Moderate deviations for the mildly stationary autoregressive models with dependent errors

In this paper, we consider the normalized least squares estimator of the parameter in a mildly stationary first-order autoregressive model with dependent errors which are modeled as a mildly stationary AR(1) process. By martingale methods, we establish the moderate deviations for the least squares estimators of the regressor and error, which can be applied to understand the near-integrated second order autoregressive processes. As an application, we obtain the moderate deviations for the Durbin-Watson statistic.Comment: Comments welcome. 28 page

The effect of Tai Chi intervention on balance in older males

AbstractPurposeThe purpose of the present study was to examine the effects of a 24-week Tai Chi exercise intervention on balance and other physical changes such as flexibility and reaction time (RT) among healthy older males.MethodsThirty-eight male subjects aged 55–65 years without prior Tai Chi experience were recruited from a local community in Shanghai, China. A 60-min Tai Chi exercise session was performed three times a week for 24 weeks. Changes in RT, sit-and-reach flexibility and balance (static balance with eyes open and closed respectively) were measured before and after the Tai Chi intervention.ResultsAfter the 24-week Tai Chi intervention, the choice RT (p < 0.05) decreased, and sit-and-reach flexibility improved (p < 0.01) over the pre-test (7.8±6.2 vs. 7.1±3.0cm). Sway length, area, X-axis deviation amplitude and Y-axis deviation amplitude performance decreased significantly after the intervention with a double-foot stance with eyes open (p < 0.05). Sway length, area and average sway speed showed a statistically significant decrease after the intervention with the double-foot stance with eyes closed. In the single-foot stance with eyes open condition, sway length and average sway speed showed a statistically significant decrease (p < 0.05).ConclusionThe 24-week Tai Chi exercise intervention had a positive influence on balance control in older males

Analyzing the Competitiveness of Intermodal Road-Rail Transport through the Lens of Cumulative Prospect Theory

Due to the long-standing government pricing system implemented by the railway, the market-oriented reform mechanism for freight transportation pricing remains imperfect. As a result, Intermodal Road-rail Transport (IRRT) has not fully utilized its advantages in the market competition against the Truck-Only Transport (TOT) mode. This paper addresses the limited rationality of decision makers and considers the interests of shippers and carriers in order to enhance the competitiveness of IRRT. To tackle the uncertainty associated with transportation costs, including economic and time costs, a two-layer programming model is employed. The upper layer model focuses on maximizing the operator\u27s profit, while the lower layer model captures the equilibrium freight volume resulting from the shippers\u27 choice behavior when competing modes reach equilibrium. In order to construct the competitiveness model accurately of IRRT, the study integrates the principles of cumulative prospect theory (CPT). Finally, the model is solved using a heuristic algorithm based on sensitivity analysis, presenting a fresh perspective for the steady development of IRRT