在动态系统中使用超值来估计局部维度和极端指数的限制
Ignacio Del Amo1, George Datseris1, Mark Holland1
1Department of Mathematics and Statistics, University of Exeter, Exeter EX4 4QF, United Kingdom.
Chaos (Woodbury, N.Y.)
|April 15, 2025
概括
用于持久性分析的局部维度和极端指数等动态指标面临估计挑战. 它们的准确性取决于数据属性和系统动态,影响现实应用中的可靠性.
科学领域:
- 动态系统理论 动态系统理论
- 统计物理 统计物理
- 时间序列分析时间序列分析
背景情况:
- 动态指标,包括局部维度和极端指数,量化相位空间中的持久性.
- 这些指标通常是通过值超值的非对称极限计算的,通常是通过通用帕雷托分布来建模的.
- 这些非对称导数的数学假设在理想化和现实世界的动态系统中经常没有得到满足.
研究的目的:
- 调查已知动态系统的动态指标估计的挑战.
- 分析不变集合几何学对不变测量的正则变异性质的影响.
- 评估连续时间过程中常见的极端指数估计方法的明确性.
主要方法:
- 检查特定动态系统中动态指标的估计问题.
- 分析不变集合的几何如何影响不变尺度的规律变化.
- 对在离散时间步骤中采样的连续时间过程的极端指数估计的评估.
主要成果:
- 在非整数维集上的单一测量通常缺乏常规变化,导致依赖于分辨率的估计.
- 由于没有定期变化,这从根本上挑战了对动态指标的可靠估计.
- 普遍存在的极端指数估计方法对于离散采样的连续时间过程数据来说定义不好.
结论:
- 估计动态指标的理论基础在实践中经常被违反.
- 不变集合的几何性质极大地影响了不变尺度的统计行为.
- 目前估计极端指数的方法需要对离散时间采样数据进行重新评估.
相关概念视频
Dimensional Analysis
14.6K
The concept of dimension is important because every mathematical equation linking physical quantities must be dimensionally consistent, implying that mathematical equations must meet the following two rules. The first rule is that, in an equation, the expressions on each side of the equal sign must have the same dimensions. This is fairly intuitive since we can only add or subtract quantities of the same type (dimension). The second rule states that, in an equation, the arguments of any of the...
14.6K
Problem Solving: Dimensional Analysis
3.2K
Every mathematical equation that connects separate distinct physical quantities must be dimensionally consistent, which implies it must abide by two rules. For this reason, the concept of dimension is crucial. The first rule is that an equation's expressions on either side of an equality must have the exact same dimension, i.e., quantities of the same dimension can be added or removed. The second rule stipulates that all popular mathematical functions, such as exponential, logarithmic, and...
3.2K
Mechanistic Models: Compartment Models in Algorithms for Numerical Problem Solving
29
Mechanistic models play a crucial role in algorithms for numerical problem-solving, particularly in nonlinear mixed effects modeling (NMEM). These models aim to minimize specific objective functions by evaluating various parameter estimates, leading to the development of systematic algorithms. In some cases, linearization techniques approximate the model using linear equations.
In individual population analyses, different algorithms are employed, such as Cauchy's method, which uses a...
In individual population analyses, different algorithms are employed, such as Cauchy's method, which uses a...
29
Constraints and Statical Determinacy
550
In structural engineering, the equilibrium of a system is not only determined by its equations of equilibrium but also with the help of constraints. Constraints refer to restrictions on the motion of a system. The proper combinations of constraints can minimize the total number of constraints needed to maintain a system in mechanical equilibrium. When this happens, the system is said to be statically determinate. For such systems, the unknown reaction supports can be estimated using equilibrium...
550
Dynamic Modulus of Elasticity of Concrete
215
The dynamic modulus of elasticity assesses how a concrete structure deforms under impact or dynamic loads. It is typically higher than the static modulus of elasticity, measured under slow, steady loading conditions.
The sonic test is a common method to determine the dynamic modulus. In this test, a concrete beam, sized either 6 x 6 x 30 inches or 4 x 4 x 20 inches, is clamped at its center. Vibrations are initiated at one end of the beam by an electromagnetic exciter unit powered by...
The sonic test is a common method to determine the dynamic modulus. In this test, a concrete beam, sized either 6 x 6 x 30 inches or 4 x 4 x 20 inches, is clamped at its center. Vibrations are initiated at one end of the beam by an electromagnetic exciter unit powered by...
215
Moment-Area Theorems
213
The Moment-Area Theorem is crucial in structural engineering for analyzing beam bending, particularly in applications like building floor supports. This theorem utilizes the geometric properties of the elastic curve, which depicts how a beam deforms under load, to simplify the calculations of deflections and slopes.
The theorem is divided into two parts. The first part connects the angle between tangents at any two points on the beam's elastic curve to the area under a curve derived by...
The theorem is divided into two parts. The first part connects the angle between tangents at any two points on the beam's elastic curve to the area under a curve derived by...
213


