Monthly Archives: April 2012

Randomly Choosing a Winner from a Weighted List with Excel

Posted on April 28, 2012 by mathscinotes

My wife is participating in a friendly contest at work that encourages employees to exercise. The employees record how many laps they walk around a set course during a month. At the end of the month, an Excel “drawing” is … Continue reading →

Posted in software | 3 Comments

A Little Specification Reading Before Bed

Posted on April 25, 2012 by mathscinotes

Introduction Nothing like reading ITU optical specifications to help you get to sleep after an active day. Since I have been doing some work on dispersion, let’s pull up ITU G.695 – Characteristics of Optical Systems. I want to see … Continue reading →

Posted in Fiber Optics | Tagged , , | Leave a comment

Optical Fiber Dispersion Formula – Where Did This Come From?

Posted on April 22, 2012 by mathscinotes

Introduction Most Fiber-To-The-Home (FTTH) deployments in North America use SMF-28e fiber from Corning, which is to fiber what Kleenex is to tissue. Unfortunately, I am so familiar with this particularly product that I can recite its specifications from memory. However, … Continue reading →

Posted in Fiber Optics | 3 Comments

Customer Service Math

Posted on April 19, 2012 by mathscinotes

While this post does not address a math problem, it does address an important aspect of mathematics — the presentation of data. I occasionally have to prepare information on various items for our Customer Service group. For a number of … Continue reading →

Posted in Management | 10 Comments

Phone Loads For Backup Time Testing

Posted on April 17, 2012 by mathscinotes

Introduction I often have to assist with writing test procedures. One of our procedures involves testing the battery backup time for the equipment we install at the subscriber’s home, which is called an Optical Network Unit (ONU). Nearly all ONUs … Continue reading →

Posted in Electronics | Leave a comment

Dimensional Analysis and Submarine Running Time

Posted on April 13, 2012 by mathscinotes

Introduction Part of my job is looking at backup power sources for remote telecommunications gear. I recently have been doing some reading on fuel cells, which we are starting to see in some backup power applications. I started googling to see … Continue reading →

Posted in Electronics | 1 Comment

Battery Self-Discharge Math

Posted on April 3, 2012 by mathscinotes

Introduction I deal with a lot of battery issues. Our products generally ship with an Uninterruptible Power Supply (UPS) that contains a 7.2 A-hr Sealed Lead-Acid (SLA) battery. I occasionally hear customers say that we shipped them bad batteries. Since … Continue reading →

Posted in Electronics | Tagged , | 4 Comments