Author Archives: R.P. Churchill

Model-Predictive Control

Model Predictive Control comes in different forms, but all variations work in roughly the same way. Traditional forms of control act on signals derived from a currently-determined (usually by sensors) state and the difference between that state and the desired … Continue reading

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“What is a Mutex?”

This was the first question I was asked in an interview sometime around 2006. I didn’t know the answer, which is exceptionally annoying because I’d been using them for years without knowing what they were called. This is a danger … Continue reading

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Course Wrap-up: JavaScript: Understanding the Weird Parts

I finished plowing though Anthony Alicea’s Udemy course, JavaScript: Understanding the Weird Parts, and found it to be quite satisfying. To answer the question left hanging yesterday, yes, the course did describe more details of prototype inheritance, and it did … Continue reading

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JavaScript Inheritance: A Form of Composition

Lectures 53 through 56 of JavaScript: Understanding the Weird Parts discuss more about the creation and manipulation of objects under the hood. I’d seen different aspects of this material previously, which gave me a different take on how to build … Continue reading

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JavaScript IIFEs

The Udemy course, JavaScript: Understanding the Weird Parts, includes 85 lectures. In lecture 45 I finally encountered something meaningfully new, IIFEs, or Immediately Invoked Function Expressions. This construction is unique to JavaScript in an explicit sense, though there is mention … Continue reading

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A Better Insight Into Agile and Scrum Roles

I’ve been attending a lot of meetups over the last few months and the one for the Pittsburgh chapter of the IIBA (International Institute of Business Analysts) was special because of the terrific speaker. A gentleman named Rick Clare gave … Continue reading

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To Do List Project: Part 10

Right now just plowing ahead with either PHP/MySQL, Bootstrap, or whatever is going to be kind of rote. Make filters, pretty up screens, etc. That would just be practice reps without much hardcore learning. Therefore, once I finish plowing through … Continue reading

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A Simple Discrete-Event Simulation: Part 89

Direct link for mobile devices. I was walking a few miles in the nice weather this evening when two possible solutions popped into my head for the DisplayGroup drag problem I had in the simulation app (where the pointer arrow … Continue reading

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To Do List Project: Part 9

I spent way too many hours not getting something to work that should be simple. I’m sure that I’m missing something obvious but I need to throw in the towel for today and get a post up. The problem is … Continue reading

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To Do List Project: Part 8

Today I began straightening out the calculation of total elapsed time for all slices associated with each To Do item. This work included three components: getting the date/time calculations correct and performed consistently (all on the PHP side and none … Continue reading

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