← 回到 Reading
Daily Dose of DS 2026-09-08

Momentum in ML, Explained Visually and Intuitively!

Strix is an open-source AI agent framework designed for automated penetration testing of applications. It addresses security gaps that traditional CI/CD pipelines and unit tests often miss, such as broken access control and business logic flaws. The tool functions by crawling live applications, dynamically probing for abuse paths, and providing verified proofs-of-concept for vulnerabilities. Benchmarks show it has identified over 600 vulnerabilities across hundreds of real-world companies and repositories. Momentum is an optimization technique designed to accelerate the training of machine learning models by smoothing the parameter update trajectory. Unlike standard gradient descent, which relies solely on the current gradient and often results in oscillations, momentum incorporates a moving average of past gradients. This helps cancel out unnecessary oscillations and directs the update process toward the optimal solution more efficiently. Proper tuning of the momentum rate hyperparameter is essential to balance convergence speed and stability. Group Relative Policy Optimization (GRPO) is a reinforcement learning method designed to enhance the reasoning and mathematical capabilities of LLMs without the need for labeled data. The process involves generating multiple candidate responses, evaluating them through deterministic reward functions, and updating the model using a specific GRPO loss function. Tools such as UnslothAI and HuggingFace TRL are utilized to implement this fine-tuning process efficiently on base models like Qwen3-4B.

閱讀原文 ↗
目錄 3 段
  1. 01Agent hackers to test your AI apps!
  2. 02Momentum in ML, explained visually and intuitively!
  3. 03Build a Reasoning LLM using GRPO
OPEN-SOURCE

Agent hackers to test your AI apps!

Strix is an open-source AI agent framework designed for automated penetration testing of applications. It addresses security gaps that traditional CI/CD pipelines and unit tests often miss, such as broken access control and business logic flaws. The tool functions by crawling live applications, dynamically probing for abuse paths, and providing verified proofs-of-concept for vulnerabilities. Benchmarks show it has identified over 600 vulnerabilities across hundreds of real-world companies and repositories.

  • Strix is an open-source AI pentesting agent with over 23,000 stars on GitHub.
  • Traditional software testing methods like unit tests and CI often fail to detect adversarial behavior or broken access control.
  • Real-world security incidents like the Moltbook token exposure and Tea App ID leak highlight the risks of unvetted code.
  • Strix maps exposed routes and dynamically probes abuse paths in running applications.
  • The framework has discovered more than 600 verified vulnerabilities, some of which resulted in assigned CVEs.
  • Strix is intended to be integrated into modern development workflows, running before releases or continuously.
HANDS-ON

Momentum in ML, explained visually and intuitively!

Momentum is an optimization technique designed to accelerate the training of machine learning models by smoothing the parameter update trajectory. Unlike standard gradient descent, which relies solely on the current gradient and often results in oscillations, momentum incorporates a moving average of past gradients. This helps cancel out unnecessary oscillations and directs the update process toward the optimal solution more efficiently. Proper tuning of the momentum rate hyperparameter is essential to balance convergence speed and stability.

  • Gradient descent often suffers from vertical oscillations that slow down the path to the optimal solution.
  • Momentum addresses oscillations by using a moving average of past gradients to update parameters.
  • The technique accelerates movement in the horizontal direction toward the minima while reducing unnecessary vertical steps.
  • The momentum rate is a hyperparameter that must be tuned to prevent overshooting or slow convergence.
  • Distributed training via PySpark MLlib and Bayesian Optimization are alternative methods mentioned for training optimization.
  • A high momentum rate can cause the optimization process to overshoot the minimum point of the loss function.
HANDS-ON

Build a Reasoning LLM using GRPO

Group Relative Policy Optimization (GRPO) is a reinforcement learning method designed to enhance the reasoning and mathematical capabilities of LLMs without the need for labeled data. The process involves generating multiple candidate responses, evaluating them through deterministic reward functions, and updating the model using a specific GRPO loss function. Tools such as UnslothAI and HuggingFace TRL are utilized to implement this fine-tuning process efficiently on base models like Qwen3-4B.

  • GRPO eliminates the need for human-labeled data by using deterministic reward functions to score model outputs.
  • The method relies on a sampling engine to generate multiple candidate responses for each reasoning task.
  • UnslothAI is used for efficient fine-tuning, while HuggingFace TRL provides the GRPOTrainer and GRPOConfig components.
  • Reward functions in this framework validate responses based on exact format, approximate format, answer correctness, and numerical values.
  • LoRA (Low-Rank Adaptation) is employed to fine-tune specific modules rather than the entire model weights.
  • The Open R1 Math dataset serves as the primary source for math problems used in the reasoning fine-tuning process.