A **Time-aware Large Kernel (TaLK) convolution** is a type of temporal [convolution](https://paperswithcode.com/method/convolution) that learns the kernel size of a summation kernel for each time-step instead of learning the kernel weights as in a typical convolution operation. For each time-step, a function is responsible for predicting the appropriate size of neighbor representations to use in the form of left and right offsets relative to the time-step.

**Absolute Position Encodings** are a type of position embeddings for [[Transformer](https://paperswithcode.com/method/transformer)-based models] where positional encodings are added to the input embeddings at the bottoms of the encoder and decoder stacks. The positional encodings have the same dimension $d\_{model}$ as the embeddings, so that the two can be summed. In the original implementation, sine and cosine functions of different frequencies are used:

$$ \text{PE}\left(pos, 2i\right) = \sin\left(pos/10000^{2i/d\_{model}}\right) $$

$$ \text{PE}\left(pos, 2i+1\right) = \cos\left(pos/10000^{2i/d\_{model}}\right) $$

where $pos$ is the position and $i$ is the dimension. That is, each dimension of the positional encoding corresponds to a sinusoid. The wavelengths form a geometric progression from $2\pi$ to $10000 \dot 2\pi$. This function was chosen because the authors hypothesized it would allow the model to easily learn to attend by relative positions, since for any fixed offset $k$,  $\text{PE}\_{pos+k}$ can be represented as a linear function of $\text{PE}\_{pos}$.

Image Source: [D2L.ai](https://d2l.ai/chapter_attention-mechanisms/self-attention-and-positional-encoding.html)

Absolute Position Encodings

Attention Is All You Need

TaLK Convolution

Time-aware Large Kernel Convolutions

**ACGPN**, or **Adaptive Content Generating and Preserving Network**, is a [generative adversarial network](https://www.paperswithcode.com/method/category/generative-adversarial-network) for virtual try-on clothing applications. 

In Step I, the Semantic Generation Module (SGM) takes the target clothing image $\mathcal{T}\_{c}$, the pose map $\mathcal{M}\_{p}$, and the fused body part mask $\mathcal{M}^{F}$ as the input to predict the semantic layout and to output the synthesized body part mask $\mathcal{M}^{S}\_{\omega}$ and the target clothing mask $\mathcal{M}^{S\_{c}$.

In Step II, the Clothes Warping Module (CWM) warps the target clothing image to $\mathcal{T}^{R}\_{c}$ according to the predicted semantic layout, where a second-order difference constraint is introduced to stabilize the warping process. 

In Steps III and IV, the Content Fusion Module (CFM) first produces the composited body part mask $\mathcal{M}^{C}\_{\omega}$ using the original clothing mask $\mathcal{M}\_{c}$, the synthesized clothing mask $\mathcal{M}^{S}\_{c}$, the body part mask $\mathcal{M}\_{\omega}$, and the synthesized body part mask $\mathcal{M}\_{\omega}^{S}$, and then exploits a fusion network to generate the try-on images $\mathcal{I}^{S}$ by utilizing the information $\mathcal{T}^{R}\_{c}$, $\mathcal{M}^{S}\_{c}$, and the body part image $I\_{\omega}$ from previous steps.

Source	Time-aware Large Kernel Convolutions
Year	2000
Data Source	CC BY-SA - https://paperswithcode.com