bluuebunny/crossref_metadata_2025 huggingface dataset:
The Interpretation of Standard Cardiopulmonary Exercise Test Indices of Cardiac Function in Chronic Kidney Disease
Authors: Chinnappa Shanmugakumar , Shih Ming-Chieh , Tu Yu-Kang , Mooney Andrew
Published: December 2023

Background and Aims: As there is growing interest in the application of cardiopulmonary exercise test (CPX) in chronic kidney disease (CKD), it is important to understand the utility of conventional exercise test parameters in quantifying the cardiopulmonary fitness of patients with CKD. Merely extrapolating information from heart failure (HF) patients would not suffice. In the present study, we evaluated the utility of CPX parameters such as the peak O2-pulse and the estimated stroke volume (SV) in assessing the peak SV by comparing with the actual measured values. Furthermore, we compared the anaerobic threshold (AT), peak circulatory power, and ventilatory power with that of the measured values of the peak cardiac power (CPOpeak) in representing the cardiac functional reserve in CKD. We also performed such analyses in patients with HF for comparison. Method: A cross sectional study of 70 asymptomatic male CKD patients [CKD stages 2–5 (pre-dialysis)] without primary cardiac disease or diabetes mellitus and 25 HF patients. A specialized CPX with a CO2 rebreathing technique was utilized to measure the peak cardiac output and peak cardiac power output. The peak O2 consumption (VO2peak) and AT were also measured during the test. Parameters such as the O2-pulse, stroke volume, arteriovenous difference in O2 concentration [C(a-v)O2], peak circulatory power, and peak ventilatory power were all calculated. Pearson’s correlation, univariate, and multivariate analyses were applied. Results: Whereas there was a strong correlation between the peak O2-pulse and measured peak SV in HF, the correlation was less robust in CKD. Similarly, the correlation between the estimated SV and the measured SV was less robust in CKD compared to HF. The AT only showed a modest correlation with the CPOpeak in HF and only a weak correlation in CKD. A stronger correlation was demonstrated between the peak circulatory power and CPOpeak, and the ventilatory power and CPOpeak. In HF, the central cardiac factor was the predominant determinant of the standard CPX-derived surrogate indices of cardiac performance. By contrast, in CKD both central and peripheral factors played an equally important role, making such indices less reliable markers of cardiac performance per se in CKD. Conclusion: The results highlight that the standard CPX-derived surrogate markers of cardiac performance may be less reliable in CKD, and that further prospective studies comparing such surrogate markers with directly measured cardiac hemodynamics are required before adopting such markers into clinical practice or research in CKD.
Effect of Nefopam on Dysesthesia, Postoperative Pain, and Satisfaction in Patients with Lumbar Spinal Stenosis Undergoing Spine Surgery: A Double-Blind, Randomized Study
Authors: Jin Sejong , Lee Yoon Sook , Kim Dahyeon , Kim Bum-Joon , Kim Jae Hwan , Choi Eun-Su
Published: December 2023

Postoperative residual pain and dysesthesia in patients with lumbar spinal stenosis (LSS) can reduce patient satisfaction. We investigated the effects of nefopam on dysesthesia, postoperative pain, and satisfaction in patients with LSS who underwent spine surgery. A total of 73 patients were randomly assigned to two groups: the nefopam group (n = 35), receiving a 20 mL normal saline-based solution containing nefopam 20 mg, and the control group (n = 38), which received 20 mL of normal saline 1 h before the end of the operation. Postoperative incisional pain, dysesthesia scores, and overall satisfaction with postoperative pain management were evaluated. The severity of dysesthesia within 12 and 24 h in the nefopam group was significantly lower than that in the control group (2.3 ± 1.9 and 1.7 ± 1.6 vs. 3.3 ± 2.1, and 2.6 ± 1.9, respectively; p = 0.029 and p = 0.048). Satisfaction scores for postoperative pain management were significantly higher in the nefopam group (3.7 ± 0.6 vs. 3.1 ± 1.0, respectively; p = 0.006). The administration of nefopam effectively reduced the severity of dysesthesia within 24 h of surgery in geriatric patients undergoing spine surgery and increased patient satisfaction with postoperative pain management.
Epidermal Barrier Development via Corneoptosis: A Unique Form of Cell Death in Stratum Granulosum Cells
Authors: Matsui Takeshi
Published: December 2023

Epidermal development is responsible for the formation of the outermost layer of the skin, the epidermis. The establishment of the epidermal barrier is a critical aspect of mammalian development. Proper formation of the epidermis, which is composed of stratified squamous epithelial cells, is essential for the survival of terrestrial vertebrates because it acts as a crucial protective barrier against external threats such as pathogens, toxins, and physical trauma. In mammals, epidermal development begins from the embryonic surface ectoderm, which gives rise to the basal layer of the epidermis. This layer undergoes a series of complex processes that lead to the formation of subsequent layers, including the stratum intermedium, stratum spinosum, stratum granulosum, and stratum corneum. The stratum corneum, which is the topmost layer of the epidermis, is formed by corneoptosis, a specialized form of cell death. This process involves the transformation of epidermal keratinocytes in the granular layer into flattened dead cells, which constitute the protective barrier. In this review, we focus on the intricate mechanisms that drive the development and establishment of the mammalian epidermis to gain insight into the complex processes that govern this vital biological system.
Experimental Study of Piezoelectric Control for Changing Tilting Pad Journal Bearing Circumferential Angle and Radial Displacement
Authors: Peng Shuxia , Qin Xin , Wang Xiaojing , Huang Guangyao , Xiong Xin
Published: December 2023

In order to improve the vibration performance of the oil-lubricated tilting pad bearing system, an experimental approach using a piezoelectric actuator to control two new flexible tilting pads is proposed. The performance test bench of the bearing–rotor system based on a tilting pad bearing with a flexible support is established. The different circumferential angles of the angle bearing tilting pad and the radial displacement of the displacement bearing are tested by a piezoelectric actuator. At the same time, the trajectory of the rotor center under actual operating conditions is analyzed. The experimental results show that the amplitude of the rotor journal can be significantly reduced by controlling the control variables related to the circumferential angle and radial displacement of the bearing bush. Therefore, this control improvement can improve the vibration performance of two new flexible tilting pad bearing–rotor systems. The technical means are provided for the active control of an oil-lubricated tilting pad bearing.
Self-Lubricating Properties of Polyether-Ether-Ketone Composites Filled with CNTs@RC2540 Nano-Capsules
Authors: Guan Jiju , Xu Zhengya , Zheng Lei , Yang Lanyu , Huang Shuiquan
Published: December 2023

Polyether-ether-ketone (PEEK) exhibits great potential in being a replacement for metal components across various applications relying on the mechanical and tribological properties. However, there is still much to be done to improve its properties. The main motivation of this paper is to improve the tribological and mechanical properties of PEEK simultaneously for more severe working environment. Therefore, dialkyl pentasulfide (RC2540) was proposed to fill into the cavity of CNTs to prepare nano-capsules, which were then filled into PEEK to prepare PEEK/nano-capsules composites. The existence of nano-capsules in PEEK was analyzed, and the friction and wear properties exhibited by PEEK composites against GCr15 steel were examined using pin-disk friction pairs, and the self-lubricating mechanism of PEEK composites in friction was revealed. Findings of this study indicated that when the mass fraction of nano-capsules was less than 5%, the filling of nano-capsules could improve the tensile strength of PEEK and reduced the friction coefficient and specific wear rate of PEEK by filling nano-capsules. During the friction process, RC2540 in the nano-capsules can be released as PEEK wears so that a self-lubricating layer can be formed for reducing PEEK composites’ friction and wear.
Genome-Wide Association Study on Seedling Phenotypic Traits of Wheat under Different Nitrogen Conditions
Authors: Hu Chenchen , Li Jinghui , Liu Jiajia , Zhang Dazhong , Jin Liqiao , Yang Nian , Bai Bipo , Wang Zenghao , Feng Suwei , Ru Zhengang , Hu Tiezhu
Published: December 2023

Nitrogen fertilizer input is the main determinant of wheat yield, and heavy nitrogen fertilizer application causes serious environmental pollution. It is important to understand the genetic response mechanism of wheat to nitrogen and select wheat germplasm with high nitrogen efficiency. In this study, 204 wheat species were used to conduct genome-wide association analysis. Nine phenotypic characteristics were obtained at the seedling stage in hydroponic cultures under low-, normal, and high-nitrogen conditions. A total of 765 significant loci were detected, including 438, 261, and 408 single nucleotide polymorphisms (SNPs) associated with high-, normal, and low-nitrogen conditions, respectively. Among these, 14 SNPs were identified under three conditions, for example, AX-10887638 and AX-94875830, which control shoot length and root–shoot ratio on chromosomes 6A and 6D, respectively. Additionally, 39 SNPs were pleiotropic for multiple traits. Further functional analysis of the genes near the 39 SNPs shows that some candidate genes play key roles in encoding proteins/enzymes, such as transporters, hydrolases, peroxidases, glycosyltransferases, oxidoreductases, acyltransferases, disease-resistant proteins, ubiquitin ligases, and sucrose synthetases. Our results can potentially be used to develop low-nitrogen-tolerant species using marker-assisted selection and provide a theoretical basis for breeding efficient nitrogen-using wheat species.
Influence of Thermal and Chemical Treatment on Biosorbent from Rice Husk and Its Application in Removal of Resorcinol from Industrial Wastewater
Authors: Saeed Salaha , Arshad Muhammad Yousaf , Raza Ahsan , Mahmood Faisal , Urbanowska Agnieszka , Ahmed Anam Suhail , Niedzwiecki Lukasz
Published: December 2023

The removal of phenolic compounds is of great importance because of their toxic nature and potentially harmful effects on the environment and human health. This study examines the use of rice husk as a biosorbent for eliminating phenolic compounds, particularly resorcinol, from industrial wastewater. Three types of rice husk, namely raw rice husk (RRH), chemically treated rice husk (CTRH), and thermally treated rice husk (TTRH), are utilized after grinding and methanol treatment. Characterization techniques including X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and optical microscopy are used to analyze the rice husk-based adsorbents. The microscopic analysis reveals the presence of nano-pores in TTRH and the existence of carbonyl and hydroxyl groups in all sorbent samples. XRD analysis confirms the presence of silica in biosorbents. This study also examines the influence of dosage and initial concentration on resorcinol sorption. Optimized dosages of 0.5 g (RRH), 0.5 g (CTRH), and 1.5 g (TTRH) result in sorption capacities of 14 mg/g (RRH), 11 mg/g (CTRH), and 5 mg/g (TTRH). Isotherm analysis indicates that the Langmuir isotherm best describes the sorption behavior of TTRH, while the Freundlich isotherm is observed for CTRH, and both RRH and CTRH follow the Temkin isotherm.
LW-BPNN: A Novel Feature Extraction Method for Rolling Bearing Fault Diagnosis
Authors: Zheng Xiaoyang , Feng Zhixia , Lei Zijian , Chen Lei
Published: December 2023

Efficiently diagnosing bearing faults is of paramount importance to enhance safety and reduce maintenance costs for rotating machinery. This paper introduces a novel bearing fault diagnosis method (LW-BPNN), which combines the rich properties of Legendre multiwavelet bases with the robust learning capabilities of a BP neural network (BPNN). The proposed method not only addresses the limitations of traditional deep networks, which rely on manual feature extraction and expert experience but also eliminates the complexity associated with designing and training deep network architectures. To be specific, only two statistical parameters, root mean square (RMS) and standard deviation (SD), are calculated on different Legendre multiwavelet decomposition levels to thoroughly represent more salient and comprehensive fault characteristics by using several scale and wavelet bases with various regularities. Then, the mapping relation between the extracted features and the health conditions of the bearing is automatically learned by the simpler BPNN classifier rather than the complex deep network structure. Finally, a few experiments on a popular bearing dataset are implemented to verify the effectiveness and robustness of the presented method. The experimental findings illustrate that the proposed method exhibits a high degree of precision in diagnosing various fault patterns. It outperforms other methods in terms of diagnostic accuracy, making it a viable and promising solution for real-world industrial applications in the field of rotating machinery.
Length Modelling of Spiral Superficial Soft Strain Sensors Using Geodesics and Covering Spaces
Authors: Al-Azzawi Abdullah , Stadler Peter , Kong He , Sukkarieh Salah
Published: December 2023

Piecewise constant curvature soft actuators can generate various types of movements. These actuators can undergo extension, bending, rotation, twist, or a combination of these. Proprioceptive sensing provides the ability to track their movement or estimate their state in 3D space. Several proprioceptive sensing solutions were developed using soft strain sensors. However, current mathematical models are only capable of modelling the length of the soft sensors when they are attached to actuators subjected to extension, bending, and rotation movements. Furthermore, these models are limited to modelling straight sensors and incapable of modelling spiral sensors. In this study, for both the spiral and straight sensors, we utilise concepts in geodesics and covering spaces to present a mathematical length model that includes twist. This study is limited to the Piecewise constant curvature actuators and demonstrates, among other things, the advantages of our model and the accuracy when including and excluding twist. We verify the model by comparing the results to a finite element analysis. This analysis involves multiple simulation scenarios designed specifically for the verification process. Finally, we validate the theoretical results with previously published experimental results. Then, we discuss the limitations and possible applications of our model using examples from the literature.
Safety, Tolerability, and Immunogenicity of Booster Dose with MVC-COV1901 or MVC-COV1901-Beta SARS-CoV-2 Vaccine in Adults: A Phase I, Prospective, Randomized, Open-Labeled Study
Authors: Lien Chia En , Liu Ming-Che , Wang Ning-Chi , Liu Luke Tzu-Chi , Wu Chung-Chin , Tang Wei-Hsuan , Lian Wei-Cheng , Huang Kuan-Ying A. , Chen Charles
Published: December 2023

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccines based on variant strains have been in use as booster doses to update immunity against circulating variants. Here we present the results of a phase one prospective, randomized, and open-labeled trial to study the safety and immunogenicity of a booster dose consisting of a subunit vaccine based on the stabilized prefusion SARS-CoV-2 spike protein, MVC-COV1901, or its Beta version, MVC-COV1901-Beta. Participants aged ≥18 and <55 years who received two or three prior doses of MVC-COV1901 vaccines were enrolled and were to receive a booster dose of either 15 mcg of MVC-COV1901, 15 mcg, or 25 mcg of MVC-COV1901-Beta in a 1:1:1 ratio. Adverse reactions after either MVC-COV1901 or MVC-COV1901-Beta booster doses after two or three doses of MVC-COV1901 were comparable and mostly mild and transient. At four weeks after the booster dose, participants with two prior doses of MVC-COV1901 had higher levels of neutralizing antibodies against ancestral SARS-CoV-2, Beta, and Omicron variants than participants with three prior doses of MVC-COV1901, regardless of the type of booster used. MVC-COV1901 and MVC-COV1901-Beta can both be effectively used as booster doses against SARS-CoV-2, including the BA.4/BA.5 Omicron variants.
Clinical Assessment of Thermotherapy Applications during Hepatectomy and Laparotomy in Sturgeon (Acipenser ruthenus): Impact on Bioparameter Variations Based on Liver Condition
Authors: Kang Gyoungsik , Woo Won-Sik , Kim Kyung-Ho , Son Ha-Jeong , Sohn Min-Young , Kong Hee Jeong , Kim Young-Ok , Kim Dong-Gyun , Kim Eun Mi , Noh Eun Soo , Park Chan-II
Published: December 2023

Surgical techniques are gaining attention for treating physical diseases in aquaculture and aquarium fish. Sturgeon is a suitable species for surgical experiments due to its industrial significance. Maintaining homeostasis is crucial during surgical procedures, and the liver plays a major role in immune regulation. High temperature is suggested to improve physiological activity and wound healing. This study investigated differences in hepatectomy sturgeons’ tolerance and histopathological responses of internal organs. Moreover, this study investigated the effects of high temperatures on wound healing and hematopoietic recovery in fish undergoing surgical procedures. The liver condition was found to play a pivotal role in the analysis, and cortisol levels were affected by anesthesia. The results showed that high temperature facilitated hematopoietic recovery and wound healing, but excessive induction of physiological activity caused damage. Managing high temperatures and liver conditions induced a remarkable improvement in wound healing. However, anesthesia itself can be a significant stressor for fish, and wound healing requires a greater amount of energy. Further research is needed to understand the stress factors caused by surgical procedures and anesthesia and to promote animal welfare in fishery products.
A study on the relationships of acoustic parameters relative to serial recall performance and acoustic satisfaction in open-plan offices
Authors: Kang Shengxian , Mak Cheuk Ming , Ou Dayi , Wong Hai Ming
Published: December 2023

Speech is one of the most annoying noises in an open-plan office. Clear speech reduces work performance, job satisfaction and acoustic satisfaction, and can even weaken mental health. In this study, a laboratory study was conducted to examine the relationships between acoustic parameters
and work performance and acoustic satisfaction in open-plan offices. Forty-one students from Huaqiao University in China participated in this study. Their work performance and acoustic environment perceptions were tested under eight acoustic conditions with different speech levels. The serial
recall task, a common cognitive task used to determine the effects of indoor environments on work performance in offices, was utilized in this study. Acoustic satisfaction and subjective performance in each acoustic condition were also collected. Examining the relationships of acoustic parameters
relative to work performance and acoustic satisfaction in open-plan offices demonstrated that the sound pressure level of speech (LA,S) had a more significant impact on the objective performance of the serial recall task and acoustic satisfaction than background noise level (Lp,A,B) and total
sound pressure level (LAeq,total). This work also shows that acoustic dissatisfaction is over 50% when LA,S is up to 48 dBA.
Diffusion equation-based modelling of reverberation chambers for sound absorption measurements
Authors: Xiang Ning , Ruiz Juan Miguel Navarro , Zhang Jiahua , Nolan Mélanie
Published: December 2023

Recent research in reverberation chambers has revealed unacceptably large variations resulting from round-robin tests of the standardized measurements of random-incidence absorption coefficients. These variations have prompted active research activities in architectural acoustics. This
study applies a diffusion equation model (DEM) in acoustics of reverberation chambers for random incidence absorption measurements by predicting both reverberant sound energies and energy flows. The DEM is of high computational efficiency when compared with other existing geometrical acoustics
and wave-based methods. The DEM modeling of the sound energy flows in a reverberation room further reveals violations of the diffuse field assumption near the boundary area of absorbing sample under test. Due to its computational efficiency and higher order of the reverberant energy prediction
of the statistical room-acoustic modeling, this work investigates an estimation approach to the absorption coefficients of the sample under test. The proposed approach estimates the absorption coefficients by pursuing both the DEM simulations and the chamber-based measurements. This paper
investigates sound energy flux over varied absorbing degrees of absorber samples in standardized sizes, computational efficiency of the DEM for reverberant energy decays in reverberation chambers, and potential significance applied to random-incident absorption coefficient measurements.
Infrasound - what it means for people and what role it plays in the acceptance of wind turbines
Authors: Schreckenberg Dirk , Belke Christin , Benz Sarah Leona , Mankarios Alexandra , Melcher Corinna , Kühner Till
Published: December 2023

An increasing number of complaints about wind turbine noise particularly refer to fears about the health effects of infrasound emitted by sources such as wind turbines (WT). Research on the health effects of infrasound emitted by WT reveals inconsistent results. While some studies report
health risks due to infrasound, most reviews conclude that there is no extra health risk due to infrasound from WT. We present a study in which the cognitive and emotional concept of infrasound and its role in the acceptance of WT is studied. First, the cognition and emotion of individuals
related to infrasound are studied in qualitative in-depth interviews among residents living near WT, heat pumps and in a residential area without such facilities. In a following quantitative survey conducted in residential areas near WT the role of the risk perception of infrasound for the
acceptance of the local WT is investigated. It is found that although subjects have no clear concept of infrasound, the main emotion is the fear of adverse health effects of infrasound. The role of this perception for the WT acceptance compared to other potential co-determinants are presented
in this paper.
A Music File Detection Method based on Convolutional Neural Network for Video-on-Demand Platform
Authors: Wu Qianping , Chen Jing , Li Fan
Published: December 2023

On the video-on-demand (VOD) platform, audio processing includes noise suppression, loudness normalization, codec and others. However, these processing are not suitable for all scenes, especially for music audio quality and subjective perceptual. Therefore, different processing will
be selected according to the music detector result. In this paper, a music or non-music audio detection used convolution neural network based on the Mel-spectrogram and modified spectral flux with music frame proportion estimation method is proposed. In the method, the Mel-spectrogram flux
will greatly improve the traditional spectral flux calculation. This paper creatively proposes a music file-wise detection algorithm based on the VOD platform compared with previous frame-wise detection method. Proposed method has strong robustness, high computing efficiency, and low delay.
It is more suitable for VOD platform audio detection requirements, and has direct benefits for audio quality control.
AI-based method for determining vehicles with illegal muffler from pass-by noise
Authors: Houzu Hiroyuki
Published: December 2023

In Japan, illegal noisy vehicle is controlled by the result of a stationary noise test. The stationary noise test used does not have a simple correlation with pass-by noise due to differences in vehicle conditions. If illegal vehicles can be identified by pass-by noise, it will lead
to more effective roadside inspections. Therefore, this study investigated whether it is possible to identify vehicles that exceed the limit value of the stationary noise test limit from pass-by noise using AI. First, we investigated the method using a single sound level meter, and then considered
the use of a microphone array to make the method more effective in road traffic flow.
Effects of Locomotive Noise Reduction to Freight Train Noise in Switzerland and Europe
Authors: Hecht Markus , Hanisch Thilo , Ullrich Anastasia , Wunderli Jean-Marc , Jäggi Jonas , Fischer Fredy , Ferrari Sandro , Kuster Franz
Published: December 2023

As freight trains are very frequently operated at night there is still big concern about freight train noise in Europe. Freight wagons in Switzerland and Germany are now all equipped with composite brake blocks instead of cast iron brake blocks which results in significant noise reductions.
Using data from the Swiss noise monitoring stations the contribution of different locomotives to the overall train noise was evaluated. For locomotive types without cast iron brake blocks the year of construction is not related to the noise behavior. Newer types are not in general less noisy
than old ones. The 30 years old type Lok 2000 is significantly less noisy than all other locomotive types, even if operated by different companies. European regulations concerning type approval allow higher noise levels for locomotives than for wagons. Therefore, the question was addressed
how the overall noise can be reduced by noise abatement at the locomotive.
The noise prediction of cassette air conditioners using AI models and analysis based on SHAP
Authors: Jeong Youngsu , Choi Seonghee , Lee Jangwoo , Chin Simwon
Published: December 2023

This paper introduces a new noise prediction method for air conditioners. In this study, XAI (eXplainable Artificial Intelligence) technology was used to identify the refrigerant flow noise of cassette air conditioners. Using the RandomForest regression method of machine learning models
and DNN and CNN of deep learning models, the noise prediction models were designed, and their performance were compared. In addition, a method of analyzing factors contributing to each model was presented using SHAP (SHapley Additive exPlanation), one of XAI that can explain the predicted
model. Based on these results, the idea of the analysis was suggested to find the control factors for reducing the air conditioner noise.
Visualization of a jet stream group influencing the noise increase phenomena in generated by airflow through a perforated metal plate
Authors: Matsumoto Hiroki , Yokoyama Kanta
Published: December 2023

The perforated plate is made by a punching process. Because of this manufacturing process, the cross section of holes in a perforated plate varies in the direction of the thickness of the plate. When an airflow passes through a group of holes in a perforated plate, the noise characteristics
change depending on the direction of passage. In the case where the cross-sectional area of holes increases in the downstream direction, the aerodynamic noise generated by airflow through holes in perforated plates increases. The cause of the noise increase is considered to be the lock-in
phenomenon between the vibration of the plates and the outflow of the vortex. For this to occur, at least seven closely spaced groups of holes are required. In this study, flow visualization using the fog method was performed to clarify the behavior of the jet stream group during the noise
increase. The results showed that the vortex outflows at each hole were in opposite phase when the lock-in phenomenon did not occur, but that the vortex outflows at adjacent holes were synchronized when the lock-in phenomenon occurred.
A neural network approach for prediction of tyre rolling noise during indoor tests
Authors: Rapino Luca , Dinosio Arianna , Ripamonti Francesco , Corradi Roberto , Baro Simone
Published: December 2023

Nowadays, noise has become one of the main concerns of environmental pollution, especially in the automotive and transport industry. Tyre noise has a core influence and manufacturers, pushed by regulations, invest several resources in experimental tests and numerical simulations to
improve their products performances. In this context, predictive models represent useful tools to support the virtual prototyping. In this paper a statistical modelling approach for the prediction of sound intensity measurements in indoor condition is proposed. Particular attention is paid
to the selection of the parameters related to tyre/road noise and to their processing. At first, sound intensity levels are measured for a set of tyres rolling on drum at different speeds. Then, noise-related tyre features are measured and processed. Eventually, an artificial neural network
is used to define the statical model relating these features with the measured sound intensities. Promising results support the proposed approach.
Numerical study on honeycomb membrane-type acoustic metamaterial with added mass
Authors: Laly Zacharie , Mechefske Christopher , Ghinet Sebastian , Ashrafi Behnam , Kone Charly T.
Published: December 2023

This paper presents numerical investigations on the transmission loss (TL) of a honeycomb structure with embedded membrane to which small masses are attached. The structure is a lightweight honeycomb membrane-type acoustic metamaterial that presents excellent transmission loss especially
at low frequencies. The added mass is a solid material that is attached to the membrane, which is modelled as a linear isotropic elastic material with fixed boundary conditions. The influences of the membrane material properties and of the added mass parameters on the transmission loss are
presented. It is demonstrated that the resonant peak amplitude of the transmission loss and its frequency band can be controlled by the properties of the added mass. The various numerical simulation results of configurations with and without added masses as well as various membrane elastic
properties are compared. The honeycomb structure used in this study constitutes generally the core layer in sandwich honeycomb panels. While the TL of the honeycomb structure alone is zero, due to the open cell distribution, the integration of a membrane within the honeycomb with added masses
induces a significant improvement of the transmission loss. This lightweight metamaterial is shown to attenuate the low frequency noise.
Direct aeroacoustic simulation of a cross-flow fan with Helmholtz resonator using lattice Boltzmann method
Authors: Imada Atsushi , Takeuchi Kimiya , Kusano Kazuya , Furukawa Masato , Sakoda Kenichi , Fukui Tomoya , Hatakenaka Kisho
Published: December 2023

It is necessary to reduce the aerodynamic sound generated by fans since they are often used for air-conditioners, which are placed in human living areas, such as homes and offices. To reduce the aerodynamic sound, we focused on the Helmholtz resonator. To develop a resonator-type silencer
for the aerodynamic sound of air-conditioners, the present study investigated the flow and acoustic fields around a cross-flow fan with a resonator and the effectiveness of the resonator for blade-passing frequency (BPF) sound using aeroacoustic simulations. As a numerical method, we used
the lattice Boltzmann method (LBM), which can simultaneously simulate aerodynamically sound generation in the fan and the acoustic resonance in the resonator. Consequently, the simulation results showed that a reduction of 2.9 dB for the BPF sound can be realized by installing a resonator
in the tongue part of the fan casing.
Influence of parameters of a piezoelectric nonlinear energy sink on targeted energy transfer characteristic
Authors: SHAO Jianwang , ZHAO Huihong , LUO Qimeng , WU Binxing , WU Xian , Xing Peng , Meng Dongxiao
Published: December 2023

In the coupling system of elastic plate and piezoelectric nonlinear energy sink, the shunt circuit of piezoelectric material as a nonlinear energy sink (NES) is coupled with the main system, where the nonlinear stiffness and damping are realized by the shunt circuit of piezoelectric
material. The targeted energy transfer (TET) characteristics of the system are analyzed by complexification-averaging method and harmonic balance method, the variation range of NES parameters is determined, and the slow invariant manifold, platform amplitude of the frequency responses, nonlinear
normal modes and threshold interval of the system under different parameters are analyzed. The influences of piezoelectric NES parameters, such as mass ratio, damping and nonlinear stiffness, on the TET characteristics are obtained, and a general criterion for design of piezoelectric NES parameters
is proposed.
Automatic detection of source direction and exclusion of irrelevant sounds in unattended noise monitoring systems
Authors: Helboe Daniela Toledo , Fasting Erlend
Published: December 2023

A device featuring 8 MEMS microphones has been designed, which allows localizing dominant sound sources in 3D space by implementing techniques based on time difference of arrival. The device, also called Noise Compass, is intended to be used together with an outdoor measurement microphone
in a noise monitoring terminal. By defining regions of interest in the vertical and horizontal planes in a monitoring and analysis system, non-relevant sounds can be automatically detected and excluded from the noise measurements. This article describes the direction detection mechanisms and
shows two examples of system application: aircraft noise monitoring and a construction site with a road and railway nearby. Finally, other system applications are discussed.
Acoustic absorption of the over-the-rotor liner applied to a ducted fan
Authors: Zhao Peidong , Yang Cheng
Published: December 2023

The shortened intake length of the ultra-high bypass ratio engine leaves limited space for acoustic liner installation. The conventional intake liner has to extend to the proximity of the fan rotor to reach the same acoustic level, forming a so-called over-the-rotor (OTR) liner. Large
eddy simulation method is used in this paper to analyze the acoustic absorption of the OTR liner. The results show that the dissipated energy of OTR liner orifices varies along the duct axial direction. The orifices close to the blade leading edge have the highest velocity and thereby dissipate
the most energy. The magnitude and pattern of orifice velocity are different distinctly at the upstream and downstream of the rotor affected by the pressure distribution inside the duct as well as the blade surface. The time delay of orifice flow along the circumferential direction indicates
that the motion of fluid inside of the orifice is primarily driven by the hydrodynamic pressure perturbance of the passing rotor. The OTR liner exhibits more complicated acoustic absorption characteristics than conventional intake liner so further investigation is necessary to understand the
underlying mechanisms.
Estimation of Japanese word intelligibility by automatic speech recognition with noise adaptation
Authors: Hattori Masaki , Kondo Kazuhiro
Published: December 2023

The purpose of this study is to estimate subjective word intelligibility using DNN-based speech recognition. The evaluation of intelligibility is important to guarantee high speech quality in ambient noise and reverberation. The Japanese Diagnostic Rhyme Test (JDRT) is one such subjective
evaluation method. In this study, we estimated Japanese word intelligibility by simulating the JDRT with cloud-based speech recognition systems. Recent DNNs can improve recognition accuracy with their robust classification ability and efficient use of high-dimensional features. We built a
DNN-based speech recognition system using cloud-based ASR APIs, and adaptively trained its model to several noise conditions to improve its intelligibility estimation accuracy. In this paper, we will report comparisons with other objective and subjective evaluations and discuss ideas for a
more generic objective evaluation method.
Study on compatibility of reduction transmitted impact sound of dry-type floating floor due to car-tire source and rubber ball source
Authors: Tomita Ryuta
Published: December 2023

In Japan, JIS A 1418-2:2019 specifies the car-tire with impact force characteristics (1) and the rubber ball with impact force characteristics (2) as standard heavy impact sources. It has also been reported that the reduction of transmitted impact sound for a dry-type floating floor
differs depending on the impact sources of the car-tire and the rubber ball. It has been reported that one of the reasons for different reduction of transmitted impact sound is excessive the car-tire impact force, and a tendency for a nonlinear response to impact force for a dry-type floating
floor. Meanwhile in inter.noise 2022, It was also suggested that the reduction of transmitted floor impact sound level of the rubber ball could be estimated from the reduction of transmitted floor impact sound level of the car-tire by considering excitation frequency characteristics. In this
paper, a consideration was conducted using the impact force exposure level of the impact source as a method of correcting the excitation frequency characteristics. Also, the results on the comparison of reduction transmitted impact sound using the A-weighted sound pressure level are described.
Correlation of Teacher's Voice Level with the Speech Comprehension and Fatigue Degree of Teachers
Authors: HAAN Chan-Hoon , LEE Jakin
Published: December 2023

Since the teacher's voice greatly affects the student's learning effect, accurate voice delivery must be important for the student's academic improvement. Also, voice level of teachers is closely correlated with both of teacher's fatigue and speech comprehension of students. The present
study aims to investigate the appropriate voice level of teachers which could optimize the two other factors. In order to this, field acoustic measurements and questionnaire survey were accomplished in 5 classrooms in a Korean elementary school. The subjects consist of 5 teachers and 115 students.
Teacher's voice levels were classified into five stages from low level (55 dB) to high level (73 dB). Also, Teacher's voice levels were measured for 15 minutes to confirm the correct level of speech during the class. As a result, it was found that the teacher's fatigue and speech comprehension
are low when low level of vocalization was given. On the other hand, when high level of vocalization was given, teacher's fatigue was increased significantly while speech comprehension of students was increased. concerning the medium (62-64 dB) voice level, it was revealed that 81.8% of the
satisfaction was acquired for speech comprehension with just one of five teachers feeling tired. Therefore, it can be suggested that 63 dB could be an appropriate voice level of teachers in classroom.
AI-technology for efficient noise monitoring and analysis in complex urban soundscapes
Authors: Ejdfors Karl Henrik
Published: December 2023

This paper presents a user-friendly, project-based noise monitoring and data analysis software called NorCloud. This software has been developed to exploit the advantages of noise monitoring terminals that allow localizing dominant sound sources in complex urban soundscapes. NorCloud
can be used with multiple microphones simultaneously and has data analysis features that enable identification, classification and extraction of sound events. The efficiency of these processes is greatly increased by using AI-technology for automatic removal of non-relevant sound sources.
In the article, the advantages and limitations of using automatic noise monitoring and analysis systems are explained. Current applications and possibilities for further development are also presented.
Theoretical and numerical investigation into the suppressing mechanism of radiated noise in an ABH-cavity system
Authors: Ye Hanfeng , Ji Hongli , Wang Chaoyan , Tao Chongcong , Cheng Li , Qiu Jinhao
Published: December 2023

The problem of radiated noise of a coupling system between acoustic space and flexible structure is very common in practical applications. In this paper, the acoustic black hole (ABHs) structure is used for reducing the radiated noise of the plate-cavity system as an efficient passive
control technology. The suppression mechanism of the ABH-cavity system is investigated. Theoretical analysis shows that enhanced radiated noise suppressing effect can be obtained by rearranging the numbers and locations of ABHs compared to its uniform counterpart at cavity modal frequencies.
Due to this suppression mechanism, ABH structure exhibits a reduced radiation efficiency of the panel, which can be explained by the wavenumber analysis that lots of high wavenumber components are generated and effective wavenumbers in the radiation region are reduced.
Perceptual dimensions of fan sounds with different tonal characteristics
Authors: Claaßen Eike , Töpken Stephan , Par Steven van de
Published: December 2023

Fan noise is a common tonal noise source in people's everyday life. While tonal sounds at high frequencies often contribute to annoyance, the perception and evaluation of low-frequency tones is not fully understood. In the present study, the perceptual dimensions of 24 tonal prototype
fan sounds were explored using a semantic differential consisting of 21 adjective scales that were rated by 40 participants. The synthesized sounds had the same sound pressure level of 55 dB(A) but differed in fundamental frequency and spectral envelope of the embedded tonal signatures Using
a factor analysis, four perceptual dimensions were found that explain 59 % of the variance. Fan sounds with a fundamental frequency of 60 Hz were rated to be more "humming" (1st dimension) and more "pleasant" (2nd dimension) but less "buzzing" and less "beeping"
(3rd dimension) in comparison to sounds with higher fundamental frequencies of 180 Hz and 300 Hz. An analysis of the relationships between the adjective scales and psychoacoustic metrics show that the "humming" ratings were highly correlated to a metric describing the relative contribution
of low frequencies to the overall loudness. In contrast, psychoacoustic sharpness and tonality had smaller correlation coefficients with the "humming" ratings.
Acoustic performance of a multi-layer vehicle interior trim sound-absorbing material
Authors: LIU Zhengqing , LIANG Jiangmei , ZHAO Yujun , GU Dawei , FARD Mohammad , DAVY John Laurence
Published: December 2023

This paper investigated the acoustic properties of a multi-layer vehicle interior trim acoustic material. In this study, a thin fiber layer was inserted between the vehicle carpet and the porous sound-absorbing material layer, and backed by the vehicle floor. The theoretical prediction
method was based on the Johnson-Champoux-Allard (JCA) model, and the sound absorption coefficient of the multi-layer vehicle interior trim acoustic material was calculated by using the transfer matrix method (TMM). An impedance tube was used to measure the normal incidence sound absorption
coefficient of the vehicle interior trim with different combinations of acoustical materials. The comparison of the theoretical and the experimental results showed that the sound absorption coefficient curves predicted using the JCA model are consistent with the measurement data across the
mid and high-frequency range (500-6400 Hz). In addition, a car cabin Statistical Energy Analysis (SEA) model was developed and used to predict the effect of the acoustic properties of the multi-layer vehicle interior trim acoustic material. The results presented in this paper, are useful for
enhancing vehicle interior acoustic design and refining vehicle cabin sound quality in future vehicles.
Minimization of acoustic power in free space using quadrupole sound sources
Authors: Ogasawara Yuta , Iwamoto Hiroyuki , Hisano Shotaro
Published: December 2023

Low-frequency noise is difficult to suppress by passive control using a sound absorbing material. Active noise control is expected to be an effective method against low-frequency noise. Minimizing the total acoustic power emitted by a sound source causes a zero-control power phenomenon.
In the zero-control power phenomenon, the absorption and blowout of sound energy around the control sound source (control sound source) are balanced, and the time average of the control power come into zero. Thus, control power suppression may be able to minimize total acoustic power. Previous
studies have assumed that the sound source is a monopole sound source, or a piston embedded in an infinite baffle, so there are restrictions on the sound source. In this research, the sound sources are regarded as quadrupole sound source. Numerical computations are performed based on the derived
control law to clarify the effect of the position and the rotation angle of the quadrupole on the acoustic power. In addition, the relationship between the wavelength and the suppression effect is examined from a numerical point of view.
Study of unsteady flow-induced vibration of centrifugal pump volute casing using fluid-solid coupling
Authors: Meng Lianghu , Wang Zhengxiang
Published: December 2023

The paper studies the flow-induced vibration of the volute of a centrifugal pump using the coupled approach of computational fluid dynamics (CFD) and finite element method (FEM). In the present paper, a numerical model of the centrifugal pump for fluid-solid coupling solution was established,
and the unsteady flow of the centrifugal pump under different working conditions was simulated by unsteady CFD calculations. Then, the fluctuation pressure on the volute inner surface was extracted and used as the fluid load that induces the volute vibration. The volute vibration response
including displacement, and acceleration was discussed based on the results of fluid-solid coupling solutions. The results show that the non-uniform distribution of fluctuation pressure along the volute, and the dominant vibration frequencies of the pump volute are blade frequency and its
harmonics, and the minimum vibration and stress of the volute appear at the design condition. Overall, this research gives insight into the flow-induced vibration of centrifugal pump volute casing.