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Related papers: A General Description of Growth Trends

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Many real-world systems modeled using differential equations involve unknown or uncertain parameters. Standard approaches to address parameter estimation inverse problems in this setting typically focus on estimating constants; yet some…

Dynamical Systems · Mathematics 2024-03-25 Anna Fitzpatrick , Molly Folino , Andrea Arnold

Ignoring the differences between countries, human reproductive and dispersal behaviors can be described by some standardized models, so whether there is a universal law of population growth hidden in the abundant and unstructured data from…

Physics and Society · Physics 2024-02-08 Jiajun Ma , Qinghua Chen , Xiaosong Chen , Jingfang Fan , Xiaomeng Li , Yi Shi

The increasing demand for Fourier transforms on geometric algebras has resulted in a large variety. Here we introduce one single straight forward definition of a general geometric Fourier transform covering most versions in the literature.…

Algebraic Geometry · Mathematics 2013-06-11 Roxana Bujack , Gerik Scheuermann , Eckhard Hitzer

Mathematical methods of analysis of data and of predicting growth are discussed. The starting point is the analysis of the growth rates, which can be expressed as a function of time or as a function of the size of the growing entity.…

Economics · Quantitative Finance 2015-10-22 Ron W Nielsen

A defining feature of non-stationary systems is the time dependence of their statistical parameters. Measured time series may exhibit Gaussian statistics on short time horizons, due to the central limit theorem. The sample statistics for…

Data Analysis, Statistics and Probability · Physics 2020-10-08 Rudi Schäfer , Sonja Barkhofen , Thomas Guhr , Hans-Jürgen Stöckmann , Ulrich Kuhl

Multivariate time series forecasting is widely used in various fields. Reasonable prediction results can assist people in planning and decision-making, generate benefits and avoid risks. Normally, there are two characteristics of time…

Machine Learning · Computer Science 2021-03-23 Yifu Zhou , Ziheng Duan , Haoyan Xu , Jie Feng , Anni Ren , Yueyang Wang , Xiaoqian Wang

To make sense of massive data, we often fit simplified models and then interpret the parameters; for example, we cluster the text embeddings and then interpret the mean parameters of each cluster. However, these parameters are often…

Artificial Intelligence · Computer Science 2025-01-14 Ruiqi Zhong , Heng Wang , Dan Klein , Jacob Steinhardt

Researchers are often interested in examining between-individual differences in within-individual processes. If the process under investigation is tracked for a long time, its trajectory may show a certain degree of nonlinearity, so that…

Methodology · Statistics 2025-12-02 Jin Liu , Robert A. Perera

This study presents the approach to analyzing the evolution of an arbitrary complex system whose behavior is characterized by a set of different time-dependent factors. The key requirement for these factors is only that they must contain an…

Data Analysis, Statistics and Probability · Physics 2020-12-01 Anatolii V. Mokshin , Vladimir V. Mokshin , Diana A. Mirziyarova

Mathematical method based on a direct or indirect analysis of growth rates is described. It is shown how simple assumptions and a relatively easy analysis can be used to describe mathematically complicated trends and to predict growth. Only…

General Finance · Quantitative Finance 2017-06-27 Ron W. Nielsen

In this paper, we study a class of population models with time-varying factors, represented by one-dimensional piecewise smooth autonomous differential equations. We provide several derivative formulas in "discrete" form for the…

Classical Analysis and ODEs · Mathematics 2024-11-07 Renhao Tian , Jianfeng Huang , Yulin Zhao

In high-dimensional time-series analysis, it is essential to have a set of key factors (namely, the style factors) that explain the change of the observed variable. For example, volatility modeling in finance relies on a set of risk…

Machine Learning · Computer Science 2023-03-27 Dapeng Li , Feiyang Pan , Jia He , Zhiwei Xu , Dandan Tu , Guoliang Fan

In this paper we show an alternative way of defining Fourier Series and Transform by using the concept of convolution with exponential signals. This approach has the advantage of simplifying proofs of transforms properties and, in our view,…

History and Overview · Mathematics 2022-01-20 Francisco Mota

With the latest advances in Deep Learning-based generative models, it has not taken long to take advantage of their remarkable performance in the area of time series. Deep neural networks used to work with time series heavily depend on the…

Machine Learning · Computer Science 2024-02-19 Guillermo Iglesias , Edgar Talavera , Ángel González-Prieto , Alberto Mozo , Sandra Gómez-Canaval

Early estimates of the transmission potential of emerging and re-emerging infections are increasingly used to inform public health authorities on the level of risk posed by outbreaks. Existing methods to estimate the reproduction number…

Quantitative Methods · Quantitative Biology 2016-10-10 Gerardo Chowell , Cécile Viboud , Lone Simonsen , Seyed Moghadas

Long-term time series forecasting is a long-standing challenge in various applications. A central issue in time series forecasting is that methods should expressively capture long-term dependency. Furthermore, time series forecasting…

Machine Learning · Computer Science 2024-11-06 Xingyu Zhang , Siyu Zhao , Zeen Song , Huijie Guo , Jianqi Zhang , Changwen Zheng , Wenwen Qiang

Starting from the characterization of the past time evolution of market prices in terms of two fundamental indicators, price velocity and price acceleration, we construct a general classification of the possible patterns characterizing the…

Statistical Mechanics · Physics 2009-10-31 J. V. Andersen , S. Gluzman , D. Sornette

Real-world growth processes, such as epidemic growth, are inherently noisy, uncertain and often involve multiple growth phases. The logistic-sigmoid function has been suggested and applied in the domain of modelling such growth processes.…

Neural and Evolutionary Computing · Computer Science 2020-12-10 Oluwasegun A. Somefun , Kayode Akingbade , Folasade Dahunsi

A phenomenological model to describe the Corona Virus(covid-19) Pandemic spread in a given population is developed. It enables the identification of the key quantities required to form adequate policies for control and mitigation in terms…

Populations and Evolution · Quantitative Biology 2020-03-31 Anantanarayanan Thyagaraja

Although Transformer-based methods have significantly improved state-of-the-art results for long-term series forecasting, they are not only computationally expensive but more importantly, are unable to capture the global view of time series…

Machine Learning · Computer Science 2022-06-17 Tian Zhou , Ziqing Ma , Qingsong Wen , Xue Wang , Liang Sun , Rong Jin