Aapeli Vuorinen Stochastic Modeling & Optimization / Software Engineering / Mathematics

Blog

I sometimes write thoughts about what I’ve been thinking or working on, and then I post them here. There’s also an assortment of other writings around the web on a handful of other blogs that I’ve contributed to.

Using Floating-Point Numbers to Represent Geographic Coordinates June 30, 2023

Using 32-bit floats to represent coordinates gives you 1.7 meters of precision in the worst-case, for 64-bit floats this goes down to about 3 nanometers.

Solving Killer Sudoku as a Mixed Integer Program January 18, 2023

Formulating and solving Killer Sudoku as a Mixed Integer Linear Program.

Bypassing Bad Certificate Pinning using mitmproxy September 13, 2022

How I managed to get around badly implemented certificate pinning for one particular app.

Transparent mitmproxy for iPhone using Tailscale in a VM September 12, 2022

Using Tailscale in a VM to transparently mitmproxy connections from an iPhone

Recitations on Simulation in Python January 28, 2022

A set of Python notebooks to work from random number generation to systems simulation and variance reduction

Quick tip: Syncing a task list using Fastmail January 26, 2022

Quick note on how to set up a task list and sync it through Fastmail

Serving your Columbia site over HTTPS December 9, 2021

How to make sure your Columbia content is accessible on modern browsers

Modeling NYC Taxi Profitability using a Leontief-style Model May 20, 2021

Exploring NYC open data to build a Leontief-style model for taxicab profitability.

A crude gRPC benchmark April 20, 2021

How fast is gRPC in Python from one machine to another in the same datacenter over a secure connection?

Postgres Text Search: Full Text vs Trigram Search February 24, 2021

A brief introduction to text search in Postgres.

Workshop on Agent-Based Modeling January 22, 2021

Workshop on Agent-Based Modeling run for Columbia Undergraduate Mathematical Modelling Workshop

Generate vector tilesets from OpenStreetMap data on Ubuntu 20.04 using OpenMapTiles January 6, 2021

Generating vector tilesets from OpenStreetMap data

Rendering a basic OpenStreetMap image on Ubuntu 20.04 October 24, 2020

Rendering a basic OpenStreetMap image

A private ngrok with WireGuard and Nginx September 17, 2020

Using WireGuard with nginx to reverse proxy TCP connections into private networks through a secure connection

Safe Blues: A Method for Estimation and Control in the Fight Against COVID-19 September 2, 2020

Battling COVID-19. Think outside the box. Think beyond contact tracing.

Installing CUDA 10.1, cuDNN, TensorFlow 2.3.0, and Python 3.8 on Ubuntu 20.04 August 14, 2020

This is annoyingly painful and I keep on rediscovering it, so here's a quick reference.

JSON to gRPC transcoding with Envoy August 1, 2020

Setting up JSON to gRPC transcoding on Envoy proxy

gRPC-Web through Envoy with nginx July 3, 2020

Setting up gRPC-Web proxied through nginx and Envoy proxy

Quick tip: Getting around IP-based geo-blocking using SSH tunnelling June 29, 2020

How to circumvent simple IP-address based geo-blocking by renting a server for a few minutes and using SSH tunnelling.

Protocol Buffers vs JSON June 12, 2020

What are Protocol Buffers and how do they compare to JSON?

Using computers efficiently June 7, 2020

How to get the most out of your most expensive tool.

Why don't protocol buffers have fixed length arrays? July 12, 2019

One of the most primitive types you'd expect from a low-level data serialisation format are fixed length arrays, so I was surprised to find out protocol buffers don't have one.

Masters Thesis May 20, 2019

The Blockchain Propagation Process: a Machine Learning and Matrix Analytic Approach

A crash course into digital audio representation December 8, 2018

We all know what sound is and how it works, but how do you digitally store and represent it?

Quick tip: Search any website instantly with Firefox keywords December 7, 2018

Learn how to quickly search your favourite website from the address bar in Firefox.

NIST weighs in on the blockchain October 30, 2018

What does the National Institute of Standards and Technology think about blockchain?

GitHub Status Generator October 23, 2018

GitHub went down with funny status messages and I was bored.

Quick tip: Enabling IPv6 on an AWS VPC October 21, 2018

Gotta get those sweet, sweet 128-bit addresses.

Using YubiKeys with X.509 certificates on macOS September 1, 2018

This tutorial will show you how to manage X.509 certificates with a YubiKey to privision your own Public Key Infrastructure with a root certificate authority, intermediate certificate authority, and end entity certificate signing.

Demystifying the blockchain July 3, 2018

Interested in blockchain but never really had time to sift through the buzzwords? Here I'll introduce the basic concepts in the area through a fairly technical point of view.

CloudFlare to the rescue December 15, 2017

I never thought DNS queries could be so slow. Here's how I made them orders of magnitude faster with CloudFlare.

Rational numbers have repeating decimal expansions March 6, 2017

A real number is rational if and only if its decimal expansion is repeating or terminating. Here's how to prove it.

Apartment hunting with Google Sheets and the Google Maps Distance Matrix API March 3, 2017

Hunting for an apartment in Melbourne during peak season with a limited budget is no trivial task! Here's how I used some online APIs to help me compare different apartments.

Enabling SSL everywhere, hooray! June 12, 2016

After several hours of fighting with nginx and SELinux, I finally got Let's Encrypt working on all my websites.