TAYSTUDIO operation notes · tool guides · tech/career · useful posts
As the sample size grows, the sample mean converges to a normal distribution for any population — verified with five distributions, plus why the CLT matters for estimation and confidence intervals.
![Testing Means: the t-test [One, Two (Student's & Welch's), Paired Samples t-test]](assets/posts/t-test/cover.webp)
Is a difference in two group means a real difference or just variability — the rationale for the t-test, its assumptions (normality, equal variance), and worked calculations for each type.
Why FastAPI (async / I/O-bound) and how it relates to Python's GIL, installing FastAPI and uvicorn with pip, the relationship between a web framework and a web application (ASGI/WSGI), and two ways to run the server with uvicorn in PyCharm plus the built-in Swagger UI.
When you overwrite PATH on Linux/macOS and basic commands like ls·vi·vim stop working with 'command not found' — check with echo $PATH and restore the base paths (/bin, /usr/bin, etc.) with export PATH, plus how :$PATH preserves the existing paths.
In Windows CMD, cd can't move to another drive. Why you must type 'D:' to go from C: to the D drive — the Windows filesystem with an independent root per drive vs Linux's single root (/).
Install Python on Windows and register the install path and the Scripts (pip) path in the system PATH so that just typing 'python' or 'pip' works in cmd. Covers the difference between user and system variables and the site-packages structure of pip-installed libraries.
From why confidence intervals exist, to the hypothesis-testing view, to the truth behind the common misconception that 'there's a 95% probability the mean is inside the interval.'
An undergraduate thesis from 2019 — using a neural network (ANN) to predict PM2.5 concentrations 6/12 hours ahead. 94,225 observations from weather + air-quality data, AIC·VIF variable selection, Window Learning. Plus the time-lag pitfall discovered two years later.
7 implementation modules (Java) that show up repeatedly in Samsung-style simulation problems — 90° rotation, Periodic Boundary Condition (PBC), reverse direction, multi-condition sort, BFS, spiral coords, concurrent List remove. Plus 3 traps I fell into. Based on codetree / Baekjoon past problems.
![[New Grad] Samsung Electronics Coding Test Review (Samsung Research / Innovation Center)](assets/posts/career-samsung-coding-test-review/cover.jpg)
5 attempts at the Samsung Research coding test — application timelines, exam environment, language restrictions, and lessons from each round.