Nan Gao

Dr. Nan Gao

orcid

Research Focus & Metrics

Academic Career Length

8Years (2019-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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19 December 2019 in IEEE Access
Verified
Journal Article
Open access
LHLiang Huang
Liang Huang
WPWeijian Pan
Weijian Pan
YZYou Zhang
You Zhang
Liping QianLiping Qian
Liping Qian
NGNan Gao
Nan Gao
YWYuan Wu
Yuan Wu
Deep learning has recently been applied to automatically classify the modulation categories of received radio signals without manual experience. However, training deep learning models requires massive volume of data. An insufficient training data will cause serious overfitting problem and degrade the classification accuracy. To cope with small dataset, data augmentation has been widely used in image processing to expand the dataset and improve the robustness of deep learning models. However, in wireless communication areas, the effect of different data augmentation methods on radio modulation classification has not been studied yet. In this paper, we evaluate different data augmentation methods via a state-of-the-art deep learning-based modulation classifier. Based on the characteristics of modulated signals, three augmentation methods are considered, i.e., rotation, flip, and Gaussian noise, which can be applied in both training phase and inference phase of the deep learning algorithm. Numerical results show that all three augmentation methods can improve the classification accuracy. Among which, the rotation augmentation method outperforms the flip method, both of which achieve higher classification accuracy than the Gaussian noise method. Given only 12.5% of training dataset, a joint rotation and flip augmentation policy can achieve even higher classification accuracy than the baseline with initial 100% training dataset without augmentation. Furthermore, with data augmentation, radio modulation categories can be successfully classified using shorter radio samples, leading to a simplified deep learning model and shorter the classification response time.

10 September 2020 in Frontiers in Genetics
Verified
Journal Article
Open access
PDF file
SLShuhao Li
Shuhao Li
LJLimin Jiang
Limin Jiang
JTJijun Tang
Jijun Tang
NGNan Gao
Nan Gao
FGFei Guo
Fei Guo
Recently, cancer has been characterized as a heterogeneous disease composed of many different subtypes. Early diagnosis of cancer subtypes is an important study of cancer research, which can be of tremendous help to patients after treatment. In this paper, we first extract a novel dataset, which contains gene expression, miRNA expression, and isoform expression of five cancers from The Cancer Genome Atlas (TCGA). Next, to avoid the effect of noise existing in 60, 483 genes, we select a small number of genes by using LASSO that employs gene expression and survival time of patients. Then, we construct one similarity kernel for each expression data by using Chebyshev distance. And also, We used SKF to fused the three similarity matrix composed of gene, Iso, and miRNA, and finally clustered the fused similarity matrix with spectral clustering. In the experimental results, our method has better P-value in the Cox model than other methods on 10 cancer data from Jiang Dataset and Novel Dataset. We have drawn different survival curves for different cancers and found that some genes play a key role in cancer. For breast cancer, we find out that HSPA2A, RNASE1, CLIC6, and IFITM1 are highly expressed in some specific groups. For lung cancer, we ensure that C4BPA, SESN3, and IRS1 are highly expressed in some specific groups. The code and all supporting data files are available from https://github.com/guofei-tju/Uncovering-Cancer-Subtypes-via-LASSO.

28 August 2023 in IEEE Transactions on Artificial Intelligence
Verified
Journal Article
Closed access
LHLiang Huang
Liang Huang
SLSenjie Liang
Senjie Liang
FYFeiyang Ye
Feiyang Ye
NGNan Gao
Nan Gao
Intent detection and slot filling are two main tasks in natural language understanding and play an essential role in task-oriented dialogue systems. The joint learning of both tasks can improve inference accuracy and is popular in recent works. However, most joint models ignore the inference latency and cannot meet the need to deploy dialogue systems at the edge. In this paper, we propose a Fast Attention Network (FAN) for joint intent detection and slot filling tasks, guaranteeing both accuracy and latency. Specifically, we introduce a clean and parameter-refined attention module to enhance the information exchange between intent and slot, improving semantic accuracy by more than 2%. FAN can be implemented on different encoders and delivers more accurate models at every speed level. Our experiments on the Jetson Nano platform show that FAN inferences fifteen utterances per second with a small accuracy drop, showing its effectiveness and efficiency on edge devices.

23 November 2024 in Expert Systems with Applications
Verified
Journal Article
Closed access
NGNan Gao
Nan Gao
RYRenyuan Yao
Renyuan Yao
PCPeng Chen
Peng Chen
RLRonghua Liang
Ronghua Liang
GSGuodao Sun
Guodao Sun
JTJijun Tang
Jijun Tang

22 February 2024 in IEEE Transactions on Multimedia
Verified
Journal Article
Closed access
NGNan Gao
Nan Gao
RYRenyuan Yao
Renyuan Yao
RLRonghua Liang
Ronghua Liang
PCPeng Chen
Peng Chen
TLTianshuang Liu
Tianshuang Liu
YDYuanjie Dang
Yuanjie Dang
Automatically generated oral panoramic X-ray report is highly beneficial for improving the efficiency of dental diagnosis. However, recent solutions adopt holistic methods, resulting in a cursory description of the oral condition. This may lead to reports lacking details, such as specific sites or lesion contours. Therefore, we propose a Multi-Level objective Alignment Transformer(MLAT) network, which integrates all tooth and disease objects into a positional alignment graph to extract fine-grained object-level features. Specifically, we introduce a novel Object-Level Collaborative Encoder (OLCE) module, which uses a positional alignment graph to construct object relationships. OLCE enhances object-level feature extraction by eliminating interference information between pathologically unrelated objects. In addition, we build a high-quality panoramic X-ray image-report dataset consisting of 562 sets of images and reports labeled by 13 experienced dental specialists. Experiments on the collected dataset show that the proposed MLAT significantly outperforms the state-of-the-art baselines by more than 5% in 4 different metrics, including BLEUs, Meteor, Rouge, and BERTScore.

8 March 2024 in ACM Transactions on Multimedia Computing, Communications, and Applications
Verified
Journal Article
Open access
YDYuanjie Dang
Yuanjie Dang
CHChunxia Huang
Chunxia Huang
PCPeng Chen
Peng Chen
DZDongdong Zhao
Dongdong Zhao
NGNan Gao
Nan Gao
RHRuohong Huan
Ruohong Huan
Weakly supervised temporal action localization (WTAL) aims to classify and localize actions in untrimmed videos with only video-level labels. Recent studies have attempted to obtain more accurate temporal boundaries by exploiting latent action instances in ambiguous snippets or propagating representative action features. However, empirically handcrafted ambiguous snippet extraction and the imprecise alignment of representative snippet propagation lead to challenges in modeling the completeness of actions for these methods. In this article, we propose a Discriminative Action Snippet Propagation Network (DASP-Net) to accurately discover ambiguous snippets in videos and propagate discriminative instance-level features throughout the video for improving action completeness. Specifically, we introduce a novel discriminative feature propagation module for capturing the global contextual attention and propagating the action concept across the whole video by perceiving the discriminative action snippets with instance information from the same video. Simultaneously, we incorporate denoised pseudo-labels as supervision, where we correct the controversial prediction based on the feature space distribution during training, thereby alleviating false detection caused by noise background features. Furthermore, we design an ambiguous feature mining module, which maximizes the feature affinity information of action and background in ambiguous snippets to generate more accurate latent action and background snippets and learns more precise action instance boundaries through contrastive learning of action and background snippets. Extensive experiments show that DASP-Net achieves state-of-the-art results on THUMOS14 and ActivityNet1.2 datasets.