Tag: Engineering

Smart Car Seat Selection: How My Tesla Knows the Driver | November 03 2025, 14:29

Incidentally, in my Tesla, there’s a very clever system for identifying the driver. If I enter the car first but sit in the passenger seat, placing my phone immediately in the central console for charging, and then Nadia enters second but sits in the driver’s seat and also places her phone there, her profile is selected automatically because she’s the driver, even though both phones are on charge under the central console.

So, there are two possibilities: either there is an antenna which can precisely detect that a phone has crossed the driver’s door rather than entering the car in any other way, or there is a camera focused on the driver. In any case, it’s very reassuring that it “just works”.

Unveiling “Recommender Algorithms”: A Comprehensive Guide on Recommendation Systems | October 25 2025, 17:36

I finally released a book on #RecSys! It’s called Recommender Algorithms, where I’ve compiled over 50 recommendation algorithms with detailed mathematical derivations, thorough explanations, and code examples.

https://www.testmysearch.com/books/recommender-algorithms.html

It all started early this spring in Germany, when I attended an ACM conference and sketched out the first structure of the book while analyzing the talks from the RecSys track. And now, just six months later, it has come to life.

Why did I write it? Because neither online nor in print is there a single, accessible resource that deeply explores recommendation algorithms of various types and purposes. There are articles focused on small subsets, but collecting and systematizing approaches—from foundational methods to the very latest—seems to have never been done before. I don’t know if I succeeded, but I’d love to hear your feedback.

Please like & share!

P.S. Click at READ SAMPLE to see the first 40 pages. The table of contents is there as well.

https://www.testmysearch.com/books/recommender-algorithms.html

https://www.testmysearch.com/books/recommender-algorithms.html

From Tesla Model Y to Model S Plaid: A Swap Experience | October 14 2025, 16:51

Recently, my Tesla Model Y fell ill, and the dealership gave me a Model S Plaid as a loaner car. It’s simply a monster, accelerating to 100 km/h in 2 seconds. Over a thousand horsepower. But after driving it for a week, Nadezhda and I realized that we would still not trade our Model Y for a Model S.

Well, the fact that it’s unusually low to the ground is a minor issue. We would get used to that. But getting out from behind the wheel is always incredibly awkward for me. My belly isn’t that big, but in the Model S, it’s like a real cockpit. You have to carefully sit down and climb out, whereas in the Model Y, you just jump in somehow and go.

Moreover, the Model S is really noisy inside compared to the Model Y. You can hear the road. And this is for a price twice that of the Model Y. Also, for some reason, the mode where you just walk away from the car works less sensitively, and locks the car only when you are already quite far away.

And then there are the turn signals. What idiot decided to put their buttons on the steering wheel? It’s impossible to get used to that. The steering wheel still turns, and the buttons are always somewhere unclear.

But, damn it, it’s very beautiful from the outside. Especially with a light interior.

By the way, Tesla has somewhat poorly thought out the mechanism for issuing a replacement car, and it works with only one driver. You can’t set two keys for two different phones. Moreover, it would be nice to store the settings in the cloud and receive a replacement car already adjusted to your preferences.

And the car fell ill in an interesting way too. It’s funny when the car on the highway tells you that there’s a little problem, the engine is dead, but you should not distract yourself, just keep driving. After parking, the car might theoretically not drive, but so far all is normal. If not, we will tell you. Meanwhile, your drive will not sound the same.

As I understood, the car simply switched from 4-wheel drive to 2-wheel drive. Funny that such a fallback exists at all. Already fixed, it needed an inverter replacement.

Gold and Gadgets: Tracing Global Influence and Metal Monopolies | October 14 2025, 03:13

Rajesh Exports states on their website that they process 35% of the gold mined on the planet. Of course, they are exaggerating, but overall, India and Rajesh do shape the market. It turns out that 11% of all the gold on the planet is adorned on Indian women. Additionally, it was found that in 1947, 70% of all mined gold was in the USA. From 1934 to 1970, it was legally prohibited for private individuals to own gold in the USA. Approximately 22% of all the gold ever accounted for on the surface of the Earth has been mined from a plateau in South Africa called the Witwatersrand. And if you consider all the gold mined throughout history, it would amount to less than an Olympic swimming pool.

China buys up silver, with India not far behind. Interestingly, platinum is significantly used in the production of catalytic converters for vehicles – almost 40% of the global production goes there. China, of course, holds much of this production.

Practically every smartphone, tablet, or touchscreen monitor that we use is coated with a thin layer of indium tin oxide (ITO). This material has a unique combination of properties: it is almost completely transparent while also conducting electricity excellently. This allows the screen to register your touches.

Although lithium is now strongly associated with batteries, historically and still today, a significant portion of it is used in the production of glass and ceramics.

From Vision to Bookshelf: Launching “Recommender Algorithms” | October 13 2025, 11:54

Finally, I have released a book! It is called Recommender Algorithms — it contains more than 50 recommendation algorithms with mathematical explanations, detailed descriptions, and code examples.

It all started early in the spring in Germany, when I attended the ACM conference and made the first sketches of the book’s structure, analyzing reports on the RecSys stream. And now, six months later, the book has been published.

Why did it appear? Because there is no single, accessible source either online or in print where the recommendation algorithms of various types and purposes are thoroughly examined. There are articles focused on narrow aspects, but to collect and systematize the developments — from fundamental to the most recent — until now, it seems, no one has managed to do it for some reason. Maybe no one needed to. Suddenly, I found I needed to. I don’t know if I succeeded, but I am eager for your feedback.

Available on Amazon and Barnes and Noble. There is a Russian automatic translation (surprisingly, but very decent), but I do not know how to sell it yet.

https://www.testmysearch.com/books/recommender-algorithms.html?FB

(This is not my only book, but today — just about this one.)

Decoding Solr and Lucene: Engineering Insights and Algorithms | October 06 2025, 17:11

Preparing a book for publication on Solr&Lucene. What do you think about publishing such a translation on Amazon? 🙂

The book is about algorithms and under-the-hood engineering. I haven’t seen books from this angle yet, maybe someone will find it interesting.

The Surprising Origins of the Word “Tumbler” for Drinking Glasses | October 05 2025, 15:32

In our language, glasses are called tumblers. I decided to find out why, because a tumbler is essentially an acrobat.

There are two mutually exclusive theories. According to one, the original tumbler glasses had a rounded or slightly convex bottom, which allowed them to “rock” or “tumble” (to tumble), but not tip over completely. So, a tumbler in this sense is kind of like a “weeble.” According to the other, they were specifically made so they could not be put down on the table open, because, say on a ship, they could tip over and the valuable rum would spill out.

Introducing the AI-Powered Text-to-Diagram Generator | September 30 2025, 20:57

While working on a book, I realized what kind of product I’m missing. It’s an AI diagram generator based on textual descriptions.

The idea is that the master document for the diagram is text. This textual description can be (and should be) quite detailed, so the generated diagram exactly matches the author’s vision. The diagram itself is not edited. That is, it can be edited – moving circles around, but ideally, after making changes, the system should update the text, generating from which will result in what the user adjusted.

The result — the diagram — should correspond as closely as possible to the description. If it does not match the description because, for example, it’s impossible to make a triangle with three obtuse angles, the system should do its best and provide a verbal response about what didn’t work. The user can then modify the task so that the system complies and produces the diagram correctly.

But then we understand that the author might have randomly achieved something that they liked with their flawed text. And if regenerated, it might turn out differently, and not necessarily better. Therefore —

You could ask the system to generate a diagram description from the diagram, which, if inputted back into the diagram generator, would result exactly in what the description was generated from. Yes, this description would be more verbose and complex, but it would more reliably describe the result.

So, from this point, you are no longer working with the diagram. You are working with text. If a diagram is needed — you simply compile the text into a diagram and it turns out as needed. But you don’t even work directly with the text. You work with this diagram-description text through an LLM, asking it to add some block, and the text changes, but changes in a way that everything doesn’t suddenly shift.

The final diagram should be in an object form, from which raster (PNG) or vector (SVG, EPS) images can be created.

It would also be great if such a system could take existing diagrams or diagram templates so that it could borrow styles and existing conventions on how to display what.

So, these are my fantasies. If anyone has ideas on how to implement this — let’s discuss 🙂

The Ingenious Mechanics of Modern Fuel Pumps | September 28 2025, 13:36

With the purchase of a Tesla, there’s sudden interest like a fuel nozzle understanding that the tank is full. And a couple of other interesting findings on the topic.

There used to be an awkward problem at gas stations. Customers didn’t know when their tank was full and gasoline often spilled over. Engineers came up with a genius solution.

Inside the fueling nozzle, there’s a thin tube that pulls air from the car’s tank into a special membrane chamber (if you look at the “nozzle,” there will be two holes) When you press the trigger, fuel flows until the tube is submerged in gasoline (which means a full tank) and the air flow stops.

This creates a vacuum, which pulls three little steel flaps into the center of the mechanism, instantly releasing the trigger and cutting off the fuel supply.

By the way, approaching the diaphragm valve in the channel there is a compartment with a small ball inside. If for some reason the fuel nozzle falls out of the tank, the ball will block the vacuum channel, provoking a sharp increase in vacuum – and triggering the process described above.

It also turned out that the diesel nozzle is larger in size so it cannot be mistakenly inserted into a gasoline tank. But the opposite mistake can happen. Although they could have invented a different design that would work both ways from the start.

When a tanker refills an underground reservoir, the valve automatically closes when the tank is nearly full, and the gasoline vapors are sucked back into the tanker through another hose, where it condenses back into liquid fuel.

And it also turned out that if you drive away with the hose still in your car, there will be no fireballs, spilled fuel, or toppled gas pump. The hose connecting the nozzle to the pump is designed to disconnect into two parts when a certain force is applied. Next time you are at the gas station, pay attention to the metal connector on the hose. That is the break point. When the hose disconnects and you drive away, the area of the hose breaks, built-in valves in the hose cut off the fuel, but, of course, the pump will not operate for some time until everything is put back to normal again. Interestingly, this risk is considered and damage is minimized.

Oh, and here’s something for those who haven’t driven in New Jersey. By law, it’s prohibited to refuel your own vehicle. At all gas stations, there are attendants who do it for you.

Childhood Curiosity and the Mysteries of Soviet Electrical Engineering | September 23 2025, 17:00

I remember being puzzled as a child by who the idiot was that decided to make the radio plug exactly the same as the one for 220 volts. This radio plug was supposed to go into a radio socket.

As a child, I used to disassemble and “improve” almost everything electrical in the house (I hadn’t graduated to electronics yet). Of course, I got shocked many times by the outlet, but to my surprise, the old Soviet phone could also give a shock. When a call came in, the voltage in the line would jump from 12-60 volts to 120 volts 🙂

I also had an interesting experience with Christmas lights. For a younger schoolchild, it was unclear why Christmas lights could shock you since they used the same bulbs that I connected to a flat “Planeta” battery. I had to learn the technicalities 🙂 By the way, those square flat batteries have disappeared; they used to be everywhere.