A method for estimating pedestrian critical gap using microsimulation

Estimating critical gap is crucial for modelling pedestrian level of service at crossings. Critical gap modelling becomes more challenging in signalized crossings because the proportion of pedestrians seeking gaps during red is usually unknown. Besides, the willingness – or lack of it – to cross during red signal indication varies by pedestrian and local characteristics, which makes gap acceptance modelling even more challenging. The main objective of this study is to propose a method for estimating pedestrian critical gap at signalized crossings using Vissim. The method considers that all pedestrians seek for gaps on red, and the critical gap parameter is calibrated for each pedestrian type having delay as calibration target. The results showed MAPE values of 2% and 9% for the two studied crossings. This method was compared to three existing methods of critical gap estimation. The results showed that the proposed method yielded the best estimations of delay, followed by the HCM’s.

Study on the Generalized Displacement Boundary and Its Analytical Prediction for Ground Movements Induced by Shield Tunneling

The process of shield tunnel excavation would inevitably cause surrounding ground movement, and excessive displacement in the soil could lead to large deformation and even collapse of the tunnel. The methods estimating convergence deformation around tunnel opening is summarized. Then, a universal pattern of displacement boundary condition around the tunnel cavity is originally introduced, which is solved as the combination of three fundamental deformation modes, namely, uniform convergence, vertical translation, and ovalization. The expression for the above-mentioned displacement boundary condition is derived, by imposing which the analytical solution for ground movements, based on the stress function method, is proposed. The reliability and applicability of this proposed solution are verified by comparing the observed data in terms of surface settlement, underground settlement, and horizontal displacement. Further parametric analyses indicate the following: (1) the maximum settlement increases linearly with the gap parameter and the tunnel radius, while it is negatively related to the tunnel depth; (2) the trough width parameter is independent of the gap parameter and the radius, while it is proportional to the tunnel depth. This study provides a new simple and reliable method for predicting ground movements induced by shield tunneling.

The Low-Temperature Expansion of the Casimir-Polder Free Energy of an Atom with Graphene

We consider the low-temperature expansion of the Casimir-Polder free energy for an atom and graphene by using the Poisson representation of the free energy. We extend our previous analysis on the different relations between chemical potential μ and mass gap parameter m. The key role plays the dependence of graphene conductivities on the μ and m. For simplicity, we made the manifest calculations for zero values of the Fermi velocity. For μ>m, the thermal correction ∼T2, and for μ<m, we confirm the recent result of Klimchitskaya and Mostepanenko, that the thermal correction ∼T5. In the case of exact equality μ=m, the correction ∼T. This point is unstable, and the system falls to the regime with μ>m or μ<m. The analytical calculations are illustrated by numerical evaluations for the Hydrogen atom/graphene system.

Examination of phenomenological formulae in superdeformed bands of A ∼ 190,150 mass regions

The rotational energy formulae viz. VMI model, ab-formula, Harris [Formula: see text] expansion, Exponential model with pairing attenuation and Nuclear softness formula are employed to the superdeformed bands of [Formula: see text] and [Formula: see text] mass regions in order to test the validity of various rotational energy formulae in describing the general nature of superdeformed bands. These formulae are used to deduce the band-head spins of the nine superdeformed bands in [Formula: see text] mass region and two superdeformed bands of [Formula: see text] mass region. The band-head spins of these superdeformed bands have been established experimentally and hence they prove to be excellent candidates to examine the adequacy of rotational energy formulae in superdeformed bands. The least-squares fitting of [Formula: see text]-transition energies is performed to calculate the model parameters such as the band-head moment of inertia, the effective pairing gap parameter and the softness parameter, and a careful analysis of these parameters is made. For the first time, we have performed a systematic study of the rotational energy formulae to establish which formula gives the best estimate of spin in [Formula: see text] mass regions.

Nonlinear inversion of subsidence signatures induced by tunnels detected with surface and remote sensing measurements

The state of the art in predicting tunnel-induced subsidence settlements is based on empirical and analytical methods. Empirical methods are useful when the equations are implemented with host medium properties where tunnels have been excavated. Analytical solutions can predict tunneling-induced ground movements, with the predictions accounting for tunnel radius and depth as well as ground-loss parameters in soft soils. The drawback is that these methods require human intervention, as each model must be adjusted manually by the interpreter until the model signature fits the observed data. It would take tremendous effort to evaluate displacement anomalies detected by remote sensing methods using such forward-modeling methods. Therefore, we present a method based on an inversion algorithm that automatically inverts subsidence signatures for tunnel radius, depth, Poisson's ratio, and the gap parameter. It is an advancement over conventional methods because it does not require a first guess, and it can invert several subsidence signatures in a matter of minutes. The algorithm, coupled with remote sensing-based displacement maps, is a cost-effective solution in operational characterization of displacement anomalies. We demonstrate that observed and predicted subsidence signatures are in good agreement with existing tunnel data in uniform clay and that the inversion parameters correspond to those predicted with forward modeling alone.

Temperature Dependence of Commensurate Magnetic Resonance in Cuprate Superconductors

Within the kinetic energy driven superconducting mechanism, we have studied the temperature dependence of commensurate magnetic resonance in cuprate superconductors. It is shown that the commensurate magnetic resonance peak at the antiferromagnetic wave vector point persists in the superconducting state until the temperature rises to the superconducting transition temperature $T_{\rm c}$. The intensity of the resonance peak decreases with increasing temperature which is just like the temperature dependence of the superconducting gap parameter. Our results are in qualitative agreement with the inelastic neutron scattering experimental data and reflect that the commensurate magnetic resonance is closely related to the creation of the charge carrier pairs and thus the superconducting mechanism of cuprate superconductors.