Lp,λ,ω2,γ(Rnk,+), where 1 < p < ∞,(ω1, ω2) ∈ Fp,γ(Rnk,+), associated with the Laplace-Bessel differential operator
HARDY-CESARO MAXIMAL OPERATOR IN LEBESGUE-BMO SPACES
Authors:   Azerbaijan State Oil and Industry University, Hasanov Javanshir
Published: November 2023

In this paper defining the Lebesgue-BMO spaces. We prove the boundedness of the Hardy-Cesaro maximal operators in such spaces. Also prove necessary and sufficient condition the boundedness of the Hardy-Cesaro maximal operators in Lebesgue spaces.
A new CADConform Method Matchs As-Built Geometry with Trimmed NURBS to Facilitate NDE Data Fusion
Authors: Liu Lijie , Li Qing , Krishnamurthy Adarsh , Holland Stephen D. , Zhang Zhan ,   Iowa State University
Published: November 2023

Manufactured parts rarely match their computer-aided design (CAD) precisely, and sometimes the difference can be significant. As industry moves toward capturing, recording, and fusing NDE data registered to physical geometry, differences between as-built and as-designed geometries will become problematic. Using the CAD model as a reference configuration, this work proposes a CADConform method for distorting the CAD model to match an as-manufactured condition, so that NDE data acquired in the context of an as-built part can be mapped onto the original CAD model for fusion or inference. Continuing our previous work, this framework fills the research gap of retaining the CAD topology while handling large-scale deformation and arbitrarily trimmed NURBS. This project will facilitate a new generation of research and applications in NDE data fusion, including over time and over different serial numbers that will allow better quantitative evaluation, detection, and prognostics.
An improved AI based semantic filtering for marker less DIC
Authors:   Indian Institute of Technology Madras, Kumar David , Prasad Sneha ,   Chaoyang University of Technology, Chiang Chih-Hung ,   Indian Institute of Technology Jodhpur
Published: November 2023

Large structures, like wind turbines, are susceptible to structural damage from environmental variables and changing operational loads, which makes their parts susceptible to mechanical and performance deterioration. The use of high-definition optical vision sensors in digital image correlation (DIC) allows for the application of a non-destructive image registration technique that measures three-dimensional deformations on surfaces through correlations of a unique pattern or a set of unique localized patterns. However, it takes time and is quite challenging to put an artificial marker on the surface of a large structure, such as a distinctive speckled pattern. Therefore, to facilitate accurate displacement measurements for vibrational study and structural health monitoring, this study proposes an AI-based approach that searches and segments clusters of interest points from a reference image which works as a unique marker for DIC. Our algorithm is tested on a utility-scale wind turbine which demonstrates its effectiveness for structural health monitoring of large structures without artificial markers
Dependence of Ultrasonic Scattering on Case Depth in Railroad Bearing Components
Authors:   University of Nebraska-Lincoln, Adelung Trevor , Islam Showmic , Matz Nathanial J. , Swerczek Nick , Brandl William , Turner Joseph A. ,   University of Nebraska-Lincoln, Fuller Allen J. , Ammerlaan Liesl F. ,   Amsted Rail Brenco
Published: November 2023

Freight rail bearings are often subjected to heavy loads such that the performance of each bearing plays a crucial role in the safe operation of the entire train. Even bearings that are properly maintained may still fail due to rolling contact fatigue if local regions within the bearing race do not meet established effective case depth standards. Ultrasonic grain scattering has shown sensitivity to both microstructure and residual stresses such that nondestructive measurement methods based on diffuse ultrasonic methods may be possible to assess the case depth. Toward this goal, this study examines the relationship between effective case depth and ultrasonic scattering. The results illustrate the potential of this approach for an important safety issue.
Elastic Waves in Polycrystals: How to Represent Actual Microstructure Statistics by A Single Exponential Autocorrelation Function?
Authors:   Imperial College London, Huang Ming , Rokhlin Stanislav ,   The Ohio State University, Lowe Michael J. S. ,   Imperial College London
Published: November 2023

The spatial two-point correlation (TPC) function is a widely used descriptor of polycrystal microstructure. If accurately known, it is advantageous to represent it mathematically by an exponential series to model wave propagation. However, in the experimental practice the measured TPC is not sufficiently accurate, and it is appropriate to use a single exponential representation. Here, we evaluate a single exponential representation by comparing to the actual TPC obtained for 3D synthetic polycrystalline microstructures. We identify characteristic parameters that are linked to wave propagation and use them as the coefficient of the single exponential to calculate wave propagation constants. We evaluate our method against numerical simulations for various polycrystals and find that the effective radius derived from the volumetric integral of the autocorrelation function is the best coefficient for the low-frequency Rayleigh regime, while the correlation length obtained from the linear integral is optimal for the high-frequency stochastic regime. These two parameters are related to the free path distribution and can be easily measured from experimental samples without knowing the accurate TPC. The simplified representation makes it easier in practice to conduct wave propagation calculations and to perform further microstructure characterization.
Enhanced Ultrasonic Monitoring Technologies for Real-Time and Full-Field Rail Track Inspection
Authors:   University of California San Diego, Hosseinzadeh Ali Zare
Published: November 2023

Poor ballast support condition in ballasted railways and internal rail flaws are some of the main reasons for train derailments. This paper presents two non-contact ultrasonic testing-based techniques devoted to support condition assessment of ties and internal defect detection in rails. The techniques can potentially be operated at revenue speeds, with real-time data acquisition and processing capabilities, highlighting the concept of a ‘smart train.’ The first technique is an ultrasonic ranging technology aimed at evaluating the support condition of railroad ties. Deterioration in the tie-ballast interface can result in excessive negative bending (or center binding) under service loads. The proposed method utilizes sonar technology to reconstruct the deflection profile of ties, which can be inspected to identify any potential deterioration in ballast level. Using artificial intelligence, the proposed technique has been automated such that the tie boundaries are demarcated by machine vision, and subsequently the ranging technique is implemented at the tie locations. The method is benchmarked by a set of the preliminary test runs performed at walking speeds at a BNSF yard in San Diego, CA. High-speed non-contact rail inspection is the other technology, where the Green’s function for a rail segment is passively extracted to identify any discontinuity (e.g., internal defect) as the changes in the arrived waves. The proposed technology has been prototyped and a Real-Time LabVIEW module is developed to acquire and analyze the data and visualize the results. Field tests were conducted at the Transportation Technology Center Inc. (TTCI), Pueblo, CO, to evaluate the performance of the technique at different speeds.
Experimental and Simulated Studies of the Variability in Eddy Current Response for Discontinuities in Complex Geometry
Authors:   KBR, Oneida Erin K. , Shell Eric B. ,   KBR, Aldrin John C. ,   Computational Tools, Murphy R. Kim , Sabbagh Harold A. , Sabbagh Elias ,   Victor Technologies LLC,, Hutson Alisha L. ,   University of Dayton Research Institute, Lindgren Eric A. ,   Air Force Research Laboratory
Published: November 2023

This work presents progress to extend eddy current model-based inversion of discontinuities from flat plates to complex geometries. An elongated scallop inspection was considered through experimental studies and the development of numerical models. Trends were observed indicating flaw response sensitivity to location in the flat-to-curved transition region and to slight variations in eddy current coil orientation.
Experimental Method for Measuring Conductivity for Carbon Fiber Composites
Authors:   Baylor University, Lowe Seamus , Jack David ,   Baylor University, Gravagne Ian ,   Baylor University
Published: November 2023

Carbon fiber composite materials feature anisotropic conductivity that arises from a combination of resistive and reactive conducting pathways. Conductivity measurements for carbon fiber reinforced polymers (CFRP) are somewhat more challenging to obtain relative to metals, and vary widely depending on how the CFRP is constructed. This paper presents background research on CFRP conductivity, along with a novel experimental method for electrical measurement on CFRP that ensures uniform current density through the sample using thermal imaging techniques and maximizes electrical contact with the fiber itself. While not considered a traditional nondestructive technique, the method of this work directly supports ongoing research efforts in the NDE community around electromagnetic and eddy current testing of CFRP, along with evaluation of CFRP for, e.g., lightning strike or electromagnetic interference suppression; those techniques require baseline conductivity measurements to calibrate and interpret their results.
Heel Effect Measurement and Compensation
Authors:   Lawrence Livermore National Laboratory, Karimi Seemeen , Hall James , Ruelas Joshua ,   Lawrence Livermore National Laboratory
Published: November 2023

The Heel effect is a phenomenon that describes how the x-ray tube output varies with the angle of x-rays. The spectrum and total intensity vary according to the effective angle. The change in spectrum is usually ignored, consequently, the apparent linear attenuation coefficients measured is therefore spatially variant. We have experimentally quantified the Heel effect on a microtomography system, and verified it with simulations. By using a position-dependent beam hardening correction, we can compensate for the Heel effect and produce CT images that are quantitatively more accurate than those without compensation. Our results show that that the discrepancy in linear attenuation coefficient is reduced from 5% to 1% or better, with position-dependent beam hardening compensation.
Improved Estimates of High-Frequency Ultrasonic Attenuation in Complex Metals
Authors:   The Pennsylvania State University, Roy Anubhav , Kube Christopher M. ,   The Pennsylvania State University
Published: November 2023

Propagation and scattering of ultrasonic waves are sensitive to spatial fluctuations in microstructural properties and hence are commonly used for non-destructive evaluation (NDE) of polycrystalline metals. Analytical models provide the quickest estimates of parameters, like wavespeed and attenuation, that are relevant to ultrasonic propagation. The existing models consider first-order smoothing approximation (FOSA) to predict the scattering of bulk elastic waves in heterogeneous media. Several factors that contribute to the aggregate anisotropy include anisotropy of the constituent crystallites, distribution of grains along a preferred orientation (texture), porous or defective microstructure etc. FOSA-based model corresponding to the unified theory of scattering can accurately predict wavespeed and attenuation in some low-anisotropy metals for a wide range of frequencies. However, the recent observations from Finite Element (FE) simulations of scattering in a variety of untextured polycrystalline aggregates reveal a considerable discrepancy in the attenuation predictions when compared to the FOSA-based analytical results. The discrepancy is thought to be caused by higher-order scattering and is as high as 70% for Lithium even at low frequencies. Thus, the third-order smoothing approximation (TOSA) has been considered in the current model for the first time to analytically explore higher-order scattering effects on the attenuation estimates. Even for frequencies within the Rayleigh limit, more than 3% improvement is observed for incorporating TOSA in the transverse attenuation estimates for certain metals. However, since the higher-order scattering effects are pronounced for high frequencies, the benefit of including TOSA-based terms can be more significantly realized for frequencies that are beyond the Rayleigh limit. Thus, the proposed model aims at capturing a broad picture of quantifying the higher-order scattering effects in high-frequency ultrasound. Moreover, the proposed TOSA-based model can be effectively used to generate accurate estimates of attenuation coefficients and wavespeeds for modern polycrystalline materials with complex microstructures.
Normalization and Processing of Rotational Eddy Current Scans for Layup Characterization of CFRP Laminates
Authors: Newton Matthew , Gravagne Ian , Jack David ,   Baylor University
Published: November 2023

A method is presented using eigenvector-based principal component analysis (PCA) and signal decomposition to normalize rotational eddy current (EC) scans and determine the ply orientation layup up for carbon fiber reinformed plastic (CFRP) laminates. These unique rotational EC scans, herein termed “r-scans”, are formed by rotating a transmit-receive (TR) pair of high-frequency (15MHz) coils above the part and about an axis orthogonal to the part surface. The PCA normalization process standardizes the r-scan data for comparison and processing. Results are presented for a multi-laminate scan, and from its decomposition into a linear combination of shifted basis signals, the fiber orientations of the individual lamina are quantified throughout the part thickness.
Online Melt Pool Monitoring for Additive Manufacturing using Ultrasound and Synchrotron X-rays
Authors: Kizer Nathan J. , Katch Lauren , Kube Christopher M. ,   Pennsylvania State University, Mutswatiwa Lovejoy , Sun Tao ,   University of Virginia, Clark samuel J. ,   Argonne National Laboratory, Lum Jordan S. , Stobbe David M. ,   Lawrence Livermore National Laboratory
Published: November 2023

Metal additive manufacturing (AM) has been a topic of interest due to its wide versatility in part geometry, material selection, and low-waste production. Many AM processes utilize a high-intensity laser to weld metal powder feedstock to form the desired part geometry. However, poor part quality is throttling the expansion of metal AM. Defects, such as gas porosity, significantly reduce the serviceability of parts produced through AM. Understanding how the melt pool geometry and dynamic behavior change during fusion is paramount to creating low-defect parts. The traditional method to monitor the melt pools is X-ray imaging conducted using a synchrotron. Since access to a synchrotron is limited and costly in addition to only providing a 2D representation of the melt pool, ultrasonic inspection has been proposed as a low-cost method to monitor melt pools in a 3D space. This work utilizes high-speed X-ray imaging to establish a ground truth of the melt pool characteristics and then maps the features to the ultrasonic data collected.
Optimising Laser Induced Phased-Arrays for Continuous Inspection of Large Components
Authors: Cantero-Chinchilla Sergio , Croxford Anthony , Wilcox Paul ,   University of Bristol, Pieris Don , Lukacs Peter , Stratoudaki Theodosia ,   University of Strathclyde
Published: November 2023

The recently proposed selective matrix capture approach used in inspections with laser induced phased-arrays has made this technology faster and more accurate. The process consists of two stages, one for rapid defect detection and another one for high fidelity defect characterisation. The phased-array configuration is optimally adapted to the current inspection scenario for each stage. This paper proposes a rigorous optimisation process for the defect detection stage for the case of a large component where the array is scanned along the length of the component. This requires an array configuration that achieves the required detection performance with the minimum number of generation and detection points per unit distance. An experiment is set-up to demonstrate the optimality of the resulting array in an aluminium specimen.
Frustrated total internal reflection of ultrasonic waves at a fluid-coupled elastic plate
Authors: Almeida A. L. , Huang M. , Cegla F. , Lan B. ,   Imperial College London, Huang P. ,   University of Cambridge
Published: November 2023

A theoretical treatment of frustrated total internal reflection (FTIR) of ultrasonic waves is presented and validated against experimental data. Two different methods are used to derive theoretical models capable of studying transmission of ultrasonic waves through a fluid-coupled elastic plate. First, a multiple reflections approach is used and shown to be inadequate for incident angles beyond the first critical angle. After that, a potentials-based model provided accurate predictions for a thin air-coupled steel sheet. The model helped forge a relation between the transmitted power and the dispersion curves for guided waves in the plate, highlighting the two fundamental causes of FTIR in such systems. The first one is that a thin plate, when compared to the wavelength of the incident wave, will always be subjected to FTIR, as the evanescent wave can never assume negligible values. But more surprisingly, the excitation of the fundamental antisymmetric mode 𝐴0 of the plate is directly related to FTIR for thicker plates.
Solving for resonant stiffnesses based on finite element pre-computation
Authors: Moldenhauer Henry , Holland Stephen D. ,   Iowa State University,
Published: November 2023

Resonance methods are used in NDE for both materials characterization (resonant ultrasound spectroscopy) and finding defects (resonance testing). In both cases, leveraging modeling to understand resonant frequency shifts for nontrivial geometries is difficult because of the cumbersome and compute intensive nature of finite element tools. In this presentation, we will show how we can systematically extract the sensitivity of resonant frequencies on stiffness components from a finite element tool. We will demonstrate that process to estimate elastic stiffnesses based on measured resonant frequencies combined with finite element modeling.
Hydrogen Induced Cracking Inline Inspection using Flexible and Differential Capacitive Sensors Array
Authors: Peng Lei , Mukherjee Subrata , Deng Yiming ,   Michigan State University
Published: November 2023

The use of existing natural gas pipelines for hydrogen transportation is a cost-effective and environmentally friendly solution. However, hydrogen gas permeation can cause small cracks in pipeline walls or degrade the piping materials through electrochemical reactions, requiring improved inspection and more stringent criteria for detecting small cracks. To address this issue, we propose a novel flexible differential capacitive sensor array probe for inspecting hydrogen-induced cracks (HICs). The differential method suppresses common mode noise, including background and lift-off noise, which improves detection sensitivity. The flexible substrate enables the sensor array to be suitable for the pipe inner wall and could be integrated into commercial inline inspection (ILI) tools. In this paper, we fabricated a prototype probe and tested it on a representative pipe sample, with experimental results demonstrating the probe's superior ability to reduce background noise and detect narrow (~1 mm) and shallow (~1 mm) defects.
Numerical analysis of an efficient analytical-3D FE framework for guided wave ultrasound reflection in pipes with corrosion defects
Authors: Qadri Abdul Mateen , Huthwaite Peter , Lowe Michael J.S. ,   Imperial College London, Vogt Thomas ,   Guided Ultrasonics Limited
Published: November 2023

Computational modelling is increasingly utilized for the design and qualification of ultrasonic inspections and monitoring applied to pipelines in the petrochemical industry. Numerical methods, and particularly the finite element method, facilitate the simulation of ultrasonic inspection with realistic geometries. However, computational memory and processing requirements limit their usage for large structures such as long lengths of pipe. This work presents and extends a methodology for integrating analytical dispersion curves, obtained from the software package Disperse, with finite element modelling: it uses dispersion curves to model guided wave propagation over long lengths where the pipe geometry is unchanged, and finite element modelling where it does, for example, because of a defect. This integrated model allows the full potential of numerical modelling to be realised without restricting computational and memory requirements. A numerical finite element study of the scattering of the torsional T(0,1) mode from defects in straight pipes is carried out using Pogo, a graphical processing unit based solver. Whilst the viability of this approach has previously been shown with notch defects, this study further extends the capability of the approach by demonstrating its applicability for pipes with corrosion defects. This has been achieved by using a Fast-Fourier Transform based decomposition of scattered wavefields across the circumference of the pipe where orthogonality based decomposition approaches have faltered. The results indicate the viability of the integrated approach thereby permitting the inspection of thick section components with large propagation distances.
Sate of Charge Estimation of Lithium-ion Battery Using Ultrasonic Technique
Authors: Borujerdi Ali Soleimani , Jin Congrui , Zhu Jinying ,   University of Nebraska-Lincoln
Published: November 2023

This paper investigates the use of the ultrasonic technique to estimate the state of charge (SOC) of an 800 mAh Lithium-ion battery that was cycled at 0.5 C-rate for four cycles. The trend in changing the time of flight (TOF) shift and signal amplitude has been investigated during the battery charge and discharge cycles. It is found that there is a repeatable pattern in the TOF and amplitude. during charging, the signal TOF shift decreased, and peak amplitude increased. On the contrary, during discharging, the signal TOF shift increased and peak amplitude decreased. In the case of the temperature effect on the TOF-SOC relationship, it is found that the hysteresis could be significantly reduced by adopting the temperature correction method.
A Spectral Collocation Method for the Retrieval of Dispersion Curves of Leaky Lamb Waves Radiating into Elastic Half-Spaces
Authors: Georgiades Evripides , Lowe Michael J.S. ,   Imperial College London, Craster Richard V. ,   Imperial College London
Published: November 2023

The study of dispersion curves and wave propagation characteristics has been of great interest in the non-destructive evaluation community for developing efficient and accurate guided wave inspection techniques. Leaky Lamb waves, which radiate from a waveguide into a surrounding fluid or elastic material, exhibit exponential growth in amplitude away from the waveguide. In previous work, the authors developed a Spectral Collocation Method based on Chebyshev polynomials that accurately and quickly found exponentially growing solutions in two different fluid half-spaces, which were then validated by the commercially available software DISPERSE. This work extends the previous method to investigate the dispersion and attenuation properties of leaky Lamb waves radiating from an elastic waveguide adjacent to another elastic solid half-space, validated again by DISPERSE. The authors plan to produce an independent validation metric with the finite elements software Pogo and to expand the method to more complex geometries and media.
Aperture-based FSS Sensor for Strain Measurement
Authors: Hook Alexander , Wilcox Logan M. , Ramesh Swathi Muthyala , Morris Lauryn , Donnell Kristen ,   Missouri University of Science and Technology, William Sarah , Motes III Doyle T. ,   Texas Research Institute (TRI) Austin, Inc.
Published: November 2023

Frequency selective surfaces (FSS) are two-dimensional periodic arrays that consist of conductive elements which have a particular reflective and/or transmissive response when illuminated with electromagnetic energy. In this work, an aperture-based FSS is designed and manufactured for measurement of small-scale (0-0.5%) strain. The sensor operates within K-band (18 – 26.5 GHz) for improved strain measurement resolution and is intended for integration in inflatable space structures. Strain measurements for small-scale strain are presented, with an achieved sensitivity of 22.5 MHz/0.1% strain.
Porosity Detection on XCT Images using Deep Learning and Artificial Data
Authors: Pentsos Vasileios , Seavers Connor , Karatzas Andreas , Chu Tsuchin Philip , Jung Sangjin ,   Southern Illinois University
Published: November 2023

Deep learning has recently gained significant attention in nondestructive testing tasks due to its ability to effectively analyze complex data and identify patterns. This paper proposes a methodology for defect detection on an X-ray computed tomography dataset utilizing the Mask R-CNN algorithm. The proposed approach generates artificial data from the original dataset and introduces a novel metric for classifying the severity of the defects. The Mask R-CNN is trained for defect localization and classification, and the results show that the proposed approach performs better than reported papers on the same dataset. This paper provides a detailed analysis of the proposed methodology, including experimental results and discussions, demonstrating its effectiveness and potential for future research.
Post-Process Semantic Segmentation of Ultrasonic M-scans from Resistance Spot Weld Process Monitoring
Authors: Scott Ryan , Chertov Arseniy , Tusinean Vlad , Stocco Danilo , Chertov Andriy M. , Maev Roman Gr. ,   The Institute for Diagnostic Imaging Research
Published: November 2023

combinations into modern vehicles. These new challenges necessitate new solutions. Resistance spot welding (RSW), a key joining process in several industries including automotive manufacturing, has become increasingly challenging in its own right, especially due to the use of novel advanced materials. Consequently, there is an increased need for nondestructive evaluation (NDE) systems that are high-resolution, fast, accurate, and fully automated – and the same needs apply to the interpretation of their outputs. Such systems also align with smart factory and Industry 4.0 ideals. In this work, we developed a semantic segmentation approach using deep learning (DL) for the automated characterization of ultrasonic M-scan data from RSW process monitoring. The approach segments nugget and stack regions in the data, and the segmentation mask outputs can be used downstream for further weld process characterization e.g. computation of nugget penetration into each sheet, nugget growth rate, nugget solidification rate, etc. Our approach yielded overall intersection-over-union (IoU) of 0.978 which shows a very strong ability to localize the nugget and stack regions in the M-scans, and an F1 score of 0.995 which indicates that it rarely misjudges nugget or stack region presence. Our work demonstrates that semantic segmentation using DL can be an extremely powerful approach for RSW ultrasonic NDE data interpretation. The approach can be used to similar effect on NDE data from other modalities and from other use cases. Our work provides the capability for immediate, accurate, and comprehensive post-process inspection for RSW which can be used for quality control as well as post-process feedback, and it represents another major advancement toward Industry/NDE 4.0.
Proton Recoil Event Localization for Fast Neutron Radiography
Authors: Young Christian , Liesenfelt Michael , Browning Chloe , Thurber Ryan , Hayward Jason ,   University of Tennessee, Preston Jeff ,   Y-12 National Security Complex
Published: November 2023

Neutron radiography is an important tool for the imaging of dense, metallic objects for a wide range of applications. Many systems currently in operation either require large-scale user facilities to produce neutrons [1, 2] or low-efficiency thin-film converters to detect neutrons [3]. These drawbacks lead to neutron radiography seeing limited use in the field. To compensate for these drawbacks, a system has been developed using a scatter-based plastic scintillator, a scalable readout module, and a D-T neutron generator. This system has been developed for use as a field-deployable neutron radiography system.
Real-Time In-Process Ultrasonic M-Scan Segmentation of Resistance Spot Welds Using Deep Learning
Authors: Tusinean Vlad , Scott Ryan , Chertov Andriy , Gras Robin , Maev Roman Gr. ,   Institute for Diagnostic Imaging Research
Published: November 2023

New developments in manufacturing have increased the need for automated analysis of resistance spot welds (RSWs). Many approaches exist to evaluate RSWs in a nondestructive manner, but there is currently a need for an adaptive system that can dynamically modify weld process parameters to prevent defects from occurring. Such a system must perform nondestructive evaluation (NDE) of the RSW process during weld formation, and feed information to a weld controller so that it can alter the welding parameters. To that end, we have developed an artificial intelligence (AI) system using deep learning (DL) that is capable of in-process NDE of RSW using ultrasonic imaging. By embedding an ultrasonic transducer directly into a welding electrode, we can obtain ultrasonic A-scans of the welding process every millisecond, which are then horizontally stacked to form M-scans. Using this ultrasonic setup, we developed and labeled a diverse dataset of ultrasonic M-scans for semantic segmentation. The model trained with this data can then be used to process ultrasonic A-scans to characterize important information about the weld nugget throughout the welding process, such as its position within the stack and its relative penetration into each metal sheet. Our work shows the feasibility of the application of DL for an adaptive welding system via ultrasonic process monitoring and is an important step towards the Industry/NDE 4.0 dream of zero-defect welding.
Spatial Registration of X-ray Computed Tomography and Optical Microscopy Serial Sectioning Data
Authors: Sparkman Daniel , Jolley Bryce , Schwalbach Edwin , Knott Christine , Uchic Michael ,   Air Force Research Laboratory, Chapman Michael ,   UES, Inc.
Published: November 2023

An additively manufactured titanium cylinder with attached fiducial markers (1mm diameter titanium balls) was imaged in 3D nondestructively with several different x-ray computed tomography (XCT) systems and using high-resolution optical microscopy with destructive serial sectioning for correlative analysis of internal porosity. The partial loss of several fiducial markers presented unique challenges to spatial registration. An approach was developed based on template matching and simulated annealing with an L1-norm. The resulting registered data showed the centroids of the largest pores were aligned within 20-60μm, or 1-3 voxel lengths.
Statistical Matching Analysis for Correlating Pores Detected with XCT and Serial Sectioning
Authors: Knott Christine , Jolley Bryce , Sparkman Daniel , Uchic Michael ,   Air Force Research Laboratory
Published: November 2023

X-ray computed tomography (XCT) can detect porosity within the volume of an additively manufactured (AM) metal specimen, but in observational studies, pores are not purposely embedded at specific sizes and locations, but allowed to form naturally. Evaluating the capability of an XCT system requires a truthful measurement to compare against, and destructive serial sectioning provides this high-quality porosity data. Each pore must be matched one-to-one between XCT and serial sectioning to estimate bias in sizing, the number of true detections, and the number of false calls. Statistical matching analysis automates this process, and the methodology and results are presented in this paper.
There’s More to NDT Reliability than POD – and Statistics Plays a Role
Authors:   Brown Engineering Statistics Technologies, LLC, Brown Jennifer
Published: November 2023

Quantifying Nondestructive Testing (NDT) detection capability using Probability of Detection (POD) methods has become a more routine and often required part of NDT, resulting in a strong partnership between NDT and statistics. However, there is more to NDT reliability than POD. Components of NDT reliability can be identified at each step of an NDT process, from the selection of the NDT method to sizing identified, relevant indications. By integrating statistical methods throughout the entire NDT process, a more comprehensive quantitative assessment of NDT reliability can be achieved. In addition to an overview of the statistical methods underlying the industry standard POD methods, this paper provides an overview of additional statistical methods that may be used to evaluate other aspects of NDT reliability such accuracy and precision in flaw sizing, stability of an NDT process, and robustness of a POD specimen set design.