UCLA modeling class

4 жыл бұрын

16.1 New Kind of Behavior Fluid Turbulence Cardiac Fibrillation

Пікірлер

@AceofDlamonds4 күн бұрын

very useful! I studied this stuff as an engineering undergrad but it's clearer to me now than before.

@Nikki-4-President13 күн бұрын

I have no doubt that Euler is one among the gods in heaven as he keeps blessing us until this day.

@mesaplayer963613 күн бұрын

17:33 unless the punch not being perpendicular is important to the explination. Which I feel like its not because the leaking faucet does have this sort of issue with a different angle punch it more so has to do with it still returning to the same state not that the faucet is "pushing" at a different angle. I feel a better way to explain it would have been a surface on a spring that is always punched in the same direction if you punch and let it return and then punch and let it return the system oscillates steadily. But if you punch it while it is on its way back, you create weird oscillation. no difference in angle of punches.

@user-ho8jz9ue7n28 күн бұрын

WOW!!!...Amazing

@user-ho8jz9ue7n28 күн бұрын

I have seen lot of videos of professionals, but this one is at another level. Huge information with an easy and clear way... Thank you Professor

@willadem8643Ай бұрын

It's almost criminal that I've been losing my mind for past week trying to start somewhere with these topics while KZread would constantly recommend the same bloody KZread videos that don't know how to explain anything and not recommend me your channel:') Great work. :))

@uclamodelingclass3003Ай бұрын

hey, thanks,!!!

@davidbuckley3628Ай бұрын

What an excellent lecturer you are. Thank you for sharing your talent of making the complex understandable.

@uclamodelingclass3003Ай бұрын

thank you so much!

@user-ve2co2ew6w2 ай бұрын

the scene in the movie about Glenn and Garfinkel's description don't match -- in the movie the computer tech results were off and Katherine corrected them.

@lonwabomfuntana61083 ай бұрын

baie dankie professor!

@AliceKMay3 ай бұрын

What a beautiful explanation. Thank you Prof.

@Idk-mc2dd4 ай бұрын

THANKS ALOT

@tvlivingroom4584 ай бұрын

4:40 Shouldn't the change vector end at (25, -15)? I'm confused by the correction.

@uclamodelingclass30034 ай бұрын

so sorry, yes it should. little brain freeze there on my part

@user-oj4xe2sp7x4 ай бұрын

does he still teach at ucla?

@-.SkyArt.-5 ай бұрын

After scavenging KZread for anyone who was able to dumb-down Euler’s method for me to understand, I have finally found it. Thank you!

@uclamodelingclass30034 ай бұрын

hah hah, that's a huge compliment! thanks!

@maxiellevillegas13885 ай бұрын

You just won't be able to understand how this video speaks to an engineer.. Unless you have the background.. Salute from the Philippines!!!

@uclamodelingclass30035 ай бұрын

thanks so much!!

@1cleandude6 ай бұрын

Who’s Raylay? Isn’t it Raalee? Like the tobacco! Great lecture!🙏

@coobit7 ай бұрын

Thanks for the actual referenc to the article of the original author of this model. Nice explanations as usual.

@uclamodelingclass30037 ай бұрын

you're very welcome!

@coobit7 ай бұрын

Thank you for the lectures. I like the way you teach. The flow of information is pretty frictionless :)

@uclamodelingclass30037 ай бұрын

You're very welcome!

@eugenebriones72007 ай бұрын

How do we know that k is exactly the probability that a successful reaction occurs?

@jurgenblick54918 ай бұрын

Is it just algorithm

@musclesmouse9 ай бұрын

Crazy, we were doing some of these trajectories in HS. I didnt know people did all this for a living.

@ruzailic72549 ай бұрын

Excellent..enjoyed so much listening ...

@uclamodelingclass30037 ай бұрын

Many thanks

@pnachtwey9 ай бұрын

So why use Euler's method? There is an improved version that is much better and then there is Runge-Kutta that is better yet. Runge-Kutta requires about 40% of the evaluations to get the same accuracy. Runge-Kutta has been known since the early 1900s. RK45 is better yet.

@uclamodelingclass30037 ай бұрын

The whole "Euler's method" scene was the screenwriters invention. RK4 was well-known. I like the fiction because using numerical methods instead of going searching for analytic formulas is the key to applied differential equations, which is what I do

@pnachtwey9 ай бұрын

Thee is Euler's method, improved Euler's method but I would have used Runge-Kutta. It was known back then. It is easy to get RK4 to work on a computer. The problem with using a lot of small steps is that round off error accumulates. So I wonder what was the precision of the computers they had back then and did it even have floating point? Probably not so the floating point was probably programmed in a custom way so it would have enough precision.

@uclamodelingclass30034 ай бұрын

I have to confess that I know absolutely nothing about the actual history of those computations. I doubt that there was a specific aha moment when Johnson exclaimed "Euler's method". They were probably doing RK4 in real life. But the Hollywood story is wonderful, isn't it?

@sandilemasuku22409 ай бұрын

I wish this man was my mentor he reveals this that are not easy to find and talk about concepts, applications modelling, i wish i have meet this man in my life, who knows maybe i could have influenced the world with innovations or worked for cia or ussr

@gordonharper91269 ай бұрын

Are you writing backwards?

@uclamodelingclass30037 ай бұрын

no, it was flipped in post-production

@sharonsolana9 ай бұрын

Very good explanation, thank you Professor.

@mikerottier713110 ай бұрын

How did the Russians do it ?

@sandilemasuku22409 ай бұрын

Remember how dunes chang due to the wind thats how the russian did it

@grav0110 ай бұрын

How did the Soviets solve the same problem?

@sandilemasuku22409 ай бұрын

Remember how dunes change in time due to win

@CCoburn310 ай бұрын

I remember back then, they always talked about "launch windows." That's what she calculated.

@jimparsons680310 ай бұрын

My thanks for the detailed explanation, that looks remarkably like an Archimedes Spiral. I was under the impression that the actual flight path looked more like a figure 8, if you considered the flight out and back You can do such a Spiral, but the propulsion type is more useful in terms of long-term low thrust like an ion drive. For those that are interested; see the Kindle/Amazon book, 'Traveling Through Space Without Rockets --- The Shorter Version,' by Jim Parsons, for the full progression of the cumulative ideas and techniques, see the longer book by a similar name by James G. Parsons. Ain't math elegant?

@RocketRay10 ай бұрын

Wow. At ~6:00 he's talking about my mom. She calculated ballistic trajectories at Aberdeen Proving Ground in Maryland during WWII.

@chadwickBU10 ай бұрын

Unfortunately the VF as portrayed in the blue heart model as correlated with the ECG is nothing like a real VF contraction and Excitation - Contraction sequence. Perhaps its a graphics thing , not a math thing but this needs input from real life experience. Theoretically the input variables H+ K+ Na+ Ca++ change dramatically over short times due to myocardial ischemia. Doubt that this modeling can capture that state.

@uclamodelingclass300310 ай бұрын

absolutely correct that this is a limited exercise, in that there is no contraction at all in this model, let alone E-C coupling. And it is also correct to point out that the model has no degradation of ion concentrations over time, which would of course happen in real VF. So this is a highly idealized example.

@amirasraf000110 ай бұрын

Pure gold content. Keep it up 😊

@uclamodelingclass300310 ай бұрын

Thank you! Will do!

@christophervillanti141710 ай бұрын

It's been 50 years since I took calculus, this was clearer than any lecture that I've heard on the subject.

@uclamodelingclass300310 ай бұрын

thanks!!

@joeprieto506310 ай бұрын

Truly masterful

@uclamodelingclass300310 ай бұрын

thank you so much!

@3dbadboy110 ай бұрын

With all those numbers, isn't it a Riemann sum?

@Listener97010 ай бұрын

They are so brilliant.

@woutzweers10 ай бұрын

Great video.

@uclamodelingclass300310 ай бұрын

Thanks!

@GenericMedusa9910 ай бұрын

6:48 can i ask why 50 000 times? or was it like a best estimate at that time to do it 50 000 times.

@uclamodelingclass300310 ай бұрын

sorry, that's a number I completely made up out of my head to mean "many many times"

@hornetscales827410 ай бұрын

Haven't had my mind blown on math (concepts: I'm not trying to UNDERSTAND this stuff, I'll just catch the edge) since looking into the basic math of Alternating Current. Had an excellent math teacher (several, really) but even if they couldn't teach me to do all, they at least taught me to appreciate the application. I could probably learn now, 20+ years out of school, but I'll just take things slow.....