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Your search keyword '"Sun, Qian"' showing total 113 results
113 results on '"Sun, Qian"'

3. Optimizing Customized Transit Service considering Stochastic Bus Arrival Time

Author

Sun, Qian, Chien, Steven, Hu, Dawei, and Chen, Xiqiong

Subjects
G.A. S.A., Algorithms -- Case studies -- Analysis, Algorithm, Transportation industry
Abstract

The introduction of customized bus (CB) service intends to expand and elevate existing transit service, which offers an efficient and sustainable alternative to serve commuters. A probabilistic model is proposed to optimize CB service with mixed vehicle sizes in an urban setting considering stochastic bus arrival time and spatiotemporal demand, which minimizes total cost subject to bus capacity and time window constraints. The studied optimization problem is combinatorial with many decision variables including vehicle assignment, bus routes, timetables, and fleet size. A heuristic algorithm is developed, which integrates a hybrid genetic algorithm (HGA) and adaptive destroy-and-repair (ADAR) method. The efficiency of HGA-ADAR is demonstrated through numerical comparisons to the solutions obtained by LINGO and HGA. Numerical instances are carried out, and the results suggested that the probabilistic model considering stochastic bus arrival time is valuable and can dramatically reduce the total cost and early and late arrival penalties. A case study is conducted in which the proposed model is applied to optimize a real-world CB service in Xi'an, China. The relationship between decision variables and model parameters is explored. The impacts of time window and variance of bus arrival time, which significantly affect service reliability, are analysed., Author(s): Qian Sun [1]; Steven Chien [1,2]; Dawei Hu (corresponding author) [1]; Xiqiong Chen [1] 1. Introduction Public transportation agencies are experimenting with on-demand and shared technologies to augment traditional [...]

Published
2021
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4. Nanometer-Scale CO2-Shale Oil Minimum Miscibility Pressure Calculations Based on Modified PR-EOS.

Author

Bu, Yahui, Sun, Qian, Fu, Shuoran, Guo, Lingkong, and Zhang, Na

Subjects
*PENG-Robinson equation, *MISCIBILITY, *SHALE oils, *WATER temperature, *INTERFACIAL tension, *OIL spill cleanup
Abstract

CO2 flooding is recognized as an efficient method for enhancing shale oil recovery, while CO2-oil MMP (minimum miscibility pressure) in the micro-nanoscale is a crucial parameter. This paper presents a method for calculating the MMPs of pure hydrocarbons (C4H10, C6H14, C8H18, and C10H22) and CO2 systems in nanopores (3 nm to 10 nm) with temperature ranging from 290.15 K to 373.15 K. Firstly, we modify the Peng-Robinson equation of state (PR-EOS) by considering the influence of confinement effect and capillary pressure in nanopores. Secondly, the flash calculation algorithm is employed to determine whether the oil and gas phases in nanopores have reached an equilibrium state according to the equality of the fugacity of the two phases. Thirdly, we calculate the interfacial tension (IFT) between the two phases using the Macleod-Sugden equation. When the extrapolated IFT is zero, we treat the corresponding pressure as the MMP of the CO2-oil system in nanopores. Simulation results indicate that the calculated MMP using this method has a relative error of about 0.62% compared to the MMP calculated using the multiple mixing cell (MMC) method, indicating high reliability for MMP prediction. Moreover, the measured MMP at the nanoscale is generally smaller than that in the bulk phase due to the influence of the confinement effect. The MMP is positively correlated with the reservoir temperature, the carbon atom number in alkanes, and the nanopore radius. [ABSTRACT FROM AUTHOR]

Published
2023
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20. Identification of Generating Units That Abuse Market Power in Electricity Spot Market Based on AdaBoost-DT Algorithm

Author

Xie Yuting, Sun Qian, Wang Yi, Ning Wang, Hu Xiuzhen, and Lu En

Subjects
Article Subject, Computer science, General Mathematics, General Engineering, System identification, Spot market, 020206 networking & telecommunications, Sample (statistics), 02 engineering and technology, Engineering (General). Civil engineering (General), Set (abstract data type), Identification (information), Collusion, 0202 electrical engineering, electronic engineering, information engineering, QA1-939, 020201 artificial intelligence & image processing, Market power, AdaBoost, TA1-2040, Algorithm, Mathematics
Abstract

The identification of generating units that abuse market power is an essential part of risk prevention in a spot market, especially in the early stage of the construction of the spot market. In this study, a model for identifying generating units that abuse market power is designed based on the AdaBoost-DT algorithm. It is targeted at the imbalance between samples of generating units that abuse market power and normal generating units in the spot market. First, the four main methods by which market power is abused by generating units in the spot market are described: collusion, economic withholding, physical withholding, and extreme quotation. Second, the specific characteristics of the four methods are analyzed, and the identification indexes for generating units that abuse market power are established. Thereafter, a sample set of generating units that abuse market power using different methods is constructed. Furthermore, a training set is formed with samples of normal generating units to construct a model based on the AdaBoost-DT algorithm, for identifying generating units that abuse market power. Finally, the spot market data of a certain region are used for an example analysis. The results show that the accuracy of model identification is 97%, which validates the method.

Published
2021

21. Trained Immunity of IL-12-, IL-15-, and IL-18-Induced CD3+CD56+ NKT-Like Cells.

Author

Zhu, Siyu, Zhang, Chen, Sun, Qian, Wang, Yang, Yu, Wenwen, Wei, Feng, and Ren, Xiubao

Subjects
IMMUNITY, KILLER cells, CYCLIN-dependent kinase inhibitors, T cells, IMMUNE response, PSYCHONEUROIMMUNOLOGY, CYCLIN-dependent kinases, GRANZYMES
Abstract

CD3+CD56+ natural killer T (NKT)-like cells have an immune function of T cells and NK cells, which play an important role in antitumor and antiviral immune responses. This study aims to establish a CD3+CD56+ NKT-like cell model by simulating the memory NK effect induced by cytokines IL-12, IL-15, and IL-18 (IL-12/15/18) and explore the formation mechanism. Our study found that the IL-12/15/18 preactivated CD3+CD56+ NKT-like cells exhibited enhanced IFN-γ production in response to restimulation with IL-12/15/18 for 6h on day 7. The intrinsic potential of these trained cells was significantly improved, showing an increase in IFN-γ, TNF-α, and cell proliferation potential. The IFN-γ release, granzyme B level, and proliferation ability significantly increased when stimulated by NK-cell-sensitive K562 tumor cells. Among these cytokines, the combination of IL-12/15/18 was particularly effective. After the preactivation of IL-12/15/18, some cell surface proteins related to function and differentiation, such as CD11b, CD62 L, NKp46, NKG2A, and CD127, showed an evident and consistent change trend. The CDK4/6 inhibitor can effectively weaken this effect, and the expression of cyclin D1, Rb protein phosphorylation, and E2F-1 decreased significantly. Our work revealed that cytokine IL-12/15/18 can induce CD3+CD56+ NKT-like cells to obtain enhanced training immunity, which was a memory-like phenomenon. [ABSTRACT FROM AUTHOR]

Published
2022
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29. Ischemic Postconditioning Alleviates Intestinal Ischemia-Reperfusion Injury by Enhancing Autophagy and Suppressing Oxidative Stress through the Akt/GSK-3β/Nrf2 Pathway in Mice

Author

Chen, Rong, primary, Zhang, Yun-yan, additional, Lan, Jia-nan, additional, Liu, Hui-min, additional, Li, Wei, additional, Wu, Yang, additional, Leng, Yan, additional, Tang, Ling-hua, additional, Hou, Jia-bao, additional, Sun, Qian, additional, Sun, Tao, additional, Zeng, Zi, additional, Xia, Zhong-yuan, additional, and Meng, Qing-tao, additional

Published
2020
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38. A SLAM Algorithm Based on Adaptive Cubature Kalman Filter

Author

Chongyang Lv, Fei Yu, Sun Qian, Yueyang Ben, and Fu Yanwei

Subjects
Article Subject, ComputingMethodologies_SIMULATIONANDMODELING, GeneralLiterature_INTRODUCTORYANDSURVEY, General Mathematics, lcsh:Mathematics, General Engineering, Statistical parameter, Estimator, Simultaneous localization and mapping, lcsh:QA1-939, Nonlinear system, Noise, Control theory, lcsh:TA1-2040, Adaptive estimator, A priori and a posteriori, Divergence (statistics), lcsh:Engineering (General). Civil engineering (General), Mathematics
Abstract

We need to predict mathematical model of the system and a priori knowledge of the noise statistics when traditional simultaneous localization and mapping (SLAM) solutions are used. However, in many practical applications, prior statistics of the noise are unknown or time-varying, which will lead to large estimation errors or even cause divergence. In order to solve the above problem, an innovative cubature Kalman filter-based SLAM (CKF-SLAM) algorithm based on an adaptive cubature Kalman filter (ACKF) was established in this paper. The novel algorithm estimates the statistical parameters of the unknown system noise by introducing the Sage-Husa noise statistic estimator. Combining the advantages of the CKF-SLAM and the adaptive estimator, the new ACKF-SLAM algorithm can reduce the state estimated error significantly and improve the navigation accuracy of the SLAM system effectively. The performance of this new algorithm has been examined through numerical simulations in different scenarios. The results have shown that the position error can be effectively reduced with the new adaptive CKF-SLAM algorithm. Compared with other traditional SLAM methods, the accuracy of the nonlinear SLAM system is significantly improved. It verifies that the proposed ACKF-SLAM algorithm is valid and feasible.

Published
2014

45. Mutation Analysis of HTRA2 Gene in Chinese Familial Essential Tremor and Familial Parkinson’s Disease.

Author

He, Ya-Chao, Huang, Pei, Li, Qiong-Qiong, Sun, Qian, Li, Dun-Hui, Wang, Tian, Shen, Jun-Yi, Du, Juan-Juan, Cui, Shi-Shuang, Gao, Chao, Fu, Rao, and Chen, Sheng-Di

Abstract

Background. HTRA2 has already been nominated as PARK13 which may cause Parkinson’s disease, though there are still discrepancies among these results. Recently, Gulsuner et al.’s study found that HTRA2 p.G399S is responsible for hereditary essential tremor and homozygotes of this allele develop Parkinson’s disease by examining a six-generation family segregating essential tremor and essential tremor coexisting with Parkinson’s disease. We performed this study to validate the condition of HTRA2 gene in Chinese familial essential tremor and familial Parkinson’s disease patients, especially essential tremor. Methods. We directly sequenced all eight exons, exon-intron boundaries, and part of the introns in 101 familial essential tremor patients, 105 familial Parkinson’s disease patients, and 100 healthy controls. Results. No exonic variant was identified, while one exon-intron boundary variant (rs2241028) and one intron variant (rs2241027) were detected, both with no clinical significance and uncertain function. There was no difference in allele, genotype, and haplotype between groups. Conclusions. HTRA2 exonic variant might be rare among Chinese Parkinson’s disease and essential tremor patients with family history, and HTRA2 may not be the cause of familial Parkinson’s disease and essential tremor in China. [ABSTRACT FROM AUTHOR]

Published
2017
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