We develop an empirical likelihood (EL) framework for random forests and related ensemble methods, providing a likelihood-based approach to quantify their statistical uncertainty. Exploiting the incomplete $U$-statistic structure inherent in ensemble predictions, we construct an EL statistic that is asymptotically chi-squared when subsampling induced by incompleteness is not overly sparse. Under sparser subsampling regimes, the EL statistic tends to over-cover due to loss of pivotality; we therefore propose a modified EL that restores pivotality through a simple adjustment. Our method retains key properties of EL while remaining computationally efficient. Theory for honest random forests and simulations demonstrate that modified EL achieves accurate coverage and practical reliability relative to existing inference methods.

Historical map legends are critical for interpreting cartographic symbols. However, their inconsistent layouts and unstructured formats make automatic extraction challenging. Prior work focuses primarily on segmentation or general optical character recognition (OCR), with few methods effectively matching legend symbols to their corresponding descriptions in a structured manner. We present a method that combines LayoutLMv3 for layout detection with GPT-4o using in-context learning to detect and link legend items and their descriptions via bounding box predictions. Our experiments show that GPT-4 with structured JSON prompts outperforms the baseline, achieving 88% F-1 and 85% IoU, and reveal how prompt design, example counts, and layout alignment affect performance. This approach supports scalable, layout-aware legend parsing and improves the indexing and searchability of historical maps across various visual styles.

Chatbot Arena is a popular platform for evaluating LLMs by pairwise battles, where users vote for their preferred response from two randomly sampled anonymous models. While Chatbot Arena is widely regarded as a reliable LLM ranking leaderboard, we show that crowdsourced voting can be rigged to improve (or decrease) the ranking of a target model $m_{t}$. We first introduce a straightforward target-only rigging strategy that focuses on new battles involving $m_{t}$, identifying it via watermarking or a binary classifier, and exclusively voting for $m_{t}$ wins. However, this strategy is practically inefficient because there are over $190$ models on Chatbot Arena and on average only about $1\%$ of new battles will involve $m_{t}$. To overcome this, we propose omnipresent rigging strategies, exploiting the Elo rating mechanism of Chatbot Arena that any new vote on a battle can influence the ranking of the target model $m_{t}$, even if $m_{t}$ is not directly involved in the battle. We conduct experiments on around $1.7$ million historical votes from the Chatbot Arena Notebook, showing that omnipresent rigging strategies can improve model rankings by rigging only hundreds of new votes. While we have evaluated several defense mechanisms, our findings highlight the importance of continued efforts to prevent vote rigging. Our code is available at https://github.com/sail-sg/Rigging-ChatbotArena.

Observing the tsunami of artificial intelligence (AI) hype that has swept over the world in the past few years, science fiction writer Ted Chiang staked out a contrarian position. "Artificial intelligence," he insisted, was just a "poor choice of words … back in the '50s" that had caused "a lot of confusion." Under the rubric of intelligence, verbs such as "learn," "understand," and "know" had been misappropriated to imply sentience where none existed. The right words, he suggested, would have been "applied statistics." Chiang was correct that AI has always been a fuzzy term used to market specific technologies in a way that has little inherent connection to cognition.

Artists and writers all over the world have spent the past two years engaged in an existential battle. Generative-AI programs such as ChatGPT and DALL-E are built on work stolen from humans, and machines threaten to replace the artists and writers who made the material in the first place. Their outrage is well warranted--but their arguments don't always make sense or substantively help defend humanity. Over the weekend, the legendary science-fiction writer Ted Chiang stepped into the fray, publishing an essay in The New Yorker arguing, as the headline says, that AI "isn't going to make art." Chiang writes not simply that AI's outputs can be or are frequently lacking value but that AI cannot be used to make art, really ever, leaving no room for the many different ways someone might use the technology.

In machine translation, rare words continue to be a problem for the dominant encoder-decoder architecture, especially in low-resource and out-of-domain translation settings. Human translators solve this problem with monolingual or bilingual dictionaries. In this paper, we propose appending definitions from a bilingual dictionary to source sentences and using attention masking to link together rare words with their definitions. We find that including definitions for rare words improves performance by up to 1.0 BLEU and 1.6 MacroF1.

Privacy-preserving regression in machine learning is a crucial area of research, aimed at enabling the use of powerful machine learning techniques while protecting individuals' privacy. In this paper, we implement privacy-preserving regression training using data encrypted under a fully homomorphic encryption scheme. We first examine the common linear regression algorithm and propose a (simplified) fixed Hessian for linear regression training, which can be applied for any datasets even not normalized into the range $[0, 1]$. We also generalize this constant Hessian matrix to the ridge regression version, namely linear regression which includes a regularization term to penalize large coefficients. However, our main contribution is to develop a novel and efficient algorithm called LFFR for homomorphic regression using the logistic function, which could model more complex relations between input values and output prediction in comparison with linear regression. We also find a constant simplified Hessian to train our LFFR algorithm using the Newton-like method and compare it against to with our new fixed Hessian linear regression training over two real-world datasets. We suggest normalizing not only the data but also the target predictions even for the original linear regression used in a privacy-preserving manner, which is helpful to remain weights in a small range, say $[-5, +5]$ good for refreshing ciphertext setting parameters, and avoid tuning the regularization parameter $\lambda$ via cross validation. The linear regression with normalized predictions could be a viable alternative to ridge regression.

We consider path planning for a rigid spatial robot with 6 degrees of freedom (6 DOFs), moving amidst polyhedral obstacles. A correct, complete and practical path planner for such a robot has never been achieved, although this is widely recognized as a key challenge in robotics. This paper provides a complete "explicit" design, down to explicit geometric primitives that are easily implementable. Our design is within an algorithmic framework for path planners, called Soft Subdivision Search (SSS). The framework is based on the twin foundations of $\epsilon$-exactness and soft predicates, which are critical for rigorous numerical implementations. The practicality of SSS has been previously demonstrated for various robots including 5-DOF spatial robots. In this paper, we solve several significant technical challenges for SE(3) robots: (1) We first ensure the correct theory by proving a general form of the Fundamental Theorem of the SSS theory. We prove this within an axiomatic framework, thus making it easy for future applications of this theory. (2) One component of $SE(3) = R^3 \times SO(3)$ is the non-Euclidean, non-orientable space SO(3). We design a novel topologically correct data structure for SO(3). Using the concept of subdivision charts and atlases for SO(3), we can now carry out subdivision of SO(3). (3) The geometric problem of collision detection takes place in $R^3$, via the footprint map. Unlike sampling-based approaches, we must reason with the notion of footprints of configuration boxes, which is much harder to characterize. Exploiting the theory of soft predicates, we design suitable approximate footprints which, when combined with the highly effective feature-set technique, lead to soft predicates. (4) Finally, we make the underlying geometric computation "explicit", i.e., avoiding a general solver of polynomial systems, in order to allow a direct implementation.

Natural languages are believed to be (mildly) context-sensitive. Despite underpinning remarkably capable large language models, transformers are unable to model many context-free language tasks. In an attempt to address this limitation in the modeling power of transformer-based language models, we propose augmenting them with a differentiable, stack-based attention mechanism. Our stack-based attention mechanism can be incorporated into any transformer-based language model and adds a level of interpretability to the model. We show that the addition of our stack-based attention mechanism enables the transformer to model some, but not all, deterministic context-free languages.

More than a decade of dating apps has shown the process can be excruciating. A new app is trying to make dating less exhausting by using artificial intelligence to help people skip the earliest, often cringey stages of chatting with a new match. On Volar, people create dating profiles by messaging with a chatbot instead of filling out a profile. They answer questions about what they do for work or fun and what they're looking for in a partner, including preferences about age, gender, and personal qualities. The app then spins up a chatbot that tries to mimic not only a person's interests but also their conversational style.