scholarly journals Analysis of Mobile Phone Data to Compare Mobility Flows and Hotspots Before and After the Opening of High-Speed Railway: Case Study of Honam KTX in Korea

2020 ◽  
Vol 10 (14) ◽  
pp. 5009
Author(s):  
Jin Ki Eom ◽  
Kwang-Sub Lee ◽  
Ji Young Song ◽  
Jun Lee

Mobile phone data provides information, such as the home (origin) and current locations of people. The data can be used to analyze the impact of new high-speed railway (HSR) openings. This study examined the population observed in stations and cities of the Honam HSR line in Korea, based on mobile phone data recorded one year before and after its opening. We analyzed the volume of the population observed at each railway station, density of the distance between home and station, and activity hotspots in a city. The results show that the number of people and travel distance increased after the opening of the HSR. The distance to access railway stations increased, as the HSR saves travel time. Moreover, the activity hotspots in a city increased after the opening of the HSR, as more people gathered near the station area. The findings show that the mobility measures enhanced after the opening of the HSR for regional travel and local activities. These measures can help transit agencies and planners in providing better intercity travel.

Energies ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4648
Author(s):  
Zhipeng Tang ◽  
Ziao Mei ◽  
Jialing Zou

The carbon intensity of China’s resource-based cities (RBCs) is much higher than the national average due to their relatively intensive mode of development. Low carbon transformation of RBCs is an important way to achieve the goal of reaching the carbon emissions peak in 2030. Based on the panel data from 116 RBCs in China from 2003 to 2018, this study takes the opening of high-speed railway (HSR) lines as a quasi-experiment, using a time-varying difference-in-difference (DID) model to empirically evaluate the impact of an HSR line on reducing the carbon intensity of RBCs. The results show that the opening of an HSR line can reduce the carbon intensity of RBCs, and this was still true after considering the possibility of problems with endogenous selection bias and after applying the relevant robustness tests. The opening of an HSR line is found to have a significant reducing effect on the carbon intensity of different types of RBC, and the decline in the carbon intensity of coal-based cities is found to be the greatest. Promoting migration of RBCs with HSR lines is found to be an effective intermediary way of reducing their carbon intensity.


Kybernetes ◽  
2020 ◽  
Vol 49 (11) ◽  
pp. 2713-2735 ◽  
Author(s):  
Xiaomin Fan ◽  
Yingzhi Xu ◽  
Yongqing Nan ◽  
Baoli Li ◽  
Haiya Cai

Purpose The purpose of this paper is to analyse the impact of high-speed railway (HSR) on industrial pollution emissions using the data for 285 prefecture-level cities in China from 2004 to 2016. Design/methodology/approach The research method used in this paper is the multi-period difference-in-differences (DID) model, which is an effective policy effect assessment method. To further address the issue of endogeneity, the DID integrated with the propensity score matching (PSM-DID) approach is employed to eliminate the potential self-selection bias. Findings The results show that the HSR has significantly reduced industrial pollution emissions, which is validated by several robustness tests. Compared with peripheral cities, HSR exerts a greater impact on industrial pollution emissions in central cities. In addition, the mechanism test reveals that the optimised allocation of inter-city industries is an important channel for HSR to mitigate industrial pollution emissions, and this is closely related to the location of HSR stations. Originality/value Previous studies have paid more attention to evaluating the economic effects of HSR, however, most of these studies overlook its environmental effects. Consequently, the impact of HSR on industrial pollution emissions is led by using multi-period DID models in this paper, in which the environmental effects are measured. The results of this paper can provide a reference for the pollution reduction policies and also the coordinated development of economic growth and environmental quality.


Epidemiology ◽  
2015 ◽  
Vol 26 (2) ◽  
pp. 223-228 ◽  
Author(s):  
Amy Wesolowski ◽  
Wendy Prudhomme O’Meara ◽  
Andrew J. Tatem ◽  
Samson Ndege ◽  
Nathan Eagle ◽  
...  

Vascular ◽  
2020 ◽  
pp. 170853812098369
Author(s):  
Stefano Fazzini ◽  
Giovanni Torsello ◽  
Martin Austermann ◽  
Efthymios Beropoulis ◽  
Roberta Munaò ◽  
...  

Objectives The results of branched endovascular repair of thoracoabdominal aneurysms are mainly dependent on durability of the graft used. The purpose of this study was to evaluate postoperative aortic main body and bridging stent-graft remodeling, and their impact on bridging stent-graft instability at one year. Methods Computed tomoangiographies of 43 patients (43 aortic main body mated with 171 bridging stent-grafts) were analyzed before and after branched endovascular repair as well as after a follow-up of 12 months. Primary endpoint was aortic main body remodeling (migration >5 mm, shortening >5 mm, scoliosis >5° or lordosis >5°). Shortening was defined as a reduced length in the long axis, scoliosis as left-right curvature, and lordosis as antero-posterior curvature. Aortic main body remodeling, aneurysm sac changes, and bridging stent-graft tortuosity were evaluated to study their correlations and the impact on the bridging stent-graft instability. Results At 12 months, aortic main body remodeling was observed in 72% of the cases, migration in 39.5% (mean 5.21 mm), shortening in 41.9% (mean 5.79 mm), scoliosis in 58.1%, (mean 10.10°), lordosis in 44.2% (mean 5.78°). Migration, shortening, and scoliosis were more frequent in patients with larger aneurysms ( p = .005), while scoliosis was significantly more frequent in type II thoracoabdominal aneurysm ( p = .019). Aortic main body remodeling was significantly associated to bridging stent-graft remodeling (r: 0.3–0.48). The bridging stent-graft instability rate was 9.3%. Despite a trend toward significance ( p = .07), none of the evaluated aortic main body and bridging stent-graft changes were associated with bridging stent-graft instability at 12 months. Conclusions Aortic main body remodeling is frequent especially in large and extended thoracoabdominal aneurysm aneurysms. Aortic main body and bridging stent-graft remodeling was significantly correlated. While these geometric changes had no significant impact on bridging stent-graft instability at one year, a close long-term follow-up after branched endovascular repair could predict bridging stent-graft failures.


Author(s):  
Minling Feng ◽  
Chaoxian Wu ◽  
Shaofeng Lu ◽  
Yihui Wang

Automatic train operation (ATO) systems are fast becoming one of the key components of the intelligent high-speed railway (HSR). Designing an effective optimal speed trajectory for ATO is critical to guide the high-speed train (HST) to operate with high service quality in a more energy-efficient way. In many advanced HSR systems, the traction/braking systems would provide multiple notches to satisfy the traction/braking demands. This paper modelled the applied force as a controlled variable based on the selection of notch to realise a notch-based train speed trajectory optimisation model to be solved by mixed integer linear programming (MILP). A notch selection model with flexible vertical relaxation was proposed to allow the traction/braking efforts to change dynamically along with the selected notch by introducing a series of binary variables. Two case studies were proposed in this paper where Case study 1 was conducted to investigate the impact of the dynamic notch selection on train operations, and the optimal result indicates that the applied force can be flexibly adjusted corresponding to different notches following a similar operation sequence determined by optimal train control theory. Moreover, in addition to the maximum traction/braking notches and coasting, medium notches with appropriate vertical relaxation would be applied in accordance with the specific traction/braking demands to make the model feasible. In Case study 2, a comprehensive numerical example with the parameters of CRH380AL HST demonstrates the robustness of the model to deal with the varying speed limit and gradient in a real-world scenario. The notch-based model is able to obtain a more realistic optimal strategy containing dynamic notch selection and speed trajectory with an increase (1.622%) in energy consumption by comparing the results of the proposed model and the non-notch model.


2018 ◽  
Vol 10 (10) ◽  
pp. 3701 ◽  
Author(s):  
Jiaping Zhang ◽  
Mingwang Cheng ◽  
Xinyu Wei ◽  
Xiaomei Gong

Marital happiness is an important symbol of social harmony and can help promote sustainable economic and social development. In recent years, the rapid rise of the divorce rate in China, a country where the divorce rate had previously been low, has attracted wide attention. However, few articles have focused on the popularization of information and communication technology's impact on China’s rising divorce rate in recent years. As a first attempt, the provincial panel data during the period 2001–2016 is applied to study quantitatively the relationship between mobile phone penetration and the divorce rate. In order to get more reliable estimation results, this paper uses two indicators to measure the divorce rate, and quantile regression is applied for further analysis. Additionally, one-year to five-year lag times of the mobile phone penetration are used as the core explanatory variables in order to analyse the lagging effect of mobile phone penetration on divorce rate. The result shows that the correlation between the mobile phone penetration and the divorce rate was statistically positive significant in China during the period 2001–2016. Furthermore, the paper also finds that mobile phone penetration had the greatest impact on divorce rate in central China, followed by eastern China, but it was not obvious in western China during this period. From a technological perspective, this paper provides some possible explanations for the rising divorce rate in China in recent years, and further enriches the relevant research on the impact of the development of information and communication technology on societal changes.


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