Search

In this paper, a multiphysics simulation workflow based on the use of reduced-order models (ROMs) to decrease the computation time is presented. Using FE pre-computed flux-linkage and lumped force lookup-tables (LUTs) in function of dq0 currents and rotor position, an electromagnetic model of a permanent-magnet synchronous machine (PMSM) is developed. Coupled to a mechanical state-space representation, the complete workflow allows to predict the vibrations of the motor. Using our model, the influence of the 0-sequence current on the vibration spectrum is investigated. A detailed description on the parameter identification for homogenized stator core of the considered 12-slot 10-pole delta-connected fractional-slot concentrated-winding (FSCW) spoke-type PMSM is also given. The numerical results are validated with experimental data for the machine at hand. Because of the large amount of FE data required, the workflow is best suited for the optimization of motor control schemes (instead of the initial design optimization) with the purpose of reducing the noise, vibration, and harshness (NVH).

A high-speed motor in a drive system causes several challenges to the reliability of the mechanical parts of electric vehicles and leads to issues with noise, vibration and harshness (NVH). Thus, a two-speed powershift transmission is considered an effective way to improve the dynamic, economic and comfort performance of electric vehicles. A newly designed dual-pump hydraulic control system for a two-speed powershift transmission with two wet clutches is presented, in which the mechanical oil pump is linearly affected by the vehicle speed and the electric oil pump is controllable. By integrating the dynamic model of the hydraulic system into one of the powertrains with a two-speed transmission, a co-simulation dynamic model is proposed. To satisfy the flow and pressure demand of the hydraulic system, a dual-pump control strategy is presented, in which the electric oil pump is controlled by the mechanical oil pump following the minimum energy consumption principle. The World Light Vehicle Test Procedure (WLTP) cycle simulation results show that the energy consumption of the proposed hydraulic system can be reduced by 58.2% compared to the previous single-pump system developed by the authors with a constant main-line pressure control strategy. On the basis, the best configuration of the two pumps can further reduce the energy consumption of the hydraulic system by 23.2% compared to that of two-oil pumps with preset displacement.

Differential susceptibility theory stipulates that individuals vary in their susceptibility to environmental effects, often implying that the same individuals differ in the same way in their susceptibility to different environmental exposures. The latter point is addressed herein by evaluating the extent to which early-life harshness and unpredictability affect mother's psychological well-being and parenting, as well as their adolescent's life-history strategy, as reflected in number of sexual partners by age 15 years, drawing on data from the National Institute of Child Health and Human Development (NICHD) Study of Early Child Care and Youth Development. Results indicated that mothers whose well-being and parenting proved more susceptible to harshness also proved somewhat more susceptible to environmental unpredictability, with the same being true of adolescent sexual behavior. Nevertheless, findings caution against overgeneralizing sample-level findings to all individuals.

Due to a large number of degrees of freedom and connected powertrain functionalities, the development of operating strategies for plug-in hybrid electric vehicles is an especially complex task. Besides optimizations of drivability, noise, vibrations and harshness as well as energy efficiency, the main challenge lies in ensuring emissions conformity. For this purpose, test vehicles are typically applied to achieve a realistic test and validation environment. However, operating strategy calibration using test vehicles has the drawbacks, that (i) it is very time consuming and cost intensive, (ii) it can only be conducted in late development phases and (iii) cannot be applied to reproducing driving loads for a valid comparison. To overcome these issues, this paper presents a consistent engine-in-the-loop approach combining real engine hardware and multiple software elements to represent PHEV behavior at the engine test bench. Thereby, an environment is created, which allows for realistic, flexible, cost efficient and reproducible testing. The effectiveness of the presented framework is evaluated by comparing relevant on-road measurements with their reproduction at the engine test bench. The results show that the vehicle on-road behavior can be replicated using the described testing environment. Particularly engine start/stop behavior and load levels—the core functionalities for operating strategy calibration—are matched. The proven level of realism in powertrain behavior enables further use cases beyond on-road measurement reproduction, i.e. varying individual component properties and observing real-world consequences at the test bench without the need for vehicle tests.

Noise, vibration, and harshness (NVH) issue in switched reluctance machines (SRMs), originating from their doubly salient structure and unique principle of operation, is addressed in this work by proposing a structural design modification in the stator, which increases stiffness to mass ratio of the structure. A 24-slot 16-pole (24s/16p) SRM designed with the aim of automotive application is studied here for the NVH optimization, at different target operating points, using stator pole bridges. Stator pole bridges link consecutive stator teeth to provide additional stiffness to the stator structure. Average torque reduction due to flux shorting in stator pole bridges is tackled by proposing a low-permeability material, with considerable stiffness, which has not yet seen its’ application in SRM NVH domain. Multiphysics aspects of stator pole bridge design encompassing electromagnetic radial force, mechanical stress, steady-state temperature distribution, and acoustic noise analyses are presented in this article. Possible manufacturing issues are considered during the design phase and appropriate measures are implemented to facilitate easier construction of two 100-kW prototypes. The final design with stator pole bridges and a baseline design without any stator pole bridges are prototyped, after rigorous multiphysics optimization, for extensive testing. Experimental results verify simulation outputs and report a maximum noise reduction of 12.52 dBA in the stator pole bridge model compared to the baseline SRM.

Las siguientes páginas ofrecen una visión de conjunto sobre las preocupaciones que el viajero tardoantiguo sufriría a la hora de emprender un viaje. Los caminos estaban llenos de problemas, ya fuera por la dureza de las jornadas o por posibles ataques violentos. A través del análisis de fuentes escritas, y prestando particular atención a la hagiografía medieval y al examen de la regulación viaria tardorromana, descubrimos la necesidad de proteger al viajero mediante la codificación de delitos que castigasen a los delincuentes. Aun así, tal y como reflejan las fuentes, no se erradicará dicha situación, pues existen numerosos ejemplos de salteadores de caminos que hacían peligrar la seguridad del viajero visigodo.

Under high-speed operating conditions, the noise caused by the vibration of the traction gear transmission system of the Electric Multiple Units (EMU) will distinctly reduce the comfort of passengers. Therefore, analyzing the dynamic characteristics of traction gears and reducing noise from the root cause through comprehensive modification of gear pairs have become a hot research topic. Taking the G301 traction gear transmission system of the CRH380A high-speed EMU as the research object and then using Romax software to establish a parametric modification model of the gear transmission system, through dynamics, modal and Noise Vibration Harshness (NVH) simulation analysis, the law of howling noise of gear pair changes with modification parameters is studied. In the small sample training environment, the noise prediction model is constructed based on the priority weighted Back Propagation (BP) neural network of small noise samples. Taking the minimum noise of high-speed EMU traction gear transmission as the optimization goal, the simulated annealing (SA) algorithm is introduced to solve the model, and the optimal combination of modification parameters and noise data is obtained. The results show that the prediction accuracy of the prediction model is as high as 98.9%, and it can realize noise prediction under any combination of modification parameters. The optimal modification parameter combination obtained by solving the model through the SA algorithm is imported into the traction gear transmission system model. The vibration acceleration level obtained by the simulation is 89.647 dB, and the amplitude of the vibration acceleration level is reduced by 25%. It is verified that this modification optimization design can effectively reduce the gear transmission. © 2021 Institute of Noise Control Engineering.

Determining the root causes of Noise, Vibration and Harshness (NVH) phenomena in modern automotive drivetrains is a task of critical importance. This research investigates the stability of dry clutch systems vibrational behaviour during engagement. A fully coupled dry clutch numerical model including the influence of friction is presented and validated using vehicle measurements. The clutch component frictional properties are measured using parts that exhibit aggressive NVH behaviour using representative tribometric experiments. The validated numerical tool highlights the occurrence of instabilities which are caused by modal couplings, particularly between the input shaft bending and clutch disc radial motions. Such a validated transient dynamics model of a dry clutch system has not hitherto been presented in the open literature.

When a certain electric vehicle is driving at a constant speed of 40 km/h on the rough asphalt road, the rear passenger can obviously feel the ear pressure, which seriously affects the comfort. Through the analysis of objective data, it was found that the problem was caused by the road excitation, which leads to the coupling between the mode of the backup door and the mode of the acoustic cavity, and causes the resonance of the car cavity, thus causing the ear pressure sensation. To solve this problem, this paper optimizes the backup door by means of experiment and simulation, increases the dynamic vibration absorber, makes its modal frequency avoid the acoustic cavity modal frequency, and achieves the purpose of reducing the interior noise. After optimization, the vehicle noise is reduced by 8 dBA at 42 Hz under 40 km/h working condition of rough road surface, and the ear pressure sensation is reduced at the same time, thus improving the NVH (noise, vibration, and harshness) performance of the vehicle.

Animals need to adjust their decision-making strategies to the ecological challenges of their environment. Variation in ecological unpredictability and harshness thus seem to affect their decisions in the wild. In our study, we combine methods from human life history theory and previous comparative work with chimpanzees to investigate whether current variability in ecological factors such as reward unpredictability and harshness affect chimpanzees' decision-making strategies in two value-based scenarios. We presented chimpanzees with choices varying in the probability of obtaining food rewards (risk-choice task) and in their temporal availability (temporal discounting task). These scenarios were preceded by different sets of priming phases mimicking variability in resource unpredictability (predictable or unpredictable rewards) and harshness (abundant or scarce rewards). In addition, we implemented a social manipulation to explore whether variations in unpredictable gains and losses affected chimpanzees' performance in both tasks. We found that chimpanzees were only affected by the social manipulation in the risk-choice scenario. Specifically, after a period of constant food losses chimpanzees became less risk prone. We discuss how different types of negative experiences affect chimpanzees' decisions. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

A growing literature uses random assignment of cases to judges to examine criminal sentencing. To extend this line of work, we directly examine how judicial “harshness” varies with the seriousness ...

We tested the hypothesis that if indefinite life extension (ILE) through medical technologies were to become a reality, then people may become harsher in their judgment of social transgressors. In support of this hypothesis, we found that higher positive attitudes towards ILE technologies related to harshness in judgment of social transgressions (Study 1), and that making ILE plausible (compared to not plausible) led participants to endorse harsher punishments for social transgressors (Studies 2–3). We replicated this effect and found that it is not amplified by subliminal death primes, although the primes also increased harshness (Study 3). These results may have implications to understanding how social judgment may be affected by the prospect of ILE.

Blame permeates our social lives. When done properly, blame can facilitate the upholding of moral norms. When done with excessive intensity or harshness, however, blame can have significant negative impacts. Here, we develop and validate a scale—the Blame Intensity Inventory—to measure individual differences in the propensity for intense blame responses. First, we present evidence for its convergent and divergent validity by examining relations with existing scales. In addition, in two studies, we show that the Blame Intensity Inventory—rooted in an affective conception of blame—predicts hostile responses to offenders better than do measures focused on blame-related cognitive appraisals (e.g., free will, intentionality). Finally, in three studies, we show that Blame Intensity uniquely predicts malicious satisfaction, or gratification upon learning that an offender has suffered gratuitous harm. Results are discussed in terms of important research questions that could be addressed using the Blame Intensity Inventory.

Considering the influence of mount structure parameters on the quality of vehicle noise, vibration and harshness (NVH), a multi-objective optimization method of the magneto-rheological (MR) mount based on vehicle vibration control was proposed. A lumped parameter model was used to establish the relationship between the structure parameters of the MR mount and the NVH performance of the vehicle. Considering the influence of current on the magneto-rheological fluid viscosity and flow rate in damping channel, the dynamic characteristics of MR mount was obtained by the lumped parameter model. Then, a 10 degrees of freedom (DOF) vehicle model with MR mounting system was established. Finally, a co-simulation optimal platform was developed by the ISIGHT, MATLAB, and ANSYS software, and the non-dominated sorting genetic algorithm II was used to optimize the design of the mount magnetic circuit with the goal of improving the quality of vehicle NVH. The results showed that under the start/stop and the constant speed conditions, the root mean square values of vibration acceleration of the driver’s seat rail of the vehicle with the optimal design magneto-rheological mount decreases by 31.6% and 7.8%, respectively compared with the initial design mount, improved the ride comfort of the vehicle.

It is well-documented that harsh environmental conditions influence appetite and food choice. However, the experience of environmental harshness is complex and shaped by several underlying dimensions, notably threats to one's social support, economic prospects, and physical safety. Here, we examined the differential effects of these three dimensions of environmental harshness on desire for specific food items. We first showed 564 participants images of 30 food items. Next, they rated how much they desired each item. The participants were then randomly assigned to a condition where they read one of six scenario stories that described someone's current living conditions. Each scenario story emphasized one of the three dimensions (social support, economic prospects, physical safety), with two levels (safe, harsh). Following this, the participants once again rated how desirable each food item was. The results showed that exposure to cues of low social support and high physical threat reduce the desire to eat, whereas cues of economic harshness had little effect. Further analysis revealed a significant interaction between energy level of different foods and perceived threat to physical safety. These findings are important in helping to understand how current environmental conditions influence changes in appetite and desire for different kinds of food items.

PurposeThis study uses the notions of institutional harshness and uncertainty avoidance in the home country to explain the choice between direct and indirect exporting strategies by emerging market firms.Design/methodology/approachThis study is based on a dataset of 23,256 observations on firms from 32 countries spread over 11 years (2006–2016). Since only some firms undertake exports, the Heckman procedure is used to control for sample self-selection. In the first stage, we predict which firms will choose to export, and, in the second stage, we examine the factors driving the choice made by firms involved in exports between direct and indirect exports strategies.FindingsThe analyses reveal that firms are more likely to choose direct exports when institutional harshness is high and when they are from countries with low uncertainty avoidance. We also find that the strength of the relationship between institutional harshness and the choice of direct exports is moderated at high levels of uncertainty avoidance.Research limitations/implicationsWhile this study's empirical models account for many firm-level factors as well as home country differences discussed in the literature, we acknowledge there could be other temporal, firm or country idiosyncratic factors not included in our analysis driving the key choices examined in the paper.Originality/valueThis study makes three contributions to exporting literature. First, it highlights the drivers of the choice between direct and indirect exports. This choice is an important facet of exporting strategy and has received scant attention in prior IB research. Second, it demonstrates how the choice between direct and indirect exports is impacted by the degree of the home country's institutional harshness and uncertainty avoidance. Third, it offers insights on how the interaction of formal and informal home market institutional factors influences export strategy.

We critically review the use of the term “life history theory” in recent publications on evolutionary psychology, focusing on how the idea of a fast-slow continuum is deployed in that literature. We raise four issues: First, concerning plasticity, should we expect the effects of plasticity on the developmental response of a trait to mirror the effects of selection on the mean of that trait? We conclude that we should not. Do only plastic responses to harsh or unpredictable environments accelerate maturation, or are there plausible alternatives, such as nutrition? In many situations better nutrition is a plausible alternative. Second, how should we conceive of the harshness of an environment? It has several important dimensions. It could mean an increase in the mean mortality rate, a decrease in the mean growth rate or fertility rate, or increases in the variances of any of those rates. Our judgement of harshness will also be affected by the distribution of such effects across patches in space and through generations in time. The combination and distribution of effects make important differences to predictions. Third, where did the fast-slow idea come from, and how much does it explain? It was initially detected in comparisons across higher taxonomic levels, whose relevance to variation among individuals is unclear and where it fails to explain much of the variation. Fourth, what sorts of processes could generate the fast-slow pattern? Here we expand on insights mentioned earlier in passing to make clear how spatial population structure and class effects generate alternative predictions. We conclude with some thoughts on the nature of theories and research strategies and on how one might respond to empirical puzzles.

Psychosocial stress in childhood and adolescence is linked to stress system dysregulation, although few studies have examined the relative impacts of parental harshness and parental disengagement. This study prospectively tested whether parental harshness and disengagement show differential associations with overall cortisol output in adolescence. Associations between overall cortisol output and adolescent mental health problems were tested concurrently. Adolescents from the Fragile Families and Child Wellbeing Study (FFCWS) provided hair samples for cortisol assay at 15 years (N = 171). Caregivers reported on parental harshness and disengagement experiences at 1, 3, 5, 9, and 15 years, and adolescents reported at 15 years. Both parent and adolescent reported depressive and anxiety symptoms and antisocial behaviors at 15. Greater parental harshness from 1–15 years, and harshness reported at 15 years in particular, was associated with higher overall cortisol output at 15. Greater parental disengagement from 1–15 years, and disengagement at 1 year specifically, was associated with lower cortisol output. There were no significant associations between cortisol output and depressive symptoms, anxiety symptoms, or antisocial behaviors. These results suggest that the unique variances of parental harshness and disengagement may have opposing associations with cortisol output at 15 years, with unclear implications for adolescent mental health.

Breasts are sexually dimorphic physical characteristics, and they are enlarged post-puberty suggesting that they have been driven by sexual selection to signal fertility and residual reproductive value. Although different hypotheses have attempted to explain why men are attracted to women’s breasts, the role that ecology plays in men’s perceptions of women’s breasts has been limited. The current study used an ecologically harsh prime to investigate if ecological harshness influenced men’s perceptions of women’s breast size, ptosis (i.e., sagginess), and intermammary distance. Men were primed with an ecological harsh prime (i.e., economy uncertainty) and asked to rate women whose breast size, ptosis, and intermammary distance (i.e., cleavage) had been manipulated. Ecological harshness only influenced men’s perceptions of women’s breasts for reproductive success. Overall, men rated women with larger breasts as more attractive, fertile, healthier, reproductively successful, and likely to befriend. The study contributes to the overall literature on men’s perceptions of women’s breasts and suggests that ecological harshness may influence men's perceptions of women's reproductive success.

Since the non-linear dynamic response under various high-speed conditions can directly affect the life of gear transmission systems. In addition, the transmission error and dynamic mesh force play a key role in noise and harshness analysis of gear bearing coupled systems. So, in this piece of work, a 12 degree of freedom dynamic model is developed to probe the vibration response by using finite element method and taking into account the bearing and flexible shafts in the first part. Subsequently, some meshing gear characteristics such as dynamic and vibration acceleration response under different rotational speeds (1000-9000 rev/minute) were analyzed whereas critical speed appeared at 6500 rev/minute. Then, the stability analysis is performed to investigate the dynamics behind the critical speed by using MASTA. It was observed that natural frequency of 0.45 kHz for a fourth harmonic order is analogous to critical speed which further causes sudden elevation in both dynamic mesh force and transmission error.

Shift shock is an important index for evaluating the noise, vibration, and harshness performance of heavy-duty vehicles owing to the changeability of driving conditions. Hence, it is imperative to design a controller for a smooth shift to enhance the shift quality of automatic transmission. In this study, a novel robust control design against the uncertainties of heavy-duty vehicles is designed after dynamic modelling is performed. First, the clutch actuator model was developed by considering the uncertainty of electrohydraulic actuators, variations in friction coefficient due to clutch slip speed, and complex and volatile driving conditions of vehicles. Next, a robust control design for the inertial phase is proposed based on the clutch slip speed, including a feedforward controller, feedback controller, and disturbance controller. Finally, it is demonstrated that the control design is highly advantageous for the shift control of heavy-duty automatic transmission by comparison with a proportional-integral-derivative controller. Numerical results indicate that the proposed controller is effective in preventing shift shock, thereby improving ride comfort.

Acoustic and rhythmic temporal patterns may have important roles both in animal vocalizations and in human music. Male rock hyraxes, Procavia capensis, advertise their quality and emotional state by singing a long complex song, comprising repetitive elements. Research has revealed that the temporal structure of hyrax songs is similar to a musical crescendo, as it includes a gradual increase in amplitude, along with several additional acoustic and structural parameters, throughout the song. In hyrax songs, the snort is a relatively rare, low and harsh vocal element, which increases in number as the song progresses. We have previously shown that mean snort harshness is positively linked to both the singer's social status and testosterone levels, possibly reflecting inner arousal. Here, we measured the changes in snort harshness and length during natural hyrax songs. Our results indicate that in mature males, harshness, quantified by shimmer and jitter, increases as the song progresses. We suggest that increasing snort harshness may either (1) indicate the progression of inner excitement or aggression throughout the song or (2) that the harshness may reflect the difficulty of vocal control following increasing effort or the physical fatigue of the vocal cords. In western culture music, such progression is used to increase listener tension and thus retain attention, preventing possible habituation. Thus, understanding the development and progression of challenging elements within animal communication systems may reveal a key fundamental root of modern musical structure, and shed light on the evolutionary basis of musical perception.

Owing to the continuous development of the automobile industry, increasingly stringent performance requirements for noise, vibration, and harshness of automobiles are being presented. Interior noise control in high-speed vehicles has not been adequately addressed, owing to the complex mechanism of noise generation. As simulations performed previously focused on vehicle wind noise and tyre noise cannot adequately predict the effect on passenger ear-side noise, these issues are investigated in this study. Their effects on passengers are investigated using transfer path analysis. An anti-noise operational transfer path analysis is proposed to study noise generated in high-speed vehicles. The established anti-noise operational transfer path analysis model can eliminate crosstalks between noise source signals of different transmission paths. The model is validated by comparing the measured and calculated values of the anti-noise operational transfer path analysis model. The coherence of the input noise signal and the ear-side noise signal of the passenger is assessed using coherence analysis. By calculating and categorising the contributions of different noise sources in different locations and types, the main noise sources affecting passenger comfort are determined. The result indicates that the main noise sources affecting the passenger’s ear-side noise change from engine noise to left-A wind noise and tyre radiation noise with increasing vehicle speed, in which the proportion also increase. The proposed anti-noise operational transfer path analysis is suitable for the interior-noise analysis of high-speed vehicles, and this study may serve as a reference for future studies regarding active and passive noise control in high-speed vehicles.

Constant velocity (CV) joints are the primary component of a vehicle that transmits the driving force from an engine/transmission to a wheel at a constant speed. A CV joint comprises numerous mechanical parts. The roller and housing are in contact and, therefore, subjected to contact stresses. Contact stress causes sliding friction because of microslip in the contact area inside the CV joint. This internal friction generates an axial force, dependent on the kinematics. A generated axial force (GAF) is caused by the internal friction in a plunging-type CV joint. This force can have a direct impact on the degradation of the noise, vibration, and harshness characteristics of a vehicle. The typical vibration of a CV joint transmitted to the vehicle is shudder, which degrades the lateral oscillation of the vehicle. Shudder is generated by the GAF and results from the rotation of the CV joint during rapid acceleration, stimulating the lateral movement of the vehicle and causing discomfort to passengers. In this study, the radii of the roller and the housing were selected as the design parameters, and the contact stress was minimized through the sensitivity analysis. The GAF of the existing CV joint and optimized CV joint are compared through a multibody dynamic simulation. An axial force test is performed on the CV joint of a C-segment vehicle to verify the dynamic simulation results. The friction characteristics of the greases used in the CV joint were also confirmed by the schwingung reibung verschleiss (SRV) friction test. The results obtained can be used to reduce the GAF of the CV joint and to build an optimized CV joint model.

Noise, vibration, and harshness (NVH) simulators enable the subjective evaluation of vehicle interior noise and improvement of the NVH performance. To achieve a powerful and sporty engine sound, several original equipment manufacturers of automobile parts introduce the engine intake noise into the vehicle cabin through pipe systems that reinforce the low-frequency engine noise components. The present study proposes an intake-noise module that simulates an intake-noise reinforcing system and can be integrated with the previously developed NVH simulator. The intake- noise simulation module is based on the intake noise source model, pipe system model, and room impulse response model. The pipe system is modeled by the transfer-matrix method (TMM), and the room impulse response is modeled using the image-source method. The intake noise source is time variant because the noise source depends on the rotational speed of the engine and the crankshaft angle. TMM is also time variant because the noise propagation characteristics in TMM vary with the throttle valve angle. Intake noise source and TMM are designed in the frequency domain. In two cases of intake-noise reinforcing system, the loudness and sharpness (which are known to be correlated with a sporty engine noise) are calculated for the simulated data. The developed NVH simulator can assist the design of intake-noise reinforcing systems that reach the targeted sound quality.

Determining the root causes of various noise, vibration and harshness phenomena in modern automotive drivetrains is a critical task for industry, since noise, vibration and harshness issues often result in worsened driving experience. The aim of the current research is to investigate the dynamics during dry clutch engagement and the associated – often problematic – oscillations. This paper reports the development and partial validation of numerical models to study dry clutch behaviour. The models are used to investigate the influence of clutch and throttle actuation on the occurrence of unwanted clutch oscillations. The dynamic coefficient of friction between the clutch interacting surfaces was measured using a pin-on-disc rig under different slip speeds and contact pressure conditions, which are representative of a typical clutch engagement manoeuvre. The paper highlights the occurrence of instability issues in clutch dynamics (disc radial mode) as potential generators of aggressive noise, vibration and harshness, particularly during two different clutch pedal actuations. Such analysis has not hitherto been reported in the open literature.

The content of noise, vibration, and harshness is an important part of the undergraduate mechanical engineering program education to prepare students ready for their future career, and it has received great attention from educators. Since course content in noise, vibration, and harshness usually requires more mathematical background knowledge and skills such as problem-solving in differential equations and linear algebra, students at the undergraduate level usually experience difficulty in the problem-solving work in noise, vibration, and harshness, though they have already completed the pre-requisite mathematics courses. In this paper, a new schedule and course content design for noise and vibration courses are introduced. By embedding active learning and design during projects, the students were able to obtain a better understanding of the concept of acoustics and vibration, as well as applying the knowledge from lectures to labs so they can connect the learning to real-world applications. Four projects are introduced and explained. To evaluate the effectiveness of the course, student outcomes are assessed and discussed.

Functional traits are commonly used to calculate a wide array of functional diversity indices to infer different mechanisms of community assembly and species coexistence. Recently, the degree of interspecific covariation between multiple functional traits has been suggested as a mechanism influencing both species distributions and abundances in communities. However, empirical assessments of this theory along environmental gradients are still scarce due to the lack of an appropriate method and of sufficiently strong environmental gradients. Here we compare interspecific trait integration (ITI) across plant communities along a marked gradient of copper toxicity in the soil, using new multivariate and bivariate indices. This was achieved using the range of the eigenvalues of a principal component analysis on the traits of the species in a local community (multivariate ITI index) and the correlations between traits in local communities (bivariate ITI index). We show that the plant metal tolerance strategy (i.e. leaf metal content) is relatively independent from leaf economics, while negatively correlated to plant size. In addition, our results indicate a weak support for the expected general patterns of trait syndromes, such as the ‘leaf economics spectrum’ or the ‘leaf–height–seed’, at the whole-community scale. This arises from an increase in multivariate trait integration along the soil copper gradient. The strongest trait integration is caused by an increase in the degree of association between certain traits on metal-rich soils. The multivariate trait integration explains species richness better than other commonly used functional diversity indices. Our study highlights the power of ITI, as well as its complementarity to other functional diversity indices, to investigate the variation in functional strategies and their drivers along environmental gradients. The increase in trait integration with soil metal toxicity in plant communities supports that highly constraining environments select increasingly coordinated sets of functional traits, in turn possibly driving the decrease in species richness. Further studies should assess the generality and underlying physiological mechanisms of such ecological patterns., SCOPUS: ar.j, info:eu-repo/semantics/published

Legislation mandating minimum distances for motorists passing cyclists is seen by advocates as a straightforward way to increase the perceived safety of cycling and thus remove a prominent barrier to the uptake of cycling. The evidence, however, is not as clear. The alternative to compliance-based enforcement via Minimum Passing Distance Laws (MPDLs) is performance-based enforcement as recently highlighted by UK Police forces under the name ‘Operation Close Pass’. This existing legislation and enforcement method relies on police officer judgement and discretion. For a MPDL to be introduced it has to show an improvement by identifying more manoeuvres that make cyclists feel unsafe, whilst at the same time not penalising drivers for manoeuvres that are benign. This study uses Signal Detection Theory to show that on almost every measure the current performance-based enforcement is preferable. Officer discretion is aligned more closely to cyclists’ real-world perceptions of risk than an objective, compliance-based MPDL. Any level of enforcement harshness can be achieved equally well, if not better, through officer discretion than through a fixed passing distance law, with the former being significantly easier to adjust if needed. Further discussion about the unintended effects of passing distance laws is discussed, such as the risk of a net loss to the effectiveness of cyclist safety because it is more difficult to prosecute and enforce manoeuvres which make cyclists feel unsafe than the performance-based alternative.

Road noise is expected to become even more important in the vehicle product development cycle due to electrification and challenging lightweight/emission targets. In this study, a topology optimization algorithm is applied to determine the damping pad layout on the roof and floor panels of a Body-in-White (BIW), being the dominant contributors on road noise, vibration and harshness (NVH) performance of an automotive. Optimization algorithm yields the prescribed % of the surface area of these panels where the damping pad should be distributed set by the automotive Original Equipment Manufacturers (OEMs). The objective function is the minimization of the overall acceleration of these panels for the frequencies up to 200 Hz, while the weight of the BIW is considered as the optimization constraint. The results of the optimization are compared with the road NVH performance of panels with full damping and no damping. The optimization results indicate that by using 25% of the damping pad on the roof and floor panels improve the vibration performance especially in the frequency range of 80 Hz to 150 Hz significantly compared to bare BIW panels. Besides, the performance of the 25% damping is almost same as the application of full damping pad for frequencies between 90 Hz to 110 Hz. The results show that the methodology is able to address the trade-offs between road NVH and weight targets effectively.

Using psychosocial acceleration theory, this multimethod, multi-reporter study examines how early adversity adaptively shapes the development of a self-regulation construct: effortful control. Investigation of links between early life harshness and unpredictability and the development of effortful control could facilitate a nuanced understanding of early environmental effects on cognitive and social development. Using the Building Strong Families national longitudinal data set, aspects of early environmental harshness and early environmental unpredictability were tested as unique predictors of effortful control at age 3 using multiple regression. Early harshness variables were financial harshness, mothers' and fathers' observed parenting, mothers' and fathers' reported use of harsh discipline, and harsh neighborhood conditions. Early unpredictability was measured by number of paternal transitions. Cues of harshness, specifically observed unresponsive parenting, observed harsh parenting, and neighborhood harshness, did significantly negatively predict effortful control. Paternal transitions also significantly predicted effortful control, but in the opposite (i.e., positive) direction. The results corroborate previous research linking quality of parenting to the development of children's effortful control and place it within an evolutionary-developmental theoretical framework. Further, the results suggest that neighborhood harshness may also direct developmental trajectories of effortful control in young children, though the mechanisms through which this occurs are still unclear. This is the first study to explicitly investigate effortful control development in early childhood within the harshness and unpredictability framework.

This article presents the optimal design and experimental prototype testing of a low-cost motor applied for a city battery electric vehicle, zero emission A-segment. Respecting the car performance specifications, the aluminum cage rotor induction machine is designed to reduce motor cost using totally enclosed fan-cooled technology and a commercial speed encoder of internal combustion engine. An optimization approach and finite elements analysis validation are coupled with thermal calculations and used to size the thermo-electromagnetic parts of the machine. The prototype is manufactured with full instrumentation. During the experiments, an indirect flux-oriented control model is built based on simulations in MATLAB/Simulink environment. Using this real time control platform, the motor control is calibrated on the prototype in test-bench, to ensure the optimum energy consumption and the current and speed regulations in the entire large operating range. Finally, the experimental prototype testing results are shared to show the ideal design solution in term of peak performances, efficiency, thermal and noise, vibration, and harshness behaviors.

In recent years, the reduction of noise and vibrations caused by the road or internal components of vehicles have been a significant factor in the satisfaction and comfort of the occupants of cars. Therefore, to minimize these vibrations, the dynamic behaviour of the components of the vehicle should be considered in detail to reduce their level by setting useful parameters on structures. Nowadays, the conceptual model method can be regarded as a suitable alternative to the fundamental sophisticated computational techniques in measuring the vibration of vehicle components. Accordingly, the advanced finite element (FE) model examined for the subframe structure under the vehicle engine, and its conceptual model is developed by the one-dimensional beam elements to justify the dynamic behaviour of the subframe. The results of the experiments in the laboratory as well as the advanced subframe model are adapted, and the integrity of the natural frequencies and the mode shapes at low frequencies represented comprehensively. The result of the subframe concept model compared to the experimental model and computer-aided-engineering (CAE) model showed that the modal assurance criterion (MAC) is above 0.75 for the first four mode shapes of subframe structure and is above 0.9 for first and fourth mode shapes, and also the error percentage of natural frequency is lower than 8%. Therefore, for the analysis of the subframe performance in noise, vibration, and harshness (NVH) domain, the presented model could be considered in the conceptual phase design to reduce the solution time significantly.

Memory is one of the most crucial cognitive functions in many organisms. It is highly implicated in everyday functioning and is an essential component for survival. Past research has revealed that spatial memory facilitates bird caching behaviours such as remembering the exact locations of their hidden food. However, there are many factors that alter the demands on memory and consequently impact the function of caching. Specifically, neurogenesis, the process of forming new neurons, has been shown to affect this behaviour. Likewise, environmental variables and selective pressures (i.e., severity of the environment) can also influence caching in birds. In this review, we present evidence for a link between environmental harshness, hippocampal neurogenesis, and caching behaviour in chickadees, with specific focus on work by Chancellor et al. [6]. Neurogenesis in chickadees may be a mechanism subject to selective pressures, in which chickadees from harsher environments have increased neurogenesis rates and consequently enhanced caching ability. However, there remain gaps in the understanding of how exactly hippocampal neurogenesis, environmental harshness, and caching behaviour interact, and future studies are needed to further explore this interaction and its implications.

A dominant spatial airgap force order-based reference current profiling scheme is proposed in this work for noise, vibration and harshness (NVH) mitigation in Switched Reluctance Machines (SRM). The current profile optimization strategy is coupled with a fast vibration prediction method. Extensive simulations and experimentations are done on an 18 slot/12 pole SRM to verify the proposed strategy. Worst case noise scenario for the 18 slot/12 pole SRM is determined through experimental run-up test under constant torque condition. The proposed current shaping strategy is applied at the operating point experiencing worst case noise and significant NVH reduction is obtained through simulation and experimentation. Experimental results show a peak noise reduction of 14.24 dBA compared to a conventional square wave based current reference.

Engine mount is an essential component to support the vehicle engine and to determine the vehicle dynamic property in terms of noise, vibration, and harshness (NVH). It works as the important interface between the engine and the chassis to reduce the bad impact of the engine-induced vibrations on the car body. To this end, this paper proposed a new semi-active engine mount capable of variable stiffness as an attempt to further improve the vibration reduction capability of the current semi-active engine mount which is only capable of varying damping. This study completed the characterization test of the proposed semi-active engine mount and evaluated its capability of stiffness variability. Then a test of an engine mounted with the new mount was performed to evaluate the vibration reduction capability. The experimental results demonstrate that this proposed engine mount show variable stiffness in response to the varied magnetic field, and that it performed well in protecting the chassis from the engine-induced vibration by reducing the vibration transmissibility.

In December 2019, the first reported case of COVID-19 was brought to notice in Wuhan, China. The virus has novel characteristics, its harshness is unpredictable, its transmission ability is extremely powerful, and its incubation period is comparatively larger. Thus the outbreak emerged as a pandemic worldwide. World health and socio-economy is getting continually affected by COVID-19 since its outbreak. It will be easier to handle the situation if an automated diagnostic system is developed, capable of separating COVID-19 affected images from bulk images obtained from a mass screening process. Kaggle’s online chest X-Ray image dataset has been considered for this work evaluation. Healthy and COVID-19 affected chest X-Ray images were used for evaluating the performance of content-based image retrieval. Image retrieval has been carried out based on the absolute difference between the encoded features of twin images obtained from the Siamese Convolutional Neural Network (SCNN). The retrieval performance is awe-inspiring as the Siamese network used for retrieval is a relatively shallow network. SCNN does not require resource-hungry training with huge samples as part of its underlying implementation characteristics. The execution time is also very encouraging as the simplicity of the method is concerned. The method achieves 94% average precision and 100% average reciprocal rank while rank = 5 has been considered. Till now, no work has been reported on content-based retrieval of COVID-19 chest X-Ray images. Thus, a comparative study of evaluation metrics and execution time requirements of similar work could not be provided.

Chapter 21 is contributed by a team of gear experts of Gear Research Center (FZG) at the Technical University of Munich, Germany. This chapter covers the noise, vibration, and harshness (NVH) behavior of geared transmissions as a major field in gear design and analysis. Gear noise is dependent on transmitted load and running speed of the gears and is characterized by distinct frequencies that may be clearly audible. In most applications gear noise is unwanted and has to be prevented. Major efforts in engineering are concentrated on low noise design on one hand and on gear noise analysis in operation on the other hand. In gear design a low noise generation is valued as a major quality criterion. Some design rules concerning gear main geometry or simple shapes of recommended micro geometry are available for the engineer. Nevertheless, a significant portion of developing silent gears is an iterative trial and error activity. That makes sound understanding of the underlying basics mandatory for today’s gear engineer. The chapter illustrates different mechanical approaches to gear mesh NVH. General basics of gear noise excitation are covered, in particular the influence of main geometry and of micro geometry. Evaluation of different design criteria (TE, etc.) will be explained. Widely used is the calculation of transmission error but also established are more complex methods like tooth force level or application force level. Gear noise analysis is a second relevant aspect. Based on general acoustics an evaluation of airborne sound and noise of transmissions will be described. More detailed methods of analysis techniques of transmissions and gear meshes will be documented which require greater effort. These include measurement of structure borne noise and measurement of transmission error in special test rig environment.

Although many societies endorse objectivity in moral judgment and punishment, humans are frequently influenced by deep-rooted biases, such that superficially irrelevant factors can influence moral judgment and decision making. Hunger is a fundamental source of motivation and is known to redirect behavior in other domains. The present research aims to test whether hunger influences moral judgments and punishments. We first report results from four pilot studies (n = 1354) which, taken together, imply a positive relationship between self-reported hunger and harsher moral judgment. The main preregistered study then examined the effect of experimentally induced hunger on judicial sentencing and moral judgments. Hunger was manipulated by asking 246 undergraduates to not eat for at least four hours before the study. Participants in the Satiated condition received a snack before taking questionnaires, while those in the Hungry condition were given the same snack after responding to the questionnaires. Contrary to our pre-registered predictions, participants in the Hungry condition recommended significantly more lenient punishments, while the manipulation had no effect on moral judgment. Overall, the results suggest caution regarding previous findings indicating that hungry people punish more, and offer tentative evidence of the opposite effect under some conditions. We discuss possible reasons for the apparent inconsistencies between studies.

Transfer Path Analysis (TPA) is widely used to identify individual path contributions and to solve Noise, Vibration and Harshness (NVH) issues in different industries. However, the complexity and technical burden of the conventional TPA calls for alternative, faster techniques. One such alternative is the Operational Transfer Path Analysis (OTPA), which uses only operational data to estimate the contributions. However, this approach has its own limitations; in some situations, the OTPA results may be affected, which can lead to the wrong engineering decisions. This paper presents an alternative formulation of OTPA, in application to structure-borne noise: Operational Transfer Path Analysis – Difference (OTPA-D). The theoretical considerations and analytical model showed that OTPA-D solves one of the crucial issue regarding the OTPA technique. The paper provides theoretical considerations behind OTPA-D; also, a laboratory model is set up to compare the results of three versions of OTPA with the results of TPA. It is shown that two experimental OTPA versions matched TPA better compared to the traditional OTPA method.

Electric vehicles generally have a better noise, vibration, and harshness quality than traditional vehicles due to the relatively quiet electric motors. By contrast, the noise, vibration, and harshness issues of the driveline system become more outstanding and significant in the absence of the “masking effect” by the engine. The electrification of the powertrain has also brought many changes in the sources or transmission of vibration, which has led to some new noise, vibration, and harshness issues. Specifically, the intense vibration of the prototype bus appears when driving in third gear, which makes the passengers uncomfortable. This paper presents an efficient analytical strategy for identifying the resonance sources and vibration transmission for a pure electric bus. The strategy incorporates order analysis, operating deflection shape, and transfer path analysis. Order analysis shows that the resonance is primarily caused by the second-order excitation associated with the driveline, and the vibration sources are further identified using operating deflection shape analysis. Moreover, the vibration transfer paths from the driveline to the bus floor are quantitatively determined by the transfer path analysis method. The results show that the coupling vibration of the powertrain and the rear drive axle, which amplifies the resonance of the whole driveline, is transmitted to the bus floor primarily through powertrain mounts and V rods. Based on the results, the design and structure modifications of the driveline and transfer paths are recommended to handle this issue. The proposed identification strategy would be beneficial for accurate and efficient engineering troubleshooting on the vibration issues.

Electric and hybrid vehicle engines produce a complex spectrum of vibration and noise. Various active mounting techniques have been developed to isolate them. These are designed to continuously control the dynamic characteristics of the mounts and improve the noise, vibration, and harshness (NVH) performance under various operating conditions. Active mounts have attracted attention as replacement for existing mounts by simultaneously realizing static and dynamic stiffness, which is important for supporting an engine. Therefore, this study focuses on the vibration isolation performance of the upper plate and lower plate when the structure, including the active mounting system, is applied to multifrequency excitation. The overall modeling is based on the lumped parameter model, and the input signal is applied to the amplitude modulated and frequency modulated signals. The adaptive filter is applied for control, and the normalization least mean square (NLMS) algorithm, which is commonly used in research, is extended to a multi-NLMS algorithm. It is shown that when multifrequency input is applied, the adaptive filter is effectively applied to the active mounting system to control vibration.

Consideration of internal combustion engine formats suitable for hybrid or range extender electric vehicles usually focuses on selecting a power plant, which is as compact as possible to meet the demands and constraints of the installation. In-line three-cylinder engines often provide an attractive solution for such vehicles. This article presents a low emission two-stroke engine of in-line three-cylinder format and draws a comparison with an equivalent four-stroke engine. The particular focus of the analysis is on strategies for minimization of noise, vibration and harshness with significant reduction in piston lateral force compared with the four-stroke unit. The design also considers a balance shaft arrangement to further assist with noise, vibration and harshness reduction. The presented arrangement demonstrates an integrated induction control/balance shaft arrangement, which erodes the usual cost penalties typical of balance shaft consideration in three-cylinder engines.

Exposure to noise and whole-body vibration (WBV) has been a key element in determining comfort levels in transportation systems. In the automotive industry, researchers and engineers continuously work on reducing noise and vibration levels to minimize discomfort. Noise annoyance in vehicles results from structure-borne as well as air-borne noise from vehicle powertrain, tires and aeroacoustics. Whole-body vibration affects vehicle passenger comfort at the seat pan, back rest and feet. The objective of this research is to evaluate the comfort level of seated passengers in a vehicle from noise and whole-body vibration by considering both separate and combined modality. The noise and vibration data were recorded and analysed in two vehicles on the same highway road with four different speeds. The vibration exposure in vehicle were evaluated based on ISO2631-1:1997. Noise exposure was based on A-weighted sound pressure level. The combined discomfort on noise and vibration were quantified. The vibration results identified clear dominant of z-axis vertical vibration on seat pan, backrest and feet in both vehicles. The discomfort of combined noise and vibration showed that vehicle B caused a higher discomfort level at the high vehicle speed of 90 km/h and 110 km/h. The Relative Discomfort Indicator (RDI) were introduced to compare levels of discomfort from noise and vibration in different vehicles with varying speeds. The result suggests that the RDI value for vehicle A relative to vehicle B is negative at higher vehicle speed which further indicates that at higher speed, vehicle B have a higher discomfort level compared to vehicle A. The RDI value is expected to be useful for automotive Noise, vibration and harshness (NVH) improvement.

Relations between two contextual challenges (low household income, difficult child temperament), maternal agreeableness and three aspects of parenting (harshness, sensitivity, stimulation) were examined when children were 6 months, 54 months old and 5th grade. Mothers with higher incomes and more education were more sensitive and provided more stimulation to their children. They also were less harsh. Mothers high in agreeableness were more likely to demonstrate sensitivity and provide stimulation; and they were less likely to manifest harshness. Maternal agreeableness moderated the effects of low income on parental behavior with significant interaction effects observed in 9 of the 12 models tested. When rearing a difficult child, mother’s high in agreeableness showed more supportive behavior in 3 of the 12 models tested.

This paper describes a method to reduce the torque ripple for the Wound Field Synchronous Motor, which does not use a permanent magnet. When a WFSM is used in an Integrated Starter Generator system, it must have a higher power density than other automotive motors in order to satisfy the size constraints and required power. An increase in the power density creates a magnetic flux saturation in the rotor, and this soon becomes the cause of an increase in the torque ripple of motor. An increase in the torque ripple can degrade the Noise Vibration Harshness characteristics of automotive by creating vibration and noise in the engine start-up mode, in which the maximum torque is generated in an ISG system. This paper proposes a method of reducing the torque ripple via a design that uses a flux barrier model in the WFSM’s rotor. The Response Surface Method is used to optimize the flux barrier model, and Finite Element Method is used to to verify the torque ripple reduction.

The ride comfort, driving safety, and handling of the vehicle should be designed and tuned to achieve the expectations defined in the company’s design. The ideal method of tuning the characteristics of the vehicle is to modify the bushings and mounts used in the chassis system. To deal with the noise, vibration and harshness on automobiles, elastomeric materials in mounts and bushings are determinant in the automotive components design, particularly those related to the suspension system. For most designs, stiffness is a key design parameter. Determination of stiffness is often necessary in order to ensure that excessive forces or deflections do not occur. Many companies use trial and error method to meet the requirements of stiffness curves. Optimization algorithms are an effective solution to this type of design problems. This paper presents a simulation-based methodology to design an automotive bushing with specific characteristic curves. Using an optimum design formulation, a mathematical model is proposed to design and then optimize structural parameters using a genetic algorithm. To validate the resulting data, a finite element analysis (FEA) is carried out with the optimized values. At the end, results between optimization, FEA, and characteristic curves are compared and discussed to establish the correlation among them.