AI Tech Journal · JA / EN
The latest in AI,
explained in depth.
New papers explained the day they land — plus the core theory, the silicon and the industry landscape. Assumes nothing.
Where to startpick by what you want
Latestupdated daily
📄
2026-10-21 · Paper walkthroughs
Paper Explained: Refusal in Language Models Is Mediated by a Single Direction — saying "no" lives on one line inside the model
When chat models turn down harmful requests, that behavior is
Paper Deep-Dives · ★
◆
2026-10-13
What Ratio Should the Validation Split Be — I Swept It, and What Mattered Was the Count, Not the Ratio
When you split your data into training and validation, is it 8
Machine Learning Basics
◆
2026-09-27
Dark Silicon — You Can Place the Transistors, You Just Can't Light Them All
The number of transistors you can put on a chip keeps rising,
Scaling & Power
◆
2026-09-23 · Paper walkthroughs
The Fourier Transform from Scratch — Reading a Signal as a Stack of Pure Tones
A signal drawn against time hides the thing you usually want t
Numerical Computing
🎲
2026-09-23 · Paper walkthroughs
Bayes' Theorem from Scratch — Why a 99% Accurate Test Can Be a Coin Flip
Bayes' theorem is four symbols that reverse a conditional prob
Probability & Statistics
◆
2026-08-27
LDPC and Turbo Codes — The Error Correction Behind 5G and Deep Space
Shannon proved in 1948 that these codes exist, and nobody coul
Coding Theory · ★
🔐
2026-09-23 · Paper walkthroughs
RSA from Scratch — The Number Theory Behind Public Keys
RSA lets you publish a key that locks but cannot unlock. This
Security
◆
2026-10-21 · Paper walkthroughs
Paper Explained: Holi-World — Turning First-Person Recordings into a Ledger of the Room, Then Teaching a VLM to Reason over It
Holi-World (arXiv:2610.26549) automatically turns first-person
Time Series · ★
🏭
2026-08-29
Mapping the Semiconductor Supply Chain — From Sand to Chip, Who Holds What
One pass through the whole chain that makes a chip — design (E
Supply Chain
◆
2026-08-27
Solving Systems of Equations — Direct Methods and Iterative Methods
How much a bridge sags, how heat spreads through a room, what
Numerical Computing · ★
📐
2026-09-13 · Paper walkthroughs
PCA from Scratch — Eigenvectors as the Axes of Your Data
A cloud of correlated data has a grain — a direction along whi
Linear Algebra
◆
2026-08-25
HLS and DASH — How Video Actually Reaches You
Streamed video does not flow — a player downloads small files
Media in Production
◆
2026-08-29
Upstream Engineering from Scratch — Why Projects Are Won or Lost at Requirements
Requirements, then high-level design, then detailed design — w
Engineering Process
◆
2026-10-20 · Paper walkthroughs
Dynamic Band Splitting — Letting Each Mixture Decide Where the Frequency Bands Go
Band-split source separators carve the spectrum into hand-desi
Audio & Speech · ★
◆
2026-09-06
RAG vs Fine-Tuning — Which One, and When
The two main ways to make an LLM better, compared on four axes
RAG & Retrieval
🏭
2026-08-29
Upstream of Semiconductors — Wafers, Photoresist, and Specialty Gases
How sand becomes silicon that is 99.999999999% pure, gets pull
Supply Chain
◆
2026-08-27
Concurrency from Scratch — Locks, Atomics, and Memory Models
Why data races happen and why they refuse to reproduce in your
Parallel & Distributed · ★
◆
2026-09-13 · Paper walkthroughs
Gradient Descent from Scratch — The Geometry of Learning
Every model that learns is walking downhill on a surface it ca
Calculus & Optimization
◆
2026-08-25 · Paper walkthroughs
Why Opus Won — The Design of a Modern Audio Codec
Audio codecs used to split cleanly into speech codecs and musi
Audio Codecs · ★
◆
2026-08-29
The Craft of Requirements — Why "We Built Exactly What They Asked For" Fails
Why shipping precisely what a stakeholder asked for produces s
Engineering Process
🏋
2026-10-12 · Paper walkthroughs
Transformers Stop Thinking Too Early — How a One-Layer Rank-8 LoRA Stretches 3-Line Reference Following to 50
Pretrained LLMs follow in-context variable references for only
Training & Alignment · ★
🏭
2026-08-29
Inside the Equipment Makers — What ASML, AMAT, TEL and Lam Actually Build
Chip manufacturing is four actions repeated hundreds of times
Supply Chain · ★
◆
2026-08-27
Build Your Own Autograd — A Mini PyTorch in 100 Lines
Start from a single Value class, add operator overloading, top
Numerical Computing · ★
🎲
2026-08-27 · Paper walkthroughs
Statistical Learning Theory — Why Does Learning Generalize?
You only ever see finitely many examples, yet the model answer
Probability & Statistics · ★
◆
2026-08-25 · Paper walkthroughs
Neural Compression — The Codec That Learns
JPEG's quantization table and H.264's prediction modes were ta
Video Codecs · ★
◆
2026-08-29
Estimation and Scope — The Cone of Uncertainty and How to Negotiate
Estimates miss because a question about a range gets answered
Engineering Process · ★
📄
2026-10-11 · Paper walkthroughs
From Evidence to Action: How Tool-Using Agents Fail — Reading the Failure Diagnostics and Interventions
SafeActBench splits tool-using agent failures into a chain of
Paper Deep-Dives · ★
🏭
2026-08-29
IP Cores and the Fabless Model — How Arm Rules Silicon Without Making a Single Chip
Why a company that only sells blueprints ends up at the center
Supply Chain · ★
◆
2026-08-26 · Paper walkthroughs
Probabilistic Data Structures — Counting Without Counting
Bloom filters, HyperLogLog and the Count-Min sketch explained
Data Structures · ★
🎲
2026-08-27 · Paper walkthroughs
Optimal Transport — The Mathematics of Moving Distributions
Optimal transport measures the distance between two probabilit
Probability & Statistics · ★
◆
2026-08-25 · Paper walkthroughs
Neural Audio Codecs — EnCodec and the Foundation Under Speech LLMs
MP3 and Opus were hand-designed around what the ear cannot hea
Audio Codecs · ★
◆
2026-08-29
Architecture Decisions — Telling Apart What You Can Undo From What You Cannot
How to separate the design decisions you can cheaply reverse f
Engineering Process · ★
🤖
2026-10-10 · Paper walkthroughs
SafeActBench explained (arXiv:2610.07753) — tool agents fail before execution
A correct outcome does not mean the action was supported by ev
Agents
🏭
2026-08-29
EDA Tools from Scratch — Chips Are Written in Software
Nobody hand-places the tens of billions of transistors on a le
Supply Chain · ★
◆
2026-08-26
Approximation Algorithms — Trading Exactness for a Guarantee
The craft of giving up on the optimal answer while attaching a
Complexity · ★
🎲
2026-08-27
Monte Carlo Methods from Scratch — Solving Integrals with Dice
An integral you cannot solve can still be estimated: scatter r
Probability & Statistics · ★
◆
2026-08-25
WebP, AVIF, JPEG XL — The Image Codec Changing of the Guard
Three successors clearly beat JPEG on efficiency, and the web
Image Codecs · ★
◆
2026-08-29
Upstream Work in the AI Era — When Code Gets Cheap, What Gets Valuable?
When implementation gets cheap, which parts of the cost remain
Engineering Process · ★
📄
2026-10-10 · Paper walkthroughs
Paper Explained: EVISKILL — Rewriting an Agent's Playbook from Replayable Evidence
A framework for automatically revising an LLM agent's skill do
Paper Deep-Dives · ★
🏭
2026-08-29
The Geopolitics of Chips — Export Controls and Supply Chain Rewiring, Explained Technically
Why chokepoints form exactly where they do, from three conditi
Supply Chain · ★
◆
2026-08-25
NP-Completeness from Scratch — Not Unsolvable, but Fast to Verify
NP does not stand for Non-Polynomial. It is the class of probl
Complexity
🎲
2026-08-27 · Paper walkthroughs
Kernel Methods and Gaussian Processes — The Champions Before Neural Nets
Before deep learning took over, kernel SVMs held the crown in
Probability & Statistics · ★
◆
2026-08-22
Motion Compensation from Scratch — Where 90% of Video Compression Happens
What decides where a video codec's bits go isn't the transform
Video Codecs · ★
◆
2026-08-27
File Systems from Scratch — What Does "Saved" Actually Guarantee?
If the power dies half a second after your editor says "Saved,
OS & Runtime · ★
◆
2026-10-09 · Paper walkthroughs
Paper Explained: STEPQuant — When and Where Quantization Errors Matter in Delta-Rule Recurrent States
Linear-attention states have a fixed size, yet under concurren
Time Series · ★
🔬
2026-08-27
The Physics of NAND Flash — Remembering by Trapping Electrons
Why does a memory stick keep your photos with the power off? S
Device Physics · ★
◆
2026-08-25
Simulated Annealing and Genetic Algorithms — What to Do When Exact Solving Breaks Down
Why search methods that guarantee nothing end up running real
Search & Optimization · ★
◆
2026-08-27
Jacobians and Hessians — Multivariable Calculus, Drawn
The Jacobian is a magnifying glass at a point; the Hessian is
Calculus & Optimization · ★
◆
2026-08-22
MP3 and Psychoacoustics — The Science of Sounds You Cannot Hear
MP3 does not throw away sounds that aren't there — it throws a
Audio Codecs
◆
2026-08-27 · Paper walkthroughs
Distributed Databases — CAP, Replication and Consensus
The moment you add a second copy of your database, a brand-new
Databases · ★
Written from the papers themselves. Every piece links the paper page and its PDF.
◉AI248
- Paper Explained: Holi-World — Turning First-Person Recordings into a Ledger of the Room, Then Teaching a VLM to Reason over It ★ MEMBER arXiv:2610.26549
- Paper Explained: Refusal in Language Models Is Mediated by a Single Direction — saying "no" lives on one line inside the model ★ MEMBER arXiv:2406.11717
- Paper Walkthrough: Dynamic Band Splitting — Letting Each Mixture Decide Where the Frequency Bands Go ★ MEMBER arXiv:2610.14993
- Paper Deep Dive: Transformers Stop Thinking Too Early — How a One-Layer Rank-8 LoRA Stretches 3-Line Reference Following to 50 ★ MEMBER "arXiv:2609.36585
- Paper Deep Dive: From Evidence to Action: How Tool-Using Agents Fail — Reading the Failure Diagnostics and Interventions ★ MEMBER arXiv:2610.07753
▣Semiconductors4
- CPU Pipelines and Branch Prediction — The Factory Inside One Clock Tick ★ MEMBER arXiv:1801.01203
- Systolic Arrays — Building the Heart of the TPU From Scratch ★ MEMBER arXiv:1704.04760
- The GPU Memory Hierarchy — HBM, SRAM, Registers, and Why Movement Wins FREE arXiv:2205.14135
- How AI Accelerators Are Designed — What Actually Separates GPUs, NPUs, and TPUs ★ MEMBER arXiv:1704.04760
◇Algorithms5
- The Fourier Transform from Scratch — Reading a Signal as a Stack of Pure Tones FREE Fourier 1822
- Probabilistic Data Structures — Counting Without Counting ★ MEMBER "doi:10.1145/362686.362692
- The FFT from Scratch — Why Convolution Turns into Multiplication ★ MEMBER "doi:10.1090/S0025-5718-1965-0178586-1
- Graph Algorithms from Scratch — Shortest Paths and Where They Lead FREE arXiv:1603.09320
- Hashing and Nearest-Neighbor Search — The Groundwork Under Vector Search FREE arXiv:1603.09320
∫Math for AI14
- Bayes' Theorem from Scratch — Why a 99% Accurate Test Can Be a Coin Flip FREE Bayes 1763
- Gradient Descent from Scratch — The Geometry of Learning FREE arXiv:1609.04747
- PCA from Scratch — Eigenvectors as the Axes of Your Data FREE Pearson 1901
- Compression Is Prediction Is Intelligence — LLMs Through Information Theory ★ MEMBER arXiv:2309.10668
- Symmetry and Equivariance — How Group Theory Shapes Network Design ★ MEMBER arXiv:1602.07576
◐Media & Compression3
- Neural Audio Codecs — EnCodec and the Foundation Under Speech LLMs ★ MEMBER arXiv:2210.13438
- Neural Compression — The Codec That Learns ★ MEMBER arXiv:1611.01704
- Why Opus Won — The Design of a Modern Audio Codec ★ MEMBER RFC 6716
⬢Systems3
- RSA from Scratch — The Number Theory Behind Public Keys FREE "Rivest
- Distributed Databases — CAP, Replication and Consensus ★ MEMBER "USENIX ATC 2014
- LLM Security — Prompt Injection and How to Actually Defend Against It ★ MEMBER arXiv:2302.12173
★
Membership unlocks every page
All articles, textbook chapters, study units and close readings. $4.99/month, cancel any time.
About membership
✉
Updates on the topics you care about
Autonomous driving, AI models, agents, semiconductors — we email you when a new paper walkthrough lands in your topics. Free readers can subscribe too.
Pick topics
⤓
Use it as an app
Add to your home screen: full screen, and articles you have opened stay readable offline.