Soonyoung Lee

Author directory

2026

In the tabular domain, which is the predominant data format in real-world applications, anomalies are extremely rare or difficult to collect, as their identification often requires domain expertise. Consequently, evaluating tabular anomaly detection models is challenging, since anomalies may be absent even in evaluation sets. To tackle this challenge, prior works have generated synthetic anomaly generation rely on statistical patterns, they often overlook domain semantics and struggle to reflect the complex, domain-specific nature of real-world anomalies. We propose AutoAnoEval, a novel evaluation framework for tabular AD that constructs pseudo-evaluation sets with semantically grounded synthetic anomalies. Our approach leverages an iterative interaction between a Large Language Model (LLM) and a decision tree (DT): the LLM generates realistic anomaly conditions based on contextual semantics, while the DT provides structural guidance by capturing feature interactions inherent in the tabular data. This iterative loop ensures the generation of diverse anomaly conditions, ranging from easily detectable outliers to subtle cases near the decision boundary. Extensive experiments on 20 tabular AD benchmarks demonstrate that AutoAnoEval achieves superior model selection performance, with high ranking alignment and minimal performance gaps compared to evaluations on anomalies encountered in practical applications.
Time series (TS) reasoning models (TSRMs) have shown promising capabilities in general domains, yet they consistently fail on financial domain, which exhibit unique characteristics. We propose a general 2 x 2 capability taxonomy for TSRMs by crossing 1) single-entity vs. multi-entity analysis with 2) assessment of the current state vs. prediction of future behavior. We instantiate this taxonomy in the financial domain—where the distinction between deterministic assessment and stochastic prediction is particularly critical—as ten financial reasoning tasks, forming the FinTSRBench benchmark based on S P stocks. To this end, we propose FinSTaR (Financial Time Series Thinking and Reasoning), trained on FinTSR-Bench with distinct chain-of-thought (CoT) strategies tailored to each category. For assessment, which is deterministic, we employ Compute-in-CoT, a programmatic CoT that enables models to derive answers directly from raw prices. For prediction, which is inherently stochastic, we adopt Scenario-Aware CoT, which generates diverse scenarios before making a judgment, mirroring how financial analysts reason under uncertainty. FinSTaR achieves 78.9% average accuracy on FinTSRBench, substantially outperforming LLM and TSRM baselines. Furthermore, we show that the four capability categories are complementary and mutually reinforcing through joint training. Code is publicly available at: https://github.com/seunghan96/FinSTaR.
Financial decision-makers face more information than they can directly inspect, making context compression necessary. Yet when large language models (LLMs) compress financial source material, they can alter the investment judgment supported by the original source. We frame this problem as information fidelity: compression loses fidelity when it changes the decision induced by the source. In agentic systems, such losses may recur across intermediate steps and amplify throughout the decision process. Across financial filings and earnings-call transcripts, we find that LLM-based compression can produce fluent and factually plausible compressed contexts that nevertheless alter downstream decisions. We analyze two diagnostic patterns associated with fidelity loss: decontextualization, where salient evidence is retained but separated from the caveats and contextual qualifiers needed for correct interpretation, and model dependency, where different compressors expose different views of the same source. We then propose Agentic Context Compression, which generates multiple candidate compressions and audits their disagreements against the original source. Our results suggest that financial compression should be evaluated not only by efficiency or factuality, but also by its ability to preserve decision-relevant context.

2024

3D dense captioning is a task to localize objects in a 3D scene and generate descriptive sentences for each object. Recent approaches in 3D dense captioning have adopted transformer encoder-decoder frameworks from object detection to build an end-to-end pipeline without hand-crafted components. However, these approaches struggle with contradicting objectives where a single query attention has to simultaneously view both the tightly localized object regions and contextual environment. To overcome this challenge, we introduce SIA (See-It-All), a transformer pipeline that engages in 3D dense captioning with a novel paradigm called late aggregation. SIA simultaneously decodes two sets of queries—context query and instance query. The instance query focuses on localization and object attribute descriptions, while the context query versatilely captures the region-of-interest of relationships between multiple objects or with the global scene, then aggregated afterwards (i.e., late aggregation) via simple distance-based measures. To further enhance the quality of contextualized caption generation, we design a novel aggregator to generate a fully informed caption based on the surrounding context, the global environment, and object instances. Extensive experiments on two of the most widely-used 3D dense captioning datasets demonstrate that our proposed method achieves a significant improvement over prior methods.