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Assessment of Stochastic Numerical Schemes for Stochastic Differential Equations with “White Noise” Using Itô’s Integral 利用Itô积分评价带有“白噪声”的随机微分方程的随机数值格式
3区 综合性期刊 Q2 MULTIDISCIPLINARY SCIENCES Pub Date : 2023-11-09 DOI: 10.3390/sym15112038
Alina Bogoi, Cătălina-Ilinca Dan, Sergiu Strătilă, Grigore Cican, Daniel-Eugeniu Crunteanu
Stochastic Differential Equations (SDEs) model physical phenomena dominated by stochastic processes. They represent a method for studying the dynamic evolution of a physical phenomenon, like ordinary or partial differential equations, but with an additional term called “noise” that represents a perturbing factor that cannot be attached to a classical mathematical model. In this paper, we study weak and strong convergence for six numerical schemes applied to a multiplicative noise, an additive, and a system of SDEs. The Efficient Runge–Kutta (ERK) technique, however, comes out as the top performer, displaying the best convergence features in all circumstances, including in the difficult setting of multiplicative noise. This result highlights the importance of researching cutting-edge numerical techniques built especially for stochastic systems and we consider to be of good help to the MATLAB function code for the ERK method.
随机微分方程(SDEs)对随机过程主导的物理现象进行建模。它们代表了一种研究物理现象动态演变的方法,就像常微分方程或偏微分方程一样,但有一个额外的术语叫做“噪声”,它代表了一个不能附加到经典数学模型上的干扰因素。本文研究了六种应用于乘性噪声、加性噪声和SDEs系统的数值格式的弱收敛性和强收敛性。然而,高效龙格-库塔(ERK)技术表现最好,在所有情况下都表现出最好的收敛特征,包括在乘法噪声的困难设置中。这一结果突出了研究专门针对随机系统的前沿数值技术的重要性,我们认为这对ERK方法的MATLAB函数代码有很好的帮助。
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引用次数: 0
Implementation of Finite Element Method Simulation in Control of Additive Manufacturing to Increase Component Strength and Productivity 有限元仿真在增材制造控制中的应用,提高零件强度和生产率
3区 综合性期刊 Q2 MULTIDISCIPLINARY SCIENCES Pub Date : 2023-11-09 DOI: 10.3390/sym15112036
Miloš Matúš, Peter Križan, Ján Kijovský, Stanislav Strigáč, Juraj Beniak, Ľubomír Šooš
Additive manufacturing (AM) technologies are becoming a global phenomenon in the manufacturing industry. The progressiveness of additive manufacturing lies in its universality. AM makes it possible to produce parts with complex shapes from different materials without any tools, using only one device. Complex and time-consuming production preparation is eliminated by using AM. It is used in a wide range of industries. Although additive manufacturing is a progressive technology, the currently applied conservative approach has significant limits. The presented work focuses on the development of a new methodology for controlling the AM process. This methodology is based on the outputs of the strength simulation of a specific component through the finite element method (FEM) and their implementation in the printing software of the production equipment. The developed algorithm for controlling the AM process consists of a sequence of successive steps. The designed CAD model of the component is subjected to FEM simulation in order to analyze the von Mises stress in the entire volume of the loaded component. Stresses are distributed asymmetrically in the volume of the component due to the shape and nature of the load. The results of the FEM analysis allow the definition of the volumes in the component with different levels of infill geometry and infill density based on different levels of stress. The FEM simulation also serves to define the effective fiber orientation. The goal of implementing FEM simulation into the building structure of the component is to achieve a symmetrical distribution of stresses in the entire volume. Through the symmetry of internal stresses, it is possible to obtain more efficient production with high productivity and component strength. The work also deals with experimental research on the effect of the building structure on flexural strength. The results of FEM simulation and experimental research are integrated into the developed slicer software to design a layering of the model and the setting of technological and material parameters of printing. This progressive approach makes it possible to generate data for 3D printing based on FEM analysis of components to obtain an optimized printed structure of components and optimized technological and material parameters with regard to maximizing the strength of components and minimizing production times and costs.
增材制造(AM)技术正在成为制造业的全球现象。增材制造的先进性在于它的通用性。增材制造可以在不使用任何工具的情况下,仅使用一台设备,从不同的材料生产具有复杂形状的零件。使用增材制造消除了复杂和耗时的生产准备。它被广泛应用于各行各业。虽然增材制造是一项进步的技术,但目前应用的保守方法有很大的局限性。提出的工作重点是开发一种控制增材制造过程的新方法。该方法基于通过有限元法(FEM)对特定部件进行强度模拟的输出,并在生产设备的打印软件中实现。所开发的用于控制AM过程的算法由一系列连续步骤组成。对所设计的构件CAD模型进行有限元仿真,分析加载构件整体内的von Mises应力。由于载荷的形状和性质,应力在部件的体积中分布不对称。有限元分析的结果允许根据不同的应力水平来定义具有不同水平充填几何和充填密度的构件的体积。有限元模拟还用于确定光纤的有效取向。在构件的建筑结构中实施有限元模拟的目标是在整个体积中实现应力的对称分布。通过内应力的对称性,可以获得更高效的生产,具有较高的生产率和构件强度。本文还对建筑结构对抗弯强度的影响进行了实验研究。将有限元模拟和实验研究的结果整合到所开发的切片机软件中,设计了模型分层、打印工艺参数和材料参数的设置。这种渐进的方法使得基于部件有限元分析生成3D打印数据成为可能,从而获得优化的部件打印结构和优化的工艺和材料参数,从而最大化部件的强度,最小化生产时间和成本。
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引用次数: 1
Multi-Attribute Group Decision-Making Methods Based on Entropy Weights with q-Rung Picture Uncertain Linguistic Fuzzy Information 基于q阶图像不确定语言模糊信息的熵权多属性群决策方法
3区 综合性期刊 Q2 MULTIDISCIPLINARY SCIENCES Pub Date : 2023-11-08 DOI: 10.3390/sym15112027
Mengran Sun, Yushui Geng, Jing Zhao
This paper introduces a new concept called q-rung picture uncertain linguistic fuzzy sets (q-RPULSs). These sets provide a reliable and comprehensive method for describing complex and uncertain decision-making information. In addition, q-RPULSs help to integrate the decision maker’s quantitative assessment ideas with qualitative assessment information. For the q-RPUL multi-attribute group decision-making problem with unknown weight information, an entropy-based fuzzy set method for q-rung picture uncertainty language is proposed. The method considers the interrelationships among attributes and builds a q-rung picture uncertain language model. In addition, the q-RPULMSM operator and its related properties are discussed in this paper. This operator enables the fusion of q-RPULSs and helps to reach consensus in decision-making scenarios. To demonstrate the validity of the methodology, we provide a real case study involving commodity selection. Based on this case study, the reasonableness and superiority of the method are evaluated, highlighting the practical advantages and applicability of q-RPULSs in decision-making processes.
本文引入了一个新的概念——q-rung图像不确定语言模糊集。这些集合为描述复杂、不确定的决策信息提供了可靠、全面的方法。此外,q- rpuls有助于将决策者的定量评估思想与定性评估信息相结合。针对权值信息未知的q-RPUL多属性群决策问题,提出了一种基于熵的q阶图像不确定性语言模糊集方法。该方法考虑了属性之间的相互关系,建立了q阶图像不确定语言模型。此外,本文还讨论了q-RPULMSM算子及其相关性质。该算子实现了q- rpulse的融合,有助于在决策场景中达成共识。为了证明该方法的有效性,我们提供了一个涉及商品选择的真实案例研究。通过实例分析,评价了该方法的合理性和优越性,突出了q- rpuls在决策过程中的实际优势和适用性。
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引用次数: 0
On the Partition Temperature of Massless Particles in High-Energy Collisions 关于高能碰撞中无质量粒子的分割温度
3区 综合性期刊 Q2 MULTIDISCIPLINARY SCIENCES Pub Date : 2023-11-08 DOI: 10.3390/sym15112035
Wei-Liang Qian, Kai Lin, Rui-Hong Yue, Yogiro Hama, Takeshi Kodama
Although partition temperature derived using the Darwin–Fowler method is exact for simple scenarios, the derivation for complex systems might reside in specific approximations whose viability is not ensured if the thermodynamic limit is not attained. This work elaborates on a related problem relevant to relativistic high-energy collisions. On the one hand, it is simple enough that closed-form expressions can be obtained precisely for the one-particle distribution function. On the other hand, the resulting expression is not an exponential form, and therefore, it is not straightforward that the notion of partition function could be implied. Specifically, we derive the one-particle distribution function for massless particles where the phase-space integration is performed exactly for the underlying canonical ensemble consisting of a given number of particles. We discuss the viability of the partition temperature in this case. Possible implications of the obtained results regarding the observed Tsallis distribution in transverse momentum spectra in high-energy collisions are also addressed.
虽然用达尔文-福勒方法推导出的分区温度对于简单的情况是精确的,但对于复杂系统的推导可能存在于特定的近似中,如果没有达到热力学极限,则无法确保其可行性。这项工作详细阐述了与相对论高能碰撞有关的一个相关问题。一方面,它足够简单,可以精确地得到单粒子分布函数的封闭表达式。另一方面,所得到的表达式不是指数形式,因此,可以隐含配分函数的概念并不简单。具体地说,我们推导了无质量粒子的单粒子分布函数,其中相空间积分是对由给定数量的粒子组成的底层正则系综精确地进行的。在这种情况下,我们讨论隔板温度的生存能力。本文还讨论了在高能碰撞中观察到的横向动量谱中Tsallis分布的可能含义。
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引用次数: 0
Scheduling of Multi-AGV Systems in Automated Electricity Meter Verification Workshops Based on an Improved Snake Optimization Algorithm 基于改进Snake优化算法的自动化电表检定车间多agv系统调度
3区 综合性期刊 Q2 MULTIDISCIPLINARY SCIENCES Pub Date : 2023-11-08 DOI: 10.3390/sym15112034
Kun Shi, Miaohan Zhang, Zhaolei He, Shi Yin, Zhen Ai, Nan Pan
Automated guided vehicles (AGVs) are one of the core technologies for building unmanned autonomous integrated automated electric meter verification workshops in metrology centers. However, complex obstacles on the verification lines, frequent AGV charging, and multi-AGV collaboration make the scheduling problem more complicated. Aiming at the characteristics and constraints of AGV transportation scheduling for metrology verification, a multi-AGV scheduling model was established to minimize the maximum completion time and charging cost, integrating collision-avoidance constraints. An improved snake optimization algorithm was proposed that first assigns and sorts tasks based on AGV-order-address three-level mapping encoding and decoding, then searches optimal paths using an improved A* algorithm solves multi-AGV path conflicts, and finally finds the minimum-charging-cost schedule through large neighborhood search. We conducted simulations using real data, and the calculated results reduced the objective function value by 16.4% compared to the traditional first-in-first-out (FIFO) method. It also reduced the number of charges by 60.3%. In addition, the proposed algorithm is compared with a variety of cutting-edge algorithms and the results show that the objective function value is reduced by 8.7–11.2%, which verifies the superiority of the proposed algorithm and the feasibility of the model.
自动导引车(agv)是计量中心建设无人自主综合自动化电表检定车间的核心技术之一。然而,验证线上复杂的障碍物、频繁的AGV充电以及多AGV协同使得调度问题更加复杂。针对计量验证AGV运输调度的特点和约束,以最大完成时间和收费成本最小为目标,结合避撞约束,建立了多AGV调度模型。提出了一种改进的蛇形优化算法,该算法首先基于agv -顺序-地址三级映射编码解码进行任务分配和排序,然后利用改进的A*算法搜索最优路径,解决多agv路径冲突,最后通过大邻域搜索找到充电成本最小的调度方案。利用真实数据进行了仿真,计算结果表明,与传统的先进先出(FIFO)方法相比,目标函数值降低了16.4%。它还将收费数量减少了60.3%。此外,将所提算法与多种前沿算法进行对比,结果表明,目标函数值降低了8.7-11.2%,验证了所提算法的优越性和模型的可行性。
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引用次数: 0
Time–Energy Uncertainty Relation for Neutrino Oscillations: Historical Development, Applications, and Future Prospects 中微子振荡的时间-能量不确定关系:历史发展、应用和未来展望
3区 综合性期刊 Q2 MULTIDISCIPLINARY SCIENCES Pub Date : 2023-11-08 DOI: 10.3390/sym15112032
Giuseppe Gaetano Luciano, Luca Smaldone
The time–energy uncertainty relation (TEUR) plays a fundamental role in quantum mechanics, as it allows the grasping of peculiar aspects of a variety of phenomena based on very general principles and symmetries of the theory. Using the Mandelstam–Tamm method, TEUR has recently been derived for neutrino oscillations by connecting the uncertainty in neutrino energy with the characteristic timescale of oscillations. Interestingly, the suggested interpretation of neutrinos as unstable-like particles has proved to naturally emerge in this context. Further aspects were later discussed in semiclassical gravity theory, by computing corrections to the neutrino energy uncertainty in a generic stationary curved spacetime, and in quantum field theory, where the clock observable turns out to be identified with the non-conserved flavor charge operator. In the present work, we give an overview on the above achievements. In particular, we analyze the implications of TEUR and explore the impact of gravitational and non-relativistic effects on the standard condition for neutrino oscillations.
时间-能量不确定性关系(TEUR)在量子力学中起着至关重要的作用,因为它允许根据理论的非常一般的原理和对称性来掌握各种现象的特殊方面。利用mandelstamm - tamm方法,最近通过将中微子能量的不确定性与振荡的特征时间尺度联系起来,推导出了中微子振荡的TEUR。有趣的是,将中微子解释为类不稳定粒子的说法被证明是在这种背景下自然出现的。后来在半经典引力理论中,通过计算一般静止弯曲时空中中微子能量不确定性的修正,以及在量子场论中,进一步讨论了这些问题,在量子场论中,可观察到的时钟被证明是与非保守的风味电荷算子相一致的。在本文中,我们对上述成果进行了综述。特别地,我们分析了TEUR的含义,并探讨了引力和非相对论效应对中微子振荡标准条件的影响。
{"title":"Time–Energy Uncertainty Relation for Neutrino Oscillations: Historical Development, Applications, and Future Prospects","authors":"Giuseppe Gaetano Luciano, Luca Smaldone","doi":"10.3390/sym15112032","DOIUrl":"https://doi.org/10.3390/sym15112032","url":null,"abstract":"The time–energy uncertainty relation (TEUR) plays a fundamental role in quantum mechanics, as it allows the grasping of peculiar aspects of a variety of phenomena based on very general principles and symmetries of the theory. Using the Mandelstam–Tamm method, TEUR has recently been derived for neutrino oscillations by connecting the uncertainty in neutrino energy with the characteristic timescale of oscillations. Interestingly, the suggested interpretation of neutrinos as unstable-like particles has proved to naturally emerge in this context. Further aspects were later discussed in semiclassical gravity theory, by computing corrections to the neutrino energy uncertainty in a generic stationary curved spacetime, and in quantum field theory, where the clock observable turns out to be identified with the non-conserved flavor charge operator. In the present work, we give an overview on the above achievements. In particular, we analyze the implications of TEUR and explore the impact of gravitational and non-relativistic effects on the standard condition for neutrino oscillations.","PeriodicalId":48874,"journal":{"name":"Symmetry-Basel","volume":"329 3","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135392742","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Adiabatic Manipulation of a System Interacting with a Spin Bath 系统与自旋浴相互作用的绝热操作
3区 综合性期刊 Q2 MULTIDISCIPLINARY SCIENCES Pub Date : 2023-11-08 DOI: 10.3390/sym15112028
Benedetto Militello, Anna Napoli
The Stimulated Raman Adiabatic Passage, a very efficient technique for manipulating a quantum system based on the adiabatic theorem, is analyzed in the case where the manipulated physical system is interacting with a spin bath. The exploitation of the rotating wave approximation allows for the identification of a constant of motion, which simplifies both the analytical and the numerical treatment, which allows for evaluating the total unitary evolution of the system and bath. The efficiency of the population transfer process is investigated in several regimes, including the weak and strong coupling with the environment and the off-resonance. The formation of appropriate Zeno subspaces explains the lowering of the efficiency in the strong damping regime.
受激拉曼绝热通道是基于绝热定理的一种非常有效的操纵量子系统的技术,本文分析了被操纵的物理系统与自旋浴相互作用的情况。利用旋转波近似可以识别运动常数,从而简化了解析和数值处理,从而可以评估系统和体系的整体统一演化。在与环境的弱耦合和强耦合以及非共振情况下,研究了种群迁移过程的效率。适当的芝诺子空间的形成解释了在强阻尼状态下效率的降低。
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引用次数: 0
An Optimal Control Perspective on Classical and Quantum Physical Systems 经典和量子物理系统的最优控制观点
3区 综合性期刊 Q2 MULTIDISCIPLINARY SCIENCES Pub Date : 2023-11-08 DOI: 10.3390/sym15112033
Mauricio Contreras G., Marcelo Villena
This paper analyzes classical and quantum physical systems from an optimal control perspective. Specifically, we explore whether their associated dynamics can correspond to an open- or closed-loop feedback evolution of a control problem. Firstly, for the classical regime, when it is viewed in terms of the theory of canonical transformations, we find that a closed-loop feedback problem can describe it. Secondly, for a quantum physical system, if one realizes that the Heisenberg commutation relations themselves can be considered constraints in a non-commutative space, then the momentum must depend on the position of any generic wave function. That implies the existence of a closed-loop strategy for the quantum case. Thus, closed-loop feedback is a natural phenomenon in the physical world. By way of completeness, we briefly review control theory and the classical mechanics of constrained systems and analyze some examples at the classical and quantum levels.
本文从最优控制的角度分析了经典物理系统和量子物理系统。具体而言,我们探讨了它们的相关动力学是否可以对应于控制问题的开环或闭环反馈演化。首先,对于经典状态,从正则变换理论的角度来看,我们发现闭环反馈问题可以描述它。其次,对于量子物理系统,如果人们意识到海森堡对易关系本身可以被认为是非对易空间中的约束,那么动量必须依赖于任何一般波函数的位置。这意味着在量子情况下存在闭环策略。因此,闭环反馈是物理世界中的一种自然现象。为了完备性,我们简要地回顾了约束系统的控制理论和经典力学,并在经典和量子水平上分析了一些例子。
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引用次数: 0
A Mixed Finite Element Approximation for Time-Dependent Navier–Stokes Equations with a General Boundary Condition 具有一般边界条件时相关Navier-Stokes方程的混合有限元逼近
3区 综合性期刊 Q2 MULTIDISCIPLINARY SCIENCES Pub Date : 2023-11-08 DOI: 10.3390/sym15112031
Omar El Moutea, Nadia Nakbi, Abdeslam El Akkad, Ahmed Elkhalfi, Lahcen El Ouadefli, Sorin Vlase, Maria Luminita Scutaru
In this paper, we present a numerical scheme for addressing the unsteady asymmetric flows governed by the incompressible Navier–Stokes equations under a general boundary condition. We utilized the Finite Element Method (FEM) for spatial discretization and the fully implicit Euler scheme for time discretization. In addition to the theoretical analysis of the error in our numerical scheme, we introduced two types of a posteriori error indicators: one for time discretization and another for spatial discretization, aimed at effectively controlling the error. We established the equivalence between these estimators and the actual error. Furthermore, we conducted numerical simulations in two dimensions to assess the accuracy and effectiveness of our scheme.
本文给出了在一般边界条件下求解不可压缩Navier-Stokes方程控制的非定常非对称流的数值格式。采用有限元法进行空间离散,采用全隐式欧拉格式进行时间离散。除了对数值方案中的误差进行理论分析外,我们还引入了时间离散和空间离散两种后验误差指标,目的是有效地控制误差。我们建立了这些估计量与实际误差之间的等价关系。此外,我们在两个维度上进行了数值模拟,以评估我们的方案的准确性和有效性。
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引用次数: 0
Q-Multi Cubic Pythagorean Fuzzy Sets and Their Correlation Coefficients for Multi-Criteria Group Decision Making 多准则群决策的q -多三次毕达哥拉斯模糊集及其相关系数
3区 综合性期刊 Q2 MULTIDISCIPLINARY SCIENCES Pub Date : 2023-11-08 DOI: 10.3390/sym15112026
Safa Hussain Almasabi, Kholood Mohammad Alsager
Q-multi cubic Pythagorean fuzzy sets (Q-mCPFSs) are influential, effective and symmetrical for representing uncertain and imprecise information in decision making processes. Q-mCPFSs extend the concept of Q-multi fuzzy sets by introducing the notion of cubic Pythagorean membership functions, which provide a more flexible and accurate representation of uncertainty. First, we will introduce the concepts of Q-mPFSs and Q-mIVPFSs. With the combination of Q-mPFSs and Q-mIVPFSs, we will present the concept of Q-mCPFSs. Then, we propose two correlation coefficients for Q-mCPFSs. Furthermore, multi-criteria GDM methods using Q-mCPFSs will be discussed, highlighting their advantages in handling uncertain and imprecise information. Finally, we will provide an illustrative example, to demonstrate the effectiveness of Q-mCPFSs in decision making processes.The main contributions of the Q-mCPFS information expression, correlation coefficients and GDM methods in the Q-mCPFS setting of both uncertainty and certainty are thus highlighted in this study. These contributions provide valuable insights into the application of Q-mCPFSs in decision making processes, allowing decision makers to make more informed and effective choices. Additionally, the illustrative example serves as a practical demonstration of how these methods can be applied in real-world scenarios, further emphasizing their effectiveness and relevance.
q -多三次毕达哥拉斯模糊集(q - mcpfs)对于表示决策过程中的不确定性和不精确信息具有影响力、有效性和对称性。q - mcpfs通过引入三次毕达哥拉斯隶属函数的概念扩展了q -多模糊集的概念,提供了更灵活和准确的不确定性表示。首先,我们将介绍q - mpfs和q - mivpfs的概念。结合q - mpfs和q - mivpfs,我们将提出q - mcpfs的概念。然后,我们提出了q - mcpfs的两个相关系数。此外,将讨论使用q - mcpfs的多准则GDM方法,突出其在处理不确定和不精确信息方面的优势。最后,我们将提供一个说明性的例子,以证明q - mcpfs在决策过程中的有效性。因此,本研究突出了Q-mCPFS信息表达、相关系数和GDM方法在不确定性和确定性两种Q-mCPFS设置中的主要贡献。这些贡献为q - mcpfs在决策过程中的应用提供了有价值的见解,使决策者能够做出更明智和有效的选择。此外,该说明性示例作为如何将这些方法应用于实际场景的实际演示,进一步强调了它们的有效性和相关性。
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引用次数: 0
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