Sijing Liu

Dr. Sijing Liu


Research Focus & Metrics

Academic Career Length

9Years (2018-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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25 May 2018 in IEEE Transactions on Intelligent Transportation Systems
Verified
Journal Article
Closed access
DYDa Yang
Da Yang
XZXiaoxia Zhou
Xiaoxia Zhou
GSGang Su
Gang Su
SLSijing Liu
Sijing Liu
Work zones exist widely in cities of many countries and have a significant negative impact on city traffic. The majority of the existing studies only focused on freeway work zones, while the work zones on urban arterials have not been investigated carefully. For the first time, this paper focuses on a specific type of work zone that is located within the area of the intersection, namely, the island work zone, and proposes a novel model for the traffic flow of the island work zone based on the social force theory. Compared to the existing traffic-flow models, such as the car-following and lane-changing models, the proposed model can capture the special characteristics of the traffic flow in the island work zone, such as heterogeneity, no lane division, and irregular boundary. The field data collected in Chengdu, China, are used to calibrate and validate the proposed model. Simulations are also conducted to investigate the variations of traffic-flow characteristics for different work zone features. The results display that the model can replicate the heterogeneous traffic flow of the intersection with island work zone with high performance. When an island work zone is located close to the intersection approach, it will significantly block the entrance of vehicles. When the work zone occupies over 1 m of the median divider, its impact on the traffic flow will become very significant.

27 August 2018 in Sustainability
Verified
Journal Article
Open access
PDF file
SLSijing Liu
Sijing Liu
JXJiuping Xu
Jiuping Xu
XSXiaoyuan Shi
Xiaoyuan Shi
GLguoqi li
guoqi li
DLDinglong Liu
Dinglong Liu
In large Chinese cities, inefficient logistics organization, a rapid increase in freight demand, and the spreading of city logistics space have jointly contributed to the urban problems related to goods movement, such as spatial conflicts, traffic congestion, and air pollution. To address these problems and improve urban sustainability, we proposed a new spatial organization model of supply–demand coordination. We used the data from the Third China Economic Census and online point-of-interest (POI) for China’s four direct-controlled municipalities and 13 sub-provincial cities. We found that: (1) the freight supply and demand in China’s large cities are both spatially decentralized and clustered. However, there is a significant spatial mismatch between freight supply and demand in most of the studied cities. (2) The 17 studied cities can be divided into three types—highly unbalanced, unbalanced, and balanced—in light of the spatial mismatch between freight supply and demand. (3) The capacities of road surface and logistics nodes spatially differ. The supply capacity of the road systems in Beijing, Shanghai, and Guangzhou can only accommodate 18.4%, 35.5%, and 32.2% of the demand, respectively, while the supply capacity of the logistics nodes is more than twice that of the actual demand in these cities. Based on the findings, this paper proposed a differentiated method of demand management in different areas of the cities. To achieve the goals of low-carbon and sustainable development in logistics distribution, policy makers may consider planning urban freight activities along metro lines and intercity rail lines. Thus, this paper will provide a new perspective for understanding the urban freight distribution and management in large Chinese cities.

13 September 2021 in BMC Health Services Research
Verified
Journal Article
Open access
PDF file
QYQing Yong
Qing Yong
DLDinglong Liu
Dinglong Liu
GLguoqi li
guoqi li
WWWanshan Wu
Wanshan Wu
WSWenjie Sun
Wenjie Sun
SLSijing Liu
Sijing Liu
The current 2019 coronavirus disease (COVID-19) pandemic is hitting citizen’s life and health like never before, with its significant loss to human life and a huge economic toll. In this case, the fever clinics (FCs) were still preserved as one of the most effective control measures in China, but this work is based on experience and lacks scientific and effective guidance. Here, we use travel time to link facilities and populations at risk of COVID-19 and identify the dynamic allocation of patients’ medical needs, and then propose the optimized allocation scheme of FCs. We selected Shenzhen, China, to collect geospatial resources of epidemic communities (ECs) and FCs to determine the ECs’ cumulative opportunities of visiting FCs, as well as evaluate the rationality of medical resources in current ECs. Also, we use the Location Set Covering Problem (LSCP) model to optimize the allocation of FCs and evaluate efficiency. Firstly, we divide the current ECs into 3 groups based on travel time and cumulative opportunities of visiting FCs within 30 min: Low-need communities (22.06%), medium-need communities (59.8%), and high-need communities (18.14%) with 0,1–2 and no less than 3 opportunities of visiting FCs. Besides, our work proposes two allocation schemes of fever clinics through the LSCP model. Among which, selecting secondary and above hospitals as an alternative in Scheme 1, will increase the coverage rate of hospitals in medium-need and high-need communities from 59.8% to 80.88%. In Scheme 2, selecting primary and above hospitals as an alternative will increase the coverage rate of hospitals in medium-need and high-need communities to 85.29%, with the average travel time reducing from 22.42 min to 17.94 min. The optimized allocation scheme can achieve two objectives: a. equal access to medical services for different types of communities has improved while reducing the overutilization of high-quality medical resources. b. the travel time for medical treatment in the community has reduced, thus improving medical accessibility. On this basis, during the early screening in prevention and control of the outbreak, the specific suggestions for implementation in developing and less developed countries are made.


26 December 2025 in Engineering Optimization
Verified
Journal Article
Closed access
JCJiahao Cheng
Jiahao Cheng
LYLei Yang
Lei Yang
SLSijing Liu
Sijing Liu
HZHuan Zhang
Huan Zhang
GLGuoqi Li
Guoqi Li