arXiv subjects

Yunwen Chen

Publications and source records attributed to Yunwen Chen.

8 recordsLinked to original sources

arXiv2025

Axial Behaviour of Pre-Damaged RC Short Columns Retrofitted with Square Corrugated Steel Jackets

This study proposes a strengthening method employing square corrugated steel jackets as external confinement, which significantly enhances both the bearing capacity and ductility of existing reinforced concrete (RC) columns. Axial compression tests were conducted on ten short column specimens to evaluate the effects of corrugated steel thickness (1.6, 2.0, and 2.7 mm), preloading level before jacketing (40%, 60%, and 100% of the original capacity), and connection type (welding vs. bolting). A computational model was developed to predict the ultimate bearing capacity of the strengthened sections. The main findings are as follows: (1) The corrugated steel jackets increased the ultimate bearing capacity of the existing RC columns by 34.6% to 67.3%. (2) Given the relatively low confinement efficiency in square sections, thinner corrugated steel plates can be used in a material-efficient manner to achieve comparable strengthening effects. (3) Fully welded connections between corrugated plates induce less stress concentration and provide better transverse confinement effectiveness compared to bolted connections. (4) In a pre-unloaded column, greater existed damage causes concrete softening and increased lateral expansion under re-compression. This dilation promotes a tighter interaction between the core concrete and the outer jacket, activating stronger passive confinement after being jacketed. (5) The low longitudinal stresses in the jacket indicate that its primary role is to provide lateral confinement rather than to resist axial loads directly. (6) It is recommended to employ a calculation method that accounts for both pre-damage and confinement effects to ensure a conservative and reliable design of corrugated steel-jacketed RC columns with pre-damage.

math.NA↗

arXiv2024

Can Pre-trained Language Models Understand Chinese Humor?

Humor understanding is an important and challenging research in natural language processing. As the popularity of pre-trained language models (PLMs), some recent work makes preliminary attempts to adopt PLMs for humor recognition and generation. However, these simple attempts do not substantially answer the question: {\em whether PLMs are capable of humor understanding?} This paper is the first work that systematically investigates the humor understanding ability of PLMs. For this purpose, a comprehensive framework with three evaluation steps and four evaluation tasks is designed. We also construct a comprehensive Chinese humor dataset, which can fully meet all the data requirements of the proposed evaluation framework. Our empirical study on the Chinese humor dataset yields some valuable observations, which are of great guiding value for future optimization of PLMs in humor understanding and generation.

cs.CL↗

arXiv2023

Enhancing Quantitative Reasoning Skills of Large Language Models through Dimension Perception

Quantities are distinct and critical components of texts that characterize the magnitude properties of entities, providing a precise perspective for the understanding of natural language, especially for reasoning tasks. In recent years, there has been a flurry of research on reasoning tasks based on large language models (LLMs), most of which solely focus on numerical values, neglecting the dimensional concept of quantities with units despite its importance. We argue that the concept of dimension is essential for precisely understanding quantities and of great significance for LLMs to perform quantitative reasoning. However, the lack of dimension knowledge and quantity-related benchmarks has resulted in low performance of LLMs. Hence, we present a framework to enhance the quantitative reasoning ability of language models based on dimension perception. We first construct a dimensional unit knowledge base (DimUnitKB) to address the knowledge gap in this area. We propose a benchmark DimEval consisting of seven tasks of three categories to probe and enhance the dimension perception skills of LLMs. To evaluate the effectiveness of our methods, we propose a quantitative reasoning task and conduct experiments. The experimental results show that our dimension perception method dramatically improves accuracy (43.55%->50.67%) on quantitative reasoning tasks compared to GPT-4.

cs.CL↗

arXiv2023

Learning "O" Helps for Learning More: Handling the Concealed Entity Problem for Class-incremental NER

As the categories of named entities rapidly increase, the deployed NER models are required to keep updating toward recognizing more entity types, creating a demand for class-incremental learning for NER. Considering the privacy concerns and storage constraints, the standard paradigm for class-incremental NER updates the models with training data only annotated with the new classes, yet the entities from other entity classes are unlabeled, regarded as "Non-entity" (or "O"). In this work, we conduct an empirical study on the "Unlabeled Entity Problem" and find that it leads to severe confusion between "O" and entities, decreasing class discrimination of old classes and declining the model's ability to learn new classes. To solve the Unlabeled Entity Problem, we propose a novel representation learning method to learn discriminative representations for the entity classes and "O". Specifically, we propose an entity-aware contrastive learning method that adaptively detects entity clusters in "O". Furthermore, we propose two effective distance-based relabeling strategies for better learning the old classes. We introduce a more realistic and challenging benchmark for class-incremental NER, and the proposed method achieves up to 10.62\% improvement over the baseline methods.

cs.CL↗

arXiv2023

HAUSER: Towards Holistic and Automatic Evaluation of Simile Generation

Similes play an imperative role in creative writing such as story and dialogue generation. Proper evaluation metrics are like a beacon guiding the research of simile generation (SG). However, it remains under-explored as to what criteria should be considered, how to quantify each criterion into metrics, and whether the metrics are effective for comprehensive, efficient, and reliable SG evaluation. To address the issues, we establish HAUSER, a holistic and automatic evaluation system for the SG task, which consists of five criteria from three perspectives and automatic metrics for each criterion. Through extensive experiments, we verify that our metrics are significantly more correlated with human ratings from each perspective compared with prior automatic metrics.

cs.CL↗

arXiv2023

Open Set Relation Extraction via Unknown-Aware Training

The existing supervised relation extraction methods have achieved impressive performance in a closed-set setting, where the relations during both training and testing remain the same. In a more realistic open-set setting, unknown relations may appear in the test set. Due to the lack of supervision signals from unknown relations, a well-performing closed-set relation extractor can still confidently misclassify them into known relations. In this paper, we propose an unknown-aware training method, regularizing the model by dynamically synthesizing negative instances. To facilitate a compact decision boundary, ``difficult'' negative instances are necessary. Inspired by text adversarial attacks, we adaptively apply small but critical perturbations to original training instances and thus synthesizing negative instances that are more likely to be mistaken by the model as known relations. Experimental results show that this method achieves SOTA unknown relation detection without compromising the classification of known relations.

cs.CL↗

arXiv2023

Farewell to Aimless Large-scale Pretraining: Influential Subset Selection for Language Model

Pretrained language models have achieved remarkable success in various natural language processing tasks. However, pretraining has recently shifted toward larger models and larger data, and this has resulted in significant computational and energy costs. In this paper, we propose Influence Subset Selection (ISS) for language model, which explicitly utilizes end-task knowledge to select a tiny subset of the pretraining corpus. Specifically, the ISS selects the samples that will provide the most positive influence on the performance of the end-task. Furthermore, we design a gradient matching based influence estimation method, which can drastically reduce the computation time of influence. With only 0.45% of the data and a three-orders-of-magnitude lower computational cost, ISS outperformed pretrained models (e.g., RoBERTa) on eight datasets covering four domains.

cs.CL↗

arXiv2021

Context-aware Ensemble of Multifaceted Factorization Models for Recommendation Prediction in Social Networks

This paper describes the solution of Shanda Innovations team to Task 1 of KDD-Cup 2012. A novel approach called Multifaceted Factorization Models is proposed to incorporate a great variety of features in social networks. Social relationships and actions between users are integrated as implicit feedbacks to improve the recommendation accuracy. Keywords, tags, profiles, time and some other features are also utilized for modeling user interests. In addition, user behaviors are modeled from the durations of recommendation records. A context-aware ensemble framework is then applied to combine multiple predictors and produce final recommendation results. The proposed approach obtained 0.43959 (public score) / 0.41874 (private score) on the testing dataset, which achieved the 2nd place in the KDD-Cup competition.

cs.IR↗