Allen Kim on Allen Kim

Buffon's Needle

Wed, 25 Jan 2017 15:43:33 -0500

Ever since learning about Buffon’s needle, I have always wanted to write a small simulation as a programming exercise for myself, and to just admire the fact that it works.

For those unaware, Buffon’s needle (or one variant of it) was a geometric probability problem that had the following setup. Given an infinite table with equally spaced vertical lines, and a needle (smaller than the spacing between lines) twirled and tossed randomly onto the table, what is the probability that it crosses one of the vertical lines?

The answer can be derived with some calculus, but I won’t go into details here. There are plenty of other sources for that. The main gist though is that the solution contains π in it! This allows us to estimate the value of π by experimentally tossing many needles and approximating the probability of crossing a line.

In the end, I wrote a small simulation with JavaScript that is running on GitHub pages. Below are relevant links.

Wikipedia

Project Page

Demo

Goto Go Trainer

Mon, 26 Dec 2016 00:00:00 +0000

Below are relevant links.

Project Page

Demo

Connect Four

Wed, 21 Dec 2016 00:00:00 +0000

Connect Four was a popular childhood game that many people played. The goal was to connect four of your own pieces either horizontally, vertically, or diagonally. This was my first time attempting to write a bot for a game. The main approach was minimax with alpha beta pruning, but I also threw in a Monte Carlo Tree Search approach to see how it would fare.

I worked on this with Porrith Suong for our graduate AI class, and we had the option for our bots to face other bots. By doing so, we were able to see their growth to the point where we cannot beat them anymore…

Below are relevant links!

Project Page

Demo

Game of Life

Fri, 04 Nov 2016 00:00:00 +0000

Game of Life is a cellular automaton, which essentially is a grid of cells that follow certain rules to evolve one generation at a time. The Game of Life is typically demonstrated on a 2D grid and it follows just 4 simple rules.

Any live cell with fewer than two live neighbours dies, as if caused by underpopulation.
Any live cell with two or three live neighbours lives on to the next generation.
Any live cell with more than three live neighbours dies, as if by overpopulation.
Any dead cell with exactly three live neighbours becomes a live cell, as if by reproduction.

These 4 rules (coming straight from Wikipedia) are simple, but the patterns that emerge are very complicated. Below are relevant links.

Wikipedia

Project Page

Demo

Fuzzy Bear

Tue, 18 Oct 2016 00:00:00 +0000

This was initially a game I worked on sophomore year of college as a side project. Called Fuzzy Bear, you controlled a skull and had to dodge many explosive teddy bears that flew in from around the borders. I hadn’t really programmed much before, so it was a nice introduction to game logic and basic programming flow.

Later on, I revisited the project in an attempt to add some neural networks to teach the skull to dodge on its own accord. It was my first time working with neural nets, and took me some time to understand. In the end, the skull was able to learn and maneuvered back and forth to dodge the bears. The system was not perfect though as the skull tended to get stuck on the boundaries.

In the demo, every time the skull dies, it attempts to learn from its mistake to do better next time around. One thing to note is that the training data is lost once the browser is refreshed or the page changes.

Below are some links.

Project Page

Demo

Network Simulations and Configuration for Delay-Tolerant Space Networks

Tue, 16 Aug 2016 00:00:00 +0000

Skill Huddle

Wed, 15 Jun 2016 00:00:00 +0000

This was a school project for Software Engineering during Spring 2016. The goal was to make a website similar to Meetup, where people would be able to create meet-ups, or as we called them, “huddles”, to meet people with similar interests in real life.

This project was my first introduction to Django and really working with object relational mapping. Overall, it was an exhausting project as we had to work out all the complex models and database structures beforehand in many diagrams…

It wasn’t my favorite project of all time, but it was a nice introduction to Django and web development.

Below are relevant links.

Project Page

Demo

Acceptance

Fri, 06 May 2016 00:00:00 +0000

Project Page

Missile Warfare

Sat, 26 Dec 2015 00:00:00 +0000

Missile Warfare was first inspired from a StarCraft custom game with the same name. The goal of the game was to “shoot” down the enemy by shooting projectiles at each other. The two teams would consist of three builders each, and would be separated into two separate islands with a large body of water in between. To “shoot” meant to summon air units that would fly towards the other island, and the builders on the other side would have to dodge them. There were many small features that made the game complicated, but I wanted to work on a simple version using Phaser.

Working with real-time action was challenging, and even now, I’m not confident that I could pull it off well. There are so many server-side issues to worry about, so I ended up delegating a lot of tasks to the client side. Of course, this can be abused to cheat the game, but as I am not intending on making this official by any means, I went that route for simplicity.

It is not hosted, but the project page can be found below.

Project Page

Analyzing Measurement Errors Associated with the Millimeter Wave Channel Sounder

Sat, 15 Aug 2015 00:00:00 +0000

Liar Game

Sat, 16 May 2015 00:00:00 +0000

The whole concept of Liar Game arose from a manga series with the same name. The characters in the series play through a series of games that require some mix of logical thinking, deception, and human psychology. Our game is based off of the final game of the series called “The Records of the Four Kingdoms”.

This was my first big team project where we tried to make a multi-player game. We used the Phaser game engine, which is JavaScript based, along with Socket.io for the real-time communication.

Below are relevant links.

Project Page

Demo