Branes, fermions, and superspace dualities

We use the superspace formulation of supergravity in eleven and ten dimensions to compute fermion couplings on the M2-brane and on Dp-branes. In this formulation fermionic couplings arise naturally from the θ-expansion of the superfields from which the brane actions are constructed. The techniques we use and develop can in principle be applied to determine the fermionic couplings to general background fields up to arbitrary order. Starting with the superspace formulation of 11-dimensional supergravity, we use a geometric technique known as the ‘normal coordinate’ method to obtain the θ-expansion of the M2-brane action. We then present a method which allows us to translate the knowledge of fermionic couplings on the M2-brane to knowledge of such couplings on the D2-brane, and then to any Dp-brane. This method is based on superspace generalizations of both the compactification taking 11-dimensional supergravity to type IIA supergravity and the T-duality rules connecting the type IIA and type IIB supergravities.

Adaptive Control of Space Robot Despinning Tumbling Target Using Flexible Brushes

A flexible brush mechanism is designed and mounted at the end of a seven-degree-of-freedom robotic arm to despin a tumbling target. The dynamics model of the flexible brush is established using the absolute nodal coordinate method (ANCF), and its contact collision with the solar wing of the tumbling target is analysed. The H ∞ optimal control is proposed for a seven-degree-of-freedom robotic arm during despinning of a tumbling target while ensuring the global robustness and stability. Simulations verify that the despinning strategy can successfully eliminate the rotation speed and is feasible and effective.

A new Xin'anjiang and Sacramento combined rainfall-runoff model and its application

The Xin'anjiang model and the Sacramento model are two widely used short-term watershed rainfall-runoff forecasting models, each with their own unique model structure, strengths, weaknesses and applicability. This paper introduces a weight factor to integrate the two models into a combined model, and uses the cyclic coordinate method to calibrate the weight factor and the parameters of the two models to explore the possibility of the complementarity between the two models. With application to the Yuxiakou watershed in Qingjiang River, it is verified that the cyclic coordinate method, although simple, can converge rapidly to a satisfactory calibration accuracy, mostly after two iterations. Also, the results in case studies show that the forecast accuracy of the new combined rainfall-runoff model can improve the forecast precision by 4.3% in a testing period, better in runoff process fitting than the Xin'anjiang model that performs better than the Sacramento model. HIGHLIGHT This paper introduces a weight factor to integrate the two models into a combined model, and uses the cyclic coordinate method to calibrate the weight factor. it is verified that the cyclic coordinate method can converge fast to a satisfactory calibration accuracy. The results show that the forecast accuracy of the new combined rainfall-runoff model can improve the forecast precision.

Determination And Evaluation Of The Minimum Allowable Train Headway Value At The Coordinate Traffic Control Method

In recent years, there has been a steady increase in the volume of traffic. According to experts ' forecasts, the demand for product transportation will continue to increase. Meanwhile, the supply for the capacity of the lines is actually exhausted. Therefore, the most important task of railway transport in the near future will be to increase the carrying capacity and capacity.Increasing the carrying capacity of railway transport can be achieved by: increasing the average speed of trains, building additional tracks, increasing the length and weight of freight trains, reducing inter-train intervals, and organizational measures. To increase the average speed of trains, it is necessary to improve the quality of track maintenance and rolling stock, in addition, certain sections of the track will need to be reconstructed. These measures, including the construction of additional tracks, are long-term and will lead to significant material costs. Increasing the length and weight of freight trains leads to an increase in the number of accidents.The most effective way to increase the carrying capacity is to reduce the inter-train intervals in conjunction with a number of organizational measures.With the coordinate method of interval control, the programs and algorithms obtained on the basis of mathematical models must guarantee the safety of trains with minimal intervals.This fact confirms the need to conduct a set of studies in the field of methodology for ensuring safety and organization of train traffic by clarifying existing and developing new mathematical models of train movement in relation to the specifics of the coordinate method of interval regulation.

Generation, contraction, and polarisation of Gaussian basis sets for atomic and molecular calculations using the generator coordinate method with polynomial discretisation: atoms from Na through Cl

The polynomial Generator Coordinate Hartree-Fock Gaussian basis sets, pGCHF, for the atoms Na, Mg, Al, Si, P, S, and Cl were generated using the generator coordinate method based on polynomial...