bluuebunny/crossref_metadata_2025 huggingface dataset:
Gamification and Gamification Mobile Application Examples in the Health Industry
Authors: Toprak Cansu , Kiliç Hicran Özgüner
Published: May 2023

Significant developments in digital marketing activities and practices have intensified the practices of businesses in this direction. They have turned to different ways to retain their customers and increase their loyalty and to motivate their employees and to strengthen their performance. One of these ways is “gamification.” Gamification is used in many sectors from informatics to retail, from production to finance, from automotive to insurance, from medicine to health sector. The fact that the COVID-19 pandemic, which deeply affected the health sector, increased the sensitivity of individuals to monitor their health, also affected the development of mobile health applications. In this respect, the use of gamified content in mobile health applications has an important place for both patients and healthcare providers. With gamification, health services can be offered to the user in a mobile environment.
Politics and Ethical Aspects in Private Engineering Colleges in India
Authors: Kulkarni Sunil Jayant
Published: May 2023

Engineering education is facing the challenging task of creating competent engineers due to COVID-19. In the pre-COVID-19 scenario also it was facing challenges like quality of teachers, infrastructure, approach of the regulating authorities, and competitiveness. Engineering education in India is imparted through government-aided, private self-financed institutes of technologies. Engineering teachers from private engineering colleges face the problems of work environment and motivation. Politics in private engineering colleges plays a demotivational role in engineering education. The political influence and unethical practices in many organizations are killing motivation for excellence in honest teaching professionals. In staff selection also, many times, political background is taken into consideration. Management many times encourages incompetent people due to the non-technical factors that are not relevant to teaching quality. Internal politics among the staff members for hiding uncompetitiveness plays deteriorator in engineering education.
Societal Transformation Projects
Authors: Trad Antoine Toni
Published: May 2023

This chapter uses the applied holistic mathematical model (AHMM) to support GA decision-making (DM) systems. GA needs a holistic, generic, and polymathic structure that is abstracted with GA's concept (GAC) for RAD (GAC4RAD), like in the cases of massive changes that are due to major crises like democracies' limits, pandemics, global regional wars, and major financial crisis/crashes. TheAHMM4RAD) was already used in various domains, like for the analyses of societal transformations, origins of Middle East's area (MEA) destabilizations, organized global financial crimes, and other geopolitical cases. One of the most important DRisk is related to the mix between the optimal RAD, societal long-term goals/stability, financial equilibrium, defense strategies, health-wellbeing strategies, defense and military technology (DMT) strategy (DMTS), financial capabilities/protections, GAC4RAD knowledge, optimal societal readiness/resistance, independent national RAD, and the evolution of equilibrated demography. Therefore, the stability depends on a holistic and polymathic RAD Strategy (RADS).
Business Transformation Projects
Authors: Trad Antoine Toni
Published: May 2023

This chapter inspects the role of psychology-based resistance (RPbR) in business or other types of transformation projects (simply the project) and establishes a new approach to organisational transformational psychology (OTP) that mainly analyses the causes of resistance to change (RtC) in projects. A project should be assisted by an optimal in-house organizational transformation framework that uses OTP for optimal educational curricula, transformation initiatives, ethical standards, heuristics, critical success factors (areas and indicators) evaluation, various types of standards, complex multicultural dispositions/local cultural specificities, project's optimal manager's profile, human resistance predictions and management, dynamic group communication, agile team collaboration/traditional team management practices, human resources (HR) activities, knowledge management system, and a dynamic decision-making system.
Natural Convection Flow of Radiative Casson Fluid Past a Stretching Cylindrical Surface in a Porous Medium with Applied Magnetic Field and Joule Heating
Authors: Samuel Damilare J. , Oladoja Adebayo
Published: May 2023

This study is based on the exploration of MHD Casson fluid flow past a stretching cylinder in the presence of non-uniform heat generation, thermal radiation and Joule heating. Boussinesq approximation is also put into consideration due to density difference in the fluid. The governing equations and their corresponding boundary conditions are changed into system of ordinary differential equations with the aid of appropriate similarity variables. The obtained ordinary differential equations are solved numerically using Runge-Kutta Fehlberg method alongside shooting technique. The flow and thermal fields are investigated in the presence of emerging parameters, namely Grashof number, Prandtl number, radiation parameter, curvature parameter, Eckert number, Casson parameter, permeability parameter, magnetic number, space and temperature dependent heat generation parameter. In this study, enhancement in velocity distributions is noticed as values of Grashof number grow but velocity profiles are depreciated by permeability parameter and curvature parameter.
Finite Volume Computational Analysis of the Heat Transfer Characteristic in a Double-Cylinder Counter-Flow Heat Exchanger with Viscoelastic Fluids
Authors: Mavi Anele , Chinyoka Tiri
Published: May 2023

This work presents a computational analysis of the heat-exchange characteristics in a double-cylinder (also known as a double-pipe) geometrical arrangement. The heat-exchange is from a hotter viscoelastic fluid flowing in the core (inner) cylinder to a cooler Newtonian fluid flowing in the shell (outer) annulus. For optimal heat-exchange characteristics, the core and shell fluid flow in opposite directions, the so-called counter-flow arrangement.The mathematical modelling of the given problem reduces to a system of nonlinear coupled Partial Differential Equations (PDEs). Specifically, the rheological behaviour of the core fluid is governed by the Giesekus viscoelastic constitutive model. The governing system of coupled nonlinear PDEs is intractable to analytic treatment and hence is solved numerically using Finite Volume Methods (FVM). The FVM numerical methodology is implemented via the open-source software package OpenFOAM. The numerical methods are stabilized, specifically to address numerical instabilities arising from the High Weissenberg Number Problem (HWNP), via a combination of the Discrete Elastic Viscous Stress Splitting (DEVSS) technique and the Log-Conformation Reformulation (LCR) methodology. The DEVSS and LCR stabilization techniques are integrated into the relevant viscoelastic fluid solvers. The novelties of the study center around the simulation and analysis of the optimal heat-exchange characteristics between the heated Giesekus fluid and the coolant Newtonian fluid within a double-pipe counter-flow arrangement. Existing studies in the literature have either focused exclusively on Newtonian fluids and/or on rectangular geometries. The existing OpenFOAM solvers have also largely focused on non-isothermal viscoelastic flows. The relevant OpenFOAM solvers are modified for the present purposes by incorporating the energy equation for viscoelastic fluid flow. The flow characteristics are presented qualitatively (graphically) via the fluid pressure, temperature, velocity, and the polymer-stress components as well as the related normal stress differences. The results illustrate the required decrease in the core fluid temperature in the longitudinal direction due to the cooling effects of the shell fluid, whose temperature predictably increases in the counter-flow direction.
Adherence to treatment and associated factors in rheumatoid arthritis patients: a cross-sectional study from Iran
Authors: Mohamadzadeh D. , Assar S. , Pournazari M. , Soufivand P. , Soleymani M.S.
Published: May 2023

The aim of this study is to evaluate adherence to treatment and its related risk factors among a sample of rheumatoid arthritis patients (RA) attending the rheumatology outpatient clinic of Kermanshah university of medical sciences. In this cross-sectional study, RA patients were asked to complete the Morisky questionnaire and 19-item compliance questionnaire for rheumatology (CQR). Patients were divided into two groups: adherent and non-adherent to treatment, based on the CQR questionnaire results. Demographic and clinical characteristics (age, sex, marital status, education level, economical condition, occupational status, place of residence, underlying diseases, type, and number of drugs) were compared between the two groups to investigate possible risk associations for poor adherence. 257 patients completed the questionnaires (mean age: 43.22, 80.2% female). 78.6% were married, 54.9% were housekeepers, 37.7% had tertiary education, 61.9% had moderate economic status, and 73.2% were residents of an urban area with a large population. Prednisolone was the most commonly used drug followed by non-steroidal anti-inflammatory drugs, sulfasalazine, hydroxychloroquine, and methotrexate. The mean score of the Morisky questionnaire was 5.528 (standard deviation=1.79). 105 patients (40.9%) were adherent to treatment based on the CQR questionnaire. High education level (college or university) was correlated with non-adherence to treatment [27 (25.71%) vs 70 (46.05%), p=0.004]. We concluded that the prevalence of non-adherence to treatment is 59.1% in rheumatoid arthritis patients in Kermanshah, Iran. Having a higher education level is a risk factor for poor treatment adherence. Other variables could not predict treatment adherence.
Pemphigus and Beyond
Authors: Poojary Shital , Baddireddy Kavya
Published: May 2023

A 23-year-old male diagnosed with pemphigus foliaceous presented with multiple asymptomatic hyperpigmented patches and plaques clinically resembling seborrheic keratoses over multiple sites on the body of 1-year duration. There were no fluid-filled lesions, active erosions, or mucosal involvement. Histopathological examination from the hyperpigmented plaque revealed marked acanthosis with intra-epidermal acantholysis. Enzyme linked immunosorbent assay (ELISA) for antidesmoglein-1 antibodies was positive with a titer of 157 units/ml. Treatment with oral azathioprine, dapsone, and topical halobetasol propionate produced a marked response with complete clearance of the lesions. A thorough workup helped us detect the persistence of disease activity and thus prevent a potential relapse. This case report highlights the unusual presentation of a common immunobullous disorder, Pemphigus acanthomata a rare entity with regard to its morphological, histopathological, and immunological features.
An Interesting Case of Synchronous Basal Cell Carcinoma of Face Successfully Treated by Surgery
Authors: Pathania Sucheta , Sharma Navneet , Bodh Tashi Dolma
Published: May 2023

Basal cell carcinoma (BCC) is the most common type of nonmelanocytic tumor. Multiple BCCs are generally associated with heredo-familial conditions or syndromes, but in sporadic cases, multiple BCCs are relatively rare. They tend to occur in synchronous or metachronous manner, but in our setup, synchronicity is uncommon and metachronous BCCs are attributed mainly to reoccurrence. We present a case of dual BCC of face with synchronicity and different histopathology, treated with wide local excision using full-thickness grafting and V-Y advancement flap.
Asymptotic dimension of minor-closed families and Assouad–Nagata dimension of surfaces
Authors: Bonamy Marthe , Bousquet Nicolas , Esperet Louis , Groenland Carla , Liu Chun-Hung , Pirot François , Scott Alexander
Published: May 2023

The asymptotic dimension is an invariant of metric spaces introduced by Gromov in the context of geometric group theory. In this paper, we study the asymptotic dimension of metric spaces generated by graphs and their shortest path metric and show their applications to some continuous spaces. The asymptotic dimension of such graph metrics can be seen as a large scale generalisation of weak diameter network decomposition which has been extensively studied in computer science.

We prove that every proper minor-closed family of graphs has asymptotic dimension at most 2, which gives optimal answers to a question of Fujiwara and Papasoglu and (in a strong form) to a problem raised by Ostrovskii and Rosenthal on minor excluded groups. For some special minorclosed families, such as the class of graphs embeddable in a surface of bounded Euler genus, we prove a stronger result and apply this to show that complete Riemannian surfaces have Assouad–Nagata dimension at most 2. Furthermore, our techniques allow us to determine the asymptotic dimension of graphs of bounded layered treewidth and graphs with any fixed growth rate, which are graph classes that are defined by purely combinatorial notions and properly contain graph classes with some natural topological and geometric flavours.
Influence of Driving Behavior on Thermal and Lifetime Characteristics of Electric Machines for Automotive Applications
Authors: Hanisch Lucas Vincent , Balasubramanian Sridhar , Sander Marcel , Henke Markus , Henze Roman , Küçükay Ferit
Published: May 2023

Increasing stress on power-dense electric traction machines is prompting scientists to intensify investigations into the reliability and lifetime of automotive drives in particular. Special focus is placed on the electrical insulation system, whose probability of failure increases sharply at higher stresses. The influence of physical parameters on the lifetime is investigated in many publications. There is consensus among scientists that high temperature significantly damages the insulation system of electric machines and leads to failures. In this article, the human influence is additionally investigated by considering three different driving behaviors. A mild, an average, and a sporty driver behavior is examined on a highway, a rural, and an urban driving cycle. The driving cycles are used as input to calculate the thermal effects in an initial model. As a further step, a lifetime model is developed on the basis of measured data, which indicates the lifetime as a function of the previously calculated temperature.
Development, Construction and Certification of a Facility for Exterior Noise Regulatory Compliance Testing
Authors: Sorenson Steve , Rasmussen Robert , Rollison Jim
Published: May 2023

Automotive OEMs are required to meet applicable regulations for exterior noise for vehicles they produce. Acceleration noise (typically called pass-by noise) regulations impose an upper limit for noise emission. In addition, vehicles which can operate without a combustion engine must comply with regulations for minimum noise emitted during low speed driving. In order to make regulation-compliant measurements for global destinations, a test track meeting requirements of ISO 10844 may be necessary. However, strictly meeting this requirement doesn’t guarantee a usable facility for efficient measurements. This paper describes design goals, challenges and construction of a regulation compliant facility in Arizona. The intent was to build a facility with a long usable life before requiring repaving, sufficient isolation from nearby test roads, 24-hour usability and onsite amenities to accommodate technical staffs and vehicle retrofits. Consideration of needs of all stakeholders was necessary to make a facility not only regulation-compliant but also attractive to internal and external customers.
Considering Electric Measurements for NVH – Voltage, Current, and Torque Ripple
Authors: Marks Mitch
Published: May 2023

The study of electronics, motors and mechanical noise and vibration have often been treated as separate fields in R&D, Production, and test/validation. In electric powertrains, the electric and mechanical must be designed and tested in parallel to really understand the machine operation. This paper will highlight an existing link between the electrical and mechanical noise in electric powertrains and what measurement/analysis tools are available for performing an NVH analysis including electrical measurements.
Development of Active Noise Control System Optimized for Road Noise Reduction
Authors: Sakamoto Kosuke , Kobayashi Yasunori
Published: May 2023

In this paper, a newly developed Active Noise Control (ANC) system is introduced, that effectively reduces road noise, which becomes a major issue with electrified vehicles, and that enhances vehicle interior sound levels matching seamless acceleration by electric drive. Conventionally, reducing road noise using ANC requires numerous sensors and speakers, as well as a processor with high computing power. Therefore, the increase in system cost and the complexity of the system are obstacles to its spread. To overcome these issues, this system is developed based on four concepts. The first is a modular system configuration with unified interface to apply to various vehicle types and grades. The second is the integration and optimal placement of noise source reference sensors to achieve both reduction in number of parts and noise reduction performance. The third is the application of digital communications that combine power superposition, low latency, and high throughput to reduce wiring. The fourth is the development of control technologies that specialize in in-vehicle acoustic characteristics to achieve both computational efficiency and noise reduction performance. The one is a technology to integrate control paths based on the sound field mode characteristics in the vehicle cabin, and another one is the frequency band restrain control technology that matches speaker output characteristics. It is confirmed that this proposed system achieves quietness improvement equivalent to the difference of vehicle segmentation with a minimum system configuration, and that this system has a high superiority in weight efficiency compared to conventional vehicle body measures.
Automotive OEM Barrier Acoustical Performance – The Ideal Application for Carbon Neutral Materials
Authors: Cleaver Ryan , Brouckaert Richard Lawrence , Skestone Andrew
Published: May 2023

The automotive acoustics arena is rich with application opportunities for carbon neutral or climate positive parts. The design of potential “green” NVH solutions however cannot compromise the intended acoustical performance of the vehicles. This paper investigates the acoustical needs of OEM vehicles with an emphasis to apply green solutions. The acoustic solutions proposal in this paper compares and contrasts barrier densities, sealing characteristics between traditional and carbon neutral acoustical barriers. It also compares important material properties. Furthermore, these comparisons demonstrate that vehicular acoustic performance need not be compromised as the industry moves towards more climate friendly initiatives. Lastly, the paper identifies an ideal application for planet friendly, carbon neutral NVH solutions. This is accomplished by using acoustical barrier applications that are production ready and commercially available today. None of these carbon neutral NVH solutions alter the anticipated acoustical performance of the target vehicle in a negative manner.
Impact of Liquid Applied Sound Damping Treatments on Sound Quality as Measured via Psychoacoustic Metrics
Authors: Robertson Ian , Thota Manoj , Padaon Matthew , Hand Joshua
Published: May 2023

Electric vehicles (EVs) are quickly growing their share of the auto market and have a much different acoustic environment than their internal combustion engine (ICE) precursors. The electric drivetrain typically results in lower magnitude broadband noise than an ICE vehicle but can produce annoying, high-frequency tonal sounds particularly noticeable to the human ear. Psychoacoustic metrics aim to characterize sounds based on human perception and have increasingly been employed to understand what noises within an EV may be considered undesirable and in need of additional acoustic treatment. Liquid applied sound damping (LASD) coatings are one method employed to minimize unwanted noises within a vehicle. LASD is typically applied to metal components of the vehicle body to dampen vibrations in the structure through its viscoelastic properties. LASD formulation, application, and polymer design has previously been shown to have a strong impact on the material’s damping performance at different frequencies. Herein, we investigate how those same variables affect the resulting sound emanating from vibrating panels coated with these materials, with particular attention to the psychoacoustic profile produced. Tying LASD design to psychoacoustic improvements will help show which material choices will be best suited for EV applications in the future to address these vehicles’ unique acoustic environment.
A Computational and Experimental Investigation on the Effect of Bleed Slits for a Shim Stack Type Hydraulic Damper
Authors: Oh Joseph , Sankaran Shivanand , Truitt Jordan
Published: May 2023

As the automotive industry undergoes significant changes in the dynamic behavior of vehicles and increasing demand for rapid product design, accurate prediction of product performance in the early stages has become more crucial than ever in the competitive environment. Shim-stack-type hydraulic dampers are widely used in automotive parts for both internal combustion engine (ICE) vehicles and electric vehicles (EV). EVs are even more sensitive to damper performance as ICE, which is a major NVH source has been removed. However, the industry still faces challenges in obtaining accurate models of dampers due to their highly nonlinear hydro-mechanical behavior. Bleed slits in a shim-stack-type hydraulic damper play a key role in determining the blow-off characteristics of dampers, and therefore, accurate prediction of the blow-off characteristics is crucial in evaluating the damping performance of a vehicle. Bleed flow analyses are conducted at two levels: component level and assembly system level. For the component level analysis, computational fluid dynamics (CFD) is utilized to analyze bleed flow characteristics corresponding to various bleed slits, which are validated by conducting experimental flow bench tests. For the assembly system level analysis, a dynamic 1-dimensional (1-D) system model is developed for a target passive hydraulic damper to evaluate the effect of bleed slits on the assembly level. The damper characteristic of the proposed method and a conventional method with a constant discharge coefficient are compared. An experimentally measured damper characteristic from a dynamo is used to validate the system model.
Study on Acoustic Characteristics of Passenger Cabin-Headrest Resonator Coupling System
Authors: Yan Zhang , Chen Liangsong , Song Jun , Bao Jian
Published: May 2023

Helmholtz resonator is a very common anechoic measure, and it is widely used in pipe acoustic fields. Based on the enlightenment of the classic Helmholtz resonator, this paper proposes a headrest resonator model and extends it to the acoustic field of the passenger cabin to improve the road noise in the car.

Firstly, through the theoretical model of Helmholtz resonator, the relationship between its resonance frequency and the geometric size of the resonator is clarified. Secondly, the influence of the headrest resonator on the acoustic field characteristics of the car is studied through finite element simulation analysis. It is demonstrated that the headrest resonator is placed in the car, and the sound pressure distribution characteristics of the passenger's inner ear near the resonance frequency change significantly. At the same time, through 3D printing, a sample of the headrest resonator is made. In addition, the acoustic test of the passenger cabin-headrest resonator coupling system is designed, and the test results are compared with the simulation results, which proves the effectiveness of the headrest resonator in improving the acoustic field characteristics in the car. And the test further verifies that the headrest resonator reduces the peak of the vehicle road noise of 120Hz by 3-5dB.

It is hoped that the research in this paper can provide a low-cost-effective solution and enlightenment for the improvement of low-frequency noise in the car.
Vehicle Idle Vibration Development with DFSS Method
Authors: Yuan Wei , Nakkash Gary , Roco Rob , Orzechowski Jeff , Bowen Brooke , Sanders Mark
Published: May 2023

This paper describes idle vibration reduction methods using a Stellantis vehicle as a case study. The causes of idle vibration are investigated using the NVH source, path, and receiver method. The torque transfer path into a vehicle has shown to be very important in determining vehicle idle vibration response. New electronic control enablers that affect idle vibration are tested and discussed, including Neutral Idle Control (NIC), Transfer-case Idle Control (TIC,®), and Switchable Engine Mounts (SEM). The Design For Six Sigma (DFSS) analysis method is used to arrive at an optimized result for vehicle idle vibration. This paper also discusses the results confirming TIC’s capability of reducing idle vibration on all-wheel drive vehicles.

Transfer-case Idle Control is a new idle vibration control enabler developed by Stellantis and a patent was awarded by the United State Patent and Trademark Office.
Acoustical Modeling and Test Correlation of an Intake Manifold and Charge Air Cooler Assembly for a 4-Cylinder Turbocharged Engine
Authors: Zhang Weiguo , Likich Mark , O'Hare Daniel
Published: May 2023

The charge air cooler (CAC), which is placed between the compressor and the engine intake manifold (IM), is an important component in a turbocharged engine. It is essential to capture the temperature change, the pressure drop or the acoustical wave behavior of the charge air cooler in the one-dimensional(1D) simulation model for the predictive accuracy of engine performance and intake noise. In this paper, the emphasis is on the acoustic modeling of an intake manifold and charge air cooler assembly for the low frequency engine intake order noise. In this assembly, the core of the charge air cooler is embedded in the plenum of the intake manifold. The modeling and correlation process is comprised of three steps. First, the charge air cooler core is removed from the intake manifold and put into a rectangular box matching its envelope with a single air inlet and outlet, thereby simplifying the complex shape of the manifold with the different runner components. The acoustic transmission loss across the charge air cooler core in this box is simulated using different modeling parameters in the 1D simulation model and compared with the transmission loss test bench results. Next, once models are established for the core itself, it is reinstalled into the plenum and the full intake manifold and charge air cooler assembly is tested and modeled. Transmission loss from the different runner paths to the zip-tube of the intake manifold are simulated and correlated to the test bench data. Finally, the transmission loss correlated model of the assembly is incorporated with the full engine performance calibrated model. The in-duct engine order sound pressure levels at the compressor outlet and inlet are simulated at full load condition across the RPM range. The simulation results are compared with the in-duct measurement data from the engine dyno test. The correlation of the firing order and its first harmonic order of the in-duct sound pressure level is evaluated. Good correlation is observed at these orders. In conclusion, the best practices of acoustic modeling of a similar assembly using the developed process are recommended.
The Effect of Speed and Road Type on Sound Pressure Level During Neonatal Patient Transport
Authors: Egwabor Richard , Langlois Robert , Kehoe Patrick , Chan Adrian , Green James , Ibey Andrew , Redpath Stephanie , Greenwood Kim , Aubertin Cheryl
Published: May 2023

Neonatal Infants (neonates) requiring a higher level of care often require transportation via road ambulance to neonatal intensive care units. The trip in the ambulance exposes these infants to potentially harmful noise and vibration. The aim of this study was to categorize the sound level in and around the Neonatal Patient Transport System (NPTS) during transport in ambulances at different speeds and different road types. Data collection was performed in Ottawa, Canada. The road types categorized in the study include arterial roads, collector/major collector roads, local roads, lanes and highways. Additionally, discrete events including rail-road crossings, speed humps and potholes were also categorized. For comparison, the sound levels in the ambulance cabin and near the driver were also taken and analyzed. By categorizing the effects these factors have on the sound level experienced by the neonate, better route planning and sound mitigation strategies can be employed. Using the sound levels in the decibel A scale (dBA) for each road test, trendlines could be created showing the variation in sound levels with speed and road type. It is observed that the average sound level experienced by the neonate in the NPTS (IsoletteMic) when stationary is approximately 56 dBA. A steady increase in sound level corresponding to an increase in speed was observed. However, there was no substantial variation in the sound level experienced on different road types at similar speeds. The results suggest that noise exposure increases significantly with vehicle speed, is largely independent of road type, and contains elements that are representative of the Children’s Hospital of Eastern Ontario (CHEO) patient transfers. Building off that knowledge, it is be suggested that improved noise shielding and route planning should be employed to improve neonates’ safety during transport.
N&V Performance of GFR Composite Powertrain Brackets Using Vehicle Simulation Models
Authors: Rengarajan Revathi , Thom Brian , Mercado Granados Ricardo
Published: May 2023

Vehicle weight reduction is important to improve the fuel mileage of Internal Combustion Engine (ICE) vehicles and to extend the range of Electric Vehicles (EVs). Glass Fiber Reinforced (GFR) Composite (Polyamide) brackets provide significant weight reductions at a competitive part price. Traditionally, metal brackets are designed to surpass a target natural frequency and static stiffness. Composite brackets are inherently less stiff and have lower natural frequencies. However, composite brackets also have higher material damping than metal brackets, and good isolation performance can be achieved. The key to integrating composite brackets into the vehicle design is to perform adequate analysis to ensure that the noise and vibration performance at the vehicle level meets expectations. In this paper, case studies are presented for two different vehicles – a Clevis bracket for an IC Engine vehicle, and an electric motor mount bracket. For each case, measurement data is used to develop simulator models for the vehicles with the traditional metal brackets as well as the composite brackets, and the models are used to make a comparative evaluation of passenger noise for different driving conditions.
Full Vehicle Virtual Acoustic Prototyping using Test-Based models and Blocked Force descriptions
Authors: de Klerk Dennis
Published: May 2023

Vehicle Acoustic Prototyping in the mid to high frequency range is challenging with numerical models only. To overcome this challenge, over the past decade, experimental techniques were developed that allow the engineer to incorporate Test-Based models in their (numerical) simulation as well. Using Virtual Point Technology these Test-Based models serve well to describe, for example, the complex dynamics of the vehicle body Noise Transfer Functions. Here the high modal density and damping characteristics are simply measured on a mule or prototype vehicle and coupled to numerical models of the drivetrain using Dynamic Substructuring. As such accurate predictions and/or risk assessments can be made much earlier in the mid and high frequency range during the vehicle development stage.

While test-based models serve well to describe the coupled vehicle dynamics, loads to compute actual vehicle responses are needed as well. Here, so-called Equivalent or Blocked Forces are ideal as they are found to be independent of the vehicle dynamics. This means they will remain the same while entering virtual Dynamic Substructuring optimization of the vehicle components with respect to their effect on the noise at the driver’s ears.

This paper introduces the technical concepts mentioned with focus on the benefits and merits with an example case of an electric vehicle’s E-compressor.
Identification of BSR Issues in Electronic Boards
Authors: Rao Sohan , Reddy Hari , Ravi Chandan
Published: May 2023

Currently the world’s transportation sector is experiencing a paradigm shift towards electric mobility where electric and electronic components form an integral part of the vehicle. The heavy usage of electronic systems needs large size printed circuit (PCB) boards with multiple subcomponents connected to it. Such a complex electronic system when excited by dynamic loads, would lead to generation of uncomfortable transient rattle events between the parts. As a result, there is an increasing requirement to analyze these subsystems to eliminate any unpleasant noise generation mechanisms. In this study, a PCB has been considered for such an analysis. A linear transient analysis was carried out for a sine-sweep excitation. Risk and root cause analysis was performed, and critical locations were identified. Variation in parameters like material properties, connection stiffness, were considered and analyzed for the same. Finally, design modification iterations were performed in which the system behavior improved substantially. This study would provide a means to quantify the rattle events occurring due to the operating conditions and provide an insight about the performance of the component in the real-world operating conditions.
A Process to Characterize the Sound Directivity Pattern of AVAS Speaker
Authors: Yang Wenlong , Wang Chong , Zhang Qijun
Published: May 2023

Speaker performance in Acoustic Vehicle Alerting System (AVAS) plays a crucial role for pedestrian safety. Sound radiation from AVAS speaker has obvious directivity pattern. Considering this feature is critical for accurately simulating the exterior sound field of electrical vehicles. This paper proposes a new process to characterize the sound directivity pattern of AVAS speaker. The first step of the process is to perform an acoustic testing to measure the sound pressure radiated from the speaker at a certain number of microphone locations in a free field environment. Based on the geometry of a virtual speaker, the locations of each microphone and measured sound pressure data, an inverse method, namely the inverse pellicular analysis, is adopted to recover a set of vibration pattern of the virtual speaker surface. The recovered surface vibration pattern can then be incorporated in the full vehicle numerical model as an excitation for simulating the exterior sound field. In this study, the process is illustrated in detail and validated with a production AVAS speaker. Using the virtual speaker and the extracted vibration information, the sound pressure level (SPL) at each microphone location is numerically calculated. The SPL from the direct measurement and the prediction matches very well. By using the virtual speaker and its surface vibration, the directivity pattern of its sound field is fully recovered. Furthermore, numerical analysis is performed to calculate the sound field of the AVAS speaker in a full vehicle model. The acoustic transfer functions from the speaker location to three regulatory microphone locations are calculated. Results clearly reveal the deficiency of using a monopole to represent AVAS speaker and the necessity to consider its directivity pattern.
Electric Motor Mounting System Validation with Subsystem and Powered e-Axle Tests
Authors: Kruse Enrico , Sell Hendrik , Loecken Florian
Published: May 2023

As more and more electric vehicles on dedicated platforms are being developed and launched, motor mounting systems evolve to focus on the specific requirements of the electric drive units (EDUs) – especially the partially opposing targets of controlling powertrain motion under torque and enhancing high frequency isolation. The initial layout of the EDU mounting system, such as the number, position and orientation of the motor mounts as well as their linear and non-linear stiffness properties, during the quotation phase as well as its continuous optimization after business nomination are the foundation for an optimal NVH performance. To support early-stage model validation, Vibracoustic analyzes the modal properties of the EDU or the EDU / subframe assembly to ground. For more comprehensive investigations, Vibracoustic has devised unique axle test rigs to analyze and optimize the NVH of entire axles without the surrounding vehicle. Load cells at all interface points, acceleration sensors and other signal sources permit a comprehensive NVH characterization of an axle. Upgrading the axle test rig with a battery simulator, external liquid cooling and an automation system has enabled the NVH investigation of electric axles under their own power – an industry first. A recently added optical kinematic measurement system now allows the tracking of all 6 DOF motions of any axle and driveline component, e.g. under EDU torque or due to wheel excitations. In this paper, we will share a first correlation study of measurements with multi-body simulations for both test approaches – the simplified experimental modal analysis and the optical kinematic measurement of a full powered e-axle test on a chassis dyno.
Analysis and Validation of Current Ripple Induced PWM Switching Noise and Vibration for Electric Vehicles
Authors: He Song , Gong Cheng , Zhang Peng , Chang Le , Koch Benjamin , GSJ Gautam
Published: May 2023

Pulse Width Modulation or PWM has been widely used in traction motor control for electric propulsion systems. The associated switching noise has become one of the major NVH concerns of electric vehicles (EVs). This paper presents a multi-disciplinary study to analyze and validate current ripple induced switching noise for EV applications. First, the root cause of the switching noise is identified as high frequency ripple components superimposed on the sinusoidal three-phase current waveforms, due to PWM switching. Measured phase currents correlate well with predictions based on an analytical method. Next, the realistic ripple currents are utilized to predict the electro-magnetic dynamic forces at both the motor pole pass orders and the switching frequency plus its harmonics. Special care is taken to ensure sufficient time step resolution to capture the ripple forces at varying motor speeds. Furthermore, the dynamic ripple forces are applied to excite the structure paths including a stator model, a motor fixture model and a detailed electric drive unit model. Both radiated sound power and vibration data are predicted at the switching orders and its super- and sub-harmonics, as a function of the motor torque, speed and the PWM mode selection. Good correlations are achieved between analyses and tests for both the motor fixture and drive unit models. The validated analysis method not only provides insights into the switching noise source, but also enables trade study to optimize switching frequency and mode selection to balance the torque, efficiency and NVH performance for the traction motor control, with successful implementation for General Motors’ Ultium electric drive units.
The Influence of Contextual Non-Auditory Factors on Drone Sound Perception
Authors: Aalmoes Roalt , de Bruijn Bram , Sieben Naomi
Published: May 2023

New forms of air transport are expected to arrive in the next decade: development of unmanned multi-rotor equipped drones, are expected to be used for not only observation purposes, but for postal package delivery as well. The impact of close-flying drones near communities is still not fully understood. One of the main concerns for public acceptability is noise impact as it may negatively affect human health and well-being. Prior research shows that non-acoustical factors play an important role in the perception of noise. A laboratory study was conducted to evaluate different subjective factors to examine their influence on noise annoyance: education on useful applications of drones (positive framing), rural versus urban environments, different visually modelled sizes of drones, and the visual noticeability of drones. Participants of the study evaluated scripted drone events using a Virtual Reality headset with a sound simulation system. Results show that drones flying in a rural environment were perceived as significantly louder, more annoying, and more noticeable compared to an urban setting. Also, noticeability of a drone significantly predicted annoyance and loudness. However, the size of the drone influenced noticeability, but not annoyance. Unexpectedly, the positive framing did not have a measurable influence in this study.
Remotely Administered Psychoacoustic Test for sUAS Noise to Gauge Feasibility of Remote UAM Noise Study
Authors: Krishnamurthy Siddhartha , Rizzi Stephen , Biziorek Ryan , Czech Joseph , Berg Jeffrey , Tannler Dillon , Bean Devin , Ayrapetyan Arman , Nguyen Andrew , Wivagg Jonathan
Published: May 2023

The National Aeronautics and Space Administration (NASA) remotely administered a psychoacoustic test in fall of 2022 as the first of two phases of a cooperative Urban Air Mobility (UAM) vehicle noise human response study. This first phase, described here, was a Feasibility Test to compare human subject responses with a previous in-person psychoacoustic test that found an annoyance response difference between small Uncrewed Aerial System (sUAS) noise and ground vehicle noise. This paper discusses the Feasibility Test online layout, sound calibration method, software development, stimuli selection, test subject recruitment, and test administration. Test performance is measured through comparison of annoyance response data with the previous in-person test. The test also investigated whether a contextual cue to test subjects influenced their annoyance response. Response differences between test subjects in geographically distinct areas are analyzed. Administrative challenges that were encountered during the test are discussed, and improvements to administering subsequent remote tests are recommended.
Advances in the Measurement and Human Response to Noise of Unmanned Aircraft Systems
Authors: Green Nathan , Ramos-Romero Carlos , Torija Martinez Antonio
Published: May 2023

The sound produced by Unmanned Aerial Systems (known as UAS or Drones) is often considered to be one of the main barriers (alongside privacy and safety concerns) preventing the widespread use of these vehicles in environments where they may be in close proximity to the general public. To better understand the potential environmental noise impact of commercial UAS operations, work undertaken by the University of Salford has focused on two key areas. Firstly, how to characterise and measure the sound produced by UAS during outdoor flight conditions and secondly, better understanding of the dose response of UAS noise when the listener is in either an indoor or outdoor environment. The paper describes a field measurement campaign undertaken to measure several UAS performing flyovers at different speeds and take-off weights. The methodology of the measurement campaign was strongly influenced by emerging guidance and has been used to calculate the directivity of sound propagation which may be of significant benefit when modelling environmental noise impacts. This paper also presents details of a listening experiment designed to investigate the subjective response to a number of UAS operations when the listener is simulated to be either in an indoor or outdoor position. The results of the listening experiment have been analysed using linear regression analysis to understand which ‘loudness’ metric either conventional (LAeq, LASmax or LAE) or more specialised loudness metrics such as Loudness (N5), Perceived Noise Level (PNL) or Effective Perceived Noise Level (EPNL) are most appropriate for estimating perceived ‘loudness’ and ‘annoyance’. The results of this experiment indicate that both LAeq, LASmax were equally good at predicting the perceived loudness and annoyance with an Adjusted R Squared value of 0.90 and 0.93 for loudness and annoyance respectively. Loudness metric performed marginally better with adjusted R Squared values of 0.96 and 0.90 for annoyance and loudness respectively.
Prediction, Validation, and Improvement of Panel Sound Transmission Loss of Agricultural Equipment Cab
Authors: Saveenkumar Valakeerthi , Mandke Devendra , Pawar Sachin , Fapal Anand , Cone Kerry
Published: May 2023

A typical cab used on agriculture machines is made up of a metal frame structure with large enclosing panels of glass, plastic, and metal. Acoustic treatments such as coatings, textiles and foams are used within the cab for aesthetics but also to mediate undesired noise. To develop effective designs for the cab to combat noise, accurate tools for measurement, and predictive methods for sound transmission loss are needed. This paper focuses on Sound Transmission Loss (STL) of the rear upper panel of a cab used in agriculture machines. Results from CAE based tools such as Statistical Energy Analysis (SEA), Finite Element Analysis (FEA) and Hybrid FE-SEA methods are compared to measurements. The panel studied included features such as curvature, deep drawn beads with a glass window and a damping coating. The simulation results are refined by incorporating methods for accurate modeling of ribs stiffness, curvature effect and radiation efficiency by synthetic modal approach. The STL predicted by this improved model correlate well with the data from test. This modeling methodology is further used to model various panels and build SEA model of the complete cab.