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Simon Kwan
Simon Kwan

58 Followers

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Jan 21, 2022

General Topology — Part 4

What is Urysohn’s Lemma ? From previous article, we have learnt many essential topological concepts. Now, you have a fair amount of topology under your belt, you are ready to tackle a deep theorem in topology: Urysohn’s lemma A topological space (X, τ) is a Normal Space iff for every two disjoint nonempty closed subsets A…

Math

8 min read

General Topology — Part 4
General Topology — Part 4
Math

8 min read


Dec 25, 2021

General Topology — Part 3

In previous articles, I have discussed the definition of a topological space and continuous function. General Topology — Part 1 What is General Topology ?simonkwan-35335.medium.com General Topology — Part 2 ε-δ Definition of Continuous Functionsimonkwan-35335.medium.com In this article, I will discuss some essential topological concepts that are closely related: Neighbourhood, Limit Point, Closed Set, Closure and Dense Set. Let’s start our journey…

Math

6 min read

General Topology — Part 3
General Topology — Part 3
Math

6 min read


Nov 28, 2021

General Topology — Part 2

ε-δ Definition of Continuous Function Remember the ε-δ definition of Continuous Function that you have learnt in your high school ? A function f : R → R is said to be continuous at x0 ∈ R if ∀ε>0, ∃δ>0 such that|x−x0|<δ ⇒|f(x)−f(x0)|< ε A function is continuous over an open interval if it is…

Math

5 min read

General Topology — Part 2
General Topology — Part 2
Math

5 min read


Nov 13, 2021

General Topology — Part 1

What is General Topology ? General topology is the branch of topology that deals with the basic set-theoretic definitions and constructions used in topology. It is the foundation of most other branches of topology, including differential topology and algebraic topology. Why should I learn General Topology? Because it is the basic language of modern mathematics…

Topology

7 min read

General Topology — Part 1
General Topology — Part 1
Topology

7 min read


Aug 11, 2020

Detail proof of Universal Approximation Theorem — Part 1

This is an article for those who are interested in Artificial Neural Network and want to know why it works. In 1989, George Cybenko has published a paper to explain why it works and proved the following theorem, Universal Approximation Theorem:

Universal Approximation

8 min read

Detail proof of Universal Approximation Theorem — Part 1
Detail proof of Universal Approximation Theorem — Part 1
Universal Approximation

8 min read

Simon Kwan

Simon Kwan

58 Followers

MSc Computer Science, BSc Math, BSc Mechanical Engineering

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