<rss xmlns:atom="http://www.w3.org/2005/Atom" version="2.0"><channel><title>Mathematics - Tag - Zhiverse</title><link>https://yao-chih.netlify.app/en/tags/mathematics/</link><description>Mathematics - Tag - Zhiverse</description><generator>Hugo -- gohugo.io</generator><language>en</language><managingEditor>yaochihh@gmail.com (Josh)</managingEditor><webMaster>yaochihh@gmail.com (Josh)</webMaster><copyright>Zhiverse</copyright><atom:link href="https://yao-chih.netlify.app/en/tags/mathematics/" rel="self" type="application/rss+xml"/><item><title>Spatiotemporal Prediction of Unknown Areas Based on Structured State Space Diffusion and Resolution Adaptive Fixed Rank Kriging</title><link>https://yao-chih.netlify.app/en/spatiotemporal-prediction-of-unknown-areas-based-on-structured-state-space-diffusion-and-resolution-adaptive-fixed-rank-kriging/</link><pubDate>Tue, 28 Jul 2026 00:00:00 +0800</pubDate><author>Author</author><guid>https://yao-chih.netlify.app/en/spatiotemporal-prediction-of-unknown-areas-based-on-structured-state-space-diffusion-and-resolution-adaptive-fixed-rank-kriging/</guid><description><![CDATA[<div class="details admonition info open">
        <div class="details-summary admonition-title">
            <i class="icon fas fa-info-circle fa-fw" aria-hidden="true"></i>Abstract<i class="details-icon fas fa-angle-right fa-fw" aria-hidden="true"></i>
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            <div class="admonition-content"><p>With the rapid advancement of sensing and remote sensing technologies, data collected in transportation, meteorology, and environmental monitoring have become increasingly characterized by high-frequency observations and cross-regional spatiotemporal dependencies. However, missing observations, irregular sampling, and prediction at unobserved locations remain major challenges for spatiotemporal forecasting. To address these issues, this study proposes a spatiotemporal forecasting framework, $\text{SSSD}^{\text{S4+MRTS}}$ + AFRK, which integrates Structured State Space Diffusion Model with S4 Layers ($\text{SSSD}^{\text{S4}}$) and Multi-Resolution Thin-Plate Spline (MRTS) basis functions to jointly model long-range temporal dependencies and spatial structural patterns. MRTS is incorporated into the S4 layers as additional spatial conditioning information, enabling $\text{SSSD}^{\text{S4+MRTS}}$ to learn spatiotemporal dynamics conditioned on observed locations. During inference, the framework further integrates MRTS-based Resolution Adaptive Fixed Rank Kriging (AFRK), which preserves the spatial consistency of the predicted field while enabling interpolation at unobserved locations. Experiments conducted on the Weather2K, MERRA-2, and the dataset from The Second Competition on Spatial Statistics for Large Datasets are used to compare the proposed framework with Temporal Fusion Transformers (TFT), Vector Autoregression (VAR), Stochastic Variational Gaussian Process (SVGP), and Spatio-temporal DeepKriging (STDK). The results demonstrate that $\text{SSSD}^{\text{S4+MRTS}}$ generally improves Mean Squared Prediction Error (MSPE) under most experimental settings, with particularly notable gains in future forecasting at unobserved locations. Overall, the findings indicate that integrating temporal dynamic modeling with spatial statistical methods effectively enhances spatiotemporal forecasting performance under missing-data and spatial extrapolation scenarios.</p>
<p><strong>Keywords</strong>: Structured State Space Diffusion Model, Multi-Resolution Thin-Plate Spline Basis Functions, Resolution Adaptive Fixed Rank Kriging, spatiotemporal forecasting, spatial interpolation, missing data imputation</p>
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        </div>
    </div>]]></description></item><item><title>Python Mathematical Computation Performance Benchmark</title><link>https://yao-chih.netlify.app/en/python-mathematical-computation-performance-benchmark/</link><pubDate>Fri, 10 Jul 2026 11:03:37 +0800</pubDate><author>Author</author><guid>https://yao-chih.netlify.app/en/python-mathematical-computation-performance-benchmark/</guid><description><![CDATA[<div class="featured-image">
                <img src="https://josh-test-lab.github.io/posts/Python%20Mathematical%20Computation%20Performance%20Benchmark/cover%20image.webp" referrerpolicy="no-referrer">
            </div><p>The cover image was generated by Google Gemini.</p>
<div class="details admonition tip open">
        <div class="details-summary admonition-title">
            <i class="icon fas fa-lightbulb fa-fw" aria-hidden="true"></i>Tip<i class="details-icon fas fa-angle-right fa-fw" aria-hidden="true"></i>
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        <div class="details-content">
            <div class="admonition-content">This project was written in October 2024.</div>
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    </div>
<p>While taking the graduate course <em>Simulation Study</em>, the instructor mentioned that the random numbers used in modern computers and programming are mostly not truly random in the strict sense, but rather <strong>pseudo-random numbers</strong>. Pseudo-random numbers are generated through mathematical algorithms that compute the next value based on the previous state. Therefore, as long as the algorithm, initial value (Seed), and current state are known, the entire random number sequence can theoretically be reproduced. This raises an interesting question: if every pseudo-random number can be calculated from the previous value, where does the very first number come from?</p>]]></description></item><item><title>Learning Control Charts</title><link>https://yao-chih.netlify.app/en/learning-control-charts/</link><pubDate>Mon, 06 Jul 2026 12:47:58 +0800</pubDate><author>Author</author><guid>https://yao-chih.netlify.app/en/learning-control-charts/</guid><description><![CDATA[<div class="featured-image">
                <img src="https://raw.githubusercontent.com/Josh-test-lab/website-assets-repository/refs/heads/main/posts/Learning%20Control%20Charts/cover%20image.webp" referrerpolicy="no-referrer">
            </div><p>The cover image was generated by ChatGPT.</p>
<p>While attending <a href="/en/the-35th-south-taiwan-statistics-conference" rel="">The 35th South Taiwan Statistics Conference</a>, I first learned about control charts from an experienced professor who had spent many years working in manufacturing environments. Intrigued by the concept, I decided to spend some time organizing my notes and gaining a foundational understanding of what control charts are.</p>]]></description></item><item><title>Time Complexity</title><link>https://yao-chih.netlify.app/en/time-complexity/</link><pubDate>Thu, 01 Jan 2026 11:36:20 +0800</pubDate><author>Author</author><guid>https://yao-chih.netlify.app/en/time-complexity/</guid><description><![CDATA[<div class="featured-image">
                <img src="https://raw.githubusercontent.com/Josh-test-lab/website-assets-repository/refs/heads/main/posts/time%20complexity/cover%20image.webp" referrerpolicy="no-referrer">
            </div><p>Time complexity is used to describe how the computation time of an algorithm grows as the input size increases during its execution. Because the processing capabilities, hardware architecture, and system environment differ across computer devices, comparing algorithms solely based on actual execution time often fails to yield representative and portable conclusions. Therefore, time complexity is usually measured by the &ldquo;number of basic operations executed,&rdquo; and asymptotic complexity is employed to analyze the efficiency of algorithms, establishing a hardware-independent and universally applicable performance evaluation method.</p>]]></description></item><item><title>Proof of the Variance of the Sum of Two Random Variables</title><link>https://yao-chih.netlify.app/en/proof-of-the-variance-of-the-sum-of-two-random-variables/</link><pubDate>Sat, 04 Oct 2025 12:06:14 +0800</pubDate><author>Author</author><guid>https://yao-chih.netlify.app/en/proof-of-the-variance-of-the-sum-of-two-random-variables/</guid><description><![CDATA[<div class="featured-image">
                <img src="https://raw.githubusercontent.com/Josh-test-lab/website-assets-repository/refs/heads/main/posts/Proof%20of%20the%20Variance%20of%20the%20Sum%20of%20Two%20Random%20Variables/cover%20image.webp" referrerpolicy="no-referrer">
            </div><p>This is a classic proof in mathematical statistics. That is, <strong>whether the variance of the sum of two random variables equals the sum of their variances</strong>.</p>]]></description></item><item><title>Logistic Regression</title><link>https://yao-chih.netlify.app/en/logistic-regression/</link><pubDate>Wed, 23 Jul 2025 10:55:24 +0800</pubDate><author>Author</author><guid>https://yao-chih.netlify.app/en/logistic-regression/</guid><description><![CDATA[<div class="featured-image">
                <img src="https://raw.githubusercontent.com/Josh-test-lab/website-assets-repository/refs/heads/main/posts/Logistic%20Regression/cover%20image.webp" referrerpolicy="no-referrer">
            </div><p>The cover image was generated by ChatGPT.</p>
<h2 id="introduction">Introduction</h2>
<p><strong>Logistic regression</strong> is a type of binary classification model derived from <strong>linear regression</strong>. Unlike linear regression, which fits a regression line that passes through the data points by minimizing the sum of squared distances, known as the <strong>least squares method</strong>. The goal of logistic regression is to find a decision boundary that clearly separates the data into two distinct classes.</p>]]></description></item><item><title>Common Distance Measures</title><link>https://yao-chih.netlify.app/en/common-distance-measures/</link><pubDate>Fri, 20 Jun 2025 11:09:08 +0800</pubDate><author>Author</author><guid>https://yao-chih.netlify.app/en/common-distance-measures/</guid><description><![CDATA[<div class="featured-image">
                <img src="https://raw.githubusercontent.com/Josh-test-lab/website-assets-repository/refs/heads/main/posts/Common%20Distance%20Measures/cover%20image.png" referrerpolicy="no-referrer">
            </div><p>Cover image generated by ChatGPT.</p>
<h2 id="introduction">Introduction</h2>
<p>How to calculate distance is an important aspect of modern statistical analysis. Choosing different distance metrics may lead to different results in statistical analysis methods. The following introduces commonly used distance metrics.</p>]]></description></item><item><title>Rectangular, Polar, and Spherical Coordinates</title><link>https://yao-chih.netlify.app/en/rectangular-polar-and-spherical-coordinates/</link><pubDate>Sun, 08 Jun 2025 14:57:34 +0800</pubDate><author>Author</author><guid>https://yao-chih.netlify.app/en/rectangular-polar-and-spherical-coordinates/</guid><description>&lt;div class="featured-image">
                &lt;img src="https://raw.githubusercontent.com/Josh-test-lab/website-assets-repository/main/posts/Rectangular%20Polar%20and%20Spherical%20Coordinates/cover%20image.png" referrerpolicy="no-referrer">
            &lt;/div>Common coordinate systems include the rectangular coordinate system, the polar coordinate system, and the spherical coordinate system. Each has its own applications, advantages, and limitations.</description></item><item><title>Anscombe's Quartet</title><link>https://yao-chih.netlify.app/en/anscombes-quartet/</link><pubDate>Mon, 02 Jun 2025 21:40:50 +0800</pubDate><author>Author</author><guid>https://yao-chih.netlify.app/en/anscombes-quartet/</guid><description><![CDATA[<div class="featured-image">
                <img src="https://raw.githubusercontent.com/Josh-test-lab/website-assets-repository/main/posts/Anscombe%27s%20quartet/cover%20image.png" referrerpolicy="no-referrer">
            </div><p>The cover image about Anscombe&rsquo;s Quartet was generated by ChatGPT, and it used the following prompt: &ldquo;The digital design highlights the title &lsquo;Anscombe&rsquo;s Quartet&rsquo; in bold, white sans-serif letters, centered against a dynamic abstract backdrop. The image is split into four colorful quadrants, each showcasing unique textures and patterns—ranging from painterly hues and curved lines to scattered circles and dots.&rdquo;</p>
<h2 id="introduction">Introduction</h2>
<p>While listening to a presentation today, I happened to hear a term——Anscombe&rsquo;s Quartet, a term I had never encountered before, yet it has significant implications in both statistics and data visualization.</p>]]></description></item><item><title>Prove $\frac{64}{16} = 4$</title><link>https://yao-chih.netlify.app/en/64-divided-by-16/</link><pubDate>Sat, 29 Mar 2025 00:06:43 +0800</pubDate><author>Author</author><guid>https://yao-chih.netlify.app/en/64-divided-by-16/</guid><description>&lt;div class="featured-image">
                &lt;img src="https://raw.githubusercontent.com/Josh-test-lab/website-assets-repository/refs/heads/main/posts/64%20divided%20by%2016/6416.png" referrerpolicy="no-referrer">
            &lt;/div>Weird proof $\frac{64}{16} = 4$ .</description></item></channel></rss>