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A probabilistic approach for the valuation of variance swaps under stochastic volatility with jump clustering and regime switching
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作者 Xin-Jiang He Sha Lin 《Financial Innovation》 2024年第1期680-702,共23页
The effects of stochastic volatility,jump clustering,and regime switching are considered when pricing variance swaps.This study established a two-stage procedure that simplifies the derivation by first isolating the r... The effects of stochastic volatility,jump clustering,and regime switching are considered when pricing variance swaps.This study established a two-stage procedure that simplifies the derivation by first isolating the regime switching from other stochastic sources.Based on this,a novel probabilistic approach was employed,leading to pricing formulas with time-dependent and regime-switching parameters.The formulated solutions were easy to implement and differed from most existing results of variance swap pricing,where Fourier inversion or fast Fourier transform must be performed to obtain the final results,since they are completely analytical without involving integrations.The numerical results indicate that jump clustering and regime switching have a significant influence on variance swap prices. 展开更多
关键词 Stochastic volatility Jump clustering Regime switching Variance swaps Probabilistic approach Closed-form solution
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Informed Trading, Heterogeneity Investment, Liquidity Shocks and the Valuation of Credit Default Swaps
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作者 杨星 范纯 李刚 《Journal of Shanghai Jiaotong university(Science)》 EI 2016年第1期69-80,共12页
This paper explores the effect of informed trading, heterogeneity investment and liquidity shocks on the valuation of credit default swaps(CDSs). Under the condition of asymmetric information, the informed trading pla... This paper explores the effect of informed trading, heterogeneity investment and liquidity shocks on the valuation of credit default swaps(CDSs). Under the condition of asymmetric information, the informed trading plays an important role in the valuation of CDS. Instruction order flow has a significant influence on CDS price.And the scope of influence changes in accordance with different time interval, company status and the size of bid-ask spread. Heterogeneity of investors seriously affects the market liquidity and subsequently affects the CDS price. The bigger heterogeneity of the investment philosophy, investment habits, investment preference and so on is the bigger risk for market liquidity, and the higher price for CDS shall be. On the contrary, the conclusion is also consistent. The effectiveness of liquidity, whether it is before or after the financial crisis, dominates the fluctuation of CDS price. The premium of liquidity accounts for 36% to 50% of the CDS price. 展开更多
关键词 informed trading HETEROGENEITY INVESTMENT LIQUIDITY shocks VALUATION of credit DEFAULT swaps
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Credit Default Swaps (CDSs) and Systemic Risks
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作者 Eliana Angelini 《Journal of Modern Accounting and Auditing》 2012年第6期880-890,共11页
The use of credit default swaps (CDSs) has become increasingly popular over time. Between 2002 and 2007, gross notional amounts outstanding grew from below S2 trillion to nearly S60 trillion. The recent crisis has r... The use of credit default swaps (CDSs) has become increasingly popular over time. Between 2002 and 2007, gross notional amounts outstanding grew from below S2 trillion to nearly S60 trillion. The recent crisis has revealed several shortcomings in CDS market practices and structure. In addition, management of counterparty risk has proved insufficient, as has in some instances the settlement of contracts following a credit event. However, past problems should not distract from the potential benefits of these instruments. In particular, CDSs help complete markets, as they provide an effective means to hedge and trade credit risk. CDSs allow financial institutions to better manage their exposures, and investors benefit from an enhanced investment universe. The purpose of this paper is to present a complete and practical exposition of the CDS market and to explore how the development of the CDS market has played an important role in the credit risk markets. Currently, the CDS market is transforming into a more stable system. Various measures are being put in place to help enhance market transparency and mitigate operational and systemic risk. In particular, central counterparties have started to operate, which will eventually lead to an improved management of individual as well as system-wide risks. 展开更多
关键词 credit derivatives credit default swap (CDS) credit risk counterpart risk systemic risk
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Significant Retest Effects in Spatial Working Memory Task
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作者 MA Xianda LAN Zhaohui +3 位作者 CHEN Zhitang MONISHA M L HE Xinyi LI Weidong 《Journal of Shanghai Jiaotong university(Science)》 2025年第1期115-120,共6页
Working memory is a core cognitive function that supports goal-directed behavior and complex thought.We developed a spatial working memory and attention test on paired symbols(SWAPS)which has been proved to be a usefu... Working memory is a core cognitive function that supports goal-directed behavior and complex thought.We developed a spatial working memory and attention test on paired symbols(SWAPS)which has been proved to be a useful and valid tool for spatial working memory and attention studies in the fields of cognitive psychology,education,and psychiatry.The repeated administration of working memory capacity tests is common in clinical and research settings.Studies suggest that repeated cognitive tests may improve the performance scores also known as retest effects.The systematic investigation of retest effects in SWAPS is critical for interpreting scientific results,but it is still not fully developed.To address this,we recruited 77 college students aged 18–21 years and used SWAPS comprising 72 trials with different memory loads,learning time,and delay span.We repeated the test once a week for five weeks to investigate the retest effects of SWAPS.There were significant retest effects in the first two tests:the accuracy of the SWAPS tests significantly increased,and then stabilized.These findings provide useful information for researchers to appropriately use or interpret the repeated working memory tests.Further experiments are still needed to clarify the factors that mediate the retest effects,and find out the cognitive mechanism that influences the retest effects. 展开更多
关键词 working memory retest effects spatial working memory and attention test on paired symbols(swaps) memory load
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适用于河套平原典型作物的SWAP模型参数 被引量:1
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作者 马颖 段绍祎 雷慧闽 《农业工程学报》 北大核心 2025年第9期73-80,共8页
为提高SWAP(soil-water-atmosphere-plant)模型在河套平原典型作物农田的模拟精度,该研究基于7个试验站点共21 a的田间试验数据,在春玉米、春小麦和向日葵农田分别构建了SWAP模型,并利用PEST(parameter estimation)算法对模型中的作物... 为提高SWAP(soil-water-atmosphere-plant)模型在河套平原典型作物农田的模拟精度,该研究基于7个试验站点共21 a的田间试验数据,在春玉米、春小麦和向日葵农田分别构建了SWAP模型,并利用PEST(parameter estimation)算法对模型中的作物参数进行了敏感性分析和优化,确定了敏感参数的在河套平原的优化值。结果表明,参数值优化后土壤含水率、含盐量、叶面积指数和产量的模拟精度均有提升。尤其是在产量方面,春小麦、春玉米和向日葵的决定系数R~2分别提升至0.89、0.34和0.96。研究得到的优化参数集可更好地为该地区农田作物和水文过程模拟提供参考。 展开更多
关键词 春玉米 春小麦 向日葵 SWAP模型 参数优化
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Pricing Variance Swaps Under Stochastic Volatility with an Ornstein-Uhlenbeck Process 被引量:3
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作者 JIA Zhaoli BI Xiuchun ZHANG Shuguang 《Journal of Systems Science & Complexity》 SCIE EI CSCD 2015年第6期1412-1425,共14页
Pricing variance swaps under stochastic volatility has been an important subject pursued recently. Various approaches have been proposed, mainly due to the substantially increased trading activities of volatility-rela... Pricing variance swaps under stochastic volatility has been an important subject pursued recently. Various approaches have been proposed, mainly due to the substantially increased trading activities of volatility-related derivatives in the past few years. In this note, the authors develop analytical method for pricing variance swaps under stochastic volatility with an Ornstein-Uhlenbeck(OU) process. By using Fourier transform algorithm, a closed-form solution for pricing variance swaps with stochastic volatility is obtained, and to give a comparison of fair strike value based on the discrete model, continuous model, and the Monte Carlo simulations. 展开更多
关键词 Closed-form solution Ornstein-Uhlenbeck process stochastic volatility variance swaps
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Multi-hop quantum teleportation based on HSES via GHZ-like states 被引量:1
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作者 She-Xiang Jiang Xiao-Long Wei +1 位作者 Jin-Huan Li Shuai-Shuai Li 《Chinese Physics B》 2025年第1期60-70,共11页
Implementing quantum wireless multi-hop network communication is essential to improve the global quantum network system. In this paper, we employ eight-level GHZ states as quantum channels to realize multi-hop quantum... Implementing quantum wireless multi-hop network communication is essential to improve the global quantum network system. In this paper, we employ eight-level GHZ states as quantum channels to realize multi-hop quantum communication, and utilize the logical relationship between the measurements of each node to derive the unitary operation performed by the end node. The hierarchical simultaneous entanglement switching(HSES) method is adopted, resulting in a significant reduction in the consumption of classical information compared to multi-hop quantum teleportation(QT)based on general simultaneous entanglement switching(SES). In addition, the proposed protocol is simulated on the IBM Quantum Experiment platform(IBM QE). Then, the data obtained from the experiment are analyzed using quantum state tomography, which verifies the protocol's good fidelity and accuracy. Finally, by calculating fidelity, we analyze the impact of four different types of noise(phase-damping, amplitude-damping, phase-flip and bit-flip) in this protocol. 展开更多
关键词 multi-hop quantum teleportation GHZ-like state hierarchical simultaneous entanglement swapping IBM Quantum Experiment platform quantum state tomography
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The voluntary national standard GB/T 29772-2024, General requirements of electric vehicle battery swap station, has taken effect since July 1, 2025.
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《China Standardization》 2025年第5期1-1,共1页
The implementation of the standard is expected to help electric vehicle battery swap stations to adapt to diversified needs and vehicle models,promoting the industry’s orderly and healthy development.
关键词 healthy development electric vehicle battery swap stations diversified needs standard orderly development electric vehicle battery swap station vehicle models
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耦合地表与地下水过程的灌区水资源管理研究
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作者 曾飞 《水利科学与寒区工程》 2025年第4期78-81,共4页
本研究旨在评估不同水文模型在永固霸太平庄灌区中地表与地下水耦合过程中的适应性和准确性。通过分析该灌区的水文特征,采用基于SWAP的物理模型和SWRRB、ALHyMUS两种蓄水池级联模型,比较其在模拟非饱和带土壤水动态方面的表现。研究利... 本研究旨在评估不同水文模型在永固霸太平庄灌区中地表与地下水耦合过程中的适应性和准确性。通过分析该灌区的水文特征,采用基于SWAP的物理模型和SWRRB、ALHyMUS两种蓄水池级联模型,比较其在模拟非饱和带土壤水动态方面的表现。研究利用十年的降雨数据和多种土壤剖面信息进行模型验证。结果显示,各模型在不同土壤类型和剖面深度上的模拟结果存在显著差异,尤其在细质土壤和深剖面条件下表现突出。本研究为灌区水资源管理提供了理论依据和实践指导,建议在实际应用中根据具体土壤和水文条件选择适宜的模型,以提高灌溉效率和水资源利用的可持续性。 展开更多
关键词 非饱和带 ALHyMUS模型 SWAP模型 SWRRB模型
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Swapping dynamics of composite knots in a stretched polymer under nanochannel confinement
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作者 Yong Li Zuoshan Liu +3 位作者 Yuyu Feng Rongri Tan Zhouhui Deng Yanhui Liu 《Communications in Theoretical Physics》 2025年第8期172-179,共8页
In this work,Langevin dynamics simulations were carried out to thoroughly investigate the swapping process of composite knots under tension in a cuboid nanochannel.From our analysis,the free energy profiles of knot sw... In this work,Langevin dynamics simulations were carried out to thoroughly investigate the swapping process of composite knots under tension in a cuboid nanochannel.From our analysis,the free energy profiles of knot swapping under different conditions were extracted from the overall probability distribution of the relative distance between the centers of composite knots.In addition,the impact of the stretching force,confinement size,and bending stiffness on the free energy profiles was directly identified.Especially,the influence of topology structure is for the first time reported.The increasing stretching force in a fixed confinement or the confinement size under a constant stretching force does not alter their respective equilibrium populations at the separate state and the entangled state.In contrast,a bending stiffness larger than 15 enhanced the formation of the entangled state.The topology structure of the 51knot,which was different from the 52knot,resulted in forming a metastable state in the free energy profiles.The increasing stretching forces yielded an enhancement of the following free energy barrier. 展开更多
关键词 swapping process composite knots Langevin dynamics simulations free energy profile
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AGV Scheduling and Bidirectional Conflict-Free Routing Problem with Battery Swapping in Automated Container Terminals
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作者 He Huang Jin Zhu 《Computer Modeling in Engineering & Sciences》 2025年第8期1717-1748,共32页
Automated guided vehicles(AGVs)are key equipment in automated container terminals(ACTs),and their operational efficiency can be impacted by conflicts and battery swapping.Additionally,AGVs have bidirectional transport... Automated guided vehicles(AGVs)are key equipment in automated container terminals(ACTs),and their operational efficiency can be impacted by conflicts and battery swapping.Additionally,AGVs have bidirectional transportation capabilities,allowing them tomove in the opposite directionwithout turning around,which helps reduce transportation time.This paper aims at the problem of AGV scheduling and bidirectional conflict-free routing with battery swapping in automated terminals.A bi-level mixed integer programming(MIP)model is proposed,taking into account task assignment,bidirectional conflict-free routing,and battery swapping.The upper model focuses on container task assignment and AGV battery swapping planning,while the lower model ensures conflict-free movement of AGVs.A double-threshold battery swapping strategy is introduced,allowing AGVs to utilize waiting time for loading for battery swapping.An improved differential evolution variable neighborhood search(IDE-VNS)algorithm is developed to solve the bi-level MIP model,aiming to minimize the completion time of all jobs.Experimental results demonstrate that compared to the differential evolution(DE)algorithm and the genetic algorithm(GA),the IDEVNS algorithmreduces fitness values by 44.49% and 45.22%,though it does increase computation time by 56.28% and 62.03%,respectively.Bidirectional transportation reduces the fitness value by an average of 10.97% when the container scale is small.As the container scale increases,the fitness value of bidirectional transportation gradually approaches that of unidirectional transportation.The results further show that the double-threshold battery swapping strategy enhances AGV utilization and reduces the fitness value. 展开更多
关键词 Automated container terminal(ACT) AGV scheduling bidirectional conflict-free routing battery swapping different evolution algorithm
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改进量子位初始映射的综合SWAP优化策略 被引量:1
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作者 李晖 韩子傲 +2 位作者 卢凯 刘述娟 鞠明媚 《计算机工程与应用》 CSCD 北大核心 2024年第14期66-73,共8页
在嘈杂的中尺度量子时代,传统的初始映射策略忽略了后续操作中可能出现的邻接性的问题。针对这一挑战,综合考虑量子比特间的距离、交互时间和门操作的错误率,设计了一个多因素交互成本函数,并提出综合SWAP优化策略(comprehensive SWAP o... 在嘈杂的中尺度量子时代,传统的初始映射策略忽略了后续操作中可能出现的邻接性的问题。针对这一挑战,综合考虑量子比特间的距离、交互时间和门操作的错误率,设计了一个多因素交互成本函数,并提出综合SWAP优化策略(comprehensive SWAP optimization strategy,CSOS)。该策略包括最佳SWAP选择和基于SWAP的批量更新策略,用于优化量子电路的局部量子位映射。最佳SWAP选择通过对比SWAP操作的效益,选择最佳收益的SWAP门;批量更新策略在映射阶段考虑即将执行的量子操作序列,预先执行批量的SWAP操作。二者综合可以减少整个电路执行过程中的SWAP数量,以最大程度减少映射开销。实验结果显示,CSOS优化方式可以平均减少38.1%的插入SWAP门数量,并降低约12%的硬件门计数开销。 展开更多
关键词 量子计算 初始映射 综合SWAP优化策略 最佳SWAP选择 批量更新
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不同矿化度水源膜下滴灌棉田土壤水盐动态和作物生长模拟 被引量:3
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作者 孔春贤 杨广 +7 位作者 刘承岳 苏军 贾伟康 田浩 赵丽 冉茂林 潘月 王海龙 《干旱地区农业研究》 CSCD 北大核心 2024年第1期108-122,共15页
为构建适用于干旱区膜下滴灌条件的土壤水盐动态分布和棉花生长模型,基于2020—2021年的田间试验,经过对SWAP模型的土壤、土壤水力功能和作物生长等模块进行率定和验证,对灌溉水矿化度为1、2、3、4、5、6 g·L^(-1)时的土壤水盐分... 为构建适用于干旱区膜下滴灌条件的土壤水盐动态分布和棉花生长模型,基于2020—2021年的田间试验,经过对SWAP模型的土壤、土壤水力功能和作物生长等模块进行率定和验证,对灌溉水矿化度为1、2、3、4、5、6 g·L^(-1)时的土壤水盐分布特征、作物生长过程和干物质累积分配进行数值模拟。结果表明:(1)土壤含水率与土壤含盐量的模拟精度以20~100 cm土层较好,0~20 cm土层模拟精度较差,其中土壤含水量的模拟效果优于土壤含盐量;随着灌溉水源矿化度的增加,土壤含水率和含盐量的模拟误差逐渐变小。(2)不同矿化度水源膜下滴灌棉花叶面积指数模拟效果较好(R2=90.72%,RMSE=0.35 cm^(2)·cm^(-2),NRMSE=8.73%,IOA=0.98)。(3)不同矿化度水源膜下滴灌棉花茎干物质累积量模拟效果较好(R2=89.08%,RMSE=6.12 g,NRMSE=23.16%,IOA=0.96)。研究结果表明,SWAP模型可以较好地对不同矿化度水源膜下滴灌的土壤水盐动态分布和棉花生长过程进行模拟。 展开更多
关键词 棉花 膜下滴灌 SWAP模型 水盐运移 作物生长 数值模拟
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暗管排水条件下棉田土壤水盐运移和作物生长模拟 被引量:1
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作者 杨阳 董建华 +4 位作者 刘义 曾文治 敖畅 黄介生 李磐 《农业资源与环境学报》 CSCD 北大核心 2024年第6期1493-1507,共15页
为探究暗管排水对抑制克孜勒苏河下游灌区土壤次生盐渍化进程和作物生长的效果,本研究于2023—2024年在新疆伽师县开展了暗管排水条件下的土壤水盐运移和作物生长试验,结合当地实际情况以埋深1.2、1.4、1.6、1.8 m和间距40、30、20 m设... 为探究暗管排水对抑制克孜勒苏河下游灌区土壤次生盐渍化进程和作物生长的效果,本研究于2023—2024年在新疆伽师县开展了暗管排水条件下的土壤水盐运移和作物生长试验,结合当地实际情况以埋深1.2、1.4、1.6、1.8 m和间距40、30、20 m设计了12个正交试验处理。利用观测数据对SWAP模型的土壤水盐运移模块和作物生长模块进行了率定和验证,对12个暗管布置参数处理试验区域的土壤水盐分布特征、作物叶面积指数(LAI)和地上干物质累积量进行数值模拟。结果表明:SWAP模型可以较好地模拟不同暗管处理下水盐运移动态,各处理土壤含水率和土壤盐浓度模拟值与实测值的平均RRMSE(相对均方根误差)分别为16.67%和23.99%;模型对于表层0~60cm土层水分和盐分的动态变化模拟精度较高,各处理平均RRMSE分别为14.46%和22.28%,深层60~100cm土层模拟精度较低,平均RRMSE分别为18.71%和29.04%;模型对于棉花LAI和地上干物质累积量的模拟具有较好的一致性以及较高的模拟精度;暗管埋深和暗管间距对0~100 cm土层土壤脱盐率有显著的影响(P<0.01),且脱盐率与暗管埋深呈正相关关系,与暗管间距呈负相关关系。研究表明,SWAP模型可以较好地对不同暗管布置参数下膜下滴灌的土壤水盐运移和棉花生长过程进行模拟,克孜勒苏河下游灌区较优的暗管布置参数为埋深1.8m、间距20m。 展开更多
关键词 暗管排水 膜下滴灌 SWAP模型 水盐运移 棉花生长
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An Improved Iterated Greedy Algorithm for Solving Rescue Robot Path Planning Problem with Limited Survival Time
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作者 Xiaoqing Wang Peng Duan +1 位作者 Leilei Meng Kaidong Yang 《Computers, Materials & Continua》 SCIE EI 2024年第7期931-947,共17页
Effective path planning is crucial for mobile robots to quickly reach rescue destination and complete rescue tasks in a post-disaster scenario.In this study,we investigated the post-disaster rescue path planning probl... Effective path planning is crucial for mobile robots to quickly reach rescue destination and complete rescue tasks in a post-disaster scenario.In this study,we investigated the post-disaster rescue path planning problem and modeled this problem as a variant of the travel salesman problem(TSP)with life-strength constraints.To address this problem,we proposed an improved iterated greedy(IIG)algorithm.First,a push-forward insertion heuristic(PFIH)strategy was employed to generate a high-quality initial solution.Second,a greedy-based insertion strategy was designed and used in the destruction-construction stage to increase the algorithm’s exploration ability.Furthermore,three problem-specific swap operators were developed to improve the algorithm’s exploitation ability.Additionally,an improved simulated annealing(SA)strategy was used as an acceptance criterion to effectively prevent the algorithm from falling into local optima.To verify the effectiveness of the proposed algorithm,the Solomon dataset was extended to generate 27 instances for simulation.Finally,the proposed IIG was compared with five state-of-the-art algorithms.The parameter analysiswas conducted using the design of experiments(DOE)Taguchi method,and the effectiveness analysis of each component has been verified one by one.Simulation results indicate that IIGoutperforms the compared algorithms in terms of the number of rescue survivors and convergence speed,proving the effectiveness of the proposed algorithm. 展开更多
关键词 Rescue robot path planning life strength improved iterative greedy algorithm problem-specific swap operators
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Solving the Generalized Traveling Salesman Problem Using Sequential Constructive Crossover Operator in Genetic Algorithm
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作者 Zakir Hussain Ahmed Maha Ata Al-Furhood +1 位作者 Abdul Khader Jilani Saudagar Shakir Khan 《Computer Systems Science & Engineering》 2024年第5期1113-1131,共19页
The generalized travelling salesman problem(GTSP),a generalization of the well-known travelling salesman problem(TSP),is considered for our study.Since the GTSP is NP-hard and very complex,finding exact solutions is h... The generalized travelling salesman problem(GTSP),a generalization of the well-known travelling salesman problem(TSP),is considered for our study.Since the GTSP is NP-hard and very complex,finding exact solutions is highly expensive,we will develop genetic algorithms(GAs)to obtain heuristic solutions to the problem.In GAs,as the crossover is a very important process,the crossovermethods proposed for the traditional TSP could be adapted for the GTSP.The sequential constructive crossover(SCX)and three other operators are adapted to use in GAs to solve the GTSP.The effectiveness of GA using SCX is verified on some GTSP Library(GTSPLIB)instances first and then compared against GAs using the other crossover methods.The computational results show the success of the GA using SCX for this problem.Our proposed GA using SCX,and swap mutation could find average solutions whose average percentage of excesses fromthe best-known solutions is between 0.00 and 14.07 for our investigated instances. 展开更多
关键词 Generalized travelling salesman problem NP-HARD genetic algorithms sequential constructive crossover swap mutation
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Cathode nanoarchitectonics with Na_(3)VFe_(0.5)Ti_(0.5)(PO_(4))_(3): Overcoming the energy barriers of multielectron reactions for sodium-ion batteries
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作者 Vaiyapuri Soundharrajan Sungjin Kim +7 位作者 Subramanian Nithiananth Muhammad H.Alfaruqi JunJi Piao Duong Tung Pham Vinod Mathew Sang A.Han Jung Ho Kim Jaekook Kim 《Carbon Energy》 SCIE EI CAS CSCD 2024年第9期1-14,共14页
High electrochemical stability and safety make Na+superionic conductor(NASICON)-class cathodes highly desirable for Na-ion batteries(SIBs).However,their practical capacity is limited,leading to low specific energy.Fur... High electrochemical stability and safety make Na+superionic conductor(NASICON)-class cathodes highly desirable for Na-ion batteries(SIBs).However,their practical capacity is limited,leading to low specific energy.Furthermore,the low electrical conductivity combined with a decline in capacity upon prolonged cycling(>1000 cycles)related to the loss of active material-carbon conducting contact regions contributes to moderate rate performance and cycling stability.The need for high specific energy cathodes that meet practical electrochemical requirements has prompted a search for new materials.Herein,we introduce a new carbon-coated Na_(3)VFe_(0.5)Ti_(0.5)(PO_(4))_(3)(NVFTP/C)material as a promising candidate in the NASICON family of cathodes for SIBs.With a high specific energy of∼457 Wh kg^(-1) and a high Na+insertion voltage of 3.0 V versus Na^(+)/Na,this cathode can undergo a reversible single-phase solid-solution and two-phase(de)sodiation evolution at 28 C(1 C=174.7 mAh g^(-1))for up to 10,000 cycles.This study highlights the potential of utilizing low-cost and highly efficient cathodes made from Earth-abundant and harmless materials(Fe and Ti)with enriched Na^(+)-storage properties in practical SIBs. 展开更多
关键词 Fe and Ti swapping Na_(3)VFe_(0.5)Ti_(0.5)(PO_(4))_(3) prolonged cycle life structural stabilit
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内蒙古河套灌区灌溉入渗对地下水的补给规律及补给系数 被引量:45
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作者 张志杰 杨树青 +4 位作者 史海滨 马金慧 李瑞平 韩文光 张武军 《农业工程学报》 EI CAS CSCD 北大核心 2011年第3期61-66,共6页
为准确估计内蒙河套灌区灌溉水入渗补给地下水量,采用试验研究与数值模拟相结合的方法,分别根据灌水前后地下水位变化和土壤含水率变化计算了灌溉水入渗补给地下水系数,并依据土壤水动力学原理,采用数值模拟验证,得到作物生育期灌溉补... 为准确估计内蒙河套灌区灌溉水入渗补给地下水量,采用试验研究与数值模拟相结合的方法,分别根据灌水前后地下水位变化和土壤含水率变化计算了灌溉水入渗补给地下水系数,并依据土壤水动力学原理,采用数值模拟验证,得到作物生育期灌溉补给地下水系数为0.15,秋浇灌溉补给地下水系数为0.3。河套灌区地下水位埋深相对较浅,通过灌水前后的土壤含水率变化情况和数值模拟结果显示,灌水2~4d补给地下水量达到最大,8~10d后即完成对地下水的入渗补给,不同灌水量灌溉水入渗规律基本一致,入渗补给量和入渗时间与灌溉水量直接相关。研究结果将为确定维持灌区生态环境良性发展的引水量阈值提供参考。 展开更多
关键词 灌溉 试验 数值方法 SWAP 补给地下水系数
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河套灌区咸水灌溉试验研究 被引量:39
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作者 王卫光 王修贵 +2 位作者 沈荣开 张仁铎 杨树青 《农业工程学报》 EI CAS CSCD 北大核心 2004年第5期92-96,共5页
以内蒙古河套灌区红卫节水示范园的咸水灌溉试验为基础,以荷兰Wageningen农业大学等单位开发的土壤—水分—大气—作物系统模拟软件SWAP为工具,应用示范园的土壤、水、盐分试验资料对模型的参数进行了率定和验证。在此基础上设计了示范... 以内蒙古河套灌区红卫节水示范园的咸水灌溉试验为基础,以荷兰Wageningen农业大学等单位开发的土壤—水分—大气—作物系统模拟软件SWAP为工具,应用示范园的土壤、水、盐分试验资料对模型的参数进行了率定和验证。在此基础上设计了示范园不同灌溉水量、不同灌溉方式、不同灌溉次数的多种灌溉方案,并应用SWAP模拟了各种方案的水盐平衡。以作物产量为指标,采用正交设计进行直观分析,提出了适合当地条件的以咸淡水轮灌作为灌溉方式,灌水3次,灌溉定额2812.5m3/hm2的咸水灌溉指导方案。研究结果对河套地区的咸水利用具有一定的借鉴意义。 展开更多
关键词 水资源 咸水灌溉 SWAP模型 土壤水分 土壤盐分
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苏北滩涂水稻微咸水灌溉模式及土壤盐分动态变化 被引量:45
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作者 王相平 杨劲松 +1 位作者 姚荣江 余世鹏 《农业工程学报》 EI CAS CSCD 北大核心 2014年第7期54-63,共10页
为研究微咸水灌溉对水稻水分利用效率和土壤盐分动态的影响,利用田间试验资料对SWAP(Soil—Water-Atmosphere.Plant)模型进行了率定和验证。用验证认可的模型模拟并分析了水稻生育期水盐运移规律和水稻水分利用效率,并预测了长期... 为研究微咸水灌溉对水稻水分利用效率和土壤盐分动态的影响,利用田间试验资料对SWAP(Soil—Water-Atmosphere.Plant)模型进行了率定和验证。用验证认可的模型模拟并分析了水稻生育期水盐运移规律和水稻水分利用效率,并预测了长期微咸水灌溉对土壤盐分的影响。结果表明:1.5mg/cm3矿化度微咸水足量灌溉可以获得较高的产量和水分利用效率;各微咸水处理在60-90cm土层均出现不同程度的盐分累积现象,具体累积深度和土壤盐分浓度与灌水量和灌水矿化度有关;采用1.5mg/cm2矿化度微咸水进行微咸水长期灌溉研究,10a的模拟结果显示此灌溉制度不会引起0—100cm土层土壤次生盐渍化。该研究为滨海地区微咸水合理利用提供了理论依据。 展开更多
关键词 灌溉 盐分 土壤 SWAP模型 微咸水 水分利用效率 盐分动态 水稻
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