high speed trains
Recently Published Documents


TOTAL DOCUMENTS

1410
(FIVE YEARS 413)

H-INDEX

44
(FIVE YEARS 11)

2022 ◽  
pp. 147592172110634
Author(s):  
Jaebeom Lee ◽  
Seunghoo Jeong ◽  
Junhwa Lee ◽  
Sung-Han Sim ◽  
Kyoung-Chan Lee ◽  
...  

Structural condition monitoring of railway bridges has been emphasized for guaranteeing the passenger comfort and safety. Various attempts have been made to monitor structural conditions, but many of them have focused on monitoring dynamic characteristics in frequency domain representation which requires additional data transformation. Occurrence of abnormal structural responses, however, can be intuitively detected by directly monitoring the time-history responses, and it may give information including the time to occur the abnormal responses and the magnitude of the dynamic amplification. Therefore, this study suggests a new Bayesian method for directly monitoring the time-history deflections induced by high-speed trains. To train the monitoring model, the data preprocessing of speed estimation and data synchronization are conducted first for the given training data of the raw time-history deflection; the Bayesian inference is then introduced for the derivation of the probability-based dynamic thresholds for each train type. After constructing the model, the detection of the abnormal deflection data is proceeded. The speed estimation and data synchronization are conducted again for the test data, and the anomaly score and ratio are estimated based on the probabilistic monitoring model. A warning is generated if the anomaly ratio is at an unacceptable level; otherwise, the deflection is considered as a normal condition. A high-speed railway bridge in operation is chosen for the verification of the proposed method, in which a probabilistic monitoring model is constructed from displacement time-histories during train passage. It is shown that the model can specify an anomaly of a train-track-bridge system.


Author(s):  
Arun Kumar. Ch

Abstract: The new challenges introduced in the wireless communication systems by the rapid developments of high-speed trains (HSTs) and more usage of the smartphones. The smart transportation involves the large crowd with smart phones, that requires a more efficient network for communication without disconnection. To achieve that, the handover process, need to be done quickly with respect to the speed of the train. To sustain its session connectivity to the internet, it requires the disconnection from the current access point (APc) to the next access point (APn). IN this project, we use the open flow and open stack protocols for integrating the interface between the infrastructure and the controller. Along with this, the integration of software-defined networking and network function virtualization is also done. The project majorly concentrated on the modification of the routes of the packet flow from one access point to the next required access point with the use of the triggering signal from the train which gives the location of the train. The suggested method works by the transmitting the signal from train to the next access point in advance so that the SDN controller changes the path of the packets to the next access point. The parameters like Signal strength, packet loss, average delay, path delay is evaluated. Along with these parameters the energy dissipation near the network also evaluated. The experimental results are evaluated using MATLAB tool. Keywords: Network Function Virtualization, OpenFlow in SDN, OpenStack, Software Defined Network.


2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Hümeyra Bolakar Tosun

The increased need for transportation worldwide has led to intense competition among several transportation types. Thus, considering factors affecting the choice of transportation means of passengers is essential. In many countries, railways have been losing market share in both freight and passenger transport, especially against highways. Railway transport systems must regain their declining share for the sake of the economy and sustainability. For this reason, many studies have been conducted to eliminate delays in high-speed trains, the speed of which is the most important criterion for preference. This study determines the reasons for train delays in a bid to make the high-speed train project successful in Turkey and for trains to serve better. Furthermore, regression analysis and the Pythagorean fuzzy analytic hierarchy process (AHP) analysis were performed according to the most effective criteria. The most effective criteria were determined as maintenance, repair, and closure due to renewal. Additionally, various suggestions regarding the effect of the obtained causes on train delays were put forward.


2021 ◽  
Vol 55 (6) ◽  
Author(s):  
Zhenhong Li ◽  
Chenxing Zhang ◽  
Chenyu Wang ◽  
Yingna Huang

Due to the large size and complicated features, the brake discs of high-speed trains are difficult to forge, so a reasonable design of the process and the die parameter are prerequisites for successful forming. The flow stress of 23CrNiMoV, a forged-steel brake disc material for high-speed trains, was investigated by a uniaxial compression experiment on a Gleeble 1500 test machine. Based on the obtained flow-stress data, a series of numerical simulation analyses of the die forging of high-speed-train brake discs were carried out by using finite-element software. The effects of forging temperature, flash groove parameters and forming speed on the flow filling, forming load and temperature change of metal during die forging were studied. The simulation results were optimized and better process parameters were obtained. Based on the obtained process parameters, the simulation of the forming process was completed and a better forming quality was obtained.


Sign in / Sign up

Export Citation Format

Share Document