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顯示具有 控制工程 標籤的文章。 顯示所有文章

8/27/2026

機率與統計的應用

生活中到處充滿著不確定性,例如吃飯排隊的等候時間、機台生產的良率、民調統計數字的分析等等。工業系也開設許多相關的課程,例如品質管制、資料分析、智慧製造、實驗設計、機器學習、人工智慧等等,以解決工商業的問題。不確定性和雜訊,也是 (電機、軟工、機械、化工、土木、生醫、材料) 工程系統中常見的問題。

許多人修這門課的時候,很痛苦 (註 1)。除了了解其應用外, 有許多的網路資源:

8/25/2026

一些常聽的 Podcast 節目和培養英文聽力的方法

一些常聽的 Podcast 節目 (*),適合坐車、(讓眼睛) 休息、睡前或運動時聽 (Some frequently listened-to podcasts (*) suitable for listening while traveling, giving your eyes a rest, before bed, or during exercise.) 
  • Acquired (You could look at its transcript using iPhone.)

8/03/2026

研究 (Research)

Journal articles:

5/11/2024

Fluid approximations for stochastic optimization

When one encounters a stochastic optimization/control problem, one popular approach is to transform it into a deterministic problem by fluid approximation. The following highly-cited classic papers illustrate the applications of this approach:   

2/05/2024

學習數學的四個層次:(3) 在許多行業的應用

學習數學的四個層次:(0) 如何學數學(1) 代表具備基礎的知識與能力(2) 邏輯推理和抽象思考的能力(3) 在許多行業的應用(4) 純粹滿足好奇心或求知慾

2015/12/1 初稿,持續更新中。

一般性說明
  • 數學是科學之母,科學則是工業的基礎,所以大學工學院的數理化課程總學分超過 1/3。可以參考如何選填大學志願
  • 應用在不同的領域 (理工商醫農、教育),如財務工程、設計電腦、貨物產銷、工程師、使用統計學分析學習成效等等。
  • 抽象的模式與思考的方式,適用於現在與未來的應用,以微分為例,物理學的距離微分是速度,經濟學中成本的微分是邊際成本,電子學的電荷微分是電流。也就是說,可以使用函數表示任何待解的問題,函數的微分便可以研究其變化和極值的情況,例如機器學習中,超參數 (hyperparameter) 的學習 。
  • 基本的原則變動不大,微積分、機率和統計學、和線性代數已經有 200 年以上的歷史,可幫助未來的自我學習。許多人說學校學的東西,畢業後立即過時或沒用,我覺得很疑惑。大學只是基礎教育,必須不斷地學習新的東西,以因應產業和職務的變化;最近熱門的大數據 (big data) 和人工智慧 (artificial intelligence),其數學基礎正是這些課程

9/02/2023

Champion-level drone racing using deep reinforcement learning

Kaufmann, E., Bauersfeld, L., Loquercio, A. et al. Champion-level drone racing using deep reinforcement learning. Nature 620, 982–987 (2023). https://doi.org/10.1038/s41586-023-06419-4

First-person view (FPV) drone racing is a televised sport in which professional competitors pilot high-speed aircraft through a 3D circuit. Each pilot sees the environment from the perspective of their drone by means of video streamed from an onboard camera. Reaching the level of professional pilots with an autonomous drone is challenging because the robot needs to fly at its physical limits while estimating its speed and location in the circuit exclusively from onboard sensors. Here we introduce Swift, an autonomous system that can race physical vehicles at the level of the human world champions. The system combines deep reinforcement learning (RL) in simulation with data collected in the physical world. Swift competed against three human champions, including the world champions of two international leagues, in real-world head-to-head races. Swift won several races against each of the human champions and demonstrated the fastest recorded race time. This work represents a milestone for mobile robotics and machine intelligence, which may inspire the deployment of hybrid learning-based solutions in other physical systems.

4/16/2023

Model-Based Deep Learning

N. Schlezinger, Y. Eldar, and S. Boyd, Model-Based Deep Learning: On the Intersection of Deep Learning and Optimization, IEEE Access, vol. 10, 2022.

Decision making algorithms are used in a multitude of different applications. Conventional approaches for designing decision algorithms employ principled and simplified modelling, based on which one can determine decisions via tractable optimization. More recently, deep learning approaches that use highly parametric architectures tuned from data without relying on mathematical models, are becoming increasingly popular. Model-based optimization and data-centric deep learning are often considered to be distinct disciplines. Here, we characterize them as edges of a continuous spectrum varying in specificity and parameterization, and provide a tutorial-style presentation to the methodologies lying in the middle ground of this spectrum, referred to as model-based deep learning. We accompany our presentation with running examples in super-resolution and stochastic control, and show how they are expressed using the provided characterization and specialized in each of the detailed methodologies. The gains of combining model-based optimization and deep learning are demonstrated using experimental results in various applications, ranging from biomedical imaging to digital communications.

11/19/2022

Robust and Adaptive Optimization

Dimitris Bertsimas and Dick Den Hertog, Robust and Adaptive Optimization, Dynamic Ideas, 2022.

The purpose of this book is to provide a unified, insightful, and original treatment of robust and adaptive optimization.

5/23/2022

Garrett van Ryzin talks about optimization

以前教營收管理的時候,讀了不少哥倫比亞商學院 van Ryzin 教授的文章,其中一篇說,他們的研究是在解決10年後的問題。各位注意喔,是商學院

最近在讀一本書,某教授寫的序,開頭四個字,就是學用落差

5/08/2022

2021 Tesla Impact Report

2021 Tesla Impact Report

Autopilot Safety

In 2021, we recorded 0.22 crashes for every million miles driven in which drivers were using Autopilot technology (Autosteer and active safety features). For drivers who were not using Autopilot technology (no Autosteer and active safety features), we recorded 0.77 crashes for every million miles driven. By comparison, NHTSA’s most recent data shows that in the United States there are 1.81 automobile crashes for every million miles driven.

5/07/2022

Outracing champion Gran Turismo drivers with deep reinforcement learning

Wurman, P.R., Barrett, S., Kawamoto, K. et al. Outracing champion Gran Turismo drivers with deep reinforcement learning. Nature 602, 223–228 (2022). https://doi.org/10.1038/s41586-021-04357-7.

Many potential applications of artificial intelligence involve making real-time decisions in physical systems while interacting with humans. Automobile racing represents an extreme example of these conditions; drivers must execute complex tactical manoeuvres to pass or block opponents while operating their vehicles at their traction limits. Racing simulations, such as the PlayStation game Gran Turismo, faithfully reproduce the non-linear control challenges of real race cars while also encapsulating the complex multi-agent interactions. Here we describe how we trained agents for Gran Turismo that can compete with the world’s best e-sports drivers. We combine state-of-the-art, model-free, deep reinforcement learning algorithms with mixed-scenario training to learn an integrated control policy that combines exceptional speed with impressive tactics. In addition, we construct a reward function that enables the agent to be competitive while adhering to racing’s important, but under-specified, sportsmanship rules. We demonstrate the capabilities of our agent, Gran Turismo Sophy, by winning a head-to-head competition against four of the world’s best Gran Turismo drivers. By describing how we trained championship-level racers, we demonstrate the possibilities and challenges of using these techniques to control complex dynamical systems in domains where agents must respect imprecisely defined human norms.

2/21/2022

7 real-world applications of reinforcement learning

 Joy Zhang, 7 real-world applications of reinforcement learning, gocoder, February 17, 2022

1. Autonomous driving with Wayve

2. Personalizing your Netflix recommendations

3. Optimizing inventory levels for Walmart

4. Improving search engine results with search.io

5. Improving language models with OpenAI's WebGPT

6. Trading on the financial markets with IBM's DSX platform

7. Robotics with the University of California, Berkeley

11/08/2021

A unified framework for stochastic optimization

W.B. Powell, A unified framework for stochastic optimization, European Journal of Operational Research, 2019, Volume 275, Issue 3, 16 June 2019, Pages 795-821. (pdf)

Stochastic optimization is an umbrella term that includes over a dozen fragmented communities, using a patchwork of sometimes overlapping notational systems with algorithmic strategies that are suited to specific classes of problems. This paper reviews the canonical models of these communities, and proposes a universal modeling framework that encompasses all of these competing approaches. At the heart is an objective function that optimizes over policies that is standard in some approaches, but foreign to others. We then identify four meta-classes of policies that encompasses all of the approaches that we have identified in the research literature or industry practice. In the process, we observe that any adaptive learning algorithm, whether it is derivative-based or derivative-free, is a form of policy that can be tuned to optimize either the cumulative reward (similar to multi-armed bandit problems) or final reward (as is used in ranking and selection or stochastic search). We argue that the principles of bandit problems, long a niche community, should become a core dimension of mainstream stochastic optimization.

9/19/2021

Unbiased Gradient Estimation in Unrolled Computation Graphs with Persistent Evolution Strategies

Paul Vicol, Luke Metz, and Jascha Sohl-Dickstein, Unbiased Gradient Estimation in Unrolled Computation Graphs with Persistent Evolution Strategies, ICML 2021. (paperOutstanding Paper Awards)

Unrolled computation graphs arise in many scenarios, including training RNNs, tuning hyperparameters through unrolled optimization, and training learned optimizers. Current approaches to optimizing parameters in such computation graphs suffer from high variance gradients, bias, slow updates, or large memory usage. We introduce a method called Persistent Evolution Strategies (PES), which divides the computation graph into a series of truncated unrolls, and performs an evolution strategies-based update step after each unroll. PES eliminates bias from these truncations by accumulating correction terms over the entire sequence of unrolls. PES allows for rapid parameter updates, has low memory usage, is unbiased, and has reasonable variance characteristics. We experimentally demonstrate the advantages of PES compared to several other methods for gradient estimation on synthetic tasks, and show its applicability to training learned optimizers and tuning hyperparameters.