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Thomas Böhme

Publications and source records attributed to Thomas Böhme.

2 recordsLinked to original sources

On Self-improving Token Embeddings

This article introduces a novel and fast method for refining pre-trained static word or, more generally, token embeddings. By incorporating the embeddings of neighboring tokens in text corpora, it continuously updates the representation of each token, including those without pre-assigned embeddings. This approach effectively addresses the out-of-vocabulary problem, too. Operating independently of large language models and shallow neural networks, it enables versatile applications such as corpus exploration, conceptual search, and word sense disambiguation. The method is designed to enhance token representations within topically homogeneous corpora, where the vocabulary is restricted to a specific domain, resulting in more meaningful embeddings compared to general-purpose pre-trained vectors. As an example, the methodology is applied to explore storm events and their impacts on infrastructure and communities using narratives from a subset of the NOAA Storm Events database. The article also demonstrates how the approach improves the representation of storm-related terms over time, providing valuable insights into the evolving nature of disaster narratives.

cs.CL↗

Rooted Minors and Locally Spanning Subgraphs

Results on the existence of various types of spanning subgraphs of graphs are milestones in structural graph theory and have been diversified in several directions. In the present paper, we consider "local" versions of such statements. In 1966, for instance, D. W. Barnette proved that a $3$-connected planar graph contains a spanning tree of maximum degree at most $3$. A local translation of this statement is that if $G$ is a planar graph, $X$ is a subset of specified vertices of $G$ such that $X$ cannot be separated in $G$ by removing $2$ or fewer vertices of $G$, then $G$ has a tree of maximum degree at most $3$ containing all vertices of $X$. Our results constitute a general machinery for strengthening statements about $k$-connected graphs (for $1 \leq k \leq 4$) to locally spanning versions, i.e. subgraphs containing a set $X\subseteq V(G)$ of a (not necessarily planar) graph $G$ in which only $X$ has high connectedness. Given a graph $G$ and $X\subseteq V(G)$, we say $M$ is a minor of $G$ rooted at $X$, if $M$ is a minor of $G$ such that each bag of $M$ contains at most one vertex of $X$ and $X$ is a subset of the union of all bags. We show that $G$ has a highly connected minor rooted at $X$ if $X\subseteq V(G)$ cannot be separated in $G$ by removing a few vertices of $G$. Combining these investigations and the theory of Tutte paths in the planar case yields to locally spanning versions of six well-known results about degree-bounded trees, hamiltonian paths and cycles, and $2$-connected subgraphs of graphs.

math.CO↗