# Category: Electronics

Dec 02 2017

## Necessity and Sufficiency

Am I sufficient? Am I even necessary? If you’re plagued by these existential questions and have ended up here in your quest for an answer, then I’ve got some bad news for you. The answer to both is no. I keed. I keed. Actually, the bad news is that this post is about necessity and …

Nov 26 2017

## NFA and DFA Equivalence Theorem Proof and Example

Finite state automata (FSA), also known as finite state machines (FSM), are usually classified as being deterministic (DFA) or non-deterministic (NFA). A deterministic finite state automaton has exactly one transition from every state for each possible input. In other words, whatever state the FSA is in, if it encounters a symbol for which a transition …

Nov 21 2017

## Proof of Kleene’s Theorem

In my last post, “Kleene’s Theorem,” I provided some useful background information about strings, regular languages, regular expressions, and finite automata before introducing the eponymously named theorem that has become one of the cornerstones of artificial intelligence and more specifically, natural language processing (NLP).  Kleene’s Theorem tells us that regular expressions and finite state automata …

Nov 17 2017

## Kleene’s Theorem

Stephen Cole Kleene was an American mathematician who’s groundbreaking work in the sub-field of logic known as recursion theory laid the groundwork for modern computing.  While most computer programmers might not know his name or the significance of his work regarding computable functions, I am willing to bet that anyone who has ever dealt with …

Nov 09 2017

## Not String Theory – String Facts

As a computer programmer for more than a quarter of century, I don’t think I have ever thought much about strings. I knew the basics. In every language I’d worked with, strings were a data type unto themselves. Superficially they are a sequence of characters, but behind the scenes, computers store and manipulate them as …

Jan 10 2017

## Number System Complements

In my last post about binary signed integers, I introduced the ones complement representation. At the time, I said that the ones complement was found by taking the bitwise complement of the number. My explanation about how to do this was simple: invert each bit, flipping 1 to 0 and vice versa. While it’s true that …

Nov 14 2016

## Osram Unveils New LIDAR System for Autonomous Vehicles

LIDAR (LIght Detecting And Ranging) sensors play a critical role in almost all autonomous and semiautonomous vehicles. Using lasers and relatively simple time of flight calculations, LIDAR can very accurately measure distances and generate detailed 3D maps of environments, but traditionally the best performing systems have been large and very expensive. German lighting manufacturer Osram Opto Semiconductors unveiled their new …

Jul 26 2016

## Binary Signed Integers – Ones Complement

In the last post, we saw that one of the major failings of the signed magnitude representation was that addition and subtraction could not be performed on the same hardware as for unsigned integers. As I pointed out, the reason for this is because negating a number in signed magnitude does not yield the additive …

Jun 23 2016

## Researchers Create Low-Power Nanowire Artificial Synapses

South Korean scientists from the Department of Materials Science and Engineering at Pohang University of Science and Technology appear to have cleared the largest obstacle to the feasibility of building brain-like computers: power consumption. In their paper “Organic core-sheath nanowire artificial synapses with femtojoule energy consumption,” published in the June 17th edition of Science Advances, …

May 04 2016

## Arduino IDE on Ubuntu – Can’t Open Device

If you’ve just installed the Arduino IDE on Ubuntu, you’ve likely encountered an error similar to the one above the first time you tried to upload a sketch to your board. The error that I specifically get reads: avrdude: ser_open(): can’t open device “/dev/tty/ACMO”: Permission denied ioctl(“TIOCMGET”): Inappropriate ioctl for device Problem uploading to board. …