Article
Green & Sustainable Science & Technology
Wendong Chen, Xuewu Chen, Jingxu Chen, Long Cheng
Summary: This study analyzes the determinants influencing the ridership of station-based bike sharing (SBBS) and free-floating bike sharing (FFBS) at rail transit stations based on user transaction records in Nanjing, China. The findings show that SBBS and FFBS ridership at rail transit stations are positively influenced by factors such as population density and the number of restaurants. The results suggest a substitution effect between SBBS and FFBS for rail transit access, with SBBS potentially being more commonly used for commuting trips.
INTERNATIONAL JOURNAL OF SUSTAINABLE TRANSPORTATION
(2022)
Article
Geography, Physical
P. Glira, K. Oelsboeck, T. Kadiofsky, M. Schoerghuber, J. Weichselbaum, C. Zinner, L. Fel
Summary: Recent developments in rail vehicles have increased the demand for accurate and up-to-date 3D maps of rail track networks. This study presents a fully automatic photogrammetric method for reconstructing 3D rail track segments. The method utilizes images from a front-looking camera and observations from a low-cost GNSS receiver as data inputs, with optional inputs such as a rail track, a digital height model, and ground control points to improve accuracy. The method was applied to reconstruct a 13 km long tram line in Vienna, demonstrating its effectiveness.
ISPRS JOURNAL OF PHOTOGRAMMETRY AND REMOTE SENSING
(2022)
Article
Engineering, Civil
Zhi Cai, Gongyu Sun, Xing Su, Tong Li, Limin Guo, Zhiming Ding
Summary: This paper proposes a visualization method of land use characteristics around urban rail transit stations based on Points of Interest (POI). The method utilizes Voronoi diagram and skyline idea to extract hierarchical POIs for each urban rail transit station, providing a visual representation of land use characteristics around the stations.
IEEE TRANSACTIONS ON INTELLIGENT TRANSPORTATION SYSTEMS
(2021)
Article
Geosciences, Multidisciplinary
Hamad Al-Ajami, Ahmed Zaki, Mostafa Rabah, Mohamed El-Ashquer
Summary: A new gravimetric geoid model, the KW-FLGM2021, is developed for Kuwait using Least Squares Collocation technique. The evaluation with GPS/leveling data shows that the residual of geoid heights obtained from the KW-FLGM2021 geoid model is 2.2 cm, making it a recommended accurate geoid model for Kuwait.
FRONTIERS IN EARTH SCIENCE
(2022)
Article
Biology
Guotong Li, Xiaoqiang Tang, Jianfeng Li, Mingjie Dong
Summary: In this study, a mapping model is established between the pose error and kinematic parameter error of a motor-driven parallel external fixator (MD-PEF). Based on the least squares method, a kinematic parameter identification and error compensation algorithm for the external fixator is developed. Experimental results show high correction accuracy after calibration, indicating the feasibility and reliability of the algorithm. Furthermore, the calibration approach used in this study can also improve the accuracy of other medical robots.
COMPUTERS IN BIOLOGY AND MEDICINE
(2023)
Article
Chemistry, Analytical
Mehdi Eshagh
Summary: A smart city is equipped with sensors that communicate with each other, and cybersecurity is crucial in such cities, especially for airports and harbours. Wireless security networks are important for localising any radio frequency interferer in smart cities to prevent potential catastrophes and risks to people's lives.
Article
Environmental Sciences
Mieczyslaw Bakula, Marcin Uradzinski, Kamil Krasuski
Summary: This paper presents numerical analyzes of code differential GPS positioning with the use of two Huawei P30 Pro mobile phones. The results show that using the P(L5) code significantly improves the positioning accuracy compared to using the P(L1) code, with average errors of horizontal and vertical coordinates reduced by 60-80%. Based on simulated statistical analysis, a smartphone with P(L5) code can achieve an accuracy of about 0.4 m (3D) with 16 satellites.
Article
Engineering, Multidisciplinary
Xia Xue, Honglei Qin, Hui Lu
Summary: The study proposes a real-time high-precision time synchronization method based on GNSS and designs a wireless navigation system based on RTK-DCPTT technology. By using Pulse Per Second signal trigger and clock correction, the accuracy of interstation time synchronization is further improved.
Article
Computer Science, Artificial Intelligence
Yuanhong Liu, Zebiao Hu, Yansheng Zhang
Summary: This study introduces two LLE-based multi-structure fusion methods to extract significant features by integrating least squares and sparse structures, with the solution of coefficient fusion being a subset of the one of the function fusion. Extensive experiments demonstrate the superior performance of the proposed multi-structure methods compared to existing state-of-art related methods.
Article
Computer Science, Artificial Intelligence
Chentao Mao, Zhangwei Chen, Shuai Li, Xiang Zhang
Summary: The unique characteristics of the MDH model enable the kinematic calibration problem to be converted into a separable nonlinear least squares problem, leading to improved robustness and convergence speed during the calibration process.
JOURNAL OF INTELLIGENT & ROBOTIC SYSTEMS
(2021)
Article
Optics
Tianxiang Ren, Yang Liu, Zeren Qiao, Zihan Qiao, Yang Li, Fujian Li, Jian Yu, Qingchuan Zhang
Summary: This paper proposes a fusion measurement method based on digital image correlation method and total station for measuring the height deviation of bearing platforms on high-speed railway ballastless tracks. The method is demonstrated to achieve high accuracy and efficiency in measuring the height deviation of each bearing platform, and increases the detection range and efficiency.
OPTICS AND LASERS IN ENGINEERING
(2023)
Article
Engineering, Mechanical
Sange Li, Xuegeng Mao, Pengjian Shang, Xiaodi Xu, Jinzhao Liu, Peng Qiao
Summary: In this paper, an intelligent method for diagnosing rail corrugation is proposed based on signal decomposition and entropy theory. The axle box acceleration signals are decomposed into different frequency components using ACMP, EEMD, and MODWT. Energy entropy is introduced to quantify the rate of energy concentration. It is found that the energy and entropy change when rail corrugation occurs, and the entropy difference based on ACMP is the most significant. By combining energy entropy with energy index and first mode energy, the accuracy of the ACMP-based technique is the highest for distinguishing rail corrugation from mass data sets.
NONLINEAR DYNAMICS
(2023)
Article
Engineering, Civil
Mohammad Shoghijavan, Uwe Starossek
Summary: This study aims to develop a robustness index for parallel load-bearing systems by calculating the stress increase ratio of the critical cable in a cable-loss scenario. Differential equations and the least squares method are used to derive an accurate approximation function, considering different levels of initial damage. The accuracy of the developed robustness index is proven through numerical models.
ENGINEERING STRUCTURES
(2021)
Article
Engineering, Electrical & Electronic
Zhengpu Wang, Baoshi Cao, Zongwu Xie, Boyu Ma, Kui Sun, Yang Liu
Summary: A calibration method based on extended Kalman filter (EKF) is proposed in this paper to improve the pose accuracy of a space manipulator. The method establishes an identification model based on the Denavit-Hartenberg (D-H) modeling method and uses a camera attached to the end-effector to capture pictures of a calibration board. The EKF is used to estimate error parameters and compensate them in the kinematic algorithm, resulting in an approximately 90% improvement in pose accuracy.
Article
Engineering, Electrical & Electronic
Tiancheng Li, Yan Song, Hongqi Fan
Summary: This paper addresses the challenge of real-time detection and tracking of a non-cooperative target in a scenario with limited prior information. A data-driven approach based on a polynomial trajectory function of time (T-FoT) is proposed to model the target's movement and estimate its continuous-time trajectory. Data-driven initiation and termination strategies are designed to identify the target's appearance and disappearance. The approach shows comparable or even better performance than existing filters/trackers, requires less prior information, and has faster computation.
