Giter Site home page Giter Site logo

paper's People

Contributors

5g4s avatar

Watchers

 avatar

paper's Issues

DIFFERENTIABLE PHYSICS SIMULATION

Most current simulation algorithms can only provide forward results but not backpropagated gradients of the input.
Many learning-based tasks involving simulation can be greatly improved if gradients of simulation can be provided.
By making use of the gradients from the physically-aware simulation, differentiable simulation can optimize the unknown parameters faster and more accurately than gradient-free methods.

https://openreview.net/pdf?id=p-SG2KFY2

Half-Inverse Gradients for Physical Deep Learning

Problem

In learning, the loss is addressed using gradient-based optimizers with data-based normalizing schemes, such as Adam. While in physics, the optimizers of choice are higher-order techniques, such as Newton's method, which inherently make use of the inversion process.
However, Holl et al. (2021) found that these approaches can not effectively handle the joint optimization of networks and physics. Gradient-descent-based optimizers suffer from vanishing or exploding gradients, preventing effective convergence, while higher-order methods do not generally scale to the high-dimensional parameter spaces required by deep learning (Goodfellow et al., 2016).

Solution

They propose a new method for joint physics and networks called half-inverse gradients.
This method is based on a half inversion of the Jacobian and combines principles of both classical network and
physics optimizers.

Effect

A property of the method is that its runtime scales linearly with the number of network parameters.
It yields significant improvements in terms of convergence speed and final loss values over existing methods.

https://arxiv.org/abs/2203.10131

The Perception-Distortion Tradeoff

https://arxiv.org/abs/1711.06077

Distortionは元画像と生成画像との相違性(画素ごとの差分など)を表し、一方Perceptual qualityはそれらを視覚のみで評価する。
DistortionとPerceptual qualityをどちらも改善することは、アルゴリズムによらず不可能であることを証明
image

End-to-End Differentiable Physics for Learning and Control

Problem

Physical simulation environments, such as MuJoCo, are poorly suited for deep learning settings.
The environments have some speed and numerical stability issues because those are not natively differentiable. So gradients (e.g., policy gradients for control tasks) must be evaluated via finite differencing.
A recent work developed a differentiable physical simulator, which was accomplished by an automatic differentiation framework.
But it only supported balls as objects, with limited extensibility.

Solution

This paper proposes and presents a differentiable two-dimensional physics simulator that addresses the main limitations of past work.
Specifically, Their system simulates rigid body dynamics via a linear complementarity problem(LCP) which computes the equations of motion subject to contact and friction constraints. It can use general simulation methods for determining the non-differentiable parts of the dynamics(namely, the presence of absence of collisions between convex shapes), while still providing a simulation environment that is end-to-end differentiable(given the observed set of collisions).

Effect

They can embed an entire physical simulation environment as a "layer" in a deep network, enabling agents to both learn the parameters of the environments to match observed behavior and improve control performance via traditional gradient-based learning.

https://papers.nips.cc/paper/2018/hash/842424a1d0595b76ec4fa03c46e8d755-Abstract.html

Interpreting Super-Resolution Networks with Local Attribution Maps

https://openaccess.thecvf.com/content/CVPR2021/papers/Gu_Interpreting_Super-Resolution_Networks_With_Local_Attribution_Maps_CVPR_2021_paper.pdf

超解像画像生成時に影響を与えたピクセルを可視化するlocal attribution map(LAM)を提案した。
LAMにより、4つのことを明らかにした。
1)広い範囲の入力画素を利用しているほど、精度が向上する(つまり、ネットワークを深く、広くすることで精度が向上)
2)Attention networkとnon-local networkにより広い範囲から特徴抽出を行うことが可能になっている
3)超解像画像の精度に影響する入力範囲よりもネットワークの受容野のほうがはるかに大きい
4)規則的なストライプやグリッドが注目される一方、複雑な模様は利用されにくい

image
image

Implicit Neural Representations with Periodic Activation Functions

paper
https://arxiv.org/abs/2006.09661

official web page
https://vsitzmann.github.io/siren/

解説blog
https://medium.com%[email protected]/@sallyrobotics.blog/sirens-implicit-neural-representations-with-periodic-activation-functions-f425c7f710fa

activationによく使われるReLUは2回微分が0になるので、高次元の微分を含んだモデル(例えば、Eikonal equationsやPoisson equation)に使うことができない。
このような高次元のcontinuous implicit neural representationにおいてactivationに三角関数のsinを適用することを提案している。

初期値のとり方についても言及している。

Differentiable Molecular Simulations for Control and Learning

One wishes to control the Hamiltonian to achieve desired simulation outcomes and structures.
We demonstrate how this can be achieved using differentiable simulations where bulk target observables and simulation outcomes can be analytically differentiated with respect to Hamiltonians, opening up new routes for parameterizing Hamiltonians to infer macroscopic models and develop control protocols.

https://arxiv.org/abs/2003.00868

Recommend Projects

  • React photo React

    A declarative, efficient, and flexible JavaScript library for building user interfaces.

  • Vue.js photo Vue.js

    🖖 Vue.js is a progressive, incrementally-adoptable JavaScript framework for building UI on the web.

  • Typescript photo Typescript

    TypeScript is a superset of JavaScript that compiles to clean JavaScript output.

  • TensorFlow photo TensorFlow

    An Open Source Machine Learning Framework for Everyone

  • Django photo Django

    The Web framework for perfectionists with deadlines.

  • D3 photo D3

    Bring data to life with SVG, Canvas and HTML. 📊📈🎉

Recommend Topics

  • javascript

    JavaScript (JS) is a lightweight interpreted programming language with first-class functions.

  • web

    Some thing interesting about web. New door for the world.

  • server

    A server is a program made to process requests and deliver data to clients.

  • Machine learning

    Machine learning is a way of modeling and interpreting data that allows a piece of software to respond intelligently.

  • Game

    Some thing interesting about game, make everyone happy.

Recommend Org

  • Facebook photo Facebook

    We are working to build community through open source technology. NB: members must have two-factor auth.

  • Microsoft photo Microsoft

    Open source projects and samples from Microsoft.

  • Google photo Google

    Google ❤️ Open Source for everyone.

  • D3 photo D3

    Data-Driven Documents codes.