scholarly journals Analysis of the Effect of the Length of Stop-Spacing on the Transport Efficiency of a Typically Formed Conventional Locomotive Hauled Passenger Train in China

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Xuesong Feng ◽  
Keqi Wu ◽  
Haidong Liu ◽  
Qipeng Sun ◽  
Hanxiao Zhang
Keyword(s):  
Simulation Approach ◽  
Transport Capacity ◽  
Transport Service ◽  
Transport Time ◽  
Transport Efficiency ◽  
Target Speed ◽  
Passenger Train ◽  
Railway Line ◽  
Computer Aided ◽  
Stop Spacing

By utilizing a computer-aided simulation approach, this research analyzes the detailed effect of the length of stop-spacing on the transport time per passenger-kilometer of a typically formed Chinese intercity passenger train hauled by, respectively, representative types of the locomotives utilized in China for different target speeds. It is empirically confirmed that a stop-spacing longer than approximately 20.00 km has little influence upon the transport efficiency of the train. In contrast, shortening the stop-spacing below about 20.00 km increases the transport time per passenger-kilometer of the train evidently, in particular for a target speed much higher than some 40.00 km/h. Therefore, the target speed of such a train providing transport service on a railway line whose transport capacity has not been much consumed ought to be changeable according to the length of each stop-spacing rather than consistent for the whole trip.

Root water gates and not changes in root structure provide new insights into plant physiological responses to drought, flooding and salinity

2021 ◽  
Author(s):  
Jean-Christophe Domec ◽  
John S King ◽  
Mary J Carmichael ◽  
Anna Treado Overby ◽  
Remi R Wortemann ◽  
...  
Keyword(s):  
Pinus Taeda ◽  
Vapor Pressure Deficit ◽  
Water Movement ◽  
Root Structure ◽  
Transport Capacity ◽  
Transport Efficiency ◽  
Xylem Structure ◽  
Plant Hydraulics ◽  
Whole Plant ◽  
The Impact

Abstract The influence of aquaporin (AQP) activity on plant water movement remains unclear, especially in plants subject to unfavorable conditions. We applied a multitiered approach at a range of plant scales to (i) characterize the resistances controlling water transport under drought, flooding and flooding plus salinity conditions; (ii) quantify the respective effects of AQP activity and xylem structure on root (Kroot), stem (Kstem) and leaf (Kleaf) conductances, and (iii) evaluate the impact of AQP-regulated transport capacity on gas exchange. We found that drought, flooding and flooding-salinity reduced Kroot and root AQP activity in Pinus taeda, whereas Kroot of the flood-tolerant Taxodium distichum did not decline under flooding. The extent of the AQP-control of transport efficiency varied among organs and species, ranging from 35%-55% in Kroot to 10%-30% in Kstem and Kleaf. In response to treatments, AQP-mediated inhibition of Kroot rather than changes in xylem acclimation controlled the fluctuations in Kroot. The reduction in stomatal conductance and its sensitivity to vapor pressure deficit were direct responses to decreased whole-plant conductance triggered by lower Kroot and larger resistance belowground. Our results provide new mechanistic and functional insights on plant hydraulics that are essential to quantifying the influences of future stress on ecosystem function.

Safe Departure Interval of Bullet Trains: Based on Block Section

2012 ◽  
Vol 253-255 ◽  
pp. 1177-1180
Author(s):  
Pei Xi Xie ◽  
Wei Yang
Keyword(s):  
Transport Capacity ◽  
Interval Time ◽  
Railway Line ◽  
Train Operation ◽  
Management Factors ◽  
Block Section

One of the important ways to improve the transport capacity of China is to reduce time of departure interval, which must be based on the premise that safety is guaranteed. In this paper, based on block section, a safe departure interval (SDI) model is constructed, which focus on technology and management factors in the train operation. Using SDI model, safe departure interval time of Shanghai-Hangzhou railway line is calculated, and sensitivity of some factors are analyzed. The rustles indicate that there is plenty of room for decrease time of departure interval safely.

A computer-aided simulation approach for mechanisms with time-varying topology

1997 ◽  
Vol 64 (1-4) ◽  
pp. 519-530 ◽  
Author(s):  
D. Wang ◽  
C. Conti ◽  
P. Dehombreux ◽  
O. Verlinden
Keyword(s):  
Time Varying ◽  
Simulation Approach ◽  
Computer Aided

scholarly journals A Benders Decomposition Algorithm for the Passenger Train Service Planning

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Song Pu
Keyword(s):  
High Speed ◽  
Benders Decomposition ◽  
Valid Inequalities ◽  
Service Planning ◽  
Decomposition Algorithm ◽  
Passenger Train ◽  
Railway Line ◽  
Passenger Demand ◽  
Benders Decomposition Algorithm ◽  
Passenger Assignment

Railway transport becomes a more popular transportation in many countries due to its large transport capacity, low energy consumption, and benign environment. The passenger train service planning is the key of the rail operations system to balance the transport service and the passenger demand. In this paper, we propose a mixed binary linear programming formulation for the passenger train service planning to optimize the train route, frequency, stop schedule, and passenger assignment simultaneously. In addition, we analyze the computational complexities of the model and develop a Benders decomposition algorithm with valid inequalities to solve this problem. Finally, our model and algorithm are tested on a real-world instance of the Beijing-Shanghai high-speed railway line. The computational results show that our approach can solve these problems within reasonable solution time and small optimality gaps (less than 2.5%).

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