How Factor Analysis and PCA Actually Differ

A deeper look beyond the textbook distinction that’s been confusing practitioners for decades The Problem We All Face Picture this: You’re sitting in a committee meeting, and someone suggests using “factor analysis to reduce dimensions” while another colleague insists “PCA will identify the underlying factors.” Both sound reasonable. Both seem to accomplish similar goals. Yet something feels… off. If you’ve found yourself nodding along while internally questioning whether these methods are really as different as your statistics textbook claimed, you’re not alone. The standard explanation—“FA finds latent factors, PCA reduces dimensions”—is technically correct but practically incomplete. It’s like saying “cars move people, planes fly people”—true, but missing the nuanced reality of when and why you’d choose one over the other. Choosing the wrong method can lead to misleading conclusions about underlying mechanisms or inefficient models that fail in production. ...

June 13, 2025 · 10 min · Sae-Hwan Park

A Second Look at Linux: Reflections from 2025

On operating systems, evolution, and the gradual convergence of computing environments The Return Ten years ago, I attempted to make Linux my daily driver and failed. Not catastrophically – more like learning to ride a bicycle and discovering that while technically possible, the experience required more effort than I was prepared to invest. My motivation wasn’t purely practical; I secretly aspired to be a Unix user because they looked like the hackers and gurus I wanted to become someday. There was an undeniable appeal to the idea of mastering a system that seemed to separate the technically sophisticated from ordinary computer users. ...

May 30, 2025 · 13 min · Sae-Hwan Park

Writing Maintainable Array Code: When NumPy Isn't Enough

Picture this: You’re implementing a complex neural network attention mechanism, and what should be elegant mathematical operations have devolved into a maze of None indexing, cryptic axis parameters, and debugging sessions that last longer than your coffee stays warm. If you’ve been there, you’re not alone. I recently read an article titled “I don’t like NumPy” that articulated some frustrations many of us have experienced when working with multi-dimensional matrices in Python. The author makes compelling points about the cognitive overhead of NumPy’s design choices, particularly when dealing with operations across multiple dimensions. ...

May 23, 2025 · 15 min · Sae-Hwan Park

How I Leveraged C Learning to Understand Rust Better

When I first encountered Rust after years of Python experience, I thought I understood it. “Ok, Rust’s way is interesting,” I told myself, nodding along to the Book’s explanations of ownership. The compiler errors were frustrating, but I got my code working eventually. I believed I had grasped the concepts. I was wrong. It wasn’t until I stepped away to learn C and systems programming that I realized how superficial my understanding had been. Only when I could visualize memory operations – seeing exactly what happened in the stack, heap, and global memory – did Rust’s ownership system transform from a set of arbitrary rules into a coherent mental model. ...

May 17, 2025 · 14 min · Sae-Hwan Park

The Linux-Windows Bridge I Wish I'd Discovered Years Ago

I built my own Linux environment on Windows using WSL2 (and you should, too) As someone deeply immersed in AI and ML development, I’ve often found myself juggling multiple computing environments. My workday typically involves switching between a Windows laptop at work, my personal MacStudio (along with one Windows desktop) at home, and SSH connections to remote computing clusters for intensive training jobs or working on data files that should not move (ruled by DUA). This fragmentation created friction in my workflow that I was eager to solve. ...

May 9, 2025 · 16 min · Sae-Hwan Park

The Quest for Heterogeneity: Understanding Conditional Average Treatment Effects (CATE)

We unmask heterogeneity, finding out how CATE learners help target interventions to those who will benefit most The Journey Beyond Average Effects In the vast landscape of causal inference, we’ve long relied on a simple compass: the Average Treatment Effect (ATE). Like ancient mariners navigating by a single star, researchers across disciplines have used this average to guide important decisions. But what if I told you that this single metric—this lone star—only reveals a fraction of the story? ...

May 3, 2025 · 23 min · Sae-Hwan Park

The Dimensional Odyssey: Navigating the Manifolds of t-SNE and UMAP

Prologue: The Curse of Dimensionality Imagine yourself as an explorer in a vast, multidimensional wilderness. Each step you take propels you along one of hundreds, perhaps thousands of different dimensions. The terrain stretches beyond what your mind can comprehend – a hyperdimensional landscape where traditional notions of distance and proximity lose their intuitive meaning. This is the world of high-dimensional data, a realm where our human perceptual limitations become painfully apparent. ...

April 18, 2025 · 25 min · Sae-Hwan Park

From Bayes to ChatGPT: Journey For Statisticians To Understand Gen-AI

“It’s genuinely amazing that… these sorts of things can be extracted from a statistical analysis of a large body of text,” science fiction author Ted Chiang remarked in a 2023 Financial Times interview. “But, in his view, that doesn’t make the tools intelligent. Applied statistics is a far more precise descriptor, but no one wants to use that term, because it’s not as sexy.” The visionary writer’s observation cuts directly to the heart of modern AI development—beneath the marketing hype and sensationalized headlines lies a sobering truth: these systems, regardless of their impressive capabilities, remain fundamentally statistical models. And yes folks, that’s what we are going to explore in this article. ...

April 11, 2025 · 16 min · Sae-Hwan Park

Beyond the Hype: Blockchain in 2025 - The Silent Revolution

“The most profound technologies are those that disappear. They weave themselves into the fabric of everyday life until they are indistinguishable from it.” - Mark Weiser A Personal Journey: From Skepticism to Appreciation I’ll admit it: when I first encountered blockchain years ago, it felt like nothing more than a buzzword. As an economist by training, I was particularly skeptical of cryptocurrency, which seemed misnamed—less a currency and more a speculative digital asset akin to gold or jewels. The hype cycle of 2017-2018 only reinforced my doubts as blockchain was touted as a solution for virtually everything. ...

April 5, 2025 · 16 min · Sae-Hwan Park

The Uncanny Valley of AI-Generated Art: Technical Challenges Behind the Artificial Aesthetic

Background In recent times, AI-generated images have captivated the public’s imagination, with platforms like OpenAI’s ChatGPT-4o enabling users to create visuals in distinctive styles, such as those reminiscent of Studio Ghibli. This phenomenon, often termed “Ghiblification,” has sparked both admiration and ethical debates regarding the use of AI in creative processes. Despite the impressive capabilities of these AI systems, many users have noticed that AI-generated images often possess certain “weird” or unnatural characteristics. But what causes these peculiarities? There are indeed interesting points that are not often discussed in AI-generated art controversies. Let me give you the latest example. ...

March 29, 2025 · 7 min · Sae-Hwan Park