首页 > 最新文献

Mathematical Problems in Engineering最新文献

英文 中文
Seismic Reliability Analysis of an Excavation Slope Based on Direct Probability Integral Method 基于直接概率积分法的开挖边坡地震可靠性分析
4区 工程技术 Q1 Mathematics Pub Date : 2024-03-30 DOI: 10.1155/2024/7012424
Junguo Han, Yuanmin Yang, Muzi Du, Rui Pang
China, situated in the circum-Pacific seismic belt, experiences frequent seismic activity and faces diverse geological conditions, making structural stability of paramount importance, especially under seismic conditions. The majority of current earthquake generation methods do not consider the nonstationary nature of earthquakes. This paper introduces a spectral representation-random function model for generating nonstationary earthquakes, effectively simulating stochastic seismic ground motion. Furthermore, traditional slope stability analysis methods are deterministic and incapable of providing probabilistic assessments of slope instability. Therefore, this paper proposes a unified framework for static and dynamic structural reliability analysis based on the direct probability integration method, quantifying the impact of stochastic seismic ground motion on the dynamic reliability of slope stability. Finally, the proposed methods are applied to an excavation slope in Nanjing, using sliding displacement and safety factors as evaluation criteria to study the reliability of the slope under the influence of stochastic seismic events.
中国地处环太平洋地震带,地震活动频繁,地质条件多样,结构稳定性至关重要,尤其是在地震条件下。目前大多数地震发生方法都没有考虑地震的非稳态性。本文介绍了一种用于生成非稳态地震的频谱表示-随机函数模型,可有效模拟随机地震地面运动。此外,传统的边坡稳定性分析方法是确定性的,无法对边坡不稳定性进行概率评估。因此,本文基于直接概率积分法,提出了静态和动态结构可靠性分析的统一框架,量化了随机地震地面运动对边坡稳定性动态可靠性的影响。最后,将提出的方法应用于南京某开挖边坡,以滑动位移和安全系数为评价标准,研究随机地震事件影响下边坡的可靠性。
{"title":"Seismic Reliability Analysis of an Excavation Slope Based on Direct Probability Integral Method","authors":"Junguo Han, Yuanmin Yang, Muzi Du, Rui Pang","doi":"10.1155/2024/7012424","DOIUrl":"https://doi.org/10.1155/2024/7012424","url":null,"abstract":"China, situated in the circum-Pacific seismic belt, experiences frequent seismic activity and faces diverse geological conditions, making structural stability of paramount importance, especially under seismic conditions. The majority of current earthquake generation methods do not consider the nonstationary nature of earthquakes. This paper introduces a spectral representation-random function model for generating nonstationary earthquakes, effectively simulating stochastic seismic ground motion. Furthermore, traditional slope stability analysis methods are deterministic and incapable of providing probabilistic assessments of slope instability. Therefore, this paper proposes a unified framework for static and dynamic structural reliability analysis based on the direct probability integration method, quantifying the impact of stochastic seismic ground motion on the dynamic reliability of slope stability. Finally, the proposed methods are applied to an excavation slope in Nanjing, using sliding displacement and safety factors as evaluation criteria to study the reliability of the slope under the influence of stochastic seismic events.","PeriodicalId":18319,"journal":{"name":"Mathematical Problems in Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140363593","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Dynamics Analysis of Separation Mechanism for Rotating Projectiles at the End of Trajectory 弹道末端旋转弹丸分离机制的动力学分析
4区 工程技术 Q1 Mathematics Pub Date : 2024-03-30 DOI: 10.1155/2024/3713958
Lei Zhao, Shuai Yue, Zhong-hua Du, Teng-fei Ma, Xing-xiao Li
Spin separation technology is a key technology for realizing the detection function at the end of the rotational trajectory. It is also a necessary condition for the fuse control system to adjust its control strategy according to actual combat needs. To explore a new type of proximity fuse detection method, this article first designs a detection separation mechanism for the end of the trajectory. An interior ballistic model of the separation mechanism was then established through closed bomb tests and equivalent interior ballistic equations, and the aerodynamic parameters of the front-stage separation body at the moment of separation were obtained based on computational fluid dynamics numerical simulation. Finally, a separation dynamics model of the separation mechanism was established to analyze the motion state after the separation action of the front-stage separation body. The results demonstrate the feasibility of the proposed separation mechanism. The discrepancy between the simulation and experiment of the velocity increment for the front-stage separation body is about 1.07%. The attack angle for the front-stage separation body is below 2°, and the period with a displacement between two stage bodies greater than 3 m is around 0.365 s. This research can provide new ideas and theoretical references for the design of a similar fuse detection separation mechanism.
自旋分离技术是实现旋转轨迹末端探测功能的关键技术。它也是引信控制系统根据实战需要调整控制策略的必要条件。为探索一种新型近炸引信探测方法,本文首先设计了一种弹道末端探测分离机构。然后,通过闭弹试验和等效内弹道方程建立了分离机构的内弹道模型,并基于计算流体力学数值仿真获得了前级分离体在分离瞬间的气动参数。最后,建立了分离机制的分离动力学模型,分析了前级分离体分离动作后的运动状态。结果证明了所提出的分离机制的可行性。前级分离体的速度增量的模拟与实验差异约为 1.07%。前级分离体的攻击角低于 2°,两级分离体之间位移大于 3 米的周期约为 0.365 秒。这项研究可为设计类似的引信探测分离机构提供新的思路和理论参考。
{"title":"Dynamics Analysis of Separation Mechanism for Rotating Projectiles at the End of Trajectory","authors":"Lei Zhao, Shuai Yue, Zhong-hua Du, Teng-fei Ma, Xing-xiao Li","doi":"10.1155/2024/3713958","DOIUrl":"https://doi.org/10.1155/2024/3713958","url":null,"abstract":"Spin separation technology is a key technology for realizing the detection function at the end of the rotational trajectory. It is also a necessary condition for the fuse control system to adjust its control strategy according to actual combat needs. To explore a new type of proximity fuse detection method, this article first designs a detection separation mechanism for the end of the trajectory. An interior ballistic model of the separation mechanism was then established through closed bomb tests and equivalent interior ballistic equations, and the aerodynamic parameters of the front-stage separation body at the moment of separation were obtained based on computational fluid dynamics numerical simulation. Finally, a separation dynamics model of the separation mechanism was established to analyze the motion state after the separation action of the front-stage separation body. The results demonstrate the feasibility of the proposed separation mechanism. The discrepancy between the simulation and experiment of the velocity increment for the front-stage separation body is about 1.07%. The attack angle for the front-stage separation body is below 2°, and the period with a displacement between two stage bodies greater than 3 m is around 0.365 s. This research can provide new ideas and theoretical references for the design of a similar fuse detection separation mechanism.","PeriodicalId":18319,"journal":{"name":"Mathematical Problems in Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140364701","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Analysis and Simulation of Lateral Collision Risk under Paired Approach 成对方法下的侧面碰撞风险分析与模拟
4区 工程技术 Q1 Mathematics Pub Date : 2024-03-29 DOI: 10.1155/2024/7021298
Fei Lu, Jian Zhang, Haonan Chen, Zichen Chen
The paired approach can improve the efficiency of closely spaced parallel runways. Calculating the probability and frequency of horizontal overlap is an indispensable step when evaluating the horizontal collision risk of the paired approach. As the generation of horizontal overlap probability is closely related to horizontal position error, we propose a calculation method of horizontal overlap probability based on position error from the perspective of pilot operation. First, according to the principle of flight mechanics, the attitude adjustment model is established for the horizontal direction of the approach process, and the pilot’s operation model for various position errors is based on the concept of the stochastic process. This attitude adjustment model can replicates the process of the pilot operating the steering column to change the aircraft’s attitude. When combined with the pilot’s operation model, it is possible to simulate the position errors generated during the approach process. Building on this, the horizontal overlapping conditions of two aircraft are analyzed to simulate the horizontal overlap process in the paired approach. The duration and instances of overlap counted and the ratio between these results and the total running time give the overlap probability and frequency. Multiple simulations in MATLAB reveal that higher pilot operating accuracy shortens the time for the aircraft to align with the course, whereas lower accuracy leads to unstable horizontal position errors. Furthermore, the horizontal overlap in paired approaches primarily occurs at the beginning of the procedure, and enhancing the pilot’s operating accuracy does not significantly affect the probability and frequency of horizontal overlap.
成对进近可以提高间距较近的平行跑道的效率。在评估成对进近的水平碰撞风险时,计算水平重叠概率和频率是不可或缺的步骤。由于水平重叠概率的产生与水平位置误差密切相关,我们从飞行员操作的角度出发,提出了基于位置误差的水平重叠概率计算方法。首先,根据飞行力学原理,建立进近过程中水平方向的姿态调整模型,并根据随机过程的概念建立飞行员对各种位置误差的操作模型。该姿态调整模型可以复制飞行员操作转向柱改变飞机姿态的过程。结合飞行员的操作模型,就可以模拟进近过程中产生的位置误差。在此基础上,分析两架飞机的水平重叠条件,模拟配对进近中的水平重叠过程。通过计算重叠的持续时间和次数,以及这些结果与总运行时间的比率,可以得出重叠概率和频率。在 MATLAB 中进行的多次模拟显示,飞行员操作精度越高,飞机对准航向的时间越短,而精度越低,水平位置误差越不稳定。此外,配对进近中的水平重叠主要发生在程序开始时,提高飞行员的操作精度对水平重叠的概率和频率影响不大。
{"title":"Analysis and Simulation of Lateral Collision Risk under Paired Approach","authors":"Fei Lu, Jian Zhang, Haonan Chen, Zichen Chen","doi":"10.1155/2024/7021298","DOIUrl":"https://doi.org/10.1155/2024/7021298","url":null,"abstract":"The paired approach can improve the efficiency of closely spaced parallel runways. Calculating the probability and frequency of horizontal overlap is an indispensable step when evaluating the horizontal collision risk of the paired approach. As the generation of horizontal overlap probability is closely related to horizontal position error, we propose a calculation method of horizontal overlap probability based on position error from the perspective of pilot operation. First, according to the principle of flight mechanics, the attitude adjustment model is established for the horizontal direction of the approach process, and the pilot’s operation model for various position errors is based on the concept of the stochastic process. This attitude adjustment model can replicates the process of the pilot operating the steering column to change the aircraft’s attitude. When combined with the pilot’s operation model, it is possible to simulate the position errors generated during the approach process. Building on this, the horizontal overlapping conditions of two aircraft are analyzed to simulate the horizontal overlap process in the paired approach. The duration and instances of overlap counted and the ratio between these results and the total running time give the overlap probability and frequency. Multiple simulations in MATLAB reveal that higher pilot operating accuracy shortens the time for the aircraft to align with the course, whereas lower accuracy leads to unstable horizontal position errors. Furthermore, the horizontal overlap in paired approaches primarily occurs at the beginning of the procedure, and enhancing the pilot’s operating accuracy does not significantly affect the probability and frequency of horizontal overlap.","PeriodicalId":18319,"journal":{"name":"Mathematical Problems in Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140324756","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Numerical Simulation and Sensitivity Analysis Using RSM on Natural Convective Heat Exchanger Containing Hybrid Nanofluids 利用 RSM 对含有混合纳米流体的自然对流换热器进行数值模拟和敏感性分析
4区 工程技术 Q1 Mathematics Pub Date : 2024-03-22 DOI: 10.1155/2024/2834556
Saiful Islam, Md. Noor-A-Alam Siddiki, Md. Shahinur Islam
This work presents a numerical analysis for exploring heat transfer phenomena in an enclosed cavity using magnetohydrodynamics natural convection. Because of the numerous real-world applications of nanofluids and hybrid nanofluids in industrial and thermal engineering developments, hybrid nanofluids are used as fluid mediums in the fluid field. A hexagonal-shaped heat exchanger is taken with two circular surfaces along the middle part. The upright circular surface acts as a homogeneous heat source, while the lower circular surface functions as a heat sink. The remaining portions of the adjacent walls are thermally insulated. The copper (Cu) and titanium dioxide (TiO2) nanoparticles are suspended into water to make a hybrid nanofluid. For solving the corresponding governing equations, the weighted-residual finite element method is applied. To explain the major outcomes, isotherms, streamlines, and many others 2D and 3D contour plots are involved graphically with a physical explanation for different magnitudes of significant parameters: Rayleigh number , Hartmann number
本研究利用磁流体力学自然对流对封闭空腔中的传热现象进行了数值分析。由于纳米流体和混合纳米流体在工业和热工程发展中的大量实际应用,混合纳米流体被用作流体领域的流体介质。一个六边形热交换器的中间部分有两个圆形表面。直立的圆形表面充当均匀热源,而较低的圆形表面则充当散热器。相邻壁的其余部分为隔热材料。铜(Cu)和二氧化钛(TiO2)纳米颗粒悬浮在水中,形成混合纳米流体。为了求解相应的控制方程,采用了加权残差有限元法。为了解释主要结果,等温线、流线和许多其他二维和三维等高线图都以图形形式出现,并对不同大小的重要参数进行了物理解释:雷利数、哈特曼数和纳米粒子体积分数。这项工作的新颖之处在于将响应面方法应用于自然对流混合纳米流体模型,将二维和三维效应可视化,并研究独立参数对响应函数的敏感性。由于混合纳米流体具有出色的热性能,在 H2O 中加入 Cu 和 TiO2 纳米粒子后,传热率比基础流体提高了 35.85%。此外,更大的 Ra 值和混合纳米粒子的积累会导致混合纳米流体的热驱动。随着磁场影响的增大,则会出现相反的反应。
{"title":"Numerical Simulation and Sensitivity Analysis Using RSM on Natural Convective Heat Exchanger Containing Hybrid Nanofluids","authors":"Saiful Islam, Md. Noor-A-Alam Siddiki, Md. Shahinur Islam","doi":"10.1155/2024/2834556","DOIUrl":"https://doi.org/10.1155/2024/2834556","url":null,"abstract":"This work presents a numerical analysis for exploring heat transfer phenomena in an enclosed cavity using magnetohydrodynamics natural convection. Because of the numerous real-world applications of nanofluids and hybrid nanofluids in industrial and thermal engineering developments, hybrid nanofluids are used as fluid mediums in the fluid field. A hexagonal-shaped heat exchanger is taken with two circular surfaces along the middle part. The upright circular surface acts as a homogeneous heat source, while the lower circular surface functions as a heat sink. The remaining portions of the adjacent walls are thermally insulated. The copper (Cu) and titanium dioxide (TiO<sub>2</sub>) nanoparticles are suspended into water to make a hybrid nanofluid. For solving the corresponding governing equations, the weighted-residual finite element method is applied. To explain the major outcomes, isotherms, streamlines, and many others 2D and 3D contour plots are involved graphically with a physical explanation for different magnitudes of significant parameters: Rayleigh number <span><svg height=\"13.8595pt\" style=\"vertical-align:-2.2681pt\" version=\"1.1\" viewbox=\"-0.0498162 -11.5914 33.234 13.8595\" width=\"33.234pt\" xmlns=\"http://www.w3.org/2000/svg\" xmlns:xlink=\"http://www.w3.org/1999/xlink\"><g transform=\"matrix(.013,0,0,-0.013,0,0)\"></path></g><g transform=\"matrix(.013,0,0,-0.013,4.498,0)\"></path></g><g transform=\"matrix(.013,0,0,-0.013,10.738,0)\"></path></g><g transform=\"matrix(.0091,0,0,-0.0091,17.025,-5.741)\"></path></g><g transform=\"matrix(.013,0,0,-0.013,25.603,0)\"></path></g></svg><span></span><svg height=\"13.8595pt\" style=\"vertical-align:-2.2681pt\" version=\"1.1\" viewbox=\"36.8161838 -11.5914 25.994 13.8595\" width=\"25.994pt\" xmlns=\"http://www.w3.org/2000/svg\" xmlns:xlink=\"http://www.w3.org/1999/xlink\"><g transform=\"matrix(.013,0,0,-0.013,36.866,0)\"></path></g><g transform=\"matrix(.013,0,0,-0.013,45.017,0)\"></path></g><g transform=\"matrix(.013,0,0,-0.013,55.229,0)\"><use xlink:href=\"#g117-93\"></use></g></svg><span></span><span><svg height=\"13.8595pt\" style=\"vertical-align:-2.2681pt\" version=\"1.1\" viewbox=\"66.44218380000001 -11.5914 22.215 13.8595\" width=\"22.215pt\" xmlns=\"http://www.w3.org/2000/svg\" xmlns:xlink=\"http://www.w3.org/1999/xlink\"><g transform=\"matrix(.013,0,0,-0.013,66.492,0)\"><use xlink:href=\"#g113-50\"></use></g><g transform=\"matrix(.013,0,0,-0.013,72.732,0)\"><use xlink:href=\"#g113-49\"></use></g><g transform=\"matrix(.0091,0,0,-0.0091,79.019,-5.741)\"></path></g><g transform=\"matrix(.013,0,0,-0.013,83.965,0)\"></path></g></svg>,</span></span> Hartmann number <span><svg height=\"11.5564pt\" style=\"vertical-align:-2.26807pt\" version=\"1.1\" viewbox=\"-0.0498162 -9.28833 22.001 11.5564\" width=\"22.001pt\" xmlns=\"http://www.w3.org/2000/svg\" xmlns:xlink=\"http://www.w3.org/1999/xlink\"><g transform=\"matrix(.013,0,0,-0.013,0,0)\"><use xlink:href=\"#g113-41\"></use></g><g transform=\"matrix(.013,0,0,-0.013,4.498,0)\"><use xlink:href=\"#g113-49\"></use></g><g transform=\"matr","PeriodicalId":18319,"journal":{"name":"Mathematical Problems in Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140197627","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Improved Model Predictive Speed Control of a PMSM via Laguerre Functions 通过拉盖尔函数改进 PMSM 的模型预测速度控制
4区 工程技术 Q1 Mathematics Pub Date : 2024-03-21 DOI: 10.1155/2024/5562771
Chala Merga Abdissa
This paper proposes a model predictive speed control strategy for a surface-mounted permanent magnet synchronous motor by applying Laguerre functions. The model predictive controller (MPC) incorporates an integrator. A quadratic programming procedure is applied to solve the constrained optimization problem online. The paper also provides a solution for stability. The performance efficiency of the proposed scheme is validated by comparing the results with the performance of an optimal linear quadratic regulator, conventional state-space model predictive control, and a simple MPC algorithm with integral action. Extensive simulation results confirm the efficacy of the proposed scheme, showing that it achieves good steady-state performance while maintaining a fast dynamic response.
本文通过应用拉盖尔函数,为表面贴装式永磁同步电机提出了一种模型预测速度控制策略。模型预测控制器(MPC)包含一个积分器。应用二次编程程序在线解决约束优化问题。本文还提供了稳定性解决方案。通过与最优线性二次调节器、传统状态空间模型预测控制和带积分作用的简单 MPC 算法的性能进行比较,验证了所提方案的性能效率。大量的仿真结果证实了所提方案的有效性,表明它在保持快速动态响应的同时,还实现了良好的稳态性能。
{"title":"Improved Model Predictive Speed Control of a PMSM via Laguerre Functions","authors":"Chala Merga Abdissa","doi":"10.1155/2024/5562771","DOIUrl":"https://doi.org/10.1155/2024/5562771","url":null,"abstract":"This paper proposes a model predictive speed control strategy for a surface-mounted permanent magnet synchronous motor by applying Laguerre functions. The model predictive controller (MPC) incorporates an integrator. A quadratic programming procedure is applied to solve the constrained optimization problem online. The paper also provides a solution for stability. The performance efficiency of the proposed scheme is validated by comparing the results with the performance of an optimal linear quadratic regulator, conventional state-space model predictive control, and a simple MPC algorithm with integral action. Extensive simulation results confirm the efficacy of the proposed scheme, showing that it achieves good steady-state performance while maintaining a fast dynamic response.","PeriodicalId":18319,"journal":{"name":"Mathematical Problems in Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140197626","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Image Edge Detection by Global Thresholding Using Riemann–Liouville Fractional Integral Operator 利用黎曼-刘维尔分式积分算子进行全局阈值图像边缘检测
4区 工程技术 Q1 Mathematics Pub Date : 2024-03-19 DOI: 10.1155/2024/9266585
S. Gaur, A. M. Khan, D. L. Suthar, Avnish Bora
It is difficult to give a fractional global threshold (FGT) that works well on all images as the image contents are totally different. This paper describes an interesting use of fractional calculus in the field of digital image processing. In the proposed method, the fractional global threshold-based edge detector (FGTED) is established using the Riemann–Liouville fractional integral operator. FGTED is used to find the microedges in minimum time for any input digital images. The results demonstrate that the FGTED outperforms conventional techniques for detecting microtype edges. The image with a higher entropy was produced by the FGT value-based approach. Tables and images are used to summarize the output performance analysis of various images using structural similarity index measure, F-score (F-measure), precision and recall, signal-to-noise ratio, peak signal-to-noise ratio, and computational time. The FGTED can be used to detect very thin or microtype edges more accurately in minimum time without training or prior knowledge.
由于图像内容完全不同,很难给出一个适用于所有图像的分数全局阈值 (FGT)。本文介绍了分数微积分在数字图像处理领域的有趣应用。在所提出的方法中,使用黎曼-刘维尔分数积分算子建立了基于分数全局阈值的边缘检测器(FGTED)。对于任何输入数字图像,FGTED 都能在最短时间内找到微边缘。结果表明,FGTED 在检测微类型边缘方面优于传统技术。基于 FGT 值的方法生成的图像熵值更高。使用结构相似性指数度量、F-分数(F-度量)、精确度和召回率、信噪比、峰值信噪比和计算时间,用表格和图像总结了各种图像的输出性能分析。FGTED 可用于在最短时间内更准确地检测极薄或微小类型的边缘,而无需培训或事先了解相关知识。
{"title":"Image Edge Detection by Global Thresholding Using Riemann–Liouville Fractional Integral Operator","authors":"S. Gaur, A. M. Khan, D. L. Suthar, Avnish Bora","doi":"10.1155/2024/9266585","DOIUrl":"https://doi.org/10.1155/2024/9266585","url":null,"abstract":"It is difficult to give a fractional global threshold (FGT) that works well on all images as the image contents are totally different. This paper describes an interesting use of fractional calculus in the field of digital image processing. In the proposed method, the fractional global threshold-based edge detector (FGTED) is established using the Riemann–Liouville fractional integral operator. FGTED is used to find the microedges in minimum time for any input digital images. The results demonstrate that the FGTED outperforms conventional techniques for detecting microtype edges. The image with a higher entropy was produced by the FGT value-based approach. Tables and images are used to summarize the output performance analysis of various images using structural similarity index measure, <i>F</i>-score (<i>F</i>-measure), precision and recall, signal-to-noise ratio, peak signal-to-noise ratio, and computational time. The FGTED can be used to detect very thin or microtype edges more accurately in minimum time without training or prior knowledge.","PeriodicalId":18319,"journal":{"name":"Mathematical Problems in Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140169323","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
A Study on the Vehicle Antilock System Based on Adaptive Neural Network Sliding Mode Control 基于自适应神经网络滑模控制的车辆防抱死系统研究
4区 工程技术 Q1 Mathematics Pub Date : 2024-03-11 DOI: 10.1155/2024/3359266
Yaoping Li, Han Li
Vehicle antilock systems play a very important role in the stability and reliability during vehicle braking. Due to the complexity of the braking process, antilock braking system (ABS) usually face the problems such as nonlinearity, time-varying, and uncertain parameter modeling. Thus, aiming at the parameter model uncertainty problem of ABS, an adaptive neural network sliding mode controller (ADRBF-SMC) is designed in this paper. On this basis, establishing the quarter-vehicle model and the seven-degree-of-freedom vehicle model, and treating the difference between the two models as a kind of disturbance, carrying out vehicle braking performance simulation experiments to analyze the variation of braking performance parameters such as vehicle and wheel speeds, slip ratio, braking distance, braking torque, under the three cases of adaptive neural network sliding mode controller, traditional sliding mode controller, and no control. Simulation results show that the adaptive neural network sliding mode controller (ADRBF-SMC) proposed in this paper can play an effective control role in both vehicle dynamics models. In addition, the control method proposed in this paper has stronger anti-interference capability and higher robustness compared with the sliding mode controller (SMC).
汽车防抱死系统对汽车制动过程中的稳定性和可靠性起着非常重要的作用。由于制动过程的复杂性,防抱死制动系统(ABS)通常面临非线性、时变和参数建模不确定等问题。因此,针对防抱死制动系统的参数模型不确定性问题,本文设计了一种自适应神经网络滑模控制器(ADRBF-SMC)。在此基础上,建立四分之一车辆模型和七自由度车辆模型,并将两个模型之间的差异视为一种扰动,进行车辆制动性能仿真实验,分析在自适应神经网络滑模控制器、传统滑模控制器和无控制三种情况下,车辆和车轮速度、滑移比、制动距离、制动力矩等制动性能参数的变化情况。仿真结果表明,本文提出的自适应神经网络滑模控制器(ADRBF-SMC)在两种车辆动力学模型中都能发挥有效的控制作用。此外,与滑模控制器(SMC)相比,本文提出的控制方法具有更强的抗干扰能力和更高的鲁棒性。
{"title":"A Study on the Vehicle Antilock System Based on Adaptive Neural Network Sliding Mode Control","authors":"Yaoping Li, Han Li","doi":"10.1155/2024/3359266","DOIUrl":"https://doi.org/10.1155/2024/3359266","url":null,"abstract":"Vehicle antilock systems play a very important role in the stability and reliability during vehicle braking. Due to the complexity of the braking process, antilock braking system (ABS) usually face the problems such as nonlinearity, time-varying, and uncertain parameter modeling. Thus, aiming at the parameter model uncertainty problem of ABS, an adaptive neural network sliding mode controller (ADRBF-SMC) is designed in this paper. On this basis, establishing the quarter-vehicle model and the seven-degree-of-freedom vehicle model, and treating the difference between the two models as a kind of disturbance, carrying out vehicle braking performance simulation experiments to analyze the variation of braking performance parameters such as vehicle and wheel speeds, slip ratio, braking distance, braking torque, under the three cases of adaptive neural network sliding mode controller, traditional sliding mode controller, and no control. Simulation results show that the adaptive neural network sliding mode controller (ADRBF-SMC) proposed in this paper can play an effective control role in both vehicle dynamics models. In addition, the control method proposed in this paper has stronger anti-interference capability and higher robustness compared with the sliding mode controller (SMC).","PeriodicalId":18319,"journal":{"name":"Mathematical Problems in Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140099263","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Optimized Distance-Based Algorithm for Cloud Space—Tourist Route Recommendation for Heritage Town, Pondicherry, India 基于距离的优化算法,为印度本迪榭里遗产小镇推荐云空间-旅游路线
4区 工程技术 Q1 Mathematics Pub Date : 2024-03-07 DOI: 10.1155/2024/1029499
Lakshmi Lakshmanan, Madhumathi A, Sudhakara Pandian R, Subhashini S, Sivakumar Paraman, Velmurugan K, Gianpaolo Di Bona
Architecture, often regarded as a three-dimensional art form, relies on a multitude of abstractions during the design process. In this context, architectural elements are effectively represented through vector-based data processing techniques, offering a canvas for creative exploration. To further our understanding of spatial configurations and generate multiple design insights, mathematical structures known as graphs come into play. Graph theory, a fundamental component of this process, it is a mathematical field that studies relationships and connections between objects using vertices and edges, finding applications in computer science, network analysis, and more finds application in architectural design. This study delves into the application of graph theory in the analytical exploration of urban networks, with a focus on tourism parameters in the picturesque town of Pondicherry, Tamil Nadu, India. Traditionally, urban network analysis seeks to determine the shortest distance between origin and destination, a metric rooted in accessibility. However, in leisure destinations, a novel approach involving an optimized distance-based algorithm is introduced. This innovative methodology aims to facilitate efficient access to all tourist destinations within the spatial extent while minimizing discrete physical distances. To illustrate this concept, we take the iconic French Quarters in the White Town of Pondicherry as a case study. By applying the optimized distance-based algorithm, we endeavor to uncover the most efficient route for tourists to navigate and leisurely explore the area. The outcome of this analysis reveals a path graph structure, which, when compared to a circular graph structure, demonstrates superior efficiency in guiding tourists through the space. The implications of this tourist route extend beyond the realm of tourism itself. It has the potential to enhance the organization of tourist activities, allowing stakeholders to manage and regulate the flow of visitors. Additionally, it presents an opportunity to promote and develop the region’s often-underestimated tourist destinations, which can, in turn, have a positive impact on the local economy. In summary, the integration of graph theory into architectural and urban design methodologies enriches the approach to tourism and offers a holistic perspective on spatial optimization.
建筑通常被视为一种三维艺术形式,在设计过程中依赖于多种抽象概念。在这种情况下,建筑元素通过基于矢量的数据处理技术得到有效表达,为创造性探索提供了画布。为了进一步了解空间配置并产生多种设计见解,被称为图形的数学结构开始发挥作用。图论是这一过程的基本组成部分,它是一个利用顶点和边研究对象之间关系和联系的数学领域,在计算机科学、网络分析以及建筑设计中都有应用。本研究深入探讨了图论在城市网络分析探索中的应用,重点是印度泰米尔纳德邦风景如画的本迪榭里镇的旅游参数。传统上,城市网络分析旨在确定出发地和目的地之间的最短距离,这是一种根植于可达性的指标。然而,在休闲旅游目的地,引入了一种新方法,即基于距离的优化算法。这种创新方法的目的是在最大限度地减少离散物理距离的同时,方便游客高效地到达空间范围内的所有旅游目的地。为说明这一概念,我们以本地治里白城的标志性法式街区为例进行研究。通过应用基于距离的优化算法,我们努力为游客找出一条最有效的路线,以便他们在该地区悠闲地游览。分析结果揭示了一种路径图结构,与圆形图结构相比,这种路径图结构在引导游客穿越空间方面表现出更高的效率。这条旅游路线的意义超出了旅游业本身。它有可能加强旅游活动的组织,使利益相关者能够管理和调节游客流量。此外,它还为推广和开发该地区往往被低估的旅游目的地提供了机会,这反过来又会对当地经济产生积极影响。总之,将图论融入建筑和城市设计方法中,可以丰富旅游方法,并为空间优化提供一个整体视角。
{"title":"Optimized Distance-Based Algorithm for Cloud Space—Tourist Route Recommendation for Heritage Town, Pondicherry, India","authors":"Lakshmi Lakshmanan, Madhumathi A, Sudhakara Pandian R, Subhashini S, Sivakumar Paraman, Velmurugan K, Gianpaolo Di Bona","doi":"10.1155/2024/1029499","DOIUrl":"https://doi.org/10.1155/2024/1029499","url":null,"abstract":"Architecture, often regarded as a three-dimensional art form, relies on a multitude of abstractions during the design process. In this context, architectural elements are effectively represented through vector-based data processing techniques, offering a canvas for creative exploration. To further our understanding of spatial configurations and generate multiple design insights, mathematical structures known as graphs come into play. Graph theory, a fundamental component of this process, it is a mathematical field that studies relationships and connections between objects using vertices and edges, finding applications in computer science, network analysis, and more finds application in architectural design. This study delves into the application of graph theory in the analytical exploration of urban networks, with a focus on tourism parameters in the picturesque town of Pondicherry, Tamil Nadu, India. Traditionally, urban network analysis seeks to determine the shortest distance between origin and destination, a metric rooted in accessibility. However, in leisure destinations, a novel approach involving an optimized distance-based algorithm is introduced. This innovative methodology aims to facilitate efficient access to all tourist destinations within the spatial extent while minimizing discrete physical distances. To illustrate this concept, we take the iconic French Quarters in the White Town of Pondicherry as a case study. By applying the optimized distance-based algorithm, we endeavor to uncover the most efficient route for tourists to navigate and leisurely explore the area. The outcome of this analysis reveals a path graph structure, which, when compared to a circular graph structure, demonstrates superior efficiency in guiding tourists through the space. The implications of this tourist route extend beyond the realm of tourism itself. It has the potential to enhance the organization of tourist activities, allowing stakeholders to manage and regulate the flow of visitors. Additionally, it presents an opportunity to promote and develop the region’s often-underestimated tourist destinations, which can, in turn, have a positive impact on the local economy. In summary, the integration of graph theory into architectural and urban design methodologies enriches the approach to tourism and offers a holistic perspective on spatial optimization.","PeriodicalId":18319,"journal":{"name":"Mathematical Problems in Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140055802","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Post-Fracture Stiffness and Residual Capacity Assessment of Film-Retrofitted Monolithic Glass Elements by Frequency Change 通过频率变化评估薄膜重装单片玻璃元件的断裂后刚度和剩余容量
4区 工程技术 Q1 Mathematics Pub Date : 2024-03-01 DOI: 10.1155/2024/8922303
Chiara Bedon, Marco Fasan
The primary goal of safety films for glass in buildings is to retrofit existing monolithic elements and prevent, in the post-fracture stage, any fall-out of shards. Their added value is that—as far as the fragments are kept bonded—a cracked film-glass element can ensure a minimum residual mechanical and load-bearing capacity, which is strictly related to the shards interlocking and debond. To prevent critical issues, such a mechanical characterization is both important and uncertain, and requires specific methodologies. In this regard, a dynamic investigation is carried out on fractured film-bonded glass samples, to assess their post-fracture stiffness trends and its sensitivity to repeated vibrations. The adopted laboratory layout is chosen to assess the effects of random vibrations (220 repetitions) on a total of 12 cracked specimens in a cantilever setup (with 0.5–5 m/s2 the range of randomly imposed acceleration peaks). By monitoring the cracked vibration frequency, the film efficiency and corresponding residual bending stiffness of cracked glass samples are quantified as a function of damage severity, with a focus on fragments interlock. Quantitative experimental estimates are comparatively analyzed and validated with the support of finite element (FE) numerical models and analytical calculations. As shown—at least at the small-scale level—a progressive post-fracture stiffness reduction takes place under repeated random vibrations, and this implicitly affects the residual load-bearing capacity of glass members. Most importantly, for the tested configurations, it is shown that the cracked vibration frequency is minimally affected by crack geometry, and follows a rather linear decrease with the number of imposed random impacts (up to an average of ≈20 for each sample), thus confirming the retrofit potential and efficiency in providing some mechanical capacity through fragments interlock.
建筑玻璃安全膜的主要目的是改造现有的整体元件,并在断裂后阶段防止碎片掉落。贴膜的附加值在于,只要碎片保持粘合,裂开的贴膜玻璃元件就能确保最低限度的残余机械和承重能力,这与碎片的交错和脱落密切相关。为了防止出现关键问题,这种机械特性分析既重要又不确定,需要采用特定的方法。为此,我们对断裂的薄膜粘接玻璃样品进行了动态调查,以评估其断裂后的刚度趋势及其对反复振动的敏感性。所采用的实验室布局是为了评估随机振动(重复 220 次)对悬臂装置中总共 12 个破裂试样的影响(随机施加的加速度峰值范围为 0.5-5 m/s2)。通过监测裂纹振动频率,量化了裂纹玻璃样品的薄膜效率和相应的残余弯曲刚度与损坏严重程度的函数关系,重点是碎片互锁。在有限元(FE)数值模型和分析计算的支持下,对定量实验估计值进行了比较分析和验证。结果表明--至少在小范围内--在反复随机振动的情况下,断裂后的刚度会逐渐降低,这隐含地影响了玻璃构件的剩余承载能力。最重要的是,在测试的结构中,裂纹振动频率受裂纹几何形状的影响极小,并且随着施加的随机冲击次数的增加而呈线性下降(每个样本平均下降 ≈20),从而证实了通过碎片互锁提供一定机械承载能力的改造潜力和效率。
{"title":"Post-Fracture Stiffness and Residual Capacity Assessment of Film-Retrofitted Monolithic Glass Elements by Frequency Change","authors":"Chiara Bedon, Marco Fasan","doi":"10.1155/2024/8922303","DOIUrl":"https://doi.org/10.1155/2024/8922303","url":null,"abstract":"The primary goal of safety films for glass in buildings is to retrofit existing monolithic elements and prevent, in the post-fracture stage, any fall-out of shards. Their added value is that—as far as the fragments are kept bonded—a cracked film-glass element can ensure a minimum residual mechanical and load-bearing capacity, which is strictly related to the shards interlocking and debond. To prevent critical issues, such a mechanical characterization is both important and uncertain, and requires specific methodologies. In this regard, a dynamic investigation is carried out on fractured film-bonded glass samples, to assess their post-fracture stiffness trends and its sensitivity to repeated vibrations. The adopted laboratory layout is chosen to assess the effects of random vibrations (220 repetitions) on a total of 12 cracked specimens in a cantilever setup (with 0.5–5 m/s<sup>2</sup> the range of randomly imposed acceleration peaks). By monitoring the cracked vibration frequency, the film efficiency and corresponding residual bending stiffness of cracked glass samples are quantified as a function of damage severity, with a focus on fragments interlock. Quantitative experimental estimates are comparatively analyzed and validated with the support of finite element (FE) numerical models and analytical calculations. As shown—at least at the small-scale level—a progressive post-fracture stiffness reduction takes place under repeated random vibrations, and this implicitly affects the residual load-bearing capacity of glass members. Most importantly, for the tested configurations, it is shown that the cracked vibration frequency is minimally affected by crack geometry, and follows a rather linear decrease with the number of imposed random impacts (up to an average of ≈20 for each sample), thus confirming the retrofit potential and efficiency in providing some mechanical capacity through fragments interlock.","PeriodicalId":18319,"journal":{"name":"Mathematical Problems in Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140004167","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Blockchain-Based Electronic Voting System: Significance and Requirements 基于区块链的电子投票系统:意义和要求
4区 工程技术 Q1 Mathematics Pub Date : 2024-02-24 DOI: 10.1155/2024/5591147
Said El Kafhali
In a democratic regime, voting is crucial to making collective decisions. Unfortunately, although this activity has great significance and value, little effort has been made to improve the way we vote. Paper ballots are still the most used method, although this method is relatively simple, brings many inconveniences, and represents a contradiction to the modern world and its advances. This paper mostly focuses on a review study of blockchain-based voting systems. It aims at identifying the strategies and the guidelines as well as provides a comprehensive end-to-end electronic voting system based on blockchain, with the help of cryptographic techniques such as zero-knowledge proofs to improve privacy. The novelty of this paper is that we tackle the limitations of electronic voting systems found in the literature, including cost, identity management, and scalability problems. Our purpose is to provide key elements for organizations on how to design their proper electronic voting system based on blockchain technology.
在民主制度中,投票对于集体决策至关重要。遗憾的是,尽管这项活动具有重大意义和价值,但在改进投票方式方面却鲜有作为。纸质选票仍然是最常用的方法,尽管这种方法相对简单,但带来了许多不便,与现代世界及其进步相矛盾。本文主要侧重于对基于区块链的投票系统进行回顾研究。其目的是确定策略和指导方针,并提供一个基于区块链的端到端综合电子投票系统,同时借助零知识证明等加密技术来提高隐私性。本文的新颖之处在于,我们解决了文献中发现的电子投票系统的局限性,包括成本、身份管理和可扩展性问题。我们的目的是为企业提供如何基于区块链技术设计合适的电子投票系统的关键要素。
{"title":"Blockchain-Based Electronic Voting System: Significance and Requirements","authors":"Said El Kafhali","doi":"10.1155/2024/5591147","DOIUrl":"https://doi.org/10.1155/2024/5591147","url":null,"abstract":"In a democratic regime, voting is crucial to making collective decisions. Unfortunately, although this activity has great significance and value, little effort has been made to improve the way we vote. Paper ballots are still the most used method, although this method is relatively simple, brings many inconveniences, and represents a contradiction to the modern world and its advances. This paper mostly focuses on a review study of blockchain-based voting systems. It aims at identifying the strategies and the guidelines as well as provides a comprehensive end-to-end electronic voting system based on blockchain, with the help of cryptographic techniques such as zero-knowledge proofs to improve privacy. The novelty of this paper is that we tackle the limitations of electronic voting systems found in the literature, including cost, identity management, and scalability problems. Our purpose is to provide key elements for organizations on how to design their proper electronic voting system based on blockchain technology.","PeriodicalId":18319,"journal":{"name":"Mathematical Problems in Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139947570","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
期刊
Mathematical Problems in Engineering
全部 Acc. Chem. Res. ACS Applied Bio Materials ACS Appl. Electron. Mater. ACS Appl. Energy Mater. ACS Appl. Mater. Interfaces ACS Appl. Nano Mater. ACS Appl. Polym. Mater. ACS BIOMATER-SCI ENG ACS Catal. ACS Cent. Sci. ACS Chem. Biol. ACS Chemical Health & Safety ACS Chem. Neurosci. ACS Comb. Sci. ACS Earth Space Chem. ACS Energy Lett. ACS Infect. Dis. ACS Macro Lett. ACS Mater. Lett. ACS Med. Chem. Lett. ACS Nano ACS Omega ACS Photonics ACS Sens. ACS Sustainable Chem. Eng. ACS Synth. Biol. Anal. Chem. BIOCHEMISTRY-US Bioconjugate Chem. BIOMACROMOLECULES Chem. Res. Toxicol. Chem. Rev. Chem. Mater. CRYST GROWTH DES ENERG FUEL Environ. Sci. Technol. Environ. Sci. Technol. Lett. Eur. J. Inorg. Chem. IND ENG CHEM RES Inorg. Chem. J. Agric. Food. Chem. J. Chem. Eng. Data J. Chem. Educ. J. Chem. Inf. Model. J. Chem. Theory Comput. J. Med. Chem. J. Nat. Prod. J PROTEOME RES J. Am. Chem. Soc. LANGMUIR MACROMOLECULES Mol. Pharmaceutics Nano Lett. Org. Lett. ORG PROCESS RES DEV ORGANOMETALLICS J. Org. Chem. J. Phys. Chem. J. Phys. Chem. A J. Phys. Chem. B J. Phys. Chem. C J. Phys. Chem. Lett. Analyst Anal. Methods Biomater. Sci. Catal. Sci. Technol. Chem. Commun. Chem. Soc. Rev. CHEM EDUC RES PRACT CRYSTENGCOMM Dalton Trans. Energy Environ. Sci. ENVIRON SCI-NANO ENVIRON SCI-PROC IMP ENVIRON SCI-WAT RES Faraday Discuss. Food Funct. Green Chem. Inorg. Chem. Front. Integr. Biol. J. Anal. At. Spectrom. J. Mater. Chem. A J. Mater. Chem. B J. Mater. Chem. C Lab Chip Mater. Chem. Front. Mater. Horiz. MEDCHEMCOMM Metallomics Mol. Biosyst. Mol. Syst. Des. Eng. Nanoscale Nanoscale Horiz. Nat. Prod. Rep. New J. Chem. Org. Biomol. Chem. Org. Chem. Front. PHOTOCH PHOTOBIO SCI PCCP Polym. Chem.
×
引用
GB/T 7714-2015
复制
MLA
复制
APA
复制
导出至
BibTeX EndNote RefMan NoteFirst NoteExpress
×
0
微信
客服QQ
Book学术公众号 扫码关注我们
反馈
×
意见反馈
请填写您的意见或建议
请填写您的手机或邮箱
×
提示
您的信息不完整,为了账户安全,请先补充。
现在去补充
×
提示
您因"违规操作"
具体请查看互助需知
我知道了
×
提示
确定
Book学术官方微信
Book学术文献互助
Book学术文献互助群
群 号:481959085
Book学术
文献互助 智能选刊 最新文献 互助须知 联系我们:info@booksci.cn
Book学术提供免费学术资源搜索服务,方便国内外学者检索中英文文献。致力于提供最便捷和优质的服务体验。
Copyright © 2023 Book学术 All rights reserved.
ghs 京公网安备 11010802042870号 京ICP备2023020795号-1