Days Postings
August 2024 M T W T F S S 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 Blog Series
Copyright Notice
© Mark Biegert and Math Encounters, 2024. Publication of this material without express and written permission from this blog’s author and/or owner is strictly prohibited. Excerpts and links may be used, provided that full and clear credit is given to Mark Biegert and Math Encounters with appropriate and specific direction to the original content.
Disclaimer
All content provided on the mathscinotes.com blog is for informational purposes only. The owner of this blog makes no representations as to the accuracy or completeness of any information on this site or found by following any link on this site. The owner of mathscinotes.com will not be liable for any errors or omissions in this information nor for the availability of this information. The owner will not be liable for any losses, injuries, or damages from the display or use of this information.
Author Archives: mathscinotes
Yet More Gift Wrapping
My sister and I talk about these practical math problems all the time. Here is another good video that covers gift wrapping with a mathematical slant. Continue reading
Posted in General Mathematics
Comments Off on Yet More Gift Wrapping
A Couple of Cost Versus Run Rate Examples
I spend a fair amount of time estimating the cost of electronic components with different purchase quantities. In earlier posts, I showed how component cost quotes often reduce by ~7 % per doubling of quantity purchased. In this post, I will present quotes from two different vendors for the same part (normalized to preserve confidentiality). The component quotes from each vendor reduced by 3.6% per doubling of quantity purchased, which differs significantly from my 7% rule. While each vendor had different costs, their rates of variation with purchase quantity were identical. As I thought about these quotes, their deviation from what I usually see made sense. Continue reading
Posted in Electronics, Financial
Comments Off on A Couple of Cost Versus Run Rate Examples
Not The Way To Take A Chimney Down
I have worked on construction sites and farms, and the lack of imagination that people show with respect to safety never ceases to amaze me. This video shows what happens when someone does not think about what could happen. Continue reading
Posted in Construction, Humor
Comments Off on Not The Way To Take A Chimney Down
Network Availability
I was in an interminable meeting the other day where we were discussing the MTBF and availability of a system. My issue with this discussion is that each person in the room preferred to think about these terms in different ways. In this post, I will show that the four individuals in the meeting were actually in violent agreement and simply did not understand that what their arguments were mathematically equivalent. I wish I could say that this was the first time in my career that this had happened, but that would not be true. It happens all the time. Continue reading
Posted in Electronics, General Science
4 Comments
A Little Sandpaper Kirigami
I started using this sandpaper folding technique years ago, but I just ran across this video that does a nice job of illustrating the technique. Continue reading
Posted in Construction
Comments Off on A Little Sandpaper Kirigami
Modeling Component Costs Over Time
I frequently am asked by marketing and finance people about how component costs will vary with time. Their motivations are clear – most market segments are strongly driven by unit cost, and the marketing folks need to determine when costs will drop enough to enlarge the Total Addressable Market (TAM) for their products. Continue reading
Posted in Electronics, Financial, Management
2 Comments
I am Battling Ladybugs This Year
We have had a warm winter in Minnesota so far this year. As with every transition from fall to winter, bugs seek warmth by taking up residence in our fiber-optic enclosures. Here is my latest example, a ladybug on a returned circuit board. Continue reading
Posted in Electronics, Fiber Optics, Humor
4 Comments
Modeling Coal Energy Output
I had never seen coal until my first trip to China when I saw people on bicycles transporting coal to their homes for heat. I started to wonder just how much coal a home would need for heating. I have seen numerous values for the heat content of the various types of coal. I recalled from primary school that there were three types of coal: anthracite, bituminous, and lignite. So I would have expected three values for the heat output of coal. When I actually looked, I found dozens of grades of three primary types of coal. Each of the different grades would generate different amounts of heat per kilogram. I thought I would take a closer look at how the heat output from coal could be modeled using regression and a simplified model based on chemical heats of formation. Continue reading
Posted in General Science, Statistics
1 Comment
Gross Margin Versus Labor and Material Markups
I have spent a fair portion of my career working as an engineering contractor. In fact, I spent five years working on new business development for a large contract firm. During this time, I was involved in writing dozens of proposals on large projects. A proposal occurs at the end of the bid and proposal process (Figure 1) and constitutes a contract firm's attempt to win the project development contract. It is a key part of new business development for many companies. Continue reading
Old Way Of Specifying Phone Wire Diameter
I still work on old copper phone networks, and today I encountered wire specified as "300 pound". I had never seen a specification like this for phone wire before. As I thought about it, this specification seemed very similar to how the diameter of thread is still specified, which is by the weight in grams of a 9000 meters of fiber – a unit of measure called the denier. Continue reading
Posted in Electronics, General Mathematics, History of Science and Technology
Comments Off on Old Way Of Specifying Phone Wire Diameter