upperbound
Review for NeurIPS paper: Self-supervised Co-Training for Video Representation Learning
Weaknesses: # Related Work I believe that the related work section has been poorly executed. It simply lists numerous papers from 4 domains of existing research. This provides limited information about the position of the proposed work w.r.t these existing works. A more detailed discussion of the contrast between the proposed work and existing literature, or the similarities, or the parts that have been directly adopted is generally expected from the related work section. Furthermore, the authors may have missed the following highly relevant papers which are also discussed in my Baselines section below: 1) Yan, Xueting, et al. "ClusterFit: Improving Generalization of Visual Representations."
XTransplant: A Probe into the Upper Bound Performance of Multilingual Capability and Culture Adaptability in LLMs via Mutual Cross-lingual Feed-forward Transplantation
Ye, Yangfan, Feng, Xiaocheng, Feng, Xiachong, Qin, Libo, Huang, Yichong, Huang, Lei, Ma, Weitao, Zhang, Zhirui, Lu, Yunfei, Yan, Xiaohui, Tang, Duyu, Tu, Dandan, Qin, Bing
Current large language models (LLMs) often exhibit imbalances in multilingual capabilities and cultural adaptability, largely due to their English-centric pretraining data. To address this imbalance, we propose a probing method named XTransplant that explores cross-lingual latent interactions via cross-lingual feed-forward transplantation during inference stage, with the hope of enabling the model to leverage the strengths of both English and non-English languages. Through extensive pilot experiments, we empirically prove that both the multilingual capabilities and cultural adaptability of LLMs hold the potential to be significantly improved by XTransplant, respectively from En -> non-En and non-En -> En, highlighting the underutilization of current LLMs' multilingual potential. And the patterns observed in these pilot experiments further motivate an offline scaling inference strategy, which demonstrates consistent performance improvements in multilingual and culture-aware tasks, sometimes even surpassing multilingual supervised fine-tuning. And we do hope our further analysis and discussion could help gain deeper insights into XTransplant mechanism.
The Complexity of Sequential Prediction in Dynamical Systems
Raman, Vinod, Subedi, Unique, Tewari, Ambuj
A discrete-time dynamical system is a mathematical model that describes the evolution of a system over discrete time steps. Formally, a discrete-time dynamical system is a tuple (N, X, f), where N is the set of natural numbers that denote the timesteps, X is a non-empty set called the state space, and f: X X is a deterministic map that describes the evolution of the state. Dynamical systems have been widely used in practice due to their ability to accurately model natural phenomena. For instance, boolean networks are an important class of discrete-time, discrete-space dynamical systems with widespread applicability to genetic modeling [Kauffman, 1969, Shmulevich et al., 2002].
Revisiting the Learnability of Apple Tasting
Raman, Vinod, Subedi, Unique, Raman, Ananth, Tewari, Ambuj
In online binary classification under \textit{apple tasting} feedback, the learner only observes the true label if it predicts "1". First studied by \cite{helmbold2000apple}, we revisit this classical partial-feedback setting and study online learnability from a combinatorial perspective. We show that the Littlestone dimension continues to prove a tight quantitative characterization of apple tasting in the agnostic setting, closing an open question posed by \cite{helmbold2000apple}. In addition, we give a new combinatorial parameter, called the Effective width, that tightly quantifies the minimax expected mistakes in the realizable setting. As a corollary, we use the Effective width to establish a \textit{trichotomy} of the minimax expected number of mistakes in the realizable setting. In particular, we show that in the realizable setting, the expected number of mistakes for any learner under apple tasting feedback can only be $\Theta(1), \Theta(\sqrt{T})$, or $\Theta(T)$.
Multiclass Online Learnability under Bandit Feedback
Raman, Ananth, Raman, Vinod, Subedi, Unique, Tewari, Ambuj
We study online multiclass classification under bandit feedback. We extend the results of Daniely and Helbertal [2013] by showing that the finiteness of the Bandit Littlestone dimension is necessary and sufficient for bandit online multiclass learnability even when the label space is unbounded. Moreover, we show that, unlike the full-information setting, sequential uniform convergence is necessary but not sufficient for bandit online learnability. Our result complements the recent work by Hanneke, Moran, Raman, Subedi, and Tewari [2023] who show that the Littlestone dimension characterizes online multiclass learnability in the full-information setting even when the label space is unbounded.
Synthesizing Policies That Account For Human Execution Errors Caused By State-Aliasing In Markov Decision Processes
Gopalakrishnan, Sriram, Verma, Mudit, Kambhampati, Subbarao
When humans are given a policy to execute, there can be policy execution errors and deviations in execution if there is uncertainty in identifying a state. So an algorithm that computes a policy for a human to execute ought to consider these effects in its computations. An optimal MDP policy that is poorly executed (because of a human agent) maybe much worse than another policy that is executed with fewer errors. In this paper, we consider the problems of erroneous execution and execution delay when computing policies for a human agent that would act in a setting modeled by a Markov Decision Process. We present a framework to model the likelihood of policy execution errors and likelihood of non-policy actions like inaction (delays) due to state uncertainty. This is followed by a hill climbing algorithm to search for good policies that account for these errors. We then use the best policy found by hill climbing with a branch and bound algorithm to find the optimal policy. We show experimental results in a Gridworld domain and analyze the performance of the two algorithms. We also present human studies that verify if our assumptions on policy execution by humans under state-aliasing are reasonable.
Adversarial Variational Inference and Learning in Markov Random Fields
Li, Chongxuan, Du, Chao, Xu, Kun, Welling, Max, Zhu, Jun, Zhang, Bo
Markov random fields (MRFs) find applications in a variety of machine learning areas, while the inference and learning of such models are challenging in general. In this paper, we propose the Adversarial Variational Inference and Learning (AVIL) algorithm to solve the problems with a minimal assumption about the model structure of an MRF. AVIL employs two variational distributions to approximately infer the latent variables and estimate the partition function, respectively. The variational distributions, which are parameterized as neural networks, provide an estimate of the negative log likelihood of the MRF. On one hand, the estimate is in an intuitive form of approximate contrastive free energy. On the other hand, the estimate is a minimax optimization problem, which is solved by stochastic gradient descent in an alternating manner. We apply AVIL to various undirected generative models in a fully black-box manner and obtain better results than existing competitors on several real datasets.
A Unified Framework for Training Neural Networks
Ghauch, Hadi, Shokri-Ghadikolaei, Hossein, Fischione, Carlo, Skoglund, Mikael
The lack of mathematical tractability of Deep Neural Networks (DNNs) has hindered progress towards having a unified convergence analysis of training algorithms, in the general setting. We propose a unified optimization framework for training different types of DNNs, and establish its convergence for arbitrary loss, activation, and regularization functions, assumed to be smooth. We show that framework generalizes well-known first- and second-order training methods, and thus allows us to show the convergence of these methods for various DNN architectures and learning tasks, as a special case of our approach. We discuss some of its applications in training various DNN architectures (e.g., feed-forward, convolutional, linear networks), to regression and classification tasks.
SimpleQuestions Nearly Solved: A New Upperbound and Baseline Approach
Petrochuk, Michael, Zettlemoyer, Luke
The SimpleQuestions dataset is one of the most commonly used benchmarks for studying single-relation factoid questions. In this paper, we present new evidence that this benchmark can be nearly solved by standard methods. First we show that ambiguity in the data bounds performance on this benchmark at 83.4%; there are often multiple answers that cannot be disambiguated from the linguistic signal alone. Second we introduce a baseline that sets a new state-of-the-art performance level at 78.1% accuracy, despite using standard methods. Finally, we report an empirical analysis showing that the upperbound is loose; roughly a third of the remaining errors are also not resolvable from the linguistic signal. Together, these results suggest that the SimpleQuestions dataset is nearly solved.