The Two Echelon Open Vehicle Routing Problem: Optimization of Crowdshipping Based Parcel Delivery

Xue Wu,Dawei Hu,Bingshan Ma,Ruisen Jiang 대한토목학회 2022 KSCE Journal of Civil Engineering Vol.26 No.9

Crowdshipping is a revolutionary concept of the sharing economy. In this study, two carriers are used to perform the following expedition: the truck starts from the depot to complete part of the deliveries, shares part of the load with the crowdshipper at the relay point, and the private driver selected as the crowdshipper continues from that point onward. This study proposes the two-echelon open vehicle routing problem with crowdshipping (2EOVRP-CS) and formulates a mathematical model to determine the crowdshipper, parcel relay location, truck route, and crowdsource route. A tangible nested genetic algorithm (NGA) is proposed, and its efficiency is demonstrated by comparison with CPLEX and genetic algorithm (GA). A real case study is investigated in Xi'an city to test the applicability of the proposed model. The results show that using crowdshipping instead of truck delivery alone can save approximately 14% of the total cost and 26% of truck vehicle miles traveled (VMT). Moreover, several sensitivity analyses are performed. The results show that crowdshipping is sensitive to the detour limit and the time value of carriers. For the detour limit, after the acceptable detour distance increases by 8%, the total cost can be reduced by up to 5.94%.

Influence of fluorinated extractant aggregation in diluent on extraction of salicylic acid: Evidence from equilibrium, SAXS and molecular dynamics simulation

Xue Wu,Zhidong Chang,Jingge Feng,Hui Dang,Hasan Uslu,Wenjun Li 한국공업화학회 2018 Journal of Industrial and Engineering Chemistry Vol.66 No.-

In order to get optimal extraction performance as well as ultra-low solvent residual, the extraction behavior of tris(2,2,3,3,4,4,4-heptafluorobutyl) phosphate (FTBP) dissolved in 2,3,4,5,6-Pentafluorotoluene (FB) was evaluated to investigate the influence of the aggregation state on the extraction of salicylic acid (SA). The effect of SA distribution and water content on aggregation structure in organic phase was assessed through analysis of SAXS data. Based on molecular dynamic simulation, FTBP tended to aggregate with the existence of FB to accommdate more SA molcules. Water in this case was not the critical factor for aggregation formation due to the hydrophobicity of fluorinated solvents.

Synergistic effect of fluorinated hexane as diluent of fluorinated octanol for salicylic acid extraction

Xue Wu,Zhidong Chang,Junchao Yuan,Jingge Feng,Hasan Uslu,Wenjun Li 한국공업화학회 2018 Journal of Industrial and Engineering Chemistry Vol.58 No.-

In order to get optimal extraction performance as well as ultra-low solvent residual, three fluorinated hexane, perfluorohexane (C6F14), 1H-perfluorohexane (C6F13H) and 1H,6H-perfluorohexane (C6F12H2), were evaluated as diluents for synergistic effect on extraction capability of 1H,1H,2H,2H-Perfluorooctan-1-ol by the way of experimental and computational investigation. Based on extraction experiments, C6F14 showed obvious antagonistic effect because of hydrophobic nature, while the synergistic effect of C6F12H2 was better than that of C6F13H. According to DFT calculation, supported by FT-IR and 1H NMR spectra, the synergistic effect was illustrated as that fluorinated hexane could interact with salicylic acid-fluorinated octanol complex through hydrogen bond.

Stretchable, electrically conductive and superhydrophobic/superoleophilic nanofibrous membrane with a hierarchical structure for efficient oil/water separation

Xuewu Huang,Bei Li,Xin Song,Ling Wang,Yue Shi,Mingjun Hu,Jiefeng Gao,Huaiguo Xue 한국공업화학회 2019 Journal of Industrial and Engineering Chemistry Vol.70 No.-

Aflexible, stretchable and electrically conductive nanofiber composite with superhydrophobicity wasfabricated by ultrasonication induced carbon nanotubes (CNTs) decoration onto the polymer nanofiber,followed by methyltrichlorosilane (MTS) modification. The introduction of CNTs and polysiloxanederived from MTS improved the superhydrophobicity, conductivity, thermal stability and mechanicalproperties of the nanofibrous membrane. The superhydrophobicity and electrical conductivity could bemaintained during the cyclic stretching. The nanofiber composite membrane could be utilized toseparate the oil from the oil/water mixture regardless of pH of water, exhibiting a largeflux, highefficiency and good recyclability.

Sliding-mode Adaptive Control for Multiple High-speed Trains With State Constraints and Input Saturation

Hui Zhao,Xuewu Dai,Yuan Zhao 제어·로봇·시스템학회 2023 International Journal of Control, Automation, and Vol.21 No.11

In this paper, for the safe and efficient cooperation of high-speed trains, a sliding-mode adaptive control strategy is investigated for cooperative control of trains subject to state constraints and input saturation. Firstly, in order to guarantee the safety of inter-train distance and over-speed protection, the position and speed limitations which could be seen as state constraints are integrated as the hybrid prescribed performance. Then, a sliding-mode surface is selected and a sliding-mode adaptive control protocol is designed to meet the input saturation and hybrid prescribed performance for the multi-train systems. Afterwards, a Barrier Lyapunov Function is designed to prove the stability of multi-train systems subject to state constraints and input saturation. Using the sliding-mode adaptive control and hybrid prescribed performance control methods, the safe and efficient operation of trains can be realized. Finally, the effectiveness of proposed method is given by the simulation results.

SAFETY ANALYSIS OF INCREASE IN HEAT REMOVAL FROM REACTOR COOLANT SYSTEM WITH INADVERTENT OPERATION OF PASSIVE RESIDUAL HEAT REMOVAL AT NO-LOAD CONDITIONS

GE SHAO,XUEWU CAO 한국원자력학회 2015 Nuclear Engineering and Technology Vol.47 No.4

The advanced passive pressurized water reactor (PWR) is being constructed in China andthe passive residual heat removal (PRHR) system was designed to remove the decay heat. During accident scenarios with increase of heat removal from the primary coolant system,the actuation of the PRHR will enhance the cooldown of the primary coolant system. Thereis a risk of power excursion during the cooldown of the primary coolant system. Therefore,it is necessary to analyze the thermal hydraulic behavior of the reactor coolant system(RCS) at this condition. The advanced passive PWR model, including major components inthe RCS, is built by SCDAP/RELAP5 code. The thermal hydraulic behavior of the core isstudied for two typical accident sequences with PRHR actuation to investigate the corecooling capability with conservative assumptions, a main steam line break (MSLB) eventand inadvertent opening of a steam generator (SG) safety valve event. The results showthat the core is ultimately shut down by the boric acid solution delivered by Core MakeupTank (CMT) injections. The effects of CMT boric acid concentration and the activation delaytime on accident consequences are analyzed for MSLB, which shows that there is noconsequential damage to the fuel or reactor coolant system in the selected conditions.

A Sliding Mode Control Scheme for Steering Flexibility and Stability in All-wheel-steering Multi-axle Vehicles

Tao Xu,Xuewu Ji,Xiangxin Liu,Zheng Li,Bo Feng,Fuwei Wu 제어·로봇·시스템학회 2023 International Journal of Control, Automation, and Vol.21 No.6

Multi-axle vehicles that have important roles in transport systems require high load-carrying capacity, steering performance, and stability. Thanks to the multiple steering characteristics, the dynamic performance of multi-axle vehicles can be greatly improved, which also brings great challenges for the design of their steering controller. Therefore, this paper proposes a steering control scheme for an all-wheel-steering multi-axle vehicle with the goal of optimizing low-speed steering flexibility and high-speed vehicle stability. With the dynamic analyses, the vehicle’s steady-state gains at different speeds are reshaped, which provide the closed-loop steering control system with good tracking performance. Correspondingly, a steering controller based on the sliding mode control approach is designed to control the steering angle of each wheel at different axles. The super-twisting control algorithm is also combined with a model-based observer to deal with disturbance while eliminating chattering effects of the control system. Simulation results based on a co-simulation platform verify the efficiency and disturbance rejection of the proposed control approach.

Interactive and Worst-Case Optimized Robust Control for Potential Application to Guaranteeing Roll Stability for Intelligent Heavy Vehicle

Liu Yulong,Ji Xuewu,Yang Kai-ming,He Xiangkun,Nakano Shirou 한국자동차공학회 2021 International journal of automotive technology Vol.22 No.5

Roll stability loss of heavy vehicle is a severe road safety problem and modern intelligent heavy vehicle (IHV) raises new requirement for advanced roll stability control technology. Two novel roll stability control frameworks, namely active steering-active anti-roll (AS-AAR) interactive control and worst-case optimized robust control, which have potential application to guaranteeing roll stability of IHV are proposed and investigated in this paper. The first control framework is implemented based on Nash dynamic game theory in which AS-AAR shared control is investigated as a dynamic difference game so that its two players, namely AS and AAR system, can interact with each other to provide satisfactory control performance. This interactive control scheme can be applied to vehicle automated driving scenario to improve vehicle tracking performance and roll stability. Based on zero-sum game theory, the second worst-case optimized robust control scheme is also developed to guarantee vehicle roll stability. This control method provides a suitable design framework to guarantee roll stability in scenario of vehicle-to-driver handover for IHV in which the steering input from human driver is regarded as uncertain disturbance. Simulation results show that both control frameworks can effectively improve roll stability as well as lateral stability while ensuing satisfied tracking performance.

Experimental study of vibration characteristics of FRP cables based on Long-Gauge strain

Qi Xia,JiaJia Wu,XueWu Zhu,Jian Zhang 국제구조공학회 2017 Structural Engineering and Mechanics, An Int'l Jou Vol.63 No.6

Steel cables as the most important components are widely used in the certain types of structures such as cablesupported bridges, but the long-span structures may result in an increase in fatigue under high stress and corrosion of steel cables. The traditional steel cable is becoming a more evident hindrance. Fiber Reinforced Polymer (FRP) cables with lightweight, high-strength are widely used in civil engineering, but there is little research in vibrational characteristics of FRP cables, especially on the damping characteristic. This article studied the two methods to evaluate dynamical damping characteristic of basalt FRP(BFRP) and glass FRP(GFRP) cables. First, the vibration tests of the B/G FRP cables with different diameter and different cable force were executed. Second, the cables forces were calculated using dynamic strain, static strain and dynamic acceleration respectively, which were further compared with the measured force. Third, experimental modal damping of each cables was calculated by the half power point method, and was compared with the calculation by Rayleigh damping theory and energy dissipation damping theory. The results indicate that (1) The experimental damping of FRP cables decreases with the increase of cable force, and the trend of experimental damping changes is roughly similar with the theoretical damping. (2) The distribution of modal damping calculated by Rayleigh damping theory is closer to the experimental results, and the damping performance of GFRP cables is better than BFRP cables.

Influence of different electrical boundary conditions on the elasticity solutions of piezoelectric plane beam

Zhang Lang,Li Xuewu,Wang Yuping,Wang Qiang,Shi Haibing 대한기계학회 2013 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.27 No.12

Influence of different electrical boundary conditions (BCs) on the elasticity solutions of piezoelectric plane beam (PPB) is investigated using analytical technique. The first case is considering electrical displacement of the two longitudinal sides of PPB. The second case is electrical potential. Firstly, the unified equations to obtain the elasticity solutions of PPB corresponding to these two cases are given briefly. Secondly, two examples are given to verify the correctness of the theoretical formulations presented in this paper. Finally, the responses of PPB acted by the same mechanical loads but with different electrical BCs are compared.