VLDB 2026 Research / reviewers in the wild / expert
Dongyeop Kang
dblp:69/9056
· DBLP profile ↗
54ranked-venue papers
12as first author
38since 2021 · last 2026
—ORCID · conflict
Domains — the database's venue-derived domains; a paper can count in several
Artificial intelligence and machine learning · 51 · 12 first-author · 36 since 2021Graphics, computer vision, multimedia, augmented reality and games · 11 · 10 since 2021Databases, data management, data science and information retrieval · 5 · 3 first-author · 2 since 2021Systems, architecture and hardware · 2 · 1 since 2021Human-computer interaction and ubiquitous computing · 1 · 1 since 2021Applied, interdisciplinary, general and emerging computing · 1 · 1 since 2021
| Year | Publication | Venue | Position |
|---|---|---|---|
| 2026 | Align to Structure: Aligning Large Language Models with Structural InformationabstractGenerating long, coherent text remains a challenge for large language models (LLMs), as they lack hierarchical planning and structured organization in discourse generation. We introduce Structural Alignment, a novel method that aligns LLMs with human-like discourse structures to enhance long-form text generation. By integrating linguistically grounded discourse frameworks into reinforcement learning, our approach guides models to produce coherent and well-organized outputs. We employ a dense reward scheme within a Proximal Policy Optimization framework, assigning fine-grained, token-level rewards based on the discourse distinctiveness relative to human writing. Two complementary reward models are evaluated: the first improves readability by scoring surface-level textual features to provide explicit structuring, while the second reinforces deeper coherence and rhetorical sophistication by analyzing global discourse patterns through hierarchical discourse motifs, outperforming both standard and RLHF-enhanced models in tasks such as essay generation and long-document summarization. Zae Myung Kim, Farideh Tavazoee, Joo-Kyung Kim, Oleg Rokhlenko, Dongyeop Kang |
AAAI | 6 |
| 2026 | ScholaWrite: A Dataset of End-to-End Scholarly WritingabstractKhanh Chi Le, Linghe Wang, Minhwa Lee, Ross Volkov, Luan Tuyen Chau, Dongyeop Kang. Proceedings of the 64th Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers). 2026. Khanh Chi Le, Linghe Wang, Minhwa Lee, Ross Volkov, Luan Tuyen Chau, Dongyeop Kang |
ACL (1) | 6 |
| 2026 | Tracing How Annotators Think: Augmenting Preference Judgments with Reading ProcessesabstractWe propose an annotation approach that captures not only labels but also the reading process underlying annotators' decisions, e.g., what parts of the text they focus on, re-read or skim. Using this framework, we conduct a case study on the preference annotation task, creating a dataset PreferRead that contains fine-grained annotator reading behaviors obtained from mouse tracking. PreferRead enables detailed analysis of how annotators navigate between a prompt and two candidate responses before selecting their preference. We find that annotators re-read a response in roughly half of all trials, most often revisiting the option they ultimately choose, and rarely revisit the prompt. Reading behaviors are also significantly related to annotation outcomes: re-reading is associated with higher inter-annotator agreement, whereas long reading paths and times are associated with lower agreement. These results demonstrate that reading processes provide a complementary cognitive dimension for understanding annotator reliability, decision-making and disagreement in complex, subjective NLP tasks. Our code and data are publicly available. Karin de Langis, William Walker, Khanh Chi Le, Dongyeop Kang |
LREC | 4 |
| 2026 | Breaking Determinism: Stochastic Modeling for Reliable Off-Policy Evaluation in Ad AuctionsabstractOnline A/B testing, the gold standard for evaluating new advertising policies, consumes substantial engineering resources and risks significant revenue loss from deploying underperforming variations. This motivates the use of Off-Policy Evaluation (OPE) for rapid, offline assessment. However, applying OPE to ad auctions is fundamentally more challenging than in domains like recommender systems, where stochastic policies are common. In online ad auctions, it is common for the highest-bidding ad to win the impression, resulting in a deterministic, winner-takes-all setting. This results in zero probability of exposure for non-winning ads, rendering standard OPE estimators inapplicable. We introduce the first principled framework for OPE in deterministic auctions by repurposing the bid landscape model to approximate the propensity score. This model allows us to derive robust approximate propensity scores, enabling the use of stable estimators like Self-Normalized Inverse Propensity Scoring (SNIPS) for counterfactual evaluation. We validate our approach on the AuctionNet simulation benchmark and against 2-weeks online A/B test from a large-scale industrial platform. Our method shows remarkable alignment with online results, achieving a 92% Mean Directional Accuracy (MDA) in CTR prediction, significantly outperforming the parametric baseline. MDA is the most critical metric for guiding deployment decisions, as it reflects the ability to correctly predict whether a new model will improve or harm performance. This work contributes the first practical and validated framework for reliable OPE in deterministic auction environments, offering an efficient alternative to costly and risky online experiments. Hongseon Yeom, Jaeyoul Shin, Soojin Min, Jeongmin Yoon, Seunghak Yu, Dongyeop Kang |
WSDM | 6 |
| 2026 | FlowForge: Guiding the Creation of Multi-Agent Workflows with Design Space Visualization as a Thinking ScaffoldabstractMulti-agent workflows have become an effective strategy for tackling complicated tasks by decomposing them into multiple sub-tasks and assigning them to specialized agents. However, designing optimal workflows remains challenging due to the vast and intricate design space. Current practices rely heavily on the intuition and expertise of practitioners, often resulting in design fixation or an unstructured, time-consuming exploration of trial-and-error. To address these challenges, this work introduces FLOWFORGE, an interactive visualization tool to facilitate the creation of multi-agent workflow through i) a structured visual exploration of the design space and ii) in-situ guidance informed by established design patterns. Based on formative studies and literature review, FLOWFORGE organizes the workflow design process into three hierarchical levels (i.e., task planning, agent assignment, and agent optimization), ranging from abstract to concrete. This structured visual exploration enables users to seamlessly move from high-level planning to detailed design decisions and implementations, while comparing alternative solutions across multiple performance metrics. Additionally, drawing from established workflow design patterns, FLOWFORGE provides context-aware, in-situ suggestions at each level as users navigate the design space, enhancing the workflow creation process with practical guidance. Use cases and user studies demonstrate the usability and effectiveness of FLOWFORGE, while also yielding valuable insights into how practitioners explore design spaces and leverage guidance during workflow development. Pan Hao, Dongyeop Kang, Nicholas Hinds, Qianwen Wang 0001 |
IEEE Trans. Vis. Comput. Graph. | 2 |
| 2025 | ISR-DPO: Aligning Large Multimodal Models for Videos by Iterative Self-Retrospective DPOabstractIterative self-improvement, a concept extending beyond personal growth, has found powerful applications in machine learning, particularly in transforming weak models into strong ones. While recent advances in natural language processing have shown its efficacy through iterative preference optimization, applying this approach to Video Large Multimodal Models (VLMMs) remains challenging due to modality misalignment. VLMMs struggle with this misalignment during iterative preference modeling, as the self-judge model often prioritizes linguistic knowledge over visual information. Additionally, iterative preference optimization can lead to visually hallucinated verbose responses due to length bias within the self-rewarding cycle. To address these issues, we propose Iterative Self-Retrospective Direct Preference Optimization (ISR-DPO), a method that uses self-retrospection to enhance preference modeling. This approach enhances the self-judge’s focus on informative video regions, resulting in more visually grounded preferences. In extensive empirical evaluations across diverse video question answering benchmarks, the ISR-DPO significantly outperforms the state of the art. We are committed to open-sourcing our code, models, and datasets to encourage further investigation. Daechul Ahn, Yura Choi, Youngjae Yu, Dongyeop Kang |
AAAI | 5 |
| 2025 | Chain-of-Instructions: Compositional Instruction Tuning on Large Language ModelsabstractFine-tuning large language models (LLMs) with a collection of large and diverse instructions has improved the model’s generalization to different tasks, even for unseen tasks. However, most existing instruction datasets include only single instructions, and they struggle to follow complex instructions composed of multiple subtasks. In this work, we propose a novel concept of compositional instructions called chain-of-instructions (CoI), where the output of one instruction becomes an input for the next like a chain. Unlike the conventional practice of solving single instruction tasks, our proposed method encourages a model to solve each subtask step by step until the final answer is reached. CoI-tuning (i.e., fine-tuning with CoI instructions) improves the model’s ability to handle instructions composed of multiple subtasks as well as unseen composite tasks such as multilingual summarization. Overall, our study find that simple CoI tuning of existing instruction data can provide consistent generalization to solve more complex, unseen, and longer chains of instructions. Shirley Anugrah Hayati, Taehee Jung, Tristan Bodding-Long, Sudipta Kar, Abhinav Sethy, Joo-Kyung Kim, Dongyeop Kang |
AAAI | 7 |
| 2025 | How LLMs Comprehend Temporal Meaning in Narratives: A Case Study in Cognitive Evaluation of LLMsabstractKarin De Langis, Jong Inn Park, Andreas Schramm, Bin Hu, Khanh Chi Le, Dongyeop Kang. Proceedings of the 63rd Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers). 2025. Karin de Langis, Jong Inn Park, Andreas Schramm, Khanh Chi Le, Dongyeop Kang |
ACL (1) | 6 |
| 2025 | BBScoreV2: Learning Time-Evolution and Latent Alignment from Stochastic RepresentationabstractAutoregressive generative models play a key role in various language tasks, especially for modeling and evaluating long text sequences.While recent methods leverage stochastic representations to better capture sequence dynamics, encoding both temporal and structural dependencies and utilizing such information for evaluation remains challenging.In this work, we observe that fitting transformer-based model embeddings into a stochastic process yields ordered latent representations from originally unordered model outputs.Building on this insight and prior work, we theoretically introduce a novel likelihood-based evaluation metric BB-ScoreV2.Empirically, we demonstrate that the stochastic latent space induces a "clustered-totemporal ordered" mapping of language model representations in high-dimensional space, offering both intuitive and quantitative support for the effectiveness of BBScoreV2.Furthermore, this structure aligns with intrinsic properties of natural language and enhances performance on tasks such as temporal consistency evaluation (e.g., Shuffle tasks) and AIgenerated content detection. Zhecheng Sheng, Zhexiao Lin, Dongyeop Kang |
EMNLP | 5 |
| 2025 | Joint Reward and Policy Learning with Demonstrations and Human Feedback Improves AlignmentabstractAligning to human preferences and/or intentions is an important requirement for contemporary foundation models. To ensure alignment, popular approaches such as reinforcement learning with human feedback (RLHF) break down the task into three stages: (i) a model is computed with supervised fine-tuning (SFT) based upon large demonstrations data, (ii) a reward model (RM) is estimated based upon human feedback data, and (iii) reinforcement learning (RL) is used to further refine the SFT model by optimizing the estimated reward model. Demonstrations and human feedback data reflect human user preferences in different ways. As a result, the reward model estimate obtained from only human feedback data is likely not as accurate as a reward model estimate obtained from both demonstration and human feedback data. A policy model that optimizes the reward model estimate obtained from both demonstration and human feedback data will likely exhibit better alignment performance. We introduce a tractable algorithm for finding the reward and policy models and provide a finite-time performance guarantee. Additionally, we demonstrate the efficiency of the proposed solution with extensive experiments including alignment problems in LLMs and robotic control problems in MuJoCo. We observe that the proposed solutions outperform the existing alignment algorithm by large margins, especially when the amounts of demonstration and preference data are unbalanced. Siliang Zeng, Zeyi Liao, Dongyeop Kang, Alfredo García 0001, Mingyi Hong 0001 |
ICLR | 5 |
| 2025 | RoSTE: An Efficient Quantization-Aware Supervised Fine-Tuning Approach for Large Language ModelsabstractSupervised fine-tuning is a standard method for adapting pre-trained large language models (LLMs) to downstream tasks. Quantization has been recently studied as a post-training technique for efficient LLM deployment. To obtain quantized fine-tuned LLMs, conventional pipelines would first fine-tune the pre-trained models, followed by post-training quantization. This often yields suboptimal performance as it fails to leverage the synergy between fine-tuning and quantization. To effectively realize low-bit quantization of weights, activations and KV caches in LLMs, we propose an algorithm named Rotated Straight-Through-Estimator (RoSTE), which combines quantization-aware supervised fine-tuning (QA-SFT) with an adaptive rotation strategy that identifies an effective rotation configuration to reduce activation outliers. We provide theoretical insights on RoSTE by analyzing its prediction error when applied to an overparameterized least square quantized training problem. Our findings reveal that the prediction error is directly proportional to the quantization error of the converged weights, which can be effectively managed through an optimized rotation configuration. Experiments on Pythia, Qwen and Llama models of different sizes demonstrate the effectiveness of RoSTE. Compared to existing post-SFT quantization baselines, our method consistently achieves superior performances across various tasks and different LLM architectures. Our code is available at https://github.com/OptimAI-Lab/RoSTE. Quan Wei 0001, Chung-Yiu Yau, Hoi-To Wai, Dongyeop Kang, Youngsuk Park, Mingyi Hong 0001 |
ICML | 5 |
| 2025 | Learning a High-Quality Robotic Wiping Policy Using Systematic Reward Analysis and Visual-Language Model Based CurriculumabstractAutonomous robotic wiping is an important task in various industries, ranging from industrial manufacturing to sanitization in healthcare. Deep reinforcement learning (Deep RL) has emerged as a promising algorithm, however, it often suffers from a high demand for repetitive reward engineering. Instead of relying on manual tuning, we first analyze the convergence of quality-critical robotic wiping, which requires both high-quality wiping and fast task completion, to show the poor convergence of the problem and propose a new bounded reward formulation to make the problem feasible. Then, we further improve the learning process by proposing a novel visual-language model (VLM) based curriculum, which actively monitors the progress and suggests hyperparameter tuning. We demonstrate that the combined method can find a desirable wiping policy on surfaces with various curvatures, frictions, and waypoints, which cannot be learned with the baseline formulation. The demo of this project can be found at: https://sites.google.com/view/highqualitywiping Dongyeop Kang, Sehoon Ha |
ICRA | 2 |
| 2024 | Meta-Crafting: Improved Detection of Out-of-Distributed Texts via Crafting Metadata Space (Student Abstract)abstractDetecting out-of-distribution (OOD) samples is crucial for robust NLP models. Recent works observe two OOD types: background shifts (style change) and semantic shifts (content change), but existing detection methods vary in effectiveness for each type. To this end, we propose Meta-Crafting, a unified OOD detection method by constructing a new discriminative feature space utilizing 7 model-driven metadata chosen empirically that well detects both types of shifts. Our experimental results demonstrate state-of-the-art robustness to both shifts and significantly improved detection on stress datasets. Ryan Koo, Yekyung Kim, Dongyeop Kang, Jaehyung Kim 0001 |
AAAI | 3 |
| 2024 | BBScore: A Brownian Bridge Based Metric for Assessing Text CoherenceabstractMeasuring the coherence of text is a vital aspect of evaluating the quality of written content. Recent advancements in neural coherence modeling have demonstrated their efficacy in capturing entity coreference and discourse relations, thereby enhancing coherence evaluation. However, many existing methods heavily depend on static embeddings or focus narrowly on nearby context, constraining their capacity to measure the overarching coherence of long texts. In this paper, we posit that coherent texts inherently manifest a sequential and cohesive interplay among sentences, effectively conveying the central theme, purpose, or standpoint. To explore this abstract relationship, we introduce the "BB Score," a novel reference-free metric grounded in Brownian bridge theory for assessing text coherence. Our findings showcase that when synergized with a simple additional classification component, this metric attains a performance level comparable to state-of-the-art techniques on standard artificial discrimination tasks. We also establish in downstream tasks that this metric effectively differentiates between human-written documents and text generated by large language models within specific domains. Furthermore, we illustrate the efficacy of this approach in detecting written styles attributed to various large language models, underscoring its potential for generalizability. In summary, we present a novel Brownian bridge coherence metric capable of measuring both local and global text coherence, while circumventing the need for end-to-end model training. This flexibility allows for its application in various downstream tasks. Zhecheng Sheng, Dongyeop Kang |
AAAI | 4 |
| 2024 | Tuning Large Multimodal Models for Videos using Reinforcement Learning from AI FeedbackabstractRecent advancements in large language models have influenced the development of video large multimodal models (VLMMs).Previous approaches for VLMMs involve Supervised Fine-Tuning (SFT) with instruction-tuned datasets, integrating LLM with visual encoders, and additional learnable parameters.Here, aligning video with text, and vice versa, remains a challenge, primarily due to the insufficient quality and quantity of multimodal instructiontune data compared to that of text-only.This discrepancy often results in alignments that poorly ground the video content.To address this, we present a novel alignment strategy that employs a multimodal AI system equipped with Reinforcement Learning from AI Feedback (RLAIF), providing self-preference feedback to refine itself and facilitating the alignment of video and text modalities.Our approach uniquely integrates detailed video descriptions as context into a multimodal AI system during preference feedback generation to enrich the understanding of video content, a process we call context-aware reward modeling.Empirical evaluations on various video benchmarks demonstrate that our VLM-RLAIF outperforms existing approaches, including the SFT model.We commit to open-sourcing our code, models, and datasets to foster further research in this area. Daechul Ahn, Yura Choi, Youngjae Yu, Dongyeop Kang |
ACL (1) | 4 |
| 2024 | Threads of Subtlety: Detecting Machine-Generated Texts Through Discourse MotifsabstractWith the advent of large language models (LLM), the line between human-crafted and machine-generated texts has become increasingly blurred.This paper delves into the inquiry of identifying discernible and unique linguistic properties in texts that were written by humans, particularly uncovering the underlying discourse structures of texts beyond their surface structures.Introducing a novel methodology, we leverage hierarchical parse trees and recursive hypergraphs to unveil distinctive discourse patterns in texts produced by both LLMs and humans.Empirical findings demonstrate that, although both LLMs and humans generate distinct discourse patterns influenced by specific domains, human-written texts exhibit more structural variability, reflecting the nuanced nature of human writing in different domains.Notably, incorporating hierarchical discourse features enhances binary classifiers' overall performance in distinguishing between human-written and machine-generated texts, even on out-of-distribution and paraphrased samples.This underscores the significance of incorporating hierarchical discourse features in the analysis of text patterns.The code and dataset are available at https://github.com/ minnesotanlp/threads-of-subtlety. Zae Myung Kim, Kwang Hee Lee, Preston Zhu, Vipul Raheja, Dongyeop Kang |
ACL (1) | 5 |
| 2024 | Skepticism and Sentiment Analysis to Understand Consumer Perception of Virtual Influencers in Social Media AdvertisingabstractSocial media advertising has become one of the most popular forms of advertising in recent years. Advancements in video and image generation have led to the creation of avatars, which have changed the landscape of online marketing. The avatars used for social media advertising are known as virtual influencers. In this paper, we use Instagram comments to observe consumer perceptions of virtual influencers (VIs) and human influencers (HIs) in social media advertising. By investigating how consumers engage with and respond to VIs, the study aims to provide insights into their effectiveness compared to HIs. In this study, we consider two timelines, pre- and post-pandemic, for different types of posts by VIs and HIs. We focus mainly on two user-affective states: sentiment and skepticism. The results show that VIs are perceived with more negativity and skepticism compared to HIs, irrespective of the type of post in both time periods. However, negative and skeptical responses towards VIs decreased post-pandemic. This empirical study provides insights into the evolving field of influencer advertising and highlights changes in consumer perception pre- and post-pandemic towards VIs and HIs. Smitha Muthya Sudheendra, Maral Abdollahi, Dongyeop Kang, Jisu Huh, Jaideep Srivastava |
IEEE Big Data | 3 |
| 2024 | SkOTaPA: A Dataset for Skepticism Detection in Online Text after Persuasion AttemptabstractIndividuals often encounter persuasion attempts, during which a persuasion agent aims to persuade a target to change the target’s emotions, beliefs, and behaviors. These persuasion attempts can be observed in various social settings, such as advertising, public health, political campaigns, and personal relationships. During these persuasion attempts, targets generally like to preserve their autonomy, so their responses often manifest in some form of resistance, like a skeptical reaction. In order to detect such skepticism in response to persuasion attempts on social media, we developed a corpus based on consumer psychology. In this paper, we consider one of the most prominent areas in which persuasion attempts unfold: social media influencer marketing. In this paper, we introduce the skepticism detection corpus, SkOTaPA, which was developed using multiple independent human annotations, and inter-coder reliability was evaluated with Krippendorff’s alpha (0.709). We performed validity tests to show skepticism cannot be detected using other potential proxy variables like sentiment and sarcasm. Smitha Muthya Sudheendra, Maral Abdollahi, Dongyeop Kang, Jisu Huh, Jaideep Srivastava |
LREC/COLING | 3 |
| 2024 | How Far Can We Extract Diverse Perspectives from Large Language Models?abstractCollecting diverse human opinions is costly and challenging.This leads to a recent trend in exploiting large language models (LLMs) for generating diverse data for potential scalable and efficient solutions.However, the extent to which LLMs can generate diverse perspectives on subjective topics is still unclear.In this study, we explore LLMs' capacity of generating diverse perspectives and rationales on subjective topics such as social norms and argumentative texts.We introduce the problem of extracting maximum diversity from LLMs.Motivated by how humans form opinions based on values, we propose a criteria-based prompting technique to ground diverse opinions.To see how far we can extract diverse perspectives from LLMs, or called diversity coverage, we employ a step-by-step recall prompting to generate more outputs from the model iteratively.Our methods, applied to various tasks, show that LLMs can indeed produce diverse opinions according to the degree of task subjectivity.We also find that LLMs performance of extracting maximum diversity is on par with human. 1 Shirley Anugrah Hayati, Minhwa Lee, Dheeraj Rajagopal, Dongyeop Kang |
EMNLP | 4 |
| 2024 | Dynamic Multi-Reward Weighting for Multi-Style Controllable GenerationabstractTextual style expresses a diverse set of information, including interpersonal dynamics (e.g., formality) and the author's emotions or attitudes (e.g., disgust).An open question is how language models can be explicitly controlled so that they weave together target styles when generating text: for example, to produce text that is both negative and non-toxic.One approach to such controlled generation is multiobjective reinforcement learning (RL), but how to best combine multiple objectives in a reward function is an open question.In this paper, we investigate various formulations of multi-style rewards, including calibrated outputs from discriminators and dynamic weighting by discriminator gradient magnitudes.We find that our proposed dynamic weighting outperforms static weighting approaches with respect style control while maintaining linguistic quality, and we explore its effectiveness in 2-and 3-style control.All code and data for the RL pipelines will be publicly available.1 Karin de Langis, Ryan Koo, Dongyeop Kang |
EMNLP | 3 |
| 2024 | LearnerVoice: A Dataset of Non-Native English Learners' Spontaneous Speech
Haechan Kim, Junho Myung, Sungpah Lee, Dongyeop Kang |
INTERSPEECH | 5 |
| 2023 | Everyone's Voice Matters: Quantifying Annotation Disagreement Using Demographic InformationabstractIn NLP annotation, it is common to have multiple annotators label the text and then obtain the ground truth labels based on major annotators’ agreement. However, annotators are individuals with different backgrounds and various voices. When annotation tasks become subjective, such as detecting politeness, offense, and social norms, annotators’ voices differ and vary. Their diverse voices may represent the true distribution of people’s opinions on subjective matters. Therefore, it is crucial to study the disagreement from annotation to understand which content is controversial from the annotators. In our research, we extract disagreement labels from five subjective datasets, then fine-tune language models to predict annotators’ disagreement. Our results show that knowing annotators’ demographic information (e.g., gender, ethnicity, education level), in addition to the task text, helps predict the disagreement. To investigate the effect of annotators’ demographics on their disagreement level, we simulate different combinations of their artificial demographics and explore the variance of the prediction to distinguish the disagreement from the inherent controversy from text content and the disagreement in the annotators’ perspective. Overall, we propose an innovative disagreement prediction mechanism for better design of the annotation process that will achieve more accurate and inclusive results for NLP systems. Our code and dataset are publicly available. Ruyuan Wan, Jaehyung Kim 0001, Dongyeop Kang |
AAAI | 3 |
| 2023 | infoVerse: A Universal Framework for Dataset Characterization with Multidimensional Meta-informationabstractThe success of NLP systems often relies on the availability of large, high-quality datasets.However, not all samples in these datasets are equally valuable for learning, as some may be redundant or noisy.Several methods for characterizing datasets based on modeldriven meta-information (e.g., model's confidence) have been developed, but the relationship and complementary effects of these methods have received less attention.In this paper, we introduce infoVerse, a universal framework for dataset characterization, which provides a new feature space that effectively captures multidimensional characteristics of datasets by incorporating various model-driven metainformation.infoVerse reveals distinctive regions of the dataset that are not apparent in the original semantic space, hence guiding users (or models) in identifying which samples to focus on for exploration, assessment, or annotation.Additionally, we propose a novel sampling method on infoVerse to select a set of data points that maximizes informativeness.In three real-world applications (data pruning, active learning, and data annotation), the samples chosen on infoVerse space consistently outperform strong baselines in all applications.Our code and demo are publicly available. Jaehyung Kim 0001, Yekyung Kim, Karin de Langis, Jinwoo Shin, Dongyeop Kang |
ACL (1) | 5 |
| 2023 | Rethinking Annotation: Can Language Learners Contribute?abstractHaneul Yoo, Rifki Afina Putri, Changyoon Lee, Youngin Lee, So-Yeon Ahn, Dongyeop Kang, Alice Oh. Proceedings of the 61st Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers). 2023. Haneul Yoo, Rifki Afina Putri, Changyoon Lee, Youngin Lee, So-Yeon Ahn, Dongyeop Kang, Alice Oh |
ACL (1) | 6 |
| 2023 | A Comparative Study on Textual Saliency of Styles from Eye Tracking, Annotations, and Language ModelsabstractThere is growing interest in incorporating eyetracking data and other implicit measures of human language processing into natural language processing (NLP) pipelines.The data from human language processing contain unique insight into human linguistic understanding that could be exploited by language models.However, many unanswered questions remain about the nature of this data and how it can best be utilized in downstream NLP tasks.In this paper, we present eyeStyliency, an eye-tracking dataset for human processing of stylistic text (e.g., politeness).We develop a variety of methods to derive style saliency scores over text using the collected eye dataset.We further investigate how this saliency data compares to both human annotation methods and model-based interpretability metrics.We find that while eyetracking data is unique, it also intersects with both human annotations and model-based importance scores, providing a possible bridge between human-and machine-based perspectives.We propose utilizing this type of data to evaluate the cognitive plausibility of models that interpret style.Our eye-tracking data and processing code are publicly available.1 Karin de Langis, Dongyeop Kang |
CoNLL | 2 |
| 2023 | Quirk or Palmer: A Comparative Study of Modal Verb Frameworks with Annotated DatasetsabstractModal verbs, such as can, may, and must, are commonly used in daily communication to convey the speaker's perspective related to the likelihood and/or mode of the proposition.They can differ greatly in meaning depending on how they're used and the context of a sentence (e.g."They must work together."vs. "They must have worked together.").Despite their practical importance in natural language understanding, linguists have yet to agree on a single, prominent framework for the categorization of modal verb senses.This lack of agreement stems from high degrees of flexibility and polysemy from the modal verbs, making it more difficult for researchers to incorporate insights from this family of words into their work.As a tool to help navigate this issue, this work presents MoVerb, a dataset consisting of 27,240 annotations of modal verb senses over 4,540 utterances containing one or more sentences from social conversations.Each utterance is annotated by three annotators using two different theoretical frameworks (i.e., Quirk and Palmer) of modal verb senses.We observe that both frameworks have similar inter-annotator agreements, despite having a different number of sense labels (eight for Quirk and three for Palmer).With RoBERTa-based classifiers finetuned on MoVerb, we achieve F1 scores of 82.2 and 78.3 on Quirk and Palmer, respectively, showing that modal verb sense disambiguation is not a trivial task. 1 Risako Owan, Maria L. Gini, Dongyeop Kang |
CoNLL | 3 |
| 2023 | StyLEx: Explaining Style Using Human Lexical AnnotationsabstractLarge pre-trained language models have achieved impressive results on various style classification tasks, but they often learn spurious domain-specific words to make predictions (Hayati et al., 2021).While human explanation highlights stylistic tokens as important features for this task, we observe that model explanations often do not align with them.To tackle this issue, we introduce StyLEx, a model that learns from human annotated explanations of stylistic features and jointly learns to perform the task and predict these features as model explanations.Our experiments show that StyLEx can provide human-like stylistic lexical explanations without sacrificing the performance of sentence-level style prediction on both indomain and out-of-domain datasets.Explanations from StyLEx show significant improvements in explanation metrics (sufficiency, plausibility) and when evaluated with human annotations.They are also more understandable by human judges compared to the widely-used saliency-based explanation baseline.1 * currently at Google Shirley Anugrah Hayati, Kyumin Park, Dheeraj Rajagopal, Lyle H. Ungar, Dongyeop Kang |
EACL | 5 |
| 2023 | Cluster-Guided Label Generation in Extreme Multi-Label ClassificationabstractFor extreme multi-label classification (XMC), existing classification-based models poorly perform for tail labels and often ignore the semantic relations among labels, like treating "Wikipedia" and "Wiki" as independent and separate labels.In this paper, we cast XMC as a generation task (XLGen), where we benefit from pre-trained text-to-text models.However, generating labels from the extremely large label space is challenging without any constraints or guidance.We, therefore, propose to guide label generation using label cluster information to hierarchically generate lower-level labels.We also find that frequency-based label ordering and using decoding ensemble methods are critical factors for the improvements in XLGen.XLGen with cluster guidance significantly outperforms the classification and generation baselines on tail labels, and also generally improves the overall performance in four popular XMC benchmarks.In human evaluation, we also find XLGen generates unseen but plausible labels.Our code is now available at https:// github.com/alexa/xlgen-eacl-2023. Taehee Jung, Joo-Kyung Kim, Dongyeop Kang |
EACL | 4 |
| 2023 | Dialogue Chain-of-Thought Distillation for Commonsense-aware Conversational AgentsabstractHyungjoo Chae, Yongho Song, Kai Ong, Taeyoon Kwon, Minjin Kim, Youngjae Yu, Dongha Lee, Dongyeop Kang, Jinyoung Yeo. Proceedings of the 2023 Conference on Empirical Methods in Natural Language Processing. 2023. Hyungjoo Chae, Yongho Song, Kai Tzu-iunn Ong, Taeyoon Kwon, Minjin Kim, Youngjae Yu, Dongha Lee 0003, Dongyeop Kang, Jinyoung Yeo |
EMNLP | 8 |
| 2023 | Story Visualization by Online Text Augmentation with Context MemoryabstractStory visualization (SV) is a challenging text-to-image generation task for the difficulty of not only rendering visual details from the text descriptions but also encoding a long-term context across multiple sentences. While prior efforts mostly focus on generating a semantically relevant image for each sentence, encoding a context spread across the given paragraph to generate contextually convincing images (e.g., with a correct character or with a proper background of the scene) remains a challenge. To this end, we propose a novel memory architecture for the Bi-directional Transformer framework with an online text augmentation that generates multiple pseudo-descriptions as supplementary supervision during training for better generalization to the language variation at inference. In extensive experiments on the two popular SV benchmarks, i.e., the Pororo-SV and Flintstones-SV, the proposed method significantly outperforms the state of the arts in various metrics including FID, character F1, frame accuracy, BLEU-2/3, and R-precision with similar or less computational complexity. Daechul Ahn, Daneul Kim, Gwangmo Song, Honglak Lee, Dongyeop Kang |
ICCV | 6 |
| 2023 | Prefer to Classify: Improving Text Classifiers via Auxiliary Preference LearningabstractThe development of largely human-annotated benchmarks has driven the success of deep neural networks in various NLP tasks. To enhance the effectiveness of existing benchmarks, collecting new additional input-output pairs is often too costly and challenging, particularly considering their marginal impact on improving the current model accuracy. Instead, additional or complementary annotations on the existing input texts in the benchmarks can be preferable as an efficient way to pay the additional human cost. In this paper, we investigate task-specific preferences between pairs of input texts as a new alternative way for such auxiliary data annotation. From pair-wise comparisons with respect to the task, the auxiliary preference learning enables the model to learn an additional informative training signal that cannot be captured with instance-wise task labels. To this end, we propose a novel multi-task learning framework, called prefer-to-classify (P2C), which can enjoy the cooperative effect of learning both the given classification task and the auxiliary preferences. Here, we provide three different ways to collect preference signals in practice: (a) implicitly extracting from annotation records (for free, but often unavailable), (b) collecting explicitly from crowd workers (high paid), or (c) pre-trained large language models such as GPT-3 (low paid). Given existing classification NLP benchmarks, we demonstrate that the proposed auxiliary preference learning via P2C on them is effective in improving text classifiers. Our codes are publicly available. Jaehyung Kim 0001, Jinwoo Shin, Dongyeop Kang |
ICML | 3 |
| 2022 | Understanding Iterative Revision from Human-Written TextabstractWriting is, by nature, a strategic, adaptive, and more importantly, an iterative process.A crucial part of writing is editing and revising the text.Previous works on text revision have focused on defining edit intention taxonomies within a single domain or developing computational models with a single level of edit granularity, such as sentence-level edits, which differ from human's revision cycles.This work describes ITERATER: the first largescale, multi-domain, edit-intention annotated corpus of iteratively revised text.In particular, ITERATER is collected based on a new framework to comprehensively model the iterative text revisions that generalize to various domains of formal writing, edit intentions, revision depths, and granularities.When we incorporate our annotated edit intentions, both generative and edit-based text revision models significantly improve automatic evaluations. 1 Through our work, we better understand the text revision process, making vital connections between edit intentions and writing quality, enabling the creation of diverse corpora to support computational modeling of iterative text revisions. Wanyu Du, Vipul Raheja, Dhruv Kumar 0005, Zae Myung Kim, Melissa Lopez, Dongyeop Kang |
ACL (1) | 6 |
| 2022 | Improving Iterative Text Revision by Learning Where to Edit from Other Revision TasksabstractIterative text revision improves text quality by fixing grammatical errors, rephrasing for better readability or contextual appropriateness, or reorganizing sentence structures throughout a document.Most recent research has focused on understanding and classifying different types of edits in the iterative revision process from human-written text instead of building accurate and robust systems for iterative text revision.In this work, we aim to build an end-to-end text revision system that can iteratively generate helpful edits by explicitly detecting editable spans (where-to-edit) with their corresponding edit intents and then instructing a revision model to revise the detected edit spans.Leveraging datasets from other related text editing NLP tasks, combined with the specification of editable spans, leads our system to more accurately model the process of iterative text refinement, as evidenced by empirical results and human evaluations.Our system significantly outperforms previous baselines on our text revision tasks and other standard text revision tasks, including grammatical error correction, text simplification, sentence fusion, and style transfer.Through extensive qualitative and quantitative analysis, we make vital connections between edit intentions and writing quality, and better computational modeling of iterative text revisions. Zae Myung Kim, Wanyu Du, Vipul Raheja, Dhruv Kumar 0005, Dongyeop Kang |
EMNLP | 5 |
| 2022 | What Makes Better Augmentation Strategies? Augment Difficult but Not too Different
Jaehyung Kim 0001, Dongyeop Kang, Sungsoo Ahn, Jinwoo Shin |
ICLR | 2 |
| 2021 | Style is NOT a single variable: Case Studies for Cross-Stylistic Language UnderstandingabstractDongyeop Kang, Eduard Hovy. Proceedings of the 59th Annual Meeting of the Association for Computational Linguistics and the 11th International Joint Conference on Natural Language Processing (Volume 1: Long Papers). 2021. Dongyeop Kang, Eduard H. Hovy |
ACL/IJCNLP (1) | 1 |
| 2021 | Augmenting Scientific Papers with Just-in-Time, Position-Sensitive Definitions of Terms and SymbolsabstractDespite the central importance of research papers to scientific progress, they can be difficult to read. Comprehension is often stymied when the information needed to understand a passage resides somewhere else—in another section, or in another paper. In this work, we envision how interfaces can bring definitions of technical terms and symbols to readers when and where they need them most. We introduce ScholarPhi, an augmented reading interface with four novel features: (1) tooltips that surface position-sensitive definitions from elsewhere in a paper, (2) a filter over the paper that “declutters” it to reveal how the term or symbol is used across the paper, (3) automatic equation diagrams that expose multiple definitions in parallel, and (4) an automatically generated glossary of important terms and symbols. A usability study showed that the tool helps researchers of all experience levels read papers. Furthermore, researchers were eager to have ScholarPhi’s definitions available to support their everyday reading. Andrew Head, Kyle Lo, Dongyeop Kang, Raymond Fok, Sam Skjonsberg, Daniel S. Weld, Marti A. Hearst |
CHI | 3 |
| 2021 | Does BERT Learn as Humans Perceive? Understanding Linguistic Styles through LexicaabstractPeople convey their intention and attitude through linguistic styles of the text that they write.In this study, we investigate lexicon usages across styles throughout two lenses: human perception and machine word importance, since words differ in the strength of the stylistic cues that they provide.To collect labels of human perception, we curate a new dataset, HUMMINGBIRD, on top of benchmarking style datasets.We have crowd workers highlight the representative words in the text that makes them think the text has the following styles: politeness, sentiment, offensiveness, and five emotion types.We then compare these human word labels with word importance derived from a popular fine-tuned style classifier like BERT.Our results show that the BERT often finds content words not relevant to the target style as important words used in style prediction, but humans do not perceive the same way even though for some styles (e.g., positive sentiment and joy) humanand machine-identified words share significant overlap for some styles.1 Shirley Anugrah Hayati, Dongyeop Kang, Lyle H. Ungar |
EMNLP (1) | 2 |
| 2021 | Zero-shot Natural Language Video LocalizationabstractUnderstanding videos to localize moments with natural language often requires large expensive annotated video regions paired with language queries. To eliminate the annotation costs, we make a first attempt to train a natural language video localization model in zero-shot manner. Inspired by unsupervised image captioning setup, we merely require random text corpora, unlabeled video collections, and an off-the-shelf object detector to train a model. With the unpaired data, we propose to generate pseudo-supervision of candidate temporal regions and corresponding query sentences, and develop a simple NLVL model to train with the pseudo-supervision. Our empirical validations show that the proposed pseudo-supervised method outperforms several baseline approaches and a number of methods using stronger supervision on Charades-STA and ActivityNet-Captions. Jinwoo Nam, Daechul Ahn, Dongyeop Kang, Seong Jong Ha |
ICCV | 3 |
| 2020 | Posterior Calibrated Training on Sentence Classification TasksabstractMost classification models work by first predicting a posterior probability distribution over all classes and then selecting that class with the largest estimated probability.In many settings however, the quality of posterior probability itself (e.g., 65% chance having diabetes), gives more reliable information than the final predicted class alone.When these methods are shown to be poorly calibrated, most fixes to date have relied on posterior calibration, which rescales the predicted probabilities but often has little impact on final classifications.Here we propose an end-to-end training procedure called posterior calibrated (PosCal) training that directly optimizes the objective while minimizing the difference between the predicted and empirical posterior probabilities.We show that PosCal not only helps reduce the calibration error but also improve task performance by penalizing drops in performance of both objectives.Our PosCal achieves about 2.5% of task performance gain and 16.1% of calibration error reduction on GLUE (Wang et al., 2018) compared to the baseline.We achieved the comparable task performance with 13.2% calibration error reduction on xSLUE (Kang and Hovy, 2019), but not outperforming the two-stage calibration baseline.PosCal training can be easily extendable to any types of classification tasks as a form of regularization term.Also, PosCal has the advantage that it incrementally tracks needed statistics for the calibration objective during the training process, making efficient use of large training sets 1 . Taehee Jung, Dongyeop Kang, Lucas K. Mentch, Thomas Schaaf |
ACL | 2 |
| 2020 | INSPIRED: Toward Sociable Recommendation Dialog SystemsabstractIn recommendation dialogs, humans commonly disclose their preference and make recommendations in a friendly manner.However, this is a challenge in developing a sociable recommendation dialog system, due to the lack of dialog dataset annotated with such sociable strategies.Therefore, we present INSPIRED, a new dataset of 1,001 human-human dialogs for movie recommendation with measures for successful recommendations.To better understand how humans make recommendations in communication, we design an annotation scheme related to recommendation strategies based on social science theories and annotate these dialogs.Our analysis shows that sociable recommendation strategies, such as sharing personal opinions or communicating with encouragement, more frequently lead to successful recommendations.Based on our dataset, we train end-to-end recommendation dialog systems with and without our strategy labels.In both automatic and human evaluation, our model with strategy incorporation outperforms the baseline model.This work is a first step for building sociable recommendation dialog systems with a basis of social science theories 1 . Shirley Anugrah Hayati, Dongyeop Kang, Qingxiaoyang Zhu, Weiyan Shi 0001, Zhou Yu 0005 |
EMNLP (1) | 2 |
| 2020 | Plan ahead: Self-Supervised Text Planning for Paragraph Completion TaskabstractDespite the recent success of contextualized language models on various NLP tasks, language model itself cannot capture textual coherence of a long, multi-sentence document (e.g., a paragraph).Humans often make structural decisions on what and how to say about before making utterances.Guiding surface realization with such high-level decisions and structuring text in a coherent way is essentially called a planning process.Where can the model learn such high-level coherence?A paragraph itself contains various forms of inductive coherence signals called self-supervision in this work, such as sentence orders, topical keywords, rhetorical structures, and so on.Motivated by that, this work proposes a new paragraph completion task PAR-COM; predicting masked sentences in a paragraph.However, the task suffers from predicting and selecting appropriate topical content with respect to the given context.To address that, we propose a self-supervised text planner SSPlanner that predicts what to say first (content prediction), then guides the pretrained language model (surface realization) using the predicted content.SSPlanner outperforms the baseline generation models on the paragraph completion task in both automatic and human evaluation.We also find that a combination of noun and verb types of keywords is the most effective for content selection.As more number of content keywords are provided, overall generation quality also increases. Dongyeop Kang, Eduard H. Hovy |
EMNLP (1) | 1 |
| 2019 | Earlier Isn't Always Better: Sub-aspect Analysis on Corpus and System Biases in SummarizationabstractTaehee Jung, Dongyeop Kang, Lucas Mentch, Eduard Hovy. Proceedings of the 2019 Conference on Empirical Methods in Natural Language Processing and the 9th International Joint Conference on Natural Language Processing (EMNLP-IJCNLP). 2019. Taehee Jung, Dongyeop Kang, Lucas K. Mentch, Eduard H. Hovy |
EMNLP/IJCNLP (1) | 2 |
| 2019 | Recommendation as a Communication Game: Self-Supervised Bot-Play for Goal-oriented DialogueabstractDongyeop Kang, Anusha Balakrishnan, Pararth Shah, Paul Crook, Y-Lan Boureau, Jason Weston. Proceedings of the 2019 Conference on Empirical Methods in Natural Language Processing and the 9th International Joint Conference on Natural Language Processing (EMNLP-IJCNLP). 2019. Dongyeop Kang, Anusha Balakrishnan, Pararth Shah, Paul A. Crook, Y-Lan Boureau, Jason Weston |
EMNLP/IJCNLP (1) | 1 |
| 2019 | (Male, Bachelor) and (Female, Ph.D) have different connotations: Parallelly Annotated Stylistic Language Dataset with Multiple PersonasabstractDongyeop Kang, Varun Gangal, Eduard Hovy. Proceedings of the 2019 Conference on Empirical Methods in Natural Language Processing and the 9th International Joint Conference on Natural Language Processing (EMNLP-IJCNLP). 2019. Dongyeop Kang, Varun Gangal, Eduard H. Hovy |
EMNLP/IJCNLP (1) | 1 |
| 2019 | Linguistic Versus Latent Relations for Modeling Coherent Flow in ParagraphsabstractDongyeop Kang, Eduard Hovy. Proceedings of the 2019 Conference on Empirical Methods in Natural Language Processing and the 9th International Joint Conference on Natural Language Processing (EMNLP-IJCNLP). 2019. Dongyeop Kang, Eduard H. Hovy |
EMNLP/IJCNLP (1) | 1 |
| 2018 | Actionable Email Intent Modeling With Reparametrized RNNsabstractEmails in the workplace are often intentional calls to action for its recipients. We propose to annotate these emails for what action its recipient will take. We argue that our approach of action-based annotation is more scalable and theory-agnostic than traditional speech-act-based email intent annotation, while still carrying important semantic and pragmatic information. We show that our action-based annotation scheme achieves good inter-annotator agreement. We also show that we can leverage threaded messages from other domains, which exhibit comparable intents in their conversation, with domain adaptive RAINBOW (Recurrently AttentIve Neural Bag-Of-Words). On a collection of datasets consisting of IRC, Reddit, and email, our reparametrized RNNs outperform common multitask/multidomain approaches on several speech act related tasks. We also experiment with a minimally supervised scenario of email recipient action classification, and find the reparametrized RNNs learn a useful representation. Chu-Cheng Lin, Dongyeop Kang, Michael Gamon, Patrick Pantel |
AAAI | 2 |
| 2018 | AdvEntuRe: Adversarial Training for Textual Entailment with Knowledge-Guided ExamplesabstractWe consider the problem of learning textual entailment models with limited supervision (5K-10K training examples), and present two complementary approaches for it.First, we propose knowledge-guided adversarial example generators for incorporating large lexical resources in entailment models via only a handful of rule templates.Second, to make the entailment model-a discriminator-more robust, we propose the first GAN-style approach for training it using a natural language example generator that iteratively adjusts based on the discriminator's performance.We demonstrate effectiveness using two entailment datasets, where the proposed methods increase accuracy by 4.7% on SciTail and by 2.8% on a 1% training sub-sample of SNLI.Notably, even a single hand-written rule, negate, improves the accuracy on the negation examples in SNLI by 6.1%.P: The dog did not eat all of the chickens.H: The dog ate all of the chickens.S: entails (score 56:5%) P: The red box is in the blue box.H: The blue box is in the red box. Dongyeop Kang, Tushar Khot, Ashish Sabharwal, Eduard H. Hovy |
ACL (1) | 1 |
| 2018 | Bridging Knowledge Gaps in Neural Entailment via Symbolic ModelsabstractMost textual entailment models focus on lexical gaps between the premise text and the hypothesis, but rarely on knowledge gaps.We focus on filling these knowledge gaps in the Science Entailment task, by leveraging an external structured knowledge base (KB) of science facts.Our new architecture combines standard neural entailment models with a knowledge lookup module.To facilitate this lookup, we propose a fact-level decomposition of the hypothesis, and verifying the resulting sub-facts against both the textual premise and the structured KB.Our model, NSnet, learns to aggregate predictions from these heterogeneous data formats.On the SciTail dataset, NSnet outperforms a simpler combination of the two predictions by 3% and the base entailment model by 5%. Dongyeop Kang, Tushar Khot, Ashish Sabharwal, Peter Clark |
EMNLP | 1 |
| 2018 | A Dataset of Peer Reviews (PeerRead): Collection, Insights and NLP ApplicationsabstractDongyeop Kang, Waleed Ammar, Bhavana Dalvi, Madeleine van Zuylen, Sebastian Kohlmeier, Eduard Hovy, Roy Schwartz. Proceedings of the 2018 Conference of the North American Chapter of the Association for Computational Linguistics: Human Language Technologies, Volume 1 (Long Papers). 2018. Dongyeop Kang, Waleed Ammar, Bhavana Dalvi, Madeleine van Zuylen, Sebastian Kohlmeier, Eduard H. Hovy, Roy Schwartz 0001 |
NAACL-HLT | 1 |
| 2017 | Detecting and Explaining Causes From Text For a Time Series EventabstractExplaining underlying causes or effects about events is a challenging but valuable task.We define a novel problem of generating explanations of a time series event by (1) searching cause and effect relationships of the time series with textual data and (2) constructing a connecting chain between them to generate an explanation.To detect causal features from text, we propose a novel method based on the Granger causality of time series between features extracted from text such as N-grams, topics, sentiments, and their composition.The generation of the sequence of causal entities requires a commonsense causative knowledge base with efficient reasoning.To ensure good interpretability and appropriate lexical usage we combine symbolic and neural representations, using a neural reasoning algorithm trained on commonsense causal tuples to predict the next cause step.Our quantitative and human analysis show empirical evidence that our method successfully extracts meaningful causality relationships between time series with textual features and generates appropriate explanation between them. Dongyeop Kang, Varun Gangal, Ang Lu, Eduard H. Hovy |
EMNLP | 1 |
| 2014 | Data/Feature Distributed Stochastic Coordinate Descent for Logistic RegressionabstractHow can we scale-up logistic regression, or L1 regularized loss minimization in general, for Terabyte-scale data which do not fit in the memory? How to design the distributed algorithm efficiently? Although there exist two major algorithms for logistic regression, namely Stochastic Gradient Descent (SGD) and Stochastic Coordinate Descent (SCD), they face limitations in distributed environments. Distributed SGD enables data parallelism (i.e., different machines access different part of the input data), but it does not allow feature parallelism (i.e., different machines compute different subsets of the output), and thus the communication cost is high. On the other hand, Distributed SCD allows feature parallelism, but it does not allow data parallelism and thus is not suitable to work in distributed environments. Dongyeop Kang, Woosang Lim, Kijung Shin, Lee Sael, U Kang |
CIKM | 1 |
| 2014 | Hetero-Labeled LDA: A Partially Supervised Topic Model with Heterogeneous Labels
Dongyeop Kang, Youngja Park, Suresh Chari |
ECML/PKDD (1) | 1 |
| 2012 | Finite-time observer-based synchronization for a class of uncertain chaotic systems using adaptive terminal sliding mode controlabstractIn this paper adaptive backstepping terminal sliding mode synchronization for a class of uncertain chaotic system is proposed. For finite-time convergence, terminal sliding mode scheme is adopted to backstepping design procedure. It is assumed that only output is measured. Error dynamics is calculated from the difference of output in drive-response system. Finite-time convergent observer is used to estimate unknown state in finite time and designed a control law which made state variables constrained to the terminal sliding surface. States converged to equilibrium in finite time. An appropriate adaptive law is chosen to estimate feedback gain and used Lyapunov theory to verify the stability. We presented a numerical simulation to demonstrate the effectiveness of the proposed method. Dongyeop Kang, Sangchul Won |
IECON | 2 |
| 2011 | Multidimensional mining of large-scale search logs: a topic-concept cube approachabstractIn addition to search queries and the corresponding clickthrough information, search engine logs record multidimensional information about user search activities, such as search time, location, vertical, and search device. Multidimensional mining of search logs can provide novel insights and useful knowledge for both search engine users and developers. In this paper, we describe our topic-concept cube project, which addresses the business need of supporting multidimensional mining of search logs effectively and efficiently. We answer two challenges. First, search queries and click-through data are well recognized sparse, and thus have to be aggregated properly for effective analysis. Second, there is often a gap between the topic hierarchies in multidimensional aggregate analysis and queries in search logs. To address those challenges, we develop a novel topic-concept model that learns a hierarchy of concepts and topics automatically from search logs. Enabled by the topicconcept model, we construct a topic-concept cube that supports online multidimensional mining of search log data. A distinct feature of our approach is that, in addition to the standard dimensions such as time and location, our topic-concept cube has a dimension of topics and concepts, which substantially facilitates the analysis of log data. To handle a huge amount of log data, we develop distributed algorithms for learning model parameters efficiently. We also devise approaches to computing a topic-concept cube. We report an empirical study verifying the effectiveness and efficiency of our approach on a real data set of 1.96 billion queries and 2.73 billion clicks. Dongyeop Kang, Daxin Jiang, Jian Pei 0001, Zhen Liao, Ho-Jin Choi |
WSDM | 1 |