# Cryptography

We are swimming in a sea of information. Without encryption this whole operation would be a very public event. Encryption enables our communications to be anonymous or secure and makes e-commerce and private communications possible. Because of this, I registered for Dan Boneth’s cryptography course. At this point, I’ve only watched one lecture, but I […]

By Tim Booher In

# Review: Boys Should Be Boys: 7 Secrets to Raising Healthy Sons

From a one-star review on Amazon: The content was obvious and the tone was judgmental. The complete lack of nuance is painful. Apparently receiving an MD over 25 years ago makes this Dr. Laura-style author an expert in child psychology? Let’s leave the psychology topics to those professionally trained in that discipline. I’ve always enjoyed […]

# GE GXULQR Twist and Lock Kitchen or Bath Filtration System Replacement Filter Won’t Fit

If you ever have to replace your under the sink GE filter (specifically the GE GXULQR), be ready for a frustrating ride. It looks like this: You can find the manual here and the ge product page here. It is billed as the “Twist and Lock” Replacement Filter, the inside female hex socket sometimes rotates […]

It has been awhile since I’ve studied optimization, but gradient descent is always good to brush up on. Most optimization involves derivatives. Often known as the method of steepest descent, gradient descent works by taking steps proportional to the negative of the gradient of the function at the current point. Mathematically, gradient descent is defined […]

By Tim Booher In

# FlexEvents: WOD 3 Simulation

During a recent CrossFit competition, flex on the mall, we had to accomplish a team chipper in which we were able to pick the order of team members in order to minimize our workout time. The workout was simple: 50 burpees, 40 over the box jumps, and 30 kettle-bell snatches. Each exercise had to be […]

By Tim Booher In

# CY2014 Quarter 1 Financial Review

Chrissy and I review our spending on a quarterly basis. Updating every 90 days isn’t too long to correct mistakes and remember purchases, but it also allows for the busy multi-week sprints that life presents us. While we have used every financial management program available, I’ve found the most straightforward and flexible solution is to […]

By Tim Booher In

# Fun with Bessel Functions

Well, I certainly forget things faster than I learn them. Today is a quick review of Bessel functions and their applications to signal processing. The Bessel functions appear in lots of situations (think wave propagation and static potentials), particularly those that involve cylindrical symmetry. While special types of what would later be known as Bessel […]

# Excel Sorting and Grouping

I had two tables downloaded from Amazon: Items Order Date Order ID Title Category 1/26/14 102-4214073-2201835 Everyday Paleo Family Cookbook 1/13/14 115-8766132-0234619 Awesome Book A 1/13/14 115-8766132-0234619 Awesome Book B and Orders Order Date Order ID Subtotal 1/6/14 102-6956821-1091413 $43.20 1/13/14 115-8766130-0234619$19.42 1/16/14 109-8688911-2954602 \$25.86 I’m building our Q1 2014 taxes and needed rows […]

By Tim Booher In

# Sampling Exploration

I needed to review the Nyquist–Shannon sampling theorem. The coolest thing about Nyquist is that it expresses the sample-rate in terms of the function’s bandwidth and leads to a formula for the mathematically ideal interpolation algorithm. What is sampling? Sampling is nothing more than converting a signal into a numeric sequence. Shannon states: If a […]

# Practical Cutting Stock Problem

Warning. This post is for an audience of close to zero. My technical friends will find this pretty basic, and my non-technical friends will find this too technical. Welcome to the middle space that I occupy between these two worlds. I wanted to build this series of retaining walls to replace the overgrown ivy and […]

By Tim Booher In