* Posts by Man inna barrel

4 posts • joined 10 Jun 2019

Electric cars can't cut UK carbon emissions while only the wealthy can afford to own one

Man inna barrel

Hydroflouric acid from burning Lithium batteries? I would like to see your chemistry. Hydroflouric acid production is already a problem with ICE engine compartment fires. It is due to PTFE insulation on wires getting hot enough to denature. Fire services are aware of this, and take precautions to avoid exposure.

Hydroflouric acid is indeed very nasty stuff. Unlike, say, sulphuric acid, it does usually not burn on contact. But over a few hours, it penetrates the skin, and the flouride ions then muck up calcium chemistry in the body, by making calcium into insoluble flouride.

Bit of a time-saver: LibreOffice emits 6.3 with new features, loading and UI boosts

Man inna barrel

Re: Fourier transform?

One of the first spreadsheets I wrote was for Fourier series analysis of non-linear distortion in amplifiers. Prior to that, I drew out a matrix of rectangles on a piece of paper, and banged out the contents of each cell on a calculator. I am a bit nerdy about Fourier transforms. Bloody useful stuff. One of the first programmes I wrote in C on my first home computer was an implementation of the Fast Fourier Transform (FFT), based purely on a couple of pages in Bracewell's excellent book. I did not understand malloc and pointer doodahs, so all the arrays were on the stack, but it worked.

I could throttle you right about now: US Navy to ditch touchscreens after kit blamed for collision

Man inna barrel

Soft keys

I detest touch screen interfaces for most things. My character error rate on texting is typically around 20%, using a modern mobile phone. I am seeing much more touch screen interface stuff on complex test equipment like spectrum analysers. One of the problems I first encountered was pointing out some interesting feature on the screen, and the stupid instrument responded to my touch and Did Something. So I had to reset to defaults and start again.

I have quickly glossed the comments, and I am surprised that I could not find a reference to a soft key interface. This is where the interface has a graphical screen surrounded by anonymous physical buttons. The functions of the hardware keys can vary depending on what task or mode the user has selected, and adjacent labels on the screen tell the user what the current function of each button is. I really like this system for controlling complex test equipment. It is often augmented by a numeric keypad and spin wheel.

I will grant that this interface is more expensive to implement than a touch screen, but for complex RF test kit and military stuff, it would appear to be vastly superior. The screen and buttons can be made very rugged. And it still has the advantage that button names/functions are programmable in firmware, and not hard wired.

Idle Computer Science skills are the Devil's playthings

Man inna barrel

Call yourself a computer scientist?

Keep him on the course, but ban him from the computer terminals.

Real computer science does not require the use of a computer. Edsger Dijstra famously did not use a computer for years. Pencil and paper were good enough for him.


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