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Were RNNs all we needed?

arxiv.org

121–130 of 269 posts

Re: Were RNNs all we needed?

#121

We really need a [preprint] flag for unreviewed papers.

IMHO reviews are almost indistinguishable from noise at the AI conferences I'm familiar with these days anyway, so I don't see much of a value add.

Sad state of affairs, people are incentivized to get more papers and citations at all costs, and quality be damned.

An AI Winter is not a great an idea, but an AI Autumn may be beneficial.

Just have no major AI conferences for ‘25, perhaps only accept really high tier literature reviews.

Re: Were RNNs all we needed?

#122
post #12

It’d be nice to see more of how this compares to Mamba. Looks like, in performance, they’re not leagues apart and it’s just a different architecture, not necessarily better or worse?

Look at the memory consumption diagram on page 6. It looks like you're basically getting the same running time for less memory usage.

Re: Were RNNs all we needed?

#123
post #98

Earlier quoted context omitted.

> This is no different than a transformer, which, after all, is bound by a finite state, just organized in a different manner. It's not just a matter of organizing things differently. Suppose your network dimension and sequence length are both X. Then your memory usage (per layer) will be O(X^2), while your training update cost will be O(X^3). That's for both Transformers and RNNs. However, at the end of the sequence…

Simplistic thinking. An RNN hidden parameter space of high dimension provides plenty of room for linear projections of token histories. I think people just do not realize just how huge R^N can be.

> Simplistic thinking. An RNN hidden parameter space of high dimension provides plenty of room for linear projections of token histories. I think people just do not realize just how huge R^N can be.

16N bits as hard limit, but more realistically, about 2N bits or less of useful information probably.

You'd need to grow the network dimension in proportion to the maximum sequence length just to avoid the information theoretical limit.

Re: Were RNNs all we needed?

#124
post #11

It's curse and a blessing that discussion of topics happens in so many different places. I found this comment on Twitter/X interesting: https://x.com/fchollet/status/1841902521717293273 "Interesting work on reviving RNNs. https://arxiv.org/abs/2410.01201 -- in general the fact that there are many recent architectures coming from different directions that roughly match Transformers is proof that architectures aren't f…

> The critical factor is the dataset, not the specific hard-coded bells and whistles that constrain the curve's shape I have almost the opposite take. We've had a lot of datasets for ages, but all the progress in the last decade has come from advances how curves are architected and fit to the dataset (including applying more computing power). Maybe there's some theoretical sense in which older models could have solve…

I see what you are saying, and I made a similar comment.

However it's still an interesting observation that many architectures can arrive at the same performance (even though the training requirements are different).

Naively, you wouldn't expect eg 'x -> a * x + b' to fit the same data as 'x -> a * sin x + b' about equally well. But that's an observation from low dimensions. It seems once you add enough parameters, the exact model doesn't matter too much for practical expressiveness.

I'm faintly reminded of the Church-Turing Thesis; the differences between different computing architectures are both 'real' but also 'just an optimisation'.

> When you start layering in normalisation techniques to minimise overfitting, and especially once you start thinking about more agentic architectures (eg. Deep Q Learning, some of the search space design going into OpenAI's o1), then I don't think the just-an-optimisation perspective can hold much water at all - more computing power simply couldn't solve those problems with older architectures.

You are right, these normalisation techniques help you economise on training data, not just on compute. Some of these techniques can be done independent of the model, eg augmenting your training data with noise. But some others are very model dependent.

I'm not sure how the 'agentic' approaches fit here.

Re: Were RNNs all we needed?

#125
post #93

Earlier quoted context omitted.

Not even then, a truly fully connected network would have super exponential runtime (it would take N^N time to evaluate)

We need quantum computing there. I remember seeing a recent article about quantum processes in the brain. If that’s true, QC may be the missing part.

Compare and contrast https://www.smbc-comics.com/comic/the-talk-3

(Summary: quantum computing is unlikely to help.)

Re: Were RNNs all we needed?

#126
I still find it remarkable how we need such an extreme amount of electrical energy to power large modern AI models.

Compare with one human brain. Far more sophisticated, even beyond our knowledge. What does it take to power it for a day? Some vegetables and rice. Still fine for a while if you supply pure junk food -- it'll still perform.

Clearly we have a long, long way to go in terms of the energy efficiency of AI approaches. Our so-called neural nets clearly don't resemble the energy efficiency of actual biological neurons.

Re: Were RNNs all we needed?

#127

Earlier quoted context omitted.

The non linearities are fundamental. Without them, any arbitrarily deep NN is equivalent to a shallow NN (easily computable, as GP was saying), and we know those can't even solve the XOR problem. > nothing but linearity No, if you have non linearities, the NN itself is not linear. The non linearities are not there primarily to keep the outputs in a given range, though that's important, too.

> The non linearities are not there primarily to keep the outputs in a given range Precisely what the `Activation Function` does is to squash an output into a range (normally below one, like tanh). That's the only non-linearity I'm aware of. What other non-linearities are there? All the training does is adjust linear weights tho, like I said. All the training is doing is adjusting the slopes of lines.

With a ReLU activation function, rather than a simple linear function of the inputs, you get a piecewise linear approximation of a nonlinear function.

ReLU enables this by being nonlinear in a simple way, specifically by outputting zero for negative inputs, so each linear unit can then limit its contribution to a portion of the output curve.

(This is a lot easier to see on a whiteboard!)

Re: Were RNNs all we needed?

#128

Earlier quoted context omitted.

You can change the subject by bringing up as many different NN architectures, Activation Functions, etc. as you want. I'm telling you the basic NN Perceptron design (what everyone means when they refer to Perceptrons in general), has something like a `tanh` and not only is it's PRIMARY function to squash a number, that's it's ONLY function.

How was that person derailing the convo? Nothing says an activation function has to "squash" a number to be in some range. Leaky ReLUs for instance do `f(x) = x if x > 0 else ax` (for some coefficient `a != 0`), that doesn't squash `x` to be in any range (unless you want to be peculiar about your precise definition of what it means to squash a number). The function takes a real in `[-inf, inf]` and produces a number…

> What is a "linear weight"?

In the context of discussing linearity v.s. non-linearity adding the word "linear" in front of "weight" is more clear, which is what my top level post on this thread was all about too.

It's astounding to me (and everyone else who's being honest) that LLMs can accomplish what they do when it's only linear "factors" (i.e. weights) that are all that's required to be adjusted during training, to achieve genuine reasoning. During training we're not [normally] adjusting any parameters or weights on any non-linear functions. I include the caveat "normally", because I'm speaking of the basic Perceptron NN using a squashing-type activation function.

Re: Were RNNs all we needed?

#129
post #11

It's curse and a blessing that discussion of topics happens in so many different places. I found this comment on Twitter/X interesting: https://x.com/fchollet/status/1841902521717293273 "Interesting work on reviving RNNs. https://arxiv.org/abs/2410.01201 -- in general the fact that there are many recent architectures coming from different directions that roughly match Transformers is proof that architectures aren't f…

Inductive bias matters. A lot.

Re: Were RNNs all we needed?

#130

Earlier quoted context omitted.

You can change the subject by bringing up as many different NN architectures, Activation Functions, etc. as you want. I'm telling you the basic NN Perceptron design (what everyone means when they refer to Perceptrons in general), has something like a `tanh` and not only is it's PRIMARY function to squash a number, that's it's ONLY function.

You need a non-linear activation function for the universal approximation theorem to hold. Otherwise, as others have said the model just collapses to a single layer. Technically the output is still what a statistician would call “linear in the parameters”, but due to the universal approximation theorem it can approximate any non-linear function. https://stats.stackexchange.com/questions/275358/why-is-incr...

As you can see in what I just posted about an inch below this, my point is that the process of training a NN does not involve adjusting any parameter to any non-linear functions. What goes into an activation function is a pure sum of linear multiplications and an add, but there's no "tunable" parameter (i.e. adjusted during training) that's fed into the activation function.
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