1,301 research outputs found
Human Resource Practices as Predictors of Work-Family Outcomes and Employee Turnover
Drawing on a non-random sample of 557 dual- earner white collar employees, this paper explores the relationship between human resource practices and three outcomes of interest to firms and employees: work-family conflict, employees’ control over managing work and family demands, and employees’ turnover intentions. We analyze three types of human resource practices: work-family policies, HR incentives designed to induce attachment to the firm, and the design of work. In a series of hierarchical regression equations, we find that work design characteristics explain the most variance in employees’ control over managing work and family demands, while HR incentives explain the most variance in work-family conflict and turnover intentions. We also find significant gender differences in each of the three models. Our results suggest that the most effective organizational responses to work-family conflict and to turnover are those that combine work-family policies with other human resource practices, including work redesign and commitment-enhancing incentives
Training LOGIC and Random Forest Models to Predict IT Spending
The Air Force must modernize, but the distribution of funds for technology remains as tight as ever. To this end, the Air Force Audit Agency is looking to utilize machine learning techniques to enhance their capabilities. This research explores Logistic Regression and Random Forest modeling to streamline data collection and cost classification. The final Logistic Regression model identified 4 significant attributes out of the 36 given and was 85 accurate in predicting whether a purchase amount was over or under $10,000. To expand beyond binary classification, a six-category classification Random Forest model was developed. It identified 6 significant attributes and was 34 accurate in in predicting whether a purchase was in 1 of 6 amount categories. Due to the class imbalance of the given data, it was necessary to use a class weighting and over-sampling technique to enhance the Random Forest model. The final class balanced model identified the same 6 significant attributes but was 78 accurate in predicting whether a purchase was in 1 of 6 amount categories. No models were able to predict whether a purchase should be classified as an information technology purchase of not
Global existence of classical solutions to the Vlasov-Poisson system in a three dimensional, cosmological setting
The initial value problem for the Vlasov-Poisson system is by now well
understood in the case of an isolated system where, by definition, the
distribution function of the particles as well as the gravitational potential
vanish at spatial infinity. Here we start with homogeneous solutions, which
have a spatially constant, non-zero mass density and which describe the mass
distribution in a Newtonian model of the universe. These homogeneous states can
be constructed explicitly, and we consider deviations from such homogeneous
states, which then satisfy a modified version of the Vlasov-Poisson system. We
prove global existence and uniqueness of classical solutions to the
corresponding initial value problem for initial data which represent spatially
periodic deviations from homogeneous states.Comment: 23 pages, Latex, report #
Motive8!: feasibility of a text messaging intervention to promote physical activity in knee osteoarthritis
Aim: To develop and test the feasibility of using a SMS text messaging intervention to promote physical activity in patients with knee OA.
Methods: 27 people (6 male, 21 female; aged 25-81 years) with knee osteoarthritis received 4 text messages per week, for 6 weeks. Telephone surveys were conducted at baseline and 6 weeks to measure physical activity levels and beliefs, including self-efficacy for exercise, barriers and benefits of exercise, social support and pain. Participants completed physical activity diaries. Process evaluation included participant perceptions of the intervention and 'real-time' data on intervention fidelity (automated collection of delivery and response data) and participant engagement (text response).
Results: 648 messages were sent, 100% were accurately delivered. From baseline to 6 weeks, physical activity, self-efficacy for exercise, perceived benefits of exercise and social support significantly increased; reductions were observed in barriers to exercise and pain. Participants engaged with the intervention; 100% read the messages, 89% responded to texts requesting replies, 64% completed physical activity diaries with low attenuation (1.8% drop) by six weeks. Participants perceived messaging to be enjoyable (96%), personally relevant (85%), of appropriate frequency (100%) and duration (88%). Mobile phones, email and web were perceived to be most acceptable for health promotion compared with other forms of technology.
Conclusions: People with knee osteoarthritis can engage meaningfully with an interactive mobile phone messaging intervention over a six-week period. Health communications promoting physical activity demonstrate potential for behaviour change and positive implications for perceptions of exercise and pain; this needs to be tested in a randomised trial. Data collected in 'real-time' can be used for process evaluation to demonstrate participant engagement and intervention fidelity
Uniqueness of the compactly supported weak solutions of the relativistic Vlasov-Darwin system
We use optimal transportation techniques to show uniqueness of the compactly
supported weak solutions of the relativistic Vlasov-Darwin system. Our proof
extends the method used by Loeper in J. Math. Pures Appl. 86, 68-79 (2006) to
obtain uniqueness results for the Vlasov-Poisson system.Comment: AMS-LaTeX, 21 page
The Newtonian Limit for Asymptotically Flat Solutions of the Vlasov-Einstein System
It is shown that there exist families of asymptotically flat solutions of the
Einstein equations coupled to the Vlasov equation describing a collisionless
gas which have a Newtonian limit. These are sufficiently general to confirm
that for this matter model as many families of this type exist as would be
expected on the basis of physical intuition. A central role in the proof is
played by energy estimates in unweighted Sobolev spaces for a wave equation
satisfied by the second fundamental form of a maximal foliation.Comment: 24 pages, plain TE
Contested resources: unions, employers, and the adoption of new work practices in US and UK telecommunications
The pattern of adoption of high-performance work practices has been explained in terms of strategic contingency and in terms of union presence. We compare the post-deregulation/privatization changes in work practice at AT&T, Bell Atlantic and British Telecom. On the basis of these cases, we argue that the choice of new work practices should be understood as a consequence not only of the company's resources or changes in its environment, nor of a simple union presence, but also as a consequence of the practices' effects on union power, the nature of the union's engagement, and the union's strategic choices
Intra-articular Injection Administration in UK Ex-professional Footballers During Their Playing Careers and the Association with Post-career Knee Osteoarthritis
© 2020, The Author(s). Background: The long-term risk from knee intra-articular (KIA) injections in professional athletes such as ex-footballers remains unknown. The use of KIA injections is controversial and remains anecdotally prolific as it is perceived as being safe/beneficial. The aim of this study was to determine the number, type and frequency KIA injections administered to retired professional footballers during their playing careers and the associations with post-career knee osteoarthritis (KOA). Methods: This is a cross-sectional study involving a postal questionnaire (n = 1207) and subsequent knee radiographs in a random sample of questionnaire responders (n = 470). Footballers self-reported in the questionnaire whether they had received KIA injections and the estimated total number over the course of their playing career. Participant characteristics and football career-related details were also recorded. KOA was measured as self-reported knee pain (KP), total knee replacement (TKR) and radiographic KOA (RKOA). Results: 44.5% of footballers had received at least one KIA injection (mean: 7.5; SD ± 11.2) during their professional career. 71% of knee injections were cortisone/corticosteroid based. Multivariate logistic regression, adjusting for age, body mass index (BMI) and significant knee injury identified that footballers with injections weretwo times more likely to have KP (OR 1.81, 95% CI 1.40–2.34) and TKR (OR 2.21, 95% CI 1.43–3.42) than those without injections. However, there was no association with RKOA (OR 1.30, 95% CI 0.85–2.01). Given, the association with KP and TKR, we found a significant dose–response relationship as the more injections a player received (by dose–response groups), the greater the risk of KP and TKR outcomes after adjustment for knee injury and other confounders (p for trend < 0.01). Conclusion: On average, 8 KIA injections were given to the ex-footballers during their professional career. The most commonly administered injections were cortisone based. These injections associated with KP and TKR after they retired. The associations are independent of knee injuries and are dose dependent. The study suggests that there may have been excessive use of KIA injections to expedite return to play and this contributed to detrimental long-term outcomes such as KP and TKR post-retirement from professional football
The Relationship Between HR Practices and Firm Performance: Examining Causal Order
Significant research attention has been devoted to examining the relationship between HR practices and firm performance, and the research support has assumed HR as the causal variable. Using data from 45 business units (with 62 data points), this study examines how measures of HR practices correlate with past, concurrent, and future operational performance measures. The results indicate that correlations with performance measures at all three times are both high and invariant, and that controlling for past or concurrent performance virtually eliminates the correlation of HR with future performance. Implications are discussed
- …