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Hidetoshi Shimodaira

18 accepted papers

2026

Beyond Chains: Bridging Large Language Models and Knowledge Bases in Complex Question Answering

AAAI 2026technical

Knowledge Base Question Answering (KBQA) aims to answer natural language questions using structured knowledge from KBs. While LLM-only approaches offer generalization, they suffer from outdated knowledge, hallucinations, and lack of transparency. Chain-based KG-RAG methods address these issues by in

Cited by 0SourcePDFScholar
2025

Likelihood Variance as Text Importance for Resampling Texts to Map Language Models

EMNLP 2025

We address the computational cost of constructing a model map, which embeds diverse language models into a common space for comparison via KL divergence. The map relies on log-likelihoods over a large text set, making the cost proportional to the number of texts. To reduce this cost, we propose a re

2025

Mapping 1,000+ Language Models via the Log-Likelihood Vector

ACL 2025long

To compare autoregressive language models at scale, we propose using log-likelihood vectors computed on a predefined text set as model features. This approach has a solid theoretical basis: when treated as model coordinates, their squared Euclidean distance approximates the Kullback-Leibler divergen…

Cited by 0SourcePDFScholar
2025

Quantifying Lexical Semantic Shift via Unbalanced Optimal Transport

ACL 2025long

Lexical semantic change detection aims to identify shifts in word meanings over time. While existing methods using embeddings from a diachronic corpus pair estimate the degree of change for target words, they offer limited insight into changes at the level of individual usage instances. To address t…

2025

Revisiting Cosine Similarity via Normalized ICA-transformed Embeddings

COLING 2025main

Cosine similarity is widely used to measure the similarity between two embeddings, while interpretations based on angle and correlation coefficient are common. In this study, we focus on the interpretable axes of embeddings transformed by Independent Component Analysis (ICA), and propose a novel int…

2024

Axis Tour: Word Tour Determines the Order of Axes in ICA-transformed Embeddings

EMNLP 2024finding

Word embedding is one of the most important components in natural language processing, but interpreting high-dimensional embeddings remains a challenging problem. To address this problem, Independent Component Analysis (ICA) is identified as an effective solution. ICA-transformed word embeddings rev…

2024

Block-Diagonal Orthogonal Relation and Matrix Entity for Knowledge Graph Embedding

EMNLP 2024finding

The primary aim of Knowledge Graph Embeddings (KGE) is to learn low-dimensional representations of entities and relations for predicting missing facts. While rotation-based methods like RotatE and QuatE perform well in KGE, they face two challenges: limited model flexibility requiring proportional i…

2024

Understanding Higher-Order Correlations Among Semantic Components in Embeddings

EMNLP 2024main

Independent Component Analysis (ICA) offers interpretable semantic components of embeddings.While ICA theory assumes that embeddings can be linearly decomposed into independent components, real-world data often do not satisfy this assumption. Consequently, non-independencies remain between the estim…

2023

Improving word mover's distance by leveraging self-attention matrix

EMNLP 2023long findings

Measuring the semantic similarity between two sentences is still an important task. The word mover's distance (WMD) computes the similarity via the optimal alignment between the sets of word embeddings. However, WMD does not utilize word order, making it challenging to distinguish sentences with sig…

Cited by 0SourcecodeScholar
2020

Extrapolation Towards Imaginary 0-Nearest Neighbour and Its Improved Convergence Rate

NeurIPS 2020poster

$k$-nearest neighbour ($k$-NN) is one of the simplest and most widely-used methods for supervised classification, that predicts a query's label by taking weighted ratio of observed labels of $k$ objects nearest to the query. The weights and the parameter $k \in \mathbb{N}$ regulate its bias-variance…

Cited by 3SourcePDFScholar
2020

More Powerful Selective Kernel Tests for Feature Selection

AISTATS 2020poster

Refining one’s hypotheses in light of data is a commonplace scientific practice, however,this approach introduces selection bias and can lead to specious statisticalanalysis.One approach of addressing this phenomena is via conditioning on the selection procedure, i.e., how we have used the data to…

2019

Graph Embedding with Shifted Inner Product Similarity and Its Improved Approximation Capability

AISTATS 2019poster

We propose shifted inner-product similarity (SIPS), which is a novel yet very simple extension of the ordinary inner-product similarity (IPS) for neural-network based graph embedding (GE). In contrast to IPS, that is limited to approximating positive-definite (PD) similarities, SIPS goes beyond the…

Cited by 12SourcePDFScholar
2018

A probabilistic framework for multi-view feature learning with many-to-many associations via neural networks

ICML 2018oral

A simple framework Probabilistic Multi-view Graph Embedding (PMvGE) is proposed for multi-view feature learning with many-to-many associations so that it generalizes various existing multi-view methods. PMvGE is a probabilistic model for predicting new associations via graph embedding of the nodes o…

Cited by 14SourcePDFScholar