EDBT 2026 Demo / reviewers in the wild / expert
Chang Xu 0008
dblp:97/2966-8
· DBLP profile ↗
24ranked-venue papers
5as first author
16since 2021 · last 2026
0000-0002-8281-2314ORCID · conflict
Domains — the database's venue-derived domains; a paper can count in several
Artificial intelligence and machine learning · 16 · 3 first-author · 12 since 2021Databases, data management, data science and information retrieval · 9 · 1 first-author · 8 since 2021Graphics, computer vision, multimedia, augmented reality and games · 8 · 3 first-author · 2 since 2021Applied, interdisciplinary, general and emerging computing · 2 · 2 since 2021Systems, architecture and hardware · 1 · 1 first-author
| Year | Publication | Venue | Position |
|---|---|---|---|
| 2026 | Controllable Financial Market Generation with Diffusion Guided Meta AgentabstractGenerative modeling has transformed many fields, such as language and visual modeling, while its application in financial markets remains under-explored. As the minimal unit within a financial market is an order, order-flow modeling represents a fundamental generative financial task. However, current approaches often yield unsatisfactory fidelity in generating order flow, and their generation lacks controllability, thereby limiting their practical applications. In this paper, we formulate the challenge of controllable financial market generation, and propose a Diffusion Guided Meta Agent (DigMA) model to address it. Specifically, we employ a conditional diffusion model to capture the dynamics of the market state represented by time-evolving distribution parameters of the mid-price return rate and the order arrival rate, and we define a meta agent with financial economic priors to generate orders from the corresponding distributions. Extensive experimental results show that DigMA achieves superior controllability and generation fidelity. Moreover, we validate its effectiveness as a generative environment for downstream high-frequency trading tasks and its computational efficiency. Yu-Hao Huang 0002, Chang Xu 0008, Yang Liu 0278, Weiqing Liu, Wu-Jun Li, Jiang Bian 0002 |
AAAI | 2 |
| 2025 | TimeDP: Learning to Generate Multi-Domain Time Series with Domain PromptsabstractTime series generation models are crucial for applications like data augmentation and privacy preservation. Most existing time series generation models are typically designed to generate data from one specified domain. While leveraging data from other domain for better generalization is proved to work in other application areas, this approach remains challenging for time series modeling due to the large divergence in patterns among different real world time series categories. In this paper, we propose a multi-domain time series diffusion model with domain prompts, named TimeDP. In TimeDP, we utilize a time series semantic prototype module which defines time series prototypes to represent time series basis, each prototype vector serving as "word" representing some elementary time series feature. A prototype assignment module is applied to extract the extract domain specific prototype weights, for learning domain prompts as generation condition. During sampling, we extract ``domain prompt" with few-shot samples from the target domain and use the domain prompts as condition to generate time series samples. Experiments demonstrate that our method outperforms baselines to provide the state-of-the-art in-domain generation quality and strong unseen domain generation capability. Yu-Hao Huang 0002, Chang Xu 0008, Yueying Wu 0004, Wu-Jun Li, Jiang Bian 0002 |
AAAI | 2 |
| 2025 | Does Acceleration Cause Hidden Instability in Vision Language Models? Uncovering Instance-Level Divergence Through a Large-Scale Empirical StudyabstractVision-Language Models (VLMs) are powerful yet computationally intensive for widespread practical deployments.To address such challenge without costly re-training, post-training acceleration techniques like quantization and token reduction are extensively explored.However, current acceleration evaluations primarily target minimal overall performance degradation, overlooking a crucial question: does the accelerated model still give the same answers to the same questions as it did before acceleration?This is vital for stability-centered industrial applications where consistently correct answers for specific, known situations are paramount, such as in AI-based disease diagnosis.We systematically investigate this for accelerated VLMs, testing four leading models (LLaVA-1.5,LLaVA-Next, Qwen2-VL, Qwen2.5-VL) with eight acceleration methods on ten multimodal benchmarks.Our findings are stark: despite minimal aggregate performance drops, accelerated models changed original answers up to 20% of the time.Critically, up to 6.5% of these changes converted correct answers to incorrect.Input perturbations magnified these inconsistencies, and the trend is confirmed by case studies with the medical VLM LLaVA-Med.This research reveals a significant oversight in VLM acceleration, stressing an urgent need for instance-level stability checks to ensure trustworthy real-world deployment. Yizheng Sun, Hao Li 0074, Chang Xu 0008, Hongpeng Zhou, Chenghua Lin 0002, Riza Theresa Batista-Navarro |
EMNLP | 3 |
| 2025 | MarS: a Financial Market Simulation Engine Powered by Generative Foundation ModelabstractGenerative models aim to simulate realistic effects of various actions across different contexts, from text generation to visual effects. Despite significant efforts to build real-world simulators, the application of generative models to virtual worlds, like financial markets, remains under-explored. In financial markets, generative models can simulate complex market effects of participants with various behaviors, enabling interaction under different market conditions, and training strategies without financial risk. This simulation relies on the finest structured data in financial market like orders thus building the finest realistic simulation. We propose Large Market Model (LMM), an order-level generative foundation model, for financial market simulation, akin to language modeling in the digital world. Our financial Market Simulation engine (MarS), powered by LMM, addresses the domain-specific need for realistic, interactive and controllable order generation. Key observations include LMM's strong scalability across data size and model complexity, and MarS's robust and practicable realism in controlled generation with market impact. We showcase MarS as a forecast tool, detection system, analysis platform, and agent training environment, thus demonstrating MarS's ``paradigm shift'' potential for a variety of financial applications. We release the code of MarS at https://github.com/microsoft/MarS/. Yang Liu 0278, Weiqing Liu, Shikai Fang, Lewen Wang, Chang Xu 0008, Jiang Bian 0002 |
ICLR | 6 |
| 2025 | BRIDGE: Bootstrapping Text to Control Time-Series Generation via Multi-Agent Iterative Optimization and Diffusion ModelingabstractTime-series Generation (TSG) is a prominent research area with broad applications in simulations, data augmentation, and counterfactual analysis. While existing methods have shown promise in unconditional single-domain TSG, real-world applications demand for cross-domain approaches capable of controlled generation tailored to domain-specific constraints and instance-level requirements. In this paper, we argue that text can provide semantic insights, domain information and instance-specific temporal patterns, to guide and improve TSG. We introduce “Text-Controlled TSG”, a task focused on generating realistic time series by incorporating textual descriptions. To address data scarcity in this setting, we propose a novel LLM-based Multi-Agent framework that synthesizes diverse, realistic text-to-TS datasets. Furthermore, we introduce Bridge, a hybrid text-controlled TSG framework that integrates semantic prototypes with text description for supporting domain-level guidance. This approach achieves state-of-the-art generation fidelity on 11 of 12 datasets, and improves controllability by up to 12% on MSE and 6% MAE compared to no text input generation, highlighting its potential for generating tailored time-series data. Hao Li 0074, Yu-Hao Huang 0002, Chang Xu 0008, Viktor Schlegel, Renhe Jiang, Riza Theresa Batista-Navarro, Goran Nenadic, Jiang Bian 0002 |
ICML | 3 |
| 2025 | TarDiff: Target-Oriented Diffusion Guidance for Synthetic Electronic Health Record Time Series GenerationabstractSynthetic Electronic Health Record (EHR) time-series generation is crucial for advancing clinical machine learning models, as it helps address data scarcity by providing more training data. However, most existing approaches focus primarily on replicating statistical distributions and temporal dependencies of real-world data. We argue that fidelity to observed data alone does not guarantee better model performance, as common patterns may dominate, limiting the representation of rare but important conditions. This highlights the need for generate synthetic samples to improve performance of specific clinical models to fulfill their target outcomes. To address this, we propose TarDiff, a novel target-oriented diffusion framework that integrates task-specific influence guidance into the synthetic data generation process. Unlike conventional approaches that mimic training data distributions, TarDiff optimizes synthetic samples by quantifying their expected contribution to improving downstream model performance through influence functions. Specifically, we measure the reduction in task-specific loss induced by synthetic samples and embed this influence gradient into the reverse diffusion process, thereby steering the generation towards utility-optimized data. Evaluated on six publicly available EHR datasets, TarDiff achieves state-of-the-art performance, outperforming existing methods by up to 20.4% in AUPRC and 18.4% in AUROC. Our results demonstrate that TarDiff not only preserves temporal fidelity but also enhances downstream model performance, offering a robust solution to data scarcity and class imbalance in healthcare analytics. Chang Xu 0008, Hao Li 0074, Yu-Hao Huang 0002, Min Hou 0004, Jiang Bian 0002 |
KDD (2) | 2 |
| 2025 | InvDiff: Invariant Guidance for Bias Mitigation in Diffusion ModelsabstractAs one of the most successful generative models, diffusion models have demonstrated remarkable efficacy in synthesizing high-quality images. These models learn the underlying high-dimensional data distribution in an unsupervised manner. Despite their success, diffusion models are highly data-driven and prone to inheriting the imbalances and biases present in real-world data. Some studies have attempted to address these issues by designing text prompts for known biases or using bias labels to construct unbiased data. While these methods have shown improved results, real-world scenarios often contain various unknown biases, and obtaining bias labels is particularly challenging. In this paper, we emphasize the necessity of mitigating bias in pre-trained diffusion models without relying on auxiliary bias annotations. To tackle this problem, we propose a framework, InvDiff, which aims to learn invariant semantic information for diffusion guidance. Specifically, we propose identifying underlying biases in the training data and designing a novel debiasing training objective. Then, we employ a lightweight trainable module that automatically preserves invariant semantic information and uses it to guide the diffusion model's sampling process toward unbiased outcomes simultaneously. Notably, we only need to learn a small number of parameters in the lightweight learnable module without altering the pre-trained diffusion model. Furthermore, we provide a theoretical guarantee that the implementation of InvDiff is equivalent to reducing the error upper bound of generalization. Extensive experimental results on three publicly available benchmarks demonstrate that InvDiff effectively reduces biases while maintaining the quality of image generation. Our code is available at https://github.com/Hundredl/InvDiff. Min Hou 0004, Yueying Wu 0004, Chang Xu 0008, Yu-Hao Huang 0002, Chenxi Bai, Le Wu 0001, Jiang Bian 0002 |
KDD (1) | 3 |
| 2025 | MIRA: Medical Time Series Foundation Model for Real-World Health DataabstractA unified foundation model for medical time series—pretrained on open access and ethically reviewed medical corpora—offers the potential to reduce annotation burdens, minimize model customization, and enable robust transfer across clinical institutions, modalities, and tasks, particularly in data-scarce or privacy-constrained environments. However, existing time series foundation models struggle to handle medical time series data due to its inherent challenges, including irregular intervals, heterogeneous sampling rates, and frequent missingness. To address these challenges, we introduce MIRA, a unified foundation model specifically designed for medical time series forecasting. MIRA incorporates a Continuous-Time Rotary Positional Encoding that enables fine-grained modeling of variable time intervals, a frequency-specific mixture-of-experts layer that routes computation across latent frequency regimes to further promote temporal specialization, and a Continuous Dynamics Extrapolation Block based on Neural ODE that models the continuous trajectory of latent states, enabling accurate forecasting at arbitrary target timestamps. Pretrained on a large-scale and diverse medical corpus comprising over 454 billion time points collect from publicly available datasets, MIRA achieving reductions in forecasting errors by an average of 8% and 6% in out-of-distribution and in-distribution scenarios, respectively. We also introduce a comprehensive benchmark spanning multiple downstream clinical tasks, establishing a foundation for future research in medical time series modeling. Hao Li 0074, Chang Xu 0008, Zhiyuan Feng, Viktor Schlegel, Yu-Hao Huang 0002, Yizheng Sun, Kailai Yang, Yiyao Yu, Jiang Bian 0002 |
NeurIPS | 3 |
| 2025 | TimeRAF: Retrieval-Augmented Foundation Model for Zero-Shot Time Series ForecastingabstractTime series forecasting plays a crucial role in data mining, driving rapid advancements across numerous industries. With the emergence of large models, time series foundation models (TSFMs) have exhibited remarkable generalization capabilities, such as zero-shot learning, through large-scale pre-training. Meanwhile, Retrieval-Augmented Generation (RAG) methods have been widely employed to enhance the performance of foundation models on unseen data, allowing models to access to external knowledge. In this paper, we introduceTimeRAF, aRetrieval-AugmentedForecasting model that enhance zero-shot time series forecasting through retrieval-augmented techniques. We develop customized time series knowledge bases that are tailored to the specific forecasting tasks. TimeRAF employs an end-to-end learnable retriever to extract valuable information from the knowledge base. Additionally, we propose Channel Prompting for knowledge integration, which effectively extracts relevant information from the retrieved knowledge along the channel dimension. Extensive experiments demonstrate the effectiveness of our model, showing significant improvement across various domains and datasets. Huanyu Zhang 0002, Chang Xu 0008, Yifan Zhang 0004, Zhang Zhang 0001, Liang Wang 0001, Jiang Bian 0002 |
IEEE Trans. Knowl. Data Eng. | 2 |
| 2024 | MG-TSD: Multi-Granularity Time Series Diffusion Models with Guided Learning ProcessabstractRecently, diffusion probabilistic models have attracted attention in generative time series forecasting due to their remarkable capacity to generate high-fidelity samples. However, the effective utilization of their strong modeling ability in the probabilistic time series forecasting task remains an open question, partially due to the challenge of instability arising from their stochastic nature. To address this challenge, we introduce a novel Multi-Granularity Time Series Diffusion (MG-TSD) model, which achieves state-of-the-art predictive performance by leveraging the inherent granularity levels within the data as given targets at intermediate diffusion steps to guide the learning process of diffusion models. The way to construct the targets is motivated by the observation that forward process of the diffusion model, which sequentially corrupts the data distribution to a standard normal distribution, intuitively aligns with the process of smoothing fine-grained data into a coarse-grained representation, both of which result in a gradual loss of fine distribution features. In the study, we derive a novel multi-granularity guidance diffusion loss function and propose a concise implementation method to effectively utilize coarse-grained data across various granularity levels.
More importantly, our approach does not rely on additional external data, making it versatile and applicable across various domains. Extensive experiments conducted on real-world datasets demonstrate that our MG-TSD model outperforms existing time series prediction methods. Xinyao Fan, Yueying Wu 0004, Chang Xu 0008, Yu-Hao Huang 0002, Weiqing Liu, Jiang Bian 0002 |
ICLR | 3 |
| 2024 | A multimodal stepwise-coordinating framework for pedestrian trajectory prediction
Yijun Wang 0002, Zekun Guo, Chang Xu 0008 |
Knowl. Based Syst. | 3 |
| 2024 | Digger-Guider: High-Frequency Factor Extraction for Stock Trend PredictionabstractRecent years have witnessed increasing attention being paid to AI-based quantitative investment. Compared to traditional low-frequency data (e.g., daily, weekly), high-frequency data (e.g., minute-level) is often underutilized for low-frequency stock trend prediction, leaving the vast potential for improvement. However, valuable and noisy information coexist in high-frequency data. The learning process of high-frequency factor extractors can easily be overwhelmed by noise, leading to overfitting. Moreover, common techniques used to prevent overfitting often result in poor performance on this task since they usually roughly restrict the model’s capacity, making it challenging to model complex trading signals in high-frequency data. When designing high-frequency factor extractors, we face a tough dilemma. A high-capacity model may easily overfit to noise, while a simple but robust model may not capture complex high-frequency patterns. To address these problems, we propose maintaining model capacity while preventing overfitting by constructing two components that balance information and noise through interactions between them. Specifically, we propose a novel learning framework calledDigger-Guiderto extract informative stock representations from noisy high-frequency data. We develop a high-capacity model calledDiggerto extract local and detailed features from the high-frequency data, and we design a robust model calledGuiderto capture global tendency features and help the Digger overcome the noise. The Digger and Guider enhance each other through mutual distillation during training, serving as data-driven regularizations that work well on this task. Extensive experiments on real-world datasets demonstrate that our framework can produce powerful high-frequency stock factors that significantly improve stock trend prediction performance and our understanding of the finance market. Yang Liu 0278, Chang Xu 0008, Min Hou 0004, Weiqing Liu, Jiang Bian 0002, Qi Liu 0003, Tie-Yan Liu |
IEEE Trans. Knowl. Data Eng. | 2 |
| 2022 | Learning Differential Operators for Interpretable Time Series ModelingabstractModeling sequential patterns from data is at the core of various time series forecasting tasks. Deep learning models have greatly outperformed many traditional models, but these black-box models generally lack explainability in prediction and decision making. To reveal the underlying trend with understandable mathematical expressions, scientists and economists tend to use partial differential equations (PDEs) to explain the highly nonlinear dynamics of sequential patterns. However, it usually requires domain expert knowledge and a series of simplified assumptions, which is not always practical and can deviate from the ever-changing world. Is it possible to learn the differential relations from data dynamically to explain the time-evolving dynamics? In this work, we propose an learning framework that can automatically obtain interpretable PDE models from sequential data. Particularly, this framework is comprised of learnable differential blocks, named P-blocks, which is proved to be able to approximate any time-evolving complex continuous functions in theory. Moreover, to capture the dynamics shift, this framework introduces a meta-learning controller to dynamically optimize the hyper-parameters of a hybrid PDE model. Extensive experiments on times series forecasting of financial, engineering, and health data show that our model can provide valuable interpretability and achieve comparable performance to state-of-the-art models. From empirical studies, we find that learning a few differential operators may capture the major trend of sequential dynamics without massive computational complexity. Yingtao Luo, Chang Xu 0008, Yang Liu 0278, Weiqing Liu, Shun Zheng 0001, Jiang Bian 0002 |
KDD | 2 |
| 2022 | Multi-Granularity Residual Learning with Confidence Estimation for Time Series PredictionabstractTime-series prediction is of high practical value in a wide range of applications such as econometrics and meteorology, where the data are commonly formed by temporal patterns. Most prior works ignore the diversity of dynamic pattern frequency, i.e., different granularities, suffering from insufficient information exploitation. Thus, multi-granularity learning is still under-explored for time-series prediction. In this paper, we propose a Multi-granularity Residual Learning Framework (MRLF) for more effective time series prediction. For a given time series, intuitively, there are more or less semantic overlaps and validity differences among its representations of different granularities. Due to the information redundancy, straightforward methods that leverage multi-granularity data, such as concatenation or ensemble, can easily lead to the model being dominated by the redundant coarse-grained trend information. Therefore, we design a novel residual learning net to model the prior knowledge of the fine-grained data’s distribution through the coarse-grained one. Then, by calculating the residual between multi-granularity data, the redundant information be removed. Furthermore, to alleviate the side effect of validity differences, we introduce a self-supervised objective for confidence estimation, which delivers more effective optimization without the requirement of additional annotation efforts. Extensive experiments on the real-world datasets indicate that multi-granular information significantly improves the time series prediction performance, and our model is superior in capturing such information. Min Hou 0004, Chang Xu 0008, Zhi Li 0057, Yang Liu 0278, Weiqing Liu, Enhong Chen, Jiang Bian 0002 |
WWW | 2 |
| 2021 | Stock Trend Prediction with Multi-granularity Data: A Contrastive Learning Approach with Adaptive FusionabstractStock trend prediction plays a crucial role in quantitative investing. Given the prediction task on a certain granularity (e.g., daily trend), a large portion of existing studies merely leverage market data of the same granularity (e.g., daily market data). In financial investment scenarios, however, there exist amounts of finer-grained information (e.g., high-frequency data) that contain more detailed investment signals beyond the original granularity data. This motivates us to investigate how to leverage multi-granularity market data to enhance the accuracy of stock trend prediction. Some straightforward methods, such as concatenating finer-grained data as features or fusing with a model based on finer-grained features, may not lead to more precise stock trend prediction due to some unique challenges. First, the inconsistency of granularity between the target trend and finer-grained data could substantially increase optimization difficulty, such as the relative sparsity of the target trend compared with higher dimensions of finer-grained features. Moreover, the continuously changing financial market state could result in varying efficacy of heterogeneous multi-granularity information, which consequently requires a dynamic approach for proper fusion among them. In this paper, we propose the Contrastive Multi-Granularity Learning Framework (CMLF) to address these challenges. Particularly, we first design two novel contrastive learning objectives at the pre-training stage to address the inconsistency issue by constructing additional self-supervised signals relying on the inherent character of stock data. We also design a gate mechanism based on market-aware technical indicators to fuse the multi-granularity features at each time step adaptively. Extensive experiments on three real-world datasets show significant improvements of our approach over the state-of-the-art baselines on stock trend prediction and profitability in real investing scenarios. Min Hou 0004, Chang Xu 0008, Yang Liu 0278, Weiqing Liu, Jiang Bian 0002, Le Wu 0001, Zhi Li 0057, Enhong Chen, Tie-Yan Liu |
CIKM | 2 |
| 2021 | REST: Relational Event-driven Stock Trend ForecastingabstractStock trend forecasting, aiming at predicting the stock future trends, is crucial for investors to seek maximized profits from the stock market. Many event-driven methods utilized the events extracted from news, social media, and discussion board to forecast the stock trend in recent years. However, existing event-driven methods have two main shortcomings: 1) overlooking the influence of event information differentiated by the stock-dependent properties; 2) neglecting the effect of event information from other related stocks. In this paper, we propose a relational event-driven stock trend forecasting (REST) framework, which can address the shortcoming of existing methods. To remedy the first shortcoming, we propose to model the stock context and learn the effect of event information on the stocks under different contexts. To address the second shortcoming, we construct a stock graph and design a new propagation layer to propagate the effect of event information from related stocks. The experimental studies on the real-world data demonstrate the efficiency of our REST framework. The results of investment simulation show that our framework can achieve a higher return of investment than baselines. Weiqing Liu, Chang Xu 0008, Jiang Bian 0002, Jian Yin 0001, Tie-Yan Liu |
WWW | 3 |
| 2019 | Modeling Local Dependence in Natural Language with Multi-Channel Recurrent Neural NetworksabstractRecurrent Neural Networks (RNNs) have been widely used in processing natural language tasks and achieve huge success. Traditional RNNs usually treat each token in a sentence uniformly and equally. However, this may miss the rich semantic structure information of a sentence, which is useful for understanding natural languages. Since semantic structures such as word dependence patterns are not parameterized, it is a challenge to capture and leverage structure information. In this paper, we propose an improved variant of RNN, Multi-Channel RNN (MC-RNN), to dynamically capture and leverage local semantic structure information. Concretely, MC-RNN contains multiple channels, each of which represents a local dependence pattern at a time. An attention mechanism is introduced to combine these patterns at each step, according to the semantic information. Then we parameterize structure information by adaptively selecting the most appropriate connection structures among channels. In this way, diverse local structures and dependence patterns in sentences can be well captured by MC-RNN. To verify the effectiveness of MC-RNN, we conduct extensive experiments on typical natural language processing tasks, including neural machine translation, abstractive summarization, and language modeling. Experimental results on these tasks all show significant improvements of MC-RNN over current top systems. Chang Xu 0008, Weiran Huang 0001, Hongwei Wang 0004, Gang Wang 0001, Tie-Yan Liu |
AAAI | 1 |
| 2019 | Polygon-Net: A General Framework for Jointly Boosting Multiple Unsupervised Neural Machine Translation ModelsabstractNeural machine translation (NMT) has achieved great success. However, collecting large-scale parallel data for training is costly and laborious. Recently, unsupervised neural machine translation has attracted more and more attention, due to its demand for monolingual corpus only, which is common and easy to obtain, and its great potentials for the low-resource or even zero-resource machine translation. In this work, we propose a general framework called Polygon-Net, which leverages multi auxiliary languages for jointly boosting unsupervised neural machine translation models. Specifically, we design a novel loss function for multi-language unsupervised neural machine translation. In addition, different from the literature that just updating one or two models individually, Polygon-Net enables multiple unsupervised models in the framework to update in turn and enhance each other for the first time. In this way, multiple unsupervised translation models are associated with each other for training to achieve better performance. Experiments on the benchmark datasets including UN Corpus and WMT show that our approach significantly improves over the two-language based methods, and achieves better performance with more languages introduced to the framework. Chang Xu 0008, Tao Qin 0001, Gang Wang 0001, Tie-Yan Liu |
IJCAI | 1 |
| 2017 | Convolutional neural networks for posed and spontaneous expression recognitionabstractDifferentiating posed expressions from spontaneous ones is a more challenging task than conventional facial expression recognition. There are many methods proposed to differentiate posed and spontaneous expressions based on pixel level information. However, these methods still have some limitations : (1) Most of the studies use the difference between onset (the early stages of an expression) and apex (the most intense stages of an expression) pixel-level raw images as inputs, which may not only contain noisy information, but also lose some useful information. (2) A lot of previous work uses hand-crafted features designed by rules, which suffers from inadequate capability of abstraction and representation. Considering that the high-level image representations usually have less noisy information, we propose a special layer named “comparison layer” for convolutional neural network (CNN) to measure the difference between onset and apex images of high-level representations (instead of pixel-level difference). We add the comparison layer to a group of CNNs, and combine the learned representations from those CNNs to form inputs of a classifier for differentiating posed and spontaneous expressions. Experiments on USTC-NVIE database (so far the largest database for this task) show that our method significantly outperforms the state-of-the-art methods (91.73% to 97.98%). Chang Xu 0008, Tao Qin 0001, Yalong Bai, Gang Wang 0001, Tie-Yan Liu |
ICME | 1 |
| 2016 | Health Status Assessment and Failure Prediction for Hard Drives with Recurrent Neural NetworksabstractRecently, in order to improve reactive fault tolerance techniques in large scale storage systems, researchers have proposed various statistical and machine learning methods based on SMART attributes. Most of these studies have focused on predicting failures of hard drives, i.e., labeling the status of a hard drive as “good” or not. However, in real-world storage systems, hard drives often deteriorate gradually rather than suddenly. Correspondingly, their SMART attributes change continuously towards failure. Inspired by this observation, we introduce a novel method based on Recurrent Neural Networks (RNN) to assess the health statuses of hard drives based on the gradually changing sequential SMART attributes. Compared to a simple failure prediction method, a health status assessment is more valuable in practice because it enables technicians to schedule the recovery of different hard drives according to the level of urgency. Experiments on real-world datasets for disks of different brands and scales demonstrate that our proposed method can not only achieve a reasonable accurate health status assessment, but also achieve better failure prediction performance than previous work. Chang Xu 0008, Gang Wang 0001, Xiaoguang Liu 0001, Dongdong Guo, Tie-Yan Liu |
IEEE Trans. Computers | 1 |
| 2015 | Automatic Image Dataset Construction from Click-through Logs Using Deep Neural NetworkabstractLabelled image datasets are the backbone for high-level image understanding tasks with wide application scenarios, and continuously drive and evaluate the progress of feature designing and supervised learning models. Recently, the million scale labelled image dataset further contributes to the rebirth of deep convolutional neural network and bypass manual designing handcraft features. However, the construction process of image dataset is mainly manual-based and quite labor intensive, which often take years' efforts to construct a million scale dataset with high quality. In this paper, we propose a deep learning based method to construct large scale image dataset in an automatic way. Specifically, word representation and image representation are learned in a deep neural network from large amount of click-through logs, and further used to define word-word similarity and image-word similarity. These two similarities are used to automatize the two labor intensive steps in manual-based image dataset construction: query formation and noisy image removal. With a new proposed cross convolutional filter regularizer, we can construct a million scale image dataset in one week. Finally, two image datasets are constructed to verify the effectiveness of the method. In addition to scale, the automatically constructed dataset has comparable accuracy, diversity and cross-dataset generalization with manually labelled image datasets. Yalong Bai, Kuiyuan Yang, Wei Yu 0004, Chang Xu 0008, Wei-Ying Ma, Tiejun Zhao |
ACM Multimedia | 4 |
| 2014 | Sequential Click Prediction for Sponsored Search with Recurrent Neural NetworksabstractClick prediction is one of the fundamental problems in sponsored search. Most of existing studies took advantage of machine learning approaches to predict ad click for each event of ad view independently. However, as observed in the real-world sponsored search system, user's behaviors on ads yield high dependency on how the user behaved along with the past time, especially in terms of what queries she submitted, what ads she clicked or ignored, and how long she spent on the landing pages of clicked ads, etc. Inspired by these observations, we introduce a novel framework based on Recurrent Neural Networks (RNN). Compared to traditional methods, this framework directly models the dependency on user's sequential behaviors into the click prediction process through the recurrent structure in RNN. Large scale evaluations on the click-through logs from a commercial search engine demonstrate that our approach can significantly improve the click prediction accuracy, compared to sequence-independent approaches. Yuyu Zhang, Hanjun Dai, Chang Xu 0008, Taifeng Wang, Jiang Bian 0002, Bin Wang 0004, Tie-Yan Liu |
AAAI | 3 |
| 2014 | RC-NET: A General Framework for Incorporating Knowledge into Word RepresentationsabstractRepresenting words into vectors in continuous space can form up a potentially powerful basis to generate high-quality textual features for many text mining and natural language processing tasks. Some recent efforts, such as the skip-gram model, have attempted to learn word representations that can capture both syntactic and semantic information among text corpus. However, they still lack the capability of encoding the properties of words and the complex relationships among words very well, since text itself often contains incomplete and ambiguous information. Fortunately, knowledge graphs provide a golden mine for enhancing the quality of learned word representations. In particular, a knowledge graph, usually composed by entities (words, phrases, etc.), relations between entities, and some corresponding meta information, can supply invaluable relational knowledge that encodes the relationship between entities as well as categorical knowledge that encodes the attributes or properties of entities. Hence, in this paper, we introduce a novel framework called RC-NET to leverage both the relational and categorical knowledge to produce word representations of higher quality. Specifically, we build the relational knowledge and the categorical knowledge into two separate regularization functions, and combine both of them with the original objective function of the skip-gram model. By solving this combined optimization problem using back propagation neural networks, we can obtain word representations enhanced by the knowledge graph. Experiments on popular text mining and natural language processing tasks, including analogical reasoning, word similarity, and topic prediction, have all demonstrated that our model can significantly improve the quality of word representations. Chang Xu 0008, Yalong Bai, Jiang Bian 0002, Bin Gao 0001, Gang Wang 0001, Xiaoguang Liu 0001, Tie-Yan Liu |
CIKM | 1 |
| 2014 | Bag-of-Words Based Deep Neural Network for Image RetrievalabstractThis work targets image retrieval task hold by MSR-Bing Grand Challenge. Image retrieval is considered as a challenge task because of the gap between low-level image representation and high-level textual query representation. Recently further developed deep neural network sheds light on narrowing the gap by learning high-level image representation from raw pixels. In this paper, we proposed a bag-of-words based deep neural network for image retrieval task, which learns high-level image representation and maps images into bag-of-words space. The DNN model is trained on the large scale clickthrough data, and the relevance between query and image is measured by the cosine similarity of query's bag-of-words representation and image's bag-of-words representation predicted by DNN, the visual similarity of images is computed by high-level image representation extracted via the DNN model too. Finally, PageRank algorithm is used to further improve the ranking list by considering visual similarity of images for each query. The experimental results achieved state-of-the-art performance and verified the effectiveness of our proposed method. Yalong Bai, Wei Yu 0004, Tianjun Xiao, Chang Xu 0008, Kuiyuan Yang, Wei-Ying Ma, Tiejun Zhao |
ACM Multimedia | 4 |