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Characteristics of wheel-rail dynamic interaction due to the rail corrugation in a high-speed railway are analyzed based on the theory of vehicle-track coupled dynamics in this paper. Influences of the corrugation wavelength and depth on the wheel-rail dynamic performance are investigated. The results show that, under the excitation of a measured rail corrugation, the wheel-rail dynamic interaction of high-speed railway is enhanced obviously, and the high-frequency dynamic force between wheel and rail is generated, which has an obvious impact on the vibrations of the wheelset and rail, and little effect on the vibration of the frame and carbody. If the corrugation wavelength is shorter than the sensitive wavelength, the wheel-rail vertical force will increase with the growth of the corrugation wavelength, otherwise, it will decrease. However, the wheel-rail vertical force keeps increasing with the growth of corrugation depth. Furthermore, if the corrugation wavelength is shorter than the sensitive wavelength, the wheel-rail vertical force will increase with the decrease of the running speed, otherwise, it will decrease. It is also found that the critical wavelength of corrugation increases with the growth of the corrugation depth and the running speed, and the critical depth of corrugation is nonlinearly related to the sensitive wavelength.

Consideration of structure-foundation-soil dynamic interaction is a basic requirement in the evaluation of the seismic safety of nuclear power facilities. An efficient and accurate dynamic interaction numerical model in the time domain has become an important topic of current research. In this study, the scaled boundary finite element method （SBFEM） is improved for use as an effective numerical approach with good application prospects. This method has several advantages, including dimensionality reduction, accuracy of the radial analytical solution, and unlike other boundary element methods, it does not require a fundamental solution. This study focuses on establishing a high performance scaled boundary finite element interaction analysis model in the time domain based on the acceleration unit-impulse response matrix, in which several new solution techniques, such as a dimensionless method to solve the interaction force, are applied to improve the numerical stability of the actual soil parameters and reduce the amount of calculation. Finally, the feasibility of the time domain methods are illustrated by the response of the nuclear power structure and the accuracy of the algorithms are dynamically verified by comparison with the refinement of a large-scale viscoelastic soil model.

Owing to the renewed interest in dark matter after the upgrade of the large hadron collider and its dedication to dark-matter research, it is timely to reassess the whole problem. Considering dark matter is one way to reconcile the discrepancy between the velocity of matter in the outer regions of galaxies and the observed galactic mass. Thus far, no credible candidate for dark matter has been identified. Here, we develop a model accounting for observations by rotations and interactions between rotating objects analogous to magnetic fields and interactions with moving charges. The magnitude of these fields is described by a fundamental constant on the order of 10^-41kg^-1. The same interactions can be observed in the solar system, where they lead to small changes in planetary orbits.

This study measured the dynamic changes and influencing factors of the Rosenberg Self-Esteem Scale across individuals and time through intensive longitudinal measurement. Participants were 119 senior elementary school students who were repeatedly measured for 100 times on the Rosenberg Self-Esteem Scale. Through the analysis of the cross-classify factor model, it was found that the reliability and validity of self-esteem did not change with time, and showed a stable measurement state across time, but the measurement intercept and factor loading of self-esteem across students have random variation. Through dynamic structural equation model analysis, it can be seen that there is a first-order correlation in students’ self-esteem. Recommendations are made based on the research findings

本文根據Merton (1 973） 跨期資本資產定價模型(Intertemporal Capitial Asset Pricing Model, ICAPM）加以計量方法與實際資料 探討台灣股票市場預期報酬與風險的跨期關係，並試圖解釋為何實 證文獻對於是否存在高風險高預期報酬的跨期關係眾說紛揉。在 Merton ICAPM 理論模型及其所對應的蝶件期望值架構下，風險 撞避係數應為正﹔ 我們將檢驗ICA PM 在台灣股票市場的適用性。 我們先使用動態條件相關模型（ Dynamic Conditional Correlation Models） 估計動態條件共變異數作為解釋變數， 再由各成份股預期 報酬作為被解變數以追蹤資料分量迴歸（ Panel Q u antile Regression) 得出相對風險堪避係數估計值。實證結果顯示，在預期報酬傑件期 望值及中位數上， 風險趨避係數皆顯著為正。我們也另外使用兩種 在帳件期望值的架構下並考盧序列相關及橫斷面相依特性的計量 模型， 所估計出的風險趨避係數也皆顯著為正。強韌性檢驗（robustness checks）顯示本文的估計結果並不會因解釋變數不同、風險替 代變數相異及使用計量方法不一而有太大的差異