Search

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.

The slamming acoustic of a vehicle door is objectively not associated to the inherent character of the automobile, however, it is associated to the inherent structure of the vehicle door, which is a vital subjective performance to evaluate the vehicle. Although it has been recognized that static indicators may engender an inferior design result in engineering practice, the majority studies in the literature have not considered dynamic indicators for the door slamming event. This paper presents a multi-objective optimization (MOO) framework of a vehicle door design in the slamming event for optimal dynamic performances. In our previous study we have obtained the transient excitation forces through the transfer path analysis (TPA), lab experiment and bench test. These transient excitation forces will be the input for the MOO algorithm. The dimensions of the vehicle door structure main components are considered as design variables. The objective functions include the first natural frequency obtained by semi-constrained modal analysis, the mass of the vehicle door, and the maximum amplitude of the target points on the vehicle door’s glass. The constraint functions include the design variable bounds, dynamic stiffness constraints of the four mounting points for the glass run channel system. In order to promote the efficiency of subsequent optimization, the response surface method (RSM) is employed instead of time-consuming finite element method. The multi-objective particle swarm optimization (MOPSO) algorithm is implemented to conduct the dynamic indicators optimization. The results show that the proposed optimization framework is successful of achieving a reliable solution with a uniformly distributed Pareto boundary, and it is recommended to choose an optimal result from relatively insensitive regions that meet the requirements. It is shown that the simulation response of the optimized door structure can reduce the acoustic pressure amplitude at the driver’s right ear employed BEA technique. The proposed framework can be adapted to optimize door structural design for any vehicle door to improve noise, vibration, and harshness (NVH) performance.

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.

Hypothesis This study tests the hypothesis that it is possible to find tone or noise vocoders that sound similar and result in similar speech perception scores to a cochlear implant (CI). This would validate the use of such vocoders as acoustic models of CIs. We further hypothesize that those valid acoustic models will require a personalized amount of frequency mismatch between input filters and output tones or noise bands. Background Noise or tone vocoders have been used as acoustic models of CIs in hundreds of publications but have never been convincingly validated. Methods Acoustic models were evaluated by single-sided deaf CI users who compared what they heard with the CI in one ear to what they heard with the acoustic model in the other ear. We evaluated frequency-matched models (both all-channel and 6-channel models, both tone and noise vocoders) as well as self-selected models that included an individualized level of frequency mismatch. Results Self-selected acoustic models resulted in similar levels of speech perception and similar perceptual quality as the CI. These models also matched the CI in terms of perceived intelligibility, harshness, and pleasantness. Conclusion Valid acoustic models of CIs exist, but they are different from the models most widely used in the literature. Individual amounts of frequency mismatch may be required to optimize the validity of the model. This may be related to the basalward frequency mismatch experienced by postlingually deaf patients after cochlear implantation.

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.

The recent climate projections predict that the intensity and frequency of extreme events will increase as a result of overall increasing mean temperature and reduced precipitations in the temperate regions of the Northern Hemisphere. How these changes will influence the harshness of the environment and the performances of trees growing under natural conditions remains an open question. In this commentary article, we would like to look at the concept of suboptimal growth conditions, widening its application from the traditional in vitro manipulation to trees growing in open air, addressing the main limitations and strengths of the upscaling results from cell to tree. We believe that the traditional single dose–effect approach is not suitable to explain the complex interactions between genotype and environment, occurring in open field or forest stands, where the intensity and frequency of the events are uncontrolled and unpredictable. As forests provide a wide range of ecosystem services, new parameters should be considered in the definition of the response thresholds in addition to growth. Thus, within this Special Issue, we stimulate the discussion over the development of new approaches and technologies that are able to define suitable threshold responses of trees under suboptimal natural conditions, with the aim to furnish new insights on the acclimation and adaptation processes in woody species under global change.

The value and importance of leadership is evident by its prevalence throughout human societies and organizations. Based on an evolutionary argument, models are presented here that provide a mathematical justification as to how and why leadership arose in the first place and then persisted. In this setting, by a leader is meant a person whose overall actions are ultimately responsible for the well-being and survival of the group. The proposed models contain parameters whose values reflect group size, harshness of the environment, diversity of actions taken by individuals, and the amount of group cohesion. Mathematical analysis and computer simulations are used to identify conditions on these parameters under which leadership results in an increased survival probability for the community.

Globally, there has been a remarkable growth in the number of underground constructions (UGC) such as railways, offices, hospitals and shopping malls. This expansion is a result of urban area extensions that are limited by the availability of buildable land. Underground construction can also be used to protect people from the harshness of the outdoor conditions. The aim of this research is to investigate the impact of underground construction in hot regions. The major issue with most of the current UGC is the lack of natural ventilation and daylight. This has a clear negative impact on the user’s perception and comfort. The new design elevates the external walls to place some of the windows above ground for the purpose of natural ventilation and providing a view. The study conducted an experiment using an underground room enhanced with field measurements to ascertain the indoor temperature as well as relative humidity. In addition, the study used an energy simulation to calculate building heat transfer and solar heat gain. It was revealed that the use of UGC in hot regions promoted with the addition of natural ventilation can lower the indoor temperature by 3 °C in summer.

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.

The sex ratio at birth (SRB) may be patterned by maternal condition and/or environmental stressors. However, despite decades of research, empirical results from across the social and biological sciences are equivocal on this topic. Using longitudinal individual-level data from a US population during the interwar period (1918–1939), inclusive of three distinct eras (Spanish Flu, Roaring ‘20 s, and the Great Depression), we evaluate predictions from two theoretical frameworks used to study patterning in SRB – (1) ‘frail males’ and (2) adaptive sex-biased investment theory (Trivers-Willard). The first approach centers on greater male susceptibility to exogenous stressors and argues that offspring survival should be expected to differ between ‘good’ and ‘bad’ times. The second approach contends that mothers themselves play a direct role in manipulating offspring SRB, and that those in better condition should invest more in sons. In-line with ‘frail male’ predictions, we find that boys are less likely to be born during the environmentally challenging times of the Spanish Flu and Great Depression. However, we find no evidence that maternal condition is associated with sex ratios at birth, a result inconsistent with the Trivers-Willard hypothesis.

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.

This study was a test of associations between measures of harsher environments and indicators of a “faster” life history strategy, including higher aggression, risk taking and a sociosexuality preference for short term and uncommitted sexual relationships. Hypotheses were derived from previous literature in evolutionary psychology proposing that harsher environments promote these faster life history strategies. Additionally, due to the potential for testosterone to act as a hormonal mechanism calibrating life history strategies, associations were tested between salivary testosterone and harsher environments and faster life history strategy indicators. Based on a sample of young adult male undergraduates (n = 99), the results of this study do not support hypothesized associations between harsher environments and faster life history strategies. The majority of tests between environmental harshness and life history strategy indicators were non-significant, with two being significant in the expected direction and one being significant in the unexpected direction. However, none of these remained significant after adjustment for multiple comparisons. There were no significant associations between testosterone and environmental harshness or life history strategy indicators. The results of this study suggest reconsideration of current uses of life history theory within evolutionary psychology intended to explain relationships between environments and psychology and behavior.

The noise, vibration and harshness (NVH) behaviors of axial piston pumps are important performance criteria for their operation. A systematic investigation is required to study their vibro-acoustic characteristics. In this investigation, the vibro-acoustic characteristics of an axial piston pump were experimentally measured under run-up and steady-state operating conditions. The sound pressure level and vibration were measured, interpreted and analyzed under the run-up operating conditions. The sound quality of the pump, including its loudness, sharpness and roughness, was also evaluated. The effects of speed and pressure on loudness, sharpness and roughness were examined. The results showed that the proposed experimental methodology is effective for evaluating the overall vibro-acoustic characteristics of axial piston pumps. The most relevant noise components can be identified and extracted by a thorough analysis of the vibro-acoustic characteristics using the proposed analysis methodology. The study contributes to better understanding the vibro-acoustic characteristics of axial piston machines.

The automotive industry has striven for fuel economy and resource efficiency through the deployment of powder metallurgy (PM) manufacturing processes for few decades. However, PM technology for transmission gears is currently only used at a small scale within the automotive industry. This is mainly due to: its shortcomings in material properties and performance gaps for final parts; lack of advancement in pressing technologies (dimensional limitation); lack of data availability (e.g. on materials, load capacity calculations; gear design experimental confirmation); premature failed attempts on PM gears; economics of scale and large initial capital investments. This article reviews the current state of the art of PM gear manufacturing technology highlighting an important gap in technical and financial data availability for PM gear economic analysis. Thus, this study seeks to give some empirical evidence of the economic aspects of PM gear manufacturing. Data availability is still the major challenge with respect to PM cost calculations thus further studies are needed to quantify both the economic and non-economic benefits e.g., sustainability, noise vibration harshness (NVH) of PM adoption.

Detecting damage in composite materials is significantly important for the utilization of them. The paper investigates the use of the experimental part of modal analysis method to indicate damage presence in FRP specimen. The study goal is to examine the efficiency of the method to detect damage by investigating the noise, vibration and harshness (NVH) behaviour of damaged and undamaged fiber glass reinforced polymer specimen with simple geometry. A defect is generated artificially in the test specimen in order to visualize the difference in the dynamic parameters such as natural frequencies, modal damping, and mode shapes between the damaged and undamaged one. The results reveal the change of the NVH characteristics of the part during the damages leading to show the sensitivity of the experimental modal analysis for damages.

Ecological communities often exhibit greater resistance to biological invasions when these communities consist of species that are not closely related. The effective size of this resistance, however, varies geographically. Here we investigate the drivers of this heterogeneity in the context of known contributions of native trees to the resistance of forests in the eastern United States of America to plant invasions. Using 42,626 spatially referenced forest community observations, we quantified spatial heterogeneity in relationships between evolutionary relatedness amongst native trees and both invasive plant species richness and cover. We then modelled the variability amongst the 91 ecological sections of our study area in the slopes of these relationships in response to three factors known to affect invasion and evolutionary relationships –environmental harshness (as estimated via tree height), relative tree density and environmental variability. Invasive species richness and cover declined in plots having less evolutionarily related native trees. The degree to which they did, however, varied considerably amongst ecological sections. This variability was explained by an ecological section’s mean maximum tree height and, to a lesser degree, SD in maximum tree height (R2GLMM = 0.47 to 0.63). In general, less evolutionarily related native tree communities better resisted overall plant invasions in less harsh forests and in forests where the degree of harshness was more homogenous. These findings can guide future investigations aimed at identifying the mechanisms by which evolutionary relatedness of native species affects exotic species invasions and the environmental conditions under which these effects are most pronounced.

It has been proposed that environmental stress acted as a selection pressure on the evolution of human cooperation. Through agent-based evolutionary modelling, mathematical analysis, and human experimental data we illuminate the mechanisms by which the environment influences cooperative success and decision making in a Stag Hunt game. The modelling and mathematical results show that only cooperative foraging phenotypes survive the harshest of environments but pay a penalty for miscoordination in favourable environments. When agents are allowed to coordinate their hunting intentions by communicating, cooperative phenotypes outcompete those who pursue individual strategies in almost all environmental and payoff scenarios examined. Data from human participants show flexible decision-making in face of cooperative uncertainty, favouring high-risk, high-reward strategy when environments are harsher and starvation is imminent. Converging lines of evidence from the three approaches indicate a significant role for environmental variability in human cooperative dynamics and the species-unique cognition designed to support it.

While sex ratios at birth (SRB) have been shown to vary within and across populations, after over a century of research, explanations have remained elusive. A variety of ecological, demographic, economic, and social variables have been evaluated, yet their association with SRB has been equivocal. Here, in an attempt to shed light on this unresolved topic within the literature, we approach the question of what drives variation in SRB using detailed longitudinal data spanning the frontier-era to the early 20th century in a population from the US state of Utah. Using several measures of environmental harshness, we find that fewer boys are born during challenging times. However, these results hold only for the frontier-era and not into a period of rapid economic and infrastructure development. We argue that the mixed state of the literature may result from the impact and frequency of exogenous stressors being dampened due to industrialization.

As battery electric vehicle (BEV) market share grows so must our understanding of the noise, vibration, and harshness (NVH) phenomenon found inside the BEVs which makes this technological revolution possible. Similar to the conventional vehicle having encountered numerous NVH issues until today, BEV has to face many new and tough NVH issues. For example, conventional vehicles are powered by the internal combustion engine (ICE) which is the dominant noise source. The noises from other sources were generally masked by the combustion engine, thus the research focus was on the reduction of combustion engine while less attention was paid to noises from other sources. A BEV does not have ICE, automatic transmission, transfer case, fuel tank, air intake, or exhaust systems. In their place, there is more than enough space to accommodate the electric drive unit and battery pack. BEV is quieter without a combustion engine, however, the research on vehicle NVH is even more significant since the elimination of the combustion engine would expose many noise behaviors of BEV that were previously ignored but would now seem clearly audible and annoying. Researches have recently been conducted on the NVH of BEV mainly emphasis on the reduction of noise induced by powertrain, tire, wind and ancillary system and the improvement of sound quality. This review paper will focus on recent progress in BEV NVH research to advance the BEV systems in the future. It is a review for theoretical, computational, and experimental work conducted by both academia and industry in the past few years.