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Question regarding the Wim Hof breathing method.

IIRC, the Wim Hof breathing method is comprised of four steps:

1) Breathe fully in, and softly out 30~40 times.

2) Hold breath for as long as one can.

3) Inhale and hold breath for 10~15 seconds.

4) Repeat above steps 3~5 times.

Upon completion, I feel relaxed, and less prone to fatigue.

However, people - myself included - might not necessarily hold world records like Wim Hof after the breathing session.

So, I wondered: "What does Wim Hof do more of from the above steps that enables him to go even further with his proposed method?"

Does he simply breathe in and out more for every set? Does he increase the number of sets? Does he hold the breath longer for every set?

What exactly does he do differently from the above steps that allows him to maximize the benefits?


[Calculus I] Find an equation of the tangent to the curve at the point corresponding to the given value of the parameter.

x = t cos t, y = t sin t; t = π(pi)

My progress thus far: dy/dx = (dy/dt)/(dx/dt) = (t cos t + sin t)/(-t sin t + cos t) = π

Thus, the integral of dy/dx is π*x + C.

Therefore, y = π*x + C

NOW, I've checked the answer key and it says C = π2

How is this so? More specifically, what is the intuition behind C being equal to the value of the parameter squared?

Your tangent line needs to pass through the point on the curve, which is (-𝜋,0), so 0 = 𝜋(-𝜋) + C -> C = 𝜋2.

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Original Poster1 point · 2 months ago



ELI5: What exactly do Neural Networks in AlphaZero/LeelaChess do?

IIRC, the MCTS rollouts determine how advantageous each move is in a given position.

So, if it's the MCTS coming up with the solutions, what is the purpose of implementing Neural Networks in the first place?

How does it differ from an MCTS-only chess AI?


The MCTS has a very intricately designed evaluation system that is basically based on the human perception of chess. Dumbed down it would be us telling the PC: That is a good place to be in (of course substantiated by massive amounts of data and so on).

The neural network only gets the basic rules of chess. Then it plays against itself and sees what happens. At the start, even a child could beat it (the moves are almost random), but every time it loses or wins it applies some math to the neurons and "changes" the way it percieves the game, basically changing the input/output function on its own.

The reason why AlphaZero beat Stockfish is that the evaluation function is still mostly made by humans, the computer is just better at doing that, AlphaZero however is more similar to a human (with the brainpower of a small mouse maybe, but optimized in a certain direction), just a human (mouse) that played 1.000.000 or so games and learned from each one without getting tired at all.

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Original Poster1 point · 2 months ago

The MCTS has a very intricately designed evaluation system that is basically based on the human perception of chess. Dumbed down it would be us telling the PC: That is a good place to be in (of course substantiated by massive amounts of data and so on.

I'm already lost here. Quick google search leads me to a wikipedia page stating that an MCTS does not need an 'explicit evaluation function', as long as one implements the allowed moves and end-game conditions.


Is running a good alternative to medication?

My mental health counselor suggested that it might help to meet a psychiatrist and receive medication for depression and anxiety -the latter being the bigger problem.

I am still unsure on whether I want medication.

So, I wanted to ask if running on a daily basis can significantly help such people suffering from anxiety and depression as me, to a point where medication would not be required.


My Caffeine dependence - How do I fix it?

I can't function without a minimum of 100mg of caffeine.

Without coffee I am not in the mood to do anything(even surfing through the web), and think gloomy thoughts.

I have a counseling appointment next week, but I am wondering what I could do in the meantime to fix this issue.


[Calculus]Question about the substitution rule for finding the area of a surface of revolution.

The given surface is rotated about the y-axis, and I am to find the area of the resulting surface.

y = (1/4)x2 - (1/2)ln x, and 1 <= x <= 2.

Thus, dy/dx = (1/2)x - 1/(2x) = (x2 -1)/(2x)

So, I have the formula: s = ∫(from x=1 to x=2) 2(pi)x * (1 + (x4 - 2x2 + 1)/(4x2 )) 1/2 dx

Then, substituting u = 1 + ((x4 - 2x2 + 1)/(4x2 )), I have du = (1/2)*(x4 - 1)/(x3 ) dx

And after finding the new limits corresponding to 'u'(1 and 25/16), I'm stuck.

Find a common denominator between 1 and (x4 - 2x2 + 1)/(4x2 ) and then combine like terms, then factor... you should have something that is a perfect square, which you can then take the square root of.

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Original Poster2 points · 3 months ago

I've added 1 and (x4 - 2x2 + 1)/(4x2 ), and still got du = (1/2)*(x4 - 1)/(x3 ) dx

After you clear out the square root there's no real reason to use a u-sub, you should just be good to go.

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Original Poster2 points · 3 months ago

Thank you!

Ugh, I can't believe I've spent hours just for this one question.


ELI5:How does Monte Carlos Tree Search run in real-time?

How can MCTS be used even in real-time when it requires playouts?

It doesn't require actual playouts. It simulates playouts based on random moves from both sides, and then weights the nodes of the resulting tree based on the final results of the simulation.

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Original Poster1 point · 3 months ago

They are random, but are still playouts.

It will still have to select a node, randomize movements from both sides until the game ends starting from the position corresponding to the selected node, and then repeat the process for about hundred more times. That should take a lot of time. Yet, it has still been used effectively in real-time. I don't know how that is possible.


Is Alphazero(Chess AI) Markovian?

This question might be more suited for /r/ComputerChess, but I decided to post here nevertheless, considering the relative inactivity of that sub-reddit.

From what I've understood from David Silver's youtube lecture, Markov Decision Process is largely characterized by rewards and discount factors - the latter being used to determine how far the computer looks ahead from a certain state to calculate how beneficial a move was.

However, the reward given for each move is unclear - that is, players don't know whether it yields victory or defeat until the end of the game.

So, I wanted to ask: Does Alphazero use a Markovian model, or does it use a model-free approach?

edit: It appears that Monte Carlos Tree Search - a system in which a value of a node is determined by the number of wins it had in x amount of randomized games - is important.

4 points · 4 months ago

This is all we know:

In theory, they will be publishing a full article with more details, more games and so on, but I haven´t seen it yet... who knows.

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Original Poster1 point · 3 months ago

Hmm.. It looks interesting, but it appears research papers aren't beginner-friendly. (But then again, machine-learning has never been an easy topic to deal with.)

It does mention MCTS, which answers how a value for each candidate move can be assigned for a Markovian model.

But aside from that, I understood next to nothing. It has many vocabulary words that can't be defined in simple sentences, but instead have to be taught in lectures.


Question about a Bishop Sacrifice.

[pgn] [FEN "rn2k2r/pppbb1p1/4p3/q3Np1p/3P4/2PB1Q2/PP1B1PPP/R3K1NR w KQ - 0 1"] [/pgn]

I was playing black, and my opponent white.

In this instance, my opponent played Bxf5. He essentially sacrificed his bishop for a pawn.

What compensation does white get from sacrificing a bishop in such manner?

Was your opponent a computer? That's a very engine-like move, I must say. Engine says it's good but there's so many less risky moves on the board that are just crushing, it's a little bit fishy for a human to play a move where if they're miscalculating something it's potentially throwing away the advantage while there's so many other strong/less risky moves on the board.

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Not real suspicious unless he's a low-rated player, it's a pretty simple "remove the defender" kind of tactic.

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Original Poster1 point · 4 months ago

Ahh, so that's what this tactic was called.

Original Poster1 point · 4 months ago

Not that I'm aware of.


How do you analyze your own chess games?

More specifically, what questions should you be asking when looking back and figuring out why you're opponent made a certain move?


ELI5:Regarding the 2020 Olympics, how will Olympic Karate look different from Olympic TKD?

Karate seems to allow punches to the head, whereas TKD bans it.

Otherwise, I don't see how the two differ in any significant way.

If this sounds awfully ignorant, feel free to enlighten me :)

I think this is totally wrong... Punching is faster, closer to the opponent, less telegraphed (don't have to shift nearly as much body weight) and more stable (again less weight shifting and you aren't on one leg). Kicks might potentially have more power/weight/range, but you could probably get off multiple punches in the time it takes to do multiple kicks.

Maybe in MMA or real life, but I'm talking about specifically when sparring in Taekwondo. It's harder to get points with punches than it is with kicks. There's only one small, easily defended target that a Taekwondo fighter is allowed to punch, and glancing blows don't count. So to effectively land a punch and get a point, you need to get within effective kicking distance of the opponent, which is a big risk. Then your opponent needs to drop their hands. Then you need to aim for a small target, fire off a quick, but solid punch, and connect cleanly so that the judges see it. It's tough to pull off, and it's a little like bringing a knife to a gunfight. It's far more effective to just stand a little farther back and use your gun too.

Again, this is just based on the rules of Taekwondo, and it's a big reason why it's different from Karate. Because punches are so much harder to land, worth fewer points, and expose the fighter to more risk, fighters tend to focus on kicking, which is the whole point of the style.

The rules of the sport always dictate who will win. A Navy Seal would be able to kill me in a dozen ways, but if they aren't allowed to use guns, knives, bombs, martial arts, etc. and the only weapon both of us are allowed to use are SUVs that we crash into each other at 50MPH, then there's a solid chance I'll be able to kill the Marine.

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Original Poster1 point · 4 months ago · edited 4 months ago

There's only one small, easily defended target that a Taekwondo fighter is allowed to punch, and glancing blows don't count. So to effectively land a punch and get a point, you need to get within effective kicking distance of the opponent, which is a big risk.

I fail to see how this wouldn't be a problem also in Karate.

Although in Karate one is allowed to punch two targets - the body and the head, these targets individually still require the puncher to close in from a kicking distance. Thus, the same risks of punching in Olympic TKD pretty much applies to Olympic Karate, which in turn means that Karate will more or less become foot-fencing? no?


About Migraines and Abdominal Pains while Dreaming.

Somehow, I am likely to induce dreams lying flat on my back.

However, doing so also induces severe headaches and sharp abdominal pain.

My questions are as follows: 1.Why is sleeping flat on my back helping me induce dreams? 2.How is it also causing pain when I'm dreaming? 3.What can I do to stop the pain?


Despite being an asymmetric sport, why doesn't Short-track Speed Skating cause muscular imbalance?

Because short-track skaters exclusively turn towards the left, they would have to put more weight on the left leg. Which in turn means their left leg would be more developed than their right leg? no?


What advice would you give to someone who wants to seek psychotherapy, but cannot afford it?

Long story short, I am struggling academically and socially.

The conclusion I drew from reading responses to my earlier post and other similar posts is that I should seek therapy.

But my entire family is on a tight budget, so I feel stuck.

What should I do?

Have you looked at resources available through your school? You don't provide enough details, but usually unis or even high schools have a mental health professional on staff that could help you. At the very least, provide you with local resources that provide low cost or no cost counseling services.

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Original Poster1 point · 5 months ago · edited 5 months ago

I've considered that, but thought about how embarrassing it would be to enter their office where every other students can see.

Also, I know this sounds ridiculous, but I fear that discussing my academic and social incompetencies with the school's mental health professional would only make me appear even less worthy of enrolling in their university. After all, the school's mental health professional is one of the school's staff.

I had the same anxiety when trying to get help from the university counseling center. In fact, I circled the entrance to the room several times before I was sure no one saw me go in, lol.

There were many students that came to the room for help but they were only worried about themselves. I got self conscious to the extreme, but I understood that they were just trying to get help for themselves just like I was.

About the staff and enrollment part... you are protected by privacy laws. Not even can a therapist speak about your details to a another member of staff due to strict laws. I was a psychology major at my university so I was paranoid about whether the mental health staff would consider me ineligible for being a student there. None of that occurred nor could have.

In fact, my psychology program director (I was a senior undergrad student) even applauded me for getting the help I needed for my issues (extreme social anxiety, GAD, and major depression) she was so nice to me and I was able to get an incomplete grade for her fieldwork course so I can have time after the semester to complete the work. I was able to graduate and she was so happy for me to have bounced back and succeeded.

It’s okay to get help. My professors strongly recommend it even for their own students. Doesn’t mean your less qualified or worthy as a student. Staff members themselves get therapy because they’re human too, just like us.

I was getting free counseling (10 sessions of individual therapy) and free unlimited group therapy... (insurance just covered my psychiatrist appointments and meds there)

Long story short, it was the best decision of my life, hands down. I was a dead man. Now, I’m alive again.

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Original Poster2 points · 5 months ago · edited 5 months ago

Wow, I just want to say congratulations.

It must have taken a lot of courage, especially for a psychology major to seek help.

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Not a single friend.

I am a college student in my early 20's.

I was verbally bullied in kindergarten, elementary, and the first two years in middle-school for being "slow", and to this day I have zero friends. People have been annoyed by my inability to understand simple conversations in one go. Often, they would repeat the phrase many times, sometimes with an explanation becoming increasingly verbose each time.

My life would be better in so many ways if I could fix this problem. It hurts to see my peers take photos with groups of close friends on social media, simply because they were able to communicate better than I could.

This inability doesn't just affect me socially, but academically as well. During high school, I couldn't keep track of the teachers' words, so by the time classes were finished, I would start at zero. The grades weren't the problem, for I was able maintain decent GPA through sheer grit. Rather, it was my inability to find balance between social-life and studying, because I would have to study longer than others.

Now, as a college student who is faced with harder concepts, I am neither academically nor socially competent. The hours I've put in studying limited the time to interact with others, but also didn't save me from F's.

I feel lost, and I believe it is rooted in one single problem: being slow at processing verbal information.


Oh man, I feel you. I think after high school it gets so much harder to find new friends. Maybe you should try thinking out of the box, since the normative lifestyle is designed in a way that isn't very inclusive. For example, try to find a way to make money that doesn't require verbal information or has loose time constraints (I think crafting or being freelancer in general). It's your life, do what's right for you, not what's right in sitcoms and stuff.
Personally, I'm also having similar problems (though for a different reason) and I changed my future plans so it'll be easier to me with my disadvantages. Hope this helps somewhat, you can also pm me if you feel like it :)

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Original Poster1 point · 5 months ago

As someone suggested, I am interested in programming. In fact, I want to become a professional programmer who deals with machine-learning someday, regardless of how distant that future may be.

However, programming isn't a loner's craft as some people may suggest. When part of a development team, I will be required to be in harmony with others; I can't be stepping too far out of the box.

1 point · 5 months ago · edited 5 months ago

What do you expect my man? Someone recommend you video and it will fix it? contact your physiologist.

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Original Poster6 points · 5 months ago · edited 5 months ago

By 'physiologist', I assume you mean psychotherapist.

Unfortunately, my entire family cannot afford psychotherapy.

So, my family suggests that I instead work more part-time jobs, so that I earn money and interact with the real world.

However, either managers don't want to hire me, or I get fired very quickly for incompetence.


Negative thoughts post-meditation.

I use the Headspace app, since the voice I hear relaxes me when I meditate. When stressed, these 10-minute guided meditation sessions help calm me, but only during the meditation. Afterwards, negative thoughts re-emerge. What can be done about this?

You might want to try meditating without the app at some point and spend some time with your raw thoughts during meditation. Dealing with negative thoughts in meditation is very useful skill that I've found transfers over to regular life. Also, I'm of the view that meditation is not just a place we go away to and then return to the world after, but rather it's a way of life and tapping into a flow. So that means there's lots of work to do off the cushion as well as on.

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Original Poster1 point · 5 months ago

So that means there's lots of work to do off the cushion

Such as?


Having a hard time visualizing inverse functions.

It should be a very easy concept, but somehow I have trouble understanding it.

When looking at 'f inverse of x', you visualize the arrows going from 'y' to 'x'.

But when you look at 'f inverse of y', how are you supposed to visualize it, in terms of an arrow diagram?

"inverse" means "reverse the arrow". It means "undo" (like division undoes multiplication). That's literally the definition. If f points from x to y, then f inverse points from y to x.

If f(5) = pi (points from 5 to pi), then f–1(pi) = 5 (points from pi to 5).

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Original Poster2 points · 5 months ago

If f(5) = pi (points from 5 to pi), then f–1(pi) = 5 (points from pi to 5).

Well then, what about f-1(5)?

I cannot say what f–1(5) is until you find me an x such that f(x) = 5. Given one arrow x ↦ y for the function f, I can deduce exactly one arrow y ↦ x for the inverse function f–1.

In my above comment, 5 is an x value, and f–1 only takes y values. Until you find out 5 is also a y value, f–1(5) is undefined.

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Original Poster4 points · 5 months ago

Ahhhhhh. I think I got it now, thank you!

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Because I want to build my cardio, I started interval training.

However, I'm not a very fit individual.

So, I start running for 5 minutes, have a minute walk, and then run again for 30 seconds less than every previous attempt(5 minutes, then 4.5 minutes, and then 4 minutes, and so on).

Am I on the right track?


WBTB done wrong?

I get 5.5 hours of sleep before waking up. Then, I don't try to stay awake for a few minutes, but instead use affirmations immediately as I drift back to sleep. Otherwise, I cannot fall back to sleep. However, my affirmations last seconds, not even a minute, before falling back asleep. I also cannot recognize my dreams before waking up, even though I can remember them. This has happened to me for the past two days. Am I doing something wrong? or does it take more time to become lucid?

1 point · 5 months ago · edited 5 months ago

I'm not sure if I understood Ramanujan's example correctly.

So basically, a dream character would frequently appear and give him answers to various mathematical problems?

That sounds too good to be true. Or is there any context I'm missing?

Cake day
December 23, 2017
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