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791.
The Incorporation of Passenger Connectivity and Intermodal Considerations in Intercity Transport Planning 总被引:2,自引:0,他引:2
Congested road and air networks, coupled with the idea that transport systems should be balanced, have spawned the field of intercity intermodal passenger transport which is based on travel across connected networks that is as seamless as possible. There is a very large number of attributes that affect the objective and subjective quality of travel. Intercity public transport planning therefore requires an excellent understanding of connections between different services and how the quality of these connections affects passengers, operators and the society at large. This article reviews the vast literature over the last 20 years from Europe, North America and Asia that is related to intercity travel, the connectivity of transport and cooperation between different modes of transport and presents a simple yet powerful way to perceive connected transport systems. The article then reviews planning practice at a variety of states worldwide, and suggests a set of focus areas of research or gaps that once filled, the authors expect, will allow further development of connected intercity passenger travel. 相似文献
792.
793.
X. Q. Sun L. Chen S. H. Wang X. L. Zhang X. F. Yang 《International Journal of Automotive Technology》2016,17(3):399-408
This paper investigates the influence of ball-screw inerter nonlinearities on the vibration isolation performance of the vehicle suspension system. That is achieved by building a nonlinear mechanics model of the ball-screw inerter with friction in ball-screw assembly and elastic effect of screw. The parameters of the nonlinear mechanics model are identified using recursive least squares algorithm based on test data. Then, the nonlinear ball-screw inerter is applied to vehicle suspension analysis of the half-car model with three passive suspension layouts. The performance of the vehicle suspension system with the nonlinear ball-screw inerter is compared with that with the linear inerter. It is demonstrated from the results that the vibration isolation performance of the vehicle suspension system is slightly influenced by considering the ball-screw inerter nonlinearities in general. The influence of the ball-screw inerter nonlinearities on every performance indicator for different suspension layouts is discussed finally. 相似文献
794.
Steffen Wagner Thomas Weiskircher Dieter Ammon Günther Prokop 《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2018,56(8):1139-1161
This paper presents a new application of active rear-wheel steering control to improve the lateral vehicle behaviour. In the state of the art, yaw or lateral velocity is used as control variable that means one degree of freedom being not directly controlled. A worse subjective impressions due to movements in the rear end of the vehicle during strong counter-steering are a consequence. To avoid this effect in urban surroundings, an innovative structure to control the pivot point distance of the vehicle is proposed. In this case the coupled elementary states yaw and lateral velocity can be influenced based on a higher level criteria. Analysis show that pivot point fixing provides a comprehensible reference behaviour. Solving the issue of singularity during disappearing yaw movement is the basis to design a performant modified feedforward input–output linearisation. An analytic stability analysis of the internal dynamics shows system immanent limitations which do not influence the target of improving the lateral vehicle dynamics in urban manoeuvres. Finally, the advantages of pivot-based control are highlighted by a comparison with state of the art rear axle control. 相似文献
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797.
The latching control represents an attractive alternative to increase the power absorption of wave energy converters (WECs) by tuning the phase of oscillator ve... 相似文献
798.
[Objectives]It is easy to produce buckling distortion when welding thin plate butt joints, which affects the construction period, cost and performance, but this can be controlled by applying external restraints. [Methods ] First, a butt welding test of a thin plate under external restraints is carried out, and the out-of-plane deformation is measured by the optical surface scanning method. At the same time, finite element (FE) models in a free state and external restraint state are established, and the thermal mechanical phenomena of the two models are subjected to thermal-elastic-plastic FE analysis (TEP FE). The influence of different external restraint distributions on the welding buckling distortion of the joints is then studied, and reasons for controlling welding buckling distortion are analyzed from the perspective of longitudinal plastic strain and longitudinal contraction force.[Results ] The out-of-plane deformation of the corresponding model is in good agreement with the measured results, and milder than the out-of-plane deformation of the model in a free state. When external restraints are applied, the longitudinal plastic strain of the weld and its adjacent metal decreases, and the longitudinal contraction force of the thin plate also decreases.[Conclusions ] The results verify that external restraints can effectively control welding buckling distortion, and the control effects are different depending on the external restraint distribution. © 2023 Chinese Journal of Ship Research. All rights reserved. 相似文献
799.
Chen Q.Liu Z.Luo F. 《中国舰船研究》2023,(1):124-140and151
[Objectives]Aiming at the problem of poor depth-changing ability of the stern rudder of submarine at low speed, and the problem of reversing the movement trend is difficult when the stern rudder is stuck and encountering abrupt changes of seawater density in the vertical steering maneuver. This paper conducts the mechanism research of static moment maneuver. [Methods]First, it is proved through theoretical analysis that the static moment maneuver can eliminate the reversed velocity phenomenon of the stern rudder. Then, the surfacing process under the static moment maneuver and the rudder hydrodynamic control is numerically simulated. [Results]The simulation results show that the static moment maneuver can make the submarine maintain good vertical plane maneuverability at low speed, eliminate the reversed velocity phenomenon of the stern rudder, and avoid excessive trim angle of the submarine at high speed. At the same time, the recovery effect of the two emergency situations of rudder jamming and falling deep has been improved. [Conclusions]The static moment maneuver is beneficial to the maneuverability and safety of the submarine. The research in this article can provide a reference for the maneuverability design of submarine. © 2023 The Author(s). 相似文献
800.
[Objectives]Electromagnetic pulse can seriously affect and even destroy naval shipborne electronic information systems, weapons, equipment and so on. Due to the complexity of the antenna port load circuit, it is necessary to formulate a numerical method which can easily obtain the antenna load current. [Methods]The induced current of the terminal is obtained on the basis of the finite-difference time-domain (FDTD) and Holland model. According to the Thévenin equivalent circuit, the conductor is equivalent to the voltage source to realize decoupling between the conductor and load end, and the load circuit is solved using Simulink software.[Results]Compared with the traditional terminal model, this method is simple and feasible for high-order circuit processing. The effectiveness of the model is verified using non-linear elements and parallel capacitors and resistors as the load respectively. The results show that the calculation results of this method are consistent with those of the traditional methods. Finally, the antenna of the end-connected protect- or is calculated. The results show that the lead inductance caused by the installation of the protector is an important factor affecting the protection performance.[Conclusions]The method proposed in this paper can greatly reduce the simulation complexity of the coupling current of an antenna with a complex load, giving it useful reference value for the field of ship electromagnetic pulse protection design. © 2023 Editorial Department of Chinese Journal of Ship Research. All Rights Reserved. 相似文献