Search results

The purpose of this study is to investigate the contact models for contact and vibration features of cylindrical roller bearings (CRBs). CRBs are important parts of rotating machinery. The contact deformation between the roller and the raceway is an essential research topic for the CRBs. The contact deformation between the roller and the raceway can greatly affect vibration characteristics and fatigue life of the CRBs. In this investigation, six different methods are adopted to calculate the contact deformation, contact area width and contact stress between the roller and raceways of a CRB.

In this paper, the contact deformations and the contact stiffnesses between the roller and the raceway of a CRB obtained by various well-known empirical methods (Lundberg’s, Palmgren’s, Houpert’s, Cheng’s and Hertzian methods) are directly compared with those by the finite element (FE) method. A two degree-of-freedom (2 DOF) dynamic model of the CRB is applied to investigate the effects of the contact stiffness obtained by different line contact deformation calculation methods on the vibration characteristics, such as the root mean square (RMS), the peak to peak (PTP), the crest factor and the kurtosis of the displacement, velocity and acceleration of the inner raceway.

The computational results show that different calculation methods for the contact deformations between rollers and raceways have significant effects on the vibrations of the CRB. It is found that that the differences of computational results obtained by Palmgren’s and Lundberg’s models with respect to the FE method are smaller than those by the other three methods, i.e. Houpert’s, Cheng’s and Hertzain models. The amplitude and peak frequency of the frequency response functions from Palmgren’s method are much more similar to those from the finite element method. The above results indicate that Palmgren’s method is a better calculation method for predicting the contact deformations and dynamics of the CRBs.

This work adopts six different methods to calculate the contact deformation, contact area width and contact stress between the roller and raceways of a CRB. Moreover, a vibration model of a CRB is used to investigate the effect of contact stiffness obtained by the above methods on the vibrations of the CRB. The works can give some guidance for the accurate analytical method for calculating the contact deformations between rollers and raceways and the vibrations of the CRB.

The global health crisis represents an unprecedented opportunity for the development of artificial intelligence (AI) solutions. This paper aims to integrate explainable AI into the decision-making process in emergency scenarios to help mitigate the high levels of complexity and uncertainty associated with these situations. An AI solution is designed to extract insights into opioid overdose (OD) that can help government agencies to improve their medical emergency response and reduce opioid-related deaths.

This paper employs the design science research paradigm as an overarching framework. Open-access digital data and AI, two essential components within the digital transformation domain, are used to accurately predict OD survival rates.

The proposed AI solution has two primary implications for the advancement of informed emergency management. Results show that it can help not only local agencies plan their resources for timely response to OD incidents, thus improving survival rates, but also governments to identify geographical areas with lower survival rates and their primary contributing factor; hence, they can plan and allocate long-term resources to increase survival rates and help in developing effective emergency-related policies.

This paper illustrates that digital transformation, particularly open-access digital data and AI, can improve the emergency management framework (EMF). It also demonstrates that the AI models developed in this study can identify opioid OD trends and determine the significant factors improving survival rates.

Patient handoffs involve the exchange of information between health professionals accompanying a transfer of responsibility for, or control of, a patient. Concerns over the safety risks of poor handoffs have resulted in regulatory pressure to standardize practice and considerable growth in research. But handoffs involve more than information transfer, and their consequences for health care organizations extend beyond the safety of patients. Using an organization theory lens, we review the literature on handoffs and propose a framework that characterizes handoffs as multifunctional, situated organizational routines. We also identify implications for researchers and hospital policymakers. Standardization and improvement efforts run the risk of causing unintended problems if they overlook the complexity of handoff and the larger organizational functions it serves. Deepening our understanding of the multifunctional, situated nature of handoff can lead to improvement efforts that not only safeguard individual patients, but also enhance the capabilities of the larger health care organization.

This research aims to illustrate the differential treatment of children and pensioners in Russia and to explain why this has not led to age group conflict through an illustration of age group interdependency.

Age group conflict is revealed through analysis of the government's policies to age groups and expenditure preferences. Interdependency is analysed by the calculation of poverty rates and contribution of age specific benefits, using nationally representative sample survey data.

The Russian government treated pensioners preferentially to children, even though children were at higher risk of poverty. However, within each age group poverty rates are mediated by household structures. Pensioners who live with children face higher poverty rates than the average for pensioners and those who co‐reside with lone mothers face the highest poverty rates of all pensioners, while their pension contribution to the household is of vital significance. Children living with one grandparent face higher poverty rates than average, whereas and those living with two grandparents face lower poverty rates.

The structure of intergenerational relationships and financial solidarity between generations provide essential context for understanding individual welfare in Russia.

Children's downgraded status in Russian society needs to be urgently addressed. Lone mothers, their children and their parents face the highest poverty rates and need of support. Amongst pensioners, women pensioners are particularly at risk.

The originality is in using two opposing perspectives on relations between age groups to show that preferential treatment of pensioners coexists with a high degree of financial linkage between generations.

Three empirical regularities characterize markets for married workers: (1) productivity and leadership potential are predicted by intelligence; (2) assortative mating based on intelligence characterizes marriages; and (3) labor force participation declines with spouse income more rapidly for married women than for married men. Taken together these characteristics imply that labor force participation will decline for women relative to their husbands as intelligence rises. These three observations suggest a nondiscriminatory explanation for the alleged under-representation of females among corporate leaders. They imply that the women who might be predicted to win the tournament for these positions often do not enter this competition. Instead they choose employment in full time household production. Both the three regularities and the implication concerning labor force participation are empirically examined. The findings of these tests are supportive on all counts.

Drawing on gender role ideology and structuralism perspectives, this study examines the impact of racial variation on the relationship between family characteristics and work–family decisions.

The study sample was drawn from the data collected by the U.S. Current Population Survey. This study used robust regression analysis to test their specific hypotheses that explore the role of racial variations on work–family decisions (measured in terms of weekly work hours).

The findings indicate that while overall men work longer hours when raising young children, both African American and Hispanic men tend to cut down on their work hours. Additionally, while marital status is associated with decreased work hours for White women, the reduction is smaller for Hispanic women. African American women actually end up increasing their work hours post marriage. Finally, while motherhood is associated with reduced work hours across racial groups, the decrease is more drastic for White women compared to their minority counterparts.

This study provides empirical evidence that work–family decision in the US African American and Hispanic households are not as strongly guided by the traditional gender role stereotypes, as is the case with White households. It also has important implications for the US employers who strive to leverage diversity and create inclusive organizations.

Given the increased population diversity in the USA, this study highlights the need to better understand the role of racial variations on the work–family decisions.

The economics literature on gender has expanded considerably in recent years, fueled in part by new sources of data, including from experimental studies of gender differences in preferences and other traits. At the same time, economists have been developing more realistic models of psychological and social influences on individual choices and the evolution of culture and social norms. Despite these innovations, much of the economics of gender has been left behind, and still employs a reductive framing in which gender gaps in economic outcomes are either due to discrimination or to “choice.” I suggest here that the persistence of this approach is due to several distinctive economic habits of mind – strong priors driven by market bias and gender essentialism, a perspective that views the default economic agent as male, and an oft-noted tendency to avoid complex problems in favor of those that can be modeled simply. I also suggest some paths forward.

This study explores feedback-induced and spontaneous postdecision restructuring in a complex decision environment. We examine the impact of experience, decision norms, and the actual decision on postdecision restructuring tendencies. Experienced and novice auditors performed an aspect rating task as part of a going concern judgment. After a break, all participants were asked to recreate their decision stage aspect ratings, but only the experiment group received outcome feedback. We find that the restructuring tendencies are impacted primarily by experience and the original audit report choice. The post-decision restructuring more often than not is a result of adjustments made by participants lacking outcome feedback. This spontaneous defense is particularly vigorous when the report choice violates perceived experience-group norms and base-rates

Awarding contracts based solely on the lowest price is unsuitable for every project. Consequently, most procurement systems in developed countries have progressed to the multicriteria selection practices (MSPs) for tender evaluation. MSPs consider a range of quality measures, such as completion time, life cycle cost, functional characteristics, environmental impact and innovation, alongside bid price. This study examines the prevailing MSPs in Sri Lankan public tender evaluations to enhance the effectiveness of the local tender evaluation process.

A desk study approach was employed to collect bidding documents, resulting in the identification of 66 documents. A systematic screening process was then applied to identify those bidding documents that incorporated MSPs. Subsequently, content analysis was conducted to determine the common features of the functions used in MSPs.

The study identified six primary functions related to MSPs incorporated in the bidding documents to procure building and substation projects. Three functions follow the price-to-quality method, while the remaining three follow the quality-to-price method. Among these identified functions, four functions employ objective evaluation criteria, such as thickness, capacity and operational loss. The other two functions utilize subjective evaluation criteria, such as the project’s design and technical specifications. Contract awarding will be based on either the highest score or the lowest bid, depending on the function type.

This study’s originality lies in exploring MSPs in the Sri Lankan public tender evaluation process and in disclosing their characteristics to promote the MSPs in Sri Lanka and developing countries.

The prevalence and stability of marriage has declined in the United States as the economic lives of men and women have converged. Family change has not been uniform, however, and the widening gaps in marital status, relationship stability, and childbearing between socioeconomic groups raise concerns about child well-being in poor families and future inequality. This paper uses data from a recent cohort of young adults – Wave IV of the National Longitudinal Study of Adolescent Health – to investigate whether disparities in cognitive ability and non-cognitive skills contribute to this gap. Blinder–Oaxaca decompositions of differences in key family outcomes across education groups show that, though individual non-cognitive traits are significantly associated with union status, relationship instability, and single motherhood, they collectively make no significant contribution to the explanation of educational gaps for almost all of these outcomes. Measured skills can explain as much as 25 percent of differences in these outcomes by family background (measured by mother’s education), but this effect disappears when own education is added to the model. Both cognitive and non-cognitive skills are strongly predictive of educational attainment but, conditional on education, explain very little of the socioeconomic gaps in family outcomes for young adults.