Technology
ALoss Derivation In this section we provide a more detailed derivation of the proposed loss function (Equation 17)
In this section we provide a more detailed derivation of the proposed loss function (Equation 17). We make use of the fact that the negative entropy of the Dirichlet distribution is equivalent to the reverse KL-divergence to a flat Dirichlet, up to an additive constant which doesn't depend on the model. Additionally, we can see that by adding +1 to the target concentration parameters ห, we are now minimizing an upper bound to the KL-divergence between the mean and the ensemble. Then we divide through by ห 0 and drop the additive constant. This yields a loss which is remarkable similar to an ELBO.
2f3c6a4cd8af177f6456e7e51a916ff3-Supplemental.pdf
"Name" is the name of the operation in our search space. "TFFunction" is the TensorFlow function that the name is mapped to when a DNA instruction is being converted to a line of TensorFlow code. "Argument Mapping" describes how the values in a DNA's argument set are mapped to the corresponding TensorFlow function arguments. This vocabulary is largely constructed from the lowest level TF operations needed to create Transformers (see Appendix A.5). We also add commonly used math primitives such as SIN and ABS. Here we provide additional implementation details. Relative Dimensions: We use relative dimensions [13] instead of absolute dimensions for each instruction's "dimension size" argument. This allows us to resize the models to fit within our parameter limits (32M to 38M parameters). The vocabulary for these relative dimensions is [1, 2, 4, 8, 12, 16, 24, 32, 48, 64].
Primer: Searching for Efficient Transformers for Language Modeling
Large Transformer models have been central to recent advances in natural language processing. The training and inference costs of these models, however, have grown rapidly and become prohibitively expensive. Here we aim to reduce the costs of Transformers by searching for a more efficient variant. Compared to previous approaches, our search is performed at a lower level, over the primitives that define a Transformer TensorFlow program. We identify an architecture, named Primer, that has a smaller training cost than the original Transformer and other variants for auto-regressive language modeling.
Overview
In this section, we mainly introduce the axiomatic properties of Shapley value. Weber et al. [17] have proved that Shapley value is the unique metric that satisfies the following axioms: Linearity, Symmetry, Dummy, and Efficiency. If two independent games u and v can be linearly merged into one game w(S) = u(S)+v(S), then the Shapley value of each player i N in the new game w is the sum of Shapley values of the player i in the game uand v, which can be formulated as: ฯw(i|N) = ฯu(i|N)+ฯv(i|N) (1) Symmetry Axiom. Considering two players i and j in a game v, if they satisfy: S N \{i,j},v(S {i}) = v(S {j}) (2) then ฯv(i|N) = ฯv(j|N). The dummy player is defined as the player that has no interaction with other players. Formally, if a player i in a game v satisfies: S N \{i},v(S {i}) = v(S)+v({i}) (3) then this player is defined as the dummy player.
Fine-Grained Semantically Aligned Vision-Language Pre-Training
Large-scale vision-language pre-training has shown impressive advances in a wide range of downstream tasks. Existing methods mainly model the cross-modal alignment by the similarity of the global representations of images and texts, or advanced cross-modal attention upon image and text features. However, they fail to explicitly learn the fine-grained semantic alignment between visual regions and textual phrases, as only global image-text alignment information is available. In this paper, we introduce LOUPE, a fine-grained semantically aLigned visiOnlangUage PrE-training framework, which learns fine-grained semantic alignment from the novel perspective of game-theoretic interactions. To efficiently compute the game-theoretic interactions, we further propose an uncertainty-aware neural Shapley interaction learning module. Experiments show that LOUPE achieves stateof-the-art performance on a variety of vision-language tasks. Furthermore, without any object-level human annotations and fine-tuning, LOUPE achieves competitive performance on object detection and visual grounding. More importantly, LOUPE opens a new promising direction of learning fine-grained semantics from largescale raw image-text pairs. The repository of this work is at https://github.
AKernelised Stein Statistic for Assessing Implicit Generative Models
Synthetic data generation has become a key ingredient for training machine learning procedures, addressing tasks such as data augmentation, analysing privacy-sensitive data, or visualising representative samples. Assessing the quality of such synthetic data generators hence has to be addressed. As (deep) generative models for synthetic data often do not admit explicit probability distributions, classical statistical procedures for assessing model goodness-of-fit may not be applicable. In this paper, we propose a principled procedure to assess the quality of a synthetic data generator. The procedure is a kernelised Stein discrepancy (KSD)-type test which is based on a non-parametric Stein operator for the synthetic data generator of interest. This operator is estimated from samples which are obtained from the synthetic data generator and hence can be applied even when the model is only implicit. In contrast to classical testing, the sample size from the synthetic data generator can be as large as desired, while the size of the observed data which the generator aims to emulate is fixed. Experimental results on synthetic distributions and trained generative models on synthetic and real datasets illustrate that the method shows improved power performance compared to existing approaches.