Kuan Xu

Large neighborhood search for the two-dimensional irregular bin packing problem

J WANG, Kuan Xu, Zhouwang Yang

cn (code pays fourni par la source)

Learning to search for vehicle routing with multiple time windows

Kuan Xu, Zhiguang Cao, Lindong Liu

In this study, we propose a reinforcement learning-based adaptive variable neighborhood search (RL-AVNS) method designed for effectively solving the Vehicle Routing Problem with Multiple Time Windows (VRPMTW). Unlike traditional adaptive approaches that rely solely on historical operator performance, our method integrates a …

Continuous cropping of Strobilanthes sarcorrhiza drives rhizosphere bacterial community dysbiosis and growth differentiation

Jiuzhou Chen, Tianchi Jiang, Kuan Xu, Xiaoxia Liu et autres

cn (code pays fourni par la source)

Learning to Search for Vehicle Routing with Multiple Time Windows

Kuan Xu, Zhiguang Cao, L.-C. H. Liu

In this study, we propose a reinforcement learning-based adaptive variable neighborhood search (RL-AVNS) method designed for effectively solving the Vehicle Routing Problem with Multiple Time Windows (VRPMTW). Unlike traditional adaptive approaches that rely solely on historical operator performance, our method integrates a …

Enhancing column generation by reinforcement learning-based hyper-heuristic for vehicle routing and scheduling problems

Kuan Xu, Shen Li, Lindong Liu

cn (code pays fourni par la source)

Enhancing Column Generation by Reinforcement Learning-Based Hyper-Heuristic for Vehicle Routing and Scheduling Problems

Kuan Xu, Shen Li, Lindong Liu

Column generation (CG) is a vital method to solve large-scale problems by dynamically generating variables. It has extensive applications in common combinatorial optimization, such as vehicle routing and scheduling problems, where each iteration step requires solving an NP-hard constrained shortest path problem. …

Enhancing Column Generation by Reinforcement Learning-Based Hyper-Heuristic for Vehicle Routing and Scheduling Problems

Kuan Xu, Shen Li, Lindong Liu

cn (code pays fourni par la source)

[Influence of two different species of aquatic plant communities on the concentration of various nitrogen forms in sediment of Lake Taihu].

Jiu-Yuan Ma, Guoxiang Wang, Zhenguo Li, Kuan Xu et autres

To investigate the spatial distribution of nitrogen in the sediment from both internal and external sites of Potamogeton malaianus and Limnanthemun nymphoides communities, levels of various forms of nitrogen were quantified in sediment samples collected from Gonghu Bay, the southern region and …

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[Influence of Vallisneria spiralis on the physicochemical properties of black-odor sediment in urban sluggish river].

Kuan Xu, Bo Liu, Guoxiang Wang, Jiu-Yuan Ma et autres

Using Indoor simulation method, the effect of Vallisneria spiralis on the physicochemical propertise of black and stink sediment was investigated. The surface sediment of urban sluggish river which had been heavily polluted was used as material in the study. The results showed …

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Comparison of different extract methods on extractable nitrogen in sediments from an urban polluted river

Kuan Xu, Bo Liu, LING Fen, DU Xu

以城市污染河道——南京仙林大学城九乡河表层沉积物为研究对象,探讨沉积物常用提取剂(1 mol/L KCl、2 mol/L KCl、4 mol/L KCl和0.01 mol/L CaCl2)在不同液土比(5:1、10:1、50:1和100:1)条件下,对城市污染河道沉积物可提取态氮(NH4+-N、NO3--N)测定的影响.结果表明:KCl的提取效果要优于CaCl2,二者NH4+-N提取量分别为312.17~479.23、177.52~339.31 mg/kg,NO3--N提取量分别为4.49~21.56、4.25~8.53 mg/kg;可提取态氮提取量随液土比增高而增大,其中1 mol/L KCl组,液土比100:1时NH4+-N和NO3--N提取量分别比液土比5:1时增加41.97%和187.08%;NH4+-N提取量随提取剂浓度增高而增大,NO3--N随提取剂浓度增高而降低;采用1 mol/L KCl提取剂、液土比100:1的组合联合提取城市污染河道沉积物中的NH4+-N、NO3--N,提取效果较好.;To explore the influence of different extractant (1 mol/L KCl, 2 mol/L KCl, 4 mol/L KCl and 0.01 mol/L CaCl2) and ratio of water to sediment (5:1, 10:1, …