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The Collapse of the American Dream: Cultural Deconstruction of the Wealth Myth in Trust
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作者 LI Shi-yu 《Journal of Literature and Art Studies》 2026年第1期53-59,共7页
This paper examines Hernán Díaz’s novel Trust (2022) through the lens of cultural deconstruction, analyzing how its four nested narratives systematically dismantle the American Dream ideology. The novel Bon... This paper examines Hernán Díaz’s novel Trust (2022) through the lens of cultural deconstruction, analyzing how its four nested narratives systematically dismantle the American Dream ideology. The novel Bonds and autobiography My Life collaboratively construct a financial myth portraying protagonist Andrew Bevel as an exemplar of self-made success. Subsequently, Ida’s Memoir exposes the subjective construction of history, declaring the American Dream’s bankruptcy at the epistemological level, while Mildred’s diary Futures deconstructs the myth from within by revealing that Bevel’s financial genius was built upon appropriation of his wife’s intellectual labor. This paper argues that Trust reveals the American Dream as an ideological illusion-narratively constructed, practically dependent on structural injustice, and essentially serving power reproduction. 展开更多
关键词 American dream TRUST Hernán díaz narrative deconstruction
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基于新型贪心-D^(*)算法的无人机全覆盖路径规划
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作者 周映江 谢明慧 +2 位作者 蒋国平 徐丰羽 高辉 《南京邮电大学学报(自然科学版)》 北大核心 2026年第1期111-123,共13页
针对动态未知环境中全覆盖路径规划面临的路径冗余率高和环境适应性差等难题,提出一种基于新型贪心-D^(*)算法(Novel Greedy-D^(*)Algorithm,NG-D^(*))的无人机全覆盖路径规划。首先,构建动态增量式环境建模系统,实现障碍物分布实时更... 针对动态未知环境中全覆盖路径规划面临的路径冗余率高和环境适应性差等难题,提出一种基于新型贪心-D^(*)算法(Novel Greedy-D^(*)Algorithm,NG-D^(*))的无人机全覆盖路径规划。首先,构建动态增量式环境建模系统,实现障碍物分布实时更新与矩阵化栅格状态精准映射,增强系统环境感知能力。其次,设计最小值优先三元组贪心决策函数,通过评估曼哈顿距离、横向优先级与纵向优先级,生成结构化有序覆盖路径。最后,引入关键节点导向D^(*)逃离算法,在检测到局部死区时高效规划平滑脱离路径。实验结果表明,相较于传统方法,NG-D^(*)算法在保持覆盖完整性的前提下,将路径冗余率降低至3.0%以下。 展开更多
关键词 d^(*)算法 贪心策略 全覆盖路径规划 未知环境 无人机
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基于D^(*)DWA的水面无人艇路径规划
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作者 段求辉 《控制工程》 北大核心 2026年第1期129-134,共6页
针对水面无人艇在动态环境下的路径规划难以满足全局最优和实时避障需求的问题,提出了一种改进D^(*)算法和改进动态窗口法相融合的算法,即D^(*)DWA。首先,对环境地图进行栅格化建模,利用层次聚类法根据障碍物的坐标位置对地图进行区域划... 针对水面无人艇在动态环境下的路径规划难以满足全局最优和实时避障需求的问题,提出了一种改进D^(*)算法和改进动态窗口法相融合的算法,即D^(*)DWA。首先,对环境地图进行栅格化建模,利用层次聚类法根据障碍物的坐标位置对地图进行区域划分;然后,建立区域障碍物复杂度量化指标向量对D^(*)算法中的代价函数进行优化,获取全局最优路径的基本信息;最后,根据全局最优路径中关键节点信息设计动态窗口法的评价函数,快速规划出全局最优光滑路径。实验将所提出的D^(*)DWA与其他路径规划算法进行了仿真对比。实验结果表明,该算法提高了路径规划的效率,增加了路径的平滑度。 展开更多
关键词 水面无人艇 路径规划 层次聚类法 改进d^(*)算法 动态窗口法
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Indoor space layout research based on redirection algorithm
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作者 Qizhao WANG 《虚拟现实与智能硬件(中英文)》 2025年第6期618-638,共21页
Background Advancements in computer science and knowledge have made the incorporation of control theory,graphics processing,and mathematical models increasingly important for urban design planning.However,challenges r... Background Advancements in computer science and knowledge have made the incorporation of control theory,graphics processing,and mathematical models increasingly important for urban design planning.However,challenges remain in aligning virtual reality(VR)environments with real-world spatial and preparation requirements,particularly in indoor urban spaces.Methods This study investigates the application of VR technology to urban design,focusing on the growth and assessment of the redirection of the space-tree sorter algorithm(STSA).It outlines various assessment indicators,organization of the VR-based system architecture,and construction of 3D urban models and databases.This research also examined methods for the interactive adjustment of indoor space layout plans within a VR environment.Results This research study involved developing and demonstrating the creation and simulation of urban indoor spaces and cityscapes in VR and implementing an experimental setup to test layout modifications and system interactivity.The results indicated enhanced alignment between the virtual and physical spatial configurations.The analysis highlights the strengths and limitations of current VR systems for urban design and identifies key areas for optimization and refinement.Conclusion High congruence between virtual simulations and real-world urban spaces is necessary for effective VR-driven urban planning.This study contributes to a clearer understanding of how 3D modeling,interactive layout design,and reproduction technology can be efficiently employed to support urban increase initiatives. 展开更多
关键词 Virtual reality(VR) Indoor space layout 3d visualization Space-Trek Sorter algorithm Redirection algorithm
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Non-Neural 3D Nasal Reconstruction:A Sparse Landmark Algorithmic Approach for Medical Applications
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作者 Nguyen Khac Toan Ho Nguyen Anh Tuan Nguyen Truong Thinh 《Computer Modeling in Engineering & Sciences》 2025年第5期1273-1295,共23页
This paper presents a novel method for reconstructing a highly accurate 3D nose model of the human from 2D images and pre-marked landmarks based on algorithmic methods.The study focuses on the reconstruction of a 3D n... This paper presents a novel method for reconstructing a highly accurate 3D nose model of the human from 2D images and pre-marked landmarks based on algorithmic methods.The study focuses on the reconstruction of a 3D nose model tailored for applications in healthcare and cosmetic surgery.The approach leverages advanced image processing techniques,3D Morphable Models(3DMM),and deformation techniques to overcome the limita-tions of deep learning models,particularly addressing the interpretability issues commonly encountered in medical applications.The proposed method estimates the 3D coordinates of landmark points using a 3D structure estimation algorithm.Sub-landmarks are extracted through image processing techniques and interpolation.The initial surface is generated using a 3DMM,though its accuracy remains limited.To enhance precision,deformation techniques are applied,utilizing the coordinates of 76 identified landmarks and sub-landmarks.The resulting 3D nose model is constructed based on algorithmic methods and pre-marked landmarks.Evaluation of the 3D model is conducted by comparing landmark distances and shape similarity with expert-determined ground truth on 30 Vietnamese volunteers aged 18 to 47,all of whom were either preparing for or required nasal surgery.Experimental results demonstrate a strong agreement between the reconstructed 3D model and the ground truth.The method achieved a mean landmark distance error of 0.631 mm and a shape error of 1.738 mm,demonstrating its potential for medical applications. 展开更多
关键词 Nose reconstruction 3d reconstruction medical applications algorithmic reconstruction enhanced 3d model
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Hybrid Framework for Structural Analysis: Integrating Topology Optimization, Adjacent Element Temperature-Driven Pre-Stress, and Greedy Algorithms
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作者 Ibrahim T.Teke Ahmet H.Ertas 《Computers, Materials & Continua》 2025年第7期243-264,共22页
This study presents a novel hybrid topology optimization and mold design framework that integrates process fitting,runner system optimization,and structural analysis to significantly enhance the performance of injecti... This study presents a novel hybrid topology optimization and mold design framework that integrates process fitting,runner system optimization,and structural analysis to significantly enhance the performance of injection-molded parts.At its core,the framework employs a greedy algorithm that generates runner systems based on adjacency and shortest path principles,leading to improvements in both mechanical strength and material efficiency.The design optimization is validated through a series of rigorous experimental tests,including three-point bending and torsion tests performed on key-socket frames,ensuring that the optimized designs meet practical performance requirements.A critical innovation of the framework is the development of the Adjacent Element Temperature-Driven Prestress Algorithm(AETDPA),which refines the prediction of mechanical failure and strength fitting.This algorithm has been shown to deliver mesh-independent accuracy,thereby enhancing the reliability of simulation results across various design iterations.The framework’s adaptability is further demonstrated by its ability to adjust optimization methods based on the unique geometry of each part,thus accelerating the overall design process while ensuring struc-tural integrity.In addition to its immediate applications in injection molding,the study explores the potential extension of this framework to metal additive manufacturing,opening new avenues for its use in advanced manufacturing technologies.Numerical simulations,including finite element analysis,support the experimental findings and confirm that the optimized designs provide a balanced combination of strength,durability,and efficiency.Furthermore,the integration challenges with existing injection molding practices are addressed,underscoring the framework’s scalability and industrial relevance.Overall,this hybrid topology optimization framework offers a computationally efficient and robust solution for advanced manufacturing applications,promising significant improvements in design efficiency,cost-effectiveness,and product performance.Future work will focus on further enhancing algorithm robustness and exploring additional applications across diverse manufacturing processes. 展开更多
关键词 Plastic injection molding 3d printing three-point bending tensile test adjacent element temperature-driven pre-stress algorithm d-S-ER S-d-S-ER thermal expansion greedy algorithm
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3D numerical manifold method for crack propagation in rock materials using a local tracking algorithm
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作者 Boyi Su Tao Xu +3 位作者 Genhua Shi Michael J.Heap Xianyang Yu Guanglei Zhou 《Journal of Rock Mechanics and Geotechnical Engineering》 2025年第6期3449-3463,共15页
The modeling of crack growth in three-dimensional(3D)space poses significant challenges in rock mechanics due to the complex numerical computation involved in simulating crack propagation and interaction in rock mater... The modeling of crack growth in three-dimensional(3D)space poses significant challenges in rock mechanics due to the complex numerical computation involved in simulating crack propagation and interaction in rock materials.In this study,we present a novel approach that introduces a 3D numerical manifold method(3D-NMM)with a geometric kernel to enhance computational efficiency.Specifically,the maximum tensile stress criterion is adopted as a crack growth criterion to achieve strong discontinuous crack growth,and a local crack tracking algorithm and an angle correction technique are incorporated to address minor limitations of the algorithm in a 3D model.The implementation of the program is carried out in Python,using object-oriented programming in two independent modules:a calculation module and a crack module.Furthermore,we propose feasible improvements to enhance the performance of the algorithm.Finally,we demonstrate the feasibility and effectiveness of the enhanced algorithm in the 3D-NMM using four numerical examples.This study establishes the potential of the 3DNMM,combined with the local tracking algorithm,for accurately modeling 3D crack propagation in brittle rock materials. 展开更多
关键词 3d numerical manifold method(3d NMM) Crack propagation Local tracking algorithm Brittle materials
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Rock discontinuity extraction from 3D point clouds using pointwise clustering algorithm
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作者 Xiaoyu Yi Wenxuan Wu +2 位作者 Wenkai Feng Yongjian Zhou Jiachen Zhao 《Journal of Rock Mechanics and Geotechnical Engineering》 2025年第7期4429-4444,共16页
Recognizing discontinuities within rock masses is a critical aspect of rock engineering.The development of remote sensing technologies has significantly enhanced the quality and quantity of the point clouds collected ... Recognizing discontinuities within rock masses is a critical aspect of rock engineering.The development of remote sensing technologies has significantly enhanced the quality and quantity of the point clouds collected from rock outcrops.In response,we propose a workflow that balances accuracy and efficiency to extract discontinuities from massive point clouds.The proposed method employs voxel filtering to downsample point clouds,constructs a point cloud topology using K-d trees,utilizes principal component analysis to calculate the point cloud normals,and employs the pointwise clustering(PWC)algorithm to extract discontinuities from rock outcrop point clouds.This method provides information on the location and orientation(dip direction and dip angle)of the discontinuities,and the modified whale optimization algorithm(MWOA)is utilized to identify major discontinuity sets and their average orientations.Performance evaluations based on three real cases demonstrate that the proposed method significantly reduces computational time costs without sacrificing accuracy.In particular,the method yields more reasonable extraction results for discontinuities with certain undulations.The presented approach offers a novel tool for efficiently extracting discontinuities from large-scale point clouds. 展开更多
关键词 Rock mass discontinuity 3d point clouds Pointwise clustering(PWC)algorithm Modified whale optimization algorithm(MWOA)
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A novel heuristic pathfinding algorithm for 3D security modeling and vulnerability assessment
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作者 Jun Yang Yue-Ming Hong +2 位作者 Yu-Ming Lv Hao-Ming Ma Wen-Lin Wang 《Nuclear Science and Techniques》 2025年第5期152-166,共15页
Vulnerability assessment is a systematic process to identify security gaps in the design and evaluation of physical protection systems.Adversarial path planning is a widely used method for identifying potential vulner... Vulnerability assessment is a systematic process to identify security gaps in the design and evaluation of physical protection systems.Adversarial path planning is a widely used method for identifying potential vulnerabilities and threats to the security and resilience of critical infrastructures.However,achieving efficient path optimization in complex large-scale three-dimensional(3D)scenes remains a significant challenge for vulnerability assessment.This paper introduces a novel A^(*)-algorithmic framework for 3D security modeling and vulnerability assessment.Within this framework,the 3D facility models were first developed in 3ds Max and then incorporated into Unity for A^(*)heuristic pathfinding.The A^(*)-heuristic pathfinding algorithm was implemented with a geometric probability model to refine the detection and distance fields and achieve a rational approximation of the cost to reach the goal.An admissible heuristic is ensured by incorporating the minimum probability of detection(P_(D)^(min))and diagonal distance to estimate the heuristic function.The 3D A^(*)heuristic search was demonstrated using a hypothetical laboratory facility,where a comparison was also carried out between the A^(*)and Dijkstra algorithms for optimal path identification.Comparative results indicate that the proposed A^(*)-heuristic algorithm effectively identifies the most vulnerable adversarial pathfinding with high efficiency.Finally,the paper discusses hidden phenomena and open issues in efficient 3D pathfinding for security applications. 展开更多
关键词 Physical protection system 3d modeling and simulation Vulnerability assessment A^(*)Heuristic Pathfinding dijkstra algorithm
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Advanced 3D Wind Farm Layout Optimization Framework via Power-Law Perturbation-Based Genetic Algorithm
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作者 Jiaru Yang Yaotong Song +3 位作者 Jun Tang Weiping Ding Zhenyu Lei Shangce Gao 《IEEE/CAA Journal of Automatica Sinica》 2025年第11期2314-2328,共15页
The modeling and optimization of wind farm layouts can effectively reduce the wake effect between turbine units,thereby enhancing the expected output power and avoiding negative influence.Traditional wind farm optimiz... The modeling and optimization of wind farm layouts can effectively reduce the wake effect between turbine units,thereby enhancing the expected output power and avoiding negative influence.Traditional wind farm optimization often uses idealized wake models,neglecting the influence of wind shear at different elevations,which leads to a lack of precision in estimating wake effects and fails to meet the accuracy and reliability requirements of practical engineering.To address this,we have constructed a three-dimensional 3D wind farm optimization model that incorporates elevation,utilizing a 3D wake model to better reflect real-world conditions.We aim to assess the optimization state of the algorithm and provide strong incentives at the right moments to ensure continuous evolution of the population.To this end,we propose an evolutionary adaptation degreeguided genetic algorithm based on power-law perturbation(PPGA)to adapt multidimensional conditions.We select the offshore wind power project in Nantong,Jiangsu,China,as a study example and compare PPGA with other well-performing algorithms under this practical project.Based on the actual wind condition data,the experimental results demonstrate that PPGA can effectively tackle this complex problem and achieve the best power efficiency. 展开更多
关键词 3d wake model China’s southeastern coast metaheuristic offshore wind farm power-law perturbation-based genetic algorithm(PPGA)
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Flexible Monolithic 3D-Integrated Self-Powered Tactile Sensing Array Based on Holey MXene Paste
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作者 Mengjie Wang Chen Chen +9 位作者 Yuhang Zhang Yanan Ma Li Xu Dan‑Dan Wu Bowen Gao Aoyun Song Li Wen Yongfa Cheng Siliang Wang Yang Yue 《Nano-Micro Letters》 2026年第2期772-785,共14页
Flexible electronics face critical challenges in achieving monolithic three-dimensional(3D)integration,including material compatibility,structural stability,and scalable fabrication methods.Inspired by the tactile sen... Flexible electronics face critical challenges in achieving monolithic three-dimensional(3D)integration,including material compatibility,structural stability,and scalable fabrication methods.Inspired by the tactile sensing mechanism of the human skin,we have developed a flexible monolithic 3D-integrated tactile sensing system based on a holey MXene paste,where each vertical one-body unit simultaneously functions as a microsupercapacitor and pressure sensor.The in-plane mesopores of MXene significantly improve ion accessibility,mitigate the self-stacking of nanosheets,and allow the holey MXene to multifunctionally act as a sensing material,an active electrode,and a conductive interconnect,thus drastically reducing the interface mismatch and enhancing the mechanical robustness.Furthermore,we fabricate a large-scale device using a blade-coating and stamping method,which demonstrates excellent mechanical flexibility,low-power consumption,rapid response,and stable long-term operation.As a proof-of-concept application,we integrate our sensing array into a smart access control system,leveraging deep learning to accurately identify users based on their unique pressing behaviors.This study provides a promising approach for designing highly integrated,intelligent,and flexible electronic systems for advanced human-computer interactions and personalized electronics. 展开更多
关键词 Holey MXene Microsupercapacitor Tactile sensor Monolithic 3d integration deep learning algorithm
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基于改进D^(*)算法的机器人室内路径规划
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作者 叶嘉琪 牛磊 《传感器与微系统》 北大核心 2026年第1期138-142,共5页
针对D^(*)算法在复杂建筑环境中路径规划效率低、易出现斜穿障碍物的问题,提出一种改进的D^(*)路径规划算法。首先,利用Delaunay三角剖分与节点优化生成关键节点无向图,替代传统网格地图,提高搜索效率;其次,引入连接所有出口的虚拟节点... 针对D^(*)算法在复杂建筑环境中路径规划效率低、易出现斜穿障碍物的问题,提出一种改进的D^(*)路径规划算法。首先,利用Delaunay三角剖分与节点优化生成关键节点无向图,替代传统网格地图,提高搜索效率;其次,引入连接所有出口的虚拟节点优化搜索策略,进一步提升执行效率;最后,通过建立障碍物及研究区缓冲区提高路径规划精度,有效避免路径穿越障碍物。通过虚拟环境及斯坦福教学楼数据验证,实验结果显示,优化后算法耗时降低77.56%,斜穿障碍物情况明显减少,尤其在区域较大、出口较多的环境下,算法搜索效率和路径准确性均显著提升。 展开更多
关键词 d^(*)算法 dELAUNAY三角剖分 节点优化体系 虚拟节点 缓冲区
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基于DREAM算法的含水层渗透系数空间变异特征识别 被引量:4
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作者 骆乾坤 吴剑锋 +2 位作者 杨运 吴吉春 马淑芬 《南京大学学报(自然科学版)》 CAS CSCD 北大核心 2016年第3期448-455,共8页
采用差分进化自适应Metropolis(DREAM)算法对描述含水层渗透系数空间变异特征的参数进行识别.利用直接傅里叶变换方法产生一组空间结构参数下的若干个渗透系数场实现,借鉴噪声遗传算法(NGA)思想,计算该组空间结构参数对应的贝叶斯后验... 采用差分进化自适应Metropolis(DREAM)算法对描述含水层渗透系数空间变异特征的参数进行识别.利用直接傅里叶变换方法产生一组空间结构参数下的若干个渗透系数场实现,借鉴噪声遗传算法(NGA)思想,计算该组空间结构参数对应的贝叶斯后验概率值,提高DREAM算法求解的效率.算例求解结果表明,DREAM算法能够有效获得含水层渗透系数空间结构参数的后验分布,并可得到对应的一系列渗透系数场,可为含水层参数空间变异性研究提供新的思路. 展开更多
关键词 渗透系数 空间变异特征 噪声遗传算法 dream
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基于DREAM算法的双超模型参数不确定性研究 被引量:2
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作者 曹玉涛 郭向红 杨玫 《水电能源科学》 北大核心 2017年第9期13-16,共4页
鉴于半干旱半湿润地区的流域水文模拟及预报一直是水文模型领域研究的重点和难点问题,基于山西省张峰水库1988~2007年间18场洪水资料,前12场用于率定模型参数,后6场用于检验模型,采用DREAM方法分析其双超模型参数的不确定性,并在此基础... 鉴于半干旱半湿润地区的流域水文模拟及预报一直是水文模型领域研究的重点和难点问题,基于山西省张峰水库1988~2007年间18场洪水资料,前12场用于率定模型参数,后6场用于检验模型,采用DREAM方法分析其双超模型参数的不确定性,并在此基础上分析由参数不确定性导致的模型输出的不确定性。结果表明,10个参数的后验分布峰值不明显,说明参数的不确定性较大;4个参数的后验分布为具有明显峰值的不规则分布,7个参数的后验分布呈现偏态分布,其峰值也比较明显,说明该参数的不确定性较小。研究结果可为双超模型不确定性分析提供一定的理论基础。 展开更多
关键词 水文模型 dream算法 不确定性 双超模型 张峰水库
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DREAM在中国农业研发效果经济评价上的应用——以大豆新品种“中豆35”研发为例
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作者 彭卓 游良志 +1 位作者 周新安 李先德 《中国农学通报》 CSCD 2008年第6期512-518,共7页
介绍了评价农业研发经济效果的动态决策支持系统-DREAM,对DREAM的核心经济理论"局部均衡模型"和"新技术的动态采用率方法"进行了重点分析。同时以评价大豆新品种中豆35的研发效果为例,阐述了DREAM系统在中国农业研... 介绍了评价农业研发经济效果的动态决策支持系统-DREAM,对DREAM的核心经济理论"局部均衡模型"和"新技术的动态采用率方法"进行了重点分析。同时以评价大豆新品种中豆35的研发效果为例,阐述了DREAM系统在中国农业研发投资效果评价上的具体应用。进而讨论了DREAM在国内的应用问题。 展开更多
关键词 农业研发 决策 支持系统 dream 大豆
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融合改进D^(*)与RRT算法的单AGV路径规划算法 被引量:2
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作者 赵学健 叶昊 +2 位作者 江宇航 袁凯 孙知信 《小型微型计算机系统》 北大核心 2025年第8期1847-1860,共14页
本研究针对单自动导引车(AGV)的路径规划问题,深入剖析了现有多阶段路径规划方法的局限性,并提出了一种融合改进D^(*)与快速探索随机树(RRT)算法的路径规划算法.该算法结合了改进D^(*)算法的高效性与RRT算法的灵活性,通过动态避障策略... 本研究针对单自动导引车(AGV)的路径规划问题,深入剖析了现有多阶段路径规划方法的局限性,并提出了一种融合改进D^(*)与快速探索随机树(RRT)算法的路径规划算法.该算法结合了改进D^(*)算法的高效性与RRT算法的灵活性,通过动态避障策略和目标约束优化,显著提升了路径规划性能.引入自适应视野、步长、威胁因子及目标点采样率等参数,以适应多变环境需求.利用Rich_Moore元胞自动机方法扩展可行区域并确定最短路径,并通过高阶贝塞尔曲线平滑路径,减少转向,提高路径平滑度.实验结果证明,该算法在精度和效率上均优于传统方法,对提升AGV作业实时性和准确性,推动自动化物流系统发展具有显著意义. 展开更多
关键词 AGV 随机树算法 d^(*)算法 路径规划 智能物流
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The parallel 3D magnetotelluric forward modeling algorithm 被引量:28
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作者 Tan Handong Tong Tuo Lin Changhong 《Applied Geophysics》 SCIE CSCD 2006年第4期197-202,共6页
The workload of the 3D magnetotelluric forward modeling algorithm is so large that the traditional serial algorithm costs an extremely large compute time. However, the 3D forward modeling algorithm can process the dat... The workload of the 3D magnetotelluric forward modeling algorithm is so large that the traditional serial algorithm costs an extremely large compute time. However, the 3D forward modeling algorithm can process the data in the frequency domain, which is very suitable for parallel computation. With the advantage of MPI and based on an analysis of the flow of the 3D magnetotelluric serial forward algorithm, we suggest the idea of parallel computation and apply it. Three theoretical models are tested and the execution efficiency is compared in different situations. The results indicate that the parallel 3D forward modeling computation is correct and the efficiency is greatly improved. This method is suitable for large size geophysical computations. 展开更多
关键词 Magnetotelluric 3d forward modeling MPI parallel programming design 3d staggered-grid finite difference method parallel algorithm.
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超高强度A柱加强板热冲压质量自适应MOEA/D优化
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作者 裴宝浩 肖振 +1 位作者 周娟 于蓬 《机械设计与制造》 北大核心 2025年第9期255-259,265,共6页
为了提高超高强度A柱加强板热冲压成形质量,提出了基于自适应MOEA/D算法的冲压参数多目标优化方法。使用数值模拟法分析了超高强度A柱加强板热冲压质量问题,并针对最大减薄率和最大增厚率建立了多目标优化模型。在仿真数据基础上,使用Kr... 为了提高超高强度A柱加强板热冲压成形质量,提出了基于自适应MOEA/D算法的冲压参数多目标优化方法。使用数值模拟法分析了超高强度A柱加强板热冲压质量问题,并针对最大减薄率和最大增厚率建立了多目标优化模型。在仿真数据基础上,使用Kriging模型拟合了质量参数与工艺参数间模型。将优化变量编码为基因,从而将冲压优化问题转化为算法寻优问题。为了提高MOEA/D算法的优化能力,在算法中引入了自适应差异性惩罚方案,进而提出了基于自适应MOEA/D算法的优化方法。经生产优化,优化后产品的金相组织实现了预期变化,最大减薄率均值由17.1%减小为14.5%,最大增厚率均值由18.1%减小为15.7%,实验结果证明了自适应MOEA/D优化算法的优越性。 展开更多
关键词 超高强度 A柱加强板 冲压优化 MOEA/d算法 自适应差异性惩罚方案
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Identification of Convective and Stratiform Clouds Based on the Improved DBSCAN Clustering Algorithm 被引量:6
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作者 Yuanyuan ZUO Zhiqun HU +3 位作者 Shujie YUAN Jiafeng ZHENG Xiaoyan YIN Boyong LI 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2022年第12期2203-2212,共10页
A convective and stratiform cloud classification method for weather radar is proposed based on the density-based spatial clustering of applications with noise(DBSCAN)algorithm.To identify convective and stratiform clo... A convective and stratiform cloud classification method for weather radar is proposed based on the density-based spatial clustering of applications with noise(DBSCAN)algorithm.To identify convective and stratiform clouds in different developmental phases,two-dimensional(2D)and three-dimensional(3D)models are proposed by applying reflectivity factors at 0.5°and at 0.5°,1.5°,and 2.4°elevation angles,respectively.According to the thresholds of the algorithm,which include echo intensity,the echo top height of 35 dBZ(ET),density threshold,andεneighborhood,cloud clusters can be marked into four types:deep-convective cloud(DCC),shallow-convective cloud(SCC),hybrid convective-stratiform cloud(HCS),and stratiform cloud(SFC)types.Each cloud cluster type is further identified as a core area and boundary area,which can provide more abundant cloud structure information.The algorithm is verified using the volume scan data observed with new-generation S-band weather radars in Nanjing,Xuzhou,and Qingdao.The results show that cloud clusters can be intuitively identified as core and boundary points,which change in area continuously during the process of convective evolution,by the improved DBSCAN algorithm.Therefore,the occurrence and disappearance of convective weather can be estimated in advance by observing the changes of the classification.Because density thresholds are different and multiple elevations are utilized in the 3D model,the identified echo types and areas are dissimilar between the 2D and 3D models.The 3D model identifies larger convective and stratiform clouds than the 2D model.However,the developing convective clouds of small areas at lower heights cannot be identified with the 3D model because they are covered by thick stratiform clouds.In addition,the 3D model can avoid the influence of the melting layer and better suggest convective clouds in the developmental stage. 展开更多
关键词 improved dBSCAN clustering algorithm cloud identification and classification 2d model 3d model weather radar
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Efficient algorithm for 3D bimodulus structures 被引量:6
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作者 Qinxue Pan Jianlong Zheng Pihua Wen 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2020年第1期143-159,共17页
The bimodulus material is a classical model to describe the elastic behavior of materials with tension-compression asymmetry.Due to the inherently nonlinear properties of bimodular materials,traditional iteration meth... The bimodulus material is a classical model to describe the elastic behavior of materials with tension-compression asymmetry.Due to the inherently nonlinear properties of bimodular materials,traditional iteration methods suffer from low convergence efficiency and poor adaptability for large-scale structures in engineering.In this paper,a novel 3D algorithm is established by complementing the three shear moduli of the constitutive equation in principal stress coordinates.In contrast to the existing 3D shear modulus constructed based on experience,in this paper the shear modulus is derived theoretically through a limit process.Then,a theoretically self-consistent complemented algorithm is established and implemented in ABAQUS via UMAT;its good stability and convergence efficiency are verified by using benchmark examples.Numerical analysis shows that the calculation error for bimodulus structures using the traditional linear elastic theory is large,which is not in line with reality. 展开更多
关键词 Elastic theory Bimodulus material 3d complemented algorithm Finite element method Generalized elastic law General 3d shear modulus
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